Loans Receivable - Loan Origination/Risk Management (Details) $ in Thousands	3 Months Ended
Mar. 31, 2021 USD ($) segment	Dec. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accrued interest receivable	$ 19,447	$ 19,418
Number of loan segments \| segment	4
Loans receivable	$ 4,595,869	4,468,647
Allowance for credit losses on loans	64,225	70,185	$ 47,540	$ 36,171
Loans and Leases Receivable, Net Amount	4,531,644	4,398,462
Financing Receivable, Unamortized Purchase Premium (Discount)	(5,501)	(6,575)
Financing Receivable, Unamortized Loan Fee (Cost) and Purchase Premium (Discount)	(24,017)	(15,458)
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accrued interest receivable	16,000	15,800
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	3,889,421	3,715,206
Allowance for credit losses on loans	45,204	49,608	27,866	23,933
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	693,539	733,098
Allowance for credit losses on loans	21,770	30,010	13,900	11,739
Commercial Portfolio Segment [Member] \| Owner Occupied Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	881,168	856,684
Allowance for credit losses on loans	10,464	9,486	6,216	4,512
Commercial Portfolio Segment [Member] \| Non Owner Occupied Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	1,427,953	1,410,303
Allowance for credit losses on loans	12,970	10,112	7,750	7,682
Commercial Portfolio Segment [Member] \| Paycheck Protection Program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	886,761	715,121
Allowance for credit losses on loans	0	0	0	0
Commercial Portfolio Segment [Member] \| SBA PPP Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	886,761	715,121
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	114,856	122,756
Allowance for credit losses on loans	1,402	1,591	3,026	1,458
Real Estate Construction and Land Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	297,693	305,713
Allowance for credit losses on loans	13,271	13,092	12,308	3,060
Real Estate Construction and Land Development \| One-to-four Family Real Estate Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	79,878	78,259
Allowance for credit losses on loans	2,048	1,951	864	1,455
Real Estate Construction and Land Development \| Five or More Family Residential and Commercial Properties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	217,815	227,454
Allowance for credit losses on loans	11,223	11,141	11,444	1,605
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	293,899	324,972
Allowance for credit losses on loans	$ 4,348	$ 5,894	$ 4,340	$ 6,821

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Amount of unamortized loan commitment, origination, and other fees (costs) and purchase premium (discount) on financing receivable. Excludes financing receivable covered under loss sharing agreement.

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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

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Amount, before allowance for credit loss, of financing receivable.

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