Subsequent Events (Details) - USD ($)		3 Months Ended	12 Months Ended
	Jan. 17, 2022	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Feb. 07, 2022
Subsequent Events [Line Items]
Goodwill impairment loss			$ 132,843,000	$ 0	$ 0
Cash used to acquire businesses, net of cash acquired			73,340,000	(590,000)	74,392,000
Tripwire
Subsequent Events [Line Items]
Goodwill impairment loss		$ 131,200,000
Tripwire | Discontinued Operations, Held-for-sale
Subsequent Events [Line Items]
Accumulated other comprehensive income (loss), net of tax		$ 3,400,000	3,400,000	3,500,000
Revenues			106,800,000	110,500,000	133,000,000
Loss before taxes			(139,100,000)	(24,800,000)	(16,000,000.0)
Depreciation and amortization			$ 11,900,000	$ 39,400,000	$ 47,900,000
Subsequent Event | Macmon
Subsequent Events [Line Items]
Cash used to acquire businesses, net of cash acquired	$ 43,300,000
Subsequent Event | Tripwire
Subsequent Events [Line Items]
Consideration						$ 350,000,000