Columbia Banking System (COLB) 10-Q 5 Nov 20 2020 Q3 Quarterly report Financial data

Document

Document - shares	9 Months Ended
	Sep. 30, 2020	Oct. 31, 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	000-20288
Entity Registrant Name	COLUMBIA BANKING SYSTEM, INC.
Entity Incorporation, State or Country Code	WA
Entity Tax Identification Number	91-1422237
Entity Address, Address Line One	1301 A Street
Entity Address, City or Town	Tacoma
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98402-2156
City Area Code	253
Local Phone Number	305-1900
Title of 12(b) Security	Common Stock, No Par Value
Trading Symbol	COLB
Security Exchange Name	NASDAQ
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		71,605,637
Entity Central Index Key	0000887343
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) shares in Thousands, $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
ASSETS
Cash and due from banks	$ 193,823	$ 223,541
Interest-earning deposits with banks	736,422	24,132
Total cash and cash equivalents	930,245	247,673
Debt securities available for sale at fair value	4,281,720	3,746,142
Equity Securities	13,425	0
FHLB stock at cost	10,280	48,120
Loans held for sale	24,407	17,718
Loans, net of unearned income	9,688,947	8,743,465
Less: Allowance for credit losses	156,968	83,968
Loans, net	9,531,979	8,659,497
Interest receivable	56,718	46,839
Premises and equipment, net	164,049	165,408
OREO	623	552
Goodwill	765,842	765,842
Other intangible assets, net	28,745	35,458
Other assets	425,391	346,275
Total assets	16,233,424	14,079,524
LIABILITIES AND SHAREHOLDERS' EQUITY
Noninterest-bearing	6,897,054	5,328,146
Interest-bearing	6,703,206	5,356,562
Total deposits	13,600,260	10,684,708
FHLB advances	7,427	953,469
Securities sold under agreements to repurchase	26,966	64,437
Subordinated debentures	35,139	35,277
Other liabilities	261,651	181,671
Total liabilities	13,931,443	11,919,562
Commitments and contingent liabilities (Note 10)
Shareholders' equity:
Preferred Stock, Authorized shares	2,000	2,000
Common Stock Authorized shares	115,000	115,000
Common Stock Shares Issued	73,797	73,577
Common Stock Issued value	$ 1,658,203	$ 1,650,753
Common Stock, Shares, Outstanding	71,613	72,124
Retained earnings	$ 537,011	$ 519,676
Accumulated other comprehensive income	$ 177,601	$ 40,367
Treasury Stock, Shares	2,184	1,453
Treasury Stock, Value	$ (70,834)	$ (50,834)
Total shareholders’ equity	2,301,981	2,159,962
Total liabilities and shareholders’ equity	$ 16,233,424	$ 14,079,524

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ / shares in Thousands, $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale, Amortized Cost	$ 4,081,118	$ 3,703,096
Preferred Stock, No Par Value	$ 0	$ 0
Common Stock, No Par Value	$ 0	$ 0

Consolidated Statements of Inco

Consolidated Statements of Income - 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	$ 105,739	$ 112,656	$ 318,601	$ 337,657
Taxable securities	19,102	16,457	58,533	49,790
Tax-exempt securities	2,340	2,556	6,899	8,237
Deposits in banks	203	864	480	1,159
Total interest income	127,384	132,533	384,513	396,843
Interest Expense
Deposits	2,005	6,863	7,741	16,337
FHLB advances	166	2,569	6,191	9,962
Subordinated debentures	468	468	1,404	1,404
Other borrowings	19	183	178	552
Total interest expense	2,658	10,083	15,514	28,255
Net Interest Income	124,726	122,450	368,999	368,588
Provision for credit losses	7,400	299	82,400	1,879
Net interest income after provision for credit losses	117,326	122,151	286,599	366,709
Noninterest Income
Deposit account and treasury management fees	6,658	9,015	20,538	27,030
Card revenue	3,834	4,006	10,431	11,431
Financial services and trust revenue	3,253	3,226	9,481	9,608
Loan revenue	6,645	3,855	16,842	9,840
Bank owned life insurance	1,585	1,528	4,799	4,644
Investment securities gains, net	0	0	16,674	2,132
Other	497	6,400	2,173	10,689
Total noninterest income	22,472	28,030	80,938	75,374
Noninterest Expense
Compensation and employee benefits	55,133	54,459	156,018	158,559
Occupancy	8,734	8,645	26,743	26,166
Data processing	4,510	5,102	14,804	14,372
Legal and professional fees	3,000	5,683	8,585	16,810
Amortization of intangibles	2,193	2,632	6,713	8,029
B&O taxes	1,559	1,325	3,427	4,612
Advertising and promotion	680	1,752	2,822	3,596
Regulatory premiums	826	(38)	1,894	1,902
Net benefit of operation of OREO	(160)	(90)	(348)	(682)
Other	8,640	7,606	29,561	25,140
Total noninterest expense	85,115	87,076	250,219	258,504
Income before income taxes	54,683	63,105	117,318	183,579
Income tax provision	9,949	12,378	21,374	35,257
Net Income	$ 44,734	$ 50,727	$ 95,944	$ 148,322
Earnings per common share
Basic	$ 0.63	$ 0.70	$ 1.35	$ 2.04
Diluted	$ 0.63	$ 0.70	$ 1.35	$ 2.04
Weighted average number of common shares outstanding	70,726	71,803	70,870	72,256
Weighted average number of diluted common shares outstanding	70,762	71,803	70,906	72,257

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
Net income	$ 44,734	$ 50,727	$ 95,944	$ 148,322
Unrealized gain from securities
Net unrealized holding gain from available for sale debt securities arising during the period, net of tax	(1,442)	14,593	121,114	86,519
Reclassification adjustment of net gain from sale of available for sale debt securities included in income, net of tax			(191)	(1,636)
Net unrealized gain from securities, net of reclassification adjustment	(1,442)	14,593	120,923	84,883
Pension plan liability adjustment:
Amortization of unrecognized net actuarial loss included in net periodic pension cost, net of tax	80	62	239	184
Pension plan liability adjustment, net	80	62	239	184
Unrealized gain from cash flow hedging instruments
Net unrealized gain (loss) in cash flow hedging instruments arising during the period, net of tax	(62)	3,137	20,526	15,180
Reclassification adjustment for net gain in cash flow hedging instruments included in income, net of tax	2,052	58	4,454	58
Net unrealized gain from cash flow hedging instruments, net of reclassification adjustment	(2,114)	3,079	16,072	15,122
Other Comprehensive Income	(3,476)	17,734	137,234	100,189
Total comprehensive income	$ 41,258	$ 68,461	$ 233,178	$ 248,511

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net unrealized holding gain (loss) from available for sale securities arising during the period, tax	$ 436	$ (4,421)	$ (36,690)	$ (26,209)
Reclassification adjustment of net gain from sale of available for sale securities included in income, tax			58	496
Less: amortization of unrecognized net actuarial loss included in net periodic pension cost, tax	(24)	(19)	(72)	(56)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax	19	(951)	(6,218)	(4,599)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax	$ 621	$ 18	$ 1,349	$ 18

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Treasury Stock [Member]
Shares, Outstanding		73,249
Adjustment to opening retained earnings, net of tax, pursuant to adoption of ASU | Accounting Standards Update 2016-02 [Member]	$ 782		$ 782
Balance, value at Dec. 31, 2018	2,033,649	$ 1,642,246	426,708	$ (35,305)
Net income	148,322		148,322
Other comprehensive income (loss)	100,189			100,189
Issuance of common stock - stock option and other plans, shares		58
Issuance of common stock - stock option and other plans, value	$ 2,025	$ 2,025
Stock Adjustment Deferred Compensation - Shares	0
Stock Adjustment Value Deferred Compensation	$ 2
Issuance of common stock - restricted stock awards, net of canceled awards, shares		354
Issuance of common stock - restricted stock awards, net of canceled awards, value	6,827	$ 6,827
Purchase and retirement of common stock, Shares		(73)
Purchase and retirement of common stock, Value	(2,765)	$ (2,765)
Cash dividends declared on common stock	(82,074)		(82,074)
Purchase of treasury stock, Shares		(1,300)
Purchase of treasury stock, value	(45,380)				$ (45,380)
Balance, value at Sep. 30, 2019	2,161,577	$ 1,648,335	493,738	64,884	(45,380)
Shares, Outstanding		72,924
Balance, value at Jun. 30, 2019	2,133,638	$ 1,644,922	463,429	47,150	(21,863)
Net income	50,727		50,727
Other comprehensive income (loss)	17,734			17,734
Issuance of common stock - stock option and other plans, shares		31
Issuance of common stock - stock option and other plans, value	$ 1,132	$ 1,132
Stock Adjustment Deferred Compensation - Shares	0
Stock Adjustment Value Deferred Compensation	$ 1
Issuance of common stock - restricted stock awards, net of canceled awards, shares		9
Issuance of common stock - restricted stock awards, net of canceled awards, value	2,299	$ 2,299
Purchase and retirement of common stock, Shares		0
Purchase and retirement of common stock, Value	(19)	$ (19)
Cash dividends declared on common stock	(20,418)		(20,418)
Purchase of treasury stock, Shares		(676)
Purchase of treasury stock, value	(23,517)				(23,517)
Balance, value at Sep. 30, 2019	2,161,577	$ 1,648,335	493,738	64,884	(45,380)
Shares, Outstanding		72,288
Shares, Outstanding		72,124
Adjustment to opening retained earnings, net of tax, pursuant to adoption of ASU | Accounting Standards Update 2016-13 [Member]	(2,500)		(2,457)
Balance, value at Dec. 31, 2019	2,159,962	$ 1,650,753	519,676	40,367	(50,834)
Net income	95,944		95,944
Other comprehensive income (loss)	137,234			137,234
Issuance of common stock - stock option and other plans, shares		65
Issuance of common stock - stock option and other plans, value	2,028	$ 2,028
Stock Adjustment Deferred Compensation - Shares		0
Stock Adjustment Value Deferred Compensation	2	$ 2
Issuance of common stock - restricted stock awards, net of canceled awards, shares		222
Issuance of common stock - restricted stock awards, net of canceled awards, value	7,918	$ 7,918
Purchase and retirement of common stock, Shares		(67)
Purchase and retirement of common stock, Value	(2,498)	$ (2,498)
Cash dividends declared on common stock	$ (76,152)		(76,152)
Purchase of treasury stock, Shares	(731)	(731)
Purchase of treasury stock, value	$ (20,000)				(20,000)
Balance, value at Sep. 30, 2020	2,301,981	$ 1,658,203	537,011	177,601	(70,834)
Shares, Outstanding		71,586
Balance, value at Jun. 30, 2020	2,276,755	$ 1,654,129	512,383	181,077	(70,834)
Net income	44,734		44,734
Other comprehensive income (loss)	(3,476)			(3,476)
Issuance of common stock - stock option and other plans, shares		39
Issuance of common stock - stock option and other plans, value	1,083	$ 1,083
Stock Adjustment Deferred Compensation - Shares		0
Stock Adjustment Value Deferred Compensation	(2)	$ (2)
Issuance of common stock - restricted stock awards, net of canceled awards, shares		(12)
Issuance of common stock - restricted stock awards, net of canceled awards, value	3,009	$ 3,009
Purchase and retirement of common stock, Shares		0
Purchase and retirement of common stock, Value	(16)	$ (16)
Cash dividends declared on common stock	(20,106)		(20,106)
Balance, value at Sep. 30, 2020	$ 2,301,981	$ 1,658,203	$ 537,011	$ 177,601	$ (70,834)
Shares, Outstanding		71,613

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Common Stock, Dividends, Per Share, Cash Paid	$ 0.28	$ 0.28	$ 1.06	$ 1.12

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	$ 95,944	$ 148,322
Adjustments to reconcile net income to net cash provided by operating activities
Provision for credit losses	82,400	1,879
Stock-based compensation expense	7,918	6,827
Depreciation, amortization and accretion	14,456	26,150
Investment securities gain, net	16,674	2,132
Net realized gain on sale of premises and equipment, loans held for investment and OPPO	953	6,787
Net realized gain on sale and valuation adjustments of OREO	64	602
Gain on bank owned life insurance death benefit	0	2,975
Originations of loans held for sale	356,962	134,634
Proceeds from sales of loans held for sale	350,273	123,447
Net change in:
Interest receivable	(9,879)	(3,180)
Interest payable	(399)	632
Other assets	(53,996)	(31,840)
Other liabilities	31,703	29,706
Net cash provided by operating activities	143,767	154,813
Cash Flows From Financing Activities
Loans originated, net of principal collected	(938,624)	(305,581)
Purchases of debt securities available for sale	(996,951)	(649,133)
Purchases of loans held for investment	0	57,075
Purchases of premises and equipment	(7,538)	(5,833)
Purchases of FHLB stock	(53,240)	(190,800)
Proceeds from sale of debt securities, available-for-sale	194,105	259,554
Proceeds from sale of equity securities	3,000	0
Proceeds from principal repayments and maturities of debt securities available for sale	406,767	287,479
Proceeds from sales of premises and equipment	2,128	7,735
Proceeds from redemption of Federal Home Loan Bank stock	91,080	187,080
Proceeds from sales of other real estate and other personal property owned	1,034	6,433
Proceeds from bank owned life insurance death benefit	1,050	0
Net cash used in investing activities	(1,297,189)	(460,141)
Cash Flows From Financing Activities
Net increase in deposits	2,915,565	397,893
Net decrease in sweep repurchase agreements	(37,471)	(36,605)
Proceeds from FHLB advances	1,331,000	4,770,000
Proceeds from FRB borrowings	222,010	36,000
Proceeds from other borrowings	9,222	100
Proceeds from exercise of stock options and employee stock purchase plan	2,028	2,025
Repayment of FHLB advances	(2,277,000)	(4,677,000)
Repayment of FRB borrowings	222,010	36,000
Repayments of other borrowings	9,222	100
Payments for common stock dividends	(75,630)	(81,822)
Purchase of treasury stock	(20,000)	(45,380)
Purchase and retirement of common stock	2,498	2,765
Net cash provided by financing activities	1,835,994	326,346
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	682,572	21,018
Cash and cash equivalents at beginning of period	247,673	277,587
Cash and cash equivalents at end of period	930,245	298,605
Supplemental Information:
Cash paid for interest	15,913	27,623
Cash paid for income tax, net of refunds	32,745	33,134
Non-cash investing and financing activities
Loans transferred to OREO	1,033	386
Premises and equipment expenditures incurred but not yet paid	301	152
Change in dividends payable on unvested shares included in other liabilities	$ 522	$ 252

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
Basis of Presentation And Significant Accounting Policies
Basis of Presentation and Significant Accounting Policies	Basis of Presentation, Significant Accounting Policies and Reclassifications Basis of Presentation The interim unaudited Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States of America for interim financial information and with instructions to Form 10-Q and Article 10 of Regulation S-X. The Consolidated Financial Statements include the accounts of Columbia Banking System, Inc. (“we”, “our”, “Columbia” or the “Company”) and its subsidiaries, including its wholly owned banking subsidiary Columbia State Bank (“Columbia Bank” or the “Bank”) and Columbia Trust Company (“Columbia Trust”). All intercompany transactions and accounts have been eliminated in consolidation. In the opinion of management, all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair statement of the results for the interim periods presented have been included. The results of operations for the nine months ended September 30, 2020 are not necessarily indicative of results to be anticipated for the year ending December 31, 2020. The accompanying interim unaudited Consolidated Financial Statements should be read in conjunction with the financial statements and related notes contained in the Company’s 2019 Annual Report on Form 10-K. Significant Accounting Policies The significant accounting policies used in preparation of our Consolidated Financial Statements are disclosed in our 2019 Annual Report on Form 10-K. In addition to the changes already disclosed in the Annual Report on Form 10-K regarding ASC 326, this ASC also made changes to the accounting for available for sale securities. One such change is to require credit losses to be presented as an allowance rather than a write-down on available for sale securities, which refers to securities management does not intend to sell or with respect to which management believes that it is more likely than not they will not be required to sell. With the exception of that change, there have not been any changes in our significant accounting policies compared to those contained in our 2019 Form 10-K disclosure for the year ended December 31, 2019. Reclassifications Certain amounts reported in prior periods have been reclassified in the Consolidated Financial Statements to conform to the current presentation. The reclassifications have no effect on net income or shareholders’ equity as previously reported.

Accounting Pronouncements Recen

Accounting Pronouncements Recently Adopted or Issued	9 Months Ended
	Sep. 30, 2020
Accounting Standards Update and Change in Accounting Principle [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles adopted	Accounting Standards Adopted in 2020 In April 2019, the FASB issued 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 this ASU clarify certain aspects of accounting for credit losses, hedging activities, and financial instruments (addressed by ASUs 2016-01, 2016-13, and 2017-12). Many of the amendments reflect decisions reached at FASB meetings or meetings of the Board’s credit losses transition resource group. Topics covered in this ASU include: accrued interest, transfers between classifications or categories for loans and debt securities, recoveries, reinsurance recoverables, projections of interest rate environments for variable-rate financial instruments, costs to sell when foreclosure is probable, consideration of expected prepayments when determining the effective interest rate, vintage disclosures, extension and renewal options, etc. As the ASU focused on clarifying certain aspects of accounting, adoption of this ASU did not have a material impact on the Company’s Consolidated Financial Statements. In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326) - Measurement of Credit Losses on Financial Instruments . The amendments included in this ASU require an entity to reflect its current estimate of all expected credit losses for assets held at an amortized cost basis. For available for sale debt securities, credit losses will be measured in a manner similar to current GAAP, however, this ASU requires that credit losses be presented as an allowance rather than as a write-down. In November 2019, the FASB subsequently issued ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments - Credit Losses. The amendments in the update require entities to include expected recoveries of the amortized cost basis previously written-off or expected to be written-off in the valuation account for purchased financial assets with credit deterioration. In addition, the amendments in this update clarify and improve various aspects of the guidance for ASU 2016-13. Unlike the incurred loss models, the CECL model in ASU 2016-13 does not specify a threshold for the recognition of an impairment allowance. Rather, the Company recognizes an impairment allowance equal to its estimate of lifetime expected credit losses, adjusted for prepayments, for in-scope financial instruments. Accordingly, the impairment allowance measured under the CECL model is expected to change significantly from the impairment allowance measured under the Company’s incurred loss model. The Company engaged a third-party vendor to assist in the CECL calculation and has developed and implemented an internal governance framework. The amendments in ASU 2016-13 and the above ASU’s related to credit losses are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption was permitted, including adoption in any interim period. The Company adopted the new standards, using a modified retrospective approach, effective January 1, 2020, which resulted in an increase of $1.6 million to its allowance for credit losses, an increase of $1.6 million to its allowance for unfunded commitments and letters of credit and a net-of-tax cumulative-effect adjustment of $2.5 million to decrease the beginning balance of retained earnings. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820) - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement. This ASU adds, eliminates and modifies certain disclosure requirements for fair value measurements. Among the changes, entities will no longer be required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, but will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. The ASU is effective for interim and annual reporting periods beginning after December 15, 2019; early adoption is permitted. Entities are also allowed to elect early adoption of the eliminated or modified disclosure requirements and delay adoption of the added disclosure requirements until their effective date. The Company adopted the new standard effective January 1, 2020. The adoption of this ASU did not have a material impact on the Company’s Consolidated Financial Statements.
Accounting Pronouncements Recently Issued not yet adopted	Recently Issued Accounting Standards, Not Yet Adopted In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848) - Facilitation of the Effects of Reference Rate Reform on Financial Reporting . In response to concerns about structural risks of the cessation of LIBOR, the amendments in this ASU provide optional guidance for a limited time to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. The amendments in this ASU provide optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. The amendments in this ASU apply only to contracts and hedging relationships that reference LIBOR or another reference rate expected to be discontinued due to reference rate reform. The expedients and exceptions provided by the amendments do not apply to contract modifications made and hedging relationships entered into or evaluated after December 31, 2022. The amendments in this ASU are elective and are effective March 12, 2020 for all entities. The adoption of this ASU is not expected to have a material impact on the Company’s Consolidated Financial Statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes. The guidance issued in this ASU simplifies the accounting for income taxes by eliminating certain exceptions to the guidance in ASC 740 related to the approach for intra-period tax allocation, the methodology for calculating income taxes in an interim period and the recognition for deferred tax liabilities for outside basis differences. This ASU also simplifies aspects of the accounting for franchise taxes and enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a step-up in the tax basis of goodwill. The ASU is effective for interim and annual reporting periods beginning after December 15, 2020; early adoption is permitted. The adoption of this ASU is not expected to have a material impact on the Company’s Consolidated Financial Statements.
New Accounting Pronouncements Recently Adopted or Issued	Accounting Pronouncements Recently Adopted or Issued Accounting Standards Adopted in 2020 In April 2019, the FASB issued 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 this ASU clarify certain aspects of accounting for credit losses, hedging activities, and financial instruments (addressed by ASUs 2016-01, 2016-13, and 2017-12). Many of the amendments reflect decisions reached at FASB meetings or meetings of the Board’s credit losses transition resource group. Topics covered in this ASU include: accrued interest, transfers between classifications or categories for loans and debt securities, recoveries, reinsurance recoverables, projections of interest rate environments for variable-rate financial instruments, costs to sell when foreclosure is probable, consideration of expected prepayments when determining the effective interest rate, vintage disclosures, extension and renewal options, etc. As the ASU focused on clarifying certain aspects of accounting, adoption of this ASU did not have a material impact on the Company’s Consolidated Financial Statements. In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326) - Measurement of Credit Losses on Financial Instruments . The amendments included in this ASU require an entity to reflect its current estimate of all expected credit losses for assets held at an amortized cost basis. For available for sale debt securities, credit losses will be measured in a manner similar to current GAAP, however, this ASU requires that credit losses be presented as an allowance rather than as a write-down. In November 2019, the FASB subsequently issued ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments - Credit Losses. The amendments in the update require entities to include expected recoveries of the amortized cost basis previously written-off or expected to be written-off in the valuation account for purchased financial assets with credit deterioration. In addition, the amendments in this update clarify and improve various aspects of the guidance for ASU 2016-13. Unlike the incurred loss models, the CECL model in ASU 2016-13 does not specify a threshold for the recognition of an impairment allowance. Rather, the Company recognizes an impairment allowance equal to its estimate of lifetime expected credit losses, adjusted for prepayments, for in-scope financial instruments. Accordingly, the impairment allowance measured under the CECL model is expected to change significantly from the impairment allowance measured under the Company’s incurred loss model. The Company engaged a third-party vendor to assist in the CECL calculation and has developed and implemented an internal governance framework. The amendments in ASU 2016-13 and the above ASU’s related to credit losses are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption was permitted, including adoption in any interim period. The Company adopted the new standards, using a modified retrospective approach, effective January 1, 2020, which resulted in an increase of $1.6 million to its allowance for credit losses, an increase of $1.6 million to its allowance for unfunded commitments and letters of credit and a net-of-tax cumulative-effect adjustment of $2.5 million to decrease the beginning balance of retained earnings. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820) - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement. This ASU adds, eliminates and modifies certain disclosure requirements for fair value measurements. Among the changes, entities will no longer be required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, but will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. The ASU is effective for interim and annual reporting periods beginning after December 15, 2019; early adoption is permitted. Entities are also allowed to elect early adoption of the eliminated or modified disclosure requirements and delay adoption of the added disclosure requirements until their effective date. The Company adopted the new standard effective January 1, 2020. The adoption of this ASU did not have a material impact on the Company’s Consolidated Financial Statements. Recently Issued Accounting Standards, Not Yet Adopted In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848) - Facilitation of the Effects of Reference Rate Reform on Financial Reporting . In response to concerns about structural risks of the cessation of LIBOR, the amendments in this ASU provide optional guidance for a limited time to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. The amendments in this ASU provide optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. The amendments in this ASU apply only to contracts and hedging relationships that reference LIBOR or another reference rate expected to be discontinued due to reference rate reform. The expedients and exceptions provided by the amendments do not apply to contract modifications made and hedging relationships entered into or evaluated after December 31, 2022. The amendments in this ASU are elective and are effective March 12, 2020 for all entities. The adoption of this ASU is not expected to have a material impact on the Company’s Consolidated Financial Statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes. The guidance issued in this ASU simplifies the accounting for income taxes by eliminating certain exceptions to the guidance in ASC 740 related to the approach for intra-period tax allocation, the methodology for calculating income taxes in an interim period and the recognition for deferred tax liabilities for outside basis differences. This ASU also simplifies aspects of the accounting for franchise taxes and enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a step-up in the tax basis of goodwill. The ASU is effective for interim and annual reporting periods beginning after December 15, 2020; early adoption is permitted. The adoption of this ASU is not expected to have a material impact on the Company’s Consolidated Financial Statements.

