Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Treasury Stock
Beginning Balance at Jun. 30, 2018	$ 1,024,311	$ 351,761	$ (3,780)	$ 836,064	$ (159,734)
Beginning Balance, shares at Jun. 30, 2018		75,693			(12,396)
Share-based and deferred compensation activities	3,727	$ 8,515			$ (4,788)
Share-based and deferred compensation activities (in shares)		382			(101)
Net earnings (loss)	26,149			26,149
Foreign currency translation adjustments	(10,651)		(10,651)
Pension adjustment, net of taxes	52		52
Ending Balance at Sep. 30, 2018	1,043,588	$ 360,276	(14,379)	862,213	$ (164,522)
Ending Balance, shares at Sep. 30, 2018		76,075			(12,497)
Beginning Balance at Jun. 30, 2019	1,133,209	$ 382,423	(24,221)	943,581	$ (168,574)
Beginning Balance, shares at Jun. 30, 2019		76,315			(12,604)
Share-based and deferred compensation activities	49,211	$ 59,043			$ (9,832)
Share-based and deferred compensation activities (in shares)		708			(251)
Shares issued related to Finisar acquisition	987,707	$ 987,707
Shares issued related to Finisar acquisition (in shares)		26,713
Net earnings (loss)	(25,998)			(25,998)
Foreign currency translation adjustments	(13,019)		(13,019)
Pension adjustment, net of taxes	84		84
Ending Balance at Sep. 30, 2019	$ 2,131,194	$ 1,429,173	$ (37,156)	$ 917,583	$ (178,406)
Ending Balance, shares at Sep. 30, 2019		103,736			(12,855)