Revenue (Schedule Of Revenue By Contract Type) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 3,790,755	$ 4,641,830	$ 5,318,763
Fixed price
Disaggregation of Revenue [Line Items]
Revenue	2,466,326	3,140,148	3,312,393
Guaranteed maximum price
Disaggregation of Revenue [Line Items]
Revenue	612,924	905,704	1,154,028
Unit price
Disaggregation of Revenue [Line Items]
Revenue	359,900	363,786	476,672
Cost plus fee and other
Disaggregation of Revenue [Line Items]
Revenue	351,605	232,192	375,670
Civil
Disaggregation of Revenue [Line Items]
Revenue	1,734,882	2,095,760	2,199,899
Civil | Fixed price
Disaggregation of Revenue [Line Items]
Revenue	1,441,547	1,815,079	1,792,765
Civil | Guaranteed maximum price
Disaggregation of Revenue [Line Items]
Revenue	1,142	2,854	1,829
Civil | Unit price
Disaggregation of Revenue [Line Items]
Revenue	274,293	268,377	392,548
Civil | Cost plus fee and other
Disaggregation of Revenue [Line Items]
Revenue	17,900	9,450	12,757
Building
Disaggregation of Revenue [Line Items]
Revenue	1,242,571	1,428,102	1,984,641
Building | Fixed price
Disaggregation of Revenue [Line Items]
Revenue	349,318	336,128	508,655
Building | Guaranteed maximum price
Disaggregation of Revenue [Line Items]
Revenue	595,907	888,345	1,136,782
Building | Unit price
Disaggregation of Revenue [Line Items]
Revenue	33	(1,373)	867
Building | Cost plus fee and other
Disaggregation of Revenue [Line Items]
Revenue	297,313	205,002	338,337
Specialty Contractors
Disaggregation of Revenue [Line Items]
Revenue	813,302	1,117,968	1,134,223
Specialty Contractors | Fixed price
Disaggregation of Revenue [Line Items]
Revenue	675,461	988,941	1,010,973
Specialty Contractors | Guaranteed maximum price
Disaggregation of Revenue [Line Items]
Revenue	15,875	14,505	15,417
Specialty Contractors | Unit price
Disaggregation of Revenue [Line Items]
Revenue	85,574	96,782	83,257
Specialty Contractors | Cost plus fee and other
Disaggregation of Revenue [Line Items]
Revenue	$ 36,392	$ 17,740	$ 24,576