CONDENSED CONSOLIDATED STATEMENT OF EQUITY (UNAUDITED) - 9 months ended Sep. 30, 2016 - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Capital in Excess of Par Value [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Balance at Dec. 31, 2015	$ 1,023.9	$ 18.1	$ 207.8	$ (4.0)	$ 964.6	$ (162.6)
Balance (in shares) at Dec. 31, 2015		72.4
Increase (Decrease) in Equity [Roll Forward]
Net income	104.5				104.5
Stock-based compensation	13.0		12.7	0.3
Shares issued under stock plans (shares)		1.2
Shares issued under stock plans	25.9	$ 0.3	16.9	8.7
Shares repurchased under share repurchase program	(26.8)			(26.8)
Shares repurchased for employee tax withholdings (shares)		(0.1)
Shares repurchased for employee tax withholdings	(3.7)		(3.7)
Excess tax benefit from employee stock plans	13.9		13.9
Dividends declared	(27.2)				(27.2)
Other comprehensive income, net of tax	18.8					18.8
Balance at Sep. 30, 2016	$ 1,142.3	$ 18.4	$ 247.6	$ (21.8)	$ 1,041.9	$ (143.8)
Balance (in shares) at Sep. 30, 2016		73.5