Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Mortgage loans (net of valuation allowances of $51 and $46, respectively; includes $96 and $115, respectively, at estimated fair value, relating to variable interest entities)	$ 12,237	$ 10,640
Assets
Amortized cost of fixed maturity securities available-for-sale	58,523	58,599
Cost of equity securities available-for-sale	140	142
Mortgage loans valuation allowances	51	46
Accrued investment income relating to variable interest entities	583	575
Liabilities
Long-term debt, at estimated fair value, relating to variable interest entities	$ 40	$ 46
Equity
Common stock, par value	$ 25,000	$ 25,000
Common stock, shares authorized	4,000	4,000
Common stock, shares issued	3,000	3,000
Common stock, shares outstanding	3,000	3,000
Variable Interest Entity, Primary Beneficiary [Member]
Mortgage loans (net of valuation allowances of $51 and $46, respectively; includes $96 and $115, respectively, at estimated fair value, relating to variable interest entities)	$ 96	$ 115
Assets
Accrued investment income relating to variable interest entities	0	1
Liabilities
Long-term debt, at estimated fair value, relating to variable interest entities	$ 5	$ 11