Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	CUMULATIVE EFFECT, PERIOD OF ADOPTION, ADJUSTMENT [Member]	Common Stock [Member]	CAPITAL SURPLUS [Member]	RETAINED EARNINGS [Member]	RETAINED EARNINGS [Member] CUMULATIVE EFFECT, PERIOD OF ADOPTION, ADJUSTMENT [Member]	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)
Balance at beginning of period, Shares at Dec. 31, 2019			32,694,268
Balance at beginning of period at Dec. 31, 2019			$ 32,694	$ 153,353	$ 815,488	$ 2,270	$ 3,454
Accounting Standards Update Extensible List		ASC 326 [Member]			ASC 326 [Member]
Shares issued for stock options, Shares			84,868
Shares issued for stock options, Value			$ 85	1,705
Net income	$ 99,586				$ 99,586
Net change							3,976
Dividends on common stock					(43,144)
Stock-based compensation arrangements				1,516
Shares acquired and canceled, Shares			(59,284)
Shares acquired and canceled, Value			$ (59)		(3,039)
Balance at end of period, Shares at Dec. 31, 2020	32,719,852		32,719,852
Balance at end of period at Dec. 31, 2020	$ 1,067,885		$ 32,720	156,574	871,161		7,430
Shares issued for stock options, Shares			95,562
Shares issued for stock options, Value			$ 95	2,165
Net income	$ 167,630				167,630
Net change							(5,280)
Dividends on common stock					(45,752)
Net cash settlement of options				(958)	(4,521)
Stock-based compensation arrangements				2,133
Shares acquired and canceled, Shares			(212,296)
Shares acquired and canceled, Value			$ (212)		(11,451)
Balance at end of period, Shares at Dec. 31, 2021	32,603,118		32,603,118
Balance at end of period at Dec. 31, 2021	$ 1,171,734		$ 32,603	159,914	977,067		2,150
Shares issued for stock options, Shares			272,442
Shares issued for stock options, Value			$ 273	7,376
Net income	$ 193,100				193,100
Net change							(73,713)
Dividends on common stock					(49,875)
Stock-based compensation arrangements				1,941
Balance at end of period, Shares at Dec. 31, 2022	32,875,560		32,875,560
Balance at end of period at Dec. 31, 2022	$ 1,250,836		$ 32,876	$ 169,231	$ 1,120,292		$ (71,563)