Basis of Presentation and Nature of Operations - Schedule of Revnue Claculated under Old and New Accounting Methods (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Revenue	$ 302,780
Contract assets	128,522	$ 123,197
Contract liabilities	32,281	38,571
ASU 2014-09 | As Reported
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Revenue	302,236
Contract assets	127,978	123,197
Contract liabilities	$ 32,281	$ 38,571