Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Paid-in Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning balance at Dec. 31, 2019		$ 1,751	$ 289,422	$ 2,141,302	$ (665)	$ (259,742)	$ (1,149,411)
Beginning balance (in shares) at Dec. 31, 2019		110,780
Increase (Decrease) in Stockholders' Equity
Net issuance of treasury stock for vested restricted stock units (in shares)		365
Repurchases of common stock (in shares)		(259)
Stock compensation expense			9,056
Net issuance of treasury stock for vested restricted stock units			(1,839)				(4,382)
Net income	$ 135,772			135,772
Dividends declared on common stock				(27,018)
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Other comprehensive income (loss)						(37,618)
Repurchases of common stock							(6,934)
Ending balance at Jun. 30, 2020	$ 1,089,694	$ 1,751	296,639	2,249,391		(297,360)	(1,160,727)
Ending balance (in shares) at Jun. 30, 2020		110,886
Increase (Decrease) in Stockholders' Equity
Dividends declared on common stock per share (usd per share)	$ 0.24
Beginning balance at Mar. 31, 2020		$ 1,751	292,283	2,184,691		(297,697)	(1,160,453)
Beginning balance (in shares) at Mar. 31, 2020		110,834
Increase (Decrease) in Stockholders' Equity
Net issuance of treasury stock for vested restricted stock units (in shares)		52
Repurchases of common stock (in shares)		0
Stock compensation expense			4,573
Net issuance of treasury stock for vested restricted stock units			(217)				(274)
Net income	$ 78,172			78,172
Dividends declared on common stock				(13,472)
Other comprehensive income (loss)						337
Repurchases of common stock							0
Ending balance at Jun. 30, 2020	$ 1,089,694	$ 1,751	296,639	2,249,391		(297,360)	(1,160,727)
Ending balance (in shares) at Jun. 30, 2020		110,886
Increase (Decrease) in Stockholders' Equity
Dividends declared on common stock per share (usd per share)	$ 0.12
Beginning balance at Dec. 31, 2020	$ 1,252,873	$ 1,751	306,363	2,395,395		(260,953)	(1,189,683)
Beginning balance (in shares) at Dec. 31, 2020		110,057
Increase (Decrease) in Stockholders' Equity
Net issuance of treasury stock for vested restricted stock units (in shares)		351
Repurchases of common stock (in shares)		0
Stock compensation expense			10,337
Net issuance of treasury stock for vested restricted stock units			(1,827)				(6,711)
Net income	167,757			167,757
Dividends declared on common stock				(31,369)
Other comprehensive income (loss)						(2,480)
Repurchases of common stock							0
Ending balance at Jun. 30, 2021	$ 1,388,580	$ 1,751	314,873	2,531,783		(263,433)	(1,196,394)
Ending balance (in shares) at Jun. 30, 2021		110,408
Increase (Decrease) in Stockholders' Equity
Dividends declared on common stock per share (usd per share)	$ 0.28
Beginning balance at Mar. 31, 2021		$ 1,751	309,635	2,452,996		(291,806)	(1,196,221)
Beginning balance (in shares) at Mar. 31, 2021		110,386
Increase (Decrease) in Stockholders' Equity
Net issuance of treasury stock for vested restricted stock units (in shares)		22
Repurchases of common stock (in shares)		0
Stock compensation expense			5,327
Net issuance of treasury stock for vested restricted stock units			(89)				(173)
Net income	$ 94,476			94,476
Dividends declared on common stock				(15,689)
Other comprehensive income (loss)						28,373
Repurchases of common stock							0
Ending balance at Jun. 30, 2021	$ 1,388,580	$ 1,751	$ 314,873	$ 2,531,783		$ (263,433)	$ (1,196,394)
Ending balance (in shares) at Jun. 30, 2021		110,408
Increase (Decrease) in Stockholders' Equity
Dividends declared on common stock per share (usd per share)	$ 0.14