Columbia Banking System (COLB) 10-Q 6 May 21 2021 Q1 Quarterly report Financial data

Document

Document - shares	3 Months Ended
	Mar. 31, 2021	Apr. 30, 2021
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
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		71,731,554
Entity Central Index Key	0000887343
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
ASSETS
Cash and due from banks	$ 178,096	$ 218,899
Interest-earning deposits with banks	706,389	434,867
Total cash and cash equivalents	884,485	653,766
Debt securities available for sale at fair value	5,496,290	5,210,134
Equity Securities	13,425	13,425
FHLB stock at cost	10,280	10,280
Loans held for sale	26,176	26,481
Loans, net of unearned income	9,676,318	9,427,660
Less: Allowance for credit losses	148,294	149,140
Loans, net	9,528,024	9,278,520
Interest receivable	52,667	54,831
Premises and equipment, net	160,179	162,059
OREO	521	553
Goodwill	765,842	765,842
Other intangible assets, net	24,810	26,734
Other assets	372,417	382,154
Total assets	17,335,116	16,584,779
LIABILITIES AND SHAREHOLDERS' EQUITY
Noninterest-bearing	7,424,472	6,913,214
Interest-bearing	7,342,994	6,956,648
Total deposits	14,767,466	13,869,862
FHLB advances	7,400	7,414
Securities sold under agreements to repurchase	38,624	73,859
Subordinated debentures	35,046	35,092
Other liabilities	211,517	250,945
Total liabilities	$ 15,060,053	$ 14,237,172
Shareholders' equity:
Preferred Stock, Authorized shares	2,000	2,000
Common Stock Authorized shares	115,000	115,000
Common Stock Shares Issued	73,923	73,782
Common Stock Issued value	$ 1,661,129	$ 1,660,998
Common Stock, Shares, Outstanding	71,739	71,598
Retained earnings	$ 607,040	$ 575,248
Accumulated other comprehensive income	$ 77,728	$ 182,195
Treasury Stock, Shares	2,184	2,184
Treasury Stock, Value	$ (70,834)	$ (70,834)
Total shareholders’ equity	2,275,063	2,347,607
Total liabilities and shareholders’ equity	$ 17,335,116	$ 16,584,779

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ / shares in Thousands, $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale, Amortized Cost	$ 5,417,373	$ 4,997,529
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
	Mar. 31, 2021	Mar. 31, 2020
Interest Income
Loans	$ 100,315	$ 107,366
Taxable securities	22,816	21,088
Tax-exempt securities	2,759	2,302
Deposits in banks	152	141
Total interest income	126,042	130,897
Interest Expense
Deposits	1,485	3,642
FHLB advances and FRB borrowings	72	4,229
Subordinated debentures	468	468
Other borrowings	23	136
Total interest expense	2,048	8,475
Net Interest Income	123,994	122,422
Provision (recapture) for credit losses	(800)	41,500
Net interest income after provision (recapture) for credit losses	124,794	80,922
Noninterest Income
Deposit account and treasury management fees	6,358	7,788
Card revenue	3,733	3,518
Financial services and trust revenue	3,381	3,065
Loan revenue	7,369	4,590
Bank owned life insurance	1,560	1,596
Investment securities gains, net	0	249
Other	765	401
Total noninterest income	23,166	21,207
Noninterest Expense
Compensation and employee benefits	51,736	54,842
Occupancy	9,006	9,197
Data processing and software	8,451	7,099
Legal and professional fees	2,815	2,102
Amortization of intangibles	1,924	2,310
B&O taxes	1,259	624
Advertising and promotion	760	1,305
Regulatory premiums	1,105	34
Net cost (benefit) of operation of OREO	(63)	12
Other	6,566	6,746
Total noninterest expense	83,559	84,271
Income before income taxes	64,401	17,858
Income tax provision	12,548	3,230
Net Income	$ 51,853	$ 14,628
Earnings per common share
Basic	$ 0.73	$ 0.20
Diluted	$ 0.73	$ 0.20
Weighted average number of common shares outstanding	70,869	71,206
Weighted average number of diluted common shares outstanding	71,109	71,264

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net Income	$ 51,853	$ 14,628
Unrealized gain from securities
Net unrealized holding gain from available for sale debt securities arising during the period, net of tax	(102,605)	79,696
Reclassification adjustment of net gain from sale of available for sale debt securities included in income, net of tax	0	(191)
Net unrealized gain from securities, net of reclassification adjustment	(102,605)	79,505
Pension plan liability adjustment:
Amortization of unrecognized net actuarial loss included in net periodic pension cost, net of tax	115	80
Pension plan liability adjustment, net	115	80
Unrealized gain from cash flow hedging instruments
Net unrealized gain (loss) in cash flow hedging instruments arising during the period, net of tax	0	17,977
Reclassification adjustment for net gain in cash flow hedging instruments included in income, net of tax	1,977	722
Net unrealized gain from cash flow hedging instruments, net of reclassification adjustment	(1,977)	17,255
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Total	(104,467)	96,840
Total comprehensive income	$ (52,614)	$ 111,468

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net unrealized holding gain (loss) from available for sale securities arising during the period, tax	$ 31,082	$ (24,143)
Reclassification adjustment of net gain from sale of available for sale securities included in income, tax	0	58
Less: amortization of unrecognized net actuarial loss included in net periodic pension cost, tax	(35)	(24)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax	0	(5,446)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax	$ 599	$ 218

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		72,124
Adjustment to opening retained earnings, net of tax, pursuant to adoption of ASU | Accounting Standards Update 2016-13 [Member]			$ (2,457)
Balance, value at Dec. 31, 2019	$ 2,159,962	$ 1,650,753	519,676	$ 40,367	$ (50,834)
Net income	14,628		14,628
Other comprehensive income (loss)	96,840			96,840
Issuance of common stock - employee stock purchase plan, shares		26
Issuance of common stock - employee stock purchase plan, value	$ 945	$ 945
Activity in Deferred Compensation Plan, shares	0
Activity in Deferred Compensation Plan, value	$ 3	$ 3
Issuance of common stock - RSAs and RSUs, net of canceled awards, shares		222
Issuance of common stock - RSAs and RSUs, net of canceled awards, value	2,172	$ 2,172
Purchase and retirement of common stock, shares		(66)
Purchase and retirement of common stock, value	(2,474)	$ (2,474)
Cash dividends declared on common stock	(36,017)		(36,017)
Purchase of treasury stock, shares		(731)
Purchase of treasury stock, value	(20,000)				(20,000)
Balance, value at Mar. 31, 2020	2,213,602	$ 1,651,399	495,830	137,207	(70,834)
Shares, Outstanding		71,575
Shares, Outstanding		71,598
Balance, value at Dec. 31, 2020	2,347,607	$ 1,660,998	575,248	182,195	(70,834)
Net income	51,853		51,853
Other comprehensive income (loss)	(104,467)			(104,467)
Issuance of common stock - employee stock purchase plan, shares		41
Issuance of common stock - employee stock purchase plan, value	1,098	$ 1,098
Issuance of common stock - RSAs and RSUs, net of canceled awards, shares		188
Issuance of common stock - RSAs and RSUs, net of canceled awards, value	3,028	$ 3,028
Purchase and retirement of common stock, shares		88
Purchase and retirement of common stock, value	(3,995)	$ (3,995)
Cash dividends declared on common stock	(20,061)		(20,061)
Balance, value at Mar. 31, 2021	$ 2,275,063	$ 1,661,129	$ 607,040	$ 77,728	$ (70,834)
Shares, Outstanding		71,739

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash dividends declared on common stock, per share	$ 0.28	$ 0.50

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash Flows From Operating Activities
Net income	$ 51,853	$ 14,628
Adjustments to reconcile net income to net cash provided by operating activities
Provision (recapture) for credit losses	(800)	41,500
Stock-based compensation expense	3,028	2,172
Depreciation, amortization and accretion	1,433	13,151
Investment securities gain, net	0	249
Net realized (gain) loss on sale of premises and equipment, loans held for investment and OPPO	(6)	25
Net realized gain on sale and valuation adjustments of OREO	100	0
Gain on bank owned life insurance death benefit	209	0
Originations of loans held for sale	107,104	58,199
Proceeds from sales of loans held for sale	107,320	66,216
Increase (Decrease) in Mortgage Loans Held-for-sale	89	0
Net change in:
Interest receivable	2,164	2,262
Interest payable	494	2,325
Other assets	11,525	(63,141)
Other liabilities	(10,627)	44,725
Net cash provided by operating activities	59,072	65,365
Cash Flows From Financing Activities
Loans originated, net of principal collected	(164,856)	(197,362)
Purchases of debt securities available for sale	(608,854)	(37,472)
Purchases of loans held for investment	74,383	0
Purchases of premises and equipment	(805)	(1,650)
Purchases of FHLB stock	0	(51,240)
Proceeds from sale of debt securities, available-for-sale	0	194,105
Proceeds from principal repayments and maturities of debt securities available for sale	180,380	134,641
Proceeds from sales of premises and equipment	0	31
Proceeds from redemption of Federal Home Loan Bank stock	0	61,080
Proceeds from sales of other real estate and other personal property owned	132	50
Proceeds from bank owned life insurance death benefit	671	1,050
Net cash provided by (used in) investing activities	(667,715)	103,233
Cash Flows From Financing Activities
Net increase in deposits	897,604	128,059
Net decrease in sweep repurchase agreements	(35,235)	(35,185)
Proceeds from FHLB advances	0	1,281,000
Proceeds from FRB borrowings	0	182,010
Proceeds from other borrowings	0	5,000
Proceeds from exercise of stock options and employee stock purchase plan	1,098	945
Repayment of FHLB advances	0	(1,527,000)
Repayment of FRB borrowings	0	177,010
Payments for common stock dividends	(20,110)	(35,860)
Purchase of treasury stock	0	(20,000)
Purchase and retirement of common stock	3,995	2,474
Net cash provided by (used in) financing activities	839,362	(200,515)
Increase (decrease) in cash and cash equivalents	230,719	(31,917)
Cash and cash equivalents at beginning of period	653,766	247,673
Cash and cash equivalents at end of period	884,485	215,756
Supplemental Information:
Cash paid for interest	1,553	6,150
Income Taxes Paid, Net	(1)	12
Non-cash investing and financing activities
Premises and equipment expenditures incurred but not yet paid	43	238
Change in dividends payable on unvested shares included in other liabilities	$ (49)	$ 157

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
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 three months ended March 31, 2021 are not necessarily indicative of results to be anticipated for the year ending December 31, 2021. The accompanying interim unaudited Consolidated Financial Statements should be read in conjunction with the financial statements and related notes contained in the Company’s 2020 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 2020 Annual Report on Form 10-K. There have not been any changes in our significant accounting policies compared to those contained in our 2020 Form 10-K disclosure for the year ended December 31, 2020. Reclassifications Certain amounts reported in prior periods have been reclassified in the Consolidated Financial Statements to conform to the current presentation. Specifically, amounts related to software expense, which have historically been included in “Other” noninterest expense, have been combined with data processing expense in the row titled “Data processing and software” in the Consolidated Statements of Income. The reclassifications have no effect on net income or shareholders’ equity as previously reported.

Accounting Pronouncements Recen

Accounting Pronouncements Recently Adopted or Issued	3 Months Ended
	Mar. 31, 2021
Accounting Standards Update and Change in Accounting Principle [Abstract]
New Accounting Pronouncements Recently Adopted or Issued	Accounting Pronouncements Recently Adopted or Issued Accounting Standards Adopted in 2021 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 did not 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 did not have a material impact on the Company’s Consolidated Financial Statements. Recently Issued Accounting Standards, Not Yet Adopted In January 2021, the FASB issued ASU 2021-01, Reference Rate Reform (Topic 848) - Scope. The amendments in this ASU clarify that certain optional expedients and exceptions for contract modifications and hedge accounting apply to derivatives that are affected by the discounting transition. Certain provisions, if elected, apply to derivative instruments that use an interest rate for margining, discounting or contract price alignment that is modified as a result of reference rate reform. Amendments in this ASU to the expedients and exceptions in Topic 848 capture the incremental consequences of the scope clarification and tailor the existing guidance to derivative instruments affected by the discounting transition. The ASU is effective for interim and annual reporting periods beginning on January 7, 2021. The adoption of this ASU is not expected to have a material impact on the Company’s Consolidated Financial Statements.

Securities

Securities	3 Months Ended
	Mar. 31, 2021
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 March 31, 2021 (in thousands) U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 4,040,359 $ 109,063 $ (45,203) $ — $ 4,104,219 Other asset-backed securities 359,259 5,216 (5,656) — 358,819 State and municipal securities 739,570 18,080 (6,365) — 751,285 U.S. government agency and government-sponsored enterprise securities 278,185 5,349 (1,567) — 281,967 Total $ 5,417,373 $ 137,708 $ (58,791) $ — $ 5,496,290 December 31, 2020 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 3,640,351 $ 178,579 $ (4,543) $ — $ 3,814,387 Other asset-backed securities 349,904 9,651 (2,076) — 357,479 State and municipal securities 729,066 25,098 (592) — 753,572 U.S. government agency and government-sponsored enterprise securities 278,208 6,545 (57) — 284,696 Total $ 4,997,529 $ 219,873 $ (7,268) $ — $ 5,210,134 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 months ended March 31, 2021 and 2020. 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 March 31, 2021 and December 31, 2020, accrued interest receivable for securities was $17.4 million and $17.1 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 and calls of debt securities available for sale as well as other securities gains and losses for the periods indicated: Three Months Ended March 31, 2021 2020 (in thousands) Proceeds from sales of debt securities available for sale $ — $ 194,105 Gross realized gains from sales of debt securities available for sale $ — $ 435 Gross realized losses from sales of debt securities available for sale — (186) Other securities gains — — Investment securities gains, net $ — $ 249 There were no gains or losses recognized on equity securities during the three month periods ended March 31, 2021 and 2020. The scheduled contractual maturities of debt securities available for sale at the period presented below are as follows: March 31, 2021 Amortized Cost Fair Value (in thousands) Due within one year $ 81,385 $ 81,986 Due after one year through five years 737,066 765,090 Due after five years through ten years 2,457,820 2,507,546 Due after ten years 2,141,102 2,141,668 Total debt securities available for sale $ 5,417,373 $ 5,496,290 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: March 31, 2021 (in thousands) To secure public funds $ 477,970 To secure borrowings 109,650 Other securities pledged 217,055 Total securities pledged as collateral $ 804,675 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 as of the dates presented: Less than 12 Months 12 Months or More Total Fair Unrealized Fair Unrealized Fair Unrealized March 31, 2021 (in thousands) U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 1,661,107 $ (44,484) $ 16,463 $ (719) $ 1,677,570 $ (45,203) Other asset-backed securities 183,636 (5,656) 69 — 183,705 (5,656) State and municipal securities 311,953 (6,365) — — 311,953 (6,365) U.S. government agency and government-sponsored enterprise securities 149,483 (1,567) — — 149,483 (1,567) Total $ 2,306,179 $ (58,072) $ 16,532 $ (719) $ 2,322,711 $ (58,791) December 31, 2020 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 575,329 $ (3,728) $ 18,527 $ (815) $ 593,856 $ (4,543) Other asset-backed securities 143,764 (2,076) 70 — 143,834 (2,076) State and municipal securities 86,471 (592) — — 86,471 (592) U.S. government agency and government-sponsored enterprise securities 74,943 (57) — — 74,943 (57) Total $ 880,507 $ (6,453) $ 18,597 $ (815) $ 899,104 $ (7,268) At March 31, 2021, there were 144 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 March 31, 2021. At March 31, 2021, there were 16 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 March 31, 2021. At March 31, 2021, there were 89 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 March 31, 2021, 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 March 31, 2021. At March 31, 2021, there were eight 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 March 31, 2021. 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. During the second quarter of 2020, the Company sold 17,360 shares of Visa Class B restricted stock, which resulted in an observable market price. As a result, the Company adjusted the carrying value of its remaining Visa Class B restricted shares upward to this observable market price. At March 31, 2021, the Company owned 77,683 Visa Class B shares, which had a carrying value of $13.4 million.

