Simmons First National (SFNC) 10-Q 7 Nov 19 2019 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2019	Nov. 04, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Entity File Number	000-06253
Document Transition Report	false
Entity Registrant Name	SIMMONS FIRST NATIONAL CORP
Entity Incorporation, State or Country Code	AR
Entity Tax Identification Number	71-0407808
Entity Address, Address Line One	501 Main Street
Entity Address, City or Town	Pine Bluff
Entity Address, State or Province	AR
Entity Address, Postal Zip Code	71601
City Area Code	870
Local Phone Number	541-1000
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
Title of 12(b) Security	Common stock, par value $0.01 per share
Trading Symbol	SFNC
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		96,654,900
Entity Central Index Key	0000090498
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Sep. 30, 2019	Dec. 31, 2018
ASSETS
Cash and non-interest bearing balances due from banks	$ 161,440,000	$ 171,792,000
Interest bearing balances due from banks and federal funds sold	368,530,000	661,666,000
Cash and cash equivalents	529,970,000	833,458,000
Interest bearing balances due from banks - time	5,041,000	4,934,000
Investment securities:
Held-to-maturity	42,237,000	289,194,000
Available-for-sale securities	2,356,134,000	2,151,752,000
Total investments	2,398,371,000	2,440,946,000
Mortgage loans held for sale	50,099,000	26,799,000
Loans:
Legacy loans	9,643,365,000	8,430,388,000
Allowance for loan losses	(65,993,000)	(56,599,000)
Loans acquired, net of discount and allowance	3,359,587,000	3,292,783,000
Net loans	12,936,959,000	11,666,572,000
Premises and equipment	378,678,000	295,060,000
Foreclosed assets and other real estate owned	19,576,000	25,565,000
Interest receivable	53,966,000	49,938,000
Bank owned life insurance	234,655,000	193,170,000
Goodwill	926,648,000	845,687,000
Other intangible assets	101,149,000	91,334,000
Other assets	123,399,000	69,874,000
Total assets	17,758,511,000	16,543,337,000
Deposits:
Non-interest bearing transaction accounts	3,044,330,000	2,672,405,000
Interest bearing transaction accounts and savings deposits	7,337,571,000	6,830,191,000
Time deposits	3,086,108,000	2,896,156,000
Total deposits	13,468,009,000	12,398,752,000
Federal funds purchased and securities sold under agreements to repurchase	116,536,000	95,792,000
Other borrowings	1,098,395,000	1,345,450,000
Subordinated debentures	354,223,000	353,950,000
Accrued interest and other liabilities	174,277,000	102,959,000
Total liabilities	15,211,440,000	14,296,903,000
Stockholders’ equity:
Common stock, Class A, $0.01 par value; 175,000,000 shares authorized at September 30, 2019 and December 31, 2018; 96,613,855 and 92,347,643 shares issued and outstanding at September 30, 2019 and December 31, 2018, respectively	966,000	923,000
Surplus	1,708,058,000	1,597,944,000
Undivided profits	814,338,000	674,941,000
Accumulated other comprehensive income (loss)	23,709,000	(27,374,000)
Total stockholders’ equity	2,547,071,000	2,246,434,000
Total liabilities and stockholders’ equity	$ 17,758,511,000	$ 16,543,337,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Common stock, Class A, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, Class A, shares authorized (in shares)	175,000,000	175,000,000
Common stock, Class A, shares issued (in shares)	96,613,855	92,347,643
Common stock, Class A, shares outstanding (in shares)	96,613,855	92,347,643

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
INTEREST INCOME
Loans	$ 179,971	$ 162,438	$ 517,533	$ 456,041
Interest bearing balances due from banks and federal funds sold	1,586	1,405	4,861	3,828
Investment securities	15,367	14,640	49,273	41,558
Mortgage loans held for sale	382	501	924	964
TOTAL INTEREST INCOME	197,306	178,984	572,591	502,391
INTEREST EXPENSE
Deposits	36,936	24,390	102,482	58,448
Federal funds purchased and securities sold under agreements to repurchase	249	104	642	302
Other borrowings	5,381	6,240	18,393	16,520
Subordinated notes and debentures	4,576	5,282	13,528	12,350
TOTAL INTEREST EXPENSE	47,142	36,016	135,045	87,620
NET INTEREST INCOME	150,164	142,968	437,546	414,771
Provision for loan losses	21,973	10,345	38,337	28,528
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	128,191	132,623	399,209	386,243
NON-INTEREST INCOME
Investment banking income	513	664	1,491	2,312
Bank owned life insurance income	1,302	1,105	3,357	3,310
Gain on sale of securities, net	7,374	54	12,937	53
Other income	43,821	4,942	52,083	14,151
TOTAL NON-INTEREST INCOME	83,775	33,725	156,542	109,308
NON-INTEREST EXPENSE
Salaries and employee benefits	52,065	55,515	164,560	167,550
Occupancy expense, net	8,342	7,713	22,736	22,594
Furniture and equipment expense	4,898	3,761	12,462	12,184
Other real estate and foreclosure expense	1,125	538	2,353	2,940
Deposit insurance	0	2,248	4,550	6,232
Merger related costs	2,556	804	11,548	3,980
Other operating expenses	37,879	29,674	100,808	81,353
TOTAL NON-INTEREST EXPENSE	106,865	100,253	319,017	296,833
INCOME BEFORE INCOME TAXES	105,101	66,095	236,734	198,718
Provision for income taxes	23,275	10,902	51,289	38,651
NET INCOME	81,826	55,193	185,445	160,067
Preferred stock dividends	0	0	326	0
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	$ 81,826	$ 55,193	$ 185,119	$ 160,067
BASIC EARNINGS PER SHARE (in dollars per share)	$ 0.85	$ 0.60	$ 1.95	$ 1.74
DILUTED EARNINGS PER SHARE (in dollars per share)	$ 0.84	$ 0.59	$ 1.94	$ 1.72
Trust income
NON-INTEREST INCOME
Non-interest income	$ 6,108	$ 6,277	$ 17,610	$ 17,148
Service charges on deposit accounts
NON-INTEREST INCOME
Non-interest income	10,825	10,837	31,450	31,245
Other service charges and fees
NON-INTEREST INCOME
Non-interest income	1,308	1,201	3,909	5,968
Mortgage lending income
NON-INTEREST INCOME
Non-interest income	4,509	1,521	10,988	7,773
SBA lending income
NON-INTEREST INCOME
Non-interest income	956	304	2,348	1,627
Debit and credit card fees
NON-INTEREST INCOME
Non-interest income	$ 7,059	$ 6,820	$ 20,369	$ 25,721

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 81,826	$ 55,193	$ 185,445	$ 160,067
OTHER COMPREHENSIVE INCOME (LOSS)
Unrealized holding gains (losses) arising during the period on available-for-sale securities	18,736	(10,583)	79,547	(41,612)
Unrealized holding gain on the transfer of held-to-maturity securities to available-for-sale per ASU 2017-12	0	0	2,547	0
Less: Reclassification adjustment for realized gains (losses) included in net income	7,374	54	12,937	53
Other comprehensive gain (loss), before tax effect	11,362	(10,637)	69,157	(41,665)
Less: Tax effect of other comprehensive income (loss)	2,969	(2,780)	18,074	(10,889)
TOTAL OTHER COMPREHENSIVE INCOME (LOSS)	8,393	(7,857)	51,083	(30,776)
COMPREHENSIVE INCOME	$ 90,219	$ 47,336	$ 236,528	$ 129,291

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
OPERATING ACTIVITIES
Net income	$ 185,445	$ 160,067
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	25,462	20,810
Provision for loan losses	38,337	28,528
Gain on sale of investments	(12,937)	(53)
Net accretion of investment securities and assets	(35,272)	(41,423)
Net amortization (accretion) on borrowings	273	(471)
Stock-based compensation expense	9,316	8,448
(Gain) loss on sale of foreclosed assets held for sale	(16)	150
Gain on sale of mortgage loans held for sale	(14,196)	(9,675)
Loss (gain) on sale of loans	4,451	(10)
Gain on sale of Visa, Inc. class B common stock	(42,860)
Fair value write-down of closed branches	0	954
Deferred income taxes	10,933	7,316
Income from bank owned life insurance	(3,438)	(3,310)
Originations of mortgage loans held for sale	(499,178)	(424,751)
Proceeds from sale of mortgage loans held for sale	490,674	410,269
Changes in assets and liabilities:
Interest receivable	(679)	(7,798)
Lease right-of-use assets	(1,370)
Other assets	3,802	(24,695)
Accrued interest and other liabilities	10,881	23,821
Income taxes payable	18,722	3,956
Net cash provided by operating activities	188,350	152,133
INVESTING ACTIVITIES
Net originations of loans	(299,013)	(1,034,175)
Proceeds from sale of loans	104,587	24,977
Decrease (increase) in due from banks - time	395	(640)
Purchases of premises and equipment, net	(37,523)	(17,084)
Proceeds from sale of foreclosed assets held for sale	16,139	20,739
Proceeds from sale of available-for-sale securities	561,374	7,726
Proceeds from maturities of available-for-sale securities	405,090	197,464
Purchases of available-for-sale securities	(593,700)	(634,791)
Proceeds from maturities of held-to-maturity securities	29,179	46,515
Purchases of held-to-maturity securities	0	(1,172)
Purchases of bank owned life insurance	0	(4,000)
Proceeds from bank owned life insurance death benefits	1,310	616
Disposition of assets and liabilities held for sale	1,245	(58,295)
Purchase of Reliance Bancshares, Inc.	(37,017)	0
Net cash provided by (used in) investing activities	152,066	(1,452,120)
FINANCING ACTIVITIES
Net change in deposits	(156,010)	995,631
Proceeds from issuance of subordinated notes	0	326,355
Repayments of subordinated debentures	0	(94,915)
Dividends paid on preferred stock	(326)	0
Dividends paid on common stock	(45,722)	(41,766)
Net change in other borrowed funds	(404,455)	40,893
Net change in federal funds purchased and securities sold under agreements to repurchase	6,598	(13,231)
Net shares issued under stock compensation plans	(3,301)	1,756
Shares issued under employee stock purchase plan	1,312	1,026
Retirement of preferred stock	(42,000)	0
Net cash (used in) provided by financing activities	(643,904)	1,215,749
DECREASE IN CASH AND CASH EQUIVALENTS	(303,488)	(84,238)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	833,458	598,042
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 529,970	$ 513,804

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Surplus	Accumulated Other Comprehensive Income (Loss)	Undivided Profits
Balance at Dec. 31, 2017	$ 2,084,564		$ 920	$ 1,586,034	$ (17,264)	$ 514,874
Comprehensive income	129,291				(30,776)	160,067
Stock issued for employee stock purchase plan	1,026			1,026
Stock-based compensation plans, net	10,204		3	10,201
Dividends on common stock	(41,766)					(41,766)
Balance at Sep. 30, 2018	2,183,319		923	1,597,261	(48,040)	633,175
Balance at Jun. 30, 2018	2,146,908		923	1,594,342	(40,183)	591,826
Comprehensive income	47,336				(7,857)	55,193
Stock-based compensation plans, net	2,919		0	2,919
Dividends on common stock	(13,844)					(13,844)
Balance at Sep. 30, 2018	2,183,319		923	1,597,261	(48,040)	633,175
Balance at Dec. 31, 2018	2,246,434		923	1,597,944	(27,374)	674,941
Comprehensive income	236,528				51,083	185,445
Stock issued for employee stock purchase plan	1,312		1	1,311
Stock-based compensation plans, net	6,015		2	6,013
Stock issued for Reliance acquisition	144,830	$ 42,000	40	102,790
Preferred stock retirement	(42,000)	$ (42,000)
Dividends on preferred stock	(326)					(326)
Dividends on common stock	(45,722)					(45,722)
Balance at Sep. 30, 2019	2,547,071		966	1,708,058	23,709	814,338
Balance at Jun. 30, 2019	2,469,513		966	1,705,262	15,316	747,969
Comprehensive income	90,219				8,393	81,826
Stock-based compensation plans, net	2,796			2,796
Dividends on common stock	(15,457)					(15,457)
Balance at Sep. 30, 2019	$ 2,547,071		$ 966	$ 1,708,058	$ 23,709	$ 814,338

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Stockholders' Equity [Abstract]
Stock issued for employee stock purchase plan, shares (in shares)			60,413	39,782
Stock issued for compensation plans, shares (in shares)	23,199	14,245	206,176	226,715
Stock issued for acquisition (in shares)			3,999,623
Cash dividends per share (in dollars per share)	$ 0.16	$ 0.15	$ 0.48	$ 0.45

Preparation of Interim Financia

Preparation of Interim Financial Statements	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Preparation of Interim Financial Statements	PREPARATION OF INTERIM FINANCIAL STATEMENTS Description of Business and Organizational Structure Simmons First National Corporation (the “Company”) is a financial holding company headquartered in Pine Bluff, Arkansas, and the parent company of Simmons Bank, an Arkansas state-chartered bank that began as a community bank in 1903. Simmons Bank is the parent company of Simmons First Insurance Services, Inc. (an insurance agency) and Simmons First Insurance Services of TN, LLC (an insurance agency). The Company through its subsidiaries, conducts banking operations from 212 financial centers conveniently located in communities throughout Arkansas, Colorado, Illinois, Kansas, Missouri, Oklahoma, Tennessee and Texas. The Company, through its subsidiaries, offers consumer, real estate and commercial loans; checking, savings and time deposits; and specialized products and services (such as credit cards, trust and fiduciary services, investments, agricultural finance lending, equipment lending, insurance and small business administration (“SBA”) lending). Basis of Presentation The accompanying unaudited consolidated financial statements have been prepared based upon Securities and Exchange Commission (“SEC”) rules that permit reduced disclosures for interim periods. Certain information and footnote disclosures have been condensed or omitted in accordance with those rules and regulations. The accompanying consolidated balance sheet as of December 31, 2018 , was derived from audited financial statements. In the opinion of management, these financial statements reflect all adjustments that are necessary for a fair presentation of interim results of operations, including normal recurring accruals. Significant intercompany accounts and transactions have been eliminated in consolidation. The results for the interim periods are not necessarily indicative of results for the full year. For a more complete discussion of significant accounting policies and certain other information, this report should be read in conjunction with the consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 , which was filed with the SEC on February 27, 2019 . The preparation of financial statements, in accordance with accounting principles generally accepted in the United States (“US GAAP”), requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, income items and expenses and disclosure of contingent assets and liabilities. The estimates and assumptions used in the accompanying consolidated financial statements are based upon management’s evaluation of the relevant facts and circumstances as of the date of the consolidated financial statements and actual results may differ from these estimates. Such estimates include, but are not limited to, the Company’s allowance for loan losses. Certain prior year amounts have been reclassified to conform to the current year financial statement presentation. These changes and reclassifications did not impact previously reported net income or comprehensive income. Recently Adopted Accounting Standards Cloud Computing Arrangements – In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract (“ASU 2018-15”), that amends the definition of a hosting arrangement and requires a customer in a hosting arrangement that is a service contract to capitalize certain implementation costs as if the arrangement was an internal-use software project. The internal-use software guidance states that only qualifying costs incurred during the application development stage can be capitalized. The effective date is for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted. Entities have the option to apply the guidance prospectively to all implementation costs incurred after the date of adoption or retrospectively in accordance with the applicable guidance. At the time of adoption, entities will be required to disclose the nature of its hosting arrangements that are service contracts and provide disclosures as if the deferred implementation costs were a separate, major depreciable asset class. The Company early adopted ASU 2018-15 in the first quarter 2019 and elected to apply the guidance prospectively to all software implementation costs incurred after the date of adoption. As of September 30, 2019 , $1.1 million of applicable software implementation costs have been capitalized and have not had a material impact on our financial position or results of operations. Derivatives and Hedging: Targeted Improvements - In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities (“ASU 2017-12”), that changes both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results in order to better align a company’s risk management activities and financial reporting for hedging relationships. In summary, this amendment 1) expands the types of transactions eligible for hedge accounting; 2) eliminates the separate measurement and presentation of hedge ineffectiveness; 3) simplifies the requirements around the assessment of hedge effectiveness; 4) provides companies more time to finalize hedge documentation; and 5) enhances presentation and disclosure requirements. The effective date was for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. All transition requirements and elections should be applied to existing hedging relationships on the date of adoption and the effects should be reflected as of the beginning of the fiscal year of adoption. As part of this new guidance, entities are allowed to designate as the hedged item, an amount that is not expected to be affected by prepayments, defaults or other events affecting the timing and amount of cash flows in a closed portfolio of prepayable financial instruments (this is referred to as the “last-of-layer” method). Under the last-of-layer method, entities are able to reclassify, only at the time of adoption, eligible callable debt securities from held-to-maturity to available-for-sale without tainting its intentions to hold future debt securities to maturity. The available-for-sale security must be reported at fair value and any unrealized gain or loss must be recorded as an adjustment to other comprehensive income upon adoption. The Company evaluated its held-to-maturity portfolio during the first quarter 2019 and identified certain municipal bonds with a fair value of $216.4 million that met the last-of-layer criteria under ASU 2017-12 and as a result, reclassified those to available-for-sale and recorded an unrealized gain of $2.5 million during the first quarter 2019. Goodwill Impairment – In January 2017, the FASB issued ASU No. 2017-04, Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment (“ASU 2017-04”), that eliminates Step 2 from the goodwill impairment test which required entities to compare the implied fair value of goodwill to its carrying amount. Under the amendments, the goodwill impairment will be measured as the excess of the reporting unit’s carrying amount over its fair value. An impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The effective date is for fiscal years beginning after December 15, 2019, with early adoption permitted for interim or annual impairment tests beginning in 2017. The Company early adopted ASU 2017-04 during the second quarter 2019 to coincide with the Company’s formal impairment analysis. See Note 7, Goodwill and Other Intangible Assets, for additional information. Leases - In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02”), that establishes the principles to report transparent and economically neutral information about the assets and liabilities that arise from leases. The new guidance results in a more consistent representation of the rights and obligations arising from leases by requiring lessees to recognize the lease asset and lease liabilities that arise from leases in the consolidated balance sheet and to disclose qualitative and quantitative information about lease transactions, such as information about variable lease payments and options to renew and terminate leases. The effective date was for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. ASU 2016-02 requires entities to adopt the new lease standard using a modified retrospective transition method, meaning an entity initially applies the new lease standard at the beginning of the earliest period presented in the financial statements. Due to complexities associated with using this method, in July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements , to relieve entities of the requirement to present prior comparative years’ results when they adopt the new lease standard and giving entities the option to recognize the cumulative effect of applying the new standard as an adjustment to the opening balance of retained earnings. Adoption of ASU 2016-02 resulted in the recognition of right-of-use assets of $32.8 million and right-of-use liabilities of $32.8 million on the consolidated balance sheet with no material impact to the results of operations. The Company has elected to adopt the guidance using the optional transition method, which allows for a modified retrospective method of adoption with a cumulative effect adjustment to retained earnings without restating comparable periods. The Company also elected the relief package of practical expedients for which there is no requirement to reassess existence of leases, their classification, and initial direct costs as well as an exemption for short-term leases with a term of less than one year, whereby the Company did not recognize a lease liability or right-of-use asset on the consolidated balance sheet but instead will recognize lease payments as an expense over the lease term as appropriate. See Note 6, Right-of-Use Lease Assets and Lease Liabilities, for additional information related to the Company’s right-of-use lease obligations. Recently Issued Accounting Standards Fair Value Measurement Disclosures – In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”), that eliminates, amends and adds disclosure requirements for fair value measurements. These amendments are part of FASB’s disclosure review project and they are expected to reduce costs for preparers while providing more decision-useful information for financial statement users. The eliminated disclosure requirements include the 1) the amount of, and reasons for, transfers between Level 1 and Level 2 of the fair value hierarchy; 2) the policy of timing of transfers between levels of the fair value hierarchy; and 3) the valuation processes for Level 3 fair value measurements. Among other modifications, the amended disclosure requirements remove the term “at a minimum” from the phrase “an entity shall disclose at a minimum” to promote the appropriate exercise of discretion by entities and clarifies that the measurement uncertainty disclosure is to communicate information about the uncertainty in measurement as of the reporting date. Under the new disclosure requirements, entities must disclose the changes in unrealized gains or losses included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period and the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. ASU 2018-13 is effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the impact this standard will have on its fair value disclosures. Credit Losses on Financial Instruments – In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which requires earlier measurement of credit losses, expands the range of information considered in determining expected credit losses and enhances disclosures. The main objective of ASU 2016-13 is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The amendments replace the incurred loss impairment methodology in current US GAAP with a methodology (the current expected credit losses, or “CECL”, methodology) that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The CECL methodology utilizes a lifetime “expected credit loss” measurement objective for the recognition of credit losses for loans, held-to-maturity debt securities and other receivables measured at amortized cost at the time the financial asset is originated or acquired. The allowance for credit losses is adjusted each period for changes in expected lifetime credit losses. This methodology replaces the multiple existing impairment methods in current guidance, which generally require that a loss be incurred before it is recognized. Within the life cycle of a loan or other financial asset, this new guidance will generally result in the earlier recognition of the provision for credit losses and the related allowance for credit losses than current practice. For available-for-sale debt securities that the Company intends to hold and where fair value is less than cost, credit-related impairment, if any, will be recognized through an allowance for credit losses and adjusted each period for changes in credit risk. The effective date for these amendments is for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company has formed a cross functional team that continues to assess its data and system needs and evaluate the potential impact of adopting the new guidance. The Company anticipates a significant change in the processes and procedures to calculate the loan losses, including changes in assumptions and estimates to consider expected credit losses over the life of the loan versus the current accounting practice that utilizes the incurred loss model. In December 2018, the Federal Reserve, Office of the Comptroller of the Currency and Federal Deposit Insurance Corporation (“FDIC”) issued a final rule revising regulatory capital rules in anticipation of the adoption of ASU 2016-13 that provides an option to phase in over a three year period on a straight line basis the day-one impact on earnings and tier one capital. Due to this final rule from the regulatory agencies, the Company is continuing to research and study options for recording a one-time adjustment or structuring any capital impact over an allowable period of time. The impact will be reflected as an adjustment to beginning retained earnings, net of income taxes, at adoption. Based on a preliminary analysis performed, the Company previously disclosed that the allowance for credit losses was estimated to increase by approximately 130% to 170% over the allowance based on June 30, 2019 loan balances. When purchase discounts are considered, the increase is expected to be 10% to 30% over the June 30, 2019 total credit coverage ratio. These estimates were based upon the Company’s analysis of current macroeconomic conditions, assumptions and forecasts at the point in time at which the initial guidance was given and did not include the impact of the Company’s acquisition of The Landrum Company. When factoring in the Company’s recent acquisition of The Landrum Company (see Note 2, Acquisitions, for additional information regarding the acquisition), the allowance for credit losses is estimated to increase by approximately 165% to 215% over the allowance and when purchase discounts are considered, the increase is expected to be 5% to 25% over the total credit coverage ratio. These estimates are subject to change based on continuing review and challenge of the models, methodologies and judgments. The impact at adoption will also be influenced by the loan portfolio composition and quality at the adoption date, as well as, macroeconomic conditions and forecast at that time. The adoption of ASU 2016-13 in 2020 could also impact the Company’s ongoing earnings, perhaps materially. Implementation efforts for the adoption of CECL have been underway, including model development and validation, fulfillment of additional data needs for new disclosures and reporting requirements, and drafting of accounting policies. Model validations and user acceptance testing commenced in the first quarter of 2019, with loss forecast modeling taking place in the third quarter of 2019. The Company intends to utilize a single macroeconomic scenario in estimating expected credit losses. Reasonable and supportable forecast periods and methods to revert to historical averages to arrive at lifetime expected credit losses vary by product. The Company has completed decisions around model methodologies, and relevant elections are being finalized. There have been no other significant changes to the Company’s accounting policies from the 2018

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Acquisitions	ACQUISITIONS Reliance Bancshares, Inc. On April 12, 2019, the Company completed its merger with Reliance Bancshares, Inc. (“Reliance”), headquartered in the St. Louis, Missouri, metropolitan area, pursuant to the terms of the Agreement and Plan of Merger (“Reliance Agreement”), dated November 13, 2018, as amended February 11, 2019. In the merger, each outstanding share of Reliance common stock, as well as each Reliance common stock equivalent was canceled and converted into the right to receive shares of the Company’s common stock and/or cash in accordance with the terms of the Reliance Agreement. In addition, each share of Reliance’s Series A Preferred Stock and Series B Preferred Stock was converted into the right to receive one share of Simmons’ comparable Series A Preferred Stock or Series B Preferred Stock, respectively, and each share of Reliance’s Series C Preferred Stock was converted into the right to receive one share of Simmons’ comparable Series C Preferred Stock (unless the holder of such Series C Preferred Stock elected to receive alternate consideration in accordance with the Reliance Agreement). The Company issued 3,999,623 shares of its common stock and paid $62.7 million in cash to effect the merger. The Company also issued $42.0 million of preferred stock in exchange for all outstanding shares of Reliance preferred stock. On May 13, 2019, the Company redeemed all of the preferred stock issued in connection with the merger, and paid all accrued and unpaid dividends up to the date of redemption. On October 29, 2019, the Company amended its Amended and Restated Articles of Incorporation to cancel the Series C Preferred Stock, having 140 authorized shares, of which no shares have ever been issued or outstanding. Prior to the merger, Reliance conducted banking business from 22 branches located in Missouri and Illinois. Including the effects of the acquisition method accounting adjustments, the Company acquired approximately $1.5 billion in assets, including approximately $1.1 billion in loans (inclusive of loan discounts), and approximately $1.2 billion in deposits. Contemporaneously with the completion of the Reliance merger, Reliance Bank was merged into Simmons Bank, with Simmons Bank as the surviving institution. Goodwill of $81.0 million was recorded as a result of the transaction. The merger strengthened the Company’s market share and brought forth additional opportunities in the Company’s St. Louis metropolitan area footprint, which gave rise to the goodwill recorded. The goodwill will not be deductible for tax purposes. A summary, at fair value, of the assets acquired and liabilities assumed in the Reliance transaction, as of the acquisition date, is as follows: (In thousands) Acquired from Reliance Fair Value Adjustments Fair Value Assets Acquired Cash and due from banks $ 25,693 $ — $ 25,693 Due from banks - time 502 — 502 Investment securities 287,983 (1,763 ) 286,220 Loans acquired 1,138,527 (41,657 ) 1,096,870 Allowance for loan losses (10,808 ) 10,808 — Foreclosed assets 11,092 (5,180 ) 5,912 Premises and equipment 32,452 (3,001 ) 29,451 Bank owned life insurance 39,348 — 39,348 Core deposit intangible — 18,350 18,350 Other assets 25,165 5,001 30,166 Total assets acquired $ 1,549,954 $ (17,442 ) $ 1,532,512 Liabilities Assumed Deposits: Non-interest bearing transaction accounts $ 108,845 $ (33 ) $ 108,812 Interest bearing transaction accounts and savings deposits 639,798 — 639,798 Time deposits 478,415 (1,758 ) 476,657 Total deposits 1,227,058 (1,791 ) 1,225,267 Securities sold under agreement to repurchase 14,146 — 14,146 Other borrowings 162,900 (5,500 ) 157,400 Accrued interest and other liabilities 8,185 936 9,121 Total liabilities assumed 1,412,289 (6,355 ) 1,405,934 Equity 137,665 (95,665 ) 42,000 Total equity assumed 137,665 (95,665 ) 42,000 Total liabilities and equity assumed $ 1,549,954 $ (102,020 ) $ 1,447,934 Net assets acquired 84,578 Purchase price 165,539 Goodwill $ 80,961 The purchase price allocation and certain fair value measurements remain preliminary due to the timing of the merger. Management will continue to review the estimated fair values and evaluate the assumed tax positions. The Company expects to finalize its analysis of the acquired assets and assumed liabilities in this transaction over the next few months, within one year of the merger. Therefore, adjustments to the estimated amounts and carrying values may occur. The following is a description of the methods used to determine the fair values of significant assets and liabilities presented in the acquisitions above. Cash and due from banks and time deposits due from banks – The carrying amount of these assets is a reasonable estimate of fair value based on the short-term nature of these assets. Investment securities – Investment securities were acquired with an adjustment to fair value based upon quoted market prices if material. Otherwise, the carrying amount of these assets was deemed to be a reasonable estimate of fair value. Loans acquired – Fair values for loans were based on a discounted cash flow methodology that considered factors including the type of loan and related collateral, classification status, fixed or variable interest rate, term of loan and whether or not the loan was amortizing, and current discount rates. The discount rates used for loans are based on current market rates for new originations of comparable loans and include adjustments for liquidity concerns. The discount rate does not include a factor for credit losses as that has been included in the estimated cash flows. Loans were grouped together according to similar characteristics and were treated in the aggregate when applying various valuation techniques. Foreclosed assets – These assets are presented at the estimated present values that management expects to receive when the properties are sold, net of related costs of disposal. Premises and equipment – Bank premises and equipment were acquired with an adjustment to fair value, which represents the difference between the Company’s current analysis of property and equipment values completed in connection with the acquisition and book value acquired. Bank owned life insurance – Bank owned life insurance is carried at its current cash surrender value, which is the most reasonable estimate of fair value. Goodwill – The consideration paid as a result of the acquisition exceeded the fair value of the assets acquired, resulting in an intangible asset, goodwill. Goodwill established prior to the acquisitions, if applicable, was written off. Core deposit intangible – This intangible asset represents the value of the relationships that the acquired banks had with their deposit customers. The fair value of this intangible asset was estimated based on a discounted cash flow methodology that gave appropriate consideration to expected customer attrition rates, cost of the deposit base and the net maintenance cost attributable to customer deposits. Other assets – The fair value adjustment results from certain assets whose value was estimated to be less than book value, such as certain prepaid assets, receivables and other miscellaneous assets. Otherwise, the carrying amount of these assets was deemed to be a reasonable estimate of fair value. Deposits – The fair values used for the demand and savings deposits that comprise the transaction accounts acquired, by definition equal the amount payable on demand at the acquisition date. The Company performed a fair value analysis of the estimated weighted average interest rate of the certificates of deposits compared to the current market rates and recorded a fair value adjustment for the difference. Securities sold under agreement to repurchase – The carrying amount of securities sold under agreement to repurchase is a reasonable estimate of fair value based on the short-term nature of these liabilities. FHLB and other borrowings – The fair value of Federal Home Loan Bank (“FHLB”) and other borrowings is estimated based on borrowing rates currently available to the Company for borrowings with similar terms and maturities. Accrued interest and other liabilities – The adjustment establishes a liability for unfunded commitments equal to the estimated fair value of that liability at the date of acquisition. The Landrum Company (Subsequent Event - Acquisition) On July 30, 2019, the Company entered into an Agreement and Plan of Merger (the “Agreement”) with The Landrum Company (“Landrum”), headquartered in Columbia, Missouri. The merger was completed on October 31, 2019, at which time The Landrum Company was merged with and into the Company, with the Company continuing as the surviving corporation. Pursuant to the terms of the Agreement, the shares of Landrum Class A Common Voting Stock, par value $0.01 per share, and Landrum Class B Common Nonvoting Stock, par value $0.01 per share, were converted into the right to receive, in the aggregate, approximately 17,350,000 shares of the Company’s common stock and each share of Landrum’s series E preferred stock was converted into the right to receive one share of the Company’s comparable series D preferred stock. Prior to the acquisition, Landrum conducted banking business from 39 branches located in Missouri, Oklahoma and Texas. As of September 30, 2019, Landrum had approximately $3.3 billion in assets, $2.0 billion in loans and $2.9 billion in deposits. The purchase price allocation and certain fair value measurements remain preliminary due to the timing of the merger. Due to the recent October 31, 2019 closing, management remains in the early stages of reviewing the estimated fair values and evaluating the assumed tax positions of this merger. The Company expects to finalize its analysis of the acquired assets and assumed liabilities in this transaction over the next few months, within one year of the merger.

