Unaudited Condensed Consolidated Statements of Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Treasury Stock, Common	Total
Beginning balance at Dec. 31, 2020	$ 1,600	$ 3,424,624	$ (2,401,988)	$ (5,006)	$ (83,673)	$ 935,557
Beginning balance (in shares) at Dec. 31, 2020	160,014,960
Treasury stock, common shares, Beginning balance (in shares) at Dec. 31, 2020					(7,052,769)
Increase (Decrease) in Stockholders' Equity
Treasury stock purchased					$ (2,409)	(2,409)
Treasury stock purchased (in shares)					(277,316)
Cash dividends			(66,992)			(66,992)
Shares issued under employee stock purchase plan ("ESPP")		546				546
Shares issued under employee stock purchase plan ("ESPP") (in shares)	66,541
Stock-based compensation, net of forfeitures	$ 10	8,731				8,741
Stock-based compensation, net of forfeitures (in shares)	1,020,756				(72,103)
Net proceeds from issuance of common stock	$ 4	3,397				3,401
Net proceeds from issuance of common stock (in shares)	357,148
Comprehensive income (loss)
Net income			22,225			22,225
Other comprehensive income				2,978		2,978
Ending balance at Sep. 30, 2021	$ 1,614	3,437,298	(2,446,755)	(2,028)	$ (86,082)	904,047
Ending balance (in shares) at Sep. 30, 2021	161,459,405
Treasury stock, common shares, Ending balance (in shares) at Sep. 30, 2021					(7,402,188)
Beginning balance at Jun. 30, 2021	$ 1,613	3,434,224	(2,433,553)	(3,044)	$ (85,419)	913,821
Beginning balance (in shares) at Jun. 30, 2021	161,339,554
Treasury stock, common shares, Beginning balance (in shares) at Jun. 30, 2021					(7,278,449)
Increase (Decrease) in Stockholders' Equity
Treasury stock purchased					$ (663)	(663)
Treasury stock purchased (in shares)					(92,540)
Cash dividends			(22,506)			(22,506)
Shares issued under employee stock purchase plan ("ESPP")		175				175
Shares issued under employee stock purchase plan ("ESPP") (in shares)	22,425
Stock-based compensation, net of forfeitures	$ 1	2,899				2,900
Stock-based compensation, net of forfeitures (in shares)	97,426				(31,199)
Comprehensive income (loss)
Net income			9,304			9,304
Other comprehensive income				1,016		1,016
Ending balance at Sep. 30, 2021	$ 1,614	3,437,298	(2,446,755)	(2,028)	$ (86,082)	904,047
Ending balance (in shares) at Sep. 30, 2021	161,459,405
Treasury stock, common shares, Ending balance (in shares) at Sep. 30, 2021					(7,402,188)
Beginning balance at Dec. 31, 2021	$ 1,615	3,440,059	(2,463,114)	(984)	$ (86,138)	$ 891,438
Beginning balance (in shares) at Dec. 31, 2021	161,482,852
Treasury stock, common shares, Beginning balance (in shares) at Dec. 31, 2021					(7,417,401)	(7,417,401)
Increase (Decrease) in Stockholders' Equity
Treasury stock purchased					$ (2,397)	$ (2,397)
Treasury stock purchased (in shares)					(276,342)
Cash dividends			(67,726)			(67,726)
Shares issued under employee stock purchase plan ("ESPP")		462				462
Shares issued under employee stock purchase plan ("ESPP") (in shares)	66,236
Stock-based compensation, net of forfeitures	$ 14	9,021				9,035
Stock-based compensation, net of forfeitures (in shares)	1,416,672				(107,407)
Net proceeds from issuance of common stock	$ 4	4,178				4,182
Net proceeds from issuance of common stock (in shares)	447,020
Comprehensive income (loss)
Net income			33,838			33,838
Other comprehensive income				$ 984		984
Ending balance at Sep. 30, 2022	$ 1,633	3,453,720	(2,497,002)		$ (88,535)	$ 869,816
Ending balance (in shares) at Sep. 30, 2022	163,412,780
Treasury stock, common shares, Ending balance (in shares) at Sep. 30, 2022					(7,801,150)	(7,801,150)
Beginning balance at Jun. 30, 2022	$ 1,633	3,450,603	(2,489,814)		$ (88,504)	$ 873,918
Beginning balance (in shares) at Jun. 30, 2022	163,385,390
Treasury stock, common shares, Beginning balance (in shares) at Jun. 30, 2022					(7,740,919)
Increase (Decrease) in Stockholders' Equity
Treasury stock purchased					$ (31)	(31)
Treasury stock purchased (in shares)					(3,636)
Cash dividends			(22,559)			(22,559)
Shares issued under employee stock purchase plan ("ESPP")		167				167
Shares issued under employee stock purchase plan ("ESPP") (in shares)	27,390
Stock-based compensation, net of forfeitures		2,998				2,998
Stock-based compensation, net of forfeitures (in shares)					(56,595)
Net proceeds from issuance of common stock		(48)				(48)
Comprehensive income (loss)
Net income			15,371			15,371
Ending balance at Sep. 30, 2022	$ 1,633	$ 3,453,720	$ (2,497,002)		$ (88,535)	$ 869,816
Ending balance (in shares) at Sep. 30, 2022	163,412,780
Treasury stock, common shares, Ending balance (in shares) at Sep. 30, 2022					(7,801,150)	(7,801,150)