Condensed Statements of Shareholders' Equity (USD $) In Millions, unless otherwise specified	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Retained Earnings
Balance at Dec. 31, 2013	$ 1,101.1	$ 79.4	$ 838.8	$ (365.1)	$ 548.0
Balance (in shares) at Dec. 31, 2013		79.4
Net income	29.5	0	0	0	29.5
Other comprehensive income	1.6	0	0	1.6	0
Dividends paid:
Common stock ($0.20 per share)	(15.9)	0	0	0	(15.9)
Common stock repurchased and retired (in shares)	(0.6)	(0.6)
Common stock repurchased and retired	(14.7)	(0.6)	(14.1)	0	0
Common stock issued for:
Stock options exercised (in shares)	0.2	0.2
Stock options exercised	5.3	0.2	5.1	0	0
Other Transactions (in shares)		0
Other Transactions	(1.0)	0	(1.0)	0	0
Stock-based compensation	1.7	0	1.7	0	0
Balance at Mar. 31, 2014	1,107.6	79.0	830.5	(363.5)	561.6
Balance (in shares) at Mar. 31, 2014		79.0
Balance at Dec. 31, 2014	1,013.3	77.4	788.3	(443.1)	590.7
Balance (in shares) at Dec. 31, 2014		77.4
Net income	13.1	0	0	0	13.1
Other comprehensive income	3.4	0	0	3.4	0
Dividends paid:
Common stock ($0.20 per share)	(15.5)	0	0	0	(15.5)
Common stock repurchased and retired	0
Common stock issued for:
Stock options exercised (in shares)	0.1	0.1
Stock options exercised	2.8	0.1	2.7	0	0
Other Transactions (in shares)		0
Other Transactions	(0.2)	0	(0.2)	0	0
Stock-based compensation	1.3	0	1.3	0	0
Balance at Mar. 31, 2015	$ 1,018.2	$ 77.5	$ 792.1	$ (439.7)	$ 588.3
Balance (in shares) at Mar. 31, 2015		77.5