Western Alliance Bancorporation (WAL) 10-Q 30 Oct 20 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Oct. 26, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	001-32550
Entity Registrant Name	WESTERN ALLIANCE BANCORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	88-0365922
Entity Address, Address Line One	One E. Washington Street, Suite 1400
Entity Address, City or Town	Phoenix
Entity Address, State or Province	AZ
Entity Address, Postal Zip Code	85004
City Area Code	602
Local Phone Number	389-3500
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		100,829,164
Entity Central Index Key	0001212545
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Common Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $0.0001 Par Value
Trading Symbol	WAL
Security Exchange Name	NYSE
Subordinated Debt [Member]
Entity Information [Line Items]
Title of 12(b) Security	6.25% Subordinated Debentures due 2056
Trading Symbol	WALA
Security Exchange Name	NYSE

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020		Sep. 30, 2020		Dec. 31, 2019
Assets:
Cash and due from banks	$ 163,893		$ 163,893		$ 185,977
Interest-bearing deposits in other financial institutions	1,254,842		1,254,842		248,619
Cash, cash equivalents, and restricted cash	1,418,735		1,418,735		434,596
Available-for-sale Securities	3,975,225	[1]	3,975,225	[1]	3,346,310	[2]
Debt Securities, Held-to-maturity	504,477		504,477		485,107
Debt Securities, Held-to-maturity, Allowance for Credit Loss	(5,964)		(5,964)		0
Debt Securities, Held-to-maturity, Net	498,513		498,513		485,107
Investment securities - equity	160,561	[1]	160,561	[1]	138,701	[2]
Investments in restricted stock, at cost	66,843		66,843		66,509
Loans Receivable Held-for-sale, Amount	20,764		20,764		21,803
Loans:
Loans and Leases Receivable, Net of Deferred Income	25,993,254		25,993,254		21,101,493
Less: Allowance for credit losses	(310,560)		(310,560)		(167,797)
Net loans held for investment	25,682,694		25,682,694		20,933,696
Premises and equipment, net	128,256		128,256		125,838
Operating Lease, Right-of-Use Asset	71,393		71,393		72,558
Bank owned life insurance	175,478		175,478		174,046
Goodwill and intangible assets, net	298,987		298,987		297,608
Deferred Income Tax Assets, Net	46,645		46,645		18,025
Investments in LIHTC and renewable energy	414,305		414,305		409,365
Other assets	377,107		377,107		297,786
Total assets	33,335,506		33,335,506		26,821,948
Deposits:
Non-interest-bearing demand	13,013,014		13,013,014		8,537,905
Interest-bearing	15,830,382		15,830,382		14,258,588
Total deposits	28,843,396		28,843,396		22,796,493
Customer repurchase agreements	19,688		19,688		16,675
Other borrowings	10,000		10,000		0
Qualifying debt	618,772		618,772		393,563
Operating Lease, Liability	78,613		78,613		78,112
Other liabilities	540,991		540,991		520,357
Total liabilities	30,111,460		30,111,460		23,805,200
Commitments and Contingencies
Common Stock, Shares, Issued	102,993,777		102,993,777		104,527,544
Common stock, shares authorized	200,000,000		200,000,000		200,000,000
Stockholders’ equity:
Common Stock, Value, Issued	$ 10		$ 10		$ 10
Treasury Stock, Shares	2,168,437		2,168,437		2,003,873
Treasury Stock, Value	$ (71,098)		$ (71,098)		$ (62,728)
Additional paid in capital	1,383,537		1,383,537		1,374,141
Accumulated other comprehensive income	78,585		78,585		25,008
Retained earnings	1,833,012		1,833,012		1,680,317
Total stockholders’ equity	3,224,046		3,224,046		3,016,748
Total liabilities and stockholders’ equity	33,335,506		33,335,506		$ 26,821,948
Dividends, Common Stock, Cash	$ (25,208)		$ (76,028)
[1]	Where ratings differ, the Company uses an average of the available ratings by major credit agencies.
[2]	Where ratings differ, the Company uses an average of the available ratings by major credit agencies.

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale, Amortized Cost	$ 3,876,586	$ 3,317,928
Debt Securities, Held-to-maturity, Fair Value	$ 548,140	$ 516,261
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	102,993,777	104,527,544
Treasury Stock, Value	$ 71,098	$ 62,728

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest income:
Loans, including fees	$ 276,623	$ 278,932	$ 843,085	$ 808,099
Investment securities	26,323	28,928	79,778	84,929
Dividends	1,397	1,289	4,305	4,452
Other	500	6,459	3,129	12,144
Total interest income	304,843	315,608	930,297	909,624
Interest expense:
Deposits	12,215	43,354	59,736	121,030
Other borrowings	5	34	75	1,344
Qualifying debt	7,872	5,785	17,833	17,898
Other	13	13	495	913
Total interest expense	20,105	49,186	78,139	141,185
Net interest income	284,738	266,422	852,158	768,439
Provision for credit losses	14,661	3,803	157,837	15,303
Net interest income after provision for credit losses	270,077	262,619	694,321	753,136
Non-interest income:
Service charges and fees	5,913	5,888	17,447	17,121
Card Income	1,873	1,729	4,768	5,195
Foreign currency income	1,755	1,321	4,242	3,564
Income from bank owned life insurance	1,345	979	8,977	2,938
Income from equity instruments	1,186	3,742	6,263	6,619
Lending related income and gains (losses) on sale of loans, net	705	539	2,072	1,343
Sales of investment securities	0	3,152	230	3,152
Unrealized gains (losses) on assets measured at fair value, net	5,882	222	(986)	4,628
Other income	1,947	1,869	3,972	4,509
Total non-interest income	20,606	19,441	46,985	49,069
Non-interest expense:
Salaries and employee benefits	78,757	70,978	220,455	205,328
Legal, professional, and directors' fees	10,034	8,248	31,105	26,885
Occupancy	9,426	8,263	25,752	24,251
Data processing	8,864	7,095	26,044	20,563
Deposit costs	3,246	11,537	14,098	24,930
Insurance	3,064	3,071	9,506	8,691
Loan and repossessed asset expenses	1,771	1,953	5,280	5,419
Business development	950	1,443	4,062	4,972
Marketing	848	842	2,621	2,640
Card expense	505	548	1,631	1,892
Intangible amortization	373	387	1,120	1,161
Net loss (gain) on sales / valuations of repossessed and other assets	123	3,379	(1,335)	2,856
Other expense	6,131	8,408	19,033	22,691
Total non-interest expense	124,092	126,152	359,372	352,279
Income before provision for income taxes	166,591	155,908	381,934	449,926
Income Tax Expense (Benefit)	30,822	28,533	68,929	78,819
Net income	$ 135,769	$ 127,375	$ 313,005	$ 371,107
Earnings per share:
Basic	$ 1.36	$ 1.25	$ 3.12	$ 3.60
Diluted	$ 1.36	$ 1.24	$ 3.11	$ 3.59
Weighted average number of common shares outstanding:
Basic	99,850	102,041	100,322	103,024
Diluted	100,059	102,451	100,574	103,468
Dividends declared per common share	$ 0.25	$ 0.25	$ 0.75	$ 0.25

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 135,769	$ 127,375	$ 313,005	$ 371,107
Other comprehensive income, net:
OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax	7,592	11,014	53,176	78,314
Unrealized gain on AFS securities, net of tax effect of $(2,520), $(3,592), $(17,310), $(25,523), respectively	(2,520)	(3,592)	(17,310)	(25,523)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	(3)	(18)	(296)	(53)
Unrealized (loss) on SERP, net of tax effect of $1, $6, $94, $18, respectively	1	6	94	18
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, after Tax	(2,681)	(598)	(871)	(6,664)
Unrealized (loss) gain on junior subordinated debt, net of tax effect of $874, $(196)$, $(285), $2,173, respectively	(874)	(196)	(285)	(2,173)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	0	(2,376)	(174)	(2,376)
Realized (gain) on sale of AFS securities included in income, net of tax effect of $0, $776, $56, $776, respectively	0	776	56	776
Net other comprehensive income	4,908	9,218	53,577	69,221
Comprehensive income	$ 140,677	$ 136,593	$ 366,582	$ 440,328

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands		Total	Common Stock [Member]	Additional Paid in Capital [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]
Beginning balance, shares at Dec. 31, 2018			104,949,000
Beginning balance at Dec. 31, 2018		$ 2,613,734	$ 10	$ 1,417,724	$ 53,083	$ (33,622)	$ 1,282,705
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		371,107					371,107
Exercise of stock options, shares			2,000
Exercise of stock options		55		55
Restricted stock grants, net, shares			(631,000)
Restricted stock grants, net		19,783		19,783
Treasury Stock, Shares, Acquired	[1]		209,000
Treasury Stock, Value, Acquired, Cost Method	[1]	$ 9,582			9,582
Stock Repurchased and Retired During Period, Shares		(2,733,603)	(2,734,000)
Stock Repurchased and Retired During Period, Value		$ (115,571)		(69,371)			(46,200)
Dividends, Common Stock, Cash		(25,684)					(25,684)
Other comprehensive (loss) income, net		69,221				69,221
Ending balance, shares at Sep. 30, 2019			102,639,000
Ending Balance at Sep. 30, 2019		2,923,063	$ 10	1,368,191	62,665	35,599	1,581,928
Beginning balance, shares at Jun. 30, 2019			103,654,000
Beginning balance at Jun. 30, 2019		2,851,264	$ 10	1,372,037	61,134	26,381	1,513,970
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		127,375					127,375
Exercise of stock options, shares			1,000
Exercise of stock options		19		19
Restricted stock grants, net, shares			(17,000)
Restricted stock grants, net		6,060		6,060
Treasury Stock, Shares, Acquired	[1]		33,000
Treasury Stock, Value, Acquired, Cost Method	[1]	$ 1,531			1,531
Stock Repurchased and Retired During Period, Shares		(1,000,000)	(1,000,000)
Stock Repurchased and Retired During Period, Value		$ (43,658)		(9,925)			(33,733)
Dividends, Common Stock, Cash							(25,684)
Other comprehensive (loss) income, net		9,218				9,218
Ending balance, shares at Sep. 30, 2019			102,639,000
Ending Balance at Sep. 30, 2019		2,923,063	$ 10	1,368,191	62,665	35,599	1,581,928
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Retained earnings		1,680,317
Beginning balance, shares at Dec. 31, 2019			102,524,000
Beginning balance at Dec. 31, 2019		3,016,748	$ 10	1,374,141	62,728	25,008	1,680,317
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		313,005					313,005
Exercise of stock options, shares			9,000
Exercise of stock options		170		170
Restricted stock grants, net, shares			(523,000)
Restricted stock grants, net		21,560		21,560
Treasury Stock, Shares, Acquired	[1]		165,000
Treasury Stock, Value, Acquired, Cost Method	[1]	$ 8,370			8,370
Stock Repurchased and Retired During Period, Shares		(2,066,479)	(2,066,000)
Stock Repurchased and Retired During Period, Value		$ (71,669)		(12,334)			(59,335)
Dividends, Common Stock, Cash		(76,028)					(76,028)
Other comprehensive (loss) income, net		53,577				53,577
Ending balance, shares at Sep. 30, 2020			100,825,000
Ending Balance at Sep. 30, 2020		3,224,046	$ 10	1,383,537	71,098	78,585	1,833,012
Beginning balance, shares at Jun. 30, 2020			100,849,000
Beginning balance at Jun. 30, 2020		3,102,414	$ 10	1,376,859	70,583	73,677	1,722,451
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		135,769					135,769
Exercise of stock options, shares			2,000
Exercise of stock options		73		73
Restricted stock grants, net, shares			(12,000)
Restricted stock grants, net		6,605		6,605
Treasury Stock, Shares, Acquired	[1]		14,000
Treasury Stock, Value, Acquired, Cost Method	[1]	515			515
Dividends, Common Stock, Cash		(25,208)					(25,208)
Other comprehensive (loss) income, net		4,908				4,908
Ending balance, shares at Sep. 30, 2020			100,825,000
Ending Balance at Sep. 30, 2020		3,224,046	$ 10	$ 1,383,537	$ 71,098	$ 78,585	$ 1,833,012
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Retained earnings		$ 1,833,012
[1]	Share amounts represent Treasury Shares, see "Note 1. Summary of Significant Accounting Policies" for further discussion.

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net income	$ 313,005	$ 371,107
Adjustments to reconcile net income to cash provided by operating activities:
Provision for credit losses	157,837	15,303
Depreciation and amortization	17,122	14,904
Stock-based compensation	21,560	19,783
Deferred income taxes	(37,414)	5,757
Amortization of net premiums for investment securities	19,015	11,031
Amortization of tax credit investments	34,244	33,551
Amortization of operating lease right of use asset	8,874	7,704
Amortization of net deferred loan fees and net purchase premiums	(34,085)	(31,838)
Income from bank owned life insurance	3,370
Income from bank owned life insurance	(8,977)	(2,938)
(Gains) / Losses on:
Sales of investment securities	(230)	(3,152)
Assets measured at fair value, net	986	(4,628)
Sale of loans	0	(530)
BOLI	5,607	0
Sales / valuations of repossessed and other assets, net	(1,335)	2,856
Changes in other assets and liabilities, net	(40,486)	94,535
Net cash provided by operating activities	450,116	534,505
Investment securities - AFS
Purchases	(1,720,604)	(746,445)
Principal pay downs and maturities	1,014,380	453,307
Proceeds from sales	156,629	150,377
Debt Securities, Held-to-maturity [Abstract]
Purchases	106,772	100,460
Principal pay downs and maturities	16,894	18,206
Proceeds from sales	0	10,000
Equity Securities, FV-NI, Gain (Loss) [Abstract]
Purchases	(31,075)	(10,662)
Redemption of principal (reinvestment of dividends)	7,003	4,535
Purchase of investment tax credits	(103,365)	(88,074)
Proceeds from (purchase of) SBIC investments	(1,463)	5,298
Purchase of money market investments, net	0	7
Proceeds from bank owned life insurance, net	6,011	0
Purchase of restricted stock	334	244
Net increase in loans	(4,806,138)	(2,445,769)
Purchase of premises, equipment, and other assets, net	(33,103)	(15,282)
Proceeds from sale of other real estate owned and repossessed assets, net	7,073	628
Net cash used in investing activities	(5,591,938)	(2,775,174)
Cash flows from financing activities:
Net increase in deposits	6,046,903	3,263,367
Net proceeds from issuance of subordinated debt	221,942	0
Net increase (decrease) in borrowings	13,013	(498,429)
Proceeds from exercise of common stock options	170	55
Cash paid for tax withholding on vested restricted stock	8,370	9,582
Common stock repurchases	71,669	115,571
Cash dividends paid on common stock	76,028	25,684
Net cash provided by financing activities	6,125,961	2,614,156
Net increase in cash, cash equivalents, and restricted cash	984,139	373,487
Cash, cash equivalents, and restricted cash at beginning of period	434,596	498,572
Cash, cash equivalents, and restricted cash at end of period	1,418,735	872,059
Cash paid (received) during the period for:
Interest	87,134	144,680
Income Taxes Paid, Net	$ 37,069	$ (26,228)

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Nature of operation WAL is a bank holding company headquartered in Phoenix, Arizona, incorporated under the laws of the state of Delaware. WAL provides a full spectrum of deposit, lending, treasury management, international banking, and online banking products and services through its wholly-owned banking subsidiary, WAB. WAB operates the following full-service banking divisions: ABA, BON, FIB, Bridge, and TPB. The Company also serves business customers through a national platform of specialized financial services. In addition, the Company has two non-bank subsidiaries: LVSP, which held and managed certain OREO properties, and CSI, a captive insurance company formed and licensed under the laws of the State of Arizona and established as part of the Company's overall enterprise risk management strategy. Basis of presentation The accounting and reporting policies of the Company are in accordance with GAAP and conform to practices within the financial services industry. The accounts of the Company and its consolidated subsidiaries are included in the Consolidated Financial Statements. Recent accounting pronouncements Convertible Debt and Derivatives and Hedging In August 2020, the FASB issued guidance within ASU 2020-06, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) . The amendments in this update affect entities that issue convertible instruments and/or contracts indexed to and potentially settled in an entity’s own equity. The new ASU simplifies the convertible accounting framework through elimination of the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of specific settlement provisions. In addition, the new guidance modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted EPS computation. The amendments to Subtopics 470 and 815 are effective for interim and annual reporting periods beginning after December 15, 2021 and are not expected to have a material impact on the Company’s Consolidated Financial Statements. Income Taxes In December 2019, the FASB issued guidance within ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The amendments in ASU 2019-12 are intended to reduce the cost and complexity of applying ASC 740. The amendments that are applicable to the Company address: 1) franchise and other taxes partially based on income; 2) step-up in basis of goodwill in a business combination; 3) allocation of tax expense in separate entity financial statements; and 4) interim recognition of enactment of tax laws or rate changes. The amendments to Topic 740 are effective for interim and annual reporting periods beginning after December 15, 2020 and are not expected to have a material impact on the Company’s Consolidated Financial Statements. Recently adopted accounting guidance Measurement of Credit Losses on Financial Instruments In June 2016, the FASB issued guidance within ASU 2016-13, Measurement of Credit Losses on Financial Instruments . The new standard significantly changes the impairment model for most financial assets that are measured at amortized cost, including off-balance sheet credit exposures, from an incurred loss model to an expected loss model. The amendments in ASU 2016-13 to Topic 326, Financial Instruments - Credit Losses , require that an organization measure all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. The ASU also requires enhanced disclosures, including qualitative and quantitative disclosures that provide additional information about the amounts recorded in the financial statements. Additionally, the ASU amends the accounting for credit losses on AFS debt securities and purchased financial assets with credit deterioration. The Company adopted the amendments within ASU 2016-13 using the modified retrospective method for all financial assets measured at amortized cost and off-balance sheet credit exposures. The Company's financial results for reporting periods beginning after January 1, 2020 are presented in accordance with ASC 326, while prior-period amounts continue to be reported in accordance with legacy GAAP. The Company recorded a cumulative effect adjustment to retained earnings, which resulted in a total decrease to retained earnings of $24.9 million as of January 1, 2020. This adjustment was due primarily to expected total losses under the new model in the Company's loan portfolio and, to a lesser extent, its off-balance sheet credit exposures. The Company applied the prospective transition approach for loans purchased with credit deterioration that were previously classified as purchased credit impaired and previously accounted for under ASC 310-30. In accordance with the new standard, management did not reassess whether PCI assets met the criteria of PCD assets as of the date of adoption. As of January 1, 2020, the amortized cost basis of the PCD loans was adjusted to reflect an allowance for credit losses of $3.3 million. The remaining noncredit discount (based on the adjusted amortized cost basis) related to PCD loans of $1.1 million will be accreted into interest income at the loan's effective interest rate as of January 1, 2020. The Company has elected not to maintain its pools of loans accounted for under ASC 310-30. The Company applied the prospective transition approach for debt securities for which other-than-temporary impairment had been recognized prior to January 1, 2020. As a result, the amortized cost basis remains the same before and after the effective date. The effective interest rate on these debt securities was not changed. Recoveries of amounts previously written off relating to improvements in cash flows after January 1, 2020 will be recorded in earnings when received. The following table summarizes the estimated allowance for credit losses related to financial assets and off-balance sheet credit exposures and the corresponding impacts on the deferred tax asset and retained earnings upon adoption of ASC 326: January 1, 2020 Pre-ASC 326 Adoption Post-ASC 326 Adoption Impact of ASC 326 Adoption (in thousands) Assets: Allowance for credit losses on HTM securities $ — $ 2,646 $ 2,646 Allowance for credit losses on loans 167,797 186,925 19,128 Deferred tax asset 18,025 26,675 8,650 Liabilities: Off-balance sheet credit exposures $ 8,955 $ 24,044 $ 15,089 Equity: Retained earnings $ 1,680,317 $ 1,655,370 $ (24,947) Management has elected to take advantage of the capital relief option that delays the estimated impact of the adoption of ASC 326 on regulatory capital by up to two years, with a three-year transition period to phase out the cumulative benefit to regulatory capital provided during the two-year delay. In April 2019, the FASB issued guidance within ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments . The amendments in ASU 2019-04 clarify or correct the guidance in these Topics. With respect to Topic 326, ASU 2019-04 addresses a number of issues as it relates to the CECL standard including consideration of accrued interest, recoveries, variable-rate financial instruments, prepayments, and extension and renewal options, among other things, in the measurement of expected credit losses. The amendments to Topic 326 were adopted concurrently with ASU 2016-13 and did not have a significant impact on the Company’s Consolidated Financial Statements. With respect to Topic 815, Derivatives and Hedging , ASU 2019-04 clarifies issues related to partial-term hedges, hedged debt securities, and transitioning from a quantitative method of assessing hedge effectiveness to a more simplified method. The Company does not have partial-term hedges or any hedged debt securities and the transition issues discussed in the ASU 2019-04 are not applicable to the Company. Accordingly, the amendments to Topic 815 did not have an impact on the Company's Consolidated Financial Statements. With respect to Topic 825, Financial Instruments, on recognizing and measuring financial instruments, ASU 2019-04 addresses: 1) the scope of the guidance; 2) the requirement for remeasurement under ASC 820 when using the measurement alternative for equity securities without readily determinable fair values; 3) certain disclosure requirements; and 4) which equity securities have to be remeasured at historical exchange rates. The amendments to Topic 825 were effective January 1, 2020 and did not have a material impact on the Company’s Consolidated Financial Statements. In May 2019, the FASB issued guidance within ASU 2019-05, Financial Instruments - Credit Losses , to provide entities with an option to irrevocably elect the fair value option for eligible financial assets measured at amortized cost. The election is to be applied on an instrument-by-instrument basis upon adoption of Topic 326 and is not available for either AFS or HTM debt securities. The amendments in ASU 2019-05 should be applied on a modified-retrospective basis through a cumulative-effect adjustment to the opening balance of retained earnings as of the date that an entity adopts the amendments in ASU 2016-13. The Company did not elect this fair value option as part of its adoption of ASU 2016-13 on January 1, 2020. In November 2019, the FASB issued guidance within ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments—Credit Losses. The amendments in ASU 2019-11 clarify or address specific issues about certain aspects of the amendments in ASU 2016-13. These issues include measurement and reporting requirements related to: 1) the allowance for credit losses for purchased assets with credit deterioration; 2) prepayment assumptions on existing troubled debt restructurings; 3) extension of disclosure relief for accrued interest receivable balances; and 4) expected credit losses on collateralized financial assets. The adoption of ASU 2019-11 is concurrent with ASU 2016-13 and, adoption of these amendments on January 1, 2020, did not have a significant impact on the Company's Consolidated Financial Statements. Fair Value Measurements In August 2018, the FASB issued guidance within ASU 2018-13, Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement . The amendments within ASU 2018-13 remove, modify, and supplement the disclosure requirements for fair value measurements. Disclosure requirements that were removed include: 1) the amount and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy; 2) the policy for timing of transfers between levels; and 3) the valuation processes for Level 3 fair value measurements. The amendments clarify that the measurement uncertainty disclosure is intended to communicate information about the uncertainty in measurement as of the reporting date. Additional disclosure requirements include: 1) the changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period; and 2) the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. With the exception of the above additional disclosure requirements, which will be applied prospectively, all other amendments should be applied retrospectively to all periods presented upon their effective date. The amendments in this ASU did not have a significant impact on the Company's Consolidated Financial Statements. Internal-Use Software In August 2018, the FASB issued guidance within ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40) . The amendments in this ASU align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). Accordingly, the amendments in this Update require an entity (customer) in a hosting arrangement that is a service contract to follow the guidance in Subtopic 350-40 to determine which implementation costs to capitalize as an asset related to the service contract and which costs to expense. The amendments in this Update also require that the capitalized implementation costs of a hosting arrangement that is a service contract be expensed over the term of the hosting arrangement. Presentation requirements include: 1) expense related to the capitalized implementation costs should be presented in the same line item in the statement of income as the fees associated with the hosting element (service) of the arrangement; 2) payments for capitalized implementation costs in the statement of cash flows should be classified in the same manner as payments made for fees associated with the hosting element; and 3) capitalized implementation costs in the statement of financial position should be presented in the same line item that a prepayment for the fees of the associated hosting arrangement would be presented. The adoption of this guidance did not have a significant impact on the Company's Consolidated Financial Statements. Reference Rate Reform In March 2020, the FASB issued guidance within ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, in response to the scheduled discontinuation of LIBOR on December 31, 2021 . The amendments in this Update provide optional guidance designed to provide relief from the accounting analysis and impacts that may otherwise be required for modifications to agreements (e.g., loans, debt securities, derivatives, borrowings) necessitated by reference rate reform. The following optional expedients for applying the requirements of certain Topics or Industry Subtopics in the Codification are permitted for contracts that are modified because of reference rate reform and that meet certain scope guidance: 1) modifications of contracts within the scope of Topics 310, Receivables , and 470, Debt , should be accounted for by prospectively adjusting the effective interest rate; 2) modifications of contracts within the scope of Topic 842, Leases , should be accounted for as a continuation of the existing contracts with no reassessments of the lease classification and the discount rate or remeasurements of lease payments that otherwise would be required under this Topic for modifications not accounted for as separate contracts; 3) modifications of contracts do not require an entity to reassess its original conclusion about whether that contract contains an embedded derivative that is clearly and closely related to the economic characteristics and risks of the host contract under Subtopic 815-15, Derivatives and Hedging- Embedded Derivatives; and 4) for other Topics or Industry Subtopics in the Codification, the amendments in this Update also include a general principle that permits an entity to consider contract modifications due to reference rate reform to be an event that does not require contract remeasurement at the modification date or reassessment of a previous accounting determination. An entity may make a one-time election to sell, transfer, or both sell and transfer debt securities classified as held to maturity that reference a rate affected by reference rate reform and that are classified as held to maturity before January 1, 2020. The amendments in this Update are effective for all entities as of March 12, 2020 through December 31, 2022. Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Management's estimates and judgments are ongoing and are based on experience, current and expected future conditions, third-party evaluations and various other assumptions that management believes are reasonable under the circumstances. The results of these estimates form the basis for making judgments about the carrying values of assets and liabilities, as well as identifying and assessing the accounting treatment with respect to commitments and contingencies. Actual results may differ from those estimates and assumptions used in the Consolidated Financial Statements and related notes. Material estimates that are susceptible to significant changes in the near term, particularly to the extent that economic conditions worsen or persist longer than expected in an adverse state, relate to: the determination of the allowance for credit losses; certain assets and liabilities carried at fair value; and accounting for income taxes. Principles of consolidation As of September 30, 2020, WAL has the following significant wholly-owned subsidiaries: WAB and eight unconsolidated subsidiaries used as business trusts in connection with the issuance of trust-preferred securities. The Bank has the following significant wholly-owned subsidiaries: WABT, which holds certain investment securities, municipal and nonprofit loans, and leases; WA PWI, which holds interests in certain limited partnerships invested primarily in low income housing tax credits and small business investment corporations; Helios Prime, which holds interests in certain limited partnerships invested in renewable energy projects; and BW Real Estate, Inc., which operates as a real estate investment trust and holds certain of WAB's real estate loans and related securities. The Company does not have any other significant entities that should be consolidated. All significant intercompany balances and transactions have been eliminated in consolidation. Reclassifications Certain amounts reported in prior periods may have been reclassified in the Consolidated Financial Statements to conform to the current presentation. The reclassifications have no effect on net income or stockholders’ equity as previously reported. Interim financial information The accompanying Unaudited Consolidated Financial Statements as of and for the three and nine months ended September 30, 2020 and 2019 have been prepared in condensed format and, therefore, do not include all of the information and footnotes required by GAAP for complete financial statements. These statements have been prepared on a basis that is substantially consistent with the accounting principles applied to the Company's audited Consolidated Financial Statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2019. The information furnished in these interim statements reflects all adjustments that are, in the opinion of management, necessary for a fair statement of the results for each respective period presented. Such adjustments are of a normal, recurring nature. The results of operations in the interim statements are not necessarily indicative of the results that may be expected for any other quarter or for the full year. The interim financial information should be read in conjunction with the Company's audited Consolidated Financial Statements. Investment securities Investment securities include debt and equity securities. Debt securities may be classified as HTM, AFS, or trading. The appropriate classification is initially decided at the time of purchase. Securities classified as HTM are those debt securities that the Company has both the intent and ability to hold to maturity regardless of changes in market conditions, liquidity needs, or general economic conditions. The sale of an HTM security within three months of its maturity date or after the majority of the principal outstanding has been collected is considered a maturity for purposes of classification and disclosure. Securities classified as AFS are securities that the Company intends to hold for an indefinite period of time, but not necessarily to maturity. Any decision to sell a security classified as AFS would be based on various factors, including significant movements in interest rates, changes in the maturity mix of the Company’s assets and liabilities, liquidity needs, decline in credit quality, and regulatory capital considerations. HTM securities are carried at amortized cost. AFS securities are carried at their estimated fair value, with unrealized holding gains and losses reported in other comprehensive income, net of tax. When AFS debt securities are sold, the unrealized gains or losses are reclassified from OCI to non-interest income. Trading securities are carried at their estimated fair value, with changes in fair value reported in earnings as part of non-interest income. Equity securities are carried at their estimated fair value, with changes in fair value reported in earnings as part of non-interest income. Interest income is recognized based on the coupon rate and includes the amortization of purchase premiums and the accretion of purchase discounts. Premiums and discounts on investment securities are generally amortized or accreted over the contractual life of the security using the interest method. For the Company's mortgage-backed securities, amortization or accretion of premiums or discounts are adjusted for anticipated prepayments. Gains and losses on the sale of investment securities are recorded on the trade date and determined using the specific identification method. A debt security is placed on nonaccrual status at the time its principal or interest payments become 90 days past due. Interest accrued but not received for a security placed on nonaccrual is reversed against interest income. Allowance for credit losses on investment securities On January 1, 2020, the Company adopted the amendments within ASU 2016-13, which replaces the legacy US GAAP OTTI model with a credit loss model. For discussion of the former OTTI methodology, refer to the Company's Annual Report on Form 10-K for the year ended December 31, 2019. The credit loss model under ASC 326-20, applicable to HTM debt securities, requires recognition of lifetime expected credit losses through an allowance account at the time the security is purchased. The Company measures expected credit losses on its HTM debt securities on a collective basis by major security type. The Company's HTM securities portfolio consists of low income housing tax-exempt bonds, which share similar risk characteristics with the Company's CRE, non-owner occupied or construction and land loan pools, given the similarity in underlying assets or collateral. Accordingly, expected credit losses on HTM securities are estimated using the same models and approaches as these loan pools, which utilize risk parameters (probability of default, loss given default, and exposure at default) in the measurement of expected credit losses. The historical data used to estimate probability of default and severity of loss in the event of default is derived or obtained from internal and external sources and adjusted for the expected effects of reasonable and supportable forecasts over the expected lives of the securities on those historical losses. Accrued interest receivable on the HTM securities, which is included in other assets on the Consolidated Balance Sheet, is excluded from the estimate of expected credit losses. The credit loss model under ASC 326-30, applicable to AFS debt securities, requires recognition of credit losses through an allowance account, but retains the concept from the OTTI model that credit losses are recognized once securities become impaired. For AFS debt securities, a decline in fair value due to credit loss results in recognition of an allowance for credit losses. Impairment may result from credit deterioration of the issuer or collateral underlying the security. The assessment of determining if a decline in fair value resulted from a credit loss is performed at the individual security level. Among other factors, the Company considers: 1) the extent to which the fair value is less than the amortized cost basis; 2) the financial condition and near term prospects of the issuer, including consideration of relevant financial metrics or ratios of the issuer; 3) any adverse conditions related to an industry or geographic area of an issuer; 4) any changes to the rating of the security by a rating agency; and 5) any past due principal or interest payments from the issuer. If an assessment of the above factors indicates that a credit loss exists, the Company records an allowance for credit losses for the excess of the amortized cost basis over the present value of cash flows expected to be collected, limited to the amount that the security's fair value is less than its amortized cost basis. Subsequent changes in the allowance for credit losses are recorded as a provision for (or reversal of) credit loss expense. Interest accruals and amortization and accretion of premiums and discounts are suspended when the credit loss is recognized in earnings. Any interest received after the security has been placed on nonaccrual status is recognized on a cash basis. Accrued interest receivable on AFS securities, which is included in other assets on the Consolidated Balance Sheet, is excluded from the estimate of expected credit losses. For each AFS security in an unrealized loss position, the Company also considers: 1) its intent to retain the security until anticipated recovery of the security's fair value; and 2) whether it is more-likely-than not that the Company would be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the debt security is written down to its fair value and the write-down is charged against the allowance for credit losses with any incremental impairment recorded in earnings. Writeoffs are made through reversal of the allowance for credit losses and direct writeoff of the amortized cost basis of the AFS security. The Company considers the following events to be indicators that a writeoff should be taken: 1) bankruptcy of the issuer; 2) significant adverse event(s) affecting the issuer in which it is improbable for the issuer to make its remaining payments on the security; and 3) significant loss of value of the underlying collateral behind a security. Recoveries on debt securities, if any, are recorded in the period received. Restricted stock WAB is a member of the Federal Reserve System and, as part of its membership, is required to maintain stock in the FRB in a specified ratio to its capital. In addition, WAB is a member of the FHLB system and, accordingly, maintains an investment in capital stock of the FHLB based on the borrowing capacity used. These investments are considered equity securities with no actively traded market. Therefore, the shares are considered restricted investment securities. These investments are carried at cost, which is equal to the value at which they may be redeemed. The dividend income received from the stock is reported in interest income. The Company conducts a periodic review and evaluation of its restricted stock to determine if any impairment exists. No impairment has been recorded to date. Loans held for sale Loans held for sale consist of loans that the Company originates (or acquires) and intends to sell. These loans are carried at the lower of aggregate cost or fair value. Fair value is determined based on quoted fair market values or, when not available, discounted cash flows or appraisals of underlying collateral or the credit quality of the borrower. Loans held for investment Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at amortized cost. Amortized cost is the amount of unpaid principal, adjusted for unamortized net deferred fees and costs, premiums and discounts, and writeoffs. In addition, the amortized cost of loans subject to a fair value hedge are adjusted for changes in value attributable to the effective portion of the hedged benchmark interest rate risk. The Company may also purchase loans or acquire loans through a business combination. At the purchase or acquisition date, loans are evaluated to determine if there has been more than insignificant credit deterioration since origination. Loans that have experienced more than insignificant credit deterioration since origination are referred to as PCD loans. In its evaluation of whether a loan has experienced more than insignificant deterioration in credit quality since origination, the Company takes into consideration loan grades, loan-to-values greater than policy limits, past due and nonaccrual status, and TDR loans. The Company may also consider external credit rating agency ratings for borrowers and for non-commercial loans, FICO score or band, probability of default levels, number of times past due, and standard deviations corresponding to FICO score or band. The initial estimate of credit losses on PCD loans is added to the purchase price on the acquisition date to establish the initial amortized cost basis of the loan; accordingly, the initial recognition of expected credit losses has no impact on net income. When the initial measurement of expected credit losses on PCD loans are calculated on a pooled loan basis, the expected credit losses are allocated to each loan within the pool. Any difference between the initial amortized cost basis and the unpaid principal balance of the loan represents a noncredit discount or premium, which is accreted (or amortized) into interest income over the life of the loan. Subsequent changes to the allowance for credit losses on PCD loans are recorded through the provision for credit losses. For purchased loans that are not deemed to have experienced more than insignificant credit deterioration since origination, any discounts or premiums included in the purchase price are accreted (or amortized) over the contractual life of the individual loan. For additional information, see "Note 3. Loans, Leases and Allowance for Credit Losses" of these Notes to Unaudited Consolidated Financial Statements. In applying the effective yield method to loans, the Company generally applies the contractual method whereby loan fees collected for the origination of loans less direct loan origination costs (net of deferred loan fees), as well as premiums and discounts and certain purchase accounting adjustments, are amortized over the contractual life of the loan through interest income. If a loan has scheduled payments, the amortization of the net deferred loan fee is calculated using the interest method over the contractual life of the loan. If a loan does not have scheduled payments, such as a line of credit, the net deferred loan fee is recognized as interest income on a straight-line basis over the contractual life of the loan commitment. Commitment fees based on a percentage of a customer’s unused line of credit and fees related to standby letters of credit are recognized over the commitment period. When loans are repaid, any remaining unamortized balances of premiums, discounts, or net deferred fees are recognized as interest income. Conversely, with respect to loans originated under the PPP, the Company incorporates projected prepayments in calculating effective yield. As a result, net deferred fees are accreted into interest income faster than would be the case when applying the contractual method based upon the timing and amount of estimated forgiven loan balances. The Company expects that a majority of PPP loans will qualify for forgiveness under the SBA program, based on requested loan amounts largely representing qualifying expenses at the time of application. Nonaccrual loans When a borrower discontinues making payments as contractually required by the note, the Company must determine whether it is appropriate to continue to accrue interest. The Company ceases accruing interest income when the loan has become delinquent by more than 90 days or when management determines that the full repayment of principal and collection of interest according to contractual terms is no longer likely. Past due status is based on the

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Investment Securities	d fair values of investment securities at September 30, 2020 and December 31, 2019 are summarized as follows: September 30, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Fair Value (in thousands) Held-to-maturity Tax-exempt $ 504,477 $ 43,663 $ — $ 548,140 Available-for-sale debt securities CDO $ 50 $ 8,126 $ — $ 8,176 Commercial MBS issued by GSEs 91,769 3,888 — 95,657 Corporate debt securities 193,798 1,081 (8,270) 186,609 Municipal securities 22,006 271 (118) 22,159 Private label residential MBS 1,245,217 19,874 (854) 1,264,237 Residential MBS issued by GSEs 1,329,773 32,314 (531) 1,361,556 Tax-exempt 961,373 51,117 (1,467) 1,011,023 Trust preferred securities 32,000 — (6,792) 25,208 U.S. treasury securities 600 — — 600 Total AFS debt securities $ 3,876,586 $ 116,671 $ (18,032) $ 3,975,225 Equity securities CRA investments $ 53,190 $ 355 $ — $ 53,545 Preferred stock 104,974 3,976 (1,934) 107,016 Total equity securities $ 158,164 $ 4,331 $ (1,934) $ 160,561 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Fair Value (in thousands) Held-to-maturity Tax-exempt $ 485,107 $ 31,303 $ (149) $ 516,261 Available-for-sale debt securities CDO $ 50 $ 10,092 $ — $ 10,142 Commercial MBS issued by GSEs 95,062 366 (1,175) 94,253 Corporate debt securities 105,015 112 (5,166) 99,961 Municipal securities 7,494 279 — 7,773 Private label residential MBS 1,129,985 3,572 (4,330) 1,129,227 Residential MBS issued by GSEs 1,406,594 9,283 (3,817) 1,412,060 Tax-exempt 530,729 24,548 (422) 554,855 Trust preferred securities 32,000 — (4,960) 27,040 U.S. government sponsored agency securities 10,000 — — 10,000 U.S. treasury securities 999 — — 999 Total AFS debt securities $ 3,317,928 $ 48,252 $ (19,870) $ 3,346,310 Equity securities CRA investments $ 52,805 $ — $ (301) $ 52,504 Preferred stock 82,514 3,881 (198) 86,197 Total equity securities $ 135,319 $ 3,881 $ (499) $ 138,701 Securities with carrying amounts of approximately $830.4 million and $962.5 million at September 30, 2020 and December 31, 2019, respectively, were pledged for various purposes as required or permitted by law. The following tables summarize the Company's AFS debt securities in an unrealized loss position at September 30, 2020 and December 31, 2019, aggregated by major security type and length of time in a continuous unrealized loss position: September 30, 2020 Less Than Twelve Months More Than Twelve Months Total Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value (in thousands) Available-for-sale debt securities Corporate debt securities $ 70 $ 31,528 $ 8,200 $ 91,800 $ 8,270 $ 123,328 Municipal securities 118 9,384 — — 118 9,384 Private label residential MBS 851 131,620 3 2,435 854 134,055 Residential MBS issued by GSEs 522 134,180 9 1,193 531 135,373 Tax-exempt 1,467 121,031 — — 1,467 121,031 Trust preferred securities — — 6,792 25,208 6,792 25,208 Total AFS securities $ 3,028 $ 427,743 $ 15,004 $ 120,636 $ 18,032 $ 548,379 December 31, 2019 Less Than Twelve Months More Than Twelve Months Total Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value (in thousands) Held-to-maturity Tax-exempt $ 149 $ 24,325 $ — $ — $ 149 $ 24,325 Available-for-sale debt securities Commercial MBS issued by GSEs $ 85 $ 9,035 $ 1,090 $ 54,604 $ 1,175 $ 63,639 Corporate debt securities — — 5,166 94,834 5,166 94,834 Private label residential MBS 1,776 337,285 2,554 258,791 4,330 596,076 Residential MBS issued by GSEs 1,740 385,643 2,077 150,419 3,817 536,062 Tax-exempt 422 67,150 — — 422 67,150 Trust preferred securities — — 4,960 27,040 4,960 27,040 Total AFS securities $ 4,023 $ 799,113 $ 15,847 $ 585,688 $ 19,870 $ 1,384,801 The total number of AFS securities in an unrealized loss position at September 30, 2020 is 73, compared to 158 at December 31, 2019. On January 1, 2020, the Company adopted the amendments within ASU 2016-13, which replaces the legacy US GAAP OTTI model with a credit loss model. The credit loss model under ASC 326-30, applicable to AFS debt securities, requires recognition of credit losses through an allowance account, but retains the concept from the OTTI model that credit losses are recognized once securities become impaired. For a detailed discussion of the impact of adoption of ASU 2016-13 and information related to investment securities, including accounting policies and methodologies used to estimate the allowance for credit losses on securities, see "Note 1. Summary of Significant Accounting Policies ." Residential MBS issued by GSEs held by the Company are issued by U.S. government entities and agencies. These securities are either explicitly or implicitly guaranteed by the U.S. government, are highly rated by major rating agencies, and have a long history of no credit losses. As the Company does not intend to sell these securities and it is more likely than not that the Company will not be required to sell the securities prior to their anticipated recovery, no credit losses have been recognized on these securities during the three and nine months ended September 30, 2020. Qualitative factors used in the Company's credit loss assessment of its securities that are not guaranteed by the U.S. government included consideration of any adverse conditions related to a specific security, industry, or geographic region of its securities, any credit ratings below investment grade, the payment structure of the security and the likelihood of the issuer to be able to make payments that increase in the future, and failure of the issuer to make any scheduled principal or interest payments. For the Company's corporate debt, municipal, and tax-exempt securities, the Company also considered various metrics of the issuer including days of cash on hand, the ratio of long-term debt to total assets, the net change in cash between reporting periods, and consideration of any breach in covenant requirements. For the Company's private label residential MBS, the Company also considered metrics such as securitization risk weight factor, current credit support, whether there were any mortgage principal losses resulting from defaults in payments on the underlying mortgage collateral, and the credit default rate over the last twelve months. As of September 30, 2020, no credit losses on the Company's corporate debt, municipal, and tax-exempt securities have been recognized. The Company's corporate debt and tax-exempt securities continue to be highly rated, issuers continue to make timely principal and interest payments, and the unrealized losses on these security portfolios primarily relate to changes in interest rates and other market conditions that are not considered to be credit-related issues. The Company is continuing to receive timely principal and interest payments on its municipal securities and the majority of these issuers have revenues pledged for payment of debt service prior to payment of other types of expenses. Further, the Company does not intend to sell these securities and it is more likely than not that the Company will not be required to sell these securities prior to their anticipated recovery. The Company's private label residential MBS are non-agency collateralized mortgage obligations and primarily carry investment grade credit ratings as of September 30, 2020. These securities are secured by pools of residential mortgage loans. Credit losses have not been recognized on these securities as of September 30, 2020 as principal and interest payments on these securities continue to be made on a timely basis, credit support for these securities is considered adequate, and as the Company does not intend to sell these securities and it is more likely than not that the Company will not be required to sell these securities prior to their anticipated recovery. The Company's trust preferred securities are investment grade and the issuer continues to make timely principal and interest payments. Based on the qualitative factors discussed above, no allowance for credit losses for the Company's AFS debt securities has been recognized as of September 30, 2020. The credit loss model under ASC 326-20, applicable to HTM debt securities, requires recognition of lifetime expected credit losses through an allowance account at the time the security is purchased. The following tables present a rollforward by major security type of the allowance for credit losses for the Company's HTM debt securities: Three Months Ended September 30, 2020 Balance, Provision for (Reversal of) Credit Losses Writeoffs Recoveries Balance, June 30, 2020 September 30, 2020 (in thousands) Held-to-maturity debt securities Tax-exempt $ 7,649 $ (1,685) $ — $ — $ 5,964 Nine Months Ended September 30, 2020 Balance, Provision for (Reversal of) Credit Losses Writeoffs Recoveries Balance, January 1, 2020 September 30, 2020 (in thousands) Held-to-maturity debt securities Tax-exempt $ 2,646 $ 3,318 $ — $ — $ 5,964 Accrued interest receivable on HTM securities totaled $1.8 million at September 30, 2020 and is excluded from the estimate of credit losses. The following tables summarize the carrying amount of the Company’s investment ratings position as of September 30, 2020 and December 31, 2019, which are updated quarterly and used to monitor the credit quality of the Company's securities: September 30, 2020 AAA Split-rated AAA/AA+ AA+ to AA- A+ to A- BBB+ to BBB- BB+ and below Unrated Totals (in thousands) Held-to-maturity Tax-exempt $ — $ — $ — $ — $ — $ — $ 504,477 $ 504,477 Available-for-sale debt securities CDO $ — $ — $ — $ — $ — $ 8,176 $ — $ 8,176 Commercial MBS issued by GSEs — 95,657 — — — — — 95,657 Corporate debt securities — — — 45,800 122,579 18,230 — 186,609 Municipal securities — — 12,143 — 2,630 — 7,386 22,159 Private label residential MBS 1,235,170 — 27,682 91 347 947 — 1,264,237 Residential MBS issued by GSEs — 1,361,556 — — — — — 1,361,556 Tax-exempt 43,328 56,725 447,629 431,459 — — 31,882 1,011,023 Trust preferred securities — — — — 25,208 — — 25,208 U.S. treasury securities — 600 — — — — — 600 Total AFS securities (1) $ 1,278,498 $ 1,514,538 $ 487,454 $ 477,350 $ 150,764 $ 27,353 $ 39,268 $ 3,975,225 Equity securities CRA investments $ — $ 27,795 $ — $ — $ — $ — $ 25,750 $ 53,545 Preferred stock — — — — 68,945 37,135 936 107,016 Total equity securities (1) $ — $ 27,795 $ — $ — $ 68,945 $ 37,135 $ 26,686 $ 160,561 (1) Where ratings differ, the Company uses an average of the available ratings by major credit agencies. December 31, 2019 AAA Split-rated AAA/AA+ AA+ to AA- A+ to A- BBB+ to BBB- BB+ and below Unrated Totals (in thousands) Held-to-maturity Tax-exempt $ — $ — $ — $ — $ — $ — $ 485,107 $ 485,107 Available-for-sale debt securities CDO $ — $ — $ — $ — $ — $ 10,142 $ — $ 10,142 Commercial MBS issued by GSEs — 94,253 — — — — — 94,253 Corporate debt securities — — — 66,530 33,431 — — 99,961 Municipal securities — — — — — — 7,773 7,773 Private label residential MBS 1,096,909 — 30,675 181 288 1,174 — 1,129,227 Residential MBS issued by GSEs — 1,412,060 — — — — — 1,412,060 Tax-exempt 52,610 2,856 327,657 171,732 — — — 554,855 Trust preferred securities — — — — 27,040 — — 27,040 U.S. government sponsored agency securities — 10,000 — — — — — 10,000 U.S. treasury securities — 999 — — — — — 999 Total AFS securities (1) $ 1,149,519 $ 1,520,168 $ 358,332 $ 238,443 $ 60,759 $ 11,316 $ 7,773 $ 3,346,310 Equity securities CRA investments $ — $ 25,375 $ — $ — $ — $ — $ 27,129 $ 52,504 Preferred stock — — — — 82,851 2,105 1,241 86,197 Total equity securities (1) $ — $ 25,375 $ — $ — $ 82,851 $ 2,105 $ 28,370 $ 138,701 (1) Where ratings differ, the Company uses an average of the available ratings by major credit agencies. A security is considered to be past due once it is 30 days contractually past due under the terms of the agreement. As of September 30, 2020, there were no investment securities that were past due. In addition, the Company does not have a significant amount of investment securities on nonaccrual status or securities that are considered to be collateral-dependent as of September 30, 2020. The amortized cost and fair value of the Company's debt securities as of September 30, 2020, by contractual maturities, are shown below. MBS are shown separately as individual MBS are comprised of pools of loans with varying maturities. Therefore, these securities are listed separately in the maturity summary. September 30, 2020 Amortized Cost Estimated Fair Value (in thousands) Held-to-maturity Due in one year or less $ 7,330 $ 7,336 After one year through five years 17,135 17,628 After ten years 480,012 523,176 Total HTM securities $ 504,477 $ 548,140 Available-for-sale Due in one year or less $ 600 $ 600 After one year through five years 9,024 9,047 After five years through ten years 229,899 223,844 After ten years 970,304 1,020,284 Mortgage-backed securities 2,666,759 2,721,450 Total AFS securities $ 3,876,586 $ 3,975,225 The following table presents gross gains and losses on sales of investment securities: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Available-for-sale securities Gross gains $ — $ 3,152 $ 405 $ 3,152 Gross losses — — (175) — Net gains (losses) on AFS securities $ — $ 3,152 $ 230 $ 3,152

Other Borrowings

Other Borrowings	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Other Borrowings	The following table summarizes the Company’s borrowings as of September 30, 2020 and December 31, 2019: September 30, 2020 December 31, 2019 (in thousands) Short-Term: Federal funds purchased $ — $ — FHLB advances 10,000 — Total short-term borrowings $ 10,000 $ — The Company maintains federal fund lines of credit totaling $2.4 billion as of September 30, 2020, which have rates comparable to the federal funds effective rate plus 0.10% to 0.20%. As of September 30, 2020 and December 31, 2019, there were no outstanding balances on the Company's federal fund lines of credit. The Company also maintains secured lines of credit with the FHLB and the FRB. The Company’s borrowing capacity is determined based on collateral pledged, generally consisting of investment securities and loans, at the time of the borrowing. The Company has a PPP lending facility with the FRB that allows the Company to pledge loans originated under the PPP in return for dollar for dollar funding from the FRB, which would provide up to $1.8 billion in additional credit. The amount of available credit under the PPP lending facility will decline each period as these loans are paid down. At September 30, 2020, the Company had no amounts outstanding under its line of credit or its PPP lending facility with the FRB and had $10.0 million in borrowings under its lines of credit with the FHLB. As of September 30, 2020 and December 31, 2019, the Company had additional available credit with the FHLB of approximately $4.4 billion and $4.5 billion, respectively, and with the FRB of approximately $2.4 billion and $1.1 billion, respectively.