Loans

Loans	3 Months Ended
	Mar. 31, 2021
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): March 31, 2021 December 31, 2020 (dollars in thousands) Commercial loans: Commercial real estate $ 4,081,915 $ 4,062,313 Commercial business 3,792,813 3,597,968 Agriculture 751,800 779,627 Construction 282,534 268,663 Consumer loans: One-to-four family residential real estate 735,314 683,570 Other consumer 31,942 35,519 Total loans 9,676,318 9,427,660 Less: Allowance for credit losses (148,294) (149,140) Total loans, net $ 9,528,024 $ 9,278,520 At March 31, 2021 and December 31, 2020, 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 March 31, 2021 and December 31, 2020, $3.49 billion and $3.46 billion of commercial and residential real estate loans were pledged as collateral on FHLB advances and additional borrowing capacity. The Company has also pledged $200.1 million and $200.4 million of commercial loans to the FRB for additional borrowing capacity at March 31, 2021 and December 31, 2020, 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 March 31, 2021 and December 31, 2020, accrued interest receivable for loans was $35.2 million and $37.8 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 at the dates presented: Current 30 - 59 60 - 89 Greater Total Nonaccrual Total Loans March 31, 2021 (in thousands) Commercial loans: Commercial real estate $ 4,067,718 $ 880 $ 6,000 $ — $ 6,880 $ 7,317 $ 4,081,915 Commercial business 3,778,955 109 198 — 307 13,551 3,792,813 Agriculture 739,599 1,060 512 — 1,572 10,629 751,800 Construction 282,343 — — — — 191 282,534 Consumer loans: One-to-four family residential real estate 728,053 5,462 48 — 5,510 1,751 735,314 Other consumer 31,758 27 15 — 42 142 31,942 Total $ 9,628,426 $ 7,538 $ 6,773 $ — $ 14,311 $ 33,581 $ 9,676,318 Current 30 - 59 60 - 89 Greater Total Nonaccrual Total Loans December 31, 2020 (in thousands) Commercial loans: Commercial real estate $ 4,037,309 $ 17,292 $ — — $ 17,292 $ 7,712 $ 4,062,313 Commercial business 3,578,905 1,282 4,559 — 5,841 13,222 3,597,968 Agriculture 767,102 911 — — 911 11,614 779,627 Construction 268,304 — 142 — 142 217 268,663 Consumer loans: One-to-four family residential real estate 677,627 2,283 1,659 — 3,942 2,001 683,570 Other consumer 35,450 24 5 — 29 40 35,519 Total $ 9,364,697 $ 21,792 $ 6,365 $ — $ 28,157 $ 34,806 $ 9,427,660 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 loans modified in association with the CARES Act or Interagency guidance 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 periods indicated: Three Months Ended March 31, 2021 2020 (in thousands) Commercial loans $ 211 $ 783 Consumer loans 7 5 Total $ 218 $ 788 The following summarizes the amortized cost of nonaccrual loans for which there was no related ACL for the periods indicated: March 31, 2021 December 31, 2020 (in thousands) Commercial loans: Commercial real estate $ 6,336 $ 6,393 Commercial business 8,682 6,382 Agriculture 8,379 8,136 Total $ 23,397 $ 20,911 The following is an analysis of loans classified as TDR for the periods indicated: Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Number of TDR Modifications Pre-Modification Post-Modification Number of TDR Modifications Pre-Modification Post-Modification (dollars in thousands) Commercial loans: Commercial real estate 1 $ 628 $ 628 — $ — $ — Commercial business 7 843 843 2 272 272 Agriculture — — — 1 895 895 Consumer loans: One-to-four family residential real estate 2 140 140 1 68 68 Total 10 $ 1,611 $ 1,611 4 $ 1,235 $ 1,235 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 $672 thousand of additional funds on loans classified as TDR as of March 31, 2021. The Company had $651 thousand of such commitments at December 31, 2020. The Company had no loans classified as TDR that defaulted within 12 months of being classified as TDR during the three months ended March 31, 2021 and 2020. Financial institutions are required to maintain records of the volume of loans involved in modifications to which troubled debt restructuring relief is applicable . At March 31, 2021, the Company had 20 short–term deferments on $71.4 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 and applicable employment levels are maintained in accordance with the requirements of the amended PPP. At March 31, 2021, we had $894.1 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	3 Months Ended
	Mar. 31, 2021
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, 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 multi-factor models utilize a mix of 15 macroeconomic factors, including the four most commonly used factors: Real GDP, National Unemployment Rate, Disposable Personal Income and Private Inventories. The Consumer segment multi-factor models utilize a mix of three macroeconomic factors: National Unemployment Rate, Home Price Index and Disposable Income. The Company utilizes an 18 month reasonable and supportable forecast for the macroeconomic factors, after which the probability of default reverts to its historical mean using a straight-line basis constructed on each macroeconomic factor’s 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 periods indicated: Beginning Balance Charge-offs Recoveries Provision Ending Balance Three Months Ended March 31, 2021 (in thousands) Commercial loans: Commercial real estate $ 68,934 $ — $ 36 $ (11,920) $ 57,050 Commercial business 45,250 (3,339) 3,214 13,280 58,405 Agriculture 9,052 — 12 423 9,487 Construction 7,636 — 46 (1,131) 6,551 Consumer loans: One-to-four family residential real estate 16,875 — 51 (1,288) 15,638 Other consumer 1,393 (127) 61 (164) 1,163 Total $ 149,140 $ (3,466) $ 3,420 $ (800) $ 148,294 Beginning Balance Impact of Adopting ASC 326 Charge-offs Recoveries Provision Ending Balance Three Months Ended March 31, 2020 (in thousands) Commercial loans: Commercial real estate $ 20,340 $ 7,533 $ (101) $ 14 $ 9,336 $ 37,122 Commercial business 30,292 762 (1,684) 860 15,340 45,570 Agriculture 15,835 (9,325) (4,726) 41 9,260 11,085 Construction 8,571 (1,750) — 442 1,582 8,845 Consumer loans: One-to-four family residential real estate 7,435 4,237 (10) 282 5,715 17,659 Other consumer 883 778 (268) 124 127 1,644 Unallocated 612 (603) — — 140 149 Total $ 83,968 $ 1,632 $ (6,789) $ 1,763 $ 41,500 $ 122,074 The $846 thousand decrease in the ACL at March 31, 2021 compared to the ACL at December 31, 2020 was primarily due to a slight improvement in the economic outlook, which remains impacted by the COVID-19 pandemic and its impact on our borrowers. Specifically regarding the forecast used in the March 31, 2021 estimate, management expects the forecasted national unemployment rate to be above the pre-pandemic levels through the forecast period due to pandemic-related effects and shifting workforce requirements. Additionally, the commercial real estate index decline is expected to continue through 2021, the home price index is projected to moderate over the forecast period and Real GDP is projected to rise above average for the remainder of the year. The models used for calculating the ACL are sensitive to changes in these and other economic factors, which could result in volatility as these assumptions change over time. The ACL at March 31, 2021 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 March 31, 2021 2020 (in thousands) Beginning balance $ 8,300 $ 3,430 Impact of adopting ASC 326 — 1,570 Net changes in the allowance for unfunded commitments and letters of credit 1,500 1,000 Ending balance $ 9,800 $ 6,000 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 the periods indicated: Revolving Loans Amortized Cost Basis Revolving Loans Converted to Term Loans Amortized Cost Basis Term Loans Amortized Cost Basis by Origination Year 2021 2020 2019 2018 2017 Prior Total (1) March 31, 2021 (in thousands) Commercial loans: Commercial real estate Pass $ 205,152 $ 668,655 $ 603,542 $ 459,888 $ 491,550 $ 1,229,742 $ 49,274 $ 2,781 $ 3,710,584 Special mention — 3,127 65,107 19,094 4,420 99,370 5 — 191,123 Substandard — 3,467 34,749 16,559 31,448 91,434 2,551 — 180,208 Total commercial real estate $ 205,152 $ 675,249 $ 703,398 $ 495,541 $ 527,418 $ 1,420,546 $ 51,830 $ 2,781 $ 4,081,915 Commercial business Pass $ 586,311 $ 829,165 $ 347,668 $ 273,408 $ 178,663 $ 376,297 $ 945,271 $ 12,322 $ 3,549,105 Special mention — 588 8,346 6,237 2,063 1,131 49,369 143 67,877 Substandard — 6,594 26,640 36,756 27,226 33,731 44,046 838 175,831 Total commercial business $ 586,311 $ 836,347 $ 382,654 $ 316,401 $ 207,952 $ 411,159 $ 1,038,686 $ 13,303 $ 3,792,813 Agriculture Pass $ 57,282 $ 121,511 $ 85,485 $ 39,930 $ 56,638 $ 106,969 $ 209,154 $ 550 $ 677,519 Special mention — 3,398 1,366 163 — 2,371 7,962 — 15,260 Substandard — 6,022 10,424 2,693 4,140 3,194 31,804 744 59,021 Total agriculture $ 57,282 $ 130,931 $ 97,275 $ 42,786 $ 60,778 $ 112,534 $ 248,920 $ 1,294 $ 751,800 Construction Pass $ 41,447 $ 130,122 $ 44,121 $ 7,909 $ 3,471 $ 5,579 $ 31,682 $ — $ 264,331 Special mention — — — — — — — — — Substandard — — 18,148 — — 55 — — 18,203 Total construction $ 41,447 $ 130,122 $ 62,269 $ 7,909 $ 3,471 $ 5,634 $ 31,682 $ — $ 282,534 Consumer loans: One-to-four family residential real estate Pass $ 106,212 $ 157,286 $ 68,489 $ 53,753 $ 25,686 $ 88,323 $ 228,917 $ 308 $ 728,974 Special mention — — — — — 125 — — 125 Substandard — 835 1,381 245 491 2,735 309 219 6,215 Total one-to-four family real estate $ 106,212 $ 158,121 $ 69,870 $ 53,998 $ 26,177 $ 91,183 $ 229,226 $ 527 $ 735,314 Other consumer Pass $ 2,107 $ 3,595 $ 2,807 $ 3,250 $ 871 $ 1,211 $ 17,277 $ 610 $ 31,728 Substandard — 36 39 — 3 3 36 97 214 Total consumer $ 2,107 $ 3,631 $ 2,846 $ 3,250 $ 874 $ 1,214 $ 17,313 $ 707 $ 31,942 Total $ 998,511 $ 1,934,401 $ 1,318,312 $ 919,885 $ 826,670 $ 2,042,270 $ 1,617,657 $ 18,612 $ 9,676,318 Less: Allowance for credit losses 148,294 Loans, net $ 9,528,024 __________ (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 2020 2019 2018 2017 2016 Prior Total December 31, 2020 (in thousands) Commercial loans: Commercial real estate Pass $ 674,444 $ 645,328 $ 478,881 $ 502,112 $ 408,972 $ 946,980 $ 52,049 $ 11,332 $ 3,720,098 Special mention 3,348 39,374 21,285 30,232 46,197 50,115 5 2,139 192,695 Substandard 2,916 24,860 13,571 15,652 43,735 41,138 3,389 4,259 149,520 Total commercial real estate $ 680,708 $ 709,562 $ 513,737 $ 547,996 $ 498,904 $ 1,038,233 $ 55,443 $ 17,730 $ 4,062,313 Commercial business Pass $ 1,087,400 $ 366,435 $ 324,360 $ 199,010 $ 218,313 $ 214,677 $ 1,000,725 $ 11,540 $ 3,422,460 Special mention 3,002 26,361 8,471 24,582 7,004 10,650 22,426 — 102,496 Substandard 3,625 7,376 11,061 5,905 6,396 3,743 32,134 2,772 73,012 Total commercial business $ 1,094,027 $ 400,172 $ 343,892 $ 229,497 $ 231,713 $ 229,070 $ 1,055,285 $ 14,312 $ 3,597,968 Agriculture Pass $ 142,163 $ 90,612 $ 44,434 $ 58,366 $ 58,893 $ 59,396 $ 244,135 $ 9,299 $ 707,298 Special mention — 90 285 33 — — 85 13 506 Substandard 5,193 12,480 5,868 4,258 284 3,502 38,780 1,458 71,823 Total agriculture $ 147,356 $ 103,182 $ 50,587 $ 62,657 $ 59,177 $ 62,898 $ 283,000 $ 10,770 $ 779,627 Construction Pass $ 134,693 $ 66,974 $ 10,066 $ 3,498 $ 763 $ 1,805 $ 29,323 $ 3,753 $ 250,875 Substandard — 17,732 — — — 56 — — 17,788 Total construction $ 134,693 $ 84,706 $ 10,066 $ 3,498 $ 763 $ 1,861 $ 29,323 $ 3,753 $ 268,663 Consumer loans: One-to-four family real estate Pass $ 161,021 $ 77,756 $ 62,696 $ 29,737 $ 20,889 $ 78,098 $ 243,325 $ 3,655 $ 677,177 Special mention — — 332 — — 195 — — 527 Substandard — 849 227 1,166 344 1,968 1,005 307 5,866 Total one-to-four family real estate $ 161,021 $ 78,605 $ 63,255 $ 30,903 $ 21,233 $ 80,261 $ 244,330 $ 3,962 $ 683,570 Other consumer Pass $ 5,548 $ 3,109 $ 3,886 $ 989 $ 244 $ 1,060 $ 19,911 $ 474 $ 35,221 Substandard 30 — — 5 — 170 53 40 298 Total consumer $ 5,578 $ 3,109 $ 3,886 $ 994 $ 244 $ 1,230 $ 19,964 $ 514 $ 35,519 Total $ 2,223,383 $ 1,379,336 $ 985,423 $ 875,545 $ 812,034 $ 1,413,553 $ 1,687,345 $ 51,041 $ 9,427,660 Less: Allowance for credit losses 149,140 Loans, net $ 9,278,520

