Debt And Shareholders' Equity Schedule of Long-Term Debt Instruments (Details) - USD ($)
$ in Millions

3 Months Ended

Mar. 31, 2018

Dec. 31, 2017

Debt Instrument [Line Items]

Subordinated Debt

$ 247

$ 247

Senior Notes

135

135

Capital Lease Obligations

1

1

Long-term Debt, Gross

$ 383

$ 383

Schedule of Long-term Debt Instruments [Table Text Block]

Long-term debt is summarized as follows:

(In millions)	March 31, 2018		December 31, 2017
Subordinated notes	$	247	$	247
Senior notes	135		135
Capital lease obligations	1		1
Total	$	383	$	383