Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2012	Jul. 01, 2011	Jun. 29, 2012	Jul. 01, 2011
Sales	$ 70,379	$ 82,609	$ 135,565	$ 160,112
Cost of goods sold	39,712	45,609	77,217	89,370
Gross profit	30,667	37,000	58,348	70,742
Operating expenses:
Research and development and engineering	5,615	5,879	11,388	11,759
Selling, general and administrative	16,841	18,638	33,049	35,410
Amortization of purchased intangible assets	663	987	1,325	1,979
Restructuring, restatement related costs and other	2,451	(61)	4,668	122
Post-emergence professional fees		94		233
Total operating expenses	25,570	25,537	50,430	49,503
Income from operations	5,097	11,463	7,918	21,239
Interest expense, net	(678)	(3,397)	(1,487)	(7,049)
Foreign exchange transaction gains (losses), net	620	(125)	(272)	(810)
Other income (expense), net	45	354	232	1,384
Income from continuing operations before income taxes	5,084	8,295	6,391	14,764
Income tax provision	617	1,363	847	3,019
Income from continuing operations	4,467	6,932	5,544	11,745
Income from discontinued operations, net of tax	414	3,143	736	4,592
Consolidated net income	4,881	10,075	6,280	16,337
Less: Net income attributable to noncontrolling interest	(8)	(9)	(26)	(64)
Net income attributable to GSI Group Inc.	$ 4,873	$ 10,066	$ 6,254	$ 16,273
Earnings per common share from continuing operations:
Basic	$ 0.13	$ 0.21	$ 0.16	$ 0.35
Diluted	$ 0.13	$ 0.21	$ 0.16	$ 0.35
Earnings per common share from discontinued operations:
Basic	$ 0.01	$ 0.09	$ 0.02	$ 0.14
Diluted	$ 0.01	$ 0.09	$ 0.02	$ 0.14
Earnings per common share attributable to GSI Group Inc.:
Basic	$ 0.14	$ 0.30	$ 0.19	$ 0.49
Diluted	$ 0.14	$ 0.30	$ 0.18	$ 0.48
Weighted average common shares outstanding-basic	33,782	33,478	33,731	33,464
Weighted average common shares outstanding-diluted	33,953	33,595	33,915	33,564