UMB Financial (UMBF) 10-Q 3 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 27, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	UMBF
Entity Registrant Name	UMB FINANCIAL CORP
Entity Central Index Key	101,382
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		50,057,311

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Loans	$ 11,458,794	$ 11,280,513
Allowance for loan losses	(100,302)	(100,604)
Net loans	11,358,492	11,179,909
Loans held for sale	4,586	1,460
Securities:
Available for sale	6,139,346	6,258,577
Held to maturity (fair value of $1,157,627 and $1,207,447, respectively)	1,246,466	1,261,014
Trading securities	65,389	54,055
Other securities	67,408	65,897
Total investment securities	7,518,609	7,639,543
Federal funds sold and securities purchased under agreements to resell	127,208	191,601
Interest-bearing due from banks	671,163	1,351,760
Cash and due from banks	279,838	392,723
Premises and equipment, net	272,632	275,942
Accrued income	97,632	98,863
Goodwill	180,867	180,867
Other intangibles, net	18,695	20,257
Other assets	458,182	438,658
Total assets	20,987,904	21,771,583
Deposits:
Noninterest-bearing demand	6,042,719	6,839,171
Interest-bearing demand and savings	10,188,367	9,903,565
Time deposits under $250,000	553,692	547,990
Time deposits of $250,000 or more	433,487	732,274
Total deposits	17,218,265	18,023,000
Federal funds purchased and repurchase agreements	1,354,615	1,260,704
Long-term debt	78,687	79,281
Accrued expenses and taxes	129,753	191,464
Other liabilities	39,198	35,603
Total liabilities	18,820,518	19,590,052
SHAREHOLDERS' EQUITY
Common stock, $1.00 par value; 80,000,000 shares authorized; 55,056,730 shares issued; and 50,046,236 and 49,894,990 shares outstanding, respectively	55,057	55,057
Capital surplus	1,046,673	1,046,095
Retained earnings	1,393,485	1,338,110
Accumulated other comprehensive loss, net	(117,391)	(45,525)
Treasury stock, 5,010,494 and 5,161,740 shares, at cost, respectively	(210,438)	(212,206)
Total shareholders' equity	2,167,386	2,181,531
Total liabilities and shareholders' equity	$ 20,987,904	$ 21,771,583

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Held to Maturity, Fair value	$ 1,157,627	$ 1,207,447
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	55,056,730	55,056,730
Common stock, shares outstanding	50,046,236	49,894,990
Treasury stock, shares	5,010,494	5,161,740

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
INTEREST INCOME
Loans	$ 126,134	$ 106,560
Securities:
Taxable interest	19,780	19,190
Tax-exempt interest	18,703	17,183
Total securities income	38,483	36,373
Federal funds and resell agreements	1,038	919
Interest-bearing due from banks	1,580	551
Trading securities	430	287
Total interest income	167,665	144,690
INTEREST EXPENSE
Deposits	13,835	5,966
Federal funds and repurchase agreements	4,732	3,469
Other	1,176	940
Total interest expense	19,743	10,375
Net interest income	147,922	134,315
Provision for loan losses	10,000	9,000
Net interest income after provision for loan losses	137,922	125,315
NONINTEREST INCOME
Trust and securities processing	44,002	42,541
Trading and investment banking	4,101	7,542
Service charges on deposit accounts	21,905	22,075
Insurance fees and commissions	301	646
Brokerage fees	6,353	5,377
Bankcard fees	18,123	17,752
Gain on sales of securities available for sale, net	139	468
Other	10,601	6,516
Total noninterest income	105,525	102,917
NONINTEREST EXPENSE
Salaries and employee benefits	107,968	103,652
Occupancy, net	10,953	10,968
Equipment	18,826	17,482
Supplies and services	3,760	4,094
Marketing and business development	5,034	4,141
