Credit Facility and Capital Leases - Additional Information (Detail) (USD $)	0 Months Ended		6 Months Ended	9 Months Ended	3 Months Ended		0 Months Ended
	Jun. 30, 2013	Jun. 29, 2012	Jun. 29, 2013	Sep. 30, 2013	Sep. 30, 2013 Minimum	Sep. 30, 2012 Maximum	Jul. 05, 2012 Line of Credit	Sep. 30, 2013 Before July 5, 2013	Jun. 18, 2013 Before July 5, 2013	Sep. 30, 2013 After July 5, 2013	Jun. 18, 2013 After July 5, 2013	Sep. 30, 2013 Letter Of Credit Sublimit
Line of Credit Facility [Line Items]
Credit agreement term							3 years
Line of credit facility maximum borrowing capacity								$ 25,000,000	$ 25,000,000	$ 30,000,000	$ 30,000,000	$ 2,000,000
Line of credit facility reduction in commitment				10,000,000
Commitment fee	0.30%		0.45%	0.30%
Outstanding balance of revolving credit facility		850,000		575,000
Interest rate				0.50%
LIBOR rate				2.00%
Revolving credit facility, maturity date				Jul. 05, 2015
Interest rate for borrowings under credit facility				2.20%
Terminated credit facility		$ 20,000,000
Underlying property and equipment expiration period					September 2019
Weighted-average imputed interest rates for the capital lease agreements					2.60%	3.80%