Other Real Estate Owned

Other Real Estate Owned	3 Months Ended
	Mar. 31, 2021
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 periods indicated: Three Months Ended March 31, 2021 2020 (in thousands) Balance, beginning of period $ 553 $ 552 Proceeds from sale of OREO property (132) (42) Gain on sale of OREO, net 100 — Balance, end of period $ 521 $ 510 At March 31, 2021, 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 $167 thousand.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2021
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. Our CDIs are evaluated for impairment if events and circumstances indicate a possible impairment. Each 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 March 31, 2021 2020 (in thousands) Goodwill Total goodwill $ 765,842 $ 765,842 Other intangible assets, net CDI: Gross CDI balance at beginning of period 105,473 105,473 Accumulated amortization at beginning of period (79,658) (70,934) CDI, net at beginning of period 25,815 34,539 CDI current period amortization (1,924) (2,310) Total CDI, net at end of period 23,891 32,229 Intangible assets not subject to amortization 919 919 Other intangible assets, net at end of period 24,810 33,148 Total goodwill and other intangible assets at end of period $ 790,652 $ 798,990 The following table provides the estimated future amortization expense of our CDI for the remaining nine months ending December 31, 2021 and the succeeding four years: Year ending December 31, (in thousands) 2021 $ 5,340 2022 5,880 2023 4,552 2024 3,432 2025 2,415

Revolving Line of Credit

Revolving Line of Credit	3 Months Ended
	Mar. 31, 2021
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 March 31, 2021 and December 31, 2020. 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 March 31, 2021.

Derivatives and Balance Sheet O

Derivatives and Balance Sheet Offsetting	3 Months Ended
	Mar. 31, 2021
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 used an interest rate collar 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 were 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 are 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 $10.4 million reclassified as an increase to interest income. The Company may use derivatives to hedge the risk or changes in the fair values of interest rate lock commitments and residential mortgage loans held for sale. These derivatives are not designated as hedging instruments. Rather, they are accounted for as free-standing derivatives, or economic hedges, with changes in the fair value of the derivatives reported in income. The Company primarily utilizes interest rate forward loan sales contracts in its derivative risk management strategy. The Company enters into forward delivery contracts to sell residential mortgage loans to broker-dealers at specific prices and dates in order to hedge the interest rate risk in its portfolio of mortgage loans held for sale and its residential mortgage interest rate lock commitments. Credit risk associated with forward contracts is limited to the replacement cost of those forward contracts in a gain position. There were no counterparty default losses on forward contracts during the three months ended March 31, 2021 and 2020. Market risk with respect to forward contracts arises principally from changes in the value of contractual positions due to changes in interest rates. The Bank limits its exposure to market risk by monitoring differences between commitments to customers and forward contracts with broker-dealers. In the event the Company has forward delivery contract commitments in excess of available mortgage loans, the Company completes the transaction by either paying or receiving a fee to or from the broker-dealer equal to the increase or decrease in the market value of the forward contract. At March 31, 2021, the Bank had commitments to originate mortgage loans held for sale totaling $60.1 million and forward sales commitments of $48.5 million, which are used to hedge both on-balance sheet and off-balance sheet exposures. 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 March 31, 2021 and December 31, 2020 was $635.1 million and $597.9 million, respectively. The following table presents the fair value of derivatives, as well as their classification on the Consolidated Balance Sheet as of the dates presented: Asset Derivatives Liability Derivatives March 31, 2021 December 31, 2020 March 31, 2021 December 31, 2020 Balance Sheet Fair Value Balance Sheet Fair Value Balance Sheet Fair Value Balance Sheet Fair Value (in thousands) Derivatives not designated as hedging instruments: Interest rate lock commitments Other assets $ 925 Other assets $ 1,096 Other liabilities $ — Other liabilities $ — Interest rate forward loan sales contracts Other assets $ 505 Other assets $ — Other liabilities $ — Other liabilities $ 165 Interest rate swap contracts Other assets $ 32,501 Other assets $ 46,184 Other liabilities $ 32,769 Other liabilities $ 46,637 The table below presents the effect of cash flow hedge accounting on accumulated other comprehensive income (loss) for the periods indicated: 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 March 31, Three Months Ended March 31, 2021 2020 2021 2020 (in thousands) Interest rate collar $ — $ 23,423 Interest income $ 2,576 $ 940 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 $34.4 million realized gain that was recorded in other comprehensive income, net of deferred income taxes. The gain will amortize through February 2024 into interest income. The gain will be amortized in this manner as long as the cash flows pertaining to the hedged item are expected to occur. The following table summarizes the types of derivatives not designated as hedging instruments and the gains (losses) recorded during the periods indicated: Three Months Ended March 31, 2021 2020 (in thousands) Interest rate lock commitments $ (171) $ — Interest rate forward loan sales contracts 670 — Interest rate swap contracts 112 — Total derivative gains (losses) $ 611 $ — The gains and losses on the Company’s mortgage banking derivatives are included in loan revenue. Mark-to-market gains and losses on the Company’s interest rate swap contracts are recorded to “Other” noninterest expense. 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 March 31, 2021 (in thousands) Assets Interest rate swap contracts $ 32,501 $ — $ 32,501 $ (1,960) $ 30,541 Liabilities Interest rate swap contracts $ 32,769 $ — $ 32,769 $ (26,848) $ 5,921 Repurchase agreements $ 38,624 $ — $ 38,624 $ (38,624) $ — December 31, 2020 Assets Interest rate swap contracts $ 46,184 $ — $ 46,184 $ — $ 46,184 Liabilities Interest rate swap contracts $ 46,637 $ — $ 46,637 $ (46,637) $ — Repurchase agreements $ 73,859 $ — $ 73,859 $ (73,859) $ — 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 March 31, 2021 (in thousands) Class of collateral pledged for repurchase agreements U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 38,624 $ — $ — $ — $ 38,624 Gross amount of recognized liabilities for repurchase agreements 38,624 Amounts related to agreements not included in offsetting disclosure $ —

Commitments and contingent liab

Commitments and contingent liabilities	3 Months Ended
	Mar. 31, 2021
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 March 31, 2021 and December 31, 2020, the Company’s loan commitments amounted to $2.93 billion and $2.80 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 $30.6 million and $29.9 million at March 31, 2021 and December 31, 2020, respectively. In addition, there were $16 thousand commitments under commercial letters of credit used to facilitate customers’ trade transactions and other off-balance sheet liabilities at March 31, 2021 and there were none at December 31, 2020. 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	3 Months Ended
	Mar. 31, 2021
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders’ Equity Dividends: The following table summarizes year-to-date dividend activity: Declared Regular Cash Dividends Per Common Share Special Cash Dividends Per Common Share Record Date Paid Date January 28, 2021 $ 0.28 $ — February 10, 2021 February 24, 2021 Subsequent to quarter end, on April 29, 2021, the Company declared a regular quarterly cash dividend of $0.28 per common share payable on May 26, 2021 to shareholders of record at the close of business on May 12, 2021. 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: For the three months ended March 31, 2021, the Company did not purchase any common shares under the share repurchase program.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	3 Months Ended
	Mar. 31, 2021
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 periods indicated: 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 March 31, 2021 (in thousands) Beginning balance $ 163,174 $ (5,833) $ 24,854 $ 182,195 Other comprehensive loss before reclassifications (102,605) — — (102,605) Amounts reclassified from accumulated other comprehensive income (2) — 115 (1,977) (1,862) Net current-period other comprehensive income (loss) (102,605) 115 (1,977) (104,467) Ending balance $ 60,569 $ (5,718) $ 22,877 $ 77,728 Three Months Ended March 31, 2020 Beginning balance $ 33,038 $ (3,974) $ 11,303 $ 40,367 Other comprehensive income before reclassifications 79,696 — 17,977 97,673 Amounts reclassified from accumulated other comprehensive income (2) (191) 80 (722) (833) Net current-period other comprehensive income 79,505 80 17,255 96,840 Ending balance $ 112,543 $ (3,894) $ 28,558 $ 137,207 __________ (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 periods indicated: Amount Reclassified from Accumulated Other Comprehensive Income (Loss) Three Months Ended March 31, Affected line Item in the Consolidated 2021 2020 Statement of Income (in thousands) Unrealized gains on available for sale debt securities $ — $ 249 Investment securities gains, net — 249 Total before tax — (58) Income tax provision $ — $ 191 Net of tax Amortization of pension plan liability actuarial losses $ (150) $ (104) Compensation and employee benefits (150) (104) Total before tax 35 24 Income tax provision $ (115) $ (80) Net of tax Unrealized gains from hedging instruments $ 2,576 $ 940 Loans 2,576 940 Total before tax (599) (218) Income tax provision $ 1,977 $ 722 Net of tax

Fair Value Accounting and Measu

Fair Value Accounting and Measurement	3 Months Ended
	Mar. 31, 2021
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. Loans held for sale include the fair value of residential mortgage loans originated as held for sale determined based on quoted secondary market prices for similar loans, including the implicit fair value of embedded servicing rights. The change in fair value of loans held for sale is primarily driven by changes in interest rates subsequent to loan funding and changes in the fair value of the related servicing asset, resulting in revaluation adjustments to the recorded fair value. The fair values of the interest rate lock commitments and interest rate forward loan sales contracts are estimated using quoted or published market prices for similar instruments, adjusted for factors such as pull-through rate assumptions based on historical information, where appropriate. The pull-through rate assumptions are considered Level 3 valuation inputs and are significant to the interest rate lock commitment valuation; as such, the interest rate lock commitment derivatives are classified as Level 3. 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 the dates presented 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 March 31, 2021 (in thousands) Assets Debt securities available for sale: U.S. government agency and government-sponsored enterprise mortgage-back securities and collateralized mortgage obligations $ 4,104,219 $ — $ 4,104,219 $ — Other asset-backed securities 358,819 — 358,819 — State and municipal securities 751,285 — 751,285 — U.S. government agency and government-sponsored enterprise securities 281,967 — 281,967 — Total debt securities available for sale $ 5,496,290 $ — $ 5,496,290 $ — Loans held for sale $ 25,587 $ — $ 25,587 $ — Other assets: Interest rate lock commitments $ 925 $ — $ — $ 925 Interest rate forward loan sales contracts $ 505 $ — $ 505 $ — Interest rate contracts $ 32,501 $ — $ 32,501 $ — Liabilities Other liabilities: Interest rate contracts $ 32,769 $ — $ 32,769 $ — Fair Value Fair Value Measurements at Reporting Date Using Level 1 Level 2 Level 3 December 31, 2020 (in thousands) Assets Debt securities available for sale: U.S. government agency and government-sponsored enterprise mortgage-back securities and collateralized mortgage obligations $ 3,814,387 $ — $ 3,814,387 $ — Other asset-backed securities 357,479 — 357,479 — State and municipal securities 753,572 — 753,572 — U.S. government agency and government-sponsored enterprise securities 284,696 — 284,696 — Total debt securities available for sale $ 5,210,134 $ — $ 5,210,134 $ — Loans held for sale $ 14,760 $ — $ 14,760 $ — Other assets: Interest rate lock commitments $ 1,096 $ — $ — $ 1,096 Interest rate contracts $ 46,184 $ — $ 46,184 $ — Liabilities Other liabilities: Interest rate forward loan sales contracts $ 165 $ — $ 165 $ — Interest rate contracts $ 46,637 $ — $ 46,637 $ — Assets and Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Level 3) The following table provides a description of the valuation technique, significant unobservable inputs, and qualitative information about the unobservable inputs for the Company’s assets and liabilities classified as Level 3 and measured at fair value on a recurring basis at the dates presented: Fair Value at March 31, 2021 Valuation Technique Unobservable Input Range (Weighted Average) (dollars in thousands) Interest rate lock commitments $ 925 Internal pricing model Pull-through rate 79.87% - 100.00% (90.39%) An increase in the pull-through rate utilized in the fair value measurement of the interest rate lock commitment derivative will result in positive fair value adjustments (and an increase in the fair value measurement). Conversely, a decrease in the pull-through rate will result in a negative fair value adjustment (and a decrease in the fair value measurement). The following table includes a rollforward of interest rate lock commitments which utilize Level 3 inputs to determine the fair value on a recurring basis. Three Months Ended March 31, 2021 2020 (in thousands) Balance at the beginning of the period $ 1,096 $ — Change included in earnings 1,710 — Settlements (1,881) — Balance at the end of the period $ 925 $ — 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 March 31, 2021, 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 March 31, 2021 2020 Equity securities without readily determinable fair values (in thousands) Carrying value, beginning of period $ 13,425 $ — Upward carrying value changes — — Carrying value, end of period $ 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 March 31, 2021 Fair Value Measurements Losses During the Three Months Ended March 31, 2021 Level 1 Level 2 Level 3 (in thousands) Collateral dependent loans $ 1,520 $ — $ — $ 1,520 $ 722 Fair Value at March 31, 2020 Fair Value Measurements Losses During the Three Months Ended March 31, 2020 Level 1 Level 2 Level 3 (in thousands) Collateral dependent loans $ 3,043 $ — $ — $ 3,043 $ 5,138 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 March 31, 2021 Valuation Technique Unobservable Input Range (Weighted Average) (1) (dollars in thousands) Collateral dependent loans (2) $ 1,520 Fair Market Value of Collateral Adjustment to Stated Value 42.96% - 75.00% (59.53%) __________ (1) Discount applied to appraised value or stated value (in the case of accounts receivable and fixed assets). (2) Collateral consists of accounts receivable and fixed assets. Fair Value at March 31, 2020 Valuation Technique Unobservable Input Range (Weighted Average) (1) (dollars in thousands) Collateral dependent loans (2) $ 3,043 Fair Market Value of Collateral Adjustment to Stated Value 0.00% - 100.00% (59.78%) __________ (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 the dates presented: March 31, 2021 Carrying Fair Level 1 Level 2 Level 3 (in thousands) Assets Cash and due from banks $ 178,096 $ 178,096 $ 178,096 $ — $ — Interest-earning deposits with banks 706,389 706,389 706,389 — — Debt securities available for sale 5,496,290 5,496,290 — 5,496,290 — FHLB stock 10,280 10,280 — 10,280 — Loans held for sale 26,176 26,176 — 26,176 — Loans 9,528,024 9,948,104 — — 9,948,104 Interest rate contracts 32,501 32,501 — 32,501 — Interest rate lock commitments 925 925 — — 925 Interest rate forward loan sales contracts 505 505 — 505 — Liabilities Time deposits $ 336,918 $ 333,169 $ — $ 333,169 $ — FHLB advances 7,400 8,764 — 8,764 — Repurchase agreements 38,624 38,624 — 38,624 — Subordinated debentures 35,046 35,102 — 35,102 — Interest rate contracts 32,769 32,769 — 32,769 — December 31, 2020 Carrying Fair Level 1 Level 2 Level 3 (in thousands) Assets Cash and due from banks $ 218,899 $ 218,899 $ 218,899 $ — $ — Interest-earning deposits with banks 434,867 434,867 434,867 — — Debt securities available for sale 5,210,134 5,210,134 — 5,210,134 — FHLB stock 10,280 10,280 — 10,280 — Loans held for sale 26,481 26,481 — 26,481 — Loans 9,278,520 9,720,592 — — 9,720,592 Interest rate contracts 46,184 46,184 — 46,184 — Interest rate lock commitments 1,096 1,096 — — 1,096 Liabilities Time deposits $ 338,845 $ 338,815 $ — $ 338,815 $ — FHLB advances and FRB borrowings 7,414 9,295 — 9,295 — Repurchase agreements 73,859 73,859 — 73,859 — Subordinated debentures 35,092 35,414 — 35,414 — Interest rate contracts 46,637 46,637 — 46,637 — Interest rate forward loan sales contracts 165 165 — 165 — The following table presents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans held for sale sold under the mandatory delivery method and accounted for under the fair value option as of the dates presented: March 31, 2021 2020 Fair Value Aggregate Unpaid Principal Balance Fair Value Less Aggregate Unpaid Principal Balance Fair Value Aggregate Unpaid Principal Balance Fair Value Less Aggregate Unpaid Principal Balance (in thousands) $ 25,587 $ 25,167 $ 420 $ — $ — $ — Residential mortgage loans held for sale that are sold under the mandatory delivery method and accounted for under the fair value option are measured initially at fair value with subsequent changes in fair value recognized in earnings. Gains and losses from such changes in fair value are reported in loan revenue. For the three months ended March 31, 2021, the Company recorded a net decrease in fair value of $88 thousand representing the change in fair value reflected in earnings. For the three months ended March 31, 2020, there were no such loans held for sale under the mandatory delivery method. At March 31, 2021 and 2020, there were no residential mortgage loans held for sale for which the fair value option was elected that were 90 days or more past due, in nonaccrual status or both.

