Goodwill and Other Intangible Assets, Net - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended					12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Customer relationships [Member]	Oct. 22, 2013 Customer relationships [Member]	Dec. 31, 2013 Other definite-lived intangibles [Member]
Goodwill and Intangible Assets Disclosure [Line Items]
Business combination, Intangible assets acquired					$ 62.0
Amortization expense	10.3	6.6	5.5
Expected amortization expense in 2014	13.6
Expected amortization expense in 2015	13.6
Expected amortization expense in 2016	13.6
Expected amortization expense in 2017	13.6
Expected amortization expense in 2018	$ 13.6
Definite-lived intangibles, weighted-average useful life (in years)				18 years		9 years