Revenues (Schedule of Contract with Customer, Assets and Liabilities) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Contract Liabilities
Beginning balance	$ 360,416	$ 246,010
Consideration earned during the period	(95,847)	(38,960)
Consideration received during the period	351,677	138,291
Ending balance	$ 616,246	$ 345,341