Investments - Investments by Category (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Current
Investments including assets of business held for sale	$ 1,584	$ 1,351
Investments classified as assets of business held for sale	(260)	(414)
Investments per Consolidated Balance Sheets	1,324	937
Long-term
Investments including assets of business held for sale	29,950	28,837
Investments classified as assets of business held for sale	(7,998)	(7,295)
Investments per Consolidated Balance Sheets	21,952	21,542
Total
Investments including assets of business held for sale	31,534	30,188
Investments classified as assets of business held for sale	(8,258)	(7,709)
Investments per Consolidated Balance Sheets	23,276	22,479
Investments	8,300	7,700
Debt securities
Current
Investments including assets of business held for sale	1,113	928
Long-term
Investments including assets of business held for sale	23,560	22,827
Total
Investments including assets of business held for sale	24,673	23,755
Equity securities
Current
Investments including assets of business held for sale	0	0
Long-term
Investments including assets of business held for sale	379	303
Total
Investments including assets of business held for sale	379	303
Commercial mortgage loans
Current
Investments including assets of business held for sale	13	0
Long-term
Investments including assets of business held for sale	1,966	1,947
Total
Investments including assets of business held for sale	1,979	1,947
Policy loans
Current
Investments including assets of business held for sale	0	0
Long-term
Investments including assets of business held for sale	1,347	1,357
Total
Investments including assets of business held for sale	1,347	1,357
Other long-term investments
Current
Investments including assets of business held for sale	0	0
Long-term
Investments including assets of business held for sale	2,698	2,403
Total
Investments including assets of business held for sale	2,698	2,403
Short-term investments
Current
Investments including assets of business held for sale	458	423
Long-term
Investments including assets of business held for sale	0	0
Total
Investments including assets of business held for sale	$ 458	$ 423

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