Accounts Receivable, Net Of Allowance (Schedule Of Accounts Receivable) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Receivables [Abstract]
Contract billings	$ 711,400,000	$ 522,000,000
Retainage	134,700,000	113,500,000
Costs and earnings in excess of billings	393,900,000	253,000,000
Accounts receivable, gross	1,240,000,000	888,500,000
Less allowance for doubtful accounts	(14,900,000)	(11,300,000)
Accounts receivable, net	$ 1,225,122,000	$ 877,214,000