Loans and Leases Receivable and Allowance for Credit Losses - Schedule of Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jan. 01, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 149,283	$ 43,679	$ 56,379	$ 39,972
Cumulative effect of change in accounting principle	149,283	48,388	159,905	39,972	$ 136,200
Charge-offs	(11,125)	(1,250)	(30,265)	(2,594)
Recoveries	801	613	1,230	897
Provision for credit losses on loans and leases	20,946	5,346	52,732	10,113
Ending balance	159,905	48,388	159,905	48,388
Multi-family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	8,750	10,630	6,157	11,462
Cumulative effect of change in accounting principle	14,697	9,926	6,157	9,926
Charge-offs	0	0	0	(541)
Recoveries	0	7	0	7
Provision for credit losses on loans and leases	5,947	(711)	6,369	(1,002)
Ending balance	14,697	9,926	14,697	9,926
Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	18,806	12,647	15,556	12,145
Cumulative effect of change in accounting principle	12,302	13,736	15,556	13,736
Charge-offs	(20)	(183)	(117)	(183)
Recoveries	25	338	79	457
Provision for credit losses on loans and leases	(6,509)	934	(3,975)	1,317
Ending balance	12,302	13,736	12,302	13,736
Commercial real estate owner occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	8,527	3,425	2,235	3,320
Cumulative effect of change in accounting principle	11,405	3,360	2,235	3,360
Charge-offs	0	(66)	0	(74)
Recoveries	2	97	5	225
Provision for credit losses on loans and leases	2,876	(96)	3,392	(111)
Ending balance	11,405	3,360	11,405	3,360
Commercial real estate non-owner occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	18,530	6,015	6,243	6,093
Cumulative effect of change in accounting principle	26,493	6,159	26,493	6,093
Charge-offs	(2,801)	0	(15,598)	0
Recoveries	0	0	0	0
Provision for credit losses on loans and leases	10,764	144	27,930	66
Ending balance	26,493	6,159	26,493	6,159
Construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,934	584	1,262	624
Cumulative effect of change in accounting principle	5,297	649	5,297	649
Charge-offs	0	0	0	0
Recoveries	113	114	116	120
Provision for credit losses on loans and leases	3,250	(49)	4,017	(95)
Ending balance	5,297	649	5,297	649
Residential real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4,180	6,572	3,218	3,654
Cumulative effect of change in accounting principle	4,550	4,168	3,218	4,168
Charge-offs	0	(69)	0	(109)
Recoveries	26	8	55	15
Provision for credit losses on loans and leases	344	(2,343)	(241)	608
Ending balance	4,550	4,168	4,550	4,168
Manufactured housing
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4,987	117	1,060	145
Cumulative effect of change in accounting principle	6,014	123	6,014	123
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision for credit losses on loans and leases	1,027	6	1,152	(22)
Ending balance	6,014	123	6,014	123
Other consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	83,569	3,689	20,648	2,529
Cumulative effect of change in accounting principle	79,147	10,267	20,648	10,267
Charge-offs	(8,304)	(932)	(14,550)	(1,687)
Recoveries	635	49	975	73
Provision for credit losses on loans and leases	3,247	7,461	14,088	9,352
Ending balance	$ 79,147	$ 10,267	79,147	$ 10,267
Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance			79,829
Cumulative effect of change in accounting principle			79,829		$ 79,829
Cumulative Effect, Period of Adoption, Adjustment | Multi-family
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance			2,171
Cumulative effect of change in accounting principle			2,171
Cumulative Effect, Period of Adoption, Adjustment | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance			759
Cumulative effect of change in accounting principle			759
Cumulative Effect, Period of Adoption, Adjustment | Commercial real estate owner occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance			5,773
Cumulative effect of change in accounting principle			5,773
Cumulative Effect, Period of Adoption, Adjustment | Commercial real estate non-owner occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance			7,918
Cumulative effect of change in accounting principle			7,918
Cumulative Effect, Period of Adoption, Adjustment | Construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance			(98)
Cumulative effect of change in accounting principle			(98)
Cumulative Effect, Period of Adoption, Adjustment | Residential real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance			1,518
Cumulative effect of change in accounting principle			1,518
Cumulative Effect, Period of Adoption, Adjustment | Manufactured housing
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance			3,802
Cumulative effect of change in accounting principle			3,802
Cumulative Effect, Period of Adoption, Adjustment | Other consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance			57,986
Cumulative effect of change in accounting principle			$ 57,986