Financial Royalty Assets, net (formerly known as Commercial License Rights) - Narrative (Details) - USD ($)		1 Months Ended	3 Months Ended
	May 31, 2017	Nov. 30, 2023	Mar. 31, 2024	Dec. 31, 2023	Oct. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Impairment of commercial license rights			$ 0
Gross carrying value(2)			73,363,000	$ 70,364,000
Tolerance Therapeutics (TZIELD)
Finite-Lived Intangible Assets [Line Items]
Product royalty (as a percent)		1.00%
Cash payments for acquisition		$ 20,000,000
Elutia (CorMatrix)
Finite-Lived Intangible Assets [Line Items]
Proceeds from royalties received	$ 10,000,000
Product royalty (as a percent)	5.00%
Credit loss adjustment			3,000,000
Gross carrying value(2)			12,680,000	13,304,000
Elutia (CorMatrix) | Maximum
Finite-Lived Intangible Assets [Line Items]
Additional royalties receivable under sales-based milestones	$ 10,000,000
Ovid (Soticlestat)
Finite-Lived Intangible Assets [Line Items]
Gross carrying value(2)			30,310,000	30,310,000
Ovid (Soticlestat) | Soticlestat
Finite-Lived Intangible Assets [Line Items]
Consideration paid for an interest in potential development milestone					$ 30,000,000
Interest in sales revenue (as a percent)					13.00%
Ensifentrine inventors
Finite-Lived Intangible Assets [Line Items]
Gross carrying value(2)			$ 3,827,000	$ 0