Fair Value - Carrying Value and Fair Value Classified by Level (Details) - Nonrecurring - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Carrying Value
Assets:
Mortgage loans	$ 1,164	$ 1,213
Equity securities	204	149
Liabilities:
Investment contracts liabilities with a fixed maturity	5	5
Investment contracts liabilities without a fixed maturity	380	372
Long-term debt	71,563	68,480
Level 1 \| Estimated Fair Value
Assets:
Mortgage loans	0	0
Liabilities:
Investment contracts liabilities with a fixed maturity	0	0
Investment contracts liabilities without a fixed maturity	0	0
Long-term debt	75,875	74,306
Level 2 \| Estimated Fair Value
Assets:
Mortgage loans	0	0
Liabilities:
Investment contracts liabilities with a fixed maturity	0	0
Investment contracts liabilities without a fixed maturity	0	0
Long-term debt	0	0
Level 3 \| Estimated Fair Value
Assets:
Mortgage loans	1,192	1,239
Liabilities:
Investment contracts liabilities with a fixed maturity	5	5
Investment contracts liabilities without a fixed maturity	383	392
Long-term debt	0	0
Total \| Estimated Fair Value
Assets:
Mortgage loans	1,192	1,239
Liabilities:
Investment contracts liabilities with a fixed maturity	5	5
Investment contracts liabilities without a fixed maturity	383	392
Long-term debt	$ 75,875	$ 74,306

Investment Contracts With Fixed Maturity, Fair Value Disclosure.

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- Definition

Investment Contracts Without A Fixed Maturity, Fair Value Disclosure.

+ References

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- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611

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- Definition

Amount of investment in equity security without readily determinable fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=116654751&loc=SL75117539-209714

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- Definition

Fair value portion of mortgage loans held-for-sale.

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