Significant Accounting Policies and Practices (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2018
Condensed Balance Sheet Statements, Captions [Line Items]
Adoption of New Accounting Pronouncements					$ 4
Contractholder funds
Condensed Balance Sheet Statements, Captions [Line Items]
Immaterial Error Correction	17
Indefinite-lived Intangible Assets [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Immaterial Error Correction	3
Deferred Tax Asset [Domain]
Condensed Balance Sheet Statements, Captions [Line Items]
Immaterial Error Correction	3
Valuation Allowance of Deferred Tax Assets [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Immaterial Error Correction	9
Total fixed maturities
Condensed Balance Sheet Statements, Captions [Line Items]
Immaterial Error Correction	627
Benefits and Other Changes in Policy Reserves [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Immaterial Error Correction		17	32	21
Amortization of Intangible Assets [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Immaterial Error Correction		3	7	4
income tax expense [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Immaterial Error Correction		3	5	4
Net Income [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Immaterial Error Correction			9