Summary of Significant Accounting Policies - Revenues by Geographic Area (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2018 USD ($) Segment	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of geographic segments | Segment									2
Revenues from unaffiliated customers
Total revenues	$ 54,033	$ 50,562	$ 49,482	$ 49,127	$ 50,641	$ 45,007	$ 48,947	$ 54,894	$ 203,204	$ 199,489	$ 206,540
Americas
Revenues from unaffiliated customers
Total revenues									151,609	150,841	158,291
Asia/Pacific & Europe
Revenues from unaffiliated customers
Total revenues									51,595	48,648	48,249
United States
Segment Reporting Information [Line Items]
Long-lived assets	9,800				6,200				9,800	6,200
Revenues from unaffiliated customers
Total revenues									142,452	144,842	152,830
Japan
Segment Reporting Information [Line Items]
Long-lived assets	$ 900				$ 900				900	900
Revenues from unaffiliated customers
Total revenues									$ 41,843	$ 39,390	$ 36,343