Revenue - Summary of Total Receivables (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Billed receivables	$ 168,973	$ 213,654
Allowance for doubtful accounts	(3,517)	(5,149)
Billed receivables, net	165,456	208,505
Accrued receivables	380,300	399,302
Significant financing component	(30,375)	(35,569)
Total accrued receivables, net	349,925	363,733
Less: current accrued receivables	154,665	161,714
Less: current significant financing component	(10,625)	(11,022)
Total long-term accrued receivables, net	205,885	213,041
Total receivables, net	$ 515,381	$ 572,238