Allowance for Loan and Lease Losses - Activity in Allowance for Loan and Lease Losses (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	$ 15,539	$ 14,153	$ 15,242
Collectively	1,782,486	1,748,412	1,735,747
Total Financing Receivables	1,798,025	1,762,565	1,750,989
Real Estate Sector [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	13,753	12,746	13,348
Collectively	1,387,435	1,389,368	1,460,502
Total Financing Receivables	1,401,188	1,402,114	1,473,850
Agricultural Sector [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	5	5	6
Collectively	49,194	48,031	52,080
Total Financing Receivables	49,199	48,036	52,086
Commercial and Industrial and Mortgage Warehouse Sector [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	1,405	977	1,099
Collectively	339,193	303,658	215,698
Total Financing Receivables	340,598	304,635	216,797
Consumer Loans Sector [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually	376	425	789
Collectively	6,664	7,355	7,467
Total Financing Receivables	$ 7,040	$ 7,780	$ 8,256

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- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524

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- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ References

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- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=118952595&loc=d3e4428-111522

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