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Investment Securities	INVESTMENT SECURITIES The amortized cost and fair value of investment securities that are classified as held-to-maturity (“HTM”) and available-for-sale (“AFS”) are as follows: September 30, 2019 December 31, 2018 (In thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Estimated Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Estimated Fair Value Held-to-Maturity U.S. Government agencies $ — $ — $ — $ — $ 16,990 $ — $ (49 ) $ 16,941 Mortgage-backed securities 11,549 93 (42 ) 11,600 13,346 5 (412 ) 12,939 State and political subdivisions 28,692 931 — 29,623 256,863 3,029 (954 ) 258,938 Other securities 1,996 83 — 2,079 1,995 17 — 2,012 Total HTM $ 42,237 $ 1,107 $ (42 ) $ 43,302 $ 289,194 $ 3,051 $ (1,415 ) $ 290,830 Available-for-Sale U.S. Government agencies $ 177,712 $ 1,629 $ (1,202 ) $ 178,139 $ 157,523 $ 518 $ (3,740 ) $ 154,301 Mortgage-backed securities 1,332,130 9,405 (3,741 ) 1,337,794 1,552,487 3,097 (32,684 ) 1,522,900 State and political subdivisions 658,984 22,290 (72 ) 681,202 320,142 171 (5,470 ) 314,843 Other securities 158,280 719 — 158,999 157,471 2,251 (14 ) 159,708 Total AFS $ 2,327,106 $ 34,043 $ (5,015 ) $ 2,356,134 $ 2,187,623 $ 6,037 $ (41,908 ) $ 2,151,752 Securities with limited marketability, such as stock in the Federal Reserve Bank and the FHLB, are carried at cost and are reported as other AFS securities in the table above. Certain investment securities are valued at less than their historical cost. Total fair value of these investments at September 30, 2019 and December 31, 2018 , was $710.6 million and $1.7 billion , which is approximately 29.6% and 70.3% , respectively, of the Company’s combined AFS and HTM investment portfolios. The following table shows the gross unrealized losses and fair value of the Company’s investments with unrealized losses, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at September 30, 2019 : Less Than 12 Months 12 Months or More Total (In thousands) Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Held-to-Maturity Mortgage-backed securities $ 3,408 $ (15 ) $ 2,575 $ (27 ) $ 5,983 $ (42 ) State and political subdivisions 635 — 15 — 650 — Total HTM $ 4,043 $ (15 ) $ 2,590 $ (27 ) $ 6,633 $ (42 ) Available-for-Sale U.S. Government agencies $ 16,662 $ (36 ) $ 90,974 $ (1,166 ) $ 107,636 $ (1,202 ) Mortgage-backed securities 133,538 (528 ) 435,207 (3,213 ) 568,745 (3,741 ) State and political subdivisions 24,278 (41 ) 3,297 (31 ) 27,575 (72 ) Total AFS $ 174,478 $ (605 ) $ 529,478 $ (4,410 ) $ 703,956 $ (5,015 ) The declines reflected in the preceding table primarily resulted from the rate for these investments yielding less than current market rates. Based on evaluation of available evidence, management believes the declines in fair value for these securities are temporary. Management does not have the intent to sell these securities, and management believes it is more likely than not the Company will not have to sell these securities before recovery of their amortized cost basis less any current period credit losses. Declines in the fair value of HTM and AFS securities below their cost that are deemed to be other than temporary are reflected in earnings as realized losses. In estimating other-than-temporary impairment losses, management considers, among other things, (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer, and (iii) the intent and ability of the Company to retain its investment in the issuer for a period of time sufficient to allow for any anticipated recovery in fair value. Management has the ability and intent to hold the securities classified as HTM until they mature, at which time the Company expects to receive full value for the securities. Furthermore, as of September 30, 2019 , management also had the ability and intent to hold the securities classified as AFS for a period of time sufficient for a recovery of cost. The unrealized losses are largely due to increases in market interest rates over the yields available at the time the underlying securities were purchased. The fair value is expected to recover as the bonds approach their maturity date or repricing date or if market yields for such investments decline. Management does not believe any of the securities are impaired due to reasons of credit quality. Accordingly, as of September 30, 2019 , management believes the impairments detailed in the table above are temporary. Should the impairment of any of these securities become other than temporary, the cost basis of the investment will be reduced and the resulting loss recognized in net income in the period the other-than-temporary impairment is identified. Income earned on securities for the three and nine months ended September 30, 2019 and 2018 , is as follows: Three Months Ended Nine Months Ended (In thousands) 2019 2018 2019 2018 Taxable: Held-to-maturity $ 248 $ 528 $ 975 $ 1,641 Available-for-sale 10,166 10,364 34,422 29,614 Non-taxable: Held-to-maturity 83 1,828 1,334 5,661 Available-for-sale 4,870 1,920 12,542 4,642 Total $ 15,367 $ 14,640 $ 49,273 $ 41,558 The amortized cost and estimated fair value by maturity of securities are shown in the following table. Securities are classified according to their contractual maturities without consideration of principal amortization, potential prepayments or call options. Accordingly, actual maturities may differ from contractual maturities. Held-to-Maturity Available-for-Sale (In thousands) Amortized Cost Fair Value Amortized Cost Fair Value One year or less $ 5,039 $ 5,057 $ 7,599 $ 7,605 After one through five years 17,346 17,703 70,442 70,750 After five through ten years 5,561 5,858 139,421 142,101 After ten years 2,742 3,084 632,504 652,404 Securities not due on a single maturity date 11,549 11,600 1,332,130 1,337,794 Other securities (no maturity) — — 145,010 145,480 Total $ 42,237 $ 43,302 $ 2,327,106 $ 2,356,134 The carrying value, which approximates the fair value, of securities pledged as collateral, to secure public deposits and for other purposes, amounted to $1.12 billion at September 30, 2019 and $1.02 billion at December 31, 2018 . There were approximately $7.6 million of gross realized gains and $3,000 of gross realized losses from the sale of securities during the three months ended September 30, 2019 , and approximately $12.9 million of gross realized gains and $3,000 of gross realized losses from the sale of securities during the nine months ended September 30, 2019 . During the third quarter 2019, the Company sold approximately $89 million of bonds as part of a plan to rebalance its investment portfolio resulting in a net gain on the sale of securities of $7.3 million . The gross realized gains recognized for the nine months ended September 30, 2019 is primarily due to the bond sale conducted during the third quarter 2019 as previously discussed and the adjustments made to the bond portfolio during the first quarter based upon projected cash flow changes. There were approximately $41,000 of gross realized gains and no gross realized losses from the sale of securities during the three months ended September 30, 2018 , and approximately $54,000 of gross realized gains and $1,000 of gross realized losses from the sale of securities during the nine months ended September 30, 2018 . The state and political subdivision debt obligations are predominately non-rated bonds representing small issuances, primarily in Arkansas, Missouri, Oklahoma, Tennessee and Texas issues, which are evaluated on an ongoing basis.

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2019
Receivables [Abstract]
Loans and Allowance for Loan Losses	LOANS AND ALLOWANCE FOR LOAN LOSSES At September 30, 2019 , the Company’s loan portfolio was $13.00 billion , compared to $11.72 billion at December 31, 2018 . The various categories of loans are summarized as follows: (In thousands) September 30, 2019 December 31, 2018 Consumer: Credit cards $ 195,083 $ 204,173 Other consumer 208,643 201,297 Total consumer 403,726 405,470 Real Estate: Construction 1,712,858 1,300,723 Single family residential 1,448,455 1,440,443 Other commercial 3,630,708 3,225,287 Total real estate 6,792,021 5,966,453 Commercial: Commercial 1,894,819 1,774,909 Agricultural 213,753 164,514 Total commercial 2,108,572 1,939,423 Other 339,046 119,042 Loans 9,643,365 8,430,388 Loans acquired, net of discount and allowance (1) 3,359,587 3,292,783 Total loans $ 13,002,952 $ 11,723,171 _____________________________ (1) See Note 5, Loans Acquired, for segregation of loans acquired by loan class. Loan Origination/Risk Management – The Company seeks to manage its credit risk by diversifying its loan portfolio, determining that borrowers have adequate sources of cash flow for loan repayment without liquidation of collateral; obtaining and monitoring collateral; providing an adequate allowance for loans losses by regularly reviewing loans through the internal loan review process. The loan portfolio is diversified by borrower, purpose and industry. The Company seeks to use diversification within the loan portfolio to reduce its credit risk, thereby minimizing the adverse impact on the portfolio if weaknesses develop in either the economy or a particular segment of borrowers. Collateral requirements are based on credit assessments of borrowers and may be used to recover the debt in case of default. Furthermore, a factor that influenced the Company’s judgment regarding the allowance for loan losses consists of a nine-year historical loss average segregated by each primary loan sector. On an annual basis, historical loss rates are calculated for each sector. Consumer – The consumer loan portfolio consists of credit card loans and other consumer loans. Credit card loans are diversified by geographic region to reduce credit risk and minimize any adverse impact on the portfolio. Although they are regularly reviewed to facilitate the identification and monitoring of creditworthiness, credit card loans are unsecured loans, making them more susceptible to be impacted by economic downturns resulting in increasing unemployment. Other consumer loans include direct and indirect installment loans and overdrafts. Loans in this portfolio segment are sensitive to unemployment and other key consumer economic measures. Real estate – The real estate loan portfolio consists of construction loans, single family residential loans and commercial loans. Construction and development loans (“C&D”) and commercial real estate loans (“CRE”) can be particularly sensitive to valuation of real estate. Commercial real estate cycles are inevitable. The long planning and production process for new properties and rapid shifts in business conditions and employment create an inherent tension between supply and demand for commercial properties. While general economic trends often move individual markets in the same direction over time, the timing and magnitude of changes are determined by other forces unique to each market. CRE cycles tend to be local in nature and longer than other credit cycles. Factors influencing the CRE market are traditionally different from those affecting residential real estate markets; thereby making predictions for one market based on the other difficult. Additionally, submarkets within commercial real estate – such as office, industrial, apartment, retail and hotel – also experience different cycles, providing an opportunity to lower the overall risk through diversification across types of CRE loans. Management realizes that local demand and supply conditions will also mean that different geographic areas will experience cycles of different amplitude and length. The Company monitors these loans closely. Commercial – The commercial loan portfolio includes commercial and agricultural loans, representing loans to commercial customers and farmers for use in normal business or farming operations to finance working capital needs, equipment purchases or other expansion projects. Collection risk in this portfolio is driven by the creditworthiness of the underlying borrowers, particularly cash flow from customers’ business or farming operations. The Company continues its efforts to keep loan terms short, reducing the negative impact of upward movement in interest rates. Term loans are generally set up with one or three year balloons, and the Company has instituted a pricing mechanism for commercial loans. It is standard practice to require personal guaranties on commercial loans for closely-held or limited liability entities. Nonaccrual and Past Due Loans – Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. Loans are placed on nonaccrual status when, in management’s opinion, the borrower may be unable to meet payment obligations as they become due, as well as when required by regulatory provisions. Loans may be placed on nonaccrual status regardless of whether or not such loans are considered past due. When interest accrual is discontinued, all unpaid accrued interest is reversed. Interest income is subsequently recognized only to the extent cash payments are received in excess of principal due. Loans are returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured. Nonaccrual loans, excluding loans acquired, segregated by class of loans, are as follows: (In thousands) September 30, 2019 December 31, 2018 Consumer: Credit cards $ 521 $ 296 Other consumer 1,634 2,159 Total consumer 2,155 2,455 Real estate: Construction 1,805 1,269 Single family residential 16,191 11,939 Other commercial 16,985 7,205 Total real estate 34,981 20,413 Commercial: Commercial 35,018 10,049 Agricultural 567 1,284 Total commercial 35,585 11,333 Total $ 72,721 $ 34,201 An age analysis of past due loans, excluding loans acquired, segregated by class of loans, is as follows: (In thousands) Gross 30-89 Days Past Due 90 Days or More Past Due Total Past Due Current Total Loans 90 Days Past Due & Accruing September 30, 2019 Consumer: Credit cards $ 958 $ 650 $ 1,608 $ 193,475 $ 195,083 $ 130 Other consumer 3,383 694 4,077 204,566 208,643 14 Total consumer 4,341 1,344 5,685 398,041 403,726 144 Real estate: Construction 3,690 613 4,303 1,708,555 1,712,858 — Single family residential 10,022 6,395 16,417 1,432,038 1,448,455 — Other commercial 8,009 3,385 11,394 3,619,314 3,630,708 — Total real estate 21,721 10,393 32,114 6,759,907 6,792,021 — Commercial: Commercial 4,999 10,990 15,989 1,878,830 1,894,819 11 Agricultural 285 349 634 213,119 213,753 — Total commercial 5,284 11,339 16,623 2,091,949 2,108,572 11 Other — — — 339,046 339,046 — Total $ 31,346 $ 23,076 $ 54,422 $ 9,588,943 $ 9,643,365 $ 155 December 31, 2018 Consumer: Credit cards $ 1,033 $ 506 $ 1,539 $ 202,634 $ 204,173 $ 209 Other consumer 4,264 896 5,160 196,137 201,297 4 Total consumer 5,297 1,402 6,699 398,771 405,470 213 Real estate: Construction 533 308 841 1,299,882 1,300,723 — Single family residential 7,769 4,127 11,896 1,428,547 1,440,443 — Other commercial 3,379 2,773 6,152 3,219,135 3,225,287 — Total real estate 11,681 7,208 18,889 5,947,564 5,966,453 — Commercial: Commercial 4,472 5,105 9,577 1,765,332 1,774,909 11 Agricultural 467 1,055 1,522 162,992 164,514 — Total commercial 4,939 6,160 11,099 1,928,324 1,939,423 11 Other — — — 119,042 119,042 — Total $ 21,917 $ 14,770 $ 36,687 $ 8,393,701 $ 8,430,388 $ 224 Impaired Loans – A loan is considered impaired when it is probable that the Company will not receive all amounts due according to the contractual terms of the loans, including scheduled principal and interest payments. This includes loans that are delinquent 90 days or more, nonaccrual loans and certain other loans identified by management. Certain other loans identified by management consist of performing loans with specific allocations of the allowance for loan losses. Impaired loans are carried at the present value of estimated future cash flows using the loan’s existing rate, or the fair value of the collateral if the loan is collateral dependent. Impairment is evaluated in total for smaller-balance loans of a similar nature and on an individual loan basis for other loans. Impaired loans, or portions thereof, are charged-off when deemed uncollectible. Impaired loans, net of government guarantees and excluding loans acquired, segregated by class of loans, are as follows: (In thousands) Unpaid Contractual Principal Balance Recorded Investment With No Allowance Recorded Investment With Allowance Total Recorded Investment Related Allowance Average Investment in Impaired Loans Interest Income Recognized Average Investment in Impaired Loans Interest Income Recognized September 30, 2019 Three Months Ended Nine Months Ended Consumer: Credit cards $ 521 $ 521 $ — $ 521 $ — $ 423 $ 40 $ 370 $ 110 Other consumer 1,783 1,634 — 1,634 — 1,603 9 1,730 33 Total consumer 2,304 2,155 — 2,155 — 2,026 49 2,100 143 Real estate: Construction 1,898 1,708 97 1,805 — 1,972 10 1,946 38 Single family residential 17,526 13,985 2,206 16,191 31 15,920 85 14,812 287 Other commercial 15,642 4,200 11,007 15,207 628 11,739 77 10,365 201 Total real estate 35,066 19,893 13,310 33,203 659 29,631 172 27,123 526 Commercial: Commercial 50,712 10,153 23,930 34,083 4,620 32,020 176 26,379 511 Agricultural 583 450 116 566 — 873 3 1,010 20 Total commercial 51,295 10,603 24,046 34,649 4,620 32,893 179 27,389 531 Total $ 88,665 $ 32,651 $ 37,356 $ 70,007 $ 5,279 $ 64,550 $ 400 $ 56,612 $ 1,200 December 31, 2018 Three Months Ended Nine Months Ended Consumer: Credit cards $ 296 $ 296 $ — $ 296 $ — $ 283 $ 35 $ 259 $ 60 Other consumer 2,311 2,159 — 2,159 — 3,561 28 4,109 96 Total consumer 2,607 2,455 — 2,455 — 3,844 63 4,368 156 Real estate: Construction 1,344 784 485 1,269 211 1,411 11 1,747 41 Single family residential 12,906 11,468 616 12,084 36 13,577 98 13,550 315 Other commercial 8,434 5,442 5,458 10,900 — 12,282 108 14,284 332 Total real estate 22,684 17,694 6,559 24,253 247 27,270 217 29,581 688 Commercial: Commercial 10,361 7,254 4,628 11,882 437 11,840 108 9,533 222 Agricultural 2,419 1,180 — 1,180 — 1,355 12 1,470 34 Total commercial 12,780 8,434 4,628 13,062 437 13,195 120 11,003 256 Total $ 38,071 $ 28,583 $ 11,187 $ 39,770 $ 684 $ 44,309 $ 400 $ 44,952 $ 1,100 At September 30, 2019 and December 31, 2018 , impaired loans, net of government guarantees and excluding loans acquired, totaled $70.0 million and $39.8 million , respectively. Allocations of the allowance for loan losses relative to impaired loans were $5.3 million and $684,000 at September 30, 2019 and December 31, 2018 , respectively. Approximately $400,000 and $1,200,000 of interest income was recognized on average impaired loans of $64.6 million and $56.6 million for the three and nine months ended September 30, 2019 . Interest income recognized on impaired loans on a cash basis during the three and nine months ended September 30, 2019 and 2018 was not material. Included in certain impaired loan categories are troubled debt restructurings (“TDRs”). When the Company restructures a loan to a borrower that is experiencing financial difficulty and grants a concession that it would not otherwise consider, a “troubled debt restructuring” results and the Company classifies the loan as a TDR. The Company grants various types of concessions, primarily interest rate reduction and/or payment modifications or extensions, with an occasional forgiveness of principal. Under ASC Topic 310-10-35 – Subsequent Measurement , a TDR is considered to be impaired, and an impairment analysis must be performed. The Company assesses the exposure for each modification, either by collateral discounting or by calculation of the present value of future cash flows, and determines if a specific allocation to the allowance for loan losses is needed. Once an obligation has been restructured because of such credit problems, it continues to be considered a TDR until paid in full; or, if an obligation yields a market interest rate and no longer has any concession regarding payment amount or amortization, then it is not considered a TDR at the beginning of the calendar year after the year in which the improvement takes place. The Company returns TDRs to accrual status only if (1) all contractual amounts due can reasonably be expected to be repaid within a prudent period, and (2) repayment has been in accordance with the contract for a sustained period, typically at least six months. The following table presents a summary of TDRs, excluding loans acquired, segregated by class of loans. Accruing TDR Loans Nonaccrual TDR Loans Total TDR Loans (Dollars in thousands) Number Balance Number Balance Number Balance September 30, 2019 Real estate: Construction — $ — 1 $ 97 1 $ 97 Single-family residential 6 549 10 627 16 1,176 Other commercial 2 3,166 2 950 4 4,116 Total real estate 8 3,715 13 1,674 21 5,389 Commercial: Commercial 4 2,804 3 84 7 2,888 Total commercial 4 2,804 3 84 7 2,888 Total 12 $ 6,519 16 $ 1,758 28 $ 8,277 December 31, 2018 Real estate: Construction — $ — 3 $ 485 3 $ 485 Single-family residential 6 230 10 616 16 846 Other commercial 2 3,306 2 1,027 4 4,333 Total real estate 8 3,536 15 2,128 23 5,664 Commercial: Commercial 4 2,833 6 718 10 3,551 Total commercial 4 2,833 6 718 10 3,551 Total 12 $ 6,369 21 $ 2,846 33 $ 9,215 The following table presents loans that were restructured as TDRs during the three and nine months ended September 30, 2019 and 2018 , excluding loans acquired, segregated by class of loans. Modification Type (Dollars in thousands) Number of Loans Balance Prior to TDR Balance at September 30, Change in Maturity Date Change in Rate Financial Impact on Date of Restructure Three and Nine Months Ended September 30, 2019 Real estate: Single-family residential 1 $ 330 $ 330 $ 330 $ — $ — Total real estate 1 330 330 330 — — Total 1 $ 330 $ 330 $ 330 $ — $ — Three Months Ended September 30, 2018 Real estate: Construction 1 $ 99 $ 98 $ 98 $ — $ — Other commercial 2 392 390 390 — 212 Total real estate 3 491 488 488 — 212 Commercial: Commercial 3 2,363 2,358 2,358 — 190 Total commercial 3 2,363 2,358 2,358 — 190 Total 6 $ 2,854 $ 2,846 $ 2,846 $ — $ 402 Nine Months Ended September 30, 2018 Consumer: Other consumer 1 $ 91 $ 91 $ 91 $ — $ — Total consumer 1 91 91 91 — — Real estate: Construction 1 99 98 98 — — Single-family residential 1 61 62 62 — — Other commercial 2 392 390 390 — 212 Total real estate 4 552 550 550 — 212 Commercial: Commercial 3 2,363 2,358 2,358 — 190 Total commercial 3 2,363 2,358 2,358 — 190 Total 8 $ 3,006 $ 2,999 $ 2,999 $ — $ 402 During the three and nine months ended September 30, 2019 , the Company modified 1 loan with a recorded investment of $330,000 prior to modification which was deemed troubled debt restructuring. The restructured loan was modified by deferring amortized principal payments, changing the maturity date and requiring interest-only payments for a period of up to 12 months. Also, there was no immediate financial impact from the restructuring of this loan, as it was not considered necessary to charge-off interest or principal on the date of restructure. During the three months ended September 30, 2018 , the Company modified 6 loans with a recorded investment of $2.9 million and during the nine months ended September 30, 2018 , the Company modified 8 loans with a recorded investment of $3.0 million prior to modification which were deemed troubled debt restructuring. The restructured loans were modified by deferring amortized principal payments, changing the maturity date and requiring interest-only payments for a period of up to 12 months. Based on the fair value of the collateral, a specific reserve of $402,000 was determined necessary for these loans. Also, there was no immediate financial impact from the restructuring of these loans, as it was not considered necessary to charge-off interest or principal on the date of restructure. There were four loans consisting of commercial and real estate construction loans, considered TDRs for which a payment default occurred during the nine months ended September 30, 2019 . The Company charged off approximately $552,000 for these loans. There was one commercial real estate loan for which a payment default occurred during the nine months ended September 30, 2018 . A charge-off of $66,300 was recorded for this loan and $294,300 was transferred to OREO. The Company defines a payment default as a payment received more than 90 days after its due date. In addition to the TDRs that occurred during the periods provided in the preceding tables, the Company had TDRs with pre-modification loan balances, specifically in commercial real estate, of $294,300 at September 30, 2018 , for which OREO was received in full or partial satisfaction of the loans. There were no TDRs with pre-modification loan balances for which OREO was received in full or partial satisfaction of the loans during the three or nine month periods ended September 30, 2019 . At September 30, 2019 and December 31, 2018 , the Company had $3,925,000 and $3,899,000 , respectively, of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process. At September 30, 2019 and December 31, 2018 , the Company had $4,401,000 and $3,530,000 , respectively, of OREO secured by residential real estate properties. Credit Quality Indicators – As part of the on-going monitoring of the credit quality of the Company’s loan portfolio, management tracks certain credit quality indicators including trends related to (i) the weighted-average risk rating of commercial and real estate loans, (ii) the level of classified commercial and real estate loans, (iii) net charge-offs, (iv) non-performing loans (see details above) and (v) the general economic conditions in the States of Arkansas, Colorado, Illinois, Kansas, Missouri, Oklahoma, Tennessee and Texas. The Company utilizes a risk rating matrix to assign a risk rate to each of its commercial and real estate loans. Loans are rated on a scale of 1 to 8. A description of the general characteristics of the 8 risk ratings is as follows: • Risk Rate 1 – Pass (Excellent) – This category includes loans which are virtually free of credit risk. Borrowers in this category represent the highest credit quality and greatest financial strength. • Risk Rate 2 – Pass (Good) - Loans under this category possess a nominal risk of default. This category includes borrowers with strong financial strength and superior financial ratios and trends. These loans are generally fully secured by cash or equivalents (other than those rated “excellent”). • Risk Rate 3 – Pass (Acceptable – Average) - Loans in this category are considered to possess a normal level of risk. Borrowers in this category have satisfactory financial strength and adequate cash flow coverage to service debt requirements. If secured, the perfected collateral should be of acceptable quality and within established borrowing parameters. • Risk Rate 4 – Pass (Monitor) - Loans in the Watch (Monitor) category exhibit an overall acceptable level of risk, but that risk may be increased by certain conditions, which represent “red flags”. These “red flags” require a higher level of supervision or monitoring than the normal “Pass” rated credit. The borrower may be experiencing these conditions for the first time, or it may be recovering from weakness, which at one time justified a higher rating. These conditions may include: weaknesses in financial trends; marginal cash flow; one-time negative operating results; non-compliance with policy or borrowing agreements; poor diversity in operations; lack of adequate monitoring information or lender supervision; questionable management ability/stability. • Risk Rate 5 – Special Mention - A loan in this category has potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the asset or in the institution’s credit position at some future date. Special Mention loans are not adversely classified (although they are “criticized”) and do not expose an institution to sufficient risk to warrant adverse classification. Borrowers may be experiencing adverse operating trends, or an ill-proportioned balance sheet. Non-financial characteristics of a Special Mention rating may include management problems, pending litigation, a non-existent, or ineffective loan agreement or other material structural weakness, and/or other significant deviation from prudent lending practices. • Risk Rate 6 – Substandard - A Substandard loan is inadequately protected by the current sound worth and paying capacity of the borrower or of the collateral pledged, if any. Loans so classified must have a well-defined weakness, or weaknesses, that jeopardize the liquidation of the debt. The loans are characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. This does not imply ultimate loss of the principal, but may involve burdensome administrative expenses and the accompanying cost to carry the loan. • Risk Rate 7 – Doubtful - A loan classified Doubtful has all the weaknesses inherent in a substandard loan except that the weaknesses make collection or liquidation in full (on the basis of currently existing facts, conditions, and values) highly questionable and improbable. Doubtful borrowers are usually in default, lack adequate liquidity, or capital, and lack the resources necessary to remain an operating entity. The possibility of loss is extremely high, but because of specific pending events that may strengthen the asset, its classification as loss is deferred. Pending factors include: proposed merger or acquisition; liquidation procedures; capital injection; perfection of liens on additional collateral; and refinancing plans. Loans classified as Doubtful are placed on nonaccrual status. • Risk Rate 8 – Loss - Loans classified Loss are considered uncollectible and of such little value that their continuance as bankable assets is not warranted. This classification does not mean that the loans has absolutely no recovery or salvage value, but rather it is not practical or desirable to defer writing off this basically worthless loan, even though partial recovery may be affected in the future. Borrowers in the Loss category are often in bankruptcy, have formally suspended debt repayments, or have otherwise ceased normal business operations. Loans should be classified as Loss and charged-off in the period in which they become uncollectible. Loans acquired are evaluated using this internal grading system. Loans acquired are evaluated individually and include purchased credit impaired loans of $3.1 million and $4.1 million that are accounted for under ASC Topic 310-30 and are classified as substandard (Risk Rating 6) as of September 30, 2019 and December 31, 2018 , respectively. Of the remaining loans acquired and accounted for under ASC Topic 310-20, $37.4 million and $50.4 million were classified (Risk Ratings 6, 7 and 8 – see classified loans discussion below) at September 30, 2019 and December 31, 2018 , respectively. Purchased credit impaired loans are loans that showed evidence of deterioration of credit quality since origination and for which it is probable, at acquisition, that the Company will be unable to collect all amounts contractually owed. Their fair value was initially based on the estimate of cash flows, both principal and interest, expected to be collected or estimated collateral values if cash flows are not estimable, discounted at prevailing market rates of interest. The difference between the undiscounted cash flows expected at acquisition and the fair value at acquisition is recognized as interest income on a level-yield method over the life of the loan. Contractually required payments for interest and principal that exceed the undiscounted cash flows expected at acquisition are not recognized as a yield adjustment. Increases in expected cash flows subsequent to the initial investment are recognized prospectively through adjustment of the yield on the loan over its remaining life. Decreases in expected cash flows are recognized as impairment. Classified loans for the Company include loans in Risk Ratings 6, 7 and 8. Loans may be classified, but not considered impaired, due to one of the following reasons: (1) The Company has established minimum dollar amount thresholds for loan impairment testing. Loans rated 6 – 8 that fall under the threshold amount are not tested for impairment and therefore are not included in impaired loans. (2) Of the loans that are above the threshold amount and tested for impairment, after testing, some are considered to not be impaired and are not included in impaired loans. Total classified loans, excluding loans accounted for under ASC Topic 310-30, were $146.2 million and $119.0 million , as of September 30, 2019 and December 31, 2018 , respectively. The following table presents a summary of loans by credit risk rating as of September 30, 2019 and December 31, 2018 , segregated by class of loans. Loans accounted for under ASC Topic 310-30 are all included in Risk Rate 1-4 in this table. (In thousands) Risk Rate 1-4 Risk Rate 5 Risk Rate 6 Risk Rate 7 Risk Rate 8 Total September 30, 2019 Consumer: Credit cards $ 194,433 $ — $ 650 $ — $ — $ 195,083 Other consumer 206,647 — 1,996 — — 208,643 Total consumer 401,080 — 2,646 — — 403,726 Real estate: Construction 1,705,376 1,456 6,026 — — 1,712,858 Single family residential 1,422,086 3,246 23,119 4 — 1,448,455 Other commercial 3,571,706 33,030 25,972 — — 3,630,708 Total real estate 6,699,168 37,732 55,117 4 — 6,792,021 Commercial: Commercial 1,837,374 10,420 47,025 — — 1,894,819 Agricultural 213,072 69 612 — — 213,753 Total commercial 2,050,446 10,489 47,637 — — 2,108,572 Other 339,046 — — — — 339,046 Loans acquired 3,272,024 46,796 40,639 128 — 3,359,587 Total $ 12,761,764 $ 95,017 $ 146,039 $ 132 $ — $ 13,002,952 (In thousands) Risk Rate 1-4 Risk Rate 5 Risk Rate 6 Risk Rate 7 Risk Rate 8 Total December 31, 2018 Consumer: Credit cards $ 203,667 $ — $ 506 $ — $ — $ 204,173 Other consumer 198,840 — 2,457 — — 201,297 Total consumer 402,507 — 2,963 — — 405,470 Real estate: Construction 1,296,988 1,910 1,825 — — 1,300,723 Single family residential 1,420,052 1,628 18,528 235 — 1,440,443 Other commercial 3,193,289 17,169 14,829 — — 3,225,287 Total real estate 5,910,329 20,707 35,182 235 — 5,966,453 Commercial: Commercial 1,742,002 8,357 24,550 — — 1,774,909 Agricultural 162,824 75 1,615 — — 164,514 Total commercial 1,904,826 8,432 26,165 — — 1,939,423 Other 119,042 — — — — 119,042 Loans acquired 3,187,083 51,255 54,097 348 — 3,292,783 Total $ 11,523,787 $ 80,394 $ 118,407 $ 583 $ — $ 11,723,171 Allowance for Loan Losses Allowance for Loan Losses – The allowance for loan losses is a reserve established through a provision for loan losses charged to expense, which represents management’s best estimate of probable losses that have been incurred within the existing portfolio of loans. The allowance, in the judgment of management, is necessary to reserve for estimated loan losses and risks inherent in the loan portfolio. The Company’s allowance for loan loss methodology includes allowance allocations calculated in accordance with ASC Topic 310-10, Receivables , and allowance allocations calculated in accordance with ASC Topic 450-20, Loss Contingencies . Accordingly, the methodology is based on the Company’s internal grading system, specific impairment analysis, qualitative and quantitative factors. As mentioned above, allocations to the allowance for loan losses are categorized as either specific allocations or general allocations. A loan is considered impaired when it is probable that the Company will not receive all amounts due according to the contractual terms of the loan, including scheduled principal and interest payments. For a collateral dependent loan, the Company’s evaluation process includes a valuation by appraisal or other collateral analysis. This valuation is compared to the remaining outstanding principal balance of the loan. If a loss is determined to be probable, the loss is included in the allowance for loan losses as a specific allocation. If the loan is not collateral dependent, the measurement of loss is based on the difference between the expected and contractual future cash flows of the loan. The general allocation is calculated monthly based on management’s assessment of several factors such as (1) historical loss experience based on volumes and types, (2) volume and trends in delinquencies and nonaccruals, (3) lending policies and procedures including those for loan losses, collections and recoveries, (4) national, state and local economic trends and conditions, (5) external factors and pressure from competition, (6) the experience, ability and depth of lending management and staff, (7) seasoning of new products obtained and new markets entered through acquisition and (8) other factors and trends that will affect specific loans and categories of loans. The Company establishes general allocations for each major loan category. This category also includes allocations to loans which are collectively evaluated for loss such as credit cards, one-to-four family owner occupied residential real estate loans and other consumer loans. The following table details activity in the allowance for loan losses by portfolio segment for legacy loans for the three and nine months ended September 30, 2019 . Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. (In thousands) Commercial Real Estate Credit Card Other Consumer and Other Total Three Months Ended September 30, 2019 Balance, beginning of period (2) $ 21,739 $ 34,917 $ 3,951 $ 2,460 $ 63,067 Provision for loan losses (1) 19,150 2,405 946 (528 ) 21,973 Charge-offs (17,729 ) (907 ) (1,117 ) (1,059 ) (20,812 ) Recoveries 65 55 223 1,422 1,765 Net charge-offs (17,664 ) (852 ) (894 ) 363 (19,047 ) Balance, September 30, 2019 (2) $ 23,225 $ 36,470 $ 4,003 $ 2,295 $ 65,993 Nine Months Ended September 30, 2019 Balance, beginning of period (2) $ 20,514 $ 29,743 $ 3,923 $ 2,419 $ 56,599 Provision for loan losses (1) 23,980 7,929 2,644 1,320 35,873 Charge-offs (21,564 ) (1,552 ) (3,298 ) (3,497 ) (29,911 ) Recoveries 295 350 734 2,053 3,432 Net charge-offs (21,269 ) (1,202 ) (2,564 ) (1,444 ) (26,479 ) Balance, September 30, 2019 (2) $ 23,225 $ 36,470 $ 4,003 $ 2,295 $ 65,993 Period-end amount allocated to: Loans individually evaluated for impairment $ 4,620 $ 659 $ — $ — $ 5,279 Loans collectively evaluated for impairment 18,605 35,811 4,003 2,295 60,714 Balance, September 30, 2019 (2) $ 23,225 $ 36,470 $ 4,003 $ 2,295 $ 65,993 (1) Provision for loan losses of $0 and $2,464,000 attributable to loans acquired was excluded from this table for the three and nine months ended September 30, 2019 , respectively (total provision for loan losses for the three and nine months ended September 30, 2019 was $21,973,000 and $38,337,000 ). There were $515,000 and $2,862,000 in charge-offs for loans acquired during the three and nine months ended September 30, 2019 , respectively, and recoveries of $900,000 for loans acquired during the nine month period ended September 30, 2019 , resulting in an ending balance in the allowance related to loans acquired of $597,000 . (2) Allowance for loan losses at September 30, 2019 includes $597,000 allowance for loans acquired (not shown in the table above). Allowance for loan losses at June 30, 2019 and December 31, 2018 includes $1,112,000 and $95,000 , respectively, of allowance for loans acquired (not shown in the table above). The total allowance for loan losses at September 30, 2019 was $66,590,000 and total allowance for loan losses at June 30, 2019 and December 31, 2018 was $64,179,000 and $56,694,000 , respectively. Activity in the allowance for loan losses for the three and nine months ended September 30, 2018 was as follows: (In thousands) Commercial Real Estate Credit Card Other Consumer and Other Total Three Months Ended September 30, 2

