Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net income (loss)	$ (226,200,000)	$ 136,100,000	$ 163,100,000
(Income) loss from discontinued operations, net of income taxes	100,000	3,100,000	(54,100,000)
Depreciation and amortization	266,000,000.0	283,600,000	251,900,000
Stock-based compensation expense	26,900,000	29,200,000	29,200,000
Provision for deferred income taxes	226,100,000	54,800,000	57,900,000
Net gains on railcar lease fleet sales owned more than one year at the time of sale	(17,300,000)	(50,500,000)	(50,400,000)
(Gains) losses on dispositions of property and other assets	(5,500,000)	(3,900,000)	9,000,000.0
Pension plan settlement	(151,500,000)	0	0
Impairment of long-lived assets	396,400,000	0	0
Non-cash impact of restructuring activities	5,300,000	10,900,000	0
Non-cash interest expense	13,700,000	16,700,000	18,100,000
Loss on early extinguishment of debt	5,000,000.0	0	0
Other	100,000	(4,300,000)	(8,000,000.0)
(Increase) decrease in receivables	59,000,000.0	15,200,000	(72,100,000)
(Increase) decrease in income tax receivable	(431,100,000)	25,700,000	(16,400,000)
(Increase) decrease in inventories	105,300,000	91,300,000	(122,000,000.0)
(Increase) decrease in other assets	146,100,000	(114,500,000)	(77,300,000)
Increase (decrease) in accounts payable	(47,500,000)	(10,000,000.0)	92,700,000
Increase (decrease) in accrued liabilities	(31,100,000)	(82,600,000)	51,500,000
Increase (decrease) in other liabilities	9,000,000.0	(4,100,000)	1,100,000
Net cash provided by operating activities – continuing operations	651,800,000	396,700,000	274,200,000
Net cash provided by (used in) operating activities – discontinued operations	(100,000)	(3,100,000)	104,900,000
Net cash provided by operating activities	651,700,000	393,600,000	379,100,000
Decrease in short-term marketable securities	0	0	319,500,000
Proceeds from dispositions of property and other assets	32,900,000	20,200,000	17,100,000
Proceeds from railcar lease fleet sales owned more than one year at the time of sale	138,700,000	205,700,000	230,500,000
Capital expenditures – leasing, net of sold lease fleet railcars owned one year or less with a net cost of $54.0, $319.3, and $92.4	(602,200,000)	(1,122,200,000)	(948,300,000)
Capital expenditures – manufacturing and other	(102,300,000)	(97,000,000.0)	(37,300,000)
Payments for (Proceeds from) Other Investing Activities	0	0	6,200,000
Net cash used in investing activities – continuing operations	(532,900,000)	(993,300,000)	(412,300,000)
Net cash used in investing activities – discontinued operations	0	0	(78,200,000)
Net cash used in investing activities	(532,900,000)	(993,300,000)	(490,500,000)
Payments to retire debt	(1,442,900,000)	(1,724,100,000)	(887,800,000)
Proceeds from issuance of debt	1,561,400,000	2,567,800,000	1,206,600,000
Shares repurchased	(191,300,000)	(224,700,000)	(506,100,000)
Dividends paid to common stockholders	(91,700,000)	(82,100,000)	(77,400,000)
Purchase of shares to satisfy employee tax on vested stock	(9,500,000)	(8,200,000)	(12,200,000)
Contributions from (distributions to) noncontrolling interest	(6,100,000)	2,200,000	10,900,000
Proceeds from (Payments for) Other Financing Activities	(100,000)	0	(3,300,000)
Net cash provided by (used in) financing activities – continuing operations	(168,000,000.0)	526,500,000	(291,100,000)
Cash distributions to Arcosa, Inc.	0	0	(220,500,000)
Net cash provided by (used in) financing activities	(168,000,000.0)	526,500,000	(511,600,000)
Net decrease in cash, cash equivalents, and restricted cash	(49,200,000)	(73,200,000)	(623,000,000.0)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	228,400,000	277,600,000	350,800,000
Interest paid	205,500,000	208,100,000	158,900,000
Income tax payments (refunds)	(62,500,000)	(16,700,000)	4,100,000
Distribution of noncash net assets to Arcosa, Inc.	0	0	1,534,900,000
Debt assumed in railcar purchase from unrelated seller	$ 0	$ 0	$ 283,900,000