Risk Management - Interest Rate Risk Management (Details) $ in Millions	Dec. 31, 2019 USD ($)
Fixed-To-Variable Interest Rate Swaps
Derivative [Line Items]
Notional amount	$ 8,725
Floating-To-Fixed Interest Rate Swap
Derivative [Line Items]
Notional amount	250
Current Portion of Debt | Fixed-To-Variable Interest Rate Swaps
Derivative [Line Items]
Principal amount of hedged senior notes	1,100
Long-term Debt | Fixed-To-Variable Interest Rate Swaps
Derivative [Line Items]
Principal amount of hedged senior notes	$ 7,625