Stock-Based Compensation (Outstanding Stock Options) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Number of Stock Options (thousands)
Outstanding, beginning balance (in shares)	11,535	11,809	12,540
Exercised (in shares)	(7,566)	(274)	(731)
Outstanding, ending balance (in shares)	3,969	11,535	11,809	12,540
Exercisable (in shares)	3,969
Weighted Average Exercise Price
Outstanding, weighted average exercise price, beginning balance (usd per share)	$ 18.04	$ 17.98	$ 18.10
Exercised (usd per share)	20.98	15.58	20.03
Outstanding, weighted average exercise price, ending balance (usd per share)	12.43	$ 18.04	$ 17.98	$ 18.10
Exercisable, weighted average exercise price (usd per share)	$ 12.43
Weighted Average Remaining Contract Life (months)	27 months	23 months	36 months	47 months
Exercisable, Weighted Average Remaining Contract Life	27 months
Total Intrinsic Value	$ 95,770	$ 151,569	$ 123,017	$ 65,051
Exercisable, Total Intrinsic Value	95,770
Exercised, total intrinsic value	$ 104,108	$ 3,989	$ 4,976