Fair Value of Financial Instruments (Fair Value Inputs Quantitative Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Assets Fair Value Disclosure [Abstract]
Assets Fair Value Disclosure	$ 224,673	$ 217,146
Liabilities Fair Value Disclosure [Abstract]
Liabilities measured at fair value	(4,397)	(4,200)
Significant Unobservable Inputs (Level 3) [Member]
Assets Fair Value Disclosure [Abstract]
Assets Fair Value Disclosure	3,747	4,163
Liabilities Fair Value Disclosure [Abstract]
Liabilities measured at fair value	$ (2,202)	$ (2,364)
Significant Unobservable Inputs (Level 3) [Member] | Minimum [Member] | Reinsurance recoverable [Member] | Other assets [Member]
Fair Value Inputs [Abstract]
Utilization of guaranteed withdrawal	85.00%
Claims Utilization Factor	60.00%
Premiums Utilization Factor	80.00%
NPR	0.02%
Volatility	1.00%
Significant Unobservable Inputs (Level 3) [Member] | Minimum [Member] | Other Liabilities GLB Reserves Embedded Derivatives [Member] | Other liabilities [Member]
Fair Value Inputs [Abstract]
Utilization of guaranteed withdrawal	85.00%
Claims Utilization Factor	60.00%
Premiums Utilization Factor	80.00%
NPR	0.02%
Volatility	1.00%
Significant Unobservable Inputs (Level 3) [Member] | Maximum [Member] | Reinsurance recoverable [Member] | Other assets [Member]
Fair Value Inputs [Abstract]
Utilization of guaranteed withdrawal	100.00%
Claims Utilization Factor	100.00%
Premiums Utilization Factor	115.00%
NPR	0.35%
Volatility	29.00%
Significant Unobservable Inputs (Level 3) [Member] | Maximum [Member] | Other Liabilities GLB Reserves Embedded Derivatives [Member] | Other liabilities [Member]
Fair Value Inputs [Abstract]
Utilization of guaranteed withdrawal	100.00%
Claims Utilization Factor	100.00%
Premiums Utilization Factor	115.00%
NPR	0.35%
Volatility	29.00%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Corporate bonds [Member] | Fixed maturity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Assets Fair Value Disclosure	$ 1,797
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | ABS [Member] | Fixed maturity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Assets Fair Value Disclosure	24
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Foreign government bonds [Member] | Fixed maturity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Assets Fair Value Disclosure	76
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Hybrid and redeemable preferred securities [Member] | Fixed maturity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Assets Fair Value Disclosure	4
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Equity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Assets Fair Value Disclosure	26
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Reinsurance recoverable [Member] | Other assets [Member]
Assets Fair Value Disclosure [Abstract]
Assets Fair Value Disclosure	203
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Future contract benefits - indexed annuity and IUL contracts embedded derivatives | Future contract benefits [Member]
Liabilities Fair Value Disclosure [Abstract]
Liabilities measured at fair value	(1,139)
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Other Liabilities GLB Reserves Embedded Derivatives [Member] | Other liabilities [Member]
Liabilities Fair Value Disclosure [Abstract]
Liabilities measured at fair value	$ (371)
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Minimum [Member] | Corporate bonds [Member] | Fixed maturity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Liquidity Duration Adjustment	0.90%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Minimum [Member] | ABS [Member] | Fixed maturity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Liquidity Duration Adjustment	3.50%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Minimum [Member] | Foreign government bonds [Member] | Fixed maturity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Liquidity Duration Adjustment	1.80%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Minimum [Member] | Hybrid and redeemable preferred securities [Member] | Fixed maturity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Liquidity Duration Adjustment	2.10%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Minimum [Member] | Equity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Liquidity Duration Adjustment	4.50%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Minimum [Member] | Reinsurance recoverable [Member] | Other assets [Member]
Fair Value Inputs [Abstract]
Lapse Rate	1.00%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Minimum [Member] | Future contract benefits - indexed annuity and IUL contracts embedded derivatives | Future contract benefits [Member]
Fair Value Inputs [Abstract]
Lapse Rate	1.00%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Minimum [Member] | Other Liabilities GLB Reserves Embedded Derivatives [Member] | Other liabilities [Member]
Fair Value Inputs [Abstract]
Lapse Rate	1.00%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Maximum [Member] | Corporate bonds [Member] | Fixed maturity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Liquidity Duration Adjustment	20.40%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Maximum [Member] | ABS [Member] | Fixed maturity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Liquidity Duration Adjustment	3.50%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Maximum [Member] | Foreign government bonds [Member] | Fixed maturity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Liquidity Duration Adjustment	5.00%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Maximum [Member] | Hybrid and redeemable preferred securities [Member] | Fixed maturity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Liquidity Duration Adjustment	2.10%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Maximum [Member] | Equity AFS securities [Member]
Assets Fair Value Disclosure [Abstract]
Liquidity Duration Adjustment	5.10%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Maximum [Member] | Reinsurance recoverable [Member] | Other assets [Member]
Fair Value Inputs [Abstract]
Lapse Rate	30.00%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Maximum [Member] | Future contract benefits - indexed annuity and IUL contracts embedded derivatives | Future contract benefits [Member]
Fair Value Inputs [Abstract]
Lapse Rate	9.00%
Significant Unobservable Inputs (Level 3) [Member] | Discounted Cash Flow Valuation Technique [Member] | Maximum [Member] | Other Liabilities GLB Reserves Embedded Derivatives [Member] | Other liabilities [Member]
Fair Value Inputs [Abstract]
Lapse Rate	30.00%