Schedule of Valuation and Qualifying Accounts Disclosure (Details) - USD ($) $ in Millions |
12 Months Ended | |||||
|---|---|---|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
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| SEC Schedule, 12-09, Allowance, Credit Loss [Member] | ||||||
| SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | ||||||
| Balance at Beginning of Year | $ 9 | $ 6 | $ 2 | |||
| Charged to Expense | 5 | 4 | 4 | |||
| Charged to Other Accounts | 1 | 2 | 0 | |||
| Deductions | [1] | (6) | 3 | 0 | ||
| Balance at End of Year | 9 | 9 | 6 | |||
| Deferred Tax Asset Valuation Allowance [Member] | ||||||
| SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | ||||||
| Balance at Beginning of Year | 1,168 | 1,581 | 1,637 | |||
| Charged to Expense | (168) | (413) | (56) | |||
| Charged to Other Accounts | 0 | 0 | 0 | |||
| Deductions | [1] | 0 | 0 | 0 | ||
| Balance at End of Year | $ 1,000 | $ 1,168 | $ 1,581 | |||
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