Qualifying Debt

Qualifying Debt	9 Months Ended
	Sep. 30, 2020
Qualifying Debt Disclosure [Abstract]
Qualifying Debt	Subordinated Debt The Company's subordinated debt consists of three separate issuances. The Parent issued $175.0 million of subordinated debentures in June 2016, which were recorded net of issuance costs of $5.5 million, and mature July 1, 2056. Beginning on or after July 1, 2021, the Company may redeem the debentures, in whole or in part, at their principal amount plus any accrued and unpaid interest. The debentures have a fixed interest rate of 6.25% per annum. In June 2015, WAB issued $150.0 million of subordinated debt, which was recorded net of debt issuance costs of $1.8 million, and matures July 15, 2025. The subordinated debt is redeemable by WAB, in whole or in part, on or after July 15, 2020 and on every interest payment date thereafter, for a price equal to the principal amount plus accrued and unpaid interest. The subordinated debt had a fixed interest rate of 5.00% through June 30, 2020, which then converted to a variable rate of 3.20% plus three-month LIBOR through maturity. Subsequent to September 30, 2020, WAB redeemed $75 million of this subordinated debt issuance. In May 2020, WAB issued $225.0 million of subordinated debt, which was recorded net of debt issuance costs of $3.1 million, and matures June 1, 2030. The subordinated debt is redeemable by WAB, in whole or in part, on or after June 1, 2025 and on every interest payment date thereafter, at a redemption price equal to the principal amount plus accrued and unpaid interest. The subordinated debt has a fixed interest rate of 5.25% through June 1, 2025 and then converts to a floating rate per annum equal to the three-month SOFR plus 512 basis points for each quarterly interest period during the floating rate period. To hedge the interest rate risk on the Company's 2015 and 2016 subordinated debt issuances, the Company entered into fair value interest rate hedges with receive fixed/pay variable swaps. The carrying value of all subordinated debt issuances, which includes the fair value of the related hedges, totals $545.3 million and $319.2 million at September 30, 2020 and December 31, 2019, respectively. Junior Subordinated Debt The Company has formed or acquired through acquisition eight statutory business trusts, which exist for the exclusive purpose of issuing Cumulative Trust Preferred Securities. With the exception of debt issued by Bridge Capital Trust I and Bridge Capital Trust II, junior subordinated debt is recorded at fair value at each reporting date due to the FVO election made by the Company under ASC 825. The Company did not make the FVO election for the junior subordinated debt acquired as part of the Bridge acquisition. Accordingly, the carrying value of these trusts does not reflect the current fair value of the debt and includes a fair market value adjustment established at acquisition that is being accreted over the remaining life of the trusts. The carrying value of junior subordinated debt was $73.5 million and $74.4 million as of September 30, 2020 and December 31, 2019, respectively. The weighted average interest rate of all junior subordinated debt as of September 30, 2020 was 2.57%, which is three-month LIBOR plus the contractual spread of 2.34%, compared to a weighted average interest rate of 4.25% at December 31, 2019. In the event of certain changes or amendments to regulatory requirements or federal tax rules, the debt is redeemable in whole. The obligations under these instruments are fully and unconditionally guaranteed by the Company and rank subordinate and junior in right of payment to all other liabilities of the Company. Based on guidance issued by the FRB, the Company's securities continue to qualify as Tier 1 Capital.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2020
Stockholders' Equity Note [Abstract]
Stockholder's Equity	Stock-Based Compensation Restricted Stock Awards Restricted stock awards granted to employees generally vest over a 3-year period. Stock grants made to non-employee WAL directors in 2020 were fully vested on July 1, 2020. The Company estimates the compensation cost for stock grants based upon the grant date fair value. Stock compensation expense is recognized on a straight-line basis over the requisite service period for the entire award. The aggregate grant date fair value for the restricted stock awards granted during the three and nine months ended September 30, 2020 was zero and $22.3 million, respectively. Stock compensation expense related to restricted stock awards granted to employees are included in Salaries and employee benefits in the Consolidated Income Statement. For restricted stock awards granted to WAL directors, related stock compensation expense is included in Legal, professional, and directors' fees. For the three and nine months ended September 30, 2020, the Company recognized $4.5 million and $15.3 million in stock-based compensation expense related to these stock grants, compared to $4.0 million and $13.7 million for the three and nine months ended September 30, 2019. In addition, the Company previously granted shares of restricted stock to certain members of executive management that had both performance and service conditions that affect vesting. There were no such grants made during the three and nine months ended September 30, 2020 and 2019, however expense is still being recognized for a grant made in 2017 with a four-year vesting period. For the three and nine months ended September 30, 2020, the Company recognized $0.3 million and $0.9 million in stock-based compensation expense related to these performance-based restricted stock grants, compared to $0.5 million and $1.5 million for the three and nine months ended September 30, 2019. Performance Stock Units The Company grants performance stock units to members of its executive management that do not vest unless the Company achieves a specified cumulative EPS target and a TSR performance measure over a three-year performance period. The number of shares issued will vary based on the cumulative EPS target and relative TSR performance factor that is achieved. The Company estimates the cost of performance stock units based upon the grant date fair value and expected vesting percentage over the three-year performance period. For the three and nine months ended September 30, 2020, the Company recognized $1.8 million and $5.3 million in stock-based compensation expense related to these performance stock units, compared to $1.6 million and $4.5 million for the three and nine months ended September 30, 2019. The three-year performance period for the 2017 grant ended on December 31, 2019, and the Company's cumulative EPS and TSR performance measure for the performance period exceeded the level required for a maximum award under the terms of the grant. As a result, 136,334 shares became fully vested and was distributed to executive management in the first quarter of 2020. Common Stock Repurchase The Company's common stock repurchase program was renewed through December 2020, authorizing the Company to repurchase up to $250.0 million of its outstanding common stock. Effective April 17, 2020, the Company temporarily suspended its stock repurchase program. Prior to this decision and pursuant to the repurchase plan, the Company repurchased 2,066,479 shares of its common stock at a weighted average price of $34.65 for a total payment of $71.7 million. During the three and nine months ended September 30, 2019, the Company repurchased 1,000,000 and 2,733,603 shares of its common stock at a weighted average price of $43.63 and $42.25 for a total payment of $43.7 million and $115.6 million, respectively. Cash Dividend During the three and nine months ended September 30, 2020, the Company declared and paid a quarterly cash dividend of $0.25 per share, for a total dividend payment to shareholders of $25.2 million and $76.0 million, respectively. During the three and nine months ended September 30, 2019, the Company declared and paid one quarterly cash dividend of $0.25 per share of common stock, totaling $25.7 million. Treasury Shares

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Accumulated Other Comprehensive Income	The following table summarizes the changes in accumulated other comprehensive income by component, net of tax, for the periods indicated: Three Months Ended September 30, Unrealized holding gains (losses) on AFS Unrealized holding gains (losses) on SERP Unrealized holding gains (losses) on junior subordinated debt Impairment loss on securities Total (in thousands) Balance, June 30, 2020 $ 66,809 $ (313) $ 7,181 $ — $ 73,677 Other comprehensive income (loss) before reclassifications 7,592 (3) (2,681) — 4,908 Amounts reclassified from AOCI — — — — — Net current-period other comprehensive income (loss) 7,592 (3) (2,681) — 4,908 Balance, September 30, 2020 $ 74,401 $ (316) $ 4,500 $ — $ 78,585 Balance, June 30, 2019 $ 19,709 $ 357 $ 6,171 $ 144 $ 26,381 Other comprehensive income (loss) before reclassifications 11,014 (18) 598 — 11,594 Amounts reclassified from AOCI (2,232) — — (144) (2,376) Net current-period other comprehensive income (loss) 8,782 (18) 598 (144) 9,218 Balance, September 30, 2019 $ 28,491 $ 339 $ 6,769 $ — $ 35,599 Nine Months Ended September 30, Unrealized holding gains (losses) on AFS Unrealized holding gains (losses) on SERP Unrealized holding gains (losses) on junior subordinated debt Impairment loss on securities Total (in thousands) Balance, December 31, 2019 $ 21,399 $ (20) $ 3,629 $ — $ 25,008 Other comprehensive income (loss) before reclassifications 53,176 (296) 871 — 53,751 Amounts reclassified from AOCI (174) — — — (174) Net current-period other comprehensive income (loss) 53,002 (296) 871 — 53,577 Balance, September 30, 2020 $ 74,401 $ (316) $ 4,500 $ — $ 78,585 Balance, December 31, 2018 $ (47,591) $ 392 $ 13,433 $ 144 $ (33,622) Other comprehensive income (loss) before reclassifications 78,314 (53) (6,664) — 71,597 Amounts reclassified from AOCI (2,232) — — (144) (2,376) Net current-period other comprehensive income (loss) 76,082 (53) (6,664) (144) 69,221 Balance, September 30, 2019 $ 28,491 $ 339 $ 6,769 $ — $ 35,599 The following table presents reclassifications out of accumulated other comprehensive income: Three Months Ended September 30, Nine Months Ended September 30, Income Statement Classification 2020 2019 2020 2019 (in thousands) Gain (loss) on sales of investment securities, net $ — $ 3,152 $ 230 $ 3,152 Income tax (expense) benefit — (776) (56) (776) Net of tax $ — $ 2,376 $ 174 $ 2,376

Derivatives and Hedging

Derivatives and Hedging	9 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	The Company is a party to various derivative instruments. Derivative instruments are contracts between two or more parties that have a notional amount and an underlying variable, require a small or no initial investment, and allow for the net settlement of positions. A derivative’s notional amount serves as the basis for the payment provision of the contract and takes the form of units, such as shares or dollars. A derivative’s underlying variable is a specified interest rate, security price, commodity price, foreign exchange rate, index, or other variable. The interaction between the notional amount and the underlying variable determines the number of units to be exchanged between the parties and influences the fair value of the derivative contract. The primary type of derivatives that the Company uses are interest rate swaps. Generally, these instruments are used to help manage the Company's exposure to interest rate risk and meet client financing and hedging needs. Derivatives are recorded at fair value on the Consolidated Balance Sheets, after taking into account the effects of bilateral collateral and master netting agreements. These agreements allow the Company to settle all derivative contracts held with the same counterparty on a net basis, and to offset net derivative positions with related cash collateral, where applicable. As of September 30, 2020, December 31, 2019, and September 30, 2019, the Company does not have any outstanding cash flow hedges. Derivatives Designated in Hedge Relationships The Company utilizes derivatives that have been designated as part of a hedge relationship in accordance with the applicable accounting guidance to minimize the exposure to changes in benchmark interest rates and volatility of net interest income and EVE to interest rate fluctuations. The primary derivative instruments used to manage interest rate risk are interest rate swaps, which convert the contractual interest rate index of agreed-upon amounts of assets and liabilities (i.e., notional amounts) from either a fixed rate to a floating rate, or from a floating rate to a fixed rate. The Company has entered into pay fixed/receive variable interest rate swaps designated as fair value hedges of certain fixed rate loans. As a result, the Company receives variable-rate interest payments in exchange for making fixed-rate payments over the lives of the contracts without exchanging the notional amounts. The Company has also entered into receive fixed/pay variable interest rate swaps, designated as fair value hedges on its fixed rate 2015 and 2016 subordinated debt offerings. As a result, the Company is paying a floating rate of three-month LIBOR plus 3.16% and is receiving semi-annual fixed payments of 5.00% to match the payments on the $150.0 million subordinated debt. For the fair value hedge on the Parent's $175.0 million subordinated debentures issued on June 16, 2016, the Company is paying a floating rate of three-month LIBOR plus 3.25% and is receiving quarterly fixed payments of 6.25% to match the payments on the debt. Derivatives Not Designated in Hedge Relationships Management also enters into certain foreign exchange derivative contracts and back-to-back interest rate swaps which are not designated as accounting hedges. Foreign exchange derivative contracts include spot, forward, forward window, and swap contracts. The purpose of these derivative contracts is to mitigate foreign currency risk on transactions entered into, or on behalf of customers. Contracts with customers, along with the related derivative trades that the Company places, are both remeasured at fair value, and are referred to as economic hedges since they economically offset the Company's exposure. The Company's back-to-back interest rate swaps are used to manage long-term interest rate risk. Fair Value Hedges As of September 30, 2020 and December 31, 2019, the following amounts are reflected on the Consolidated Balance Sheets related to cumulative basis adjustments for fair value hedges: September 30, 2020 December 31, 2019 Carrying Value of Hedged Assets/(Liabilities) Cumulative Fair Value Hedging Adjustment (1) Carrying Value of Hedged Assets/(Liabilities) Cumulative Fair Value Hedging Adjustment (1) (in thousands) Loans - HFI, net of deferred loan fees and costs $ 596,505 $ 92,352 $ 578,063 $ 53,292 Qualifying debt (323,386) (3,417) (319,197) 401 (1) Included in the carrying value of the hedged assets/(liabilities). For the Company's derivative instruments that are designated and qualify as a fair value hedge, the effective portion is recorded as a basis adjustment to the hedged asset or liability, and the ineffective portion is recorded in non-interest income. Fair Values, Volume of Activity, and Gain/Loss Information Related to Derivative Instruments The following table summarizes the fair values of the Company's derivative instruments on a gross and net basis as of September 30, 2020, December 31, 2019, and September 30, 2019. The change in the notional amounts of these derivatives from September 30, 2019 to September 30, 2020 indicates the volume of the Company's derivative transaction activity during these periods. The derivative asset and liability balances are presented on a gross basis, prior to the application of bilateral collateral and master netting agreements. Total derivative assets and liabilities are adjusted to take into account the impact of legally enforceable master netting agreements that allow the Company to settle all derivative contracts with the same counterparty on a net basis and to offset the net derivative position with the related collateral. Where master netting agreements are not in effect or are not enforceable under bankruptcy laws, the Company does not adjust those derivative amounts with counterparties. The fair value of derivative contracts, after taking into account the effects of master netting agreements, is included in other assets or other liabilities on the Consolidated Balance Sheets, as indicated in the following table: September 30, 2020 December 31, 2019 September 30, 2019 Fair Value Fair Value Fair Value Notional Derivative Assets Derivative Liabilities Notional Derivative Assets Derivative Liabilities Notional Derivative Assets Derivative Liabilities (in thousands) Derivatives designated as hedging instruments: Fair value hedges Interest rate swaps $ 692,348 $ 3,417 $ 92,352 $ 862,952 $ 1,778 $ 55,471 $ 865,321 $ — $ 63,970 Total 692,348 3,417 92,352 862,952 1,778 55,471 865,321 — 63,970 Netting adjustments (1) — — — — 21 21 — — — Net $ 692,348 $ 3,417 $ 92,352 $ 862,952 $ 1,757 $ 55,450 $ 865,321 $ — $ 63,970 Derivatives not designated as hedging instruments: Foreign currency contracts $ 38,922 $ 460 $ 401 $ 6,711 $ 44 $ 18 $ 15,329 $ 191 $ 127 Interest rate swaps 3,517 242 242 2,932 81 81 2,932 124 124 Total $ 42,439 $ 702 $ 643 $ 9,643 $ 125 $ 99 $ 18,261 $ 315 $ 251 (1) Netting adjustments represent the amounts recorded to convert the Company's derivative balances from a gross basis to a net basis in accordance with the applicable accounting guidance. Counterparty Credit Risk Like other financial instruments, derivatives contain an element of credit risk. This risk is measured as the expected replacement value of the contracts. Management enters into bilateral collateral and master netting agreements that provide for the net settlement of all contracts with the same counterparty. Additionally, management monitors counterparty credit risk exposure on each contract to determine appropriate limits on the Company's total credit exposure across all product types, which may require the Company to post collateral to counterparties when these contracts are in a net liability position and conversely, for counterparties to post collateral to the Company when these contracts are in a net asset position. In general, the Company has a zero credit threshold with regard to derivative exposure with counterparties. Management reviews the Company's collateral positions on a daily basis and exchanges collateral with counterparties in accordance with standard ISDA documentation and other related agreements. The Company generally posts or holds collateral in the form of cash deposits or highly rated securities issued by the U.S. Treasury or government-sponsored enterprises, such as GNMA, FNMA, and FHLMC. The total collateral pledged by the Company to counterparties exceeded its net derivative liabilities as of September 30, 2020, December 31, 2019, and September 30, 2019, resulting in excess collateral postings of $14.6 million, $29.2 million and $31.0 million, respectively. The following table summarizes the Company's largest exposure to an individual counterparty at the dates indicated: September 30, 2020 December 31, 2019 September 30, 2019 (in thousands) Largest gross exposure (derivative asset) to an individual counterparty $ 3,417 $ 1,757 $ — Collateral posted by this counterparty — 1,610 — Derivative liability with this counterparty — — — Collateral pledged to this counterparty — — — Net exposure after netting adjustments and collateral $ 3,417 $ 147 $ —

Earnings per Share

Earnings per Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Share	Diluted EPS is based on the weighted average outstanding common shares during each period, including common stock equivalents. Basic EPS is based on the weighted average outstanding common shares during the period. The following table presents the calculation of basic and diluted EPS: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands, except per share amounts) Weighted average shares - basic 99,850 102,041 100,322 103,024 Dilutive effect of stock awards 209 410 252 444 Weighted average shares - diluted 100,059 102,451 100,574 103,468 Net income $ 135,769 $ 127,375 $ 313,005 $ 371,107 Earnings per share - basic 1.36 1.25 3.12 3.60 Earnings per share - diluted 1.36 1.24 3.11 3.59 The Company had no anti-dilutive stock options outstanding at each of the periods ended September 30, 2020 and 2019.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	The Company's effective tax rate was 18.50% and 18.30% for the three months ended September 30, 2020 and 2019, respectively. For the nine months ended September 30, 2020 and 2019, the Company's effective tax rate was 18.05% and 17.52%, respectively. The increase in the effective tax rate from the three and nine months ended September 30, 2019 is due primarily to tax expense associated with a surrender of bank owned life insurance, detriments from vested stock compensation and increased state tax accruals, partially offset by increases in forecasted tax-exempt income and investment tax credits in 2020. As of September 30, 2020, the net deferred tax asset was $46.6 million, an increase of $28.6 million from December 31, 2019. This overall increase in the net deferred tax asset was primarily the result of an increase in the allowance for credit losses under the new CECL accounting guidance, which upon adoption on January 1, 2020, increased the deferred tax asset by $8.7 million. Expected tax credit carryovers which were not fully offset by additional unrealized gains on AFS securities also contributed to the increase. For a detailed discussion of the impact of adoption of CECL, see "Note 1. Summary of Significant Accounting Policies ." Although realization is not assured, the Company believes that the realization of the recognized deferred tax asset of $46.6 million at September 30, 2020 is more-likely-than-not based on expectations as to future taxable income and based on available tax planning strategies that could be implemented if necessary to prevent a carryover from expiring. At September 30, 2020 and December 31, 2019, the Company had no deferred tax valuation allowance. As of September 30, 2020, the Company’s gross federal NOL carryovers after current year-to-date utilization, all of which are subject to limitations under Section 382 of the IRC, totaled approximately $44.6 million for which a deferred tax asset of $5.2 million has been recorded, reflecting the expected benefit of these remaining federal NOL carryovers. The Company also has varying gross amounts of state NOL carryovers, with the most significant in Arizona. The gross Arizona NOL carryovers totaled approximately $0.7 million. A deferred tax asset balance of $0.1 million as of September 30, 2020 has been recorded to reflect the expected benefit of all remaining state NOL carryovers. LIHTC and renewable energy projects The Company holds ownership interests in limited partnerships and limited liability companies that invest in affordable housing and renewable energy projects. These investments are designed to generate a return primarily through the realization of federal tax credits and deductions. The limited liability entities are considered to be VIEs; however, as a limited partner, the Company is not the primary beneficiary and is not required to consolidate these entities.

Fair Value Accounting

Fair Value Accounting	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Accounting	The fair value of an asset or liability is the price that would be received to sell that asset or paid to transfer that liability in an orderly transaction occurring in the principal market (or most advantageous market in the absence of a principal market) for such asset or liability. In estimating fair value, the Company utilizes valuation techniques that are consistent with the market approach, the income approach, and/or the cost approach. Such valuation techniques are consistently applied. Inputs to valuation techniques include the assumptions that market participants would use in pricing an asset or liability. ASC 825 establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy under ASC 825 are described in "Note 1. Summary of Significant Accounting Policies" of these Notes to Unaudited Consolidated Financial Statements. In general, fair value is based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon internally-developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments may include amounts to reflect counterparty credit quality and the Company’s creditworthiness, among other things, as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. The Company’s valuation methodologies may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. While management believes the Company’s valuation methodologies are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date. Furthermore, the reported fair value amounts have not been comprehensively revalued since the presentation dates, and therefore, estimates of fair value after the balance sheet date may differ significantly from the amounts presented herein. A more detailed description of the valuation methodologies used for assets and liabilities measured at fair value is set forth below. Under ASC 825, the Company elected the FVO treatment for junior subordinated debt issued by WAL. This election is irrevocable and results in the recognition of unrealized gains and losses on these items at each reporting date. These unrealized gains and losses are recognized as part of other comprehensive income rather than earnings. The Company did not elect FVO treatment for the junior subordinated debt assumed in the Bridge Capital Holdings acquisition. For the three and nine months ended September 30, 2020 and 2019, unrealized gains and losses from fair value changes on junior subordinated debt were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Unrealized (losses)/gains $ (3,555) $ 794 $ 1,156 $ (8,837) Changes included in OCI, net of tax (2,681) 598 871 (6,664) Fair value on a recurring basis Financial assets and financial liabilities measured at fair value on a recurring basis include the following: AFS securities: Securities classified as AFS are reported at fair value utilizing Level 1 and Level 2 inputs. For these securities, the Company obtains fair value measurements from an independent pricing service. The fair value measurements consider observable data that may include quoted prices in active markets, dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information, and the bond’s terms and conditions, among other things. Equity securities: Preferred stock and CRA investments are reported at fair value primarily utilizing Level 1 inputs. Independent pricing service: The Company's independent pricing service provides pricing information on the majority of the Company's Level 1 and Level 2 AFS securities. For a small subset of securities, other pricing sources are used, including observed prices on publicly traded securities and dealer quotes. Management independently evaluates the fair value measurements received from the Company's third-party pricing service through multiple review steps. First, management reviews what has transpired in the marketplace with respect to interest rates, credit spreads, volatility, and mortgage rates, among other things, and develops an expectation of changes to the securities' valuations from the previous quarter. Then, management selects a sample of investment securities and compares the values provided by its primary third-party pricing service to the market values obtained from secondary sources, including other pricing services and safekeeping statements, and evaluates those with notable variances. In instances where there are discrepancies in pricing from various sources and management expectations, management may manually price securities using currently observed market data to determine whether they can develop similar prices or may utilize bid information from broker dealers. Any remaining discrepancies between management’s review and the prices provided by the vendor are discussed with the vendor and/or the Company’s other valuation advisors. Interest rate swaps: Interest rate swaps are reported at fair value utilizing Level 2 inputs. The Company obtains dealer quotations to value its interest rate swaps. Junior subordinated debt: The Company estimates the fair value of its junior subordinated debt using a discounted cash flow model which incorporates the effect of the Company’s own credit risk in the fair value of the liabilities (Level 3). The Company’s cash flow assumptions are based on contractual cash flows as the Company anticipates that it will pay the debt according to its contractual terms. The fair value of assets and liabilities measured at fair value on a recurring basis was determined using the following inputs as of the periods presented: Fair Value Measurements at the End of the Reporting Period Using: Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Fair Value (in thousands) September 30, 2020 Assets: Available-for-sale debt securities CDO $ — $ 8,176 $ — $ 8,176 Commercial MBS issued by GSEs — 95,657 — 95,657 Corporate debt securities — 186,609 — 186,609 Municipal securities — 22,159 — 22,159 Private label residential MBS — 1,264,237 — 1,264,237 Residential MBS issued by GSEs — 1,361,556 — 1,361,556 Tax-exempt — 1,011,023 — 1,011,023 Trust preferred securities 25,208 — — 25,208 U.S. treasury securities — 600 — 600 Total AFS debt securities $ 25,208 $ 3,950,017 $ — $ 3,975,225 Equity securities CRA investments $ 27,795 $ 25,750 $ — $ 53,545 Preferred stock 107,016 — — 107,016 Total equity securities $ 134,811 $ 25,750 $ — $ 160,561 Loans - HFS $ — $ 20,764 $ — $ 20,764 Derivative assets (1) — 4,119 — 4,119 Liabilities: Junior subordinated debt (2) $ — $ — $ 60,529 $ 60,529 Derivative liabilities (1) — 92,995 — 92,995 (1) Derivative assets and liabilities relate primarily to interest rate swaps, see "Note 8. Derivatives and Hedging Activities." In addition, the carrying value of loans is increased by $92,352 and the net carrying value of subordinated debt is increased by $3,417 as of September 30, 2020 for the effective portion of the hedge, which relates to the fair value of the hedges put in place to mitigate against fluctuations in interest rates. (2) Includes only the portion of junior subordinated debt that is recorded at fair value at each reporting period pursuant to the election of FVO treatment. Fair Value Measurements at the End of the Reporting Period Using: Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Fair Value (in thousands) December 31, 2019 Assets: Available-for-sale debt securities CDO $ — $ 10,142 $ — $ 10,142 Commercial MBS issued by GSEs — 94,253 — 94,253 Corporate debt securities 5,127 94,834 — 99,961 Municipal securities — 7,773 — 7,773 Private label residential MBS — 1,129,227 — 1,129,227 Residential MBS issued by GSEs — 1,412,060 — 1,412,060 Tax-exempt — 554,855 — 554,855 Trust preferred securities 27,040 — — 27,040 U.S. government sponsored agency securities — 10,000 — 10,000 U.S. treasury securities — 999 — 999 Total AFS debt securities $ 32,167 $ 3,314,143 $ — $ 3,346,310 Equity securities CRA investments $ 52,504 $ — $ — $ 52,504 Preferred stock 86,197 — — 86,197 Total equity securities $ 138,701 $ — $ — $ 138,701 Loans - HFS $ — $ 21,803 $ — $ 21,803 Derivative assets (1) — 1,903 — 1,903 Liabilities: Junior subordinated debt (2) $ — $ — $ 61,685 $ 61,685 Derivative liabilities (1) — 55,570 — 55,570 (1) Derivative assets and liabilities relate primarily to interest rate swaps, see "Note 8. Derivatives and Hedging Activities." In addition, the carrying value of loans is increased by $53,292 and the net carrying value of subordinated debt is decreased by $401 as of December 31, 2019 for the effective portion of the hedge, which relates to the fair value of the hedges put in place to mitigate against fluctuations in interest rates. (2) Includes only the portion of junior subordinated debt that is recorded at fair value at each reporting period pursuant to the election of FVO treatment. For the three and nine months ended September 30, 2020 and 2019, the change in Level 3 liabilities measured at fair value on a recurring basis was as follows: Junior Subordinated Debt Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Beginning balance $ (56,974) $ (58,315) $ (61,685) $ (48,684) Change in fair value (1) (3,555) 794 1,156 (8,837) Ending balance $ (60,529) $ (57,521) $ (60,529) $ (57,521) (1) Unrealized gains/(losses) attributable to changes in the fair value of junior subordinated debt are recorded as part of OCI, net of tax, and totaled $(2.7) million and $0.6 million for three months ended September 30, 2020 and 2019, respectively, and $0.9 million and $(6.7) million for the nine months ended September 30, 2020 and 2019, respectively. For Level 3 liabilities measured at fair value on a recurring basis as of September 30, 2020 and December 31, 2019, the significant unobservable inputs used in the fair value measurements were as follows: September 30, 2020 Valuation Technique Significant Unobservable Inputs Input Value (in thousands) Junior subordinated debt $ 60,529 Discounted cash flow Implied credit rating of the Company 3.65 % December 31, 2019 Valuation Technique Significant Unobservable Inputs Input Value (in thousands) Junior subordinated debt $ 61,685 Discounted cash flow Implied credit rating of the Company 5.09 % The significant unobservable inputs used in the fair value measurement of the Company’s junior subordinated debt as of September 30, 2020 and December 31, 2019 was the implied credit risk for the Company. As of September 30, 2020, the implied credit risk spread was calculated as the difference between the average of the 15-year 'BB' and 'BBB' rated financial indexes over the corresponding swap index. As of December 31, 2019, the implied credit risk spread was calculated as the difference between the 15-year 'BB' rated financial index over the corresponding swap index. As of September 30, 2020, the Company estimates the discount rate at 3.65%, which represents an implied credit spread of 3.42% plus three-month LIBOR (0.23%). As of December 31, 2019, the Company estimated the discount rate at 5.09%, which was a 3.18% credit spread plus three-month LIBOR (1.91%). Fair value on a nonrecurring basis Certain assets are measured at fair value on a nonrecurring basis. That is, the assets are not measured at fair value on an ongoing basis, but are subject to fair value adjustments in certain circumstances (for example, when there is evidence of credit deterioration). The following table presents such assets carried on the Consolidated Balance Sheet by caption and by level within the ASC 825 hierarchy: Fair Value Measurements at the End of the Reporting Period Using Total Quoted Prices in Active Markets for Identical Assets Active Markets for Similar Assets Unobservable Inputs (in thousands) As of September 30, 2020: Loans $ 245,219 $ — $ — $ 245,219 Other assets acquired through foreclosure 8,591 — — 8,591 As of December 31, 2019: Loans $ 110,272 $ — $ — $ 110,272 Other assets acquired through foreclosure 13,850 — — 13,850 For Level 3 assets measured at fair value on a nonrecurring basis as of September 30, 2020 and December 31, 2019, the significant unobservable inputs used in the fair value measurements were as follows: September 30, 2020 Valuation Technique(s) Significant Unobservable Inputs Range (in thousands) Loans $ 245,219 Collateral method Third party appraisal Costs to sell 4.0% to 10.0% Discounted cash flow method Discount rate Contractual loan rate 4.0% to 7.0% Other assets acquired through foreclosure 8,591 Collateral method Third party appraisal Costs to sell 4.0% to 10.0% December 31, 2019 Valuation Technique(s) Significant Unobservable Inputs Range (in thousands) Loans $ 110,272 Collateral method Third party appraisal Costs to sell 4.0% to 10.0% Discounted cash flow method Discount rate Contractual loan rate 4.0% to 7.0% Scheduled cash collections Probability of default 0% to 20.0% Proceeds from non-real estate collateral Loss given default 0% to 70.0% Other assets acquired through foreclosure 13,850 Collateral method Third party appraisal Costs to sell 4.0% to 10.0% Loans: Loans measured at fair value on a nonrecurring basis include collateral dependent loans held for investment. The specific reserves for these loans are based on collateral value, net of estimated disposition costs and other identified quantitative inputs. Collateral value is determined based on independent third-party appraisals or internally-developed discounted cash flow analyses. Appraisals may utilize a single valuation approach or a combination of approaches, including comparable sales and the income approach. Fair value is determined, where possible, using market prices derived from an appraisal or evaluation, which are considered to be Level 2. However, certain assumptions and unobservable inputs are often used by the appraiser, therefore qualifying the assets as Level 3 in the fair value hierarchy. In addition, when adjustments are made to an appraised value to reflect various factors such as the age of the appraisal or known changes in the market or the collateral, such valuation inputs are considered unobservable and the fair value measurement is categorized as a Level 3 measurement. Internal discounted cash flow analyses are also utilized to estimate the fair value of these loans, which considers internally-developed, unobservable inputs such as discount rates, default rates, and loss severity. Total Level 3 collateral dependent loans had an estimated fair value of $245.2 million and $110.3 million at September 30, 2020 and December 31, 2019, respectively, net of a specific valuation allowance of $9.6 million and $2.8 million at September 30, 2020 and December 31, 2019, respectively. Other assets acquired through foreclosure: Other assets acquired through foreclosure consist of properties acquired as a result of, or in-lieu-of, foreclosure. These assets are initially reported at the fair value determined by independent appraisals using appraised value less estimated cost to sell. Such properties are generally re-appraised every twelve months. There is risk for subsequent volatility. Costs relating to the development or improvement of the assets are capitalized and costs relating to holding the assets are charged to expense. Fair value is determined, where possible, using market prices derived from an appraisal or evaluation, which are considered to be Level 2. However, certain assumptions and unobservable inputs are often used by the appraiser, therefore qualifying the assets as Level 3 in the fair value hierarchy. When significant adjustments are based on unobservable inputs, such as when a current appraised value is not available or management determines the fair value of the collateral is further impaired below the appraised value and there is no observable market price, the resulting fair value measurement has been categorized as a Level 3 measurement. The Company had $8.6 million and $13.9 million of such assets at September 30, 2020 and December 31, 2019, respectively. Fair Value of Financial Instruments The estimated fair value of the Company’s financial instruments is as follows: September 30, 2020 Carrying Amount Fair Value Level 1 Level 2 Level 3 Total (in thousands) Financial assets: Investment securities: HTM $ 504,477 $ — $ 548,140 $ — $ 548,140 AFS 3,975,225 25,208 3,950,017 — 3,975,225 Equity 160,561 134,811 25,750 — 160,561 Derivative assets 4,119 — 4,119 — 4,119 Loans, net 25,703,458 — — 26,107,177 26,107,177 Accrued interest receivable 140,827 — 140,827 — 140,827 Financial liabilities: Deposits $ 28,843,396 $ — $ 28,850,576 $ — $ 28,850,576 Customer repurchase agreements 19,688 — 19,688 — 19,688 Qualifying debt 618,772 — 566,308 72,628 638,936 Derivative liabilities 92,995 — 92,995 — 92,995 Accrued interest payable 15,666 — 15,666 — 15,666 December 31, 2019 Carrying Amount Fair Value Level 1 Level 2 Level 3 Total (in thousands) Financial assets: Investment securities: HTM $ 485,107 $ — $ 516,261 $ — $ 516,261 AFS 3,346,310 32,167 3,314,143 — 3,346,310 Equity securities 138,701 138,701 — — 138,701 Derivative assets 1,903 — 1,903 — 1,903 Loans, net 20,955,499 — — 21,256,462 21,256,462 Accrued interest receivable 108,694 — 108,694 — 108,694 Financial liabilities: Deposits $ 22,796,493 $ — $ 22,813,265 $ — $ 22,813,265 Customer repurchase agreements 16,675 — 16,675 — 16,675 Qualifying debt 393,563 — 332,635 74,155 406,790 Derivative liabilities 55,570 — 55,570 — 55,570 Accrued interest payable 24,661 — 24,661 — 24,661 Interest rate risk The Company assumes interest rate risk (the risk to the Company’s earnings and capital from changes in interest rate levels) as a result of its normal operations. As a result, the fair values of the Company’s financial instruments, as well as its future net interest income, will change when interest rate levels change and that change may be either favorable or unfavorable to the Company. Interest rate risk exposure is measured using interest rate sensitivity analysis to determine the Company's change in EVE and net interest income resulting from hypothetical changes in interest rates. If potential changes to EVE and net interest income resulting from hypothetical interest rate changes are not within the limits established by the BOD, the BOD may direct management to adjust the asset and liability mix to bring interest rate risk within BOD-approved limits. WAB has an ALCO charged with managing interest rate risk within the BOD-approved limits. Limits are structured to preclude an interest rate risk profile that does not conform to both management and BOD risk tolerances without ALCO approval. There is also ALCO reporting at the Parent level for reviewing interest rate risk for the Company, which gets reported to the BOD and its Finance and Investment Committee. Fair value of commitments The estimated fair value of standby letters of credit outstanding at September 30, 2020 and December 31, 2019 approximates zero as there have been no significant changes in borrower creditworthiness. Loan commitments on which the committed interest rates are less than the current market rate are insignificant at September 30, 2020 and December 31, 2019.

