v3.19.2

Debt (Fair Value of Debt) (Details) - USD ($) $ in Millions | Jun. 30, 2019 | Dec. 31, 2018
--- | --- | ---
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | $ 10,677 | $ 10,156
Unsecured Debt [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 2,990 | 3,036
Loans Payable [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 2,979 | 2,976
Corporate Debt Securities [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 2,402 | 2,400
Reported Value Measurement [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 10,570 | 10,604
Reported Value Measurement [Member] | Unsecured Debt [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 2,990 | 3,036
Reported Value Measurement [Member] | Loans Payable [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 2,979 | 2,976
Reported Value Measurement [Member] | Corporate Debt Securities [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 2,402 | 2,400
Reported Value Measurement [Member] | Notes Payable, Other Payable excluding Capital Leases [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt | [1] | 1,153 | 1,188
Reported Value Measurement [Member] | Secured Debt [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 971 | 974
Reported Value Measurement [Member] | Revolving Credit Facility [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 75 | 30
Fair Value, Inputs, Level 2 [Member] | Unsecured Debt [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 3,011 | 2,803
Fair Value, Inputs, Level 2 [Member] | Loans Payable [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 3,013 | 2,877
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 2,462 | 2,299
Fair Value, Inputs, Level 2 [Member] | Secured Debt [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 980 | 938
Fair Value, Inputs, Level 2 [Member] | Revolving Credit Facility [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt |  | 75 | 30
Fair Value, Inputs, Level 3 [Member] | Notes Payable, Other Payable excluding Capital Leases [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Long-term Debt | [1] | $ 1,136 | $ 1,209
[1] | Excludes an agreement that is accounted for as a failed sale-leaseback transaction under U.S. GAAP.

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