Stock-Based Compensation (Details 3) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Sep. 30, 2015 USD ($) $ / shares shares	Sep. 30, 2014 USD ($) $ / shares	Jun. 30, 2015 USD ($) $ / shares shares
Weighted Average Grant Date Fair Value
Total unrecognized compensation cost | $	$ 7,700	$ 25,800
Total unrecognized compensation cost, period of recognition	3 years	3 years
Payment related to tax withholding | $	$ 1,125	$ 1,411
Stock Options
Stock options activity
Outstanding, beginning of period (in shares) | shares	1,214,257
Granted (in shares) | shares	356,097
Exercised (in shares) | shares	(39,313)
Cancelled / Forfeited (in shares) | shares	(41,374)
Outstanding, end of period (in shares) | shares	1,489,667		1,214,257
Vested and exercisable, end of period (in shares) | shares	811,059
Vested and expected to vest, end of period (in shares) | shares	1,413,489
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 27.25
Granted (in dollars per share)	44.33
Exercised (in dollars per share)	15.46
Cancelled / Forfeited (in dollars per share)	34.81
Outstanding, end of period (in dollars per share)	31.43		$ 27.25
Vested and exercisable, end of period (in dollars per share)	24.03
Vested and expected to vest, end of period (in dollars per share)	$ 30.95
Weighted Average Remaining Contractual Term
Outstanding, end of period	7 years 7 months 2 days		7 years 3 months 4 days
Vested and exercisable, end of period	6 years 4 months 24 days
Vested and expected to vest, end of period	7 years 6 months 7 days
Aggregate Intrinsic Value
Outstanding, beginning of period | $	$ 22,232
Outstanding, end of period | $	13,439		$ 22,232
Vested and exercisable, end of period | $	12,031
Vested and expected to vest, end of period | $	13,278
Weighted Average Grant Date Fair Value
Total intrinsic value of options exercised | $	900	2,300
Cash proceeds from option exercises | $	$ 600	$ 1,100
Restricted Stock Units
Restricted stock units activity
Outstanding, beginning of period (in shares) | shares	542,432
Granted (in shares) | shares	326,382
Settled (in shares) | shares	(89,900)
Cancelled / Forfeited (in shares) | shares	(47,848)
Outstanding, end of period (in shares) | shares	731,066		542,432
Vested and expected to vest (in shares) | shares	649,061
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share)	$ 36.13
Granted (in dollars per share)	44.33	$ 43.44
Settled (RSUs) (in dollars per share)	36.62
Cancelled / Forfeited (in dollars per share)	35.47
Outstanding, end of period (in dollars per share)	$ 39.78		$ 36.13
Vested and expected to vest, end of period (in dollars per share)	39.78
Total fair value of shares vested from RSU grants | $	$ 3,400	$ 4,300
Payment related to tax withholding | $	$ 1,100	$ 1,400