Segments

Segments	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Segments	The Company's reportable segments are aggregated based primarily on geographic location, services offered, and markets served. The Company's regional segments, which include Arizona, Nevada, Southern California, and Northern California, provide full service banking and related services to their respective markets. The operations from the regional segments correspond to the following banking divisions: ABA in Arizona, BON and FIB in Nevada, TPB in Southern California, and Bridge in Northern California. The Company's NBL segments provide specialized banking services to niche markets. The Company's NBL reportable segments include HOA Services, Public & Nonprofit Finance, Technology & Innovation, HFF, and Other NBLs. These NBLs are managed centrally and are broader in geographic scope than the Company's other segments, though still predominately located within the Company's core market areas. The Corporate & Other segment consists of corporate-related items, income and expense items not allocated to the Company's other reportable segments, and inter-segment eliminations. The Company's segment reporting process begins with the assignment of all loan and deposit accounts directly to the segments where these products are originated and/or serviced. Equity capital is assigned to each segment based on the risk profile of their assets and liabilities. With the exception of goodwill, which is assigned a 100% weighting, equity capital allocations ranged from 0% to 12% during the year, with a funds credit provided for the use of this equity as a funding source. Any excess or deficient equity not allocated to segments based on risk is assigned to the Corporate & Other segment. Net interest income, provision for credit losses, and non-interest expense amounts are recorded in their respective segment to the extent that the amounts are directly attributable to those segments. Net interest income is recorded in each segment on a TEB with a corresponding increase in income tax expense, which is eliminated in the Corporate & Other segment. Further, net interest income of a reportable segment includes a funds transfer pricing process that matches assets and liabilities with similar interest rate sensitivity and maturity characteristics. Using this funds transfer pricing methodology, liquidity is transferred between users and providers. A net user of funds has lending/investing in excess of deposits/borrowings and a net provider of funds has deposits/borrowings in excess of lending/investing. A segment that is a user of funds is charged for the use of funds, while a provider of funds is credited through funds transfer pricing, which is determined based on the average life of the assets or liabilities in the portfolio. Residual funds transfer pricing mismatches are allocable to the Corporate & Other segment and presented as part of net interest income. The net income amount for each reportable segment is further derived by the use of expense allocations. Certain expenses not directly attributable to a specific segment are allocated across all segments based on key metrics, such as number of employees, average loan balances, and average deposit balances. These types of expenses include information technology, operations, human resources, finance, risk management, credit administration, legal, and marketing. Income taxes are applied to each segment based on the effective tax rate for the geographic location of the segment. Any difference in the corporate tax rate and the aggregate effective tax rates in the segments are adjusted in the Corporate & Other segment. The following is a summary of operating segment information for the periods indicated: Regional Segments Balance Sheet: Consolidated Company Arizona Nevada Southern California Northern California At September 30, 2020 (in millions) Assets: Cash, cash equivalents, and investment securities $ 6,119.8 $ 1.5 $ 8.8 $ 1.8 $ 2.3 Loans, net of deferred loan fees and costs 26,014.0 4,388.1 2,612.2 2,376.7 1,785.8 Less: allowance for credit losses (310.5) (57.0) (36.4) (31.5) (19.3) Total loans 25,703.5 4,331.1 2,575.8 2,345.2 1,766.5 Other assets acquired through foreclosure, net 8.6 — 8.5 — — Goodwill and other intangible assets, net 299.0 — 23.2 — 153.9 Other assets 1,204.6 47.8 60.1 16.2 20.1 Total assets $ 33,335.5 $ 4,380.4 $ 2,676.4 $ 2,363.2 $ 1,942.8 Liabilities: Deposits $ 28,843.4 $ 8,541.5 $ 4,733.9 $ 3,502.0 $ 2,741.1 Borrowings and qualifying debt 628.8 — — — — Other liabilities 639.3 28.7 18.8 8.6 20.0 Total liabilities 30,111.5 8,570.2 4,752.7 3,510.6 2,761.1 Allocated equity: 3,224.0 576.4 343.7 281.2 361.5 Total liabilities and stockholders' equity $ 33,335.5 $ 9,146.6 $ 5,096.4 $ 3,791.8 $ 3,122.6 Excess funds provided (used) — 4,766.2 2,420.0 1,428.6 1,179.8 Income Statement: Three Months Ended September 30, 2020 (in thousands) Net interest income $ 284,738 $ 83,492 $ 46,625 $ 35,656 $ 28,353 Provision for (recovery of) credit losses 14,661 9,830 8,548 5,213 1,856 Net interest income after provision for credit losses 270,077 73,662 38,077 30,443 26,497 Non-interest income 20,606 1,771 2,391 1,186 2,381 Non-interest expense (124,092) (17,644) (15,800) (14,020) (12,885) Income (loss) before income taxes 166,591 57,789 24,668 17,609 15,993 Income tax expense (benefit) 30,822 14,447 5,180 4,930 4,478 Net income $ 135,769 $ 43,342 $ 19,488 $ 12,679 $ 11,515 Nine Months Ended September 30, 2020 (in thousands) Net interest income $ 852,158 $ 229,701 $ 139,328 $ 104,348 $ 85,345 Provision for (recovery of) credit losses 157,837 46,623 25,015 23,750 12,680 Net interest income after provision for credit losses 694,321 183,078 114,313 80,598 72,665 Non-interest income 46,985 4,943 7,355 3,269 6,450 Non-interest expense (359,372) (58,674) (44,414) (43,216) (38,460) Income (loss) before income taxes 381,934 129,347 77,254 40,651 40,655 Income tax expense (benefit) 68,929 32,207 16,164 11,241 11,340 Net income $ 313,005 $ 97,140 $ 61,090 $ 29,410 $ 29,315 National Business Lines Balance Sheet: HOA Public & Nonprofit Finance Technology & Innovation Hotel Franchise Finance Other NBLs Corporate & Other At September 30, 2020 Assets: (in millions) Cash, cash equivalents, and investment securities $ — $ — $ — $ — $ 26.6 $ 6,078.8 Loans, net of deferred loan fees and costs 280.0 1,686.7 2,329.3 2,099.3 8,451.8 4.1 Less: allowance for credit losses (2.3) (17.9) (41.5) (40.7) (63.9) — Total loans 277.7 1,668.8 2,287.8 2,058.6 8,387.9 4.1 Other assets acquired through foreclosure, net — — — — 0.1 — Goodwill and other intangible assets, net — — 119.3 0.1 2.5 — Other assets 5.4 11.9 9.2 33.4 110.3 890.2 Total assets $ 283.1 $ 1,680.7 $ 2,416.3 $ 2,092.1 $ 8,527.4 $ 6,973.1 Liabilities: Deposits $ 3,697.9 $ — $ 4,646.4 $ — $ 61.4 $ 919.2 Borrowings and qualifying debt — — — — — 628.8 Other liabilities (2.7) 91.8 5.4 0.9 56.8 411.0 Total liabilities 3,695.2 91.8 4,651.8 0.9 118.2 1,959.0 Allocated equity: 104.9 130.3 397.5 167.5 673.2 187.8 Total liabilities and stockholders' equity $ 3,800.1 $ 222.1 $ 5,049.3 $ 168.4 $ 791.4 $ 2,146.8 Excess funds provided (used) 3,517.0 (1,458.6) 2,633.0 (1,923.7) (7,736.0) (4,826.3) Income Statement: Three Months Ended September 30, 2020 (in thousands) Net interest income $ 22,184 $ 2,800 $ 48,013 $ 12,536 $ 46,582 $ (41,503) Provision for (recovery of) credit losses (138) 781 (9,048) 2,200 (2,706) (1,875) Net interest income after provision for credit losses 22,322 2,019 57,061 10,336 49,288 (39,628) Non-interest income 134 — 3,126 — 2,924 6,693 Non-interest expense (9,896) (1,724) (11,530) (2,596) (12,335) (25,662) Income (loss) before income taxes 12,560 295 48,657 7,740 39,877 (58,597) Income tax expense (benefit) 2,889 68 11,191 1,780 9,172 (23,313) Net income $ 9,671 $ 227 $ 37,466 $ 5,960 $ 30,705 $ (35,284) Nine Months Ended September 30, 2020 (in thousands) Net interest income $ 67,740 $ 6,351 $ 137,436 $ 39,442 $ 128,096 $ (85,629) Provision for (recovery of) credit losses (2,198) 553 25,471 27,530 (4,737) 3,150 Net interest income after provision for credit losses 69,938 5,798 111,965 11,912 132,833 (88,779) Non-interest income 350 — 9,247 — 4,108 11,263 Non-interest expense (29,965) (5,114) (36,188) (7,353) (35,674) (60,314) Income (loss) before income taxes 40,323 684 85,024 4,559 101,267 (137,830) Income tax expense (benefit) 9,361 380 19,461 893 23,083 (55,201) Net income $ 30,962 $ 304 $ 65,563 $ 3,666 $ 78,184 $ (82,629) Regional Segments Balance Sheet: Consolidated Company Arizona Nevada Southern California Northern California At December 31, 2019 (in millions) Assets: Cash, cash equivalents, and investment securities $ 4,471.2 $ 1.8 $ 9.0 $ 2.3 $ 2.2 Loans, net of deferred loan fees and costs 21,123.3 3,847.9 2,252.5 2,253.9 1,311.2 Less: allowance for credit losses (167.8) (31.6) (18.0) (18.3) (9.7) Total loans 20,955.5 3,816.3 2,234.5 2,235.6 1,301.5 Other assets acquired through foreclosure, net 13.9 — 13.0 0.9 — Goodwill and other intangible assets, net 297.6 — 23.2 — 154.6 Other assets 1,083.7 48.6 59.4 15.0 19.8 Total assets $ 26,821.9 $ 3,866.7 $ 2,339.1 $ 2,253.8 $ 1,478.1 Liabilities: Deposits $ 22,796.5 $ 5,384.7 $ 4,350.1 $ 2,585.3 $ 2,373.6 Borrowings and qualifying debt 393.6 — — — — Other liabilities 615.1 17.8 11.9 1.2 15.9 Total liabilities 23,805.2 5,402.5 4,362.0 2,586.5 2,389.5 Allocated equity: 3,016.7 453.6 301.0 253.3 312.5 Total liabilities and stockholders' equity $ 26,821.9 $ 5,856.1 $ 4,663.0 $ 2,839.8 $ 2,702.0 Excess funds provided (used) — 1,989.4 2,323.9 586.0 1,223.9 Income Statement: Three Months Ended September 30, 2019 (in thousands) Net interest income $ 266,422 $ 68,828 $ 40,565 $ 33,630 $ 23,504 Provision for (recovery of) credit losses 3,803 103 (62) (189) 218 Net interest income (expense) after provision for credit losses 262,619 68,725 40,627 33,819 23,286 Non-interest income 19,441 1,821 2,677 1,079 1,917 Non-interest expense (126,152) (27,241) (15,211) (15,185) (12,379) Income (loss) before income taxes 155,908 43,305 28,093 19,713 12,824 Income tax expense (benefit) 28,533 10,826 5,899 5,520 3,591 Net income $ 127,375 $ 32,479 $ 22,194 $ 14,193 $ 9,233 Nine Months Ended September 30, 2019 (in thousands) Net interest income $ 768,439 $ 183,772 $ 119,191 $ 95,751 $ 70,533 Provision for (recovery of) credit losses 15,303 1,705 166 611 (653) Net interest income (expense) after provision for credit losses 753,136 182,067 119,025 95,140 71,186 Non-interest income 49,069 5,050 7,926 3,054 6,299 Non-interest expense (352,279) (72,183) (45,099) (44,890) (38,419) Income (loss) before income taxes 449,926 114,934 81,852 53,304 39,066 Income tax expense (benefit) 78,819 28,733 17,189 14,925 10,939 Net income $ 371,107 $ 86,201 $ 64,663 $ 38,379 $ 28,127 National Business Lines Balance Sheet: HOA Public & Nonprofit Finance Technology & Innovation Hotel Franchise Finance Other NBLs Corporate & Other At December 31, 2019 Assets: (in millions) Cash, cash equivalents, and investment securities $ — $ — $ — $ — $ 10.1 $ 4,445.8 Loans, net of deferred loan fees and costs 237.2 1,635.6 1,552.0 1,930.8 6,098.7 3.5 Less: allowance for credit losses (2.0) (13.7) (12.6) (12.6) (49.3) — Total loans 235.2 1,621.9 1,539.4 1,918.2 6,049.4 3.5 Other assets acquired through foreclosure, net — — — — — — Goodwill and other intangible assets, net — — 119.7 0.1 — — Other assets 1.2 18.3 7.3 8.8 64.3 841.0 Total assets $ 236.4 $ 1,640.2 $ 1,666.4 $ 1,927.1 $ 6,123.8 $ 5,290.3 Liabilities: Deposits $ 3,210.1 $ 0.1 $ 3,771.5 $ — $ 36.9 $ 1,084.2 Borrowings and qualifying debt — — — — — 393.6 Other liabilities 1.8 52.9 0.1 — 2.8 510.7 Total liabilities 3,211.9 53.0 3,771.6 — 39.7 1,988.5 Allocated equity: 84.5 131.6 317.5 158.5 494.3 509.9 Total liabilities and stockholders' equity $ 3,296.4 $ 184.6 $ 4,089.1 $ 158.5 $ 534.0 $ 2,498.4 Excess funds provided (used) 3,060.0 (1,455.6) 2,422.7 (1,768.6) (5,589.8) (2,791.9) Income Statement: Three Months Ended September 30, 2019 (in thousands) Net interest income (expense) $ 21,974 $ 3,394 $ 33,932 $ 12,845 $ 32,935 $ (5,185) Provision for (recovery of) credit losses 60 (191) 895 1,956 1,210 (197) Net interest income (expense) after provision for credit losses 21,914 3,585 33,037 10,889 31,725 (4,988) Non-interest income 84 — 5,422 — 1,708 4,733 Non-interest expense (9,769) (1,845) (12,068) (2,197) (11,320) (18,937) Income (loss) before income taxes 12,229 1,740 26,391 8,692 22,113 (19,192) Income tax expense (benefit) 2,813 400 6,070 1,999 5,086 (13,671) Net income $ 9,416 $ 1,340 $ 20,321 $ 6,693 $ 17,027 $ (5,521) Nine Months Ended September 30, 2019 (in thousands) Net interest income $ 64,520 $ 10,278 $ 91,871 $ 39,279 $ 88,212 $ 5,032 Provision for (recovery of) credit losses 27 (136) 2,635 3,587 6,558 803 Net interest income (expense) after provision for credit losses 64,493 10,414 89,236 35,692 81,654 4,229 Non-interest income 268 — 10,946 — 3,915 11,611 Non-interest expense (27,777) (5,683) (33,971) (6,757) (31,729) (45,771) Income (loss) before income taxes 36,984 4,731 66,211 28,935 53,840 (29,931) Income tax expense (benefit) 8,506 1,088 15,229 6,655 12,383 (36,828) Net income $ 28,478 $ 3,643 $ 50,982 $ 22,280 $ 41,457 $ 6,897

