Revolving Credit Facility and Long-Term Debt - Additional Information (Detail) - Agreement [Member] - USD ($)		6 Months Ended
	Jun. 29, 2016	Jun. 30, 2016	Dec. 31, 2015
Line of Credit Facility [Line Items]
Restricted money market funds and restricted certificates of deposit, current		$ 44,000,000
Line of credit facility commitment fee description		The Agreement also provides for an unused commitment fee of 0.35% per year on the average daily unused amount of the revolving credit facility, and a fee of 1.75% of the face amount of each letter of credit
Amount divided to calculate amended fixed charge coverage ratio		$ 9,425,000
Maximum amount of capital expenditures in 2016		4,000,000
Wells Fargo [Member] | Due on September 30, 2016 [Member]
Line of Credit Facility [Line Items]
Term loan payment		5,000,000
Wells Fargo [Member] | Due on December 31, 2016 [Member]
Line of Credit Facility [Line Items]
Term loan payment		$ 2,500,000
Minimum [Member]
Line of Credit Facility [Line Items]
Minimum fixed charge coverage ratio	150.00%	225.00%
Ratio of restricted and unrestricted cash and marketable securities to workers' compensation and safety incentive liabilities		100.00%
Prohibition on incurring additional indebtedness without the prior approval of the Bank in purchase money financing		$ 200,000
Maximum [Member]
Line of Credit Facility [Line Items]
Prohibition on incurring additional indebtedness without the prior approval of the Bank in purchase money financing		$ 400,000
Cash dividend		$ 0.22
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Outstanding balance on term loan and revolving credit facility		$ 0	$ 0
Unused commitment fee on unused amount		0.35%
Credit facility, expiration date		Oct. 01, 2017
Revolving Credit Facility [Member] | Wells Fargo [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity		$ 14,000,000
Revolving Credit Facility [Member] | Daily Floating Rate [Member]
Line of Credit Facility [Line Items]
Term loan from Bank, Interest rate description		A daily floating rate of one month LIBOR plus 2.0%
LIBOR plus rate		2.00%
Revolving Credit Facility [Member] | Fixed Rate [Member]
Line of Credit Facility [Line Items]
Term loan from Bank, Interest rate description		A fixed rate of LIBOR plus 2.0%
LIBOR plus rate		2.00%
Unsecured Letters Of Credit [Member]
Line of Credit Facility [Line Items]
Unused commitment fee on unused amount		1.75%
Term Loan [Member]
Line of Credit Facility [Line Items]
Outstanding balance on term loan and revolving credit facility		$ 7,500,000	15,000,000
Term loan from Bank, Interest rate description		One month LIBOR plus 2.25%
Term loan with principal bank		$ 4,700,000	$ 4,800,000
Payment of monthly principal installments of term loan		18,375
Term Loan [Member] | Wells Fargo [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity		$ 40,000,000
Term loan maturity date		Dec. 31, 2016
Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
LIBOR plus rate		2.25%
Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member] | Wells Fargo [Member]
Line of Credit Facility [Line Items]
Term loan from Bank, Interest rate description		One month LIBOR plus 4.0%
LIBOR plus rate		4.00%
Standby Letters of Credit [Member] | Wells Fargo [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity		$ 6,000,000
Cash-Secured Letters of Credit [Member] | Wells Fargo [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity		$ 42,300,000