Computation of Basic and Diluted Earnings (Loss) Per Share (Parenthetical) (Detail) (Segment, Discontinued Operations) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2010
Segment, Discontinued Operations
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Dilutive shares excluded	14

Dilutive impact of shares for discontinued operations which were not included in the calculation of earnings per share as their impact on earnings per share was immaterial for the period presented.

No definition available.

Name:	gsig_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShare
Namespace Prefix:	gsig_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration