Cover Page - shares	9 Months Ended
	Sep. 30, 2019	Nov. 01, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Entity File Number	001-31456
Entity Registrant Name	GENESEE & WYOMING INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	06-0984624
Entity Address, Address Line One	20 West Avenue
Entity Address, City or Town	Darien
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06820
City Area Code	203
Local Phone Number	202-8900
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Class A Common Stock
Trading Symbol	GWR
Security Exchange Name	NYSE
Document Information [Line Items]
Document Transition Report	false
Entity Central Index Key	0001012620
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
Class A Common Shares [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		57,037,678
Class B Common Shares [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		2,072