Derivative Instruments and Hedging Activities: (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Beginning of period	$ (12,231)	$ (12,925)	$ (12,183)	$ (12,027)
Other comprehensive loss before reclassifications
Total before tax	(635)	(912)	(3,047)	(3,172)
Tax effect	249	358	1,195	1,244
Net of tax	(386)	(554)	(1,852)	(1,928)
Amounts reclassified from accumulated other comprehensive income (loss)
Total before tax	1,116	377	3,449	1,160
Tax effect	(438)	(148)	(1,353)	(455)
Net of tax	678	229	2,096	705
Net other comprehensive (loss) income	292	(325)	244	(1,223)
End of period	$ (11,939)	$ (13,250)	$ (11,939)	$ (13,250)