Accounts Receivable, Net Of Allowance (Schedule Of Accounts Receivable, Net of Allowance) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Receivables [Abstract]
Contract billings	$ 775,600,000	$ 606,500,000
Retainage	179,300,000	159,300,000
Costs and earnings in excess of billings	451,700,000	384,600,000
Accounts receivable, gross	1,406,600,000	1,150,400,000
Less allowance for doubtful accounts	(16,700,000)	(15,700,000)
Accounts receivable, net	$ 1,389,903,000	$ 1,134,693,000