Employee Stock-Based Compensation and Benefit Plans (Schedule of Stock Option Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Number of Options
Outstanding at December 31, 2013 (in shares)	5,406,977
Exercised (in shares)	(1,308,653)
Forfeited or expired (in shares)	(520,775)
Outstanding at December 31, 2014 (in shares)	3,577,549	5,406,977
Weighted- Average Exercise Price
Outstanding at December 31, 2013 (in dollars per share)	$ 59.64
Exercised (in dollars per share)	$ 35.62
Forfeited or expired (in dollars per share)	$ 65.20
Outstanding at December 31, 2014 (in dollars per share)	$ 67.60	$ 59.64
Additional Disclosures on Options
Weighted- Average Remaining Contractual Life, Outstanding at December 31, 2013 (in years)	1 year 3 months 15 days	2 years 1 month 25 days
Aggregate Intrinsic Value, Outstanding at December 31, 2014	$ 17,061
Weighted- Average Remaining Contractual Life, Outstanding at December 31, 2014 (in years)	1 year 3 months 15 days	2 years 1 month 25 days
Exercisable at December 31, 2014 (in shares)	3,483,456
Weighted Average Exercise Price, Exercisable at December 31, 2014 (in dollars per share)	$ 68.06
Weighted-Average Remaining Contractual Life, Exercisable at December 31, 2014 (in years)	1 year 3 months 1 day
Aggregate intrinsic value, options exercisable at December 31, 2014	15,368
Vested or expected to vest
Vested or expected to vest (in shares)	3,574,580
Weighted- Average Exercise Price (in dollars per share)	$ 67.62
Weighted- Average Remaining Contractual Life (in years)	1 year 3 months 15 days
Aggregate Intrinsic Value	$ 16,980