Revenue (Breakdown of Revenues by Accounting Standards) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	$ 459,105	$ 494,266	$ 806,607	$ 809,438
Total Revenues	1,890,180	2,325,041	3,743,286	4,301,833
Revenues under ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	459,105	494,266	806,607	809,438
Revenues under ASC 842
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total Revenues	24,768	31,836	50,319	60,704
Revenues under ASC 815
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total Revenues	$ 1,406,307	$ 1,798,939	$ 2,886,360	$ 3,431,691