Investments (Rollforward of the Allowance for Credit Losses for Mortgage Loans by Portfolio Segment) (Details) - Mortgage Loans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of year	$ 94	$ 64
Current period provision	27	28
PCD credit allowance	2	3
Financing receivable, allowance for credit losses, end of year	123	94
Cumulative Effect, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of year		2
Cumulative Effect, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of year		66
Commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of year	44	47
Current period provision	23	17
PCD credit allowance	0
Financing receivable, allowance for credit losses, end of year	67	44
Commercial | Cumulative Effect, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of year		(20)
Commercial | Cumulative Effect, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of year		27
Agricultural
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of year	15	10
Current period provision	(3)	(2)
PCD credit allowance	0
Financing receivable, allowance for credit losses, end of year	12	15
Agricultural | Cumulative Effect, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of year		7
Agricultural | Cumulative Effect, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of year		17
Residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of year	35	7
Current period provision	7	13
PCD credit allowance	2
Financing receivable, allowance for credit losses, end of year	$ 44	35
Residential | Cumulative Effect, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of year		15
Residential | Cumulative Effect, Adjusted Balance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of year		$ 22