Consolidated Statements of Cash Flows $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 136.1	$ 163.1	$ 713.6
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	3.1	(54.1)	(103.4)
Depreciation, Depletion and Amortization	283.6	251.9	229.7
Share-based Payment Arrangement, Noncash Expense	29.2	29.2	22.1
Deferred Income Tax Expense (Benefit)	54.8	57.9	(357.1)
Gain (Loss) on Sale of Property, Plant and Equipment, Railroad Transportation Equipment	(50.5)	(50.4)	(83.5)
Gain (Loss) on Disposition of Property, Plant and Equipment, Other	(3.9)	9.0	(1.9)
Asset Impairment Charges	10.9	0.0	0.0
Amortization of Debt Issuance Costs and Discounts	16.7	18.1	31.8
Other Noncash Income (Expense)	(4.3)	(8.0)	(1.2)
Increase (Decrease) in Accounts Receivable	40.9	(88.5)	117.2
Increase (Decrease) in Inventories	91.3	(122.0)	8.9
Increase (Decrease) in Other Operating Assets	(114.5)	(77.3)	(17.1)
Increase (Decrease) in Accounts Payable	(10.0)	92.7	12.2
Increase (Decrease) in Accrued Liabilities	(82.6)	51.5	49.0
Increase (Decrease) in Other Operating Liabilities	(4.1)	1.1	(10.2)
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	396.7	274.2	610.1
Cash Provided by (Used in) Operating Activities, Discontinued Operations	(3.1)	104.9	151.5
Net Cash Provided by (Used in) Operating Activities	393.6	379.1	761.6
Payments for (Proceeds from) Short-term Investments	0.0	319.5	(84.8)
Proceeds from Sale of Other Productive Assets	20.2	17.1	7.8
Proceeds from Sales of Railcars Owned More Than One Year at the Time of Sale	205.7	230.5	360.7
Payments to Acquire Leasing Assets Net of Sold Railcars Owned One Year or Less	(1,122.2)	(948.3)	(608.3)
Payments to Acquire Property, Plant, and Equipment	(97.0)	(37.3)	(22.0)
Payments for (Proceeds from) Other Investing Activities	0.0	6.2	0.3
Net Cash Provided by (Used in) Investing Activities, Continuing Operations	(993.3)	(412.3)	(346.3)
Cash Provided by (Used in) Investing Activities, Discontinued Operations	0.0	(78.2)	(126.4)
Net Cash Provided by (Used in) Investing Activities	(993.3)	(490.5)	(472.7)
Repayment of Long-term Debt, Long-term Lease Obligation, and Capital Security	(1,724.1)	(887.8)	(375.3)
Proceeds from Issuance of Long-term Debt and Capital Securities, Net	2,567.8	1,206.6	533.5
Payments for Repurchase of Common Stock	(224.7)	(506.1)	(79.4)
Payments of Ordinary Dividends, Common Stock	(82.1)	(77.4)	(72.6)
Payment, Tax Withholding, Share-based Payment Arrangement	(8.2)	(12.2)	(14.4)
Payments of Ordinary Dividends, Noncontrolling Interest	(2.2)	(10.9)	(48.7)
Proceeds from (Payments for) Other Financing Activities	0.0	(3.3)	0.2
Net Cash Provided by (Used in) Financing Activities, Continuing Operations	526.5	(291.1)	(56.7)
Cash Provided by (Used in) Financing Activities, Discontinued Operations	0.0	(220.5)	0.0
Net Cash Provided by (Used in) Financing Activities	526.5	(511.6)	(56.7)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	(73.2)	(623.0)	232.2
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	277.6	350.8	973.8
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	208.1	158.9	151.2
Income Taxes Paid, Net	(16.7)	4.1	(79.9)
Discontinued Operations, NonCash Net Assets Distribution	0.0	1,534.9	0.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt	$ 0.0	$ 283.9	$ 0.0