Securities

Securities	9 Months Ended
	Sep. 30, 2020
Debt Securities, Available-for-sale [Abstract]
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]	Securities The following table summarizes the amortized cost, gross unrealized gains and losses, the allowance for credit losses and the resulting fair value of debt securities available for sale: Amortized Gross Gross Allowance for Credit Fair Value September 30, 2020 (in thousands) U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 2,957,028 $ 168,271 $ (3,657) $ — $ 3,121,642 Other asset-backed securities 284,499 9,055 (530) — 293,024 State and municipal securities 536,861 21,396 (813) — 557,444 U.S. government agency and government-sponsored enterprise securities 302,730 6,932 (52) — 309,610 Total $ 4,081,118 $ 205,654 $ (5,052) $ — $ 4,281,720 December 31, 2019 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 2,864,949 $ 47,223 $ (19,222) $ — $ 2,892,950 Other asset-backed securities 194,563 2,476 (989) — 196,050 State and municipal securities 478,366 10,660 (224) — 488,802 U.S. government agency and government-sponsored enterprise securities 165,218 3,127 (5) — 168,340 Total $ 3,703,096 $ 63,486 $ (20,440) $ — $ 3,746,142 A debt security is placed on nonaccrual status at the time any principal or interest payments become 90 days delinquent. Interest accrued but not received for a security placed on nonaccrual is reversed against interest income. There were no amounts of accrued interest reversed against interest income for the three and nine months ended September 30, 2020 and 2019. Accrued interest receivable for securities available for sale is included in “Interest receivable” on the Company’s Consolidated Balance Sheet and is not reflected in the balances in the table above. At September 30, 2020 and December 31, 2019, accrued interest receivable for securities was $13.3 million and $13.9 million, respectively. The Company does not measure an allowance for credit losses for accrued interest receivable. The following table provides the proceeds and both gross realized gains and losses on sales of debt securities available for sale as well as other securities gains and losses for the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Proceeds from sales of debt securities available for sale $ — $ — $ 194,105 $ 259,554 Gross realized gains from sales of debt securities available for sale $ — $ — $ 435 $ 3,357 Gross realized losses from sales of debt securities available for sale — — (186) (1,225) Other securities gains (1) — — 16,425 — Investment securities gains, net $ — $ — $ 16,674 $ 2,132 __________ (1) Other securities gains includes gain from sale of Visa Class B restricted stock and subsequent write up to fair value of remaining Visa Class B shares. For additional information, please see Note 13 to the Consolidated Financial Statements in “Item 1. Financial Statements (unaudited)” of this report. The following table provides the unrealized gains and losses on equity securities at the reporting date: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Gains recognized during the period on equity securities (1) $ — $ — $ 16,425 $ — Less: Gains recognized during the period on equity securities sold during the period (1) — — (3,000) — Unrealized gains recognized during the reporting period on equity securities still held at the reporting date (1) $ — $ — $ 13,425 $ — __________ (1) Visa Class B restricted stock owned by the Company was previously carried at a zero-cost basis due to existing transfer restrictions and uncertainty of covered litigation. The sale of shares by the Company of Visa Class B restricted shares during the second quarter of 2020 resulted in an observable market price. As a result, the Company adjusted the carrying value of its remaining shares of Visa Class B restricted shares upward to this observable market price. The scheduled contractual maturities of debt securities available for sale at September 30, 2020 are presented as follows: September 30, 2020 Amortized Cost Fair Value (in thousands) Due within one year $ 92,028 $ 92,931 Due after one year through five years 595,979 626,018 Due after five years through ten years 2,000,662 2,133,751 Due after ten years 1,392,449 1,429,020 Total debt securities available for sale $ 4,081,118 $ 4,281,720 The following table summarizes the carrying value of securities pledged as collateral to secure public funds, borrowings and other purposes as permitted or required by law: September 30, 2020 (in thousands) To secure public funds $ 441,379 To secure borrowings 111,978 Other securities pledged 168,870 Total securities pledged as collateral $ 722,227 The following table shows the gross unrealized losses and fair value of the Company’s debt securities available for sale for which an allowance for credit losses has not been recorded, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at September 30, 2020 and December 31, 2019: Less than 12 Months 12 Months or More Total Fair Unrealized Fair Unrealized Fair Unrealized September 30, 2020 (in thousands) U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 318,868 $ (2,817) $ 23,084 $ (840) $ 341,952 $ (3,657) Other asset-backed securities 71,552 (530) 95 — 71,647 (530) State and municipal securities 90,620 (813) — — 90,620 (813) U.S. government agency and government-sponsored enterprise securities 99,946 (52) — — 99,946 (52) Total $ 580,986 $ (4,212) $ 23,179 $ (840) $ 604,165 $ (5,052) December 31, 2019 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 1,055,903 $ (12,424) $ 491,539 $ (6,798) $ 1,547,442 $ (19,222) Other asset-backed securities 89,508 (880) 6,799 (109) 96,307 (989) State and municipal securities 12,363 (142) 12,587 (82) 24,950 (224) U.S. government agency and government-sponsored enterprise securities — — 10,495 (5) 10,495 (5) Total $ 1,157,774 $ (13,446) $ 521,420 $ (6,994) $ 1,679,194 $ (20,440) At September 30, 2020, there were 62 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligation securities in an unrealized loss position. The decline in fair value is attributable to changes in interest rates relative to where these investments fall within the yield curve and their individual characteristics. Because the Company does not intend to sell these securities nor does the Company consider it more likely than not that it will be required to sell these securities before the recovery of amortized cost basis, which may be upon maturity, the Company concluded an allowance for credit losses is unnecessary at September 30, 2020. At September 30, 2020, there were five other asset-backed securities in an unrealized loss position. The decline in fair value is attributable to changes in interest rates relative to where these investments fall within the yield curve and their individual characteristics. Because the Company does not intend to sell these securities nor does the Company consider it more likely than not that it will be required to sell these securities before the recovery of amortized cost basis, which may be upon maturity, the Company concluded an allowance for credit losses is unnecessary at September 30, 2020. At September 30, 2020, there were 29 state and municipal government securities in an unrealized loss position. The unrealized losses on state and municipal securities were caused by interest rate changes or widening of market spreads subsequent to the purchase of the individual securities. Management monitors published credit ratings of these securities for adverse changes. As of September 30, 2020, none of the rated obligations of state and local government entities held by the Company had a below investment grade credit rating. Because the credit quality of these securities are investment grade and the Company does not intend to sell these securities nor does the Company consider it more likely than not that it will be required to sell these securities before the recovery of amortized cost basis, which may be upon maturity, the Company concluded an allowance for credit losses is unnecessary at September 30, 2020. At September 30, 2020, there were four U.S. government securities in an unrealized loss position. The decline in fair value is attributable to changes in interest rates relative to where these investments fall within the yield curve and their individual characteristics. Because the Company does not intend to sell these securities nor does the Company consider it more likely than not that it will be required to sell these securities before the recovery of amortized cost basis, which may be upon maturity, the Company concluded an allowance for credit losses is unnecessary at September 30, 2020. Equity Securities without Readily Determinable Fair Values Visa Class B Restricted Shares In 2008, the Company received Visa Class B restricted shares as part of Visa’s initial public offering. These shares are transferable only under limited circumstances until they can be converted into publicly traded Visa Class A common shares. This conversion will not occur until the settlement of certain litigation which is indemnified by Visa members, including the Company. Visa funded an escrow account from its initial public offering to settle these litigation claims. Should this escrow account not be sufficient to cover these litigation claims, Visa is entitled to fund additional amounts to the escrow account by reducing each member bank’s Visa Class B conversion ratio to unrestricted Visa Class A shares.

Loans

Loans	9 Months Ended
	Sep. 30, 2020
Loans and Leases Receivable, Net Amount [Abstract]
Loans	Loans The Company’s loan portfolio includes originated and purchased loans. The following is an analysis of the loan portfolio by segment and class (net of unearned income): September 30, 2020 December 31, 2019 (dollars in thousands) Commercial loans: Commercial real estate $ 4,027,035 $ 3,945,853 Commercial business 3,836,009 2,989,613 Agriculture 850,290 765,371 Construction 273,176 361,533 Consumer loans: One-to-four family residential real estate 665,432 637,325 Other consumer 37,005 43,770 Total loans 9,688,947 8,743,465 Less: Allowance for credit losses (156,968) (83,968) Total loans, net $ 9,531,979 $ 8,659,497 Loans held for sale $ 24,407 $ 17,718 At September 30, 2020 and December 31, 2019, the Company had no material foreign activities. Substantially all of the Company’s loans and unfunded commitments are geographically concentrated in its service areas within the states of Washington, Oregon and Idaho. At September 30, 2020 and December 31, 2019, $3.49 billion and $3.24 billion of commercial and residential real estate loans were pledged as collateral on FHLB borrowings and additional borrowing capacity. The Company has also pledged $200.6 million and $151.3 million of commercial loans to the FRB for additional borrowing capacity at September 30, 2020 and December 31, 2019, respectively. Accrued interest receivable for loans is included in “Interest receivable” on the Company’s Consolidated Balance Sheet and is not reflected in the balances in the table above. At September 30, 2020 and December 31, 2019, accrued interest receivable for loans was $43.4 million and $33.0 million, respectively. The Company does not measure an allowance for credit losses for accrued interest receivable. The following is an aging of the recorded investment of the loan portfolio as of September 30, 2020 and December 31, 2019: Current 30 - 59 60 - 89 Greater Total Nonaccrual Total Loans September 30, 2020 (in thousands) Commercial loans: Commercial real estate $ 4,015,038 $ 547 $ 1,088 $ — $ 1,635 $ 10,362 $ 4,027,035 Commercial business 3,808,794 6,987 915 — 7,902 19,313 3,836,009 Agriculture 833,408 1,710 259 — 1,969 14,913 850,290 Construction 272,959 — — — — 217 273,176 Consumer loans: One-to-four family residential real estate 658,468 4,559 — — 4,559 2,405 665,432 Other consumer 36,744 215 25 — 240 21 37,005 Total $ 9,625,411 $ 14,018 $ 2,287 $ — $ 16,305 $ 47,231 $ 9,688,947 Current 30 - 59 60 - 89 Greater Total Nonaccrual Total Loans December 31, 2019 (in thousands) Commercial loans: Commercial real estate $ 3,935,633 $ 6,421 $ — — $ 6,421 $ 3,799 $ 3,945,853 Commercial business 2,959,826 6,081 2,769 — 8,850 20,937 2,989,613 Agriculture 755,719 2,283 2,346 — 4,629 5,023 765,371 Construction 360,582 951 — — 951 — 361,533 Consumer loans: One-to-four family residential real estate 631,109 2,516 408 — 2,924 3,292 637,325 Other consumer 43,654 80 27 — 107 9 43,770 Total $ 8,686,523 $ 18,332 $ 5,550 $ — $ 23,882 $ 33,060 $ 8,743,465 Loan payments are considered timely when the contractual principal or interest due in accordance with the terms of the loan agreement or any portion thereof is received on the due date of the scheduled payment. In addition, the risk rating on COVID-19 modified loans did not change. These loans are not considered past due until after the deferral period is over and scheduled payments resume. Accrued interest on these COVID-19 modified loans is due, in full, when the deferral period ends. The credit quality of these loans will be reevaluated after the deferral period ends. Nonaccrual loans are generally loans placed on a nonaccrual basis when they become 90 days past due or when there are otherwise serious doubts about the collectability of principal or interest within the existing terms of the loan. The Company’s policy is to write-off all accrued interest on loans when they are placed on nonaccrual status. The following table summarizes written-off interest on nonaccrual loans for the three and nine months ended September 30, 2020 and 2019: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Commercial loans $ 387 $ 149 $ 1,835 $ 1,316 Consumer loans 6 26 19 146 Total $ 393 $ 175 $ 1,854 $ 1,462 The following summarizes the amortized cost of nonaccrual loans for which there was no related ACL as of September 30, 2020 and December 31, 2019: September 30, 2020 December 31, 2019 (in thousands) Commercial loans: Commercial real estate $ 9,092 $ 1,715 Commercial business 11,713 15,762 Agriculture 11,074 1,798 Total $ 31,879 $ 19,275 The following is an analysis of loans classified as TDR during the three and nine months ended September 30, 2020 and 2019: Three Months Ended September 30, 2020 Three Months Ended September 30, 2019 Number of TDR Modifications Pre-Modification Post-Modification Number of TDR Modifications Pre-Modification Post-Modification (dollars in thousands) Commercial loans: Commercial business 4 $ 795 795 5 5,026 5,026 Agriculture 1 2,600 2,600 — — — Consumer loans: One-to-four family residential real estate 4 618 618 5 357 357 Other consumer — — — 1 1 1 Total 9 $ 4,013 $ 4,013 11 $ 5,384 $ 5,384 Nine Months Ended September 30, 2020 Nine Months Ended September 30, 2019 Number of TDR Modifications Pre-Modification Post-Modification Number of TDR Modifications Pre-Modification Post-Modification (dollars in thousands) Commercial loans: Commercial business 10 $ 2,757 $ 2,757 10 $ 6,560 $ 6,560 Agriculture 2 3,495 3,495 — — — Consumer loans: One-to-four family residential real estate 6 814 814 10 692 692 Other consumer — — — 1 1 1 Total 18 $ 7,066 $ 7,066 21 $ 7,253 $ 7,253 The Company’s loans classified as TDR are loans that have been modified or with respect to which the borrower has been granted special concessions due to financial difficulties that, if not for the challenges of the borrower, the Company would not otherwise consider. The TDR modifications or concessions are made to increase the likelihood that these borrowers with financial difficulties will be able to satisfy their debt obligations as amended. The concessions granted in the restructurings, summarized in the table above, largely consisted of maturity extensions, interest rate modifications or a combination of both. In limited circumstances, a reduction in the principal balance of the loan could also be made as a concession. Loans classified as TDR are included with the loans collectively measured for credit losses. The Company had commitments to lend $641 thousand of additional funds on loans classified as TDR as of September 30, 2020. The Company had $1.1 million of such commitments at December 31, 2019. The Company had no loans modified as TDR that defaulted within 12 months of being modified as TDR during the three and nine months ended September 30, 2020. During three months ended September 30, 2019, the Company had no loans that defaulted within 12 months of being modified as a TDR. During the nine months ended September 30, 2019, the Company had one $26 thousand consumer loan that defaulted within 12 months of being modified as a TDR. The defaulted TDR loan was collateralized and included with the loans individually measured for credit loss. Loan modifications and PPP loans in response to COVID-19 Financial institutions are required to maintain records of the volume of loans involved in modifications to which troubled debt restructuring relief is applicable . At September 30, 2020, the Company had 103 short–term deferments on $114.4 million of loans, gross of unearned income . These short–term deferments are not classified as TDR’s and will not be reported as past due provided that they are performing in accordance with the modified terms. The Company offered PPP loans to provide financial support to small and medium-size businesses to cover payroll and certain other expenses during the COVID-19 pandemic. The PPP was established by the CARES Act and is implemented by the U.S. SBA with support from the U.S. Department of Treasury. The program, which was amended by the Paycheck Protection Flexibility Act of 2020, provides small businesses with funds to pay up to 24 weeks of payroll costs including benefits, as well as interest on mortgages, rent and utilities. Funds are provided to small businesses in the form of loans that will be fully forgiven when used for permitted purposes and when at least 60% of the funds are used for payroll costs in accordance with the requirements of the amended PPP. At September 30, 2020, we had $953.2 million of PPP loans outstanding, which are included in commercial business loans.

