Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating activities:
Net income	$ 253.7	$ 145.7	$ 75.4
Adjustments to reconcile net income to net cash provided by operating activities:
(Income) loss from discontinued operations	(1.8)	1.1	(6.0)
Depreciation and amortization	193.7	187.7	180.9
Stock-based compensation expense	27.7	22.8	14.4
Excess tax benefits from stock-based compensation	(0.6)	(3.2)	(0.6)
Provision for deferred income taxes	126.3	60.5	68.5
Net gains on sales of railcars owned more than one year at the time of sale	(33.5)	(16.2)	(6.6)
Gain on disposition of property, plant, equipment, and other assets	(4.6)	(6.2)	(3.8)
Gain on disposition of flood-damaged property, plant, equipment, and other assets	(0.4)	(17.6)	(9.7)
Non-cash interest expense	22.0	18.6	13.6
Other	(3.2)	1.4	(6.0)
Changes in assets and liabilities:
(Increase) decrease in receivables	2.7	(150.3)	(56.0)
(Increase) decrease in inventories	(117.2)	(212.5)	(88.3)
(Increase) decrease in other assets	(43.1)	(7.7)	27.5
Increase (decrease) in accounts payable	(16.7)	74.9	50.9
Increase (decrease) in accrued liabilities	125.5	(11.5)	(62.0)
Increase (decrease) in other liabilities	(3.9)	14.0	(25.4)
Net cash provided by operating activities - continuing operations	526.6	101.5	166.8
Net cash provided by operating activities - discontinued operations	0.8	9.4	3.7
Net cash provided by operating activities	527.4	110.9	170.5
Investing activities:
(Increase) decrease in short-term marketable securities	0	158.0	(88.0)
Proceeds from sales of railcars owned more than one year at the time of sale	126.3	60.6	33.6
Proceeds from lease fleet sales – sale and leaseback	58.3	44.4	0
Proceeds from disposition of property, plant, equipment, and other assets	16.8	8.5	7.0
Proceeds from disposition of flood-damaged property, plant, and equipment	0	23.3	12.0
Capital expenditures – leasing, net of sold railcars owned one year or less	(352.6)	(258.6)	(213.8)
Capital expenditures – manufacturing and other	(116.6)	(47.6)	(27.0)
Capital expenditures – replacement of flood-damaged property, plant, and equipment	0	(29.4)	(12.0)
Acquisitions, net of cash acquired	(46.2)	(42.5)	(47.9)
Other	1.7	0	0
Net cash required by investing activities - continuing operations	(312.3)	(83.3)	(336.1)
Net cash provided (required) by investing activities - discontinued operations	0.9	(1.7)	27.9
Net cash required by investing activities	(311.4)	(85.0)	(308.2)
Financing activities:
Proceeds from issuance of common stock, net	4.1	2.1	1.7
Excess tax benefits from stock-based compensation	0.6	3.2	0.6
Payments to retire debt	(378.4)	(1,112.3)	(363.5)
Payments to retire debt - assumed debt of Quixote	0	0	(40.0)
Proceeds from issuance of debt	443.8	1,143.3	362.7
(Increase) decrease in restricted cash	17.1	(33.2)	(25.4)
Shares repurchased	(45.2)	0	0
Purchase of additional interest in TRIP Holdings	0	0	(28.6)
Dividends paid to common shareholders	(31.7)	(27.2)	(25.4)
Distribution to noncontrolling interest	0	0	(2.6)
Other	(5.3)	(6.6)	0
Net cash provided (required) by financing activities - continuing operations	5.0	(30.7)	(120.5)
Net cash provided by financing activities - discontinued operations	0.9	1.9	0.4
Net cash provided (required) by financing activities	5.9	(28.8)	(120.1)
Net increase (decrease) in cash and cash equivalents	221.9	(2.9)	(257.8)
Cash and cash equivalents at beginning of period	351.1	354.0	611.8
Cash and cash equivalents at end of period	573.0	351.1	354.0
Supplemental Cash Flow Information
Interest paid	174.8	154.9	160.5
Net tax payments received (made)	$ (18.4)	$ (2.5)	$ 16.0