Investments (Credit Quality of Agricultural and Residential 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
Mortgage Loans in Process of Foreclosure, Amount	80	70
Residential Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	238
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,299
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	430
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,187
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	552
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	7,759
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 11,465	11,196
Loans Receivable Residential Mortgage Percentage	100.00%
Residential Mortgage Loans | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 238
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,296
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	421
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,125
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	530
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	7,305
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 10,915
Loans Receivable Residential Mortgage Percentage	95.20%
Residential Mortgage Loans | Nonperforming
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	3
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	9
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	62
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	22
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	454
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 550
Loans Receivable Residential Mortgage Percentage	4.80%
Agricultural Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 537
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,852
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	3,142
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,099
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,613
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	5,510
Financing Receivable, Revolving	1,129
Mortgage Loans, Gross	$ 17,882	$ 18,111
Loans Receivable Agricultural Mortgage Percentage	100.00%
Agricultural Mortgage Loans | Less than 65%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 437
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,524
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,765
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,790
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,497
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	4,855
Financing Receivable, Revolving	1,045
Mortgage Loans, Gross	$ 15,913
Loans Receivable Agricultural Mortgage Percentage	89.00%
Agricultural Mortgage Loans | 65% to 75%
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 100
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	328
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	377
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	233
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	116
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	602
Financing Receivable, Revolving	82
Mortgage Loans, Gross	$ 1,838
Loans Receivable Agricultural Mortgage Percentage	10.30%
Agricultural 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	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	11
Financing Receivable, Revolving	0
Mortgage Loans, Gross	$ 11
Loans Receivable Agricultural Mortgage Percentage	0.00%
Agricultural 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	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	76
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	42
Financing Receivable, Revolving	2
Mortgage Loans, Gross	$ 120
Loans Receivable Agricultural Mortgage Percentage	0.70%