Investments (Mortgage Loans Allowance for Credit Loss Rollforward by Portfolio Segment) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at January 1,	$ 590	$ 353	$ 342
Adoption of credit loss guidance	0	78	0
Provision (release)	67	176	26
Initial credit losses on PCD loans (1)	3	18	0
Charge-offs, net of recoveries	(26)	(34)	(15)
HFS transfer	0	(1)	0
Balance at December 31,	634	590	353
Commercial Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at January 1,	252	246	238
Adoption of credit loss guidance	0	(118)	0
Provision (release)	88	124	8
Initial credit losses on PCD loans (1)	0	0	0
Charge-offs, net of recoveries	0	0	0
HFS transfer	0	0	0
Balance at December 31,	340	252	246
Residential Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at January 1,	232	55	58
Adoption of credit loss guidance	0	161	0
Provision (release)	(27)	30	7
Initial credit losses on PCD loans (1)	3	18	0
Charge-offs, net of recoveries	(2)	(32)	(10)
HFS transfer	0	0	0
Balance at December 31,	206	232	55
Agricultural Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at January 1,	106	52	46
Adoption of credit loss guidance	0	35	0
Provision (release)	6	22	11
Initial credit losses on PCD loans (1)	0	0	0
Charge-offs, net of recoveries	(24)	(2)	(5)
HFS transfer	0	(1)	0
Balance at December 31,	$ 88	$ 106	$ 52