Revenue from Contracts with Cus

Revenue from Contracts with Customers (Notes)	9 Months Ended
	Sep. 30, 2020
Revenue from Contracts with Customers [Abstract]
Revenue from Contract with Customer [Text Block]	14. REVENUE FROM CONTRACTS WITH CUSTOMERS ASC 606, Revenue from Contracts with Customers, requires revenue to be recognized at an amount that reflects the consideration to which the entity expects to be entitled in exchange for transferring goods or services to a customer. ASC 606 applies to all contracts with customers to provide goods or services in the ordinary course of business, except for contracts that are specifically excluded from its scope. The majority of the Company’s revenue streams including interest income, credit and debit card fees, income from equity investments including warrants and SBIC equity income, income from bank owned life insurance, foreign currency income, lending related income, and gains and losses on sales of investment securities are outside the scope of ASC 606. Revenue streams including service charges and fees, interchange fees on credit and debit cards, and success fees are within the scope of ASC 606. Disaggregation of Revenue The following table represents a disaggregation of revenue from contracts with customers for the periods indicated along with the reportable segment for each revenue category: Regional Segments Consolidated Company Arizona Nevada Southern California Northern California Three Months Ended September 30, 2020 (in thousands) Revenue from contracts with customers: Service charges and fees $ 5,913 $ 1,188 $ 1,826 $ 889 $ 930 Debit and credit card interchange (1) 1,597 426 306 167 686 Success fees (2) 38 — — — — Other income 69 8 6 (1) 18 Total revenue from contracts with customers $ 7,617 $ 1,622 $ 2,138 $ 1,055 $ 1,634 Revenues outside the scope of ASC 606 (3) 12,989 149 253 131 747 Total non-interest income $ 20,606 $ 1,771 $ 2,391 $ 1,186 $ 2,381 Regional Segments Consolidated Company Arizona Nevada Southern California Northern California Nine Months Ended September 30, 2020 (in thousands) Revenue from contracts with customers: Service charges and fees $ 17,447 $ 3,525 $ 5,572 $ 2,466 $ 2,863 Debit and credit card interchange (1) 3,942 990 770 401 1,754 Success fees (2) 423 — — — 144 Other income 231 20 15 (6) 59 Total revenue from contracts with customers $ 22,043 $ 4,535 $ 6,357 $ 2,861 $ 4,820 Revenues outside the scope of ASC 606 (3) 24,942 408 998 408 1,630 Total non-interest income $ 46,985 $ 4,943 $ 7,355 $ 3,269 $ 6,450 (1) Included as part of Card income in the Consolidated Income Statement. (2) Included as part of Income from equity investments in the Consolidated Income Statement. (3) Amounts are accounted for under separate guidance. Refer to discussion of revenue sources not subject to ASC 606 under the Non-interest income section in "Note 1. Summary of Significant Accounting Policies." National Business Lines HOA Public & Nonprofit Finance Technology & Innovation Hotel Franchise Finance Other NBLs Corporate & Other Three Months Ended September 30, 2020 (in thousands) Revenue from contracts with customers: Service charges and fees $ 114 $ — $ 963 $ — $ 3 $ — Debit and credit card interchange (1) 12 — — — — — Success fees (2) — — 38 — — — Other income 2 — — — 35 1 Total revenue from contracts with customers $ 128 $ — $ 1,001 $ — $ 38 $ 1 Revenues outside the scope of ASC 606 (3) 6 — 2,125 — 2,886 6,692 Total non-interest income $ 134 $ — $ 3,126 $ — $ 2,924 $ 6,693 National Business Lines HOA Public & Nonprofit Finance Technology & Innovation Hotel Franchise Finance Other NBLs Corporate & Other Nine Months Ended September 30, 2020 (in thousands) Revenue from contracts with customers: Service charges and fees $ 308 $ — $ 2,707 $ — $ 6 $ — Debit and credit card interchange (1) 27 — — — — — Success fees (2) — — 279 — — — Other income 4 — — — 125 14 Total revenue from contracts with customers $ 339 $ — $ 2,986 $ — $ 131 $ 14 Revenues outside the scope of ASC 606 (3) 11 — 6,261 — 3,977 11,249 Total non-interest income $ 350 $ — $ 9,247 $ — $ 4,108 $ 11,263 (1) Included as part of Card income in the Consolidated Income Statement. (2) Included as part of Income from equity investments in the Consolidated Income Statement. (3) Amounts are accounted for under separate guidance. Refer to discussion of revenue sources not subject to ASC 606 under the Non-interest income section in "Note 1. Summary of Significant Accounting Policies." Regional Segments Consolidated Company Arizona Nevada Southern California Northern California Three Months Ended September 30, 2019 (in thousands) Revenue from contracts with customers: Service charges and fees $ 5,888 $ 1,226 $ 2,036 $ 770 $ 965 Debit and credit card interchange (1) 1,977 451 440 229 845 Success fees (2) 605 — — — — Other income 80 8 14 4 19 Total revenue from contracts with customers $ 8,550 $ 1,685 $ 2,490 $ 1,003 $ 1,829 Revenues outside the scope of ASC 606 (3) 10,891 136 187 76 88 Total non-interest income $ 19,441 $ 1,821 $ 2,677 $ 1,079 $ 1,917 Regional Segments Consolidated Company Arizona Nevada Southern California Northern California Nine Months Ended September 30, 2019 (in thousands) Revenue from contracts with customers: Service charges and fees $ 17,121 $ 3,525 $ 5,980 $ 2,218 $ 2,821 Debit and credit card interchange (1) 5,830 1,125 1,200 596 2,878 Success fees (2) 1,125 — — — — Other income 187 8 8 6 43 Total revenue from contracts with customers $ 24,263 $ 4,658 $ 7,188 $ 2,820 $ 5,742 Revenues outside the scope of ASC 606 (3) 24,806 392 738 234 557 Total non-interest income $ 49,069 $ 5,050 $ 7,926 $ 3,054 $ 6,299 National Business Lines HOA Public & Nonprofit Finance Technology & Innovation Hotel Franchise Finance Other NBLs Corporate & Other Three Months Ended September 30, 2019 (in thousands) Revenue from contracts with customers: Service charges and fees $ 77 $ — $ 813 $ — $ 1 $ — Debit and credit card interchange (1) 12 — — — — — Success fees (2) — — 605 — — — Other income (3) — — — 35 3 Total revenue from contracts with customers $ 86 $ — $ 1,418 $ — $ 36 $ 3 Revenues outside the scope of ASC 606 (3) (2) — 4,004 — 1,672 4,730 Total non-interest income $ 84 $ — $ 5,422 $ — $ 1,708 $ 4,733 National Business Lines HOA Services Public & Nonprofit Finance Technology & Innovation Hotel Franchise Finance Other NBLs Corporate & Other Nine Months Ended September 30, 2019 (in thousands) Revenue from contracts with customers: Service charges and fees $ 241 $ — $ 2,333 $ — $ 3 $ — Debit and credit card interchange (1) 31 — — — — — Success fees (2) — — 1,125 — — — Other income 2 — 4 — 109 7 Total revenue from contracts with customers $ 274 $ — $ 3,462 $ — $ 112 $ 7 Revenues outside the scope of ASC 606 (3) (6) — 7,484 — 3,803 11,604 Total non-interest income $ 268 $ — $ 10,946 $ — $ 3,915 $ 11,611 (1) Included as part of Card income in the Consolidated Income Statement. (2) Included as part of Income from equity investments in the Consolidated Income Statement. (3) Amounts are accounted for under separate guidance. Refer to discussion of revenue sources not subject to ASC 606 under the Non-interest income section in "Note 1. Summary of Significant Accounting Policies." Performance Obligations Many of the services the Company performs for its customers are ongoing, and either party may cancel at any time. The fees for these contracts are dependent upon various underlying factors, such as customer deposit balances, and as such may be considered variable. The Company’s performance obligations for these services are satisfied as the services are rendered and payment is collected on a monthly, quarterly, or semi-annual basis. Other contracts with customers are for services to be provided at a point in time, and fees are recognized at the time such services are rendered. The Company had no material unsatisfied performance obligations as of September 30, 2020. The revenue streams within the scope of ASC 606 are described in further detail below. Service Charges and Fees The Company performs deposit account services for its customers, which include analysis and treasury management services, use of safe deposit boxes, check upcharges, and other ancillary services. The depository arrangements the Company holds with its customers are considered day-to-day contracts with ongoing renewals and optional purchases, and as such, the contract duration does not extend beyond the services performed. Due to the short-term nature of such contracts, the Company generally recognizes revenue for deposit related fees as services are rendered. From time to time, the Company may waive certain fees for its customers. The Company considers historical experience when recognizing revenue from contracts with customers, and may reduce the transaction price to account for fee waivers or refunds. Debit and Credit Card Interchange When a credit or debit card issued by the Company is used to purchase goods or services from a merchant, the Company earns an interchange fee. The Company considers the merchant its customer in these transactions as the Company provides the merchant with the service of enabling the cardholder to purchase the merchant’s goods or services with increased convenience, and it enables the merchants to transact with a class of customer that may not have access to sufficient funds at the time of purchase. The Company acts as an agent to the payment network by providing nightly settlement services between the network and the merchant. This transmission of data and funds represents the Company’s performance obligation and is performed nightly. As the payment network is in direct control of setting the rates and the Company is acting as an agent, the interchange fee is recorded net of expenses as the services are provided. Success Fees Success fees are one-time fees detailed as part of certain loan agreements and are earned immediately upon occurrence of a triggering event. Examples of triggering events include: a borrower obtaining its next round of funding, an acquisition, or completion of a public offering. Success fees are variable consideration as the transaction price can vary and is contingent on the occurrence or non-occurrence of a future event. As the consideration is highly susceptible to factors outside of the Company’s influence and uncertainty about the amount of consideration is not expected to be resolved for an extended period of time, the variable consideration is constrained and is not recognized until the achievement of the triggering event. Principal versus Agent Considerations When more than one party is involved in providing goods or services to a customer, ASC 606 requires the Company to determine whether it is the principal or an agent in these transactions by evaluating the nature of its promise to the customer. An entity is a principal and therefore records revenue on a gross basis, if it controls a promised good or service before transferring that good or service to the customer. An entity is an agent and records as revenue the net amount it retains for its agency services if its role is to arrange for another entity to provide the goods or services. The Company most commonly acts as a principal and records revenue on a gross basis, except in certain circumstances. As an example, revenues earned from interchange fees, in which the Company acts as an agent, are recorded as non-interest income, net of the related expenses paid to the principal. Contract Balances The timing of revenue recognition may differ from the timing of cash settlements or invoicing to customers. The Company records contract liabilities, or deferred revenue, when payments from customers are received or due in advance of providing services to customers. The Company generally receives payments for its services during the period or at the time services are provided, therefore, does not have material contract liability balances at period-end. The Company records contract assets or receivables when revenue is recognized prior to receipt of cash from the customer. Accounts receivable totals $1.5 million and $1.6 million at each of the periods ended September 30, 2020 and December 31, 2019, respectively, and are presented in Other assets on the Consolidated Balance Sheets.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Nature of Operation	Nature of operation WAL is a bank holding company headquartered in Phoenix, Arizona, incorporated under the laws of the state of Delaware. WAL provides a full spectrum of deposit, lending, treasury management, international banking, and online banking products and services through its wholly-owned banking subsidiary, WAB.
Basis of Presentation	Basis of presentation The accounting and reporting policies of the Company are in accordance with GAAP and conform to practices within the financial services industry. The accounts of the Company and its consolidated subsidiaries are included in the Consolidated Financial Statements.
Recent Accounting Pronouncements	Recent accounting pronouncements Convertible Debt and Derivatives and Hedging In August 2020, the FASB issued guidance within ASU 2020-06, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) . The amendments in this update affect entities that issue convertible instruments and/or contracts indexed to and potentially settled in an entity’s own equity. The new ASU simplifies the convertible accounting framework through elimination of the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of specific settlement provisions. In addition, the new guidance modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted EPS computation. The amendments to Subtopics 470 and 815 are effective for interim and annual reporting periods beginning after December 15, 2021 and are not expected to have a material impact on the Company’s Consolidated Financial Statements. Income Taxes In December 2019, the FASB issued guidance within ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The amendments in ASU 2019-12 are intended to reduce the cost and complexity of applying ASC 740. The amendments that are applicable to the Company address: 1) franchise and other taxes partially based on income; 2) step-up in basis of goodwill in a business combination; 3) allocation of tax expense in separate entity financial statements; and 4) interim recognition of enactment of tax laws or rate changes. The amendments to Topic 740 are effective for interim and annual reporting periods beginning after December 15, 2020 and are not expected to have a material impact on the Company’s Consolidated Financial Statements. Recently adopted accounting guidance Measurement of Credit Losses on Financial Instruments In June 2016, the FASB issued guidance within ASU 2016-13, Measurement of Credit Losses on Financial Instruments . The new standard significantly changes the impairment model for most financial assets that are measured at amortized cost, including off-balance sheet credit exposures, from an incurred loss model to an expected loss model. The amendments in ASU 2016-13 to Topic 326, Financial Instruments - Credit Losses , require that an organization measure all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. The ASU also requires enhanced disclosures, including qualitative and quantitative disclosures that provide additional information about the amounts recorded in the financial statements. Additionally, the ASU amends the accounting for credit losses on AFS debt securities and purchased financial assets with credit deterioration. The Company adopted the amendments within ASU 2016-13 using the modified retrospective method for all financial assets measured at amortized cost and off-balance sheet credit exposures. The Company's financial results for reporting periods beginning after January 1, 2020 are presented in accordance with ASC 326, while prior-period amounts continue to be reported in accordance with legacy GAAP. The Company recorded a cumulative effect adjustment to retained earnings, which resulted in a total decrease to retained earnings of $24.9 million as of January 1, 2020. This adjustment was due primarily to expected total losses under the new model in the Company's loan portfolio and, to a lesser extent, its off-balance sheet credit exposures. The Company applied the prospective transition approach for loans purchased with credit deterioration that were previously classified as purchased credit impaired and previously accounted for under ASC 310-30. In accordance with the new standard, management did not reassess whether PCI assets met the criteria of PCD assets as of the date of adoption. As of January 1, 2020, the amortized cost basis of the PCD loans was adjusted to reflect an allowance for credit losses of $3.3 million. The remaining noncredit discount (based on the adjusted amortized cost basis) related to PCD loans of $1.1 million will be accreted into interest income at the loan's effective interest rate as of January 1, 2020. The Company has elected not to maintain its pools of loans accounted for under ASC 310-30. The Company applied the prospective transition approach for debt securities for which other-than-temporary impairment had been recognized prior to January 1, 2020. As a result, the amortized cost basis remains the same before and after the effective date. The effective interest rate on these debt securities was not changed. Recoveries of amounts previously written off relating to improvements in cash flows after January 1, 2020 will be recorded in earnings when received. The following table summarizes the estimated allowance for credit losses related to financial assets and off-balance sheet credit exposures and the corresponding impacts on the deferred tax asset and retained earnings upon adoption of ASC 326: January 1, 2020 Pre-ASC 326 Adoption Post-ASC 326 Adoption Impact of ASC 326 Adoption (in thousands) Assets: Allowance for credit losses on HTM securities $ — $ 2,646 $ 2,646 Allowance for credit losses on loans 167,797 186,925 19,128 Deferred tax asset 18,025 26,675 8,650 Liabilities: Off-balance sheet credit exposures $ 8,955 $ 24,044 $ 15,089 Equity: Retained earnings $ 1,680,317 $ 1,655,370 $ (24,947) Management has elected to take advantage of the capital relief option that delays the estimated impact of the adoption of ASC 326 on regulatory capital by up to two years, with a three-year transition period to phase out the cumulative benefit to regulatory capital provided during the two-year delay. In April 2019, the FASB issued guidance within ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments . The amendments in ASU 2019-04 clarify or correct the guidance in these Topics. With respect to Topic 326, ASU 2019-04 addresses a number of issues as it relates to the CECL standard including consideration of accrued interest, recoveries, variable-rate financial instruments, prepayments, and extension and renewal options, among other things, in the measurement of expected credit losses. The amendments to Topic 326 were adopted concurrently with ASU 2016-13 and did not have a significant impact on the Company’s Consolidated Financial Statements. With respect to Topic 815, Derivatives and Hedging , ASU 2019-04 clarifies issues related to partial-term hedges, hedged debt securities, and transitioning from a quantitative method of assessing hedge effectiveness to a more simplified method. The Company does not have partial-term hedges or any hedged debt securities and the transition issues discussed in the ASU 2019-04 are not applicable to the Company. Accordingly, the amendments to Topic 815 did not have an impact on the Company's Consolidated Financial Statements. With respect to Topic 825, Financial Instruments, on recognizing and measuring financial instruments, ASU 2019-04 addresses: 1) the scope of the guidance; 2) the requirement for remeasurement under ASC 820 when using the measurement alternative for equity securities without readily determinable fair values; 3) certain disclosure requirements; and 4) which equity securities have to be remeasured at historical exchange rates. The amendments to Topic 825 were effective January 1, 2020 and did not have a material impact on the Company’s Consolidated Financial Statements. In May 2019, the FASB issued guidance within ASU 2019-05, Financial Instruments - Credit Losses , to provide entities with an option to irrevocably elect the fair value option for eligible financial assets measured at amortized cost. The election is to be applied on an instrument-by-instrument basis upon adoption of Topic 326 and is not available for either AFS or HTM debt securities. The amendments in ASU 2019-05 should be applied on a modified-retrospective basis through a cumulative-effect adjustment to the opening balance of retained earnings as of the date that an entity adopts the amendments in ASU 2016-13. The Company did not elect this fair value option as part of its adoption of ASU 2016-13 on January 1, 2020. In November 2019, the FASB issued guidance within ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments—Credit Losses. The amendments in ASU 2019-11 clarify or address specific issues about certain aspects of the amendments in ASU 2016-13. These issues include measurement and reporting requirements related to: 1) the allowance for credit losses for purchased assets with credit deterioration; 2) prepayment assumptions on existing troubled debt restructurings; 3) extension of disclosure relief for accrued interest receivable balances; and 4) expected credit losses on collateralized financial assets. The adoption of ASU 2019-11 is concurrent with ASU 2016-13 and, adoption of these amendments on January 1, 2020, did not have a significant impact on the Company's Consolidated Financial Statements. Fair Value Measurements In August 2018, the FASB issued guidance within ASU 2018-13, Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement . The amendments within ASU 2018-13 remove, modify, and supplement the disclosure requirements for fair value measurements. Disclosure requirements that were removed include: 1) the amount and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy; 2) the policy for timing of transfers between levels; and 3) the valuation processes for Level 3 fair value measurements. The amendments clarify that the measurement uncertainty disclosure is intended to communicate information about the uncertainty in measurement as of the reporting date. Additional disclosure requirements include: 1) the changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period; and 2) the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. With the exception of the above additional disclosure requirements, which will be applied prospectively, all other amendments should be applied retrospectively to all periods presented upon their effective date. The amendments in this ASU did not have a significant impact on the Company's Consolidated Financial Statements. Internal-Use Software In August 2018, the FASB issued guidance within ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40) . The amendments in this ASU align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). Accordingly, the amendments in this Update require an entity (customer) in a hosting arrangement that is a service contract to follow the guidance in Subtopic 350-40 to determine which implementation costs to capitalize as an asset related to the service contract and which costs to expense. The amendments in this Update also require that the capitalized implementation costs of a hosting arrangement that is a service contract be expensed over the term of the hosting arrangement. Presentation requirements include: 1) expense related to the capitalized implementation costs should be presented in the same line item in the statement of income as the fees associated with the hosting element (service) of the arrangement; 2) payments for capitalized implementation costs in the statement of cash flows should be classified in the same manner as payments made for fees associated with the hosting element; and 3) capitalized implementation costs in the statement of financial position should be presented in the same line item that a prepayment for the fees of the associated hosting arrangement would be presented. The adoption of this guidance did not have a significant impact on the Company's Consolidated Financial Statements. Reference Rate Reform In March 2020, the FASB issued guidance within ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, in response to the scheduled discontinuation of LIBOR on December 31, 2021 . The amendments in this Update provide optional guidance designed to provide relief from the accounting analysis and impacts that may otherwise be required for modifications to agreements (e.g., loans, debt securities, derivatives, borrowings) necessitated by reference rate reform. The following optional expedients for applying the requirements of certain Topics or Industry Subtopics in the Codification are permitted for contracts that are modified because of reference rate reform and that meet certain scope guidance: 1) modifications of contracts within the scope of Topics 310, Receivables , and 470, Debt , should be accounted for by prospectively adjusting the effective interest rate; 2) modifications of contracts within the scope of Topic 842, Leases , should be accounted for as a continuation of the existing contracts with no reassessments of the lease classification and the discount rate or remeasurements of lease payments that otherwise would be required under this Topic for modifications not accounted for as separate contracts; 3) modifications of contracts do not require an entity to reassess its original conclusion about whether that contract contains an embedded derivative that is clearly and closely related to the economic characteristics and risks of the host contract under Subtopic 815-15, Derivatives and Hedging- Embedded Derivatives; and 4) for other Topics or Industry Subtopics in the Codification, the amendments in this Update also include a general principle that permits an entity to consider contract modifications due to reference rate reform to be an event that does not require contract remeasurement at the modification date or reassessment of a previous accounting determination. An entity may make a one-time election to sell, transfer, or both sell and transfer debt securities classified as held to maturity that reference a rate affected by reference rate reform and that are classified as held to maturity before January 1, 2020. The amendments in this Update are effective for all entities as of March 12, 2020 through December 31, 2022.
Use of Estimates	Use of estimatesThe preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Management's estimates and judgments are ongoing and are based on experience, current and expected future conditions, third-party evaluations and various other assumptions that management believes are reasonable under the circumstances. The results of these estimates form the basis for making judgments about the carrying values of assets and liabilities, as well as identifying and assessing the accounting treatment with respect to commitments and contingencies. Actual results may differ from those estimates and assumptions used in the Consolidated Financial Statements and related notes. Material estimates that are susceptible to significant changes in the near term, particularly to the extent that economic conditions worsen or persist longer than expected in an adverse state, relate to: the determination of the allowance for credit losses; certain assets and liabilities carried at fair value; and accounting for income taxes.
Principles of Consolidation	Principles of consolidation As of September 30, 2020, WAL has the following significant wholly-owned subsidiaries: WAB and eight unconsolidated subsidiaries used as business trusts in connection with the issuance of trust-preferred securities. The Bank has the following significant wholly-owned subsidiaries: WABT, which holds certain investment securities, municipal and nonprofit loans, and leases; WA PWI, which holds interests in certain limited partnerships invested primarily in low income housing tax credits and small business investment corporations; Helios Prime, which holds interests in certain limited partnerships invested in renewable energy projects; and BW Real Estate, Inc., which operates as a real estate investment trust and holds certain of WAB's real estate loans and related securities. The Company does not have any other significant entities that should be consolidated. All significant intercompany balances and transactions have been eliminated in consolidation.
Reclassifications	Reclassifications Certain amounts reported in prior periods may have been reclassified in the Consolidated Financial Statements to conform to the current presentation. The reclassifications have no effect on net income or stockholders’ equity as previously reported.
Investment Securities	Investment securities Investment securities include debt and equity securities. Debt securities may be classified as HTM, AFS, or trading. The appropriate classification is initially decided at the time of purchase. Securities classified as HTM are those debt securities that the Company has both the intent and ability to hold to maturity regardless of changes in market conditions, liquidity needs, or general economic conditions. The sale of an HTM security within three months of its maturity date or after the majority of the principal outstanding has been collected is considered a maturity for purposes of classification and disclosure. Securities classified as AFS are securities that the Company intends to hold for an indefinite period of time, but not necessarily to maturity. Any decision to sell a security classified as AFS would be based on various factors, including significant movements in interest rates, changes in the maturity mix of the Company’s assets and liabilities, liquidity needs, decline in credit quality, and regulatory capital considerations. HTM securities are carried at amortized cost. AFS securities are carried at their estimated fair value, with unrealized holding gains and losses reported in other comprehensive income, net of tax. When AFS debt securities are sold, the unrealized gains or losses are reclassified from OCI to non-interest income. Trading securities are carried at their estimated fair value, with changes in fair value reported in earnings as part of non-interest income. Equity securities are carried at their estimated fair value, with changes in fair value reported in earnings as part of non-interest income. Interest income is recognized based on the coupon rate and includes the amortization of purchase premiums and the accretion of purchase discounts. Premiums and discounts on investment securities are generally amortized or accreted over the contractual life of the security using the interest method. For the Company's mortgage-backed securities, amortization or accretion of premiums or discounts are adjusted for anticipated prepayments. Gains and losses on the sale of investment securities are recorded on the trade date and determined using the specific identification method.
Credit Loss, Financial Instrument [Policy Text Block]	Allowance for credit losses on investment securities On January 1, 2020, the Company adopted the amendments within ASU 2016-13, which replaces the legacy US GAAP OTTI model with a credit loss model. For discussion of the former OTTI methodology, refer to the Company's Annual Report on Form 10-K for the year ended December 31, 2019. The credit loss model under ASC 326-20, applicable to HTM debt securities, requires recognition of lifetime expected credit losses through an allowance account at the time the security is purchased. The Company measures expected credit losses on its HTM debt securities on a collective basis by major security type. The Company's HTM securities portfolio consists of low income housing tax-exempt bonds, which share similar risk characteristics with the Company's CRE, non-owner occupied or construction and land loan pools, given the similarity in underlying assets or collateral. Accordingly, expected credit losses on HTM securities are estimated using the same models and approaches as these loan pools, which utilize risk parameters (probability of default, loss given default, and exposure at default) in the measurement of expected credit losses. The historical data used to estimate probability of default and severity of loss in the event of default is derived or obtained from internal and external sources and adjusted for the expected effects of reasonable and supportable forecasts over the expected lives of the securities on those historical losses. Accrued interest receivable on the HTM securities, which is included in other assets on the Consolidated Balance Sheet, is excluded from the estimate of expected credit losses. The credit loss model under ASC 326-30, applicable to AFS debt securities, requires recognition of credit losses through an allowance account, but retains the concept from the OTTI model that credit losses are recognized once securities become impaired. For AFS debt securities, a decline in fair value due to credit loss results in recognition of an allowance for credit losses. Impairment may result from credit deterioration of the issuer or collateral underlying the security. The assessment of determining if a decline in fair value resulted from a credit loss is performed at the individual security level. Among other factors, the Company considers: 1) the extent to which the fair value is less than the amortized cost basis; 2) the financial condition and near term prospects of the issuer, including consideration of relevant financial metrics or ratios of the issuer; 3) any adverse conditions related to an industry or geographic area of an issuer; 4) any changes to the rating of the security by a rating agency; and 5) any past due principal or interest payments from the issuer. If an assessment of the above factors indicates that a credit loss exists, the Company records an allowance for credit losses for the excess of the amortized cost basis over the present value of cash flows expected to be collected, limited to the amount that the security's fair value is less than its amortized cost basis. Subsequent changes in the allowance for credit losses are recorded as a provision for (or reversal of) credit loss expense. Interest accruals and amortization and accretion of premiums and discounts are suspended when the credit loss is recognized in earnings. Any interest received after the security has been placed on nonaccrual status is recognized on a cash basis. Accrued interest receivable on AFS securities, which is included in other assets on the Consolidated Balance Sheet, is excluded from the estimate of expected credit losses. For each AFS security in an unrealized loss position, the Company also considers: 1) its intent to retain the security until anticipated recovery of the security's fair value; and 2) whether it is more-likely-than not that the Company would be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the debt security is written down to its fair value and the write-down is charged against the allowance for credit losses with any incremental impairment recorded in earnings. Off-balance sheet credit exposures, including unfunded loan commitments The Company maintains a separate allowance for credit losses on off-balance-sheet credit exposures, including unfunded loan commitments, financial guarantees, and letters of credit, which is classified in other liabilities on the Consolidated Balance Sheet. The allowance for credit losses on off-balance sheet credit exposures is adjusted through increases or decreases to the provision for credit loss expense. The estimate includes consideration of the likelihood that funding will occur, an estimate of exposure at default that is derived from utilization rate assumptions using a non-modeled approach, and PD and LGD estimates that are derived from the same models and approaches for the Company's other loan portfolio segments described above as these unfunded commitments share similar risk characteristics with these loan portfolio segments. No credit loss estimate is reported for off-balance sheet credit exposures that are unconditionally cancellable by the Company or for undrawn amounts under such arrangements that may be drawn prior to the cancellation of the arrangement.
Restricted Stock	Restricted stockWAB is a member of the Federal Reserve System and, as part of its membership, is required to maintain stock in the FRB in a specified ratio to its capital. In addition, WAB is a member of the FHLB system and, accordingly, maintains an investment in capital stock of the FHLB based on the borrowing capacity used. These investments are considered equity securities with no actively traded market. Therefore, the shares are considered restricted investment securities. These investments are carried at cost, which is equal to the value at which they may be redeemed. The dividend income received from the stock is reported in interest income. The Company conducts a periodic review and evaluation of its restricted stock to determine if any impairment exists. No impairment has been recorded to date.
Nonmortgage Loan Held-for-sale	Loans held for sale Loans held for sale consist of loans that the Company originates (or acquires) and intends to sell. These loans are carried at the lower of aggregate cost or fair value. Fair value is determined based on quoted fair market values or, when not available, discounted cash flows or appraisals of underlying collateral or the credit quality of the borrower.
Loans, Interest and Fees from Loans	Loans held for investment Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at amortized cost. Amortized cost is the amount of unpaid principal, adjusted for unamortized net deferred fees and costs, premiums and discounts, and writeoffs. In addition, the amortized cost of loans subject to a fair value hedge are adjusted for changes in value attributable to the effective portion of the hedged benchmark interest rate risk. The Company may also purchase loans or acquire loans through a business combination. At the purchase or acquisition date, loans are evaluated to determine if there has been more than insignificant credit deterioration since origination. Loans that have experienced more than insignificant credit deterioration since origination are referred to as PCD loans. In its evaluation of whether a loan has experienced more than insignificant deterioration in credit quality since origination, the Company takes into consideration loan grades, loan-to-values greater than policy limits, past due and nonaccrual status, and TDR loans. The Company may also consider external credit rating agency ratings for borrowers and for non-commercial loans, FICO score or band, probability of default levels, number of times past due, and standard deviations corresponding to FICO score or band. The initial estimate of credit losses on PCD loans is added to the purchase price on the acquisition date to establish the initial amortized cost basis of the loan; accordingly, the initial recognition of expected credit losses has no impact on net income. When the initial measurement of expected credit losses on PCD loans are calculated on a pooled loan basis, the expected credit losses are allocated to each loan within the pool. Any difference between the initial amortized cost basis and the unpaid principal balance of the loan represents a noncredit discount or premium, which is accreted (or amortized) into interest income over the life of the loan. Subsequent changes to the allowance for credit losses on PCD loans are recorded through the provision for credit losses. For purchased loans that are not deemed to have experienced more than insignificant credit deterioration since origination, any discounts or premiums included in the purchase price are accreted (or amortized) over the contractual life of the individual loan. For additional information, see "Note 3. Loans, Leases and Allowance for Credit Losses" of these Notes to Unaudited Consolidated Financial Statements. In applying the effective yield method to loans, the Company generally applies the contractual method whereby loan fees collected for the origination of loans less direct loan origination costs (net of deferred loan fees), as well as premiums and discounts and certain purchase accounting adjustments, are amortized over the contractual life of the loan through interest income. If a loan has scheduled payments, the amortization of the net deferred loan fee is calculated using the interest method over the contractual life of the loan. If a loan does not have scheduled payments, such as a line of credit, the net deferred loan fee is recognized as interest income on a straight-line basis over the contractual life of the loan commitment. Commitment fees based on a percentage of a customer’s unused line of credit and fees related to standby letters of credit are recognized over the commitment period. When loans are repaid, any remaining unamortized balances of premiums, discounts, or net deferred fees are recognized as interest income. Conversely, with respect to loans originated under the PPP, the Company incorporates projected prepayments in calculating effective yield. As a result, net deferred fees are accreted into interest income faster than would be the case when applying the contractual method based upon the timing and amount of estimated forgiven loan balances. The Company expects that a majority of PPP loans will qualify for forgiveness under the SBA program, based on requested loan amounts largely representing qualifying expenses at the time of application. Nonaccrual loans When a borrower discontinues making payments as contractually required by the note, the Company must determine whether it is appropriate to continue to accrue interest. The Company ceases accruing interest income when the loan has become delinquent by more than 90 days or when management determines that the full repayment of principal and collection of interest according to contractual terms is no longer likely. Past due status is based on the contractual terms of the loan. The Company may decide to continue to accrue interest on certain loans more than 90 days delinquent if the loans are well secured by collateral and in the process of collection. For all loan types, when a loan is placed on nonaccrual status, all interest accrued but uncollected is reversed against interest income in the period in which the status is changed, and the Company makes a loan-level decision to apply either the cash basis or cost recovery method. The Company may recognize income on a cash basis when a payment is received and only for those nonaccrual loans for which the collection of the remaining principal balance is not in doubt. Under the cost recovery method, subsequent payments received from the customer are applied to principal and generally no further interest income is recognized until the principal has been paid in full or until circumstances have changed such that payments are again consistently received as contractually required. Loans are returned to accrual status when all of the principal and interest amounts contractually due are brought current and future payments are reasonably assured. Troubled Debt Restructured Loans A TDR loan is a loan on which the Company, for reasons related to a borrower’s financial difficulties, grants a concession to the borrower that the Company would not otherwise consider. In order to determine whether a borrower is experiencing financial difficulty, an evaluation is performed of the probability that the borrower will be in payment default on any of its debt in the foreseeable future without the modification. The evaluation is performed under the Company's internal underwriting policy. The loan terms that may be modified or restructured due to a borrower’s financial situation include, but are not limited to, a reduction in the stated interest rate, an extension of the maturity or renewal of the loan at an interest rate below current market, a reduction in the face amount of the debt, a reduction in the accrued interest, or deferral of interest payments. A TDR loan may be returned to accrual status when the loan is brought current, has performed in accordance with the contractual restructured terms for a reasonable period of time (generally six months), and the ultimate collectability of the total contractual restructured principal and interest is no longer in doubt. Consistent with regulatory guidance, a TDR loan that is subsequently modified in another restructuring agreement but has shown sustained performance and classification as a TDR, will be removed from TDR status provided that the modified terms were market-based at the time of modification. The CARES Act, signed into law on March 27, 2020, permits financial institutions to suspend requirements under GAAP for loan modifications to borrowers affected by COVID-19 that would otherwise be characterized as TDRs and suspend any determination related thereto if (i) the loan modification is made between March 1, 2020 and the earlier of December 31, 2020 or 60 days after the end of the coronavirus emergency declaration and (ii) the applicable loan was not more than 30 days past due as of December 31, 2019. In addition, federal bank regulatory authorities have issued guidance to encourage financial institutions to make loan modifications for borrowers affected by COVID-19 and have assured financial institutions that they will neither receive supervisory criticism for such prudent loan modifications, nor be required by examiners to automatically categorize COVID-19-related loan modifications as TDRs. The Company is applying this guidance to qualifying loan modifications. Credit quality indicators Loans are regularly reviewed to assess credit quality indicators and to determine appropriate loan classification and grading in accordance with applicable bank regulations. The Company’s risk rating methodology assigns risk ratings ranging from 1 to 9, where a higher rating represents higher risk. The Company differentiates its loan segments based on shared risk characteristics for which expected credit loss is measured on a pool basis. The nine risk rating categories can be generally described by the following groupings for loans: "Pass" (grades 1 through 5): The Company has five pass risk ratings, which represent a level of credit quality that ranges from no well-defined deficiency or weakness to some noted weakness; however, the risk of default on any loan classified as pass is expected to be remote. The five pass risk ratings are described below: Minimal risk. These consist of loans that are fully secured either with cash held in a deposit account at the Bank or by readily marketable securities with an acceptable margin based on the type of security pledged. Low risk. These consist of loans with a high investment grade rating equivalent. Modest risk. These consist of loans where the credit facility greatly exceeds all policy requirements or with policy exceptions that are appropriately mitigated. A secondary source of repayment is verified and considered sustainable. Collateral coverage on these loans is sufficient to fully cover the debt as a tertiary source of repayment. Debt of the borrower is low relative to borrower’s financial strength and ability to pay. Average risk. These consist of loans where the credit facility meets or exceeds all policy requirements or with policy exceptions that are appropriately mitigated. A secondary source of repayment is available to service the debt. Collateral coverage is more than adequate to cover the debt. The borrower exhibits acceptable cash flow and moderate leverage. Acceptable risk. These consist of loans with an acceptable primary source of repayment, but a less than preferable secondary source of repayment. Cash flow is adequate to service debt, but there is minimal excess cash flow. Leverage is moderate or high. "Special mention" (grade 6): Generally these are assets that possess potential weaknesses that warrant management's close attention. These loans may involve borrowers with adverse financial trends, higher debt-to-equity ratios, or weaker liquidity positions, but not to the degree of being considered a “problem loan” where risk of loss may be apparent. Loans in this category are usually performing as agreed, although there may be non-compliance with financial covenants. "Substandard" (grade 7): These assets are characterized by well-defined credit weaknesses and carry the distinct possibility that the Company will sustain some loss if such weakness or deficiency is not corrected. All loans 90 days or more past due and all loans on nonaccrual status are considered at least "Substandard," unless extraordinary circumstances would suggest otherwise. "Doubtful" (grade 8): These assets have all the weaknesses inherent in those classified as "Substandard" with the added characteristic that the weaknesses present make collection or liquidation in full, on the basis of currently existing facts, conditions and values, highly questionable and improbable, but because of certain known factors that may work to the advantage and strengthening of the asset (for example, capital injection, perfecting liens on additional collateral and refinancing plans), classification as an estimated loss is deferred until a more precise status may be determined. Due to the high probability of loss, loans classified as "Doubtful" are placed on nonaccrual status. "Loss" (grade 9): These assets are considered uncollectible and having such little recoverable value that it is not practical to defer writing off the asset. This classification does not mean that the loan has absolutely no recovery or salvage value, but rather that it is not practicable or desirable to defer writing off the asset, even though partial recovery may be achieved in the future.
Allowance for Credit Losses	Allowance for credit losses on loans On January 1, 2020, the Company adopted the amendments within ASU 2016-13, Measurement of Credit Losses on Financial Instruments , which changes the impairment model for most financial assets carried at amortized cost from an incurred loss model to an expected loss model. The discussion below reflects the current expected credit loss model methodology. For discussion of the former incurred loss model methodology, refer to the Company's Annual Report on Form 10-K for the year ended December 31, 2019. Credit risk is inherent in the business of extending loans and leases to borrowers and is continuously monitored by management and reflected within the allowance for credit losses for loans. The allowance for credit losses is an estimate of life-of-loan losses for the Company's loans held for investment. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of a loan to present the net amount expected to be collected on the loan. Accrued interest receivable on loans, which is included in other assets on the Consolidated Balance Sheet, is excluded from the estimate of expected credit losses. Expected recoveries of amounts previously written off and expected to be written off are included in the valuation account and may not exceed the aggregate of amounts previously written off and expected to be written off. The Company formally re-evaluates and establishes the appropriate level of the allowance for credit losses on a quarterly basis. Determining the appropriateness of the allowance is complex and requires judgment by management about the effect of matters that are inherently uncertain. In future periods, evaluations of the overall loan portfolio or particular segments of the loan portfolio, in light of the factors and forecasts then prevailing, may result in significant changes in the allowance for credit losses and credit loss expense in those future periods. The allowance level is influenced by loan volumes, mix, loan performance metrics, asset quality characteristics, delinquency status, historical credit loss experience, and the inputs and assumptions in economic forecasts, such as macroeconomic inputs, length of reasonable and supportable forecast periods, and reversion methods. The methodology for estimating the amount of expected credit losses reported in the allowance for credit losses has two basic components: first, an asset-specific component involving individual loans that do not share risk characteristics with other loans and the measurement of expected credit losses for such individual loans and; second, a pooled component for estimated expected credit losses for pools of loans that share similar risk characteristics. Loans that do not share risk characteristics with other loans Loans that do not share risk characteristics with other loans are evaluated on an individual basis. Loans evaluated individually are not included in the collective evaluation. These loans consist of loans with unique features or loans that no longer share risk characteristics with other pooled loans. The process for determining whether a loan should be evaluated on an individual basis begins with determination of credit rating. All loans graded substandard or worse and all PCD loans, irrespective of credit rating, are specifically reviewed for loss potential and, when deemed appropriate, are assigned a reserve based on an individual evaluation. For these loans, the allowance is based primarily on the fair value of the underlying collateral, utilizing independent third-party appraisals. Loans that share similar risk characteristics with other loans In estimating the component of the allowance for credit losses for loans that share similar risk characteristics with other loans, such loans are segregated into loan segments. The Company's primary portfolio segments have changed due to adoption of the amendments within ASU 2016-13 to align with the methodology applied in estimating the allowance for credit losses under CECL. Loans are designated into loan segments based on loans pooled by product types, business lines, and similar risk characteristics or areas of risk concentration. In determining the allowance for credit losses, the Company derives an estimate of expected credit losses primarily using an expected loss methodology that incorporates risk parameters (probability of default, loss given default, and exposure at default), which are derived from various vendor models, internally-developed statistical models, or non-statistical estimation approaches. Probability of default is projected in these models or estimation approaches using multiple economic scenarios, whose outcomes are weighted based on the Company's economic outlook and were developed to incorporate relevant information about past events, current conditions, and reasonable and supportable forecasts. With the exception of the Company's residential loan segment, the Company's PD models share a common definition of default, which include loans that are 90 days past due, on nonaccrual status, have a writeoff, or obligor bankruptcy. Input reversion is used for all loan segment models, except for the commercial and industrial and CRE, owner-occupied loan segments. Output reversion is used for the commercial and industrial and CRE, owner-occupied segments by incorporating, after the forecast period, a one-year linear reversion to the long-term reversion rate in year three through the remaining life of the loans within the respective segments. LGDs are typically derived from the Company's historical loss experience. However, for the residential, warehouse lending, and municipal and nonprofit loan segments, where the Company has either zero (or near zero) losses, or has a limited loss history through the last economic downturn, certain non-modeled methodologies are employed. Factors utilized in calculating average LGD vary for each loan segment and are further described below. Exposure at default refers to the Company's exposure to loss at the time of borrower default and is calculated using an amortization schedule based on contractual loan terms, adjusted for a prepayment rate assumption. For most of the Company's loan segments, prepayment rate assumptions are based on a non-modeled approach that calculates the number of loans that were prepaid in full during the period divided by the total number of loans outstanding at the beginning of the period. Prepayment trends are sensitive to interest rates and the macroeconomic environment. Fixed rate loans are more influenced by interest rates, whereas variable rate loans are more influenced by the macroeconomic environment. After the quantitative expected loss estimates are calculated, management then adjusts these estimates to incorporate considerations of current trends and conditions that are not captured in the quantitative loss estimates, through the use of qualitative and/or environmental factors. The following provides credit quality indicators and risk elements most relevant in monitoring and measuring the allowance for credit losses for each of the loan portfolio segments identified: Commercial and industrial The commercial and industrial portfolio segment is comprised of commercial loans that are not collateralized by real estate. The source of repayment of these loans is generally expected to be the income that is generated from the business. The models used to estimate expected credit losses for this loan segment include a combination of a vendor model and an internally-developed model. These models incorporate both market level and company-specific factors such as financial statement variables, adjusted for the current stage of the credit cycle and for the Company's loan performance data such as delinquency, utilization, maturity, and size of the loan commitment under specific macroeconomic scenarios to produce a probability of default. Macroeconomic variables include the Dow Jones Index, credit spread between the BBB Bond Yield and 10-Year Treasury Bond Yield, unemployment rate, and CBOE VIX Index quarterly high. LGD and the prepayment rate assumption for EAD for this loan segment are driven by unemployment levels. Commercial real estate, owner-occupied The CRE, owner-occupied portfolio segment is comprised of commercial loans that are collateralized by real estate, where the primary source of repayment is the business that occupies the property. These loans are typically entered into for the purpose of providing real estate finance or improvement. The primary source of repayment of these loans is the income generated by the business and where rental or sale of the property may provide secondary support for the loan. These loans are sensitive to general economic conditions as well as the market valuation of CRE properties. The probability of default estimate for this loan segment is modeled using the same model as the commercial and industrial loan segment. LGD for this loan segment is driven by property appreciation and the prepayment rate assumption for EAD is driven by unemployment levels. Commercial real estate, non-owner occupied The CRE, non-owner occupied segment is comprised of loans that are collateralized by real estate, where the owner is not the primary tenant. These loans are typically entered into for the purpose of financing or the improvement of commercial investment properties. The primary source of repayment of these loans are the rents paid by tenants and where the sale of the property may provide secondary support for the loan. These loans are sensitive to the market valuation of CRE properties, rental rates, and general economic conditions. The vendor model used to estimate expected credit losses for this loan segment projects probabilities of default and exposure at default based on multiple macroeconomic scenarios by modeling how macroeconomic conditions affect the commercial real estate market. Real estate market factors utilized in this model include vacancy rate, rental growth rate, net operating income growth rate, and commercial property price changes for each specific property type. The model then incorporates loan and property-level characteristics including debt coverage, leverage, collateral size, seasoning, and property type. LGD for this loan segment is derived from a non-modeled approach that is driven by property appreciation and the prepayment rate assumption for EAD is driven by the property appreciation for fixed rate loans and unemployment levels for variable rate loans. Residential The residential loan portfolio segment is comprised of loans collateralized primarily by first liens on 1-4 residential family properties and home equity lines of credit that are collateralized by either first liens or junior liens on residential properties. The primary source of repayment of these loans is the value of the property and the capacity of the owner to make payments on the loan. Unemployment rates and the market valuation of residential properties will impact the ultimate repayment of these loans. The residential mortgage loan model is a vendor model that projects probability of default, loss given default severity, prepayment rate, and exposure at default to calculate expected losses. The model is intended to capture the borrower's payment behavior during the lifetime of the residential loan by incorporating loan level characteristics such as loan type, coupon, age, loan-to-value, and credit score and economic conditions such as Home Price Index, interest rate, and unemployment rate. A default event for residential loans is defined as 60 days or more past due, with property appreciation as the driver for LGD results. The prepayment rate assumption for exposure at default for residential loans is based on industry prepayment history. Probability of default for HELOCs is derived from an internally-developed model that projects PD by incorporating loan level information such as FICO score, lien position, balloon payments, and macroeconomic conditions such as property appreciation. LGD for this loan segment is driven by property appreciation and lien position. Exposure at default for HELOCs is calculated based on utilization rate assumptions using a non-modeled approach and incorporates management judgment. Construction and land development The construction and land portfolio segment is comprised of loans collateralized by land or real estate, which are entered into for the purpose of real estate development. The primary source of repayment of loans is the eventual sale or refinance of the completed project and where claims on the property provide secondary support for the loan. These loans are impacted by the market valuation of CRE and residential properties and general economic conditions that have a higher sensitivity to real estate markets compared to other real estate loans. Default risk of a property is driven by loan-specific drivers, including loan-to-value, maturity, origination date, and the metropolitan statistical area ("MSA") in which the property is located, among other items. The variables used in the internally-developed model include loan level drivers such as origination loan-to-value, loan maturity, and macroeconomic drivers such as property appreciation, MSA level unemployment rate, and national GDP growth. LGD for this loan segment is driven by property appreciation. The prepayment rate assumption for EAD is driven by the property appreciation for fixed rate loans and unemployment levels for variable rate loans. Warehouse lending The warehouse lending portfolio segment consists of loans that have a monitored borrowing base to mortgage companies and similar lenders. These loans are collateralized by real estate notes and mortgages or mortgage servicing rights and the borrowing base of these loans is tightly monitored and controlled by the Company. The primary support for the loan takes the form of pledged collateral, with secondary support provided by the capacity of the financial institution. The collateral-driven nature of these loans distinguish them from traditional commercial and industrial loans. These loans are impacted by interest rate shocks, residential lending rates, prepayment assumptions, and general real estate stress. As a result of the unique loan characteristics, limited historical default and loss experience, and the collateral nature of this loan portfolio segment, the Company uses a non-modeled approach to estimate expected credit losses, leveraging grade information, grade migration history, and management judgment. Municipal and nonprofit The municipal and nonprofit portfolio segment consists of loans to local governments, government-operated utilities, special assessment districts, hospitals, schools and other nonprofits. These loans are generally, but not exclusively, entered into for the purpose of financing real estate investment or for refinancing existing debt. Loans are supported by taxes or utility fees, and in some cases tax liens on real estate, operating revenue of the institution, or other collateral support the loans. Unemployment rates and the market valuation of residential properties have an effect on the tax revenues supporting these loans; however, these loans tend to be less cyclical in comparison to similar commercial loans as these loans rely on diversified tax bases. The Company uses a non-modeled approach to estimate expected credit losses, leveraging grade information and historical municipal default rates. Other
Lessee, Leases [Policy Text Block]	Leases (lessee) At inception, contracts are evaluated to determine whether the contract constitutes a lease agreement. For contracts that are determined to be an operating lease, a corresponding ROU asset and operating lease liability are recorded in separate line items on the Consolidated Balance Sheet. A ROU asset represents the Company’s right to use an underlying asset during the lease term and a lease liability represents the Company’s commitment to make contractually obligated lease payments. Operating lease ROU assets and liabilities are recognized at the commencement date of the lease and are based on the present value of lease payments over the lease term. The measurement of the operating lease ROU asset includes any lease payments made and is reduced by lease incentives that are paid or are payable to the Company. Variable lease payments that depend on an index or rate such as the Consumer Price Index are included in lease payments based on the rate in effect at the commencement date of the lease. Lease payments are recognized on a straight-line basis as part of occupancy expense over the lease term. As the rate implicit in the lease is not readily determinable, the Company's incremental collateralized borrowing rate is used to determine the present value of lease payments. This rate gives consideration to the applicable FHLB collateralized borrowing rates and is based on the information available at the commencement date. The Company has elected to apply the short-term lease measurement and recognition exemption to leases with an initial term of 12 months or less; therefore, these leases are not recorded on the Company’s Consolidated Balance Sheet, but rather, lease expense is recognized over the lease term on a straight-line basis. The Company’s lease agreements may include options to extend or terminate the lease. These options are included in the lease term when it is reasonably certain that the options will be exercised.
Goodwill and Other Intangible Assets	Goodwill and other intangible assets The Company records as goodwill the excess of the purchase price in a business combination over the fair value of the identifiable net assets acquired in accordance with applicable guidance. The Company performs its annual goodwill and intangibles impairment tests as of October 1 each year, or more often if events or circumstances indicate that the carrying value may not be recoverable. The Company can first elect to assess, through qualitative factors, whether it is more likely than not that goodwill is impaired. If the qualitative assessment indicates potential impairment, a quantitative impairment test is necessary. If, based on the quantitative test, a reporting unit's carrying amount exceeds its fair value, a goodwill impairment charge for this difference is recorded to current period earnings as non-interest expense. The Company’s intangible assets consist primarily of core deposit intangible assets that are amortized over periods ranging from five to 10 years. The Company considers the remaining useful lives of its core deposit intangible assets each reporting period, as required by ASC 350, Intangibles—Goodwill and Other, to determine whether events and circumstances warrant a revision to the remaining period of amortization. If the estimate of an intangible asset’s remaining useful life has changed, the remaining carrying amount of the intangible asset is amortized prospectively over the revised remaining useful life. The Company did not revise its estimates of the useful lives of its core deposit intangibles during the three and nine months ended September 30, 2020 or 2019.
Stockholders' Equity, Policy	Treasury shares The Company separately presents treasury shares, which represent shares surrendered to the Company equal in value to the statutory payroll tax withholding obligations arising from the vesting of employee restricted stock awards. Treasury shares are carried at cost. Common stock repurchases
Derivative Financial Instruments	Derivative financial instruments The Company uses interest rate swaps to mitigate interest-rate risk associated with changes to the fair value of certain fixed-rate financial instruments (fair value hedges). The Company recognizes derivatives as assets or liabilities on the Consolidated Balance Sheet at their fair value in accordance with ASC 815, Derivatives and Hedging . The accounting for changes in the fair value of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship and further, on the type of hedging relationship. Derivative instruments designated in a hedge relationship to mitigate exposure to changes in the fair value of an asset or liability attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Changes in the fair value of a derivative that is designated and qualifies as a fair value hedge, along with changes in the fair value of the hedged asset or liability that are attributable to the hedged risk, are recorded in current period earnings. Changes in the fair value of derivatives not considered to be highly effective in hedging the change in fair value of the hedged item are recognized in earnings as non-interest income during the period of the change. The Company documents its hedge relationships, including identification of the hedging instruments and the hedged items, as well as its risk management objectives and strategies for undertaking the hedge transaction after the derivative contract is executed. At inception, the Company performs a quantitative assessment to determine whether the derivatives used in hedging transactions are highly effective (as defined in the guidance) in offsetting changes in the fair value of the hedged item. Retroactive effectiveness is assessed, as well as the continued expectation that the hedge will remain effective prospectively. After the initial quantitative assessment is performed, on a quarterly basis, the Company performs a qualitative hedge effectiveness assessment. This assessment takes into consideration any adverse developments related to the counterparty's risk of default and any negative events or circumstances that affect the factors that originally enabled the Company to assess that it could reasonably support, qualitatively, an expectation that the hedging relationship was and will continue to be highly effective. The Company discontinues hedge accounting prospectively when it is determined that a hedge is no longer highly effective. When hedge accounting is discontinued on a fair value hedge that no longer qualifies as an effective hedge, the derivative instrument continues to be reported at fair value on the Consolidated Balance Sheet, but the carrying amount of the hedged item is no longer adjusted for future changes in fair value. The adjustment to the carrying amount of the hedged item that existed at the date hedge accounting is discontinued is amortized over the remaining life of the hedged item into earnings. Derivative instruments that are not designated as hedges, so called free-standing derivatives, are reported on the Consolidated Balance Sheet at fair value and the changes in fair value are recognized in earnings as non-interest income during the period of change. The Company may in the normal course of business purchase a financial instrument or originate a loan that contains an embedded derivative instrument. Upon purchasing the instrument or originating the loan, the Company assesses whether the economic characteristics of the embedded derivative are clearly and closely related to the economic characteristics of the remaining component of the financial instrument (i.e., the host contract) and whether a separate instrument with the same terms as the embedded instrument would meet the definition of a derivative instrument. When it is determined that the embedded derivative possesses economic characteristics that are not clearly and closely related to the economic characteristics of the host contract and a separate instrument with the same terms would qualify as a derivative instrument, the embedded derivative is separated from the host contract and carried at fair value. However, in cases where the host contract is measured at fair value, with changes in fair value reported in current earnings, or the Company is unable to reliably identify and measure an embedded derivative for separation from its host contract, the entire contract is carried on the Consolidated Balance Sheet at fair value and is not designated as a hedging instrument.
Off-Balance Sheet Instruments	Off-balance sheet instruments In the ordinary course of business, the Company has entered into off-balance sheet financial instrument arrangements consisting of commitments to extend credit and standby letters of credit. Such financial instruments are recorded in the Consolidated Financial Statements when they are funded. They involve, to varying degrees, elements of credit risk in excess of amounts recognized on the Consolidated Balance Sheet. Losses could be experienced when the Company is contractually obligated to make a payment under these instruments and must seek repayment from the borrower, which may not be as financially sound in the current period as they were when the commitment was originally made. Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract and, in certain instances, may be unconditionally cancelable. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. The Company enters into credit arrangements that generally provide for the termination of advances in the event of a covenant violation or other event of default. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by the Company upon extension of credit, is based on management’s credit evaluation of the party. The commitments are collateralized by the same types of assets used as loan collateral. The Company also has off-balance sheet arrangements related to its derivative instruments. Derivative instruments are recognized in the Consolidated Financial Statements at fair value and their notional values are carried off-balance sheet. See "Note 8. Derivatives and Hedging Activities" of these Notes to Unaudited Consolidated Financial Statements for further discussion.
Fair Values of Financial Instruments	Fair values of financial instruments The Company uses fair value measurements to record fair value adjustments to certain assets and liabilities. ASC 820, Fair Value Measurement , establishes a framework for measuring fair value and a three-level valuation hierarchy for disclosure of fair value measurement, and also sets forth disclosure requirements for fair value measurements. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. The Company uses various valuation approaches, including market, income, and/or cost approaches. ASC 820 establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing the asset or liability developed based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the factors market participants would consider in pricing the asset or liability developed based on the best information available in the circumstances. The hierarchy is broken down into three levels based on the reliability of inputs, as follows: • Level 1 - Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. • Level 2 - Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These might include quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, prepayment speeds, volatilities, etc.) or model-based valuation techniques where all significant assumptions are observable, either directly or indirectly, in the market. • Level 3 - Valuation is generated from model-based techniques where one or more significant inputs are not observable, either directly or indirectly, in the market. These unobservable assumptions reflect the Company’s own estimates of assumptions that market participants would use in pricing the asset or liability. Valuation techniques may include use of matrix pricing, discounted cash flow models, and similar techniques. The availability of observable inputs varies based on the nature of the specific financial instrument. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, for disclosure purposes, the level in the fair value hierarchy within which the fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety. Fair value is a market-based measure considered from the perspective of a market participant who may purchase the asset or assume the liability, rather than an entity-specific measure. When market assumptions are available, ASC 820 requires that the Company make assumptions regarding the assumptions that market participants would use to estimate the fair value of the financial instrument at the measurement date. ASC 825, Financial Instruments , requires disclosure of fair value information about financial instruments, whether or not recognized in the balance sheet, for which it is practicable to estimate that value. Management uses its best judgment in estimating the fair value of the Company’s financial instruments; however, there are inherent limitations in any estimation technique. Therefore, for substantially all financial instruments, the fair value estimates presented herein are not necessarily indicative of the amounts the Company could have realized in a sales transaction at September 30, 2020 and December 31, 2019. The estimated fair value amounts for September 30, 2020 and December 31, 2019 have been measured as of period-end, and have not been re-evaluated or updated for purposes of these Unaudited Consolidated Financial Statements subsequent to those dates. As such, the estimated fair values of these financial instruments subsequent to the reporting date may be different than the amounts reported at period-end. The information in "Note 12. Fair Value Accounting" of these Notes to Unaudited Consolidated Financial Statements should not be interpreted as an estimate of the fair value of the entire Company since a fair value calculation is only required for a limited portion of the Company’s assets and liabilities. Due to the wide range of valuation techniques and the degree of subjectivity used in making the estimate, comparisons between the Company’s disclosures and those of other companies or banks may not be meaningful. The following methods and assumptions were used by the Company in estimating the fair value of its financial instruments: Cash, cash equivalents, and restricted cash The carrying amounts reported on the Consolidated Balance Sheet for cash and due from banks approximate their fair value. Money market investments The carrying amounts reported on the Consolidated Balance Sheet for money market investments approximate their fair value. Investment securities The fair values of CRA investments, exchange-listed preferred stock, trust preferred securities, and certain corporate debt securities are based on quoted market prices and are categorized as Level 1 in the fair value hierarchy. The fair values of debt securities are primarily determined based on matrix pricing. Matrix pricing is a mathematical technique that utilizes observable market inputs including, for example, yield curves, credit ratings, and prepayment speeds. Fair values determined using matrix pricing are generally categorized as Level 2 in the fair value hierarchy. For a small subset of securities, other pricing sources are used, including observed prices on publicly traded securities and dealer quotes. Restricted stock WAB is a member of the Federal Reserve System and the FHLB and, accordingly, maintains investments in the capital stock of the FRB and the FHLB. These investments are carried at cost since no ready market exists for them, and they have no quoted market value. The Company conducts a periodic review and evaluation of its restricted stock to determine if any impairment exists. The fair values of these investments have been categorized as Level 2 in the fair value hierarchy. Loans The fair value of loans is estimated based on discounted cash flows using interest rates currently being offered for loans with similar terms to borrowers with similar credit quality and adjustments that the Company believes a market participant would consider in determining fair value based on a third-party independent valuation. As a result, the fair value for loans is categorized as Level 2 in the fair value hierarchy, excluding collateral dependent and impaired loans, which are categorized as Level 3. Accrued interest receivable and payable The carrying amounts reported on the Consolidated Balance Sheet for accrued interest receivable and payable approximate their fair values. Derivative financial instruments All derivatives are recognized on the Consolidated Balance Sheets at their fair value. The fair value for derivatives is determined based on market prices, broker-dealer quotations on similar products, or other related input parameters. As a result, the fair values have been categorized as Level 2 in the fair value hierarchy. Deposits The fair value disclosed for demand and savings deposits is by definition equal to the amount payable on demand at their reporting date (that is, their carrying amount) as these deposits do not have a contractual term. The carrying amount for variable rate deposit accounts approximates their fair value. Fair values for fixed rate certificates of deposit are estimated using a discounted cash flow calculation that applies interest rates currently being offered on certificates to a schedule of aggregated expected monthly maturities on these deposits. The fair value measurement of the deposit liabilities is categorized as Level 2 in the fair value hierarchy. FHLB advances and customer repurchase agreements The fair values of the Company’s borrowings are estimated using discounted cash flow analyses, based on the market rates for similar types of borrowing arrangements. The FHLB advances and customer repurchase agreements have been categorized as Level 2 in the fair value hierarchy due to their short durations. Subordinated debt The fair value of subordinated debt is based on the market rate for the respective subordinated debt security. Subordinated debt has been categorized as Level 2 in the fair value hierarchy. Junior subordinated debt Junior subordinated debt is valued based on a discounted cash flow model which uses as inputs Treasury Bond rates and the 'BB' and 'BBB' rated financial indexes. Junior subordinated debt has been categorized as Level 3 in the fair value hierarchy. Off-balance sheet instruments The fair value of the Company’s off-balance sheet instruments (lending commitments and letters of credit) is based on quoted fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements, and the counterparties’ credit standing.
Income Taxes	Income taxes The Company is subject to income taxes in the United States and files a consolidated federal income tax return with all of its subsidiaries, with the exception of BW Real Estate, Inc. Deferred income taxes are recorded to reflect the effects of temporary differences between the financial reporting carrying amounts of assets and liabilities and their income tax bases using enacted tax rates that are expected to be in effect when the taxes are actually paid or recovered. As changes in tax laws or rates are enacted, deferred tax assets and liabilities are adjusted through the provision for income taxes. Net deferred tax assets are recorded to the extent that these assets will more-likely-than-not be realized. In making these determinations, all available positive and negative evidence is considered, including scheduled reversals of deferred tax liabilities, tax planning strategies, projected future taxable income, and recent operating results. If it is determined that deferred income tax assets to be realized in the future are in excess of their net recorded amount, an adjustment to the valuation allowance will be recorded, which will reduce the Company's provision for income taxes. A tax benefit from an unrecognized tax benefit may be recognized when it is more-likely-than-not that the position will be sustained upon examination, including related appeals or litigation, based on technical merits. Income tax benefits must meet a more-likely-than-not recognition threshold at the effective date to be recognized.
Revenue from Contract with Customer [Policy Text Block]	Non-interest income Non-interest income includes service charges and fees, income from equity investments, card income, foreign currency income, income from bank owned life insurance, lending related income, net gain or loss on sales of investment securities, net fair value gain or loss adjustments on assets measured at fair value, and other income. Service charges and fees consist of fees earned from performance of account analysis, general account services, and other deposit account services. These fees are recognized as the related services are provided in accordance with ASC 606, Revenue from Contracts with Customers . Income from equity investments includes gains on equity warrant assets, SBIC equity income, and success fees. Card income includes fees earned from customer use of debit and credit cards, interchange income from merchants, and international charges. Card income is generally within the scope of ASC 310, Receivables ; however, certain processing transactions for merchants, such as interchange fees, are within the scope of ASC 606. Foreign currency income represents fees earned on the differential between purchases and sales of foreign currency on behalf of the Company’s clients. Income from bank owned life insurance is accounted for in accordance with ASC 325, Investments - Other . Lending related income includes fees earned from gains or losses on the sale of loans, SBA income, and letter of credit fees. Gains and losses on the sale of loans and SBA income are recognized pursuant to ASC 860, Transfers and Servicing . Net unrealized gains or losses on assets measured at fair value represent fair value changes in equity securities and are accounted for in accordance with ASC 321, Investments - Equity Securities . Fees related to standby letters of credit are accounted for in accordance with ASC 440, Commitments . Other income includes operating lease income, which is recognized on a straight-line basis over the lease term in accordance with ASC 842, Leases . Net gain or loss on sales/valuations of repossessed and other assets is presented as a component of non-interest expense, but may also be presented as a component of non-interest income in the event that a net gain is recognized. Net gain or loss on sales of repossessed and other assets are accounted for in accordance with ASC 610, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Table Text Block]	Three Months Ended September 30, 2020 Balance, Provision for (Reversal of) Credit Losses Writeoffs Recoveries Balance, June 30, 2020 September 30, 2020 (in thousands) Held-to-maturity debt securities Tax-exempt $ 7,649 $ (1,685) $ — $ — $ 5,964 Nine Months Ended September 30, 2020 Balance, Provision for (Reversal of) Credit Losses Writeoffs Recoveries Balance, January 1, 2020 September 30, 2020 (in thousands) Held-to-maturity debt securities Tax-exempt $ 2,646 $ 3,318 $ — $ — $ 5,964
Carrying Amounts and Fair Values of Investment Securities	The carrying amounts and fair values of investment securities at September 30, 2020 and December 31, 2019 are summarized as follows: September 30, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Fair Value (in thousands) Held-to-maturity Tax-exempt $ 504,477 $ 43,663 $ — $ 548,140 Available-for-sale debt securities CDO $ 50 $ 8,126 $ — $ 8,176 Commercial MBS issued by GSEs 91,769 3,888 — 95,657 Corporate debt securities 193,798 1,081 (8,270) 186,609 Municipal securities 22,006 271 (118) 22,159 Private label residential MBS 1,245,217 19,874 (854) 1,264,237 Residential MBS issued by GSEs 1,329,773 32,314 (531) 1,361,556 Tax-exempt 961,373 51,117 (1,467) 1,011,023 Trust preferred securities 32,000 — (6,792) 25,208 U.S. treasury securities 600 — — 600 Total AFS debt securities $ 3,876,586 $ 116,671 $ (18,032) $ 3,975,225 Equity securities CRA investments $ 53,190 $ 355 $ — $ 53,545 Preferred stock 104,974 3,976 (1,934) 107,016 Total equity securities $ 158,164 $ 4,331 $ (1,934) $ 160,561 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Fair Value (in thousands) Held-to-maturity Tax-exempt $ 485,107 $ 31,303 $ (149) $ 516,261 Available-for-sale debt securities CDO $ 50 $ 10,092 $ — $ 10,142 Commercial MBS issued by GSEs 95,062 366 (1,175) 94,253 Corporate debt securities 105,015 112 (5,166) 99,961 Municipal securities 7,494 279 — 7,773 Private label residential MBS 1,129,985 3,572 (4,330) 1,129,227 Residential MBS issued by GSEs 1,406,594 9,283 (3,817) 1,412,060 Tax-exempt 530,729 24,548 (422) 554,855 Trust preferred securities 32,000 — (4,960) 27,040 U.S. government sponsored agency securities 10,000 — — 10,000 U.S. treasury securities 999 — — 999 Total AFS debt securities $ 3,317,928 $ 48,252 $ (19,870) $ 3,346,310 Equity securities CRA investments $ 52,805 $ — $ (301) $ 52,504 Preferred stock 82,514 3,881 (198) 86,197 Total equity securities $ 135,319 $ 3,881 $ (499) $ 138,701 Securities with carrying amounts of approximately $830.4 million and $962.5 million at September 30, 2020 and December 31, 2019, respectively, were pledged for various purposes as required or permitted by law.
Unrealized Losses and Fair Value of Investment Securities in Continuous Unrealized Loss Position	unrealized loss position at September 30, 2020 and December 31, 2019, aggregated by major security type and length of time in a continuous unrealized loss position: September 30, 2020 Less Than Twelve Months More Than Twelve Months Total Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value (in thousands) Available-for-sale debt securities Corporate debt securities $ 70 $ 31,528 $ 8,200 $ 91,800 $ 8,270 $ 123,328 Municipal securities 118 9,384 — — 118 9,384 Private label residential MBS 851 131,620 3 2,435 854 134,055 Residential MBS issued by GSEs 522 134,180 9 1,193 531 135,373 Tax-exempt 1,467 121,031 — — 1,467 121,031 Trust preferred securities — — 6,792 25,208 6,792 25,208 Total AFS securities $ 3,028 $ 427,743 $ 15,004 $ 120,636 $ 18,032 $ 548,379 December 31, 2019 Less Than Twelve Months More Than Twelve Months Total Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value (in thousands) Held-to-maturity Tax-exempt $ 149 $ 24,325 $ — $ — $ 149 $ 24,325 Available-for-sale debt securities Commercial MBS issued by GSEs $ 85 $ 9,035 $ 1,090 $ 54,604 $ 1,175 $ 63,639 Corporate debt securities — — 5,166 94,834 5,166 94,834 Private label residential MBS 1,776 337,285 2,554 258,791 4,330 596,076 Residential MBS issued by GSEs 1,740 385,643 2,077 150,419 3,817 536,062 Tax-exempt 422 67,150 — — 422 67,150 Trust preferred securities — — 4,960 27,040 4,960 27,040 Total AFS securities $ 4,023 $ 799,113 $ 15,847 $ 585,688 $ 19,870 $ 1,384,801
Amortized Cost and Fair Value of Investment Securities by Contractual Maturities	A security is considered to be past due once it is 30 days contractually past due under the terms of the agreement. As of September 30, 2020, there were no investment securities that were past due. In addition, the Company does not have a significant amount of investment securities on nonaccrual status or securities that are considered to be collateral-dependent as of September 30, 2020. The amortized cost and fair value of the Company's debt securities as of September 30, 2020, by contractual maturities, are shown below. MBS are shown separately as individual MBS are comprised of pools of loans with varying maturities. Therefore, these securities are listed separately in the maturity summary. September 30, 2020 Amortized Cost Estimated Fair Value (in thousands) Held-to-maturity Due in one year or less $ 7,330 $ 7,336 After one year through five years 17,135 17,628 After ten years 480,012 523,176 Total HTM securities $ 504,477 $ 548,140 Available-for-sale Due in one year or less $ 600 $ 600 After one year through five years 9,024 9,047 After five years through ten years 229,899 223,844 After ten years 970,304 1,020,284 Mortgage-backed securities 2,666,759 2,721,450 Total AFS securities $ 3,876,586 $ 3,975,225
Investment Securities by Credit Rating Type	The following tables summarize the carrying amount of the Company’s investment ratings position as of September 30, 2020 and December 31, 2019, which are updated quarterly and used to monitor the credit quality of the Company's securities: September 30, 2020 AAA Split-rated AAA/AA+ AA+ to AA- A+ to A- BBB+ to BBB- BB+ and below Unrated Totals (in thousands) Held-to-maturity Tax-exempt $ — $ — $ — $ — $ — $ — $ 504,477 $ 504,477 Available-for-sale debt securities CDO $ — $ — $ — $ — $ — $ 8,176 $ — $ 8,176 Commercial MBS issued by GSEs — 95,657 — — — — — 95,657 Corporate debt securities — — — 45,800 122,579 18,230 — 186,609 Municipal securities — — 12,143 — 2,630 — 7,386 22,159 Private label residential MBS 1,235,170 — 27,682 91 347 947 — 1,264,237 Residential MBS issued by GSEs — 1,361,556 — — — — — 1,361,556 Tax-exempt 43,328 56,725 447,629 431,459 — — 31,882 1,011,023 Trust preferred securities — — — — 25,208 — — 25,208 U.S. treasury securities — 600 — — — — — 600 Total AFS securities (1) $ 1,278,498 $ 1,514,538 $ 487,454 $ 477,350 $ 150,764 $ 27,353 $ 39,268 $ 3,975,225 Equity securities CRA investments $ — $ 27,795 $ — $ — $ — $ — $ 25,750 $ 53,545 Preferred stock — — — — 68,945 37,135 936 107,016 Total equity securities (1) $ — $ 27,795 $ — $ — $ 68,945 $ 37,135 $ 26,686 $ 160,561 (1) Where ratings differ, the Company uses an average of the available ratings by major credit agencies. December 31, 2019 AAA Split-rated AAA/AA+ AA+ to AA- A+ to A- BBB+ to BBB- BB+ and below Unrated Totals (in thousands) Held-to-maturity Tax-exempt $ — $ — $ — $ — $ — $ — $ 485,107 $ 485,107 Available-for-sale debt securities CDO $ — $ — $ — $ — $ — $ 10,142 $ — $ 10,142 Commercial MBS issued by GSEs — 94,253 — — — — — 94,253 Corporate debt securities — — — 66,530 33,431 — — 99,961 Municipal securities — — — — — — 7,773 7,773 Private label residential MBS 1,096,909 — 30,675 181 288 1,174 — 1,129,227 Residential MBS issued by GSEs — 1,412,060 — — — — — 1,412,060 Tax-exempt 52,610 2,856 327,657 171,732 — — — 554,855 Trust preferred securities — — — — 27,040 — — 27,040 U.S. government sponsored agency securities — 10,000 — — — — — 10,000 U.S. treasury securities — 999 — — — — — 999 Total AFS securities (1) $ 1,149,519 $ 1,520,168 $ 358,332 $ 238,443 $ 60,759 $ 11,316 $ 7,773 $ 3,346,310 Equity securities CRA investments $ — $ 25,375 $ — $ — $ — $ — $ 27,129 $ 52,504 Preferred stock — — — — 82,851 2,105 1,241 86,197 Total equity securities (1) $ — $ 25,375 $ — $ — $ 82,851 $ 2,105 $ 28,370 $ 138,701 (1) Where ratings differ, the Company uses an average of the available ratings by major credit agencies.
Gross Gains and (Losses) on Sales of Investment Securities	Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Available-for-sale securities Gross gains $ — $ 3,152 $ 405 $ 3,152 Gross losses — — (175) — Net gains (losses) on AFS securities $ — $ 3,152 $ 230 $ 3,152