Allowance for Credit Losses and

Allowance for Credit Losses and Allowance for Unfunded Commitments and Letters of Credit	9 Months Ended
	Sep. 30, 2020
Allowance For Credit Losses and Allowance for Unfunded Commitments and Letters Of Credit [Abstract]
Allowance For Credit Losses And Allowance for Unfunded Loan Commitments And Letters Of Credit Text Block	Allowance for Credit Losses and Allowance for Unfunded Commitments and Letters of Credit The ACL is determined through quarterly assessments of expected credit losses within the loan portfolio and is deducted from the loan’s amortized cost basis to present the net amount of loans expected to be collected. We estimate the ACL using relevant and reliable available information, which is derived from both internal and external sources, relating to past events, current conditions, and reasonable and supportable forecasts. Additions to and recaptures from the ACL are charged to current period earnings through the provision for credit losses. Loan amounts that are determined to be uncollectible are charged directly against the ACL and netted against amounts recovered on previously charged-off loans. For the purpose of calculating portfolio level reserves, we have segmented our loan portfolio into two portfolio segments (Commercial and Consumer). The Commercial and Consumer portfolio segments are then further broken down into loan classes by risk characteristics. The risk characteristics include regulatory call codes, type of industry and collateral type. The ACL is comprised of reserves measured on a collective (pool) basis using a quantitative DCF model for all loan classes with similar risk characteristics and then qualitatively adjusted for large loan concentrations, trends in problem loans, policy exemptions granted, and other factors. The quantitative DCF model utilizes anticipated period cash flows determined on a loan-level basis. The anticipated cash flows take into account contractual principal and interest payments, anticipated segment level prepayments, probability of defaults and historical loss given defaults. The majority of our loan classes utilize regression models to calculate probability of defaults, in which macroeconomic factors are correlated to historical quarterly defaults. The Commercial segment two-factor models utilize a mix of seven macroeconomic factors, including the four most commonly used factors: Real GDP, National Unemployment Rate, Home Price Index and Commercial Real Estate Index. The three additional factors are Nominal GDP, Producer Price Index and Core Consumer Price Index. The Consumer segment two-factor models utilize a mix of three macroeconomic factors: National Unemployment Rate, Home Price Index and Prime Rate. The Company utilizes an 18 month reasonable and supportable forecast for the macroeconomic factors, after which they revert to their historical mean using a straight-line basis constructed on their absolute historical quarterly change. Loans are individually measured for credit losses if they do not share similar risk characteristics of other loans within their respective pools. Individually measured loans are primarily nonaccrual and collateral dependent with balances equal to or greater than $500,000 and for which foreclosure is probable. Commercial real estate loans are secured by commercial real estate, including owner occupied and non-owner occupied commercial real estate, as well as multifamily residential real estate. Commercial business loans are primarily secured by non-real estate collateral, including equipment and other non-real estate fixed assets, inventory, receivables, and cash. Agricultural loans are secured by farmland and other agricultural real estate, as well as equipment, inventory, such as crops and livestock, non-real estate fixed assets, and cash. Construction loans are secured by one-to-four family residential real estate and commercial real estate in varying stages of development. One-to-four family residential real estate loans are secured by one-to-four family residential properties. Other consumer loans are secured by personal property. For loans measured on an individual basis, the Company calculates the allowance as the difference between the amortized cost of the loan and the fair market value of the collateral. The fair market value of the collateral is determined by either the discounted expected future cash flows from the operation of the collateral or the appraised value of the collateral, less costs to sell. If the fair value of the collateral is greater than the amortized cost of the loan, no reserve is recorded. The Company also records an allowance for credit losses on unfunded loan commitments and letters of credit. We estimate expected credit losses on unfunded commitments in which we are exposed to credit risk, unless we have the option to unconditionally cancel the obligation. Expected credit losses are calculated based on the likelihood that funding will occur and an estimate of what will be funded by analyzing the most recent four-quarter utilization rates, current utilization, and our quantitative ACL rate. The allowance for unfunded commitments and letters of credit is included in “Other Liabilities” on the Consolidated Balance Sheets, with changes to the balance being charged to noninterest expense. We do not measure an allowance for credit losses on accrued interest receivable balances because these balances are written-off in a timely manner as a reduction to interest income when loans are placed on nonaccrual status. The following tables show a detailed analysis of the ACL for the three and nine months ended September 30, 2020: Beginning Balance Charge-offs Recoveries Provision Ending Balance Three Months Ended September 30, 2020 (in thousands) Commercial loans: Commercial real estate $ 50,233 $ — $ 65 $ 11,026 $ 61,324 Commercial business 53,186 (3,164) 1,124 (574) 50,572 Agriculture 14,868 (1,269) 27 (1,165) 12,461 Construction 7,953 — 11 999 8,963 Consumer loans: One-to-four family residential real estate 23,711 (16) 1,301 (2,889) 22,107 Other consumer 1,595 (133) 76 3 1,541 Total $ 151,546 $ (4,582) $ 2,604 $ 7,400 $ 156,968 Prior Year Impact of Adopting ASC 326 Beginning Balance Charge-offs Recoveries Provision Ending Balance Nine Months Ended September 30, 2020 (in thousands) Commercial loans: Commercial real estate $ 20,340 $ 7,533 $ 27,873 $ (101) $ 92 $ 33,460 $ 61,324 Commercial business 30,292 762 31,054 (10,290) 2,795 27,013 50,572 Agriculture 15,835 (9,325) 6,510 (5,995) 69 11,877 12,461 Construction 8,571 (1,750) 6,821 — 688 1,454 8,963 Consumer loans: One-to-four family residential real estate 7,435 4,237 11,672 (26) 2,005 8,456 22,107 Other consumer 883 778 1,661 (599) 330 149 1,541 Unallocated 612 (603) 9 — — (9) — Total $ 83,968 $ 1,632 $ 85,600 $ (17,011) $ 5,979 $ 82,400 $ 156,968 The following tables show a detailed analysis of the ALLL for the three and nine months ended September 30, 2019: Beginning Balance Charge-offs Recoveries Provision Ending Balance Three Months Ended September 30, 2019 (in thousands) Commercial loans: Commercial real estate $ 15,648 $ (466) $ 1,731 $ 1,009 $ 17,922 Commercial business 29,700 (2,623) 349 3,453 30,879 Agriculture 12,671 (55) 67 1,216 13,899 Construction 12,457 (17) 2,555 (3,143) 11,852 Consumer loans: One-to-four family residential real estate 7,619 (202) 440 (399) 7,458 Other consumer 715 (9) 74 (201) 579 Unallocated 1,707 — — (1,636) 71 Total $ 80,517 $ (3,372) $ 5,216 $ 299 $ 82,660 Beginning Balance Charge-offs Recoveries Provision Ending Balance Nine Months Ended September 30, 2019 (in thousands) Commercial loans: Commercial real estate $ 14,766 $ (1,708) $ 2,801 $ 2,063 $ 17,922 Commercial business 34,658 (8,445) 1,368 3,298 30,879 Agriculture 9,589 (194) 189 4,315 13,899 Construction 14,395 (232) 3,329 (5,640) 11,852 Consumer loans: One-to-four family residential real estate 8,024 (1,004) 1,224 (786) 7,458 Other consumer 787 (64) 148 (292) 579 Unallocated 1,150 — — (1,079) 71 Total 83,369 (11,647) 9,059 1,879 82,660 The $73.0 million increase in the ACL at September 30, 2020 compared to the ALLL at December 31, 2019 was primarily the result of COVID-19 and the 2020 downturn in the national and global economies as well as increased unemployment rates. The ACL at September 30, 2020 does not include a reserve for the PPP loans as these loans are fully guaranteed by the SBA. Changes in the allowance for unfunded commitments and letters of credit, a component of “Other liabilities” in the Consolidated Balance Sheets, are summarized as follows: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 (in thousands) Beginning balance $ 8,800 $ 3,980 $ 3,430 $ 4,330 Impact of adopting ASC 326 — — 1,570 $ — Net changes in the allowance for unfunded commitments and letters of credit 800 (400) 4,600 (750) Ending balance $ 9,600 $ 3,580 $ 9,600 $ 3,580 Credit Quality Indicators The extension of credit in the form of loans or other credit products to consumer and commercial clients is one of our principal business activities. Our policies and applicable laws and regulations require risk analysis as well as ongoing portfolio and credit management. We manage our credit risk through lending limit constraints, credit review, approval policies and extensive, ongoing internal monitoring. We also manage credit risk through diversification of the loan portfolio by type of loan, type of industry and type of borrower and by limiting the aggregation of debt to a single borrower. We evaluate the credit quality of our loan portfolio using regulatory risk ratings, which are based on relevant information about the borrower’s financial condition, including current financial condition, historical payment experience, credit documentation and current economic trends. Risk ratings are reviewed and updated whenever appropriate, with more periodic reviews as the risk and dollar value of the loss on the loan increases. All loans risk rated special mention or worse with amortized costs exceeding $100,000 are reviewed at least quarterly with more frequent review for specific loans. Pass rated loans are generally considered to have sufficient sources of repayment in order to repay the loan in full in accordance with all terms and conditions. Special Mention rated loans have potential weaknesses that, if left uncorrected, may result in deterioration of the repayment prospects for the asset or in the Company’s credit position at some future date. Loans with a risk rating of Substandard or worse are reviewed to assess the ability of our borrowers to service all interest and principal obligations and, as a result, the risk rating or accrual status may be adjusted accordingly. Loans risk rated as Substandard reflect loans where a loss is possible if loan weaknesses are not corrected. Doubtful rated loans have a high probability of loss; however, the amount of loss has not yet been determined. Loss rated loans are considered uncollectible and when identified, are charged-off. The following is an analysis of the credit quality of our loan portfolio, as of September 30, 2020 and December 31, 2019: Revolving Loans Amortized Cost Basis Revolving Loans Converted to Term Loans Amortized Cost Basis Term Loans Amortized Cost Basis by Origination Year 2020 2019 2018 2017 2016 Prior Total (1) September 30, 2020 (in thousands) Commercial loans: Commercial real estate Pass $ 491,625 $ 636,127 $ 499,924 $ 542,049 $ 434,390 $ 1,032,016 $ 48,664 $ 3,552 $ 3,688,347 Special mention 8,717 59,899 18,993 15,175 47,881 50,571 2,148 — 203,384 Substandard — 9,977 17,307 13,014 45,421 43,650 5,935 — 135,304 Total commercial real estate $ 500,342 $ 706,003 $ 536,224 $ 570,238 $ 527,692 $ 1,126,237 $ 56,747 $ 3,552 $ 4,027,035 Commercial business Pass $ 1,175,587 $ 409,759 $ 357,128 $ 233,037 $ 240,648 $ 256,178 $ 915,373 $ 8,674 $ 3,596,384 Special mention 4,856 51,204 8,635 25,626 6,514 11,907 35,819 — 144,561 Substandard 3,791 6,005 17,758 5,836 7,153 6,369 44,651 3,501 95,064 Total commercial business $ 1,184,234 $ 466,968 $ 383,521 $ 264,499 $ 254,315 $ 274,454 $ 995,843 $ 12,175 $ 3,836,009 Agriculture Pass $ 147,892 $ 99,483 $ 42,464 $ 59,828 $ 60,007 $ 62,529 $ 290,986 $ 12,273 $ 775,462 Special mention — 519 — 33 272 — 1,801 — 2,625 Substandard 2,676 13,010 6,950 4,278 2,399 4,482 37,918 490 72,203 Total agriculture $ 150,568 $ 113,012 $ 49,414 $ 64,139 $ 62,678 $ 67,011 $ 330,705 $ 12,763 $ 850,290 Construction Pass $ 89,744 $ 101,060 $ 24,130 $ 4,531 $ 782 $ 1,883 $ 25,536 $ — $ 247,666 Special mention — 2,259 — — — — — — 2,259 Substandard — 17,622 5,539 — — 57 33 — 23,251 Total construction $ 89,744 $ 120,941 $ 29,669 $ 4,531 $ 782 $ 1,940 $ 25,569 $ — $ 273,176 Consumer loans: One-to-four family residential real estate Pass $ 88,632 $ 83,137 $ 72,896 $ 33,149 $ 24,987 $ 87,267 $ 265,475 $ 3,110 $ 658,653 Special mention — — — — — 206 297 — 503 Substandard — 735 227 1,177 344 2,463 1,133 197 6,276 Total one-to-four family real estate $ 88,632 $ 83,872 $ 73,123 $ 34,326 $ 25,331 $ 89,936 $ 266,905 $ 3,307 $ 665,432 Other consumer Pass $ 4,412 $ 3,684 $ 4,299 $ 1,172 $ 327 $ 1,161 $ 20,937 $ 736 $ 36,728 Substandard 31 — — 6 4 171 24 41 277 Total consumer $ 4,443 $ 3,684 $ 4,299 $ 1,178 $ 331 $ 1,332 $ 20,961 $ 777 $ 37,005 Total $ 2,017,963 $ 1,494,480 $ 1,076,250 $ 938,911 $ 871,129 $ 1,560,910 $ 1,696,730 $ 32,574 $ 9,688,947 Less: Allowance for credit losses 156,968 Loans, net $ 9,531,979 __________ (1) Loans that are on short-term deferments are treated as Pass loans and will not be reported as past due provided that they are performing in accordance with the modified terms. Revolving Loans Amortized Cost Basis Revolving Loans Converted to Term Loans Amortized Cost Basis Term Loans Amortized Cost Basis by Origination Year 2019 2018 2017 2016 2015 Prior Total December 31, 2019 (in thousands) Commercial loans: Commercial real estate Pass $ 699,336 $ 562,992 $ 621,113 $ 565,928 $ 441,220 $ 873,687 $ 52,276 $ 19,986 $ 3,836,538 Special mention 1,824 305 7,019 3,360 — 3,426 — — 15,934 Substandard 47 10,698 9,320 36,229 20,278 11,738 — 5,071 93,381 Total commercial real estate $ 701,207 $ 573,995 $ 637,452 $ 605,517 $ 461,498 $ 888,851 $ 52,276 $ 25,057 $ 3,945,853 Commercial business Pass $ 479,481 $ 442,222 $ 330,934 $ 301,337 $ 157,436 $ 199,089 $ 963,663 $ 25,577 $ 2,899,739 Special mention 2,241 6,673 56 2,006 52 585 12,710 — 24,323 Substandard 85 17,240 3,458 9,534 3,227 3,972 26,639 1,396 65,551 Total commercial business $ 481,807 $ 466,135 $ 334,448 $ 312,877 $ 160,715 $ 203,646 $ 1,003,012 $ 26,973 $ 2,989,613 Agriculture Pass $ 107,152 $ 54,950 $ 70,337 $ 71,874 $ 33,597 $ 56,342 $ 280,984 $ 10,036 $ 685,272 Special mention 557 2,535 1,381 — 64 576 5,336 — 10,449 Substandard 7,291 6,047 6,173 5,907 1,477 5,698 30,669 6,388 69,650 Total agriculture $ 115,000 $ 63,532 $ 77,891 $ 77,781 $ 35,138 $ 62,616 $ 316,989 $ 16,424 $ 765,371 Construction Pass $ 183,525 $ 91,342 $ 40,514 $ 1,067 $ 939 $ 1,601 $ 33,388 $ 7,793 $ 360,169 Special mention — 1,264 — — — — 41 — 1,305 Substandard — — — — — 59 — — 59 Total construction $ 183,525 $ 92,606 $ 40,514 $ 1,067 $ 939 $ 1,660 $ 33,429 $ 7,793 $ 361,533 Consumer loans: One-to-four family real estate Pass $ 103,315 $ 77,877 $ 32,440 $ 25,052 $ 27,294 $ 80,370 $ 283,830 $ 554 $ 630,732 Substandard — 228 800 400 623 3,156 905 481 6,593 Total one-to-four family real estate $ 103,315 $ 78,105 $ 33,240 $ 25,452 $ 27,917 $ 83,526 $ 284,735 $ 1,035 $ 637,325 Other consumer Pass $ 9,276 $ 5,713 $ 1,974 $ 758 $ 848 $ 1,306 $ 23,351 $ 508 $ 43,734 Substandard — — 1 — — 8 27 — 36 Total consumer $ 9,276 $ 5,713 $ 1,975 $ 758 $ 848 $ 1,314 $ 23,378 $ 508 $ 43,770 Total $ 1,594,130 $ 1,280,086 $ 1,125,520 $ 1,023,452 $ 687,055 $ 1,241,613 $ 1,713,819 $ 77,790 $ 8,743,465 Less: Allowance for credit losses 83,968 Loans, net $ 8,659,497

Other Real Estate Owned

Other Real Estate Owned	9 Months Ended
	Sep. 30, 2020
Other Real Estate, Foreclosed Assets, and Repossessed Assets [Abstract]
Other Real Estate Owned	Other Real Estate Owned The following tables set forth activity in OREO for the three and nine months ended September 30, 2020 and 2019: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 (in thousands) Balance, beginning of period $ 747 $ 1,118 $ 552 $ 6,019 Transfers in 475 — 1,033 386 Valuation adjustments — — — (195) Proceeds from sale of OREO property (681) (588) (1,026) (6,382) Gain on sale of OREO, net 82 95 64 797 Balance, end of period $ 623 $ 625 $ 623 $ 625 At September 30, 2020, there were no foreclosed residential real estate properties held as OREO. The recorded investment of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings were in process was $436 thousand.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Other Intangible Assets In accordance with the Intangibles – Goodwill and Other topic of the FASB ASC, goodwill is not amortized but is reviewed for potential impairment at the reporting unit level. Management analyzes its goodwill for impairment on an annual basis on July 31 and between annual tests in certain circumstances such as material adverse changes in legal, business, regulatory and economic factors. An impairment loss is recorded to the extent that the carrying amount of goodwill exceeds its implied fair value. The Company performed an annual impairment assessment as of July 31, 2020 and concluded that there was no impairment. The CDI is evaluated for impairment if events and circumstances indicate a possible impairment. The CDI is amortized on an accelerated basis over an estimated life of 10 years. The following table sets forth activity for goodwill and other intangible assets for the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Goodwill Total goodwill $ 765,842 $ 765,842 $ 765,842 $ 765,842 Other intangible assets, net CDI: Gross CDI balance at beginning of period 105,473 105,473 105,473 105,473 Accumulated amortization at beginning of period (75,454) (65,852) (70,934) (60,455) CDI, net at beginning of period 30,019 39,621 34,539 45,018 CDI current period amortization (2,193) (2,632) (6,713) (8,029) Total CDI, net at end of period 27,826 36,989 27,826 36,989 Intangible assets not subject to amortization 919 919 919 919 Other intangible assets, net at end of period 28,745 37,908 28,745 37,908 Total goodwill and other intangible assets at end of period $ 794,587 $ 803,750 $ 794,587 $ 803,750 The following table provides the estimated future amortization expense of our CDI for the remaining three months ending December 31, 2020 and the succeeding four years: Year ending December 31, (in thousands) 2020 $ 2,012 2021 7,264 2022 5,880 2023 4,552 2024 3,432

Revolving Line of Credit

Revolving Line of Credit	9 Months Ended
	Sep. 30, 2020
Line of Credit [Member]
Line of Credit Facility [Line Items]
Short-term Debt [Text Block]	Revolving Line of CreditThe Company has a $15.0 million short-term credit facility with an unaffiliated bank that expires May 27, 2021. This facility has a variable interest rate and provides the Company additional liquidity, if needed, for various corporate activities including the repurchase of shares of Columbia Banking System, Inc. common stock. There was no outstanding balance at both September 30, 2020 and December 31, 2019. The credit agreement requires the Company to comply with certain covenants including those related to asset quality and capital levels. The Company was in compliance with all covenants associated with this facility at September 30, 2020.

Derivatives and Balance Sheet O

Derivatives and Balance Sheet Offsetting	9 Months Ended
	Sep. 30, 2020
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Derivatives and Hedging Activities	Derivatives, Hedging Activities and Balance Sheet Offsetting The Company is exposed to certain risks arising from both its business and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of its assets and liabilities and the use of derivative financial instruments. Specifically, the Company enters into interest rate-based derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts. The Company’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Company’s known or expected cash receipts and its known or expected cash payments principally related to the Company’s loan portfolio. The Company’s objectives in using interest rate derivatives are to add stability to interest income and to manage its exposure to interest rate movements. To accomplish this objective, the Company uses interest rate collars as part of its interest rate risk management strategy. Interest rate collars designated as cash flow hedges involve the payments of variable-rate amounts if interest rates rise above the cap strike rate on the contract and receipts of variable-rate amounts if interest rates fall below the floor strike rate on the contract. These derivative contracts are used to hedge the variable cash flows associated with existing variable-rate assets. With respect to derivatives designated and that qualify as cash flow hedges of interest rate risk, the gain or loss on the derivative is recorded in accumulated other comprehensive income (loss) and subsequently reclassified into interest income in the same period(s) during which the hedged transaction affects earnings. Amounts reported in accumulated other comprehensive income (loss) related to derivatives will be reclassified to interest income as interest payments are received on the Company’s variable-rate assets. During the next 12 months, the Company estimates that there will be $10.7 million reclassified as an increase to interest income. In addition, the Company periodically enters into certain commercial loan interest rate swap agreements in order to provide commercial loan customers the ability to convert from variable to fixed interest rates. Under these agreements, the Company enters into a variable-rate loan agreement with a customer in addition to a swap agreement. This swap agreement effectively converts the customer’s variable rate loan into a fixed rate. The Company then enters into a corresponding swap agreement with a third-party in order to offset its exposure on the variable and fixed components of the customer agreement. As the interest rate swap agreements with the customers and third parties are not designated as hedges under the Derivatives and Hedging topic of the FASB ASC, the instruments are marked to market in earnings. The notional amount of open interest rate swap agreements at September 30, 2020 and December 31, 2019 was $575.4 million and $428.6 million, respectively. During the three and nine month periods ended September 30, 2020, mark-to-market losses of $2 thousand and $475 thousand, respectively, were recorded to “Other” noninterest expense. During the three months ended September 30, 2019, there was no mark-to-market gain or loss recorded. During the nine months ended September 30, 2019, there was a $2 thousand mark-to-market loss recorded to “Other” noninterest expense. The following table presents the fair value of derivatives, as well as their classification on the Consolidated Balance Sheet at September 30, 2020 and December 31, 2019: Asset Derivatives Liability Derivatives September 30, 2020 December 31, 2019 September 30, 2020 December 31, 2019 Balance Sheet Fair Value Balance Sheet Fair Value Balance Sheet Fair Value Balance Sheet Fair Value (in thousands) Derivatives designated as hedging instruments: Interest rate collar Other assets $ 35,668 Other assets $ 14,727 Other liabilities $ — Other liabilities $ — Derivatives not designated as hedging instruments: Interest rate swap contracts Other assets $ 53,202 Other assets $ 19,144 Other liabilities $ 53,677 Other liabilities $ 19,145 The table below presents the effect of cash flow hedge accounting on accumulated other comprehensive income (loss) at September 30, 2020 and 2019: Amount of Gain or (Loss) Recognized in Accumulated Other Comprehensive Income on Derivative Location of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income into Income Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income into Income Three Months Ended September 30, Three Months Ended September 30, 2020 2019 2020 2019 (in thousands) Interest rate collar $ (81) $ 4,088 Interest income $ 2,673 $ 76 Nine Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Interest rate collar $ 26,744 $ 19,779 Interest income $ 5,803 $ 76 The notional amount of the interest rate collar was $500.0 million at September 30, 2020. The cash flow hedge was determined to be effective during the periods presented and, as a result, qualifies for hedge accounting treatment. The Company is party to interest rate swap contracts, interest rate collar and repurchase agreements that are subject to enforceable master netting arrangements or similar agreements. Under these agreements, the Company may have the right to net settle multiple contracts with the same counterparty. The following tables show the gross interest rate swap contracts, collar agreements and repurchase agreements in the Consolidated Balance Sheets and the respective collateral received or pledged in the form of cash or other financial instruments. The collateral amounts in these tables are limited to the outstanding balances of the related asset or liability. Therefore, instances of over-collateralization are not shown. Gross Amounts of Recognized Assets/Liabilities Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts of Assets/Liabilities Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Collateral Pledged/Received Net Amount September 30, 2020 (in thousands) Assets Interest rate swap contracts $ 53,202 $ — $ 53,202 $ — $ 53,202 Interest rate collar $ 35,668 $ — $ 35,668 $ (35,668) — Liabilities Interest rate swap contracts $ 53,677 $ — $ 53,677 $ (53,677) $ — Repurchase agreements $ 26,966 $ — $ 26,966 $ (26,966) $ — December 31, 2019 Assets Interest rate swap contracts $ 19,144 $ — $ 19,144 $ — $ 19,144 Interest rate collar $ 14,727 $ — $ 14,727 $ (14,727) — Liabilities Interest rate swap contracts $ 19,145 $ — $ 19,145 $ (19,145) $ — Repurchase agreements $ 64,437 $ — $ 64,437 $ (64,437) $ — The Company’s agreements with each of its derivative counterparties provide that if the Company defaults or is capable of being declared in default on any of its indebtedness, then the Company could also be declared in default on its derivative obligations. The following table presents the class of collateral pledged for repurchase agreements as well as the remaining contractual maturity of the repurchase agreements: Remaining contractual maturity of the agreements Overnight and continuous Up to 30 days 30 - 90 days Greater than 90 days Total September 30, 2020 (in thousands) Class of collateral pledged for repurchase agreements U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 26,966 $ — $ — $ — $ 26,966 Gross amount of recognized liabilities for repurchase agreements 26,966 Amounts related to agreements not included in offsetting disclosure $ — The collateral utilized for the Company’s repurchase agreements is subject to market fluctuations as well as prepayments of principal. The Company monitors the risk of the fair value of its pledged collateral falling below acceptable amounts based on the type of the underlying repurchase agreement. The pledged collateral related to the Company’s $27.0 million sweep repurchase agreements, which mature on an overnight basis, is monitored on a daily basis as the underlying sweep accounts can have frequent transaction activity and the amount of pledged collateral is adjusted as necessary.

