Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net Income	$ 25.9		$ 35.4
Defined benefit pension plans:
Amortization of prior service credit included in net periodic pension cost	(0.3)	[1]	(0.3)	[1]
Amortization of net loss included in net periodic pension cost	1.1	[1]	1.9	[1]
Income taxes related to other comprehensive income	(0.3)		(0.6)
Other Comprehensive Income	0.5		1.0
Comprehensive Income	26.4		36.4
Comprehensive income attributable to noncontrolling interest	(0.6)		(0.4)
Comprehensive income attributable to A&B	$ 25.8		$ 36.0

[1] These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 9 for additional details).