Share-Based Compensation (Stock Option Activity) (Details) - Stock Options $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Options (Number of Shares):
Outstanding at beginning of period | shares	7,155
Exercised | shares	(127)
Forfeited and expired | shares	(700)
Outstanding at end of period | shares	6,328
Vested and expected to vest at end of period | shares	6,200
Eligible for exercise at end of period | shares	4,810
Weighted Average Exercise Price (in dollars per share):
Outstanding at beginning of period | $ / shares	$ 13.81
Exercised | $ / shares	11.00
Forfeited and expired | $ / shares	17.70
Outstanding at end of period | $ / shares	13.43
Vested and expected to vest at end of period | $ / shares	13.46
Eligible for exercise at end of period | $ / shares	$ 13.72
Outstanding, weighted average remaining contractual term (in years)	5 years 6 months
Vested and expected to vest, weighted average remaining contractual term (in years)	5 years 6 months
Eligible for exercise, weighted average remaining contractual term (in years)	4 years 9 months 18 days
Outstanding, intrinsic value | $	$ 2
Vested and expected to vest, intrinsic value | $	2
Eligible for exercise, intrinsic value | $	$ 2