Debt (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Line of Credit Facility [Line Items]
Non-Recourse Debt	$ 72.6	$ 130.6
Operating assets pledged as collateral for notes	264.2
Fixed charge coverage ratio	2.2
Minimum debt covenant fixed charge coverage ratio	1.2
Amount of secured debt available to be borrowed in accordance with public debt covenants	1,165.8
Line of Credit US [Member]
Line of Credit Facility [Line Items]
Unsecured revolving credit facility	575	560
Availability under credit facility	575
Annual commitment fees	1.0	1.2	0.9
Line of Credit Europe [Member]
Line of Credit Facility [Line Items]
Maximum amount of GRE transfer to GATX relating to loans and dividends	87.3
Restricted net assets	$ 447.5
Fair Value Hedging [Member]
Line of Credit Facility [Line Items]
Derivative, Number of Instruments Held	3	1