Processing fees	11,161	9,199
Legal and consulting	3,844	5,050
Bankcard	4,626	4,903
Amortization of other intangible assets	1,562	2,046
Regulatory fees	2,905	3,833
Other	5,237	8,442
Total noninterest expense	175,876	173,810
Income before income taxes	67,571	54,422
Income tax expense	10,038	12,446
Income from continuing operations	57,533	41,976
Discontinued Operations
(Loss) income from discontinued operations before income taxes	(917)	2,907
Income tax (benefit) expense	(170)	702
(Loss) income from discontinued operations	(747)	2,205
NET INCOME	$ 56,786	$ 44,181
Basic:
Income from continuing operations	$ 1.16	$ 0.85
(Loss) income from discontinued operations	(0.01)	0.05
Net income – basic	1.15	0.90
Diluted:
Income from continuing operations	1.15	0.84
(Loss) income from discontinued operations	(0.01)	0.05
Net income - diluted	1.14	0.89
Dividends	$ 0.290	$ 0.255
Weighted average shares outstanding - basic	49,420,606	49,109,872
Weighted average shares outstanding - diluted	49,917,454	49,829,508

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income		$ 56,786	$ 44,181
Unrealized gains and losses on debt securities:
Change in unrealized holding gains and losses, net		(80,662)	22,271
Less: Reclassification adjustment for gains included in net income		(139)	(468)
Change in unrealized gains and losses on debt securities during the period		(80,801)	21,803
Change in unrealized gains and losses on derivative hedges		2,202	246
Income tax benefit (expense)		19,782	(8,666)
Other comprehensive (loss) income before reclassifications		(58,817)	13,383
Amounts reclassified from accumulated other comprehensive income	[1],[2]	(13,049)
Net current-period other comprehensive (loss) income		(71,866)	13,383
Comprehensive (loss) income		$ (15,080)	$ 57,564
[1]	See Note 3, “New Accounting Pronouncements”, for discussion of the Company’s adoption of ASU No. 2018-02.
[2]	See Note 3, “New Accounting Pronouncements”, for discussion of the Company’s adoption of Accounting Standards Update (ASU) No. 2016-01.

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands		Total	Common Stock	Capital Surplus	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning Balance at Dec. 31, 2016		$ 1,962,384	$ 55,057	$ 1,033,419	$ 1,142,887	$ (57,542)	$ (211,437)
Total comprehensive income (loss)		57,564			44,181	13,383
Cash dividends		(12,481)			(12,481)
Purchase of treasury stock		(4,028)					(4,028)
Issuance of equity awards		471		(4,140)			4,611
Recognition of equity-based compensation		2,861		2,861
Sale of treasury stock		267		150			117
Exercise of stock options		3,840		935			2,905
Ending Balance at Mar. 31, 2017		2,010,878	55,057	1,033,225	1,174,587	(44,159)	(207,832)
Beginning Balance at Dec. 31, 2017		2,181,531	55,057	1,046,095	1,338,110	(45,525)	(212,206)
Total comprehensive income (loss)		(15,080)			56,786	(71,866)
Reclassification of certain tax effects	[1]	12,917			12,917
Cash dividends		(14,473)			(14,473)
Purchase of treasury stock		(5,951)					(5,951)
Issuance of equity awards		495		(2,959)			3,454
Recognition of equity-based compensation		2,270		2,270
Sale of treasury stock		285		145			140
Exercise of stock options		5,247		1,122			4,125
Cumulative effect adjustment | ASU Nos. 2016-01 and 2017-12 [Member]	[2]	145			145
Ending Balance at Mar. 31, 2018		$ 2,167,386	$ 55,057	$ 1,046,673	$ 1,393,485	$ (117,391)	$ (210,438)
[1]	Related to the adoption of ASU No. 2018-02. See Note 3, “New Accounting Pronouncements”, for further detail.
[2]	Related to the adoption of ASU Nos. 2016-01 and 2017-12. See Note 3, “New Accounting Pronouncements”, for further detail.

