Consolidated Statements of Cash Flows $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 350.8	$ 973.8	$ 741.6
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	158.9	151.2	151.0
Operating activities:
Net income	163.1	713.6	364.7
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	(54.1)	(103.4)	(161.5)
Adjustments to reconcile net income to net cash provided by operating activities:
Income from discontinued operations	(54.1)	(103.4)	(161.5)
Depreciation and amortization	251.9	229.7	217.3
Stock-based compensation expense	29.2	22.1	30.9
Excess tax benefits from stock-based compensation	0.0	0.0	(1.0)
Provision (benefit) for deferred income taxes	57.9	(357.1)	301.5
Net gains on railcar lease fleet sales owned more than one year at the time of sale	(50.4)	(83.5)	(13.5)
Loss (gains) on disposition of property and other assets	9.0	(1.9)	(1.5)
Non-cash interest expense	18.1	31.8	28.5
Other	(8.0)	(1.2)	(3.5)
Changes in assets and liabilities:
(Increase) decrease in receivables	(88.5)	117.2	(14.1)
(Increase) decrease in inventories	(122.0)	8.9	223.2
(Increase) decrease in other assets	(77.3)	(17.1)	21.0
Increase (decrease) in accounts payable	92.7	12.2	(40.3)
Increase (decrease) in accrued liabilities	51.5	49.0	(76.1)
Increase (decrease) in other liabilities	1.1	(10.2)	(38.1)
Net cash provided by operating activities - continuing operations	274.2	610.1	837.5
Net cash provided by operating activities - discontinued operations	104.9	151.5	252.7
Net cash provided by operating activities	379.1	761.6	1,090.2
Investing activities:
Decrease (increase) in short-term marketable securities	319.5	(84.8)	(149.8)
Proceeds from railcar lease fleet sales owned more than one year at the time of sale	230.5	360.7	37.7
Proceeds from disposition of property and other assets	17.1	7.8	11.0
Capital expenditures – leasing, net of sold lease fleet railcars owned one year or less with a net cost of $92.4, $79.9, and $92.0	(948.3)	(608.3)	(799.1)
Capital expenditures – manufacturing and other	(37.3)	(22.0)	(49.5)
Acquisitions, net of cash acquired	0.0
Divestitures	0.0
Other	6.2	0.3	6.8
Net cash required by investing activities - continuing operations	(412.3)	(346.3)	(942.9)
Net cash required by investing activities - discontinued operations	(78.2)	(126.4)	(79.8)
Net cash required by investing activities	(490.5)	(472.7)	(1,022.7)
Financing activities:
Proceeds from issuance of common stock, net	0.0
Excess tax benefits from stock-based compensation	0.0	0.0	1.0
Payments to retire debt	(887.8)	(375.3)	(162.0)
Proceeds from issuance of debt	1,206.6	533.5	0.0
Shares repurchased	(506.1)	(79.4)	(34.7)
Dividends paid to common shareholders	(77.4)	(72.6)	(66.7)
Purchase of shares to satisfy employee tax on vested stock	(12.2)	(14.4)	(16.3)
Distributions to noncontrolling interest	(10.9)	(48.7)	(26.4)
Other	(3.3)	0.2	(2.6)
Net cash provided (required) by financing activities - continuing	(291.1)	(56.7)	(307.7)
Cash distributions to Arcosa, Inc. in connection with the spin-off transaction	(220.5)	0.0	0.0
Net cash required by financing activities	(511.6)	(56.7)	(307.7)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	(623.0)	232.2	(240.2)
Cash and cash equivalents at beginning of period	778.6	741.6	981.8
Cash and cash equivalents at end of period	179.2	778.6	741.6
Income Taxes Paid, Net	4.1	$ (79.9)	$ (65.5)
Discontinued Operations, Noncash Net Assets Distribution	$ 1,534.9