Debt (Detail)		3 Months Ended		6 Months Ended
	Jun. 26, 2014 CNY (¥)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)	Jun. 26, 2014 USD ($)
Basis spread on variable rate (as percent)				3.00%
Annual capital expenditure limit				$ 5,000,000
Domestic Line of Credit
Letters of credit, amount outstanding		$ 8,171,000		8,171,000		$ 8,284,000
Line of credit, remaining borrowing capacity		6,829,000		$ 6,829,000		6,716,000
Line of credit, commitment fee percentage				0.25%
China Facility
Line of credit, maximum borrowing capacity	¥ 35,000,000						$ 5,748,000
Line of credit, amount outstanding		$ 0		$ 0		$ 1,625,000
Interest rate period end (as a percent)		6.70%		6.70%		7.00%
Interest paid		$ 3,000	$ 34,000	$ 30,000	$ 63,000
Standby Letters of Credit
Letters of credit, amount outstanding		174,000		174,000		$ 336,000
Line of credit, remaining borrowing capacity		5,574,000		5,574,000		$ 3,727,000
Amended Amount
Line of credit, maximum borrowing capacity		15,000,000		15,000,000
Amount Available for Increase Upon Approval of Lender
Line of credit, maximum borrowing capacity		25,000,000		25,000,000
Base Rate | China Facility
Basis spread on variable rate (as percent)	125.00%
Debt Instrument, Redemption, Period One | Revolving Credit Facility
Minimum EBITDA				500,000
Shareholder equity		69,000,000		69,000,000
Debt Instrument, Redemption, Period Two | Revolving Credit Facility
Minimum EBITDA				1,000,000
Shareholder equity		$ 70,000,000		$ 70,000,000