Fair value of financial instruments (Details) (USD $) | Sep. 30, 2013 | Jun. 30, 2013 |
In Thousands, unless otherwise specified |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | $181,526 | $191,685 |
Short-term investments | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 165,652 | 165,898 |
Short-term investments | Certificates of deposit | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 1,002 | 1,003 |
Short-term investments | Municipal securities | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 141,923 | 148,993 |
Short-term investments | Commercial paper | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 3,396 | 3,391 |
Short-term investments | Corporate bonds | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 19,331 | 12,511 |
Total | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 169,129 | 168,139 |
Total | Short-term investments | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 165,652 | 165,898 |
Total | Short-term investments | Certificates of deposit | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 1,002 | 1,003 |
Total | Short-term investments | Municipal securities | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 141,923 | 148,993 |
Total | Short-term investments | Commercial paper | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 3,396 | 3,391 |
Total | Short-term investments | Corporate bonds | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 19,331 | 12,511 |
Total | Cash equivalents | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 3,477 | 2,241 |
Total | Cash equivalents | Money market mutual funds | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 3,477 | 2,241 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 3,477 | 2,241 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments | Certificates of deposit | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments | Municipal securities | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments | Commercial paper | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments | Corporate bonds | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash equivalents | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 3,477 | 2,241 |
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash equivalents | Money market mutual funds | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 3,477 | 2,241 |
Significant Other Observable Inputs (Level 2) | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 165,652 | 165,898 |
Significant Other Observable Inputs (Level 2) | Short-term investments | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 165,652 | 165,898 |
Significant Other Observable Inputs (Level 2) | Short-term investments | Certificates of deposit | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 1,002 | 1,003 |
Significant Other Observable Inputs (Level 2) | Short-term investments | Municipal securities | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 141,923 | 148,993 |
Significant Other Observable Inputs (Level 2) | Short-term investments | Commercial paper | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 3,396 | 3,391 |
Significant Other Observable Inputs (Level 2) | Short-term investments | Corporate bonds | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 19,331 | 12,511 |
Significant Other Observable Inputs (Level 2) | Cash equivalents | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Significant Other Observable Inputs (Level 2) | Cash equivalents | Money market mutual funds | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Significant Unobservable Inputs (Level 3) | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Significant Unobservable Inputs (Level 3) | Short-term investments | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Significant Unobservable Inputs (Level 3) | Short-term investments | Certificates of deposit | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Significant Unobservable Inputs (Level 3) | Short-term investments | Municipal securities | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Significant Unobservable Inputs (Level 3) | Short-term investments | Commercial paper | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Significant Unobservable Inputs (Level 3) | Short-term investments | Corporate bonds | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Significant Unobservable Inputs (Level 3) | Cash equivalents | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | 0 | 0 |
Significant Unobservable Inputs (Level 3) | Cash equivalents | Money market mutual funds | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Estimated Fair Value | $0 | $0 |