Revenue (Breakdown of Revenues by Accounting Standards) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	$ 295,850	$ 273,945	$ 1,102,457	$ 1,083,383
Total Revenues	1,922,233	1,982,755	5,665,519	6,284,588
Revenues under ASC 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	295,850	273,945	1,102,457	1,083,383
Revenues under ASC 842
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total Revenues	23,056	26,418	73,375	87,122
Revenues under ASC 815
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total Revenues	$ 1,603,327	$ 1,682,392	$ 4,489,687	$ 5,114,083