Acquisitions - Additional Information (Details) - USD ($)		12 Months Ended
	Nov. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Contingent consideration		$ 1,445,000	$ 0	$ 0
Tax deductible goodwill		11,500,000	$ 13,500,000
Employment Background Investigations, Inc.
Business Acquisition [Line Items]
Purchase price	$ 67,800,000
Cash	66,300,000
Contingent consideration	1,500,000
Contingent consideration, maximum additional payments	8,500,000
Contingent consideration fair value		$ 900,000
Contingent consideration period		2 years
Current portion of contingent consideration		$ 600,000
Transaction costs	1,900,000
Tax deductible goodwill	0
Employment Background Investigations, Inc. | Customer lists
Business Acquisition [Line Items]
Finite lived assets acquired	$ 56,000,000
Useful life of assets acquired	15 years
Employment Background Investigations, Inc. | Trade Names
Business Acquisition [Line Items]
Useful life of assets acquired	2 years
Employment Background Investigations, Inc. | Non-compete agreement
Business Acquisition [Line Items]
Useful life of assets acquired	5 years