Marketable Securities (Details) (U.S. corporate bonds, USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Dec. 31, 2014	Jun. 30, 2014
Short-term Marketable Securities
Marketable Securities
Fair Value	$ 72,675	$ 67,619
Cost	72,722	67,587
Unrealized Gain	5	39
Unrealized Loss	(51)	(7)
Long-term Marketable Securities
Marketable Securities
Fair Value	25,334	31,270
Cost	25,397	31,290
Unrealized Gain	5	1
Unrealized Loss	$ (67)	$ (21)