Stock-Based Compensation - Stock Option Activity (Details) - Stock Options - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017
Stock options activity
Outstanding, beginning of period (in shares)	1,353,558
Granted (in shares)	375,330
Exercised (in shares)	(66,567)
Cancelled / Forfeited (in shares)	(26,747)
Outstanding, end of period (in shares)	1,635,574	1,353,558
Vested and exercisable, end of period (in shares)	836,448
Vested and expected to vest, end of period (in shares)	1,556,485
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 37.98
Granted (in dollars per share)	63.14
Exercised (in dollars per share)	36.21
Cancelled / Forfeited (in dollars per share)	50.72
Outstanding, end of period (in dollars per share)	43.62	$ 37.98
Vested and exercisable, end of period (in dollars per share)	35.08
Vested and expected to vest, end of period (in dollars per share)	$ 43.16
Weighted Average Remaining Contractual Term
Outstanding, end of period	7 years 8 months 24 days	7 years 3 months 17 days
Vested and exercisable, end of period	6 years 5 months 13 days
Vested and expected to vest, end of period	7 years 7 months 29 days
Aggregate Intrinsic Value
Outstanding, end of period	$ 31,553	$ 23,535
Vested and exercisable, end of period	23,214
Vested and expected to vest, end of period	$ 30,741