Comprehensive Income (Loss) (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Discount rate - used at year end to value obligation	4.00%	4.50%
Other Comprehensive Income (Loss), before Reclassifications, before Tax	$ (105)
Pension Benefits [Member] | Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	$ 105