Commitments and Contingencies - Additional Information (Detail) In Millions, unless otherwise specified	1 Months Ended			1 Months Ended	6 Months Ended					1 Months Ended	3 Months Ended
	Jul. 13, 2010 USD ($)	May 06, 2011 EUR (€)	Apr. 18, 2006 EUR (€)	Jul. 28, 2013 Internal Revenue Service (IRS) USD ($)	Jun. 28, 2013 Internal Revenue Service (IRS)	Apr. 05, 2010 Internal Revenue Service (IRS) USD ($)	Sep. 28, 2013 Internal Revenue Service (IRS) Scenario, Forecast Minimum USD ($)	Sep. 28, 2013 Internal Revenue Service (IRS) Scenario, Forecast Maximum USD ($)	May 06, 2011 GSI Group GmbH EUR (€)	Apr. 18, 2006 GSI's French Subsidiary	Sep. 30, 2005 GSI's French Subsidiary
Commitments and Contingencies Disclosure [Line Items]
Filed for bankruptcy protection date											Jul. 07, 2005
Actions taken										On April 18, 2006, the commercial court of Le Creusot (France) ordered GSI France to pay approximately 0.7 million Euros to SCGI in the context of a claim filed by SCGI that a Laserdyne 890 system delivered in 1999 had unresolved technical problems.
Payment to settle claim filed, minimum			€ 0.7
Payment to settle claim filed, maximum		3.1
Payment in the respect of a claim filed									2.4
IRS filed amended proofs of claim date					April 5, 2010
IRS filed aggregate claims						7.7
IRS Claims	On July 13, 2010, the Company filed a complaint, GSI Group Corporation v. United States of America, in Bankruptcy Court in an attempt to recover refunds totaling approximately $18.8 million in federal income taxes the Company asserts it overpaid to the IRS relating to tax years 2000 through 2009, together with applicable interest.
Amount of claim we filed with the IRS for federal income taxes overpaid	18.8
Expected income tax refund							11.5	13.5
Partial income tax refund				$ 9.8