Summary of Significant Accounting Policies - Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017		Mar. 31, 2016	Jun. 30, 2016
Basic and diluted income (loss) per share computation:
Net income (loss) attributable to common stockholders	$ 9,115	$ 14,273	$ 6,934	[1]	$ 10,018
Weighted average common shares—basic	38,376,984	37,692,826	38,145,671		37,562,106
Effect of dilutive stock options and restricted stock awards (in shares)	951,143	1,307,045	810,410		997,098
Weighted average common shares—diluted	39,328,127	38,999,871	38,956,081		38,559,204
Basic net income (loss) per share (in dollars per share)	$ 0.24	$ 0.38	$ 0.18		$ 0.27
Diluted net income (loss) per share	$ 0.23	$ 0.37	$ 0.18		$ 0.26
Additional disclosures
Common stock, shares issued	44,061,275		44,061,275			43,184,068
Common stock, shares outstanding	40,558,677		40,558,677			39,681,470
Stock options and restricted stock
Basic and diluted income (loss) per share computation:
Anti-dilutive shares	1,283,168	3,249,351	2,064,498		3,066,694

[1] Net income excludes $0.8 million due to the redeemable noncontrolling interest related to Middlebury Interactive Languages and LearnBop, which are reported outside of permanent equity in the accompanying unaudited condensed consolidated balance sheets.