Marketable Securities - Details of Marketable Securities (Details) - IronNet [Member] - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Marketable Securities [Line Items]
Fair Value	$ 16,585	$ 16,157
Basis	21,297	38,990
Cumulative Unrealized (Loss) Gain	(4,712)	(22,833)
Put Options [Member]
Marketable Securities [Line Items]
Fair Value		1,245
Basis		489
Cumulative Unrealized (Loss) Gain		756
Common Shares - Restricted [Member]
Marketable Securities [Line Items]
Fair Value		4,734
Basis		26,501
Cumulative Unrealized (Loss) Gain		(21,767)
Common Shares - Unrestricted [Member]
Marketable Securities [Line Items]
Fair Value	46	372
Basis	4,273	2,195
Cumulative Unrealized (Loss) Gain	(4,227)	(1,823)
IronNet Securities [Member]
Marketable Securities [Line Items]
Fair Value	46	6,351
Basis	4,273	29,185
Cumulative Unrealized (Loss) Gain	(4,227)	(22,834)
Equity Funds and Other Securities [Member]
Marketable Securities [Line Items]
Fair Value	16,539	9,806
Basis	17,024	9,805
Cumulative Unrealized (Loss) Gain	$ (485)	$ 1