Earnings Per Common Share Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Numerators: [Abstract]
Net income attributable to Genesee & Wyoming Inc. common stockholders	$ 84,934	$ 63,362	$ 52,837	$ 23,904	$ 87,373	$ 72,650	$ 60,728	$ 40,004	$ 225,037	$ 260,755	$ 271,296
Series A-1 Preferred Stock dividend									0	0	2,139
Net income available to common stockholders									$ 225,037	$ 260,755	$ 269,157
Denominators: [Abstract]
Weighted average Class A common shares outstanding, Basic									56,734	55,305	53,788
Incremental Common Shares Attributable to Dilutive Effect of Class B Shares									884	1,305	1,675
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements									230	362	494
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock									0	0	722
Weighted average shares—Diluted									57,848	56,972	56,679
Earnings per common share attributable to Genesee & Wyoming Inc. common stockholders:
Basic earnings per common share									$ 3.97	$ 4.71	$ 5.00
Diluted earnings per common share (US$ per share)	$ 1.47	$ 1.10	$ 0.92	$ 0.42	$ 1.53	$ 1.27	$ 1.07	$ 0.70	$ 3.89	$ 4.58	$ 4.79