Contract Assets And Liabilities (Schedule Of Contract Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Contract Assets And Liabilities [Abstract]
Retainage receivable	$ 581,495	$ 562,375
Claims	729,170	705,993
Unapproved change orders	348,043	362,264
Other unbilled costs and profits	71,890	55,287
Total costs and estimated earnings in excess of billings	1,149,103	1,123,544
Capitalized contract costs	88,185	80,294
Total contract assets	$ 1,818,783	$ 1,766,213