Fair Value Measurements (Financial Assets and Liabilities) (Details) - USD ($) $ in Thousands | Jun. 30, 2016 | Sep. 30, 2015 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | $ 70,458 | [1] | $ 60,817 | [2] |
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Total assets measured at fair value | 27,646 | | 14,436 | |
Total liabilities measured at fair value | 0 | | | |
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Total assets measured at fair value | 70,458 | | 60,817 | |
Total liabilities measured at fair value | 0 | | | |
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Total assets measured at fair value | 0 | | 0 | |
Total liabilities measured at fair value | 10,587 | | | |
Liability | Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Contingent consideration on acquired business | 0 | | | |
Liability | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Contingent consideration on acquired business | 0 | | | |
Liability | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Contingent consideration on acquired business | 10,587 | | | |
Money market | Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Cash equivalents | 27,646 | | 14,436 | |
Money market | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Cash equivalents | 0 | | 0 | |
Money market | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Cash equivalents | 0 | | 0 | |
Corporate Bonds | Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 0 | | 0 | |
Corporate Bonds | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 34,073 | | 35,840 | |
Corporate Bonds | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 0 | | 0 | |
Commercial Paper | Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 0 | | 0 | |
Commercial Paper | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 23,954 | | 7,985 | |
Commercial Paper | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 0 | | 0 | |
Certificates of Deposit | Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 0 | | 0 | |
Certificates of Deposit | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 9,327 | | 13,768 | |
Certificates of Deposit | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 0 | | 0 | |
Government municipal bonds | Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 0 | | 0 | |
Government municipal bonds | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 3,104 | | 3,224 | |
Government municipal bonds | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 0 | | 0 | |
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Total assets measured at fair value | 98,104 | | 75,253 | |
Total liabilities measured at fair value | 10,587 | | | |
Estimate of Fair Value Measurement | Money market | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Cash equivalents | 27,646 | | 14,436 | |
Estimate of Fair Value Measurement | Corporate Bonds | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 34,073 | | 35,840 | |
Estimate of Fair Value Measurement | Commercial Paper | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 23,954 | | 7,985 | |
Estimate of Fair Value Measurement | Certificates of Deposit | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | 9,327 | | 13,768 | |
Estimate of Fair Value Measurement | Government municipal bonds | Fair Value, Measurements, Recurring | | | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | | | |
Available-for-sale marketable securities | $ 3,104 | | $ 3,224 | |
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[1] | Included in amortized cost and fair value is purchased and accrued interest of $282 |
[2] | Included in amortized cost and fair value is purchased and accrued interest of $252. |