Consolidated Statements of Stockholders' Equity (USD $) In Millions, except Share data, unless otherwise specified	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock	Trinity Stockholders' Equity	Noncontrolling Interest
Beginning balance at Dec. 31, 2010	$ 1,845.7	$ 81.7	$ 606.1	$ 1,200.5	$ (95.5)	$ (28.0)	$ 1,764.8	$ 80.9
Beginning balance, Shares at Dec. 31, 2010		81,700,000				(1,900,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	145.7			142.2			142.2	3.5
Other comprehensive income (loss)	(28.4)				(28.5)		(28.5)	0.1
Cash dividends on common stock	(28.0)			(28.0)			(28.0)
Restricted shares, net	7.0		6.7			0.3	7.0
Restricted shares, net, Shares						200,000
Stock options exercised	2.1		(0.5)			2.6	2.1
Stock options exercised, Shares						200,000
Excess tax benefits from stock-based compensation	3.5		3.5				3.5
Stock-based compensation expense	0.6		0.6				0.6
Reclassification of purchase of additional interest in TRIP Holdings			15.5		(15.5)
Tax expense allocation related to TRIP Holdings unrealized loss on derivative financial instruments			(5.5)		5.5
Other	0.1		0.1				0.1
Contributions from noncontrolling interest	0
Ending balance at Dec. 31, 2011	1,948.3	81.7	626.5	1,314.7	(134.0)	(25.1)	1,863.8	84.5
Ending balance, Shares at Dec. 31, 2011		81,700,000				(1,500,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	253.7			255.2			255.2	(1.5)
Other comprehensive income (loss)	(14.5)				(16.1)		(16.1)	1.6
Cash dividends on common stock	(33.2)			(33.2)			(33.2)
Restricted shares, net	24.7		26.4			(1.7)	24.7
Restricted shares, net, Shares						400,000
Stock options exercised	4.1		(0.7)			4.8	4.1
Stock options exercised, Shares						300,000
Excess tax benefits from stock-based compensation	0.2		0.2				0.2
Stock-based compensation expense	0.2		0.2				0.2
Other	(0.7)		0			(0.7)	(0.7)
Other, Shares						0
Shares repurchased	(45.2)					(45.2)	(45.2)
Shares repurchased, Shares	(1,834,221)					(1,800,000)
Contributions from noncontrolling interest	0
Ending balance at Dec. 31, 2012	2,137.6	81.7	652.6	1,536.7	(150.1)	(67.9)	2,053.0	84.6
Ending balance, Shares at Dec. 31, 2012		81,700,000				(2,600,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	392.4			375.5			375.5	16.9
Other comprehensive income (loss)	74.7				70.5		70.5	4.2
Cash dividends on common stock	(42.2)			(42.2)			(42.2)
Restricted shares, net	37.1		23.3			13.8	37.1
Restricted shares, net, Shares						700,000
Stock options exercised	2.3		(2.0)			4.3	2.3
Stock options exercised, Shares	152,783					100,000
Excess tax benefits from stock-based compensation	8.7		8.7				8.7
Other	(0.5)		(0.5)				(0.5)
Shares repurchased	(108.2)					(108.2)	(108.2)
Shares repurchased, Shares	(2,473,189)					(2,500,000)
Repurchase of interests in partially-owned leasing subsidiary	(84.2)		11.8		(11.8)			(84.2)
Sale of interests in partially-owned leasing subsidiaries	291.3		(7.3)		13.2		5.9	285.4
Contributions from noncontrolling interest	50.0							50.0
Distributions to noncontrolling interest	(9.9)							(9.9)
Ending balance at Dec. 31, 2013	$ 2,749.1	$ 81.7	$ 686.6	$ 1,870.0	$ (78.2)	$ (158.0)	$ 2,402.1	$ 347.0
Ending balance, Shares at Dec. 31, 2013		81,700,000				(4,300,000)