Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Treasury Stock
Beginning Balance, shares (in shares) at Jun. 30, 2017		74,081			(10,940)
Beginning Balance at Jun. 30, 2017	$ 900,563	$ 269,638	$ (13,778)	$ 748,062	$ (103,359)
Share-based and deferred compensation activities (in shares)		1,612			(41)
Share-based and deferred compensation activities	(19,217)	$ 25,717			$ (6,500)
Purchases of treasury/common stock (in shares)					(1,415)
Purchases of treasury stock	(49,875)				$ (49,875)
Net earnings (loss)	88,002			88,002
Foreign currency translation adjustments	7,152		7,152
Equity portion of convertible debt, net of issuance costs of $1,694	56,406	$ 56,406
Change in fair value of interest rate swap	0
Pension adjustment, net of taxes	2,846		2,846
Ending Balance, shares (in shares) at Jun. 30, 2018		75,693			(12,396)
Ending Balance at Jun. 30, 2018	1,024,311	$ 351,761	(3,780)	836,064	$ (159,734)
Share-based and deferred compensation activities (in shares)		622			(158)
Share-based and deferred compensation activities	23,438	$ 30,662			$ (7,224)
Purchases of treasury/common stock (in shares)					(50)
Purchases of treasury stock	(1,616)				$ (1,616)
Net earnings (loss)	107,517			107,517
Foreign currency translation adjustments	(14,319)		(14,319)
Change in fair value of interest rate swap	0
Pension adjustment, net of taxes	(6,122)		(6,122)
Ending Balance, shares (in shares) at Jun. 30, 2019		76,315			(12,604)
Ending Balance at Jun. 30, 2019	1,133,209	$ 382,423	(24,221)	943,581	$ (168,574)
Share-based and deferred compensation activities (in shares)		2,888			(702)
Share-based and deferred compensation activities	87,703	$ 116,817			$ (29,114)
Purchases of treasury/common stock (in shares)					(50)
Purchases of treasury stock	(1,625)				$ (1,625)
Shares issued related to Finisar acquisition (in shares)		26,713
Shares issued related to Finisar acquisition	987,707	$ 987,707
Net earnings (loss)	(67,029)			(67,029)
Foreign currency translation adjustments	(15,969)		(15,969)
Change in fair value of interest rate swap	(44,085)		(44,085)
Pension adjustment, net of taxes	(3,108)		(3,108)
Ending Balance, shares (in shares) at Jun. 30, 2020		105,916			(13,356)
Ending Balance at Jun. 30, 2020	$ 2,076,803	$ 1,486,947	$ (87,383)	$ 876,552	$ (199,313)