Fair Value Measurements (Level 3 Significant Unobservable Inputs) (Details) $ in Millions	Mar. 31, 2020	Mar. 31, 2020 USD ($)	Mar. 31, 2020 year	Dec. 31, 2019 USD ($) year
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability		$ 1,059.8		$ 1,694.6
Swap | Fair Value, Measurements, Recurring | LEVEL 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability		$ 26.5		$ 33.4
Swap | Conversion Rate | Fair Value, Measurements, Recurring | LEVEL 3 | Lower Limit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input	1.62			1.62
Swap | Conversion Rate | Fair Value, Measurements, Recurring | LEVEL 3 | Upper Limit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input	1.62			1.62
Swap | Visa Class A Appreciation | Fair Value, Measurements, Recurring | LEVEL 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input	0.0993
Swap | Visa Class A Appreciation | Fair Value, Measurements, Recurring | LEVEL 3 | Lower Limit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input				0.0854
Swap | Visa Class A Appreciation | Fair Value, Measurements, Recurring | LEVEL 3 | Upper Limit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input	0.0993			0.0854
Swap | Expected Duration | Fair Value, Measurements, Recurring | LEVEL 3 | Lower Limit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input			12	12
Swap | Expected Duration | Fair Value, Measurements, Recurring | LEVEL 3 | Upper Limit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input | year			3.25	36
Swap | Weighted Average Input Values | Fair Value, Measurements, Recurring | LEVEL 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input	20		22