Financial Instruments (Tables)

12 Months Ended

Jun. 30, 2017

Financial Instruments

Summary of amortized cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category for cash, cash equivalents and short-term investments

        The following tables summarize the amortized cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category for cash, cash equivalents and short-term investments (in thousands):

	June 30, 2017
								Estimated Fair Value
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Cash and Cash Equivalents		Short-term Investments
Cash	$	70,515	$	—	$	—		$	70,515	$	—
Level 1
Money market funds		1,569		—		—			1,569		—
Level 2
U.S. government agency securities		23,998		—		(89	)		—		23,909
Total	$	96,082	$	—	$	(89	)	$	72,084	$	23,909

	June 30, 2016
								Estimated Fair Value
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Cash and Cash Equivalents		Short-term Investments
Cash	$	95,906	$	—	$	—		$	95,906	$	—
Level 1
Money market funds		13,362		—		—			13,362		—
		13,362		—		—			13,362		—
Level 2
Commercial paper		14,704		—		—			8,938		5,766
U.S. government agency securities		28,000		7		(17	)		—		27,990
U. S. treasury securities		3,997		1		—			—		3,998
Municipal debt securities		1,565		—		—			1,565		—
Corporate debt securities		9,491		—		(6	)		—		9,485
		57,757		8		(23	)		10,503		47,239
Total	$	167,025	$	8	$	(23	)	$	119,771	$	47,239

Schedule of contractual maturities of available-for-sale securities

        Contractual maturities of available-for-sale securities at June 30, 2017 were as follows (in thousands):

	June 30, 2017
	Amortized Cost		Estimated Fair Value
Due in 1 year or less	$	12,000	$	11,970
Due in 1 - 2 years		11,998		11,939
Total	$	23,998	$	23,909

Schedule of available-for-sale debt securities that were in a continuous unrealized loss position

        The following table summarizes our available-for-sale debt securities that were in a continuous unrealized loss position, but were not deemed to be other-than-temporarily impaired (in thousands):

	Less Than 12 Months					12 Months or Greater					Total
	Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value
June 30, 2017
Debt Securities:
U. S. government agency securities	$	(31	)	$	11,970	$	(58	)	$	11,939	$	(89	)	$	23,909
Total	$	(31	)	$	11,970	$	(58	)	$	11,939	$	(89	)	$	23,909
June 30, 2016
Debt Securities:
Corporate debt securities	$	(3	)	$	6,325	$	(3	)	$	3,160	$	(6	)	$	9,485
U. S. government agency securities		—			—		(17	)		19,988		(17	)		19,988
Total	$	(3	)	$	6,325	$	(20	)	$	23,148	$	(23	)	$	29,473

Schedule of carrying values and estimated fair values of long-term debt that are measured on a non-recurring basis

	June 30, 2017				June 30, 2016
	Carrying Value		Fair Value		Carrying Value		Fair Value
3.75% Convertible Notes	$	—	$	—	$	36,400	$	36,487
3.50% Convertible Notes		44,099		48,146		43,195		51,450
3.50% Series A Convertible Notes		68,924		74,982		66,613		81,053
Secured Loan		—				64,204		64,204
Revolver Credit Facility		51,548		51,548		—		—
Total	$	164,571	$	174,676	$	210,412	$	233,194