Stock-based Compensation Expense (Details 2) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price range, options outstanding (in shares)	13,097	13,097
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)		7 years 3 months 4 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 56.20	$ 56.20
Exercise price range, options exercisable (in shares)	5,479	5,479
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 43.53	$ 43.53
$10.41–$20.00
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price, low end of range (usd per share)	$ 10.41
Exercise price, high end of range (usd per share)	$ 20.00
Exercise price range, options outstanding (in shares)	297	297
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)		1 year 11 months 19 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 16.16	$ 16.16
Exercise price range, options exercisable (in shares)	297	297
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 16.16	$ 16.16
$20.01–$30.00
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price, low end of range (usd per share)	$ 20.01
Exercise price, high end of range (usd per share)	$ 30.00
Exercise price range, options outstanding (in shares)	633	633
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)		4 years 7 months 21 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 29.32	$ 29.32
Exercise price range, options exercisable (in shares)	482	482
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 29.13	$ 29.13
$30.01–$40.00
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price, low end of range (usd per share)	$ 30.01
Exercise price, high end of range (usd per share)	$ 40.00
Exercise price range, options outstanding (in shares)	3,458	3,458
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)		4 years 9 months
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 36.24	$ 36.24
Exercise price range, options exercisable (in shares)	2,627	2,627
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 35.71	$ 35.71
$40.01–$50.00
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price, low end of range (usd per share)	$ 40.01
Exercise price, high end of range (usd per share)	$ 50.00
Exercise price range, options outstanding (in shares)	2,934	2,934
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)		8 years 1 month 10 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 46.32	$ 46.32
Exercise price range, options exercisable (in shares)	661	661
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 46.67	$ 46.67
$50.01–$60.00
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price, low end of range (usd per share)	$ 50.01
Exercise price, high end of range (usd per share)	$ 60.00
Exercise price range, options outstanding (in shares)	1,093	1,093
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)		7 years 26 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 54.27	$ 54.27
Exercise price range, options exercisable (in shares)	655	655
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 54.80	$ 54.80
$60.01–$70.00
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price, low end of range (usd per share)	$ 60.01
Exercise price, high end of range (usd per share)	$ 70.00
Exercise price range, options outstanding (in shares)	126	126
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)		8 years 11 months 1 day
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 65.78	$ 65.78
Exercise price range, options exercisable (in shares)	28	28
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 64.76	$ 64.76
$70.01–$80.00
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price, low end of range (usd per share)	$ 70.01
Exercise price, high end of range (usd per share)	$ 80
Exercise price range, options outstanding (in shares)	1,998	1,998
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)		9 years 4 months 10 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 76.71	$ 76.71
Exercise price range, options exercisable (in shares)	360	360
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 74.59	$ 74.59
$80.01–$90.00
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price, low end of range (usd per share)	$ 80.01
Exercise price, high end of range (usd per share)	$ 90.00
Exercise price range, options outstanding (in shares)	1,231	1,231
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)		8 years 9 months 22 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 83.09	$ 83.09
Exercise price range, options exercisable (in shares)	369	369
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 82.53	$ 82.53
$90.01–$96.87
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price, low end of range (usd per share)	$ 90.01
Exercise price, high end of range (usd per share)	$ 96.87
Exercise price range, options outstanding (in shares)	1,327	1,327
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)		9 years 9 months 18 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 96.73	$ 96.73
Exercise price range, options exercisable (in shares)	0	0
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 0.00	$ 0.00