Organization and Summary of Significant Accounting Policies New Accounting Pronouncements (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Jan. 01, 2016	Dec. 31, 2015
New Accounting Pronouncement, Early Adoption [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets							$ 42
Net Income	$ 143	$ 156	$ 128	$ 1	$ 427	$ 110
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 10				$ 21
Earnings Per Share, Basic	$ 0.40	$ 0.44	$ 0.36	$ 0.00	$ 1.19	$ 0.31
Earnings Per Share, Diluted	$ 0.39	$ 0.43	$ 0.36	$ 0.00	$ 1.18	$ 0.31
Weighted Average Number of Shares Outstanding, Diluted	361,907	361,250	360,745	358,714	361,072	355,453
Accumulated deficit	$ (8,750)	$ (8,893)	$ (9,049)		$ (8,750)			$ (9,219)
Scenario, Previously Reported [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Net Income		$ 149	$ 124
Earnings Per Share, Basic		$ 0.42	$ 0.35
Earnings Per Share, Diluted		$ 0.41	$ 0.34
Weighted Average Number of Shares Outstanding, Diluted		360,867	360,339
Accumulated deficit		$ (8,946)	$ (9,095)