Consolidated Statements of Cha7

Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement Of Stockholders Equity [Abstract]
Cash Dividends, per share	$ 0.290	$ 0.255

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
OPERATING ACTIVITIES
Net income	$ 56,786	$ 44,181
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	10,000	9,000
Net accretion of premiums and discounts from acquisition	(10)	(838)
Depreciation and amortization	13,371	14,375
Deferred income tax benefit	(7,760)	(322)
Net increase in trading securities and other earning assets	(13,628)	(35,278)
Gains on sales of securities available for sale, net	(139)	(468)
Losses (gains) on sales of assets	142	(1,020)
Amortization of securities premiums, net of discount accretion	11,640	12,081
Originations of loans held for sale	(12,520)	(10,818)
Gains on sales of loans held for sale, net	(270)	(299)
Proceeds from sales of loans held for sale	9,664	14,462
Equity-based compensation	2,765	3,332
Net tax benefit related to equity compensation plans	1,713	1,783
Changes in:
Accrued income	1,231	2,010
Accrued expenses and taxes	(61,711)	(29,980)
Other assets and liabilities, net	8,345	(5,533)
Net cash provided by operating activities	19,619	16,668
INVESTING ACTIVITIES
Proceeds from maturities of securities held to maturity	21,303	16,682
Proceeds from sales of securities available for sale	41,273	86,069
Proceeds from maturities of securities available for sale	328,267	405,500
Purchases of securities held to maturity	(6,756)	(108,215)
Purchases of securities available for sale	(340,795)	(550,920)
Net increase in loans	(188,349)	(222,959)
Net decrease in fed funds sold and resell agreements	64,393	127,860
Net cash activity from acquisitions and divestitures	2,874
Net decrease in interest bearing balances due from other financial institutions	6,674	22,362
Purchases of premises and equipment	(8,639)	(4,985)
Proceeds from sales of premises and equipment		173
Net cash used in investing activities	(79,755)	(228,433)
FINANCING ACTIVITIES
Net decrease in demand and savings deposits	(511,650)	(610,428)
Net decrease in time deposits	(293,085)	(65,002)
Net increase in fed funds purchased and repurchase agreements	93,911	533,427
Repayment of long-term debt	(898)	(938)
Cash dividends paid	(14,531)	(12,710)
Proceeds from exercise of stock options and sales of treasury shares	5,532	4,107
Purchases of treasury stock	(5,951)	(4,028)
Net cash used in financing activities	(726,672)	(155,572)
Decrease in cash and cash equivalents	(786,808)	(367,337)
Cash and cash equivalents at beginning of period	1,716,262	1,063,967
Cash and cash equivalents at end of period	929,454	696,630
Supplemental Disclosures:
Income taxes paid	5,972	668
Total interest paid	$ 19,168	$ 10,250

Financial Statement Presentatio

Financial Statement Presentation	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Financial Statement Presentation	1. Financial Statement Presentation The Consolidated Financial Statements include the accounts of UMB Financial Corporation and its subsidiaries (collectively, the Company) after elimination of all intercompany transactions. In the opinion of management of the Company, all adjustments relating to items that are of a normal recurring nature and necessary for a fair presentation of the financial position and results of operations have been made. The results of operations and cash flows for the interim periods presented may not be indicative of the results of the full year ending December 31, 2018. The financial statements should be read in conjunction with “Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations” within this Quarterly Report on Form 10-Q (the Form 10-Q) and in conjunction with the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2017 filed with the Securities and Exchange Commission (SEC) on February 22, 2018 (the Form 10-K). The Company is a financial holding company, which offers a wide range of banking and other financial services to its customers through its branches and offices. The Company’s national bank, UMB Bank, National Association (the Bank), has its principal office in Missouri and also has branches in Arizona, Colorado, Illinois, Kansas, Nebraska, Oklahoma, and Texas. The Company also has offices in Pennsylvania, South Dakota, Indiana, Utah, Minnesota, California, and Wisconsin. Until November 17, 2017, the Company owned Scout Investments, Inc. (Scout), an institutional asset-management company that offered domestic and international equity strategies. On November 17, 2017, the Company closed on the sale of Scout to Carillon Tower Advisers, Inc., a Florida corporation, for a purchase price of approximately $172.5 million, after giving effect to customary purchase price adjustments. In accordance with Accounting Standards Codification (ASC) Topic 205-20, Discontinued Operations

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP) requires management to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. These estimates and assumptions also impact reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. A summary of the significant accounting policies to assist the reader in understanding the financial presentation is provided in the Notes to Consolidated Financial Statements in the Form 10-K. Cash and cash equivalents Cash and cash equivalents include Cash and due from banks and amounts due from the Federal Reserve Bank (FRB). Cash on hand, cash items in the process of collection, and amounts due from correspondent banks are included in Cash and due from banks. Amounts due from the FRB are interest-bearing for all periods presented and are included in the Interest-bearing due from banks line on the Company’s Consolidated Balance Sheets. This table provides a summary of cash and cash equivalents as presented on the Consolidated Statements of Cash Flows as of March 31, 2018 and March 31, 2017 (in thousands) March 31, 2018 2017 Due from the FRB $ 649,616 $ 322,959 Cash and due from banks 279,838 373,671 Cash and cash equivalents at end of period $ 929,454 $ 696,630 Also included in the Interest-bearing due from banks, but not considered cash and cash equivalents, are interest-bearing accounts held at other financial institutions, which totaled $21.5 million and $51.6 million at March 31, 2018 and March 31, 2017, respectively. Per Share Data Basic net income per share is computed based on the weighted average number of shares of common stock outstanding during each period. Diluted net income per share includes the dilutive effect of 496,848 and 719,637 shares issuable upon the exercise of options granted by the Company and outstanding at March 31, 2018 and 2017, respectively. Options issued under employee benefits plans to purchase 141,870 and 151,002 shares of common stock were outstanding at March 31, 2018 and 2017, respectively, but were not included in the computation of diluted earnings per share because the options were anti-dilutive. Derivatives The Company records all derivatives on the Consolidated Balance Sheets at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Currently, three of the Company’s derivatives are designated in qualifying hedging relationships. However, the remainder of the Company’s derivatives are not designated in qualifying hedging relationships, as the derivatives are not used to manage risks within the Company’s assets or liabilities. All changes in fair value of the Company’s non-designated derivatives are recognized directly in earnings. Changes in fair value of the Company’s fair value hedges are recognized directly in earnings. Changes in fair value of the Company’s cash flow hedges are recognized in accumulated other comprehensive income (AOCI).

