Organization and Summary of Significant Accounting Policies (Schedule of Earnings Per Share) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Organization and Summary of Significant Accounting Policies [Abstract]
Net income (loss)									$ 1,046	[1]	$ (2,643)	$ (4,556)
Mandatory convertible preferred stock dividend									108		108	106
Participating securities - mandatory convertible preferred stock									123
Net Income (Loss) Attributable to Common Stock	$ 267	$ 43	$ 224	$ 281	$ (237)	$ (735)	$ (620)	$ (1,159)	$ 815		$ (2,751)	$ (4,662)
Number of common shares: Weighted average outstanding									498,264,321		435,337,402	380,521,039
Number of common shares: Issued upon assumed exercise of outstanding stock options
Number of common shares: Effect of issuance of non-vested restricted common stock									1,061,056
Number of common shares: Effect of issuance of non-vested performance units									1,478,920
Number of common shares: Effect of issuance of mandatory convertible preferred stock
Number of common shares: Effect of declaration of preferred stock dividends
Number of common shares: Weighted average and potential dilutive outstanding									500,804,297		435,337,402	380,521,039
Basic	$ 0.53	$ 0.09	$ 0.45	$ 0.57	$ (0.48)	$ (1.52)	$ (1.61)	$ (3.03)	$ 1.64		$ (6.32)	$ (12.25)
Diluted	$ 0.53	$ 0.09	$ 0.45	$ 0.57	$ (0.48)	$ (1.52)	$ (1.61)	$ (3.03)	$ 1.63		$ (6.32)	$ (12.25)

[1] In 2017, deferred tax activity incurred in other comprehensive income was offset by a valuation allowance.