Commitments and contingent liab

Commitments and contingent liabilities	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	Commitments and Contingent Liabilities Lease Commitments: The Company’s lease commitments consist primarily of leased locations under various non-cancellable operating leases that expire between 2021 and 2043. The majority of the leases contain renewal options and provisions for increases in rental rates based on an agreed upon index or predetermined escalation schedule. Financial Instruments with Off-Balance Sheet Risk: In the normal course of business, the Company makes loan commitments (typically unfunded loans and unused lines of credit) and issues standby letters of credit to accommodate the financial needs of its customers. At September 30, 2020 and December 31, 2019, the Company’s loan commitments amounted to $3.79 billion and $2.67 billion, respectively. Standby letters of credit commit the Company to make payments on behalf of customers under specified conditions. Historically, no significant losses have been incurred by the Company under standby letters of credit. Both arrangements have credit risk essentially the same as that involved in extending loans to customers and are subject to the Company’s normal credit policies, including collateral requirements, where appropriate. Standby letters of credit were $30.3 million and $25.7 million at September 30, 2020 and December 31, 2019, respectively. In addition, there were $23 thousand commitments under commercial letters of credit used to facilitate customers’ trade transactions and other off-balance sheet liabilities at both September 30, 2020 and December 31, 2019. Legal Proceedings: The Company and its subsidiaries are from time to time defendants in and are threatened with various legal proceedings arising from their regular business activities. Management, after consulting with legal counsel, is of the opinion that the ultimate liability, if any, resulting from these pending or threatened actions and proceedings will not have a material effect on the financial statements of the Company.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2020
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders’ Equity Dividends: The following table summarizes year-to-date dividend activity as of September 30, 2020: Declared Regular Cash Dividends Per Common Share Special Cash Dividends Per Common Share Record Date Paid Date January 23, 2020 $ 0.28 $ 0.22 February 5, 2020 February 19, 2020 April 30, 2020 $ 0.28 $ — May 14, 2020 May 28, 2020 July 23, 2020 $ 0.28 $ — August 5, 2020 August 19, 2020 Subsequent to quarter end, on October 29, 2020, the Company declared a regular quarterly cash dividend of $0.28 per common share payable on November 25, 2020 to shareholders of record at the close of business on November 11, 2020. The payment of cash dividends is subject to federal regulatory requirements for capital levels and other restrictions. In addition, the cash dividends paid by Columbia Bank to the Company are subject to both federal and state regulatory requirements. Share Repurchase Program:

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income The following table shows changes in accumulated other comprehensive income (loss) by component for the three and nine months ended September 30, 2020 and 2019: Unrealized Gains and Losses on Available for Sale Securities (1) Unrealized Gains and Losses on Pension Plan Liability (1) Unrealized Gains and Losses on Hedging Instruments (1) Total (1) Three Months Ended September 30, 2020 (in thousands) Beginning balance $ 155,403 $ (3,815) $ 29,489 $ 181,077 Other comprehensive loss before reclassifications (1,442) — (62) (1,504) Amounts reclassified from accumulated other comprehensive income (2) — 80 (2,052) (1,972) Net current-period other comprehensive income (loss) (1,442) 80 (2,114) (3,476) Ending balance $ 153,961 $ (3,735) $ 27,375 $ 177,601 Three Months Ended September 30, 2019 Beginning balance $ 37,162 $ (2,055) $ 12,043 $ 47,150 Other comprehensive income before reclassifications 14,593 — 3,137 17,730 Amounts reclassified from accumulated other comprehensive income (2) — 62 (58) 4 Net current-period other comprehensive income 14,593 62 3,079 17,734 Ending balance $ 51,755 $ (1,993) $ 15,122 $ 64,884 Nine Months Ended September 30, 2020 Beginning balance $ 33,038 $ (3,974) $ 11,303 $ 40,367 Other comprehensive income before reclassifications 121,114 — 20,526 141,640 Amounts reclassified from accumulated other comprehensive income (2) (191) 239 (4,454) (4,406) Net current-period other comprehensive income 120,923 239 16,072 137,234 Ending balance $ 153,961 $ (3,735) $ 27,375 $ 177,601 Nine Months Ended September 30, 2019 Beginning balance $ (33,128) $ (2,177) $ — $ (35,305) Other comprehensive income before reclassifications 86,519 — 15,180 101,699 Amounts reclassified from accumulated other comprehensive loss (2) (1,636) 184 (58) (1,510) Net current-period other comprehensive income 84,883 184 15,122 100,189 Ending balance $ 51,755 $ (1,993) $ 15,122 $ 64,884 __________ (1) All amounts are net of tax. Amounts in parentheses indicate debits. (2) See following table for details about these reclassifications. The following table shows details regarding the reclassifications from accumulated other comprehensive income (loss) for the three and nine months ended September 30, 2020 and 2019: Amount Reclassified from Accumulated Other Comprehensive Income (Loss) Three Months Ended September 30, Nine Months Ended September 30, Affected line Item in the Consolidated 2020 2019 2020 2019 Statement of Income (in thousands) Unrealized gains on available for sale debt securities $ — $ — $ 249 $ 2,132 Investment securities gains, net — — 249 2,132 Total before tax — — (58) (496) Income tax provision $ — $ — $ 191 $ 1,636 Net of tax Amortization of pension plan liability actuarial losses $ (104) $ (81) $ (311) $ (240) Compensation and employee benefits (104) (81) (311) (240) Total before tax 24 19 72 56 Income tax provision $ (80) $ (62) $ (239) $ (184) Net of tax Unrealized gains from hedging instruments $ 2,673 $ 76 $ 5,803 $ 76 Loans 2,673 76 5,803 76 Total before tax (621) (18) (1,349) (18) Income tax provision $ 2,052 $ 58 $ 4,454 $ 58 Net of tax

Fair Value Accounting and Measu

Fair Value Accounting and Measurement	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Accounting and Measurement	Fair Value Accounting and Measurement The Fair Value Measurements and Disclosures topic of the FASB ASC defines fair value, establishes a consistent framework for measuring fair value and expands disclosure requirements about fair value. We hold fixed and variable rate interest-bearing securities, investments in marketable equity securities and certain other financial instruments, which are carried at fair value. Fair value is determined based upon quoted prices when available or through the use of alternative approaches, such as matrix or model pricing, when market quotes are not readily accessible or available. The valuation techniques are based upon observable and unobservable inputs. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect our own market assumptions. These two types of inputs create the following fair value hierarchy: Level 1 – Quoted prices for identical instruments in active markets that are accessible at the measurement date. Level 2 – Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model derived valuations whose inputs are observable or whose significant value drivers are observable. Level 3 – Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable. Fair values are determined as follows: Debt securities available for sale at fair value are priced using a combination of market activity, industry recognized information sources, yield curves, discounted cash flow models and other factors. These fair value calculations are considered a Level 2 input method under the provisions of the Fair Value Measurements and Disclosures topic of the FASB ASC for all debt securities available for sale. Interest rate contracts and the interest rate collar are valued in models, which use as their basis, readily observable market parameters and are classified within Level 2 of the valuation hierarchy .The following table sets forth the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis at September 30, 2020 and December 31, 2019 by level within the fair value hierarchy. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement: Fair Value Fair Value Measurements at Reporting Date Using Level 1 Level 2 Level 3 September 30, 2020 (in thousands) Assets Debt securities available for sale: U.S. government agency and government-sponsored enterprise mortgage-back securities and collateralized mortgage obligations $ 3,121,642 $ — $ 3,121,642 $ — Other asset-backed securities 293,024 — 293,024 — State and municipal securities 557,444 — 557,444 — U.S. government agency and government-sponsored enterprise securities 309,610 — 309,610 — Total debt securities available for sale $ 4,281,720 $ — $ 4,281,720 $ — Other assets: Interest rate contracts $ 53,202 $ — $ 53,202 $ — Interest rate collar $ 35,668 $ — $ 35,668 $ — Liabilities Other liabilities: Interest rate contracts $ 53,677 $ — $ 53,677 $ — Fair Value Fair Value Measurements at Reporting Date Using Level 1 Level 2 Level 3 December 31, 2019 (in thousands) Assets Debt securities available for sale: U.S. government agency and government-sponsored enterprise mortgage-back securities and collateralized mortgage obligations $ 2,892,950 $ — $ 2,892,950 $ — Other asset-backed securities 196,050 — 196,050 — State and municipal securities 488,802 — 488,802 — U.S. government agency and government-sponsored enterprise securities 168,340 — 168,340 — Total debt securities available for sale $ 3,746,142 $ — $ 3,746,142 $ — Other assets: Interest rate contracts $ 19,144 $ — $ 19,144 $ — Interest rate collar $ 14,727 $ — $ 14,727 $ — Liabilities Other liabilities: Interest rate contracts $ 19,145 $ — $ 19,145 $ — Nonrecurring Measurements Certain assets and liabilities are measured at fair value on a nonrecurring basis after initial recognition such as collateral dependent loans. The following valuation techniques and inputs were used to estimate the fair value of collateral dependent loans and equity securities without readily determinable fair value. Collateral dependent loans - A collateral dependent loan is a loan in which repayment is expected to be provided solely by the underlying collateral. The fair market value of the collateral is determined by either the discounted expected future cash flows from the operation of the collateral or the appraised value of the collateral, less costs to sell. The collateral dependent loan valuations are performed in conjunction with the allowance for credit losses process on a quarterly basis. Equity securities without readily determinable fair value - The Company measures equity securities without readily determinable fair values at cost less impairment (if any), plus or minus observable price changes from an identical or similar investment of the same issuer, with such changes recognized in earnings. Our equity securities without readily determinable fair values consist of 77,683 Visa Class B shares. These shares are currently subject to certain transfer restrictions and will be convertible into Visa Class A shares upon final resolution of certain litigation matters involving Visa. For additional information, please see Note 3 to the Consolidated Financial Statements in “Item 1. Financial Statements (unaudited)” of this report. The following table presents the carrying value of equity securities, without readily determinable fair values, still held as of September 30, 2020, that are measured under the measurement alternative and related adjustments recorded during the periods presented for those securities with observable price changes. These securities are included in the nonrecurring fair value tables when applicable price changes are observable. Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Equity securities without readily determinable fair values (in thousands) Carrying value, beginning of period $ 13,425 $ — $ — $ — Upward carrying value changes — — 13,425 — Carrying value, end of period $ 13,425 $ — $ 13,425 $ — The following tables set forth information related to the Company’s assets that were measured using fair value estimates on a nonrecurring basis during the current and prior year quarterly periods: Fair Value at September 30, 2020 Fair Value Measurements Gains During the Three Months Ended September 30, 2020 Losses During the Nine Months Ended September 30, 2020 Level 1 Level 2 Level 3 (in thousands) Collateral dependent loans $ 11,899 $ — $ — $ 11,899 $ (153) $ 4,941 Fair Value at September 30, 2019 Fair Value Measurements Losses During the Three Months Ended September 30, 2019 Losses During the Nine Months Ended September 30, 2019 Level 1 Level 2 Level 3 (in thousands) Collateral dependent loans $ 8,990 $ — $ — $ 8,990 $ 1,722 $ 3,299 The losses on collateral dependent loans disclosed above represent the amount of the allowance for credit losses and/or charge-offs during the period applicable to loans held at period-end. The amount of the allowance is included in the ACL. Quantitative information about Level 3 fair value measurements The range and weighted average of the significant unobservable inputs used to fair value our Level 3 nonrecurring assets, along with the valuation techniques used, are shown in the following table: Fair Value at September 30, 2020 Valuation Technique Unobservable Input Range (Weighted Average) (1) (dollars in thousands) Collateral dependent loans (2) $ 11,899 Fair Market Value of Collateral Adjustment to Stated Value 0.00% - 100.00% (15.57%) __________ (1) Discount applied to appraised value or stated value (in the case of accounts receivable, fixed assets and inventory). (2) Collateral consists of accounts receivable, fixed assets, inventory and real estate. Fair Value at September 30, 2019 Valuation Technique Unobservable Input Range (Weighted Average) (1) (dollars in thousands) Collateral dependent loans (2) $ 8,990 Fair Market Value of Collateral Adjustment to Stated Value 0.00% - 100.00% (42.09%) __________ (1) Discount applied to appraised value or stated value (in the case of accounts receivable, fixed assets and inventory). (2) Collateral consists of cash, accounts receivable, fixed assets, inventory and real estate. The following tables summarize carrying amounts and estimated fair values of selected financial instruments by level within the fair value hierarchy at September 30, 2020 and December 31, 2019: September 30, 2020 Carrying Fair Level 1 Level 2 Level 3 (in thousands) Assets Cash and due from banks $ 193,823 $ 193,823 $ 193,823 $ — $ — Interest-earning deposits with banks 736,422 736,422 736,422 — — Debt securities available for sale 4,281,720 4,281,720 — 4,281,720 — Equity securities without readily determinable fair values 13,425 13,425 — — 13,425 FHLB stock 10,280 10,280 — 10,280 — Loans held for sale 24,407 24,407 — 24,407 — Loans 9,531,979 9,980,912 — — 9,980,912 Interest rate contracts 53,202 53,202 — 53,202 — Interest rate collar 35,668 35,668 — 35,668 — Liabilities Time deposits $ 337,228 $ 337,386 $ — $ 337,386 $ — FHLB advances 7,427 9,354 — 9,354 — Repurchase agreements 26,966 26,966 — 26,966 — Subordinated debentures 35,139 35,368 — 35,368 — Interest rate contracts 53,677 53,677 — 53,677 — December 31, 2019 Carrying Fair Level 1 Level 2 Level 3 (in thousands) Assets Cash and due from banks $ 223,541 $ 223,541 $ 223,541 $ — $ — Interest-earning deposits with banks 24,132 24,132 24,132 — — Debt securities available for sale 3,746,142 3,746,142 — 3,746,142 — FHLB stock 48,120 48,120 — 48,120 — Loans held for sale 17,718 17,718 — 17,718 — Loans 8,659,497 8,883,865 — — 8,883,865 Interest rate contracts 19,144 19,144 — 19,144 — Interest rate collar 14,727 14,727 — 14,727 — Liabilities Time deposits $ 400,070 $ 397,736 $ — $ 397,736 $ — FHLB advances 953,469 952,762 — 952,762 — Repurchase agreements 64,437 64,437 — 64,437 — Subordinated debentures 35,277 35,491 — 35,491 — Interest rate contracts 19,145 19,145 — 19,145 —

Earnings per Common Share

Earnings per Common Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share The Company applies the two-class method of computing basic and diluted EPS. Under the two-class method, EPS is determined for each class of common stock and participating security according to dividends declared and participation rights in undistributed earnings. The Company issues restricted shares under share-based compensation plans which qualify as participating securities. The following table sets forth the computation of basic and diluted EPS for the three and nine months ended September 30, 2020 and 2019: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 (in thousands except per share amounts) Basic EPS: Net income $ 44,734 $ 50,727 $ 95,944 $ 148,322 Less: Earnings allocated to participating securities: Nonvested restricted shares 164 358 487 1,204 Earnings allocated to common shareholders $ 44,570 $ 50,369 $ 95,457 $ 147,118 Weighted average common shares outstanding 70,726 71,803 70,870 72,256 Basic earnings per common share $ 0.63 $ 0.70 $ 1.35 $ 2.04 Diluted EPS: Earnings allocated to common shareholders $ 44,570 $ 50,369 $ 95,457 $ 147,118 Weighted average common shares outstanding 70,726 71,803 70,870 72,256 Dilutive effect of equity awards 36 — 36 1 Weighted average diluted common shares outstanding 70,762 71,803 70,906 72,257 Diluted earnings per common share $ 0.63 $ 0.70 $ 1.35 $ 2.04 Potentially dilutive share options that were not included in the computation of diluted EPS because to do so would be anti-dilutive 596 — 487 —

Revenue from Contracts with Cus

Revenue from Contracts with Customers	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	Revenue from Contracts with Customers Revenue in the scope of Topic 606, Revenue from Contracts with Customers is measured based on the consideration specified in the contract with a customer and excludes amounts collected on behalf of third parties. The vast majority of the Company’s revenue is specifically outside the scope of Topic 606. For in-scope revenue, the following is a description of principal activities, separated by the timing of revenue recognition from which the Company generates its revenue from contracts with customers. a. Revenue earned at a point in time - Examples of revenue earned at a point in time are ATM transaction fees, wire transfer fees, overdraft fees, interchange fees and foreign exchange transaction fees. Revenue is primarily based on the number and type of transactions and is generally derived from transactional information accumulated by our systems and is recognized immediately as the transactions occur or upon providing the service to complete the customer’s transaction. The Company is the principal in each of these contracts, with the exception of interchange fees, in which case we are acting as the agent and record revenue net of expenses paid to the principal. b. Revenue earned over time - The Company earns revenue from contracts with customers in a variety of ways where the revenue is earned over a period of time - generally monthly. Examples of this type of revenue are deposit account maintenance fees, investment advisory fees, merchant revenue and safe deposit box fees. Revenue is generally derived from transactional information accumulated by our systems or those of third-parties and is recognized as the related transactions occur or services are rendered to the customer. The Company recognizes revenue from contracts with customers when it satisfies its performance obligations. The Company’s performance obligations are typically satisfied as services are rendered and our contracts generally do not include multiple performance obligations. As a result, there are no contract balances as payments and services are rendered simultaneously. Payment is generally collected at the time services are rendered, monthly or quarterly. Unsatisfied performance obligations at the report date are not material to our Consolidated Financial Statements. In certain cases, other parties are involved with providing products and services to our customers. If the Company is principal in the transaction (providing goods or services itself), revenues are reported based on the gross consideration received from the customer and any related expenses are reported gross in noninterest expense. If the Company is an agent in the transaction (arranging for another party to provide goods or services), the Company reports its net fee or commission retained as revenue. Rebates, waivers and reversals are recorded as a reduction of the transaction price either when the revenue is recognized by the Company or at the time the rebate, waiver or reversal is earned by the customer. Practical expedients The Company applies the practical expedient in paragraph 606-10-32-18 and does not adjust the consideration from customers for the effects of a significant financing component if at contract inception the period between when the entity transfers the goods or services and when the customer pays for that good or service will be one year or less. The Company pays sales commissions to its employees in accordance with certain incentive plans and in connection with obtaining certain contracts with customers. The Company applies the practical expedient in paragraph 340-40-25-4 and expenses such sales commissions when incurred if the amortization period of the asset the Company otherwise would have recognized is one year or less. Sales commissions are included in compensation and employee benefits expense. For the Company’s contracts that have an original expected duration of one year or less, the Company uses the practical expedient in paragraph 606-10-50-14 and has not disclosed the amount of the transaction price allocated to unsatisfied performance obligations as of the end of each reporting period or when the Company expects to recognize this revenue. Disaggregation of revenue The following table shows the disaggregation of revenue from contracts with customers for the three and nine month periods ended September 30, 2020 and 2019: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Noninterest income: Revenue from contracts with customers: Deposit account and treasury management fees $ 6,658 $ 9,015 $ 20,538 $ 27,030 Card revenue 3,834 4,006 10,431 11,431 Financial services and trust revenue 3,253 3,226 9,481 9,608 Total revenue from contracts with customers 13,745 16,247 40,450 48,069 Other sources of noninterest income 8,727 11,783 40,488 27,305 Total noninterest income $ 22,472 $ 28,030 $ 80,938 $ 75,374

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Stock Repurchase Program On October 28, 2020, the board of directors approved a stock repurchase program to purchase up to 3.5 million shares, up to a maximum aggregate purchase price of $100.0 million. Interest rate collar In January 2019, the Company entered into a $500.0 million notional interest rate collar with a five-year term. In October 2020, the collar was terminated and resulted in a $34.9 million realized gain that was recorded in other comprehensive income, net of deferred income taxes. The gain will amortize into interest income through February 2024 which is in line with the initial term of the interest rate collar. The gain will be amortized in this manner as long as the cash flows pertaining to the hedged item are expected to occur.

