Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Assets and Liabilities at Fair Value (Details)

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Summary of Significant Accounting Policies - Assets and Liabilities at Fair Value (Details) - USD ($)
$ in Millions
Mar. 31, 2020
Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt $ 8,013 $ 8,378
Fair Value, Inputs, Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt 0 0
Fair Value, Inputs, Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt 8,013 8,378
Fair Value, Inputs, Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt $ 0 $ 0