Debt - Additional Information (Detail) (USD $)	1 Months Ended	6 Months Ended
	Sep. 21, 2011	Jun. 30, 2013	Jul. 01, 2012	Dec. 30, 2012	Feb. 10, 2010
Line of Credit Facility [Line Items]
Unsecured revolving credit agreement	$ 200,000,000	$ 200,000,000
Period of Unsecured revolving credit agreement	5 years
Maturity date of unsecured revolving credit agreement	Sep. 21, 2016
Amount available for issuance of letters of credit from revolving credit facility		25,000,000
Annual facility fee		0.175%
Outstanding borrowings on unsecured revolving credit agreement		55,000,000	0	30,000,000
Available to meet its cash requirements under revolving credit facility		145,000,000
Uncommitted Line of Credit Agreement					20,000,000
Uncommitted line of credit initiation date		Feb. 10, 2010
Uncommitted line of credit period 1		7 days
Uncommitted line of credit period 2		30 days
Uncommitted line of credit period 3		60 days
Uncommitted line of credit period 4		90 days
Outstanding borrowing on uncommitted line of credit		20,000,000	0	20,000,000
Uncommitted line of credit, weighted average interest rate		0.94%		0.94%
Senior notes maturity prior year				150,000,000
Maturity date of long-term debt maturing prior year				2012-11
Weighted average interest rate on its debt and capital lease obligations spot rate		5.70%	6.10%	5.90%
Overall weighted average interest rate on its debt and capital lease obligations		5.70%	6.10%
Debt and capital lease obligations subject to changes in short-term interest rates		75,000,000
Debt and capital lease obligations		515,900,000
Debt issued by subsidiaries		0
Guarantees of company debt		$ 0
Minimum [Member]
Line of Credit Facility [Line Items]
Fixed charges ratio		1.0
Operating cash flow ratio		1.0
Maximum [Member]
Line of Credit Facility [Line Items]
Fixed charges ratio		1.5
Operating cash flow ratio		6.0