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2020
Debt Securities, Available-for-sale [Abstract]
Securities Available for Sale	The following table summarizes the amortized cost, gross unrealized gains and losses, the allowance for credit losses and the resulting fair value of debt securities available for sale: Amortized Gross Gross Allowance for Credit Fair Value September 30, 2020 (in thousands) U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 2,957,028 $ 168,271 $ (3,657) $ — $ 3,121,642 Other asset-backed securities 284,499 9,055 (530) — 293,024 State and municipal securities 536,861 21,396 (813) — 557,444 U.S. government agency and government-sponsored enterprise securities 302,730 6,932 (52) — 309,610 Total $ 4,081,118 $ 205,654 $ (5,052) $ — $ 4,281,720 December 31, 2019 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 2,864,949 $ 47,223 $ (19,222) $ — $ 2,892,950 Other asset-backed securities 194,563 2,476 (989) — 196,050 State and municipal securities 478,366 10,660 (224) — 488,802 U.S. government agency and government-sponsored enterprise securities 165,218 3,127 (5) — 168,340 Total $ 3,703,096 $ 63,486 $ (20,440) $ — $ 3,746,142
Schedule of gross realized gains and losses on sales and calls of securities available for sale	The following table provides the proceeds and both gross realized gains and losses on sales of debt securities available for sale as well as other securities gains and losses for the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Proceeds from sales of debt securities available for sale $ — $ — $ 194,105 $ 259,554 Gross realized gains from sales of debt securities available for sale $ — $ — $ 435 $ 3,357 Gross realized losses from sales of debt securities available for sale — — (186) (1,225) Other securities gains (1) — — 16,425 — Investment securities gains, net $ — $ — $ 16,674 $ 2,132 __________ (1) Other securities gains includes gain from sale of Visa Class B restricted stock and subsequent write up to fair value of remaining Visa Class B shares. For additional information, please see Note 13 to the Consolidated Financial Statements in “Item 1. Financial Statements (unaudited)” of this report.
Unrealized gains and losses on equity securities	The following table provides the unrealized gains and losses on equity securities at the reporting date: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Gains recognized during the period on equity securities (1) $ — $ — $ 16,425 $ — Less: Gains recognized during the period on equity securities sold during the period (1) — — (3,000) — Unrealized gains recognized during the reporting period on equity securities still held at the reporting date (1) $ — $ — $ 13,425 $ — __________ (1) Visa Class B restricted stock owned by the Company was previously carried at a zero-cost basis due to existing transfer restrictions and uncertainty of covered litigation. The sale of shares by the Company of Visa Class B restricted shares during the second quarter of 2020 resulted in an observable market price. As a result, the Company adjusted the carrying value of its remaining shares of Visa Class B restricted shares upward to this observable market price.
Schedule of Contractual Maturities of Investment Securities Available for Sale	The scheduled contractual maturities of debt securities available for sale at September 30, 2020 are presented as follows: September 30, 2020 Amortized Cost Fair Value (in thousands) Due within one year $ 92,028 $ 92,931 Due after one year through five years 595,979 626,018 Due after five years through ten years 2,000,662 2,133,751 Due after ten years 1,392,449 1,429,020 Total debt securities available for sale $ 4,081,118 $ 4,281,720
Carrying Value of Securities Pledged As Collateral	The following table summarizes the carrying value of securities pledged as collateral to secure public funds, borrowings and other purposes as permitted or required by law: September 30, 2020 (in thousands) To secure public funds $ 441,379 To secure borrowings 111,978 Other securities pledged 168,870 Total securities pledged as collateral $ 722,227
Summary of Gross Unrealized Losses and Fair Value of the Investments with Unrealized Losses	The following table shows the gross unrealized losses and fair value of the Company’s debt securities available for sale for which an allowance for credit losses has not been recorded, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at September 30, 2020 and December 31, 2019: Less than 12 Months 12 Months or More Total Fair Unrealized Fair Unrealized Fair Unrealized September 30, 2020 (in thousands) U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 318,868 $ (2,817) $ 23,084 $ (840) $ 341,952 $ (3,657) Other asset-backed securities 71,552 (530) 95 — 71,647 (530) State and municipal securities 90,620 (813) — — 90,620 (813) U.S. government agency and government-sponsored enterprise securities 99,946 (52) — — 99,946 (52) Total $ 580,986 $ (4,212) $ 23,179 $ (840) $ 604,165 $ (5,052) December 31, 2019 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 1,055,903 $ (12,424) $ 491,539 $ (6,798) $ 1,547,442 $ (19,222) Other asset-backed securities 89,508 (880) 6,799 (109) 96,307 (989) State and municipal securities 12,363 (142) 12,587 (82) 24,950 (224) U.S. government agency and government-sponsored enterprise securities — — 10,495 (5) 10,495 (5) Total $ 1,157,774 $ (13,446) $ 521,420 $ (6,994) $ 1,679,194 $ (20,440)

Loans (Tables)

Loans (Tables)	9 Months Ended
	Sep. 30, 2020
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Analysis of Loan Portfolio by Major Types of Loans	The Company’s loan portfolio includes originated and purchased loans. The following is an analysis of the loan portfolio by segment and class (net of unearned income): September 30, 2020 December 31, 2019 (dollars in thousands) Commercial loans: Commercial real estate $ 4,027,035 $ 3,945,853 Commercial business 3,836,009 2,989,613 Agriculture 850,290 765,371 Construction 273,176 361,533 Consumer loans: One-to-four family residential real estate 665,432 637,325 Other consumer 37,005 43,770 Total loans 9,688,947 8,743,465 Less: Allowance for credit losses (156,968) (83,968) Total loans, net $ 9,531,979 $ 8,659,497 Loans held for sale $ 24,407 $ 17,718
Analysis of the Aged Loan Portfolio	The following is an aging of the recorded investment of the loan portfolio as of September 30, 2020 and December 31, 2019: Current 30 - 59 60 - 89 Greater Total Nonaccrual Total Loans September 30, 2020 (in thousands) Commercial loans: Commercial real estate $ 4,015,038 $ 547 $ 1,088 $ — $ 1,635 $ 10,362 $ 4,027,035 Commercial business 3,808,794 6,987 915 — 7,902 19,313 3,836,009 Agriculture 833,408 1,710 259 — 1,969 14,913 850,290 Construction 272,959 — — — — 217 273,176 Consumer loans: One-to-four family residential real estate 658,468 4,559 — — 4,559 2,405 665,432 Other consumer 36,744 215 25 — 240 21 37,005 Total $ 9,625,411 $ 14,018 $ 2,287 $ — $ 16,305 $ 47,231 $ 9,688,947 Current 30 - 59 60 - 89 Greater Total Nonaccrual Total Loans December 31, 2019 (in thousands) Commercial loans: Commercial real estate $ 3,935,633 $ 6,421 $ — — $ 6,421 $ 3,799 $ 3,945,853 Commercial business 2,959,826 6,081 2,769 — 8,850 20,937 2,989,613 Agriculture 755,719 2,283 2,346 — 4,629 5,023 765,371 Construction 360,582 951 — — 951 — 361,533 Consumer loans: One-to-four family residential real estate 631,109 2,516 408 — 2,924 3,292 637,325 Other consumer 43,654 80 27 — 107 9 43,770 Total $ 8,686,523 $ 18,332 $ 5,550 $ — $ 23,882 $ 33,060 $ 8,743,465
Interest written off on nonaccrual loans	The following table summarizes written-off interest on nonaccrual loans for the three and nine months ended September 30, 2020 and 2019: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Commercial loans $ 387 $ 149 $ 1,835 $ 1,316 Consumer loans 6 26 19 146 Total $ 393 $ 175 $ 1,854 $ 1,462
Analysis of Nonaccrual Loans	The following summarizes the amortized cost of nonaccrual loans for which there was no related ACL as of September 30, 2020 and December 31, 2019: September 30, 2020 December 31, 2019 (in thousands) Commercial loans: Commercial real estate $ 9,092 $ 1,715 Commercial business 11,713 15,762 Agriculture 11,074 1,798 Total $ 31,879 $ 19,275
Analysis of loans classified as Troubled Debt Restructurings (“TDR”)	The following is an analysis of loans classified as TDR during the three and nine months ended September 30, 2020 and 2019: Three Months Ended September 30, 2020 Three Months Ended September 30, 2019 Number of TDR Modifications Pre-Modification Post-Modification Number of TDR Modifications Pre-Modification Post-Modification (dollars in thousands) Commercial loans: Commercial business 4 $ 795 795 5 5,026 5,026 Agriculture 1 2,600 2,600 — — — Consumer loans: One-to-four family residential real estate 4 618 618 5 357 357 Other consumer — — — 1 1 1 Total 9 $ 4,013 $ 4,013 11 $ 5,384 $ 5,384 Nine Months Ended September 30, 2020 Nine Months Ended September 30, 2019 Number of TDR Modifications Pre-Modification Post-Modification Number of TDR Modifications Pre-Modification Post-Modification (dollars in thousands) Commercial loans: Commercial business 10 $ 2,757 $ 2,757 10 $ 6,560 $ 6,560 Agriculture 2 3,495 3,495 — — — Consumer loans: One-to-four family residential real estate 6 814 814 10 692 692 Other consumer — — — 1 1 1 Total 18 $ 7,066 $ 7,066 21 $ 7,253 $ 7,253

Allowance for Credit Losses a_2

Allowance for Credit Losses and Allowance for Unfunded Commitments and Letters of Credit (Tables)	9 Months Ended
	Sep. 30, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Credit Losses on Financing Receivables	The following tables show a detailed analysis of the ACL for the three and nine months ended September 30, 2020: Beginning Balance Charge-offs Recoveries Provision Ending Balance Three Months Ended September 30, 2020 (in thousands) Commercial loans: Commercial real estate $ 50,233 $ — $ 65 $ 11,026 $ 61,324 Commercial business 53,186 (3,164) 1,124 (574) 50,572 Agriculture 14,868 (1,269) 27 (1,165) 12,461 Construction 7,953 — 11 999 8,963 Consumer loans: One-to-four family residential real estate 23,711 (16) 1,301 (2,889) 22,107 Other consumer 1,595 (133) 76 3 1,541 Total $ 151,546 $ (4,582) $ 2,604 $ 7,400 $ 156,968 Prior Year Impact of Adopting ASC 326 Beginning Balance Charge-offs Recoveries Provision Ending Balance Nine Months Ended September 30, 2020 (in thousands) Commercial loans: Commercial real estate $ 20,340 $ 7,533 $ 27,873 $ (101) $ 92 $ 33,460 $ 61,324 Commercial business 30,292 762 31,054 (10,290) 2,795 27,013 50,572 Agriculture 15,835 (9,325) 6,510 (5,995) 69 11,877 12,461 Construction 8,571 (1,750) 6,821 — 688 1,454 8,963 Consumer loans: One-to-four family residential real estate 7,435 4,237 11,672 (26) 2,005 8,456 22,107 Other consumer 883 778 1,661 (599) 330 149 1,541 Unallocated 612 (603) 9 — — (9) — Total $ 83,968 $ 1,632 $ 85,600 $ (17,011) $ 5,979 $ 82,400 $ 156,968 The following tables show a detailed analysis of the ALLL for the three and nine months ended September 30, 2019: Beginning Balance Charge-offs Recoveries Provision Ending Balance Three Months Ended September 30, 2019 (in thousands) Commercial loans: Commercial real estate $ 15,648 $ (466) $ 1,731 $ 1,009 $ 17,922 Commercial business 29,700 (2,623) 349 3,453 30,879 Agriculture 12,671 (55) 67 1,216 13,899 Construction 12,457 (17) 2,555 (3,143) 11,852 Consumer loans: One-to-four family residential real estate 7,619 (202) 440 (399) 7,458 Other consumer 715 (9) 74 (201) 579 Unallocated 1,707 — — (1,636) 71 Total $ 80,517 $ (3,372) $ 5,216 $ 299 $ 82,660 Beginning Balance Charge-offs Recoveries Provision Ending Balance Nine Months Ended September 30, 2019 (in thousands) Commercial loans: Commercial real estate $ 14,766 $ (1,708) $ 2,801 $ 2,063 $ 17,922 Commercial business 34,658 (8,445) 1,368 3,298 30,879 Agriculture 9,589 (194) 189 4,315 13,899 Construction 14,395 (232) 3,329 (5,640) 11,852 Consumer loans: One-to-four family residential real estate 8,024 (1,004) 1,224 (786) 7,458 Other consumer 787 (64) 148 (292) 579 Unallocated 1,150 — — (1,079) 71 Total 83,369 (11,647) 9,059 1,879 82,660
Changes in the Allowance for Unfunded Commitments and Letters of Credit	Changes in the allowance for unfunded commitments and letters of credit, a component of “Other liabilities” in the Consolidated Balance Sheets, are summarized as follows: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 (in thousands) Beginning balance $ 8,800 $ 3,980 $ 3,430 $ 4,330 Impact of adopting ASC 326 — — 1,570 $ — Net changes in the allowance for unfunded commitments and letters of credit 800 (400) 4,600 (750) Ending balance $ 9,600 $ 3,580 $ 9,600 $ 3,580
Financing Receivable Credit Quality Indicators	The following is an analysis of the credit quality of our loan portfolio, as of September 30, 2020 and December 31, 2019: Revolving Loans Amortized Cost Basis Revolving Loans Converted to Term Loans Amortized Cost Basis Term Loans Amortized Cost Basis by Origination Year 2020 2019 2018 2017 2016 Prior Total (1) September 30, 2020 (in thousands) Commercial loans: Commercial real estate Pass $ 491,625 $ 636,127 $ 499,924 $ 542,049 $ 434,390 $ 1,032,016 $ 48,664 $ 3,552 $ 3,688,347 Special mention 8,717 59,899 18,993 15,175 47,881 50,571 2,148 — 203,384 Substandard — 9,977 17,307 13,014 45,421 43,650 5,935 — 135,304 Total commercial real estate $ 500,342 $ 706,003 $ 536,224 $ 570,238 $ 527,692 $ 1,126,237 $ 56,747 $ 3,552 $ 4,027,035 Commercial business Pass $ 1,175,587 $ 409,759 $ 357,128 $ 233,037 $ 240,648 $ 256,178 $ 915,373 $ 8,674 $ 3,596,384 Special mention 4,856 51,204 8,635 25,626 6,514 11,907 35,819 — 144,561 Substandard 3,791 6,005 17,758 5,836 7,153 6,369 44,651 3,501 95,064 Total commercial business $ 1,184,234 $ 466,968 $ 383,521 $ 264,499 $ 254,315 $ 274,454 $ 995,843 $ 12,175 $ 3,836,009 Agriculture Pass $ 147,892 $ 99,483 $ 42,464 $ 59,828 $ 60,007 $ 62,529 $ 290,986 $ 12,273 $ 775,462 Special mention — 519 — 33 272 — 1,801 — 2,625 Substandard 2,676 13,010 6,950 4,278 2,399 4,482 37,918 490 72,203 Total agriculture $ 150,568 $ 113,012 $ 49,414 $ 64,139 $ 62,678 $ 67,011 $ 330,705 $ 12,763 $ 850,290 Construction Pass $ 89,744 $ 101,060 $ 24,130 $ 4,531 $ 782 $ 1,883 $ 25,536 $ — $ 247,666 Special mention — 2,259 — — — — — — 2,259 Substandard — 17,622 5,539 — — 57 33 — 23,251 Total construction $ 89,744 $ 120,941 $ 29,669 $ 4,531 $ 782 $ 1,940 $ 25,569 $ — $ 273,176 Consumer loans: One-to-four family residential real estate Pass $ 88,632 $ 83,137 $ 72,896 $ 33,149 $ 24,987 $ 87,267 $ 265,475 $ 3,110 $ 658,653 Special mention — — — — — 206 297 — 503 Substandard — 735 227 1,177 344 2,463 1,133 197 6,276 Total one-to-four family real estate $ 88,632 $ 83,872 $ 73,123 $ 34,326 $ 25,331 $ 89,936 $ 266,905 $ 3,307 $ 665,432 Other consumer Pass $ 4,412 $ 3,684 $ 4,299 $ 1,172 $ 327 $ 1,161 $ 20,937 $ 736 $ 36,728 Substandard 31 — — 6 4 171 24 41 277 Total consumer $ 4,443 $ 3,684 $ 4,299 $ 1,178 $ 331 $ 1,332 $ 20,961 $ 777 $ 37,005 Total $ 2,017,963 $ 1,494,480 $ 1,076,250 $ 938,911 $ 871,129 $ 1,560,910 $ 1,696,730 $ 32,574 $ 9,688,947 Less: Allowance for credit losses 156,968 Loans, net $ 9,531,979 __________ (1) Loans that are on short-term deferments are treated as Pass loans and will not be reported as past due provided that they are performing in accordance with the modified terms. Revolving Loans Amortized Cost Basis Revolving Loans Converted to Term Loans Amortized Cost Basis Term Loans Amortized Cost Basis by Origination Year 2019 2018 2017 2016 2015 Prior Total December 31, 2019 (in thousands) Commercial loans: Commercial real estate Pass $ 699,336 $ 562,992 $ 621,113 $ 565,928 $ 441,220 $ 873,687 $ 52,276 $ 19,986 $ 3,836,538 Special mention 1,824 305 7,019 3,360 — 3,426 — — 15,934 Substandard 47 10,698 9,320 36,229 20,278 11,738 — 5,071 93,381 Total commercial real estate $ 701,207 $ 573,995 $ 637,452 $ 605,517 $ 461,498 $ 888,851 $ 52,276 $ 25,057 $ 3,945,853 Commercial business Pass $ 479,481 $ 442,222 $ 330,934 $ 301,337 $ 157,436 $ 199,089 $ 963,663 $ 25,577 $ 2,899,739 Special mention 2,241 6,673 56 2,006 52 585 12,710 — 24,323 Substandard 85 17,240 3,458 9,534 3,227 3,972 26,639 1,396 65,551 Total commercial business $ 481,807 $ 466,135 $ 334,448 $ 312,877 $ 160,715 $ 203,646 $ 1,003,012 $ 26,973 $ 2,989,613 Agriculture Pass $ 107,152 $ 54,950 $ 70,337 $ 71,874 $ 33,597 $ 56,342 $ 280,984 $ 10,036 $ 685,272 Special mention 557 2,535 1,381 — 64 576 5,336 — 10,449 Substandard 7,291 6,047 6,173 5,907 1,477 5,698 30,669 6,388 69,650 Total agriculture $ 115,000 $ 63,532 $ 77,891 $ 77,781 $ 35,138 $ 62,616 $ 316,989 $ 16,424 $ 765,371 Construction Pass $ 183,525 $ 91,342 $ 40,514 $ 1,067 $ 939 $ 1,601 $ 33,388 $ 7,793 $ 360,169 Special mention — 1,264 — — — — 41 — 1,305 Substandard — — — — — 59 — — 59 Total construction $ 183,525 $ 92,606 $ 40,514 $ 1,067 $ 939 $ 1,660 $ 33,429 $ 7,793 $ 361,533 Consumer loans: One-to-four family real estate Pass $ 103,315 $ 77,877 $ 32,440 $ 25,052 $ 27,294 $ 80,370 $ 283,830 $ 554 $ 630,732 Substandard — 228 800 400 623 3,156 905 481 6,593 Total one-to-four family real estate $ 103,315 $ 78,105 $ 33,240 $ 25,452 $ 27,917 $ 83,526 $ 284,735 $ 1,035 $ 637,325 Other consumer Pass $ 9,276 $ 5,713 $ 1,974 $ 758 $ 848 $ 1,306 $ 23,351 $ 508 $ 43,734 Substandard — — 1 — — 8 27 — 36 Total consumer $ 9,276 $ 5,713 $ 1,975 $ 758 $ 848 $ 1,314 $ 23,378 $ 508 $ 43,770 Total $ 1,594,130 $ 1,280,086 $ 1,125,520 $ 1,023,452 $ 687,055 $ 1,241,613 $ 1,713,819 $ 77,790 $ 8,743,465 Less: Allowance for credit losses 83,968 Loans, net $ 8,659,497

Other Real Estate Owned (Tables

Other Real Estate Owned (Tables)	9 Months Ended
	Sep. 30, 2020
Other Real Estate, Foreclosed Assets, and Repossessed Assets [Abstract]
Summary of Other Real Estate Owned	The following tables set forth activity in OREO for the three and nine months ended September 30, 2020 and 2019: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 (in thousands) Balance, beginning of period $ 747 $ 1,118 $ 552 $ 6,019 Transfers in 475 — 1,033 386 Valuation adjustments — — — (195) Proceeds from sale of OREO property (681) (588) (1,026) (6,382) Gain on sale of OREO, net 82 95 64 797 Balance, end of period $ 623 $ 625 $ 623 $ 625

