Business Acquisitions -Fair Value of Assets Acquired and Liabilities Assumed at the Acquisition Date (Details) - USD ($) $ in Millions	3 Months Ended	11 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Oct. 01, 2018	Nov. 01, 2017
Business Acquisition [Line Items]
Cash and invested assets [1]	$ 3,405	$ 3,405	$ 45	$ 3,360
Premiums receivable	103	103		96
Deferred income taxes, net	69	69		56
Other intangible assets	629	629		629
Property and equipment	68	68		68
Reinsurance recoverables	31	31		0
Other assets	0	0		16
Total Assets Acquired	4,305	4,305		4,225
Unpaid losses and loss adjustment expenses	2,904	2,904		2,833
Reserve for future policy benefits payable	347	347		346
Other policyholder funds and benefits payable	246	246		245
Unearned premiums	4	4		3
Other liabilities	75	75		69
Total Liabilities Assumed	3,576	3,576		3,496
Net identifiable assets acquired	729	729		729
Goodwill, Fair Value Disclosure	723	723		723
Net Assets Acquired	1,452	1,452		$ 1,452
Business Acquisition, Goodwill, Expected Tax Deductible Amount	610	610
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments [Abstract]
Cash and invested assets [1]	45
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Premiums Receivable	7
Deferred income taxes, net	13
Other intangible assets	0
Property and equipment	0
Reinsurance recoverables	31
Other assets	(16)
Total Assets Acquired	80	80
Unpaid losses and loss adjustment expenses	71
Reserve for future policy benefits payable	1
Other policyholder funds and benefits payable	1
Unearned premiums	1
Other liabilities	6
Total Liabilities Assumed	80	$ 80
Net identifiable assets acquired	0
Goodwill [2]	0
Net Assets Acquired	$ 0