Loans and Leases Receivable and Allowance for Credit Losses on Loans and Leases - Credit Ratings (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	$ 1,700,985	$ 1,515,239
Fiscal year before current year	1,249,900	1,599,431
Two years before current year	1,154,989	786,506
Three years before current year	620,329	1,055,134
Four years before current year	786,670	578,390
Prior	1,259,055	1,130,969
Revolving loans amortized cost basis	1,198,671	909,699
Revolving loans converted to term	0	0
Loans and leases receivable	7,970,599	7,575,368
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivable	6,042,396	5,960,549
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivable	1,928,203	1,614,819
Commercial loans and leases receivable | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	990,168	1,188,773
Fiscal year before current year	835,217	791,958
Two years before current year	701,421	663,454
Three years before current year	538,678	1,038,646
Four years before current year	777,019	538,340
Prior	1,109,633	994,535
Revolving loans amortized cost basis	1,090,260	744,843
Revolving loans converted to term	0	0
Loans and leases receivable	6,042,396	5,960,549
Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivable	1,369,876	1,761,301
Multi-family | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	126,265	150,835
Fiscal year before current year	132,433	23,716
Two years before current year	22,974	299,319
Three years before current year	237,557	590,608
Four years before current year	376,046	245,946
Prior	474,601	450,877
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	1,369,876	1,761,301
Multi-family | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	126,265	150,835
Fiscal year before current year	132,433	23,716
Two years before current year	22,974	299,319
Three years before current year	232,655	535,510
Four years before current year	331,909	227,296
Prior	422,484	420,809
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	1,268,720	1,657,485
Multi-family | Special mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	0
Two years before current year	0	0
Three years before current year	4,902	20,901
Four years before current year	2,773	10,394
Prior	18,029	26,708
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	25,704	58,003
Multi-family | Substandard | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	0
Two years before current year	0	0
Three years before current year	0	34,197
Four years before current year	41,364	8,256
Prior	34,088	3,360
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	75,452	45,813
Multi-family | Doubtful | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	0	0
Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivable	2,673,226	2,289,441
Commercial and industrial | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	587,400	752,438
Fiscal year before current year	394,979	381,057
Two years before current year	289,360	161,444
Three years before current year	111,324	122,807
Four years before current year	100,224	54,201
Prior	101,792	74,245
Revolving loans amortized cost basis	1,088,147	743,249
Revolving loans converted to term	0	0
Loans and leases receivable	2,673,226	2,289,441
Commercial and industrial | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	568,013	729,270
Fiscal year before current year	381,413	373,050
Two years before current year	276,126	141,943
Three years before current year	94,175	116,793
Four years before current year	93,126	45,367
Prior	94,554	71,502
Revolving loans amortized cost basis	1,067,761	717,007
Revolving loans converted to term	0	0
Loans and leases receivable	2,575,168	2,194,932
Commercial and industrial | Special mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	19,387	13,200
Fiscal year before current year	3,186	1,117
Two years before current year	5,750	436
Three years before current year	5,084	113
Four years before current year	0	516
Prior	210	21
Revolving loans amortized cost basis	13,171	17,524
Revolving loans converted to term	0	0
Loans and leases receivable	46,788	32,927
Commercial and industrial | Substandard | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	9,968
Fiscal year before current year	10,380	6,890
Two years before current year	7,484	19,065
Three years before current year	12,065	5,901
Four years before current year	7,098	8,318
Prior	7,028	2,722
Revolving loans amortized cost basis	7,215	8,718
Revolving loans converted to term	0	0
Loans and leases receivable	51,270	61,582
Commercial and industrial | Doubtful | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	0	0
Commercial real estate owner occupied
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivable	656,044	572,338
Commercial real estate owner occupied | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	153,865	82,343
Fiscal year before current year	83,893	176,289
Two years before current year	148,946	82,114
Three years before current year	72,532	80,040
Four years before current year	70,106	48,741
Prior	126,030	102,070
Revolving loans amortized cost basis	672	741
Revolving loans converted to term	0	0
Loans and leases receivable	656,044	572,338
Commercial real estate owner occupied | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	153,865	82,343
Fiscal year before current year	83,893	168,977
Two years before current year	142,061	72,615
Three years before current year	62,723	70,642
Four years before current year	59,116	46,510
Prior	114,479	91,798
Revolving loans amortized cost basis	672	741
Revolving loans converted to term	0	0
Loans and leases receivable	616,809	533,626
Commercial real estate owner occupied | Special mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	4,464
Two years before current year	0	0
Three years before current year	318	9,056
Four years before current year	2,058	0
Prior	579	555
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	2,955	14,075
Commercial real estate owner occupied | Substandard | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	2,848
Two years before current year	6,885	9,499
Three years before current year	9,491	342
Four years before current year	8,932	2,231
Prior	10,972	9,717
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	36,280	24,637
Commercial real estate owner occupied | Doubtful | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	0	0
Commercial real estate non-owner occupied
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivable	1,144,643	1,196,564
Commercial real estate non-owner occupied | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	109,585	183,225
Fiscal year before current year	179,514	105,430
Two years before current year	114,802	115,623