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill and Intangible Assets	The following table sets forth activity for goodwill and other intangible assets for the periods indicated: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Goodwill Total goodwill $ 765,842 $ 765,842 $ 765,842 $ 765,842 Other intangible assets, net CDI: Gross CDI balance at beginning of period 105,473 105,473 105,473 105,473 Accumulated amortization at beginning of period (75,454) (65,852) (70,934) (60,455) CDI, net at beginning of period 30,019 39,621 34,539 45,018 CDI current period amortization (2,193) (2,632) (6,713) (8,029) Total CDI, net at end of period 27,826 36,989 27,826 36,989 Intangible assets not subject to amortization 919 919 919 919 Other intangible assets, net at end of period 28,745 37,908 28,745 37,908 Total goodwill and other intangible assets at end of period $ 794,587 $ 803,750 $ 794,587 $ 803,750
Estimated Future Amortization Expense of Core Deposit Intangibles	The following table provides the estimated future amortization expense of our CDI for the remaining three months ending December 31, 2020 and the succeeding four years: Year ending December 31, (in thousands) 2020 $ 2,012 2021 7,264 2022 5,880 2023 4,552 2024 3,432

Derivatives and Balance Sheet_2

Derivatives and Balance Sheet Offsetting (Tables)	9 Months Ended
	Sep. 30, 2020
Derivative [Line Items]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following table presents the fair value of derivatives, as well as their classification on the Consolidated Balance Sheet at September 30, 2020 and December 31, 2019: Asset Derivatives Liability Derivatives September 30, 2020 December 31, 2019 September 30, 2020 December 31, 2019 Balance Sheet Fair Value Balance Sheet Fair Value Balance Sheet Fair Value Balance Sheet Fair Value (in thousands) Derivatives designated as hedging instruments: Interest rate collar Other assets $ 35,668 Other assets $ 14,727 Other liabilities $ — Other liabilities $ — Derivatives not designated as hedging instruments: Interest rate swap contracts Other assets $ 53,202 Other assets $ 19,144 Other liabilities $ 53,677 Other liabilities $ 19,145
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The table below presents the effect of cash flow hedge accounting on accumulated other comprehensive income (loss) at September 30, 2020 and 2019: Amount of Gain or (Loss) Recognized in Accumulated Other Comprehensive Income on Derivative Location of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income into Income Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income into Income Three Months Ended September 30, Three Months Ended September 30, 2020 2019 2020 2019 (in thousands) Interest rate collar $ (81) $ 4,088 Interest income $ 2,673 $ 76 Nine Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Interest rate collar $ 26,744 $ 19,779 Interest income $ 5,803 $ 76
Balance Sheet Offsetting [Table Text Block]	The following tables show the gross interest rate swap contracts, collar agreements and repurchase agreements in the Consolidated Balance Sheets and the respective collateral received or pledged in the form of cash or other financial instruments. The collateral amounts in these tables are limited to the outstanding balances of the related asset or liability. Therefore, instances of over-collateralization are not shown. Gross Amounts of Recognized Assets/Liabilities Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts of Assets/Liabilities Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Collateral Pledged/Received Net Amount September 30, 2020 (in thousands) Assets Interest rate swap contracts $ 53,202 $ — $ 53,202 $ — $ 53,202 Interest rate collar $ 35,668 $ — $ 35,668 $ (35,668) — Liabilities Interest rate swap contracts $ 53,677 $ — $ 53,677 $ (53,677) $ — Repurchase agreements $ 26,966 $ — $ 26,966 $ (26,966) $ — December 31, 2019 Assets Interest rate swap contracts $ 19,144 $ — $ 19,144 $ — $ 19,144 Interest rate collar $ 14,727 $ — $ 14,727 $ (14,727) — Liabilities Interest rate swap contracts $ 19,145 $ — $ 19,145 $ (19,145) $ — Repurchase agreements $ 64,437 $ — $ 64,437 $ (64,437) $ —
Carrying Value of Securities Pledged As Collateral	The following table summarizes the carrying value of securities pledged as collateral to secure public funds, borrowings and other purposes as permitted or required by law: September 30, 2020 (in thousands) To secure public funds $ 441,379 To secure borrowings 111,978 Other securities pledged 168,870 Total securities pledged as collateral $ 722,227
Available-for-sale Securities [Member]
Derivative [Line Items]
Carrying Value of Securities Pledged As Collateral	The following table presents the class of collateral pledged for repurchase agreements as well as the remaining contractual maturity of the repurchase agreements: Remaining contractual maturity of the agreements Overnight and continuous Up to 30 days 30 - 90 days Greater than 90 days Total September 30, 2020 (in thousands) Class of collateral pledged for repurchase agreements U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 26,966 $ — $ — $ — $ 26,966 Gross amount of recognized liabilities for repurchase agreements 26,966 Amounts related to agreements not included in offsetting disclosure $ —

Shareholders' Equity Dividends

Shareholders' Equity Dividends Declared (Tables)	9 Months Ended
	Sep. 30, 2020
Shareholders' Equity [Abstract]
Dividends Declared [Table Text Block]	The following table summarizes year-to-date dividend activity as of September 30, 2020: Declared Regular Cash Dividends Per Common Share Special Cash Dividends Per Common Share Record Date Paid Date January 23, 2020 $ 0.28 $ 0.22 February 5, 2020 February 19, 2020 April 30, 2020 $ 0.28 $ — May 14, 2020 May 28, 2020 July 23, 2020 $ 0.28 $ — August 5, 2020 August 19, 2020

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table shows changes in accumulated other comprehensive income (loss) by component for the three and nine months ended September 30, 2020 and 2019: Unrealized Gains and Losses on Available for Sale Securities (1) Unrealized Gains and Losses on Pension Plan Liability (1) Unrealized Gains and Losses on Hedging Instruments (1) Total (1) Three Months Ended September 30, 2020 (in thousands) Beginning balance $ 155,403 $ (3,815) $ 29,489 $ 181,077 Other comprehensive loss before reclassifications (1,442) — (62) (1,504) Amounts reclassified from accumulated other comprehensive income (2) — 80 (2,052) (1,972) Net current-period other comprehensive income (loss) (1,442) 80 (2,114) (3,476) Ending balance $ 153,961 $ (3,735) $ 27,375 $ 177,601 Three Months Ended September 30, 2019 Beginning balance $ 37,162 $ (2,055) $ 12,043 $ 47,150 Other comprehensive income before reclassifications 14,593 — 3,137 17,730 Amounts reclassified from accumulated other comprehensive income (2) — 62 (58) 4 Net current-period other comprehensive income 14,593 62 3,079 17,734 Ending balance $ 51,755 $ (1,993) $ 15,122 $ 64,884 Nine Months Ended September 30, 2020 Beginning balance $ 33,038 $ (3,974) $ 11,303 $ 40,367 Other comprehensive income before reclassifications 121,114 — 20,526 141,640 Amounts reclassified from accumulated other comprehensive income (2) (191) 239 (4,454) (4,406) Net current-period other comprehensive income 120,923 239 16,072 137,234 Ending balance $ 153,961 $ (3,735) $ 27,375 $ 177,601 Nine Months Ended September 30, 2019 Beginning balance $ (33,128) $ (2,177) $ — $ (35,305) Other comprehensive income before reclassifications 86,519 — 15,180 101,699 Amounts reclassified from accumulated other comprehensive loss (2) (1,636) 184 (58) (1,510) Net current-period other comprehensive income 84,883 184 15,122 100,189 Ending balance $ 51,755 $ (1,993) $ 15,122 $ 64,884 __________ (1) All amounts are net of tax. Amounts in parentheses indicate debits. (2) See following table for details about these reclassifications.
Schedule of reclassifications from accumulated other comprehensive income [Table Text Block]	The following table shows details regarding the reclassifications from accumulated other comprehensive income (loss) for the three and nine months ended September 30, 2020 and 2019: Amount Reclassified from Accumulated Other Comprehensive Income (Loss) Three Months Ended September 30, Nine Months Ended September 30, Affected line Item in the Consolidated 2020 2019 2020 2019 Statement of Income (in thousands) Unrealized gains on available for sale debt securities $ — $ — $ 249 $ 2,132 Investment securities gains, net — — 249 2,132 Total before tax — — (58) (496) Income tax provision $ — $ — $ 191 $ 1,636 Net of tax Amortization of pension plan liability actuarial losses $ (104) $ (81) $ (311) $ (240) Compensation and employee benefits (104) (81) (311) (240) Total before tax 24 19 72 56 Income tax provision $ (80) $ (62) $ (239) $ (184) Net of tax Unrealized gains from hedging instruments $ 2,673 $ 76 $ 5,803 $ 76 Loans 2,673 76 5,803 76 Total before tax (621) (18) (1,349) (18) Income tax provision $ 2,052 $ 58 $ 4,454 $ 58 Net of tax

Fair Value Accounting and Mea_2

Fair Value Accounting and Measurement (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table sets forth the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis at September 30, 2020 and December 31, 2019 by level within the fair value hierarchy. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement: Fair Value Fair Value Measurements at Reporting Date Using Level 1 Level 2 Level 3 September 30, 2020 (in thousands) Assets Debt securities available for sale: U.S. government agency and government-sponsored enterprise mortgage-back securities and collateralized mortgage obligations $ 3,121,642 $ — $ 3,121,642 $ — Other asset-backed securities 293,024 — 293,024 — State and municipal securities 557,444 — 557,444 — U.S. government agency and government-sponsored enterprise securities 309,610 — 309,610 — Total debt securities available for sale $ 4,281,720 $ — $ 4,281,720 $ — Other assets: Interest rate contracts $ 53,202 $ — $ 53,202 $ — Interest rate collar $ 35,668 $ — $ 35,668 $ — Liabilities Other liabilities: Interest rate contracts $ 53,677 $ — $ 53,677 $ — Fair Value Fair Value Measurements at Reporting Date Using Level 1 Level 2 Level 3 December 31, 2019 (in thousands) Assets Debt securities available for sale: U.S. government agency and government-sponsored enterprise mortgage-back securities and collateralized mortgage obligations $ 2,892,950 $ — $ 2,892,950 $ — Other asset-backed securities 196,050 — 196,050 — State and municipal securities 488,802 — 488,802 — U.S. government agency and government-sponsored enterprise securities 168,340 — 168,340 — Total debt securities available for sale $ 3,746,142 $ — $ 3,746,142 $ — Other assets: Interest rate contracts $ 19,144 $ — $ 19,144 $ — Interest rate collar $ 14,727 $ — $ 14,727 $ — Liabilities Other liabilities: Interest rate contracts $ 19,145 $ — $ 19,145 $ —
Equity Securities without Readily Determinable Fair Value [Table Text Block]	The following table presents the carrying value of equity securities, without readily determinable fair values, still held as of September 30, 2020, that are measured under the measurement alternative and related adjustments recorded during the periods presented for those securities with observable price changes. These securities are included in the nonrecurring fair value tables when applicable price changes are observable. Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Equity securities without readily determinable fair values (in thousands) Carrying value, beginning of period $ 13,425 $ — $ — $ — Upward carrying value changes — — 13,425 — Carrying value, end of period $ 13,425 $ — $ 13,425 $ —
Financial Assets Accounted For Fair Value On Nonrecurring Basis	The following tables set forth information related to the Company’s assets that were measured using fair value estimates on a nonrecurring basis during the current and prior year quarterly periods: Fair Value at September 30, 2020 Fair Value Measurements Gains During the Three Months Ended September 30, 2020 Losses During the Nine Months Ended September 30, 2020 Level 1 Level 2 Level 3 (in thousands) Collateral dependent loans $ 11,899 $ — $ — $ 11,899 $ (153) $ 4,941 Fair Value at September 30, 2019 Fair Value Measurements Losses During the Three Months Ended September 30, 2019 Losses During the Nine Months Ended September 30, 2019 Level 1 Level 2 Level 3 (in thousands) Collateral dependent loans $ 8,990 $ — $ — $ 8,990 $ 1,722 $ 3,299
Fair Value, by Balance Sheet Grouping	The following tables summarize carrying amounts and estimated fair values of selected financial instruments by level within the fair value hierarchy at September 30, 2020 and December 31, 2019: September 30, 2020 Carrying Fair Level 1 Level 2 Level 3 (in thousands) Assets Cash and due from banks $ 193,823 $ 193,823 $ 193,823 $ — $ — Interest-earning deposits with banks 736,422 736,422 736,422 — — Debt securities available for sale 4,281,720 4,281,720 — 4,281,720 — Equity securities without readily determinable fair values 13,425 13,425 — — 13,425 FHLB stock 10,280 10,280 — 10,280 — Loans held for sale 24,407 24,407 — 24,407 — Loans 9,531,979 9,980,912 — — 9,980,912 Interest rate contracts 53,202 53,202 — 53,202 — Interest rate collar 35,668 35,668 — 35,668 — Liabilities Time deposits $ 337,228 $ 337,386 $ — $ 337,386 $ — FHLB advances 7,427 9,354 — 9,354 — Repurchase agreements 26,966 26,966 — 26,966 — Subordinated debentures 35,139 35,368 — 35,368 — Interest rate contracts 53,677 53,677 — 53,677 — December 31, 2019 Carrying Fair Level 1 Level 2 Level 3 (in thousands) Assets Cash and due from banks $ 223,541 $ 223,541 $ 223,541 $ — $ — Interest-earning deposits with banks 24,132 24,132 24,132 — — Debt securities available for sale 3,746,142 3,746,142 — 3,746,142 — FHLB stock 48,120 48,120 — 48,120 — Loans held for sale 17,718 17,718 — 17,718 — Loans 8,659,497 8,883,865 — — 8,883,865 Interest rate contracts 19,144 19,144 — 19,144 — Interest rate collar 14,727 14,727 — 14,727 — Liabilities Time deposits $ 400,070 $ 397,736 $ — $ 397,736 $ — FHLB advances 953,469 952,762 — 952,762 — Repurchase agreements 64,437 64,437 — 64,437 — Subordinated debentures 35,277 35,491 — 35,491 — Interest rate contracts 19,145 19,145 — 19,145 —
Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Assets, Quantitative Information	The range and weighted average of the significant unobservable inputs used to fair value our Level 3 nonrecurring assets, along with the valuation techniques used, are shown in the following table: Fair Value at September 30, 2020 Valuation Technique Unobservable Input Range (Weighted Average) (1) (dollars in thousands) Collateral dependent loans (2) $ 11,899 Fair Market Value of Collateral Adjustment to Stated Value 0.00% - 100.00% (15.57%) __________ (1) Discount applied to appraised value or stated value (in the case of accounts receivable, fixed assets and inventory). (2) Collateral consists of accounts receivable, fixed assets, inventory and real estate. Fair Value at September 30, 2019 Valuation Technique Unobservable Input Range (Weighted Average) (1) (dollars in thousands) Collateral dependent loans (2) $ 8,990 Fair Market Value of Collateral Adjustment to Stated Value 0.00% - 100.00% (42.09%) __________ (1) Discount applied to appraised value or stated value (in the case of accounts receivable, fixed assets and inventory). (2) Collateral consists of cash, accounts receivable, fixed assets, inventory and real estate.

Earnings per Common Share (Tabl

Earnings per Common Share (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Earnings Per Share	The following table sets forth the computation of basic and diluted EPS for the three and nine months ended September 30, 2020 and 2019: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 (in thousands except per share amounts) Basic EPS: Net income $ 44,734 $ 50,727 $ 95,944 $ 148,322 Less: Earnings allocated to participating securities: Nonvested restricted shares 164 358 487 1,204 Earnings allocated to common shareholders $ 44,570 $ 50,369 $ 95,457 $ 147,118 Weighted average common shares outstanding 70,726 71,803 70,870 72,256 Basic earnings per common share $ 0.63 $ 0.70 $ 1.35 $ 2.04 Diluted EPS: Earnings allocated to common shareholders $ 44,570 $ 50,369 $ 95,457 $ 147,118 Weighted average common shares outstanding 70,726 71,803 70,870 72,256 Dilutive effect of equity awards 36 — 36 1 Weighted average diluted common shares outstanding 70,762 71,803 70,906 72,257 Diluted earnings per common share $ 0.63 $ 0.70 $ 1.35 $ 2.04 Potentially dilutive share options that were not included in the computation of diluted EPS because to do so would be anti-dilutive 596 — 487 —

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Disaggregation of Revenue [Table Text Block]	The following table shows the disaggregation of revenue from contracts with customers for the three and nine month periods ended September 30, 2020 and 2019: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (in thousands) Noninterest income: Revenue from contracts with customers: Deposit account and treasury management fees $ 6,658 $ 9,015 $ 20,538 $ 27,030 Card revenue 3,834 4,006 10,431 11,431 Financial services and trust revenue 3,253 3,226 9,481 9,608 Total revenue from contracts with customers 13,745 16,247 40,450 48,069 Other sources of noninterest income 8,727 11,783 40,488 27,305 Total noninterest income $ 22,472 $ 28,030 $ 80,938 $ 75,374

Accounting Pronouncements Rec_2

Accounting Pronouncements Recently Adopted or Issued Narrative - Impact of implementation of new accounting standards (Details) - Accounting Standards Update 2016-13 [Member] - USD ($) $ in Thousands	Jun. 30, 2020	Jan. 01, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Change in allowance for credit losses due to adoption of new ASU		$ 1,632
Change in allowance for unfunded commitments and letters of credit due to adoption of new ASU	$ 0	$ 1,570		$ 0	$ 0
Adjustment to opening retained earnings, net of tax, pursuant to adoption of ASU			$ (2,500)

Securities (Summary of Gross Un

Securities (Summary of Gross Unrealized Losses and Fair Value of the Investments with Unrealized Losses) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months Fair Value	$ 580,986	$ 1,157,774
Less than 12 Months Unrealized Losses	(4,212)	(13,446)
12 Months or More Fair Value	23,179	521,420
12 Months or More Unrealized Losses	(840)	(6,994)
Total Fair Value	604,165	1,679,194
Total Unrealized Losses	(5,052)	(20,440)
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months Fair Value	318,868	1,055,903
Less than 12 Months Unrealized Losses	(2,817)	(12,424)
12 Months or More Fair Value	23,084	491,539
12 Months or More Unrealized Losses	(840)	(6,798)
Total Fair Value	341,952	1,547,442
Total Unrealized Losses	(3,657)	(19,222)
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months Fair Value	71,552	89,508
Less than 12 Months Unrealized Losses	(530)	(880)
12 Months or More Fair Value	95	6,799
12 Months or More Unrealized Losses	0	(109)
Total Fair Value	71,647	96,307
Total Unrealized Losses	(530)	(989)
State and Municipal Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months Fair Value	90,620	12,363
Less than 12 Months Unrealized Losses	(813)	(142)
12 Months or More Fair Value	0	12,587
12 Months or More Unrealized Losses	0	(82)
Total Fair Value	90,620	24,950
Total Unrealized Losses	(813)	(224)
U.S. Government and Government-Sponsored Enterprise Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months Fair Value	99,946	0
Less than 12 Months Unrealized Losses	(52)	0
12 Months or More Fair Value	0	10,495
12 Months or More Unrealized Losses	0	(5)
Total Fair Value	99,946	10,495
Total Unrealized Losses	$ (52)	$ (5)

Securities Securities (Summary

Securities Securities (Summary of Gross Realized Gains and Gross Realized Losses (Details) - 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]
Proceeds from Sale of Debt Securities, Available-for-sale	$ 0	$ 0	$ 194,105	$ 259,554
Gross Realized Gains from sales of debt securities available for sale	0	0	435	3,357
Gross Realized Losses from sales of debt securities available for sale	0	0	(186)	(1,225)
Other securities gains	0	0	16,425	0
Investment securities gain (loss), net	$ 0	$ 0	$ 16,674	$ 2,132

Securities Equity Securities -

Securities Equity Securities - unrealized gains and losses (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Gains recognized during the period on equity securities	$ 0		$ 0	$ 16,425	$ 0
Less: Gains recognized during the period on equity securities sold during the period	0		0	(3,000)	0
Unrealized gains recognized during the reporting period on equity securities still held at the reporting date	$ 0		0	$ 13,425	0
Visa Class B shares, shares sold		17,360
Visa Class B shares, gain on sale		$ 3,000
Visa Class B shares, remaining shares	77,683			77,683
Equity Securities	$ 13,425	$ 13,425	$ 0	$ 13,425	$ 0	$ 0	$ 0	$ 0

Securities (Schedule of Contrac

Securities (Schedule of Contractual Maturities of Investment Securities Available for Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Abstract]
Due within one year, Amortized Cost	$ 92,028
Due after one year through five years, Amortized Cost	595,979
Due after five years through ten years, Amortized Cost	2,000,662
Due after ten years, Amortized Cost	1,392,449
Debt securities available-for-sale, amortized cost	4,081,118	$ 3,703,096
Due within one year, Fair Value	92,931
Due after one year through five years, Fair Value	626,018
Due after five years through ten years, Fair Value	2,133,751
Due after ten years, Fair Value	1,429,020
Debt securities available for sale at fair value	$ 4,281,720	$ 3,746,142

Securities (Carrying Value of S

Securities (Carrying Value of Securities Pledged as Collateral) (Details) $ in Thousands	Sep. 30, 2020USD ($)
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Restricted	$ 722,227
To secure public funds
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Restricted	441,379
To secure borrowings
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Restricted	111,978
Other securities pledged
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Restricted	$ 168,870

