Stock-Based Compensation (Details 2) - May. 31, 2015 - $ / shares shares in Thousands	Total
Options Outstanding
Number Outstanding at the end of the period (in shares)	1,857
Weighted-Average Remaining Contractual Life in Years	7 years 1 month 6 days
Weighted-Average Exercise Price (in dollars per Share)	$ 21.05
Options Exercisable
Number Outstanding at the end of the period (in shares)	627
Weighted-Average Exercise Price (in dollar per Share)	$ 21.78
$10.00 - $15.00
Share-Based Compensation
Option Exercise Price Range, low end of range (in dollars per share)	10.00
Option Exercise Price Range, high end of range (in dollars per share)	$ 15.00
Options Outstanding
Number Outstanding at the end of the period (in shares)	564
Weighted-Average Remaining Contractual Life in Years	7 years 1 month 6 days
Weighted-Average Exercise Price (in dollars per Share)	$ 12.90
Options Exercisable
Number Outstanding at the end of the period (in shares)	94
Weighted-Average Exercise Price (in dollar per Share)	$ 12.90
$15.01 - $20.00
Share-Based Compensation
Option Exercise Price Range, low end of range (in dollars per share)	15.01
Option Exercise Price Range, high end of range (in dollars per share)	$ 20.00
Options Outstanding
Number Outstanding at the end of the period (in shares)	226
Weighted-Average Remaining Contractual Life in Years	4 years 8 months 12 days
Weighted-Average Exercise Price (in dollars per Share)	$ 16.79
Options Exercisable
Number Outstanding at the end of the period (in shares)	220
Weighted-Average Exercise Price (in dollar per Share)	$ 16.81
$20.01 - $34.50
Share-Based Compensation
Option Exercise Price Range, low end of range (in dollars per share)	20.01
Option Exercise Price Range, high end of range (in dollars per share)	$ 34.50
Options Outstanding
Number Outstanding at the end of the period (in shares)	1,067
Weighted-Average Remaining Contractual Life in Years	7 years 6 months
Weighted-Average Exercise Price (in dollars per Share)	$ 26.26
Options Exercisable
Number Outstanding at the end of the period (in shares)	313
Weighted-Average Exercise Price (in dollar per Share)	$ 27.94