Asset Impairments and Assets Held for Sale (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets Held-for-sale, Long Lived, Fair Value Disclosure	$ 4.8	$ 3.4
Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property	39.5	56.2	$ 79.3
Asset Impairment Charges	0.3	6.6	9.0
Rail North America [Member]
Asset Impairment Charges	0.3	0.4	0.6
Rail International [Member]
Asset Impairment Charges	0.0	0.0	3.9
Portfolio Management [Member]
Asset Impairment Charges	0.0	6.2	4.5
Fair Value, Nonrecurring [Member] | Changes Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Asset Impairment Charges	$ 0.0		3.0
Fair Value, Nonrecurring [Member] | Changes Measurement [Member] | Fair Value, Inputs, Level 3 [Member] | Facility Closing [Member] | Rail International [Member]
Asset Impairment Charges		$ 0.0	3.0
Fair Value, Nonrecurring [Member] | Changes Measurement [Member] | Fair Value, Inputs, Level 3 [Member] | Railcars [Member] | Rail International [Member]
Asset Impairment Charges			$ 0.9