Derivative Financial Instruments (Schedule of Pre-Tax Impact of Items Designated as Fair Value Hedges) (Details) - Fair Value Hedging - Designated as Hedging Instrument - USD ($) |
3 Months Ended | 6 Months Ended | ||
---|---|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2017 |
Jun. 30, 2018 |
Jun. 30, 2017 |
|
Derivative [Line Items] | ||||
Total in other expense, net | $ 0 | $ 0 | $ 0 | |
Equity Contract | ||||
Derivative [Line Items] | ||||
Gains on changes in fair value of hedged AFS | $ 4,000,000 | 4,000,000 | ||
Gains on changes in the intrinsic value of equity contracts | (4,000,000) | (4,000,000) | ||
Fair value of equity contracts excluded from effectiveness assessment | 3,000,000 | 1,000,000 | ||
Equity Contract | Other expense, net | ||||
Derivative [Line Items] | ||||
Total in other expense, net | $ 3,000,000 | $ 1,000,000 |