New Accounting Pronouncements

New Accounting Pronouncements	3 Months Ended
	Mar. 31, 2018
Accounting Changes And Error Corrections [Abstract]
New Accounting Pronouncements	3. New Accounting Pronouncements Revenue Recognition In May 2014, the Financial Accounting Standards Board (FASB) issued ASU No. 2014-09, “Revenue from Contracts with Customers.” The ASU replaced most existing revenue recognition guidance in U.S. GAAP when it became effective. In August 2015, the FASB issued ASU No. 2015-14, which deferred the effective date of ASU No. 2014-09 to annual reporting periods that begin after December 15, 2017. In March, April, and May 2016, the FASB issued implementation amendments to the May 2014 ASU (collectively, the amended guidance). The amended guidance affects any entity that enters into contracts with customers to transfer goods and services, unless those contracts are within the scope of other standards. The amended guidance specifically excludes interest income, as well as other revenues associated with financial assets and liabilities, including loans, leases, securities, and derivatives. The amended guidance permits the use of either the full retrospective approach or a modified retrospective approach. The Company adopted the amended guidance using the modified retrospective approach on January 1, 2018. The adoption of this guidance had no impact on the Company’s Consolidated Financial Statements, except for additional financial statement disclosures. See Note 9, “Revenue Recognition” for related disclosures. Financial Instruments In January 2016, the FASB issued ASU No. 2016-01, “Recognition and Measurement of Financial Assets and Financial Liabilities.” The amendment is intended to address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The amendments in this update were adopted on January 1, 2018. Upon adoption, the Company recorded a cumulative effect adjustment to the Company’s Consolidated Balance Sheets of $132 thousand as an increase to the opening balance of total shareholders’ equity. Leases In February 2016, the FASB issued ASU No. 2016-02, “Leases.” The amendment changes the accounting treatment of leases, in that lessees will recognize most leases on-balance sheet. This will increase reported assets and liabilities, as lessees will be required to recognize a right-of-use asset along with a lease liability, measured on a discounted basis. Lessees are allowed to account for short-term leases (those with a term of twelve months or less) off-balance sheet. The amendments in this update are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The standard requires the use of the modified retrospective transition method. Early adoption is permitted. The Company is currently evaluating the impact that this standard will have on its Consolidated Financial Statements. Extinguishments of Liabilities In March 2016, the FASB issued ASU No. 2016-04, “Recognition of Breakage for Certain Prepaid Stored-Value Products.” The amendment is intended to reduce the diversity in practice related to the recognition of breakage. Breakage refers to the portion of a prepaid stored-value product, such as a gift card, that goes unused wholly or partially for an indefinite period of time. This amendment requires that breakage be accounted for consistent with the breakage guidance within ASU No. 2014-09, “Revenue from Contracts with Customers.” The amendments in this update were adopted January 1, 2018 in conjunction with the adoption of ASU 2014-09, and the adoption had no impact on the Company’s Consolidated Financial Statements. Credit Losses In September 2016, the FASB issued ASU 2016-13, “Measurement of Credit Losses on Financial Instruments.” This update replaces the current incurred loss methodology for recognizing credit losses with a current expected credit loss model, which requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. This amendment broadens the information that an entity must consider in developing its expected credit loss estimates. Additionally, the update amends the accounting for credit losses for available-for-sale debt securities and purchased financial assets with a more-than-insignificant amount of credit deterioration since origination. This update requires enhanced disclosures to help investors and other financial statement users better understand significant estimates and judgments used in estimating credit losses, as well as the credit quality and underwriting standards of a company’s loan portfolio. The amendments in this update are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption in fiscal years beginning after December 15, 2018 is permitted. The amendment requires the use of the modified retrospective approach for adoption. The Company is currently evaluating the impact that this standard will have on its Consolidated Financial Statements. Statement of Cash Flows In August 2016, the FASB issued ASU 2016-15 “Classification of Certain Receipts and Cash Payments.” This amendment adds to and clarifies existing guidance regarding the classification of certain cash receipts and payments in the