DAC, VOBA, DSI, and DFEL (DAC) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Changes in DAC [Roll Forward]
Balance as of beginning-of-year	$ 8,243	$ 8,617	$ 7,558
Business acquired (sold) through reinsurance			38
Deferrals	1,348	1,344	1,490
Amortization, net of interest:
Amortization, excluding unlocking, net of interest	(965)	(981)	(879)
Unlocking	61	(276)	(238)
Adjustment related to realized (gains) losses	(12)	22	(15)
Adjustment related to unrealized (gains) losses	(788)	(483)	663
Balance as of end-of-year	$ 7,887	$ 8,243	$ 8,617

The amount of other amortization of deferred policy acquisition costs, net of interest, during the period.

No definition available.

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- Definition

Additions (reductions) in deferred policy acquisition costs during the year arising from acquisitions and dispositions of insurance entities.

+ References

No definition available.

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- References

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- Definition

Amount of amortization expense (reversal of amortization expense) of deferred policy acquisition costs from a revision in estimated gross profit or estimated gross margin.

+ References

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- Definition

Amount of amortization expense (reversal of amortization expense) of deferred policy acquisition costs from realized net investment gain (loss).

+ References

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- Definition

Amount of unrealized investment gain (loss) which decreases (increases) deferred policy acquisition cost.

+ References

No definition available.

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- Definition

Net amount of deferred policy acquisition costs capitalized on contracts remaining in force as of the balance sheet date.

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- Definition

Total amount of policy acquisition costs capitalized during the income statement period.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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