CONDENSED CONSOLIDATED STATEMENTS OF FINANCIAL POSITION (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Fixed income securities, at fair value, amortized cost (in dollars)	$ 21,291	$ 22,004
Equity securities, at fair value, cost (in dollars)	1,193	1,306
Short-term, at fair value, amortized cost (in dollars)	$ 926	$ 725
Common stock, par value (in dollars per share)	$ 227	$ 227
Common stock, shares authorized (in shares)	23,800	23,800
Common stock, shares outstanding (in shares)	23,800	23,800
Series A
Redeemable preferred stock, par value (in dollars per share)	$ 100	$ 100
Redeemable preferred stock, shares authorized (in shares)	1,500,000	1,500,000
Redeemable preferred stock, shares issued (in shares)	0	0
Series B
Redeemable preferred stock, par value (in dollars per share)	$ 100	$ 100
Redeemable preferred stock, shares authorized (in shares)	1,500,000	1,500,000
Redeemable preferred stock, shares issued (in shares)	0	0