Components of Accumulated Other Comprehensive Income (Loss) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ (345.6)	$ (305.3)
Net Change	58.2	10.8	129.7	72.8
Ending Balance	(215.9)	(232.5)	(215.9)	(232.5)
Net Unrealized Gains (Losses) on Securities Available for Sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			39.8	(13.5)
Net Change			67.3	55.2
Ending Balance	107.1	41.7	107.1	41.7
Net Unrealized Gains (Losses) on Cash Flow Hedge Designations
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(7.0)	11.4
Net Change			5.5	(9.6)
Ending Balance	(1.5)	1.8	(1.5)	1.8
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(9.5)	(7.0)
Net Change			24.1	10.6
Ending Balance	14.6	3.6	14.6	3.6
Net Pension and Other Postretirement Benefit Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(368.9)	(296.2)
Net Change			32.8	16.6
Ending Balance	$ (336.1)	$ (279.6)	$ (336.1)	$ (279.6)