Loans, Leases and Allowance for

Loans, Leases and Allowance for Credit Losses (Tables)	9 Months Ended
	Sep. 30, 2020
Receivables [Abstract]
Financing Receivable, Troubled Debt Restructuring [Table Text Block]	The following table presents TDR loans for the periods presented: September 30, 2020 Number of Loans Recorded Investment (dollars in thousands) Commercial and industrial Tech & Innovation 3 $ 12,111 Other commercial and industrial 16 30,270 CRE - owner occupied 3 2,335 CRE - non-owner occupied Hotel Franchise Finance 2 5,746 Other CRE - non-owned occupied 3 10,295 Total 27 $ 60,757
Schedule of Held for Investment Loan Portfolio Composition of Loans, Leases and Allowance for Credit Losses	The Company's primary portfolio segments have changed to align with the methodology applied in estimating the allowance for credit losses under CECL. In addition, as the concept of impaired loans does not exist under CECL, disclosures that related solely to impaired loans have been removed. The composition of the Company's held for investment loan portfolio is as follows: September 30, 2020 (in thousands) Commercial and industrial Tech & Innovation $ 2,277,889 Other commercial and industrial 5,993,712 CRE - owner occupied 1,970,163 CRE - non-owner occupied Hotel Franchise Finance 1,942,886 Other CRE - non-owned occupied 3,433,932 Residential 2,330,064 Construction and land development 2,267,922 Warehouse lending 3,926,852 Municipal & nonprofit 1,686,690 Other 163,144 Total loans HFI 25,993,254 Allowance for credit losses (310,560) Total loans HFI, net of allowance $ 25,682,694 December 31, 2019 (in thousands) Commercial and industrial $ 9,382,043 Commercial real estate - non-owner occupied 5,245,634 Commercial real estate - owner occupied 2,316,913 Construction and land development 1,952,156 Residential real estate 2,147,664 Consumer 57,083 Loans, net of deferred loan fees and costs 21,101,493 Allowance for credit losses (167,797) Total loans HFI $ 20,933,696
Contractual Aging of Loan Portfolio by Class of Loans Including Loans Held for Sale and Excluding Deferred Fees/Costs	The following table presents an aging analysis of past due loans by loan portfolio segment: September 30, 2020 Current 30-59 Days 60-89 Days Over 90 days Total Total (in thousands) Commercial and industrial Tech & Innovation $ 2,277,889 $ — $ — $ — $ — $ 2,277,889 Other commercial and industrial 5,969,739 4,617 2,490 16,866 23,973 5,993,712 CRE - owner occupied 1,970,163 — — — — 1,970,163 CRE - non-owner occupied Hotel Franchise Finance 1,931,623 — — 11,263 11,263 1,942,886 Other CRE - non-owned occupied 3,433,932 — — — — 3,433,932 Residential 2,319,530 10,325 209 — 10,534 2,330,064 Construction and land development 2,261,348 6,574 — — 6,574 2,267,922 Warehouse lending 3,926,852 — — — — 3,926,852 Municipal & nonprofit 1,686,690 — — — — 1,686,690 Other 163,101 38 5 — 43 163,144 Total loans $ 25,940,867 $ 21,554 $ 2,704 $ 28,129 $ 52,387 $ 25,993,254 December 31, 2019 Current 30-59 Days 60-89 Days Over 90 days Total Total (in thousands) Commercial and industrial $ 9,376,377 $ 2,501 $ 637 $ 2,528 $ 5,666 $ 9,382,043 Commercial real estate Owner occupied 2,316,165 624 — 124 748 2,316,913 Non-owner occupied 5,007,644 4,661 — 11,913 16,574 5,024,218 Multi-family 221,416 — — — — 221,416 Construction and land development Construction 1,176,908 — — — — 1,176,908 Land 775,248 — — — — 775,248 Residential real estate 2,134,346 7,627 1,721 3,970 13,318 2,147,664 Consumer 57,083 — — — — 57,083 Total loans $ 21,065,187 $ 15,413 $ 2,358 $ 18,535 $ 36,306 $ 21,101,493
Summary of Recorded Investment in Nonaccrual Loans and Loans Past Due 90 Days Still Accruing Interest by Loan Class	Loans are placed on nonaccrual status when management determines that the full repayment of principal and collection of interest according to contractual terms is no longer likely, generally when the loan becomes 90 days or more past due. The following tables present nonperforming loan balances by loan portfolio segment: September 30, 2020 Nonaccrual with No Allowance for Credit Loss Nonaccrual with an Allowance for Credit Loss Total Nonaccrual Loans Past Due 90 Days or More and Still Accruing (in thousands) Commercial and industrial Tech & Innovation $ 18,725 $ — $ 18,725 $ — Other commercial and industrial 26,997 4,614 31,611 16,866 CRE - owner occupied 38,567 — 38,567 — CRE - non-owner occupied Hotel Franchise Finance — — — 11,263 Other CRE - non-owned occupied 18,404 10,667 29,071 — Residential 5,388 — 5,388 — Construction and land development — 192 192 — Warehouse lending — — — — Municipal & nonprofit — 1,952 1,952 — Other 158 45 203 — Total $ 108,239 $ 17,470 $ 125,709 $ 28,129 In addition, the Company also has HFS loans totaling $20.8 million that are on nonaccrual status as of September 30, 2020. December 31, 2019 Non-accrual loans Loans past due 90 days or more and still accruing Current Past Due/ Total (in thousands) Commercial and industrial $ 19,080 $ 5,421 $ 24,501 $ — Commercial real estate Owner occupied 4,418 124 4,542 — Non-owner occupied 7,265 11,913 19,178 — Multi-family — — — — Construction and land development Construction 2,147 — 2,147 — Land — — — — Residential real estate 1,231 4,369 5,600 — Consumer — — — — Total $ 34,141 $ 21,827 $ 55,968 $ —
Loans by Risk Rating	Credit Quality Indicators The Company categorizes loans into risk categories based on relevant information about the ability of borrowers to service their debt such as current financial information, historical payment experience, credit documentation, public information, and current economic trends, among other factors. The Company analyzes loans individually to classify the loans as to credit risk. This analysis is performed on a quarterly basis. The risk rating categories are described in "Note 1. Summary of Significant Accounting Policies ." The following tables present risk ratings as of September 30, 2020 by loan portfolio segment: Term Loan Amortized Cost Basis by Origination Year Revolving Loans Amortized Cost Basis Total September 30, 2020 2020 2019 2018 2017 2016 Prior (in thousands) Tech & Innovation Pass $ 524,508 $ 315,900 $ 132,566 $ 1,459 $ 1,898 $ — $ 1,236,377 $ 2,212,708 Special mention 3,499 8,957 2,651 — — — — 15,107 Substandard 32,412 2,006 — — — — 15,656 50,074 Doubtful — — — — — — — — Loss — — — — — — — — Total $ 560,419 $ 326,863 $ 135,217 $ 1,459 $ 1,898 $ — $ 1,252,033 $ 2,277,889 Other commercial and industrial Pass $ 2,067,599 $ 920,820 $ 469,602 $ 289,894 $ 113,199 $ 123,061 $ 1,735,701 $ 5,719,876 Special mention 129 51,516 32,172 36,017 6,130 15,885 43,378 185,227 Substandard 18,169 8,420 3,465 31,349 9,876 1,001 16,102 88,382 Doubtful — — — 177 — — — 177 Loss — 50 — — — — — 50 Total $ 2,085,897 $ 980,806 $ 505,239 $ 357,437 $ 129,205 $ 139,947 $ 1,795,181 $ 5,993,712 CRE - owner occupied Pass $ 173,784 $ 327,618 $ 322,396 $ 423,987 $ 167,304 $ 376,175 $ 74,887 $ 1,866,151 Special mention 877 11,412 4,411 17,306 3,309 10,658 — 47,973 Substandard 2,237 7,573 4,926 10,483 6,311 22,460 2,049 56,039 Doubtful — — — — — — — — Loss — — — — — — — — Total $ 176,898 $ 346,603 $ 331,733 $ 451,776 $ 176,924 $ 409,293 $ 76,936 $ 1,970,163 Hotel Franchise Finance Pass $ 156,816 $ 754,537 $ 464,842 $ 140,424 $ — $ 96,306 $ 162,567 $ 1,775,492 Special mention — 32,643 55,798 27,389 — 23,914 — 139,744 Substandard — — — 12,774 2,129 12,747 — 27,650 Doubtful — — — — — — — — Loss — — — — — — — — Total $ 156,816 $ 787,180 $ 520,640 $ 180,587 $ 2,129 $ 132,967 $ 162,567 $ 1,942,886 Other CRE - non-owned occupied Pass $ 648,330 $ 961,315 $ 663,375 $ 431,032 $ 182,475 $ 232,800 $ 211,671 $ 3,330,998 Special mention — 13,217 7,031 5,458 4,257 7,288 — 37,251 Substandard 8,350 26,454 — 12,432 6,652 11,795 — 65,683 Doubtful — — — — — — — — Loss — — — — — — — — Total $ 656,680 $ 1,000,986 $ 670,406 $ 448,922 $ 193,384 $ 251,883 $ 211,671 $ 3,433,932 Term Loan Amortized Cost Basis by Origination Year Revolving Loans Amortized Cost Basis Total September 30, 2020 2020 2019 2018 2017 2016 Prior (in thousands) Residential Pass $ 524,852 $ 1,018,264 $ 472,941 $ 121,970 $ 91,138 $ 50,087 $ 45,392 $ 2,324,644 Special mention — — — — — — — — Substandard — 2,169 1,327 1,134 15 517 258 5,420 Doubtful — — — — — — — — Loss — — — — — — — — Total $ 524,852 $ 1,020,433 $ 474,268 $ 123,104 $ 91,153 $ 50,604 $ 45,650 $ 2,330,064 Construction and land development Pass $ 492,218 $ 777,114 $ 422,749 $ 21,028 $ 1,403 $ 14,953 $ 496,079 $ 2,225,544 Special mention 1,463 — 36,476 — — — 4,247 42,186 Substandard — — 192 — — — — 192 Doubtful — — — — — — — — Loss — — — — — — — — Total $ 493,681 $ 777,114 $ 459,417 $ 21,028 $ 1,403 $ 14,953 $ 500,326 $ 2,267,922 Warehouse lending Pass $ 155,588 $ 48,455 $ 990 $ 1,640 $ 78 $ — $ 3,720,101 $ 3,926,852 Special mention — — — — — — — — Substandard — — — — — — — — Doubtful — — — — — — — — Loss — — — — — — — — Total $ 155,588 $ 48,455 $ 990 $ 1,640 $ 78 $ — $ 3,720,101 $ 3,926,852 Municipal & nonprofit Pass $ 137,047 $ 170,963 $ 76,133 $ 232,816 $ 129,957 $ 927,762 $ 3,535 $ 1,678,213 Special mention — 4,194 2,331 — — — — 6,525 Substandard — — — 1,952 — — — 1,952 Doubtful — — — — — — — — Loss — — — — — — — — Total $ 137,047 $ 175,157 $ 78,464 $ 234,768 $ 129,957 $ 927,762 $ 3,535 $ 1,686,690 Other Pass $ 17,738 $ 16,175 $ 14,671 $ 6,909 $ 2,177 $ 71,880 $ 30,133 $ 159,683 Special mention 961 — 97 1,691 — 42 35 2,826 Substandard — 135 189 — 97 196 18 635 Doubtful — — — — — — — — Loss — — — — — — — — Total $ 18,699 $ 16,310 $ 14,957 $ 8,600 $ 2,274 $ 72,118 $ 30,186 $ 163,144 Total by Risk Category Pass $ 4,898,480 $ 5,311,161 $ 3,040,265 $ 1,671,159 $ 689,629 $ 1,893,024 $ 7,716,443 $ 25,220,161 Special mention 6,929 121,939 140,967 87,861 13,696 57,787 47,660 476,839 Substandard 61,168 46,757 10,099 70,124 25,080 48,716 34,083 296,027 Doubtful — — — 177 — — — 177 Loss — 50 — — — — — 50 Total $ 4,966,577 $ 5,479,907 $ 3,191,331 $ 1,829,321 $ 728,405 $ 1,999,527 $ 7,798,186 $ 25,993,254 December 31, 2019 Pass Special Mention Substandard Doubtful Loss Total (in thousands) Commercial and industrial $ 9,265,823 $ 65,893 $ 49,878 $ 449 $ — $ 9,382,043 Commercial real estate Owner occupied 2,265,566 9,579 41,768 — — 2,316,913 Non-owner occupied 4,913,007 64,161 47,050 — — 5,024,218 Multi-family 221,416 — — — — 221,416 Construction and land development Construction 1,157,169 17,592 2,147 — — 1,176,908 Land 773,868 1,380 — — — 775,248 Residential real estate 2,141,336 366 5,962 — — 2,147,664 Consumer 57,073 10 — — — 57,083 Total $ 20,795,258 $ 158,981 $ 146,805 $ 449 $ — $ 21,101,493 December 31, 2019 Pass Special Mention Substandard Doubtful Loss Total (in thousands) Current (up to 29 days past due) $ 20,785,118 $ 158,907 $ 120,897 $ 265 $ — $ 21,065,187 Past due 30 - 59 days 8,263 58 7,092 — — 15,413 Past due 60 - 89 days 1,481 16 861 — — 2,358 Past due 90 days or more 396 — 17,955 184 — 18,535 Total $ 20,795,258 $ 158,981 $ 146,805 $ 449 $ — $ 21,101,493
Allowances for Credit Losses	The below tables reflect the activity in the allowance for credit losses for loans held for investment by loan portfolio segment: Three Months Ended September 30, 2020 Balance, Provision for (Reversal of) Credit Losses Writeoffs Recoveries Balance, June 30, 2020 September 30, 2020 (1) (1) (in thousands) Commercial and industrial Tech & Innovation $ 54,559 $ (9,359) $ 6,364 $ — $ 38,836 Other commercial and industrial 109,930 (621) 748 (192) 108,753 CRE - owner occupied 15,587 3,897 83 (5) 19,406 CRE - non-owner occupied Hotel Franchise Finance 35,864 2,163 — — 38,027 Other CRE - non-owned occupied 32,672 9,196 1,246 — 40,622 Residential 1,725 16 307 (355) 1,789 Construction and land development 35,792 2,983 — (6) 38,781 Warehouse lending 743 95 — — 838 Municipal & nonprofit 17,128 768 — — 17,896 Other 6,550 (934) 25 (21) 5,612 Total $ 310,550 $ 8,204 $ 8,773 $ (579) $ 310,560 (1) Includes an estimate of future recoveries. Nine Months Ended September 30, 2020 Balance, Provision for (Reversal of) Credit Losses Writeoffs Recoveries Balance, January 1, 2020 September 30, 2020 (1) (1) (in thousands) Commercial and industrial Tech & Innovation $ 22,394 $ 25,556 $ 9,114 $ — $ 38,836 Other commercial and industrial 95,784 13,653 2,684 (2,000) 108,753 CRE - owner occupied 10,420 9,100 126 (12) 19,406 CRE - non-owner occupied Hotel Franchise Finance 14,104 23,923 — — 38,027 Other CRE - non-owned occupied 10,503 30,684 2,131 (1,566) 40,622 Residential 3,814 (2,103) 307 (385) 1,789 Construction and land development 6,218 32,540 — (23) 38,781 Warehouse lending 246 592 — — 838 Municipal & nonprofit 17,397 499 — — 17,896 Other 6,045 (314) 231 (112) 5,612 Total $ 186,925 $ 134,130 $ 14,593 $ (4,098) $ 310,560 (1) Includes an estimate of future recoveries. Accrued interest receivable on loans totaled $120.1 million at September 30, 2020 and is excluded from the estimate of credit losses. Three Months Ended September 30, 2019 June 30, 2019 Charge-offs Recoveries Provision for (Reversal of) Credit Losses September 30, 2019 (in thousands) Construction and land development $ 26,091 $ — $ (17) $ 1,210 $ 27,318 Commercial real estate 41,258 139 (8) 4,817 45,944 Residential real estate 12,606 9 (131) 804 13,532 Commercial and industrial 79,635 1,950 (2,549) (2,815) 77,419 Consumer 819 1 (6) (16) 808 Total $ 160,409 $ 2,099 $ (2,711) $ 4,000 $ 165,021 Nine Months Ended September 30, 2019 December 31, 2018 Charge-offs Recoveries Provision for (Reversal of) Credit Losses September 30, 2019 (in thousands) Construction and land development $ 22,513 $ 141 $ (81) $ 4,865 $ 27,318 Commercial real estate 34,829 139 (900) 10,354 45,944 Residential real estate 11,276 594 (251) 2,599 13,532 Commercial and industrial 83,118 6,092 (3,521) (3,128) 77,419 Consumer 981 2 (19) (190) 808 Total $ 152,717 $ 6,968 $ (4,772) $ 14,500 $ 165,021 The following tables disaggregate the Company's allowance for credit losses and loan balance by measurement methodology: September 30, 2020 Loans Allowance Collectively Evaluated for Credit Loss Individually Evaluated for Credit Loss Total Collectively Evaluated for Credit Loss Individually Evaluated for Credit Loss Total (in thousands) Commercial and industrial Tech & Innovation $ 2,227,995 $ 49,894 $ 2,277,889 $ 38,836 $ — $ 38,836 Other commercial and industrial 5,906,731 86,981 5,993,712 102,011 6,742 108,753 CRE - owner occupied 1,912,127 58,036 1,970,163 19,406 — 19,406 CRE - non-owner occupied Hotel Franchise Finance 1,885,451 57,435 1,942,886 35,312 2,715 38,027 Other CRE - non-owned occupied 3,355,259 78,673 3,433,932 40,518 104 40,622 Residential 2,324,676 5,388 2,330,064 1,789 — 1,789 Construction and land development 2,267,922 — 2,267,922 38,781 — 38,781 Warehouse lending 3,926,852 — 3,926,852 838 — 838 Municipal & nonprofit 1,684,738 1,952 1,686,690 17,454 442 17,896 Other 162,518 626 163,144 5,569 43 5,612 Total $ 25,654,269 $ 338,985 $ 25,993,254 $ 300,514 $ 10,046 $ 310,560 Commercial Real Estate-Owner Occupied Commercial Real Estate-Non-Owner Occupied Commercial and Industrial Residential Real Estate Construction and Land Development Consumer Total Loans (in thousands) Loans as of December 31, 2019: Recorded Investment Impaired loans with an allowance recorded $ — $ 11,913 $ 6,919 $ — $ 2,147 $ — $ 20,979 Impaired loans with no allowance recorded 17,736 23,625 42,065 5,600 6,274 24 95,324 Total loans individually evaluated for impairment 17,736 35,538 48,984 5,600 8,421 24 116,303 Loans collectively evaluated for impairment 2,296,342 5,159,921 9,333,059 2,142,045 1,943,735 57,059 20,932,161 Loans acquired with deteriorated credit quality 2,835 50,175 — 19 — — 53,029 Total recorded investment $ 2,316,913 $ 5,245,634 $ 9,382,043 $ 2,147,664 $ 1,952,156 $ 57,083 $ 21,101,493 Unpaid Principal Balance Impaired loans with an allowance recorded $ — $ 11,949 $ 9,844 $ — $ 2,262 $ — 24,055 Impaired loans with no allowance recorded 18,681 24,738 43,848 5,708 6,413 52 99,440 Total loans individually evaluated for impairment 18,681 36,687 53,692 5,708 8,675 52 123,495 Loans collectively evaluated for impairment 2,297,168 5,177,477 9,312,100 2,113,893 1,963,116 57,383 20,921,137 Loans acquired with deteriorated credit quality 3,577 60,191 — 72 — — 63,840 Total unpaid principal balance $ 2,319,426 $ 5,274,355 $ 9,365,792 $ 2,119,673 $ 1,971,791 $ 57,435 $ 21,108,472 Related Allowance for Credit Losses Impaired loans with an allowance recorded $ — $ 1,219 $ 1,050 $ — $ 507 $ — $ 2,776 Impaired loans with no allowance recorded — — — — — — — Total loans individually evaluated for impairment — 1,219 1,050 — 507 — 2,776 Loans collectively evaluated for impairment 13,842 32,114 81,252 13,714 23,387 614 164,923 Loans acquired with deteriorated credit quality — 98 — — — — 98 Total allowance for credit losses $ 13,842 $ 33,431 $ 82,302 $ 13,714 $ 23,894 $ 614 $ 167,797

Other Borrowings (Tables)

Other Borrowings (Tables)	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Company's Borrowings	The following table summarizes the Company’s borrowings as of September 30, 2020 and December 31, 2019: September 30, 2020 December 31, 2019 (in thousands) Short-Term: Federal funds purchased $ — $ — FHLB advances 10,000 — Total short-term borrowings $ 10,000 $ —

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Summary of Changes in Accumulated Other Comprehensive Income	The following table summarizes the changes in accumulated other comprehensive income by component, net of tax, for the periods indicated: Three Months Ended September 30, Unrealized holding gains (losses) on AFS Unrealized holding gains (losses) on SERP Unrealized holding gains (losses) on junior subordinated debt Impairment loss on securities Total (in thousands) Balance, June 30, 2020 $ 66,809 $ (313) $ 7,181 $ — $ 73,677 Other comprehensive income (loss) before reclassifications 7,592 (3) (2,681) — 4,908 Amounts reclassified from AOCI — — — — — Net current-period other comprehensive income (loss) 7,592 (3) (2,681) — 4,908 Balance, September 30, 2020 $ 74,401 $ (316) $ 4,500 $ — $ 78,585 Balance, June 30, 2019 $ 19,709 $ 357 $ 6,171 $ 144 $ 26,381 Other comprehensive income (loss) before reclassifications 11,014 (18) 598 — 11,594 Amounts reclassified from AOCI (2,232) — — (144) (2,376) Net current-period other comprehensive income (loss) 8,782 (18) 598 (144) 9,218 Balance, September 30, 2019 $ 28,491 $ 339 $ 6,769 $ — $ 35,599 Nine Months Ended September 30, Unrealized holding gains (losses) on AFS Unrealized holding gains (losses) on SERP Unrealized holding gains (losses) on junior subordinated debt Impairment loss on securities Total (in thousands) Balance, December 31, 2019 $ 21,399 $ (20) $ 3,629 $ — $ 25,008 Other comprehensive income (loss) before reclassifications 53,176 (296) 871 — 53,751 Amounts reclassified from AOCI (174) — — — (174) Net current-period other comprehensive income (loss) 53,002 (296) 871 — 53,577 Balance, September 30, 2020 $ 74,401 $ (316) $ 4,500 $ — $ 78,585 Balance, December 31, 2018 $ (47,591) $ 392 $ 13,433 $ 144 $ (33,622) Other comprehensive income (loss) before reclassifications 78,314 (53) (6,664) — 71,597 Amounts reclassified from AOCI (2,232) — — (144) (2,376) Net current-period other comprehensive income (loss) 76,082 (53) (6,664) (144) 69,221 Balance, September 30, 2019 $ 28,491 $ 339 $ 6,769 $ — $ 35,599

Derivatives and Hedging (Tables

Derivatives and Hedging (Tables)	9 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position	The fair value of derivative contracts, after taking into account the effects of master netting agreements, is included in other assets or other liabilities on the Consolidated Balance Sheets, as indicated in the following table: September 30, 2020 December 31, 2019 September 30, 2019 Fair Value Fair Value Fair Value Notional Derivative Assets Derivative Liabilities Notional Derivative Assets Derivative Liabilities Notional Derivative Assets Derivative Liabilities (in thousands) Derivatives designated as hedging instruments: Fair value hedges Interest rate swaps $ 692,348 $ 3,417 $ 92,352 $ 862,952 $ 1,778 $ 55,471 $ 865,321 $ — $ 63,970 Total 692,348 3,417 92,352 862,952 1,778 55,471 865,321 — 63,970 Netting adjustments (1) — — — — 21 21 — — — Net $ 692,348 $ 3,417 $ 92,352 $ 862,952 $ 1,757 $ 55,450 $ 865,321 $ — $ 63,970 Derivatives not designated as hedging instruments: Foreign currency contracts $ 38,922 $ 460 $ 401 $ 6,711 $ 44 $ 18 $ 15,329 $ 191 $ 127 Interest rate swaps 3,517 242 242 2,932 81 81 2,932 124 124 Total $ 42,439 $ 702 $ 643 $ 9,643 $ 125 $ 99 $ 18,261 $ 315 $ 251 (1) Netting adjustments represent the amounts recorded to convert the Company's derivative balances from a gross basis to a net basis in accordance with the applicable accounting guidance.
Largest Exposure To Individual Counterparty	The following table summarizes the Company's largest exposure to an individual counterparty at the dates indicated: September 30, 2020 December 31, 2019 September 30, 2019 (in thousands) Largest gross exposure (derivative asset) to an individual counterparty $ 3,417 $ 1,757 $ — Collateral posted by this counterparty — 1,610 — Derivative liability with this counterparty — — — Collateral pledged to this counterparty — — — Net exposure after netting adjustments and collateral $ 3,417 $ 147 $ —

Earnings per Share (Tables)

Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table presents the calculation of basic and diluted EPS: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands, except per share amounts) Weighted average shares - basic 99,850 102,041 100,322 103,024 Dilutive effect of stock awards 209 410 252 444 Weighted average shares - diluted 100,059 102,451 100,574 103,468 Net income $ 135,769 $ 127,375 $ 313,005 $ 371,107 Earnings per share - basic 1.36 1.25 3.12 3.60 Earnings per share - diluted 1.36 1.24 3.11 3.59

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Summary of Contractual Amounts for Unfunded Commitments and Letters of Credit	A summary of the contractual amounts for unfunded commitments and letters of credit are as follows: September 30, 2020 December 31, 2019 (in thousands) Commitments to extend credit, including unsecured loan commitments of $1,046,504 at September 30, 2020 and $895,175 at December 31, 2019 $ 8,379,196 $ 8,348,421 Credit card commitments and financial guarantees 283,703 302,909 Letters of credit, including unsecured letters of credit of $9,513 at September 30, 2020 and $5,850 at December 31, 2019 156,170 175,778 Total $ 8,819,069 $ 8,827,108

Fair Value Accounting (Tables)

Fair Value Accounting (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Gains and Losses from Fair Value Changes Included in Consolidated Statement of Operations	For the three and nine months ended September 30, 2020 and 2019, unrealized gains and losses from fair value changes on junior subordinated debt were as follows:
Fair Value of Assets and Liabilities	The fair value of assets and liabilities measured at fair value on a recurring basis was determined using the following inputs as of the periods presented: Fair Value Measurements at the End of the Reporting Period Using: Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Fair Value (in thousands) September 30, 2020 Assets: Available-for-sale debt securities CDO $ — $ 8,176 $ — $ 8,176 Commercial MBS issued by GSEs — 95,657 — 95,657 Corporate debt securities — 186,609 — 186,609 Municipal securities — 22,159 — 22,159 Private label residential MBS — 1,264,237 — 1,264,237 Residential MBS issued by GSEs — 1,361,556 — 1,361,556 Tax-exempt — 1,011,023 — 1,011,023 Trust preferred securities 25,208 — — 25,208 U.S. treasury securities — 600 — 600 Total AFS debt securities $ 25,208 $ 3,950,017 $ — $ 3,975,225 Equity securities CRA investments $ 27,795 $ 25,750 $ — $ 53,545 Preferred stock 107,016 — — 107,016 Total equity securities $ 134,811 $ 25,750 $ — $ 160,561 Loans - HFS $ — $ 20,764 $ — $ 20,764 Derivative assets (1) — 4,119 — 4,119 Liabilities: Junior subordinated debt (2) $ — $ — $ 60,529 $ 60,529 Derivative liabilities (1) — 92,995 — 92,995 (1) Derivative assets and liabilities relate primarily to interest rate swaps, see "Note 8. Derivatives and Hedging Activities." In addition, the carrying value of loans is increased by $92,352 and the net carrying value of subordinated debt is increased by $3,417 as of September 30, 2020 for the effective portion of the hedge, which relates to the fair value of the hedges put in place to mitigate against fluctuations in interest rates. (2) Includes only the portion of junior subordinated debt that is recorded at fair value at each reporting period pursuant to the election of FVO treatment. Fair Value Measurements at the End of the Reporting Period Using: Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Fair Value (in thousands) December 31, 2019 Assets: Available-for-sale debt securities CDO $ — $ 10,142 $ — $ 10,142 Commercial MBS issued by GSEs — 94,253 — 94,253 Corporate debt securities 5,127 94,834 — 99,961 Municipal securities — 7,773 — 7,773 Private label residential MBS — 1,129,227 — 1,129,227 Residential MBS issued by GSEs — 1,412,060 — 1,412,060 Tax-exempt — 554,855 — 554,855 Trust preferred securities 27,040 — — 27,040 U.S. government sponsored agency securities — 10,000 — 10,000 U.S. treasury securities — 999 — 999 Total AFS debt securities $ 32,167 $ 3,314,143 $ — $ 3,346,310 Equity securities CRA investments $ 52,504 $ — $ — $ 52,504 Preferred stock 86,197 — — 86,197 Total equity securities $ 138,701 $ — $ — $ 138,701 Loans - HFS $ — $ 21,803 $ — $ 21,803 Derivative assets (1) — 1,903 — 1,903 Liabilities: Junior subordinated debt (2) $ — $ — $ 61,685 $ 61,685 Derivative liabilities (1) — 55,570 — 55,570 (1) Derivative assets and liabilities relate primarily to interest rate swaps, see "Note 8. Derivatives and Hedging Activities." In addition, the carrying value of loans is increased by $53,292 and the net carrying value of subordinated debt is decreased by $401 as of December 31, 2019 for the effective portion of the hedge, which relates to the fair value of the hedges put in place to mitigate against fluctuations in interest rates. (2) Includes only the portion of junior subordinated debt that is recorded at fair value at each reporting period pursuant to the election of FVO treatment.
Change in Level 3 Liabilities Measured at Fair Value on Recurring Basis	For the three and nine months ended September 30, 2020 and 2019, the change in Level 3 liabilities measured at fair value on a recurring basis was as follows: Junior Subordinated Debt Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Beginning balance $ (56,974) $ (58,315) $ (61,685) $ (48,684) Change in fair value (1) (3,555) 794 1,156 (8,837) Ending balance $ (60,529) $ (57,521) $ (60,529) $ (57,521)
Assets Measured at Fair Value on Nonrecurring Basis	The following table presents such assets carried on the Consolidated Balance Sheet by caption and by level within the ASC 825 hierarchy: Fair Value Measurements at the End of the Reporting Period Using Total Quoted Prices in Active Markets for Identical Assets Active Markets for Similar Assets Unobservable Inputs (in thousands) As of September 30, 2020: Loans $ 245,219 $ — $ — $ 245,219 Other assets acquired through foreclosure 8,591 — — 8,591 As of December 31, 2019: Loans $ 110,272 $ — $ — $ 110,272 Other assets acquired through foreclosure 13,850 — — 13,850
Estimated Fair Value of Financial Instruments	The estimated fair value of the Company’s financial instruments is as follows: September 30, 2020 Carrying Amount Fair Value Level 1 Level 2 Level 3 Total (in thousands) Financial assets: Investment securities: HTM $ 504,477 $ — $ 548,140 $ — $ 548,140 AFS 3,975,225 25,208 3,950,017 — 3,975,225 Equity 160,561 134,811 25,750 — 160,561 Derivative assets 4,119 — 4,119 — 4,119 Loans, net 25,703,458 — — 26,107,177 26,107,177 Accrued interest receivable 140,827 — 140,827 — 140,827 Financial liabilities: Deposits $ 28,843,396 $ — $ 28,850,576 $ — $ 28,850,576 Customer repurchase agreements 19,688 — 19,688 — 19,688 Qualifying debt 618,772 — 566,308 72,628 638,936 Derivative liabilities 92,995 — 92,995 — 92,995 Accrued interest payable 15,666 — 15,666 — 15,666 December 31, 2019 Carrying Amount Fair Value Level 1 Level 2 Level 3 Total (in thousands) Financial assets: Investment securities: HTM $ 485,107 $ — $ 516,261 $ — $ 516,261 AFS 3,346,310 32,167 3,314,143 — 3,346,310 Equity securities 138,701 138,701 — — 138,701 Derivative assets 1,903 — 1,903 — 1,903 Loans, net 20,955,499 — — 21,256,462 21,256,462 Accrued interest receivable 108,694 — 108,694 — 108,694 Financial liabilities: Deposits $ 22,796,493 $ — $ 22,813,265 $ — $ 22,813,265 Customer repurchase agreements 16,675 — 16,675 — 16,675 Qualifying debt 393,563 — 332,635 74,155 406,790 Derivative liabilities 55,570 — 55,570 — 55,570 Accrued interest payable 24,661 — 24,661 — 24,661

Segments (Tables)

Segments (Tables)	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Operating Segment Information	The following is a summary of operating segment information for the periods indicated: Regional Segments Balance Sheet: Consolidated Company Arizona Nevada Southern California Northern California At September 30, 2020 (in millions) Assets: Cash, cash equivalents, and investment securities $ 6,119.8 $ 1.5 $ 8.8 $ 1.8 $ 2.3 Loans, net of deferred loan fees and costs 26,014.0 4,388.1 2,612.2 2,376.7 1,785.8 Less: allowance for credit losses (310.5) (57.0) (36.4) (31.5) (19.3) Total loans 25,703.5 4,331.1 2,575.8 2,345.2 1,766.5 Other assets acquired through foreclosure, net 8.6 — 8.5 — — Goodwill and other intangible assets, net 299.0 — 23.2 — 153.9 Other assets 1,204.6 47.8 60.1 16.2 20.1 Total assets $ 33,335.5 $ 4,380.4 $ 2,676.4 $ 2,363.2 $ 1,942.8 Liabilities: Deposits $ 28,843.4 $ 8,541.5 $ 4,733.9 $ 3,502.0 $ 2,741.1 Borrowings and qualifying debt 628.8 — — — — Other liabilities 639.3 28.7 18.8 8.6 20.0 Total liabilities 30,111.5 8,570.2 4,752.7 3,510.6 2,761.1 Allocated equity: 3,224.0 576.4 343.7 281.2 361.5 Total liabilities and stockholders' equity $ 33,335.5 $ 9,146.6 $ 5,096.4 $ 3,791.8 $ 3,122.6 Excess funds provided (used) — 4,766.2 2,420.0 1,428.6 1,179.8 Income Statement: Three Months Ended September 30, 2020 (in thousands) Net interest income $ 284,738 $ 83,492 $ 46,625 $ 35,656 $ 28,353 Provision for (recovery of) credit losses 14,661 9,830 8,548 5,213 1,856 Net interest income after provision for credit losses 270,077 73,662 38,077 30,443 26,497 Non-interest income 20,606 1,771 2,391 1,186 2,381 Non-interest expense (124,092) (17,644) (15,800) (14,020) (12,885) Income (loss) before income taxes 166,591 57,789 24,668 17,609 15,993 Income tax expense (benefit) 30,822 14,447 5,180 4,930 4,478 Net income $ 135,769 $ 43,342 $ 19,488 $ 12,679 $ 11,515 Nine Months Ended September 30, 2020 (in thousands) Net interest income $ 852,158 $ 229,701 $ 139,328 $ 104,348 $ 85,345 Provision for (recovery of) credit losses 157,837 46,623 25,015 23,750 12,680 Net interest income after provision for credit losses 694,321 183,078 114,313 80,598 72,665 Non-interest income 46,985 4,943 7,355 3,269 6,450 Non-interest expense (359,372) (58,674) (44,414) (43,216) (38,460) Income (loss) before income taxes 381,934 129,347 77,254 40,651 40,655 Income tax expense (benefit) 68,929 32,207 16,164 11,241 11,340 Net income $ 313,005 $ 97,140 $ 61,090 $ 29,410 $ 29,315 National Business Lines Balance Sheet: HOA Public & Nonprofit Finance Technology & Innovation Hotel Franchise Finance Other NBLs Corporate & Other At September 30, 2020 Assets: (in millions) Cash, cash equivalents, and investment securities $ — $ — $ — $ — $ 26.6 $ 6,078.8 Loans, net of deferred loan fees and costs 280.0 1,686.7 2,329.3 2,099.3 8,451.8 4.1 Less: allowance for credit losses (2.3) (17.9) (41.5) (40.7) (63.9) — Total loans 277.7 1,668.8 2,287.8 2,058.6 8,387.9 4.1 Other assets acquired through foreclosure, net — — — — 0.1 — Goodwill and other intangible assets, net — — 119.3 0.1 2.5 — Other assets 5.4 11.9 9.2 33.4 110.3 890.2 Total assets $ 283.1 $ 1,680.7 $ 2,416.3 $ 2,092.1 $ 8,527.4 $ 6,973.1 Liabilities: Deposits $ 3,697.9 $ — $ 4,646.4 $ — $ 61.4 $ 919.2 Borrowings and qualifying debt — — — — — 628.8 Other liabilities (2.7) 91.8 5.4 0.9 56.8 411.0 Total liabilities 3,695.2 91.8 4,651.8 0.9 118.2 1,959.0 Allocated equity: 104.9 130.3 397.5 167.5 673.2 187.8 Total liabilities and stockholders' equity $ 3,800.1 $ 222.1 $ 5,049.3 $ 168.4 $ 791.4 $ 2,146.8 Excess funds provided (used) 3,517.0 (1,458.6) 2,633.0 (1,923.7) (7,736.0) (4,826.3) Income Statement: Three Months Ended September 30, 2020 (in thousands) Net interest income $ 22,184 $ 2,800 $ 48,013 $ 12,536 $ 46,582 $ (41,503) Provision for (recovery of) credit losses (138) 781 (9,048) 2,200 (2,706) (1,875) Net interest income after provision for credit losses 22,322 2,019 57,061 10,336 49,288 (39,628) Non-interest income 134 — 3,126 — 2,924 6,693 Non-interest expense (9,896) (1,724) (11,530) (2,596) (12,335) (25,662) Income (loss) before income taxes 12,560 295 48,657 7,740 39,877 (58,597) Income tax expense (benefit) 2,889 68 11,191 1,780 9,172 (23,313) Net income $ 9,671 $ 227 $ 37,466 $ 5,960 $ 30,705 $ (35,284) Nine Months Ended September 30, 2020 (in thousands) Net interest income $ 67,740 $ 6,351 $ 137,436 $ 39,442 $ 128,096 $ (85,629) Provision for (recovery of) credit losses (2,198) 553 25,471 27,530 (4,737) 3,150 Net interest income after provision for credit losses 69,938 5,798 111,965 11,912 132,833 (88,779) Non-interest income 350 — 9,247 — 4,108 11,263 Non-interest expense (29,965) (5,114) (36,188) (7,353) (35,674) (60,314) Income (loss) before income taxes 40,323 684 85,024 4,559 101,267 (137,830) Income tax expense (benefit) 9,361 380 19,461 893 23,083 (55,201) Net income $ 30,962 $ 304 $ 65,563 $ 3,666 $ 78,184 $ (82,629) Regional Segments Balance Sheet: Consolidated Company Arizona Nevada Southern California Northern California At December 31, 2019 (in millions) Assets: Cash, cash equivalents, and investment securities $ 4,471.2 $ 1.8 $ 9.0 $ 2.3 $ 2.2 Loans, net of deferred loan fees and costs 21,123.3 3,847.9 2,252.5 2,253.9 1,311.2 Less: allowance for credit losses (167.8) (31.6) (18.0) (18.3) (9.7) Total loans 20,955.5 3,816.3 2,234.5 2,235.6 1,301.5 Other assets acquired through foreclosure, net 13.9 — 13.0 0.9 — Goodwill and other intangible assets, net 297.6 — 23.2 — 154.6 Other assets 1,083.7 48.6 59.4 15.0 19.8 Total assets $ 26,821.9 $ 3,866.7 $ 2,339.1 $ 2,253.8 $ 1,478.1 Liabilities: Deposits $ 22,796.5 $ 5,384.7 $ 4,350.1 $ 2,585.3 $ 2,373.6 Borrowings and qualifying debt 393.6 — — — — Other liabilities 615.1 17.8 11.9 1.2 15.9 Total liabilities 23,805.2 5,402.5 4,362.0 2,586.5 2,389.5 Allocated equity: 3,016.7 453.6 301.0 253.3 312.5 Total liabilities and stockholders' equity $ 26,821.9 $ 5,856.1 $ 4,663.0 $ 2,839.8 $ 2,702.0 Excess funds provided (used) — 1,989.4 2,323.9 586.0 1,223.9 Income Statement: Three Months Ended September 30, 2019 (in thousands) Net interest income $ 266,422 $ 68,828 $ 40,565 $ 33,630 $ 23,504 Provision for (recovery of) credit losses 3,803 103 (62) (189) 218 Net interest income (expense) after provision for credit losses 262,619 68,725 40,627 33,819 23,286 Non-interest income 19,441 1,821 2,677 1,079 1,917 Non-interest expense (126,152) (27,241) (15,211) (15,185) (12,379) Income (loss) before income taxes 155,908 43,305 28,093 19,713 12,824 Income tax expense (benefit) 28,533 10,826 5,899 5,520 3,591 Net income $ 127,375 $ 32,479 $ 22,194 $ 14,193 $ 9,233 Nine Months Ended September 30, 2019 (in thousands) Net interest income $ 768,439 $ 183,772 $ 119,191 $ 95,751 $ 70,533 Provision for (recovery of) credit losses 15,303 1,705 166 611 (653) Net interest income (expense) after provision for credit losses 753,136 182,067 119,025 95,140 71,186 Non-interest income 49,069 5,050 7,926 3,054 6,299 Non-interest expense (352,279) (72,183) (45,099) (44,890) (38,419) Income (loss) before income taxes 449,926 114,934 81,852 53,304 39,066 Income tax expense (benefit) 78,819 28,733 17,189 14,925 10,939 Net income $ 371,107 $ 86,201 $ 64,663 $ 38,379 $ 28,127 National Business Lines Balance Sheet: HOA Public & Nonprofit Finance Technology & Innovation Hotel Franchise Finance Other NBLs Corporate & Other At December 31, 2019 Assets: (in millions) Cash, cash equivalents, and investment securities $ — $ — $ — $ — $ 10.1 $ 4,445.8 Loans, net of deferred loan fees and costs 237.2 1,635.6 1,552.0 1,930.8 6,098.7 3.5 Less: allowance for credit losses (2.0) (13.7) (12.6) (12.6) (49.3) — Total loans 235.2 1,621.9 1,539.4 1,918.2 6,049.4 3.5 Other assets acquired through foreclosure, net — — — — — — Goodwill and other intangible assets, net — — 119.7 0.1 — — Other assets 1.2 18.3 7.3 8.8 64.3 841.0 Total assets $ 236.4 $ 1,640.2 $ 1,666.4 $ 1,927.1 $ 6,123.8 $ 5,290.3 Liabilities: Deposits $ 3,210.1 $ 0.1 $ 3,771.5 $ — $ 36.9 $ 1,084.2 Borrowings and qualifying debt — — — — — 393.6 Other liabilities 1.8 52.9 0.1 — 2.8 510.7 Total liabilities 3,211.9 53.0 3,771.6 — 39.7 1,988.5 Allocated equity: 84.5 131.6 317.5 158.5 494.3 509.9 Total liabilities and stockholders' equity $ 3,296.4 $ 184.6 $ 4,089.1 $ 158.5 $ 534.0 $ 2,498.4 Excess funds provided (used) 3,060.0 (1,455.6) 2,422.7 (1,768.6) (5,589.8) (2,791.9) Income Statement: Three Months Ended September 30, 2019 (in thousands) Net interest income (expense) $ 21,974 $ 3,394 $ 33,932 $ 12,845 $ 32,935 $ (5,185) Provision for (recovery of) credit losses 60 (191) 895 1,956 1,210 (197) Net interest income (expense) after provision for credit losses 21,914 3,585 33,037 10,889 31,725 (4,988) Non-interest income 84 — 5,422 — 1,708 4,733 Non-interest expense (9,769) (1,845) (12,068) (2,197) (11,320) (18,937) Income (loss) before income taxes 12,229 1,740 26,391 8,692 22,113 (19,192) Income tax expense (benefit) 2,813 400 6,070 1,999 5,086 (13,671) Net income $ 9,416 $ 1,340 $ 20,321 $ 6,693 $ 17,027 $ (5,521) Nine Months Ended September 30, 2019 (in thousands) Net interest income $ 64,520 $ 10,278 $ 91,871 $ 39,279 $ 88,212 $ 5,032 Provision for (recovery of) credit losses 27 (136) 2,635 3,587 6,558 803 Net interest income (expense) after provision for credit losses 64,493 10,414 89,236 35,692 81,654 4,229 Non-interest income 268 — 10,946 — 3,915 11,611 Non-interest expense (27,777) (5,683) (33,971) (6,757) (31,729) (45,771) Income (loss) before income taxes 36,984 4,731 66,211 28,935 53,840 (29,931) Income tax expense (benefit) 8,506 1,088 15,229 6,655 12,383 (36,828) Net income $ 28,478 $ 3,643 $ 50,982 $ 22,280 $ 41,457 $ 6,897

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2020
Revenue from Contracts with Customers [Abstract]
Disaggregation of Revenue [Table Text Block]	Regional Segments Consolidated Company Arizona Nevada Southern California Northern California Three Months Ended September 30, 2020 (in thousands) Revenue from contracts with customers: Service charges and fees $ 5,913 $ 1,188 $ 1,826 $ 889 $ 930 Debit and credit card interchange (1) 1,597 426 306 167 686 Success fees (2) 38 — — — — Other income 69 8 6 (1) 18 Total revenue from contracts with customers $ 7,617 $ 1,622 $ 2,138 $ 1,055 $ 1,634 Revenues outside the scope of ASC 606 (3) 12,989 149 253 131 747 Total non-interest income $ 20,606 $ 1,771 $ 2,391 $ 1,186 $ 2,381 Regional Segments Consolidated Company Arizona Nevada Southern California Northern California Nine Months Ended September 30, 2020 (in thousands) Revenue from contracts with customers: Service charges and fees $ 17,447 $ 3,525 $ 5,572 $ 2,466 $ 2,863 Debit and credit card interchange (1) 3,942 990 770 401 1,754 Success fees (2) 423 — — — 144 Other income 231 20 15 (6) 59 Total revenue from contracts with customers $ 22,043 $ 4,535 $ 6,357 $ 2,861 $ 4,820 Revenues outside the scope of ASC 606 (3) 24,942 408 998 408 1,630 Total non-interest income $ 46,985 $ 4,943 $ 7,355 $ 3,269 $ 6,450 (1) Included as part of Card income in the Consolidated Income Statement. (2) Included as part of Income from equity investments in the Consolidated Income Statement. (3) Amounts are accounted for under separate guidance. Refer to discussion of revenue sources not subject to ASC 606 under the Non-interest income section in "Note 1. Summary of Significant Accounting Policies." National Business Lines HOA Public & Nonprofit Finance Technology & Innovation Hotel Franchise Finance Other NBLs Corporate & Other Three Months Ended September 30, 2020 (in thousands) Revenue from contracts with customers: Service charges and fees $ 114 $ — $ 963 $ — $ 3 $ — Debit and credit card interchange (1) 12 — — — — — Success fees (2) — — 38 — — — Other income 2 — — — 35 1 Total revenue from contracts with customers $ 128 $ — $ 1,001 $ — $ 38 $ 1 Revenues outside the scope of ASC 606 (3) 6 — 2,125 — 2,886 6,692 Total non-interest income $ 134 $ — $ 3,126 $ — $ 2,924 $ 6,693 National Business Lines HOA Public & Nonprofit Finance Technology & Innovation Hotel Franchise Finance Other NBLs Corporate & Other Nine Months Ended September 30, 2020 (in thousands) Revenue from contracts with customers: Service charges and fees $ 308 $ — $ 2,707 $ — $ 6 $ — Debit and credit card interchange (1) 27 — — — — — Success fees (2) — — 279 — — — Other income 4 — — — 125 14 Total revenue from contracts with customers $ 339 $ — $ 2,986 $ — $ 131 $ 14 Revenues outside the scope of ASC 606 (3) 11 — 6,261 — 3,977 11,249 Total non-interest income $ 350 $ — $ 9,247 $ — $ 4,108 $ 11,263 (1) Included as part of Card income in the Consolidated Income Statement. (2) Included as part of Income from equity investments in the Consolidated Income Statement. (3) Amounts are accounted for under separate guidance. Refer to discussion of revenue sources not subject to ASC 606 under the Non-interest income section in "Note 1. Summary of Significant Accounting Policies." Regional Segments Consolidated Company Arizona Nevada Southern California Northern California Three Months Ended September 30, 2019 (in thousands) Revenue from contracts with customers: Service charges and fees $ 5,888 $ 1,226 $ 2,036 $ 770 $ 965 Debit and credit card interchange (1) 1,977 451 440 229 845 Success fees (2) 605 — — — — Other income 80 8 14 4 19 Total revenue from contracts with customers $ 8,550 $ 1,685 $ 2,490 $ 1,003 $ 1,829 Revenues outside the scope of ASC 606 (3) 10,891 136 187 76 88 Total non-interest income $ 19,441 $ 1,821 $ 2,677 $ 1,079 $ 1,917 Regional Segments Consolidated Company Arizona Nevada Southern California Northern California Nine Months Ended September 30, 2019 (in thousands) Revenue from contracts with customers: Service charges and fees $ 17,121 $ 3,525 $ 5,980 $ 2,218 $ 2,821 Debit and credit card interchange (1) 5,830 1,125 1,200 596 2,878 Success fees (2) 1,125 — — — — Other income 187 8 8 6 43 Total revenue from contracts with customers $ 24,263 $ 4,658 $ 7,188 $ 2,820 $ 5,742 Revenues outside the scope of ASC 606 (3) 24,806 392 738 234 557 Total non-interest income $ 49,069 $ 5,050 $ 7,926 $ 3,054 $ 6,299 National Business Lines HOA Public & Nonprofit Finance Technology & Innovation Hotel Franchise Finance Other NBLs Corporate & Other Three Months Ended September 30, 2019 (in thousands) Revenue from contracts with customers: Service charges and fees $ 77 $ — $ 813 $ — $ 1 $ — Debit and credit card interchange (1) 12 — — — — — Success fees (2) — — 605 — — — Other income (3) — — — 35 3 Total revenue from contracts with customers $ 86 $ — $ 1,418 $ — $ 36 $ 3 Revenues outside the scope of ASC 606 (3) (2) — 4,004 — 1,672 4,730 Total non-interest income $ 84 $ — $ 5,422 $ — $ 1,708 $ 4,733 National Business Lines HOA Services Public & Nonprofit Finance Technology & Innovation Hotel Franchise Finance Other NBLs Corporate & Other Nine Months Ended September 30, 2019 (in thousands) Revenue from contracts with customers: Service charges and fees $ 241 $ — $ 2,333 $ — $ 3 $ — Debit and credit card interchange (1) 31 — — — — — Success fees (2) — — 1,125 — — — Other income 2 — 4 — 109 7 Total revenue from contracts with customers $ 274 $ — $ 3,462 $ — $ 112 $ 7 Revenues outside the scope of ASC 606 (3) (6) — 7,484 — 3,803 11,604 Total non-interest income $ 268 $ — $ 10,946 $ — $ 3,915 $ 11,611

