Earnings per Share Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Numerator:
Net income	$ 63,362	$ 72,650	$ 140,103	$ 173,382
Denominators:
Weighted average Class A common shares outstanding - Basic	56,819,000	55,600,000	56,673,000	55,167,000
Weighted average Class B common shares outstanding	828,000	1,059,000	915,000	1,394,000
Dilutive effect of employee stock-based awards	199,000	355,000	245,000	382,000
Weighted average shares - Diluted	57,846,000	57,014,000	57,833,000	56,943,000
Earnings per common share attributable to Genesee & Wyoming Inc. common stockholders:
Basic earnings per common share	$ 1.12	$ 1.31	$ 2.47	$ 3.14
Diluted earnings per common share	$ 1.10	$ 1.27	$ 2.42	$ 3.05
Weighted average number of shares included for conversion of TEUs	3,539,240	2,841,650	3,539,240	2,841,650
Class A Common Shares [Member]
Denominators:
Weighted average Class A common shares outstanding - Basic	56,819,000	55,600,000	56,673,000	55,167,000