Segment information Segment Information (narrative Detail (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
---|---|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2017 |
Jun. 30, 2018 |
Jun. 30, 2017 |
|
Segment Reporting Information [Line Items] | ||||
Gain (Loss) on Derivative | $ 29 | $ 63 | $ 108 | $ 90 |
Net investment income | 828 | 770 | 1,634 | 1,515 |
North America Agricultural Insurance [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Segment Income Loss Including Gains Losses On Crop Derivatives | 43 | |||
Gain (Loss) on Derivative | 8 | |||
Net investment income | 6 | 6 | 13 | 12 |
Segment Life [Member] | ||||
Segment Reporting Information [Line Items] | ||||
Net investment income | 85 | $ 77 | $ 168 | $ 152 |
Management Underwriting Income (Loss) | 75 | |||
Gains(Losses) On Fair Value Changes In Separate Account Assets | $ (10) |