Equity Method Investment, Cost Per Share to acquire 100% of outstanding shares

No definition available.

Name:	gwr_EquityMethodInvestmentCostPerShare
Namespace Prefix:	gwr_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

This item represents the amount of intercompany profits and losses on transactions between the Entity and unconsolidated subsidiaries (including certain corporate joint ventures, and noncontrolled corporations), accounted for under the equity method of accounting, which have been eliminated in preparing the Entity's financial statements.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of integration and acquisition-related costs, net of tax, incurred by an equity method investment of the entity.

+ References

No definition available.

+ Details

Name:	gwr_EquityMethodInvestmentSummarizedFinancialInformationIntegrationandAcquisitionrelatedCostsnetoftax
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of net income (loss) attributable to parent reported by an equity method investment of the entity.

+ References

No definition available.

+ Details

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

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 9

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35755396&loc=d3e33749-111570

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.12)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 11

-Article 7

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Equity Investment Equity Investment (Details) (USD $)	12 Months Ended			3 Months Ended
Equity Investment Equity Investment (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 28, 2012	Oct. 02, 2012
Income from equity investment in RailAmerica, net	$ 0	$ 0	$ 15,557,000
RailAmerica [Member]
RailAmerica, Ownership Percentage					100.00%
RailAmerica Acquisition, Price Per Share					$ 27.50
Income from equity investment in RailAmerica, net				15,600,000
Net income reported by RailAmerica, Inc.				15,806,000
Equity investment intercompany elimination				200,000
After-tax impact of integration and acquisition-related costs incurred by RailAmerica and included in income from equity investment				$ 3,500,000