Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Series A 3% Preferred Stock [Member]	Series B-1 8.48% Preferred Stock [Member]	Preferred Equity [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Series A 3% Preferred Stock [Member]	Retained Earnings [Member] Series B-1 8.48% Preferred Stock [Member]	Accumulated Other Comprehensive income [Member]	Treasury Stock [Member]
Balance at Dec. 31, 2020	$ 468,363			$ 17,328	$ 161	$ 125,118	$ 324,850			$ 2,128	$ (1,222)
Comprehensive income:
Net income	20,710						20,710
Other comprehensive loss, net of tax	(12,700)									(12,700)	0
Common stock issued	301					3					298
Purchases of common stock for treasury	(5,963)										(5,963)
Purchases of 8.48% preferred stock	(6)			(6)
Share-based compensation plans:
Share-based compensation	216					216
Restricted stock units released						(446)					446
Cash dividends declared:
Preferred stock dividends per share		$ (1)	$ (364)					$ (1)	$ (364)
Common stock dividends per share	(4,272)						(4,272)
Balance at Mar. 31, 2021	466,284			17,322	161	124,891	340,923			(10,572)	(6,441)
Balance at Dec. 31, 2021	505,142			17,292	161	126,105	384,007			(13,207)	(9,216)
Comprehensive income:
Net income	14,983						14,983
Other comprehensive loss, net of tax	(53,887)									(53,887)
Purchases of common stock for treasury	(15,026)										(15,026)
Share-based compensation plans:
Share-based compensation	443					443
Restricted stock units released						(667)					667
Cash dividends declared:
Preferred stock dividends per share		$ (1)	$ (364)					$ (1)	$ (364)
Common stock dividends per share	(4,444)						(4,444)
Balance at Mar. 31, 2022	$ 446,846			$ 17,292	$ 161	$ 125,881	$ 394,181			$ (67,094)	$ (23,575)