Revenue Recognition - Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Unbilled receivables	$ 114,357	$ 140,318
Performance obligation	39,500
Receivables (Included in Trade Receivables)
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Unbilled receivables	$ 65,000	$ 98,200