Consolidated Statements of Shareholders' Equity and Comprehensive Income (USD $) In Thousands, except Share data	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance, Value at Jun. 30, 2008	$ 242,505	$ 683	$ 0	$ 190,632	$ 43,098	$ 8,092
Beginning Balance, Shares at Jun. 30, 2008		48,779,000	(4,500,000)
Issuance of ordinary shares due to share option exercises, Value	12,067	11		12,056
Issuance of ordinary shares due to share option exercises, Shares		807,000
Restricted share units vested, net of shares withheld for taxes, Value	(4,176)	5	(2,818)	(1,363)
Restricted share units vested, net of shares withheld for taxes, Shares		359,000	(85,000)
Excess tax benefits from share-based compensation	9,603			9,603
Share-based compensation expense	19,737			19,737
Repurchase of shares, Value	(45,518)	(11)	(27,063)	(18,444)
Repurchase of shares, Shares		(770,000)	(1,784,000)
Comprehensive income:
Net income	55,686				55,686
Foreign currency translation	(4,382)					(4,382)
Unrealized gain ( loss) on marketable securities	12					12
Total comprehensive income	51,316
Ending Balance, Value at Jun. 30, 2009	285,534	688	(29,881)	212,221	98,784	3,722
Ending Balance, Shares at Jun. 30, 2009		49,175,000	(6,369,000)
Issuance of ordinary shares due to share option exercises, Value	14,977	9	721	14,247
Issuance of ordinary shares due to share option exercises, Shares		633,000	151,000
Restricted share units vested, net of shares withheld for taxes, Value	(6,142)	1	(477)	(5,666)
Restricted share units vested, net of shares withheld for taxes, Shares		83,000	182,000
Excess tax benefits from share-based compensation	6,272			6,272
Share-based compensation expense	22,079			22,079
Comprehensive income:
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 ( loss) on marketable securities	(28)					(28)
Total comprehensive income	53,394
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, Value	7,013	1	3,035	3,977
Issuance of ordinary shares due to share option exercises, Shares	315,175	59,000	256,000
Restricted share units vested, net of shares withheld for taxes, Value	(5,653)		(1,840)	(3,813)
Restricted share units vested, net of shares withheld for taxes, Shares			301,000
Excess tax benefits from share-based compensation	2,515			2,515
Share-based compensation expense	21,428			21,428
Repurchase of shares, Value	(56,935)		(56,935)
Repurchase of shares, Shares	(1,326,933)		(1,326,933)
Comprehensive income:
Net income	82,109				82,109
Foreign currency translation	23,483					23,483
Reclassification of unrealized gains (losses) to net income	19					19
Total comprehensive income	105,611
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)