Earnings per Common Share

Earnings per Common Share	3 Months Ended
	Mar. 31, 2021
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 has issued 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 periods presented: Three Months Ended March 31, 2021 2020 (in thousands except per share amounts) Basic EPS: Net income $ 51,853 $ 14,628 Less: Earnings allocated to participating securities: Nonvested restricted shares 155 249 Earnings allocated to common shareholders $ 51,698 $ 14,379 Weighted average common shares outstanding 70,869 71,206 Basic earnings per common share $ 0.73 $ 0.20 Diluted EPS: Earnings allocated to common shareholders $ 51,698 $ 14,379 Weighted average common shares outstanding 70,869 71,206 Dilutive effect of equity awards 240 58 Weighted average diluted common shares outstanding 71,109 71,264 Diluted earnings per common share $ 0.73 $ 0.20 Potentially dilutive RSAs and RSUs that were not included in the computation of diluted EPS because to do so would be anti-dilutive 70 6

Revenue from Contracts with Cus

Revenue from Contracts with Customers	3 Months Ended
	Mar. 31, 2021
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 periods presented: Three Months Ended March 31, 2021 2020 (in thousands) Noninterest income: Revenue from contracts with customers: Deposit account and treasury management fees $ 6,358 $ 7,788 Card revenue 3,733 3,518 Financial services and trust revenue 3,381 3,065 Total revenue from contracts with customers 13,472 14,371 Other sources of noninterest income 9,694 6,836 Total noninterest income $ 23,166 $ 21,207

Securities (Tables)

Securities (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Securities, Available-for-sale [Abstract]
Debt 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 March 31, 2021 (in thousands) U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 4,040,359 $ 109,063 $ (45,203) $ — $ 4,104,219 Other asset-backed securities 359,259 5,216 (5,656) — 358,819 State and municipal securities 739,570 18,080 (6,365) — 751,285 U.S. government agency and government-sponsored enterprise securities 278,185 5,349 (1,567) — 281,967 Total $ 5,417,373 $ 137,708 $ (58,791) $ — $ 5,496,290 December 31, 2020 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 3,640,351 $ 178,579 $ (4,543) $ — $ 3,814,387 Other asset-backed securities 349,904 9,651 (2,076) — 357,479 State and municipal securities 729,066 25,098 (592) — 753,572 U.S. government agency and government-sponsored enterprise securities 278,208 6,545 (57) — 284,696 Total $ 4,997,529 $ 219,873 $ (7,268) $ — $ 5,210,134
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 and calls of debt securities available for sale as well as other securities gains and losses for the periods indicated: Three Months Ended March 31, 2021 2020 (in thousands) Proceeds from sales of debt securities available for sale $ — $ 194,105 Gross realized gains from sales of debt securities available for sale $ — $ 435 Gross realized losses from sales of debt securities available for sale — (186) Other securities gains — — Investment securities gains, net $ — $ 249
Schedule of Contractual Maturities of Debt Securities Available for Sale	The scheduled contractual maturities of debt securities available for sale at the period presented below are as follows: March 31, 2021 Amortized Cost Fair Value (in thousands) Due within one year $ 81,385 $ 81,986 Due after one year through five years 737,066 765,090 Due after five years through ten years 2,457,820 2,507,546 Due after ten years 2,141,102 2,141,668 Total debt securities available for sale $ 5,417,373 $ 5,496,290
Schedule 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: March 31, 2021 (in thousands) To secure public funds $ 477,970 To secure borrowings 109,650 Other securities pledged 217,055 Total securities pledged as collateral $ 804,675
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 as of the dates presented: Less than 12 Months 12 Months or More Total Fair Unrealized Fair Unrealized Fair Unrealized March 31, 2021 (in thousands) U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 1,661,107 $ (44,484) $ 16,463 $ (719) $ 1,677,570 $ (45,203) Other asset-backed securities 183,636 (5,656) 69 — 183,705 (5,656) State and municipal securities 311,953 (6,365) — — 311,953 (6,365) U.S. government agency and government-sponsored enterprise securities 149,483 (1,567) — — 149,483 (1,567) Total $ 2,306,179 $ (58,072) $ 16,532 $ (719) $ 2,322,711 $ (58,791) December 31, 2020 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 575,329 $ (3,728) $ 18,527 $ (815) $ 593,856 $ (4,543) Other asset-backed securities 143,764 (2,076) 70 — 143,834 (2,076) State and municipal securities 86,471 (592) — — 86,471 (592) U.S. government agency and government-sponsored enterprise securities 74,943 (57) — — 74,943 (57) Total $ 880,507 $ (6,453) $ 18,597 $ (815) $ 899,104 $ (7,268)

Loans (Tables)

Loans (Tables)	3 Months Ended
	Mar. 31, 2021
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): March 31, 2021 December 31, 2020 (dollars in thousands) Commercial loans: Commercial real estate $ 4,081,915 $ 4,062,313 Commercial business 3,792,813 3,597,968 Agriculture 751,800 779,627 Construction 282,534 268,663 Consumer loans: One-to-four family residential real estate 735,314 683,570 Other consumer 31,942 35,519 Total loans 9,676,318 9,427,660 Less: Allowance for credit losses (148,294) (149,140) Total loans, net $ 9,528,024 $ 9,278,520
Analysis of the Aged Loan Portfolio	The following is an aging of the recorded investment of the loan portfolio at the dates presented: Current 30 - 59 60 - 89 Greater Total Nonaccrual Total Loans March 31, 2021 (in thousands) Commercial loans: Commercial real estate $ 4,067,718 $ 880 $ 6,000 $ — $ 6,880 $ 7,317 $ 4,081,915 Commercial business 3,778,955 109 198 — 307 13,551 3,792,813 Agriculture 739,599 1,060 512 — 1,572 10,629 751,800 Construction 282,343 — — — — 191 282,534 Consumer loans: One-to-four family residential real estate 728,053 5,462 48 — 5,510 1,751 735,314 Other consumer 31,758 27 15 — 42 142 31,942 Total $ 9,628,426 $ 7,538 $ 6,773 $ — $ 14,311 $ 33,581 $ 9,676,318 Current 30 - 59 60 - 89 Greater Total Nonaccrual Total Loans December 31, 2020 (in thousands) Commercial loans: Commercial real estate $ 4,037,309 $ 17,292 $ — — $ 17,292 $ 7,712 $ 4,062,313 Commercial business 3,578,905 1,282 4,559 — 5,841 13,222 3,597,968 Agriculture 767,102 911 — — 911 11,614 779,627 Construction 268,304 — 142 — 142 217 268,663 Consumer loans: One-to-four family residential real estate 677,627 2,283 1,659 — 3,942 2,001 683,570 Other consumer 35,450 24 5 — 29 40 35,519 Total $ 9,364,697 $ 21,792 $ 6,365 $ — $ 28,157 $ 34,806 $ 9,427,660
Interest written off on nonaccrual loans	The following table summarizes written-off interest on nonaccrual loans for the periods indicated: Three Months Ended March 31, 2021 2020 (in thousands) Commercial loans $ 211 $ 783 Consumer loans 7 5 Total $ 218 $ 788
Analysis of Nonaccrual Loans	The following summarizes the amortized cost of nonaccrual loans for which there was no related ACL for the periods indicated: March 31, 2021 December 31, 2020 (in thousands) Commercial loans: Commercial real estate $ 6,336 $ 6,393 Commercial business 8,682 6,382 Agriculture 8,379 8,136 Total $ 23,397 $ 20,911
Analysis of loans classified as Troubled Debt Restructurings (“TDR”)	The following is an analysis of loans classified as TDR for the periods indicated: Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Number of TDR Modifications Pre-Modification Post-Modification Number of TDR Modifications Pre-Modification Post-Modification (dollars in thousands) Commercial loans: Commercial real estate 1 $ 628 $ 628 — $ — $ — Commercial business 7 843 843 2 272 272 Agriculture — — — 1 895 895 Consumer loans: One-to-four family residential real estate 2 140 140 1 68 68 Total 10 $ 1,611 $ 1,611 4 $ 1,235 $ 1,235

