Condensed Statements of Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Retained Earnings
Balance (in shares) at Dec. 31, 2013		79.4
Balance at Dec. 31, 2013	$ 1,101.1	$ 79.4	$ 838.8	$ (365.1)	$ 548.0
Net income	92.9	0.0	0.0	0.0	92.9
Other comprehensive income	8.7	0.0	0.0	8.7	0.0
Dividends paid:
Common stock ($0.60 per share)	$ (47.4)	$ 0.0	0.0	0.0	(47.4)
Common stock repurchased and retired (in shares)	(1.7)	(1.7)
Common stock repurchased and retired	$ (44.7)	$ (1.7)	(43.0)	0.0	0.0
Common stock issued for:
Stock options exercised (in shares)	0.4	0.4
Stock options exercised	$ 8.6	$ 0.4	8.2	0.0	0.0
Other Transactions (in shares)		0.1
Other Transactions	2.0	$ 0.1	1.9	0.0	0.0
Balance (in shares) at Sep. 30, 2014		78.2
Balance at Sep. 30, 2014	1,121.2	$ 78.2	805.9	(356.4)	593.5
Balance (in shares) at Dec. 31, 2014		77.4
Balance at Dec. 31, 2014	1,013.3	$ 77.4	788.3	(443.1)	590.7
Net income	61.3	0.0	0.0	0.0	61.3
Other comprehensive income	9.9	0.0	0.0	9.9	0.0
Dividends paid:
Common stock ($0.60 per share)	$ (46.5)	$ 0.0	0.0	0.0	(46.5)
Common stock repurchased and retired (in shares)	0.0
Common stock repurchased and retired	$ 0.0
Common stock issued for:
Stock options exercised (in shares)	0.1	0.1
Stock options exercised	$ 3.1	$ 0.1	3.0	0.0	0.0
Other Transactions (in shares)		0.1
Other Transactions	2.2	$ 0.1	2.1	0.0	0.0
Stock-based compensation	2.8	$ 0.0	2.8	0.0	0.0
Balance (in shares) at Sep. 30, 2015		77.6
Balance at Sep. 30, 2015	$ 1,046.1	$ 77.6	$ 796.2	$ (433.2)	$ 605.5