Fair Value - Carrying Value and Fair Value Classified by Level (Details) - Nonrecurring - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Carrying Value
Assets:
Mortgage loans	$ 1,290	$ 1,361
Equity securities	142	140
Liabilities:
Investment contracts liabilities with a fixed maturity	5	5
Investment contracts liabilities without a fixed maturity	372	382
Long-term debt	67,984	72,709
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	72,823	71,252
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	1,317	1,366
Liabilities:
Investment contracts liabilities with a fixed maturity	5	5
Investment contracts liabilities without a fixed maturity	385	357
Long-term debt	0	0
Total \| Estimated Fair Value
Assets:
Mortgage loans	1,317	1,366
Liabilities:
Investment contracts liabilities with a fixed maturity	5	5
Investment contracts liabilities without a fixed maturity	385	357
Long-term debt	$ 72,823	$ 71,252

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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