Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Schedule of Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities [Line Items]
Provision (recovery) for credit losses			$ (11,000)	$ 14,200
Contract liabilities	$ 247,315		247,315		$ 228,388
Contract with customer liability, deferred revenue current	225,300		225,300		$ 203,000
Deferred revenue, revenue recognized	15,600		181,700
Non-recourse financing agreement, discount charge	13,091	$ 13,553	39,379	45,365
Receivables, Non-Recourse Arrangement
Schedule of Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities [Line Items]
Non-recourse financing agreement, discount charge	$ 800	$ 900	$ 2,300	$ 4,100
Minimum
Schedule of Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities [Line Items]
Retainage, percentage of contract billings			5.00%
Maximum
Schedule of Accounts Receivable, Net of Allowance, and Contract Assets and Liabilities [Line Items]
Retainage, percentage of contract billings			10.00%