Revenue - Summary of Total Receivables, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue from Contract with Customer [Abstract]
Billed receivables	$ 213,654	$ 239,275
Allowance for doubtful accounts	(5,149)	(3,912)	$ (4,799)	$ (3,873)
Billed receivables, net	208,505	235,363
Accrued receivables	399,302	336,858
Significant financing component	(35,569)	(35,029)
Total accrued receivables, net	363,733	301,829
Less: current accrued receivables	161,714	123,053
Less: current significant financing component	(11,022)	(10,234)
Total long-term accrued receivables, net	213,041	189,010
Total receivables, net	$ 572,238	$ 537,192