Derivative Financial Instruments (Schedule of Offsetting Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Derivative Assets [Abstract]
Gross amount recognized	$ 3	$ 55
Gross amount offset in the consolidated balance sheets	0	0
Net amount presented in the consolidated balance sheets	3	55
Gross amount not offset in the consolidated balance sheets	1	4
Net amount	$ 2	$ 51