Accounts Receivable Financing - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Accounts Receivable [Line Items]
Amount of total outstanding receivables transferred	$ 32.6	$ 6.8	$ 83.3	$ 7.2
Amount due from the financing company	20.6		20.6		15.4
Fees incurred pursuant to the factoring agreement	0.5		1.2
Maximum
Accounts Receivable [Line Items]
Fees incurred pursuant to the factoring agreement		0.1		0.1
Accounts Receivable Sold
Accounts Receivable [Line Items]
Amount of total outstanding receivables transferred	27.9	5.4	73.1	5.4
Amount due from the financing company	$ 18.3		$ 18.3		$ 12.4