Loans Acquired

Loans Acquired	9 Months Ended
	Sep. 30, 2019
Receivables [Abstract]
Loans Acquired	LOANS ACQUIRED The Company accounts for its acquisitions under ASC Topic 805, Business Combinations , which requires the use of the acquisition method of accounting. All identifiable assets acquired, including loans, are recorded at fair value. No allowance for loan losses related to the loans acquired is recorded on the acquisition date as the fair value of the loans acquired incorporates assumptions regarding credit risk. Loans acquired are recorded at fair value in accordance with the fair value methodology prescribed in ASC Topic 820, Fair Value Measurement . The fair value estimates associated with the loans include estimates related to expected prepayments and the amount and timing of undiscounted expected principal, interest and other cash flows. The Company evaluates non-impaired loans acquired in accordance with the provisions of ASC Topic 310-20, Nonrefundable Fees and Other Costs . The fair value discount on these loans is accreted into interest income over the weighted average life of the loans using a constant yield method. The Company evaluates purchased impaired loans in accordance with the provisions of ASC Topic 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality . Purchased loans are considered impaired if there is evidence of credit deterioration since origination and if it is probable that not all contractually required payments will be collected. For impaired loans accounted for under ASC Topic 310-30, the Company continues to estimate cash flows expected to be collected on purchased credit impaired loans. The Company evaluates, at each balance sheet date, whether the present value of the purchased credit impaired loans determined using the effective interest rates has decreased significantly and if so, recognize a provision for loan loss in the consolidated statement of income. For any significant increases in cash flows expected to be collected, the Company adjusts the amount of accretable yield recognized on a prospective basis over the remaining life of the purchased credit impaired loan. During the second quarter 2019, the Company evaluated $1.097 billion of net loans ( $1.127 billion gross loans less $30.6 million discount) purchased in conjunction with the acquisition of Reliance, described in Note 2, Acquisitions, in accordance with the provisions of ASC Topic 310-20. The Company evaluated the remaining $176,000 of net loans ( $385,000 gross loans less $209,000 discount) purchased in conjunction with the acquisition of Reliance for impairment in accordance with the provisions of ASC Topic 310-30. The following table reflects the carrying value of all loans acquired as of September 30, 2019 and December 31, 2018 : Loans Acquired (In thousands) September 30, 2019 December 31, 2018 Consumer: Other consumer $ 7,431 $ 15,658 Real estate: Construction 362,000 429,605 Single family residential 504,490 566,188 Other commercial 2,134,973 1,848,679 Total real estate 3,001,463 2,844,472 Commercial: Commercial 349,821 430,914 Agricultural 872 1,739 Total commercial 350,693 432,653 Total loans acquired (1) $ 3,359,587 $ 3,292,783 ________________________ (1) Loans acquired are reported net of a $597,000 and $95,000 allowance at September 30, 2019 and December 31, 2018 , respectively. Nonaccrual loans acquired, excluding purchased credit impaired loans accounted for under ASC Topic 310-30, segregated by class of loans, are as follows (see Note 4, Loans and Allowance for Loan Losses, for discussion of nonaccrual loans): (In thousands) September 30, 2019 December 31, 2018 Consumer: Other consumer $ 71 $ 140 Real estate: Construction 48 114 Single family residential 4,492 6,603 Other commercial 1,029 1,167 Total real estate 5,569 7,884 Commercial: Commercial 1,636 13,578 Agricultural 23 38 Total commercial 1,659 13,616 Total $ 7,299 $ 21,640 An age analysis of past due loans acquired segregated by class of loans, is as follows (see Note 4, Loans and Allowance for Loan Losses, for discussion of past due loans): (In thousands) Gross 30-89 Days Past Due 90 Days or More Past Due Total Past Due Current Total Loans 90 Days Past Due & Accruing September 30, 2019 Consumer: Other consumer $ 131 $ 36 $ 167 $ 7,264 $ 7,431 $ 4 Real estate: Construction 30 12 42 361,958 362,000 — Single family residential 3,664 1,790 5,454 499,036 504,490 17 Other commercial 1,888 943 2,831 2,132,142 2,134,973 — Total real estate 5,582 2,745 8,327 2,993,136 3,001,463 17 Commercial: Commercial 607 724 1,331 348,490 349,821 — Agricultural — — — 872 872 — Total commercial 607 724 1,331 349,362 350,693 — Total $ 6,320 $ 3,505 $ 9,825 $ 3,349,762 $ 3,359,587 $ 21 December 31, 2018 Consumer: Other consumer $ 337 $ 49 $ 386 $ 15,272 $ 15,658 $ 2 Real estate: Construction 8,283 27 8,310 421,295 429,605 — Single family residential 4,706 3,049 7,755 558,433 566,188 — Other commercial 168 577 745 1,847,934 1,848,679 — Total real estate 13,157 3,653 16,810 2,827,662 2,844,472 — Commercial: Commercial 1,302 9,542 10,844 420,070 430,914 — Agricultural 31 5 36 1,703 1,739 — Total commercial 1,333 9,547 10,880 421,773 432,653 — Total $ 14,827 $ 13,249 $ 28,076 $ 3,264,707 $ 3,292,783 $ 2 The following table presents a summary of loans acquired by credit risk rating, segregated by class of loans (see Note 4, Loans and Allowance for Loan Losses, for discussion of loan risk rating). Loans accounted for under ASC Topic 310-30 are all included in Risk Rate 1-4 in this table. (In thousands) Risk Rate 1-4 Risk Rate 5 Risk Rate 6 Risk Rate 7 Risk Rate 8 Total September 30, 2019 Consumer: Other consumer $ 7,285 $ — $ 146 $ — $ — $ 7,431 Real estate: Construction 344,075 17,874 51 — — 362,000 Single family residential 492,826 1,224 10,312 128 — 504,490 Other commercial 2,085,649 26,207 23,117 — — 2,134,973 Total real estate 2,922,550 45,305 33,480 128 — 3,001,463 Commercial: Commercial 341,385 1,491 6,945 — — 349,821 Agricultural 804 — 68 — — 872 Total commercial 342,189 1,491 7,013 — — 350,693 Total $ 3,272,024 $ 46,796 $ 40,639 $ 128 $ — $ 3,359,587 December 31, 2018 Consumer: Other consumer $ 15,380 $ — $ 278 $ — $ — $ 15,658 Real estate: Construction 393,122 27,621 8,862 — — 429,605 Single family residential 553,460 2,081 10,299 348 — 566,188 Other commercial 1,822,179 9,137 17,363 — — 1,848,679 Total real estate 2,768,761 38,839 36,524 348 — 2,844,472 Commercial: Commercial 401,300 12,416 17,198 — — 430,914 Agricultural 1,642 — 97 — — 1,739 Total commercial 402,942 12,416 17,295 — — 432,653 Total $ 3,187,083 $ 51,255 $ 54,097 $ 348 $ — $ 3,292,783 Loans acquired were individually evaluated and recorded at estimated fair value, including estimated credit losses, at the time of acquisition. These loans are systematically reviewed by the Company to determine the risk of losses that may exceed those identified at the time of the acquisition. Techniques used in determining risk of loss are similar to the Company’s legacy loan portfolio, with most focus being placed on those loans which include the larger loan relationships and those loans which exhibit higher risk characteristics. In addition to the accretable yield on loans acquired not considered to be impaired, the amount of the estimated cash flows expected to be received from the purchased credit impaired loans in excess of the fair values recorded for the purchased credit impaired loans is referred to as the accretable yield. The accretable yield is recognized as interest income over the estimated lives of the loans. Each quarter, the Company estimates the cash flows expected to be collected from the acquired purchased credit impaired loans, and adjustments may or may not be required. This has resulted in an increase in interest income that is spread on a level-yield basis over the remaining expected lives of the loans. Changes in the carrying amount of the accretable yield for all purchased impaired loans were as follows for the three and nine months ended September 30, 2019 and 2018 . Three Months Ended Nine Months Ended (In thousands) Accretable Yield Carrying Amount of Loans Accretable Yield Carrying Amount of Loans Beginning balance $ 1,461 $ 3,487 $ 1,460 $ 4,050 Additions — — — 175 Accretable yield adjustments 10 — 38 — Accretion (12 ) 12 (39 ) 39 Payments and other reductions, net — (422 ) — (1,187 ) Balance, ending $ 1,459 $ 3,077 $ 1,459 $ 3,077 Three Months Ended Nine Months Ended (In thousands) Accretable Yield Carrying Amount of Loans Accretable Yield Carrying Amount of Loans Beginning balance $ 1,382 $ 13,995 $ 620 $ 17,116 Additions — — — — Accretable yield adjustments 717 — 1,895 — Accretion (635 ) 635 (1,051 ) 1,051 Payments and other reductions, net — (9,664 ) — (13,201 ) Balance, ending $ 1,464 $ 4,966 $ 1,464 $ 4,966 Purchased impaired loans are evaluated on an individual borrower basis. Because some loans evaluated by the Company were determined to have experienced impairment in the estimated credit quality or cash flows, the Company recorded a provision and established an allowance for loan loss for loans acquired resulting in a total allowance on loans acquired of $597,000 at September 30, 2019 and $95,000 at December 31, 2018 . The provision on loans acquired for the three and nine months ended September 30, 2019 was $0 and $2,464,000 , respectively. The provision on loans acquired for the three and nine months ended September 30, 2018 was $0 and $1,837,000 , respectively.

Right-of-Use Lease Assets and L

Right-of-Use Lease Assets and Lease Liabilities	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Right-of-Use Lease Assets and Lease Liabilities	RIGHT-OF-USE LEASE ASSETS AND LEASE LIABILITIES As of the first quarter 2019, the Company accounts for its leases in accordance with ASC Topic 842, Leases , which requires recognition of most leases, including operating leases, with a term greater than 12 months, on the balance sheet. At lease commencement, the lease contract is reviewed to determine whether the contract is a finance lease or an operating lease; a lease liability is recognized on a discounted basis, related to the Company’s obligation to make lease payments; and a right-of-use asset is also recognized related to the Company’s right to use, or control the use of, a specified asset for the lease term. The Company accounts for lease and non-lease components (such as taxes, insurance and common area maintenance costs) separately as such amounts are generally readily determinable under the lease contracts. Lease payments over the expected term are discounted using the Company’s FHLB advance rates for borrowings of similar term. If it is reasonably certain that a renewal or termination option will be exercised, the effects of such options are included in the determination of the expected lease term. Leases with an initial term of 12 months or less are not recorded on the balance sheet; the Company recognizes lease expense for these leases on a straight-line basis over the lease term. The Company’s leases are classified as operating leases with a term, including expected renewal or termination options, greater than one year, and are related to certain office facilities and office equipment. As of September 30, 2019 , right-of-use lease assets included in premises and equipment are $34.1 million and lease liabilities included in other liabilities are $34.3 million . During the three and nine months ended September 30, 2019 , the Company recognized lease expense of $2.8 million and $8.1 million , respectively, and the weighted average discount rate was 3.47% . At September 30, 2019 , the weighted average remaining lease term was 8.63 years . See the Recently Adopted Accounting Standards section of Note 1, Preparation of Interim Financial Statements, for additional information related to the adoption of ASC Topic 842.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill is tested annually, or more often than annually, if circumstances warrant, for impairment. If the implied fair value of goodwill is lower than its carrying amount, goodwill impairment is indicated, and goodwill is written down to its implied fair value. Subsequent increases in goodwill value are not recognized in the financial statements. Goodwill totaled $926.6 million at September 30, 2019 and $845.7 million at December 31, 2018 . The Company recorded $81.0 million of goodwill during the second quarter 2019 as a result of its acquisition of Reliance. Goodwill impairment was neither indicated nor recorded during the nine months ended September 30, 2019 or the year ended December 31, 2018 . Core deposit premiums are amortized over periods ranging from 10 years to 15 years and are periodically evaluated, at least annually, as to the recoverability of their carrying value. Core deposit premiums of $18.4 million were recorded during the second quarter 2019 as part of the Reliance acquisition. Additionally, intangible assets are being amortized over various periods ranging from 10 years to 15 years . The Company’s goodwill and other intangibles (carrying basis and accumulated amortization) at September 30, 2019 and December 31, 2018 , were as follows: (In thousands) September 30, 2019 December 31, 2018 Goodwill $ 926,648 $ 845,687 Core deposit premiums: Gross carrying amount 124,334 105,984 Accumulated amortization (33,918 ) (26,177 ) Core deposit premiums, net 90,416 79,807 Books of business intangible: Gross carrying amount 15,234 15,234 Accumulated amortization (4,501 ) (3,707 ) Books of business intangible, net 10,733 11,527 Other intangible assets, net 101,149 91,334 Total goodwill and other intangible assets $ 1,027,797 $ 937,021 The Company’s estimated remaining amortization expense on intangibles as of September 30, 2019 is as follows: (In thousands) Year Amortization Expense Remainder of 2019 $ 2,947 2020 11,776 2021 11,714 2022 11,662 2023 11,379 Thereafter 51,671 Total $ 101,149

Time Deposits

Time Deposits	9 Months Ended
	Sep. 30, 2019
Banking and Thrift [Abstract]
Time Deposits	TIME DEPOSITS Time deposits include approximately $1.679 billion and $1.443 billion of certificates of deposit of $100,000 or more at September 30, 2019 , and December 31, 2018 , respectively. Of this total approximately $777.5 million and $753.2 million of certificates of deposit were over $250,000 at September 30, 2019 and December 31, 2018 , respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The provision for income taxes is comprised of the following components for the periods indicated below: Three Months Ended Nine Months Ended (In thousands) 2019 2018 2019 2018 Income taxes currently payable $ 17,282 $ 5,638 $ 40,356 $ 31,335 Deferred income taxes 5,993 5,264 10,933 7,316 Provision for income taxes $ 23,275 $ 10,902 $ 51,289 $ 38,651 The tax effects of temporary differences between the tax basis of assets and liabilities and their financial reporting amounts that give rise to deferred income tax assets and liabilities, and their appropriate tax effects, are as follows: (In thousands) September 30, 2019 December 31, 2018 Deferred tax assets: Loans acquired $ 15,906 $ 12,536 Allowance for loan losses 16,332 13,947 Valuation of foreclosed assets 2,706 1,474 Tax NOLs from acquisition 18,021 7,242 Deferred compensation payable 2,572 2,707 Accrued equity and other compensation 8,340 8,182 Acquired securities 2,598 397 Unrealized loss on available-for-sale securities — 9,196 Other 5,409 7,042 Gross deferred tax assets 71,884 62,723 (In thousands) September 30, 2019 December 31, 2018 Deferred tax liabilities: Goodwill and other intangible amortization $ (34,304 ) $ (30,471 ) Accumulated depreciation (16,587 ) (13,361 ) Unrealized gain on available-for-sale securities (6,811 ) — Other (5,304 ) (5,360 ) Gross deferred tax liabilities (63,006 ) (49,192 ) Net deferred tax asset, included in other assets $ 8,878 $ 13,531 A reconciliation of income tax expense at the statutory rate to the Company’s actual income tax expense is shown for the periods indicated below: Three Months Ended Nine Months Ended (In thousands) 2019 2018 2019 2018 Computed at the statutory rate (21%) $ 22,071 $ 13,880 $ 49,646 $ 41,731 Increase (decrease) in taxes resulting from: State income taxes, net of federal tax benefit 2,956 986 5,721 4,073 Tax exempt interest income (1,105 ) (833 ) (3,090 ) (2,292 ) Tax exempt earnings on BOLI (225 ) (186 ) (619 ) (562 ) Federal tax credits (730 ) — (2,188 ) — Other differences, net 308 (2,945 ) 1,819 (4,299 ) Actual tax provision $ 23,275 $ 10,902 $ 51,289 $ 38,651 The Company follows ASC Topic 740, Income Taxes , which prescribes a recognition threshold and a measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. Benefits from tax positions should be recognized in the financial statements only when it is more likely than not that the tax position will be sustained upon examination by the appropriate taxing authority that would have full knowledge of all relevant information. A tax position that meets the more-likely-than-not recognition threshold is measured at the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement. Tax positions that previously failed to meet the more-likely-than-not recognition threshold should be recognized in the first subsequent financial reporting period in which that threshold is met. Previously recognized tax positions that no longer meet the more-likely-than-not recognition threshold should be derecognized in the first subsequent financial reporting period in which that threshold is no longer met. ASC Topic 740 also provides guidance on the accounting for and disclosure of unrecognized tax benefits, interest and penalties. The Company has no history of expiring net operating loss carryforwards and is projecting significant pre-tax and financial taxable income in 2019 and in future years. The Company expects to fully realize its deferred tax assets in the future. The amount of unrecognized tax benefits may increase or decrease in the future for various reasons including adding amounts for current tax year positions, expiration of open income tax returns due to the statutes of limitation, changes in management’s judgment about the level of uncertainty, status of examinations, litigation and legislative activity and the addition or elimination of uncertain tax positions. Section 382 of the Internal Revenue Code imposes an annual limit on the ability of a corporation that undergoes an “ownership change” to use its U.S. net operating losses to reduce its tax liability. The Company has engaged in two tax-free reorganization transactions in which acquired net operating losses are limited pursuant to Section 382. In total, approximately $85.9 million of federal net operating losses subject to the IRC Section 382 annual limitation are expected to be utilized by the Company, of which $53.6 million is related to the Reliance acquisition during second quarter 2019. All of the acquired Reliance net operating losses are expected to be fully utilized by 2029, with the remaining acquired net operating loss carryforwards expected to be fully utilized by 2036. The Company files income tax returns in the U.S. federal jurisdiction. The Company’s U.S. federal income tax returns are open and subject to examinations from the 2015 tax year and forward. The Company’s various state income tax returns are generally open from the 2015 and later tax return years based on individual state statute of limitations.

Securities Sold Under Agreement

Securities Sold Under Agreements to Repurchase	9 Months Ended
	Sep. 30, 2019
Banking and Thrift [Abstract]
Securities Sold Under Agreements to Repurchase	SECURITIES SOLD UNDER AGREEMENTS TO REPURCHASE The Company utilizes securities sold under agreements to repurchase to facilitate the needs of its customers and to facilitate secured short-term funding needs. Securities sold under agreements to repurchase are stated at the amount of cash received in connection with the transaction. The Company monitors collateral levels on a continuous basis. The Company may be required to provide additional collateral based on the fair value of the underlying securities. Securities pledged as collateral under repurchase agreements are maintained with safekeeping agents. The gross amount of recognized liabilities for repurchase agreements was $116.3 million and $95.5 million at September 30, 2019 and December 31, 2018 , respectively. The remaining contractual maturity of the securities sold under agreements to repurchase in the consolidated balance sheets as of September 30, 2019 and December 31, 2018 is presented in the following tables. Remaining Contractual Maturity of the Agreements (In thousands) Overnight and Continuous Up to 30 Days 30-90 Days Greater than 90 Days Total September 30, 2019 Repurchase agreements: U.S. Government agencies $ 116,286 $ — $ — $ — $ 116,286 December 31, 2018 Repurchase agreements: U.S. Government agencies $ 95,542 $ — $ — $ — $ 95,542

Other Borrowings and Subordinat

Other Borrowings and Subordinated Notes and Debentures	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Other Borrowings and Subordinated Notes and Debentures	OTHER BORROWINGS AND SUBORDINATED NOTES AND DEBENTURES Debt at September 30, 2019 and December 31, 2018 consisted of the following components: (In thousands) September 30, 2019 December 31, 2018 Other Borrowings FHLB advances, net of discount, due 2019 to 2033, 1.38% to 7.37% secured by real estate loans $ 1,098,395 $ 1,345,450 Revolving credit agreement, due 10/4/2019, floating rate of 1.50% above the one month LIBOR rate, unsecured — — Total other borrowings 1,098,395 1,345,450 Subordinated Notes and Debentures Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly) 330,000 330,000 Trust preferred securities, net of discount, due 9/15/2037, floating rate of 1.37% above the three month LIBOR rate, reset quarterly 10,310 10,310 Trust preferred securities, net of discount, due 6/6/2037, floating rate of 1.57% above the three month LIBOR rate, reset quarterly, callable without penalty 10,310 10,310 Trust preferred securities, due 12/15/2035, floating rate of 1.45% above the three month LIBOR rate, reset quarterly, callable without penalty 6,702 6,702 Unamortized debt issuance costs (3,099 ) (3,372 ) Total subordinated notes and debentures 354,223 353,950 Total other borrowings and subordinated debt $ 1,452,618 $ 1,699,400 In March 2018, the Company issued $330.0 million in aggregate principal amount, of 5.00% Fixed-to-Floating Rate Subordinated Notes (“the Notes”) at a public offering price equal to 100% of the aggregate principal amount of the Notes. The Company incurred $3.6 million in debt issuance costs related to the offering during March 2018. The Notes will mature on April 1, 2028 and will bear interest at an initial fixed rate of 5.00% per annum, payable semi-annually in arrears. From and including April 1, 2023 to, but excluding, the maturity date or the date of earlier redemption, the interest rate will reset quarterly to an annual interest rate equal to the then-current three month LIBOR rate plus 215 basis points, payable quarterly in arrears. The Notes will be subordinated in right of payment to the payment of the Company’s other existing and future senior indebtedness, including all of its general creditors. The Notes are obligations of Simmons First National Corporation only and are not obligations of, and are not guaranteed by, any of its subsidiaries. During 2018, the Company used a portion of the net proceeds from the sale of the Notes to repay certain outstanding indebtedness, including the amounts borrowed under the Credit Agreement (described below), certain trust preferred securities, both discussed below, and unsecured debt from correspondent banks. The Notes qualify for Tier 2 capital treatment. In 2017, the Company entered into a Revolving Credit Agreement with U.S. Bank National Association (the “Credit Agreement”) and executed an unsecured Revolving Credit Note pursuant to which the Company may borrow, prepay and re-borrow up to $75.0 million , the proceeds of which were primarily used to pay off amounts outstanding under a term note assumed with the First Texas acquisition. The Credit Agreement contained customary representations, warranties, and covenants of the Company, including, among other things, covenants that impose various financial ratio requirements. In October 2018, the Company and U.S. Bank National Association entered into a First Amendment to the Credit Agreement, which extended the expiration date from October 5, 2018 to October 4, 2019, reduced the $75.0 million to $50.0 million , and increased the commitment fee on the unused portion from an annual rate of 0.25% to 0.30% . In December 2018, the Company entered into a Second Amendment to the Credit Agreement that clarified the financial metrics contained in certain affirmative covenants are evaluated on a consolidated basis. All amounts borrowed, together with applicable interest, fees, and other amounts owed by the Company were due and payable on October 4, 2019. The balance due under the Credit Agreement at September 30, 2019 and October 4, 2019 was $0 . The Company did not renew the Credit Agreement upon the expiration date. At September 30, 2019 , the Company had $1.09 billion of FHLB advances outstanding with original or expected maturities of one year or less, of which $1.03 billion are FHLB Owns the Option (“FOTO”) advances. FOTO advances are a low cost, fixed-rate source of funding in return for granting to FHLB the flexibility to choose a termination date earlier than the maturity date. Typically, FOTO exercise dates follow a specified lockout period at the beginning of the term when FHLB cannot terminate the FOTO advance. If FHLB exercises its option to terminate the FOTO advance at one of the specified option exercise dates, there is no termination or prepayment fee, and replacement funding will be available at then-prevailing market rates, subject to FHLB’s credit and collateral requirements. The Company’s FOTO advances outstanding at the end of the third quarter have maturity dates of ten years to fifteen years with lockout periods that have expired and, as a result, are considered and monitored by the Company as short-term advances. The possibility of the FHLB exercising the options is analyzed by the Company along with the market expected rate outcome. The Company had total FHLB advances of $1.10 billion at September 30, 2019 , with approximately $3.1 billion of additional advances available from the FHLB. The FHLB advances are secured by mortgage loans and investment securities totaling approximately $5.4 billion at September 30, 2019 . The trust preferred securities are tax-advantaged issues that qualified for Tier 1 capital treatment until December 31, 2017, when the Company reached $15 billion in assets. They still qualify for inclusion as Tier 2 capital at September 30, 2019 . Distributions on these securities are included in interest expense on long-term debt. Each of the trusts is a statutory business trust organized for the sole purpose of issuing trust securities and investing the proceeds thereof in junior subordinated debentures of the Company, the sole asset of each trust. The preferred securities of each trust represent preferred beneficial interests in the assets of the respective trusts and are subject to mandatory redemption upon payment of the junior subordinated debentures held by the trust. The common securities of each trust are wholly-owned by the Company. Each trust’s ability to pay amounts due on the trust preferred securities is solely dependent upon the Company making payments on the related junior subordinated debentures. The Company’s obligations under the junior subordinated securities and other relevant trust agreements, in the aggregate, constitute a full and unconditional guarantee by the Company of each respective trust’s obligations under the trust securities issued by each respective trust. The Company’s long-term debt includes subordinated debt and long-term FHLB advances with an original maturity of greater than one year. Aggregate annual maturities of long-term debt at September 30, 2019 , are as follows: (In thousands) Year Annual Maturities 2019 $ 356 2020 2,105 2021 1,804 2022 948 2023 925 Thereafter 361,480 Total $ 367,618

Contingent Liabilities

Contingent Liabilities	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Contingent Liabilities	CONTINGENT LIABILITIES The Company and/or its subsidiaries have various unrelated legal proceedings, which, in the aggregate, are not expected to have a material adverse effect on the financial position of the Company and its subsidiaries.

Capital Stock

Capital Stock	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Capital Stock	CAPITAL STOCK On January 18, 2018, the Board of Directors of the Company approved a two-for-one stock split of the Company’s outstanding Class A common stock (“Common Stock”) in the form of a 100% stock dividend for shareholders of record as of the close of business on January 30, 2018. The new shares were distributed by the Company’s transfer agent, Computershare, and the Company’s Common Stock began trading on a split-adjusted basis on the Nasdaq Global Select Market on February 9, 2018. All previously reported share and per share data included in filings subsequent to February 8, 2018 are restated to reflect the retroactive effect of this two -for-one stock split. On March 19, 2018, the Company filed a shelf registration with the SEC. The shelf registration statement provides increased flexibility and more efficient access to raise capital from time to time through the sale of common stock, preferred stock, debt securities, depository shares, warrants, purchase contracts, purchase units, subscription rights, units or a combination thereof, subject to market conditions. Specific terms and prices are determined at the time of any offering under a separate prospectus supplement that the Company is required to file with the SEC at the time of the specific offering. On April 19, 2018, shareholders of the Company approved an increase in the number of authorized shares from 120,000,000 to 175,000,000 . On July 23, 2012, the Company approved a stock repurchase program which authorized the repurchase of up to 1,700,000 shares (split adjusted) of Common Stock. On October 22, 2019, the Company announced a new stock repurchase program that replaces the program approved on July 23, 2012. See Note 22, Subsequent Events, for additional information regarding this subsequent event. The Company had no repurchases of its common stock pursuant to the repurchase program during the three and nine month periods ended September 30, 2019 . On April 12, 2019, as part of the acquisition of Reliance, the Company issued 40,000 shares of Simmons Series A Preferred Stock and 2,000 shares Simmons Series B Preferred Stock in exchange for the outstanding shares of Reliance’s Series A Preferred Stock and Series B Preferred Stock. On May 13, 2019, the Company redeemed all of the preferred stock, including accrued and unpaid dividends.

Undivided Profits

Undivided Profits	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Undivided Profits	UNDIVIDED PROFITS The Company’s subsidiary bank is subject to legal limitations on dividends that can be paid to the parent company without prior approval of the applicable regulatory agencies. The approval of the Commissioner of the Arkansas State Bank Department is required if the total of all dividends declared by an Arkansas state bank in any calendar year exceeds seventy-five percent ( 75% ) of the total of its net profits, as defined, for that year combined with seventy-five percent ( 75% ) of its retained net profits of the preceding year. At September 30, 2019 , the Company’s subsidiary bank had approximately $128.8 million available for payment of dividends to the Company, without prior regulatory approval. The risk-based capital guidelines of the Federal Reserve Board and the Arkansas State Bank Department include the definitions for (1) a well-capitalized institution, (2) an adequately-capitalized institution, and (3) an undercapitalized institution. Under the Basel III Rules effective January 1, 2015, the criteria for a well-capitalized institution are: a 5% “Tier l leverage capital” ratio, an 8% “Tier 1 risk-based capital” ratio, 10% “total risk-based capital” ratio; and a 6.50% “common equity Tier 1 (CET1)” ratio. The Company and Bank must hold a capital conservation buffer composed of CET1 capital above its minimum risk-based capital requirements. The implementation of the capital conservation buffer began on January 1, 2016, at the 0.625% level and was phased in over a four year period (increasing by that amount on each subsequent January 1 until it reached 2.5% on January 1, 2019). As of September 30, 2019 , the Company and its subsidiary bank met all capital adequacy requirements under the Basel III Capital Rules. The Company’s CET1 ratio was 10.25% at September 30, 2019

Stock Based Compensation

Stock Based Compensation	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
Stock Based Compensation	STOCK BASED COMPENSATION The Company’s Board of Directors has adopted various stock-based compensation plans. The plans provide for the grant of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock awards, restricted stock units, and performance stock units. Pursuant to the plans, shares are reserved for future issuance by the Company upon exercise of stock options or awarding of performance or bonus shares granted to directors, officers and other key employees. The table below summarizes the transactions under the Company’s active stock compensation plans for the nine months ended September 30, 2019 : Stock Options Outstanding Non-vested Stock Awards Outstanding Non-vested Stock Units Outstanding (Shares in thousands) Number of Shares Weighted Average Exercise Price Number of Shares Weighted Average Grant-Date Fair Value Number of Shares Weighted Average Grant-Date Fair Value Balance, January 1, 2019 695 $ 22.42 72 $ 21.45 817 $ 27.65 Granted — — — — 516 26.07 Stock options exercised (1 ) 10.65 — — — — Stock awards/units vested (earned) — — (39 ) 20.12 (334 ) 26.45 Forfeited/expired — — (2 ) 21.82 (90 ) 28.29 Balance, September 30, 2019 694 $ 22.43 31 $ 23.16 909 $ 27.18 Exercisable, September 30, 2019 694 $ 22.43 The following table summarizes information about stock options under the plans outstanding at September 30, 2019 : Options Outstanding Options Exercisable Range of Exercise Prices Number of Shares (In thousands) Weighted Average Remaining Contractual Life (Years) Weighted Average Exercise Price Number of Shares (In thousands) Weighted Average Exercise Price $ 9.46 — $ 9.46 1 2.30 $9.46 1 $9.46 10.65 — 10.65 3 3.32 10.65 3 10.65 10.76 — 10.76 2 0.30 10.76 2 10.76 20.29 — 20.29 71 5.25 20.29 71 20.29 20.36 — 20.36 3 5.13 20.36 3 20.36 22.20 — 22.20 74 5.48 22.20 74 22.20 22.75 — 22.75 436 5.86 22.75 436 22.75 23.51 — 23.51 97 6.30 23.51 97 23.51 24.07 — 24.07 7 5.96 24.07 7 24.07 $ 9.46 — $ 24.07 694 5.78 $22.43 694 $22.43 The table below summarizes the Company’s performance stock unit activity for the nine months ended September 30, 2019 : (In thousands) Performance Stock Units Non-vested, January 1, 2019 177 Granted 118 Vested (earned) (93 ) Forfeited (3 ) Non-vested, September 30, 2019 199 Stock-based compensation expense was $9,316,000 and $9,818,000 during the nine months ended September 30, 2019 and 2018 , respectively. Stock-based compensation expense is recognized ratably over the requisite service period for all stock-based awards. There was no unrecognized stock-based compensation expense related to stock options at September 30, 2019 . Unrecognized stock-based compensation expense related to non-vested stock awards and stock units was $16,269,000 at September 30, 2019 . At such date, the weighted-average period over which this unrecognized expense is expected to be recognized was 1.7 years . The intrinsic value of stock options outstanding and stock options exercisable at September 30, 2019 was $1,717,000 and $1,714,000 , respectively. Aggregate intrinsic value represents the difference between the Company’s closing stock price on the last trading day of the period, which was $24.90 as of September 30, 2019 , and the exercise price multiplied by the number of options outstanding. The total intrinsic value of stock options exercised during the nine months ended September 30, 2019 and September 30, 2018 , was $6,000 and $1,155,000 , respectively. The fair value of the Company’s employee stock options granted is estimated on the date of grant using the Black-Scholes option-pricing model. This model requires the input of highly subjective assumptions, changes to which can materially affect the fair value estimate. There were no stock options granted during the nine months ended September 30, 2019 and 2018 .

Earnings Per Share ("EPS")

Earnings Per Share ("EPS")	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Share (EPS)	EARNINGS PER SHARE (“EPS”) Basic EPS is computed by dividing reported net income available to common stockholders by weighted average number of common shares outstanding during each period. Diluted EPS is computed by dividing reported net income available to common stockholders by the weighted average common shares and all potential dilutive common shares outstanding during the period. The computation of earnings per share is as follows: Three Months Ended Nine Months Ended (In thousands, except per share data) 2019 2018 2019 2018 Net income available to common stockholders $ 81,826 $ 55,193 $ 185,119 $ 160,067 Average common shares outstanding 96,608 92,290 95,090 92,246 Average potential dilutive common shares 360 551 360 551 Average diluted common shares 96,968 92,841 95,450 92,797 Basic earnings per share $ 0.85 $ 0.60 $ 1.95 $ 1.74 Diluted earnings per share $ 0.84 $ 0.59 $ 1.94 $ 1.72 There were no stock options excluded from the earnings per share calculation due to the related exercise price exceeding the average market price for the three and nine months ended September 30, 2019 and 2018 .

Additional Cash Flow Informatio

Additional Cash Flow Information	9 Months Ended
	Sep. 30, 2019
Supplemental Cash Flow Information [Abstract]
Additional Cash Flow Information	ADDITIONAL CASH FLOW INFORMATION The following is a summary of the Company’s additional cash flow information: Nine Months Ended (In thousands) 2019 2018 Interest paid $ 130,904 $ 78,987 Income taxes (refunded) paid 34,028 25,576 Transfers of loans to foreclosed assets held for sale 3,666 7,745 Transfers of premises to foreclosed assets and other real estate owned 556 3,690 Right-of use lease assets obtained in exchange for lessee operating lease liabilities (adoption of ASU 2016-02) 32,757 —

Other Income and Other Operatin

Other Income and Other Operating Expenses	9 Months Ended
	Sep. 30, 2019
Other Income and Expenses [Abstract]
Other Income and Other Operating Expenses	OTHER INCOME AND OTHER OPERATING EXPENSES Other income for the three and nine months ended September 30, 2019 was $43.8 million and $52.1 million , respectively, and primarily consisted of the gain on sale of Visa Inc. class B common stock of $42.9 million . Other income for the three and nine months ended September 30, 2018 was $4.9 million and $14.2 million , respectively. Other operating expenses consist of the following: Three Months Ended Nine Months Ended (In thousands) 2019 2018 2019 2018 Professional services $ 4,310 $ 4,616 $ 12,125 $ 13,896 Postage 1,471 1,262 4,642 4,103 Telephone 2,507 1,248 5,605 4,217 Credit card expense 4,200 3,405 11,822 9,820 Marketing 7,021 2,912 12,514 6,334 Software and technology 6,531 4,733 16,607 10,716 Operating supplies 493 585 1,671 1,917 Amortization of intangibles 2,947 2,772 8,535 8,394 Branch right sizing expense 160 970 3,092 1,049 Other expense 8,239 7,171 24,195 20,907 Total other operating expenses $ 37,879 $ 29,674 $ 100,808 $ 81,353

Certain Transactions

Certain Transactions	9 Months Ended
	Sep. 30, 2019
Related Party Transactions [Abstract]
Certain Transactions	CERTAIN TRANSACTIONS From time to time, the Company and its subsidiaries have made loans, other extensions of credit, and vendor contracts to directors, officers, their associates and members of their immediate families. Additionally, some directors, officers and their associates and members of their immediate families have placed deposits with the Company’s subsidiary bank, Simmons Bank. Such loans and other extensions of credit, deposits and vendor contracts (which were not material) were made in the ordinary course of business, on substantially the same terms (including interest rates and collateral) as those prevailing at the time for comparable transactions with unrelated persons or through a competitive bid process. Further, in management’s opinion, these extensions of credit did not involve more than normal risk of collectability or present other unfavorable features.

