Schedule of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Goodwill [Abstract]
Goodwill Deductible For Federal Income Tax Purpose	$ 56
Goodwill	302	$ 301	$ 274
Goodwill, Acquired During Period	$ 1	$ 27