Contract Assets and Liabilities - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Loss Contingencies [Line Items]
Revenue recognized	$ 96,800,000	$ 89,300,000
Aggregate claim recovery estimate included in contract assets and liability	42,600,000	34,000,000
Contract retention, uncollectable amount	0
Performance Obligations [Member]
Loss Contingencies [Line Items]
Contracts Revenue	$ 41,300,000	$ 27,700,000