Stock-based compensation - Options - General Information (Details)	1 Months Ended											3 Months Ended		12 Months Ended
	Apr. 30, 2025 USD ($) installment $ / shares shares	Mar. 31, 2025 USD ($) installment $ / shares shares	Apr. 30, 2024 USD ($) installment $ / shares shares	Mar. 31, 2024 USD ($) installment $ / shares shares	May 31, 2023 USD ($) installment $ / shares shares	Apr. 30, 2023 USD ($) installment $ / shares shares	Mar. 31, 2023 USD ($) installment $ / shares shares	May 31, 2022 USD ($) installment $ / shares shares	Apr. 30, 2022 USD ($) installment $ / shares shares	Mar. 31, 2022 USD ($) installment $ / shares shares	Jan. 31, 2022 USD ($) shares	Mar. 31, 2025 USD ($) installment $ / shares shares	Mar. 31, 2024 USD ($) installment	Dec. 31, 2024 shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)												873,246
Options issued, exercise price (in dollars per share) \| $ / shares												$ 0.81
Weighted average grant date fair value, granted (in dollars per share) \| $ / shares												$ 0.59
Awards Issued 24 March 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)										98,747
Options issued, exercise price (in dollars per share) \| $ / shares										$ 3.07
Weighted average grant date fair value, granted (in dollars per share) \| $ / shares										$ 1.43
Awards Issued 13 April 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)									97,371
Options issued, exercise price (in dollars per share) \| $ / shares									$ 2.52
Weighted average grant date fair value, granted (in dollars per share) \| $ / shares									$ 1.18
Awards Issued 11 May 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)								159,881
Options issued, exercise price (in dollars per share) \| $ / shares								$ 2.26
Weighted average grant date fair value, granted (in dollars per share) \| $ / shares								$ 1.07
Awards Issued 29 March 2023, Officers
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)							158,976
Options issued, exercise price (in dollars per share) \| $ / shares							$ 2.08
Weighted average grant date fair value, granted (in dollars per share) \| $ / shares							$ 1.26
Awards Issued April 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)						106,341
Options issued, exercise price (in dollars per share) \| $ / shares						$ 1.74
Weighted average grant date fair value, granted (in dollars per share) \| $ / shares						$ 1.06
Awards Issued May 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)					11,444
Options issued, exercise price (in dollars per share) \| $ / shares					$ 1.89
Weighted average grant date fair value, granted (in dollars per share) \| $ / shares					$ 1.12
Awards Issued 22 March 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)				529,635
Options issued, exercise price (in dollars per share) \| $ / shares				$ 1.50
Weighted average grant date fair value, granted (in dollars per share) \| $ / shares				$ 0.84
Awards Issued April 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)			167,994
Options issued, exercise price (in dollars per share) \| $ / shares			$ 1.32
Weighted average grant date fair value, granted (in dollars per share) \| $ / shares			$ 0.75
Vested (in shares)		0										0
Awards Issued March 2025
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)		873,246
Options issued, exercise price (in dollars per share) \| $ / shares		$ 0.81
Weighted average grant date fair value, granted (in dollars per share) \| $ / shares		$ 0.59
Awards Issued April 2025
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vested (in shares)		0										0
Awards Issued April 2025 \| Subsequent Event
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)	170,005
Options issued, exercise price (in dollars per share) \| $ / shares	$ 0.49
Weighted average grant date fair value, granted (in dollars per share) \| $ / shares	$ 0.36
Employee Stock Option
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Fair value of awards granted \| $												$ 511,200	$ 447,000
Employee Stock Option \| Awards Issued 24 March 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Contractual life										10 years
Fair value of awards granted \| $										$ 141,401
Vested (in shares)		98,747										98,747
Employee Stock Option \| Awards Issued 24 March 2022 \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)										33.33%
Vesting period										1 year
Employee Stock Option \| Awards Issued 24 March 2022 \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights, successive equal monthly installments \| installment										24
Employee Stock Option \| Awards Issued 24 March 2022 \| Share-Based Payment Arrangement, Tranche Two Through Twenty-Five
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)										2.78%
Employee Stock Option \| Awards Issued 13 April 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Contractual life									10 years
Fair value of awards granted \| $									$ 114,972
Vested (in shares)		94,666										94,666
Employee Stock Option \| Awards Issued 13 April 2022 \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)									33.33%
Vesting period									1 year
Employee Stock Option \| Awards Issued 13 April 2022 \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights, successive equal monthly installments \| installment									24
Employee Stock Option \| Awards Issued 13 April 2022 \| Share-Based Payment Arrangement, Tranche Two Through Twenty-Five
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)									2.78%
Employee Stock Option \| Awards Issued 11 May 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Contractual life								10 years
Fair value of awards granted \| $								$ 171,462
Vested (in shares)		159,881										159,881
Employee Stock Option \| Awards Issued 11 May 2022 \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)								33.33%
Vesting period								1 year
Employee Stock Option \| Awards Issued 11 May 2022 \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights, successive equal monthly installments \| installment								24
Employee Stock Option \| Awards Issued 11 May 2022 \| Share-Based Payment Arrangement, Tranche Two Through Twenty-Five
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)								2.78%
Employee Stock Option \| Awards Issued 29 March 2023, Officers
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Contractual life							10 years
Fair value of awards granted \| $							$ 201,000
Vested (in shares)		0										0
Employee Stock Option \| Awards Issued 29 March 2023, Officers \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)							33.33%
Vesting period							1 year
Employee Stock Option \| Awards Issued 29 March 2023, Officers \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights, successive equal monthly installments \| installment							24
Employee Stock Option \| Awards Issued 29 March 2023, Officers \| Share-Based Payment Arrangement, Tranche Two Through Twenty-Five
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)							2.78%
Employee Stock Option \| Awards Issued April 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Contractual life						10 years
