Debt - Additional Information (Detail) (Term Facility [Member], USD $) In Millions, unless otherwise specified	1 Months Ended	9 Months Ended
	Jan. 31, 2013	Sep. 30, 2013 Payment
Term Facility [Member]
Debt [Line Items]
Additional term loan facility in an aggregate amount	$ 40
Line of Credit Facility, Maximum Amount Outstanding During Period	40
Amortization period of term facility		5 years
Number of quarterly payments		15
Amount of quarterly payment		1.5
Number of quarterly payment of term loan facility in fifth year under Amendment Agreement		4
Quarterly payment of term loan facility in fifth year under Amendment Agreement		$ 2
Interest rate swap		2.54%