Business Held for Sale and Discontinued Operations - Held for Sale Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Investments:
Cash and cash equivalents	$ 291	$ 301	$ 862
Total assets held for sale	20,069	20,045
Liabilities:
Total liabilities held for sale	18,498	17,903
Held for sale
Investments:
Total assets held for sale	20,069	20,045
Liabilities:
Total liabilities held for sale	18,498	17,903
Held for sale | Individual Life Transaction
Investments:
Fixed maturities, available-for-sale, at fair value	11,483	9,401
Fixed maturities, at fair value using the fair value option	752	722
Mortgage loans on real estate, net of valuation allowance	1,319	1,395
Policy loans	1,005	1,019
Derivatives	304	131
Other investments	430	333
Securities pledged	235	405
Total investments	15,528	13,406
Cash and cash equivalents	291	301
Short-term investments under securities loan agreements, including collateral delivered	216	391
Premium receivable and reinsurance recoverable	3,101	3,309
Deferred policy acquisition costs and Value of business acquired	607	1,143
Current income taxes	136	220
Deferred income taxes	(757)	(452)
Other assets	570	430
Assets held in separate accounts	1,485	1,297
Write-down of businesses held for sale to fair value less cost to sell	(1,108)	0
Total assets held for sale	20,069	20,045
Liabilities:
Future policy benefits and contract owner account balances	15,472	15,008
Payables under securities loan and repurchase agreements, including collateral held	428	455
Derivatives	77	53
Notes payable	252	222
Other liabilities	784	868
Liabilities related to separate accounts	1,485	1,297
Total liabilities held for sale	18,498	17,903
Held for sale | 2018 Transaction
Investments:
Total assets held for sale	0	0
Liabilities:
Total liabilities held for sale	$ 0	$ 0