Revenue (Disaggregation Of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Revenue	$ 1,021,751	$ 861,027	$ 1,798,051	$ 1,813,181
State and local agencies
Disaggregation of Revenue [Line Items]
Revenue	635,139	500,701	1,070,849	1,030,464
Federal agencies
Disaggregation of Revenue [Line Items]
Revenue	140,387	108,579	279,999	216,705
Private owners
Disaggregation of Revenue [Line Items]
Revenue	246,225	251,747	447,203	566,012
Civil
Disaggregation of Revenue [Line Items]
Revenue	554,123	403,622	903,993	794,417
Civil | State and local agencies
Disaggregation of Revenue [Line Items]
Revenue	403,013	319,411	616,440	633,253
Civil | Federal agencies
Disaggregation of Revenue [Line Items]
Revenue	98,711	62,991	194,695	113,685
Civil | Private owners
Disaggregation of Revenue [Line Items]
Revenue	52,399	21,220	92,858	47,479
Civil | Mass transit
Disaggregation of Revenue [Line Items]
Revenue	361,082	225,574	549,542	482,712
Civil | Military facilities
Disaggregation of Revenue [Line Items]
Revenue	83,811	60,355	169,378	110,149
Civil | Bridges
Disaggregation of Revenue [Line Items]
Revenue	51,326	85,073	81,971	126,320
Civil | Commercial and industrial sites
Disaggregation of Revenue [Line Items]
Revenue	29,089	11,694	51,593	23,604
Civil | Other
Disaggregation of Revenue [Line Items]
Revenue	28,815	20,926	51,509	51,632
Building
Disaggregation of Revenue [Line Items]
Revenue	331,342	266,941	560,995	597,589
Building | State and local agencies
Disaggregation of Revenue [Line Items]
Revenue	177,247	89,473	313,848	213,163
Building | Federal agencies
Disaggregation of Revenue [Line Items]
Revenue	47,090	42,402	88,825	88,500
Building | Private owners
Disaggregation of Revenue [Line Items]
Revenue	107,005	135,066	158,322	295,926
Building | Mass transit
Disaggregation of Revenue [Line Items]
Revenue	62,871	10,447	96,191	70,648
Building | Other
Disaggregation of Revenue [Line Items]
Revenue	14,029	12,655	(49,095)	20,951
Building | Municipal and government
Disaggregation of Revenue [Line Items]
Revenue	97,814	83,826	187,434	159,781
Building | Health care facilities
Disaggregation of Revenue [Line Items]
Revenue	55,839	50,277	106,256	85,837
Building | Education facilities
Disaggregation of Revenue [Line Items]
Revenue	54,420	31,176	102,497	61,036
Building | Commercial and industrial facilities
Disaggregation of Revenue [Line Items]
Revenue	16,026	49,309	54,297	88,395
Building | Hospitality and gaming
Disaggregation of Revenue [Line Items]
Revenue	16,979	24,077	36,585	100,995
Building | Sports and entertainment
Disaggregation of Revenue [Line Items]
Revenue	13,364	5,174	26,830	9,946
Specialty Contractors
Disaggregation of Revenue [Line Items]
Revenue	136,286	190,464	333,063	421,175
Specialty Contractors | State and local agencies
Disaggregation of Revenue [Line Items]
Revenue	54,879	91,817	140,561	184,048
Specialty Contractors | Federal agencies
Disaggregation of Revenue [Line Items]
Revenue	(5,414)	3,186	(3,521)	14,520
Specialty Contractors | Private owners
Disaggregation of Revenue [Line Items]
Revenue	86,821	95,461	196,023	222,607
Specialty Contractors | Mass transit
Disaggregation of Revenue [Line Items]
Revenue	4,973	75,395	52,518	194,422
Specialty Contractors | Other
Disaggregation of Revenue [Line Items]
Revenue	3,118	15,922	14,843	36,040
Specialty Contractors | Health care facilities
Disaggregation of Revenue [Line Items]
Revenue	14,048	6,382	23,579	14,957
Specialty Contractors | Commercial and industrial facilities
Disaggregation of Revenue [Line Items]
Revenue	53,583	36,444	107,810	66,301
Specialty Contractors | Multi-unit residential
Disaggregation of Revenue [Line Items]
Revenue	29,207	28,243	62,003	53,181
Specialty Contractors | Water
Disaggregation of Revenue [Line Items]
Revenue	20,147	13,972	48,481	35,419
Specialty Contractors | Federal government
Disaggregation of Revenue [Line Items]
Revenue	$ 11,210	$ 14,106	$ 23,829	$ 20,855