Revenue Recognition Revenue Contract Assets and Liabilities Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Revenue Recognition and Deferred Revenue [Abstract]
Contract with Customer, net		$ 59,808
Contract with Customer, Liability, Increase (Decrease) for Contract Acquired in Business Combination		38,816
Revenue recognized from beginning contract liability		(30,045)
Increases due to amounts billed in the current period		137,882
Revenue recognized from amounts added in the current period	$ 2,800	(75,618)
Other adjustments		(2,687)
Contract with Customer, net	$ 128,156	$ 128,156