Three years before current year	112,396	245,191
Four years before current year	230,643	179,752
Prior	397,703	367,343
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	1,144,643	1,196,564
Commercial real estate non-owner occupied | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	109,585	143,231
Fiscal year before current year	157,702	105,430
Two years before current year	103,630	97,882
Three years before current year	66,994	157,835
Four years before current year	166,532	155,168
Prior	324,225	313,559
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	928,668	973,105
Commercial real estate non-owner occupied | Special mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	39,994
Fiscal year before current year	21,812	0
Two years before current year	11,172	0
Three years before current year	9,445	66,745
Four years before current year	43,500	24,218
Prior	32,777	14,613
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	118,706	145,570
Commercial real estate non-owner occupied | Substandard | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	0
Two years before current year	0	17,741
Three years before current year	35,957	20,611
Four years before current year	20,611	366
Prior	40,701	39,171
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	97,269	77,889
Commercial real estate non-owner occupied | Doubtful | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	0
Two years before current year	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	0	0
Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivable	198,607	140,905
Construction | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	13,053	19,932
Fiscal year before current year	44,398	105,466
Two years before current year	125,339	4,954
Three years before current year	4,869	0
Four years before current year	0	9,700
Prior	9,507	0
Revolving loans amortized cost basis	1,441	853
Revolving loans converted to term	0	0
Loans and leases receivable	198,607	140,905
Construction | Pass | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	13,053	19,932
Fiscal year before current year	42,888	105,466
Two years before current year	125,339	4,954
Three years before current year	4,869	0
Four years before current year	0	9,700
Prior	9,507	0
Revolving loans amortized cost basis	1,441	853
Revolving loans converted to term	0	0
Loans and leases receivable	197,097	140,905
Construction | Special mention | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	1,510	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	1,510	0
Construction | Substandard | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	0	0
Construction | Doubtful | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	0	0
Consumer loans | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	710,817	326,466
Fiscal year before current year	414,683	807,473
Two years before current year	453,568	123,052
Three years before current year	81,651	16,488
Four years before current year	9,651	40,050
Prior	149,422	136,434
Revolving loans amortized cost basis	108,411	164,856
Revolving loans converted to term	0	0
Loans and leases receivable	1,928,203	1,614,819
Residential real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivable	248,153	317,170
Residential real estate | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	4,481	6,708
Fiscal year before current year	8,272	13,617
Two years before current year	13,877	6,970
Three years before current year	12,433	11,635
Four years before current year	7,404	39,493
Prior	93,275	73,891
Revolving loans amortized cost basis	108,411	164,856
Revolving loans converted to term	0	0
Loans and leases receivable	248,153	317,170
Residential real estate | Consumer | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	4,481	6,708
Fiscal year before current year	8,272	13,617
Two years before current year	13,738	6,810
Three years before current year	11,413	10,850
Four years before current year	6,735	38,143
Prior	89,259	69,496
Revolving loans amortized cost basis	106,649	161,576
Revolving loans converted to term	0	0
Loans and leases receivable	240,547	307,200
Residential real estate | Consumer | Non-performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	0
Two years before current year	139	160
Three years before current year	1,020	785
Four years before current year	669	1,350
Prior	4,016	4,395
Revolving loans amortized cost basis	1,762	3,280
Revolving loans converted to term	0	0
Loans and leases receivable	7,606	9,970
Manufactured housing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivable	55,635	62,243
Manufactured housing | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	295
Two years before current year	293	609
Three years before current year	304	76
Four years before current year	75	41
Prior	54,963	61,222
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	55,635	62,243
Manufactured housing | Consumer | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	295
Two years before current year	293	609
Three years before current year	304	76
Four years before current year	75	41
Prior	49,606	56,837
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	50,278	57,858
Manufactured housing | Consumer | Non-performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	0	0
Fiscal year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	5,357	4,385
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	5,357	4,385
Installment
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases receivable	1,624,415	1,235,406
Installment | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	706,336	319,758
Fiscal year before current year	406,411	793,561
Two years before current year	439,398	115,473
Three years before current year	68,914	4,777
Four years before current year	2,172	516
Prior	1,184	1,321
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	1,624,415	1,235,406
Installment | Consumer | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	706,050	319,453
Fiscal year before current year	405,796	791,235
Two years before current year	437,711	114,988
Three years before current year	68,720	4,736
Four years before current year	2,168	514
Prior	1,123	1,204
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	1,621,568	1,232,130
Installment | Consumer | Non-performing
Financing Receivable, Credit Quality Indicator [Line Items]
Current year	286	305
Fiscal year before current year	615	2,326
Two years before current year	1,687	485
Three years before current year	194	41
Four years before current year	4	2
Prior	61	117
Revolving loans amortized cost basis	0	0
Revolving loans converted to term	0	0
Loans and leases receivable	$ 2,847	$ 3,276