Shareholders' Equity Shareholders' Equity (Tables)

3 Months Ended

Mar. 31, 2019

Equity [Abstract]

Schedule of Stockholders Equity [Table Text Block]

The following table presents the changes in shareholders’ equity for the three months endedMarch 31, 2019:

	Common Shares Issued	Common Stock		Capital in Excess of Par Value			Number of Treasury Shares		Treasury Stock			Retained earnings			Accumulated other comprehensive loss			Total
($ in millions)
Balance, December 31, 2018	75.3	$	18.8	$	282.0		1.2		$	(103.7	)	$	1,353.4		$	(154.2	)	$	1,396.3
Net income	—	—		—			—		—			55.4			—			55.4
Activity related to stock-based compensation	—	—		(3.5		)	(0.2	)	14.2			—			—			10.7
Shares purchased under share repurchase program	—	—		—			0.8		(83.1		)	—			—			(83.1		)
Dividends declared ($0.15 per share)	—	—		—			—		—			(10.6		)	—			(10.6		)
Other comprehensive income, net of tax	—	—		—			—		—			—			0.8			0.8
Balance, March 31, 2019	75.3	$	18.8	$	278.5		1.8		$	(172.6	)	$	1,398.2		$	(153.4	)	$	1,369.5

The following table presents the changes in shareholders’ equity for the three months endedMarch 31, 2018:

	Common Shares Issued	Common Stock		Capital in Excess of Par Value			Number of Treasury Shares		Treasury Stock			Retained earnings			Accumulated other comprehensive loss			Total
($ in millions)
Balance, December 31, 2017	75.2	$	18.8	$	309.3		1.3		$	(109.1	)	$	1,178.2		$	(117.3	)	$	1,279.9
Effect of modified retrospective application of a new accounting standard	—	—		—			—		—			11.4			—			11.4
Net income	—	—		—			—		—			43.6			—			43.6
Activity related to stock-based compensation	0.1	—		(0.8		)	(0.1	)	8.0			—			—			7.2
Shares purchased under share repurchase program	—	—		—			0.5		(47.9		)	—			—			(47.9		)
Dividends declared ($0.14 per share)	—	—		—			—		—			(10.4		)	—			(10.4		)
Other comprehensive income, net of tax	—	—		—			—		—			—			21.5			21.5
Balance, March 31, 2018	75.3	$	18.8	$	308.5		1.7		$	(149.0	)	$	1,222.8		$	(95.8	)	$	1,305.3