Consolidated Statements of Changes in Equity Statement - USD ($) $ in Thousands	Total	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]	Class A Common Stock [Member] Common Stock [Member]	Class B Common Stock [Member] Common Stock [Member]	Conversion of Class B Common Stock to Class A Common Stock [Member]	Conversion of Class B Common Stock to Class A Common Stock [Member] Class A Common Stock [Member] Common Stock [Member]	Conversion of Class B Common Stock to Class A Common Stock [Member] Class B Common Stock [Member] Common Stock [Member]	Settlement of the prepaid stock purchase contract component of the TEUs [Member]	Settlement of the prepaid stock purchase contract component of the TEUs [Member] Additional Paid-in Capital [Member]	Settlement of the prepaid stock purchase contract component of the TEUs [Member] Class A Common Stock [Member] Common Stock [Member]
Stockholders' equity, balance at Dec. 31, 2014	$ 2,357,980	$ 1,333,353	$ 1,319,639	$ (72,252)	$ (224,547)	$ 1,121	$ 656	$ 10
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Genesee & Wyoming Inc.	225,037		225,037
Net income/(loss) attributable to noncontrolling interest	0
Net income/(loss) including portion attributable to noncontrolling interest	225,037
Other comprehensive income/(loss) including portion attributable to noncontrolling interest	(81,205)			(81,205)
Conversion of shares to Class A common stock									$ 0	$ (2)	$ (2)	$ 0	$ (36)	$ (36)
Value of stock issued for stock-based compensation	6,829	6,826					3
Compensation cost related to stock-based compensation	14,421	14,421
Excess income tax benefits from stock-based compensation	1,432	1,432
Purchase of noncontrolling interest	(2,582)	(1,461)				(1,121)
Value of treasury stock repurchased	(3,261)				(3,261)
Other	810	810
Stockholders' equity, balance at Dec. 31, 2015	2,519,461	1,355,345	1,544,676	(153,457)	(227,808)	0	697	8
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Genesee & Wyoming Inc.	141,137		141,137
Net income/(loss) attributable to noncontrolling interest	(41)					(41)
Net income/(loss) including portion attributable to noncontrolling interest	141,096
Other comprehensive income/(loss) attributable to G&W	(57,879)			(92,517)
Other comprehensive income/(loss) attributable to noncontrolling interest						8,549
Other comprehensive income/(loss) including portion attributable to noncontrolling interest	(83,968)
Value of stock issued - equity offering	285,756	285,716					40
Conversion of shares to Class A common stock									0	0	0
Value of stock issued for stock-based compensation	8,294	8,289					5
Compensation cost related to stock-based compensation	18,884	18,884
Income tax deficiencies from stock-based compensation	(281)	(281)
Value of treasury stock repurchased	(4,540)				(4,540)
Settlement of deferred stock awards	2,069	2,069
Issuance of noncontrolling interest	300,342	(18,327)		34,638		(284,031)
Other	8	8
Stockholders' equity, balance at Dec. 31, 2016	3,187,121	1,651,703	1,685,813	(211,336)	(232,348)	292,539	742	8
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Genesee & Wyoming Inc.	549,051		549,051
Net income/(loss) attributable to noncontrolling interest	7,727					7,727
Net income/(loss) including portion attributable to noncontrolling interest	556,778
Other comprehensive income/(loss) attributable to G&W	91,782			91,782
Other comprehensive income/(loss) attributable to noncontrolling interest						17,296
Other comprehensive income/(loss) including portion attributable to noncontrolling interest	109,078
Conversion of shares to Class A common stock									$ 0	$ (1)	$ (1)
Value of stock issued for stock-based compensation	11,584	11,581					3
Compensation cost related to stock-based compensation	17,476	17,476
Value of treasury stock repurchased	(4,603)				(4,603)
Settlement of deferred stock awards	738	738
Other	429	433				(4)
Value of stock issued from sale of unregistered securities	17,491	17,489					2
Stockholders' equity, balance at Dec. 31, 2017	$ 3,896,092	$ 1,699,420	$ 2,234,864	$ (119,554)	$ (236,951)	$ 317,558	$ 748	$ 7