Description of Business and Summary of Significant Accounting Policies - Accounts Receivables and Allowances (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 151,793		$ 153,609
Allowance for doubtful accounts	19,225		19,874
Provision for doubtful accounts	(360)	$ (2,060)
Billed Revenues
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	151,800		153,600
Unbilled Revenues
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 46,300		$ 50,100