Schedule II - Valuation and Qualifying Accounts and Reserves (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Commercial mortgage loans [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period		$ 0	$ 5
Charged (Credited) to costs and expenses			1
Charged (Credited) to other accounts			0
Other deductions			(6)
Balance at end of period			0
Premiums, accounts and notes receivable [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 217	207	200
Charged (Credited) to costs and expenses	51	18	19
Charged (Credited) to other accounts	0	(3)	(11)
Other deductions	(16)	(5)	(1)
Balance at end of period	252	217	207
Deferred tax asset valuation allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	199	72	87
Charged (Credited) to costs and expenses	(6)	(5)	11
Charged (Credited) to other accounts	3	132	(26)
Other deductions	0	0	0
Balance at end of period	196	199	72
Reinsurance recoverables [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	2	3	3
Charged (Credited) to costs and expenses	0	(1)	0
Charged (Credited) to other accounts	0	0	0
Other deductions	0	0	0
Balance at end of period	$ 2	$ 2	$ 3