Allowance for Credit Losses and Allowance for Unfunded Commitments and Letters of Credit (Allowance for Credit Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	$ 154,871	$ 142,785	$ 154,871	$ 142,785	$ 149,935	$ 155,578	$ 142,988	$ 149,140
Financing Receivable, Allowance for Credit Loss, Writeoff	(1,432)	(1,479)	(3,969)	(6,885)
Financing Receivable, Allowance for Credit Loss, Recovery	1,118	1,276	3,712	6,830
Provision (recapture) for credit losses	5,250	0	(450)	(6,300)
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	57,381	51,752	57,381	51,752	57,119	61,254	53,250	68,934
Financing Receivable, Allowance for Credit Loss, Writeoff	0	0	(299)	(316)
Financing Receivable, Allowance for Credit Loss, Recovery	11	518	172	570
Provision (recapture) for credit losses	251	(2,016)	(3,746)	(17,436)
Commercial Business [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	54,085	55,561	54,085	55,561	51,985	54,712	57,554	45,250
Financing Receivable, Allowance for Credit Loss, Writeoff	(295)	(1,183)	(2,019)	(5,493)
Financing Receivable, Allowance for Credit Loss, Recovery	482	328	1,570	4,416
Provision (recapture) for credit losses	1,913	(1,138)	(178)	11,388
Agriculture [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	9,433	8,965	9,433	8,965	8,895	8,148	7,920	9,052
Financing Receivable, Allowance for Credit Loss, Writeoff	(706)	0	(730)	(122)
Financing Receivable, Allowance for Credit Loss, Recovery	98	6	247	23
Provision (recapture) for credit losses	1,146	1,039	1,768	12
Construction [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	8,147	6,367	8,147	6,367	5,914	5,397	6,559	7,636
Financing Receivable, Allowance for Credit Loss, Writeoff	0	0	0	0
Financing Receivable, Allowance for Credit Loss, Recovery	9	8	153	575
Provision (recapture) for credit losses	2,224	(200)	2,597	(1,844)
One-to-Four Family Residential [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	24,014	18,855	24,014	18,855	24,626	24,123	16,519	16,875
Financing Receivable, Allowance for Credit Loss, Writeoff	0	0	(3)	(146)
Financing Receivable, Allowance for Credit Loss, Recovery	331	203	916	757
Provision (recapture) for credit losses	(943)	2,133	(1,022)	1,369
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	1,811	1,285	1,811	1,285	$ 1,396	$ 1,944	$ 1,186	$ 1,393
Financing Receivable, Allowance for Credit Loss, Writeoff	(431)	(296)	(918)	(808)
Financing Receivable, Allowance for Credit Loss, Recovery	187	213	654	489
Provision (recapture) for credit losses	$ 659	$ 182	$ 131	$ 211