Fair Value Measurements, Assets and Liabilities are Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands		Jun. 30, 2023	Mar. 31, 2023
Assets: [Abstract]
Investment		$ 296,243	$ 304,317
Earn-Out Shares [Member]
Recurring Fair Value Measurements [Abstract]
Non financial liabilities at fair value		24,000
Private Placement Warrants [Member]
Liabilities: [Abstract]
Total liabilities at fair value		25,600
Arbutus Biopharma Corporation [Member]
Assets: [Abstract]
Investment		89,300	117,700
Level 1 [Member] | Warrant [Member] | Public Warrants [Member]
Recurring Fair Value Measurements [Abstract]
Financial liabilities at fair value		50,800	29,900
Level 3 [Member] | Earn-Out Shares [Member]
Recurring Fair Value Measurements [Abstract]
Non financial liabilities at fair value		24,000	15,200
Level 3 [Member] | Warrant [Member] | Private Placement Warrants [Member]
Recurring Fair Value Measurements [Abstract]
Financial liabilities at fair value		25,600	15,200
Level 3 [Member] | Liability Instruments Measured at Fair Value [Member]
Recurring Fair Value Measurements [Abstract]
Non financial liabilities at fair value		3,300	3,300
Recurring [Member]
Assets: [Abstract]
Total assets at fair value		1,537,155	1,801,043
Liabilities: [Abstract]
Debt issued by Dermavant to NovaQuest		214,630	207,640
Liability instruments measured at fair value	[1]	103,723	63,546
Total liabilities at fair value		318,353	271,186
Recurring [Member] | Money Market Funds [Member]
Assets: [Abstract]
Money market funds		1,240,912	1,496,726
Recurring [Member] | Common Shares [Member] | Datavant [Member]
Assets: [Abstract]
Investment		199,448	178,579
Recurring [Member] | Common Shares [Member] | Arbutus Biopharma Corporation [Member]
Assets: [Abstract]
Investment		89,349	117,708
Recurring [Member] | Other Investments [Member]
Assets: [Abstract]
Investment		7,446	8,030
Recurring [Member] | Level 1 [Member]
Assets: [Abstract]
Total assets at fair value		1,337,707	1,622,464
Liabilities: [Abstract]
Debt issued by Dermavant to NovaQuest		0	0
Liability instruments measured at fair value	[1]	50,780	29,895
Total liabilities at fair value		50,780	29,895
Recurring [Member] | Level 1 [Member] | Money Market Funds [Member]
Assets: [Abstract]
Money market funds		1,240,912	1,496,726
Recurring [Member] | Level 1 [Member] | Common Shares [Member] | Datavant [Member]
Assets: [Abstract]
Investment		0	0
Recurring [Member] | Level 1 [Member] | Common Shares [Member] | Arbutus Biopharma Corporation [Member]
Assets: [Abstract]
Investment		89,349	117,708
Recurring [Member] | Level 1 [Member] | Other Investments [Member]
Assets: [Abstract]
Investment		7,446	8,030
Recurring [Member] | Level 2 [Member]
Assets: [Abstract]
Total assets at fair value		0	0
Liabilities: [Abstract]
Debt issued by Dermavant to NovaQuest		0	0
Liability instruments measured at fair value	[1]	0	0
Total liabilities at fair value		0	0
Recurring [Member] | Level 2 [Member] | Money Market Funds [Member]
Assets: [Abstract]
Money market funds		0	0
Recurring [Member] | Level 2 [Member] | Common Shares [Member] | Datavant [Member]
Assets: [Abstract]
Investment		0	0
Recurring [Member] | Level 2 [Member] | Common Shares [Member] | Arbutus Biopharma Corporation [Member]
Assets: [Abstract]
Investment		0	0
Recurring [Member] | Level 2 [Member] | Other Investments [Member]
Assets: [Abstract]
Investment		0	0
Recurring [Member] | Level 3 [Member]
Assets: [Abstract]
Total assets at fair value		199,448	178,579
Liabilities: [Abstract]
Debt issued by Dermavant to NovaQuest		214,630	207,640
Liability instruments measured at fair value	[1]	52,943	33,651
Total liabilities at fair value		267,573	241,291
Recurring [Member] | Level 3 [Member] | Money Market Funds [Member]
Assets: [Abstract]
Money market funds		0	0
Recurring [Member] | Level 3 [Member] | Common Shares [Member] | Datavant [Member]
Assets: [Abstract]
Investment		199,448	178,579
Recurring [Member] | Level 3 [Member] | Common Shares [Member] | Arbutus Biopharma Corporation [Member]
Assets: [Abstract]
Investment		0	0
Recurring [Member] | Level 3 [Member] | Other Investments [Member]
Assets: [Abstract]
Investment		$ 0	$ 0

[1] At June 30, 2023, Level 1 includes the fair value of the Public Warrants of $50.8 million, and Level 3 includes the fair value of the Earn-Out Shares of $24.0 million, Private Placement Warrants of $25.6 million, and other liability instruments issued of $3.3 million. At March 31, 2023, Level 1 includes the fair value of the Public Warrants of $29.9 million, and Level 3 includes the fair value of the Earn-Out Shares of $15.2 million, Private Placement Warrants of $15.2 million, and other liability instruments issued of $3.3 million.