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	66.8	0.0	0.0	0.0	66.8
Other comprehensive income	8.7	0.0	0.0	8.7	0.0
Dividends paid:
Common stock ($0.40 per share)	$ (31.7)	$ 0.0	0.0	0.0	(31.7)
Common stock repurchased and retired (in shares)	(1.1)	(1.1)
Common stock repurchased and retired	$ (29.7)	$ (1.1)	(28.6)	0.0	0.0
Common stock issued for:
Stock options exercised (in shares)	0.3	0.3
Stock options exercised	$ 7.3	$ 0.3	7.0	0.0	0.0
Other Transactions (in shares)		0.0
Other Transactions	(0.7)	$ 0.0	(0.7)	0.0	0.0
Stock-based compensation	2.0	$ 0.0	2.0	0.0	0.0
Balance (in shares) at Jun. 30, 2014		78.6
Balance at Jun. 30, 2014	1,123.8	$ 78.6	818.5	(356.4)	583.1
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	55.4	0.0	0.0	0.0	55.4
Other comprehensive income	8.8	0.0	0.0	8.8	0.0
Dividends paid:
Common stock ($0.40 per share)	$ (31.0)	$ 0.0	0.0	0.0	(31.0)
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)		0.0
Other Transactions	(0.3)	$ 0.0	(0.3)	0.0	0.0
Stock-based compensation	3.2	$ 0.0	3.2	0.0	0.0
Balance (in shares) at Jun. 30, 2015		77.5
Balance at Jun. 30, 2015	$ 1,052.5	$ 77.5	$ 794.2	$ (434.3)	$ 615.1