Revenue Recognition Revenue Contract Assets and Liabilities Rollforward (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
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	(24,549)
Revenue recognized from amounts added in the current period	(6,352)
Increases due to amounts billed in the current period	56,051
Other adjustments	(1,243)
Contract with Customer, net	$ 122,531