Employee Benefit Plans (Tables)

9 Months Ended

Mar. 31, 2015

Compensation and Retirement Disclosure [Abstract]

Schedule of net periodic pension expense

​	Three Months						Nine Months
For the Periods Ended March 31	2015			2014			2015			2014
Service cost – benefits earned during the period	​	$	739	​	$	535	​	$	2,217	​	$	1,843
Interest cost on benefit obligation	​	​	654	​	​	532	​	​	1,963	​	​	1,750
Expected return on plan assets	​	​	(707)	​	​	(476)	​	​	(2,121)	​	​	(1,751)
Amortization of net actuarial loss and prior service costs	​	​	351	​	​	249	​	​	1,053	​	​	678
Net periodic pension expense	​	$	1,037	​	$	840	​	$	3,112	​	$	2,520