Financial Royalty Assets, net (formerly known as Commercial License Rights) - Narrative (Details)		1 Months Ended	3 Months Ended		6 Months Ended
	May 31, 2017 USD ($)	Nov. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Oct. 31, 2023 USD ($)
Finite-Lived Intangible Assets
Impairment loss of financial royalty assets				$ 0	$ 26,491,000	$ 0
Gross carrying value			$ 85,282,000		85,282,000			$ 70,364,000
Tolerance Therapeutics (TZIELD)
Finite-Lived Intangible Assets
Product royalty (as a percent)		1.00%
Cash payments for acquisition		$ 20,000,000
Deferred tax liability		$ 5,500,000
Ovid (Soticlestat)
Finite-Lived Intangible Assets
Impairment loss of financial royalty assets			26,200,000		26,200,000
Gross carrying value			$ 4,122,000		$ 4,122,000			30,310,000
Ovid (Soticlestat) | Discount Rate
Finite-Lived Intangible Assets
Discount rate (as a percent)			0.17		0.17
Ovid (Soticlestat) | Soticlestat
Finite-Lived Intangible Assets
Consideration paid for an interest in potential development milestone									$ 30,000,000
Interest in sales revenue (as a percent)									13.00%
Selexis
Finite-Lived Intangible Assets
Impairment loss of financial royalty assets			$ 300,000		$ (300,000)
Gross carrying value			290,000		290,000			940,000
Elutia (CorMatrix)
Finite-Lived Intangible Assets
Proceeds from royalties received	$ 10,000,000
Product royalty (as a percent)	5.00%
Credit loss adjustment			(1,500,000)		(4,600,000)
Gross carrying value			10,615,000		10,615,000			13,304,000
Elutia (CorMatrix) | Maximum
Finite-Lived Intangible Assets
Additional royalties receivable under sales-based milestones	$ 10,000,000
Ensifentrine inventors
Finite-Lived Intangible Assets
Gross carrying value			$ 3,685,000		$ 3,685,000		$ 3,800,000	$ 0