Shareholders' Equity (Details) (USD $)	12 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2009
Summary of weighted average values used for option grants
Risk-free interest rate	1.79%	2.03%	1.48%
Expected dividend yield	0.00%	0.00%	0.00%
Expected life (years)	5.00	4.92	3.94
Expected volatility	57.00%	57.00%	58.00%
Weighted average fair value of options granted	$ 24.47	$ 24.34	$ 14.06

The period of time an equity-based award is expected to be outstanding. An equity-based award's expected term is generally determined based on, among other factors, the instrument's contractual term and the effects of employees' expected exercise and post-vesting employment termination behavior.

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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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