Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 28, 2013	Dec. 31, 2012
Current Assets
Cash and cash equivalents	$ 52,058	$ 65,788
Accounts receivable, net of allowance of $839 and $374, respectively	55,314	42,652
Income taxes receivable	16,539	16,540
Inventories	62,555	52,801
Deferred tax assets	6,881	7,583
Prepaid expenses and other current assets	5,575	5,486
Assets of discontinued operations	1,894	17,618
Total current assets	200,816	208,468
Property, plant and equipment, net	33,959	32,338
Deferred tax assets	2,694	3,884
Other assets	8,515	8,172
Intangible assets, net	70,531	40,020
Goodwill	73,514	44,578
Total assets	390,029	337,460
Current Liabilities
Current portion of long-term debt	7,500	7,500
Accounts payable	25,569	18,824
Income taxes payable	2,919	3,317
Deferred revenue	816	316
Deferred tax liabilities	376	402
Accrued expenses and other current liabilities	22,665	18,962
Liabilities of discontinued operations	2,681	5,605
Total current liabilities	62,526	54,926
Long-term debt	87,750	42,500
Deferred tax liabilities	816	255
Income taxes payable	2,620	1,764
Other liabilities	9,486	9,809
Total liabilities	163,198	109,254
Commitments and Contingencies (Note 14)
Stockholders' Equity:
Common shares, no par value; Authorized shares: unlimited; Issued and outstanding: 33,940 and 33,796, respectively	423,856	423,856
Additional paid-in capital	23,892	21,924
Accumulated deficit	(207,011)	(208,222)
Accumulated other comprehensive loss	(14,357)	(9,749)
Total GSI Group Inc. stockholders' equity	226,380	227,809
Noncontrolling interest	451	397
Total stockholders' equity	226,831	228,206
Total liabilities and stockholders' equity	$ 390,029	$ 337,460