Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Sales	$ 341,612	$ 271,498	$ 304,296
Cost of goods sold	202,163	157,022	171,196
Gross profit	139,449	114,476	133,100
Operating expenses:
Research and development and engineering	26,352	22,393	23,454
Selling, general and administrative	81,449	65,584	67,877
Amortization of purchased intangible assets	7,270	2,650	3,515
Restructuring, restatement related costs, post-emergence fees and other	6,687	8,842	2,406
Total operating expenses	121,758	99,469	97,252
Income from operations	17,691	15,007	35,848
Interest expense, net	(3,455)	(2,788)	(12,977)
Foreign exchange transaction gains (losses), net	(1,208)	(1,267)	172
Other income (expense), net	1,502	582	1,177
Income from continuing operations before income taxes	14,530	11,534	24,220
Income tax provision (benefit)	5,680	(10,940)	2,544
Income from continuing operations	8,850	22,474	21,676
Income (loss) from discontinued operations, net of tax	(927)	(5,151)	7,325
Gain (loss) on disposal of discontinued operations, net of tax	(592)	2,255
Consolidated net income	7,331	19,578	29,001
Less: Net income attributable to noncontrolling interest	(22)	(40)	(28)
Net income attributable to GSI Group Inc.	7,309	19,538	28,973
Earnings per common share from continuing operations:
Basic	$ 0.26	$ 0.66	$ 0.65
Diluted	$ 0.26	$ 0.66	$ 0.64
Earnings (Loss) per common share from discontinued operations:
Basic	$ (0.05)	$ (0.08)	$ 0.22
Diluted	$ (0.05)	$ (0.08)	$ 0.22
Earnings per common share attributable to GSI Group Inc.:
Basic	$ 0.21	$ 0.58	$ 0.87
Diluted	$ 0.21	$ 0.58	$ 0.86
Weighted average common shares outstanding-basic	34,073	33,775	33,481
Weighted average common shares outstanding-diluted	34,396	33,936	33,589
Amounts attributable to GSI Group Inc.:
Income from continuing operations	8,828	22,434	21,648
Income (loss) from discontinued operations	(1,519)	(2,896)	7,325
Net income attributable to GSI Group Inc.	$ 7,309	$ 19,538	$ 28,973