Income Taxes - Additional Information (Detail) £ in Millions	12 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2017 GBP (£)
Income Tax [Line Items]
Federal alternative minimum tax			$ 263,000
Foreign current income tax benefit		$ 159,000	167,000
Domestic or federal tax expense before utilization of loss carry forwards			2,800,000
Domestic tax benefit from utilizing loss carry forwards			2,500,000
Statutory U.S. federal tax rate	34.00%
Changes in valuation allowance	$ (7,489,000)	(6,789,000)	3,572,000
Increase (decrease) in deferred tax assets, net			(1,100,000)
Net operating loss carryforwards	39,439,000	31,299,000	$ 2,500,000
Unrecognized tax benefits	0	0
Accrued penalties or interest related to uncertain tax positions	0	$ 0
Federal and State Research and Development Tax Credit Carryforward [Member]
Income Tax [Line Items]
Research and development tax credit carry forwards	1,200,000
U.S. Federal [Member]
Income Tax [Line Items]
Operating loss carry forwards	$ 92,600,000
Operating loss carry forwards, expiration range start dates	2023
Operating loss carry forwards, expiration range end dates	2037
U.S. Federal [Member] | Earliest Tax Year [Member]
Income Tax [Line Items]
Tax years subject to examination	2003
U.S. Federal [Member] | Latest Tax Year [Member]
Income Tax [Line Items]
Tax years subject to examination	2016
State [Member]
Income Tax [Line Items]
Operating loss carry forwards	$ 51,600,000
Federal and State Tax [Member]
Income Tax [Line Items]
Research and development tax credit carry forwards expiration begin date	2017
Research and development tax credit carry forwards expiration end date	2037
United Kingdom Tax Authority [Member]
Income Tax [Line Items]
Operating loss carry forwards	$ 27,400,000			£ 21.1
United Kingdom Tax Authority [Member] | Earliest Tax Year [Member]
Income Tax [Line Items]
Tax years subject to examination	2006
United Kingdom Tax Authority [Member] | Latest Tax Year [Member]
Income Tax [Line Items]
Tax years subject to examination	2016
Australian Tax Authority [Member] | Earliest Tax Year [Member]
Income Tax [Line Items]
Tax years subject to examination	2004
Australian Tax Authority [Member] | Latest Tax Year [Member]
Income Tax [Line Items]
Tax years subject to examination	2008