Contract Assets (Schedule Of Changes) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Change in Contract with Customer, Asset [Abstract]
Beginning balance	$ 161,061	$ 140,082
Revenue recognized	1,382,582	1,613,047
Amounts collected or invoiced	(1,382,247)	(1,592,061)
Ending balance	$ 161,396	$ 161,068