Investments (Credit Quality of Commercial Mortgage Loans) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Mortgage Loans, Gross	$ 80,464	$ 79,860
Commercial Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,675
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	7,228
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	5,637
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	8,298
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	7,231
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	18,748
Financing Receivable, Revolving	2,300
Mortgage Loans, Gross	$ 51,117	$ 50,553
Loans Receivable Commercial Mortgage Percentage	100.00%
Commercial Mortgage Loans | Greater than 1.20x
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 1,652
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	6,503
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	5,325
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	7,582
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	6,689
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	15,547
Financing Receivable, Revolving	2,300
Mortgage Loans, Gross	$ 45,598
Loans Receivable Commercial Mortgage Percentage	89.20%
Commercial Mortgage Loans | 1.00x - 1.20x
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	297
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	18
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	76
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	258
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	907
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 1,556
Loans Receivable Commercial Mortgage Percentage	3.00%
Commercial Mortgage Loans | Less than 1.00x
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 23
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	428
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	294
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	640
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	284
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,294
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 3,963
Loans Receivable Commercial Mortgage Percentage	7.80%
Commercial Mortgage Loans | Less than 65%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 1,134
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	5,671
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	4,841
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	5,306
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	5,547
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	14,767
Financing Receivable, Revolving	2,300
Mortgage Loans, Gross	$ 39,566
Loans Receivable Commercial Mortgage Percentage	77.40%
Commercial Mortgage Loans | 65% to 75%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 528
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,528
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	744
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,577
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,404
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,177
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 8,958
Loans Receivable Commercial Mortgage Percentage	17.50%
Commercial Mortgage Loans | 76% to 80%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 5
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	29
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	52
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	411
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	201
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	309
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 1,007
Loans Receivable Commercial Mortgage Percentage	2.00%
Commercial Mortgage Loans | Greater than 80%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 8
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	4
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	79
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,495
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 1,586
Loans Receivable Commercial Mortgage Percentage	3.10%