Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current Assets
Cash and cash equivalents	$ 65,788	$ 54,835
Accounts receivable, net of allowance of $374 and $337, respectively	42,652	38,847
Income taxes receivable	16,540	22,707
Inventories	52,801	51,539
Deferred tax assets	7,583	5,335
Prepaid expenses and other current assets	5,486	5,385
Assets of discontinued operations	17,618	35,663
Total current assets	208,468	214,311
Property, plant and equipment, net	32,338	35,955
Deferred tax assets	3,884	814
Other assets	8,172	7,048
Intangible assets, net	40,020	45,797
Goodwill	44,578	44,578
Total assets	337,460	348,503
Current Liabilities
Current portion of long-term debt	7,500	10,000
Accounts payable	18,824	12,532
Income taxes payable	3,317	1,835
Deferred revenue	316	852
Deferred tax liabilities	402	109
Accrued expenses and other current liabilities	18,962	18,927
Liabilities of discontinued operations	5,605	14,806
Total current liabilities	54,926	59,061
Long-term debt	42,500	58,000
Deferred tax liabilities	255	8,722
Income taxes payable	1,764	8,057
Other liabilities	9,809	5,303
Total liabilities	109,254	139,143
Commitments and Contingencies (Note 15)
Stockholders' Equity:
Common shares, no par value; Authorized shares: unlimited; Issued and outstanding: 33,796 and 33,478, respectively	423,856	423,856
Additional paid-in capital	21,924	17,931
Accumulated deficit	(208,222)	(227,760)
Accumulated other comprehensive loss	(9,749)	(5,024)
Total GSI Group Inc. stockholders' equity	227,809	209,003
Noncontrolling interest	397	357
Total stockholders' equity	228,206	209,360
Total liabilities and stockholders' equity	$ 337,460	$ 348,503