Investments Investments (Realized GL info) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Gross realized investment gains	$ 4	$ 3	$ 10	$ 22
Gross realized investment losses	(1)	(3)	(2)	(12)
Credit Losses	0		(13)
Total	$ 3	$ 0	$ (5)	$ 10

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration