Revenue Recognition - Other Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues from contracts with customers	$ 432,991		$ 806,694
Accounting Standards Update 2014-09 | Revenue gross-up
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues from contracts with customers	$ 56,335	$ 44,908	$ 102,026	$ 102,473