Subsequent Events - Major Classes of Assets and Liabilities (Details) - Discontinued Operations, Held-for-sale - Tripwire - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets:
Cash and cash equivalents	$ 2,194	$ 1,328
Receivables, net	28,773	26,001
Inventories, net	150	126
Other current assets	7,418	9,798
Property, plant and equipment, less accumulated depreciation	6,250	7,588
Operating lease right-of-use assets	3,893	5,151
Goodwill	331,024	462,202
Intangible assets, less accumulated amortization	63,541	67,979
Deferred income taxes	834	800
Other long-lived assets	5,325	2,653
Total assets of Tripwire disposal group	449,402	583,626
Liabilities:
Accounts payable	6,458	4,868
Accrued liabilities	56,208	61,769
Deferred income taxes	10,964	12,599
Long-term operating lease liabilities	5,257	7,019
Other long-term liabilities	20,192	17,214
Total liabilities of Tripwire disposal group	$ 99,079	$ 103,469