Commitments and Credit Risk

Commitments and Credit Risk	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Credit Risk	COMMITMENTS AND CREDIT RISK The Company grants agri-business, commercial and residential loans to customers primarily throughout Arkansas, Colorado, Illinois, Kansas, Missouri, Oklahoma, Tennessee and Texas, along with credit card loans to customers throughout the United States. Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since a portion of the commitments may expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. Each customer’s creditworthiness is evaluated on a case-by-case basis. The amount of collateral obtained, if deemed necessary, is based on management’s credit evaluation of the counterparty. Collateral held varies, but may include accounts receivable, inventory, property, plant and equipment, commercial real estate and residential real estate. At September 30, 2019 , the Company had outstanding commitments to extend credit aggregating approximately $598,992,000 and $3,310,794,000 for credit card commitments and other loan commitments. At December 31, 2018 , the Company had outstanding commitments to extend credit aggregating approximately $560,863,000 and $3,455,471,000 for credit card commitments and other loan commitments, respectively. Standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. Those guarantees are primarily issued to support public and private borrowing arrangements, including commercial paper, bond financing, and similar transactions. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loans to customers. The Company had total outstanding letters of credit amounting to $49,447,000 and $39,101,000 at September 30, 2019 , and December 31, 2018 , respectively, with terms ranging from 9 months to 15 years . At September 30, 2019 and December 31, 2018 , the Company had no deferred revenue under standby letter of credit agreements.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS ASC Topic 820, Fair Value Measurements defines fair value, establishes a framework for measuring fair value and expands disclosures about fair value measurements. ASC Topic 820 defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The guidance also establishes a fair value hierarchy that requires the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value. Topic 820 describes three levels of inputs that may be used to measure fair value: • Level 1 Inputs – Quoted prices in active markets for identical assets or liabilities. • Level 2 Inputs – Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities in active markets; quoted prices for similar assets or liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3 Inputs – Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. In general, fair value is based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon internally developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments may include amounts to reflect counterparty credit quality and the Company’s creditworthiness, among other things, as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. The Company’s valuation methodologies may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. While management believes the Company’s valuation methodologies are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date. Furthermore, the reported fair value amounts have not been comprehensively revalued since the presentation dates, and therefore, estimates of fair value after the balance sheet date may differ significantly from the amounts presented herein. A more detailed description of the valuation methodologies used for assets and liabilities measured at fair value, as well as the general classification of such instruments pursuant to the valuation hierarchy, is set forth below. Following is a description of the inputs and valuation methodologies used for assets measured at fair value on a recurring basis and recognized in the accompanying consolidated balance sheets, as well as the general classification of such assets pursuant to the valuation hierarchy. Available-for-sale securities – Where quoted market prices are available in an active market, securities are classified within Level 1 of the valuation hierarchy. Level 1 securities would include highly liquid government bonds, mortgage products and exchange traded equities. Other securities classified as available-for-sale are reported at fair value utilizing Level 2 inputs. For these securities, the Company obtains fair value measurements from an independent pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the security’s terms and conditions, among other things. In order to ensure the fair values are consistent with ASC Topic 820, the Company periodically checks the fair values by comparing them to another pricing source, such as Bloomberg. The availability of pricing confirms Level 2 classification in the fair value hierarchy. The third-party pricing service is subject to an annual review of internal controls (SSAE 16), which is made available for the Company’s review. In certain cases where Level 1 or Level 2 inputs are not available, securities are classified within Level 3 of the hierarchy. The Company’s investment in U.S. Treasury securities, if any, is reported at fair value utilizing Level 1 inputs. The remainder of the Company’s available-for-sale securities are reported at fair value utilizing Level 2 inputs. Derivative instruments – The Company’s derivative instruments are reported at fair value utilizing Level 2 inputs. The Company obtains fair value measurements from dealer quotes. The following table sets forth the Company’s financial assets by level within the fair value hierarchy that were measured at fair value on a recurring basis as of September 30, 2019 and December 31, 2018 . Fair Value Measurements Using (In thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2019 Available-for-sale securities U.S. Government agencies $ 178,139 $ — $ 178,139 $ — Mortgage-backed securities 1,337,794 — 1,337,794 — State and political subdivisions 681,202 — 681,202 — Other securities 158,999 — 158,999 — Derivative asset 14,377 — 14,377 — Derivative liability (14,478 ) — (14,478 ) — December 31, 2018 Available-for-sale securities U.S. Government agencies $ 154,301 $ — $ 154,301 $ — Mortgage-backed securities 1,522,900 — 1,522,900 — States and political subdivisions 314,843 — 314,843 — Other securities 159,708 — 159,708 — Derivative asset 6,242 — 6,242 — Derivative liability (5,283 ) — (5,283 ) — Certain financial assets and liabilities are measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment). Financial assets and liabilities measured at fair value on a nonrecurring basis include the following: Impaired loans (collateral dependent) – Loan impairment is reported when full payment under the loan terms is not expected. Allowable methods for determining the amount of impairment include estimating fair value using the fair value of the collateral for collateral-dependent loans. If the impaired loan is identified as collateral dependent, then the fair value method of measuring the amount of impairment is utilized. This method requires obtaining a current independent appraisal of the collateral and applying a discount factor to the value. A portion of the allowance for loan losses is allocated to impaired loans if the value of such loans is deemed to be less than the unpaid balance. If these allocations cause the allowance for loan losses to require an increase, such increase is reported as a component of the provision for loan losses. Loan losses are charged against the allowance when management believes the uncollectability of a loan is confirmed. Impaired loans that are collateral dependent are classified within Level 3 of the fair value hierarchy when impairment is determined using the fair value method. Appraisals are updated at renewal, if not more frequently, for all collateral dependent loans that are deemed impaired by way of impairment testing. Impairment testing is performed on all loans over $1.5 million rated Substandard or worse, all existing impaired loans regardless of size and all TDRs. All collateral dependent impaired loans meeting these thresholds have had updated appraisals or internally prepared evaluations within the last one to two years and these updated valuations are considered in the quarterly review and discussion of the corporate Special Asset Committee. On targeted CRE loans, appraisals/internally prepared valuations may be updated before the typical 1-3 year balloon/maturity period. If an updated valuation results in decreased value, a specific (ASC 310) impairment is placed against the loan, or a partial charge-down is initiated, depending on the circumstances and anticipation of the loan’s ability to remain a going concern, possibility of foreclosure, certain market factors, etc. Foreclosed assets and other real estate owned – Foreclosed assets and other real estate owned are reported at fair value, less estimated costs to sell. At foreclosure, if the fair value, less estimated costs to sell, of the real estate acquired is less than the Company’s recorded investment in the related loan, a write-down is recognized through a charge to the allowance for loan losses. Additionally, valuations are periodically performed by management and any subsequent reduction in value is recognized by a charge to income. The fair value of foreclosed assets and other real estate owned is estimated using Level 3 inputs based on unobservable market data. As of September 30, 2019 and December 31, 2018 , the fair value of foreclosed assets and other real estate owned less estimated costs to sell was $19.6 million and $25.6 million , respectively. The significant unobservable inputs (Level 3) used in the fair value measurement of collateral for collateral-dependent impaired loans and foreclosed assets primarily relate to the specialized discounting criteria applied to the borrower’s reported amount of collateral. The amount of the collateral discount depends upon the condition and marketability of the collateral, as well as other factors which may affect the collectability of the loan. Management’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset. It is reasonably possible that a change in the estimated fair value for instruments measured using Level 3 inputs could occur in the future. As the Company’s primary objective in the event of default would be to liquidate the collateral to settle the outstanding balance of the loan, collateral that is less marketable would receive a larger discount. During the reported periods, collateral discounts ranged from 10% to 40% for commercial and residential real estate collateral. Mortgage loans held for sale – Mortgage loans held for sale are reported at fair value if, on an aggregate basis, the fair value of the loans is less than cost. In determining whether the fair value of loans held for sale is less than cost when quoted market prices are not available, the Company may consider outstanding investor commitments, discounted cash flow analyses with market assumptions or the fair value of the collateral if the loan is collateral dependent. Such loans are classified within either Level 2 or Level 3 of the fair value hierarchy. Where assumptions are made using significant unobservable inputs, such loans held for sale are classified as Level 3. At September 30, 2019 and December 31, 2018 , the aggregate fair value of mortgage loans held for sale exceeded their cost. Accordingly, no mortgage loans held for sale were marked down and reported at fair value. The following table sets forth the Company’s financial assets by level within the fair value hierarchy that were measured at fair value on a nonrecurring basis as of September 30, 2019 and December 31, 2018 . Fair Value Measurements Using (In thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2019 Impaired loans (1) (2) (collateral dependent) $ 46,903 $ — $ — $ 46,903 Foreclosed assets and other real estate owned (1) 15,046 — — 15,046 December 31, 2018 Impaired loans (1) (2) (collateral dependent) $ 17,789 $ — $ — $ 17,789 Foreclosed assets and other real estate owned (1) 23,714 — — 23,714 ________________________ (1) These amounts represent the resulting carrying amounts on the consolidated balance sheets for impaired collateral dependent loans and foreclosed assets and other real estate owned for which fair value re-measurements took place during the period. (2) Specific allocations of $1,297,000 and $2,738,000 were related to the impaired collateral dependent loans for which fair value re-measurements took place during the periods ended September 30, 2019 and December 31, 2018 , respectively. ASC Topic 825, Financial Instruments , requires disclosure in annual and interim financial statements of the fair value of financial assets and financial liabilities, including those financial assets and financial liabilities that are not measured and reported at fair value on a recurring basis or nonrecurring basis. The following methods and assumptions were used to estimate the fair value of each class of financial instruments not previously disclosed. Cash and cash equivalents – The carrying amount for cash and cash equivalents approximates fair value (Level 1). Interest bearing balances due from banks – The fair value of interest bearing balances due from banks – time is estimated using a discounted cash flow calculation that applies the rates currently offered on deposits of similar remaining maturities (Level 2). Held-to-maturity securities – Fair values for held-to-maturity securities equal quoted market prices, if available, such as for highly liquid government bonds (Level 1). If quoted market prices are not available, fair values are estimated based on quoted market prices of similar securities. For these securities, the Company obtains fair value measurements from an independent pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the security’s terms and conditions, among other things (Level 2). In certain cases where Level 1 or Level 2 inputs are not available, securities are classified within Level 3 of the hierarchy. Loans – The fair value of loans is estimated by discounting the future cash flows, using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities. Additional factors considered include the type of loan and related collateral, variable or fixed rate, classification status, remaining term, interest rate, historical delinquencies, loan to value ratios, current market rates and remaining loan balance. The loans were grouped together according to similar characteristics and were treated in the aggregate when applying various valuation techniques. The discount rates used for loans were based on current market rates for new originations of similar loans. Estimated credit losses were also factored into the projected cash flows of the loans. The fair value of loans is estimated on an exit price basis incorporating the above factors (Level 3). Deposits – The fair value of demand deposits, savings accounts and money market deposits is the amount payable on demand at the reporting date (i.e., their carrying amount) (Level 2). The fair value of fixed-maturity time deposits is estimated using a discounted cash flow calculation that applies the rates currently offered for deposits of similar remaining maturities (Level 3). Federal Funds purchased, securities sold under agreement to repurchase and short-term debt – The carrying amount for Federal funds purchased, securities sold under agreement to repurchase and short-term debt are a reasonable estimate of fair value (Level 2). Other borrowings – For short-term instruments, the carrying amount is a reasonable estimate of fair value. For long-term debt, rates currently available to the Company for debt with similar terms and remaining maturities are used to estimate the fair value (Level 2). Subordinated debentures – The fair value of subordinated debentures is estimated using the rates that would be charged for subordinated debentures of similar remaining maturities (Level 2). Accrued interest receivable/payable – The carrying amounts of accrued interest approximated fair value (Level 2). Commitments to extend credit, letters of credit and lines of credit – The fair value of commitments is estimated using the fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and the present creditworthiness of the counterparties. For fixed rate loan commitments, fair value also considers the difference between current levels of interest rates and the committed rates. The fair values of letters of credit and lines of credit are based on fees currently charged for similar agreements or on the estimated cost to terminate or otherwise settle the obligations with the counterparties at the reporting date. The fair value of a financial instrument is the current amount that would be exchanged between willing parties, other than in a forced liquidation. Fair value is best determined based upon quoted market prices. However, in many instances, there are no quoted market prices for the Company’s various financial instruments. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Accordingly, the fair value estimates may not be realized in an immediate settlement of the instrument. The estimated fair values, and related carrying amounts, of the Company’s financial instruments are as follows: Carrying Fair Value Measurements (In thousands) Amount Level 1 Level 2 Level 3 Total September 30, 2019 Financial assets: Cash and cash equivalents $ 529,970 $ 529,970 $ — $ — $ 529,970 Interest bearing balances due from banks - time 5,041 — 5,041 — 5,041 Held-to-maturity securities 42,237 — 43,302 — 43,302 Mortgage loans held for sale 50,099 — — 50,099 50,099 Interest receivable 53,966 — 53,966 — 53,966 Legacy loans, net 9,577,372 — — 9,505,701 9,505,701 Loans acquired, net 3,359,587 — — 3,334,446 3,334,446 Financial liabilities: Non-interest bearing transaction accounts 3,044,330 — 3,044,330 — 3,044,330 Interest bearing transaction accounts and savings deposits 7,337,571 — 7,337,571 — 7,337,571 Time deposits 3,086,108 — — 3,080,775 3,080,775 Federal funds purchased and securities sold under agreements to repurchase 116,536 — 116,536 — 116,536 Other borrowings 1,098,395 — 1,099,171 — 1,099,171 Subordinated notes and debentures 354,223 — 366,289 — 366,289 Interest payable 15,404 — 15,404 — 15,404 December 31, 2018 Financial assets: Cash and cash equivalents $ 833,458 $ 833,458 $ — $ — $ 833,458 Interest bearing balances due from banks - time 4,934 — 4,934 — 4,934 Held-to-maturity securities 289,194 — 290,830 — 290,830 Mortgage loans held for sale 26,799 — — 26,799 26,799 Interest receivable 49,938 — 49,938 — 49,938 Legacy loans, net 8,373,789 — — 8,280,690 8,280,690 Loans acquired, net 3,292,783 — — 3,256,174 3,256,174 Financial liabilities: Non-interest bearing transaction accounts 2,672,405 — 2,672,405 — 2,672,405 Interest bearing transaction accounts and savings deposits 6,830,191 — 6,830,191 — 6,830,191 Time deposits 2,896,156 — — 2,872,342 2,872,342 Federal funds purchased and securities sold under agreements to repurchase 95,792 — 95,792 — 95,792 Other borrowings 1,345,450 — 1,342,868 — 1,342,868 Subordinated debentures 353,950 — 355,812 — 355,812 Interest payable 9,897 — 9,897 — 9,897 The fair value of commitments to extend credit, letters of credit and lines of credit is not presented since management believes the fair value to be insignificant.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS On October 22, 2019, the Company announced that its Board of Directors authorized a new stock repurchase program (the “Program”) under which the Company may repurchase up to $60,000,000 of its Class A common stock currently issued and outstanding. The Program will terminate on October 31, 2021 (unless terminated sooner). The new Program replaces the Company’s existing stock repurchase program, which was announced on July 23, 2012. Under the Program, the Company may repurchase shares of its common stock through open market and privately negotiated transactions or otherwise. The timing, pricing, and amount of any repurchases under the Program will be determined by the Company’s management at its discretion based on a variety of factors, including, but not limited to, trading volume and market price of the Company’s common stock, corporate considerations, the Company’s working capital and investment requirements, general market and economic conditions, and legal requirements. The Program does not obligate the Company to repurchase any common stock and may be modified, discontinued, or suspended at any time without prior notice. The Company anticipates funding for this Program to come from available sources of liquidity, including cash on hand and future cash flow. On October 29, 2019, the Company filed its Amended and Restated Articles of Incorporation (“Amended Articles”) with the Arkansas Secretary of State. The Amended Articles classified and designated Series D Preferred Stock, Par Value $0.01 Per Share (“Series D Preferred Stock”) out of the Company’s authorized preferred stock. The Amended Articles also canceled the Company’s 7% Perpetual Convertible Preferred Stock, Par Value $0.01 Per Share, Series C (“Series C Preferred Stock”), having 140 authorized shares, of which no shares have ever been issued or outstanding. The Amended Articles were effective as of October 29, 2019. Please refer to Note 2, Acquisitions, for a discussion of the Company’s recent acquisition of The Landrum Company that closed on October 31, 2019.

Preparation of Interim Financ_2

Preparation of Interim Financial Statements (Policies)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited consolidated financial statements have been prepared based upon Securities and Exchange Commission (“SEC”) rules that permit reduced disclosures for interim periods. Certain information and footnote disclosures have been condensed or omitted in accordance with those rules and regulations. The accompanying consolidated balance sheet as of December 31, 2018 , was derived from audited financial statements. In the opinion of management, these financial statements reflect all adjustments that are necessary for a fair presentation of interim results of operations, including normal recurring accruals. Significant intercompany accounts and transactions have been eliminated in consolidation. The results for the interim periods are not necessarily indicative of results for the full year. For a more complete discussion of significant accounting policies and certain other information, this report should be read in conjunction with the consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 , which was filed with the SEC on February 27, 2019 . The preparation of financial statements, in accordance with accounting principles generally accepted in the United States (“US GAAP”), requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, income items and expenses and disclosure of contingent assets and liabilities. The estimates and assumptions used in the accompanying consolidated financial statements are based upon management’s evaluation of the relevant facts and circumstances as of the date of the consolidated financial statements and actual results may differ from these estimates. Such estimates include, but are not limited to, the Company’s allowance for loan losses.
Reclassification	Certain prior year amounts have been reclassified to conform to the current year financial statement presentation. These changes and reclassifications did not impact previously reported net income or comprehensive income.
Recently Adopted and Issued Accounting Standards	Recently Adopted Accounting Standards Cloud Computing Arrangements – In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract (“ASU 2018-15”), that amends the definition of a hosting arrangement and requires a customer in a hosting arrangement that is a service contract to capitalize certain implementation costs as if the arrangement was an internal-use software project. The internal-use software guidance states that only qualifying costs incurred during the application development stage can be capitalized. The effective date is for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted. Entities have the option to apply the guidance prospectively to all implementation costs incurred after the date of adoption or retrospectively in accordance with the applicable guidance. At the time of adoption, entities will be required to disclose the nature of its hosting arrangements that are service contracts and provide disclosures as if the deferred implementation costs were a separate, major depreciable asset class. The Company early adopted ASU 2018-15 in the first quarter 2019 and elected to apply the guidance prospectively to all software implementation costs incurred after the date of adoption. As of September 30, 2019 , $1.1 million of applicable software implementation costs have been capitalized and have not had a material impact on our financial position or results of operations. Derivatives and Hedging: Targeted Improvements - In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities (“ASU 2017-12”), that changes both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results in order to better align a company’s risk management activities and financial reporting for hedging relationships. In summary, this amendment 1) expands the types of transactions eligible for hedge accounting; 2) eliminates the separate measurement and presentation of hedge ineffectiveness; 3) simplifies the requirements around the assessment of hedge effectiveness; 4) provides companies more time to finalize hedge documentation; and 5) enhances presentation and disclosure requirements. The effective date was for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption permitted. All transition requirements and elections should be applied to existing hedging relationships on the date of adoption and the effects should be reflected as of the beginning of the fiscal year of adoption. As part of this new guidance, entities are allowed to designate as the hedged item, an amount that is not expected to be affected by prepayments, defaults or other events affecting the timing and amount of cash flows in a closed portfolio of prepayable financial instruments (this is referred to as the “last-of-layer” method). Under the last-of-layer method, entities are able to reclassify, only at the time of adoption, eligible callable debt securities from held-to-maturity to available-for-sale without tainting its intentions to hold future debt securities to maturity. The available-for-sale security must be reported at fair value and any unrealized gain or loss must be recorded as an adjustment to other comprehensive income upon adoption. The Company evaluated its held-to-maturity portfolio during the first quarter 2019 and identified certain municipal bonds with a fair value of $216.4 million that met the last-of-layer criteria under ASU 2017-12 and as a result, reclassified those to available-for-sale and recorded an unrealized gain of $2.5 million during the first quarter 2019. Goodwill Impairment – In January 2017, the FASB issued ASU No. 2017-04, Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment (“ASU 2017-04”), that eliminates Step 2 from the goodwill impairment test which required entities to compare the implied fair value of goodwill to its carrying amount. Under the amendments, the goodwill impairment will be measured as the excess of the reporting unit’s carrying amount over its fair value. An impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The effective date is for fiscal years beginning after December 15, 2019, with early adoption permitted for interim or annual impairment tests beginning in 2017. The Company early adopted ASU 2017-04 during the second quarter 2019 to coincide with the Company’s formal impairment analysis. See Note 7, Goodwill and Other Intangible Assets, for additional information. Leases - In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02”), that establishes the principles to report transparent and economically neutral information about the assets and liabilities that arise from leases. The new guidance results in a more consistent representation of the rights and obligations arising from leases by requiring lessees to recognize the lease asset and lease liabilities that arise from leases in the consolidated balance sheet and to disclose qualitative and quantitative information about lease transactions, such as information about variable lease payments and options to renew and terminate leases. The effective date was for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. ASU 2016-02 requires entities to adopt the new lease standard using a modified retrospective transition method, meaning an entity initially applies the new lease standard at the beginning of the earliest period presented in the financial statements. Due to complexities associated with using this method, in July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements , to relieve entities of the requirement to present prior comparative years’ results when they adopt the new lease standard and giving entities the option to recognize the cumulative effect of applying the new standard as an adjustment to the opening balance of retained earnings. Adoption of ASU 2016-02 resulted in the recognition of right-of-use assets of $32.8 million and right-of-use liabilities of $32.8 million on the consolidated balance sheet with no material impact to the results of operations. The Company has elected to adopt the guidance using the optional transition method, which allows for a modified retrospective method of adoption with a cumulative effect adjustment to retained earnings without restating comparable periods. The Company also elected the relief package of practical expedients for which there is no requirement to reassess existence of leases, their classification, and initial direct costs as well as an exemption for short-term leases with a term of less than one year, whereby the Company did not recognize a lease liability or right-of-use asset on the consolidated balance sheet but instead will recognize lease payments as an expense over the lease term as appropriate. See Note 6, Right-of-Use Lease Assets and Lease Liabilities, for additional information related to the Company’s right-of-use lease obligations. Recently Issued Accounting Standards Fair Value Measurement Disclosures – In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”), that eliminates, amends and adds disclosure requirements for fair value measurements. These amendments are part of FASB’s disclosure review project and they are expected to reduce costs for preparers while providing more decision-useful information for financial statement users. The eliminated disclosure requirements include the 1) the amount of, and reasons for, transfers between Level 1 and Level 2 of the fair value hierarchy; 2) the policy of timing of transfers between levels of the fair value hierarchy; and 3) the valuation processes for Level 3 fair value measurements. Among other modifications, the amended disclosure requirements remove the term “at a minimum” from the phrase “an entity shall disclose at a minimum” to promote the appropriate exercise of discretion by entities and clarifies that the measurement uncertainty disclosure is to communicate information about the uncertainty in measurement as of the reporting date. Under the new disclosure requirements, entities must disclose the changes in unrealized gains or losses included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period and the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. ASU 2018-13 is effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted. The Company is currently evaluating the impact this standard will have on its fair value disclosures. Credit Losses on Financial Instruments – In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which requires earlier measurement of credit losses, expands the range of information considered in determining expected credit losses and enhances disclosures. The main objective of ASU 2016-13 is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The amendments replace the incurred loss impairment methodology in current US GAAP with a methodology (the current expected credit losses, or “CECL”, methodology) that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The CECL methodology utilizes a lifetime “expected credit loss” measurement objective for the recognition of credit losses for loans, held-to-maturity debt securities and other receivables measured at amortized cost at the time the financial asset is originated or acquired. The allowance for credit losses is adjusted each period for changes in expected lifetime credit losses. This methodology replaces the multiple existing impairment methods in current guidance, which generally require that a loss be incurred before it is recognized. Within the life cycle of a loan or other financial asset, this new guidance will generally result in the earlier recognition of the provision for credit losses and the related allowance for credit losses than current practice. For available-for-sale debt securities that the Company intends to hold and where fair value is less than cost, credit-related impairment, if any, will be recognized through an allowance for credit losses and adjusted each period for changes in credit risk. The effective date for these amendments is for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company has formed a cross functional team that continues to assess its data and system needs and evaluate the potential impact of adopting the new guidance. The Company anticipates a significant change in the processes and procedures to calculate the loan losses, including changes in assumptions and estimates to consider expected credit losses over the life of the loan versus the current accounting practice that utilizes the incurred loss model. In December 2018, the Federal Reserve, Office of the Comptroller of the Currency and Federal Deposit Insurance Corporation (“FDIC”) issued a final rule revising regulatory capital rules in anticipation of the adoption of ASU 2016-13 that provides an option to phase in over a three year period on a straight line basis the day-one impact on earnings and tier one capital. Due to this final rule from the regulatory agencies, the Company is continuing to research and study options for recording a one-time adjustment or structuring any capital impact over an allowable period of time. The impact will be reflected as an adjustment to beginning retained earnings, net of income taxes, at adoption. Based on a preliminary analysis performed, the Company previously disclosed that the allowance for credit losses was estimated to increase by approximately 130% to 170% over the allowance based on June 30, 2019 loan balances. When purchase discounts are considered, the increase is expected to be 10% to 30% over the June 30, 2019 total credit coverage ratio. These estimates were based upon the Company’s analysis of current macroeconomic conditions, assumptions and forecasts at the point in time at which the initial guidance was given and did not include the impact of the Company’s acquisition of The Landrum Company. When factoring in the Company’s recent acquisition of The Landrum Company (see Note 2, Acquisitions, for additional information regarding the acquisition), the allowance for credit losses is estimated to increase by approximately 165% to 215% over the allowance and when purchase discounts are considered, the increase is expected to be 5% to 25% over the total credit coverage ratio. These estimates are subject to change based on continuing review and challenge of the models, methodologies and judgments. The impact at adoption will also be influenced by the loan portfolio composition and quality at the adoption date, as well as, macroeconomic conditions and forecast at that time. The adoption of ASU 2016-13 in 2020 could also impact the Company’s ongoing earnings, perhaps materially. Implementation efforts for the adoption of CECL have been underway, including model development and validation, fulfillment of additional data needs for new disclosures and reporting requirements, and drafting of accounting policies. Model validations and user acceptance testing commenced in the first quarter of 2019, with loss forecast modeling taking place in the third quarter of 2019. The Company intends to utilize a single macroeconomic scenario in estimating expected credit losses. Reasonable and supportable forecast periods and methods to revert to historical averages to arrive at lifetime expected credit losses vary by product. The Company has completed decisions around model methodologies, and relevant elections are being finalized. There have been no other significant changes to the Company’s accounting policies from the 2018
Loans Acquired	The Company accounts for its acquisitions under ASC Topic 805, Business Combinations , which requires the use of the acquisition method of accounting. All identifiable assets acquired, including loans, are recorded at fair value. No allowance for loan losses related to the loans acquired is recorded on the acquisition date as the fair value of the loans acquired incorporates assumptions regarding credit risk. Loans acquired are recorded at fair value in accordance with the fair value methodology prescribed in ASC Topic 820, Fair Value Measurement . The fair value estimates associated with the loans include estimates related to expected prepayments and the amount and timing of undiscounted expected principal, interest and other cash flows. The Company evaluates non-impaired loans acquired in accordance with the provisions of ASC Topic 310-20, Nonrefundable Fees and Other Costs . The fair value discount on these loans is accreted into interest income over the weighted average life of the loans using a constant yield method. The Company evaluates purchased impaired loans in accordance with the provisions of ASC Topic 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality . Purchased loans are considered impaired if there is evidence of credit deterioration since origination and if it is probable that not all contractually required payments will be collected. For impaired loans accounted for under ASC Topic 310-30, the Company continues to estimate cash flows expected to be collected on purchased credit impaired loans. The Company evaluates, at each balance sheet date, whether the present value of the purchased credit impaired loans determined using the effective interest rates has decreased significantly and if so, recognize a provision for loan loss in the consolidated statement of income. For any significant increases in cash flows expected to be collected, the Company adjusts the amount of accretable yield recognized on a prospective basis over the remaining life of the purchased credit impaired loan.
Income Taxes	The Company follows ASC Topic 740, Income Taxes , which prescribes a recognition threshold and a measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. Benefits from tax positions should be recognized in the financial statements only when it is more likely than not that the tax position will be sustained upon examination by the appropriate taxing authority that would have full knowledge of all relevant information. A tax position that meets the more-likely-than-not recognition threshold is measured at the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement. Tax positions that previously failed to meet the more-likely-than-not recognition threshold should be recognized in the first subsequent financial reporting period in which that threshold is met. Previously recognized tax positions that no longer meet the more-likely-than-not recognition threshold should be derecognized in the first subsequent financial reporting period in which that threshold is no longer met. ASC Topic 740 also provides guidance on the accounting for and disclosure of unrecognized tax benefits, interest and penalties. The Company has no history of expiring net operating loss carryforwards and is projecting significant pre-tax and financial taxable income in 2019 and in future years. The Company expects to fully realize its deferred tax assets in the future.

