Stock-based Compensation Expense (Details 2) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Jun. 30, 2013
Exercise Price Range from Dollars 9.07 to Dollars 20.00 [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price, low end of range (usd per share)	$ 9.07
Exercise price, high end of range (usd per share)	$ 20.00
Exercise price range, options outstanding (in shares)	547
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	2 years 10 months 28 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 15.39
Exercise price range, options exercisable (in shares)	547
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 15.39
Exercise Price Range from Dollars 20.01 to Dollars 30.00 [Member]
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)	1,149
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	6 years 2 months 5 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 29.38
Exercise price range, options exercisable (in shares)	839
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 29.21
Exercise Price Range from Dollars 30.01 to Dollars 40.00 [Member]
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)	8,026
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	5 years 10 months 13 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 36.48
Exercise price range, options exercisable (in shares)	4,684
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 35.71
Exercise Price Range from Dollars 40.01 to Dollars 50.00 [Member]
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)	4,860
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	9 years 2 months 5 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 46.32
Exercise price range, options exercisable (in shares)	361
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 47.01
Exercise Price Range from Dollars 50.01 to Dollars 60.00 [Member]
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)	1,916
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	7 years 9 months 26 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 53.68
Exercise price range, options exercisable (in shares)	733
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 54.65
Exercise Price Range From Dollars 60.01 to 64.30 [Member]
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)	$ 64.30
Exercise price range, options outstanding (in shares)	47
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	8 years 10 months 10 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 63.29
Exercise price range, options exercisable (in shares)	9
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 63.23
Exercise Price Range From Dollars 70.01 to 80.00 [Member] [Domain]
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price range, options outstanding (in shares)	72
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	9 years 10 months 17 days
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 77.73
Exercise price range, options exercisable (in shares)	0
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 0.00
Exercise Price Range From Dollars 80.01 to 84.18 [Member] [Domain] [Domain]
Share-based Compensation Arrangement by Share-based Payment Award
Exercise price range, options outstanding (in shares)	186
Exercise price range, options outstanding, weighted-average remaining contractual life (in years)	9 years 11 months 1 day
Exercise price range, options outstanding, weighted-average exercise price (in dollars per share)	$ 81.55
Exercise price range, options exercisable (in shares)	165
Exercise price range, options exercisable, weighted-average exercise price (in dollars per share)	$ 81.54