Contract Receivables (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retainages	$ 98,042	$ 133,619
Less allowances	0	0
Accounts receivable-trade, net	443,182	428,800
Contract Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retainages	98,042	133,619
Unbilled	4,710	4,710
Less allowances	(22,116)	(22,116)
Accounts receivable-trade, net	443,182	428,800
Contract Receivable | Contracts in progress
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contracts receivable	239,823	273,729
Contract Receivable | Completed contracts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contracts receivable	$ 122,723	$ 38,858