Gain (Losses) on Derivative Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Not Designated as Hedging Instrument [Member] | Forward exchange contract
Derivative Instruments, Gain (Loss)
Gains (losses) on derivative financial instruments that were recorded in the consolidated statement of income	$ (331)	$ 442	$ 148	$ (182)
Not Designated as Hedging Instrument [Member] | Costless collar contracts
Derivative Instruments, Gain (Loss)
Gains (losses) on derivative financial instruments that were recorded in the consolidated statement of income	(424)	766	(1,788)	7,486
Designated as Hedging Instrument [Member] | Cross currency swap
Derivative Instruments, Gain (Loss)
Derivative and non derivative instruments gain (loss) recognized in accumulated oher comprehensive income (loss)	22,684	(2,393)	44,813	(13,881)
Designated as Hedging Instrument [Member] | Foreign denominated debt
Derivative Instruments, Gain (Loss)
Derivative and non derivative instruments gain (loss) recognized in accumulated oher comprehensive income (loss)	$ 17,151	$ (1,013)	$ 42,296	$ (7,895)