Assets Measured at Fair Value on a Nonrecurring Basis (Parenthetical) (Detail) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Provision for Credit Losses	$ 10.0	$ 50.0	$ 25.0	$ 90.0
Other Operating Expenses	56.7	63.8	130.9	130.8
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Nonrecurring | Loans | Specific Reserve
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Provision for Credit Losses	5.2	4.5	4.7	18.0
Other Operating Expenses	$ 0.8	$ 0.5	$ 0.9	$ 1.0