Earnings Per Common Share Basic and Diluted EPS (Details) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Numerators: [Abstract]
Net income attributable to Genesee & Wyoming Inc. common stockholders									$ 260,755,000	$ 271,296,000	$ 52,433,000
Less: Series A-1 Preferred Stock dividend									0	2,139,000	4,375,000
Net income available to common stockholders									$ 260,755,000	$ 269,157,000	$ 48,058,000
Denominators: [Abstract]
Weighted average Class A common shares outstanding, Basic									55,305	53,788	42,693
Incremental Common Shares Attributable to Dilutive Effect of Class B Shares									1,305	1,675	2,038
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements									362	494	601
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock									0	722	5,984
Weighted average shares—Diluted									56,972	56,679	51,316
Earnings per common share attributable to Genesee & Wyoming Inc. common stockholders:
Basic earnings per common share									$ 4.71	$ 5.00	$ 1.13
Diluted earnings per common share	$ 1.53	$ 1.27	$ 1.07	$ 0.70	$ 1.03	$ 1.16	$ 1.14	$ 1.46	$ 4.58	$ 4.79	$ 1.02