Restructuring - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Mar. 31, 2018	Mar. 31, 2017
Restructuring Cost [Line Items]
Restructuring charges			$ 472,000
U.K. [Member]
Restructuring Cost [Line Items]
Extended lease term expiration date		Nov. 30, 2016
Restructuring charges			472,000
Discretionary termination benefits			273,000
Other restructuring costs			199,000
Increase in stock-based compensation expense to account for the extension of the exercise period of all vested stock options	$ 99,000		99,000
Reduction of stock-based compensation to account for forfeitures of non-vested stock options	$ 133,000		$ 133,000