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)Subsidiary	Jun. 30, 2020USD ($)	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)
Significant Of Accounting Policies [Line Items]
Number Of Wholly Owned Subsidiaries Non Bank Subsidiaries | Subsidiary	2
Number Of Unconsolidated Subsidiaries | Subsidiary	8
Debt Securities, Held-to-maturity, Allowance for Credit Loss	$ 5,964	$ 7,649	$ 2,646	$ 0
Loans and Leases Receivable, Allowance	310,560			167,797
Deferred Income Tax Assets, Net	46,645			18,025
Off-Balance Sheet, Credit Loss, Liability	44,400			8,955
Retained earnings	$ (1,833,012)			$ (1,680,317)
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Significant Of Accounting Policies [Line Items]
Debt Securities, Held-to-maturity, Allowance for Credit Loss			2,646
Loans and Leases Receivable, Allowance			186,925
Deferred Income Tax Assets, Net			26,675
Off-Balance Sheet, Credit Loss, Liability			24,044
Retained earnings			(1,655,370)
Cumulative Effect, Period of Adoption, Adjustment [Member]
Significant Of Accounting Policies [Line Items]
Debt Securities, Held-to-maturity, Allowance for Credit Loss			2,646
Loans and Leases Receivable, Allowance			19,128
Deferred Income Tax Assets, Net			8,650
Off-Balance Sheet, Credit Loss, Liability			15,089
Retained earnings			$ (24,947)

Investment Securities - Carryin

Investment Securities - Carrying Amounts and Fair Values of Investment Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2020		Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	$ 160,561	[1]	$ 138,701	[2]
Debt Securities, Held-to-maturity	504,477		485,107
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	43,663		31,303
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0		(149)
Debt Securities, Held-to-maturity, Fair Value	548,140		516,261
Securities available for sale Total, Amortized Cost	3,876,586		3,317,928
Securities available-for-sale, Gross Unrealized Gains	116,671		48,252
Securities available-for-sale, Gross Unrealized (Losses)	(18,032)		(19,870)
Securities available for sale Total, Estimated Fair Value	3,975,225	[1]	3,346,310	[2]
Equity Securities, FV-NI, Cost	158,164		135,319
Equity Securities, FV-NI, Unrealized Gain	4,331		3,881
Equity Securities, FV-NI, Unrealized Loss	1,934		499
Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Amortized Cost	50		50
Securities available-for-sale, Gross Unrealized Gains	8,126		10,092
Securities available-for-sale, Gross Unrealized (Losses)	0		0
Securities available for sale Total, Estimated Fair Value	8,176		10,142
Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Amortized Cost	91,769		95,062
Securities available-for-sale, Gross Unrealized Gains	3,888		366
Securities available-for-sale, Gross Unrealized (Losses)	0		(1,175)
Securities available for sale Total, Estimated Fair Value	95,657		94,253
Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Amortized Cost	193,798		105,015
Securities available-for-sale, Gross Unrealized Gains	1,081		112
Securities available-for-sale, Gross Unrealized (Losses)	(8,270)		(5,166)
Securities available for sale Total, Estimated Fair Value	186,609		99,961
Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Amortized Cost	22,006		7,494
Securities available-for-sale, Gross Unrealized Gains	271		279
Securities available-for-sale, Gross Unrealized (Losses)	(118)		0
Securities available for sale Total, Estimated Fair Value	22,159		7,773
Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Amortized Cost	1,245,217		1,129,985
Securities available-for-sale, Gross Unrealized Gains	19,874		3,572
Securities available-for-sale, Gross Unrealized (Losses)	(854)		(4,330)
Securities available for sale Total, Estimated Fair Value	1,264,237		1,129,227
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Amortized Cost	1,329,773		1,406,594
Securities available-for-sale, Gross Unrealized Gains	32,314		9,283
Securities available-for-sale, Gross Unrealized (Losses)	(531)		(3,817)
Securities available for sale Total, Estimated Fair Value	1,361,556		1,412,060
Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	504,477		485,107
Securities available for sale Total, Amortized Cost	961,373		530,729
Securities available-for-sale, Gross Unrealized Gains	51,117		24,548
Securities available-for-sale, Gross Unrealized (Losses)	(1,467)		(422)
Securities available for sale Total, Estimated Fair Value	1,011,023		554,855
Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Amortized Cost	32,000		32,000
Securities available-for-sale, Gross Unrealized Gains	0		0
Securities available-for-sale, Gross Unrealized (Losses)	(6,792)		(4,960)
Securities available for sale Total, Estimated Fair Value	25,208		27,040
US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Amortized Cost			10,000
Securities available-for-sale, Gross Unrealized Gains			0
Securities available-for-sale, Gross Unrealized (Losses)			0
Securities available for sale Total, Estimated Fair Value			10,000
US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Amortized Cost	600		999
Securities available-for-sale, Gross Unrealized Gains	0		0
Securities available-for-sale, Gross Unrealized (Losses)	0		0
Securities available for sale Total, Estimated Fair Value	600		999
CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	53,545		52,504
Equity Securities, FV-NI, Cost	53,190		52,805
Equity Securities, FV-NI, Unrealized Gain	355		0
Equity Securities, FV-NI, Unrealized Loss	0		301
Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	107,016		86,197
Equity Securities, FV-NI, Cost	104,974		82,514
Equity Securities, FV-NI, Unrealized Gain	3,976		3,881
Equity Securities, FV-NI, Unrealized Loss	1,934		198
AAA [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0	[1]	0	[2]
Securities available for sale Total, Estimated Fair Value	1,278,498	[1]	1,149,519	[2]
AAA [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
AAA [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
AAA [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
AAA [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
AAA [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	1,235,170		1,096,909
AAA [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
AAA [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	0		0
Securities available for sale Total, Estimated Fair Value	43,328		52,610
AAA [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
AAA [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value			0
AAA [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
AAA [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
AAA [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
Split-rated AAA/AA Plus [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	27,795	[1]	25,375	[2]
Securities available for sale Total, Estimated Fair Value	1,514,538	[1]	1,520,168	[2]
Split-rated AAA/AA Plus [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
Split-rated AAA/AA Plus [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	95,657		94,253
Split-rated AAA/AA Plus [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
Split-rated AAA/AA Plus [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
Split-rated AAA/AA Plus [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
Split-rated AAA/AA Plus [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	1,361,556		1,412,060
Split-rated AAA/AA Plus [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	0		0
Securities available for sale Total, Estimated Fair Value	56,725		2,856
Split-rated AAA/AA Plus [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
Split-rated AAA/AA Plus [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value			10,000
Split-rated AAA/AA Plus [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	600		999
Split-rated AAA/AA Plus [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	27,795		25,375
Split-rated AAA/AA Plus [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
AA Plus to AA- [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0	[1]	0	[2]
Securities available for sale Total, Estimated Fair Value	487,454	[1]	358,332	[2]
AA Plus to AA- [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
AA Plus to AA- [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
AA Plus to AA- [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
AA Plus to AA- [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	12,143		0
AA Plus to AA- [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	27,682		30,675
AA Plus to AA- [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
AA Plus to AA- [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	0		0
Securities available for sale Total, Estimated Fair Value	447,629		327,657
AA Plus to AA- [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
AA Plus to AA- [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value			0
AA Plus to AA- [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
AA Plus to AA- [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
AA Plus to AA- [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
A Plus to A- [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0	[1]	0	[2]
Securities available for sale Total, Estimated Fair Value	477,350	[1]	238,443	[2]
A Plus to A- [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
A Plus to A- [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
A Plus to A- [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	45,800		66,530
A Plus to A- [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
A Plus to A- [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	91		181
A Plus to A- [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
A Plus to A- [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	0		0
Securities available for sale Total, Estimated Fair Value	431,459		171,732
A Plus to A- [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
A Plus to A- [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value			0
A Plus to A- [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
A Plus to A- [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
A Plus to A- [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
BBB Plus to BBB- [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	68,945	[1]	82,851	[2]
Securities available for sale Total, Estimated Fair Value	150,764	[1]	60,759	[2]
BBB Plus to BBB- [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
BBB Plus to BBB- [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
BBB Plus to BBB- [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	122,579		33,431
BBB Plus to BBB- [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	2,630		0
BBB Plus to BBB- [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	347		288
BBB Plus to BBB- [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
BBB Plus to BBB- [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	0		0
Securities available for sale Total, Estimated Fair Value	0		0
BBB Plus to BBB- [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	25,208		27,040
BBB Plus to BBB- [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value			0
BBB Plus to BBB- [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
BBB Plus to BBB- [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
BBB Plus to BBB- [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	68,945		82,851
BB Plus and below [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	37,135	[1]	2,105	[2]
Securities available for sale Total, Estimated Fair Value	27,353	[1]	11,316	[2]
BB Plus and below [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	8,176		10,142
BB Plus and below [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
BB Plus and below [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	18,230		0
BB Plus and below [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
BB Plus and below [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	947		1,174
BB Plus and below [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
BB Plus and below [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	0		0
Securities available for sale Total, Estimated Fair Value	0		0
BB Plus and below [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
BB Plus and below [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value			0
BB Plus and below [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
BB Plus and below [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
BB Plus and below [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	37,135		2,105
Corporate Credit Quality Indicator Unrated [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	26,686	[1]	28,370	[2]
Securities available for sale Total, Estimated Fair Value	39,268	[1]	7,773	[2]
Corporate Credit Quality Indicator Unrated [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
Corporate Credit Quality Indicator Unrated [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
Corporate Credit Quality Indicator Unrated [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
Corporate Credit Quality Indicator Unrated [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	7,386		7,773
Corporate Credit Quality Indicator Unrated [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
Corporate Credit Quality Indicator Unrated [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
Corporate Credit Quality Indicator Unrated [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	504,477		485,107
Securities available for sale Total, Estimated Fair Value	31,882		0
Corporate Credit Quality Indicator Unrated [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
Corporate Credit Quality Indicator Unrated [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value			0
Corporate Credit Quality Indicator Unrated [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities available for sale Total, Estimated Fair Value	0		0
Corporate Credit Quality Indicator Unrated [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	25,750		27,129
Corporate Credit Quality Indicator Unrated [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	$ 936		$ 1,241
[1]	Where ratings differ, the Company uses an average of the available ratings by major credit agencies.
[2]	Where ratings differ, the Company uses an average of the available ratings by major credit agencies.

Investment Securities - Additio

Investment Securities - Additional Information (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Pledged Securities [Abstract]
Accrued Investment Income Receivable	$ 1.8
Pledged Financial Instruments, Not Separately Reported, Other Debt Securities Available-for-sale or Held-for-investment	$ 830.4	$ 962.5

Investment Securities - Unreali

Investment Securities - Unrealized Losses and Fair Value of Investment Securities in Continuous Unrealized Loss Position (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)positions	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)positions	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)positions
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | positions	73		73		158
Available-for-sale securities, Less Than Twelve Months, Aggregate Losses	$ 3,028		$ 3,028		$ 4,023
Available-for-sale securities, Less Than Twelve Months, Fair Value	427,743		427,743		799,113
Available-for-sale securities, Twelve Months or Longer, Aggregate Losses	15,004		15,004		15,847
Available-for-sale securities, Twelve Months or Longer, Fair Value	120,636		120,636		585,688
Available-for-sale securities, Continuous Unrealized Loss Position, Aggregate Losses, Total	18,032		18,032		19,870
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Total	548,379		548,379		1,384,801
Unrealized gains (losses) on assets measured at fair value, net	5,882	$ 222	(986)	$ 4,628
Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Less Than Twelve Months, Aggregate Losses	70		70		0
Available-for-sale securities, Less Than Twelve Months, Fair Value	31,528		31,528		0
Available-for-sale securities, Twelve Months or Longer, Aggregate Losses	8,200		8,200		5,166
Available-for-sale securities, Twelve Months or Longer, Fair Value	91,800		91,800		94,834
Available-for-sale securities, Continuous Unrealized Loss Position, Aggregate Losses, Total	8,270		8,270		5,166
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Total	123,328		123,328		94,834
Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Less Than Twelve Months, Aggregate Losses	118		118
Available-for-sale securities, Less Than Twelve Months, Fair Value	9,384		9,384
Available-for-sale securities, Twelve Months or Longer, Aggregate Losses	0		0
Available-for-sale securities, Twelve Months or Longer, Fair Value	0		0
Available-for-sale securities, Continuous Unrealized Loss Position, Aggregate Losses, Total	118		118
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Total	9,384		9,384
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Less Than Twelve Months, Aggregate Losses	522		522		1,740
Available-for-sale securities, Less Than Twelve Months, Fair Value	134,180		134,180		385,643
Available-for-sale securities, Twelve Months or Longer, Aggregate Losses	9		9		2,077
Available-for-sale securities, Twelve Months or Longer, Fair Value	1,193		1,193		150,419
Available-for-sale securities, Continuous Unrealized Loss Position, Aggregate Losses, Total	531		531		3,817
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Total	135,373		135,373		536,062
Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss					149
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value					24,325
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss					0
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value					0
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain					149
Held-to-maturity Securities, Fair Value					24,325
Available-for-sale securities, Less Than Twelve Months, Aggregate Losses	1,467		1,467		422
Available-for-sale securities, Less Than Twelve Months, Fair Value	121,031		121,031		67,150
Available-for-sale securities, Twelve Months or Longer, Aggregate Losses	0		0		0
Available-for-sale securities, Twelve Months or Longer, Fair Value	0		0		0
Available-for-sale securities, Continuous Unrealized Loss Position, Aggregate Losses, Total	1,467		1,467		422
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Total	121,031		121,031		67,150
Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Less Than Twelve Months, Aggregate Losses	851		851		1,776
Available-for-sale securities, Less Than Twelve Months, Fair Value	131,620		131,620		337,285
Available-for-sale securities, Twelve Months or Longer, Aggregate Losses	3		3		2,554
Available-for-sale securities, Twelve Months or Longer, Fair Value	2,435		2,435		258,791
Available-for-sale securities, Continuous Unrealized Loss Position, Aggregate Losses, Total	854		854		4,330
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Total	134,055		134,055		596,076
Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Less Than Twelve Months, Aggregate Losses	0		0		0
Available-for-sale securities, Less Than Twelve Months, Fair Value	0		0		0
Available-for-sale securities, Twelve Months or Longer, Aggregate Losses	6,792		6,792		4,960
Available-for-sale securities, Twelve Months or Longer, Fair Value	25,208		25,208		27,040
Available-for-sale securities, Continuous Unrealized Loss Position, Aggregate Losses, Total	6,792		6,792		4,960
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Total	$ 25,208		$ 25,208		27,040
Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, Less Than Twelve Months, Aggregate Losses					85
Available-for-sale securities, Less Than Twelve Months, Fair Value					9,035
Available-for-sale securities, Twelve Months or Longer, Aggregate Losses					1,090
Available-for-sale securities, Twelve Months or Longer, Fair Value					54,604
Available-for-sale securities, Continuous Unrealized Loss Position, Aggregate Losses, Total					1,175
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Total					$ 63,639

Investment Securities - Amortiz

Investment Securities - Amortized Cost and Fair Value of Investment Securities by Contractual Maturities (Detail) - USD ($) $ in Thousands	Sep. 30, 2020		Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost	$ 7,330
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost	17,135
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Amortized Cost	480,012
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value	7,336
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value	17,628
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value	523,176
Debt Securities, Held-to-maturity	504,477		$ 485,107
Debt Securities, Held-to-maturity, Fair Value	548,140		516,261
Securities available for sale, Due in one year or less, Amortized Cost	600
Securities available for sale, After one year through five years, Amortized Cost	9,024
Securities available for sale, After five years through ten years, Amortized Cost	229,899
Securities available for sale, After ten years, Amortized Cost	970,304
Securities available for sale, Mortgage backed securities, Amortized Cost	2,666,759
Securities available for sale Total, Amortized Cost	3,876,586		3,317,928
Securities available for sale, Due in one year or less, Estimated Fair Value	600
Securities available for sale, After one year through five years, Estimated Fair Value	9,047
Securities available for sale, After five years through ten years, Estimated Fair Value	223,844
Securities available for sale, After ten years, Estimated Fair Value	1,020,284
Securities available for sale, Mortgage backed securities, Estimated Fair Value	2,721,450
Securities available for sale Total, Estimated Fair Value	$ 3,975,225	[1]	$ 3,346,310	[2]
[1]	Where ratings differ, the Company uses an average of the available ratings by major credit agencies.
[2]	Where ratings differ, the Company uses an average of the available ratings by major credit agencies.

Investment Securities - Investm

Investment Securities - Investment Securities by Credit Rating Type (Detail) - USD ($) $ in Thousands	Sep. 30, 2020		Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	$ 504,477		$ 485,107
Available-for-sale Securities	3,975,225	[1]	3,346,310	[2]
Investment securities - equity	160,561	[1]	138,701	[2]
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	1,361,556		1,412,060
Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	504,477		485,107
Available-for-sale Securities	1,011,023		554,855
Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	95,657		94,253
Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	1,264,237		1,129,227
US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities			10,000
US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	600		999
Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	107,016		86,197
Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	25,208		27,040
Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	8,176		10,142
Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	186,609		99,961
Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	22,159		7,773
CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	53,545		52,504
AAA [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	1,278,498	[1]	1,149,519	[2]
Investment securities - equity	0	[1]	0	[2]
AAA [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
AAA [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	0		0
Available-for-sale Securities	43,328		52,610
AAA [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
AAA [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	1,235,170		1,096,909
AAA [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities			0
AAA [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
AAA [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
AAA [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
AAA [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
AAA [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
AAA [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
AAA [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
Split-rated AAA/AA Plus [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	1,514,538	[1]	1,520,168	[2]
Investment securities - equity	27,795	[1]	25,375	[2]
Split-rated AAA/AA Plus [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	1,361,556		1,412,060
Split-rated AAA/AA Plus [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	0		0
Available-for-sale Securities	56,725		2,856
Split-rated AAA/AA Plus [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	95,657		94,253
Split-rated AAA/AA Plus [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
Split-rated AAA/AA Plus [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities			10,000
Split-rated AAA/AA Plus [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	600		999
Split-rated AAA/AA Plus [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
Split-rated AAA/AA Plus [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
Split-rated AAA/AA Plus [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
Split-rated AAA/AA Plus [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
Split-rated AAA/AA Plus [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
Split-rated AAA/AA Plus [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	27,795		25,375
AA Plus to AA- [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	487,454	[1]	358,332	[2]
Investment securities - equity	0	[1]	0	[2]
AA Plus to AA- [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
AA Plus to AA- [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	0		0
Available-for-sale Securities	447,629		327,657
AA Plus to AA- [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
AA Plus to AA- [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	27,682		30,675
AA Plus to AA- [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities			0
AA Plus to AA- [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
AA Plus to AA- [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
AA Plus to AA- [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
AA Plus to AA- [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
AA Plus to AA- [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
AA Plus to AA- [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	12,143		0
AA Plus to AA- [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
A Plus to A- [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	477,350	[1]	238,443	[2]
Investment securities - equity	0	[1]	0	[2]
A Plus to A- [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
A Plus to A- [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	0		0
Available-for-sale Securities	431,459		171,732
A Plus to A- [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
A Plus to A- [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	91		181
A Plus to A- [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities			0
A Plus to A- [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
A Plus to A- [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
A Plus to A- [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
A Plus to A- [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
A Plus to A- [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	45,800		66,530
A Plus to A- [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
A Plus to A- [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
BBB Plus to BBB- [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	150,764	[1]	60,759	[2]
Investment securities - equity	68,945	[1]	82,851	[2]
BBB Plus to BBB- [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
BBB Plus to BBB- [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	0		0
Available-for-sale Securities	0		0
BBB Plus to BBB- [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
BBB Plus to BBB- [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	347		288
BBB Plus to BBB- [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities			0
BBB Plus to BBB- [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
BBB Plus to BBB- [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	68,945		82,851
BBB Plus to BBB- [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	25,208		27,040
BBB Plus to BBB- [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
BBB Plus to BBB- [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	122,579		33,431
BBB Plus to BBB- [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	2,630		0
BBB Plus to BBB- [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
BB Plus and below [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	27,353	[1]	11,316	[2]
Investment securities - equity	37,135	[1]	2,105	[2]
BB Plus and below [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
BB Plus and below [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	0		0
Available-for-sale Securities	0		0
BB Plus and below [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
BB Plus and below [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	947		1,174
BB Plus and below [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities			0
BB Plus and below [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
BB Plus and below [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	37,135		2,105
BB Plus and below [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
BB Plus and below [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	8,176		10,142
BB Plus and below [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	18,230		0
BB Plus and below [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
BB Plus and below [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	0		0
Corporate Credit Quality Indicator Unrated [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	39,268	[1]	7,773	[2]
Investment securities - equity	26,686	[1]	28,370	[2]
Corporate Credit Quality Indicator Unrated [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
Corporate Credit Quality Indicator Unrated [Member] | Nontaxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Held-to-maturity	504,477		485,107
Available-for-sale Securities	31,882		0
Corporate Credit Quality Indicator Unrated [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
Corporate Credit Quality Indicator Unrated [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
Corporate Credit Quality Indicator Unrated [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities			0
Corporate Credit Quality Indicator Unrated [Member] | US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
Corporate Credit Quality Indicator Unrated [Member] | Preferred Stock [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	936		1,241
Corporate Credit Quality Indicator Unrated [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
Corporate Credit Quality Indicator Unrated [Member] | Collateralized Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
Corporate Credit Quality Indicator Unrated [Member] | Corporate Bond Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	0		0
Corporate Credit Quality Indicator Unrated [Member] | Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	7,386		7,773
Corporate Credit Quality Indicator Unrated [Member] | CRA investments [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities - equity	$ 25,750		$ 27,129
[1]	Where ratings differ, the Company uses an average of the available ratings by major credit agencies.
[2]	Where ratings differ, the Company uses an average of the available ratings by major credit agencies.

Investment Securities - Gross G

Investment Securities - Gross Gains and (Losses) on Sales of Investments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities, Gross Realized Gains	$ 0	$ 3,152	$ 405	$ 3,152
Available-for-sale Securities, Gross Realized Losses	0	0	(175)	0
Debt Securities, Available-for-sale, Realized Gain (Loss)	$ 0	$ 3,152	$ 230	$ 3,152

Investment Securities Investmen

Investment Securities Investment Securities - Allowance for Credit Losses - HTM (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Jun. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Debt Securities, Held-to-maturity, Allowance for Credit Loss	$ 5,964	$ 5,964	$ 7,649	$ 2,646	$ 0
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Period Increase (Decrease)	(1,685)	3,318
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Writeoff	0	0
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Recovery	$ 0	$ 0
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Debt Securities, Held-to-maturity, Allowance for Credit Loss				$ 2,646

Loans, Leases and Allowance f_2

Loans, Leases and Allowance for Credit Losses - Schedule of Held for Investment Loan Portfolio Composition of Loans, Leases and Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$ 25,993,254	$ 21,101,493
Loans and Leases Receivable, Allowance	(310,560)	(167,797)
Loans, net	25,682,694	20,933,696
Net deferred loan fees and costs	(81,400)	(47,700)
Receivable with Imputed Interest, Premium	22,100	19,600
Loans Receivable Held-for-sale, Amount	20,764	21,803
Tech & Innovation [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	2,277,889
Other commercial and industrial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	5,993,712
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,970,163	2,316,913
Loans and Leases Receivable, Allowance		(13,842)
Hotel franchise finance [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,942,886
Other Commercial Real Estate Non owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	3,433,932
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	2,330,064	2,147,664
Loans and Leases Receivable, Allowance		(13,714)
Construction And Land Development Land [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	2,267,922	775,248
Warehouse lending [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	3,926,852
Municipal and nonprofit [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,686,690
Other, loan segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$ 163,144
Commercial and industrial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		9,382,043
Loans and Leases Receivable, Allowance		(82,302)
Commercial Real Estate Non Owner Occupied Multi Family [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		5,245,634
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		57,083
Loans and Leases Receivable, Allowance		$ (614)

Loans, Leases and Allowance f_3

Loans, Leases and Allowance for Credit Losses - Summary of Recorded Investment in Nonaccrual Loans and Loans Past Due 90 Days Still Accruing Interest by Loan Class (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual with No Allowance for Credit Loss	$ 108,239		$ 108,239
Nonaccrual with an Allowance for Credit Loss	17,470		17,470
Total Non-accrual	125,709		125,709		$ 55,968
Financing Receivable, 90 Days or More Past Due, Still Accruing	28,129		28,129		0
Loans Receivable Held-for-sale, Amount	20,764		20,764		21,803
Financing Receivable, Not Past Due	25,940,867		25,940,867		21,065,187
Financing Receivable, Past Due	52,387		52,387		36,306
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	1,700	$ 700	4,100	$ 1,500
Loans and Leases Receivable, Net of Deferred Income	25,993,254		25,993,254		21,101,493
Tech & Innovation [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual with No Allowance for Credit Loss	18,725		18,725
Nonaccrual with an Allowance for Credit Loss	0		0
Total Non-accrual	18,725		18,725
Financing Receivable, 90 Days or More Past Due, Still Accruing	0		0
Financing Receivable, Not Past Due	2,277,889		2,277,889
Financing Receivable, Past Due	0		0
Loans and Leases Receivable, Net of Deferred Income	2,277,889		2,277,889
Other commercial and industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual with No Allowance for Credit Loss	26,997		26,997
Nonaccrual with an Allowance for Credit Loss	4,614		4,614
Total Non-accrual	31,611		31,611
Financing Receivable, 90 Days or More Past Due, Still Accruing	16,866		16,866
Financing Receivable, Not Past Due	5,969,739		5,969,739
Financing Receivable, Past Due	23,973		23,973
Loans and Leases Receivable, Net of Deferred Income	5,993,712		5,993,712
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual with No Allowance for Credit Loss	38,567		38,567
Nonaccrual with an Allowance for Credit Loss	0		0
Total Non-accrual	38,567		38,567		4,542
Financing Receivable, 90 Days or More Past Due, Still Accruing	0		0		0
Financing Receivable, Not Past Due	1,970,163		1,970,163
Financing Receivable, Past Due	0		0
Loans and Leases Receivable, Net of Deferred Income	1,970,163		1,970,163		2,316,913
Hotel franchise finance [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual with No Allowance for Credit Loss	0		0
Nonaccrual with an Allowance for Credit Loss	0		0
Total Non-accrual	0		0
Financing Receivable, 90 Days or More Past Due, Still Accruing	11,263		11,263
Financing Receivable, Not Past Due	1,931,623		1,931,623
Financing Receivable, Past Due	11,263		11,263
Loans and Leases Receivable, Net of Deferred Income	1,942,886		1,942,886
Other Commercial Real Estate Non owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual with No Allowance for Credit Loss	18,404		18,404
Nonaccrual with an Allowance for Credit Loss	10,667		10,667
Total Non-accrual	29,071		29,071
Financing Receivable, 90 Days or More Past Due, Still Accruing	0		0
Financing Receivable, Not Past Due	3,433,932		3,433,932
Financing Receivable, Past Due	0		0
Loans and Leases Receivable, Net of Deferred Income	3,433,932		3,433,932
Residential Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual with No Allowance for Credit Loss	5,388		5,388
Nonaccrual with an Allowance for Credit Loss	0		0
Total Non-accrual	5,388		5,388		5,600
Financing Receivable, 90 Days or More Past Due, Still Accruing	0		0		0
Financing Receivable, Not Past Due	2,319,530		2,319,530		2,134,346
Financing Receivable, Past Due	10,534		10,534		13,318
Loans and Leases Receivable, Net of Deferred Income	2,330,064		2,330,064		2,147,664
Construction And Land Development [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual with No Allowance for Credit Loss	0		0
Nonaccrual with an Allowance for Credit Loss	192		192
Total Non-accrual	192		192
Financing Receivable, 90 Days or More Past Due, Still Accruing	0		0
Financing Receivable, Not Past Due	2,261,348		2,261,348
Financing Receivable, Past Due	6,574		6,574
Loans and Leases Receivable, Net of Deferred Income	2,267,922		2,267,922		1,952,156
Warehouse lending [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual with No Allowance for Credit Loss	0		0
Nonaccrual with an Allowance for Credit Loss	0		0
Total Non-accrual	0		0
Financing Receivable, 90 Days or More Past Due, Still Accruing	0		0
Financing Receivable, Not Past Due	3,926,852		3,926,852
Financing Receivable, Past Due	0		0
Loans and Leases Receivable, Net of Deferred Income	3,926,852		3,926,852
Municipal and nonprofit [Member]
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual with No Allowance for Credit Loss	0		0
Nonaccrual with an Allowance for Credit Loss	1,952		1,952
Total Non-accrual	1,952		1,952
Financing Receivable, 90 Days or More Past Due, Still Accruing	0		0
Financing Receivable, Not Past Due	1,686,690		1,686,690
Financing Receivable, Past Due	0		0
Loans and Leases Receivable, Net of Deferred Income	1,686,690		1,686,690
Other, loan segment
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual with No Allowance for Credit Loss	158		158
Nonaccrual with an Allowance for Credit Loss	45		45
Total Non-accrual	203		203
Financing Receivable, 90 Days or More Past Due, Still Accruing	0		0
Financing Receivable, Not Past Due	163,101		163,101
Financing Receivable, Past Due	43		43
Loans and Leases Receivable, Net of Deferred Income	163,144		163,144
Commercial and industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					24,501
Financing Receivable, 90 Days or More Past Due, Still Accruing					0
Financing Receivable, Not Past Due					9,376,377
Financing Receivable, Past Due					5,666
Loans and Leases Receivable, Net of Deferred Income					9,382,043
Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					19,178
Financing Receivable, 90 Days or More Past Due, Still Accruing					0
Loans and Leases Receivable, Net of Deferred Income					5,245,634
Multi-family [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					0
Financing Receivable, 90 Days or More Past Due, Still Accruing					0
Construction And Land Development Construction [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					2,147
Financing Receivable, 90 Days or More Past Due, Still Accruing					0
Financing Receivable, Not Past Due					1,176,908
Financing Receivable, Past Due					0
Loans and Leases Receivable, Net of Deferred Income					1,176,908
Construction And Land Development Land [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					0
Financing Receivable, 90 Days or More Past Due, Still Accruing					0
Financing Receivable, Not Past Due					775,248
Financing Receivable, Past Due					0
Loans and Leases Receivable, Net of Deferred Income	2,267,922		2,267,922		775,248
Consumer Loan [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					0
Financing Receivable, 90 Days or More Past Due, Still Accruing					0
Financing Receivable, Not Past Due					57,083
Financing Receivable, Past Due					0
Loans and Leases Receivable, Net of Deferred Income					57,083
Performing Financial Instruments [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					34,141
Performing Financial Instruments [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					4,418
Performing Financial Instruments [Member] | Residential Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					1,231
Performing Financial Instruments [Member] | Commercial and industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					19,080
Performing Financial Instruments [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					7,265
Performing Financial Instruments [Member] | Multi-family [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					0
Performing Financial Instruments [Member] | Construction And Land Development Construction [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					2,147
Performing Financial Instruments [Member] | Construction And Land Development Land [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					0
Performing Financial Instruments [Member] | Consumer Loan [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					0
Nonperforming Financial Instruments [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					21,827
Nonperforming Financial Instruments [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					124
Nonperforming Financial Instruments [Member] | Residential Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					4,369
Nonperforming Financial Instruments [Member] | Commercial and industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					5,421
Nonperforming Financial Instruments [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					11,913
Nonperforming Financial Instruments [Member] | Multi-family [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					0
Nonperforming Financial Instruments [Member] | Construction And Land Development Construction [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					0
Nonperforming Financial Instruments [Member] | Construction And Land Development Land [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					0
Nonperforming Financial Instruments [Member] | Consumer Loan [Member]
Financing Receivable, Nonaccrual [Line Items]
Total Non-accrual					$ 0
Non Accrual Loans [Member]
Financing Receivable, Nonaccrual [Line Items]
Loans Receivable Held-for-sale, Amount	$ 20,800		$ 20,800

Contractual Aging of Loan Portf

Contractual Aging of Loan Portfolio by Segment - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due	$ 25,940,867	$ 21,065,187
Financing Receivable, Past Due	52,387	36,306
Loans and Leases Receivable, Net of Deferred Income	25,993,254	21,101,493
Tech & Innovation [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due	2,277,889
Financing Receivable, Past Due	0
Loans and Leases Receivable, Net of Deferred Income	2,277,889
Other commercial and industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due	5,969,739
Financing Receivable, Past Due	23,973
Loans and Leases Receivable, Net of Deferred Income	5,993,712
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due	1,970,163
Financing Receivable, Past Due	0
Loans and Leases Receivable, Net of Deferred Income	1,970,163	2,316,913
Hotel franchise finance [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due	1,931,623
Financing Receivable, Past Due	11,263
Loans and Leases Receivable, Net of Deferred Income	1,942,886
Other Commercial Real Estate Non owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due	3,433,932
Financing Receivable, Past Due	0
Loans and Leases Receivable, Net of Deferred Income	3,433,932
Residential Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due	2,319,530	2,134,346
Financing Receivable, Past Due	10,534	13,318
Loans and Leases Receivable, Net of Deferred Income	2,330,064	2,147,664
Construction And Land Development [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due	2,261,348
Financing Receivable, Past Due	6,574
Loans and Leases Receivable, Net of Deferred Income	2,267,922	1,952,156
Warehouse lending [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due	3,926,852
Financing Receivable, Past Due	0
Loans and Leases Receivable, Net of Deferred Income	3,926,852
Municipal and nonprofit [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due	1,686,690
Financing Receivable, Past Due	0
Loans and Leases Receivable, Net of Deferred Income	1,686,690
Other, loan segment
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due	163,101
Financing Receivable, Past Due	43
Loans and Leases Receivable, Net of Deferred Income	163,144
Commercial and industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due		9,376,377
Financing Receivable, Past Due		5,666
Loans and Leases Receivable, Net of Deferred Income		9,382,043
Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Loans and Leases Receivable, Net of Deferred Income		5,245,634
Construction And Land Development Construction [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due		1,176,908
Financing Receivable, Past Due		0
Loans and Leases Receivable, Net of Deferred Income		1,176,908
Construction And Land Development Land [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due		775,248
Financing Receivable, Past Due		0
Loans and Leases Receivable, Net of Deferred Income	2,267,922	775,248
Consumer Loan [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due		57,083
Financing Receivable, Past Due		0
Loans and Leases Receivable, Net of Deferred Income		57,083
Commercial Real Estate [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due		2,316,165
Financing Receivable, Past Due		748
Loans and Leases Receivable, Net of Deferred Income		2,316,913
Commercial Real Estate [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due		5,007,644
Financing Receivable, Past Due		16,574
Loans and Leases Receivable, Net of Deferred Income		5,024,218
Commercial Real Estate [Member] | Multi-family [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Not Past Due		221,416
Financing Receivable, Past Due		0
Loans and Leases Receivable, Net of Deferred Income		221,416
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	21,554	15,413
Financial Asset, 30 to 59 Days Past Due [Member] | Tech & Innovation [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, 30 to 59 Days Past Due [Member] | Other commercial and industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	4,617
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, 30 to 59 Days Past Due [Member] | Hotel franchise finance [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, 30 to 59 Days Past Due [Member] | Other Commercial Real Estate Non owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	10,325	7,627
Financial Asset, 30 to 59 Days Past Due [Member] | Construction And Land Development [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	6,574
Financial Asset, 30 to 59 Days Past Due [Member] | Warehouse lending [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, 30 to 59 Days Past Due [Member] | Municipal and nonprofit [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, 30 to 59 Days Past Due [Member] | Other, loan segment
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	38
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial and industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		2,501
Financial Asset, 30 to 59 Days Past Due [Member] | Construction And Land Development Construction [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		0
Financial Asset, 30 to 59 Days Past Due [Member] | Construction And Land Development Land [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		0
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		624
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		4,661
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member] | Multi-family [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		0
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	2,704	2,358
Financial Asset, 60 to 89 Days Past Due [Member] | Tech & Innovation [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, 60 to 89 Days Past Due [Member] | Other commercial and industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	2,490
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, 60 to 89 Days Past Due [Member] | Hotel franchise finance [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, 60 to 89 Days Past Due [Member] | Other Commercial Real Estate Non owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	209	1,721
Financial Asset, 60 to 89 Days Past Due [Member] | Construction And Land Development [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, 60 to 89 Days Past Due [Member] | Warehouse lending [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, 60 to 89 Days Past Due [Member] | Municipal and nonprofit [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, 60 to 89 Days Past Due [Member] | Other, loan segment
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	5
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial and industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		637
Financial Asset, 60 to 89 Days Past Due [Member] | Construction And Land Development Construction [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		0
Financial Asset, 60 to 89 Days Past Due [Member] | Construction And Land Development Land [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		0
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member] | Multi-family [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	28,129	18,535
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Tech & Innovation [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Other commercial and industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	16,866
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Hotel franchise finance [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	11,263
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Other Commercial Real Estate Non owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0	3,970
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Construction And Land Development [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Warehouse lending [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Municipal and nonprofit [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Other, loan segment
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due	$ 0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial and industrial [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		2,528
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Construction And Land Development Construction [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Construction And Land Development Land [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		124
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		11,913
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate [Member] | Multi-family [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Past Due		$ 0

Loans, Leases and Allowance f_4

Loans, Leases and Allowance for Credit Losses - Loans by Risk Rating (Detail) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 4,966,577,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	5,479,907,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	3,191,331,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,829,321,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	728,405,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,999,527,000
Financing Receivable, Revolving	7,798,186,000
Loans and Leases Receivable, Net of Deferred Income	25,993,254,000	$ 21,101,493,000
Financing Receivable, Not Past Due	25,940,867,000	21,065,187,000
Financing Receivable, Past Due	52,387,000	36,306,000
Loans and Leases Receivable, Collateral for Secured Borrowings	254,780,000
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	21,554,000	15,413,000
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	2,704,000	2,358,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	28,129,000	18,535,000
Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	4,898,480,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	5,311,161,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	3,040,265,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,671,159,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	689,629,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,893,024,000
Financing Receivable, Revolving	7,716,443,000
Loans and Leases Receivable, Net of Deferred Income	25,220,161,000	20,795,258,000
Financing Receivable, Not Past Due		20,785,118,000
Pass [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		8,263,000
Pass [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		1,481,000
Pass [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		396,000
Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	6,929,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	121,939,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	140,967,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	87,861,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	13,696,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	57,787,000
Financing Receivable, Revolving	47,660,000
Loans and Leases Receivable, Net of Deferred Income	476,839,000	158,981,000
Financing Receivable, Not Past Due		158,907,000
Special Mention [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		58,000
Special Mention [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		16,000
Special Mention [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	61,168,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	46,757,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	10,099,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	70,124,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	25,080,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	48,716,000
Financing Receivable, Revolving	34,083,000
Loans and Leases Receivable, Net of Deferred Income	296,027,000	146,805,000
Financing Receivable, Not Past Due		120,897,000
Substandard [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		7,092,000
Substandard [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		861,000
Substandard [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		17,955,000
Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	177,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	177,000	449,000
Financing Receivable, Not Past Due		265,000
Doubtful [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Doubtful [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Doubtful [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		184,000
Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	50,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	50,000	0
Financing Receivable, Not Past Due		0
Loss [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Loss [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Loss [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Tech & Innovation [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	560,419,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	326,863,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	135,217,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,459,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,898,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	1,252,033,000
Loans and Leases Receivable, Net of Deferred Income	2,277,889,000
Financing Receivable, Not Past Due	2,277,889,000
Financing Receivable, Past Due	0
Loans and Leases Receivable, Collateral for Secured Borrowings	49,921,000
Tech & Innovation [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Tech & Innovation [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Tech & Innovation [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Tech & Innovation [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	524,508,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	315,900,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	132,566,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,459,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,898,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	1,236,377,000
Loans and Leases Receivable, Net of Deferred Income	2,212,708,000
Tech & Innovation [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	3,499,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	8,957,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	2,651,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	15,107,000
Tech & Innovation [Member] | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	32,412,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	2,006,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	15,656,000
Loans and Leases Receivable, Net of Deferred Income	50,074,000
Tech & Innovation [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Tech & Innovation [Member] | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Other commercial and industrial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	2,085,897,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	980,806,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	505,239,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	357,437,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	129,205,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	139,947,000
Financing Receivable, Revolving	1,795,181,000
Loans and Leases Receivable, Net of Deferred Income	5,993,712,000
Financing Receivable, Not Past Due	5,969,739,000
Financing Receivable, Past Due	23,973,000
Loans and Leases Receivable, Collateral for Secured Borrowings	70,407,000
Other commercial and industrial [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	4,617,000
Other commercial and industrial [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	2,490,000
Other commercial and industrial [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	16,866,000
Other commercial and industrial [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	2,067,599,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	920,820,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	469,602,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	289,894,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	113,199,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	123,061,000
Financing Receivable, Revolving	1,735,701,000
Loans and Leases Receivable, Net of Deferred Income	5,719,876,000
Other commercial and industrial [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	129,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	51,516,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	32,172,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	36,017,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	6,130,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	15,885,000
Financing Receivable, Revolving	43,378,000
Loans and Leases Receivable, Net of Deferred Income	185,227,000
Other commercial and industrial [Member] | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	18,169,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	8,420,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	3,465,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	31,349,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	9,876,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,001,000
Financing Receivable, Revolving	16,102,000
Loans and Leases Receivable, Net of Deferred Income	88,382,000
Other commercial and industrial [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	177,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	177,000
Other commercial and industrial [Member] | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	50,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	50,000
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	176,898,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	346,603,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	331,733,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	451,776,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	176,924,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	409,293,000
Financing Receivable, Revolving	76,936,000
Loans and Leases Receivable, Net of Deferred Income	1,970,163,000	2,316,913,000
Financing Receivable, Not Past Due	1,970,163,000
Financing Receivable, Past Due	0
Loans and Leases Receivable, Collateral for Secured Borrowings	44,213,000
Commercial Real Estate Owner Occupied [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Commercial Real Estate Owner Occupied [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Commercial Real Estate Owner Occupied [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Commercial Real Estate Owner Occupied [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	173,784,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	327,618,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	322,396,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	423,987,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	167,304,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	376,175,000
Financing Receivable, Revolving	74,887,000
Loans and Leases Receivable, Net of Deferred Income	1,866,151,000
Commercial Real Estate Owner Occupied [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	877,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	11,412,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	4,411,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	17,306,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	3,309,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	10,658,000
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	47,973,000
Commercial Real Estate Owner Occupied [Member] | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	2,237,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	7,573,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	4,926,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	10,483,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	6,311,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	22,460,000
Financing Receivable, Revolving	2,049,000
Loans and Leases Receivable, Net of Deferred Income	56,039,000
Commercial Real Estate Owner Occupied [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Commercial Real Estate Owner Occupied [Member] | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Hotel franchise finance [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	156,816,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	787,180,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	520,640,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	180,587,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	2,129,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	132,967,000
Financing Receivable, Revolving	162,567,000
Loans and Leases Receivable, Net of Deferred Income	1,942,886,000
Financing Receivable, Not Past Due	1,931,623,000
Financing Receivable, Past Due	11,263,000
Loans and Leases Receivable, Collateral for Secured Borrowings	27,649,000
Hotel franchise finance [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Hotel franchise finance [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Hotel franchise finance [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	11,263,000
Hotel franchise finance [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	156,816,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	754,537,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	464,842,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	140,424,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	96,306,000
Financing Receivable, Revolving	162,567,000
Loans and Leases Receivable, Net of Deferred Income	1,775,492,000
Hotel franchise finance [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	32,643,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	55,798,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	27,389,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	23,914,000
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	139,744,000
Hotel franchise finance [Member] | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	12,774,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	2,129,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	12,747,000
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	27,650,000
Hotel franchise finance [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Hotel franchise finance [Member] | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Other Commercial Real Estate Non owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	656,680,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,000,986,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	670,406,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	448,922,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	193,384,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	251,883,000
Financing Receivable, Revolving	211,671,000
Loans and Leases Receivable, Net of Deferred Income	3,433,932,000
Financing Receivable, Not Past Due	3,433,932,000
Financing Receivable, Past Due	0
Loans and Leases Receivable, Collateral for Secured Borrowings	61,403,000
Other Commercial Real Estate Non owner Occupied [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Other Commercial Real Estate Non owner Occupied [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Other Commercial Real Estate Non owner Occupied [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Other Commercial Real Estate Non owner Occupied [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	648,330,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	961,315,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	663,375,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	431,032,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	182,475,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	232,800,000
Financing Receivable, Revolving	211,671,000
Loans and Leases Receivable, Net of Deferred Income	3,330,998,000
Other Commercial Real Estate Non owner Occupied [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	13,217,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	7,031,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	5,458,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	4,257,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	7,288,000
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	37,251,000
Other Commercial Real Estate Non owner Occupied [Member] | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	8,350,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	26,454,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	12,432,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	6,652,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	11,795,000
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	65,683,000
Other Commercial Real Estate Non owner Occupied [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Other Commercial Real Estate Non owner Occupied [Member] | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	524,852,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,020,433,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	474,268,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	123,104,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	91,153,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	50,604,000
Financing Receivable, Revolving	45,650,000
Loans and Leases Receivable, Net of Deferred Income	2,330,064,000	2,147,664,000
Financing Receivable, Not Past Due	2,319,530,000	2,134,346,000
Financing Receivable, Past Due	10,534,000	13,318,000
Loans and Leases Receivable, Collateral for Secured Borrowings	758,000
Residential Real Estate [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	10,325,000	7,627,000
Residential Real Estate [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	209,000	1,721,000
Residential Real Estate [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0	3,970,000
Residential Real Estate [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	524,852,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,018,264,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	472,941,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	121,970,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	91,138,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	50,087,000
Financing Receivable, Revolving	45,392,000
Loans and Leases Receivable, Net of Deferred Income	2,324,644,000	2,141,336,000
Residential Real Estate [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0	366,000
Residential Real Estate [Member] | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	2,169,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,327,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,134,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	15,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	517,000
Financing Receivable, Revolving	258,000
Loans and Leases Receivable, Net of Deferred Income	5,420,000	5,962,000
Residential Real Estate [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0	0
Residential Real Estate [Member] | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0	0
Construction And Land Development Land [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	493,681,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	777,114,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	459,417,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	21,028,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,403,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	14,953,000
Financing Receivable, Revolving	500,326,000
Loans and Leases Receivable, Net of Deferred Income	2,267,922,000	775,248,000
Financing Receivable, Not Past Due		775,248,000
Financing Receivable, Past Due		0
Construction And Land Development Land [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Construction And Land Development Land [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Construction And Land Development Land [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Construction And Land Development Land [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	492,218,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	777,114,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	422,749,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	21,028,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,403,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	14,953,000
Financing Receivable, Revolving	496,079,000
Loans and Leases Receivable, Net of Deferred Income	2,225,544,000
Construction And Land Development Land [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	1,463,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	36,476,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	4,247,000
Loans and Leases Receivable, Net of Deferred Income	42,186,000
Construction And Land Development Land [Member] | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	192,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	192,000
Construction And Land Development Land [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Construction And Land Development Land [Member] | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Warehouse lending [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	155,588,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	48,455,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	990,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,640,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	78,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	3,720,101,000
Loans and Leases Receivable, Net of Deferred Income	3,926,852,000
Financing Receivable, Not Past Due	3,926,852,000
Financing Receivable, Past Due	0
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Warehouse lending [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Warehouse lending [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Warehouse lending [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Warehouse lending [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	155,588,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	48,455,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	990,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,640,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	78,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	3,720,101,000
Loans and Leases Receivable, Net of Deferred Income	3,926,852,000
Warehouse lending [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Warehouse lending [Member] | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Warehouse lending [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Warehouse lending [Member] | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Municipal and nonprofit [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	137,047,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	175,157,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	78,464,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	234,768,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	129,957,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	927,762,000
Financing Receivable, Revolving	3,535,000
Loans and Leases Receivable, Net of Deferred Income	1,686,690,000
Financing Receivable, Not Past Due	1,686,690,000
Financing Receivable, Past Due	0
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Municipal and nonprofit [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Municipal and nonprofit [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Municipal and nonprofit [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Municipal and nonprofit [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	137,047,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	170,963,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	76,133,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	232,816,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	129,957,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	927,762,000
Financing Receivable, Revolving	3,535,000
Loans and Leases Receivable, Net of Deferred Income	1,678,213,000
Municipal and nonprofit [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	4,194,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	2,331,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	6,525,000
Municipal and nonprofit [Member] | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,952,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	1,952,000
Municipal and nonprofit [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Municipal and nonprofit [Member] | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Other, loan segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	18,699,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	16,310,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	14,957,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	8,600,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	2,274,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	72,118,000
Financing Receivable, Revolving	30,186,000
Loans and Leases Receivable, Net of Deferred Income	163,144,000
Financing Receivable, Not Past Due	163,101,000
Financing Receivable, Past Due	43,000
Loans and Leases Receivable, Collateral for Secured Borrowings	429,000
Other, loan segment | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	38,000
Other, loan segment | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	5,000
Other, loan segment | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due	0
Other, loan segment | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	17,738,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	16,175,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	14,671,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	6,909,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	2,177,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	71,880,000
Financing Receivable, Revolving	30,133,000
Loans and Leases Receivable, Net of Deferred Income	159,683,000
Other, loan segment | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	961,000
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	97,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,691,000
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	42,000
Financing Receivable, Revolving	35,000
Loans and Leases Receivable, Net of Deferred Income	2,826,000
Other, loan segment | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	135,000
Financing Receivable, Originated Two Years before Latest Fiscal Year	189,000
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	97,000
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	196,000
Financing Receivable, Revolving	18,000
Loans and Leases Receivable, Net of Deferred Income	635,000
Other, loan segment | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Other, loan segment | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	$ 0
Commercial and industrial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		9,382,043,000
Financing Receivable, Not Past Due		9,376,377,000
Financing Receivable, Past Due		5,666,000
Commercial and industrial [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		2,501,000
Commercial and industrial [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		637,000
Commercial and industrial [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		2,528,000
Commercial and industrial [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		9,265,823,000
Commercial and industrial [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		65,893,000
Commercial and industrial [Member] | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		49,878,000
Commercial and industrial [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		449,000
Commercial and industrial [Member] | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		5,245,634,000
Construction And Land Development Construction [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		1,176,908,000
Financing Receivable, Not Past Due		1,176,908,000
Financing Receivable, Past Due		0
Construction And Land Development Construction [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Construction And Land Development Construction [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Construction And Land Development Construction [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Construction And Land Development Construction [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		1,157,169,000
Construction And Land Development Construction [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		17,592,000
Construction And Land Development Construction [Member] | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		2,147,000
Construction And Land Development Construction [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Construction And Land Development Construction [Member] | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Land [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		775,248,000
Land [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		773,868,000
Land [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		1,380,000
Land [Member] | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Land [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Land [Member] | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		57,083,000
Financing Receivable, Not Past Due		57,083,000
Financing Receivable, Past Due		0
Consumer Loan [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Consumer Loan [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Consumer Loan [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Consumer Loan [Member] | Pass [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		57,073,000
Consumer Loan [Member] | Special Mention [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		10,000
Consumer Loan [Member] | Substandard [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Consumer Loan [Member] | Doubtful [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Consumer Loan [Member] | Loss [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Commercial Real Estate [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		2,316,913,000
Financing Receivable, Not Past Due		2,316,165,000
Financing Receivable, Past Due		748,000
Commercial Real Estate [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		5,024,218,000
Financing Receivable, Not Past Due		5,007,644,000
Financing Receivable, Past Due		16,574,000
Commercial Real Estate [Member] | Multi-family [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		221,416,000
Financing Receivable, Not Past Due		221,416,000
Financing Receivable, Past Due		0
Commercial Real Estate [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		624,000
Commercial Real Estate [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		4,661,000
Commercial Real Estate [Member] | Financial Asset, 30 to 59 Days Past Due [Member] | Multi-family [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Commercial Real Estate [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Commercial Real Estate [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Commercial Real Estate [Member] | Financial Asset, 60 to 89 Days Past Due [Member] | Multi-family [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Commercial Real Estate [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		124,000
Commercial Real Estate [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		11,913,000
Commercial Real Estate [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Multi-family [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Past Due		0
Commercial Real Estate [Member] | Pass [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		2,265,566,000
Commercial Real Estate [Member] | Pass [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		4,913,007,000
Commercial Real Estate [Member] | Pass [Member] | Multi-family [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		221,416,000
Commercial Real Estate [Member] | Special Mention [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		9,579,000
Commercial Real Estate [Member] | Special Mention [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		64,161,000
Commercial Real Estate [Member] | Special Mention [Member] | Multi-family [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Commercial Real Estate [Member] | Substandard [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		41,768,000
Commercial Real Estate [Member] | Substandard [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		47,050,000
Commercial Real Estate [Member] | Substandard [Member] | Multi-family [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Commercial Real Estate [Member] | Doubtful [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Commercial Real Estate [Member] | Doubtful [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Commercial Real Estate [Member] | Doubtful [Member] | Multi-family [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Commercial Real Estate [Member] | Loss [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Commercial Real Estate [Member] | Loss [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Commercial Real Estate [Member] | Loss [Member] | Multi-family [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and Leases Receivable, Net of Deferred Income		$ 0