statement of cash flows with the intent of reducing diversity in practice with respect to eight types of cash flows. The amendments in this update require full retrospective adoption. The amendments in this update were adopted on January 1, 2018 and did not have an impact on the Company’s Consolidated Financial Statements. Derivatives and Hedging In August 2017, the FASB issued ASU No. 2017-12, “Targeted Improvements to Accounting for Hedging Activities.” The purpose of this updated guidance is to better align financial reporting for hedging activities with the economic objectives of those activities. The amendments in this update are effective for fiscal years beginning after December 15, 2018, with early adoption, including adoption in an interim period, permitted, and require the modified retrospective transition approach as of the date of adoption. The Company early adopted ASU 2017-12 with an effective date of January 1, 2018. Upon adoption, the Company recorded a cumulative effect adjustment to the Company’s Consolidated Balance Sheets of $13 thousand as an increase to the opening balance of total shareholders’ equity. Comprehensive Income In February 2018, the FASB issued ASU No. 2018-02, “Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” Under existing U.S. GAAP, the effects of changes in tax rates and laws on deferred tax balances are recorded as a component of income tax expense in the period in which the law was enacted. When deferred tax balances related to items originally recorded in AOCI are adjusted, certain tax effects become stranded in AOCI. This amendment allows a reclassification from AOCI to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act (the Tax Act), and requires certain disclosures about stranded tax effects. The amendments in this update are effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption, including adoption in any interim period, is permitted. The Company early adopted ASU 2018-02 using a security-by-security approach with an effective date of January 1, 2018. Upon adoption, the Company reclassified stranded tax effects totaling $12.9 million from AOCI to retained earnings.

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Loans and Allowance for Loan Losses	4. Loans and Allowance for Loan Losses Loan Origination/Risk Management The Company has certain lending policies and procedures in place that are designed to minimize the level of risk within the loan portfolio. Diversification of the loan portfolio manages the risk associated with fluctuations in economic conditions. Authority levels are established for the extension of credit to ensure consistency throughout the Company. It is necessary that policies, processes and practices implemented to control the risks of individual credit transactions and portfolio segments are sound and adhered to. The Company maintains an independent loan review department that reviews and validates the risk assessment on a continual basis. Management regularly evaluates the results of the loan reviews. The loan review process complements and reinforces the risk identification and assessment decisions made by lenders and credit personnel, as well as the Company’s policies and procedures. Commercial loans are underwritten after evaluating and understanding the borrower’s ability to operate profitably and prudently expand its business. Commercial loans are made based on the identified cash flows of the borrower and on the underlying collateral provided by the borrower. The cash flows of the borrower, however, may not be as expected and the collateral securing these loans may fluctuate in value. Most commercial loans are secured by the assets being financed or other business assets such as accounts receivable or inventory and may incorporate a personal guarantee. In the case of loans secured by accounts receivable, the availability of funds for the repayment of these loans may be substantially dependent on the ability of the borrower to collect amounts from its customers. Commercial credit cards are generally unsecured and are underwritten with criteria similar to commercial loans including an analysis of the borrower’s cash flow, available business capital, and overall credit-worthiness of the borrower. Asset-based loans are offered primarily in the form of revolving lines of credit to commercial borrowers that do not generally qualify for traditional bank financing. Asset-based loans are underwritten based primarily upon the value of the collateral pledged to secure the loan, rather than on the borrower’s general financial condition. The Company utilizes pre-loan due diligence techniques, monitoring disciplines, and loan management practices common within the asset-based lending industry to underwrite loans to these borrowers. Factoring loans provide working capital through the purchase and/or financing of accounts receivable to borrowers in the transportation industry and to commercial borrowers that do not generally qualify for traditional bank financing. Commercial real estate loans are subject to underwriting standards and processes similar