Investments - Details of Investments Carried at Cost (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Investment [Line Items]
Investments	$ 20,938	$ 14,238
Securrency Inc. - Series A Convertible Preferred Stock - Carrying Value [Member]
Investment [Line Items]
Investments	8,488	8,488
Securrency Inc. - Series A Convertible Preferred Stock - Cost [Member]
Investment [Line Items]
Investments	8,112	8,112
Securrency Inc. - Series B Convertible Preferred Stock - Carrying Value [Member]
Investment [Line Items]
Investments	5,500	5,500
Securrency Inc. - Series B Convertible Preferred Stock - Cost [Member]
Investment [Line Items]
Investments	5,500	5,500
Subtotal – Securrency, Inc. - Carrying Value [Member]
Investment [Line Items]
Investments	13,988	13,988
Subtotal – Securrency, Inc. - Cost [Member]
Investment [Line Items]
Investments	13,612	13,612
Onramp Invest, Simple Agreement for Future Equity - Carrying Value
Investment [Line Items]
Investments	250	250
Onramp Invest, Simple Agreement for Future Equity - Cost
Investment [Line Items]
Investments	250	250
Investments - Carrying Value
Investment [Line Items]
Investments	20,938	14,238
Investments - Cost
Investment [Line Items]
Investments	20,725	13,862
Fnality International Limited Convertible Note Carrying Value [Member]
Investment [Line Items]
Investments	6,700	0
Fnality International Limited Convertible Note Cost [Member]
Investment [Line Items]
Investments	$ 6,863	$ 0