Investments (Internal Credit Quality Indicators) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 6,329	$ 5,861
High Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	4,111	3,438
Internal Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	2,069	2,271
Average Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	109	111
Watch List
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	4	4
Internal Noninvestment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	36	37
Year Of Origination 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	674	763
Year Of Origination 2020 | High Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	402	411
Year Of Origination 2020 | Internal Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	272	352
Year Of Origination 2020 | Average Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	0	0
Year Of Origination 2020 | Watch List
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	0	0
Year Of Origination 2020 | Internal Noninvestment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	0	0
Year Of Origination 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	1,003	1,112
Year Of Origination 2019 | High Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	645	616
Year Of Origination 2019 | Internal Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	331	496
Year Of Origination 2019 | Average Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	27	0
Year Of Origination 2019 | Watch List
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	0	0
Year Of Origination 2019 | Internal Noninvestment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	0	0
Year Of Origination 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	801	892
Year Of Origination 2018 | High Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	461	493
Year Of Origination 2018 | Internal Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	301	399
Year Of Origination 2018 | Average Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	39	0
Year Of Origination 2018 | Watch List
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	0	0
Year Of Origination 2018 | Internal Noninvestment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	0	0
Year Of Origination 2017
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	645	762
Year Of Origination 2017 | High Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	344	336
Year Of Origination 2017 | Internal Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	296	407
Year Of Origination 2017 | Average Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	5	19
Year Of Origination 2017 | Watch List
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	0	0
Year Of Origination 2017 | Internal Noninvestment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	0	0
Year Of Origination 2016
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate		860
Year Of Origination 2016 | High Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate		574
Year Of Origination 2016 | Internal Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate		249
Year Of Origination 2016 | Average Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate		37
Year Of Origination 2016 | Watch List
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate		0
Year Of Origination 2016 | Internal Noninvestment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate		0
Year Of Origination Prior Periods
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	2,108	1,472
Year Of Origination Prior Periods | High Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	1,534	1,008
Year Of Origination Prior Periods | Internal Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	502	368
Year Of Origination Prior Periods | Average Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	32	55
Year Of Origination Prior Periods | Watch List
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	4	4
Year Of Origination Prior Periods | Internal Noninvestment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	36	$ 37
Year of Origination 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	1,098
Year of Origination 2021 | High Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	725
Year of Origination 2021 | Internal Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	367
Year of Origination 2021 | Average Investment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	6
Year of Origination 2021 | Watch List
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	0
Year of Origination 2021 | Internal Noninvestment Grade
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 0