Restatement of Previously issued Financial Statements and Financial Information (Consolidated Statement of Cash Flows) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income (loss)	$ 7,174,000	$ (1,438,000)	$ (6,056,000)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation	7,051,000	6,800,000	6,027,000
Amortization of intangible assets	441,000	559,000	535,000
Amortization of debt discount and prepaid debt costs	57,000	55,000	83,000
Gain on embedded derivatives and warrants	0	(1,086,000)	(2,341,000)
Pension (benefit) cost	437,000	(109,000)	(209,000)
Stock based-compensation expense	3,088,000	2,582,000	2,627,000
Loss on impairment of property and equipment	0	0	880,000
Provision for (recovery of) losses on accounts receivable	(245,000)	300,000	(159,000)
Changes in operating assets and liabilities:
Trade and other accounts receivable	(4,914,000)	(827,000)	(4,485,000)
Inventories	(8,290,000)	(14,123,000)	(1,175,000)
Prepaid expenses and other assets	333,000	122,000	(19,000)
Deferred income taxes	550,000	(1,108,000)	(110,000)
Accounts payable and accrued liabilities and deferred revenue	(3,122,000)	8,466,000	4,012,000
Accrued employee compensation	(1,699,000)	278,000	1,374,000
Other long-term liabilities	(2,007,000)	(5,572,000)	7,764,000
Net Cash Provided by (Used in) Operating Activities	(1,146,000)	(5,101,000)	8,748,000
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment	(15,200,000)	(14,466,000)	(8,794,000)
Net cash used in investing activities	(15,200,000)	(14,466,000)	(8,794,000)
Financing activities:
Principal payments on long-term debt and short-term borrowings	(9,638,000)	(12,462,000)	(11,073,000)
Proceeds from long-term and short-term borrowings	13,481,000	12,229,000	10,749,000
Proceeds from exercise of stock warrants	0	0	7,500,000
Repurchase of shares for employee tax withholding obligation	(319,000)	(154,000)	(546,000)
Proceeds from issuance of common stock under equity compensation plans	1,762,000	2,819,000	3,290,000
Proceeds from issuance of common stock under secondary security offering	10,283,000	0	0
Release of restricted cash	0	8,000,000	0
Net cash provided by financing activities	15,569,000	10,432,000	9,920,000
Increase (decrease) in cash and cash equivalents from operations	(777,000)	(9,135,000)	9,874,000
Effect of exchange rate changes on cash and cash equivalents	227,000	(1,405,000)	373,000
Decrease in cash and cash equivalents	(550,000)	(10,540,000)	10,247,000
Cash and cash equivalents, beginning of period	29,289,000	39,829,000	29,582,000
Cash and cash equivalents, end of period	28,739,000	29,289,000	39,829,000
Cash paid for:
Interest	174,000	166,000	267,000
Income taxes	1,594,000	3,329,000	12,000
Supplemental schedule of noncash investing and financing activities:
Landlord funding of leasehold improvements	1,002,000	1,522,000	434,000
Conversion of debenture into shares of common stock	0	9,341,000	0
Stock warrant liability settled in shares of common stock	0	0	1,055,000
Scenario, Previously Reported [Member]
Net income (loss)		849,000
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation		6,800,000
Amortization of intangible assets		559,000
Amortization of debt discount and prepaid debt costs		55,000
Gain on embedded derivatives and warrants		(1,086,000)
Pension (benefit) cost		(109,000)
Stock based-compensation expense		2,582,000
Loss on impairment of property and equipment		0
Provision for (recovery of) losses on accounts receivable		427,000
Changes in operating assets and liabilities:
Trade and other accounts receivable		(9,112,000)
Inventories		(8,121,000)
Prepaid expenses and other assets		87,000
Deferred income taxes		(1,108,000)
Accounts payable and accrued liabilities and deferred revenue		8,469,000
Accrued employee compensation		179,000
Other long-term liabilities		(5,572,000)
Net Cash Provided by (Used in) Operating Activities		(5,101,000)
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment		(14,466,000)
Net cash used in investing activities		(14,466,000)
Financing activities:
Principal payments on long-term debt and short-term borrowings		(12,462,000)
Proceeds from long-term and short-term borrowings		12,229,000
Proceeds from exercise of stock warrants		0
Repurchase of shares for employee tax withholding obligation		(154,000)
Proceeds from issuance of common stock under equity compensation plans		2,819,000
Proceeds from issuance of common stock under secondary security offering		0
Release of restricted cash		8,000,000
Net cash provided by financing activities		10,432,000
Increase (decrease) in cash and cash equivalents from operations		(9,135,000)
Effect of exchange rate changes on cash and cash equivalents		(1,405,000)
Decrease in cash and cash equivalents		(10,540,000)
Cash and cash equivalents, beginning of period	29,289,000	39,829,000
Cash and cash equivalents, end of period		29,289,000
Cash paid for:
Interest		166,000
Income taxes		3,329,000
Supplemental schedule of noncash investing and financing activities:
Landlord funding of leasehold improvements		1,522,000
Conversion of debenture into shares of common stock		9,341,000
Stock warrant liability settled in shares of common stock		0
Restatement Adjustment [Member]
Net income (loss)		(2,287,000)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation		0
Amortization of intangible assets		0
Amortization of debt discount and prepaid debt costs		0
Gain on embedded derivatives and warrants		0
Pension (benefit) cost
Stock based-compensation expense		0
Loss on impairment of property and equipment		0
Provision for (recovery of) losses on accounts receivable		(127,000)
Changes in operating assets and liabilities:
Trade and other accounts receivable		8,285,000
Inventories		(6,002,000)
Prepaid expenses and other assets		35,000
Deferred income taxes		0
Accounts payable and accrued liabilities and deferred revenue		(3,000)
Accrued employee compensation		99,000
Other long-term liabilities
Net Cash Provided by (Used in) Operating Activities		0
Net Cash Provided by (Used in) Investing Activities [Abstract]
Purchases of property and equipment		0
Net cash used in investing activities		0
Financing activities:
Principal payments on long-term debt and short-term borrowings		0
Proceeds from long-term and short-term borrowings		0
Proceeds from exercise of stock warrants		0
Repurchase of shares for employee tax withholding obligation		0
Proceeds from issuance of common stock under equity compensation plans		0
Proceeds from issuance of common stock under secondary security offering		0
Release of restricted cash		0
Net cash provided by financing activities		0
Increase (decrease) in cash and cash equivalents from operations		0
Effect of exchange rate changes on cash and cash equivalents		0
Decrease in cash and cash equivalents		0
Cash and cash equivalents, beginning of period	0	0
Cash and cash equivalents, end of period		0
Cash paid for:
Interest		0
Income taxes		0
Supplemental schedule of noncash investing and financing activities:
Landlord funding of leasehold improvements		0
Conversion of debenture into shares of common stock		0
Stock warrant liability settled in shares of common stock		$ 0