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Fair Value of Assets Acquired and Liabilities Assumed	A summary, at fair value, of the assets acquired and liabilities assumed in the Reliance transaction, as of the acquisition date, is as follows: (In thousands) Acquired from Reliance Fair Value Adjustments Fair Value Assets Acquired Cash and due from banks $ 25,693 $ — $ 25,693 Due from banks - time 502 — 502 Investment securities 287,983 (1,763 ) 286,220 Loans acquired 1,138,527 (41,657 ) 1,096,870 Allowance for loan losses (10,808 ) 10,808 — Foreclosed assets 11,092 (5,180 ) 5,912 Premises and equipment 32,452 (3,001 ) 29,451 Bank owned life insurance 39,348 — 39,348 Core deposit intangible — 18,350 18,350 Other assets 25,165 5,001 30,166 Total assets acquired $ 1,549,954 $ (17,442 ) $ 1,532,512 Liabilities Assumed Deposits: Non-interest bearing transaction accounts $ 108,845 $ (33 ) $ 108,812 Interest bearing transaction accounts and savings deposits 639,798 — 639,798 Time deposits 478,415 (1,758 ) 476,657 Total deposits 1,227,058 (1,791 ) 1,225,267 Securities sold under agreement to repurchase 14,146 — 14,146 Other borrowings 162,900 (5,500 ) 157,400 Accrued interest and other liabilities 8,185 936 9,121 Total liabilities assumed 1,412,289 (6,355 ) 1,405,934 Equity 137,665 (95,665 ) 42,000 Total equity assumed 137,665 (95,665 ) 42,000 Total liabilities and equity assumed $ 1,549,954 $ (102,020 ) $ 1,447,934 Net assets acquired 84,578 Purchase price 165,539 Goodwill $ 80,961

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Investment Securities	The amortized cost and fair value of investment securities that are classified as held-to-maturity (“HTM”) and available-for-sale (“AFS”) are as follows: September 30, 2019 December 31, 2018 (In thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Estimated Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Estimated Fair Value Held-to-Maturity U.S. Government agencies $ — $ — $ — $ — $ 16,990 $ — $ (49 ) $ 16,941 Mortgage-backed securities 11,549 93 (42 ) 11,600 13,346 5 (412 ) 12,939 State and political subdivisions 28,692 931 — 29,623 256,863 3,029 (954 ) 258,938 Other securities 1,996 83 — 2,079 1,995 17 — 2,012 Total HTM $ 42,237 $ 1,107 $ (42 ) $ 43,302 $ 289,194 $ 3,051 $ (1,415 ) $ 290,830 Available-for-Sale U.S. Government agencies $ 177,712 $ 1,629 $ (1,202 ) $ 178,139 $ 157,523 $ 518 $ (3,740 ) $ 154,301 Mortgage-backed securities 1,332,130 9,405 (3,741 ) 1,337,794 1,552,487 3,097 (32,684 ) 1,522,900 State and political subdivisions 658,984 22,290 (72 ) 681,202 320,142 171 (5,470 ) 314,843 Other securities 158,280 719 — 158,999 157,471 2,251 (14 ) 159,708 Total AFS $ 2,327,106 $ 34,043 $ (5,015 ) $ 2,356,134 $ 2,187,623 $ 6,037 $ (41,908 ) $ 2,151,752
Gross Unrealized Losses and Fair Value of Investments	The following table shows the gross unrealized losses and fair value of the Company’s investments with unrealized losses, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at September 30, 2019 : Less Than 12 Months 12 Months or More Total (In thousands) Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Held-to-Maturity Mortgage-backed securities $ 3,408 $ (15 ) $ 2,575 $ (27 ) $ 5,983 $ (42 ) State and political subdivisions 635 — 15 — 650 — Total HTM $ 4,043 $ (15 ) $ 2,590 $ (27 ) $ 6,633 $ (42 ) Available-for-Sale U.S. Government agencies $ 16,662 $ (36 ) $ 90,974 $ (1,166 ) $ 107,636 $ (1,202 ) Mortgage-backed securities 133,538 (528 ) 435,207 (3,213 ) 568,745 (3,741 ) State and political subdivisions 24,278 (41 ) 3,297 (31 ) 27,575 (72 ) Total AFS $ 174,478 $ (605 ) $ 529,478 $ (4,410 ) $ 703,956 $ (5,015 )
Income Earned on Securities	Income earned on securities for the three and nine months ended September 30, 2019 and 2018 , is as follows: Three Months Ended Nine Months Ended (In thousands) 2019 2018 2019 2018 Taxable: Held-to-maturity $ 248 $ 528 $ 975 $ 1,641 Available-for-sale 10,166 10,364 34,422 29,614 Non-taxable: Held-to-maturity 83 1,828 1,334 5,661 Available-for-sale 4,870 1,920 12,542 4,642 Total $ 15,367 $ 14,640 $ 49,273 $ 41,558
Amortized Cost and Estimated Fair Value by Maturity of Securities	The amortized cost and estimated fair value by maturity of securities are shown in the following table. Securities are classified according to their contractual maturities without consideration of principal amortization, potential prepayments or call options. Accordingly, actual maturities may differ from contractual maturities. Held-to-Maturity Available-for-Sale (In thousands) Amortized Cost Fair Value Amortized Cost Fair Value One year or less $ 5,039 $ 5,057 $ 7,599 $ 7,605 After one through five years 17,346 17,703 70,442 70,750 After five through ten years 5,561 5,858 139,421 142,101 After ten years 2,742 3,084 632,504 652,404 Securities not due on a single maturity date 11,549 11,600 1,332,130 1,337,794 Other securities (no maturity) — — 145,010 145,480 Total $ 42,237 $ 43,302 $ 2,327,106 $ 2,356,134

Loans and Allowance for Loan _2

Loans and Allowance for Loan Losses (Tables)	9 Months Ended
	Sep. 30, 2019
Receivables [Abstract]
Loan Portfolio	The various categories of loans are summarized as follows: (In thousands) September 30, 2019 December 31, 2018 Consumer: Credit cards $ 195,083 $ 204,173 Other consumer 208,643 201,297 Total consumer 403,726 405,470 Real Estate: Construction 1,712,858 1,300,723 Single family residential 1,448,455 1,440,443 Other commercial 3,630,708 3,225,287 Total real estate 6,792,021 5,966,453 Commercial: Commercial 1,894,819 1,774,909 Agricultural 213,753 164,514 Total commercial 2,108,572 1,939,423 Other 339,046 119,042 Loans 9,643,365 8,430,388 Loans acquired, net of discount and allowance (1) 3,359,587 3,292,783 Total loans $ 13,002,952 $ 11,723,171 _____________________________ (1) See Note 5, Loans Acquired, for segregation of loans acquired by loan class. Changes in the carrying amount of the accretable yield for all purchased impaired loans were as follows for the three and nine months ended September 30, 2019 and 2018 . Three Months Ended Nine Months Ended (In thousands) Accretable Yield Carrying Amount of Loans Accretable Yield Carrying Amount of Loans Beginning balance $ 1,461 $ 3,487 $ 1,460 $ 4,050 Additions — — — 175 Accretable yield adjustments 10 — 38 — Accretion (12 ) 12 (39 ) 39 Payments and other reductions, net — (422 ) — (1,187 ) Balance, ending $ 1,459 $ 3,077 $ 1,459 $ 3,077 Three Months Ended Nine Months Ended (In thousands) Accretable Yield Carrying Amount of Loans Accretable Yield Carrying Amount of Loans Beginning balance $ 1,382 $ 13,995 $ 620 $ 17,116 Additions — — — — Accretable yield adjustments 717 — 1,895 — Accretion (635 ) 635 (1,051 ) 1,051 Payments and other reductions, net — (9,664 ) — (13,201 ) Balance, ending $ 1,464 $ 4,966 $ 1,464 $ 4,966 The following table reflects the carrying value of all loans acquired as of September 30, 2019 and December 31, 2018 : Loans Acquired (In thousands) September 30, 2019 December 31, 2018 Consumer: Other consumer $ 7,431 $ 15,658 Real estate: Construction 362,000 429,605 Single family residential 504,490 566,188 Other commercial 2,134,973 1,848,679 Total real estate 3,001,463 2,844,472 Commercial: Commercial 349,821 430,914 Agricultural 872 1,739 Total commercial 350,693 432,653 Total loans acquired (1) $ 3,359,587 $ 3,292,783 ________________________ (1) Loans acquired are reported net of a $597,000 and $95,000 allowance at September 30, 2019 and December 31, 2018 , respectively.
Nonaccrual Loans	Nonaccrual loans, excluding loans acquired, segregated by class of loans, are as follows: (In thousands) September 30, 2019 December 31, 2018 Consumer: Credit cards $ 521 $ 296 Other consumer 1,634 2,159 Total consumer 2,155 2,455 Real estate: Construction 1,805 1,269 Single family residential 16,191 11,939 Other commercial 16,985 7,205 Total real estate 34,981 20,413 Commercial: Commercial 35,018 10,049 Agricultural 567 1,284 Total commercial 35,585 11,333 Total $ 72,721 $ 34,201 Nonaccrual loans acquired, excluding purchased credit impaired loans accounted for under ASC Topic 310-30, segregated by class of loans, are as follows (see Note 4, Loans and Allowance for Loan Losses, for discussion of nonaccrual loans): (In thousands) September 30, 2019 December 31, 2018 Consumer: Other consumer $ 71 $ 140 Real estate: Construction 48 114 Single family residential 4,492 6,603 Other commercial 1,029 1,167 Total real estate 5,569 7,884 Commercial: Commercial 1,636 13,578 Agricultural 23 38 Total commercial 1,659 13,616 Total $ 7,299 $ 21,640
Past Due Loans	An age analysis of past due loans, excluding loans acquired, segregated by class of loans, is as follows: (In thousands) Gross 30-89 Days Past Due 90 Days or More Past Due Total Past Due Current Total Loans 90 Days Past Due & Accruing September 30, 2019 Consumer: Credit cards $ 958 $ 650 $ 1,608 $ 193,475 $ 195,083 $ 130 Other consumer 3,383 694 4,077 204,566 208,643 14 Total consumer 4,341 1,344 5,685 398,041 403,726 144 Real estate: Construction 3,690 613 4,303 1,708,555 1,712,858 — Single family residential 10,022 6,395 16,417 1,432,038 1,448,455 — Other commercial 8,009 3,385 11,394 3,619,314 3,630,708 — Total real estate 21,721 10,393 32,114 6,759,907 6,792,021 — Commercial: Commercial 4,999 10,990 15,989 1,878,830 1,894,819 11 Agricultural 285 349 634 213,119 213,753 — Total commercial 5,284 11,339 16,623 2,091,949 2,108,572 11 Other — — — 339,046 339,046 — Total $ 31,346 $ 23,076 $ 54,422 $ 9,588,943 $ 9,643,365 $ 155 December 31, 2018 Consumer: Credit cards $ 1,033 $ 506 $ 1,539 $ 202,634 $ 204,173 $ 209 Other consumer 4,264 896 5,160 196,137 201,297 4 Total consumer 5,297 1,402 6,699 398,771 405,470 213 Real estate: Construction 533 308 841 1,299,882 1,300,723 — Single family residential 7,769 4,127 11,896 1,428,547 1,440,443 — Other commercial 3,379 2,773 6,152 3,219,135 3,225,287 — Total real estate 11,681 7,208 18,889 5,947,564 5,966,453 — Commercial: Commercial 4,472 5,105 9,577 1,765,332 1,774,909 11 Agricultural 467 1,055 1,522 162,992 164,514 — Total commercial 4,939 6,160 11,099 1,928,324 1,939,423 11 Other — — — 119,042 119,042 — Total $ 21,917 $ 14,770 $ 36,687 $ 8,393,701 $ 8,430,388 $ 224 An age analysis of past due loans acquired segregated by class of loans, is as follows (see Note 4, Loans and Allowance for Loan Losses, for discussion of past due loans): (In thousands) Gross 30-89 Days Past Due 90 Days or More Past Due Total Past Due Current Total Loans 90 Days Past Due & Accruing September 30, 2019 Consumer: Other consumer $ 131 $ 36 $ 167 $ 7,264 $ 7,431 $ 4 Real estate: Construction 30 12 42 361,958 362,000 — Single family residential 3,664 1,790 5,454 499,036 504,490 17 Other commercial 1,888 943 2,831 2,132,142 2,134,973 — Total real estate 5,582 2,745 8,327 2,993,136 3,001,463 17 Commercial: Commercial 607 724 1,331 348,490 349,821 — Agricultural — — — 872 872 — Total commercial 607 724 1,331 349,362 350,693 — Total $ 6,320 $ 3,505 $ 9,825 $ 3,349,762 $ 3,359,587 $ 21 December 31, 2018 Consumer: Other consumer $ 337 $ 49 $ 386 $ 15,272 $ 15,658 $ 2 Real estate: Construction 8,283 27 8,310 421,295 429,605 — Single family residential 4,706 3,049 7,755 558,433 566,188 — Other commercial 168 577 745 1,847,934 1,848,679 — Total real estate 13,157 3,653 16,810 2,827,662 2,844,472 — Commercial: Commercial 1,302 9,542 10,844 420,070 430,914 — Agricultural 31 5 36 1,703 1,739 — Total commercial 1,333 9,547 10,880 421,773 432,653 — Total $ 14,827 $ 13,249 $ 28,076 $ 3,264,707 $ 3,292,783 $ 2
Impaired Loans	Impaired loans, net of government guarantees and excluding loans acquired, segregated by class of loans, are as follows: (In thousands) Unpaid Contractual Principal Balance Recorded Investment With No Allowance Recorded Investment With Allowance Total Recorded Investment Related Allowance Average Investment in Impaired Loans Interest Income Recognized Average Investment in Impaired Loans Interest Income Recognized September 30, 2019 Three Months Ended Nine Months Ended Consumer: Credit cards $ 521 $ 521 $ — $ 521 $ — $ 423 $ 40 $ 370 $ 110 Other consumer 1,783 1,634 — 1,634 — 1,603 9 1,730 33 Total consumer 2,304 2,155 — 2,155 — 2,026 49 2,100 143 Real estate: Construction 1,898 1,708 97 1,805 — 1,972 10 1,946 38 Single family residential 17,526 13,985 2,206 16,191 31 15,920 85 14,812 287 Other commercial 15,642 4,200 11,007 15,207 628 11,739 77 10,365 201 Total real estate 35,066 19,893 13,310 33,203 659 29,631 172 27,123 526 Commercial: Commercial 50,712 10,153 23,930 34,083 4,620 32,020 176 26,379 511 Agricultural 583 450 116 566 — 873 3 1,010 20 Total commercial 51,295 10,603 24,046 34,649 4,620 32,893 179 27,389 531 Total $ 88,665 $ 32,651 $ 37,356 $ 70,007 $ 5,279 $ 64,550 $ 400 $ 56,612 $ 1,200 December 31, 2018 Three Months Ended Nine Months Ended Consumer: Credit cards $ 296 $ 296 $ — $ 296 $ — $ 283 $ 35 $ 259 $ 60 Other consumer 2,311 2,159 — 2,159 — 3,561 28 4,109 96 Total consumer 2,607 2,455 — 2,455 — 3,844 63 4,368 156 Real estate: Construction 1,344 784 485 1,269 211 1,411 11 1,747 41 Single family residential 12,906 11,468 616 12,084 36 13,577 98 13,550 315 Other commercial 8,434 5,442 5,458 10,900 — 12,282 108 14,284 332 Total real estate 22,684 17,694 6,559 24,253 247 27,270 217 29,581 688 Commercial: Commercial 10,361 7,254 4,628 11,882 437 11,840 108 9,533 222 Agricultural 2,419 1,180 — 1,180 — 1,355 12 1,470 34 Total commercial 12,780 8,434 4,628 13,062 437 13,195 120 11,003 256 Total $ 38,071 $ 28,583 $ 11,187 $ 39,770 $ 684 $ 44,309 $ 400 $ 44,952 $ 1,100
Troubled Debt Restructuring	The following table presents a summary of TDRs, excluding loans acquired, segregated by class of loans. Accruing TDR Loans Nonaccrual TDR Loans Total TDR Loans (Dollars in thousands) Number Balance Number Balance Number Balance September 30, 2019 Real estate: Construction — $ — 1 $ 97 1 $ 97 Single-family residential 6 549 10 627 16 1,176 Other commercial 2 3,166 2 950 4 4,116 Total real estate 8 3,715 13 1,674 21 5,389 Commercial: Commercial 4 2,804 3 84 7 2,888 Total commercial 4 2,804 3 84 7 2,888 Total 12 $ 6,519 16 $ 1,758 28 $ 8,277 December 31, 2018 Real estate: Construction — $ — 3 $ 485 3 $ 485 Single-family residential 6 230 10 616 16 846 Other commercial 2 3,306 2 1,027 4 4,333 Total real estate 8 3,536 15 2,128 23 5,664 Commercial: Commercial 4 2,833 6 718 10 3,551 Total commercial 4 2,833 6 718 10 3,551 Total 12 $ 6,369 21 $ 2,846 33 $ 9,215 The following table presents loans that were restructured as TDRs during the three and nine months ended September 30, 2019 and 2018 , excluding loans acquired, segregated by class of loans. Modification Type (Dollars in thousands) Number of Loans Balance Prior to TDR Balance at September 30, Change in Maturity Date Change in Rate Financial Impact on Date of Restructure Three and Nine Months Ended September 30, 2019 Real estate: Single-family residential 1 $ 330 $ 330 $ 330 $ — $ — Total real estate 1 330 330 330 — — Total 1 $ 330 $ 330 $ 330 $ — $ — Three Months Ended September 30, 2018 Real estate: Construction 1 $ 99 $ 98 $ 98 $ — $ — Other commercial 2 392 390 390 — 212 Total real estate 3 491 488 488 — 212 Commercial: Commercial 3 2,363 2,358 2,358 — 190 Total commercial 3 2,363 2,358 2,358 — 190 Total 6 $ 2,854 $ 2,846 $ 2,846 $ — $ 402 Nine Months Ended September 30, 2018 Consumer: Other consumer 1 $ 91 $ 91 $ 91 $ — $ — Total consumer 1 91 91 91 — — Real estate: Construction 1 99 98 98 — — Single-family residential 1 61 62 62 — — Other commercial 2 392 390 390 — 212 Total real estate 4 552 550 550 — 212 Commercial: Commercial 3 2,363 2,358 2,358 — 190 Total commercial 3 2,363 2,358 2,358 — 190 Total 8 $ 3,006 $ 2,999 $ 2,999 $ — $ 402
Loans by Credit Risk Ratings	The following table presents a summary of loans by credit risk rating as of September 30, 2019 and December 31, 2018 , segregated by class of loans. Loans accounted for under ASC Topic 310-30 are all included in Risk Rate 1-4 in this table. (In thousands) Risk Rate 1-4 Risk Rate 5 Risk Rate 6 Risk Rate 7 Risk Rate 8 Total September 30, 2019 Consumer: Credit cards $ 194,433 $ — $ 650 $ — $ — $ 195,083 Other consumer 206,647 — 1,996 — — 208,643 Total consumer 401,080 — 2,646 — — 403,726 Real estate: Construction 1,705,376 1,456 6,026 — — 1,712,858 Single family residential 1,422,086 3,246 23,119 4 — 1,448,455 Other commercial 3,571,706 33,030 25,972 — — 3,630,708 Total real estate 6,699,168 37,732 55,117 4 — 6,792,021 Commercial: Commercial 1,837,374 10,420 47,025 — — 1,894,819 Agricultural 213,072 69 612 — — 213,753 Total commercial 2,050,446 10,489 47,637 — — 2,108,572 Other 339,046 — — — — 339,046 Loans acquired 3,272,024 46,796 40,639 128 — 3,359,587 Total $ 12,761,764 $ 95,017 $ 146,039 $ 132 $ — $ 13,002,952 (In thousands) Risk Rate 1-4 Risk Rate 5 Risk Rate 6 Risk Rate 7 Risk Rate 8 Total December 31, 2018 Consumer: Credit cards $ 203,667 $ — $ 506 $ — $ — $ 204,173 Other consumer 198,840 — 2,457 — — 201,297 Total consumer 402,507 — 2,963 — — 405,470 Real estate: Construction 1,296,988 1,910 1,825 — — 1,300,723 Single family residential 1,420,052 1,628 18,528 235 — 1,440,443 Other commercial 3,193,289 17,169 14,829 — — 3,225,287 Total real estate 5,910,329 20,707 35,182 235 — 5,966,453 Commercial: Commercial 1,742,002 8,357 24,550 — — 1,774,909 Agricultural 162,824 75 1,615 — — 164,514 Total commercial 1,904,826 8,432 26,165 — — 1,939,423 Other 119,042 — — — — 119,042 Loans acquired 3,187,083 51,255 54,097 348 — 3,292,783 Total $ 11,523,787 $ 80,394 $ 118,407 $ 583 $ — $ 11,723,171 The following table presents a summary of loans acquired by credit risk rating, segregated by class of loans (see Note 4, Loans and Allowance for Loan Losses, for discussion of loan risk rating). Loans accounted for under ASC Topic 310-30 are all included in Risk Rate 1-4 in this table. (In thousands) Risk Rate 1-4 Risk Rate 5 Risk Rate 6 Risk Rate 7 Risk Rate 8 Total September 30, 2019 Consumer: Other consumer $ 7,285 $ — $ 146 $ — $ — $ 7,431 Real estate: Construction 344,075 17,874 51 — — 362,000 Single family residential 492,826 1,224 10,312 128 — 504,490 Other commercial 2,085,649 26,207 23,117 — — 2,134,973 Total real estate 2,922,550 45,305 33,480 128 — 3,001,463 Commercial: Commercial 341,385 1,491 6,945 — — 349,821 Agricultural 804 — 68 — — 872 Total commercial 342,189 1,491 7,013 — — 350,693 Total $ 3,272,024 $ 46,796 $ 40,639 $ 128 $ — $ 3,359,587 December 31, 2018 Consumer: Other consumer $ 15,380 $ — $ 278 $ — $ — $ 15,658 Real estate: Construction 393,122 27,621 8,862 — — 429,605 Single family residential 553,460 2,081 10,299 348 — 566,188 Other commercial 1,822,179 9,137 17,363 — — 1,848,679 Total real estate 2,768,761 38,839 36,524 348 — 2,844,472 Commercial: Commercial 401,300 12,416 17,198 — — 430,914 Agricultural 1,642 — 97 — — 1,739 Total commercial 402,942 12,416 17,295 — — 432,653 Total $ 3,187,083 $ 51,255 $ 54,097 $ 348 $ — $ 3,292,783
Allowance for Loan Losses	The Company’s recorded investment in loans, excluding loans acquired, related to each balance in the allowance for loan losses by portfolio segment on the basis of the Company’s impairment methodology was as follows: (In thousands) Commercial Real Estate Credit Card Other Consumer and Other Total September 30, 2019 Loans individually evaluated for impairment $ 34,649 $ 33,203 $ 521 $ 1,634 $ 70,007 Loans collectively evaluated for impairment 2,073,923 6,758,818 194,562 546,055 9,573,358 Balance, end of period $ 2,108,572 $ 6,792,021 $ 195,083 $ 547,689 $ 9,643,365 December 31, 2018 Loans individually evaluated for impairment $ 13,062 $ 24,253 $ 296 $ 2,159 $ 39,770 Loans collectively evaluated for impairment 1,926,361 5,942,200 203,877 318,180 8,390,618 Balance, end of period $ 1,939,423 $ 5,966,453 $ 204,173 $ 320,339 $ 8,430,388 The following table details activity in the allowance for loan losses by portfolio segment for legacy loans for the three and nine months ended September 30, 2019 . Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. (In thousands) Commercial Real Estate Credit Card Other Consumer and Other Total Three Months Ended September 30, 2019 Balance, beginning of period (2) $ 21,739 $ 34,917 $ 3,951 $ 2,460 $ 63,067 Provision for loan losses (1) 19,150 2,405 946 (528 ) 21,973 Charge-offs (17,729 ) (907 ) (1,117 ) (1,059 ) (20,812 ) Recoveries 65 55 223 1,422 1,765 Net charge-offs (17,664 ) (852 ) (894 ) 363 (19,047 ) Balance, September 30, 2019 (2) $ 23,225 $ 36,470 $ 4,003 $ 2,295 $ 65,993 Nine Months Ended September 30, 2019 Balance, beginning of period (2) $ 20,514 $ 29,743 $ 3,923 $ 2,419 $ 56,599 Provision for loan losses (1) 23,980 7,929 2,644 1,320 35,873 Charge-offs (21,564 ) (1,552 ) (3,298 ) (3,497 ) (29,911 ) Recoveries 295 350 734 2,053 3,432 Net charge-offs (21,269 ) (1,202 ) (2,564 ) (1,444 ) (26,479 ) Balance, September 30, 2019 (2) $ 23,225 $ 36,470 $ 4,003 $ 2,295 $ 65,993 Period-end amount allocated to: Loans individually evaluated for impairment $ 4,620 $ 659 $ — $ — $ 5,279 Loans collectively evaluated for impairment 18,605 35,811 4,003 2,295 60,714 Balance, September 30, 2019 (2) $ 23,225 $ 36,470 $ 4,003 $ 2,295 $ 65,993 (1) Provision for loan losses of $0 and $2,464,000 attributable to loans acquired was excluded from this table for the three and nine months ended September 30, 2019 , respectively (total provision for loan losses for the three and nine months ended September 30, 2019 was $21,973,000 and $38,337,000 ). There were $515,000 and $2,862,000 in charge-offs for loans acquired during the three and nine months ended September 30, 2019 , respectively, and recoveries of $900,000 for loans acquired during the nine month period ended September 30, 2019 , resulting in an ending balance in the allowance related to loans acquired of $597,000 . (2) Allowance for loan losses at September 30, 2019 includes $597,000 allowance for loans acquired (not shown in the table above). Allowance for loan losses at June 30, 2019 and December 31, 2018 includes $1,112,000 and $95,000 , respectively, of allowance for loans acquired (not shown in the table above). The total allowance for loan losses at September 30, 2019 was $66,590,000 and total allowance for loan losses at June 30, 2019 and December 31, 2018 was $64,179,000 and $56,694,000 , respectively. Activity in the allowance for loan losses for the three and nine months ended September 30, 2018 was as follows: (In thousands) Commercial Real Estate Credit Card Other Consumer and Other Total Three Months Ended September 30, 2018 Balance, beginning of period (4) $ 15,767 $ 28,904 $ 3,822 $ 3,239 $ 51,732 Provision for loan losses (3) 3,589 5,308 719 729 10,345 Charge-offs (592 ) (4,952 ) (919 ) (1,321 ) (7,784 ) Recoveries 450 210 229 176 1,065 Net charge-offs (142 ) (4,742 ) (690 ) (1,145 ) (6,719 ) Balance, September 30, 2018 (4) $ 19,214 $ 29,470 $ 3,851 $ 2,823 $ 55,358 Nine Months Ended September 30, 2018 Balance, beginning of period (4) $ 7,007 $ 27,281 $ 3,784 $ 3,596 $ 41,668 Provision for loan losses (3) 14,772 7,133 2,219 2,567 26,691 Charge-offs (3,143 ) (5,568 ) (2,930 ) (3,743 ) (15,384 ) Recoveries 578 624 778 403 2,383 Net charge-offs (2,565 ) (4,944 ) (2,152 ) (3,340 ) (13,001 ) Balance, September 30, 2018 (4) $ 19,214 $ 29,470 $ 3,851 $ 2,823 $ 55,358 Period-end amount allocated to: Loans individually evaluated for impairment $ 191 $ 268 $ — $ — $ 459 Loans collectively evaluated for impairment 19,023 29,202 3,851 2,823 54,899 Balance, September 30, 2018 (4) $ 19,214 $ 29,470 $ 3,851 $ 2,823 $ 55,358 Period-end amount allocated to: Loans individually evaluated for impairment $ 437 $ 247 $ — $ — $ 684 Loans collectively evaluated for impairment 20,077 29,496 3,923 2,419 55,915 Balance, December 31, 2018 (5) $ 20,514 $ 29,743 $ 3,923 $ 2,419 $ 56,599 ______________________ (3) Provision for loan losses of $0 and $1,837,000 attributable to loans acquired was excluded from this table for the three and nine months ended September 30, 2018 , respectively (total provision for loan losses for the three and nine months ended September 30, 2018 was $10,345,000 and $28,528,000 , respectively). There were $699,000 and $910,000 in charge-offs for loans acquired during the three and nine months ended September 30, 2018 , respectively, resulting in an ending balance in the allowance related to loans acquired of $1,345,000 . (4) Allowance for loan losses at September 30, 2018 , June 30, 2018 and December 31, 2017 includes $1,345,000 , $2,044,000 and $418,000 , respectively, of allowance for loans acquired (not shown in the table above). The total allowance for loan losses at September 30, 2018 , June 30, 2018 and December 31, 2017 was $56,703,000 , $53,776,000 and $42,086,000 , respectively. (5) Allowance for loan losses at December 31, 2018 includes $95,000 allowance for loans acquired (not shown in the table above). The total allowance for loan losses at December 31, 2018 was $56,694,000 .

Loans Acquired (Tables)

Loans Acquired (Tables)	9 Months Ended
	Sep. 30, 2019
Receivables [Abstract]
Loans Acquired	The various categories of loans are summarized as follows: (In thousands) September 30, 2019 December 31, 2018 Consumer: Credit cards $ 195,083 $ 204,173 Other consumer 208,643 201,297 Total consumer 403,726 405,470 Real Estate: Construction 1,712,858 1,300,723 Single family residential 1,448,455 1,440,443 Other commercial 3,630,708 3,225,287 Total real estate 6,792,021 5,966,453 Commercial: Commercial 1,894,819 1,774,909 Agricultural 213,753 164,514 Total commercial 2,108,572 1,939,423 Other 339,046 119,042 Loans 9,643,365 8,430,388 Loans acquired, net of discount and allowance (1) 3,359,587 3,292,783 Total loans $ 13,002,952 $ 11,723,171 _____________________________ (1) See Note 5, Loans Acquired, for segregation of loans acquired by loan class. Changes in the carrying amount of the accretable yield for all purchased impaired loans were as follows for the three and nine months ended September 30, 2019 and 2018 . Three Months Ended Nine Months Ended (In thousands) Accretable Yield Carrying Amount of Loans Accretable Yield Carrying Amount of Loans Beginning balance $ 1,461 $ 3,487 $ 1,460 $ 4,050 Additions — — — 175 Accretable yield adjustments 10 — 38 — Accretion (12 ) 12 (39 ) 39 Payments and other reductions, net — (422 ) — (1,187 ) Balance, ending $ 1,459 $ 3,077 $ 1,459 $ 3,077 Three Months Ended Nine Months Ended (In thousands) Accretable Yield Carrying Amount of Loans Accretable Yield Carrying Amount of Loans Beginning balance $ 1,382 $ 13,995 $ 620 $ 17,116 Additions — — — — Accretable yield adjustments 717 — 1,895 — Accretion (635 ) 635 (1,051 ) 1,051 Payments and other reductions, net — (9,664 ) — (13,201 ) Balance, ending $ 1,464 $ 4,966 $ 1,464 $ 4,966 The following table reflects the carrying value of all loans acquired as of September 30, 2019 and December 31, 2018 : Loans Acquired (In thousands) September 30, 2019 December 31, 2018 Consumer: Other consumer $ 7,431 $ 15,658 Real estate: Construction 362,000 429,605 Single family residential 504,490 566,188 Other commercial 2,134,973 1,848,679 Total real estate 3,001,463 2,844,472 Commercial: Commercial 349,821 430,914 Agricultural 872 1,739 Total commercial 350,693 432,653 Total loans acquired (1) $ 3,359,587 $ 3,292,783 ________________________ (1) Loans acquired are reported net of a $597,000 and $95,000 allowance at September 30, 2019 and December 31, 2018 , respectively.
Nonaccrual Loans	Nonaccrual loans, excluding loans acquired, segregated by class of loans, are as follows: (In thousands) September 30, 2019 December 31, 2018 Consumer: Credit cards $ 521 $ 296 Other consumer 1,634 2,159 Total consumer 2,155 2,455 Real estate: Construction 1,805 1,269 Single family residential 16,191 11,939 Other commercial 16,985 7,205 Total real estate 34,981 20,413 Commercial: Commercial 35,018 10,049 Agricultural 567 1,284 Total commercial 35,585 11,333 Total $ 72,721 $ 34,201 Nonaccrual loans acquired, excluding purchased credit impaired loans accounted for under ASC Topic 310-30, segregated by class of loans, are as follows (see Note 4, Loans and Allowance for Loan Losses, for discussion of nonaccrual loans): (In thousands) September 30, 2019 December 31, 2018 Consumer: Other consumer $ 71 $ 140 Real estate: Construction 48 114 Single family residential 4,492 6,603 Other commercial 1,029 1,167 Total real estate 5,569 7,884 Commercial: Commercial 1,636 13,578 Agricultural 23 38 Total commercial 1,659 13,616 Total $ 7,299 $ 21,640
Past Due Loans	An age analysis of past due loans, excluding loans acquired, segregated by class of loans, is as follows: (In thousands) Gross 30-89 Days Past Due 90 Days or More Past Due Total Past Due Current Total Loans 90 Days Past Due & Accruing September 30, 2019 Consumer: Credit cards $ 958 $ 650 $ 1,608 $ 193,475 $ 195,083 $ 130 Other consumer 3,383 694 4,077 204,566 208,643 14 Total consumer 4,341 1,344 5,685 398,041 403,726 144 Real estate: Construction 3,690 613 4,303 1,708,555 1,712,858 — Single family residential 10,022 6,395 16,417 1,432,038 1,448,455 — Other commercial 8,009 3,385 11,394 3,619,314 3,630,708 — Total real estate 21,721 10,393 32,114 6,759,907 6,792,021 — Commercial: Commercial 4,999 10,990 15,989 1,878,830 1,894,819 11 Agricultural 285 349 634 213,119 213,753 — Total commercial 5,284 11,339 16,623 2,091,949 2,108,572 11 Other — — — 339,046 339,046 — Total $ 31,346 $ 23,076 $ 54,422 $ 9,588,943 $ 9,643,365 $ 155 December 31, 2018 Consumer: Credit cards $ 1,033 $ 506 $ 1,539 $ 202,634 $ 204,173 $ 209 Other consumer 4,264 896 5,160 196,137 201,297 4 Total consumer 5,297 1,402 6,699 398,771 405,470 213 Real estate: Construction 533 308 841 1,299,882 1,300,723 — Single family residential 7,769 4,127 11,896 1,428,547 1,440,443 — Other commercial 3,379 2,773 6,152 3,219,135 3,225,287 — Total real estate 11,681 7,208 18,889 5,947,564 5,966,453 — Commercial: Commercial 4,472 5,105 9,577 1,765,332 1,774,909 11 Agricultural 467 1,055 1,522 162,992 164,514 — Total commercial 4,939 6,160 11,099 1,928,324 1,939,423 11 Other — — — 119,042 119,042 — Total $ 21,917 $ 14,770 $ 36,687 $ 8,393,701 $ 8,430,388 $ 224 An age analysis of past due loans acquired segregated by class of loans, is as follows (see Note 4, Loans and Allowance for Loan Losses, for discussion of past due loans): (In thousands) Gross 30-89 Days Past Due 90 Days or More Past Due Total Past Due Current Total Loans 90 Days Past Due & Accruing September 30, 2019 Consumer: Other consumer $ 131 $ 36 $ 167 $ 7,264 $ 7,431 $ 4 Real estate: Construction 30 12 42 361,958 362,000 — Single family residential 3,664 1,790 5,454 499,036 504,490 17 Other commercial 1,888 943 2,831 2,132,142 2,134,973 — Total real estate 5,582 2,745 8,327 2,993,136 3,001,463 17 Commercial: Commercial 607 724 1,331 348,490 349,821 — Agricultural — — — 872 872 — Total commercial 607 724 1,331 349,362 350,693 — Total $ 6,320 $ 3,505 $ 9,825 $ 3,349,762 $ 3,359,587 $ 21 December 31, 2018 Consumer: Other consumer $ 337 $ 49 $ 386 $ 15,272 $ 15,658 $ 2 Real estate: Construction 8,283 27 8,310 421,295 429,605 — Single family residential 4,706 3,049 7,755 558,433 566,188 — Other commercial 168 577 745 1,847,934 1,848,679 — Total real estate 13,157 3,653 16,810 2,827,662 2,844,472 — Commercial: Commercial 1,302 9,542 10,844 420,070 430,914 — Agricultural 31 5 36 1,703 1,739 — Total commercial 1,333 9,547 10,880 421,773 432,653 — Total $ 14,827 $ 13,249 $ 28,076 $ 3,264,707 $ 3,292,783 $ 2
Loans by Credit Risk Ratings	The following table presents a summary of loans by credit risk rating as of September 30, 2019 and December 31, 2018 , segregated by class of loans. Loans accounted for under ASC Topic 310-30 are all included in Risk Rate 1-4 in this table. (In thousands) Risk Rate 1-4 Risk Rate 5 Risk Rate 6 Risk Rate 7 Risk Rate 8 Total September 30, 2019 Consumer: Credit cards $ 194,433 $ — $ 650 $ — $ — $ 195,083 Other consumer 206,647 — 1,996 — — 208,643 Total consumer 401,080 — 2,646 — — 403,726 Real estate: Construction 1,705,376 1,456 6,026 — — 1,712,858 Single family residential 1,422,086 3,246 23,119 4 — 1,448,455 Other commercial 3,571,706 33,030 25,972 — — 3,630,708 Total real estate 6,699,168 37,732 55,117 4 — 6,792,021 Commercial: Commercial 1,837,374 10,420 47,025 — — 1,894,819 Agricultural 213,072 69 612 — — 213,753 Total commercial 2,050,446 10,489 47,637 — — 2,108,572 Other 339,046 — — — — 339,046 Loans acquired 3,272,024 46,796 40,639 128 — 3,359,587 Total $ 12,761,764 $ 95,017 $ 146,039 $ 132 $ — $ 13,002,952 (In thousands) Risk Rate 1-4 Risk Rate 5 Risk Rate 6 Risk Rate 7 Risk Rate 8 Total December 31, 2018 Consumer: Credit cards $ 203,667 $ — $ 506 $ — $ — $ 204,173 Other consumer 198,840 — 2,457 — — 201,297 Total consumer 402,507 — 2,963 — — 405,470 Real estate: Construction 1,296,988 1,910 1,825 — — 1,300,723 Single family residential 1,420,052 1,628 18,528 235 — 1,440,443 Other commercial 3,193,289 17,169 14,829 — — 3,225,287 Total real estate 5,910,329 20,707 35,182 235 — 5,966,453 Commercial: Commercial 1,742,002 8,357 24,550 — — 1,774,909 Agricultural 162,824 75 1,615 — — 164,514 Total commercial 1,904,826 8,432 26,165 — — 1,939,423 Other 119,042 — — — — 119,042 Loans acquired 3,187,083 51,255 54,097 348 — 3,292,783 Total $ 11,523,787 $ 80,394 $ 118,407 $ 583 $ — $ 11,723,171 The following table presents a summary of loans acquired by credit risk rating, segregated by class of loans (see Note 4, Loans and Allowance for Loan Losses, for discussion of loan risk rating). Loans accounted for under ASC Topic 310-30 are all included in Risk Rate 1-4 in this table. (In thousands) Risk Rate 1-4 Risk Rate 5 Risk Rate 6 Risk Rate 7 Risk Rate 8 Total September 30, 2019 Consumer: Other consumer $ 7,285 $ — $ 146 $ — $ — $ 7,431 Real estate: Construction 344,075 17,874 51 — — 362,000 Single family residential 492,826 1,224 10,312 128 — 504,490 Other commercial 2,085,649 26,207 23,117 — — 2,134,973 Total real estate 2,922,550 45,305 33,480 128 — 3,001,463 Commercial: Commercial 341,385 1,491 6,945 — — 349,821 Agricultural 804 — 68 — — 872 Total commercial 342,189 1,491 7,013 — — 350,693 Total $ 3,272,024 $ 46,796 $ 40,639 $ 128 $ — $ 3,359,587 December 31, 2018 Consumer: Other consumer $ 15,380 $ — $ 278 $ — $ — $ 15,658 Real estate: Construction 393,122 27,621 8,862 — — 429,605 Single family residential 553,460 2,081 10,299 348 — 566,188 Other commercial 1,822,179 9,137 17,363 — — 1,848,679 Total real estate 2,768,761 38,839 36,524 348 — 2,844,472 Commercial: Commercial 401,300 12,416 17,198 — — 430,914 Agricultural 1,642 — 97 — — 1,739 Total commercial 402,942 12,416 17,295 — — 432,653 Total $ 3,187,083 $ 51,255 $ 54,097 $ 348 $ — $ 3,292,783