Securities (Debt securities Ava

Securities (Debt securities Available for Sale) (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
Debt Securities, Available-for-sale [Line Items]
Proceeds from Sale of Debt Securities, Available-for-sale	$ 0	$ 0	$ 194,105	$ 259,554
Debt securities available-for-sale, amortized cost	4,081,118		4,081,118		$ 3,703,096
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	205,654		205,654		63,486
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(5,052)		(5,052)		(20,440)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0		0		0
Debt securities available for sale at fair value	4,281,720		4,281,720		3,746,142
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities available-for-sale, amortized cost	2,957,028		2,957,028		2,864,949
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	168,271		168,271		47,223
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(3,657)		(3,657)		(19,222)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0		0		0
Debt securities available for sale at fair value	3,121,642		3,121,642		2,892,950
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities available-for-sale, amortized cost	284,499		284,499		194,563
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	9,055		9,055		2,476
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(530)		(530)		(989)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0		0		0
Debt securities available for sale at fair value	293,024		293,024		196,050
State and Municipal Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities available-for-sale, amortized cost	536,861		536,861		478,366
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	21,396		21,396		10,660
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(813)		(813)		(224)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0		0		0
Debt securities available for sale at fair value	557,444		557,444		488,802
U.S. Government and Government-Sponsored Enterprise Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities available-for-sale, amortized cost	302,730		302,730		165,218
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	6,932		6,932		3,127
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(52)		(52)		(5)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0		0		0
Debt securities available for sale at fair value	$ 309,610		$ 309,610		$ 168,340

Securities (Narrative) (Details

Securities (Narrative) (Details) $ in Thousands	Sep. 30, 2020USD ($)security	Dec. 31, 2019USD ($)
Debt Securities, Available-for-sale [Line Items]
Interest receivable | $	$ 56,718	$ 46,839
Available-for-sale Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Interest receivable | $	$ 13,300	$ 13,900
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	62
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	5
State and Municipal Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	29
U.S. Government and Government-Sponsored Enterprise Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	4

Loans (Analysis of Loan Portfol

Loans (Analysis of Loan Portfolio by Major Types of Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Jan. 01, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$ 9,688,947			$ 8,743,465
Financing Receivable, Allowance for Credit Loss	(156,968)	$ (151,546)	$ (85,600)	(83,968)	$ (82,660)	$ (80,517)	$ (83,369)
Loans and Leases Receivable, Net Amount	9,531,979			8,659,497
Loans held for sale	24,407			17,718
Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans and Leases Receivable, Net of Deferred Income	4,027,035			3,945,853
Financing Receivable, Allowance for Credit Loss	(61,324)	(50,233)	(27,873)	(20,340)	(17,922)	(15,648)	(14,766)
Commercial Business [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans and Leases Receivable, Net of Deferred Income	3,836,009			2,989,613
Financing Receivable, Allowance for Credit Loss	(50,572)	(53,186)	(31,054)	(30,292)	(30,879)	(29,700)	(34,658)
Agriculture [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans and Leases Receivable, Net of Deferred Income	850,290			765,371
Financing Receivable, Allowance for Credit Loss	(12,461)	(14,868)	(6,510)	(15,835)	(13,899)	(12,671)	(9,589)
Construction [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans and Leases Receivable, Net of Deferred Income	273,176			361,533
Financing Receivable, Allowance for Credit Loss	(8,963)	(7,953)	(6,821)	(8,571)	(11,852)	(12,457)	(14,395)
One-to-Four Family Residential [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans and Leases Receivable, Net of Deferred Income	665,432			637,325
Financing Receivable, Allowance for Credit Loss	(22,107)	(23,711)	(11,672)	(7,435)	(7,458)	(7,619)	(8,024)
Consumer Loan [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans and Leases Receivable, Net of Deferred Income	37,005			43,770
Financing Receivable, Allowance for Credit Loss	$ (1,541)	$ (1,595)	$ (1,661)	$ (883)	$ (579)	$ (715)	$ (787)

Loans (Analysis of the Aged Loa

Loans (Analysis of the Aged Loan Portfolio) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Current Loans	$ 9,625,411	$ 8,686,523
Past Due Loans	16,305	23,882
Nonaccrual Loans	47,231	33,060
Total Loans	9,688,947	8,743,465
Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	4,015,038	3,935,633
Past Due Loans	1,635	6,421
Nonaccrual Loans	10,362	3,799
Total Loans	4,027,035	3,945,853
Commercial Business [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	3,808,794	2,959,826
Past Due Loans	7,902	8,850
Nonaccrual Loans	19,313	20,937
Total Loans	3,836,009	2,989,613
Agriculture [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	833,408	755,719
Past Due Loans	1,969	4,629
Nonaccrual Loans	14,913	5,023
Total Loans	850,290	765,371
Construction [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	272,959	360,582
Past Due Loans	0	951
Nonaccrual Loans	217	0
Total Loans	273,176	361,533
One-to-Four Family Residential [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	658,468	631,109
Past Due Loans	4,559	2,924
Nonaccrual Loans	2,405	3,292
Total Loans	665,432	637,325
Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	36,744	43,654
Past Due Loans	240	107
Nonaccrual Loans	21	9
Total Loans	37,005	43,770
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	14,018	18,332
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	547	6,421
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Business [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	6,987	6,081
Financial Asset, 30 to 59 Days Past Due [Member] | Agriculture [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	1,710	2,283
Financial Asset, 30 to 59 Days Past Due [Member] | Construction [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	0	951
Financial Asset, 30 to 59 Days Past Due [Member] | One-to-Four Family Residential [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	4,559	2,516
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	215	80
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	2,287	5,550
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	1,088	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Business [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	915	2,769
Financial Asset, 60 to 89 Days Past Due [Member] | Agriculture [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	259	2,346
Financial Asset, 60 to 89 Days Past Due [Member] | Construction [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | One-to-Four Family Residential [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	0	408
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	25	27
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Business [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Agriculture [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Construction [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | One-to-Four Family Residential [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	$ 0	$ 0

Loans (Interest written off on

Loans (Interest written off on nonaccual loans) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Financing Receivable, Credit Quality Indicator - nonaccrual loans written off interest [Line Items]
Financing Receivable Accrued Interest Reversed Through Interest Income	$ 393	$ 175	$ 1,854	$ 1,462
Commercial Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator - nonaccrual loans written off interest [Line Items]
Financing Receivable Accrued Interest Reversed Through Interest Income	387	149	1,835	1,316
Consumer Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator - nonaccrual loans written off interest [Line Items]
Financing Receivable Accrued Interest Reversed Through Interest Income	$ 6	$ 26	$ 19	$ 146

Loans (Analysis of Nonaccrual L

Loans (Analysis of Nonaccrual Loans with no ACL) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, No Allowance	$ 31,879	$ 19,275
Commercial Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, No Allowance	9,092	1,715
Commercial Business [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, No Allowance	11,713	15,762
Agriculture [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, No Allowance	$ 11,074	$ 1,798

Loans Loans (Analysis of Troubl

Loans Loans (Analysis of Troubled Debt Restructurings) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)Modifications	Sep. 30, 2019USD ($)Modifications	Sep. 30, 2020USD ($)Modifications	Sep. 30, 2019USD ($)Modifications
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	9	11	18	21
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 4,013	$ 5,384	$ 7,066	$ 7,253
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 4,013	$ 5,384	$ 7,066	$ 7,253
Commercial Business [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	4	5	10	10
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 795	$ 5,026	$ 2,757	$ 6,560
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 795	$ 5,026	$ 2,757	$ 6,560
Agriculture [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	1	0	2	0
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 2,600	$ 0	$ 3,495	$ 0
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 2,600	$ 0	$ 3,495	$ 0
One-to-Four Family Residential [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	4	5	6	10
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 618	$ 357	$ 814	$ 692
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 618	$ 357	$ 814	$ 692
Consumer Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	0	1	0	1
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 0	$ 1	$ 0	$ 1
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 0	$ 1	$ 0	$ 1

Loans (Narrative) (Details)

Loans (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)contract	Sep. 30, 2019USD ($)contract	Sep. 30, 2020USD ($)contract	Sep. 30, 2019USD ($)contract	Dec. 31, 2019USD ($)
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Interest Receivable, loans	$ 56,718		$ 56,718		$ 46,839
Financing Receivable Modifications Additional Commitment To Lend	$ 641		$ 641		1,100
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts | contract	0	0	0	1
Financing Receivable, Troubled Debt Restructuring, Subsequent Default		$ 26		$ 26
Loan modifications, short-term deferments not classified as TDR, Number of contracts | contract			103
Loan modifications, short-term deferments not classified as TDR, net of unearned income			$ 114,400
Paycheck Protection Program (PPP) loans, net of unearned income	$ 953,200		953,200
Loans Receivable [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	3,490,000		3,490,000		3,240,000
Commercial Loan [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans pledged to collateralize Federal Reserve Bank Borrowings	200,600		200,600		151,300
Loans [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Interest Receivable, loans	$ 43,400		$ 43,400		$ 33,000

Allowance for Credit Losses a_3

Allowance for Credit Losses and Allowance for Unfunded Commitments and Letters of Credit (Allowance for Credit Losses) (Details) - 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
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	$ 156,968	$ 82,660	$ 156,968	$ 82,660	$ 151,546	$ 85,600	$ 83,968	$ 80,517	$ 83,369
Financing Receivable, Allowance for Credit Loss, Writeoff	(4,582)	(3,372)	(17,011)	(11,647)
Financing Receivable, Allowance for Credit Loss, Recovery	2,604	5,216	5,979	9,059
Provision for credit losses	7,400	299	82,400	1,879
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	61,324	17,922	61,324	17,922	50,233	27,873	20,340	15,648	14,766
Financing Receivable, Allowance for Credit Loss, Writeoff	0	(466)	(101)	(1,708)
Financing Receivable, Allowance for Credit Loss, Recovery	65	1,731	92	2,801
Provision for credit losses	11,026	1,009	33,460	2,063
Commercial Business [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	50,572	30,879	50,572	30,879	53,186	31,054	30,292	29,700	34,658
Financing Receivable, Allowance for Credit Loss, Writeoff	(3,164)	(2,623)	(10,290)	(8,445)
Financing Receivable, Allowance for Credit Loss, Recovery	1,124	349	2,795	1,368
Provision for credit losses	(574)	3,453	27,013	3,298
Agriculture [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	12,461	13,899	12,461	13,899	14,868	6,510	15,835	12,671	9,589
Financing Receivable, Allowance for Credit Loss, Writeoff	(1,269)	(55)	(5,995)	(194)
Financing Receivable, Allowance for Credit Loss, Recovery	27	67	69	189
Provision for credit losses	(1,165)	1,216	11,877	4,315
Construction [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	8,963	11,852	8,963	11,852	7,953	6,821	8,571	12,457	14,395
Financing Receivable, Allowance for Credit Loss, Writeoff	0	(17)	0	(232)
Financing Receivable, Allowance for Credit Loss, Recovery	11	2,555	688	3,329
Provision for credit losses	999	(3,143)	1,454	(5,640)
One-to-Four Family Residential [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	22,107	7,458	22,107	7,458	23,711	11,672	7,435	7,619	8,024
Financing Receivable, Allowance for Credit Loss, Writeoff	(16)	(202)	(26)	(1,004)
Financing Receivable, Allowance for Credit Loss, Recovery	1,301	440	2,005	1,224
Provision for credit losses	(2,889)	(399)	8,456	(786)
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	1,541	579	1,541	579	$ 1,595	1,661	883	715	787
Financing Receivable, Allowance for Credit Loss, Writeoff	(133)	(9)	(599)	(64)
Financing Receivable, Allowance for Credit Loss, Recovery	76	74	330	148
Provision for credit losses	3	(201)	149	(292)
Unallocated Financing Receivables [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	$ 0	71	0	71		9	$ 612	$ 1,707	$ 1,150
Financing Receivable, Allowance for Credit Loss, Writeoff		0	0	0
Financing Receivable, Allowance for Credit Loss, Recovery		0	0	0
Provision for credit losses		$ (1,636)	$ (9)	$ (1,079)
Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Change in allowance for credit losses due to adoption of new ASU						1,632
Accounting Standards Update 2016-13 [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Change in allowance for credit losses due to adoption of new ASU						7,533
Accounting Standards Update 2016-13 [Member] | Commercial Business [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Change in allowance for credit losses due to adoption of new ASU						762
Accounting Standards Update 2016-13 [Member] | Agriculture [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Change in allowance for credit losses due to adoption of new ASU						(9,325)
Accounting Standards Update 2016-13 [Member] | Construction [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Change in allowance for credit losses due to adoption of new ASU						(1,750)
Accounting Standards Update 2016-13 [Member] | One-to-Four Family Residential [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Change in allowance for credit losses due to adoption of new ASU						4,237
Accounting Standards Update 2016-13 [Member] | Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Change in allowance for credit losses due to adoption of new ASU						778
Accounting Standards Update 2016-13 [Member] | Unallocated Financing Receivables [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Change in allowance for credit losses due to adoption of new ASU						$ (603)

Allowance for Credit Losses a_4

Allowance for Credit Losses and Allowance for Unfunded Commitments and Letters of Credit (Changes in the Allowance for Unfunded Commitments and Letters of Credit) (Details) - 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
Schedule of Allowance for Unfunded Commitments and Letters of Credit [Line Items]
Allowance For Unfunded Loan Commitments And Letters Of Credit	$ 9,600	$ 3,580	$ 9,600	$ 3,580	$ 8,800		$ 3,430	$ 3,980	$ 4,330
Allowance for Loan and Lease Losses, Net Changes In Unfunded Commitments and Letters Of Credit Allowance	$ 800	$ (400)	$ 4,600	$ (750)
Accounting Standards Update 2016-13 [Member]
Schedule of Allowance for Unfunded Commitments and Letters of Credit [Line Items]
Change in allowance for unfunded commitments and letters of credit due to adoption of new ASU					$ 0	$ 1,570		$ 0	$ 0

Allowance for Credit Losses a_5

Allowance for Credit Losses and Allowance for Unfunded Commitments and Letters of Credit (Analysis of Credit Quality of the Loan Portfolio) (Details) - USD ($)	Sep. 30, 2020	Jun. 30, 2020	Jan. 01, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 2,017,963,000			$ 1,594,130,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,494,480,000			1,280,086,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,076,250,000			1,125,520,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	938,911,000			1,023,452,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	871,129,000			687,055,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,560,910,000			1,241,613,000
Financing Receivable, Revolving	1,696,730,000			1,713,819,000
Financing Receivable, Revolving Converted to Term Loans	32,574,000			77,790,000
Loans and Leases Receivable, Net of Deferred Income	9,688,947,000			8,743,465,000
Financing Receivable, Allowance for Credit Loss	156,968,000	$ 151,546,000	$ 85,600,000	83,968,000	$ 82,660,000	$ 80,517,000	$ 83,369,000
Loans, net	9,531,979,000			8,659,497,000
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	500,342,000			701,207,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	706,003,000			573,995,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	536,224,000			637,452,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	570,238,000			605,517,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	527,692,000			461,498,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,126,237,000			888,851,000
Financing Receivable, Revolving	56,747,000			52,276,000
Financing Receivable, Revolving Converted to Term Loans	3,552,000			25,057,000
Loans and Leases Receivable, Net of Deferred Income	4,027,035,000			3,945,853,000
Financing Receivable, Allowance for Credit Loss	61,324,000	50,233,000	27,873,000	20,340,000	17,922,000	15,648,000	14,766,000
Commercial Real Estate [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	491,625,000			699,336,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	636,127,000			562,992,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	499,924,000			621,113,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	542,049,000			565,928,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	434,390,000			441,220,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,032,016,000			873,687,000
Financing Receivable, Revolving	48,664,000			52,276,000
Financing Receivable, Revolving Converted to Term Loans	3,552,000			19,986,000
Loans and Leases Receivable, Net of Deferred Income	3,688,347,000			3,836,538,000
Commercial Real Estate [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	8,717,000			1,824,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	59,899,000			305,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	18,993,000			7,019,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	15,175,000			3,360,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	47,881,000			0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	50,571,000			3,426,000
Financing Receivable, Revolving	2,148,000			0
Financing Receivable, Revolving Converted to Term Loans	0			0
Loans and Leases Receivable, Net of Deferred Income	203,384,000			15,934,000
Commercial Real Estate [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0			47,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	9,977,000			10,698,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	17,307,000			9,320,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	13,014,000			36,229,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	45,421,000			20,278,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	43,650,000			11,738,000
Financing Receivable, Revolving	5,935,000			0
Financing Receivable, Revolving Converted to Term Loans	0			5,071,000
Loans and Leases Receivable, Net of Deferred Income	135,304,000			93,381,000
Commercial Business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,184,234,000			481,807,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	466,968,000			466,135,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	383,521,000			334,448,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	264,499,000			312,877,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	254,315,000			160,715,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	274,454,000			203,646,000
Financing Receivable, Revolving	995,843,000			1,003,012,000
Financing Receivable, Revolving Converted to Term Loans	12,175,000			26,973,000
Loans and Leases Receivable, Net of Deferred Income	3,836,009,000			2,989,613,000
Financing Receivable, Allowance for Credit Loss	50,572,000	53,186,000	31,054,000	30,292,000	30,879,000	29,700,000	34,658,000
Commercial Business [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,175,587,000			479,481,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	409,759,000			442,222,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	357,128,000			330,934,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	233,037,000			301,337,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	240,648,000			157,436,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	256,178,000			199,089,000
Financing Receivable, Revolving	915,373,000			963,663,000
Financing Receivable, Revolving Converted to Term Loans	8,674,000			25,577,000
Loans and Leases Receivable, Net of Deferred Income	3,596,384,000			2,899,739,000
Commercial Business [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	4,856,000			2,241,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	51,204,000			6,673,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	8,635,000			56,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	25,626,000			2,006,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	6,514,000			52,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	11,907,000			585,000
Financing Receivable, Revolving	35,819,000			12,710,000
Financing Receivable, Revolving Converted to Term Loans	0			0
Loans and Leases Receivable, Net of Deferred Income	144,561,000			24,323,000
Commercial Business [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	3,791,000			85,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	6,005,000			17,240,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	17,758,000			3,458,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	5,836,000			9,534,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	7,153,000			3,227,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	6,369,000			3,972,000
Financing Receivable, Revolving	44,651,000			26,639,000
Financing Receivable, Revolving Converted to Term Loans	3,501,000			1,396,000
Loans and Leases Receivable, Net of Deferred Income	95,064,000			65,551,000
Agriculture [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	150,568,000			115,000,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	113,012,000			63,532,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	49,414,000			77,891,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	64,139,000			77,781,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	62,678,000			35,138,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	67,011,000			62,616,000
Financing Receivable, Revolving	330,705,000			316,989,000
Financing Receivable, Revolving Converted to Term Loans	12,763,000			16,424,000
Loans and Leases Receivable, Net of Deferred Income	850,290,000			765,371,000
Financing Receivable, Allowance for Credit Loss	12,461,000	14,868,000	6,510,000	15,835,000	13,899,000	12,671,000	9,589,000
Agriculture [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	147,892,000			107,152,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	99,483,000			54,950,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	42,464,000			70,337,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	59,828,000			71,874,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	60,007,000			33,597,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	62,529,000			56,342,000
Financing Receivable, Revolving	290,986,000			280,984,000
Financing Receivable, Revolving Converted to Term Loans	12,273,000			10,036,000
Loans and Leases Receivable, Net of Deferred Income	775,462,000			685,272,000
Agriculture [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0			557,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	519,000			2,535,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0			1,381,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	33,000			0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	272,000			64,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0			576,000
Financing Receivable, Revolving	1,801,000			5,336,000
Financing Receivable, Revolving Converted to Term Loans	0			0
Loans and Leases Receivable, Net of Deferred Income	2,625,000			10,449,000
Agriculture [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	2,676,000			7,291,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	13,010,000			6,047,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	6,950,000			6,173,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	4,278,000			5,907,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,399,000			1,477,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	4,482,000			5,698,000
Financing Receivable, Revolving	37,918,000			30,669,000
Financing Receivable, Revolving Converted to Term Loans	490,000			6,388,000
Loans and Leases Receivable, Net of Deferred Income	72,203,000			69,650,000
Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	89,744,000			183,525,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	120,941,000			92,606,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	29,669,000			40,514,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	4,531,000			1,067,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	782,000			939,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,940,000			1,660,000
Financing Receivable, Revolving	25,569,000			33,429,000
Financing Receivable, Revolving Converted to Term Loans	0			7,793,000
Loans and Leases Receivable, Net of Deferred Income	273,176,000			361,533,000
Financing Receivable, Allowance for Credit Loss	8,963,000	7,953,000	6,821,000	8,571,000	11,852,000	12,457,000	14,395,000
Construction [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	89,744,000			183,525,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	101,060,000			91,342,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	24,130,000			40,514,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	4,531,000			1,067,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	782,000			939,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,883,000			1,601,000
Financing Receivable, Revolving	25,536,000			33,388,000
Financing Receivable, Revolving Converted to Term Loans	0			7,793,000
Loans and Leases Receivable, Net of Deferred Income	247,666,000			360,169,000
Construction [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0			0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,259,000			1,264,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0			0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0			0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0			0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0			0
Financing Receivable, Revolving	0			41,000
Financing Receivable, Revolving Converted to Term Loans	0			0
Loans and Leases Receivable, Net of Deferred Income	2,259,000			1,305,000
Construction [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0			0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	17,622,000			0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	5,539,000			0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0			0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0			0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	57,000			59,000
Financing Receivable, Revolving	33,000			0
Financing Receivable, Revolving Converted to Term Loans	0			0
Loans and Leases Receivable, Net of Deferred Income	23,251,000			59,000
One-to-Four Family Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	88,632,000			103,315,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	83,872,000			78,105,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	73,123,000			33,240,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	34,326,000			25,452,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	25,331,000			27,917,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	89,936,000			83,526,000
Financing Receivable, Revolving	266,905,000			284,735,000
Financing Receivable, Revolving Converted to Term Loans	3,307,000			1,035,000
Loans and Leases Receivable, Net of Deferred Income	665,432,000			637,325,000
Financing Receivable, Allowance for Credit Loss	22,107,000	23,711,000	11,672,000	7,435,000	7,458,000	7,619,000	8,024,000
One-to-Four Family Residential [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	88,632,000			103,315,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	83,137,000			77,877,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	72,896,000			32,440,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	33,149,000			25,052,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	24,987,000			27,294,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	87,267,000			80,370,000
Financing Receivable, Revolving	265,475,000			283,830,000
Financing Receivable, Revolving Converted to Term Loans	3,110,000			554,000
Loans and Leases Receivable, Net of Deferred Income	658,653,000			630,732,000
One-to-Four Family Residential [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	206,000
Financing Receivable, Revolving	297,000
Financing Receivable, Revolving Converted to Term Loans	0
Loans and Leases Receivable, Net of Deferred Income	503,000
One-to-Four Family Residential [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0			0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	735,000			228,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	227,000			800,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,177,000			400,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	344,000			623,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,463,000			3,156,000
Financing Receivable, Revolving	1,133,000			905,000
Financing Receivable, Revolving Converted to Term Loans	197,000			481,000
Loans and Leases Receivable, Net of Deferred Income	6,276,000			6,593,000
Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	4,443,000			9,276,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,684,000			5,713,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	4,299,000			1,975,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,178,000			758,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	331,000			848,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,332,000			1,314,000
Financing Receivable, Revolving	20,961,000			23,378,000
Financing Receivable, Revolving Converted to Term Loans	777,000			508,000
Loans and Leases Receivable, Net of Deferred Income	37,005,000			43,770,000
Financing Receivable, Allowance for Credit Loss	1,541,000	$ 1,595,000	$ 1,661,000	883,000	$ 579,000	$ 715,000	$ 787,000
Consumer Loan [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	4,412,000			9,276,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,684,000			5,713,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	4,299,000			1,974,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,172,000			758,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	327,000			848,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,161,000			1,306,000
Financing Receivable, Revolving	20,937,000			23,351,000
Financing Receivable, Revolving Converted to Term Loans	736,000			508,000
Loans and Leases Receivable, Net of Deferred Income	36,728,000			43,734,000
Consumer Loan [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	31,000			0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0			0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0			1,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6,000			0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4,000			0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	171,000			8,000
Financing Receivable, Revolving	24,000			27,000
Financing Receivable, Revolving Converted to Term Loans	41,000			0
Loans and Leases Receivable, Net of Deferred Income	$ 277,000			$ 36,000

