Quarterly Financial Data Table of Quarterly Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating revenues	$ 575,595	$ 603,304	$ 594,990	$ 574,661	$ 571,576	$ 576,927	$ 540,433	$ 519,108
Operating income	105,654	127,820	103,125	86,913	106,506	109,842	99,733	75,900	$ 423,512	$ 391,981	$ 286,362
Net income attributable to Genesee & Wyoming Inc.	$ 55,562	$ 69,590	$ 44,168	$ 75,098	$ 426,566	$ 50,240	$ 46,007	$ 26,238	$ 244,418	$ 549,051	$ 141,137
Basic earnings per common share attributable to G&W: (US$ per share)	$ 0.96	$ 1.18	$ 0.74	$ 1.21	$ 6.90	$ 0.82	$ 0.75	$ 0.43	$ 4.09	$ 8.92	$ 2.46
Diluted earnings per common share attributable to G&W: (US$ per share)	$ 0.94	$ 1.16	$ 0.73	$ 1.19	$ 6.81	$ 0.80	$ 0.74	$ 0.42	$ 4.03	$ 8.79	$ 2.42