Financial Instruments - Investment (Details) $ in Thousands	12 Months Ended
	Jun. 30, 2017 USD ($) position	Jun. 30, 2016 USD ($) position
Cash, cash equivalents and short-term investments
Amortized Cost	$ 96,082	$ 167,025
Gross Unrealized Gains		8
Gross Unrealized Losses	(89)	(23)
Cash and Cash Equivalents	72,084	119,771
Short-term Investments	23,909	47,239
Other-than-temporary impairments	0	0
Amortized Cost
Due in 1 year or less	12,000
Due in 1-2 years	11,998
Total Amortized Cost	23,998
Estimated Fair Value
Due in 1 year or less	11,970
Due in 1-2 years	11,939
Available-for-sale Securities	23,909
Gross Unrealized Losses
Less Than 12 Months	(31)	(3)
12 Months or Greater	(58)	(20)
Total	(89)	(23)
Estimated Fair Value
Less Than 12 Months	11,970	6,325
12 Months or Greater	11,939	23,148
Total	$ 23,909	$ 29,473
Number of positions held in an unrealized loss position | position	8	11
U.S. government agency securities
Gross Unrealized Losses
Less Than 12 Months	$ (31)
12 Months or Greater	(58)	$ (17)
Total	(89)	(17)
Estimated Fair Value
Less Than 12 Months	11,970
12 Months or Greater	11,939	19,988
Total	23,909	19,988
Corporate debt securities
Gross Unrealized Losses
Less Than 12 Months		(3)
12 Months or Greater		(3)
Total		(6)
Estimated Fair Value
Less Than 12 Months		6,325
12 Months or Greater		3,160
Total		9,485
Cash.
Cash, cash equivalents and short-term investments
Amortized Cost	70,515	95,906
Cash and Cash Equivalents	70,515	95,906
Level 1
Cash, cash equivalents and short-term investments
Amortized Cost		13,362
Cash and Cash Equivalents		13,362
Level 1 | Money market funds
Cash, cash equivalents and short-term investments
Amortized Cost	1,569	13,362
Cash and Cash Equivalents	1,569	13,362
Level 2
Cash, cash equivalents and short-term investments
Amortized Cost		57,757
Gross Unrealized Gains		8
Gross Unrealized Losses		(23)
Cash and Cash Equivalents		10,503
Short-term Investments		47,239
Level 2 | Commercial paper
Cash, cash equivalents and short-term investments
Amortized Cost		14,704
Cash and Cash Equivalents		8,938
Short-term Investments		5,766
Level 2 | U.S. government agency securities
Cash, cash equivalents and short-term investments
Amortized Cost	23,998	28,000
Gross Unrealized Gains		7
Gross Unrealized Losses	(89)	(17)
Short-term Investments	$ 23,909	27,990
Level 2 | U.S. Treasury securities
Cash, cash equivalents and short-term investments
Amortized Cost		3,997
Gross Unrealized Gains		1
Short-term Investments		3,998
Level 2 | Municipal debt securities
Cash, cash equivalents and short-term investments
Amortized Cost		1,565
Cash and Cash Equivalents		1,565
Level 2 | Corporate debt securities
Cash, cash equivalents and short-term investments
Amortized Cost		9,491
Gross Unrealized Losses		(6)
Short-term Investments		$ 9,485