Accounts Receivable Grants from Outside Parties (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Nontrade Receivables [Abstract]
Grant proceeds received from outside parties			$ 16,700	$ 16,000
Amortization of deferred grants	$ 3,173	$ 2,978	$ 8,776	$ 9,287

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