Loans, Leases and Allowance f_5

Loans, Leases and Allowance for Credit Losses Loans, Leases and Allowance for Credit Losses - Troubled Debt Restructurings (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)SecurityLoan	Sep. 30, 2019USD ($)SecurityLoan	Sep. 30, 2020USD ($)SecurityLoan	Sep. 30, 2019USD ($)SecurityLoan	Dec. 31, 2019USD ($)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	$ 254,780,000		$ 254,780,000
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts | SecurityLoan	1	0	2	2
Financing Receivable, Troubled Debt Restructuring, Commitment to Lend	$ 4,200,000		$ 4,200,000		$ 200,000
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	800,000		1,500,000	$ 400,000
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 25,000,000		$ 35,700,000
Financing Receivable, Modifications, Number of Contracts | SecurityLoan	20	3	22	7
Financing Receivable, Troubled Debt Restructuring	$ 60,757,000		$ 60,757,000
Financing Receivable, Troubled Debt Restructuring, Premodification		$ 11,800,000		$ 40,700,000
Reserves allocated to customers whose loan terms modified in troubled debt restructurings	$ 2,700,000		$ 2,700,000
Financing Receivable, Troubled Debt Restructured Loans, Number of Outstanding Contracts | SecurityLoan	27		27
Tech & Innovation [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	$ 49,921,000		$ 49,921,000
Financing Receivable, Troubled Debt Restructuring	$ 12,111,000		$ 12,111,000
Financing Receivable, Troubled Debt Restructured Loans, Number of Outstanding Contracts | SecurityLoan	3		3
Other commercial and industrial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	$ 70,407,000		$ 70,407,000
Financing Receivable, Troubled Debt Restructuring	$ 30,270,000		$ 30,270,000
Financing Receivable, Troubled Debt Restructured Loans, Number of Outstanding Contracts | SecurityLoan	16		16
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	$ 44,213,000		$ 44,213,000
Financing Receivable, Troubled Debt Restructuring	$ 2,335,000		$ 2,335,000
Financing Receivable, Troubled Debt Restructured Loans, Number of Outstanding Contracts | SecurityLoan	3		3
Hotel franchise finance [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	$ 27,649,000		$ 27,649,000
Financing Receivable, Troubled Debt Restructuring	$ 5,746,000		$ 5,746,000
Financing Receivable, Troubled Debt Restructured Loans, Number of Outstanding Contracts | SecurityLoan	2		2
Other Commercial Real Estate Non owner Occupied [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	$ 61,403,000		$ 61,403,000
Financing Receivable, Troubled Debt Restructuring	$ 10,295,000		$ 10,295,000
Financing Receivable, Troubled Debt Restructured Loans, Number of Outstanding Contracts | SecurityLoan	3		3
Residential Real Estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	$ 758,000		$ 758,000
Construction And Land Development [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0		0
Warehouse lending [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0		0
Municipal and nonprofit [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	$ 0		$ 0

Loans, Leases and Allowance f_6

Loans, Leases and Allowance for Credit Losses Loans, Leases and Allowance for Credit Losses - Collateral Dependent Loans (Details) $ in Thousands	Sep. 30, 2020USD ($)
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	$ 254,780
Real Estate Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	134,023
Other Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	120,757
Tech & Innovation [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	49,921
Tech & Innovation [Member] | Real Estate Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Tech & Innovation [Member] | Other Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	49,921
Other commercial and industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	70,407
Other commercial and industrial [Member] | Real Estate Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Other commercial and industrial [Member] | Other Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	70,407
Commercial Real Estate Owner Occupied [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	44,213
Commercial Real Estate Owner Occupied [Member] | Real Estate Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	44,213
Commercial Real Estate Owner Occupied [Member] | Other Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Hotel franchise finance [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	27,649
Hotel franchise finance [Member] | Real Estate Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	27,649
Hotel franchise finance [Member] | Other Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Other Commercial Real Estate Non owner Occupied [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	61,403
Other Commercial Real Estate Non owner Occupied [Member] | Real Estate Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	61,403
Other Commercial Real Estate Non owner Occupied [Member] | Other Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Residential Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	758
Residential Real Estate [Member] | Real Estate Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	758
Residential Real Estate [Member] | Other Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Construction And Land Development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Construction And Land Development [Member] | Real Estate Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Construction And Land Development [Member] | Other Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Warehouse lending [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Warehouse lending [Member] | Real Estate Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Warehouse lending [Member] | Other Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Municipal and nonprofit [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Municipal and nonprofit [Member] | Real Estate Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Municipal and nonprofit [Member] | Other Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Other, loan segment
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	429
Other, loan segment | Real Estate Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	0
Other, loan segment | Other Collateral [Member]
Loans and Leases Receivable Disclosure [Line Items]
Loans and Leases Receivable, Collateral for Secured Borrowings	$ 429

Loans, Leases and Allowance f_7

Loans, Leases and Allowance for Credit Losses - Allowances for Credit Losses (Detail) Valuation - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Jan. 01, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 310,560	$ 165,021	$ 310,560	$ 165,021	$ 310,550	$ 186,925		$ 160,409	$ 152,717
Provision for Loan and Lease Losses	(8,204)	(4,000)	(134,130)	(14,500)
Financing Receivable, Allowance for Credit Loss, Writeoff	8,773	2,099	14,593	6,968
Financing Receivable, Allowance for Credit Loss, Recovery	(579)	(2,711)	(4,098)	(4,772)
Financing Receivable, Collectively Evaluated for Impairment	25,654,269		25,654,269				$ 20,932,161
Financing Receivable, Individually Evaluated for Impairment	338,985		338,985				116,303
Loans and Leases Receivable, Net of Deferred Income	25,993,254		25,993,254				21,101,493
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	300,514		300,514				164,923
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	10,046		10,046				2,776
Impaired Financing Receivable, with Related Allowance, Recorded Investment							20,979
Impaired Financing Receivable, with No Related Allowance, Recorded Investment							95,324
Off-Balance Sheet, Credit Loss, Liability	44,400		44,400				8,955
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance							24,055
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance							99,440
Impaired Financing Receivable Unpaid Principal Balance Individually Evaluated For Impairment							123,495
Financing Receivable Unpaid Principal Balance Collectively Evaluated For Impairment							20,921,137
Financing Receivable Unpaid Principal Balance							21,108,472
Impaired Financing Receivable, Related Allowance							2,776
Impaired Financing Receivable With No Related Allowance							0
Loans and Leases Receivable, Allowance	310,560		310,560				167,797
Interest Receivable	120,100		120,100
Financial Asset Acquired with Credit Deterioration [Member]
Valuation Allowance [Line Items]
Impaired Financing Receivable, Recorded Investment							53,029
Impaired Financing Receivable, Unpaid Principal Balance							63,840
Impaired Financing Receivable, Related Allowance							98
Commercial and industrial [Member]
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss		77,419		77,419				79,635	83,118
Provision for Loan and Lease Losses		(2,815)		(3,128)
Financing Receivable, Allowance for Credit Loss, Writeoff		1,950		6,092
Financing Receivable, Allowance for Credit Loss, Recovery		(2,549)		(3,521)
Financing Receivable, Collectively Evaluated for Impairment							9,333,059
Financing Receivable, Individually Evaluated for Impairment							48,984
Loans and Leases Receivable, Net of Deferred Income							9,382,043
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment							81,252
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment							1,050
Impaired Financing Receivable, with Related Allowance, Recorded Investment							6,919
Impaired Financing Receivable, with No Related Allowance, Recorded Investment							42,065
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance							9,844
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance							43,848
Impaired Financing Receivable Unpaid Principal Balance Individually Evaluated For Impairment							53,692
Financing Receivable Unpaid Principal Balance Collectively Evaluated For Impairment							9,312,100
Financing Receivable Unpaid Principal Balance							9,365,792
Impaired Financing Receivable, Related Allowance							1,050
Impaired Financing Receivable With No Related Allowance							0
Loans and Leases Receivable, Allowance							82,302
Commercial and industrial [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Valuation Allowance [Line Items]
Impaired Financing Receivable, Recorded Investment							0
Impaired Financing Receivable, Unpaid Principal Balance							0
Impaired Financing Receivable, Related Allowance							0
Tech & Innovation [Member]
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss	38,836		38,836		54,559	22,394
Provision for Loan and Lease Losses	(9,359)		(25,556)
Financing Receivable, Allowance for Credit Loss, Writeoff	6,364		9,114
Financing Receivable, Allowance for Credit Loss, Recovery	0		0
Financing Receivable, Collectively Evaluated for Impairment	2,227,995		2,227,995
Financing Receivable, Individually Evaluated for Impairment	49,894		49,894
Loans and Leases Receivable, Net of Deferred Income	2,277,889		2,277,889
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	38,836		38,836
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0		0
Other commercial and industrial [Member]
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss	108,753		108,753		109,930	95,784
Provision for Loan and Lease Losses	(621)		(13,653)
Financing Receivable, Allowance for Credit Loss, Writeoff	748		2,684
Financing Receivable, Allowance for Credit Loss, Recovery	(192)		(2,000)
Financing Receivable, Collectively Evaluated for Impairment	5,906,731		5,906,731
Financing Receivable, Individually Evaluated for Impairment	86,981		86,981
Loans and Leases Receivable, Net of Deferred Income	5,993,712		5,993,712
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	102,011		102,011
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	6,742		6,742
Commercial Real Estate Owner Occupied [Member]
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss	19,406		19,406		15,587	10,420
Provision for Loan and Lease Losses	(3,897)		(9,100)
Financing Receivable, Allowance for Credit Loss, Writeoff	83		126
Financing Receivable, Allowance for Credit Loss, Recovery	(5)		(12)
Financing Receivable, Collectively Evaluated for Impairment	1,912,127		1,912,127				2,296,342
Financing Receivable, Individually Evaluated for Impairment	58,036		58,036				17,736
Loans and Leases Receivable, Net of Deferred Income	1,970,163		1,970,163				2,316,913
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	19,406		19,406				13,842
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0		0				0
Impaired Financing Receivable, with Related Allowance, Recorded Investment							0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment							17,736
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance							0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance							18,681
Impaired Financing Receivable Unpaid Principal Balance Individually Evaluated For Impairment							18,681
Financing Receivable Unpaid Principal Balance Collectively Evaluated For Impairment							2,297,168
Financing Receivable Unpaid Principal Balance							2,319,426
Impaired Financing Receivable, Related Allowance							0
Impaired Financing Receivable With No Related Allowance							0
Loans and Leases Receivable, Allowance							13,842
Commercial Real Estate Owner Occupied [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Valuation Allowance [Line Items]
Impaired Financing Receivable, Recorded Investment							2,835
Impaired Financing Receivable, Unpaid Principal Balance							3,577
Impaired Financing Receivable, Related Allowance							0
Commercial Real Estate Non Owner Occupied [Member]
Valuation Allowance [Line Items]
Financing Receivable, Collectively Evaluated for Impairment							5,159,921
Financing Receivable, Individually Evaluated for Impairment							35,538
Loans and Leases Receivable, Net of Deferred Income							5,245,634
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment							32,114
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment							1,219
Impaired Financing Receivable, with Related Allowance, Recorded Investment							11,913
Impaired Financing Receivable, with No Related Allowance, Recorded Investment							23,625
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance							11,949
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance							24,738
Impaired Financing Receivable Unpaid Principal Balance Individually Evaluated For Impairment							36,687
Financing Receivable Unpaid Principal Balance Collectively Evaluated For Impairment							5,177,477
Financing Receivable Unpaid Principal Balance							5,274,355
Impaired Financing Receivable, Related Allowance							1,219
Impaired Financing Receivable With No Related Allowance							0
Loans and Leases Receivable, Allowance							33,431
Commercial Real Estate Non Owner Occupied [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Valuation Allowance [Line Items]
Impaired Financing Receivable, Recorded Investment							50,175
Impaired Financing Receivable, Unpaid Principal Balance							60,191
Impaired Financing Receivable, Related Allowance							98
Hotel franchise finance [Member]
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss	38,027		38,027		35,864	14,104
Provision for Loan and Lease Losses	(2,163)		(23,923)
Financing Receivable, Allowance for Credit Loss, Writeoff	0		0
Financing Receivable, Allowance for Credit Loss, Recovery	0		0
Financing Receivable, Collectively Evaluated for Impairment	1,885,451		1,885,451
Financing Receivable, Individually Evaluated for Impairment	57,435		57,435
Loans and Leases Receivable, Net of Deferred Income	1,942,886		1,942,886
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	35,312		35,312
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	2,715		2,715
Other Commercial Real Estate Non owner Occupied [Member]
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss	40,622		40,622		32,672	10,503
Provision for Loan and Lease Losses	(9,196)		(30,684)
Financing Receivable, Allowance for Credit Loss, Writeoff	1,246		2,131
Financing Receivable, Allowance for Credit Loss, Recovery	0		(1,566)
Financing Receivable, Collectively Evaluated for Impairment	3,355,259		3,355,259
Financing Receivable, Individually Evaluated for Impairment	78,673		78,673
Loans and Leases Receivable, Net of Deferred Income	3,433,932		3,433,932
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	40,518		40,518
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	104		104
Residential Real Estate [Member]
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss	1,789	13,532	1,789	13,532	1,725	3,814		12,606	11,276
Provision for Loan and Lease Losses	(16)	(804)	(2,103)	(2,599)
Financing Receivable, Allowance for Credit Loss, Writeoff	307	9	307	594
Financing Receivable, Allowance for Credit Loss, Recovery	(355)	(131)	(385)	(251)
Financing Receivable, Collectively Evaluated for Impairment	2,324,676		2,324,676				2,142,045
Financing Receivable, Individually Evaluated for Impairment	5,388		5,388				5,600
Loans and Leases Receivable, Net of Deferred Income	2,330,064		2,330,064				2,147,664
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	1,789		1,789				13,714
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0		0				0
Impaired Financing Receivable, with Related Allowance, Recorded Investment							0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment							5,600
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance							0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance							5,708
Impaired Financing Receivable Unpaid Principal Balance Individually Evaluated For Impairment							5,708
Financing Receivable Unpaid Principal Balance Collectively Evaluated For Impairment							2,113,893
Financing Receivable Unpaid Principal Balance							2,119,673
Impaired Financing Receivable, Related Allowance							0
Impaired Financing Receivable With No Related Allowance							0
Loans and Leases Receivable, Allowance							13,714
Residential Real Estate [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Valuation Allowance [Line Items]
Impaired Financing Receivable, Recorded Investment							19
Impaired Financing Receivable, Unpaid Principal Balance							72
Impaired Financing Receivable, Related Allowance							0
Construction And Land Development [Member]
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss	38,781	27,318	38,781	27,318	35,792	6,218		26,091	22,513
Provision for Loan and Lease Losses	(2,983)	(1,210)	(32,540)	(4,865)
Financing Receivable, Allowance for Credit Loss, Writeoff	0	0	0	141
Financing Receivable, Allowance for Credit Loss, Recovery	(6)	(17)	(23)	(81)
Financing Receivable, Collectively Evaluated for Impairment	2,267,922		2,267,922				1,943,735
Financing Receivable, Individually Evaluated for Impairment	0		0				8,421
Loans and Leases Receivable, Net of Deferred Income	2,267,922		2,267,922				1,952,156
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	38,781		38,781				23,387
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0		0				507
Impaired Financing Receivable, with Related Allowance, Recorded Investment							2,147
Impaired Financing Receivable, with No Related Allowance, Recorded Investment							6,274
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance							2,262
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance							6,413
Impaired Financing Receivable Unpaid Principal Balance Individually Evaluated For Impairment							8,675
Financing Receivable Unpaid Principal Balance Collectively Evaluated For Impairment							1,963,116
Financing Receivable Unpaid Principal Balance							1,971,791
Impaired Financing Receivable, Related Allowance							507
Impaired Financing Receivable With No Related Allowance							0
Loans and Leases Receivable, Allowance							23,894
Construction And Land Development [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Valuation Allowance [Line Items]
Impaired Financing Receivable, Recorded Investment							0
Impaired Financing Receivable, Unpaid Principal Balance							0
Impaired Financing Receivable, Related Allowance							0
Warehouse lending [Member]
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss	838		838		743	246
Provision for Loan and Lease Losses	(95)		(592)
Financing Receivable, Allowance for Credit Loss, Writeoff	0		0
Financing Receivable, Allowance for Credit Loss, Recovery	0		0
Financing Receivable, Collectively Evaluated for Impairment	3,926,852		3,926,852
Financing Receivable, Individually Evaluated for Impairment	0		0
Loans and Leases Receivable, Net of Deferred Income	3,926,852		3,926,852
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	838		838
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0		0
Municipal and nonprofit [Member]
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss	17,896		17,896		17,128	17,397
Provision for Loan and Lease Losses	(768)		(499)
Financing Receivable, Allowance for Credit Loss, Writeoff	0		0
Financing Receivable, Allowance for Credit Loss, Recovery	0		0
Financing Receivable, Collectively Evaluated for Impairment	1,684,738		1,684,738
Financing Receivable, Individually Evaluated for Impairment	1,952		1,952
Loans and Leases Receivable, Net of Deferred Income	1,686,690		1,686,690
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	17,454		17,454
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	442		442
Other, loan segment
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss	5,612		5,612		$ 6,550	$ 6,045
Provision for Loan and Lease Losses	(934)		(314)
Financing Receivable, Allowance for Credit Loss, Writeoff	25		231
Financing Receivable, Allowance for Credit Loss, Recovery	(21)		(112)
Financing Receivable, Collectively Evaluated for Impairment	162,518		162,518
Financing Receivable, Individually Evaluated for Impairment	626		626
Loans and Leases Receivable, Net of Deferred Income	163,144		163,144
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	5,569		5,569
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 43		$ 43
Commercial Real Estate [Member]
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss		45,944		45,944				41,258	34,829
Provision for Loan and Lease Losses		(4,817)		(10,354)
Financing Receivable, Allowance for Credit Loss, Writeoff		139		139
Financing Receivable, Allowance for Credit Loss, Recovery		(8)		(900)
Commercial Real Estate [Member] | Commercial Real Estate Owner Occupied [Member]
Valuation Allowance [Line Items]
Loans and Leases Receivable, Net of Deferred Income							2,316,913
Commercial Real Estate [Member] | Commercial Real Estate Non Owner Occupied [Member]
Valuation Allowance [Line Items]
Loans and Leases Receivable, Net of Deferred Income							5,024,218
Consumer Loan [Member]
Valuation Allowance [Line Items]
Financing Receivable, Allowance for Credit Loss		808		808				$ 819	$ 981
Provision for Loan and Lease Losses		(16)		(190)
Financing Receivable, Allowance for Credit Loss, Writeoff		1		2
Financing Receivable, Allowance for Credit Loss, Recovery		$ (6)		$ (19)
Financing Receivable, Collectively Evaluated for Impairment							57,059
Financing Receivable, Individually Evaluated for Impairment							24
Loans and Leases Receivable, Net of Deferred Income							57,083
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment							614
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment							0
Impaired Financing Receivable, with Related Allowance, Recorded Investment							0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment							24
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance							0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance							52
Impaired Financing Receivable Unpaid Principal Balance Individually Evaluated For Impairment							52
Financing Receivable Unpaid Principal Balance Collectively Evaluated For Impairment							57,383
Financing Receivable Unpaid Principal Balance							57,435
Impaired Financing Receivable, Related Allowance							0
Impaired Financing Receivable With No Related Allowance							0
Loans and Leases Receivable, Allowance							614
Consumer Loan [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Valuation Allowance [Line Items]
Impaired Financing Receivable, Recorded Investment							0
Impaired Financing Receivable, Unpaid Principal Balance							0
Impaired Financing Receivable, Related Allowance							$ 0

Loans, Leases and Allowance f_8

Loans, Leases and Allowance for Credit Losses Loans, Leases and Allowance for Credit Losses - Loan Purchases and Sales (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Purchase	$ 514,396	$ 709,071	$ 1,683,720	$ 1,830,177
Loans and Leases Receivable, Gain (Loss) on Sales, Net		100		(500)
Loans And Loans Receivable Purchases			0
Financing Receivable, Sale		14,238		49,068
Commercial and industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Purchase	271,085	260,621	663,171	787,286
Financing Receivable, Sale		14,238		49,068
Commercial Real Estate Non Owner Occupied [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Purchase		19,177		49,211
Financing Receivable, Sale		0		0
Residential Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Purchase	243,311	428,665	919,509	959,190
Financing Receivable, Sale		0		0
Construction And Land Development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Purchase		608		34,490
Financing Receivable, Sale		$ 0		$ 0
Warehouse lending [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Purchase	0		99,446
Municipal and nonprofit [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Purchase	$ 0		$ 1,594

Other Borrowings - Additional I

Other Borrowings - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt [Line Items]
FHLB advances	$ 10,000	$ 0
Short-term Debt	10,000	0
Customer repurchase agreements	19,688	16,675
Federal Funds Purchased	0	0
Federal Home Loan Bank Advances [Member]
Debt [Line Items]
Additional available credit with the entity	4,400,000	4,500,000
FRB [Member]
Debt [Line Items]
Additional available credit with the entity	2,400,000	$ 1,100,000
Unsecured Credit Facility [Member]
Debt [Line Items]
Secured borrowing credit line	$ 2,400,000

Qualifying Debt (Details)

Qualifying Debt (Details)	Oct. 15, 2020USD ($)	Sep. 30, 2020USD ($)$ / shares	Sep. 30, 2020USD ($)Trust	Dec. 31, 2019USD ($)	Jun. 16, 2016USD ($)	Jun. 29, 2015USD ($)
Debt Instrument [Line Items]
Common Stock, Dividends, Per Share, Cash Paid | $ / shares		$ 0.25
Subordinated Debt		$ 545,300,000	$ 545,300,000	$ 319,200,000
Number of Statutory Business Trusts Formed or Acquired | Trust			8
Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust		73,500,000	$ 73,500,000	$ 74,400,000
Subsequent Event [Member]
Debt Instrument [Line Items]
Early Repayment of Subordinated Debt	$ 75,000,000
Subordinated Debt [Member] | Subordinated Debentures Maturing July 2056 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 175,000,000	$ 175,000,000
Debt Issuance Cost					$ 5,500,000
Debt Instrument, Interest Rate, Stated Percentage		6.25%	6.25%
Subordinated Debt [Member] | Subordinated Debentures Maturing July 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 150,000,000	$ 150,000,000
Debt Issuance Cost						$ 1,800,000
Debt Instrument, Interest Rate, Stated Percentage		5.00%	5.00%
Subordinated Debt [Member] | Subordinated Debentures Maturing June 2030 [Member] [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 225,000,000	$ 225,000,000
Debt Issuance Cost		$ 3,100,000	$ 3,100,000
Debt Instrument, Interest Rate, Stated Percentage		5.25%	5.25%
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Weighted Average Interest Rate, at Point in Time		2.57%	2.57%	4.25%

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Repurchased and Retired During Period, Shares		1,000,000	2,066,479	2,733,603
Weighted Average Selling Price Per Share		$ 43.63	$ 34.65	$ 42.25
Stock Repurchased and Retired During Period, Value		$ 43,658	$ 71,669	$ 115,571
Dividends, Common Stock, Cash	$ 25,208		$ 76,028	$ 25,684
Common Stock, Dividends, Per Share, Cash Paid	$ 0.25
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation	14,398	33,031	164,564	209,183
Treasury Stock Acquired, Average Cost Per Share	$ 35.73	$ 46.33	$ 50.86	$ 45.78
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period			136,334
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense	$ 1,800	$ 1,600	$ 5,300	$ 4,500
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Granted, Value, Share-based Payment Arrangement, before Forfeiture	0		22,300
Share-based Payment Arrangement, Expense	4,500	4,000	15,300	13,700
Executive Officer [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense	300	500	900	1,500
Retained Earnings [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Repurchased and Retired During Period, Value		33,733	59,335	46,200
Dividends, Common Stock, Cash	$ 25,208	$ 25,684	$ 76,028	$ 25,684

Stockholders' Equity Common Sto

Stockholders' Equity Common Stock Repurchase (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Repurchase Program, Authorized Amount		$ 250,000
Stock Repurchased and Retired During Period, Shares	1,000,000	2,066,479	2,733,603
Weighted Average Selling Price Per Share	$ 43.63	$ 34.65	$ 42.25
Stock Repurchased and Retired During Period, Value	$ (43,658)	$ (71,669)	$ (115,571)
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Repurchased and Retired During Period, Shares	1,000,000	2,066,000	2,734,000

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income - Summary of Changes in Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 73,677	$ 26,381	$ 25,008	$ 33,622
Other comprehensive income before reclassifications	(4,908)	(11,594)	(53,751)	(71,597)
Amounts reclassified from accumulated other comprehensive income	0	(2,376)	(174)	(2,376)
Net other comprehensive income	(4,908)	(9,218)	(53,577)	(69,221)
Ending balance	78,585	35,599	78,585	35,599
Unrealized holding gains (losses) on AFS
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	66,809	19,709	21,399	47,591
Other comprehensive income before reclassifications	(7,592)	(11,014)	(53,176)	(78,314)
Amounts reclassified from accumulated other comprehensive income	0	(2,232)	(174)	(2,232)
Net other comprehensive income	(7,592)	(8,782)	(53,002)	(76,082)
Ending balance	74,401	28,491	74,401	28,491
Accumulated Gain (Loss), Financial Liability, Fair Value Option, Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	7,181	6,171	3,629	13,433
Other comprehensive income before reclassifications	(2,681)	(598)	(871)	(6,664)
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Net other comprehensive income	(2,681)	(598)	(871)	(6,664)
Ending balance	4,500	6,769	4,500	6,769
Impairment loss on securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	0	144	0	144
Other comprehensive income before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income	0	(144)	0	(144)
Net other comprehensive income	0	(144)	0	(144)
Ending balance	0	0	0	0
Supplemental Employee Retirement Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	313	357	20	392
Other comprehensive income before reclassifications	(3)	(18)	(296)	(53)
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Net other comprehensive income	(3)	(18)	(296)	(53)
Ending balance	$ 316	$ 339	$ 316	$ 339

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income - Schedule of Reclassifications Out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Realized gains on sales of investment securities	$ 0	$ 3,152	$ 230	$ 3,152
Amount reclassified from accumulated other comprehensive income	0	(776)	(56)	(776)
Amount reclassified from accumulated other comprehensive income	$ 0	$ 2,376	$ 174	$ 2,376

Derivatives and Hedging Fair Va

Derivatives and Hedging Fair Value of Derivative Contracts (Detail) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value		$ 702	$ 125	$ 315
Derivative Liability, Fair Value		643	99	251
Derivative, Notional Amount		42,439	9,643	18,261
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value		242	81	124
Derivative Liability, Fair Value		242	81	124
Derivative, Notional Amount		3,517	2,932	2,932
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value		460	44	191
Derivative Liability, Fair Value		401	18	127
Derivative, Notional Amount		38,922	6,711	15,329
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value		3,417	1,778	0
Derivative Liability, Fair Value		92,352	55,471	63,970
Notional Amount, Netting Adjustments	[1]	0	0	0
Derivative Netting Adjustments	[1]	0	21	0
Derivative, Notional Amount		692,348	862,952	865,321
Positive NPVs		3,417	1,757	0
Negative NPVs		92,352	55,450	63,970
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value		3,417	1,778	0
Derivative Liability, Fair Value		92,352	55,471	63,970
Derivative, Notional Amount		$ 692,348	$ 862,952	$ 865,321
[1]	Netting adjustments represent the amounts recorded to convert the Company's derivative balances from a gross basis to a net basis in accordance with the applicable accounting guidance.

Derivatives and Hedging Largest

Derivatives and Hedging Largest Exposure to Individual Counterparty (Detail) - Individual Counterparty - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Largest gross exposure (positive derivative NPV) to an individual counterparty	$ 3,417	$ 1,757	$ 0
Collateral posted by this counterparty	0	1,610	0
Negative derivative NPV with this counterparty	0	0	0
Collateral pledged to this counterparty	0	0	0
Net exposure after netting adjustments and collateral	$ 3,417	$ 147	$ 0

Derivatives and Hedging Additio

Derivatives and Hedging Additional Information (Detail) - USD ($)		Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Derivative [Line Items]
Hedged Asset, Fair Value Hedge		$ 596,505,000	$ 578,063,000
Fair Value Hedge Assets, Loans	[1]	92,352,000	53,292,000
Hedged Liability, Fair Value Hedge		(323,386,000)	(319,197,000)
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	[1]	(3,417,000)	401,000
Derivative, Collateral, Right to Reclaim Securities		14,600,000	29,200,000	$ 31,000,000
Subordinated Debentures Maturing July 2025 [Member] | Subordinated Debt [Member]
Derivative [Line Items]
Debt Instrument, Face Amount		150,000,000
Subordinated Debentures Maturing July 2056 [Member] | Subordinated Debt [Member]
Derivative [Line Items]
Debt Instrument, Face Amount		175,000,000
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Liability, Fair Value		92,352,000	55,471,000	63,970,000
Negative NPVs		$ 92,352,000	$ 55,450,000	$ 63,970,000
[1]	Included in the carrying value of the hedged assets/(liabilities).

Earnings per Share (Details)

Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Basic	99,850	102,041	100,322	103,024
Weighted Average Number Diluted Shares Outstanding Adjustment	209	410	252	444
Diluted	100,059	102,451	100,574	103,468
Net income available to common shareholders	$ 135,769	$ 127,375	$ 313,005	$ 371,107
Earnings (loss) per share - basic	$ 1.36	$ 1.25	$ 3.12	$ 3.60
Earnings (loss) per share - diluted	$ 1.36	$ 1.24	$ 3.11	$ 3.59
Anti-dilutive stock options outstanding that were not included in computation of diluted earnings per common share			0

Income Taxes Additional Informa

Income Taxes Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Effective Income Tax Rate Reconciliation, Percent	18.50%	18.30%	18.05%	17.52%
Deferred Income Tax Assets, Net	$ 46,645		$ 46,645		$ 18,025
Increase (Decrease) in Deferred Income Taxes			28,600
Operating Loss Carryforwards, Valuation Allowance	0		0
Investments in LIHTC and renewable energy	414,305		414,305		409,365
Investment-related Liabilities	161,500		161,500		$ 191,000
Amortization of tax credit investments	14,500	$ 13,000	34,244	$ 33,551
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	44,600		44,600
Deferred Tax Assets, Operating Loss Carryforwards	5,200		5,200
ARIZONA
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	700		700
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards	$ 100		$ 100

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019	Jan. 01, 2020
Loss Contingencies [Line Items]
Letters of credit expiration period	1 year
Off-Balance Sheet, Credit Loss, Liability	$ 44,400	$ 8,955
Percentage of first liens initial loan to value ratio	75.00%
Percentage Of Commercial Real Estate Loans Occupied By Owners	29.00%	31.00%
Commercial Real Estate Portfolio Segment [Member] | Loans Receivable [Member] | Credit Concentration Risk [Member]
Loss Contingencies [Line Items]
Percent of commercial real estate related loans	38.00%	45.00%
Unfunded Loan Commitment [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual	$ 44,400	$ 9,000
Cumulative Effect, Period of Adoption, Adjustment [Member]
Loss Contingencies [Line Items]
Off-Balance Sheet, Credit Loss, Liability			$ 15,089

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Contractual Amounts for Unfunded Commitments and Letters of Credit (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Other Commitments [Line Items]
Total amount	$ 8,819,069	$ 8,827,108
Percentage Of Commercial Real Estate Loans Occupied By Owners	29.00%	31.00%
Commitments to extend credit [Member]
Other Commitments [Line Items]
Unsecured Loan Commitments	$ 1,046,504	$ 895,175
Total amount	8,379,196	8,348,421
Credit card guarantees [Member]
Other Commitments [Line Items]
Total amount	283,703	302,909
Standby letters of credit [Member]
Other Commitments [Line Items]
Total amount	156,170	175,778
Unsecured Letters Of Credit	$ 9,513	$ 5,850
Commercial Real Estate Portfolio Segment [Member] | Credit Concentration Risk [Member] | Loans Receivable [Member]
Other Commitments [Line Items]
Concentration Risk, Percentage	38.00%	45.00%

Commitments and Contingencies L

Commitments and Contingencies Lease Commitments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Lease, Cost	$ 3.9	$ 3.2	$ 10.9	$ 9.5
Lessee, operating lease, other cost	1	1	2.9	3
Other Commitments [Line Items]
Lease, Cost	3.9	3.2	10.9	9.5
Lessee, operating lease, other cost	$ 1	$ 1	$ 2.9	$ 3

Fair Value Accounting - Gains a

Fair Value Accounting - Gains and Losses from Fair Value Changes Included in Consolidated Statement of Operations (Detail) $ in Thousands		3 Months Ended			9 Months Ended
		Sep. 30, 2020USD ($)		Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)		Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Subordinated Debt Obligations, Fair Value Disclosure		$ 60,529	[1]		$ 60,529	[1]		$ 61,685	[2]
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, after Tax		$ (2,681)		$ (598)	$ (871)		$ (6,664)
Junior Subordinated Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Measurement Input		0.0365			0.0365			0.0509
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)		$ (3,555)		794	$ 1,156		(8,837)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss)	[3]	$ (3,555)		$ 794	$ 1,156		$ (8,837)
Period of basis point spread					3.42%		3.18%
Percentage of LIBOR					0.23%		1.91%
[1]	Includes only the portion of junior subordinated debt that is recorded at fair value at each reporting period pursuant to the election of FVO treatment.
[2]	Includes only the portion of junior subordinated debt that is recorded at fair value at each reporting period pursuant to the election of FVO treatment.
[3]	Unrealized gains/(losses) attributable to changes in the fair value of junior subordinated debt are recorded as part of OCI, net of tax, and totaled $(2.7) million and $0.6 million for three months ended September 30, 2020 and 2019, respectively, and $0.9 million and $(6.7) million for the nine months ended September 30, 2020 and 2019, respectively.

