| 
         Net Income Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified | 3 Months Ended | 12 Months Ended | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 
         Jun. 30, 2014 | 
         Mar. 31, 2014 | 
         Dec. 31, 2013 | 
         Sep. 30, 2013 | 
         Jun. 30, 2013 | 
         Mar. 31, 2013 | 
         Dec. 31, 2012 | 
         Sep. 30, 2012 | 
         Jun. 30, 2014 | 
         Jun. 30, 2013 | 
         Jun. 30, 2012 | |||||||||||
| Earnings Per Share [Abstract] | |||||||||||||||||||||
| Net income | $ 128,731 | $ 203,581 | $ 139,246 | $ 111,197 | $ 134,770 | $ 166,382 | $ 106,630 | $ 135,367 | $ 582,755 | $ 543,149 | $ 756,015 | ||||||||||
| Denominator: | |||||||||||||||||||||
| Weighted-average shares-basic, excluding unvested restricted stock units | 166,016 | 166,089 | 166,795 | ||||||||||||||||||
| Effect of dilutive options and restricted stock units (in shares) | 2,102 | 3,171 | 3,352 | ||||||||||||||||||
| Weighted-average shares-diluted | 168,118 | 169,260 | 170,147 | ||||||||||||||||||
| Basic net income per share (in dollars per share) | $ 0.78 | [1] | 1.22美元 | [1] | $ 0.84 | [1] | $ 0.67 | [1] | $ 0.81 | [1] | $ 1.00 | [1] | $ 0.64 | [1] | $ 0.81 | [1] | $ 3.51 | $ 3.27 | $ 4.53 | ||
| Diluted net income per share (in dollars per share) | $ 0.77 | [1] | $ 1.21 | [1] | $ 0.83 | [1] | $ 0.66 | [1] | $ 0.80 | [1] | $ 0.98 | [1] | $ 0.63 | [1] | $ 0.80 | [1] | $ 3.47 | $ 3.21 | $ 4.44 | ||
| Anti-dilutive securities excluded from the computation of diluted net income per share (in shares) | 0 | 1,366 | 3,123 | ||||||||||||||||||
| 
 | |||||||||||||||||||||