Share-Based Compensation Plans (Schedule of Summary of Stock Options) (Details) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Outstanding, beginning balance, in shares | shares	11,648
Granted, in shares | shares	6,059
Exercised, in shares | shares	0
Forfeited, in shares | shares	(634)
Expired, in shares | shares	(2,249)
Outstanding, ending balance, in shares | shares	14,824
Exercisable, ending balance, in shares | shares	8,744
Outstanding, beginning balance, weighted-average exercise price | $ / shares	$ 28.70
Granted, weighted-average exercise price | $ / shares	5.53
Exercised, weighted-average exercise price | $ / shares	0.00
Forfeited, weighted-average exercise price | $ / shares	5.49
Expired, weighted-average exercise price | $ / shares	29.28
Outstanding, ending balance, weighted-average exercise price | $ / shares	20.09
Exercisable, ending balance, weighted-average exercise price | $ / shares	$ 27.94
Outstanding, ending balance, weighted-average contractual term, years	4 years 9 months 18 days
Outstanding, exercisable, weighted-average contractual term, years	2 years 2 months 12 days
Outstanding, ending balance, aggregate intrinsic value | $	$ 0.0
Exercisable, ending balance, aggregate intrinsic value | $	$ 0.0