Assets Held for Sale Asset Held For Sale (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Long Lived Assets Held-for-sale [Line Items]
Portfolio Proceeds			$ 131.0	$ 170.6
Disposition Gains on Owned Assets	$ 7.6	$ 11.6	41.4	36.7
Asset Impairment Charges			1.9	1.8
Assets Held-for-sale, Long Lived, Fair Value Disclosure	23.6		23.6		$ 89.5
Portfolio Management [Member]
Long Lived Assets Held-for-sale [Line Items]
Disposition Gains on Owned Assets	0.0	(0.3)	1.8	4.2
Asset Impairment Charges			0.0	(1.8)
Assets Held-for-sale, Long Lived, Fair Value Disclosure	19.2		19.2		45.6
Rail North America [Member]
Long Lived Assets Held-for-sale [Line Items]
Disposition Gains on Owned Assets	7.5	$ 11.9	39.5	32.5
Asset Impairment Charges			1.9	$ 0.0
Assets Held-for-sale, Long Lived, Fair Value Disclosure	$ 4.4		$ 4.4		$ 43.9
Marine vessels [Member] | Portfolio Management [Member]
Long Lived Assets Held-for-sale [Line Items]
Property, Plant and Equipment, Dispositions			26.4
Portfolio Proceeds			$ 28.2
Railcars [Member] | Rail North America [Member]
Long Lived Assets Held-for-sale [Line Items]
Property, Plant and Equipment, Dispositions			21.8
Portfolio Proceeds			$ 49.9
Property, Plant and Equipment, Transfers and Changes			19.7
Railcars [Member]
Long Lived Assets Held-for-sale [Line Items]
Disposition Gains on Owned Assets			$ 28.1