Deferred Compensation Plan - Available-for-sale Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Jun. 30, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total short-term investments	$ 741	$ 684
Mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total short-term investments	741	684
Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total short-term investments	741	684
Recurring | Mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total short-term investments	741	684
Recurring | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total short-term investments	479	425
Recurring | Level 1 | Mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total short-term investments	479	425
Recurring | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total short-term investments	262	259
Recurring | Level 2 | Mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total short-term investments	262	259
Recurring | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total short-term investments	0	0
Recurring | Level 3 | Mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total short-term investments	$ 0	$ 0