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Loans and Allowance for Credit Losses - Financing Receivable, Allowance for Credit Loss (Details) - USD ($) $ in Thousands		12 Months Ended
	Jan. 01, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Balance at beginning of period	$ 55,743	$ 55,743
Provision for Loan and Lease Losses		(6,700)	$ 15,871	$ 6,150
Balance at end of period		60,754	55,743
Allowance for unfunded commitment
Balance at beginning of period	0	0
Provision (credit) charged to expense		939
Balance at end of period	8,690	9,629	0
CECL adoption \| Allowance for unfunded commitment
Provision for Loan and Lease Losses	8,690
Loans Receivable
Balance at beginning of period			40,294	38,409
Provision (credit) charged to expense				6,150
Losses charged off				(8,062)
Recoveries				3,797
Balance at end of period				40,294
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			713	929
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			54,350	38,704
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses			680	661
Financing Receivable, Individually Evaluated for Impairment			9,048	10,267
Financing Receivable, Collectively Evaluated for Impairment			5,117,838	4,914,573
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model			98,643	127,206
Loans Receivable \| Allowance for credit losses
Balance at beginning of period	55,743	55,743	40,294
Provision (credit) charged to expense		(6,700)	15,871
Losses charged off		(2,621)	(3,294)
Recoveries		2,737	2,872
Balance at end of period	67,338	60,754	55,743	40,294
Loans Receivable \| CECL adoption \| Allowance for credit losses
Provision (credit) charged to expense	11,595
Commercial Real Estate
Balance at beginning of period			24,334	19,803
Provision (credit) charged to expense				4,651
Losses charged off				(144)
Recoveries				24
Balance at end of period				24,334
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			445	517
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			32,937	23,570
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses			325	247
Financing Receivable, Individually Evaluated for Impairment			3,438	4,020
Financing Receivable, Collectively Evaluated for Impairment			1,550,239	1,490,152
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model			24,613	29,158
Commercial Real Estate \| Allowance for unfunded commitment
Balance at beginning of period	0	0
Provision (credit) charged to expense		13
Balance at end of period	354	367	0
Commercial Real Estate \| Allowance for credit losses
Balance at beginning of period	33,707	33,707	24,334
Provision (credit) charged to expense		(2,478)	9,343
Losses charged off		(142)	(43)
Recoveries		48	73
Balance at end of period	31,176	28,604	33,707	24,334
Commercial Real Estate \| CECL adoption \| Allowance for unfunded commitment
Provision for Loan and Lease Losses	354
Commercial Real Estate \| CECL adoption \| Allowance for credit losses
Provision (credit) charged to expense	(2,531)
Commercial construction
Balance at beginning of period			3,076	3,105
Provision (credit) charged to expense				22
Losses charged off				(101)
Recoveries				50
Balance at end of period				3,076
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			3,378	2,940
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses			143	136
Financing Receivable, Collectively Evaluated for Impairment			1,266,847	1,363,292
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model			2,551	3,606
Commercial construction \| Allowance for unfunded commitment
Balance at beginning of period	0	0
Provision (credit) charged to expense		(2)
Balance at end of period	910	908	0
Commercial construction \| Allowance for credit losses
Balance at beginning of period	3,521	3,521	3,076
Provision (credit) charged to expense		575	242
Losses charged off		(154)	(1)
Recoveries		20	204
Balance at end of period	2,356	2,797	3,521	3,076
Commercial construction \| CECL adoption \| Allowance for unfunded commitment
Provision for Loan and Lease Losses	910
Commercial construction \| CECL adoption \| Allowance for credit losses
Provision (credit) charged to expense	(1,165)
One- to four-family residential construction
Balance at beginning of period			4,339	3,122
Provision (credit) charged to expense				1,625
Losses charged off				(534)
Recoveries				126
Balance at end of period				4,339
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			90	198
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			4,382	3,973
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses			64	168
