Asset Impairments and Assets Held for Sale Asset Held For Sale (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Long Lived Assets Held-for-sale [Line Items]
Asset Impairment Charges		$ 6.6	$ 9.0	$ 8.6
Assets Held-for-sale, Long Lived, Fair Value Disclosure		3.4	1.3
Portfolio Management [Member]
Long Lived Assets Held-for-sale [Line Items]
Asset Impairment Charges		6.2	4.5	3.7
Rail North America [Member]
Long Lived Assets Held-for-sale [Line Items]
Asset Impairment Charges		0.4	0.6	4.6
Rail International [Member]
Long Lived Assets Held-for-sale [Line Items]
Asset Impairment Charges		0.0	3.9	0.3
Adler Funding Llc [Member]
Long Lived Assets Held-for-sale [Line Items]
Asset Impairment Charges		0.0	0.0	3.0
Changes Measurement [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member]
Long Lived Assets Held-for-sale [Line Items]
Asset Impairment Charges		$ 0.0		$ 0.0
Changes Measurement [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member] | Railcars [Member] | Rail International [Member]
Long Lived Assets Held-for-sale [Line Items]
Asset Impairment Charges			0.9
Changes Measurement [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member] | Facility Closing [Member] | Rail International [Member]
Long Lived Assets Held-for-sale [Line Items]
Asset Impairment Charges	$ 5.8		$ 3.0