Components of Accumulated Other Comprehensive Income (Loss) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ (244.3)	$ (283.0)
Net Change	30.9	(66.6)	39.1	(67.7)
Ending Balance	(205.2)	(350.7)	(205.2)	(350.7)
Net Unrealized Gains (Losses) on Securities Available for Sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			6.0	101.0
Net Change			38.0	(80.2)
Ending Balance	44.0	20.8	44.0	20.8
Net Unrealized Gains (Losses) on Cash Flow Hedge Designations
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			2.9	(1.4)
Net Change			1.0	(3.1)
Ending Balance	3.9	(4.5)	3.9	(4.5)
Net Foreign Currency Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			7.1	10.5
Net Change			(6.9)	1.6
Ending Balance	0.2	12.1	0.2	12.1
Net Pension and Other Postretirement Benefit Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(260.3)	(393.1)
Net Change			7.0	14.0
Ending Balance	$ (253.3)	$ (379.1)	$ (253.3)	$ (379.1)