v3.25.4

Marketable Securities and Other Investments - Summary of Fair Values and Unrealized Losses of Marketable Securities Held by the Company in an Unrealized Loss Position for Less Than 12 months and 12 Months or Greater (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	$ 36,965	$ 21,317
Less than 12 Months, Unrealized Losses	(17)	(45)
12 Months or Greater, Fair Value		24,138
12 Months or Greater, Unrealized Losses		(81)
Total, Fair Value	36,965	45,455
Total, Unrealized Losses	(17)	(126)
U.S. Government and Agency Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	4,676	0
Less than 12 Months, Unrealized Losses		0
12 Months or Greater, Fair Value		22,917
12 Months or Greater, Unrealized Losses		(77)
Total, Fair Value	4,676	22,917
Total, Unrealized Losses		(77)
Certificates of Deposit [Member]
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value		0
Less than 12 Months, Unrealized Losses		0
12 Months or Greater, Fair Value		1,221
12 Months or Greater, Unrealized Losses		(4)
Total, Fair Value		1,221
Total, Unrealized Losses		(4)
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Less than 12 Months, Fair Value	32,289	21,317
Less than 12 Months, Unrealized Losses	(17)	(45)
12 Months or Greater, Fair Value		0
12 Months or Greater, Unrealized Losses		0
Total, Fair Value	32,289	21,317
Total, Unrealized Losses	$ (17)	$ (45)

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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REGENXBIO Inc. 10-K