Allowance for Credit Losses a_6

Allowance for Credit Losses and Allowance for Unfunded Commitments and Letters of Credit (Narrative) (Details)	3 Months Ended
	Sep. 30, 2020USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Minimum loan balance of nonaccrual, collateral dependent loans considered for ACL	$ 500,000
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)	$ 73,000,000

Other Real Estate Owned (Summar

Other Real Estate Owned (Summary of Other Real Estate Owned) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Other Real Estate Owned [Line Items]
Balance, beginning of period	$ 747	$ 1,118	$ 552	$ 6,019
Transfers in	475	0	1,033	386
Valuation adjustments	0	0	0	(195)
Proceeds from Sale of OREO Property	681	588	1,026	6,382
Gain on sale of OREO, net	82	95	64	797
Total OREO, end of period	623	$ 625	623	$ 625
Mortgage Loans in Process of Foreclosure, Amount	436		436
One-to-Four Family Residential [Member]
Other Real Estate Owned [Line Items]
Total OREO, end of period	$ 0		$ 0

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets (Schedule of Goodwill and Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Goodwill and Intangible Assets [Roll Forward]
Total goodwill, beginning of period			$ 765,842
Total goodwill, end of period	$ 765,842	$ 765,842	765,842	$ 765,842
CDI current period amortization	(2,193)	(2,632)	(6,713)	(8,029)
Indefinite-lived Intangible Assets (Excluding Goodwill)	919	919	919	919
Other intangible assets, net	28,745	37,908	28,745	37,908		$ 35,458
Total goodwill and intangible assets, end of period	794,587	803,750	$ 794,587	803,750
Core Deposits [Member]
Goodwill and Intangible Assets [Line Items]
Estimated life of CDI, in years			10 years
Goodwill and Intangible Assets [Roll Forward]
Gross core deposit intangible balance, beginning of period					$ 105,473	105,473	$ 105,473	$ 105,473
Accumulated amortization at beginning of period					$ (75,454)	$ (70,934)	$ (65,852)	$ (60,455)
Core deposit intangible, net, beginning of period	30,019	39,621	$ 34,539	45,018
CDI current period amortization	(2,193)	(2,632)	(6,713)	(8,029)
Total core deposit intangible, end of period	$ 27,826	$ 36,989	$ 27,826	$ 36,989

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets (Estimated Future Amortization Expense of Core Deposit Intangibles) (Details) $ in Thousands	Sep. 30, 2020USD ($)
Future Amortization Expense For Core Deposit Intangibles
2020	$ 2,012
2021	7,264
2022	5,880
2023	4,552
2024	$ 3,432

Revolving Line of Credit (Detai

Revolving Line of Credit (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 15,000
Line of Credit [Member]
Line of Credit Facility [Line Items]
Short-term Debt	$ 0	$ 0

Derivatives and Balance Sheet_3

Derivatives and Balance Sheet Offsetting - Fair value of derivatives & classifications table (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Designated as Hedging Instrument [Member] | Interest rate collar [Domain]
Derivative [Line Items]
Fair value of asset derivative instruments	$ 35,668	$ 14,727
Designated as Hedging Instrument [Member] | Other Assets [Member] | Interest rate collar [Domain]
Derivative [Line Items]
Fair value of asset derivative instruments	35,668	14,727
Designated as Hedging Instrument [Member] | Other Liabilities [Member] | Interest rate collar [Domain]
Derivative [Line Items]
Fair value of liability derivative instruments	0	0
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Fair value of asset derivative instruments	53,202	19,144
Fair value of liability derivative instruments	53,677	19,145
Not Designated as Hedging Instrument [Member] | Other Assets [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Fair value of asset derivative instruments	53,202	19,144
Not Designated as Hedging Instrument [Member] | Other Liabilities [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Fair value of liability derivative instruments	$ 53,677	$ 19,145

Derivatives and Balance Sheet_4

Derivatives and Balance Sheet Offsetting - Cash flow hedge effect on AOCI table (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Balance Sheet Offsetting [Line Items]
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss)	$ (81)	$ 4,088	$ 26,744	$ 19,779
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	$ 2,673	$ 76	$ 5,803	$ 76

Derivatives and Balance Sheet_5

Derivatives and Balance Sheet Offsetting - Collateral pledged table (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Balance Sheet Offsetting [Line Items]
Repurchase agreements, amounts offset in balance sheet	$ 0	$ 0
Repurchase agreements, net amount presented in statement of financial position	26,966	64,437
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	(26,966)	(64,437)
Securities sold under agreements to repurchase, amount not offset	0	0
Interest Rate Contracts [Member]
Balance Sheet Offsetting [Line Items]
Derivative Assets, Gross Amounts Offset in the Balance Sheets	0	0
Derivative Asset	53,202	19,144
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	53,202	19,144
Derivative Liability, Gross Amounts Offset in Balance Sheets	0	0
Derivative Liability	53,677	19,145
Derivative, Collateral, Right to Reclaim Cash	53,677	19,145
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	0	0
Interest rate collar [Domain]
Balance Sheet Offsetting [Line Items]
Derivative Assets, Gross Amounts Offset in the Balance Sheets	0	0
Derivative Asset	35,668	14,727
Derivative, Collateral, Obligation to Return Cash	(35,668)	(14,727)
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	0	0
Available-for-sale Securities [Member]
Balance Sheet Offsetting [Line Items]
Securities Sold under Agreements to Repurchase, Gross	26,966	64,437
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Balance Sheet Offsetting [Line Items]
Fair value of asset derivative instruments	53,202	19,144
Fair value of liability derivative instruments	53,677	19,145
Designated as Hedging Instrument [Member] | Interest rate collar [Domain]
Balance Sheet Offsetting [Line Items]
Fair value of asset derivative instruments	$ 35,668	$ 14,727

Derivatives and Balance Sheet_6

Derivatives and Balance Sheet Offsetting - Collateral pledged for repurchase agreements table (Details) $ in Thousands	Sep. 30, 2020USD ($)
Balance Sheet Offsetting [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	$ 26,966
Secured Borrowings, Gross, Difference, Amount	0
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Balance Sheet Offsetting [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	26,966
Maturity Overnight [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Balance Sheet Offsetting [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	26,966
Maturity Less than 30 Days [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Balance Sheet Offsetting [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	0
Maturity 30 to 90 Days [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Balance Sheet Offsetting [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	0
Maturity Greater than 90 Days [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Balance Sheet Offsetting [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	$ 0

Derivatives and Balance Sheet_7

Derivatives and Balance Sheet Offsetting (Narative) (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
Balance Sheet Offsetting [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ 10,700		$ 10,700
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	26,966		26,966
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Balance Sheet Offsetting [Line Items]
Derivative, Notional Amount	575,400		575,400		$ 428,600
Gain (Loss) on Derivative Instruments, Net, Pretax	(2)	$ 0	(475)	$ (2)
Designated as Hedging Instrument [Member] | Interest rate collar [Domain]
Balance Sheet Offsetting [Line Items]
Derivative, Notional Amount	500,000		500,000
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Balance Sheet Offsetting [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	$ 26,966		$ 26,966

Commitments and contingent li_2

Commitments and contingent liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Commitments to Extend Credit [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	$ 3,790,000	$ 2,670,000
Standby Letters of Credit [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	30,300	25,700
Commercial Letter of Credit and other off-balance sheet liabilities [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	$ 23	$ 23

Shareholders' Equity (Details)

Shareholders' Equity (Details) - $ / shares	Oct. 29, 2020	Jul. 23, 2020	Apr. 30, 2020	Jan. 23, 2020
Subsequent Event [Line Items]
Declared quarterly cash dividend		$ 0.28	$ 0.28	$ 0.28
Common Stock, Special Cash Dividends, Per Share, Declared		$ 0	$ 0	$ 0.22
Subsequent Event [Member]
Subsequent Event [Line Items]
Declared quarterly cash dividend	$ 0.28

Shareholders' Equity Share repu

Shareholders' Equity Share repurchase (Details) - $ / shares shares in Thousands	Oct. 29, 2020	Jul. 23, 2020	Apr. 30, 2020	Jan. 23, 2020	Sep. 30, 2020	Sep. 30, 2020
Class of Stock [Line Items]
Common Stock, Dividends, Per Share, Declared		$ 0.28	$ 0.28	$ 0.28
Treasury Stock, Shares, Acquired						731
Treasury Stock Acquired, Average Cost Per Share					$ 27.36
Subsequent Event [Member]
Class of Stock [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.28

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Changes in AOCI by Component) (Details) - 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) [Roll Forward]
Beginning balance	$ 181,077	$ 47,150	$ 40,367	$ (35,305)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(1,504)	17,730	141,640	101,699
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax	(1,972)	4	(4,406)	(1,510)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Total	(3,476)	17,734	137,234	100,189
Ending balance	177,601	64,884	177,601	64,884
Unrealized Gains and Losses on Available-for-Sale Debt Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	155,403	37,162	33,038	(33,128)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(1,442)	14,593	121,114	86,519
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax	0	0	(191)	(1,636)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Total	(1,442)	14,593	120,923	84,883
Ending balance	153,961	51,755	153,961	51,755
Unrealized Gains and Losses on Pension Plan Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(3,815)	(2,055)	(3,974)	(2,177)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0	0	0
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax	80	62	239	184
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Total	80	62	239	184
Ending balance	(3,735)	(1,993)	(3,735)	(1,993)
Unrealized gains and losses on cash flow hedge
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	29,489	12,043	11,303	0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(62)	3,137	20,526	15,180
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax	(2,052)	(58)	(4,454)	(58)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Total	(2,114)	3,079	16,072	15,122
Ending balance	$ 27,375	$ 15,122	$ 27,375	$ 15,122

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Reclassification out of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment securities gains, net			$ 16,674	$ 2,132
Total before tax	$ 54,683	$ 63,105	117,318	183,579
Income tax provision	(9,949)	(12,378)	(21,374)	(35,257)
Compensation and employee benefits	55,133	54,459	156,018	158,559
Net income	44,734	50,727	95,944	148,322
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains and Losses on Available-for-Sale Debt Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment securities gains, net	0	0	249	2,132
Total before tax	0	0	249	2,132
Income tax provision	0	0	(58)	(496)
Net income	0	0	191	1,636
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains and Losses on Pension Plan Liability [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(104)	(81)	(311)	(240)
Income tax provision	24	19	72	56
Compensation and employee benefits	(104)	(81)	(311)	(240)
Net income	(80)	(62)	(239)	(184)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized gains and losses from hedging instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	2,673	76	5,803	76
Income tax provision	(621)	(18)	(1,349)	(18)
Net income	2,052	58	4,454	58
Interest income, Loans	$ 2,673	$ 76	$ 5,803	$ 76

Fair Value Accounting and Mea_3

Fair Value Accounting and Measurement (Financial Assets And Liabilities Accounted for Fair Value On Recurring Basis) (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	$ 4,281,720	$ 3,746,142
Other assets (Interest rate contracts)	53,202	19,144
Interest Rate Cash Flow Hedge Asset at Fair Value	35,668	14,727
Other liabilities (Interest rate contracts)	53,677	19,145
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Other assets (Interest rate contracts)	0	0
Interest Rate Cash Flow Hedge Asset at Fair Value	0	0
Other liabilities (Interest rate contracts)	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	4,281,720	3,746,142
Other assets (Interest rate contracts)	53,202	19,144
Interest Rate Cash Flow Hedge Asset at Fair Value	35,668	14,727
Other liabilities (Interest rate contracts)	53,677	19,145
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Other assets (Interest rate contracts)	0	0
Interest Rate Cash Flow Hedge Asset at Fair Value	0	0
Other liabilities (Interest rate contracts)	0	0
U.S. Government Agency and Sponsored Enterprise Mortgage-Back Securities and Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	3,121,642	2,892,950
U.S. Government Agency and Sponsored Enterprise Mortgage-Back Securities and Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
U.S. Government Agency and Sponsored Enterprise Mortgage-Back Securities and Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	3,121,642	2,892,950
U.S. Government Agency and Sponsored Enterprise Mortgage-Back Securities and Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	293,024	196,050
Asset-backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	293,024	196,050
Asset-backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
State and Municipal Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	557,444	488,802
State and Municipal Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
State and Municipal Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	557,444	488,802
State and Municipal Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
U.S. Government Agency [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	309,610	168,340
U.S. Government Agency [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	0	0
U.S. Government Agency [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	309,610	168,340
U.S. Government Agency [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	$ 0	$ 0

Fair Value Accounting and Mea_4

Fair Value Accounting and Measurement Equity securities without readily determinable values (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Visa Class B shares, remaining shares	77,683		77,683
Equity Securities	$ 13,425	$ 0	$ 13,425	$ 0	$ 13,425	$ 0	$ 0	$ 0
Equity Securities without Readily Determinable Fair Value, Upward Price Adjustment, Annual Amount	$ 0	$ 0	$ 13,425	$ 0

Fair Value Accounting and Mea_5

Fair Value Accounting and Measurement (Financial Assets Accounted For Fair Value On Nonrecurring Basis) (Details) - Fair Value, Nonrecurring [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans, Fair Value	$ 11,899	$ 8,990	$ 11,899	$ 8,990
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans, Fair Value	0	0	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans, Fair Value	0	0	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans, Fair Value	11,899	8,990	11,899	8,990
Collateral dependent loans [Domain]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ (153)	$ 1,722	$ 4,941	$ 3,299

Fair Value Accounting and Mea_6

Fair Value Accounting and Measurement (Quantitative Information About Level 3 Fair Value Measurements) (Details) - Fair Value, Nonrecurring [Member] $ in Thousands	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)
Fair Value Measurements Inputs and Valuation Techniques
Collateral dependent loans, Fair Value	$ 11,899	$ 8,990
Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Collateral dependent loans, Fair Value	$ 11,899	$ 8,990
Valuation, Market Approach [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Collateral dependent loans, Measurement Input	0	0
Valuation, Market Approach [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Collateral dependent loans, Measurement Input	1	1
Valuation, Market Approach [Member] | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Collateral dependent loans, Measurement Input	0.1557	0.4209

Fair Value Accounting and Mea_7

Fair Value Accounting and Measurement (Carrying Amounts and Estimated Fair Values of Selected Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Assets
Interest-earning deposits with banks	$ 736,422		$ 24,132
Debt securities available for sale at fair value	4,281,720		3,746,142
Equity Securities	13,425	$ 13,425	0	$ 0	$ 0	$ 0
Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	193,823		223,541
Interest-earning deposits with banks	736,422		24,132
Debt securities available for sale at fair value	4,281,720		3,746,142
Equity Securities	13,425
FHLB stock	10,280		48,120
Loans held for sale	24,407		17,718
Loans	9,980,912		8,883,865
Interest rate contracts	53,202		19,144
Interest Rate Cash Flow Hedge Asset at Fair Value	35,668		14,727
Liabilities
Deposits	337,386		397,736
FHLB advances	9,354		952,762
Repurchase agreements	26,966		64,437
Subordinated Debentures	35,368		35,491
Interest rate contracts	53,677		19,145
Reported Value Measurement [Member]
Assets
Cash and due from banks	193,823		223,541
Interest-earning deposits with banks	736,422		24,132
Debt securities available for sale at fair value	4,281,720		3,746,142
Equity Securities	13,425
FHLB stock	10,280		48,120
Loans held for sale	24,407		17,718
Loans	9,531,979		8,659,497
Interest rate contracts	53,202		19,144
Interest Rate Cash Flow Hedge Asset at Fair Value	35,668		14,727
Liabilities
Deposits	337,228		400,070
FHLB advances	7,427		953,469
Repurchase agreements	26,966		64,437
Subordinated Debentures	35,139		35,277
Interest rate contracts	53,677		19,145
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	193,823		223,541
Interest-earning deposits with banks	736,422		24,132
Debt securities available for sale at fair value	0		0
Equity Securities	0
FHLB stock	0		0
Loans held for sale	0		0
Loans	0		0
Interest rate contracts	0		0
Interest Rate Cash Flow Hedge Asset at Fair Value	0		0
Liabilities
Deposits	0		0
FHLB advances	0		0
Repurchase agreements	0		0
Subordinated Debentures	0		0
Interest rate contracts	0		0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	0		0
Interest-earning deposits with banks	0		0
Debt securities available for sale at fair value	4,281,720		3,746,142
Equity Securities	0
FHLB stock	10,280		48,120
Loans held for sale	24,407		17,718
Loans	0		0
Interest rate contracts	53,202		19,144
Interest Rate Cash Flow Hedge Asset at Fair Value	35,668		14,727
Liabilities
Deposits	337,386		397,736
FHLB advances	9,354		952,762
Repurchase agreements	26,966		64,437
Subordinated Debentures	35,368		35,491
Interest rate contracts	53,677		19,145
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	0		0
Interest-earning deposits with banks	0		0
Debt securities available for sale at fair value	0		0
Equity Securities	13,425
FHLB stock	0		0
Loans held for sale	0		0
Loans	9,980,912		8,883,865
Interest rate contracts	0		0
Interest Rate Cash Flow Hedge Asset at Fair Value	0		0
Liabilities
Deposits	0		0
FHLB advances	0		0
Repurchase agreements	0		0
Subordinated Debentures	0		0
Interest rate contracts	$ 0		$ 0

Earnings per Common Share (Deta

Earnings per Common 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, Diluted, by Common Class, Including Two Class Method [Line Items]
Net Income	$ 44,734	$ 50,727	$ 95,944	$ 148,322
Earnings allocated to participating securities - nonvested restricted shares	164	358	487	1,204
Earnings allocated to common shareholders, Basic	$ 44,570	$ 50,369	$ 95,457	$ 147,118
Weighted average common shares outstanding	70,726	71,803	70,870	72,256
Basic earnings per common share	$ 0.63	$ 0.70	$ 1.35	$ 2.04
Earnings allocated to common shareholders, Diluted	$ 44,570	$ 50,369	$ 95,457	$ 147,118
Dilutive effect of equity awards	36	0	36	1
Weighted average diluted common shares outstanding	70,762	71,803	70,906	72,257
Diluted earnings per common share	$ 0.63	$ 0.70	$ 1.35	$ 2.04
Potentially dilutive share options that were not included in the computation of diluted EPS because to do so would be anti-dilutive.	596	0	487	0

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
Revenue from Contract with Customer [Abstract]
Deposit account and treasury management fees	$ 6,658	$ 9,015	$ 20,538	$ 27,030
Card revenue	3,834	4,006	10,431	11,431
Financial services and trust revenue	3,253	3,226	9,481	9,608
Revenue from contracts with customers	13,745	16,247	40,450	48,069
Noninterest income, excluding revenue from contracts with customers	8,727	11,783	40,488	27,305
Noninterest Income	$ 22,472	$ 28,030	$ 80,938	$ 75,374

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event [Member] - USD ($) $ in Thousands, shares in Millions	Oct. 20, 2020	Oct. 28, 2020
Subsequent Event [Line Items]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased		3.5
Stock Repurchase Program, Authorized Amount		$ 100,000
Gain on termination of interest rate collar	$ 34,900