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangibles	The Company’s goodwill and other intangibles (carrying basis and accumulated amortization) at September 30, 2019 and December 31, 2018 , were as follows: (In thousands) September 30, 2019 December 31, 2018 Goodwill $ 926,648 $ 845,687 Core deposit premiums: Gross carrying amount 124,334 105,984 Accumulated amortization (33,918 ) (26,177 ) Core deposit premiums, net 90,416 79,807 Books of business intangible: Gross carrying amount 15,234 15,234 Accumulated amortization (4,501 ) (3,707 ) Books of business intangible, net 10,733 11,527 Other intangible assets, net 101,149 91,334 Total goodwill and other intangible assets $ 1,027,797 $ 937,021
Estimated Remaining Amortization Expense	The Company’s estimated remaining amortization expense on intangibles as of September 30, 2019 is as follows: (In thousands) Year Amortization Expense Remainder of 2019 $ 2,947 2020 11,776 2021 11,714 2022 11,662 2023 11,379 Thereafter 51,671 Total $ 101,149

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Provision for Income Taxes	The provision for income taxes is comprised of the following components for the periods indicated below: Three Months Ended Nine Months Ended (In thousands) 2019 2018 2019 2018 Income taxes currently payable $ 17,282 $ 5,638 $ 40,356 $ 31,335 Deferred income taxes 5,993 5,264 10,933 7,316 Provision for income taxes $ 23,275 $ 10,902 $ 51,289 $ 38,651
Schedule of Deferred Tax Assets and Liabilities	The tax effects of temporary differences between the tax basis of assets and liabilities and their financial reporting amounts that give rise to deferred income tax assets and liabilities, and their appropriate tax effects, are as follows: (In thousands) September 30, 2019 December 31, 2018 Deferred tax assets: Loans acquired $ 15,906 $ 12,536 Allowance for loan losses 16,332 13,947 Valuation of foreclosed assets 2,706 1,474 Tax NOLs from acquisition 18,021 7,242 Deferred compensation payable 2,572 2,707 Accrued equity and other compensation 8,340 8,182 Acquired securities 2,598 397 Unrealized loss on available-for-sale securities — 9,196 Other 5,409 7,042 Gross deferred tax assets 71,884 62,723 (In thousands) September 30, 2019 December 31, 2018 Deferred tax liabilities: Goodwill and other intangible amortization $ (34,304 ) $ (30,471 ) Accumulated depreciation (16,587 ) (13,361 ) Unrealized gain on available-for-sale securities (6,811 ) — Other (5,304 ) (5,360 ) Gross deferred tax liabilities (63,006 ) (49,192 ) Net deferred tax asset, included in other assets $ 8,878 $ 13,531
Reconciliation of Income Tax Expense	A reconciliation of income tax expense at the statutory rate to the Company’s actual income tax expense is shown for the periods indicated below: Three Months Ended Nine Months Ended (In thousands) 2019 2018 2019 2018 Computed at the statutory rate (21%) $ 22,071 $ 13,880 $ 49,646 $ 41,731 Increase (decrease) in taxes resulting from: State income taxes, net of federal tax benefit 2,956 986 5,721 4,073 Tax exempt interest income (1,105 ) (833 ) (3,090 ) (2,292 ) Tax exempt earnings on BOLI (225 ) (186 ) (619 ) (562 ) Federal tax credits (730 ) — (2,188 ) — Other differences, net 308 (2,945 ) 1,819 (4,299 ) Actual tax provision $ 23,275 $ 10,902 $ 51,289 $ 38,651

Securities Sold Under Agreeme_2

Securities Sold Under Agreements to Repurchase (Tables)	9 Months Ended
	Sep. 30, 2019
Banking and Thrift [Abstract]
Contractual Maturity of Securities Sold Under Agreements to Repurchase	The remaining contractual maturity of the securities sold under agreements to repurchase in the consolidated balance sheets as of September 30, 2019 and December 31, 2018 is presented in the following tables. Remaining Contractual Maturity of the Agreements (In thousands) Overnight and Continuous Up to 30 Days 30-90 Days Greater than 90 Days Total September 30, 2019 Repurchase agreements: U.S. Government agencies $ 116,286 $ — $ — $ — $ 116,286 December 31, 2018 Repurchase agreements: U.S. Government agencies $ 95,542 $ — $ — $ — $ 95,542

Other Borrowings and Subordin_2

Other Borrowings and Subordinated Notes and Debentures (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Debt	Debt at September 30, 2019 and December 31, 2018 consisted of the following components: (In thousands) September 30, 2019 December 31, 2018 Other Borrowings FHLB advances, net of discount, due 2019 to 2033, 1.38% to 7.37% secured by real estate loans $ 1,098,395 $ 1,345,450 Revolving credit agreement, due 10/4/2019, floating rate of 1.50% above the one month LIBOR rate, unsecured — — Total other borrowings 1,098,395 1,345,450 Subordinated Notes and Debentures Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly) 330,000 330,000 Trust preferred securities, net of discount, due 9/15/2037, floating rate of 1.37% above the three month LIBOR rate, reset quarterly 10,310 10,310 Trust preferred securities, net of discount, due 6/6/2037, floating rate of 1.57% above the three month LIBOR rate, reset quarterly, callable without penalty 10,310 10,310 Trust preferred securities, due 12/15/2035, floating rate of 1.45% above the three month LIBOR rate, reset quarterly, callable without penalty 6,702 6,702 Unamortized debt issuance costs (3,099 ) (3,372 ) Total subordinated notes and debentures 354,223 353,950 Total other borrowings and subordinated debt $ 1,452,618 $ 1,699,400
Aggregate Annual Maturities of Long-term Debt	Aggregate annual maturities of long-term debt at September 30, 2019 , are as follows: (In thousands) Year Annual Maturities 2019 $ 356 2020 2,105 2021 1,804 2022 948 2023 925 Thereafter 361,480 Total $ 367,618

Stock Based Compensation (Table

Stock Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
Stock Compensation Plans	The table below summarizes the transactions under the Company’s active stock compensation plans for the nine months ended September 30, 2019 : Stock Options Outstanding Non-vested Stock Awards Outstanding Non-vested Stock Units Outstanding (Shares in thousands) Number of Shares Weighted Average Exercise Price Number of Shares Weighted Average Grant-Date Fair Value Number of Shares Weighted Average Grant-Date Fair Value Balance, January 1, 2019 695 $ 22.42 72 $ 21.45 817 $ 27.65 Granted — — — — 516 26.07 Stock options exercised (1 ) 10.65 — — — — Stock awards/units vested (earned) — — (39 ) 20.12 (334 ) 26.45 Forfeited/expired — — (2 ) 21.82 (90 ) 28.29 Balance, September 30, 2019 694 $ 22.43 31 $ 23.16 909 $ 27.18 Exercisable, September 30, 2019 694 $ 22.43
Stock Options	The following table summarizes information about stock options under the plans outstanding at September 30, 2019 : Options Outstanding Options Exercisable Range of Exercise Prices Number of Shares (In thousands) Weighted Average Remaining Contractual Life (Years) Weighted Average Exercise Price Number of Shares (In thousands) Weighted Average Exercise Price $ 9.46 — $ 9.46 1 2.30 $9.46 1 $9.46 10.65 — 10.65 3 3.32 10.65 3 10.65 10.76 — 10.76 2 0.30 10.76 2 10.76 20.29 — 20.29 71 5.25 20.29 71 20.29 20.36 — 20.36 3 5.13 20.36 3 20.36 22.20 — 22.20 74 5.48 22.20 74 22.20 22.75 — 22.75 436 5.86 22.75 436 22.75 23.51 — 23.51 97 6.30 23.51 97 23.51 24.07 — 24.07 7 5.96 24.07 7 24.07 $ 9.46 — $ 24.07 694 5.78 $22.43 694 $22.43
Restricted Performance Stock Unit Activity	The table below summarizes the Company’s performance stock unit activity for the nine months ended September 30, 2019 : (In thousands) Performance Stock Units Non-vested, January 1, 2019 177 Granted 118 Vested (earned) (93 ) Forfeited (3 ) Non-vested, September 30, 2019 199

Earnings Per Share ("EPS") (Tab

Earnings Per Share ("EPS") (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Computation of Earnings Per Share	The computation of earnings per share is as follows: Three Months Ended Nine Months Ended (In thousands, except per share data) 2019 2018 2019 2018 Net income available to common stockholders $ 81,826 $ 55,193 $ 185,119 $ 160,067 Average common shares outstanding 96,608 92,290 95,090 92,246 Average potential dilutive common shares 360 551 360 551 Average diluted common shares 96,968 92,841 95,450 92,797 Basic earnings per share $ 0.85 $ 0.60 $ 1.95 $ 1.74 Diluted earnings per share $ 0.84 $ 0.59 $ 1.94 $ 1.72

Additional Cash Flow Informat_2

Additional Cash Flow Information (Tables)	9 Months Ended
	Sep. 30, 2019
Supplemental Cash Flow Information [Abstract]
Additional Cash Flow Information	The following is a summary of the Company’s additional cash flow information: Nine Months Ended (In thousands) 2019 2018 Interest paid $ 130,904 $ 78,987 Income taxes (refunded) paid 34,028 25,576 Transfers of loans to foreclosed assets held for sale 3,666 7,745 Transfers of premises to foreclosed assets and other real estate owned 556 3,690 Right-of use lease assets obtained in exchange for lessee operating lease liabilities (adoption of ASU 2016-02) 32,757 —

Other Income and Other Operat_2

Other Income and Other Operating Expenses (Tables)	9 Months Ended
	Sep. 30, 2019
Other Income and Expenses [Abstract]
Other Operating Expenses	Other operating expenses consist of the following: Three Months Ended Nine Months Ended (In thousands) 2019 2018 2019 2018 Professional services $ 4,310 $ 4,616 $ 12,125 $ 13,896 Postage 1,471 1,262 4,642 4,103 Telephone 2,507 1,248 5,605 4,217 Credit card expense 4,200 3,405 11,822 9,820 Marketing 7,021 2,912 12,514 6,334 Software and technology 6,531 4,733 16,607 10,716 Operating supplies 493 585 1,671 1,917 Amortization of intangibles 2,947 2,772 8,535 8,394 Branch right sizing expense 160 970 3,092 1,049 Other expense 8,239 7,171 24,195 20,907 Total other operating expenses $ 37,879 $ 29,674 $ 100,808 $ 81,353

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Financial Instruments Measured on Recurring Basis	The following table sets forth the Company’s financial assets by level within the fair value hierarchy that were measured at fair value on a recurring basis as of September 30, 2019 and December 31, 2018 . Fair Value Measurements Using (In thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2019 Available-for-sale securities U.S. Government agencies $ 178,139 $ — $ 178,139 $ — Mortgage-backed securities 1,337,794 — 1,337,794 — State and political subdivisions 681,202 — 681,202 — Other securities 158,999 — 158,999 — Derivative asset 14,377 — 14,377 — Derivative liability (14,478 ) — (14,478 ) — December 31, 2018 Available-for-sale securities U.S. Government agencies $ 154,301 $ — $ 154,301 $ — Mortgage-backed securities 1,522,900 — 1,522,900 — States and political subdivisions 314,843 — 314,843 — Other securities 159,708 — 159,708 — Derivative asset 6,242 — 6,242 — Derivative liability (5,283 ) — (5,283 ) —
Financial Assets Measure on Nonrecurring Basis	The following table sets forth the Company’s financial assets by level within the fair value hierarchy that were measured at fair value on a nonrecurring basis as of September 30, 2019 and December 31, 2018 . Fair Value Measurements Using (In thousands) Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2019 Impaired loans (1) (2) (collateral dependent) $ 46,903 $ — $ — $ 46,903 Foreclosed assets and other real estate owned (1) 15,046 — — 15,046 December 31, 2018 Impaired loans (1) (2) (collateral dependent) $ 17,789 $ — $ — $ 17,789 Foreclosed assets and other real estate owned (1) 23,714 — — 23,714 ________________________ (1) These amounts represent the resulting carrying amounts on the consolidated balance sheets for impaired collateral dependent loans and foreclosed assets and other real estate owned for which fair value re-measurements took place during the period. (2) Specific allocations of $1,297,000 and $2,738,000 were related to the impaired collateral dependent loans for which fair value re-measurements took place during the periods ended September 30, 2019 and December 31, 2018 , respectively.
Estimated Fair Values and Related Carrying Amounts	The estimated fair values, and related carrying amounts, of the Company’s financial instruments are as follows: Carrying Fair Value Measurements (In thousands) Amount Level 1 Level 2 Level 3 Total September 30, 2019 Financial assets: Cash and cash equivalents $ 529,970 $ 529,970 $ — $ — $ 529,970 Interest bearing balances due from banks - time 5,041 — 5,041 — 5,041 Held-to-maturity securities 42,237 — 43,302 — 43,302 Mortgage loans held for sale 50,099 — — 50,099 50,099 Interest receivable 53,966 — 53,966 — 53,966 Legacy loans, net 9,577,372 — — 9,505,701 9,505,701 Loans acquired, net 3,359,587 — — 3,334,446 3,334,446 Financial liabilities: Non-interest bearing transaction accounts 3,044,330 — 3,044,330 — 3,044,330 Interest bearing transaction accounts and savings deposits 7,337,571 — 7,337,571 — 7,337,571 Time deposits 3,086,108 — — 3,080,775 3,080,775 Federal funds purchased and securities sold under agreements to repurchase 116,536 — 116,536 — 116,536 Other borrowings 1,098,395 — 1,099,171 — 1,099,171 Subordinated notes and debentures 354,223 — 366,289 — 366,289 Interest payable 15,404 — 15,404 — 15,404 December 31, 2018 Financial assets: Cash and cash equivalents $ 833,458 $ 833,458 $ — $ — $ 833,458 Interest bearing balances due from banks - time 4,934 — 4,934 — 4,934 Held-to-maturity securities 289,194 — 290,830 — 290,830 Mortgage loans held for sale 26,799 — — 26,799 26,799 Interest receivable 49,938 — 49,938 — 49,938 Legacy loans, net 8,373,789 — — 8,280,690 8,280,690 Loans acquired, net 3,292,783 — — 3,256,174 3,256,174 Financial liabilities: Non-interest bearing transaction accounts 2,672,405 — 2,672,405 — 2,672,405 Interest bearing transaction accounts and savings deposits 6,830,191 — 6,830,191 — 6,830,191 Time deposits 2,896,156 — — 2,872,342 2,872,342 Federal funds purchased and securities sold under agreements to repurchase 95,792 — 95,792 — 95,792 Other borrowings 1,345,450 — 1,342,868 — 1,342,868 Subordinated debentures 353,950 — 355,812 — 355,812 Interest payable 9,897 — 9,897 — 9,897

Preparation of Interim Financ_3

Preparation of Interim Financial Statements (Details) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2019USD ($)financial_center	Mar. 31, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)financial_center	Sep. 30, 2018USD ($)	Apr. 11, 2019financial_center	Jan. 01, 2019USD ($)
Lessee, Lease, Description [Line Items]
Number of financial centers | financial_center	212			212
Unrealized holding gain on the transfer of held-to-maturity securities to available-for-sale per ASU 2017-12	$ 0		$ 0	$ 2,547	$ 0
Right-of-use asset	34,100			34,100
Right-of-use liabilities	34,300			34,300
Accounting Standards Update 2018-15
Lessee, Lease, Description [Line Items]
Software implementation costs, not yet capitalized	$ 1,100			$ 1,100
Accounting Standards Update 2017-12
Lessee, Lease, Description [Line Items]
Fair value of HTM municipal bonds		$ 216,400
Unrealized holding gain on the transfer of held-to-maturity securities to available-for-sale per ASU 2017-12		$ 2,500
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Right-of-use asset							$ 32,800
Right-of-use liabilities							$ 32,800
Minimum | Accounting Standards Update 2016-13
Lessee, Lease, Description [Line Items]
Allowance for loan and lease losses, period increase, percent				130.00%
AllowAllowance for loan and lease losses including purchase discounts, period increase, percent				10.00%
Maximum | Accounting Standards Update 2016-13
Lessee, Lease, Description [Line Items]
Allowance for loan and lease losses, period increase, percent				170.00%
AllowAllowance for loan and lease losses including purchase discounts, period increase, percent				30.00%
Reliance Bancshares, Inc.
Lessee, Lease, Description [Line Items]
Number of financial centers | financial_center						22
Reliance Bancshares, Inc. | Minimum | Accounting Standards Update 2016-13
Lessee, Lease, Description [Line Items]
Allowance for loan and lease losses, period increase, percent				165.00%
AllowAllowance for loan and lease losses including purchase discounts, period increase, percent				5.00%
Reliance Bancshares, Inc. | Maximum | Accounting Standards Update 2016-13
Lessee, Lease, Description [Line Items]
Allowance for loan and lease losses, period increase, percent				215.00%
AllowAllowance for loan and lease losses including purchase discounts, period increase, percent				25.00%

Acquisitions - Textual (Details

Acquisitions - Textual (Details)	Jul. 30, 2019$ / sharesshares	Apr. 12, 2019USD ($)shares	Sep. 30, 2019USD ($)financial_center$ / shares	Oct. 29, 2019shares	Jun. 30, 2019USD ($)	Apr. 11, 2019financial_center	Dec. 31, 2018USD ($)$ / shares	Dec. 31, 2017USD ($)
Business Acquisition [Line Items]
Stock issued for Reliance acquisition			$ 144,830,000
Number of financial centers | financial_center			212
Assets			$ 17,758,511,000				$ 16,543,337,000	$ 15,000,000,000
Net loans			12,936,959,000				11,666,572,000
Deposits			13,468,009,000				12,398,752,000
Goodwill			$ 926,648,000				$ 845,687,000
Common stock, Class A, par value (in dollars per share) | $ / shares			$ 0.01				$ 0.01
Reliance Bancshares, Inc.
Business Acquisition [Line Items]
Shares issued (in shares) | shares		3,999,623
Payments to acquire businesses, gross		$ 62,700,000
Stock issued for Reliance acquisition		42,000,000
Number of financial centers | financial_center						22
Assets		1,500,000,000
Net loans		1,100,000,000
Deposits		1,200,000,000
Goodwill		$ 80,961,000			$ 81,000,000
Landrum Company
Business Acquisition [Line Items]
Shares issued (in shares) | shares	17,350,000
Number of financial centers | financial_center			39
Assets			$ 3,300,000,000
Net loans			2,000,000,000
Deposits			$ 2,900,000,000
Series A or B Preferred Stock | Reliance Bancshares, Inc.
Business Acquisition [Line Items]
Shares issued, conversion ratio (in shares)		1
Series C Preferred Stock | Reliance Bancshares, Inc.
Business Acquisition [Line Items]
Shares issued, conversion ratio (in shares)		1
Common Class A | Landrum Company
Business Acquisition [Line Items]
Common stock, Class A, par value (in dollars per share) | $ / shares	$ 0.01
Preferred Class B | Landrum Company
Business Acquisition [Line Items]
Preferred stock, Class B, par value (in dollars per share) | $ / shares	$ 0.01
Subsequent Event | Series C Preferred Stock | Reliance Bancshares, Inc.
Business Acquisition [Line Items]
Preferred stock, shares authorized (in shares) | shares				140
Preferred stock, shares issued (in shares) | shares				0
Preferred stock, shares outstanding (in shares) | shares				0

Acquisitions - Assets Acquired

Acquisitions - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Apr. 12, 2019	Sep. 30, 2019	Jun. 30, 2019	Apr. 11, 2019	Dec. 31, 2018
Liabilities Assumed
Goodwill		$ 926,648			$ 845,687
Reliance Bancshares, Inc.
Assets Acquired
Cash and due from banks	$ 25,693			$ 25,693
Due from banks - time	502			502
Investment securities	286,220			287,983
Loans acquired	1,096,870			1,138,527
Allowance for loan losses	0			(10,808)
Foreclosed assets	5,912			11,092
Premises and equipment	29,451			32,452
Bank owned life insurance	39,348			39,348
Core deposit intangible	18,350			0
Other assets	30,166			25,165
Total assets acquired	1,532,512			1,549,954
Liabilities Assumed
Non-interest bearing transaction accounts	108,812			108,845
Interest bearing transaction accounts and savings deposits	639,798			639,798
Time deposits	476,657			478,415
Total deposits	1,225,267			1,227,058
Securities sold under agreement to repurchase	14,146			14,146
Other borrowings	157,400			162,900
Accrued interest and other liabilities	9,121			8,185
Total liabilities assumed	1,405,934			1,412,289
Total equity assumed	42,000			137,665
Total liabilities and equity assumed	1,447,934			$ 1,549,954
Net assets acquired	84,578
Purchase price	165,539
Goodwill	80,961		$ 81,000
Reliance Bancshares, Inc. | Fair Value Adjustments
Assets Acquired
Cash and due from banks	0
Due from banks - time	0
Investment securities	(1,763)
Loans acquired	(41,657)
Allowance for loan losses	10,808
Foreclosed assets	(5,180)
Premises and equipment	(3,001)
Bank owned life insurance	0
Core deposit intangible	18,350
Other assets	5,001
Total assets acquired	(17,442)
Liabilities Assumed
Non-interest bearing transaction accounts	(33)
Interest bearing transaction accounts and savings deposits	0
Time deposits	(1,758)
Total deposits	(1,791)
Securities sold under agreement to repurchase	0
Other borrowings	(5,500)
Accrued interest and other liabilities	936
Total liabilities assumed	(6,355)
Total equity assumed	(95,665)
Total liabilities and equity assumed	$ (102,020)

Investment Securities - Summary

Investment Securities - Summary of Investment Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Held-to-Maturity
Amortized Cost	$ 42,237	$ 289,194
Gross Unrealized Gains	1,107	3,051
Gross Unrealized (Losses)	(42)	(1,415)
Estimated Fair Value	43,302	290,830
Available-for-Sale
Amortized Cost	2,327,106	2,187,623
Gross Unrealized Gains	34,043	6,037
Gross Unrealized (Losses)	(5,015)	(41,908)
Estimated Fair Value	2,356,134	2,151,752
U.S. Government agencies
Held-to-Maturity
Amortized Cost	0	16,990
Gross Unrealized Gains	0	0
Gross Unrealized (Losses)	0	(49)
Estimated Fair Value	0	16,941
Available-for-Sale
Amortized Cost	177,712	157,523
Gross Unrealized Gains	1,629	518
Gross Unrealized (Losses)	(1,202)	(3,740)
Estimated Fair Value	178,139	154,301
Mortgage-backed securities
Held-to-Maturity
Amortized Cost	11,549	13,346
Gross Unrealized Gains	93	5
Gross Unrealized (Losses)	(42)	(412)
Estimated Fair Value	11,600	12,939
Available-for-Sale
Amortized Cost	1,332,130	1,552,487
Gross Unrealized Gains	9,405	3,097
Gross Unrealized (Losses)	(3,741)	(32,684)
Estimated Fair Value	1,337,794	1,522,900
State and political subdivisions
Held-to-Maturity
Amortized Cost	28,692	256,863
Gross Unrealized Gains	931	3,029
Gross Unrealized (Losses)	0	(954)
Estimated Fair Value	29,623	258,938
Available-for-Sale
Amortized Cost	658,984	320,142
Gross Unrealized Gains	22,290	171
Gross Unrealized (Losses)	(72)	(5,470)
Estimated Fair Value	681,202	314,843
Other securities
Held-to-Maturity
Amortized Cost	1,996	1,995
Gross Unrealized Gains	83	17
Gross Unrealized (Losses)	0	0
Estimated Fair Value	2,079	2,012
Available-for-Sale
Amortized Cost	158,280	157,471
Gross Unrealized Gains	719	2,251
Gross Unrealized (Losses)	0	(14)
Estimated Fair Value	$ 158,999	$ 159,708

Investment Securities - Textual

Investment Securities - Textual (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Securities valued at less than historical cost, amount	$ 710,600,000		$ 710,600,000		$ 1,700,000,000
Securities valued at less than historical cost (as percent)	29.60%		29.60%		70.30%
Securities pledged as collateral	$ 1,120,000,000		$ 1,120,000,000		$ 1,020,000,000
Realized gains	7,600,000	$ 41,000	12,900,000	$ 54,000
Realized losses	3,000	$ 0	$ 3,000	$ 1,000
Bonds
Debt Securities, Available-for-sale [Line Items]
Realized gains	7,300,000
Bonds sold, amount	$ 89,000,000

Investment Securities - Securit

Investment Securities - Securities With Unrealized Losses (Details) $ in Thousands	Sep. 30, 2019USD ($)
Held-to-Maturity
Held-to-maturity, less than 12 months, estimated fair value	$ 4,043
Held-to-maturity, less than 12 months, gross unrealized losses	(15)
Held-to-maturity, 12 months or more, estimated fair value	2,590
Held-to-maturity, 12 months or more, gross unrealized losses	(27)
Held-to-maturity, total, estimated fair value	6,633
Held-to-maturity, total, gross unrealized losses	(42)
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, less than 12 months, estimated fair value	174,478
Available-for-sale, less than 12 months, gross unrealized losses	(605)
Available-for-sale, 12 months or more, estimated fair value	529,478
Available-for-sale, 12 months or more, gross unrealized losses	(4,410)
Available-for-sale, total, estimated fair value	703,956
Available-for-sale, total, gross unrealized losses	(5,015)
U.S. Government agencies
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, less than 12 months, estimated fair value	16,662
Available-for-sale, less than 12 months, gross unrealized losses	(36)
Available-for-sale, 12 months or more, estimated fair value	90,974
Available-for-sale, 12 months or more, gross unrealized losses	(1,166)
Available-for-sale, total, estimated fair value	107,636
Available-for-sale, total, gross unrealized losses	(1,202)
Mortgage-backed securities
Held-to-Maturity
Held-to-maturity, less than 12 months, estimated fair value	3,408
Held-to-maturity, less than 12 months, gross unrealized losses	(15)
Held-to-maturity, 12 months or more, estimated fair value	2,575
Held-to-maturity, 12 months or more, gross unrealized losses	(27)
Held-to-maturity, total, estimated fair value	5,983
Held-to-maturity, total, gross unrealized losses	(42)
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, less than 12 months, estimated fair value	133,538
Available-for-sale, less than 12 months, gross unrealized losses	(528)
Available-for-sale, 12 months or more, estimated fair value	435,207
Available-for-sale, 12 months or more, gross unrealized losses	(3,213)
Available-for-sale, total, estimated fair value	568,745
Available-for-sale, total, gross unrealized losses	(3,741)
State and political subdivisions
Held-to-Maturity
Held-to-maturity, less than 12 months, estimated fair value	635
Held-to-maturity, less than 12 months, gross unrealized losses	0
Held-to-maturity, 12 months or more, estimated fair value	15
Held-to-maturity, 12 months or more, gross unrealized losses	0
Held-to-maturity, total, estimated fair value	650
Held-to-maturity, total, gross unrealized losses	0
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, less than 12 months, estimated fair value	24,278
Available-for-sale, less than 12 months, gross unrealized losses	(41)
Available-for-sale, 12 months or more, estimated fair value	3,297
Available-for-sale, 12 months or more, gross unrealized losses	(31)
Available-for-sale, total, estimated fair value	27,575
Available-for-sale, total, gross unrealized losses	$ (72)

Investment Securities - Income

Investment Securities - Income Earned on Securities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Non-taxable:
Total	$ 15,367	$ 14,640	$ 49,273	$ 41,558
Held-to-maturity
Taxable:
Taxable	248	528	975	1,641
Non-taxable:
Non-taxable	83	1,828	1,334	5,661
Available-for-sale
Taxable:
Taxable	10,166	10,364	34,422	29,614
Non-taxable:
Non-taxable	$ 4,870	$ 1,920	$ 12,542	$ 4,642

Investment Securities - Maturit

Investment Securities - Maturities of Investment Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Held-to-maturity, amortized cost, one year or less	$ 5,039
Held-to-maturity, amortized cost, after one through five years	17,346
Held-to-maturity, amortized cost, after five through ten years	5,561
Held-to-maturity, amortized cost, after ten years	2,742
Held-to-maturity, amortized cost, securities not due on a single maturity date	11,549
Amortized Cost	42,237	$ 289,194
Held-to-maturity, fair value, one year or less	5,057
Held-to-maturity, fair value, after one through five years	17,703
Held-to-maturity, fair value, after five through ten years	5,858
Held-to-maturity, fair value, after ten years	3,084
Held-to-maturity, fair value, securities not due on a single maturity date	11,600
Held-to-maturity, fair value, total	43,302	290,830
Available-for-sale, amortized cost, one year or less	7,599
Available-for-sale, amortized cost, after one through five years	70,442
Available-for-sale, amortized cost, after five through ten years	139,421
Available-for-sale, amortized cost, after ten years	632,504
Available-for-sale, amortized cost, securities not due on a single maturity date	1,332,130
Available-for-sale, amortized cost, other securities (no maturity)	145,010
Amortized Cost	2,327,106	2,187,623
Available-for-sale, fair value, one year or less	7,605
Available-for-sale, fair value, after one through five years	70,750
Available-for-sale, fair value, after five through ten years	142,101
Available-for-sale, fair value, after ten years	652,404
Available-for-sale, fair value, securities not due on a single maturity date	1,337,794
Available-for-sale, fair value, other securities (no maturity)	145,480
Available-for-sale, fair value, total	$ 2,356,134	$ 2,151,752

Loans and Allowance for Loan _3

Loans and Allowance for Loan Losses - Textual (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)loan	Sep. 30, 2018USD ($)loan	Sep. 30, 2019USD ($)loan	Sep. 30, 2018USD ($)loan	Dec. 31, 2018USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 13,000,000,000		$ 13,000,000,000		$ 11,720,000,000
Recorded investment	70,007,000		70,007,000		39,770,000
Impaired loan, related allowance	5,279,000		5,279,000		684,000
Interest income recognized	400,000	$ 400,000	1,200,000	$ 1,100,000
Average Investment in Impaired Loans	$ 64,550,000	$ 44,309,000	$ 56,612,000	$ 44,952,000
Troubled debt, number of contracts | loan	1	6	1	8
Balance prior to TDR	$ 330,000	$ 2,854,000	$ 330,000	$ 3,006,000
Financial impact on date of restructure	0	402,000	0	402,000
Foreclosed assets and other real estate owned	19,576,000		19,576,000		25,565,000
Risk Rate 6 | Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired	3,100,000		3,100,000		4,100,000
Risk Ratings 6,7, and 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired excluding loans accounted for under ASC Topic 310-30	146,200,000		146,200,000		119,000,000
Risk Ratings 6,7, and 8 | Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired excluding loans accounted for under ASC Topic 310-30	37,400,000		37,400,000		50,400,000
Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans in process of foreclosure, amount	3,925,000		3,925,000		3,899,000
OREO Received in Full or Partial Satisfaction of Loans | Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Foreclosed assets and other real estate owned	4,401,000		4,401,000		3,530,000
Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	6,792,021,000		6,792,021,000		5,966,453,000
Recorded investment	33,203,000		33,203,000		24,253,000
Impaired loan, related allowance	659,000		659,000		$ 247,000
Interest income recognized	172,000	217,000	526,000	688,000
Average Investment in Impaired Loans	$ 29,631,000	$ 27,270,000	$ 27,123,000	$ 29,581,000
Troubled debt, number of contracts | loan	1	3	1	4
Balance prior to TDR	$ 330,000	$ 491,000	$ 330,000	$ 552,000
Financial impact on date of restructure	$ 0	$ 212,000	0	212,000
Real Estate | OREO Received in Full or Partial Satisfaction of Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance prior to TDR			$ 0	$ 294,300
Commercial Real Estate | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans with subsequent default | loan			4	1
Write-down of impaired loans			$ 552,000	$ 66,300
Transfers of loans				$ 294,300

Loans and Allowance for Loan _4

Loans and Allowance for Loan Losses - Loan Portfolio by Categories (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 13,000,000	$ 11,720,000
Loans acquired, net of discount and allowance	3,359,587	3,292,783
Total loans	13,002,952	11,723,171
Loans, Excluding Acquired Loans
Loans and Leases Receivable Disclosure [Line Items]
Loans	9,643,365	8,430,388
Consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans	403,726	405,470
Consumer | Credit cards
Loans and Leases Receivable Disclosure [Line Items]
Loans	195,083	204,173
Consumer | Other consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans	208,643	201,297
Real Estate
Loans and Leases Receivable Disclosure [Line Items]
Loans	6,792,021	5,966,453
Real Estate | Construction
Loans and Leases Receivable Disclosure [Line Items]
Loans	1,712,858	1,300,723
Real Estate | Single family residential
Loans and Leases Receivable Disclosure [Line Items]
Loans	1,448,455	1,440,443
Real Estate | Other commercial
Loans and Leases Receivable Disclosure [Line Items]
Loans	3,630,708	3,225,287
Commercial
Loans and Leases Receivable Disclosure [Line Items]
Loans	2,108,572	1,939,423
Commercial | Commercial
Loans and Leases Receivable Disclosure [Line Items]
Loans	1,894,819	1,774,909
Commercial | Agricultural
Loans and Leases Receivable Disclosure [Line Items]
Loans	213,753	164,514
Other
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 339,046	$ 119,042

