Accounts Receivable Grants from Outside Parties (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
GRANTS FROM OUTSIDE PARTIES: [Abstract]
Grant proceeds received from outside parties			$ 11,600	$ 26,000
Amortization of deferred grants	$ 3,065	$ 2,912	$ 6,310	$ 5,861

Non-cash offset to depreciation expense from the amortization of grants from outside parties

No definition available.

Name:	gwr_AmortizationOfDeferredGrants
Namespace Prefix:	gwr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration