Commitments and Contingencies (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating Leases, Rent Expense	$ 2,500,000	$ 1,800,000	$ 1,100,000
Machinery and Equipment, Gross	973,000
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	24,107,000	26,867,000
Letters of Credit Outstanding, Amount	1,700,000
Certain Machinery and Equipment [Member]
Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments	717,000
Capital Lease Obligations, Current	137,000
Capital Lease Obligations, Noncurrent	580,000
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$ 149,000