Consolidated Statements of Shareholders Equity (USD $) In Thousands, except Share data	Total	Ordinary Shares [Member]	Treasury Shares [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning balance, Value at Jun. 30, 2009	$ 285,534	$ 688	$ (29,881)	$ 212,221	$ 98,784	$ 3,722
Beginning balance, Shares at Jun. 30, 2009		49,175,000	(6,369,000)
Issuance of ordinary shares due to share option exercises, Shares		633,000	151,000
Issuance of ordinary shares due to share option exercises, Value	14,977	9	721	14,247
Restricted share units vested, net of shares withheld for taxes, Shares		83,000	182,000
Restricted share units vested, net of shares withheld for taxes, Value	(6,142)	1	(477)	(5,666)
Excess tax benefits from share-based compensation	6,272			6,272
Share-based compensation expense	22,079			22,079
Net income	67,741				67,741
Foreign currency translation	(14,368)					(14,368)
Unrealized gain on cash flow hedge, net of tax	49					49
Unrealized gain on marketable securities	(28)					(28)
Ending Balance, Value at Jun. 30, 2010	376,114	698	(29,637)	249,153	166,525	(10,625)
Ending balance, Shares at Jun. 30, 2010		49,891,000	(6,036,000)
Issuance of ordinary shares due to share option exercises, Shares		59,000	256,000
Issuance of ordinary shares due to share option exercises, Value	7,013	1	3,035	3,977
Restricted share units vested, net of shares withheld for taxes, Shares			301,000
Restricted share units vested, net of shares withheld for taxes, Value	(5,653)		(1,840)	(3,813)
Excess tax benefits from share-based compensation	2,515			2,515
Share-based compensation expense	21,428			21,428
Net income	82,109				82,109
Foreign currency translation	23,483					23,483
Unrealized gain on cash flow hedge, net of tax	0
Unrealized gain on marketable securities	0
Purchase of shares, Shares			(1,327,000)
Purchase of shares, Value	(56,935)		(56,935)
Reclassification of unrealized gains to net income	19					19
Ending Balance, Value at Jun. 30, 2011	450,093	699	(85,377)	273,260	248,634	12,877
Ending balance, Shares at Jun. 30, 2011		49,950,000	(6,806,000)
Issuance of ordinary shares due to share option exercises, Shares			92,000
Issuance of ordinary shares due to share option exercises, Value	1,394		1,938	(544)
Restricted share units vested, net of shares withheld for taxes, Shares			278,000
Restricted share units vested, net of shares withheld for taxes, Value	(4,149)		3,445	(7,594)
Excess tax benefits from share-based compensation	6,108			6,108
Share-based compensation expense	25,157			25,157
Net income	43,994				43,994
Foreign currency translation	(23,609)					(23,609)
Unrealized gain on cash flow hedge, net of tax	0
Unrealized gain on marketable securities	0
Purchase of shares, Shares	(9,900,980)		(9,901,000)
Purchase of shares, Value	(309,701)		(309,701)
Grant of restricted share awards, Shares			506,000
Grant of restricted shares awards, Value	0		10,754	(10,754)
Ending Balance, Value at Jun. 30, 2012	$ 189,287	$ 699	$ (378,941)	$ 285,633	$ 292,628	$ (10,732)
Ending balance, Shares at Jun. 30, 2012		49,950,000	(15,831,000)