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Schedule IV - (Reinsurance) (Detail) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Supplemental Schedule of Reinsurance Premiums for Insurance Companies [Abstract] |  |  |
Direct Amount | $ 3 | $ (1) | $ 37
Ceded to Others | 1 | 1 | 1
Assumed From Other Companies | 0 | 0 | 0
Net Amount | $ 2 | $ (2) | $ 36
Percentage of Amount Assumed to Net | 0.00% | 0.00% | 0.00%

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