Financing Receivable, Individually Evaluated for Impairment			3,546	2,960
Financing Receivable, Collectively Evaluated for Impairment			655,146	554,450
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model			57,113	74,562
One- to four-family residential construction \| Allowance for unfunded commitment
Balance at beginning of period	0	0
Provision (credit) charged to expense		(230)
Balance at end of period	917	687	0
One- to four-family residential construction \| Allowance for credit losses
Balance at beginning of period	4,536	4,536	4,339
Provision (credit) charged to expense			84
Losses charged off		(190)	(70)
Recoveries		485	183
Balance at end of period	9,069	9,364	4,536	4,339
One- to four-family residential construction \| CECL adoption \| Allowance for unfunded commitment
Provision for Loan and Lease Losses	917
One- to four-family residential construction \| CECL adoption \| Allowance for credit losses
Provision (credit) charged to expense	4,533
Other residential
Balance at beginning of period			5,153	4,713
Provision (credit) charged to expense				603
Losses charged off				(189)
Recoveries				26
Balance at end of period				5,153
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			9,282	5,101
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses			93	52
Financing Receivable, Collectively Evaluated for Impairment			1,021,145	866,006
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model			6,150	5,334
Other residential \| Allowance for unfunded commitment
Balance at beginning of period	0	0
Provision (credit) charged to expense		476
Balance at end of period	5,227	5,703	0
Other residential \| Allowance for credit losses
Balance at beginning of period	9,375	9,375	5,153
Provision (credit) charged to expense		(4,797)	4,042
Recoveries		92	180
Balance at end of period	15,207	10,502	9,375	5,153
Other residential \| CECL adoption \| Allowance for unfunded commitment
Provision for Loan and Lease Losses	5,227
Other residential \| CECL adoption \| Allowance for credit losses
Provision (credit) charged to expense	5,832
Commercial business
Balance at beginning of period			1,355	1,568
Provision (credit) charged to expense				(309)
Losses charged off				(371)
Recoveries				467
Balance at end of period				1,355
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			14	13
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			2,331	1,306
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses			45	36
Financing Receivable, Individually Evaluated for Impairment			167	1,286
Financing Receivable, Collectively Evaluated for Impairment			384,734	325,112
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model			2,549	3,356
Commercial business \| Allowance for unfunded commitment
Balance at beginning of period	0	0
Provision (credit) charged to expense		647
Balance at end of period	935	1,582	0
Commercial business \| Allowance for credit losses
Balance at beginning of period	2,390	2,390	1,355
Provision (credit) charged to expense			914
Losses charged off		(81)	(28)
Recoveries		334	149
Balance at end of period	3,889	4,142	2,390	1,355
Commercial business \| CECL adoption \| Allowance for unfunded commitment
Provision for Loan and Lease Losses	935
Commercial business \| CECL adoption \| Allowance for credit losses
Provision (credit) charged to expense	1,499
Consumer
Balance at beginning of period			2,037	6,098
Provision (credit) charged to expense				(442)
Losses charged off				(6,723)
Recoveries				3,104
Balance at end of period				2,037
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			164	201
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			2,040	1,814
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses			10	22
Financing Receivable, Individually Evaluated for Impairment			1,897	2,001
Financing Receivable, Collectively Evaluated for Impairment			239,727	315,561
All Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Not Accounted for Using Income Recognition Model			5,667	11,190
Consumer \| Allowance for unfunded commitment
Balance at beginning of period	0	0
Provision (credit) charged to expense		35
Balance at end of period	347	382	0
Consumer \| Allowance for credit losses
Balance at beginning of period	2,214	2,214	2,037
Provision (credit) charged to expense			1,246
Losses charged off		(2,054)	(3,152)
Recoveries		1,758	2,083
Balance at end of period	5,641	$ 5,345	$ 2,214	$ 2,037
Consumer \| CECL adoption \| Allowance for unfunded commitment
Provision for Loan and Lease Losses	347
Consumer \| CECL adoption \| Allowance for credit losses
Provision (credit) charged to expense	$ 3,427