Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), net [Member]	Treasury Stock [Member]
Beginning balance at Dec. 31, 2018	$ 975,389	$ 113,915	$ 492,273	$ 511,409	$ (11,341)	$ (130,867)
Beginning balance, shares at Dec. 31, 2018		98,518,668
Net Income	24,589			24,589
Other comprehensive income (loss)	7,239				7,239
Dividends, declared (USD per share)	(9,862)			(9,862)
Treasury stock acquired	(2,074)					(2,074)
Treasury stock acquired, shares		(159,562)
Stock Issued During Period, Value, Treasury Stock Reissued	2,531		941	0		1,590
Stock Issued During Period, Shares, Treasury Stock Reissued		188,700
Restricted stock	207	$ 0	450	0		(243)
Restricted stock, shares		78,000
Stock Issued During Period, Value, Treasury Stock Reissued	2,531
Ending balance at Mar. 31, 2019	998,019	$ 113,915	493,664	526,136	(4,102)	(131,594)
Ending balance, shares at Mar. 31, 2019		98,625,806
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	98,518,668	98,311,840
Net Income	$ 4,727			4,727
Other comprehensive income (loss)	11,773				11,773
Dividends, declared (USD per share)	(10,819)			(10,819)
Treasury stock acquired	(5,220)					(5,220)
Treasury stock acquired, shares		(430,896)
Stock Issued During Period, Value, Treasury Stock Reissued	1,594		444	0		1,150
Stock Issued During Period, Shares, Treasury Stock Reissued		134,452
Restricted stock	204	$ 0	0	0		204
Restricted stock, shares		0
Stock Issued During Period, Value, Treasury Stock Reissued	1,594
Ending balance at Mar. 31, 2020	$ 1,057,924	$ 113,915	$ 494,181	$ 571,256	$ 17,352	$ (138,780)
Ending balance, shares at Mar. 31, 2020	98,015,396	98,015,396