Operations by Segments and Geographic Areas - Schedule of Revenue Based on Point of Sale (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from unaffiliated customers	$ 101,136	$ 86,099	$ 287,627	$ 255,911
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from unaffiliated customers	61,400	54,073	178,006	160,785
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from unaffiliated customers	24,388	20,096	66,927	60,240
Continental Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from unaffiliated customers	11,607	9,475	32,138	28,009
Asia-Pacific and Middle East [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from unaffiliated customers	$ 3,741	$ 2,455	$ 10,556	$ 6,877