Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Jun. 30, 2015	$ 1,727,667	$ 1,058	$ 1,072,427	$ 753,963	$ (58,150)	$ (41,631)
Beginning balance, shares at Jun. 30, 2015		105,841			3,229
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	47,429			47,429
Other comprehensive income (loss)	(130,480)					(130,480)
Issuance of common stock pursuant to compensation plans	4,400	$ 14	9,749		$ (5,363)
Issuance of common stock pursuant to compensation plans, shares		1,398			151
Issuance of common stock in connection with acquisition	16,308	$ 3	16,305
Issuance of common stock in connection with acquisition, shares		240
Stock-based compensation income tax effects	12,037		12,037
Shares withheld for payment of employee payroll taxes due on shares issued under stock-based compensation plans	(25,535)				$ (25,535)
Shares withheld for payment of employee payroll taxes due on shares issued under stock-based compensation plans, shares					638
Stock-based compensation expense	12,688		12,688
Ending balance at Jun. 30, 2016	1,664,514	$ 1,075	1,123,206	801,392	$ (89,048)	(172,111)
Ending balance, shares at Jun. 30, 2016		107,479			4,018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	67,430			67,430
Other comprehensive income (loss)	(23,368)					(23,368)
Issuance of common stock pursuant to compensation plans	1	$ 5	1,995		$ (1,999)
Issuance of common stock pursuant to compensation plans, shares		510			52
Stock-based compensation income tax effects	2,865		2,865
Shares withheld for payment of employee payroll taxes due on shares issued under stock-based compensation plans	(8,268)				$ (8,268)
Shares withheld for payment of employee payroll taxes due on shares issued under stock-based compensation plans, shares					217
Stock-based compensation expense	9,658		9,658
Ending balance at Jun. 30, 2017	$ 1,712,832	$ 1,080	1,137,724	868,822	$ (99,315)	(195,479)
Ending balance, shares at Jun. 30, 2017	107,989,000	107,989			4,287
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 9,694			9,694
Other comprehensive income (loss)	11,239					11,239
Issuance of common stock pursuant to compensation plans	0	$ 4	(4)		$ 0
Issuance of common stock pursuant to compensation plans, shares		433			0
Shares withheld for payment of employee payroll taxes due on shares issued under stock-based compensation plans	(7,192)				$ (7,192)
Shares withheld for payment of employee payroll taxes due on shares issued under stock-based compensation plans, shares					183
Stock-based compensation expense	10,476		10,476
Ending balance at Jun. 30, 2018	$ 1,737,049	$ 1,084	$ 1,148,196	$ 878,516	$ (106,507)	$ (184,240)
Ending balance, shares at Jun. 30, 2018	108,422,000	108,422			4,470