Marketable Securities - Details of Marketable Securities (Details) - IronNet [Member] - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Marketable Securities [Line Items]
Fair Value	$ 16,167	$ 5,791
Basis	38,993	5,668
Cumulative Unrealized (Loss) Gain	(22,826)	123
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	372
Basis	2,195
Cumulative Unrealized (Loss) Gain	(1,823)
IronNet Securities [Member]
Marketable Securities [Line Items]
Fair Value	6,351
Basis	29,185
Cumulative Unrealized (Loss) Gain	(22,834)
Equity Funds and Other Securities [Member]
Marketable Securities [Line Items]
Fair Value	9,816	5,791
Basis	9,808	5,668
Cumulative Unrealized (Loss) Gain	$ 8	$ 123