Changes in Operations RailAmerica Pro Forma Financial Results (Details) (RailAmerica [Member], USD $) Share data in Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Business Acquisition [Line Items]
Operating revenues	$ 1,461,419,000
Net income attributable to Genesee & Wyoming Inc.	112,191,000
Less: Series A-1 Preferred Stock dividends	17,500,000
Net income available to common stockholders	94,691,000
Basic earnings per common share attributable to Genesee & Wyoming Inc. common stockholders	$ 1.99
Diluted earnings per common share attributable to Genesee & Wyoming Inc. common stockholders	$ 1.89
Pro Forma [Member]
Business Acquisition [Line Items]
Costs incurred by RailAmerica included in pro forma results	55,000,000
If converted shares excluded from weighted average diluted shares outstanding	6.0
Acquisition-related Costs [Member] | Pro Forma [Member]
Business Acquisition [Line Items]
Net income attributable to Genesee & Wyoming Inc.	$ 50,100,000