Components of Accumulated Other Comprehensive Income (Loss) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ (244.3)	$ (283.0)
Net Change	(13.2)	12.8	25.9	(54.9)
Ending Balance	(218.4)	(337.9)	(218.4)	(337.9)
Net Unrealized Gains (Losses) on Securities Available for Sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			6.0	101.0
Net Change			32.3	(74.4)
Ending Balance	38.3	26.6	38.3	26.6
Net Unrealized Gains (Losses) on Cash Flow Hedge Designations
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			2.9	(1.4)
Net Change			(6.4)	1.2
Ending Balance	(3.5)	(0.2)	(3.5)	(0.2)
Net Foreign Currency Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			7.1	10.5
Net Change			(10.5)	(2.8)
Ending Balance	(3.4)	7.7	(3.4)	7.7
Net Pension and Other Postretirement Benefit Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(260.3)	(393.1)
Net Change			10.5	21.1
Ending Balance	$ (249.8)	$ (372.0)	$ (249.8)	$ (372.0)