Revenue (Breakdown of Revenues by Accounting Standards) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	$ 315,172	$ 193,650
Total Revenues	1,976,792	635,739
Revenues under ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	315,172	193,650
Revenues under ASC 842
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total Revenues	28,868	26,029
Revenues under ASC 815
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total Revenues	$ 1,632,752	$ 416,060