Accounts Receivable, Net Of Allowance (Tables)

12 Months Ended

Dec. 31, 2011

Accounts Receivable, Net Of Allowance [Abstract]

Schedule Of Accounts Receivable

	December 31,
	2011			2010
Contract billings	$	398.8		$	309.8
Retainage		43.7			32.7
Costs and earnings in excess of billings		229.8			110.4
Accounts receivable, gross	$	672.3		$	452.9
Less allowance for doubtful accounts		(7.7	)		(8.5	)
Accounts receivable, net	$	664.6		$	444.4

Schedule Of Allowance For Doubtful Accounts

	Year Ended December 31,
	2011			2010
Allowance for doubtful accounts at beginning of year	$	8.5		$	10.3
Provision for doubtful accounts		2.0			2.9
Amounts charged against the allowance		(2.8	)		(4.7	)
Allowance for doubtful accounts at end of year	$	7.7		$	8.5