Document and Entity Information Document (USD $)	3 Months Ended
	Mar. 31, 2013	Jun. 30, 2012	Apr. 30, 2013 Class A common shares [Member]	Apr. 30, 2013 Class B common shares [Member]
Document Information [Line Items]
Entity Registrant Name	GENESEE & WYOMING INC.
Entity Central Index Key	0001012620
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding			51,525,941	1,720,839
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float		$ 2,084,513,852