Subsequent Event - Additional Information (Detail) (Subsequent Event, USD $) In Millions, unless otherwise specified	1 Months Ended											1 Months Ended
	Jul. 16, 2013	Jul. 16, 2013 Prime Rate Minimum	Jul. 16, 2013 Prime Rate Maximum	Jul. 16, 2013 Libor Rate Plus	Jul. 16, 2013 Libor Rate Plus Minimum	Jul. 16, 2013 Libor Rate Plus Maximum	Jul. 16, 2013 Rate Spread	Jul. 16, 2013 Senior Credit Facility	Sep. 30, 2013 Senior Credit Facility Term Loan	Jul. 16, 2013 Senior Credit Facility Term Loan	Jul. 16, 2013 Senior Credit Facility Revolving Credit Facility	Jul. 16, 2013 New Senior Credit Facility	Jul. 16, 2013 New Senior Credit Facility Revolving Credit Facility
Subsequent Event [Line Items]
Credit facility								$ 775	$ 375	$ 375	$ 400		$ 850
Transaction fee												6.4
Transaction fees recorded as Deferred asset												6.4
Amortization of debt issuance costs												$ 1.3
Federal funds effective rate plus	0.50%
Prime rate or one month LIBOR plus	1.00%
Applicable margin		0.25%	1.00%		1.25%	2.00%
Senior credit facility interest rate	1.94%			0.19%			1.75%