Fair Value Accounting - Fair Va

Fair Value Accounting - Fair Value of Assets and Liabilities (Detail) - USD ($)		3 Months Ended			9 Months Ended
		Sep. 30, 2020		Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		$ 3,975,225,000	[1]		$ 3,975,225,000	[1]		$ 3,346,310,000	[2]
Investment securities - equity		160,561,000	[1]		160,561,000	[1]		138,701,000	[2]
Subordinated Debt Obligations, Fair Value Disclosure		60,529,000	[3]		60,529,000	[3]		61,685,000	[4]
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		3,975,225,000			3,975,225,000			3,346,310,000
Investment securities - equity		160,561,000			160,561,000			138,701,000
Derivative Liability		92,995,000	[5]		92,995,000	[5]		55,570,000	[6]
Loans Held-for-sale, Fair Value Disclosure		20,764,000			20,764,000			21,803,000
Fair Value, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		25,208,000			25,208,000			32,167,000
Investment securities - equity		134,811,000			134,811,000			138,701,000
Subordinated Debt Obligations, Fair Value Disclosure		0	[3]		0	[3]		0	[4]
Derivative Liability		0	[5]		0	[5]		0	[6]
Loans Held-for-sale, Fair Value Disclosure		0			0			0
Fair Value, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		3,950,017,000			3,950,017,000			3,314,143,000
Investment securities - equity		25,750,000			25,750,000			0
Subordinated Debt Obligations, Fair Value Disclosure		0	[3]		0	[3]		0	[4]
Derivative Liability		92,995,000	[5]		92,995,000	[5]		55,570,000	[6]
Loans Held-for-sale, Fair Value Disclosure		20,764,000			20,764,000			21,803,000
Fair Value, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Investment securities - equity		0			0			0
Subordinated Debt Obligations, Fair Value Disclosure		60,529,000	[3]		60,529,000	[3]		61,685,000	[4]
Derivative Liability		0	[5]		0	[5]		0	[6]
Loans Held-for-sale, Fair Value Disclosure		0			0			0
Fair Value, Recurring [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		1,361,556,000			1,361,556,000			1,412,060,000
Fair Value, Recurring [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		1,361,556,000			1,361,556,000			1,412,060,000
Fair Value, Recurring [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Nontaxable Municipal Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		1,011,023,000			1,011,023,000			554,855,000
Fair Value, Recurring [Member] | Nontaxable Municipal Bonds [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Nontaxable Municipal Bonds [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		1,011,023,000			1,011,023,000			554,855,000
Fair Value, Recurring [Member] | Nontaxable Municipal Bonds [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		1,264,237,000			1,264,237,000			1,129,227,000
Fair Value, Recurring [Member] | Residential Mortgage Backed Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Residential Mortgage Backed Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		1,264,237,000			1,264,237,000			1,129,227,000
Fair Value, Recurring [Member] | Residential Mortgage Backed Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		95,657,000			95,657,000			94,253,000
Fair Value, Recurring [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		95,657,000			95,657,000			94,253,000
Fair Value, Recurring [Member] | Commercial Mortgage Backed Securities Issued By US Government Sponsored Enterprise [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Corporate Bond Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		186,609,000			186,609,000			99,961,000
Fair Value, Recurring [Member] | Corporate Bond Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			5,127,000
Fair Value, Recurring [Member] | Corporate Bond Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		186,609,000			186,609,000			94,834,000
Fair Value, Recurring [Member] | Corporate Bond Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Taxable Municipal Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		22,159,000			22,159,000			7,773,000
Fair Value, Recurring [Member] | Taxable Municipal Bonds [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Taxable Municipal Bonds [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		22,159,000			22,159,000			7,773,000
Fair Value, Recurring [Member] | Taxable Municipal Bonds [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Preferred Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - equity		107,016,000			107,016,000			86,197,000
Fair Value, Recurring [Member] | Preferred Stock [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - equity		107,016,000			107,016,000			86,197,000
Fair Value, Recurring [Member] | Preferred Stock [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - equity		0			0			0
Fair Value, Recurring [Member] | Preferred Stock [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - equity		0			0			0
Fair Value, Recurring [Member] | CRA investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - equity		53,545,000			53,545,000			52,504,000
Fair Value, Recurring [Member] | CRA investments [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - equity		27,795,000			27,795,000			52,504,000
Fair Value, Recurring [Member] | CRA investments [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - equity		25,750,000			25,750,000			0
Fair Value, Recurring [Member] | CRA investments [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - equity		0			0			0
Fair Value, Recurring [Member] | Collateralized Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		8,176,000			8,176,000			10,142,000
Fair Value, Recurring [Member] | Collateralized Debt Obligations [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Collateralized Debt Obligations [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		8,176,000			8,176,000			10,142,000
Fair Value, Recurring [Member] | Collateralized Debt Obligations [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		25,208,000			25,208,000			27,040,000
Fair Value, Recurring [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		25,208,000			25,208,000			27,040,000
Fair Value, Recurring [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale								10,000,000
Fair Value, Recurring [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale								0
Fair Value, Recurring [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale								10,000,000
Fair Value, Recurring [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale								0
Fair Value, Recurring [Member] | US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		600,000			600,000			999,000
Fair Value, Recurring [Member] | US Treasury Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Fair Value, Recurring [Member] | US Treasury Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		600,000			600,000			999,000
Fair Value, Recurring [Member] | US Treasury Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Reported Value Measurement [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		3,975,225,000			3,975,225,000			3,346,310,000
Investment securities - equity		160,561,000			160,561,000			138,701,000
Derivative Liability		92,995,000			92,995,000			55,570,000
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		3,975,225,000			3,975,225,000			3,346,310,000
Investment securities - equity		160,561,000			160,561,000			138,701,000
Derivative Liability		92,995,000			92,995,000			55,570,000
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		25,208,000			25,208,000			32,167,000
Investment securities - equity		134,811,000			134,811,000			138,701,000
Derivative Liability		0			0			0
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		3,950,017,000			3,950,017,000			3,314,143,000
Investment securities - equity		25,750,000			25,750,000			0
Derivative Liability		92,995,000			92,995,000			55,570,000
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale		0			0			0
Investment securities - equity		0			0			0
Derivative Liability		0			0			0
Junior Subordinated Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)		(3,555,000)		$ 794,000	1,156,000		$ (8,837,000)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss)	[7]	(3,555,000)		$ 794,000	1,156,000		$ (8,837,000)
Junior Subordinated Debt [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Subordinated Debt Obligations, Fair Value Disclosure		$ 60,529,000			$ 60,529,000			$ 61,685,000
[1]	Where ratings differ, the Company uses an average of the available ratings by major credit agencies.
[2]	Where ratings differ, the Company uses an average of the available ratings by major credit agencies.
[3]	Includes only the portion of junior subordinated debt that is recorded at fair value at each reporting period pursuant to the election of FVO treatment.
[4]	Includes only the portion of junior subordinated debt that is recorded at fair value at each reporting period pursuant to the election of FVO treatment.
[5]	Derivative assets and liabilities relate primarily to interest rate swaps, see "Note 8. Derivatives and Hedging Activities." In addition, the carrying value of loans is increased by $92,352 and the net carrying value of subordinated debt is increased by $3,417 as of September 30, 2020 for the effective portion of the hedge, which relates to the fair value of the hedges put in place to mitigate against fluctuations in interest rates.
[6]	Derivative assets and liabilities relate primarily to interest rate swaps, see "Note 8. Derivatives and Hedging Activities." In addition, the carrying value of loans is increased by $53,292 and the net carrying value of subordinated debt is decreased by $401 as of December 31, 2019 for the effective portion of the hedge, which relates to the fair value of the hedges put in place to mitigate against fluctuations in interest rates.
[7]	Unrealized gains/(losses) attributable to changes in the fair value of junior subordinated debt are recorded as part of OCI, net of tax, and totaled $(2.7) million and $0.6 million for three months ended September 30, 2020 and 2019, respectively, and $0.9 million and $(6.7) million for the nine months ended September 30, 2020 and 2019, respectively.

Fair Value Accounting - Change

Fair Value Accounting - Change in Level 3 Liabilities Measured at Fair Value on Recurring Basis (Detail) $ in Thousands		3 Months Ended			9 Months Ended			12 Months Ended
		Sep. 30, 2020USD ($)		Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)		Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, after Tax		$ 2,681		$ 598	$ 871		$ 6,664
Junior subordinated debt		60,529	[1]		60,529	[1]		$ 61,685	[2]
Fair Value, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Junior subordinated debt		60,529	[1]		$ 60,529	[1]		$ 61,685	[2]
Loans and Finance Receivables [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description					Discounted cash flow method			Discounted cash flow method
Other Assets [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description					Collateral method			Collateral method
Junior Subordinated Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss)	[3]	$ (3,555)		794	$ 1,156		$ (8,837)
Debt Instrument, Measurement Input		0.0365			0.0365			0.0509
Junior Subordinated Debt [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Junior subordinated debt		$ 60,529			$ 60,529			$ 61,685
Fair Value Measurements, Valuation Processes, Description					Implied credit rating of the Company		Implied credit rating of the Company
Junior Subordinated Debt [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning balance		(56,974)		58,315	$ (61,685)		$ (48,684)	(48,684)
Closing balance		$ (60,529)		$ (57,521)	$ (60,529)		$ (57,521)	$ (61,685)
Valuation Technique, Discounted Cash Flow [Member] | Junior Subordinated Debt [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description					Discounted cash flow		Discounted cash flow
Collateral Method [Member] | Loans and Finance Receivables [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description					Collateral method			Collateral method
Third Party Appraisal [Member] | Loans and Finance Receivables [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description					Third party appraisal			Third party appraisal
Third Party Appraisal [Member] | Other Assets [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description					Third party appraisal			Third party appraisal
Discount Rate [Member] | Loans and Finance Receivables [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description					Discount rate			Discount rate
Scheduled Cash Collections [Member] | Loans and Finance Receivables [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description								Scheduled cash collections
Proceeds from Non-Real Estate Collateral [Member] | Loans and Finance Receivables [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description								Proceeds from non-real estate collateral
[1]	Includes only the portion of junior subordinated debt that is recorded at fair value at each reporting period pursuant to the election of FVO treatment.
[2]	Includes only the portion of junior subordinated debt that is recorded at fair value at each reporting period pursuant to the election of FVO treatment.
[3]	Unrealized gains/(losses) attributable to changes in the fair value of junior subordinated debt are recorded as part of OCI, net of tax, and totaled $(2.7) million and $0.6 million for three months ended September 30, 2020 and 2019, respectively, and $0.9 million and $(6.7) million for the nine months ended September 30, 2020 and 2019, respectively.

Fair Value Accounting - Assets

Fair Value Accounting - Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans without specific valuation allowance		$ 95,324
Impaired loans with an allowance recorded	$ (9,600)
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans with an allowance recorded		2,800
Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets acquired through foreclosure	8,591	13,850
Collateral Dependent Loans, Net of Allowance	245,219	110,272
Fair Value, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets acquired through foreclosure	0	0
Collateral Dependent Loans, Net of Allowance	0	0
Fair Value, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets acquired through foreclosure	0	0
Collateral Dependent Loans, Net of Allowance	0	0
Fair Value, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets acquired through foreclosure	8,591	13,850
Collateral Dependent Loans, Net of Allowance	$ 245,219	$ 110,272
Loans and Finance Receivables [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description	Discounted cash flow method	Discounted cash flow method
Other Assets [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description	Collateral method	Collateral method
Collateral Method [Member] | Loans and Finance Receivables [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description	Collateral method	Collateral method
Third Party Appraisal [Member] | Loans and Finance Receivables [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description	Third party appraisal	Third party appraisal
Level 3 Fair Value Measurement Inputs	Costs to sell	Costs to sell
Third Party Appraisal [Member] | Other Assets [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description	Third party appraisal	Third party appraisal
Level 3 Fair Value Measurement Inputs	Costs to sell	Costs to sell
Discount Rate [Member] | Loans and Finance Receivables [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description	Discount rate	Discount rate
Level 3 Fair Value Measurement Inputs	Contractual loan rate	Contractual loan rate
Scheduled Cash Collections [Member] | Loans and Finance Receivables [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description		Scheduled cash collections
Level 3 Fair Value Measurement Inputs		Probability of default
Proceeds from Non-Real Estate Collateral [Member] | Loans and Finance Receivables [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Valuation Processes, Description		Proceeds from non-real estate collateral
Level 3 Fair Value Measurement Inputs		Loss given default

Fair Value Accounting - Estimat

Fair Value Accounting - Estimated Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2020		Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Repossessed Assets	$ 8,600		$ 13,900
Financial assets
Debt Securities, Held-to-maturity	504,477		485,107
Available-for-sale Securities	3,975,225	[1]	3,346,310	[2]
Investment securities - equity	160,561	[1]	138,701	[2]
Loans, net	25,682,694		20,933,696
Accrued Investment Income Receivable	1,800
Financial liabilities
Deposits	28,843,396		22,796,493
Customer repurchase agreements	19,688		16,675
Junior subordinated debt	60,529	[3]	61,685	[4]
Fair Value, Nonrecurring [Member] | Reported Value Measurement [Member]
Financial assets
Debt Securities, Held-to-maturity	504,477		485,107
Loans, net	25,703,458		20,955,499
Financial liabilities
Deposits	28,843,396		22,796,493
Junior subordinated debt	618,772		393,563
Fair Value, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member]
Financial assets
Debt Securities, Held-to-maturity	548,140		516,261
Loans, net	26,107,177		21,256,462
Financial liabilities
Deposits	28,850,576		22,813,265
Junior subordinated debt	638,936		406,790
Fair Value, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member] | Level 1 [Member]
Financial assets
Debt Securities, Held-to-maturity	0		0
Loans, net	0		0
Financial liabilities
Deposits	0		0
Junior subordinated debt	0		0
Fair Value, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member] | Level 2 [Member]
Financial assets
Debt Securities, Held-to-maturity	548,140		516,261
Loans, net	0		0
Financial liabilities
Deposits	28,850,576		22,813,265
Junior subordinated debt	566,308		332,635
Fair Value, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member] | Level 3 [Member]
Financial assets
Debt Securities, Held-to-maturity	0		0
Loans, net	26,107,177		21,256,462
Financial liabilities
Deposits	0		0
Junior subordinated debt	72,628		74,155
Fair Value, Recurring [Member]
Financial assets
Available-for-sale Securities	3,975,225		3,346,310
Investment securities - equity	160,561		138,701
Derivative Asset	4,119	[5]	1,903	[6]
Financial liabilities
Derivative Liability	92,995	[5]	55,570	[6]
Fair Value, Recurring [Member] | Level 1 [Member]
Financial assets
Available-for-sale Securities	25,208		32,167
Investment securities - equity	134,811		138,701
Derivative Asset	0	[5]	0	[6]
Financial liabilities
Junior subordinated debt	0	[3]	0	[4]
Derivative Liability	0	[5]	0	[6]
Fair Value, Recurring [Member] | Level 2 [Member]
Financial assets
Available-for-sale Securities	3,950,017		3,314,143
Investment securities - equity	25,750		0
Derivative Asset	4,119	[5]	1,903	[6]
Financial liabilities
Junior subordinated debt	0	[3]	0	[4]
Derivative Liability	92,995	[5]	55,570	[6]
Fair Value, Recurring [Member] | Level 3 [Member]
Financial assets
Available-for-sale Securities	0		0
Investment securities - equity	0		0
Derivative Asset	0	[5]	0	[6]
Financial liabilities
Junior subordinated debt	60,529	[3]	61,685	[4]
Derivative Liability	0	[5]	0	[6]
Fair Value, Recurring [Member] | Reported Value Measurement [Member]
Financial assets
Available-for-sale Securities	3,975,225		3,346,310
Investment securities - equity	160,561		138,701
Derivative Asset	4,119		1,903
Accrued Investment Income Receivable	140,827		108,694
Financial liabilities
Customer repurchase agreements	19,688		16,675
Derivative Liability	92,995		55,570
Interest Payable, Current	15,666		24,661
Fair Value, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial assets
Available-for-sale Securities	3,975,225		3,346,310
Investment securities - equity	160,561		138,701
Derivative Asset	4,119		1,903
Accrued Investment Income Receivable	140,827		108,694
Financial liabilities
Customer repurchase agreements	19,688		16,675
Derivative Liability	92,995		55,570
Interest Payable, Current	15,666		24,661
Fair Value, Recurring [Member] | Estimate of Fair Value Measurement [Member] | Level 1 [Member]
Financial assets
Available-for-sale Securities	25,208		32,167
Investment securities - equity	134,811		138,701
Derivative Asset	0		0
Accrued Investment Income Receivable	0		0
Financial liabilities
Customer repurchase agreements	0		0
Derivative Liability	0		0
Interest Payable, Current	0		0
Fair Value, Recurring [Member] | Estimate of Fair Value Measurement [Member] | Level 2 [Member]
Financial assets
Available-for-sale Securities	3,950,017		3,314,143
Investment securities - equity	25,750		0
Derivative Asset	4,119		1,903
Accrued Investment Income Receivable	140,827		108,694
Financial liabilities
Customer repurchase agreements	19,688		16,675
Derivative Liability	92,995		55,570
Interest Payable, Current	15,666		24,661
Fair Value, Recurring [Member] | Estimate of Fair Value Measurement [Member] | Level 3 [Member]
Financial assets
Available-for-sale Securities	0		0
Investment securities - equity	0		0
Derivative Asset	0		0
Accrued Investment Income Receivable	0		0
Financial liabilities
Customer repurchase agreements	0		0
Derivative Liability	0		0
Interest Payable, Current	$ 0		$ 0
[1]	Where ratings differ, the Company uses an average of the available ratings by major credit agencies.
[2]	Where ratings differ, the Company uses an average of the available ratings by major credit agencies.
[3]	Includes only the portion of junior subordinated debt that is recorded at fair value at each reporting period pursuant to the election of FVO treatment.
[4]	Includes only the portion of junior subordinated debt that is recorded at fair value at each reporting period pursuant to the election of FVO treatment.
[5]	Derivative assets and liabilities relate primarily to interest rate swaps, see "Note 8. Derivatives and Hedging Activities." In addition, the carrying value of loans is increased by $92,352 and the net carrying value of subordinated debt is increased by $3,417 as of September 30, 2020 for the effective portion of the hedge, which relates to the fair value of the hedges put in place to mitigate against fluctuations in interest rates.
[6]	Derivative assets and liabilities relate primarily to interest rate swaps, see "Note 8. Derivatives and Hedging Activities." In addition, the carrying value of loans is increased by $53,292 and the net carrying value of subordinated debt is decreased by $401 as of December 31, 2019 for the effective portion of the hedge, which relates to the fair value of the hedges put in place to mitigate against fluctuations in interest rates.

Fair Value Accounting - Additio

Fair Value Accounting - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans with an allowance recorded			$ 20,979
Impaired loans with an allowance recorded			(2,776)
Other assets acquired through foreclosure	$ 8,600		$ 13,900
Common Stock, Shares, Issued	102,993,777		104,527,544
Junior Subordinated Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Period of basis point spread	3.42%	3.18%
Percentage of LIBOR	0.23%	1.91%
Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral Dependent Loans, Net of Allowance	$ 245,219		$ 110,272
Fair Value, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral Dependent Loans, Net of Allowance	$ 245,219		$ 110,272

Segments - Operating Segment In

Segments - Operating Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019		Jun. 30, 2020	Jan. 01, 2020	[1]	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Operating Statistics [Line Items]
Service charges and fees	$ 5,913	$ 5,888	$ 17,447		$ 17,121
Cash, Cash Equivalents and Investment Securities	6,119,800		6,119,800							$ 4,471,200
Loans and Leases Receivable, Net of Deferred Income	25,993,254		25,993,254							21,101,493
Less: Allowance for credit losses	(310,560)		(310,560)							(167,797)
Loans and Leases Receivable Including Held for Sale, Net	25,703,500		25,703,500							20,955,500
Other Repossessed Assets	8,600		8,600							13,900
Goodwill and intangible assets, net	298,987		298,987							297,608
Other Assets Segment	1,204,600		1,204,600							1,083,700
Assets	33,335,506		33,335,506							26,821,948
Deposits	28,843,396		28,843,396							22,796,493
Other borrowings	628,800		628,800							393,600
Other Liabilities Segment	639,300		639,300							615,100
Total liabilities	30,111,460		30,111,460							23,805,200
Stockholders' equity	3,224,046	2,923,063	3,224,046		2,923,063		$ 3,102,414	$ 2,991,801		3,016,748	$ 2,851,264	$ 2,613,734
Liabilities and Equity	33,335,506		33,335,506							26,821,948
Excess Funds Provided by (Used in) Segment Basis	0		0							0
Net interest income	284,738	266,422	852,158		768,439
Provision for Loan, Lease, and Other Losses	(14,661)	(3,803)	(157,837)		(15,303)
Net interest income (loss) after provision for credit losses	270,077	262,619	694,321		753,136
Total non-interest income	20,606	19,441	46,985		49,069
Non-interest expense	(124,092)	(126,152)	(359,372)		(352,279)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	166,591	155,908	381,934		449,926
Income tax expense (benefit)	30,822	28,533	68,929		78,819
Net income	135,769	127,375	313,005		371,107
Debit and credit card interchange fees	1,597	1,977	3,942	[2]	5,830
Success fees (2)	38	605	423	[3]	1,125
Other income	69	80	231		187
Total revenue from contracts with customers	7,617	8,550	22,043		24,263
Revenues outside the scope of ASC 606 (3)	12,989	10,891	24,942	[4]	24,806
Operating Segments [Member] | HOA Services [Member]
Operating Statistics [Line Items]
Service charges and fees	114	77	308		241
Cash, Cash Equivalents and Investment Securities	0		0							0
Loans and Leases Receivable, Net of Deferred Income	280,000		280,000							237,200
Less: Allowance for credit losses	(2,300)		(2,300)							(2,000)
Loans and Leases Receivable Including Held for Sale, Net	277,700		277,700							235,200
Other Repossessed Assets	0		0							0
Goodwill and intangible assets, net	0		0							0
Other Assets Segment	5,400		5,400							1,200
Assets	283,100		283,100							236,400
Deposits	3,697,900		3,697,900							3,210,100
Other borrowings	0		0							0
Other Liabilities Segment	(2,700)		(2,700)							1,800
Total liabilities	3,695,200		3,695,200							3,211,900
Stockholders' equity	104,900		104,900							84,500
Liabilities and Equity	3,800,100		3,800,100							3,296,400
Excess Funds Provided by (Used in) Segment Basis	3,517,000		3,517,000							3,060,000
Net interest income	22,184	21,974	67,740		64,520
Provision for Loan, Lease, and Other Losses	(138)	(60)	(2,198)		(27)
Net interest income (loss) after provision for credit losses	22,322	21,914	69,938		64,493
Total non-interest income	134	84	350		268
Non-interest expense	(9,896)	(9,769)	(29,965)		(27,777)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	12,560	12,229	40,323		36,984
Income tax expense (benefit)	2,889	2,813	9,361		8,506
Net income	9,671	9,416	30,962		28,478
Debit and credit card interchange fees	12	12	27	[5]	31	[6]
Success fees (2)	0	0	0	[7]	0	[8]
Other income	2	(3)	4		2
Total revenue from contracts with customers	128	86	339		274
Revenues outside the scope of ASC 606 (3)	6	(2)	11	[9]	(6)	[10]
Operating Segments [Member] | Public and Non-Profit Finance [Member]
Operating Statistics [Line Items]
Service charges and fees	0	0	0		0
Cash, Cash Equivalents and Investment Securities	0		0							0
Loans and Leases Receivable, Net of Deferred Income	1,686,700		1,686,700							1,635,600
Less: Allowance for credit losses	(17,900)		(17,900)							(13,700)
Loans and Leases Receivable Including Held for Sale, Net	1,668,800		1,668,800							1,621,900
Other Repossessed Assets	0		0							0
Goodwill and intangible assets, net	0		0							0
Other Assets Segment	11,900		11,900							18,300
Assets	1,680,700		1,680,700							1,640,200
Deposits	0		0							100
Other borrowings	0		0							0
Other Liabilities Segment	91,800		91,800							52,900
Total liabilities	91,800		91,800							53,000
Stockholders' equity	130,300		130,300							131,600
Liabilities and Equity	222,100		222,100							184,600
Excess Funds Provided by (Used in) Segment Basis	(1,458,600)		(1,458,600)							(1,455,600)
Net interest income	2,800	3,394	6,351		10,278
Provision for Loan, Lease, and Other Losses	(781)	(191)	(553)		(136)
Net interest income (loss) after provision for credit losses	2,019	3,585	5,798		10,414
Total non-interest income	0	0	0		0
Non-interest expense	(1,724)	(1,845)	(5,114)		(5,683)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	295	1,740	684		4,731
Income tax expense (benefit)	68	400	380		1,088
Net income	227	1,340	304		3,643
Debit and credit card interchange fees	0	0	0	[5]	0	[6]
Success fees (2)	0	0	0	[7]	0	[8]
Other income	0	0	0		0
Total revenue from contracts with customers	0	0	0		0
Revenues outside the scope of ASC 606 (3)	0	0	0	[9]	0	[10]
Operating Segments [Member] | Technology and Innovation [Member]
Operating Statistics [Line Items]
Service charges and fees	963	813	2,707		2,333
Cash, Cash Equivalents and Investment Securities	0		0							0
Loans and Leases Receivable, Net of Deferred Income	2,329,300		2,329,300							1,552,000
Less: Allowance for credit losses	(41,500)		(41,500)							(12,600)
Loans and Leases Receivable Including Held for Sale, Net	2,287,800		2,287,800							1,539,400
Other Repossessed Assets	0		0							0
Goodwill and intangible assets, net	119,300		119,300							119,700
Other Assets Segment	9,200		9,200							7,300
Assets	2,416,300		2,416,300							1,666,400
Deposits	4,646,400		4,646,400							3,771,500
Other borrowings	0		0							0
Other Liabilities Segment	5,400		5,400							100
Total liabilities	4,651,800		4,651,800							3,771,600
Stockholders' equity	397,500		397,500							317,500
Liabilities and Equity	5,049,300		5,049,300							4,089,100
Excess Funds Provided by (Used in) Segment Basis	2,633,000		2,633,000							2,422,700
Net interest income	48,013	33,932	137,436		91,871
Provision for Loan, Lease, and Other Losses	(9,048)	(895)	(25,471)		(2,635)
Net interest income (loss) after provision for credit losses	57,061	33,037	111,965		89,236
Total non-interest income	3,126	5,422	9,247		10,946
Non-interest expense	(11,530)	(12,068)	(36,188)		(33,971)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	48,657	26,391	85,024		66,211
Income tax expense (benefit)	11,191	6,070	19,461		15,229
Net income	37,466	20,321	65,563		50,982
Debit and credit card interchange fees	0	0	0	[5]	0	[6]
Success fees (2)	38	605	279	[7]	1,125	[8]
Other income	0	0	0		4
Total revenue from contracts with customers	1,001	1,418	2,986		3,462
Revenues outside the scope of ASC 606 (3)	2,125	4,004	6,261	[9]	7,484	[10]
Operating Segments [Member] | HFF Loan Portfolio [Member]
Operating Statistics [Line Items]
Service charges and fees	0	0	0		0
Cash, Cash Equivalents and Investment Securities	0		0							0
Loans and Leases Receivable, Net of Deferred Income	2,099,300		2,099,300							1,930,800
Less: Allowance for credit losses	(40,700)		(40,700)							(12,600)
Loans and Leases Receivable Including Held for Sale, Net	2,058,600		2,058,600							1,918,200
Other Repossessed Assets	0		0							0
Goodwill and intangible assets, net	100		100							100
Other Assets Segment	33,400		33,400							8,800
Assets	2,092,100		2,092,100							1,927,100
Deposits	0		0							0
Other borrowings	0		0							0
Other Liabilities Segment	900		900							0
Total liabilities	900		900							0
Stockholders' equity	167,500		167,500							158,500
Liabilities and Equity	168,400		168,400							158,500
Excess Funds Provided by (Used in) Segment Basis	(1,923,700)		(1,923,700)							(1,768,600)
Net interest income	12,536	12,845	39,442		39,279
Provision for Loan, Lease, and Other Losses	(2,200)	(1,956)	(27,530)		(3,587)
Net interest income (loss) after provision for credit losses	10,336	10,889	11,912		35,692
Total non-interest income	0	0	0		0
Non-interest expense	(2,596)	(2,197)	(7,353)		(6,757)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	7,740	8,692	4,559		28,935
Income tax expense (benefit)	1,780	1,999	893		6,655
Net income	5,960	6,693	3,666		22,280
Debit and credit card interchange fees	0	0	0	[5]	0	[6]
Success fees (2)	0	0	0	[7]	0	[8]
Other income	0	0	0		0
Total revenue from contracts with customers	0	0	0		0
Revenues outside the scope of ASC 606 (3)	0	0	0	[9]	0	[10]
Operating Segments [Member] | Other National Business Lines [Member]
Operating Statistics [Line Items]
Service charges and fees	3	1	6		3
Cash, Cash Equivalents and Investment Securities	26,600		26,600							10,100
Loans and Leases Receivable, Net of Deferred Income	8,451,800		8,451,800							6,098,700
Less: Allowance for credit losses	(63,900)		(63,900)							(49,300)
Loans and Leases Receivable Including Held for Sale, Net	8,387,900		8,387,900							6,049,400
Other Repossessed Assets	100		100							0
Goodwill and intangible assets, net	2,500		2,500							0
Other Assets Segment	110,300		110,300							64,300
Assets	8,527,400		8,527,400							6,123,800
Deposits	61,400		61,400							36,900
Other borrowings	0		0							0
Other Liabilities Segment	56,800		56,800							2,800
Total liabilities	118,200		118,200							39,700
Stockholders' equity	673,200		673,200							494,300
Liabilities and Equity	791,400		791,400							534,000
Excess Funds Provided by (Used in) Segment Basis	(7,736,000)		(7,736,000)							(5,589,800)
Net interest income	46,582	32,935	128,096		88,212
Provision for Loan, Lease, and Other Losses	(2,706)	(1,210)	(4,737)		(6,558)
Net interest income (loss) after provision for credit losses	49,288	31,725	132,833		81,654
Total non-interest income	2,924	1,708	4,108		3,915
Non-interest expense	(12,335)	(11,320)	(35,674)		(31,729)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	39,877	22,113	101,267		53,840
Income tax expense (benefit)	9,172	5,086	23,083		12,383
Net income	30,705	17,027	78,184		41,457
Debit and credit card interchange fees	0	0	0	[5]	0	[6]
Success fees (2)	0	0	0	[7]	0	[8]
Other income	35	35	125		109
Total revenue from contracts with customers	38	36	131		112
Revenues outside the scope of ASC 606 (3)	2,886	1,672	3,977	[9]	3,803	[10]
Reportable Geographical Components [Member] | ARIZONA
Operating Statistics [Line Items]
Service charges and fees	1,188	1,226	3,525		3,525
Cash, Cash Equivalents and Investment Securities	1,500		1,500							1,800
Loans and Leases Receivable, Net of Deferred Income	4,388,100		4,388,100							3,847,900
Less: Allowance for credit losses	(57,000)		(57,000)							(31,600)
Loans and Leases Receivable Including Held for Sale, Net	4,331,100		4,331,100							3,816,300
Other Repossessed Assets	0		0							0
Goodwill and intangible assets, net	0		0							0
Other Assets Segment	47,800		47,800							48,600
Assets	4,380,400		4,380,400							3,866,700
Deposits	8,541,500		8,541,500							5,384,700
Other borrowings	0		0							0
Other Liabilities Segment	28,700		28,700							17,800
Total liabilities	8,570,200		8,570,200							5,402,500
Stockholders' equity	576,400		576,400							453,600
Liabilities and Equity	9,146,600		9,146,600							5,856,100
Excess Funds Provided by (Used in) Segment Basis	4,766,200		4,766,200							1,989,400
Net interest income	83,492	68,828	229,701		183,772
Provision for Loan, Lease, and Other Losses	(9,830)	(103)	(46,623)		(1,705)
Net interest income (loss) after provision for credit losses	73,662	68,725	183,078		182,067
Total non-interest income	1,771	1,821	4,943		5,050
Non-interest expense	(17,644)	(27,241)	(58,674)		(72,183)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	57,789	43,305	129,347		114,934
Income tax expense (benefit)	14,447	10,826	32,207		28,733
Net income	43,342	32,479	97,140		86,201
Debit and credit card interchange fees	426	451	990	[2]	1,125
Success fees (2)	0	0	0	[3]	0
Other income	8	8	20		8
Total revenue from contracts with customers	1,622	1,685	4,535		4,658
Revenues outside the scope of ASC 606 (3)	149	136	408	[4]	392
Reportable Geographical Components [Member] | NEVADA
Operating Statistics [Line Items]
Service charges and fees	1,826	2,036	5,572		5,980
Cash, Cash Equivalents and Investment Securities	8,800		8,800							9,000
Loans and Leases Receivable, Net of Deferred Income	2,612,200		2,612,200							2,252,500
Less: Allowance for credit losses	(36,400)		(36,400)							(18,000)
Loans and Leases Receivable Including Held for Sale, Net	2,575,800		2,575,800							2,234,500
Other Repossessed Assets	8,500		8,500							13,000
Goodwill and intangible assets, net	23,200		23,200							23,200
Other Assets Segment	60,100		60,100							59,400
Assets	2,676,400		2,676,400							2,339,100
Deposits	4,733,900		4,733,900							4,350,100
Other borrowings	0		0							0
Other Liabilities Segment	18,800		18,800							11,900
Total liabilities	4,752,700		4,752,700							4,362,000
Stockholders' equity	343,700		343,700							301,000
Liabilities and Equity	5,096,400		5,096,400							4,663,000
Excess Funds Provided by (Used in) Segment Basis	2,420,000		2,420,000							2,323,900
Net interest income	46,625	40,565	139,328		119,191
Provision for Loan, Lease, and Other Losses	(8,548)	(62)	(25,015)		(166)
Net interest income (loss) after provision for credit losses	38,077	40,627	114,313		119,025
Total non-interest income	2,391	2,677	7,355		7,926
Non-interest expense	(15,800)	(15,211)	(44,414)		(45,099)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	24,668	28,093	77,254		81,852
Income tax expense (benefit)	5,180	5,899	16,164		17,189
Net income	19,488	22,194	61,090		64,663
Debit and credit card interchange fees	306	440	770	[2]	1,200
Success fees (2)	0	0	0	[3]	0
Other income	6	14	15		8
Total revenue from contracts with customers	2,138	2,490	6,357		7,188
Revenues outside the scope of ASC 606 (3)	253	187	998	[4]	738
Reportable Geographical Components [Member] | Southern California [Member]
Operating Statistics [Line Items]
Service charges and fees	889	770	2,466		2,218
Cash, Cash Equivalents and Investment Securities	1,800		1,800							2,300
Loans and Leases Receivable, Net of Deferred Income	2,376,700		2,376,700							2,253,900
Less: Allowance for credit losses	(31,500)		(31,500)							(18,300)
Loans and Leases Receivable Including Held for Sale, Net	2,345,200		2,345,200							2,235,600
Other Repossessed Assets	0		0							900
Goodwill and intangible assets, net	0		0							0
Other Assets Segment	16,200		16,200							15,000
Assets	2,363,200		2,363,200							2,253,800
Deposits	3,502,000		3,502,000							2,585,300
Other borrowings	0		0							0
Other Liabilities Segment	8,600		8,600							1,200
Total liabilities	3,510,600		3,510,600							2,586,500
Stockholders' equity	281,200		281,200							253,300
Liabilities and Equity	3,791,800		3,791,800							2,839,800
Excess Funds Provided by (Used in) Segment Basis	1,428,600		1,428,600							586,000
Net interest income	35,656	33,630	104,348		95,751
Provision for Loan, Lease, and Other Losses	(5,213)	(189)	(23,750)		(611)
Net interest income (loss) after provision for credit losses	30,443	33,819	80,598		95,140
Total non-interest income	1,186	1,079	3,269		3,054
Non-interest expense	(14,020)	(15,185)	(43,216)		(44,890)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	17,609	19,713	40,651		53,304
Income tax expense (benefit)	4,930	5,520	11,241		14,925
Net income	12,679	14,193	29,410		38,379
Debit and credit card interchange fees	167	229	401	[2]	596
Success fees (2)	0	0	0	[3]	0
Other income	(1)	4	(6)		6
Total revenue from contracts with customers	1,055	1,003	2,861		2,820
Revenues outside the scope of ASC 606 (3)	131	76	408	[4]	234
Reportable Geographical Components [Member] | Northern California [Member]
Operating Statistics [Line Items]
Service charges and fees	930	965	2,863		2,821
Cash, Cash Equivalents and Investment Securities	2,300		2,300							2,200
Loans and Leases Receivable, Net of Deferred Income	1,785,800		1,785,800							1,311,200
Less: Allowance for credit losses	(19,300)		(19,300)							(9,700)
Loans and Leases Receivable Including Held for Sale, Net	1,766,500		1,766,500							1,301,500
Other Repossessed Assets	0		0							0
Goodwill and intangible assets, net	153,900		153,900							154,600
Other Assets Segment	20,100		20,100							19,800
Assets	1,942,800		1,942,800							1,478,100
Deposits	2,741,100		2,741,100							2,373,600
Other borrowings	0		0							0
Other Liabilities Segment	20,000		20,000							15,900
Total liabilities	2,761,100		2,761,100							2,389,500
Stockholders' equity	361,500		361,500							312,500
Liabilities and Equity	3,122,600		3,122,600							2,702,000
Excess Funds Provided by (Used in) Segment Basis	1,179,800		1,179,800							1,223,900
Net interest income	28,353	23,504	85,345		70,533
Provision for Loan, Lease, and Other Losses	(1,856)	(218)	(12,680)		(653)
Net interest income (loss) after provision for credit losses	26,497	23,286	72,665		71,186
Total non-interest income	2,381	1,917	6,450		6,299
Non-interest expense	(12,885)	(12,379)	(38,460)		(38,419)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	15,993	12,824	40,655		39,066
Income tax expense (benefit)	4,478	3,591	11,340		10,939
Net income	11,515	9,233	29,315		28,127
Debit and credit card interchange fees	686	845	1,754	[2]	2,878
Success fees (2)	0	0	144	[3]	0
Other income	18	19	59		43
Total revenue from contracts with customers	1,634	1,829	4,820		5,742
Revenues outside the scope of ASC 606 (3)	747	88	1,630	[4]	557
Corporate & Other
Operating Statistics [Line Items]
Service charges and fees	0	0	0		0
Cash, Cash Equivalents and Investment Securities	6,078,800		6,078,800							4,445,800
Loans and Leases Receivable, Net of Deferred Income	4,100		4,100							3,500
Less: Allowance for credit losses	0		0							0
Loans and Leases Receivable Including Held for Sale, Net	4,100		4,100							3,500
Other Repossessed Assets	0		0							0
Goodwill and intangible assets, net	0		0							0
Other Assets Segment	890,200		890,200							841,000
Assets	6,973,100		6,973,100							5,290,300
Deposits	919,200		919,200							1,084,200
Other borrowings	628,800		628,800							393,600
Other Liabilities Segment	411,000		411,000							510,700
Total liabilities	1,959,000		1,959,000							1,988,500
Stockholders' equity	187,800		187,800							509,900
Liabilities and Equity	2,146,800		2,146,800							2,498,400
Excess Funds Provided by (Used in) Segment Basis	(4,826,300)		(4,826,300)							$ (2,791,900)
Net interest income	(41,503)	(5,185)	(85,629)		5,032
Provision for Loan, Lease, and Other Losses	1,875	197	(3,150)		(803)
Net interest income (loss) after provision for credit losses	(39,628)	(4,988)	(88,779)		4,229
Total non-interest income	6,693	4,733	11,263		11,611
Non-interest expense	(25,662)	(18,937)	(60,314)		(45,771)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	(58,597)	(19,192)	(137,830)		(29,931)
Income tax expense (benefit)	(23,313)	(13,671)	(55,201)		(36,828)
Net income	(35,284)	(5,521)	(82,629)		6,897
Debit and credit card interchange fees	0	0	0	[5]	0	[6]
Success fees (2)	0	0	0	[7]	0	[8]
Other income	1	3	14		7
Total revenue from contracts with customers	1	3	14		7
Revenues outside the scope of ASC 606 (3)	$ 6,692	$ 4,730	$ 11,249	[9]	$ 11,604	[10]
[1]	As adjusted for adoption of ASU 2016-13, Measurement of Credit Losses on Financial Instruments . The cumulative effect of adoption of this guidance at January 1, 2020 resulted in a decrease to retained earnings of $24.9 million due to an increase in the allowance for credit losses. See "Note 1. Summary of Significant Accounting Policies for further discussion."
[2]	Included as part of Card income in the Consolidated Income Statement.
[3]	Included as part of Income from equity investments in the Consolidated Income Statement.
[4]	Amounts are accounted for under separate guidance. Refer to discussion of revenue sources not subject to ASC 606 under the Non-interest income section in "Note 1. Summary of Significant Accounting Policies."
[5]	Included as part of Card income in the Consolidated Income Statement.
[6]	Included as part of Card income in the Consolidated Income Statement.
[7]	Included as part of Income from equity investments in the Consolidated Income Statement.
[8]	Included as part of Income from equity investments in the Consolidated Income Statement.
[9]	Amounts are accounted for under separate guidance. Refer to discussion of revenue sources not subject to ASC 606 under the Non-interest income section in "Note 1. Summary of Significant Accounting Policies."
[10]	Amounts are accounted for under separate guidance. Refer to discussion of revenue sources not subject to ASC 606 under the Non-interest income section in "Note 1. Summary of Significant Accounting Policies."

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019		Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Service charges and fees	$ 5,913	$ 5,888	$ 17,447		$ 17,121
Accounts Receivable, after Allowance for Credit Loss	1,500		1,500				$ 1,600
Debit and credit card interchange fees	1,597	1,977	3,942	[1]	5,830
Success fees (2)	38	605	423	[2]	1,125
Other income	69	80	231		187
Total revenue from contracts with customers	7,617	8,550	22,043		24,263
Revenues outside the scope of ASC 606 (3)	12,989	10,891	24,942	[3]	24,806
Total non-interest income	20,606	19,441	46,985		49,069
Operating Segments [Member] | HOA Services [Member]
Disaggregation of Revenue [Line Items]
Service charges and fees	114	77	308		241
Debit and credit card interchange fees	12	12	27	[4]	31	[5]
Success fees (2)	0	0	0	[6]	0	[7]
Other income	2	(3)	4		2
Total revenue from contracts with customers	128	86	339		274
Revenues outside the scope of ASC 606 (3)	6	(2)	11	[8]	(6)	[9]
Total non-interest income	134	84	350		268
Operating Segments [Member] | Public and Non-Profit Finance [Member]
Disaggregation of Revenue [Line Items]
Service charges and fees	0	0	0		0
Debit and credit card interchange fees	0	0	0	[4]	0	[5]
Success fees (2)	0	0	0	[6]	0	[7]
Other income	0	0	0		0
Total revenue from contracts with customers	0	0	0		0
Revenues outside the scope of ASC 606 (3)	0	0	0	[8]	0	[9]
Total non-interest income	0	0	0		0
Operating Segments [Member] | Technology and Innovation [Member]
Disaggregation of Revenue [Line Items]
Service charges and fees	963	813	2,707		2,333
Debit and credit card interchange fees	0	0	0	[4]	0	[5]
Success fees (2)	38	605	279	[6]	1,125	[7]
Other income	0	0	0		4
Total revenue from contracts with customers	1,001	1,418	2,986		3,462
Revenues outside the scope of ASC 606 (3)	2,125	4,004	6,261	[8]	7,484	[9]
Total non-interest income	3,126	5,422	9,247		10,946
Operating Segments [Member] | HFF Loan Portfolio [Member]
Disaggregation of Revenue [Line Items]
Service charges and fees	0	0	0		0
Debit and credit card interchange fees	0	0	0	[4]	0	[5]
Success fees (2)	0	0	0	[6]	0	[7]
Other income	0	0	0		0
Total revenue from contracts with customers	0	0	0		0
Revenues outside the scope of ASC 606 (3)	0	0	0	[8]	0	[9]
Total non-interest income	0	0	0		0
Operating Segments [Member] | Other National Business Lines [Member]
Disaggregation of Revenue [Line Items]
Service charges and fees	3	1	6		3
Debit and credit card interchange fees	0	0	0	[4]	0	[5]
Success fees (2)	0	0	0	[6]	0	[7]
Other income	35	35	125		109
Total revenue from contracts with customers	38	36	131		112
Revenues outside the scope of ASC 606 (3)	2,886	1,672	3,977	[8]	3,803	[9]
Total non-interest income	2,924	1,708	4,108		3,915
Reportable Geographical Components [Member] | ARIZONA
Disaggregation of Revenue [Line Items]
Service charges and fees	1,188	1,226	3,525		3,525
Debit and credit card interchange fees	426	451	990	[1]	1,125
Success fees (2)	0	0	0	[2]	0
Other income	8	8	20		8
Total revenue from contracts with customers	1,622	1,685	4,535		4,658
Revenues outside the scope of ASC 606 (3)	149	136	408	[3]	392
Total non-interest income	1,771	1,821	4,943		5,050
Reportable Geographical Components [Member] | NEVADA
Disaggregation of Revenue [Line Items]
Service charges and fees	1,826	2,036	5,572		5,980
Debit and credit card interchange fees	306	440	770	[1]	1,200
Success fees (2)	0	0	0	[2]	0
Other income	6	14	15		8
Total revenue from contracts with customers	2,138	2,490	6,357		7,188
Revenues outside the scope of ASC 606 (3)	253	187	998	[3]	738
Total non-interest income	2,391	2,677	7,355		7,926
Reportable Geographical Components [Member] | Southern California [Member]
Disaggregation of Revenue [Line Items]
Service charges and fees	889	770	2,466		2,218
Debit and credit card interchange fees	167	229	401	[1]	596
Success fees (2)	0	0	0	[2]	0
Other income	(1)	4	(6)		6
Total revenue from contracts with customers	1,055	1,003	2,861		2,820
Revenues outside the scope of ASC 606 (3)	131	76	408	[3]	234
Total non-interest income	1,186	1,079	3,269		3,054
Reportable Geographical Components [Member] | Northern California [Member]
Disaggregation of Revenue [Line Items]
Service charges and fees	930	965	2,863		2,821
Debit and credit card interchange fees	686	845	1,754	[1]	2,878
Success fees (2)	0	0	144	[2]	0
Other income	18	19	59		43
Total revenue from contracts with customers	1,634	1,829	4,820		5,742
Revenues outside the scope of ASC 606 (3)	747	88	1,630	[3]	557
Total non-interest income	2,381	1,917	6,450		6,299
Corporate & Other
Disaggregation of Revenue [Line Items]
Service charges and fees	0	0	0		0
Debit and credit card interchange fees	0	0	0	[4]	0	[5]
Success fees (2)	0	0	0	[6]	0	[7]
Other income	1	3	14		7
Total revenue from contracts with customers	1	3	14		7
Revenues outside the scope of ASC 606 (3)	6,692	4,730	11,249	[8]	11,604	[9]
Total non-interest income	$ 6,693	$ 4,733	$ 11,263		$ 11,611
[1]	Included as part of Card income in the Consolidated Income Statement.
[2]	Included as part of Income from equity investments in the Consolidated Income Statement.
[3]	Amounts are accounted for under separate guidance. Refer to discussion of revenue sources not subject to ASC 606 under the Non-interest income section in "Note 1. Summary of Significant Accounting Policies."
[4]	Included as part of Card income in the Consolidated Income Statement.
[5]	Included as part of Card income in the Consolidated Income Statement.
[6]	Included as part of Income from equity investments in the Consolidated Income Statement.
[7]	Included as part of Income from equity investments in the Consolidated Income Statement.
[8]	Amounts are accounted for under separate guidance. Refer to discussion of revenue sources not subject to ASC 606 under the Non-interest income section in "Note 1. Summary of Significant Accounting Policies."
[9]	Amounts are accounted for under separate guidance. Refer to discussion of revenue sources not subject to ASC 606 under the Non-interest income section in "Note 1. Summary of Significant Accounting Policies."

Uncategorized Items - wal-20200

Label	Element	Value	[1]
Retained Earnings [Member]
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	$ 1,655,370,000
Common Stock [Member]
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	$ 10,000
Shares, Issued	us-gaap_SharesIssued	102,524,000
AOCI Attributable to Parent [Member]
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	$ 25,008,000
Treasury Stock [Member]
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	62,728,000
Additional Paid-in Capital [Member]
Stockholders' Equity Attributable to Parent	us-gaap_StockholdersEquity	$ 1,374,141,000
[1]	As adjusted for adoption of ASU 2016-13, Measurement of Credit Losses on Financial Instruments . The cumulative effect of adoption of this guidance at January 1, 2020 resulted in a decrease to retained earnings of $24.9 million due to an increase in the allowance for credit losses. See "Note 1. Summary of Significant Accounting Policies for further discussion."