Accounts Receivable, Net Of Allowance (Schedule Of Accounts Receivable, Net of Allowance) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Receivables [Abstract]
Contract billings	$ 627,100,000	$ 606,500,000
Retainage	135,600,000	159,300,000
Costs and earnings in excess of billings	448,600,000	384,600,000
Accounts receivable, gross	1,211,300,000	1,150,400,000
Less allowance for doubtful accounts	(15,700,000)	(15,800,000)
Accounts receivable, net	$ 1,195,603,000	$ 1,134,577,000