Consolidated Statement of Stockholders' Equity (USD $) In Millions, unless otherwise specified	Common Stock	Treasury	Additional Paid In Capital	Accumulated Other Comprehensive Income	Retained Earnings	Total
Balance at Dec. 31, 2011	$ 34.0	$ (10.9)	$ 238.3	$ (91.9)	$ 953.0	$ 1,122.5
Balance (in shares) at Dec. 31, 2011	45.3	(3.6)
Increase (Decrease) in Stockholders' Equity
Net income					45.9	45.9
Other comprehensive income, net of tax				(0.5)		(0.5)
Excess tax benefit and share withholding	(0.1)		0.5		(2.4)	(2.0)
Excess tax benefit and share withholding (in shares)	(0.1)
Share-based compensation			6.5			6.5
Shares issued	0.7		22.4			23.1
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 ($0.66, $0.62, and $0.93 per share) for the years 2014, 2013 and 2012 respectively					(39.5)	(39.5)
Distribution of A&B Stock			(6.8)	46.9	(916.2)	(876.1)
Balance at Dec. 31, 2012	31.9		252.7	(45.5)	40.8	279.9
Balance (in shares) at Dec. 31, 2012	42.6
Increase (Decrease) in Stockholders' Equity
Net income					53.7	53.7
Other comprehensive income, net of tax				22.0		22.0
Excess tax benefit and share withholding			1.8			1.8
Share-based compensation			5.9			5.9
Shares issued	0.2		1.5			1.7
Shares issued (in shares)	0.2
Dividends ($0.66, $0.62, and $0.93 per share) for the years 2014, 2013 and 2012 respectively					(26.8)	(26.8)
Balance at Dec. 31, 2013	32.1		261.9	(23.5)	67.7	338.2
Balance (in shares) at Dec. 31, 2013	42.8					42.8
Increase (Decrease) in Stockholders' Equity
Net income					70.8	70.8
Other comprehensive income, net of tax				(29.8)		(29.8)
Excess tax benefit and share withholding			0.8			0.8
Share-based compensation			8.7			8.7
Shares issued	0.3		3.5			3.8
Shares issued (in shares)	0.4
Dividends ($0.66, $0.62, and $0.93 per share) for the years 2014, 2013 and 2012 respectively					(28.7)	(28.7)
Balance at Dec. 31, 2014	$ 32.4		$ 274.9	$ (53.3)	$ 109.8	$ 363.8
Balance (in shares) at Dec. 31, 2014	43.2					43.2