Investments (Credit Quality of Commercial Mortgage Loans) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Mortgage Loans, Gross	$ 79,860	$ 84,344
Commercial Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	7,139
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	5,780
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	8,398
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	7,329
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	5,221
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	14,243
Financing Receivable, Revolving	2,443
Mortgage Loans, Gross	$ 50,553	$ 52,434
Loans Receivable Commercial Mortgage Percentage	100.00%
Commercial Mortgage Loans | Greater than 1.2x
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 6,418
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	5,288
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	7,682
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6,787
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4,780
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	11,199
Financing Receivable, Revolving	2,164
Mortgage Loans, Gross	$ 44,318
Loans Receivable Commercial Mortgage Percentage	87.70%
Commercial Mortgage Loans | 1.00x - 1.20x
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 272
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	133
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	76
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	258
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	29
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,000
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 1,768
Loans Receivable Commercial Mortgage Percentage	3.50%
Commercial Mortgage Loans | Less than 1.0x
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 449
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	359
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	640
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	284
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	412
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,044
Financing Receivable, Revolving	279
Mortgage Loans, Gross	$ 4,467
Loans Receivable Commercial Mortgage Percentage	8.80%
Commercial Mortgage Loans | Less than 65%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 5,675
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	4,970
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	5,379
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	5,650
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4,176
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	10,873
Financing Receivable, Revolving	2,443
Mortgage Loans, Gross	$ 39,166
Loans Receivable Commercial Mortgage Percentage	77.50%
Commercial Mortgage Loans | 65% to 75%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 1,461
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	760
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,601
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,400
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	594
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,857
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 8,673
Loans Receivable Commercial Mortgage Percentage	17.10%
Commercial Mortgage Loans | 76% to 80%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 3
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	50
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	414
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	200
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	161
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	218
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 1,046
Loans Receivable Commercial Mortgage Percentage	2.10%
Commercial Mortgage Loans | Greater than 80%
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	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	4
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	79
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	290
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,295
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 1,668
Loans Receivable Commercial Mortgage Percentage	3.30%