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	0		$ 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	1,521,083		$ 1,091	1,164,618	586,593		$ (111,022)	(120,197)
Balance (shares) at Sep. 30, 2019			109,019				4,658
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)	(107,985)
Balance at Dec. 31, 2019	1,470,938		$ 1,089	1,161,537	587,557		$ (110,351)	(168,894)
Balance (shares) at Dec. 31, 2019			108,873				4,631
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
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
Accounting Standards Update	us-gaap:AccountingStandardsUpdate201613Member
Balance at Sep. 30, 2019	$ 1,521,083		$ 1,091	1,164,618	586,593		$ (111,022)	(120,197)
Balance (shares) at Sep. 30, 2019			109,019				4,658
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(964)				(964)
Other comprehensive income (loss)	48,697							48,697
Issuance of common stock pursuant to stock-based compensation plans	0		$ 2	(2)
Issuance of common stock pursuant to stock-based compensation plans (shares)			146
Shares withheld for payment of employee payroll taxes due on shares issued under stock-based compensation plans	(671)						$ (671)
Shares withheld for payment of employee payroll taxes due on shares issued under stock based compensation plans (shares)							27
Stock-based compensation expense	3,083			3,083
Balance at Dec. 31, 2019	1,470,938		$ 1,089	1,161,537	587,557		$ (110,351)	(168,894)
Balance (shares) at Dec. 31, 2019			108,873				4,631
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	0		$ 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				8,539
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)	$ 2,625
Balance at Dec. 31, 2020	$ 1,454,649		$ 1,095	1,180,062	616,486		$ (245,651)	(97,343)
Balance (shares) at Dec. 31, 2020	109,339		109,339				9,500
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				8,539
Increase (Decrease) in Stockholders' Equity
Net income (loss)	2,140				2,140
Other comprehensive income (loss)	43,044							43,044
Issuance of common stock pursuant to stock-based compensation plans	0		$ 2	(2)
Issuance of common stock pursuant to stock-based compensation plans (shares)			162
Shares withheld for payment of employee payroll taxes due on shares issued under stock-based compensation plans	(1,255)						$ (1,255)
Shares withheld for payment of employee payroll taxes due on shares issued under stock based compensation plans (shares)							38
Repurchases of common stock	(29,684)						$ (29,684)
Repurchases of common stock (shares)							923
Stock-based compensation expense	3,823			3,823
Balance at Dec. 31, 2020	$ 1,454,649		$ 1,095	$ 1,180,062	$ 616,486		$ (245,651)	$ (97,343)
Balance (shares) at Dec. 31, 2020	109,339		109,339				9,500