Loans and Allowance for Loan _5

Loans and Allowance for Loan Losses - Nonaccrual Loans, Excluding Loans Acquired, Segregated by Class of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	$ 72,721	$ 34,201
Consumer
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	2,155	2,455
Consumer | Credit cards
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	521	296
Consumer | Other consumer
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	1,634	2,159
Real Estate
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	34,981	20,413
Real Estate | Construction
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	1,805	1,269
Real Estate | Single family residential
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	16,191	11,939
Real Estate | Other commercial
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	16,985	7,205
Commercial
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	35,585	11,333
Commercial | Commercial
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	35,018	10,049
Commercial | Agricultural
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	$ 567	$ 1,284

Loans and Allowance for Loan _6

Loans and Allowance for Loan Losses - Age Analysis of Past Due Loans, Excluding Loans Acquired, Segregated by Class of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Total Loans	$ 13,002,952	$ 11,723,171
Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	54,422	36,687
Current	9,588,943	8,393,701
Total Loans	9,643,365	8,430,388
90 Days Past Due & Accruing	155	224
Gross 30-89 Days Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	31,346	21,917
90 Days or More Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	23,076	14,770
Consumer | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	5,685	6,699
Current	398,041	398,771
Total Loans	403,726	405,470
90 Days Past Due & Accruing	144	213
Consumer | Gross 30-89 Days Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	4,341	5,297
Consumer | 90 Days or More Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	1,344	1,402
Consumer | Credit cards | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	1,608	1,539
Current	193,475	202,634
Total Loans	195,083	204,173
90 Days Past Due & Accruing	130	209
Consumer | Credit cards | Gross 30-89 Days Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	958	1,033
Consumer | Credit cards | 90 Days or More Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	650	506
Consumer | Other consumer | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	4,077	5,160
Current	204,566	196,137
Total Loans	208,643	201,297
90 Days Past Due & Accruing	14	4
Consumer | Other consumer | Gross 30-89 Days Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	3,383	4,264
Consumer | Other consumer | 90 Days or More Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	694	896
Real Estate | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	32,114	18,889
Current	6,759,907	5,947,564
Total Loans	6,792,021	5,966,453
90 Days Past Due & Accruing	0	0
Real Estate | Gross 30-89 Days Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	21,721	11,681
Real Estate | 90 Days or More Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	10,393	7,208
Real Estate | Construction | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	4,303	841
Current	1,708,555	1,299,882
Total Loans	1,712,858	1,300,723
90 Days Past Due & Accruing	0	0
Real Estate | Construction | Gross 30-89 Days Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	3,690	533
Real Estate | Construction | 90 Days or More Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	613	308
Real Estate | Single family residential | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	16,417	11,896
Current	1,432,038	1,428,547
Total Loans	1,448,455	1,440,443
90 Days Past Due & Accruing	0	0
Real Estate | Single family residential | Gross 30-89 Days Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	10,022	7,769
Real Estate | Single family residential | 90 Days or More Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	6,395	4,127
Real Estate | Other commercial | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	11,394	6,152
Current	3,619,314	3,219,135
Total Loans	3,630,708	3,225,287
90 Days Past Due & Accruing	0	0
Real Estate | Other commercial | Gross 30-89 Days Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	8,009	3,379
Real Estate | Other commercial | 90 Days or More Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	3,385	2,773
Commercial | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	16,623	11,099
Current	2,091,949	1,928,324
Total Loans	2,108,572	1,939,423
90 Days Past Due & Accruing	11	11
Commercial | Gross 30-89 Days Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	5,284	4,939
Commercial | 90 Days or More Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	11,339	6,160
Commercial | Commercial | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	15,989	9,577
Current	1,878,830	1,765,332
Total Loans	1,894,819	1,774,909
90 Days Past Due & Accruing	11	11
Commercial | Commercial | Gross 30-89 Days Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	4,999	4,472
Commercial | Commercial | 90 Days or More Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	10,990	5,105
Commercial | Agricultural | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	634	1,522
Current	213,119	162,992
Total Loans	213,753	164,514
90 Days Past Due & Accruing	0	0
Commercial | Agricultural | Gross 30-89 Days Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	285	467
Commercial | Agricultural | 90 Days or More Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	349	1,055
Other | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	0	0
Current	339,046	119,042
Total Loans	339,046	119,042
90 Days Past Due & Accruing	0	$ 0
Other | Gross 30-89 Days Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	0
Other | 90 Days or More Past Due | Loans, Excluding Acquired Loans
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 0

Loans and Allowance for Loan _7

Loans and Allowance for Loan Losses - Impaired Loans, Net of Government Guarantees and Excluding Loans Acquired, Segregated by Class of Loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	$ 88,665		$ 88,665		$ 38,071
Recorded Investment With No Allowance	32,651		32,651		28,583
Recorded Investment With Allowance	37,356		37,356		11,187
Total Recorded Investment	70,007		70,007		39,770
Related Allowance	5,279		5,279		684
Average Investment in Impaired Loans	64,550	$ 44,309	56,612	$ 44,952
Interest Income Recognized	400	400	1,200	1,100
Consumer
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	2,304		2,304		2,607
Recorded Investment With No Allowance	2,155		2,155		2,455
Recorded Investment With Allowance	0		0		0
Total Recorded Investment	2,155		2,155		2,455
Related Allowance	0		0		0
Average Investment in Impaired Loans	2,026	3,844	2,100	4,368
Interest Income Recognized	49	63	143	156
Consumer | Credit cards
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	521		521		296
Recorded Investment With No Allowance	521		521		296
Recorded Investment With Allowance	0		0		0
Total Recorded Investment	521		521		296
Related Allowance	0		0		0
Average Investment in Impaired Loans	423	283	370	259
Interest Income Recognized	40	35	110	60
Consumer | Other consumer
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	1,783		1,783		2,311
Recorded Investment With No Allowance	1,634		1,634		2,159
Recorded Investment With Allowance	0		0		0
Total Recorded Investment	1,634		1,634		2,159
Related Allowance	0		0		0
Average Investment in Impaired Loans	1,603	3,561	1,730	4,109
Interest Income Recognized	9	28	33	96
Real Estate
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	35,066		35,066		22,684
Recorded Investment With No Allowance	19,893		19,893		17,694
Recorded Investment With Allowance	13,310		13,310		6,559
Total Recorded Investment	33,203		33,203		24,253
Related Allowance	659		659		247
Average Investment in Impaired Loans	29,631	27,270	27,123	29,581
Interest Income Recognized	172	217	526	688
Real Estate | Construction
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	1,898		1,898		1,344
Recorded Investment With No Allowance	1,708		1,708		784
Recorded Investment With Allowance	97		97		485
Total Recorded Investment	1,805		1,805		1,269
Related Allowance	0		0		211
Average Investment in Impaired Loans	1,972	1,411	1,946	1,747
Interest Income Recognized	10	11	38	41
Real Estate | Single family residential
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	17,526		17,526		12,906
Recorded Investment With No Allowance	13,985		13,985		11,468
Recorded Investment With Allowance	2,206		2,206		616
Total Recorded Investment	16,191		16,191		12,084
Related Allowance	31		31		36
Average Investment in Impaired Loans	15,920	13,577	14,812	13,550
Interest Income Recognized	85	98	287	315
Real Estate | Other commercial
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	15,642		15,642		8,434
Recorded Investment With No Allowance	4,200		4,200		5,442
Recorded Investment With Allowance	11,007		11,007		5,458
Total Recorded Investment	15,207		15,207		10,900
Related Allowance	628		628		0
Average Investment in Impaired Loans	11,739	12,282	10,365	14,284
Interest Income Recognized	77	108	201	332
Commercial
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	51,295		51,295		12,780
Recorded Investment With No Allowance	10,603		10,603		8,434
Recorded Investment With Allowance	24,046		24,046		4,628
Total Recorded Investment	34,649		34,649		13,062
Related Allowance	4,620		4,620		437
Average Investment in Impaired Loans	32,893	13,195	27,389	11,003
Interest Income Recognized	179	120	531	256
Commercial | Commercial
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	50,712		50,712		10,361
Recorded Investment With No Allowance	10,153		10,153		7,254
Recorded Investment With Allowance	23,930		23,930		4,628
Total Recorded Investment	34,083		34,083		11,882
Related Allowance	4,620		4,620		437
Average Investment in Impaired Loans	32,020	11,840	26,379	9,533
Interest Income Recognized	176	108	511	222
Commercial | Agricultural
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	583		583		2,419
Recorded Investment With No Allowance	450		450		1,180
Recorded Investment With Allowance	116		116		0
Total Recorded Investment	566		566		1,180
Related Allowance	0		0		$ 0
Average Investment in Impaired Loans	873	1,355	1,010	1,470
Interest Income Recognized	$ 3	$ 12	$ 20	$ 34

Loans and Allowance for Loan _8

Loans and Allowance for Loan Losses - Troubled Debt Restructurings, Excluding Loans Acquired, Segregated by Class of Loans (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019USD ($)loan	Sep. 30, 2018loan	Sep. 30, 2019USD ($)loan	Sep. 30, 2018loan	Dec. 31, 2018USD ($)loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts	1	6	1	8
Loans, Excluding Acquired Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			28		33
Troubled debt, balance | $	$ 8,277		$ 8,277		$ 9,215
Loans, Excluding Acquired Loans | Accruing TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			12		12
Troubled debt, balance | $	6,519		$ 6,519		$ 6,369
Loans, Excluding Acquired Loans | Nonaccrual TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			16		21
Troubled debt, balance | $	$ 1,758		$ 1,758		$ 2,846
Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts	1	3	1	4
Real Estate | Loans, Excluding Acquired Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			21		23
Troubled debt, balance | $	$ 5,389		$ 5,389		$ 5,664
Real Estate | Loans, Excluding Acquired Loans | Accruing TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			8		8
Troubled debt, balance | $	3,715		$ 3,715		$ 3,536
Real Estate | Loans, Excluding Acquired Loans | Nonaccrual TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			13		15
Troubled debt, balance | $	1,674		$ 1,674		$ 2,128
Real Estate | Construction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts		1		1
Real Estate | Construction | Loans, Excluding Acquired Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			1		3
Troubled debt, balance | $	97		$ 97		$ 485
Real Estate | Construction | Loans, Excluding Acquired Loans | Accruing TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			0		0
Troubled debt, balance | $	0		$ 0		$ 0
Real Estate | Construction | Loans, Excluding Acquired Loans | Nonaccrual TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			1		3
Troubled debt, balance | $	$ 97		$ 97		$ 485
Real Estate | Single family residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts	1		1	1
Real Estate | Single family residential | Loans, Excluding Acquired Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			16		16
Troubled debt, balance | $	$ 1,176		$ 1,176		$ 846
Real Estate | Single family residential | Loans, Excluding Acquired Loans | Accruing TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			6		6
Troubled debt, balance | $	549		$ 549		$ 230
Real Estate | Single family residential | Loans, Excluding Acquired Loans | Nonaccrual TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			10		10
Troubled debt, balance | $	627		$ 627		$ 616
Real Estate | Other commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts		2		2
Real Estate | Other commercial | Loans, Excluding Acquired Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			4		4
Troubled debt, balance | $	4,116		$ 4,116		$ 4,333
Real Estate | Other commercial | Loans, Excluding Acquired Loans | Accruing TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			2		2
Troubled debt, balance | $	3,166		$ 3,166		$ 3,306
Real Estate | Other commercial | Loans, Excluding Acquired Loans | Nonaccrual TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			2		2
Troubled debt, balance | $	950		$ 950		$ 1,027
Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts		3		3
Commercial | Loans, Excluding Acquired Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			7		10
Troubled debt, balance | $	2,888		$ 2,888		$ 3,551
Commercial | Loans, Excluding Acquired Loans | Accruing TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			4		4
Troubled debt, balance | $	2,804		$ 2,804		$ 2,833
Commercial | Loans, Excluding Acquired Loans | Nonaccrual TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			3		6
Troubled debt, balance | $	84		$ 84		$ 718
Commercial | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts		3		3
Commercial | Commercial | Loans, Excluding Acquired Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			7		10
Troubled debt, balance | $	2,888		$ 2,888		$ 3,551
Commercial | Commercial | Loans, Excluding Acquired Loans | Accruing TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			4		4
Troubled debt, balance | $	2,804		$ 2,804		$ 2,833
Commercial | Commercial | Loans, Excluding Acquired Loans | Nonaccrual TDR Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt, number of contracts			3		6
Troubled debt, balance | $	$ 84		$ 84		$ 718

Loans and Allowance for Loan _9

Loans and Allowance for Loan Losses - Loans Restructured as TDRs, Excluding Loans Acquired, Segregated by Class of Loans (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)loan	Sep. 30, 2018USD ($)loan	Sep. 30, 2019USD ($)loan	Sep. 30, 2018USD ($)loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	1	6	1	8
Balance Prior to TDR	$ 330	$ 2,854	$ 330	$ 3,006
Balance	330	2,846	330	2,999
Financial Impact on Date of Restructure	0	402	0	402
Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	330	2,846	330	2,999
Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 0	$ 0	$ 0
Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan				1
Balance Prior to TDR				$ 91
Balance				91
Financial Impact on Date of Restructure				0
Consumer | Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance				91
Consumer | Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance				$ 0
Consumer | Other consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan				1
Balance Prior to TDR				$ 91
Balance				91
Financial Impact on Date of Restructure				0
Consumer | Other consumer | Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance				91
Consumer | Other consumer | Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance				$ 0
Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	1	3	1	4
Balance Prior to TDR	$ 330	$ 491	$ 330	$ 552
Balance	330	488	330	550
Financial Impact on Date of Restructure	0	212	0	212
Real Estate | Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	330	488	330	550
Real Estate | Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 0	$ 0	$ 0
Real Estate | Construction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		1		1
Balance Prior to TDR		$ 99		$ 99
Balance		98		98
Financial Impact on Date of Restructure		0		0
Real Estate | Construction | Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance		98		98
Real Estate | Construction | Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance		$ 0		$ 0
Real Estate | Single family residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	1		1	1
Balance Prior to TDR	$ 330		$ 330	$ 61
Balance	330		330	62
Financial Impact on Date of Restructure	0		0	0
Real Estate | Single family residential | Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	330		330	62
Real Estate | Single family residential | Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0		$ 0	$ 0
Real Estate | Other commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		2		2
Balance Prior to TDR		$ 392		$ 392
Balance		390		390
Financial Impact on Date of Restructure		212		212
Real Estate | Other commercial | Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance		390		390
Real Estate | Other commercial | Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance		$ 0		$ 0
Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		3		3
Balance Prior to TDR		$ 2,363		$ 2,363
Balance		2,358		2,358
Financial Impact on Date of Restructure		190		190
Commercial | Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance		2,358		2,358
Commercial | Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance		$ 0		$ 0
Commercial | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		3		3
Balance Prior to TDR		$ 2,363		$ 2,363
Balance		2,358		2,358
Financial Impact on Date of Restructure		190		190
Commercial | Commercial | Change in Maturity Date
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance		2,358		2,358
Commercial | Commercial | Change in Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance		$ 0		$ 0

Loans and Allowance for Loan_10

Loans and Allowance for Loan Losses - Loans by Credit Risk Rating, Segregated by Class of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	$ 13,002,952	$ 11,723,171
Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	12,761,764	11,523,787
Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	95,017	80,394
Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	146,039	118,407
Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	132	583
Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	9,643,365	8,430,388
Loans, Excluding Acquired Loans | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,108,572	1,939,423
Loans, Excluding Acquired Loans | Commercial | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,050,446	1,904,826
Loans, Excluding Acquired Loans | Commercial | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	10,489	8,432
Loans, Excluding Acquired Loans | Commercial | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	47,637	26,165
Loans, Excluding Acquired Loans | Commercial | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Commercial | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Commercial | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,894,819	1,774,909
Loans, Excluding Acquired Loans | Commercial | Commercial | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,837,374	1,742,002
Loans, Excluding Acquired Loans | Commercial | Commercial | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	10,420	8,357
Loans, Excluding Acquired Loans | Commercial | Commercial | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	47,025	24,550
Loans, Excluding Acquired Loans | Commercial | Commercial | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Commercial | Commercial | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Commercial | Agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	213,753	164,514
Loans, Excluding Acquired Loans | Commercial | Agricultural | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	213,072	162,824
Loans, Excluding Acquired Loans | Commercial | Agricultural | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	69	75
Loans, Excluding Acquired Loans | Commercial | Agricultural | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	612	1,615
Loans, Excluding Acquired Loans | Commercial | Agricultural | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Commercial | Agricultural | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	6,792,021	5,966,453
Loans, Excluding Acquired Loans | Real Estate | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	6,699,168	5,910,329
Loans, Excluding Acquired Loans | Real Estate | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	37,732	20,707
Loans, Excluding Acquired Loans | Real Estate | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	55,117	35,182
Loans, Excluding Acquired Loans | Real Estate | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	4	235
Loans, Excluding Acquired Loans | Real Estate | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Real Estate | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,712,858	1,300,723
Loans, Excluding Acquired Loans | Real Estate | Construction | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,705,376	1,296,988
Loans, Excluding Acquired Loans | Real Estate | Construction | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,456	1,910
Loans, Excluding Acquired Loans | Real Estate | Construction | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	6,026	1,825
Loans, Excluding Acquired Loans | Real Estate | Construction | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Real Estate | Construction | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Real Estate | Single family residential
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,448,455	1,440,443
Loans, Excluding Acquired Loans | Real Estate | Single family residential | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,422,086	1,420,052
Loans, Excluding Acquired Loans | Real Estate | Single family residential | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	3,246	1,628
Loans, Excluding Acquired Loans | Real Estate | Single family residential | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	23,119	18,528
Loans, Excluding Acquired Loans | Real Estate | Single family residential | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	4	235
Loans, Excluding Acquired Loans | Real Estate | Single family residential | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Real Estate | Other commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	3,630,708	3,225,287
Loans, Excluding Acquired Loans | Real Estate | Other commercial | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	3,571,706	3,193,289
Loans, Excluding Acquired Loans | Real Estate | Other commercial | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	33,030	17,169
Loans, Excluding Acquired Loans | Real Estate | Other commercial | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	25,972	14,829
Loans, Excluding Acquired Loans | Real Estate | Other commercial | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Real Estate | Other commercial | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	403,726	405,470
Loans, Excluding Acquired Loans | Consumer | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	401,080	402,507
Loans, Excluding Acquired Loans | Consumer | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Consumer | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,646	2,963
Loans, Excluding Acquired Loans | Consumer | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Consumer | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Consumer | Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	195,083	204,173
Loans, Excluding Acquired Loans | Consumer | Credit cards | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	194,433	203,667
Loans, Excluding Acquired Loans | Consumer | Credit cards | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Consumer | Credit cards | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	650	506
Loans, Excluding Acquired Loans | Consumer | Credit cards | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Consumer | Credit cards | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Consumer | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	208,643	201,297
Loans, Excluding Acquired Loans | Consumer | Other consumer | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	206,647	198,840
Loans, Excluding Acquired Loans | Consumer | Other consumer | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Consumer | Other consumer | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,996	2,457
Loans, Excluding Acquired Loans | Consumer | Other consumer | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Consumer | Other consumer | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	339,046	119,042
Loans, Excluding Acquired Loans | Other | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	339,046	119,042
Loans, Excluding Acquired Loans | Other | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Other | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Other | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans, Excluding Acquired Loans | Other | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	3,359,587	3,292,783
Loans Acquired | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	3,272,024	3,187,083
Loans Acquired | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	46,796	51,255
Loans Acquired | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	40,639	54,097
Loans Acquired | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	128	348
Loans Acquired | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	350,693	432,653
Loans Acquired | Commercial | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	342,189	402,942
Loans Acquired | Commercial | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,491	12,416
Loans Acquired | Commercial | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	7,013	17,295
Loans Acquired | Commercial | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Commercial | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Commercial | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	349,821	430,914
Loans Acquired | Commercial | Commercial | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	341,385	401,300
Loans Acquired | Commercial | Commercial | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,491	12,416
Loans Acquired | Commercial | Commercial | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	6,945	17,198
Loans Acquired | Commercial | Commercial | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Commercial | Commercial | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Commercial | Agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	872	1,739
Loans Acquired | Commercial | Agricultural | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	804	1,642
Loans Acquired | Commercial | Agricultural | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Commercial | Agricultural | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	68	97
Loans Acquired | Commercial | Agricultural | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Commercial | Agricultural | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	3,001,463	2,844,472
Loans Acquired | Real Estate | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,922,550	2,768,761
Loans Acquired | Real Estate | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	45,305	38,839
Loans Acquired | Real Estate | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	33,480	36,524
Loans Acquired | Real Estate | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	128	348
Loans Acquired | Real Estate | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Real Estate | Construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	362,000	429,605
Loans Acquired | Real Estate | Construction | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	344,075	393,122
Loans Acquired | Real Estate | Construction | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	17,874	27,621
Loans Acquired | Real Estate | Construction | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	51	8,862
Loans Acquired | Real Estate | Construction | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Real Estate | Construction | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Real Estate | Single family residential
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	504,490	566,188
Loans Acquired | Real Estate | Single family residential | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	492,826	553,460
Loans Acquired | Real Estate | Single family residential | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,224	2,081
Loans Acquired | Real Estate | Single family residential | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	10,312	10,299
Loans Acquired | Real Estate | Single family residential | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	128	348
Loans Acquired | Real Estate | Single family residential | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Real Estate | Other commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,134,973	1,848,679
Loans Acquired | Real Estate | Other commercial | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,085,649	1,822,179
Loans Acquired | Real Estate | Other commercial | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	26,207	9,137
Loans Acquired | Real Estate | Other commercial | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	23,117	17,363
Loans Acquired | Real Estate | Other commercial | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Real Estate | Other commercial | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Consumer | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	7,431	15,658
Loans Acquired | Consumer | Other consumer | Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	7,285	15,380
Loans Acquired | Consumer | Other consumer | Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Consumer | Other consumer | Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	146	278
Loans Acquired | Consumer | Other consumer | Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Loans Acquired | Consumer | Other consumer | Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	$ 0	$ 0

Loans and Allowance for Loan_11

Loans and Allowance for Loan Losses - Activity in the Allowance for Loan Losses, by Portfolio Segment, for the Current Year (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	$ 64,179,000	$ 53,776,000	$ 56,694,000	$ 42,086,000
Provision for loan losses	21,973,000	10,345,000	38,337,000	28,528,000
Balance, end of year	66,590,000	56,703,000	66,590,000	56,703,000
Loans, Excluding Acquired Loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	63,067,000	51,732,000	56,599,000	41,668,000
Provision for loan losses	21,973,000	10,345,000	35,873,000	26,691,000
Charge-offs	(20,812,000)	(7,784,000)	(29,911,000)	(15,384,000)
Recoveries	1,765,000	1,065,000	3,432,000	2,383,000
Net charge-offs	(19,047,000)	(6,719,000)	(26,479,000)	(13,001,000)
Balance, end of year	65,993,000	55,358,000	65,993,000	55,358,000
Period-end amount allocated to:
Loans individually evaluated for impairment	5,279,000	459,000	5,279,000	459,000	$ 684,000
Loans collectively evaluated for impairment	60,714,000	54,899,000	60,714,000	54,899,000	55,915,000
Loans, Excluding Acquired Loans | Other Consumer and Other
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	2,460,000	3,239,000	2,419,000	3,596,000
Provision for loan losses	(528,000)	729,000	1,320,000	2,567,000
Charge-offs	(1,059,000)	(1,321,000)	(3,497,000)	(3,743,000)
Recoveries	1,422,000	176,000	2,053,000	403,000
Net charge-offs	363,000	(1,145,000)	(1,444,000)	(3,340,000)
Balance, end of year	2,295,000	2,823,000	2,295,000	2,823,000
Period-end amount allocated to:
Loans individually evaluated for impairment	0	0	0	0	0
Loans collectively evaluated for impairment	2,295,000	2,823,000	2,295,000	2,823,000	2,419,000
Loans, Excluding Acquired Loans | Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	21,739,000	15,767,000	20,514,000	7,007,000
Provision for loan losses	19,150,000	3,589,000	23,980,000	14,772,000
Charge-offs	(17,729,000)	(592,000)	(21,564,000)	(3,143,000)
Recoveries	65,000	450,000	295,000	578,000
Net charge-offs	(17,664,000)	(142,000)	(21,269,000)	(2,565,000)
Balance, end of year	23,225,000	19,214,000	23,225,000	19,214,000
Period-end amount allocated to:
Loans individually evaluated for impairment	4,620,000	191,000	4,620,000	191,000	437,000
Loans collectively evaluated for impairment	18,605,000	19,023,000	18,605,000	19,023,000	20,077,000
Loans, Excluding Acquired Loans | Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	34,917,000	28,904,000	29,743,000	27,281,000
Provision for loan losses	2,405,000	5,308,000	7,929,000	7,133,000
Charge-offs	(907,000)	(4,952,000)	(1,552,000)	(5,568,000)
Recoveries	55,000	210,000	350,000	624,000
Net charge-offs	(852,000)	(4,742,000)	(1,202,000)	(4,944,000)
Balance, end of year	36,470,000	29,470,000	36,470,000	29,470,000
Period-end amount allocated to:
Loans individually evaluated for impairment	659,000	268,000	659,000	268,000	247,000
Loans collectively evaluated for impairment	35,811,000	29,202,000	35,811,000	29,202,000	29,496,000
Loans, Excluding Acquired Loans | Credit Card | Credit cards
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	3,951,000	3,822,000	3,923,000	3,784,000
Provision for loan losses	946,000	719,000	2,644,000	2,219,000
Charge-offs	(1,117,000)	(919,000)	(3,298,000)	(2,930,000)
Recoveries	223,000	229,000	734,000	778,000
Net charge-offs	(894,000)	(690,000)	(2,564,000)	(2,152,000)
Balance, end of year	4,003,000	3,851,000	4,003,000	3,851,000
Period-end amount allocated to:
Loans individually evaluated for impairment	0	0	0	0	0
Loans collectively evaluated for impairment	4,003,000	3,851,000	4,003,000	3,851,000	$ 3,923,000
Loans Acquired
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	1,112,000	2,044,000	95,000	418,000
Provision for loan losses	0	0	2,464,000	1,837,000
Charge-offs	(515,000)	(699,000)	(2,862,000)	(910,000)
Recoveries			900,000
Balance, end of year	$ 597,000	$ 1,345,000	$ 597,000	$ 1,345,000

Loans and Allowance for Loan_12

Loans and Allowance for Loan Losses - Recorded Investment in Loans, Excluding Loans Acquired (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Loss [Line Items]
Total Loans	$ 13,002,952	$ 11,723,171
Loans, Excluding Acquired Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans individually evaluated for impairment	70,007	39,770
Loans collectively evaluated for impairment	9,573,358	8,390,618
Total Loans	9,643,365	8,430,388
Loans, Excluding Acquired Loans | Other Consumer and Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans individually evaluated for impairment	1,634	2,159
Loans collectively evaluated for impairment	546,055	318,180
Total Loans	547,689	320,339
Loans, Excluding Acquired Loans | Commercial
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans individually evaluated for impairment	34,649	13,062
Loans collectively evaluated for impairment	2,073,923	1,926,361
Total Loans	2,108,572	1,939,423
Loans, Excluding Acquired Loans | Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans individually evaluated for impairment	33,203	24,253
Loans collectively evaluated for impairment	6,758,818	5,942,200
Total Loans	6,792,021	5,966,453
Loans, Excluding Acquired Loans | Credit Card
Financing Receivable, Allowance for Credit Loss [Line Items]
Total Loans	403,726	405,470
Loans, Excluding Acquired Loans | Credit Card | Credit cards
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans individually evaluated for impairment	521	296
Loans collectively evaluated for impairment	194,562	203,877
Total Loans	$ 195,083	$ 204,173

Loans Acquired - Textual (Detai

Loans Acquired - Textual (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Apr. 12, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net loans	$ 12,936,959,000		$ 12,936,959,000				$ 11,666,572,000
Loans	13,000,000,000		13,000,000,000				11,720,000,000
Allowance for loan losses	66,590,000	$ 56,703,000	66,590,000	$ 56,703,000	$ 64,179,000		56,694,000	$ 53,776,000	$ 42,086,000
Provision for loan losses	21,973,000	10,345,000	38,337,000	28,528,000
Loans acquired, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	597,000	1,345,000	597,000	1,345,000	$ 1,112,000		$ 95,000	$ 2,044,000	$ 418,000
Provision for loan losses	$ 0	$ 0	$ 2,464,000	$ 1,837,000
Reliance Bancshares, Inc.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net loans						$ 1,100,000,000
Accounting Standards Update 2017-08 | Reliance Bancshares, Inc.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net loans						1,097,000,000
Loans						1,127,000,000
Allowance for loan losses						30,600,000
Accounting Standards Update 2016-13 | Reliance Bancshares, Inc.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net loans						176,000
Loans						385,000
Allowance for loan losses						$ 209,000

Loans Acquired - Carrying Value

Loans Acquired - Carrying Value of all Acquired Impaired Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired loans	$ 13,002,952		$ 11,723,171
Allowance for loan losses	66,590	$ 64,179	56,694	$ 56,703	$ 53,776	$ 42,086
Loans Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired loans	3,359,587		3,292,783
Allowance for loan losses	597	$ 1,112	95	$ 1,345	$ 2,044	$ 418
Loans Acquired | Consumer | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired loans	7,431		15,658
Loans Acquired | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired loans	3,001,463		2,844,472
Loans Acquired | Real Estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired loans	362,000		429,605
Loans Acquired | Real Estate | Single family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired loans	504,490		566,188
Loans Acquired | Real Estate | Other commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired loans	2,134,973		1,848,679
Loans Acquired | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired loans	350,693		432,653
Loans Acquired | Commercial | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired loans	349,821		430,914
Loans Acquired | Commercial | Agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired loans	$ 872		$ 1,739

Loans Acquired - Nonaccrual Acq

Loans Acquired - Nonaccrual Acquired Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	$ 72,721	$ 34,201
Consumer
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	2,155	2,455
Consumer | Other consumer
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	1,634	2,159
Real Estate
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	34,981	20,413
Real Estate | Construction
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	1,805	1,269
Real Estate | Single family residential
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	16,191	11,939
Real Estate | Other commercial
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	16,985	7,205
Commercial
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	35,585	11,333
Commercial | Commercial
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	35,018	10,049
Commercial | Agricultural
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	567	1,284
Loans Acquired
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	7,299	21,640
Loans Acquired | Consumer | Other consumer
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	71	140
Loans Acquired | Real Estate
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	5,569	7,884
Loans Acquired | Real Estate | Construction
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	48	114
Loans Acquired | Real Estate | Single family residential
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	4,492	6,603
Loans Acquired | Real Estate | Other commercial
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	1,029	1,167
Loans Acquired | Commercial
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	1,659	13,616
Loans Acquired | Commercial | Commercial
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	1,636	13,578
Loans Acquired | Commercial | Agricultural
Financing Receivable, Past Due [Line Items]
Loans in nonaccrual status	$ 23	$ 38

Loans Acquired - Age Analysis o

Loans Acquired - Age Analysis of Past Due Acquired Loans, Excluding Loans Covered by Loss Share (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Total Loans	$ 13,002,952	$ 11,723,171
Loans Acquired
Financing Receivable, Past Due [Line Items]
Total Past Due	9,825	28,076
Current	3,349,762	3,264,707
Total Loans	3,359,587	3,292,783
90 Days Past Due & Accruing	21	2
Loans Acquired | Gross 30-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	6,320	14,827
Loans Acquired | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	3,505	13,249
Loans Acquired | Consumer | Other consumer
Financing Receivable, Past Due [Line Items]
Total Past Due	167	386
Current	7,264	15,272
Total Loans	7,431	15,658
90 Days Past Due & Accruing	4	2
Loans Acquired | Consumer | Other consumer | Gross 30-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	131	337
Loans Acquired | Consumer | Other consumer | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	36	49
Loans Acquired | Real Estate
Financing Receivable, Past Due [Line Items]
Total Past Due	8,327	16,810
Current	2,993,136	2,827,662
Total Loans	3,001,463	2,844,472
90 Days Past Due & Accruing	17	0
Loans Acquired | Real Estate | Gross 30-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	5,582	13,157
Loans Acquired | Real Estate | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	2,745	3,653
Loans Acquired | Real Estate | Construction
Financing Receivable, Past Due [Line Items]
Total Past Due	42	8,310
Current	361,958	421,295
Total Loans	362,000	429,605
90 Days Past Due & Accruing	0	0
Loans Acquired | Real Estate | Construction | Gross 30-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	30	8,283
Loans Acquired | Real Estate | Construction | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	12	27
Loans Acquired | Real Estate | Single family residential
Financing Receivable, Past Due [Line Items]
Total Past Due	5,454	7,755
Current	499,036	558,433
Total Loans	504,490	566,188
90 Days Past Due & Accruing	17	0
Loans Acquired | Real Estate | Single family residential | Gross 30-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	3,664	4,706
Loans Acquired | Real Estate | Single family residential | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	1,790	3,049
Loans Acquired | Real Estate | Other commercial
Financing Receivable, Past Due [Line Items]
Total Past Due	2,831	745
Current	2,132,142	1,847,934
Total Loans	2,134,973	1,848,679
90 Days Past Due & Accruing	0	0
Loans Acquired | Real Estate | Other commercial | Gross 30-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	1,888	168
Loans Acquired | Real Estate | Other commercial | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	943	577
Loans Acquired | Commercial
Financing Receivable, Past Due [Line Items]
Total Past Due	1,331	10,880
Current	349,362	421,773
Total Loans	350,693	432,653
90 Days Past Due & Accruing	0	0
Loans Acquired | Commercial | Gross 30-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	607	1,333
Loans Acquired | Commercial | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	724	9,547
Loans Acquired | Commercial | Commercial
Financing Receivable, Past Due [Line Items]
Total Past Due	1,331	10,844
Current	348,490	420,070
Total Loans	349,821	430,914
90 Days Past Due & Accruing	0	0
Loans Acquired | Commercial | Commercial | Gross 30-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	607	1,302
Loans Acquired | Commercial | Commercial | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	724	9,542
Loans Acquired | Commercial | Agricultural
Financing Receivable, Past Due [Line Items]
Total Past Due	0	36
Current	872	1,703
Total Loans	872	1,739
90 Days Past Due & Accruing	0	0
Loans Acquired | Commercial | Agricultural | Gross 30-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	0	31
Loans Acquired | Commercial | Agricultural | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 0	$ 5

