Consolidated Statement of Stockholders' Equity (unaudited) - USD ($) shares in Millions, $ in Millions		Total	Accelerated Share Repurchase Program	Common Stock	Capital in Excess of Par Value	Capital in Excess of Par Value Accelerated Share Repurchase Program	Retained Earnings	Accumulated other comprehensive income (loss)	Treasury Stock	Treasury Stock Accelerated Share Repurchase Program	Trinity Stockholders’ Equity	Noncontrolling Interest
$0.01 Par Value		$ 0.01
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Issued				(83.3)					0.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Beginning Balance at Dec. 31, 2021		$ 1,296.8		$ 0.8	$ 0.0		$ 1,046.6	$ (17.0)	$ (0.6)		$ 1,029.8	$ 267.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		1.9					(0.7)				(0.7)	2.6
Other comprehensive loss		17.3						17.1			17.1	0.2
Cash dividends declared on common stock (1)	[1]	(19.3)					(19.3)				(19.3)
Distributions to noncontrolling interest		(6.2)										(6.2)
Stock-based compensation expense		5.1			5.1						5.1
Settlement of share-based awards, net		0.0			0.2				(0.2)		0.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Ending Balance at Mar. 31, 2022		$ 1,295.6		0.8	5.3		1,026.6	0.1	(0.8)		1,032.0	263.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared		$ 0.23
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Beginning Balance at Dec. 31, 2021		$ 1,296.8		0.8	0.0		1,046.6	(17.0)	(0.6)		1,029.8	267.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		10.4
Other comprehensive loss		22.6
Stock-based compensation expense		10.8
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Ending Balance at Jun. 30, 2022		$ 1,256.2		$ 0.8	0.0		991.1	6.4	$ (0.7)		997.6	258.6
$0.01 Par Value		$ 0.01
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Issued				(83.3)					0.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Beginning Balance at Mar. 31, 2022		$ 1,295.6		$ 0.8	5.3		1,026.6	0.1	$ (0.8)		1,032.0	263.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		8.5					3.7				3.7	4.8
Other comprehensive loss		5.3						6.3			6.3	(1.0)
Cash dividends declared on common stock (1)	[1]	(19.1)					(19.1)				(19.1)
Distributions to noncontrolling interest		(8.8)										(8.8)
Stock-based compensation expense		5.7			5.7						5.7
Settlement of share-based awards, net		(5.7)			0.4				(6.1)		(5.7)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Ending Balance at Jun. 30, 2022		1,256.2		$ 0.8	0.0		991.1	6.4	$ (0.7)		997.6	258.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted shares, net, (in shares)				(0.8)					(0.2)
Shares repurchased			(0.8)						(1.0)	(0.8)
Shares repurchased		(25.3)	$ 0.0			$ (25.0)			$ (25.3)	$ (25.0)	(25.3)
Treasury Stock, Shares, Retired				(2.0)					(2.0)
Retirement of treasury stock		$ 0.0		$ 0.0	(36.4)		(20.1)		$ (56.5)		0.0
Common Stock, Dividends, Per Share, Declared		$ 0.23
$0.01 Par Value		0.01
Common Stock, Shares, Issued				(82.1)					0.0
$0.01 Par Value		$ 0.01
Common Stock, Shares, Issued				(81.1)					0.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Beginning Balance at Dec. 31, 2022		$ 1,269.6		$ 0.8	0.0		992.6	19.7	$ (0.7)		1,012.4	257.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		13.7					4.4				4.4	9.3
Other comprehensive loss		(14.4)						(7.0)			(7.0)	(7.4)
Cash dividends declared on common stock (1)	[2]	(21.4)					(21.4)				(21.4)
Distributions to noncontrolling interest		(2.9)										(2.9)
Stock-based compensation expense		6.2			6.2						6.2
Settlement of share-based awards, net		(0.4)			0.4				(0.8)		(0.4)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Ending Balance at Mar. 31, 2023		$ 1,250.4		0.8	6.6		975.6	12.7	(1.5)		994.2	256.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared		$ 0.26
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Beginning Balance at Dec. 31, 2022		$ 1,269.6		0.8	0.0		992.6	19.7	(0.7)		1,012.4	257.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		34.9
Other comprehensive loss		(9.4)										(7.3)
Stock-based compensation expense		12.7
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Ending Balance at Jun. 30, 2023		$ 1,249.0		$ 0.8	5.9		971.0	17.6	$ (0.7)		994.6	254.4
$0.01 Par Value		$ 0.01
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Issued				(81.1)					0.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Beginning Balance at Mar. 31, 2023		$ 1,250.4		$ 0.8	6.6		975.6	12.7	$ (1.5)		994.2	256.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		21.2					17.0				17.0	4.2
Other comprehensive loss		5.0						4.9			4.9	0.1
Cash dividends declared on common stock (1)	[2]	(21.6)					(21.6)				(21.6)
Distributions to noncontrolling interest		(6.1)										(6.1)
Stock-based compensation expense		6.5			6.5						6.5
Settlement of share-based awards, net		(6.4)			0.0				(6.4)		(6.4)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Ending Balance at Jun. 30, 2023		1,249.0		$ 0.8	5.9		971.0	$ 17.6	$ (0.7)		994.6	$ 254.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted shares, net, (in shares)				(1.0)					(0.3)
Treasury Stock, Shares, Retired				(0.3)					(0.3)
Retirement of treasury stock		$ 0.0			$ (7.2)		$ 0.0		$ (7.2)		$ 0.0
Common Stock, Dividends, Per Share, Declared		$ 0.26
$0.01 Par Value		$ 0.01
Common Stock, Shares, Issued				(81.8)					0.0

[1] Dividends of $0.23 per common share for all periods presented in 2022

[2] Dividends of $0.26 per common share for all periods presented in 2023.