Revenue (Breakdown of Revenues by Accounting Standards) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	$ 347,502	$ 315,172
Total Revenues	1,853,105	1,976,792
Revenues under ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	347,502	315,172
Revenues under ASC 842
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total Revenues	25,551	28,868
Revenues under ASC 815
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total Revenues	$ 1,480,052	$ 1,632,752