Fair value of awards granted \| $						$ 112,423
Vested (in shares)		67,940										67,940
Employee Stock Option \| Awards Issued April 2023 \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)						33.33%
Vesting period						1 year
Employee Stock Option \| Awards Issued April 2023 \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights, successive equal monthly installments \| installment						24
Employee Stock Option \| Awards Issued April 2023 \| Share-Based Payment Arrangement, Tranche Two Through Twenty-Five
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)						2.78%
Employee Stock Option \| Awards Issued May 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Contractual life					10 years
Fair value of awards granted \| $					$ 12,800
Vested (in shares)		0										0
Employee Stock Option \| Awards Issued May 2023 \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period					1 year
Employee Stock Option \| Awards Issued May 2023 \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights, successive equal monthly installments \| installment					24
Employee Stock Option \| Awards Issued 22 March 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Contractual life				10 years
Fair value of awards granted \| $				$ 447,000
Vested (in shares)		0										0
Employee Stock Option \| Awards Issued 22 March 2024 \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)				33.33%
Vesting period				1 year
Employee Stock Option \| Awards Issued 22 March 2024 \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights, successive equal monthly installments \| installment				24									24
Employee Stock Option \| Awards Issued 22 March 2024 \| Share-Based Payment Arrangement, Tranche Two Through Twenty-Five
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)				2.78%
Employee Stock Option \| Awards Issued April 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Contractual life			10 years
Fair value of awards granted \| $			$ 126,163
Employee Stock Option \| Awards Issued April 2024 \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)			33.33%
Vesting period			1 year
Employee Stock Option \| Awards Issued April 2024 \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights, successive equal monthly installments \| installment			24
Employee Stock Option \| Awards Issued April 2024 \| Share-Based Payment Arrangement, Tranche Two Through Twenty-Five
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)			2.78%
Employee Stock Option \| Awards Issued March 2025
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Contractual life		10 years
Fair value of awards granted \| $		$ 511,200
Vested (in shares)		0										0
Employee Stock Option \| Awards Issued March 2025 \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)		33.33%
Vesting period		1 year
Employee Stock Option \| Awards Issued March 2025 \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights, successive equal monthly installments \| installment		24										24
Employee Stock Option \| Awards Issued March 2025 \| Share-Based Payment Arrangement, Tranche Two Through Twenty-Five
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)		2.78%
Employee Stock Option \| Awards Issued April 2025 \| Subsequent Event
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Contractual life	10 years
Fair value of awards granted \| $	$ 61,559
Employee Stock Option \| Awards Issued April 2025 \| Share-Based Payment Arrangement, Tranche One \| Subsequent Event
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)	33.33%
Vesting period	1 year
Employee Stock Option \| Awards Issued April 2025 \| Share-Based Payment Arrangement, Tranche Two \| Subsequent Event
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights, successive equal monthly installments \| installment	24
Employee Stock Option \| Awards Issued April 2025 \| Share-Based Payment Arrangement, Tranche Two Through Twenty-Five \| Subsequent Event
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights (as a percent)	2.78%
Restricted Stock Units (RSUs)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)												833,832		426,687
Restricted Stock Units (RSUs) \| Awards Issued 13 April 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Fair value of awards granted \| $									$ 22,050
Granted (in shares)									8,750
Restricted Stock Units (RSUs) \| Awards Issued 13 April 2022 \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period									1 year
Percentage of award									33.33%
Restricted Stock Units (RSUs) \| Awards Issued 13 April 2022 \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights, successive equal monthly installments \| installment									24
Restricted Stock Units (RSUs) \| Awards Issued 13 April 2022 \| Share-Based Payment Arrangement, Tranche Two Through Twenty-Five
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Percentage of award									2.78%
Restricted Stock Units (RSUs) \| Awards Issued 29 March 2023, Officers
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Fair value of awards granted \| $							$ 201,000
Granted (in shares)							96,635
Restricted Stock Units (RSUs) \| Awards Issued 22 March 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Fair value of awards granted \| $				$ 620,031
Granted (in shares)				413,354
Restricted Stock Units (RSUs) \| Awards Issued April 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Fair value of awards granted \| $			$ 20,000
Granted (in shares)			13,333
Restricted Stock Units (RSUs) \| Awards Issued 27 January 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Fair value of awards granted \| $											$ 716,625
Vesting period											3 years
Granted (in shares)											183,750
Restricted Stock Units (RSUs) \| Awards Issued 27 January 2022 \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Percentage of award											33.33%
Restricted Stock Units (RSUs) \| Awards Issued 27 January 2022 \| Share-Based Payment Arrangement, Tranche Two Through Twenty-Five
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Percentage of award											2.78%
Restricted Stock Units (RSUs) \| Awards Issued March 2025
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Fair value of awards granted \| $		$ 559,489
Granted (in shares)		690,641
Restricted Stock Units (RSUs) \| Awards Issued March 2025 - Grant 2
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Fair value of awards granted \| $		$ 80,000
Percentage of award		33.33%
Granted (in shares)		98,753
Restricted Stock Units (RSUs) \| Awards Issued March 2025 - Grant 2 \| Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period		1 year
Restricted Stock Units (RSUs) \| Awards Issued March 2025 - Grant 2 \| Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting rights, successive equal monthly installments \| installment		24										24
Restricted Stock Units (RSUs) \| Awards Issued March 2025 - Grant 2 \| Share-Based Payment Arrangement, Tranche Two Through Twenty-Five
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Percentage of award		2.78%

FGI Industries Ltd. 10-Q