Allowance for Credit Losses a_2

Allowance for Credit Losses and Allowance for Unfunded Commitments and Letters of Credit (Tables)	3 Months Ended
	Mar. 31, 2021
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 periods indicated: Beginning Balance Charge-offs Recoveries Provision Ending Balance Three Months Ended March 31, 2021 (in thousands) Commercial loans: Commercial real estate $ 68,934 $ — $ 36 $ (11,920) $ 57,050 Commercial business 45,250 (3,339) 3,214 13,280 58,405 Agriculture 9,052 — 12 423 9,487 Construction 7,636 — 46 (1,131) 6,551 Consumer loans: One-to-four family residential real estate 16,875 — 51 (1,288) 15,638 Other consumer 1,393 (127) 61 (164) 1,163 Total $ 149,140 $ (3,466) $ 3,420 $ (800) $ 148,294 Beginning Balance Impact of Adopting ASC 326 Charge-offs Recoveries Provision Ending Balance Three Months Ended March 31, 2020 (in thousands) Commercial loans: Commercial real estate $ 20,340 $ 7,533 $ (101) $ 14 $ 9,336 $ 37,122 Commercial business 30,292 762 (1,684) 860 15,340 45,570 Agriculture 15,835 (9,325) (4,726) 41 9,260 11,085 Construction 8,571 (1,750) — 442 1,582 8,845 Consumer loans: One-to-four family residential real estate 7,435 4,237 (10) 282 5,715 17,659 Other consumer 883 778 (268) 124 127 1,644 Unallocated 612 (603) — — 140 149 Total $ 83,968 $ 1,632 $ (6,789) $ 1,763 $ 41,500 $ 122,074
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 March 31, 2021 2020 (in thousands) Beginning balance $ 8,300 $ 3,430 Impact of adopting ASC 326 — 1,570 Net changes in the allowance for unfunded commitments and letters of credit 1,500 1,000 Ending balance $ 9,800 $ 6,000
Financing Receivable Credit Quality Indicators	The following is an analysis of the credit quality of our loan portfolio as of the periods indicated: Revolving Loans Amortized Cost Basis Revolving Loans Converted to Term Loans Amortized Cost Basis Term Loans Amortized Cost Basis by Origination Year 2021 2020 2019 2018 2017 Prior Total (1) March 31, 2021 (in thousands) Commercial loans: Commercial real estate Pass $ 205,152 $ 668,655 $ 603,542 $ 459,888 $ 491,550 $ 1,229,742 $ 49,274 $ 2,781 $ 3,710,584 Special mention — 3,127 65,107 19,094 4,420 99,370 5 — 191,123 Substandard — 3,467 34,749 16,559 31,448 91,434 2,551 — 180,208 Total commercial real estate $ 205,152 $ 675,249 $ 703,398 $ 495,541 $ 527,418 $ 1,420,546 $ 51,830 $ 2,781 $ 4,081,915 Commercial business Pass $ 586,311 $ 829,165 $ 347,668 $ 273,408 $ 178,663 $ 376,297 $ 945,271 $ 12,322 $ 3,549,105 Special mention — 588 8,346 6,237 2,063 1,131 49,369 143 67,877 Substandard — 6,594 26,640 36,756 27,226 33,731 44,046 838 175,831 Total commercial business $ 586,311 $ 836,347 $ 382,654 $ 316,401 $ 207,952 $ 411,159 $ 1,038,686 $ 13,303 $ 3,792,813 Agriculture Pass $ 57,282 $ 121,511 $ 85,485 $ 39,930 $ 56,638 $ 106,969 $ 209,154 $ 550 $ 677,519 Special mention — 3,398 1,366 163 — 2,371 7,962 — 15,260 Substandard — 6,022 10,424 2,693 4,140 3,194 31,804 744 59,021 Total agriculture $ 57,282 $ 130,931 $ 97,275 $ 42,786 $ 60,778 $ 112,534 $ 248,920 $ 1,294 $ 751,800 Construction Pass $ 41,447 $ 130,122 $ 44,121 $ 7,909 $ 3,471 $ 5,579 $ 31,682 $ — $ 264,331 Special mention — — — — — — — — — Substandard — — 18,148 — — 55 — — 18,203 Total construction $ 41,447 $ 130,122 $ 62,269 $ 7,909 $ 3,471 $ 5,634 $ 31,682 $ — $ 282,534 Consumer loans: One-to-four family residential real estate Pass $ 106,212 $ 157,286 $ 68,489 $ 53,753 $ 25,686 $ 88,323 $ 228,917 $ 308 $ 728,974 Special mention — — — — — 125 — — 125 Substandard — 835 1,381 245 491 2,735 309 219 6,215 Total one-to-four family real estate $ 106,212 $ 158,121 $ 69,870 $ 53,998 $ 26,177 $ 91,183 $ 229,226 $ 527 $ 735,314 Other consumer Pass $ 2,107 $ 3,595 $ 2,807 $ 3,250 $ 871 $ 1,211 $ 17,277 $ 610 $ 31,728 Substandard — 36 39 — 3 3 36 97 214 Total consumer $ 2,107 $ 3,631 $ 2,846 $ 3,250 $ 874 $ 1,214 $ 17,313 $ 707 $ 31,942 Total $ 998,511 $ 1,934,401 $ 1,318,312 $ 919,885 $ 826,670 $ 2,042,270 $ 1,617,657 $ 18,612 $ 9,676,318 Less: Allowance for credit losses 148,294 Loans, net $ 9,528,024 __________ (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 2020 2019 2018 2017 2016 Prior Total December 31, 2020 (in thousands) Commercial loans: Commercial real estate Pass $ 674,444 $ 645,328 $ 478,881 $ 502,112 $ 408,972 $ 946,980 $ 52,049 $ 11,332 $ 3,720,098 Special mention 3,348 39,374 21,285 30,232 46,197 50,115 5 2,139 192,695 Substandard 2,916 24,860 13,571 15,652 43,735 41,138 3,389 4,259 149,520 Total commercial real estate $ 680,708 $ 709,562 $ 513,737 $ 547,996 $ 498,904 $ 1,038,233 $ 55,443 $ 17,730 $ 4,062,313 Commercial business Pass $ 1,087,400 $ 366,435 $ 324,360 $ 199,010 $ 218,313 $ 214,677 $ 1,000,725 $ 11,540 $ 3,422,460 Special mention 3,002 26,361 8,471 24,582 7,004 10,650 22,426 — 102,496 Substandard 3,625 7,376 11,061 5,905 6,396 3,743 32,134 2,772 73,012 Total commercial business $ 1,094,027 $ 400,172 $ 343,892 $ 229,497 $ 231,713 $ 229,070 $ 1,055,285 $ 14,312 $ 3,597,968 Agriculture Pass $ 142,163 $ 90,612 $ 44,434 $ 58,366 $ 58,893 $ 59,396 $ 244,135 $ 9,299 $ 707,298 Special mention — 90 285 33 — — 85 13 506 Substandard 5,193 12,480 5,868 4,258 284 3,502 38,780 1,458 71,823 Total agriculture $ 147,356 $ 103,182 $ 50,587 $ 62,657 $ 59,177 $ 62,898 $ 283,000 $ 10,770 $ 779,627 Construction Pass $ 134,693 $ 66,974 $ 10,066 $ 3,498 $ 763 $ 1,805 $ 29,323 $ 3,753 $ 250,875 Substandard — 17,732 — — — 56 — — 17,788 Total construction $ 134,693 $ 84,706 $ 10,066 $ 3,498 $ 763 $ 1,861 $ 29,323 $ 3,753 $ 268,663 Consumer loans: One-to-four family real estate Pass $ 161,021 $ 77,756 $ 62,696 $ 29,737 $ 20,889 $ 78,098 $ 243,325 $ 3,655 $ 677,177 Special mention — — 332 — — 195 — — 527 Substandard — 849 227 1,166 344 1,968 1,005 307 5,866 Total one-to-four family real estate $ 161,021 $ 78,605 $ 63,255 $ 30,903 $ 21,233 $ 80,261 $ 244,330 $ 3,962 $ 683,570 Other consumer Pass $ 5,548 $ 3,109 $ 3,886 $ 989 $ 244 $ 1,060 $ 19,911 $ 474 $ 35,221 Substandard 30 — — 5 — 170 53 40 298 Total consumer $ 5,578 $ 3,109 $ 3,886 $ 994 $ 244 $ 1,230 $ 19,964 $ 514 $ 35,519 Total $ 2,223,383 $ 1,379,336 $ 985,423 $ 875,545 $ 812,034 $ 1,413,553 $ 1,687,345 $ 51,041 $ 9,427,660 Less: Allowance for credit losses 149,140 Loans, net $ 9,278,520

Other Real Estate Owned (Tables

Other Real Estate Owned (Tables)	3 Months Ended
	Mar. 31, 2021
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 periods indicated: Three Months Ended March 31, 2021 2020 (in thousands) Balance, beginning of period $ 553 $ 552 Proceeds from sale of OREO property (132) (42) Gain on sale of OREO, net 100 — Balance, end of period $ 521 $ 510

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2021
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 March 31, 2021 2020 (in thousands) Goodwill Total goodwill $ 765,842 $ 765,842 Other intangible assets, net CDI: Gross CDI balance at beginning of period 105,473 105,473 Accumulated amortization at beginning of period (79,658) (70,934) CDI, net at beginning of period 25,815 34,539 CDI current period amortization (1,924) (2,310) Total CDI, net at end of period 23,891 32,229 Intangible assets not subject to amortization 919 919 Other intangible assets, net at end of period 24,810 33,148 Total goodwill and other intangible assets at end of period $ 790,652 $ 798,990
Estimated Future Amortization Expense of Core Deposit Intangibles	The following table provides the estimated future amortization expense of our CDI for the remaining nine months ending December 31, 2021 and the succeeding four years: Year ending December 31, (in thousands) 2021 $ 5,340 2022 5,880 2023 4,552 2024 3,432 2025 2,415

Derivatives and Balance Sheet_2

Derivatives and Balance Sheet Offsetting (Tables)	3 Months Ended
	Mar. 31, 2021
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 as of the dates presented: Asset Derivatives Liability Derivatives March 31, 2021 December 31, 2020 March 31, 2021 December 31, 2020 Balance Sheet Fair Value Balance Sheet Fair Value Balance Sheet Fair Value Balance Sheet Fair Value (in thousands) Derivatives not designated as hedging instruments: Interest rate lock commitments Other assets $ 925 Other assets $ 1,096 Other liabilities $ — Other liabilities $ — Interest rate forward loan sales contracts Other assets $ 505 Other assets $ — Other liabilities $ — Other liabilities $ 165 Interest rate swap contracts Other assets $ 32,501 Other assets $ 46,184 Other liabilities $ 32,769 Other liabilities $ 46,637
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) for the periods indicated: 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 March 31, Three Months Ended March 31, 2021 2020 2021 2020 (in thousands) Interest rate collar $ — $ 23,423 Interest income $ 2,576 $ 940
Derivative Instruments, Gain (Loss)	The following table summarizes the types of derivatives not designated as hedging instruments and the gains (losses) recorded during the periods indicated: Three Months Ended March 31, 2021 2020 (in thousands) Interest rate lock commitments $ (171) $ — Interest rate forward loan sales contracts 670 — Interest rate swap contracts 112 — Total derivative gains (losses) $ 611 $ —
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 March 31, 2021 (in thousands) Assets Interest rate swap contracts $ 32,501 $ — $ 32,501 $ (1,960) $ 30,541 Liabilities Interest rate swap contracts $ 32,769 $ — $ 32,769 $ (26,848) $ 5,921 Repurchase agreements $ 38,624 $ — $ 38,624 $ (38,624) $ — December 31, 2020 Assets Interest rate swap contracts $ 46,184 $ — $ 46,184 $ — $ 46,184 Liabilities Interest rate swap contracts $ 46,637 $ — $ 46,637 $ (46,637) $ — Repurchase agreements $ 73,859 $ — $ 73,859 $ (73,859) $ —
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 March 31, 2021 (in thousands) Class of collateral pledged for repurchase agreements U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 38,624 $ — $ — $ — $ 38,624 Gross amount of recognized liabilities for repurchase agreements 38,624 Amounts related to agreements not included in offsetting disclosure $ —

Shareholders' Equity Dividends

Shareholders' Equity Dividends Declared (Tables)	3 Months Ended
	Mar. 31, 2021
Shareholders' Equity [Abstract]
Dividends Declared [Table Text Block]	The following table summarizes year-to-date dividend activity: Declared Regular Cash Dividends Per Common Share Special Cash Dividends Per Common Share Record Date Paid Date January 28, 2021 $ 0.28 $ — February 10, 2021 February 24, 2021

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2021
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 periods indicated: 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 March 31, 2021 (in thousands) Beginning balance $ 163,174 $ (5,833) $ 24,854 $ 182,195 Other comprehensive loss before reclassifications (102,605) — — (102,605) Amounts reclassified from accumulated other comprehensive income (2) — 115 (1,977) (1,862) Net current-period other comprehensive income (loss) (102,605) 115 (1,977) (104,467) Ending balance $ 60,569 $ (5,718) $ 22,877 $ 77,728 Three Months Ended March 31, 2020 Beginning balance $ 33,038 $ (3,974) $ 11,303 $ 40,367 Other comprehensive income before reclassifications 79,696 — 17,977 97,673 Amounts reclassified from accumulated other comprehensive income (2) (191) 80 (722) (833) Net current-period other comprehensive income 79,505 80 17,255 96,840 Ending balance $ 112,543 $ (3,894) $ 28,558 $ 137,207 __________ (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 periods indicated: Amount Reclassified from Accumulated Other Comprehensive Income (Loss) Three Months Ended March 31, Affected line Item in the Consolidated 2021 2020 Statement of Income (in thousands) Unrealized gains on available for sale debt securities $ — $ 249 Investment securities gains, net — 249 Total before tax — (58) Income tax provision $ — $ 191 Net of tax Amortization of pension plan liability actuarial losses $ (150) $ (104) Compensation and employee benefits (150) (104) Total before tax 35 24 Income tax provision $ (115) $ (80) Net of tax Unrealized gains from hedging instruments $ 2,576 $ 940 Loans 2,576 940 Total before tax (599) (218) Income tax provision $ 1,977 $ 722 Net of tax

Fair Value Accounting and Mea_2

Fair Value Accounting and Measurement (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table sets forth the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis at the dates presented 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 March 31, 2021 (in thousands) Assets Debt securities available for sale: U.S. government agency and government-sponsored enterprise mortgage-back securities and collateralized mortgage obligations $ 4,104,219 $ — $ 4,104,219 $ — Other asset-backed securities 358,819 — 358,819 — State and municipal securities 751,285 — 751,285 — U.S. government agency and government-sponsored enterprise securities 281,967 — 281,967 — Total debt securities available for sale $ 5,496,290 $ — $ 5,496,290 $ — Loans held for sale $ 25,587 $ — $ 25,587 $ — Other assets: Interest rate lock commitments $ 925 $ — $ — $ 925 Interest rate forward loan sales contracts $ 505 $ — $ 505 $ — Interest rate contracts $ 32,501 $ — $ 32,501 $ — Liabilities Other liabilities: Interest rate contracts $ 32,769 $ — $ 32,769 $ — Fair Value Fair Value Measurements at Reporting Date Using Level 1 Level 2 Level 3 December 31, 2020 (in thousands) Assets Debt securities available for sale: U.S. government agency and government-sponsored enterprise mortgage-back securities and collateralized mortgage obligations $ 3,814,387 $ — $ 3,814,387 $ — Other asset-backed securities 357,479 — 357,479 — State and municipal securities 753,572 — 753,572 — U.S. government agency and government-sponsored enterprise securities 284,696 — 284,696 — Total debt securities available for sale $ 5,210,134 $ — $ 5,210,134 $ — Loans held for sale $ 14,760 $ — $ 14,760 $ — Other assets: Interest rate lock commitments $ 1,096 $ — $ — $ 1,096 Interest rate contracts $ 46,184 $ — $ 46,184 $ — Liabilities Other liabilities: Interest rate forward loan sales contracts $ 165 $ — $ 165 $ — Interest rate contracts $ 46,637 $ — $ 46,637 $ —
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	The following table includes a rollforward of interest rate lock commitments which utilize Level 3 inputs to determine the fair value on a recurring basis. Three Months Ended March 31, 2021 2020 (in thousands) Balance at the beginning of the period $ 1,096 $ — Change included in earnings 1,710 — Settlements (1,881) — Balance at the end of the period $ 925 $ —
Equity Securities without Readily Determinable Fair Value	The following table presents the carrying value of equity securities, without readily determinable fair values, still held as of March 31, 2021, 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 March 31, 2021 2020 Equity securities without readily determinable fair values (in thousands) Carrying value, beginning of period $ 13,425 $ — Upward carrying value changes — — Carrying value, end of period $ 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 March 31, 2021 Fair Value Measurements Losses During the Three Months Ended March 31, 2021 Level 1 Level 2 Level 3 (in thousands) Collateral dependent loans $ 1,520 $ — $ — $ 1,520 $ 722 Fair Value at March 31, 2020 Fair Value Measurements Losses During the Three Months Ended March 31, 2020 Level 1 Level 2 Level 3 (in thousands) Collateral dependent loans $ 3,043 $ — $ — $ 3,043 $ 5,138
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 the dates presented: March 31, 2021 Carrying Fair Level 1 Level 2 Level 3 (in thousands) Assets Cash and due from banks $ 178,096 $ 178,096 $ 178,096 $ — $ — Interest-earning deposits with banks 706,389 706,389 706,389 — — Debt securities available for sale 5,496,290 5,496,290 — 5,496,290 — FHLB stock 10,280 10,280 — 10,280 — Loans held for sale 26,176 26,176 — 26,176 — Loans 9,528,024 9,948,104 — — 9,948,104 Interest rate contracts 32,501 32,501 — 32,501 — Interest rate lock commitments 925 925 — — 925 Interest rate forward loan sales contracts 505 505 — 505 — Liabilities Time deposits $ 336,918 $ 333,169 $ — $ 333,169 $ — FHLB advances 7,400 8,764 — 8,764 — Repurchase agreements 38,624 38,624 — 38,624 — Subordinated debentures 35,046 35,102 — 35,102 — Interest rate contracts 32,769 32,769 — 32,769 — December 31, 2020 Carrying Fair Level 1 Level 2 Level 3 (in thousands) Assets Cash and due from banks $ 218,899 $ 218,899 $ 218,899 $ — $ — Interest-earning deposits with banks 434,867 434,867 434,867 — — Debt securities available for sale 5,210,134 5,210,134 — 5,210,134 — FHLB stock 10,280 10,280 — 10,280 — Loans held for sale 26,481 26,481 — 26,481 — Loans 9,278,520 9,720,592 — — 9,720,592 Interest rate contracts 46,184 46,184 — 46,184 — Interest rate lock commitments 1,096 1,096 — — 1,096 Liabilities Time deposits $ 338,845 $ 338,815 $ — $ 338,815 $ — FHLB advances and FRB borrowings 7,414 9,295 — 9,295 — Repurchase agreements 73,859 73,859 — 73,859 — Subordinated debentures 35,092 35,414 — 35,414 — Interest rate contracts 46,637 46,637 — 46,637 — Interest rate forward loan sales contracts 165 165 — 165 —
Fair Value Option, Disclosures	The following table presents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans held for sale sold under the mandatory delivery method and accounted for under the fair value option as of the dates presented: March 31, 2021 2020 Fair Value Aggregate Unpaid Principal Balance Fair Value Less Aggregate Unpaid Principal Balance Fair Value Aggregate Unpaid Principal Balance Fair Value Less Aggregate Unpaid Principal Balance (in thousands) $ 25,587 $ 25,167 $ 420 $ — $ — $ —
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 March 31, 2021 Valuation Technique Unobservable Input Range (Weighted Average) (1) (dollars in thousands) Collateral dependent loans (2) $ 1,520 Fair Market Value of Collateral Adjustment to Stated Value 42.96% - 75.00% (59.53%) __________ (1) Discount applied to appraised value or stated value (in the case of accounts receivable and fixed assets). (2) Collateral consists of accounts receivable and fixed assets. Fair Value at March 31, 2020 Valuation Technique Unobservable Input Range (Weighted Average) (1) (dollars in thousands) Collateral dependent loans (2) $ 3,043 Fair Market Value of Collateral Adjustment to Stated Value 0.00% - 100.00% (59.78%) __________ (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.
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets And Liabilities Measured On Recurring Basis ValuationTechniques	The following table provides a description of the valuation technique, significant unobservable inputs, and qualitative information about the unobservable inputs for the Company’s assets and liabilities classified as Level 3 and measured at fair value on a recurring basis at the dates presented: Fair Value at March 31, 2021 Valuation Technique Unobservable Input Range (Weighted Average) (dollars in thousands) Interest rate lock commitments $ 925 Internal pricing model Pull-through rate 79.87% - 100.00% (90.39%)

