CONSOLIDATED STATEMENT OF EQUITY (USD $) In Millions, unless otherwise specified	Total	Common Stock [Member]	Capital in Excess of Par Value [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) Income [Member]
Balance at Dec. 31, 2011	$ 654.9	$ 17.2	$ 67.7	$ (23.0)	$ 664.5	$ (71.5)
Balance (in shares) at Dec. 31, 2011		68.6		1.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	80.7				80.7
Stock-based compensation	10.9		10.9
Shares issued under stock plans	11.9		(12.5)	24.4
Shares repurchased for employee tax withholdings (in shares)				0.2
Shares repurchased for employee tax withholdings	(4.7)		(0.3)	(4.4)
Shares issued under stock plans (in shares)		0.2		(1.2)
Excess tax benefit from employee stock plans	4.9		4.9
Dividends declared	(25.3)				(25.3)
Other comprehensive income (loss), net of tax	(4.4)					(4.4)
Balance at Dec. 31, 2012	728.9	17.2	70.7	(3.0)	719.9	(75.9)
Balance (in shares) at Dec. 31, 2012		68.8		0.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	112.3				112.3
Stock-based compensation	15.3		15.3
Shares issued under stock plans	30.5	0.4	30.9	(0.8)
Shares repurchased for employee tax withholdings (in shares)		(0.2)
Shares repurchased for employee tax withholdings	(5.2)		(5.2)
Shares issued under stock plans (in shares)		1.8
Excess tax benefit from employee stock plans	8.3		8.3
Dividends declared	(27.2)				(27.2)
Other comprehensive income (loss), net of tax	43.5					43.5
Balance at Dec. 31, 2013	906.4	17.6	120.0	(3.8)	805.0	(32.4)
Balance (in shares) at Dec. 31, 2013		70.4		0.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	127.1				127.1
Stock-based compensation	15.2		15.5	(0.3)
Shares issued under stock plans	21.1	0.2	20.9
Shares repurchased for employee tax withholdings (in shares)		(0.1)
Shares repurchased for employee tax withholdings	(4.1)		(4.1)
Shares issued under stock plans (in shares)		1.1		(0.1)
Excess tax benefit from employee stock plans	7.9		7.9
Dividends declared	(29.9)				(29.9)
Other comprehensive income (loss), net of tax	(86.8)					(86.8)
Balance at Dec. 31, 2014	$ 956.9	$ 17.8	$ 160.2	$ (4.1)	$ 902.2	$ (119.2)
Balance (in shares) at Dec. 31, 2014		71.4		0.1