Business, Basis of Presentation, and Significant Accounting Policies - Prior Period Statement of Cash Flows Revision (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities
Net income		$ 326	$ 193	$ 710	$ 278
Changes in operating assets and liabilities:
Net cash provided by operating activities				1,073	704
Cash flows from investing activities
Net cash used in investing activities				(2,640)	(33)
Cash flows from financing activities
Net cash provided by (used in) financing activities				2,569	(74)
Effect of exchange rate changes on cash and cash equivalents				19	(4)
Net increase in cash and cash equivalents				1,021	593
Cash and cash equivalents at beginning of year	[1]			2,459	2,720
Cash and cash equivalents at end of year	[1]	3,480	3,313	3,480	3,313
Scenario, Previously Reported
Cash flows from operating activities
Net income			192		279
Changes in operating assets and liabilities:
Net cash provided by operating activities					708
Cash flows from investing activities
Net cash used in investing activities					(37)
Cash flows from financing activities
Net cash provided by (used in) financing activities					(74)
Effect of exchange rate changes on cash and cash equivalents					(4)
Net increase in cash and cash equivalents					593
Cash and cash equivalents at beginning of year	[1]				2,720
Cash and cash equivalents at end of year	[1]		3,313		3,313
Consolidated Entity Excluding Variable Interest Entities (VIE)
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income tax expense				31	17
Changes in operating assets and liabilities:
Interest sensitive contract liabilities				1,140	611
Future policy benefits, other policy claims and benefits, dividends payable to policyholders and reinsurance recoverable				387	(20)
Other assets and liabilities				15	(19)
Cash flows from investing activities
Other investing activities, net				748	123
Cash flows from financing activities
Cash and cash equivalents at beginning of year				2,445
Cash and cash equivalents at end of year		$ 3,478		$ 3,478
Consolidated Entity Excluding Variable Interest Entities (VIE) | Scenario, Previously Reported
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income tax expense					19
Changes in operating assets and liabilities:
Interest sensitive contract liabilities					607
Future policy benefits, other policy claims and benefits, dividends payable to policyholders and reinsurance recoverable					(17)
Other assets and liabilities					(17)
Cash flows from investing activities
Other investing activities, net					119
Prior Period Immaterial Revisions | Revisions
Cash flows from operating activities
Net income			1		(1)
Changes in operating assets and liabilities:
Net cash provided by operating activities					(4)
Cash flows from investing activities
Net cash used in investing activities					4
Cash flows from financing activities
Net cash provided by (used in) financing activities					0
Effect of exchange rate changes on cash and cash equivalents					0
Net increase in cash and cash equivalents					0
Cash and cash equivalents at beginning of year	[1]				0
Cash and cash equivalents at end of year	[1]		$ 0		0
Prior Period Immaterial Revisions | Consolidated Entity Excluding Variable Interest Entities (VIE) | Revisions
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income tax expense					(2)
Changes in operating assets and liabilities:
Interest sensitive contract liabilities					4
Future policy benefits, other policy claims and benefits, dividends payable to policyholders and reinsurance recoverable					(3)
Other assets and liabilities					(2)
Cash flows from investing activities
Other investing activities, net					$ 4

[1] Includes cash and cash equivalents of consolidated variable interest entities