Consolidated Statements of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues
Lease revenue	$ 271.5	$ 271.9	$ 819.9	$ 816.1
Revenue Recognition, Cargo and Freight, Policy [Policy Text Block]	62.8	60.8	136.8	130.8
Other revenue	26.4	17.0	80.4	57.6
Total Revenues	360.7	349.7	1,037.1	1,004.5
Expenses
Maintenance expense	84.4	77.5	251.3	240.7
Marine operating expense	39.7	39.4	92.8	89.5
Depreciation	83.6	81.6	247.3	240.1
Operating lease expense	13.7	11.8	41.1	37.5
Other operating expense	7.7	8.5	23.5	26.2
Selling, general and administrative	44.4	46.5	135.6	137.6
Total Expenses	273.5	265.3	791.6	771.6
Other Income (Expense)
Net gain on asset dispositions	5.1	10.3	46.9	72.5
Interest expense, net	(46.3)	(42.6)	(139.9)	(124.7)
Other (expense) income	(1.8)	(3.8)	(5.6)	(14.9)
Income before Income Taxes and Share of Affiliates’ Earnings	44.2	48.3	146.9	165.8
Income Taxes	(11.9)	(13.1)	(35.9)	(42.8)
Share of Affiliates’ Earnings (net of tax)	12.8	11.8	43.6	39.1
Net Income	45.1	47.0	154.6	162.1
Other Comprehensive Income, net of taxes
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(33.6)	(4.7)	(32.4)	(40.2)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(1.0)	1.6	2.1	2.3
Post-retirement benefit plans	1.4	5.3	5.9	9.1
Other comprehensive income (loss)	(33.2)	2.2	(24.4)	(28.8)
Comprehensive Income	$ 11.9	$ 49.2	$ 130.2	$ 133.3
Share Data
Basic earnings per share (in dollars per share)	$ 1.28	$ 1.25	$ 4.30	$ 4.29
Average number of common shares (in shares)	35.4	37.7	35.9	37.8
Diluted earnings per share (in dollars per share)	$ 1.25	$ 1.22	$ 4.22	$ 4.21
Average number of common shares and common share equivalents (in shares)	36.0	38.5	36.6	38.5