Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Previously Reported [Member]	Common Stock [Member]	Common Stock [Member] Previously Reported [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Previously Reported [Member]	Retained Earnings [Member]	Retained Earnings [Member] Previously Reported [Member]	Accumulated Other Comprehensive Income (Loss), net [Member]	Accumulated Other Comprehensive Income (Loss), net [Member] Previously Reported [Member]	Treasury Stock [Member]	Treasury Stock [Member] Previously Reported [Member]
Beginning balance at Dec. 31, 2019	$ 1,055,665		$ 113,915		$ 493,737		$ 577,348		$ 5,579		$ (134,914)
Beginning balance, shares at Dec. 31, 2019			98,311,840
Net Income	47,764						47,764
Other comprehensive income (loss)	13,532								13,532
Dividends, declared (USD per share)	(32,408)						(32,408)
Treasury stock acquired	(14,373)										(14,373)
Treasury stock acquired, shares			(1,638,812)
Stock Issued During Period, Value, Treasury Stock Reissued	1,816				458		0				1,358
Stock Issued During Period, Shares, Treasury Stock Reissued			158,453
Restricted stock	835		$ 0		487		0				348
Restricted stock, shares			93,300
Stock Issued During Period, Value, Treasury Stock Reissued	1,594
Ending balance at Sep. 30, 2020	$ 1,072,831		$ 113,915		494,682		592,704		19,111		(147,581)
Ending balance, shares at Sep. 30, 2020			96,924,781
Cash Dividends Declared per Common Share (in dollars per share)	$ 0.330
Beginning balance at Jun. 30, 2020		$ 1,075,705		$ 113,915		$ 494,682		$ 584,312		$ 21,522		$ (138,726)
Beginning balance, shares at Jun. 30, 2020				98,132,697
Net Income	$ 19,186						19,186
Other comprehensive income (loss)	(2,411)								(2,411)
Dividends, declared (USD per share)	(10,794)						(10,794)
Treasury stock acquired	(9,153)										(9,153)
Treasury stock acquired, shares			(1,207,916)
Stock Issued During Period, Value, Treasury Stock Reissued	0				0		0				0
Stock Issued During Period, Shares, Treasury Stock Reissued			0
Restricted stock	298		$ 0		0		0				298
Restricted stock, shares			0
Ending balance at Sep. 30, 2020	$ 1,072,831		$ 113,915		494,682		592,704		19,111		(147,581)
Ending balance, shares at Sep. 30, 2020			96,924,781
Cash Dividends Declared per Common Share (in dollars per share)	$ 0.110
Beginning balance at Dec. 31, 2020	$ 1,068,617		$ 113,915		494,683		596,614		17,233		(153,828)
Beginning balance, shares at Dec. 31, 2020	96,130,751		96,130,751
Net Income	$ 103,481						103,481
Other comprehensive income (loss)	(13,717)								(13,717)
Dividends, declared (USD per share)	(32,673)						(32,673)
Treasury stock acquired	(15,985)										(15,985)
Treasury stock acquired, shares			(1,194,062)
Stock Issued During Period, Value, Treasury Stock Reissued	2,264				771		0				1,493
Stock Issued During Period, Shares, Treasury Stock Reissued			173,907
Restricted stock	868		$ 0		475		0				393
Restricted stock, shares			99,089
Stock Issued During Period, Value, Treasury Stock Reissued	2,042
Ending balance at Sep. 30, 2021	$ 1,112,855		$ 113,915		495,929		667,422		3,516		(167,927)
Ending balance, shares at Sep. 30, 2021	95,209,685		95,209,685
Cash Dividends Declared per Common Share (in dollars per share)	$ 0.340
Beginning balance at Jun. 30, 2021	$ 1,106,419		$ 113,915		495,899		644,362		7,115		(154,872)
Beginning balance, shares at Jun. 30, 2021			96,201,628
Net Income	34,092						34,092
Other comprehensive income (loss)	(3,599)								(3,599)
Dividends, declared (USD per share)	(11,032)						(11,032)
Treasury stock acquired	(13,327)										(13,327)
Treasury stock acquired, shares			(997,943)
Stock Issued During Period, Value, Treasury Stock Reissued	0				0		0				0
Stock Issued During Period, Shares, Treasury Stock Reissued			0
Restricted stock	302		$ 0		30		0				272
Restricted stock, shares			6,000
Ending balance at Sep. 30, 2021	$ 1,112,855		$ 113,915		$ 495,929		$ 667,422		$ 3,516		$ (167,927)
Ending balance, shares at Sep. 30, 2021	95,209,685		95,209,685
Cash Dividends Declared per Common Share (in dollars per share)	$ 0.115