Consolidated Statements of Operations and Comprehensive Income (Parentheticals) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Total net realized gains (losses) reclassified from AOCI	$ 12	$ (33)	$ 36	$ (352)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax	$ (6)	$ (2)	$ (2)	$ (42)

Amount before tax of reclassification adjustments of other comprehensive income (loss).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 45
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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