Loans and Allowance for Loan Losses - Financing Receivable, Allowance for Credit Loss (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Provision for Loan and Lease Losses	$ 15,871	$ 6,150	$ 7,150
Loans Receivable
Provision for Loan and Lease Losses	55,743	40,294	38,409	$ 36,492
Financing Receivable, Credit Loss, Expense (Reversal)	15,871	6,150	7,150
Financing Receivable, Allowance for Credit Loss, Writeoff	(3,294)	(8,062)	(11,356)
Accounts Receivable, Allowance for Credit Loss, Recovery	2,872	3,797	6,123
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	713	929	2,041
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	54,350	38,704	35,947
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	680	661	421
Financing Receivable, Individually Evaluated for Impairment	9,048	10,267	13,939
Financing Receivable, Collectively Evaluated for Impairment	5,117,838	4,914,573	4,811,661
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	98,643	127,206	167,651
Individually evaluated for impairment	713	929	2,041
Collectively evaluated for impairment	54,350	38,704	35,947
Individually evaluated for impairment	9,048	10,267	13,939
Collectively evaluated for impairment	5,117,838	4,914,573	4,811,661
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	98,643	127,206	167,651
Commercial Real Estate
Provision for Loan and Lease Losses	33,707	24,334	19,803	18,639
Financing Receivable, Credit Loss, Expense (Reversal)	9,343	4,651	1,094
Financing Receivable, Allowance for Credit Loss, Writeoff	(43)	(144)	(102)
Accounts Receivable, Allowance for Credit Loss, Recovery	73	24	172
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	445	517	613
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	32,937	23,570	18,958
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	325	247	232
Financing Receivable, Individually Evaluated for Impairment	3,438	4,020	3,501
Financing Receivable, Collectively Evaluated for Impairment	1,550,239	1,490,152	1,367,934
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	24,613	29,158	33,620
Individually evaluated for impairment	445	517	613
Collectively evaluated for impairment	32,937	23,570	18,958
Individually evaluated for impairment	3,438	4,020	3,501
Collectively evaluated for impairment	1,550,239	1,490,152	1,367,934
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	24,613	29,158	33,620
Commercial construction
Provision for Loan and Lease Losses	3,521	3,076	3,105	1,767
Financing Receivable, Credit Loss, Expense (Reversal)	242	22	1,031
Financing Receivable, Allowance for Credit Loss, Writeoff	(1)	(101)	(87)
Accounts Receivable, Allowance for Credit Loss, Recovery	204	50	394
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	3,378	2,940	3,029
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	143	136	76
Financing Receivable, Individually Evaluated for Impairment			14
Financing Receivable, Collectively Evaluated for Impairment	1,266,847	1,363,292	1,461,644
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	2,551	3,606	4,093
Collectively evaluated for impairment	3,378	2,940	3,029
Individually evaluated for impairment			14
Collectively evaluated for impairment	1,266,847	1,363,292	1,461,644
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	2,551	3,606	4,093
One- to four-family residential construction
Provision for Loan and Lease Losses	4,536	4,339	3,122	2,108
Financing Receivable, Credit Loss, Expense (Reversal)	84	1,625	742
Financing Receivable, Allowance for Credit Loss, Writeoff	(70)	(534)	(62)
Accounts Receivable, Allowance for Credit Loss, Recovery	183	126	334
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	90	198	694
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	4,382	3,973	2,392
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	64	168	36
Financing Receivable, Individually Evaluated for Impairment	3,546	2,960	6,116
Financing Receivable, Collectively Evaluated for Impairment	655,146	554,450	433,209
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	57,113	74,562	93,841
Individually evaluated for impairment	90	198	694
Collectively evaluated for impairment	4,382	3,973	2,392
Individually evaluated for impairment	3,546	2,960	6,116
Collectively evaluated for impairment	655,146	554,450	433,209
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	57,113	74,562	93,841
Other residential
Provision for Loan and Lease Losses	9,375	5,153	4,713	2,839
Financing Receivable, Credit Loss, Expense (Reversal)	4,042	603	1,982
Financing Receivable, Allowance for Credit Loss, Writeoff		(189)	(525)
Accounts Receivable, Allowance for Credit Loss, Recovery	180	26	417
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	9,282	5,101	4,681
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	93	52	32
Financing Receivable, Collectively Evaluated for Impairment	1,021,145	866,006	784,894
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	6,150	5,334	12,790
Collectively evaluated for impairment	9,282	5,101	4,681
Collectively evaluated for impairment	1,021,145	866,006	784,894
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	6,150	5,334	12,790
Commercial business
Provision for Loan and Lease Losses	2,390	1,355	1,568	3,581
Financing Receivable, Credit Loss, Expense (Reversal)	914	(309)	(1,613)
Financing Receivable, Allowance for Credit Loss, Writeoff	(28)	(371)	(1,155)
Accounts Receivable, Allowance for Credit Loss, Recovery	149	467	755
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	14	13	309
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	2,331	1,306	1,247
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	45	36	12
Financing Receivable, Individually Evaluated for Impairment	167	1,286	1,844
Financing Receivable, Collectively Evaluated for Impairment	384,734	325,112	334,214
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	2,549	3,356	4,347
Individually evaluated for impairment	14	13	309
Collectively evaluated for impairment	2,331	1,306	1,247
Individually evaluated for impairment	167	1,286	1,844
Collectively evaluated for impairment	384,734	325,112	334,214
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	2,549	3,356	4,347
Consumer other
Provision for Loan and Lease Losses	2,214	2,037	6,098	$ 7,558
Financing Receivable, Credit Loss, Expense (Reversal)	1,246	(442)	3,914
Financing Receivable, Allowance for Credit Loss, Writeoff	(3,152)	(6,723)	(9,425)
Accounts Receivable, Allowance for Credit Loss, Recovery	2,083	3,104	4,051
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	164	201	425
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	2,040	1,814	5,640
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses	10	22	33
Financing Receivable, Individually Evaluated for Impairment	1,897	2,001	2,464
Financing Receivable, Collectively Evaluated for Impairment	239,727	315,561	429,766
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	5,667	11,190	18,960
Individually evaluated for impairment	164	201	425
Collectively evaluated for impairment	2,040	1,814	5,640
Individually evaluated for impairment	1,897	2,001	2,464
Collectively evaluated for impairment	239,727	315,561	429,766
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model	$ 5,667	$ 11,190	$ 18,960

The carrying amount as of the balance sheet date of loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer, for which it was deemed probable at acquisition that the investor would be unable to collect all contractually required payments, and to which the income recognition total model was not applied.

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Reserve for loans impairments recorded after acquisition as a result of current information and events which result in it being probable that estimated cash flows will be less than previously expected or because actual cash flows are less than cash flows previously expected. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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