Accounts Receivable, Net of Allowance (Tables) - Accounts Receivable [Member]

12 Months Ended

Dec. 31, 2015

Schedule of Accounts Receivable, Net of Allowance [Line Items]

Schedule of Accounts Receivable, Net of Allowance

The following table provides details of accounts receivable, net of allowance, as of the dates indicated (in millions):

	December 31,
	2015			2014
Contract billings	$	437.3		$	669.7
Retainage	148.8			162.2
Costs and earnings in excess of billings	332.7			485.6
Accounts receivable, gross	$	918.8		$	1,317.5
Less allowance for doubtful accounts	(7.7		)	(13.9		)
Accounts receivable, net	$	911.1		$	1,303.6

Schedule of Activity, Allowance for Doubtful Accounts

Activity in the allowance for doubtful accounts for the periods indicated is as follows (in millions):

	For the Years Ended December 31,
	2015			2014
Allowance for doubtful accounts at beginning of year	$	13.9		$	15.7
Provision for doubtful accounts	2.1			1.8
Amounts charged against the allowance	(8.3		)	(3.6		)
Allowance for doubtful accounts at end of year	$	7.7		$	13.9