to commercial loans, in addition to those of real estate loans. These loans are viewed primarily as cash flow loans and secondarily as loans secured by real estate. Commercial real estate lending typically involves higher loan principal amounts, and the repayment of these loans is largely dependent on the successful operation of the property securing the loan or the business conducted on the property securing the loan. The Company requires that an appraisal of the collateral be made at origination and on an as-needed basis, in conformity with current market conditions and regulatory requirements. The underwriting standards address both owner and non-owner occupied real estate. Construction loans are underwritten using feasibility studies, independent appraisal reviews, sensitivity analysis or absorption and lease rates and financial analysis of the developers and property owners. Construction loans are based upon estimates of costs and value associated with the complete project. Construction loans often involve the disbursement of substantial funds with repayment substantially dependent on the success of the ultimate project. Sources of repayment for these types of loans may be pre-committed permanent loans, sales of developed property or an interim loan commitment from the Company until permanent financing is obtained. These loans are closely monitored by on-site inspections and are considered to have higher risks than other real estate loans due to their repayment being sensitive to interest rate changes, governmental regulation of real property, economic conditions, and the availability of long-term financing. Underwriting standards for residential real estate and home equity loans are based on the borrower’s loan-to-value percentage, collection remedies, and overall credit history. Consumer loans are underwritten based on the borrower’s repayment ability. The Company monitors delinquencies on all of its consumer loans and leases and periodically reviews the distribution of FICO scores relative to historical periods to monitor credit risk on its credit card loans. The underwriting and review practices combined with the relatively small loan amounts that are spread across many individual borrowers, minimizes risk. Consumer loans and leases that are 90 days past due or more are considered non-performing. Credit risk is a potential loss resulting from nonpayment of either the primary or secondary exposure. Credit risk is mitigated with formal risk management practices and a thorough initial credit-granting process including consistent underwriting standards and approval process. Control factors or techniques to minimize credit risk include knowing the client, understanding total exposure, analyzing the client and debtor’s financial capacity, and monitoring the client’s activities. Credit risk and portions of the portfolio risk are managed through concentration considerations, average risk ratings, and other aggregate characteristics. Loan Aging Analysis This table provides a summary of loan classes and an aging of past due loans at March 31, 2018 and December 31, 2017 (in thousands): March 31, 2018 30-89 Days Past Due and Accruing Greater than 90 Days Past Due and Accruing Non- Accrual Loans Total Past Due Current Total Loans Loans Commercial: Commercial $ 7,988 $ 1,508 $ 44,253 $ 53,749 $ 4,415,694 $ 4,469,443 Asset-based — — — — 345,980 345,980 Factoring — — — — 234,148 234,148 Commercial – credit card 640 54 — 694 192,042 192,736 Real estate: Real estate – construction 195 — — 195 789,650 789,845 Real estate – commercial 2,294 1,908 18,816 23,018 3,687,450 3,710,468 Real estate – residential 32 — 686 718 649,630 650,348 Real estate – HELOC 87 — 3,434 3,521 610,216 613,737 Consumer: Consumer – credit card 1,914 2,138 393 4,445 225,169 229,614 Consumer – other 266 42 22 330 198,994 199,324 Leases — — — — 23,151 23,151 Total loans $ 13,416 $ 5,650 $ 67,604 $ 86,670 $ 11,372,124 $ 11,458,794 December 31, 2017 30-89 Days Past Due and Accruing Greater than 90 Days Past Due and Accruing Non- Accrual Loans Total Past Due Current Total Loans Loans Commercial: Commercial $ 11,216 $ 672 $ 38,644 $ 50,532 $ 4,502,508 $ 4,553,040 Asset-based — — — — 336,614 336,614 Factoring — — — — 221,672 221,672 Commercial – credit card 387 79 — 466 171,825 172,291 Real estate: Real estate – construction 6,666 243 93 7,002 710,847 717,849 Real estate – commercial 832 — 16,115 16,947 3,546,683 3,563,630 Real estate – residential 791 — 929 1,720 636,871 638,591 Real estate – HELOC 1,254 — 3,013 4,267 644,112 648,379 Consumer: Consumer – credit card 2,155 2,057 312 4,524 248,173 252,697 Consumer – other 835 40 36 911 150,872 151,783 Leases — — — — 23,967 23,967 Total loans $ 24,136 $ 3,091 $ 59,142 $ 86,369 $ 11,194,144 $ 11,280,513 The Company sold residential real estate loans with proceeds of $9.7 million and $14.5 million in the secondary market without recourse during the three months ended March 31, 2018 and March 31, 2017, respectively. The Company has ceased the recognition of interest on loans with a carrying value of $67.6 million and $59.1 million at March 31, 2018 and December 31, 2017, respectively. Restructured loans totaled $20.7 million and $41.0 million at March 31, 2018 and December 31, 2017, respectively. Loans 90 days past due and still accruing interest amounted to $5.7 million and $3.1 million at March 31, 2018 and December 31, 2017, respectively. There was an insignificant amount of interest recognized on impaired loans during 2018 and 2017. 