Earnings per Share Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Numerator [Line items]
Net income attributable to Genesee & Wyoming Inc.	$ 75,098	$ 26,238
Denominators [Line Items]
Weighted average Class A common shares outstanding – Basic	61,918	61,413
Weighted average Class B common shares outstanding	701	758
Dilutive effect of employee stock-based awards	268	182
Weighted average shares - Diluted	62,887	62,353
Earnings per common share [Line Items]
Basic earnings per common share attributable to Genesee & Wyoming Inc. common stockholders:	$ 1.21	$ 0.43
Diluted earnings per common share attributable to Genesee & Wyoming Inc. common stockholders	$ 1.19	$ 0.42

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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