Business Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Reportable segment information
Total revenues	$ 1,058,335	$ 929,476
Elimination of intersegment revenues	(65,407)	(16,942)
Revenues from external customers	992,928	912,534
Income from construction operations	36,079	16,963
Building
Reportable segment information
Total revenues	425,114	343,039
Elimination of intersegment revenues	(11,475)	(2,245)
Revenues from external customers	413,639	340,794
Income from construction operations	4,237	(8,897)
Civil
Reportable segment information
Total revenues	283,975	250,589
Elimination of intersegment revenues	(51,288)	(1,216)
Revenues from external customers	232,687	249,373
Income from construction operations	21,554	16,842
Specialty Contractors
Reportable segment information
Total revenues	301,877	267,736
Elimination of intersegment revenues	(10)	(298)
Revenues from external customers	301,867	267,438
Income from construction operations	19,286	19,748
Management Services
Reportable segment information
Total revenues	47,369	68,112
Elimination of intersegment revenues	(2,634)	(13,183)
Revenues from external customers	44,735	54,929
Income from construction operations	2,806	1,886
Total Reportable Segments
Reportable segment information
Total revenues	1,058,335	929,476
Elimination of intersegment revenues	(65,407)	(16,942)
Revenues from external customers	992,928	912,534
Income from construction operations	47,883	29,579
Corporate
Reportable segment information
Income from construction operations	$ 11,804	$ (12,616)