Employee Retirement Benefits (Reconciliation Of The Funded Status For Qualified Plan And SERP) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Other assets	$ 0	$ 0
Other liabilities	(45)	(31)
Net amount recognized	(45)	(31)
Pension amounts recognized in accumulated other comprehensive income:
Net actuarial loss	41	34
Prior service cost	1	2
Total	$ 42	$ 36