Fair Value Measurements (Details) - USD ($) $ in Thousands | Mar. 31, 2018 | Jun. 30, 2017 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | $ 61,124 | $ 42,344 |
Available-for-sale Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 16,243 | |
Common Stock [Member] | Available-for-sale Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 2,943 | |
Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 44,881 | 35,474 |
Short-term Investments [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | | 6,870 |
Fair Value, Inputs, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 45,827 | 31,278 |
Fair Value, Inputs, Level 1 [Member] | Available-for-sale Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 2,943 | |
Fair Value, Inputs, Level 1 [Member] | Common Stock [Member] | Available-for-sale Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 2,943 | |
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 42,884 | 31,278 |
Fair Value, Inputs, Level 1 [Member] | Short-term Investments [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | | 0 |
Fair Value, Inputs, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 15,297 | 11,066 |
Fair Value, Inputs, Level 2 [Member] | Available-for-sale Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 13,300 | |
Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 1,997 | 4,196 |
Fair Value, Inputs, Level 2 [Member] | Short-term Investments [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | | 6,870 |
Fair Value, Inputs, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 0 | 0 |
Fair Value, Inputs, Level 3 [Member] | Available-for-sale Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 0 | |
Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 0 | 0 |
Fair Value, Inputs, Level 3 [Member] | Short-term Investments [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | | 0 |
Cash [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 20,321 | 5,227 |
Cash [Member] | Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 20,321 | 5,227 |
Cash [Member] | Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 0 | 0 |
Cash [Member] | Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 0 | 0 |
Money Market Funds [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 22,563 | 26,051 |
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 22,563 | 26,051 |
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 0 | 0 |
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 0 | 0 |
Commercial Paper [Member] | Available-for-sale Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 7,824 | |
Commercial Paper [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 1,997 | 4,196 |
Commercial Paper [Member] | Short-term Investments [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | | 6,870 |
Commercial Paper [Member] | Fair Value, Inputs, Level 1 [Member] | Available-for-sale Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 0 | |
Commercial Paper [Member] | Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 0 | 0 |
Commercial Paper [Member] | Fair Value, Inputs, Level 1 [Member] | Short-term Investments [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | | 0 |
Commercial Paper [Member] | Fair Value, Inputs, Level 2 [Member] | Available-for-sale Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 7,824 | |
Commercial Paper [Member] | Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 1,997 | 4,196 |
Commercial Paper [Member] | Fair Value, Inputs, Level 2 [Member] | Short-term Investments [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | | 6,870 |
Commercial Paper [Member] | Fair Value, Inputs, Level 3 [Member] | Available-for-sale Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 0 | |
Commercial Paper [Member] | Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 0 | 0 |
Commercial Paper [Member] | Fair Value, Inputs, Level 3 [Member] | Short-term Investments [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | | $ 0 |
Repurchase Agreements [Member] | Available-for-sale Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | 5,476 | |
Repurchase Agreements [Member] | Fair Value, Inputs, Level 2 [Member] | Available-for-sale Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets, Fair Value Disclosure, Recurring | $ 5,476 | |