Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Assets
Amortized cost of fixed maturity securities available-for-sale	$ 58,460	$ 58,599
Cost of equity securities available-for-sale	142	142
Mortgage loans valuation allowances	49	46
Mortgage loans, at estimated fair value, relating to variable interest entities	11,206	10,640
Accrued investment income relating to variable interest entities	614	575
Liabilities
Long-term debt, at estimated fair value, relating to variable interest entities	$ 43	$ 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]
Assets
Mortgage loans, at estimated fair value, relating to variable interest entities	$ 105	$ 115
Accrued investment income relating to variable interest entities	1	1
Liabilities
Long-term debt, at estimated fair value, relating to variable interest entities	$ 8	$ 11