Contract Assets And Liabilities (Schedule Of Contract Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Contract Assets and Liabilities [Abstract]
Retainage receivable	$ 562,375	$ 478,744
Claims	705,993	698,274
Unapproved change orders	362,264	354,000
Other unbilled costs and profits	55,287	90,021
Total costs and estimated earnings in excess of billings	1,123,544	1,142,295
Capitalized contract costs	80,294	37,404
Total contract assets	$ 1,766,213	$ 1,658,443