Investments (Credit Quality of Commercial Mortgage Loans) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Mortgage Loans, Gross	$ 92,272	$ 93,227
Commercial Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	959
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,962
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	8,635
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	7,275
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4,662
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	32,405
Financing Receivable, Revolving	2,461
Mortgage Loans, Gross	$ 59,359	$ 60,326
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	$ 904
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,149
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	7,587
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6,682
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4,320
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	27,206
Financing Receivable, Revolving	2,461
Mortgage Loans, Gross	$ 51,309
Loans Receivable Commercial Mortgage Percentage	86.40%
Commercial Mortgage Loans | 1.00x - 1.20x
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 55
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	544
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	431
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	593
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	105
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	3,260
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 4,988
Loans Receivable Commercial Mortgage Percentage	8.40%
Commercial Mortgage Loans | Less than 1.00x
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	269
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	617
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	237
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,939
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 3,062
Loans Receivable Commercial Mortgage Percentage	5.20%
Commercial Mortgage Loans | Less than 65%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 936
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,519
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,674
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	3,227
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,734
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	16,181
Financing Receivable, Revolving	2,461
Mortgage Loans, Gross	$ 29,732
Loans Receivable Commercial Mortgage Percentage	50.10%
Commercial Mortgage Loans | 65% to 75%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 22
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	362
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	4,500
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,781
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,655
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	7,358
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 16,678
Loans Receivable Commercial Mortgage Percentage	28.10%
Commercial Mortgage Loans | 76% to 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	15
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	664
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	289
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	376
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,917
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 4,261
Loans Receivable Commercial Mortgage Percentage	7.20%
Commercial Mortgage Loans | Greater than 80%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 1
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	66
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	797
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	978
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	897
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	5,949
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 8,688
Loans Receivable Commercial Mortgage Percentage	14.60%