Fair Value Measurements (Level 3 Significant Unobservable Inputs) (Details) - Fair Value, Measurements, Recurring - Level 3 $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($)
Swap Related to Sale of Certain Visa Class B Common Shares
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument, fair value liabilities	$ 10.9
Swap Related to Sale of Certain Visa Class B Common Shares | Group One
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Valuation Technique	Discounted Cash Flow
Unobservable inputs	Visa Class A Appreciation
Swap Related to Sale of Certain Visa Class B Common Shares | Group Two
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable inputs	Conversion Rate
Swap Related to Sale of Certain Visa Class B Common Shares | Group Three
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable inputs	Expected Conversion Rate
Swap Related to Sale of Certain Visa Class B Common Shares | Lower Limit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument visa class A appreciation	9.50%
Financial instrument conversion rate	1.61%
Financial instrument expected conversion rate	1 year 9 months
Swap Related to Sale of Certain Visa Class B Common Shares | Upper Limit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument visa class A appreciation	15.00%
Financial instrument conversion rate	1.65%
Financial instrument expected conversion rate	5 years
Auction Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 16.2
Auction Rate | Group One
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Valuation Technique	Discounted Cash Flow
Unobservable inputs	Remaining lives
Auction Rate | Group Two
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable inputs	Discount rates
Auction Rate | Lower Limit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument remaining lives	8 months 1 day
Financial instrument discount rate	0.01%
Auction Rate | Upper Limit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instrument remaining lives	8 years 7 months 21 days
Financial instrument discount rate	8.48%