Net Income (Loss) per Share - Basic and Diluted Net Income (Loss) Per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Numerator:
Net income (loss) from continuing operations attributable to common stockholders	$ (19,855)	$ (26,196)	$ 12,827	$ (59,099)
Net loss from discontinuing operations attributable to common stockholders	0	(6,674)	0	(13,904)
Net income (loss) attributable to common stockholders - basic	$ (19,855)	$ (32,870)	$ 12,827	$ (73,003)
Denominator:
Weighted-average shares outstanding - basic	8,743,733	7,575,620	8,723,589	7,440,323
Net income (loss) from continuing operations per share attributable to common stockholders - basic	$ (2.27)	$ (3.46)	$ 1.47	$ (7.94)
Net loss from discontinued operations per share attributable to common stockholders - basic	0	(0.88)	0	(1.87)
Net income (loss) per share attributable to common stockholders - basic	$ (2.27)	$ (4.34)	$ 1.47	$ (9.81)
Numerator
Net loss from continuing operations	$ (19,855)	$ (26,196)	$ 12,827	$ (59,099)
Net (loss) from discontinuing operations, net of tax	0	(6,674)	0	(13,904)
Net income (loss) attributable to common stockholders - diluted	$ (19,855)	$ (32,870)	$ 12,827	$ (73,003)
Denominator:
Weighted-average shares outstanding	8,743,733	7,575,620	8,723,589	7,440,323
Dilutive impact from:
Stock options to purchase common stock	0	0	0	0
Unvested restricted stock units	0	0	8,586	0
Shares issuable under employee stock purchase plan	0	0	1	0
Weighted-average shares outstanding - diluted	8,743,733	7,575,620	8,732,176	7,440,323
Net income (loss) from continuing operations per share attributable to common stockholders - diluted	$ (2.27)	$ (3.46)	$ 1.47	$ (7.94)
Net (loss) from discontinuing operations attributable to common stockholders - diluted	0	(0.88)	0	(1.87)
Net income (loss) per share attributable to common stockholders, diluted	$ (2.27)	$ (4.34)	$ 1.47	$ (9.81)
Employee Stock Option
Anti-dilutive potential common stock equivalents excluded from the calculation of net (loss) income per share
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:	1,200,467	965,154	1,200,467	965,154
Unvested Restricted Stock Units [Member]
Anti-dilutive potential common stock equivalents excluded from the calculation of net (loss) income per share
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:	51,199	190,237	51,199	190,237
Shares Issuable under employee stock purchase plan [Member]
Anti-dilutive potential common stock equivalents excluded from the calculation of net (loss) income per share
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:	19,991	15,312	12,701	9,675
Shares Issuable under employee stock purchase plan [Member] \| Warrants [Member]
Anti-dilutive potential common stock equivalents excluded from the calculation of net (loss) income per share
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:	32,379	58,871	32,379	58,871

Seres Therapeutics, Inc. 10-Q