Financial Instruments (Tables)

3 Months Ended

Sep. 30, 2015

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):

	September 30, 2015
								Estimated Market Value
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Cash and Cash Equivalents		Short-term Investments
Cash	$	84,458	$	—	$	—		$	84,458	$	—
Level 1
Money market funds	1,126		—		—			1,126		—
	1,126		—		—			1,126		—
Level 2
Commercial paper	11,991		—		—			—		11,991
U.S. Agency securities	25,000		6		(2		)	—		25,004
Non-U.S. government securities	1,500		—		—			—		1,500
Corporate notes	29,060		3		(45		)	—		29,018
	67,551		9		(47		)	—		67,513
Total	$	153,135	$	9	$	(47	)	$	85,584	$	67,513

	June 30, 2015
								Estimated Market Value
	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. Agency securities	21,999		6		(14		)	—		21,991
Non-U.S. government securities	1,504		—		(3		)	—		1,501
Corporate notes	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

Contractual maturities of available-for-sale securities at September 30, 2015 were as follows (in thousands):

	September 30, 2015
	Amortized Cost		Fair Value
Due in 1 year or less	$	55,551	$	55,529
Due in 1-2 years	12,000		11,984
Due in 2-3 years	—		—
	$	67,551	$	67,513

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

The following table summarizes the carrying values and estimated fair values of our short-term and long-term debt (in thousands):

	September 30, 2015				June 30, 2015
	Carrying Value		Fair Value		Carrying Value		Fair Value
3.75% Convertible Notes	$	95,134	$	100,910	$	93,739	$	102,645
3.50% Convertible Notes	44,654		49,424		44,654		65,230
3.50% Series A Convertible Notes	64,985		77,861		64,460		102,760
Total	$	204,773	$	228,195	$	202,853	$	270,635