Earnings per Common Share (Tabl

Earnings per Common Share (Tables)	3 Months Ended
	Mar. 31, 2021
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 periods presented: Three Months Ended March 31, 2021 2020 (in thousands except per share amounts) Basic EPS: Net income $ 51,853 $ 14,628 Less: Earnings allocated to participating securities: Nonvested restricted shares 155 249 Earnings allocated to common shareholders $ 51,698 $ 14,379 Weighted average common shares outstanding 70,869 71,206 Basic earnings per common share $ 0.73 $ 0.20 Diluted EPS: Earnings allocated to common shareholders $ 51,698 $ 14,379 Weighted average common shares outstanding 70,869 71,206 Dilutive effect of equity awards 240 58 Weighted average diluted common shares outstanding 71,109 71,264 Diluted earnings per common share $ 0.73 $ 0.20 Potentially dilutive RSAs and RSUs that were not included in the computation of diluted EPS because to do so would be anti-dilutive 70 6

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	3 Months Ended
	Mar. 31, 2021
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 periods presented: Three Months Ended March 31, 2021 2020 (in thousands) Noninterest income: Revenue from contracts with customers: Deposit account and treasury management fees $ 6,358 $ 7,788 Card revenue 3,733 3,518 Financial services and trust revenue 3,381 3,065 Total revenue from contracts with customers 13,472 14,371 Other sources of noninterest income 9,694 6,836 Total noninterest income $ 23,166 $ 21,207

Securities (Debt securities Ava

Securities (Debt securities Available for Sale) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Debt securities available-for-sale, amortized cost	$ 5,417,373	$ 4,997,529
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	137,708	219,873
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(58,791)	(7,268)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt securities available for sale at fair value	5,496,290	5,210,134
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	4,040,359	3,640,351
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	109,063	178,579
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(45,203)	(4,543)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt securities available for sale at fair value	4,104,219	3,814,387
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities available-for-sale, amortized cost	359,259	349,904
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	5,216	9,651
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(5,656)	(2,076)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt securities available for sale at fair value	358,819	357,479
State and Municipal Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities available-for-sale, amortized cost	739,570	729,066
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	18,080	25,098
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(6,365)	(592)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt securities available for sale at fair value	751,285	753,572
U.S. Government and Government-Sponsored Enterprise Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities available-for-sale, amortized cost	278,185	278,208
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	5,349	6,545
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(1,567)	(57)
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt securities available for sale at fair value	$ 281,967	$ 284,696

Securities Securities (Summary

Securities Securities (Summary of Gross Realized Gains and Gross Realized Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Proceeds from Sale of Debt Securities, Available-for-sale	$ 0	$ 194,105
Gross Realized Gains from sales of debt securities available for sale	0	435
Gross Realized Losses from sales of debt securities available for sale	0	(186)
Other securities gains	0	0
Investment securities gain (loss), net	$ 0	$ 249

Securities (Schedule of Contrac

Securities (Schedule of Contractual Maturities of Investment Securities Available for Sale) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Abstract]
Due within one year, Amortized Cost	$ 81,385
Due after one year through five years, Amortized Cost	737,066
Due after five years through ten years, Amortized Cost	2,457,820
Due after ten years, Amortized Cost	2,141,102
Debt securities available-for-sale, amortized cost	5,417,373	$ 4,997,529
Due within one year, Fair Value	81,986
Due after one year through five years, Fair Value	765,090
Due after five years through ten years, Fair Value	2,507,546
Due after ten years, Fair Value	2,141,668
Debt securities available for sale at fair value	$ 5,496,290	$ 5,210,134

Securities (Carrying Value of S

Securities (Carrying Value of Securities Pledged as Collateral) (Details) $ in Thousands	Mar. 31, 2021USD ($)
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Restricted	$ 804,675
To secure public funds
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Restricted	477,970
To secure borrowings
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Restricted	109,650
Other securities pledged
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Restricted	$ 217,055

Securities (Summary of Gross Un

Securities (Summary of Gross Unrealized Losses and Fair Value of the Investments with Unrealized Losses) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months Fair Value	$ 2,306,179	$ 880,507
Less than 12 Months Unrealized Losses	(58,072)	(6,453)
12 Months or More Fair Value	16,532	18,597
12 Months or More Unrealized Losses	(719)	(815)
Total Fair Value	2,322,711	899,104
Total Unrealized Losses	(58,791)	(7,268)
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	1,661,107	575,329
Less than 12 Months Unrealized Losses	(44,484)	(3,728)
12 Months or More Fair Value	16,463	18,527
12 Months or More Unrealized Losses	(719)	(815)
Total Fair Value	1,677,570	593,856
Total Unrealized Losses	(45,203)	(4,543)
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months Fair Value	183,636	143,764
Less than 12 Months Unrealized Losses	(5,656)	(2,076)
12 Months or More Fair Value	69	70
12 Months or More Unrealized Losses	0	0
Total Fair Value	183,705	143,834
Total Unrealized Losses	(5,656)	(2,076)
State and Municipal Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months Fair Value	311,953	86,471
Less than 12 Months Unrealized Losses	(6,365)	(592)
12 Months or More Fair Value	0	0
12 Months or More Unrealized Losses	0	0
Total Fair Value	311,953	86,471
Total Unrealized Losses	(6,365)	(592)
U.S. Government and Government-Sponsored Enterprise Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months Fair Value	149,483	74,943
Less than 12 Months Unrealized Losses	(1,567)	(57)
12 Months or More Fair Value	0	0
12 Months or More Unrealized Losses	0	0
Total Fair Value	149,483	74,943
Total Unrealized Losses	$ (1,567)	$ (57)

Securities (Narrative) (Details

Securities (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)securityshares	Jun. 30, 2020shares	Dec. 31, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Debt Securities, Available-for-sale [Line Items]
Interest receivable | $	$ 52,667		$ 54,831
Unrealized gains recognized during the reporting period on equity securities still held at the reporting date | $	$ 0
Visa Class B shares, shares sold | shares		17,360
Visa Class B shares, remaining shares | shares	77,683
Equity Securities | $	$ 13,425		13,425	$ 0	$ 0
Available-for-sale Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Interest receivable | $	$ 17,400		$ 17,100
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 | security	144
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	16
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 | security	89
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 | security	8

Loans (Analysis of Loan Portfol

Loans (Analysis of Loan Portfolio by Major Types of Loans) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$ 9,676,318	$ 9,427,660
Financing Receivable, Allowance for Credit Loss	(148,294)	(149,140)	$ (122,074)	$ (83,968)
Loans and Leases Receivable, Net Amount	9,528,024	9,278,520
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	4,081,915	4,062,313
Financing Receivable, Allowance for Credit Loss	(57,050)	(68,934)	(37,122)	(20,340)
Commercial Business [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans and Leases Receivable, Net of Deferred Income	3,792,813	3,597,968
Financing Receivable, Allowance for Credit Loss	(58,405)	(45,250)	(45,570)	(30,292)
Agriculture [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans and Leases Receivable, Net of Deferred Income	751,800	779,627
Financing Receivable, Allowance for Credit Loss	(9,487)	(9,052)	(11,085)	(15,835)
Construction [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans and Leases Receivable, Net of Deferred Income	282,534	268,663
Financing Receivable, Allowance for Credit Loss	(6,551)	(7,636)	(8,845)	(8,571)
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	735,314	683,570
Financing Receivable, Allowance for Credit Loss	(15,638)	(16,875)	(17,659)	(7,435)
Consumer Loan [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans and Leases Receivable, Net of Deferred Income	31,942	35,519
Financing Receivable, Allowance for Credit Loss	$ (1,163)	$ (1,393)	$ (1,644)	$ (883)

Loans (Analysis of the Aged Loa

Loans (Analysis of the Aged Loan Portfolio) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Current Loans	$ 9,628,426	$ 9,364,697
Past Due Loans	14,311	28,157
Nonaccrual Loans	33,581	34,806
Total Loans	9,676,318	9,427,660
Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	4,067,718	4,037,309
Past Due Loans	6,880	17,292
Nonaccrual Loans	7,317	7,712
Total Loans	4,081,915	4,062,313
Commercial Business [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	3,778,955	3,578,905
Past Due Loans	307	5,841
Nonaccrual Loans	13,551	13,222
Total Loans	3,792,813	3,597,968
Agriculture [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	739,599	767,102
Past Due Loans	1,572	911
Nonaccrual Loans	10,629	11,614
Total Loans	751,800	779,627
Construction [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	282,343	268,304
Past Due Loans	0	142
Nonaccrual Loans	191	217
Total Loans	282,534	268,663
One-to-Four Family Residential [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	728,053	677,627
Past Due Loans	5,510	3,942
Nonaccrual Loans	1,751	2,001
Total Loans	735,314	683,570
Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Current Loans	31,758	35,450
Past Due Loans	42	29
Nonaccrual Loans	142	40
Total Loans	31,942	35,519
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	7,538	21,792
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	880	17,292
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Business [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	109	1,282
Financial Asset, 30 to 59 Days Past Due [Member] | Agriculture [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	1,060	911
Financial Asset, 30 to 59 Days Past Due [Member] | Construction [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | One-to-Four Family Residential [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	5,462	2,283
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	27	24
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	6,773	6,365
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	6,000	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Business [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	198	4,559
Financial Asset, 60 to 89 Days Past Due [Member] | Agriculture [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	512	0
Financial Asset, 60 to 89 Days Past Due [Member] | Construction [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	0	142
Financial Asset, 60 to 89 Days Past Due [Member] | One-to-Four Family Residential [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	48	1,659
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Past Due Loans	15	5
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
	Mar. 31, 2021	Mar. 31, 2020
Financing Receivable, Credit Quality Indicator - nonaccrual loans written off interest [Line Items]
Financing Receivable Accrued Interest Reversed Through Interest Income	$ 218	$ 788
Commercial Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator - nonaccrual loans written off interest [Line Items]
Financing Receivable Accrued Interest Reversed Through Interest Income	211	783
Consumer Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator - nonaccrual loans written off interest [Line Items]
Financing Receivable Accrued Interest Reversed Through Interest Income	$ 7	$ 5

Loans (Analysis of Nonaccrual L

Loans (Analysis of Nonaccrual Loans with no ACL) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, No Allowance	$ 23,397	$ 20,911
Commercial Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, No Allowance	6,336	6,393
Commercial Business [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, No Allowance	8,682	6,382
Agriculture [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, No Allowance	$ 8,379	$ 8,136

Loans Loans (Analysis of Troubl

Loans Loans (Analysis of Troubled Debt Restructurings) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)Modifications	Mar. 31, 2020USD ($)Modifications
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	10	4
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 1,611	$ 1,235
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 1,611	$ 1,235
Commercial Real Estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	1	0
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 628	$ 0
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 628	$ 0
Commercial Business [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	7	2
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 843	$ 272
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 843	$ 272
Agriculture [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	0	1
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 0	$ 895
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 0	$ 895
One-to-Four Family Residential [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	2	1
Financing Receivable, Troubled Debt Restructuring, Premodification	$ 140	$ 68
Financing Receivable, Troubled Debt Restructuring, Postmodification	$ 140	$ 68

Loans (Narrative) (Details)

Loans (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)contract	Mar. 31, 2020contract	Dec. 31, 2020USD ($)
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Interest Receivable, loans	$ 52,667		$ 54,831
Financing Receivable Modifications Additional Commitment To Lend	$ 672		651
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts | contract	0	0
Loan modifications, short-term deferments not classified as TDR, Number of contracts | contract	20
Loan modifications, short-term deferments not classified as TDR, net of unearned income	$ 71,400
Paycheck Protection Program (PPP) loans, net of unearned income	894,100
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		3,460,000
Commercial Loan [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans pledged to collateralize Federal Reserve Bank Borrowings	200,100		200,400
Loans [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Interest Receivable, loans	$ 35,200		$ 37,800

