Marketable Securities - Additional Information (Details) - USD ($)		3 Months Ended			9 Months Ended
	May 05, 2022	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Marketable Securities [Line Items]
Investment income (loss)		$ (2,121,000)		$ (18,867,000)	$ (4,449,000)	$ (18,665,000)
Realized gain on sale of marketable securities					112,000
Realized loss on sale of marketable securities					$ 744,000
Realized gain or (loss) on marketable securities				$ 0		$ 0
IronNet [Member]
Marketable Securities [Line Items]
Number of put options sold, shares					250,000
Common stock, delivery of shares					50,000
IronNet [Member] | IronNet [Member] | Common Stock [Member]
Marketable Securities [Line Items]
Distribution of shares by sponsor subject to certain founder share restrictions							1,250,000
IronNet [Member] | IronNet [Member] | Put Options [Member]
Marketable Securities [Line Items]
Common stock, delivery of shares			50,000
IronNet [Member] | IronNet [Member] | Put Options [Member] | Common Stock [Member]
Marketable Securities [Line Items]
Shares issued by sponsor		100,500			100,500		300,000
Shares sold	250,000
Shares sold value	$ 1,263,000
IronNet [Member] | Put Options [Member]
Marketable Securities [Line Items]
Gain on sale of put options					$ 856,000