Accounts Payable and Accrued Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Accounts Payable and Accrued Liabilities
Retention amounts included in accounts payable	$ 13,326	$ 15,946
Accrued expenses and other current liabilities
Payroll and related employee benefits	29,190	33,086
Insurance, including self-insurance reserves	25,275	22,982
Reserve for estimated losses on uncompleted contracts	593	764
Corporate income taxes and other taxes	6,177	3,779
Accrued overhead cost	1,745	2,007
Current liabilities of discontinued operations	133	133
Other	12,883	13,401
Total accrued expenses and other current liabilities	$ 75,996	$ 76,152