Estimated Fair Value of Financial Instruments (Tables)

12 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Financial Instruments Recorded on Condensed Consolidated Balance Sheets

	($ in thousands)
June 30, 2018	Level 1		Level 2		Level 3		Total
Money Market Funds Note (a)	$	300,865	$	—	$	—	$	300,865
Marketable Securities:
U.S. Treasury Bonds	9,632		—		—		9,632
Certificate of Deposits	5,610		—		—		5,610
U.S. Government Sponsored Agencies	6,749		—		—		6,749
Corporate Debt Securities	4,505		—		—		4,505
Commercial Paper	249		—		—		249
Total	$	327,610	$	—	$	—	$	327,610

	($ in thousands)
June 30, 2017	Level 1		Level 2		Level 3		Total
Money Market Funds Note (a)	$	36,776	$	—	$	—	$	36,776
Marketable Securities:
U.S. Treasury Bonds	35,062		—		—		35,062
Certificate of Deposits	15,298		—		—		15,298
U.S. Government Sponsored Agencies	18,344		—		—		18,344
Corporate Debt Securities	32,659		—		—		32,659
Commercial Paper	10,145		—		—		10,145
Total	$	148,284	$	—	$	—	$	148,284

(a)The money market funds noted above are included in cash and cash equivalents.

Schedule of Carrying Amounts and Estimated Fair Values (Level 2) of Debt Instruments

The carrying amounts and estimated fair values (Level 2) of debt instruments are as follows (in thousands):

	As of June 30, 2018				As of June 30, 2017
	Carrying		Estimated		Carrying		Estimated
	Amount		Fair Value		Amount		Fair Value
Convertible Senior Notes	$	19,763	$	89,436	$	98,084	$	180,950

Schedule of assumptions used in estimating fair value of the warrant liability

	June 30, 2018 (2)	June 30, 2017 (1)	June 30, 2017 (2)	February 10, 2017	October 11, 2016
Risk-free interest rate	1.95%	1.14%	1.38%	1.47%	0.87%
Expected remaining term	0.28 years	0.5 years	1.3 years	3.0 years	2.0 years
Expected volatility	60.00%	69.34%	73.85%	71.42%	75.00%
Dividend yield	—%	—%	—%	—%	—%

(1) Represents the fair value assumptions for the warrants issued in connection with February 10, 2017 stock purchase agreement.

(2) Represents the fair value assumptions for the warrants issued in connection with October 11, 2016 public offering.

Schedule of warrant liability

The following table sets forth the warrant activity for the year ended June 30, 2018 ($ in thousands):

	Number of		Estimated Fair Value
(in thousands)	Warrants		Level 2
Fair value - 6/30/2017	18,656		$	90,706
Reclassification of warrant liability to equity	(18,206	)	(190,369		)
Changes in fair market value of warrant liabilities	—		108,636
Fair value - 6/30/2018	450		$	8,973