Long-Term Debt (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
long-term debt issued	$ 500
debt called	162
Senior Medium Term Notes, Par Amount	$ 636
Long-term debt, interest rate 3.5%	3.50%
Extinguishment of Debt, Amount	$ 0	$ 0	$ 0
Capital Lease Obligations	$ 0	1
Long-term Debt, Interest Rate 6.95%	6.95%
Stock Redeemed or Called During Period, Value	$ 144	(144)	(126)
Subordinated debt converted to preferred stock	0	(332)	$ (97)
Senior medium-term notes	637	135
Long-term debt, Parent only maturities	87
Debt maturing		$ 153
Subordinated Notes Interest Rate 6.95 Percent [Member]
Debt Instrument [Line Items]
Subordinated Notes Par Amount	$ 88
New interest rate	3mL+3.89%
Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Senior Medium Term Notes, Par Amount	$ 500
Senior Notes, Maturity Date.	44435
Senior medium-term notes	$ 502