Fair Value (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Fair Value Disclosures [Abstract]
Fair Value, Assets, Level 2 to Level 1, Transfers	$ 0	$ 1	$ 0	$ 24
Fair Value, Assets, Level 1 to Level 2, Transfers	$ 0	$ 0	$ 0	$ 1