Financial Instruments (Tables)

6 Months Ended

Dec. 31, 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

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):

	December 31, 2016
								Estimated Fair Value
			Gross		Gross			Cash and
	Amortized		Unrealized		Unrealized			Cash		Short-term
	Cost		Gains		Losses			Equivalents		Investments
Cash	$	67,350	$	—	$	—		$	67,350	$	—
Level 1
Money market funds	2,122		—		—			2,122		—
Level 2
U.S. government agency securities	38,993		—		(85		)	—		38,908
Total	$	108,465	$	—	$	(85	)	$	69,472	$	38,908

	June 30, 2016
								Estimated Fair Value
			Gross		Gross			Cash and
	Amortized		Unrealized		Unrealized			Cash		Short-term
	Cost		Gains		Losses			Equivalents		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 December 31, 2016 were as follows (in thousands):

	December 31, 2016
	Amortized		Estimated
	Cost		Fair Value
Due in 1 year or less	$	14,122	$	14,110
Due in 1-2 years	26,993		26,920
	$	41,115	$	41,030

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

The following table summarizes the 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					Gross					Gross
	Unrealized			Estimated		Unrealized			Estimated		Unrealized			Estimated
	Losses			Fair Value		Losses			Fair Value		Losses			Fair Value
December 31, 2016
Debt Securities:
U. S. government agency securities	$	(12	)	$	11,988	$	(73	)	$	26,920	$	(85	)	$	38,908
Total	$	(12	)	$	11,988	$	(73	)	$	26,920	$	(85	)	$	38,908
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

Summary of carrying values and estimated fair values of short-term and long-term debt

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

	December 31, 2016				June 30, 2016
	Carrying Value		Fair Value		Carrying Value		Fair Value
3.75% Convertible Notes	$	—	$	—	$	36,400	$	36,487
3.50% Convertible Notes	43,642		47,472		43,195		51,450
3.50% Series A Convertible Notes	67,748		74,785		66,613		81,053
Secured Loan (1)	58,778		58,778		64,204		64,204
Total	$	170,168	$	181,035	$	210,412	$	233,194

(1) The carrying value of the Secured Loan approximates fair value as the Company did not elect the fair value option for the Secured Loan.