Investments - Additional Information (Detail) £ in Thousands, $ in Thousands		3 Months Ended		12 Months Ended
	Mar. 08, 2021 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($) shares	Dec. 31, 2021 USD ($)	Mar. 31, 2031	Dec. 31, 2029	Mar. 31, 2022 GBP (£)	Dec. 31, 2019 shares
Investment [Line Items]
Cost of Investments		$ 20,938		$ 14,238
Unrealized gain on Series A Shares		$ (5,142)	$ (549)
Percentage Of Voting Approval Required To Redeem All Of The Outstanding Notes At Maturity		50.00%
Percentage of voting approval required to redeem all of the outstanding notes before maturity		75.00%
Subsequent Event [Member]
Investment [Line Items]
Percentage of voting approval required to redeem all of the outstanding series a shares						60.00%
Percentage of voting approval required to redeem all of the outstanding series B shares					90.00%
Securrency Inc [Member]
Investment [Line Items]
Cost of Investments				$ 13,612
Ownership interest percentage				22.00%
Original fully diluted ownership interest percentage				17.00%
Securrency - Series A Preferred Stock [Member]
Investment [Line Items]
Number of shares purchased | shares								5,178,488
Non-cumulative dividend				6.00%
Unrealized gain on Series A Shares	$ 237
Securrency - Series B Convertible Preferred Stock [Member]
Investment [Line Items]
Number of shares purchased | shares			2,004,665
Onramp Invest, LLC [Member]
Investment [Line Items]
Cost of Investments				$ 250
Percentage of discount on future equity financing for preferred stock				20.00%
Impairment Of Investments		$ 0
Fnality International Limited [Member]
Investment [Line Items]
Ownership interest percentage		5.00%					5.00%
Percentage of discount on future equity financing for preferred stock		20.00%					20.00%
Debt Instrument Maturity Date		Dec. 31, 2023
Percentage of voting approval required to redeem all of the outstanding notes before maturity		163.00%
Fnality International Limited [Member] | Accounting Standards Update 2016-01 [Member]
Investment [Line Items]
Fair value		$ 6,863					£ 5,000