Loans Acquired - Summary of Acq

Loans Acquired - Summary of Acquired Loans, Excluding Loans Covered by Loss Share (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	$ 13,002,952	$ 11,723,171
Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	3,359,587	3,292,783
Risk Rate 1-4
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	12,761,764	11,523,787
Risk Rate 1-4 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	3,272,024	3,187,083
Risk Rate 5
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	95,017	80,394
Risk Rate 5 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	46,796	51,255
Risk Rate 6
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	146,039	118,407
Risk Rate 6 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	40,639	54,097
Risk Rate 7
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	132	583
Risk Rate 7 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	128	348
Risk Rate 8
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Risk Rate 8 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Consumer | Other consumer | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	7,431	15,658
Consumer | Other consumer | Risk Rate 1-4 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	7,285	15,380
Consumer | Other consumer | Risk Rate 5 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Consumer | Other consumer | Risk Rate 6 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	146	278
Consumer | Other consumer | Risk Rate 7 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Consumer | Other consumer | Risk Rate 8 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Real Estate | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	3,001,463	2,844,472
Real Estate | Risk Rate 1-4 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,922,550	2,768,761
Real Estate | Risk Rate 5 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	45,305	38,839
Real Estate | Risk Rate 6 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	33,480	36,524
Real Estate | Risk Rate 7 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	128	348
Real Estate | Risk Rate 8 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Real Estate | Construction | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	362,000	429,605
Real Estate | Construction | Risk Rate 1-4 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	344,075	393,122
Real Estate | Construction | Risk Rate 5 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	17,874	27,621
Real Estate | Construction | Risk Rate 6 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	51	8,862
Real Estate | Construction | Risk Rate 7 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Real Estate | Construction | Risk Rate 8 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Real Estate | Single family residential | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	504,490	566,188
Real Estate | Single family residential | Risk Rate 1-4 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	492,826	553,460
Real Estate | Single family residential | Risk Rate 5 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,224	2,081
Real Estate | Single family residential | Risk Rate 6 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	10,312	10,299
Real Estate | Single family residential | Risk Rate 7 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	128	348
Real Estate | Single family residential | Risk Rate 8 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Real Estate | Other commercial | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,134,973	1,848,679
Real Estate | Other commercial | Risk Rate 1-4 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,085,649	1,822,179
Real Estate | Other commercial | Risk Rate 5 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	26,207	9,137
Real Estate | Other commercial | Risk Rate 6 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	23,117	17,363
Real Estate | Other commercial | Risk Rate 7 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Real Estate | Other commercial | Risk Rate 8 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	350,693	432,653
Commercial | Risk Rate 1-4 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	342,189	402,942
Commercial | Risk Rate 5 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,491	12,416
Commercial | Risk Rate 6 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	7,013	17,295
Commercial | Risk Rate 7 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial | Risk Rate 8 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial | Commercial | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	349,821	430,914
Commercial | Commercial | Risk Rate 1-4 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	341,385	401,300
Commercial | Commercial | Risk Rate 5 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,491	12,416
Commercial | Commercial | Risk Rate 6 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	6,945	17,198
Commercial | Commercial | Risk Rate 7 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial | Commercial | Risk Rate 8 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial | Agricultural | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	872	1,739
Commercial | Agricultural | Risk Rate 1-4 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	804	1,642
Commercial | Agricultural | Risk Rate 5 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial | Agricultural | Risk Rate 6 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	68	97
Commercial | Agricultural | Risk Rate 7 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	0	0
Commercial | Agricultural | Risk Rate 8 | Loans acquired, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	$ 0	$ 0

Loans Acquired - Changes in the

Loans Acquired - Changes in the Carrying Amount of the Accretable Yield for All Purchased Impaired and Non-impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accretable Yield
Beginning balance	$ 1,461	$ 1,382	$ 1,460	$ 620
Additions	0	0	0	0
Accretable yield adjustments	10	717	38	1,895
Accretion	(12)	(635)	(39)	(1,051)
Payments and other reductions, net	0	0	0	0
Balance, ending	1,459	1,464	1,459	1,464
Carrying Amount of Loans
Beginning balance	3,487	13,995	4,050	17,116
Additions	0	0	175	0
Accretion	12	635	39	1,051
Payments and other reductions, net	(422)	(9,664)	(1,187)	(13,201)
Balance, ending	$ 3,077	$ 4,966	$ 3,077	$ 4,966

Right-of-Use Lease Assets and_2

Right-of-Use Lease Assets and Lease Liabilities (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)
Leases [Abstract]
Operating lease, right-of-use asset	$ 34.1	$ 34.1
Operating lease, liability	34.3	34.3
Operating lease, expense	$ 2.8	$ 8.1
Operating ease, weighted average discount rate, percent	3.47%	3.47%
Operating lease, weighted average remaining lease term	8 years 7 months 17 days	8 years 7 months 17 days

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Textual (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Apr. 12, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 926,648			$ 845,687
Finite-Lived Intangible Assets [Line Items]
Core deposit premiums	$ 101,149			91,334
Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life	10 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life	15 years
Core Deposit Premium
Finite-Lived Intangible Assets [Line Items]
Core deposit premiums	$ 90,416			$ 79,807
Core Deposit Premium | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life	10 years
Core Deposit Premium | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life	15 years
Reliance Bancshares, Inc.
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill		$ 81,000	$ 80,961
Reliance Bancshares, Inc. | Core Deposit Premium
Finite-Lived Intangible Assets [Line Items]
Core deposit premiums	$ 18,400

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Goodwill and Other Intangibles (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 926,648	$ 845,687
Finite-Lived Intangible Assets [Line Items]
Other intangible assets, net	101,149	91,334
Total goodwill and other intangible assets	1,027,797	937,021
Core Deposit Premium
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	124,334	105,984
Accumulated amortization	(33,918)	(26,177)
Other intangible assets, net	90,416	79,807
Books of Business Intangible
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	15,234	15,234
Accumulated amortization	(4,501)	(3,707)
Other intangible assets, net	$ 10,733	$ 11,527

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Amortization Expense (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of 2019	$ 2,947
2020	11,776
2021	11,714
2022	11,662
2023	11,379
Thereafter	51,671
Other intangible assets, net	$ 101,149	$ 91,334

Time Deposits - Textual (Detail

Time Deposits - Textual (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Banking and Thrift [Abstract]
Time deposits certificates of $100,000 or more	$ 1,679	$ 1,443
Time deposits certificates over $250,000	$ 777.5	$ 753.2

Income Taxes - Provision for In

Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income taxes currently payable	$ 17,282	$ 5,638	$ 40,356	$ 31,335
Deferred income taxes	5,993	5,264	10,933	7,316
Provision for income taxes	$ 23,275	$ 10,902	$ 51,289	$ 38,651

Income Taxes - Tax Effects of T

Income Taxes - Tax Effects of Temporary Differences Related to Deferred Taxes Included in Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Deferred tax assets:
Loans acquired	$ 15,906	$ 12,536
Allowance for loan losses	16,332	13,947
Valuation of foreclosed assets	2,706	1,474
Tax NOLs from acquisition	18,021	7,242
Deferred compensation payable	2,572	2,707
Accrued equity and other compensation	8,340	8,182
Acquired securities	2,598	397
Unrealized loss on available-for-sale securities	0	9,196
Other	5,409	7,042
Gross deferred tax assets	71,884	62,723
Deferred tax liabilities:
Goodwill and other intangible amortization	(34,304)	(30,471)
Accumulated depreciation	(16,587)	(13,361)
Unrealized gain on available-for-sale securities	(6,811)	0
Other	(5,304)	(5,360)
Gross deferred tax liabilities	(63,006)	(49,192)
Net deferred tax asset, included in other assets	$ 8,878	$ 13,531

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Computed at the statutory rate	$ 22,071	$ 13,880	$ 49,646	$ 41,731
State income taxes, net of federal tax benefit	2,956	986	5,721	4,073
Tax exempt interest income	(1,105)	(833)	(3,090)	(2,292)
Tax exempt earnings on BOLI	(225)	(186)	(619)	(562)
Federal tax credits	(730)	0	(2,188)	0
Other differences, net	308	(2,945)	1,819	(4,299)
Provision for income taxes	$ 23,275	$ 10,902	$ 51,289	$ 38,651

Income Taxes - Textual (Details

Income Taxes - Textual (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
U.S. federal | Earliest Tax Year
Operating Loss Carryforwards [Line Items]
Open tax year	2015
State | Earliest Tax Year
Operating Loss Carryforwards [Line Items]
Open tax year	2015
Metropolitan
Operating Loss Carryforwards [Line Items]
Net operating losses	$ 85.9
Reliance Bancshares, Inc.
Operating Loss Carryforwards [Line Items]
Net operating losses	$ 53.6

Securities Sold Under Agreeme_3

Securities Sold Under Agreements to Repurchase - Textual (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Banking and Thrift [Abstract]
Repurchase agreements	$ 116.3	$ 95.5

Securities Sold Under Agreeme_4

Securities Sold Under Agreements to Repurchase - Contractual Maturity of the Agreements (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	$ 116,300	$ 95,500
U.S. Government agencies
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	116,286	95,542
U.S. Government agencies | Overnight and Continuous
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	116,286	95,542
U.S. Government agencies | Up to 30 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	0	0
U.S. Government agencies | 30-90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	0	0
U.S. Government agencies | Greater than 90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	$ 0	$ 0

Other Borrowings and Subordin_3

Other Borrowings and Subordinated Notes and Debentures - Debt Components (Details) - USD ($)	1 Months Ended	9 Months Ended
	Mar. 31, 2018	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total other borrowings and subordinated debt		$ 1,452,618,000	$ 1,699,400,000
U.S. Bank National Association | Revolving credit facility
Debt Instrument [Line Items]
Total other borrowings and subordinated debt		$ 0	0
U.S. Bank National Association | Revolving credit facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Floating rate (as percent)		1.50%
Total other borrowings
Debt Instrument [Line Items]
Total other borrowings and subordinated debt		$ 1,098,395,000	1,345,450,000
FHLB advances, net of discount, due 2019 to 2033, 1.38% to 7.37% secured by real estate loans
Debt Instrument [Line Items]
Total other borrowings and subordinated debt		$ 1,098,395,000	1,345,450,000
FHLB advances, net of discount, due 2019 to 2033, 1.38% to 7.37% secured by real estate loans | Minimum
Debt Instrument [Line Items]
Fixed rate (as percent)		1.38%
FHLB advances, net of discount, due 2019 to 2033, 1.38% to 7.37% secured by real estate loans | Maximum
Debt Instrument [Line Items]
Fixed rate (as percent)		7.37%
Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly)
Debt Instrument [Line Items]
Fixed rate (as percent)	5.00%	5.00%
Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly) | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Floating rate (as percent)	2.15%
Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly) | Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly)
Debt Instrument [Line Items]
Long-term debt, gross		$ 330,000,000	330,000,000
Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly) | Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly) | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Floating rate (as percent)		2.15%
Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly) | Trust preferred securities, net of discount, due 9/15/2037, floating rate of 1.37% above the three month LIBOR rate, reset quarterly
Debt Instrument [Line Items]
Long-term debt, gross		$ 10,310,000	10,310,000
Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly) | Trust preferred securities, net of discount, due 9/15/2037, floating rate of 1.37% above the three month LIBOR rate, reset quarterly | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Floating rate (as percent)		1.37%
Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly) | Trust preferred securities, net of discount, due 6/6/2037, floating rate of 1.57% above the three month LIBOR rate, reset quarterly, callable without penalty
Debt Instrument [Line Items]
Long-term debt, gross		$ 10,310,000	10,310,000
Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly) | Trust preferred securities, net of discount, due 6/6/2037, floating rate of 1.57% above the three month LIBOR rate, reset quarterly, callable without penalty | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Floating rate (as percent)		1.57%
Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly) | Trust preferred securities, due 12/15/2035, floating rate of 1.45% above the three month LIBOR rate, reset quarterly, callable without penalty
Debt Instrument [Line Items]
Long-term debt, gross		$ 6,702,000	6,702,000
Subordinated notes payable, due 4/1/2028, fixed-to-floating rate (fixed rate of 5.00% through 3/31/2023, floating rate of 2.15% above the three month LIBOR rate, reset quarterly) | Trust preferred securities, due 12/15/2035, floating rate of 1.45% above the three month LIBOR rate, reset quarterly, callable without penalty | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Floating rate (as percent)		1.45%
Subordinated Notes and Debentures
Debt Instrument [Line Items]
Total other borrowings and subordinated debt		$ 354,223,000	353,950,000
Unamortized debt issuance costs		$ (3,099,000)	$ (3,372,000)

Other Borrowings and Subordin_4

Other Borrowings and Subordinated Notes and Debentures - Textual (Details) - USD ($)	1 Months Ended			9 Months Ended
	Oct. 31, 2018	Mar. 31, 2018	Oct. 31, 2017	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2017
Short-term Debt [Line Items]
FHLB advances outstanding				$ 1,090,000,000
FHLB advances				1,100,000,000
Additional advances from FHLB				3,100,000,000
Debt Instrument [Line Items]
Commitment fee on unused portion (as percent)			0.25%
Long-term debt				1,452,618,000	$ 1,699,400,000
Mortgage loans and investment securities securing FHLB advances				5,400,000,000
Assets				17,758,511,000	16,543,337,000	$ 15,000,000,000
U.S. Bank National Association | Revolving credit facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 50,000,000		$ 75,000,000
Commitment fee on unused portion (as percent)	0.30%
Long-term debt				$ 0	$ 0
London Interbank Offered Rate (LIBOR) | U.S. Bank National Association | Revolving credit facility
Debt Instrument [Line Items]
Floating rate (as percent)				1.50%
Federal Home Loan Bank Owns the Options (FOTO) Advances
Short-term Debt [Line Items]
FHLB advances outstanding				$ 1,030,000,000
Federal Home Loan Bank Owns the Options (FOTO) Advances | Minimum
Short-term Debt [Line Items]
Debt term				10 years
Federal Home Loan Bank Owns the Options (FOTO) Advances | Maximum
Short-term Debt [Line Items]
Debt term				15 years
Federal Home Loan Bank Advances
Short-term Debt [Line Items]
Debt term				1 year
Subordinated debt
Debt Instrument [Line Items]
Subordinated debentures		$ 330,000,000
Fixed rate (as percent)		5.00%		5.00%
Debt issuance costs		$ 3,600,000
Subordinated debt | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Floating rate (as percent)		2.15%

Other Borrowings and Subordin_5

Other Borrowings and Subordinated Notes and Debentures - Aggregate Annual Maturities of Long-term Debt (Details) $ in Thousands	Sep. 30, 2019USD ($)
Debt Disclosure [Abstract]
2019	$ 356
2020	2,105
2021	1,804
2022	948
2023	925
Thereafter	361,480
Total	$ 367,618

Capital Stock - Textual (Detail

Capital Stock - Textual (Details)	Apr. 12, 2019shares	Feb. 08, 2018	Sep. 30, 2019shares	Sep. 30, 2019shares	Dec. 31, 2018shares	Apr. 19, 2018shares	Apr. 18, 2018shares	Jul. 23, 2012shares
Class of Stock [Line Items]
Conversion ratio		2
Common stock, shares authorized (in shares)			175,000,000	175,000,000	175,000,000	175,000,000	120,000,000
Number of shares authorized to be repurchased (in shares)								1,700,000
Repurchase of common stock (in shares)			0	0
Stock issued for acquisition (in shares)				3,999,623
Series A Preferred Stock
Class of Stock [Line Items]
Stock issued for acquisition (in shares)	40,000
Series B Preferred Stock
Class of Stock [Line Items]
Stock issued for acquisition (in shares)	2,000

Undivided Profits - Textual (De

Undivided Profits - Textual (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Equity [Abstract]
Threshold percentage of net profits exceeded by dividends declared, any calendar year (as percent)	75.00%
Threshold percentage of net profits exceeded by dividends declared, combined with preceding year (as percent)	75.00%
Statutory accounting practices, statutory amount available for dividend payments without regulatory approval	$ 128.8
Tier 1 leverage capital required to be well capitalized to average assets (as percent)	5.00%
Tier 1 risk-based capital required to be well capitalized to risk weighted assets (as percent)	8.00%
Capital required to be well-capitalized to risk weighted assets (as percent)	10.00%
Common equity Tier 1 ratio required to be well capitalized (as percent)	6.50%
Capital conservation buffer phase in amount	0.625%
Capital conservation buffer phase in period	4 years
Capital conservation buffer (as percent)	2.50%
CET1 ratio (as percent)	10.25%

Stock Based Compensation - Stoc

Stock Based Compensation - Stock Compensation Plans (Details)	9 Months Ended
	Sep. 30, 2019$ / sharesshares
Stock Options Outstanding
Stock options outstanding, number of shares, balance (in shares) | shares	695,000
Stock options exercised, exercised (in shares) | shares	(1,000)
Stock options outstanding, number of shares, balance (in shares) | shares	694,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Stock options, weighted average exercise price, balance (in dollars per share) | $ / shares	$ 22.42
Stock options, weighted average exercise price, exercised (in dollars per share) | $ / shares	10.65
Stock options, weighted average exercise price, balance (in dollars per share) | $ / shares	$ 22.43
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Stock options outstanding, number of shares, exercisable (in shares) | shares	694,000
Stock options outstanding, weighted average exercise price, exercisable (in dollars per share) | $ / shares	$ 22.43
Non-vested Stock Awards Outstanding
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Non-vested shares outstanding, balance (in shares) | shares	72,000
Non-vested shares outstanding, vested (earned) (in shares) | shares	(39,000)
Non-vested shares outstanding, forfeited/expired (in shares) | shares	(2,000)
Non-vested shares outstanding, balance (in shares) | shares	31,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Non-vested shares outstanding. weighted-average grant-date fair value, balance (in dollars per share) | $ / shares	$ 21.45
Non-vested shares outstanding. weighted-average grant-date fair value, vested (earned) (in dollars per share) | $ / shares	20.12
Non-vested shares outstanding. weighted-average grant-date fair value, forfeited/expired (in dollars per share) | $ / shares	21.82
Non-vested shares outstanding. weighted-average grant-date fair value, balance (in dollars per share) | $ / shares	$ 23.16
Non-vested Stock Units Outstanding
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Non-vested shares outstanding, balance (in shares) | shares	817,000
Non-vested shares outstanding, granted (in shares) | shares	516,000
Non-vested shares outstanding, vested (earned) (in shares) | shares	(334,000)
Non-vested shares outstanding, forfeited/expired (in shares) | shares	(90,000)
Non-vested shares outstanding, balance (in shares) | shares	909,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Non-vested shares outstanding. weighted-average grant-date fair value, balance (in dollars per share) | $ / shares	$ 27.65
Non-vested shares outstanding. weighted-average grant-date fair value, granted (in dollars per share) | $ / shares	26.07
Non-vested shares outstanding. weighted-average grant-date fair value, vested (earned) (in dollars per share) | $ / shares	26.45
Non-vested shares outstanding. weighted-average grant-date fair value, forfeited/expired (in dollars per share) | $ / shares	28.29
Non-vested shares outstanding. weighted-average grant-date fair value, balance (in dollars per share) | $ / shares	$ 27.18

Stock Based Compensation - St_2

Stock Based Compensation - Stock Options (Details)	9 Months Ended
	Sep. 30, 2019$ / sharesshares
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	$ 9.46
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 24.07
Options outstanding, number of shares (in shares) | shares	694,000
Options outstanding, weighted average remaining contractual life	5 years 9 months 10 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 22.43
Options exercisable, number of shares (in shares) | shares	694,000
Options exercisable, weighted average exercise price (in dollars per share)	$ 22.43
Range 01
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	9.46
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 9.46
Options outstanding, number of shares (in shares) | shares	1,000
Options outstanding, weighted average remaining contractual life	2 years 3 months 18 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 9.46
Options exercisable, number of shares (in shares) | shares	1,000
Options exercisable, weighted average exercise price (in dollars per share)	$ 9.46
Range 02
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	10.65
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 10.65
Options outstanding, number of shares (in shares) | shares	3,000
Options outstanding, weighted average remaining contractual life	3 years 3 months 25 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 10.65
Options exercisable, number of shares (in shares) | shares	3,000
Options exercisable, weighted average exercise price (in dollars per share)	$ 10.65
Range 03
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	10.76
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 10.76
Options outstanding, number of shares (in shares) | shares	2,000
Options outstanding, weighted average remaining contractual life	9 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 10.76
Options exercisable, number of shares (in shares) | shares	2,000
Options exercisable, weighted average exercise price (in dollars per share)	$ 10.76
Range 04
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	20.29
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 20.29
Options outstanding, number of shares (in shares) | shares	71,000
Options outstanding, weighted average remaining contractual life	5 years 3 months
Options outstanding, weighted average exercise price (in dollars per share)	$ 20.29
Options exercisable, number of shares (in shares) | shares	71,000
Options exercisable, weighted average exercise price (in dollars per share)	$ 20.29
Range 05
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	20.36
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 20.36
Options outstanding, number of shares (in shares) | shares	3,000
Options outstanding, weighted average remaining contractual life	5 years 1 month 17 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 20.36
Options exercisable, number of shares (in shares) | shares	3,000
Options exercisable, weighted average exercise price (in dollars per share)	$ 20.36
Range 06
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	22.20
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 22.20
Options outstanding, number of shares (in shares) | shares	74,000
Options outstanding, weighted average remaining contractual life	5 years 5 months 23 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 22.20
Options exercisable, number of shares (in shares) | shares	74,000
Options exercisable, weighted average exercise price (in dollars per share)	$ 22.20
Range 07
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	22.75
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 22.75
Options outstanding, number of shares (in shares) | shares	436,000
Options outstanding, weighted average remaining contractual life	5 years 10 months 9 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 22.75
Options exercisable, number of shares (in shares) | shares	436,000
Options exercisable, weighted average exercise price (in dollars per share)	$ 22.75
Range 08
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	23.51
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 23.51
Options outstanding, number of shares (in shares) | shares	97,000
Options outstanding, weighted average remaining contractual life	6 years 3 months 18 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 23.51
Options exercisable, number of shares (in shares) | shares	97,000
Options exercisable, weighted average exercise price (in dollars per share)	$ 23.51
Range 09
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options outstanding, range of exercise prices, minimum (in dollars per share)	24.07
Options outstanding, range of exercise prices, maximum (in dollars per share)	$ 24.07
Options outstanding, number of shares (in shares) | shares	7,000
Options outstanding, weighted average remaining contractual life	5 years 11 months 15 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 24.07
Options exercisable, number of shares (in shares) | shares	7,000
Options exercisable, weighted average exercise price (in dollars per share)	$ 24.07

Stock Based Compensation - Summ

Stock Based Compensation - Summary of Company's Restricted Performance Stock Unit Activity (Details) - Restricted Stock Units (RSUs) shares in Thousands	9 Months Ended
	Sep. 30, 2019shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-vested shares outstanding, balance (in shares)	177
Granted (in shares)	118
Vested (earned) (in shares)	(93)
Forfeited (in shares)	(3)
Non-vested shares outstanding, balance (in shares)	199

Stock Based Compensation - Text

Stock Based Compensation - Textual (Details) - USD ($)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement [Abstract]
Stock-based compensation expense	$ 9,316,000	$ 9,818,000
Unrecognized stock-based compensation expense related to stock options	0
Unrecognized stock-based compensation expense related to non-vested stock awards	$ 16,269,000
Period unrecognized expenses is expected to be recognized	1 year 8 months 12 days
Intrinsic value of stock options outstanding	$ 1,717,000
Intrinsic value of stock options exercisable	$ 1,714,000
Share price (in dollars per share)	$ 24.90
Stock options exercised	$ 6,000	$ 1,155,000
Stock options granted	0	0

Earnings Per Share ("EPS") (Det

Earnings Per Share ("EPS") (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income available to common stockholders	$ 81,826	$ 55,193		$ 185,119	$ 160,067
Average common shares outstanding (in shares)	96,608	92,290		95,090	92,246
Average potential dilutive common shares (in shares)	360	551		360	551
Average diluted common shares (in shares)	96,968	92,841		95,450	92,797
Basic earnings per share (in dollars per share)	$ 0.85	$ 0.60		$ 1.95	$ 1.74
Diluted earnings per share (in dollars per share)	$ 0.84	$ 0.59	$ 0.59	$ 1.94	$ 1.72

Earnings Per Share ("EPS") - Te

Earnings Per Share ("EPS") - Textual (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from earnings per share calculation (in shares)	0	0	0	0

Additional Cash Flow Informat_3

Additional Cash Flow Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Other Significant Noncash Transactions [Line Items]
Interest paid	$ 130,904	$ 78,987
Income taxes (refunded) paid	34,028	25,576
Right-of use lease assets obtained in exchange for lessee operating lease liabilities (adoption of ASU 2016-02)	32,757	0
Transfers of loans to foreclosed assets held for sale
Other Significant Noncash Transactions [Line Items]
Transfers of loans	3,666	7,745
Transfers of premises to foreclosed assets and other real estate owned
Other Significant Noncash Transactions [Line Items]
Transfers of loans	$ 556	$ 3,690

Other Income and Other Operat_3

Other Income and Other Operating Expenses - Textual (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other Income and Expenses [Abstract]
Other income	$ 43,821	$ 4,942	$ 52,083	$ 14,151
Gain on sale of Visa, Inc. class B common stock			$ 42,860

Other Income and Other Operat_4

Other Income and Other Operating Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other Income and Expenses [Abstract]
Professional services	$ 4,310	$ 4,616	$ 12,125	$ 13,896
Postage	1,471	1,262	4,642	4,103
Telephone	2,507	1,248	5,605	4,217
Credit card expense	4,200	3,405	11,822	9,820
Marketing	7,021	2,912	12,514	6,334
Software and technology	6,531	4,733	16,607	10,716
Operating supplies	493	585	1,671	1,917
Amortization of intangibles	2,947	2,772	8,535	8,394
Branch right sizing expense	160	970	3,092	1,049
Other expense	8,239	7,171	24,195	20,907
Total other operating expenses	$ 37,879	$ 29,674	$ 100,808	$ 81,353

Commitments and Credit Risk - T

Commitments and Credit Risk - Textual (Details) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Other Commitments [Line Items]
Outstanding letters of credit	$ 49,447,000	$ 39,101,000
Standby Letters of Credit
Other Commitments [Line Items]
Deferred revenue	$ 0	0
Minimum
Other Commitments [Line Items]
Term of letter of credit	9 months
Maximum
Other Commitments [Line Items]
Term of letter of credit	15 years
Credit card commitments
Other Commitments [Line Items]
Outstanding commitments	$ 598,992,000	560,863,000
Other loan commitments
Other Commitments [Line Items]
Outstanding commitments	$ 3,310,794,000	$ 3,455,471,000

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Financial Assets Measure on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 2,356,134	$ 2,151,752
U.S. Government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	178,139	154,301
Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	1,337,794	1,522,900
State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	681,202	314,843
Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	158,999	159,708
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	14,377	6,242
Derivative liability	(14,478)	(5,283)
Fair Value, Measurements, Recurring | U.S. Government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	178,139	154,301
Fair Value, Measurements, Recurring | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	1,337,794	1,522,900
Fair Value, Measurements, Recurring | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	681,202	314,843
Fair Value, Measurements, Recurring | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	158,999	159,708
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	14,377	6,242
Derivative liability	(14,478)	(5,283)
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | U.S. Government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	178,139	154,301
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	1,337,794	1,522,900
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	681,202	314,843
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	158,999	159,708
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	0	0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | U.S. Government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 0	$ 0

Fair Value Measurements - Textu

Fair Value Measurements - Textual (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets and other real estate owned	$ 19,576,000	$ 25,565,000
Impaired loan, related allowance	5,279,000	684,000
Collateral dependent
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loan, related allowance	$ 1,297,000	2,738,000
Commercial Real Estate | Discount Rate | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input (as percent)	10.00%
Commercial Real Estate | Discount Rate | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input (as percent)	40.00%
Residential Real Estate | Discount Rate | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input (as percent)	10.00%
Residential Real Estate | Discount Rate | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement input (as percent)	40.00%
Foreclosed Assets Not Covered By FDIC Loss Share
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreclosed assets and other real estate owned	$ 19,600,000	25,600,000
Ratings of Substandard or worse
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Threshold value for performing impairment testing on loans	1,500,000
Residential Mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of financing receivable, held-for-sale	$ 0	$ 0

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair Value of Financial Assets Measured on a Nonrecurring Basis (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans (collateral dependent)	$ 46,903	$ 17,789
Foreclosed assets and other real estate owned	15,046	23,714
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans (collateral dependent)	0	0
Foreclosed assets and other real estate owned	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans (collateral dependent)	0	0
Foreclosed assets and other real estate owned	0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans (collateral dependent)	46,903	17,789
Foreclosed assets and other real estate owned	$ 15,046	$ 23,714

Fair Value Measurements - Estim

Fair Value Measurements - Estimated Fair Values and Related Carrying Amounts of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	$ 43,302	$ 290,830
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	529,970	833,458
Interest bearing balances due from banks - time	5,041	4,934
Held-to-maturity securities	42,237	289,194
Mortgage loans held for sale	50,099	26,799
Interest receivable	53,966	49,938
Federal funds purchased and securities sold under agreements to repurchase	116,536	95,792
Other borrowings	1,098,395	1,345,450
Subordinated notes and debentures	354,223	353,950
Interest payable	15,404	9,897
Carrying Amount | Non-interest bearing transaction accounts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	3,044,330	2,672,405
Carrying Amount | Interest bearing transaction accounts and savings deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	7,337,571	6,830,191
Carrying Amount | Time deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	3,086,108	2,896,156
Carrying Amount | Legacy loans, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net	9,577,372	8,373,789
Carrying Amount | Loans acquired, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net	3,359,587	3,292,783
Fair Value Measurements
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	529,970	833,458
Interest bearing balances due from banks - time	5,041	4,934
Held-to-maturity securities	43,302	290,830
Mortgage loans held for sale	50,099	26,799
Interest receivable	53,966	49,938
Federal funds purchased and securities sold under agreements to repurchase	116,536	95,792
Other borrowings	1,099,171	1,342,868
Subordinated notes and debentures	366,289	355,812
Interest payable	15,404	9,897
Fair Value Measurements | Non-interest bearing transaction accounts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	3,044,330	2,672,405
Fair Value Measurements | Interest bearing transaction accounts and savings deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	7,337,571	6,830,191
Fair Value Measurements | Time deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	3,080,775	2,872,342
Fair Value Measurements | Legacy loans, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net	9,505,701	8,280,690
Fair Value Measurements | Loans acquired, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net	3,334,446	3,256,174
Fair Value Measurements | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	529,970	833,458
Interest bearing balances due from banks - time	0	0
Held-to-maturity securities	0	0
Mortgage loans held for sale	0	0
Interest receivable	0	0
Federal funds purchased and securities sold under agreements to repurchase	0	0
Other borrowings	0	0
Subordinated notes and debentures	0	0
Interest payable	0	0
Fair Value Measurements | Quoted Prices in Active Markets for Identical Assets (Level 1) | Non-interest bearing transaction accounts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	0	0
Fair Value Measurements | Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest bearing transaction accounts and savings deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	0	0
Fair Value Measurements | Quoted Prices in Active Markets for Identical Assets (Level 1) | Time deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	0	0
Fair Value Measurements | Quoted Prices in Active Markets for Identical Assets (Level 1) | Legacy loans, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net	0	0
Fair Value Measurements | Quoted Prices in Active Markets for Identical Assets (Level 1) | Loans acquired, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net	0	0
Fair Value Measurements | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Interest bearing balances due from banks - time	5,041	4,934
Held-to-maturity securities	43,302	290,830
Mortgage loans held for sale	0	0
Interest receivable	53,966	49,938
Federal funds purchased and securities sold under agreements to repurchase	116,536	95,792
Other borrowings	1,099,171	1,342,868
Subordinated notes and debentures	366,289	355,812
Interest payable	15,404	9,897
Fair Value Measurements | Significant Other Observable Inputs (Level 2) | Non-interest bearing transaction accounts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	3,044,330	2,672,405
Fair Value Measurements | Significant Other Observable Inputs (Level 2) | Interest bearing transaction accounts and savings deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	7,337,571	6,830,191
Fair Value Measurements | Significant Other Observable Inputs (Level 2) | Time deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	0	0
Fair Value Measurements | Significant Other Observable Inputs (Level 2) | Legacy loans, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net	0	0
Fair Value Measurements | Significant Other Observable Inputs (Level 2) | Loans acquired, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net	0	0
Fair Value Measurements | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Interest bearing balances due from banks - time	0	0
Held-to-maturity securities	0	0
Mortgage loans held for sale	50,099	26,799
Interest receivable	0	0
Federal funds purchased and securities sold under agreements to repurchase	0	0
Other borrowings	0	0
Subordinated notes and debentures	0	0
Interest payable	0	0
Fair Value Measurements | Significant Unobservable Inputs (Level 3) | Non-interest bearing transaction accounts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	0	0
Fair Value Measurements | Significant Unobservable Inputs (Level 3) | Interest bearing transaction accounts and savings deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	0	0
Fair Value Measurements | Significant Unobservable Inputs (Level 3) | Time deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits	3,080,775	2,872,342
Fair Value Measurements | Significant Unobservable Inputs (Level 3) | Legacy loans, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net	9,505,701	8,280,690
Fair Value Measurements | Significant Unobservable Inputs (Level 3) | Loans acquired, net
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net	$ 3,334,446	$ 3,256,174

Subsequent Events - Textual (De

Subsequent Events - Textual (Details) - Subsequent Event - USD ($)	Oct. 29, 2019	Oct. 22, 2019
The Program | Common Class A
Subsequent Event [Line Items]
Stock repurchase program, authorized amount		$ 60,000,000
Reliance Bancshares, Inc. | Series D Preferred Stock
Subsequent Event [Line Items]
Preferred stock, Class B, par value (in dollars per share)	$ 0.01
Reliance Bancshares, Inc. | Convertible Preferred Stock
Subsequent Event [Line Items]
Preferred stock, Class B, par value (in dollars per share)	$ 0.01
Preferred stock, dividend rate, percentage	7.00%
Reliance Bancshares, Inc. | Series C Preferred Stock
Subsequent Event [Line Items]
Preferred stock, shares authorized (in shares)	140
Preferred stock, shares issued (in shares)	0
Preferred stock, shares outstanding (in shares)	0