Financial Instruments (Tables)

12 Months Ended

Jun. 30, 2016

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

	June 30, 2016
								Estimated Market Value
(in thousands)	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 agencies 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

	June 30, 2015
								Estimated Market Value
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Cash and Cash Equivalents		Short-term Investments
Cash	$	73,444	$	—	$	—		$	73,444	$	—
Level 1
Money market funds		6,107		—		—			6,107		—
		6,107		—		—			6,107		—
Level 2
Commercial paper		11,989		—		—			—		11,989
U.S. government agencies securities		21,999		6		(14	)		—		21,991
Non-U.S. government securities		1,504		—		(3	)		—		1,501
Corporate debt securities		28,891		—		(66	)		—		28,825
		64,383		6		(83	)		—		64,306
Total	$	143,934	$	6	$	(83	)	$	79,551	$	64,306

Schedule of contractual maturities of available-for-sale securities

	June 30, 2016
(in thousands)	Amortized Cost		Fair Value
Due in 1 year or less	$	24,091	$	24,091
Due in 1 - 2 years		23,163		23,148
Due in 2 - 3 years		—		—
	$	47,254	$	47,239

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

	Less Than 12 Months					12 Months or Greater					Total
(in thousands)	Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value
June 30, 2016
Debt securities:
Corporate debt securities	$	(3	)	$	6,325	$	(3	)	$	3,160	$	(6	)	$	9,485
U.S. government agencies securities		—			—		(17	)		19,988		(17	)		19,988
Total	$	(3	)	$	6,325	$	(20	)	$	23,148	$	(23	)	$	29,473
June 30, 2015
Debt securities:
Corporate debt securities	$	(45	)	$	23,428	$	(21	)	$	5,397	$	(66	)	$	28,825
U.S. government agencies securities		(1	)		11,004		(13	)		10,987		(14	)		21,991
Non—U.S. government securities		(3	)		1,501		—			—		(3	)		1,501
Total	$	(49	)	$	35,933	$	(34	)	$	16,384	$	(83	)	$	52,317

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

	June 30, 2016				June 30, 2015
(in thousands)	Carrying Value		Fair Value		Carrying Value		Fair Value
3.75% Convertible Notes	$	36,400	$	36,487	$	92,863	$	102,645
3.50% Convertible Notes		43,195		51,450		42,332		65,230
3.50% Series A Convertible Notes		66,613		81,053		64,460		102,760
Secured Loan		64,204		64,204		—		—
Total	$	210,412	$	233,194	$	199,655	$	270,635