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
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	$ 148,294	$ 122,074	$ 149,140		$ 83,968
Financing Receivable, Allowance for Credit Loss, Writeoff	(3,466)	(6,789)
Financing Receivable, Allowance for Credit Loss, Recovery	3,420	1,763
Provision (recapture) for credit losses	(800)	41,500
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	57,050	37,122	68,934		20,340
Financing Receivable, Allowance for Credit Loss, Writeoff	0	(101)
Financing Receivable, Allowance for Credit Loss, Recovery	36	14
Provision (recapture) for credit losses	(11,920)	9,336
Commercial Business [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	58,405	45,570	45,250		30,292
Financing Receivable, Allowance for Credit Loss, Writeoff	(3,339)	(1,684)
Financing Receivable, Allowance for Credit Loss, Recovery	3,214	860
Provision (recapture) for credit losses	13,280	15,340
Agriculture [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	9,487	11,085	9,052		15,835
Financing Receivable, Allowance for Credit Loss, Writeoff	0	(4,726)
Financing Receivable, Allowance for Credit Loss, Recovery	12	41
Provision (recapture) for credit losses	423	9,260
Construction [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	6,551	8,845	7,636		8,571
Financing Receivable, Allowance for Credit Loss, Writeoff	0	0
Financing Receivable, Allowance for Credit Loss, Recovery	46	442
Provision (recapture) for credit losses	(1,131)	1,582
One-to-Four Family Residential [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	15,638	17,659	16,875		7,435
Financing Receivable, Allowance for Credit Loss, Writeoff	0	(10)
Financing Receivable, Allowance for Credit Loss, Recovery	51	282
Provision (recapture) for credit losses	(1,288)	5,715
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss	1,163	1,644	$ 1,393		883
Financing Receivable, Allowance for Credit Loss, Writeoff	(127)	(268)
Financing Receivable, Allowance for Credit Loss, Recovery	61	124
Provision (recapture) for credit losses	$ (164)	127
Unallocated Financing Receivables [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss		149			$ 612
Financing Receivable, Allowance for Credit Loss, Writeoff		0
Financing Receivable, Allowance for Credit Loss, Recovery		0
Provision (recapture) for credit losses		$ 140
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
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Schedule of Allowance for Unfunded Commitments and Letters of Credit [Line Items]
Allowance For Unfunded Loan Commitments And Letters Of Credit	$ 9,800	$ 6,000	$ 8,300	$ 3,430
Allowance for Loan and Lease Losses, Net Changes In Unfunded Commitments and Letters Of Credit Allowance	$ 1,500	$ 1,000
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

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 ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 998,511	$ 2,223,383
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,934,401	1,379,336
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,318,312	985,423
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	919,885	875,545
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	826,670	812,034
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,042,270	1,413,553
Financing Receivable, Revolving	1,617,657	1,687,345
Financing Receivable, Revolving Converted to Term Loans	18,612	51,041
Loans and Leases Receivable, Net of Deferred Income	9,676,318	9,427,660
Financing Receivable, Allowance for Credit Loss	148,294	149,140	$ 122,074	$ 83,968
Loans, net	9,528,024	9,278,520
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	205,152	680,708
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	675,249	709,562
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	703,398	513,737
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	495,541	547,996
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	527,418	498,904
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,420,546	1,038,233
Financing Receivable, Revolving	51,830	55,443
Financing Receivable, Revolving Converted to Term Loans	2,781	17,730
Loans and Leases Receivable, Net of Deferred Income	4,081,915	4,062,313
Financing Receivable, Allowance for Credit Loss	57,050	68,934	37,122	20,340
Commercial Real Estate [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	205,152	674,444
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	668,655	645,328
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	603,542	478,881
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	459,888	502,112
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	491,550	408,972
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,229,742	946,980
Financing Receivable, Revolving	49,274	52,049
Financing Receivable, Revolving Converted to Term Loans	2,781	11,332
Loans and Leases Receivable, Net of Deferred Income	3,710,584	3,720,098
Commercial Real Estate [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	3,348
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,127	39,374
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	65,107	21,285
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	19,094	30,232
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4,420	46,197
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	99,370	50,115
Financing Receivable, Revolving	5	5
Financing Receivable, Revolving Converted to Term Loans	0	2,139
Loans and Leases Receivable, Net of Deferred Income	191,123	192,695
Commercial Real Estate [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	2,916
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,467	24,860
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	34,749	13,571
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	16,559	15,652
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	31,448	43,735
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	91,434	41,138
Financing Receivable, Revolving	2,551	3,389
Financing Receivable, Revolving Converted to Term Loans	0	4,259
Loans and Leases Receivable, Net of Deferred Income	180,208	149,520
Commercial Business [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	586,311	1,094,027
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	836,347	400,172
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	382,654	343,892
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	316,401	229,497
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	207,952	231,713
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	411,159	229,070
Financing Receivable, Revolving	1,038,686	1,055,285
Financing Receivable, Revolving Converted to Term Loans	13,303	14,312
Loans and Leases Receivable, Net of Deferred Income	3,792,813	3,597,968
Financing Receivable, Allowance for Credit Loss	58,405	45,250	45,570	30,292
Commercial Business [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	586,311	1,087,400
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	829,165	366,435
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	347,668	324,360
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	273,408	199,010
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	178,663	218,313
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	376,297	214,677
Financing Receivable, Revolving	945,271	1,000,725
Financing Receivable, Revolving Converted to Term Loans	12,322	11,540
Loans and Leases Receivable, Net of Deferred Income	3,549,105	3,422,460
Commercial Business [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	3,002
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	588	26,361
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	8,346	8,471
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6,237	24,582
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,063	7,004
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,131	10,650
Financing Receivable, Revolving	49,369	22,426
Financing Receivable, Revolving Converted to Term Loans	143	0
Loans and Leases Receivable, Net of Deferred Income	67,877	102,496
Commercial Business [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	3,625
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	6,594	7,376
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	26,640	11,061
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	36,756	5,905
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	27,226	6,396
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	33,731	3,743
Financing Receivable, Revolving	44,046	32,134
Financing Receivable, Revolving Converted to Term Loans	838	2,772
Loans and Leases Receivable, Net of Deferred Income	175,831	73,012
Agriculture [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	57,282	147,356
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	130,931	103,182
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	97,275	50,587
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	42,786	62,657
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	60,778	59,177
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	112,534	62,898
Financing Receivable, Revolving	248,920	283,000
Financing Receivable, Revolving Converted to Term Loans	1,294	10,770
Loans and Leases Receivable, Net of Deferred Income	751,800	779,627
Financing Receivable, Allowance for Credit Loss	9,487	9,052	11,085	15,835
Agriculture [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	57,282	142,163
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	121,511	90,612
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	85,485	44,434
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	39,930	58,366
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	56,638	58,893
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	106,969	59,396
Financing Receivable, Revolving	209,154	244,135
Financing Receivable, Revolving Converted to Term Loans	550	9,299
Loans and Leases Receivable, Net of Deferred Income	677,519	707,298
Agriculture [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	3,398	90
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,366	285
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	163	33
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,371	0
Financing Receivable, Revolving	7,962	85
Financing Receivable, Revolving Converted to Term Loans	0	13
Loans and Leases Receivable, Net of Deferred Income	15,260	506
Agriculture [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	5,193
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	6,022	12,480
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	10,424	5,868
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,693	4,258
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4,140	284
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	3,194	3,502
Financing Receivable, Revolving	31,804	38,780
Financing Receivable, Revolving Converted to Term Loans	744	1,458
Loans and Leases Receivable, Net of Deferred Income	59,021	71,823
Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	41,447	134,693
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	130,122	84,706
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	62,269	10,066
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	7,909	3,498
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	3,471	763
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	5,634	1,861
Financing Receivable, Revolving	31,682	29,323
Financing Receivable, Revolving Converted to Term Loans	0	3,753
Loans and Leases Receivable, Net of Deferred Income	282,534	268,663
Financing Receivable, Allowance for Credit Loss	6,551	7,636	8,845	8,571
Construction [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	41,447	134,693
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	130,122	66,974
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	44,121	10,066
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	7,909	3,498
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	3,471	763
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	5,579	1,805
Financing Receivable, Revolving	31,682	29,323
Financing Receivable, Revolving Converted to Term Loans	0	3,753
Loans and Leases Receivable, Net of Deferred Income	264,331	250,875
Construction [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	0
Financing Receivable, Revolving	0
Financing Receivable, Revolving Converted to Term Loans	0
Loans and Leases Receivable, Net of Deferred Income	0
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	0	17,732
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	18,148	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	55	56
Financing Receivable, Revolving	0	0
Financing Receivable, Revolving Converted to Term Loans	0	0
Loans and Leases Receivable, Net of Deferred Income	18,203	17,788
One-to-Four Family Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	106,212	161,021
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	158,121	78,605
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	69,870	63,255
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	53,998	30,903
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	26,177	21,233
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	91,183	80,261
Financing Receivable, Revolving	229,226	244,330
Financing Receivable, Revolving Converted to Term Loans	527	3,962
Loans and Leases Receivable, Net of Deferred Income	735,314	683,570
Financing Receivable, Allowance for Credit Loss	15,638	16,875	17,659	7,435
One-to-Four Family Residential [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	106,212	161,021
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	157,286	77,756
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	68,489	62,696
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	53,753	29,737
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	25,686	20,889
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	88,323	78,098
Financing Receivable, Revolving	228,917	243,325
Financing Receivable, Revolving Converted to Term Loans	308	3,655
Loans and Leases Receivable, Net of Deferred Income	728,974	677,177
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	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	332
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	125	195
Financing Receivable, Revolving	0	0
Financing Receivable, Revolving Converted to Term Loans	0	0
Loans and Leases Receivable, Net of Deferred Income	125	527
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	835	849
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,381	227
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	245	1,166
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	491	344
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,735	1,968
Financing Receivable, Revolving	309	1,005
Financing Receivable, Revolving Converted to Term Loans	219	307
Loans and Leases Receivable, Net of Deferred Income	6,215	5,866
Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	2,107	5,578
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,631	3,109
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,846	3,886
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	3,250	994
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	874	244
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,214	1,230
Financing Receivable, Revolving	17,313	19,964
Financing Receivable, Revolving Converted to Term Loans	707	514
Loans and Leases Receivable, Net of Deferred Income	31,942	35,519
Financing Receivable, Allowance for Credit Loss	1,163	1,393	$ 1,644	$ 883
Consumer Loan [Member] | Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	2,107	5,548
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,595	3,109
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,807	3,886
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	3,250	989
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	871	244
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,211	1,060
Financing Receivable, Revolving	17,277	19,911
Financing Receivable, Revolving Converted to Term Loans	610	474
Loans and Leases Receivable, Net of Deferred Income	31,728	35,221
Consumer Loan [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	30
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	36	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	39	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	5
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	3	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	3	170
Financing Receivable, Revolving	36	53
Financing Receivable, Revolving Converted to Term Loans	97	40
Loans and Leases Receivable, Net of Deferred Income	$ 214	$ 298

Allowance for Credit Losses a_6

Allowance for Credit Losses and Allowance for Unfunded Commitments and Letters of Credit (Narrative) (Details)	3 Months Ended
	Mar. 31, 2021USD ($)
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)	$ (846,000)

Other Real Estate Owned (Summar

Other Real Estate Owned (Summary of Other Real Estate Owned) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Other Real Estate Owned [Line Items]
Balance, beginning of period	$ 553	$ 552
Proceeds from Sale of OREO Property	132	42
Gain on sale of OREO, net	100	0
Total OREO, end of period	$ 521	$ 510

Other Real Estate Owned (Narrat

Other Real Estate Owned (Narrative) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Other Real Estate Owned [Line Items]
Foreclosed residential real estate properties	$ 521	$ 553	$ 510	$ 552
Mortgage Loans in Process of Foreclosure, Amount	167
One-to-Four Family Residential [Member]
Other Real Estate Owned [Line Items]
Foreclosed residential real estate properties	$ 0

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets (Schedule of Goodwill and Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Goodwill and Intangible Assets [Roll Forward]
Total goodwill, beginning of period	$ 765,842
Total goodwill, end of period	765,842	$ 765,842
CDI current period amortization	(1,924)	(2,310)
Indefinite-lived Intangible Assets (Excluding Goodwill)	919	919
Other intangible assets, net	24,810	33,148	$ 26,734
Total goodwill and intangible assets, end of period	790,652	798,990
Core Deposits [Member]
Goodwill and Intangible Assets [Roll Forward]
Gross core deposit intangible balance, beginning of period			105,473	$ 105,473
Accumulated amortization at beginning of period			$ (79,658)	$ (70,934)
Core deposit intangible, net, beginning of period	25,815	34,539
CDI current period amortization	(1,924)	(2,310)
Total core deposit intangible, end of period	$ 23,891	$ 32,229

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets (Estimated Future Amortization Expense of Core Deposit Intangibles) (Details) $ in Thousands	Mar. 31, 2021USD ($)
Future Amortization Expense For Core Deposit Intangibles
2021	$ 5,340
2022	5,880
2023	4,552
2024	3,432
2025	$ 2,415

Intangible Assets, Goodwill and

Intangible Assets, Goodwill and Other (Details) - Narrative	3 Months Ended
	Mar. 31, 2021
Core Deposits [Member]
Goodwill and Intangible Assets [Line Items]
Estimated life of CDI, in years	10 years

Revolving Line of Credit (Detai

Revolving Line of Credit (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
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) - Not Designated as Hedging Instrument [Member] - Interest Rate Contracts [Member] - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Fair value of asset derivative instruments	$ 32,501	$ 46,184
Fair value of liability derivative instruments	32,769	46,637
Other Assets [Member] | Interest Rate Lock Commitments
Derivative [Line Items]
Fair value of asset derivative instruments	925	1,096
Other Assets [Member] | Forward Sales Contracts
Derivative [Line Items]
Fair value of asset derivative instruments	505	0
Other Assets [Member] | Interest Rate Swap
Derivative [Line Items]
Fair value of asset derivative instruments	32,501	46,184
Other Liabilities [Member] | Interest Rate Lock Commitments
Derivative [Line Items]
Fair value of liability derivative instruments	0	0
Other Liabilities [Member] | Forward Sales Contracts
Derivative [Line Items]
Fair value of liability derivative instruments	0	165
Other Liabilities [Member] | Interest Rate Swap
Derivative [Line Items]
Fair value of liability derivative instruments	$ 32,769	$ 46,637

