Share-Based Compensation (Summary Of Stock Option Plans) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Summary of Stock Option Activity [Roll Forward]
Number of Shares, Beginning (in shares)	5,200,000
Number of Shares, Granted (in shares)	0	0	0
Number of Shares, Exercised (in shares)	(1,800,000)
Number of Shares, Canceled (in shares)	(100,000)
Number of Shares, Ending (in shares)	3,300,000	5,200,000
Number of Shares, Exercisable (in shares)	3,300,000
Weighted Average Exercise Price [Roll Forward]
Weighted-Average Exercise Price, Beginning (in dollars per share)	$ 7.85
Weighted-Average Exercise Price. Granted (in dollars per share)	0.00
Weighted-Average Exercise Price, Exercised (in dollars per share)	8.03
Weighted-Average Exercise Price, Canceled (in dollars per share)	8.53
Weighted-Average Exercise Price, Ending (in dollars per share)	7.75	$ 7.85
Weighted-Average Exercise Price, Exercisable (in dollars per share)	$ 7.75
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Term (in years), Outstanding	1 year 9 months 11 days
Weighted-Average Remaining Contractual Term (in years), Exercisable	1 year 9 months 11 days
Aggregate Intrinsic Value, Outstanding	$ 16.7
Aggregate Intrinsic Value, Exercisable	$ 16.7