Investments - Additional Information (Detail) £ in Thousands, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Mar. 31, 2031	Dec. 31, 2029	Sep. 30, 2022 GBP (£)	Dec. 31, 2021 USD ($)	Mar. 31, 2021 shares	Dec. 31, 2019 shares
Investment [Line Items]
Cost of Investments	$ 26,339	$ 26,339					$ 14,238
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%
Unrealized gain (loss) on investments		$ (15,633)	$ (2,099)
Percentage of outstanding convertible note		75
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	$ 13,612
Ownership interest percentage	22.00%	22.00%				22.00%
Original fully diluted ownership interest percentage	18.00%	18.00%				18.00%
Securrency - Series A Preferred Stock [Member]
Investment [Line Items]
Number of shares purchased | shares									5,178,488
Non-cumulative dividend		6.00%
Unrealized gain (loss) on investments			$ 376
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	$ 250
Percentage of discount on future equity financing for preferred stock	20.00%	20.00%				20.00%
Impairment Of Investments	$ 0	$ 0
Unrealized gain (loss) on investments	$ 0	$ 62
Fnality International Limited [Member]
Investment [Line Items]
Ownership interest percentage	5.00%	5.00%				5.00%
Percentage of discount on future equity financing for preferred stock	20.00%	20.00%				20.00%
Debt Instrument Maturity Date		Dec. 31, 2023
Unrealized gain (loss) on investments	$ (238)	$ (668)
Fnality International Limited [Member] | Accounting Standards Update 2016-01 [Member]
Investment [Line Items]
Fair value	$ 6,863	$ 6,863				£ 5,000
Securrency Convertible Note [Member]
Investment [Line Items]
Ownership interest percentage	7.00%	7.00%				7.00%
Percentage of discount on future equity financing for preferred stock	25.00%	25.00%				25.00%
Debt Instrument Maturity Date		Apr. 21, 2023
Unrealized gain (loss) on investments	$ 565	$ 844
Securrency Convertible Note [Member] | Accounting Standards Update 2016-01 [Member]
Investment [Line Items]
Fair value	$ 5,000	$ 5,000