Derivatives and Balance Sheet_4

Derivatives and Balance Sheet Offsetting - Cash flow hedge effect on AOCI table (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Balance Sheet Offsetting [Line Items]
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss)	$ 0	$ 23,423
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	$ 2,576	$ 940

Derivatives and Balance Sheet_5

Derivatives and Balance Sheet Offsetting - Not designated as hedging instruments gain/loss table (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Balance Sheet Offsetting [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	$ 611	$ 0
Interest Rate Contracts [Member] | Interest Rate Lock Commitments
Balance Sheet Offsetting [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	(171)	0
Interest Rate Contracts [Member] | Forward Sales Contracts
Balance Sheet Offsetting [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	670	0
Interest Rate Contracts [Member] | Interest Rate Swap
Balance Sheet Offsetting [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	$ 112	$ 0

Derivatives and Balance Sheet_6

Derivatives and Balance Sheet Offsetting - Collateral pledged table (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Balance Sheet Offsetting [Line Items]
Repurchase agreements, amounts offset in balance sheet	$ 0	$ 0
Repurchase agreements, net amount presented in statement of financial position	38,624	73,859
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	(38,624)	(73,859)
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	32,501	46,184
Derivative, Collateral, Obligation to Return Cash	(1,960)	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	30,541	46,184
Derivative Liability, Gross Amounts Offset in Balance Sheets	0	0
Derivative Liability	32,769	46,637
Derivative, Collateral, Right to Reclaim Cash	26,848	46,637
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	5,921	0
Available-for-sale Securities [Member]
Balance Sheet Offsetting [Line Items]
Securities Sold under Agreements to Repurchase, Gross	38,624	73,859
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Balance Sheet Offsetting [Line Items]
Fair value of asset derivative instruments	32,501	46,184
Fair value of liability derivative instruments	$ 32,769	$ 46,637

Derivatives and Balance Sheet_7

Derivatives and Balance Sheet Offsetting - Collateral pledged for repurchase agreements table (Details) $ in Thousands	Mar. 31, 2021USD ($)
Balance Sheet Offsetting [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	$ 38,624
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	38,624
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	38,624
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_8

Derivatives and Balance Sheet Offsetting (Narative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Balance Sheet Offsetting [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ 10,400
Gain on termination of interest rate collar	34,400
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	38,624
Commitments To Originate Loans Held For Sale Member
Balance Sheet Offsetting [Line Items]
Commitments and contingent liabilities (Note 10)	60,100
Forward Sales Contracts
Balance Sheet Offsetting [Line Items]
Commitments and contingent liabilities (Note 10)	48,500
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Balance Sheet Offsetting [Line Items]
Derivative, Notional Amount	635,100	$ 597,900
Designated as Hedging Instrument [Member] | Interest rate collar [Domain]
Balance Sheet Offsetting [Line Items]
Derivative, Notional Amount	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	$ 38,624

Commitments and contingent li_2

Commitments and contingent liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Commitments to Extend Credit [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	$ 2,930,000	$ 2,800,000
Standby Letters of Credit [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	30,600	29,900
Commercial Letter of Credit and other off-balance sheet liabilities [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	$ 16	$ 0

Shareholders' Equity (Details)

Shareholders' Equity (Details) - $ / shares	Apr. 29, 2021	Jan. 28, 2021
Subsequent Event [Line Items]
Declared quarterly cash dividend		$ 0.28
Common Stock, Special Cash Dividends, Per Share, Declared		$ 0
Subsequent Event [Member]
Subsequent Event [Line Items]
Declared quarterly cash dividend	$ 0.28

Shareholders' Equity Share repu

Shareholders' Equity Share repurchase (Details) - $ / shares	Apr. 29, 2021	Jan. 28, 2021
Class of Stock [Line Items]
Common Stock, Dividends, Per Share, Declared		$ 0.28
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
	Mar. 31, 2021	Mar. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 182,195	$ 40,367
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(102,605)	97,673
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax	(1,862)	(833)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Total	(104,467)	96,840
Ending balance	77,728	137,207
Unrealized Gains and Losses on Available-for-Sale Debt Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	163,174	33,038
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(102,605)	79,696
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax	0	(191)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Total	(102,605)	79,505
Ending balance	60,569	112,543
Unrealized Gains and Losses on Pension Plan Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(5,833)	(3,974)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax	115	80
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Total	115	80
Ending balance	(5,718)	(3,894)
Unrealized gains and losses on cash flow hedge
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	24,854	11,303
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	17,977
Reclassification from Accumulated Other Comprehensive Income (Loss), Current Period, Net of Tax	(1,977)	(722)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Total	(1,977)	17,255
Ending balance	$ 22,877	$ 28,558

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Reclassification out of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment securities gains, net	$ 0	$ 249
Total before tax	64,401	17,858
Income tax provision	(12,548)	(3,230)
Net Income	51,853	14,628
Compensation and employee benefits	51,736	54,842
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	249
Total before tax	0	249
Income tax provision	0	(58)
Net Income	0	191
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	(150)	(104)
Income tax provision	35	24
Net Income	(115)	(80)
Compensation and employee benefits	(150)	(104)
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	2,576	940
Income tax provision	(599)	(218)
Net Income	1,977	722
Interest income, Loans	$ 2,576	$ 940

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	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale	$ 5,496,290	$ 5,210,134
Loans held for sale	25,587	14,760
Interest rate derivative asset	32,501	46,184
Interest rate derivative liability	32,769	46,637
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
Loans held for sale	0	0
Interest rate derivative asset	0	0
Interest rate derivative liability	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	5,496,290	5,210,134
Loans held for sale	25,587	14,760
Interest rate derivative asset	32,501	46,184
Interest rate derivative liability	32,769	46,637
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
Loans held for sale	0	0
Interest rate derivative asset	0	0
Interest rate derivative liability	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	4,104,219	3,814,387
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	4,104,219	3,814,387
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	358,819	357,479
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	358,819	357,479
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	751,285	753,572
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	751,285	753,572
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	281,967	284,696
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	281,967	284,696
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
Interest Rate Lock Commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate derivative asset	925	1,096
Interest Rate Lock Commitments | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate derivative asset	0	0
Interest Rate Lock Commitments | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate derivative asset	0	0
Interest Rate Lock Commitments | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate derivative asset	925	1,096
Forward Sales Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate derivative asset	505
Derivative Liability		165
Forward Sales Contracts | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate derivative asset	0
Derivative Liability		0
Forward Sales Contracts | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate derivative asset	505
Derivative Liability		165
Forward Sales Contracts | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate derivative asset	$ 0
Derivative Liability		$ 0

Fair Value Accounting and Mea_4

Fair Value Accounting and Measurement (IRL Quantitative Information About Level 3 Fair Value Measurements) (Details) $ in Thousands	Mar. 31, 2021USD ($)	Dec. 31, 2020USD ($)
Measurement input pull through rate member | Valuation technique internal pricing model member | Interest Rate Lock Commitments | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset, Measurement Input	0.7987
Measurement input pull through rate member | Valuation technique internal pricing model member | Interest Rate Lock Commitments | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset, Measurement Input	1
Measurement input pull through rate member | Valuation technique internal pricing model member | Interest Rate Lock Commitments | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset, Measurement Input	0.9039
Fair Value, Recurring [Member]
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset	$ 32,501	$ 46,184
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset	0	0
Fair Value, Recurring [Member] | Interest Rate Lock Commitments
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset	925	1,096
Fair Value, Recurring [Member] | Interest Rate Lock Commitments | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Interest rate derivative asset	$ 925	$ 1,096

Fair Value Accounting and Mea_5

Fair Value Accounting and Measurement (IRL rollforward) (Details) - Interest Rate Lock Commitments - Fair Value, Inputs, Level 3 [Member] - Fair Value, Recurring [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Balance - Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 925	$ 0	$ 1,096	$ 0
Change included in Earnings - Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings	1,710	0
Settlements - Fair Value Net Derivative Asset (Liability) Measured on Recurring Basis with Unobserved Inputs reconciliation, Sales and Settlements	$ (1,881)	$ 0

Fair Value Accounting and Mea_6

Fair Value Accounting and Measurement Equity securities without readily determinable values (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Equity Securities	$ 13,425	$ 0	$ 13,425	$ 0
Equity Securities without Readily Determinable Fair Value, Upward Price Adjustment, Annual Amount	$ 0	$ 0

Fair Value Accounting and Mea_7

Fair Value Accounting and Measurement (Financial Assets Accounted For Fair Value On Nonrecurring Basis) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ 88	$ 0
Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans, Fair Value	1,520	3,043
Fair Value, Inputs, Level 1 [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans, Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans, Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans, Fair Value	1,520	3,043
Collateral dependent loans [Domain] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ 722	$ 5,138

Fair Value Accounting and Mea_8

Fair Value Accounting and Measurement (Quantitative Information About Level 3 Fair Value Measurements) (Details) - Fair Value, Nonrecurring [Member] $ in Thousands	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)
Fair Value Measurements Inputs and Valuation Techniques
Collateral dependent loans, Fair Value	$ 1,520	$ 3,043
Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Collateral dependent loans, Fair Value	$ 1,520	$ 3,043
Valuation, Market Approach [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Inputs and Valuation Techniques
Collateral dependent loans, Measurement Input	0.4296	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	0.7500	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	0.5953	0.5978

Fair Value Accounting and Mea_9

Fair Value Accounting and Measurement (Carrying Amounts and Estimated Fair Values of Selected Financial Instruments) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets
Interest-earning deposits with banks	$ 706,389	$ 434,867
Debt securities available for sale at fair value	5,496,290	5,210,134
Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	178,096	218,899
Interest-earning deposits with banks	706,389	434,867
Debt securities available for sale at fair value	5,496,290	5,210,134
FHLB stock	10,280	10,280
Loans held for sale	26,176	26,481
Loans	9,948,104	9,720,592
Liabilities
Deposits	333,169	338,815
FHLB advances	8,764	9,295
Repurchase agreements	38,624	73,859
Subordinated Debentures	35,102	35,414
Carrying Amount
Assets
Cash and due from banks	178,096	218,899
Interest-earning deposits with banks	706,389	434,867
Debt securities available for sale at fair value	5,496,290	5,210,134
FHLB stock	10,280	10,280
Loans held for sale	26,176	26,481
Loans	9,528,024	9,278,520
Liabilities
Deposits	336,918	338,845
FHLB advances	7,400	7,414
Repurchase agreements	38,624	73,859
Subordinated Debentures	35,046	35,092
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	178,096	218,899
Interest-earning deposits with banks	706,389	434,867
Debt securities available for sale at fair value	0	0
FHLB stock	0	0
Loans held for sale	0	0
Loans	0	0
Liabilities
Deposits	0	0
FHLB advances	0	0
Repurchase agreements	0	0
Subordinated Debentures	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	5,496,290	5,210,134
FHLB stock	10,280	10,280
Loans held for sale	26,176	26,481
Loans	0	0
Liabilities
Deposits	333,169	338,815
FHLB advances	8,764	9,295
Repurchase agreements	38,624	73,859
Subordinated Debentures	35,102	35,414
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
FHLB stock	0	0
Loans held for sale	0	0
Loans	9,948,104	9,720,592
Liabilities
Deposits	0	0
FHLB advances	0	0
Repurchase agreements	0	0
Subordinated Debentures	0	0
Interest Rate Swap | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	32,501	46,184
Liabilities
Interest rate derivative liability	32,769	46,637
Interest Rate Swap | Carrying Amount
Assets
Interest rate derivative asset	32,501	46,184
Liabilities
Interest rate derivative liability	32,769	46,637
Interest Rate Swap | Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	0	0
Liabilities
Interest rate derivative liability	0	0
Interest Rate Swap | Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	32,501	46,184
Liabilities
Interest rate derivative liability	32,769	46,637
Interest Rate Swap | Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	0	0
Liabilities
Interest rate derivative liability	0	0
Interest Rate Lock Commitments | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	925	1,096
Interest Rate Lock Commitments | Carrying Amount
Assets
Interest rate derivative asset	925	1,096
Interest Rate Lock Commitments | Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	0	0
Interest Rate Lock Commitments | Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	0	0
Interest Rate Lock Commitments | Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	925	1,096
Forward Sales Contracts | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	505
Liabilities
Interest rate derivative liability		165
Forward Sales Contracts | Carrying Amount
Assets
Interest rate derivative asset	505
Liabilities
Interest rate derivative liability		165
Forward Sales Contracts | Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	0
Liabilities
Interest rate derivative liability		0
Forward Sales Contracts | Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	505
Liabilities
Interest rate derivative liability		165
Forward Sales Contracts | Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Interest rate derivative asset	$ 0
Liabilities
Interest rate derivative liability		$ 0

Fair Value Accounting and Me_10

Fair Value Accounting and Measurement (Aggregate FV and aggregate unpaid principal balance of LHFS under FV option (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Fair Value Disclosures [Abstract]
FV, Loans held for sale, FV option, Mandatory Delivery method	$ 25,587	$ 0
Fair Value, Loans held for sale, FV option, Aggregate Unpaid Principal Balance	25,167	0
Fair Value, Option, Aggregate Differences, Loans and Long-term Receivables	$ 420	$ 0

Fair Value Accounting and Me_11

Fair Value Accounting and Measurement - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Visa Class B shares, remaining shares	77,683
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ 88	$ 0

Earnings per Common Share (Deta

Earnings per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net Income	$ 51,853	$ 14,628
Earnings allocated to participating securities - nonvested restricted shares	155	249
Earnings allocated to common shareholders, Basic	$ 51,698	$ 14,379
Weighted average common shares outstanding	70,869	71,206
Basic earnings per common share	$ 0.73	$ 0.20
Earnings allocated to common shareholders, Diluted	$ 51,698	$ 14,379
Dilutive effect of equity awards	240	58
Weighted average diluted common shares outstanding	71,109	71,264
Diluted earnings per common share	$ 0.73	$ 0.20
Potentially dilutive stock awards and units that were not included in the computation of diluted EPS because to do so would be anti-dilutive.	70	6

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Deposit account and treasury management fees	$ 6,358	$ 7,788
Card revenue	3,733	3,518
Financial services and trust revenue	3,381	3,065
Revenue from contracts with customers	13,472	14,371
Noninterest income, excluding revenue from contracts with customers	9,694	6,836
Noninterest Income	$ 23,166	$ 21,207