Earning Per Common Share (Tables)

12 Months Ended

Dec. 31, 2011

Earnings Per Common Share [Abstract]

Computation of basic and diluted net income attributable to Trinity Industries, Inc

	Year Ended December 31, 2011
	Income (Loss)			Avg. Shares Outstanding		Earnings Per Share
	(in millions, except per share amounts)
Net income attributable to Trinity Industries, Inc.	$	142.2
Unvested restricted share participation		(4.8	)
Net income attributable to Trinity Industries, Inc. — basic		137.4			77.5	$	1.77
Effect of dilutive securities:
Stock options		—			0.3
Net income attributable to Trinity Industries, Inc. — diluted	$	137.4			77.8	$	1.77

	Year Ended December 31, 2010
	Income (Loss)			Avg. Shares Outstanding		Earnings Per Share
	(in millions, except per share amounts)
Net income attributable to Trinity Industries, Inc.	$	67.4
Unvested restricted share participation		(2.3	)
Net income attributable to Trinity Industries, Inc. — basic		65.1			76.8	$	0.85
Effect of dilutive securities:
Stock options		—			0.2
Net income attributable to Trinity Industries, Inc. — diluted	$	65.1			77.0	$	0.85

	Year Ended December 31, 2009
	Income (Loss)			Avg. Shares Outstanding		Loss Per Share
	(in millions, except per share amounts)
Net loss attributable to Trinity Industries, Inc.	$	(137.7	)
Unvested restricted share participation		(1.0	)
Net loss attributable to Trinity Industries, Inc. — basic		(138.7	)		76.4	$	(1.81	)
Effect of dilutive securities:
Stock options		—			—
Net loss attributable to Trinity Industries, Inc. — diluted	$	(138.7	)		76.4	$	(1.81	)