Investments (Rollforward of the Allowance for Credit Losses for Mortgage Loans by Portfolio Segment) (Details) - Mortgage Loans - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of period	$ 137	$ 119
Current period provision	5	17
Financing receivable, allowance for credit losses, end of period	142	136
Commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of period	69	49
Current period provision	9	15
Financing receivable, allowance for credit losses, end of period	78	64
Agricultural
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of period	19	15
Current period provision	0	(1)
Financing receivable, allowance for credit losses, end of period	19	14
Residential
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing receivable, allowance for credit losses, beginning of period	49	55
Current period provision	(4)	3
Financing receivable, allowance for credit losses, end of period	$ 45	$ 58