Quarterly Financial Data Table of Quarterly Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating revenues	$ 571,576	$ 576,927	$ 540,433	$ 519,108	$ 516,534	$ 501,002	$ 501,375	$ 482,616
Operating income	108,179	111,489	101,340	77,454	53,571	91,851	87,194	56,996	$ 398,462	$ 289,612	$ 384,261
Net income attributable to Genesee & Wyoming Inc.	$ 426,566	$ 50,240	$ 46,007	$ 26,238	$ 8,934	$ 56,785	$ 48,399	$ 27,019	$ 549,051	$ 141,137	$ 225,037
Basic earnings per common share attributable to G&W: (US$ per share)	$ 6.90	$ 0.82	$ 0.75	$ 0.43	$ 0.15	$ 0.99	$ 0.85	$ 0.47	$ 8.92	$ 2.46	$ 3.97
Diluted earnings per common share attributable to G&W: (US$ per share)	$ 6.81	$ 0.80	$ 0.74	$ 0.42	$ 0.15	$ 0.98	$ 0.83	$ 0.47	$ 8.79	$ 2.42	$ 3.89