Consolidated Statements of Changes in Shareholders' Equity - USD ($)	Total	Series A 3% Preferred Stock [Member]	Series B-1 8.48% Preferred Stock [Member]	Cumulative-Effect Adjustment [Member]	Adjusted Balance [Member]	Preferred Equity [Member]	Preferred Equity [Member] Adjusted Balance [Member]	Common Stock [Member]	Common Stock [Member] Adjusted Balance [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Adjusted Balance [Member]	Retained Earnings [Member]	Retained Earnings [Member] Series A 3% Preferred Stock [Member]	Retained Earnings [Member] Series B-1 8.48% Preferred Stock [Member]	Retained Earnings [Member] Cumulative-Effect Adjustment [Member]	Retained Earnings [Member] Adjusted Balance [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Adjusted Balance [Member]	Treasury Stock [Member]	Treasury Stock [Member] Adjusted Balance [Member]
Balance at Dec. 31, 2018	$ 396,293,000			$ (710,000)	$ 395,583,000	$ 17,328,000	$ 17,328,000	$ 161,000	$ 161,000	$ 122,704,000	$ 122,704,000	$ 279,867,000			$ (710,000)	$ 279,157,000	$ (21,281,000)	$ (21,281,000)	$ (2,486,000)	$ (2,486,000)
Comprehensive income:
Net income	48,862,000											48,862,000
Other comprehensive income (loss), net of tax	9,551,000																9,551,000
Reclassification of income tax effects												2,783,000					(2,783,000)
Common stock issued	1,151,000									1,151,000
Purchase of common stock for treasury	(293,000)																		293,000
Share-based compensation plans:
Share-based compensation	1,406,000									1,406,000
Restricted stock units released										(554,000)									554,000
Restricted stock awards issued, net										(165,000)									165,000
Stock awards	125,000									40,000									85,000
Cash dividends declared:
Preferred stock dividends per share		$ (4,000)	$ (1,457,000)										$ (4,000)	$ (1,457,000)
Common stock dividends per share	(15,977,000)											(15,977,000)
Balance at Dec. 31, 2019	438,947,000			$ (8,719,000)	$ 430,228,000	17,328,000	$ 17,328,000	161,000	$ 161,000	124,582,000	$ 124,582,000	313,364,000			$ (8,719,000)	$ 304,645,000	(14,513,000)	$ (14,513,000)	(1,975,000)	$ (1,975,000)
Comprehensive income:
Net income	38,332,000											38,332,000
Other comprehensive income (loss), net of tax	16,641,000																16,641,000
Purchase of common stock for treasury	(209,000)																		(209,000)
Share-based compensation plans:
Share-based compensation	1,333,000									1,333,000
Restricted stock units released										(511,000)									511,000
Restricted stock awards issued, net										(272,000)									272,000
Stock awards	165,000									(14,000)									179,000
Cash dividends declared:
Preferred stock dividends per share		(4,000)	(1,457,000)										(4,000)	(1,457,000)
Common stock dividends per share	(16,666,000)											(16,666,000)
Balance at Dec. 31, 2020	468,363,000					17,328,000		161,000		125,118,000		324,850,000					2,128,000		(1,222,000)
Comprehensive income:
Net income	77,697,000											77,697,000
Other comprehensive income (loss), net of tax	(15,335,000)																(15,335,000)		0
Common stock issued	301,000									3,000									298,000
Purchase of common stock for treasury	(9,235,000)																		(9,235,000)
Purchases of 8.48% preferred stock	(43,000)					36,000				(7,000)
Share-based compensation plans:
Share-based compensation	1,743,000									1,743,000
Restricted stock units released										(574,000)									574,000
Restricted stock awards issued, net										(223,000)									223,000
Stock awards	191,000									(45,000)									146,000
Cash dividends declared:
Preferred stock dividends per share		$ (4,000)	$ (1,456,000)										$ (4,000)	$ (1,456,000)
Common stock dividends per share	(17,080,000)											(17,080,000)
Balance at Dec. 31, 2021	$ 505,142,000					$ 17,292,000		$ 161,000		$ 126,105,000		$ 384,007,000					$ (13,207,000)		$ (9,216,000)