CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-In Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Treasury Stock	Accumulated Other Comprehensive (Loss) Income
Balance at Jun. 30, 2019	$ 1,519,319	$ (439)	$ 1,088	$ 1,158,257	$ 695,017	$ (439)	$ (110,039)	$ (225,004)
Balance (shares) at Jun. 30, 2019			108,833				4,614
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(107,021)				(107,021)
Other comprehensive income (loss)	56,110							56,110
Issuance of common stock pursuant to stock-based compensation plans			$ 1	(1)
Issuance of common stock pursuant to stock-based compensation plans (shares)			40
Shares withheld for payment of employee payroll taxes due on shares issued under stock-based compensation plans	(312)						$ (312)
Shares withheld for payment of employee payroll taxes due on shares issued under stock based compensation plans (shares)							17
Stock-based compensation expense	3,281			3,281
Balance at Sep. 30, 2019	$ 1,470,938		$ 1,089	1,161,537	587,557		$ (110,351)	(168,894)
Balance (shares) at Sep. 30, 2019			108,873				4,631
Increase (Decrease) in Stockholders' Equity
Accounting Standards Update	us-gaap:AccountingStandardsUpdate201602Member
Balance at Jun. 30, 2020	$ 1,443,554	$ (310)	$ 1,092	1,171,875	614,171	$ (310)	$ (172,192)	(171,392)
Balance (shares) at Jun. 30, 2020	109,123		109,123				7,238
Increase (Decrease) in Stockholders' Equity
Net income (loss)	$ 485				485
Other comprehensive income (loss)	31,005							31,005
Issuance of common stock pursuant to stock-based compensation plans			$ 1	(1)
Issuance of common stock pursuant to stock-based compensation plans (shares)			54
Shares withheld for payment of employee payroll taxes due on shares issued under stock-based compensation plans	(468)						$ (468)
Shares withheld for payment of employee payroll taxes due on shares issued under stock based compensation plans (shares)							20
Repurchases of common stock	(42,052)						$ (42,052)
Repurchases of common stock (shares)							1,281
Stock-based compensation expense	4,367			4,367
Balance at Sep. 30, 2020	$ 1,436,581		$ 1,093	$ 1,176,241	$ 614,346		$ (214,712)	$ (140,387)
Balance (shares) at Sep. 30, 2020	109,177		109,177				8,539
Increase (Decrease) in Stockholders' Equity
Accounting Standards Update	us-gaap:AccountingStandardsUpdate201613Member