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, 2018		$ 1,751	$ 276,062	$ 1,997,785	$ (593)	$ (268,808)	$ (1,125,525)
Beginning balance (in shares) at Dec. 31, 2018		110,430
Increase (Decrease) in Stockholders' Equity
Net issuance of treasury stock for vested restricted stock units (in shares)		746
Repurchases of common stock (in shares)		(408)
Repurchases of common stock							(12,112)
Stock compensation expense			12,669
Net issuance of treasury stock for vested restricted stock units			(3,670)				(11,582)
Net income	$ 158,970			158,970
Dividends declared on common stock				(37,302)
Other comprehensive income (loss)						(19,115)
Ending balance at Sep. 30, 2019	$ 968,530	$ 1,751	285,061	2,118,860		(287,923)	(1,149,219)
Ending balance (in shares) at Sep. 30, 2019		110,768
Increase (Decrease) in Stockholders' Equity
Dividends per share (usd per share)	$ 0.33
Beginning balance at Jun. 30, 2019		$ 1,751	280,636	2,049,995		(265,373)	(1,137,107)
Beginning balance (in shares) at Jun. 30, 2019		111,176
Increase (Decrease) in Stockholders' Equity
Net issuance of treasury stock for vested restricted stock units (in shares)		0
Repurchases of common stock (in shares)		(408)
Repurchases of common stock							(12,112)
Stock compensation expense			4,425
Net issuance of treasury stock for vested restricted stock units			0				0
Net income	$ 81,274			81,274
Dividends declared on common stock				(12,409)
Other comprehensive income (loss)						(22,550)
Ending balance at Sep. 30, 2019	$ 968,530	$ 1,751	285,061	2,118,860		(287,923)	(1,149,219)
Ending balance (in shares) at Sep. 30, 2019		110,768
Increase (Decrease) in Stockholders' Equity
Dividends per share (usd per share)	$ 0.11
Beginning balance at Dec. 31, 2019	$ 1,023,322	$ 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)
Repurchases of common stock							(6,934)
Stock compensation expense			13,880
Net issuance of treasury stock for vested restricted stock units			(1,839)				(4,382)
Net income	248,623			248,623
Dividends declared on common stock				(40,532)
Other comprehensive income (loss)						(12,610)
Ending balance at Sep. 30, 2020	$ 1,218,863	$ 1,751	301,463	2,348,728		(272,352)	(1,160,727)
Ending balance (in shares) at Sep. 30, 2020		110,886
Increase (Decrease) in Stockholders' Equity
Dividends per share (usd per share)	$ 0.36
Beginning balance at Jun. 30, 2020		$ 1,751	296,639	2,249,391		(297,360)	(1,160,727)
Beginning balance (in shares) at Jun. 30, 2020		110,886
Increase (Decrease) in Stockholders' Equity
Net issuance of treasury stock for vested restricted stock units (in shares)		0
Repurchases of common stock (in shares)		0
Repurchases of common stock							0
Stock compensation expense			4,824
Net issuance of treasury stock for vested restricted stock units			0				0
Net income	$ 112,851			112,851
Dividends declared on common stock				(13,514)
Other comprehensive income (loss)						25,008
Ending balance at Sep. 30, 2020	$ 1,218,863	$ 1,751	$ 301,463	$ 2,348,728		$ (272,352)	$ (1,160,727)
Ending balance (in shares) at Sep. 30, 2020		110,886
Increase (Decrease) in Stockholders' Equity
Dividends per share (usd per share)	$ 0.12