NET LOSS PER COMMON SHARE (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Nonvested shares outstanding	1,110,600
Anti-dilutive shares (in shares)	1,110,600
Common shares outstanding, basic:
Weighted average common shares outstanding - Basic	60,430,789
Common shares outstanding, diluted:
Weighted average common shares outstanding - Basic	60,430,789
Weighted-average common shares outstanding, diluted (in shares)	60,430,789
Reconciliation of the net loss attributable to GS&T and the net loss attributable to GS&T for diluted net loss per share
Net loss attributable to GS&T	$ (38,442)
Net loss attributable to GS&T for the computation of diluted net loss per share	(38,442)
Predecessor
Common shares outstanding, basic:
Weighted average common shares outstanding - Basic		43,568,942
Common shares outstanding, diluted:
Weighted average common shares outstanding - Basic		43,568,942
Weighted-average common shares outstanding, diluted (in shares)		43,568,942
Reconciliation of the net loss attributable to GS&T and the net loss attributable to GS&T for diluted net loss per share
Net loss attributable to GS&T		(39,105)
Net loss attributable to GS&T for the computation of diluted net loss per share		$ (39,105)

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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