Revenue (Schedule Of Revenue By Contract Type) (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
Adverse Legal Ruling Pertaining to Mixed-Use Project in New York
Disaggregation of Revenue [Line Items]
Loss contingency			83,600
Fixed price
Disaggregation of Revenue [Line Items]
Revenue	734,948	559,746	1,308,592	1,198,320
Guaranteed maximum price
Disaggregation of Revenue [Line Items]
Revenue	123,229	149,616	194,825	326,751
Unit price
Disaggregation of Revenue [Line Items]
Revenue	79,730	94,274	136,806	159,639
Cost plus fee and other
Disaggregation of Revenue [Line Items]
Revenue	83,844	57,391	157,828	128,471
Civil
Disaggregation of Revenue [Line Items]
Revenue	554,123	403,622	903,993	794,417
Civil | Fixed price
Disaggregation of Revenue [Line Items]
Revenue	488,343	337,414	799,716	674,407
Civil | Guaranteed maximum price
Disaggregation of Revenue [Line Items]
Revenue	(107)	301	(45)	594
Civil | Unit price
Disaggregation of Revenue [Line Items]
Revenue	58,662	72,210	91,674	122,720
Civil | Cost plus fee and other
Disaggregation of Revenue [Line Items]
Revenue	7,225	(6,303)	12,648	(3,304)
Building
Disaggregation of Revenue [Line Items]
Revenue	331,342	266,941	560,995	597,589
Building | Adverse Legal Ruling Pertaining to Mixed-Use Project in New York
Disaggregation of Revenue [Line Items]
Loss contingency			72,200
Building | Fixed price
Disaggregation of Revenue [Line Items]
Revenue	136,053	64,296	232,169	166,814
Building | Guaranteed maximum price
Disaggregation of Revenue [Line Items]
Revenue	125,070	145,954	194,848	317,463
Building | Unit price
Disaggregation of Revenue [Line Items]
Revenue	0	0	0	33
Building | Cost plus fee and other
Disaggregation of Revenue [Line Items]
Revenue	70,219	56,691	133,978	113,279
Specialty Contractors
Disaggregation of Revenue [Line Items]
Revenue	136,286	190,464	333,063	421,175
Specialty Contractors | Adverse Legal Ruling Pertaining to Mixed-Use Project in New York
Disaggregation of Revenue [Line Items]
Loss contingency			11,400
Specialty Contractors | Fixed price
Disaggregation of Revenue [Line Items]
Revenue	110,552	158,036	276,707	357,099
Specialty Contractors | Guaranteed maximum price
Disaggregation of Revenue [Line Items]
Revenue	(1,734)	3,361	22	8,694
Specialty Contractors | Unit price
Disaggregation of Revenue [Line Items]
Revenue	21,068	22,064	45,132	36,886
Specialty Contractors | Cost plus fee and other
Disaggregation of Revenue [Line Items]
Revenue	$ 6,400	$ 7,003	$ 11,202	$ 18,496