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 the risk grading of specified classes of loans, net charge-offs, non-performing loans, and general economic conditions. The Company utilizes a risk grading matrix to assign a rating to each of its commercial, commercial real estate, and construction real estate loans. The loan ratings are summarized into the following categories: Non-watch list, Watch, Special Mention, and Substandard. Any loan not classified in one of the categories described below is considered to be a Non-watch list loan. A description of the general characteristics of the loan rating categories is as follows: • Watch – This rating represents credit exposure that presents higher than average risk and warrants greater than routine attention by Company personnel due to conditions affecting the borrower, the borrower’s industry or the economic environment. These conditions have resulted in some degree of uncertainty that results in higher than average credit risk. • Special Mention – This rating reflects a potential weakness that deserves management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the asset or the borrower’s credit position at some future date. The rating is not adversely classified and does not expose an institution to sufficient risk to warrant adverse classification. • Substandard – This rating represents an asset inadequately protected by the current sound worth and paying capacity of the borrower or of the collateral pledged, if any. Assets so classified must have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. Loans in this category are characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. Loss potential, while existing in the aggregate amount of substandard assets, does not have to exist in individual assets classified substandard. This category may include loans where the collection of full principal is doubtful or remote. All other classes of loans are generally evaluated and monitored based on payment activity. Non-performing loans include restructured loans on non-accrual and all other non-accrual loans. This table provides an analysis of the credit risk profile of each loan class excluded from ASC 310-30, Loans and Debt Securities Purchased with Deteriorated Credit Quality (in thousands) Credit Exposure Credit Risk Profile by Risk Rating Commercial Asset-based Factoring March 31, December 31, March 31, December 31, March 31, December 31, 2018 2017 2018 2017 2018 2017 Non-watch list $ 3,914,518 $ 4,048,238 $ 287,754 $ 306,899 $ 233,291 $ 220,795 Watch 206,883 162,788 — — — — Special Mention 128,015 106,638 58,226 29,715 282 47 Substandard 220,027 235,376 — — 575 830 Total $ 4,469,443 $ 4,553,040 $ 345,980 $ 336,614 $ 234,148 $ 221,672 Real estate – construction Real estate – commercial March 31, December 31, March 31, December 31, 2018 2017 2018 2017 Non-watch list $ 787,898 $ 716,830 $ 3,562,117 $ 3,434,982 Watch 1,725 631 74,060 50,715 Special Mention — — 27,843 35,940 Substandard 222 388 46,448 41,993 Total $ 789,845 $ 717,849 $ 3,710,468 $ 3,563,630 Credit Exposure Credit Risk Profile Based on Payment Activity Commercial – credit card Real estate – residential Real estate – HELOC March 31, December 31, March 31, December 31, March 31, December 31, 2018 2017 2018 2017 2018 2017 Performing $ 192,736 $ 172,291 $ 649,662 $ 637,662 $ 610,303 $ 645,366 Non-performing — — 686 929 3,434 3,013 Total $ 192,736 $ 172,291 $ 650,348 $ 638,591 $ 613,737 $ 648,379 Consumer – credit card Consumer – other Leases March 31, December 31, March 31, December 31, March 31, December 31, 2018 2017 2018 2017 2018 2017 Performing $ 229,221 $ 252,385 $ 199,302 $ 151,747 $ 23,151 $ 23,967 Non-performing 393 312 22 36 — — Total $ 229,614 $ 252,697 $ 199,324 $ 151,783 $ 23,151 $ 23,967 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 judgment of inherent probable losses within the Company’s loan portfolio as of the balance sheet date. The allowance is necessary to reserve for estimated loan losses and risks inherent in the loan portfolio. Accordingly, the methodology is based on historical loss trends. The Company’s process for determining the appropriate level of the allowance for loan losses is designed to account for credit deterioration as it occurs. The provision for probable loan losses reflects loan quality trends, including the levels of, and trends related to, non-accrual loans, past due loans, potential problem loans, criticized loans and net charge-offs or recoveries, among other factors. The level of the allowance reflects management’s continuing evaluation of industry concentrations, specific credit risks, loan loss experience, current loan portfolio quality, present