Income Taxes - Effective Income tax Rate (Details)	12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
The effective income tax rate differs from the U.S. Federal statutory income tax rate
Federal statutory income tax rate	35.00%	35.00%	35.00%
State income taxes, net of federal benefit	2.00%	1.90%	1.80%
Tax return to provision true-up	1.20%	(3.00%)	(2.50%)
Permanent differences:
— stock based compensation	1.20%	1.30%	0.80%
— domestic production activities deduction	(1.60%)	(1.80%)	(2.70%)
— credit for increasing research activities	(3.80%)	(1.50%)	(0.70%)
— other	0.40%	(0.50%)	0.00%
Change in valuation allowance	0.00%	0.10%	0.00%
Net income tax provision	34.40%	31.50%	31.70%