Condensed Consolidated Statement of Stockholders' Equity (USD $) In Millions, unless otherwise specified	Total	Common Stock	Treasury	Additional Capital	Accumulated Other Comprehensive Income	Retained Earnings
Balance at Dec. 31, 2011	$ 1,122.5	$ 34.0	$ (10.9)	$ 238.3	$ (91.9)	$ 953.0
Balance (in shares) at Dec. 31, 2011		45.3	(3.6)
Increase (Decrease) in Stockholders' Equity
Net Income	30.3					30.3
Other comprehensive income	2.1				2.1
Excess tax benefit and share withholding	(2.2)	(0.1)		0.5		(2.6)
Excess tax benefit and share withholding (in shares)		(0.1)
Share-based compensation	5.4			5.4
Shares issued	23.0	0.7		22.3
Shares issued (in shares)		1.0
Retirement of treasury shares		(2.7)	10.9	(8.2)
Retirement of treasury shares (in shares)		(3.6)	3.6
Dividends	(33.1)					(33.1)
Distribution of A&B Stock	(876.1)			(6.8)	46.9	(916.2)
Balance at Sep. 30, 2012	$ 271.9	$ 31.9		$ 251.5	$ (42.9)	$ 31.4
Balance (in shares) at Sep. 30, 2012		42.6