Investments - Investments by Category (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Current
Investments including assets held for sale	$ 1,320	$ 1,351
Investments classified as assets held for sale	(347)	(414)
Investments per Consolidated Balance Sheets	973	937
Long-term
Investments including assets held for sale	27,920	28,837
Investments classified as assets held for sale	(7,312)	(7,295)
Investments per Consolidated Balance Sheets	20,608	21,542
Total
Investments including assets held for sale	29,240	30,188
Investments classified as assets held for sale	(7,659)	(7,709)
Investments per Consolidated Balance Sheets	21,581	22,479
Investments	7,700	7,700
Debt securities
Current
Investments including assets held for sale	1,014	928
Long-term
Investments including assets held for sale	21,559	22,827
Total
Investments including assets held for sale	22,573	23,755
Equity securities
Current
Investments including assets held for sale	0	0
Long-term
Investments including assets held for sale	347	303
Total
Investments including assets held for sale	347	303
Commercial mortgage loans
Current
Investments including assets held for sale	0	0
Long-term
Investments including assets held for sale	1,935	1,947
Total
Investments including assets held for sale	1,935	1,947
Policy loans
Current
Investments including assets held for sale	0	0
Long-term
Investments including assets held for sale	1,344	1,357
Total
Investments including assets held for sale	1,344	1,357
Other long-term investments
Current
Investments including assets held for sale	0	0
Long-term
Investments including assets held for sale	2,735	2,403
Total
Investments including assets held for sale	2,735	2,403
Short-term investments
Current
Investments including assets held for sale	306	423
Long-term
Investments including assets held for sale	0	0
Total
Investments including assets held for sale	$ 306	$ 423

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