economic, political and regulatory conditions and estimated losses inherent in the current loan portfolio. Portions of the allowance may be allocated for specific loans; however, the entire allowance is available for any loan that, in management’s judgment, should be charged off. While management utilizes its best judgment and information available at the time, the adequacy of the allowance is dependent upon a variety of factors beyond the Company’s control, including, among other things, the performance of the Company’s loan portfolio, the economy, changes in interest rates and changes in the regulatory environment. The Company’s allowance for loan losses consists of specific valuation allowances and general valuation allowances based on historical loan loss experience for similar loans with similar characteristics and trends, general economic conditions and other qualitative risk factors both internal and external to the Company. The allowances established for probable losses on specific loans are based on a regular analysis and evaluation of impaired loans. Loans are classified based on an internal risk grading process that evaluates the obligor’s ability to repay, the underlying collateral, if any, and the economic environment and industry in which the borrower operates. When a loan is considered impaired, the loan is analyzed to determine the need, if any, to specifically allocate a portion of the allowance for loan losses to the loan. Specific valuation allowances are determined by analyzing the borrower’s ability to repay amounts owed, collateral deficiencies, the relative risk rating of the loan and economic conditions affecting the borrower’s industry. General valuation allowances are calculated based on the historical loss experience of specific types of loans including an evaluation of the time span and volume of the actual charge-off. The Company calculates historical loss ratios for pools of similar loans with similar characteristics based on the proportion of actual charge-offs experienced to the total population of loans in the pool. The historical loss ratios are updated based on actual charge-off experience. A valuation allowance is established for each pool of similar loans based upon the product of the historical loss ratio, time span to charge-off, and the total dollar amount of the loans in the pool. The Company’s pools of similar loans include similarly risk-graded groups of commercial loans, commercial real estate loans, commercial credit card, home equity loans, consumer real estate loans and consumer and other loans. The Company also considers a loan migration analysis for criticized loans. This analysis includes an assessment of the probability that a loan will move to a loss position based on its risk rating. The consumer credit card pool is evaluated based on delinquencies and credit scores. In addition, a portion of the allowance is determined by a review of qualitative factors by management. Generally, the unsecured portion of a commercial or commercial real estate loan is charged off when, after analyzing the borrower’s financial condition, it is determined that the borrower is incapable of servicing the debt, little or no prospect for near term improvement exists, and no realistic and significant strengthening action is pending. For collateral dependent commercial or commercial real estate loans, an analysis is completed regarding the Company’s collateral position to determine if the amounts due from the borrower are in excess of the calculated current fair value of the collateral. Specific allocations of the allowance for loan losses are made for any collateral deficiency. If a collateral deficiency is ultimately deemed to be uncollectible, the amount is charged off. Revolving commercial loans (such as commercial credit cards) which are past due 90 cumulative days are classified as a loss and charged off. Generally, a consumer loan, or a portion thereof, is charged off in accordance with regulatory guidelines which provide that such loans be charged off when the Company becomes aware of the loss, such as from a triggering event that may include, but is not limited to, new information about a borrower’s intent and ability to repay the loan, bankruptcy, fraud, or death. However, the charge-off timeframe should not exceed the specified delinquency time frames, which state that closed-end retail loans (such as real estate mortgages, home equity loans and consumer installment loans) that become past due ALLOWANCE FOR LOAN LOSSES AND RECORDED INVESTMENT IN LOANS This table provides a rollforward of the allowance for loan losses by portfolio segment for the three months ended March 31, 2018 (in thousands): Three Months Ended March 31, 2018 Commercial Real estate Consumer Leases Total Allowance for loan losses: Beginning balance $ 81,156 $ 9,312 $ 10,083 $ 53 $ 100,604 Charge-offs (7,318 ) (1,742 ) (2,700 ) — (11,760 ) Recoveries 471 230 757 — 1,458 Provision 6,748 1,938 1,320 (6 ) 10,000 Ending balance $ 81,057 $ 9,738 $ 9,460 $ 47 $ 100,302 Ending balance: individually evaluated for impairment $ 4,986 $ 127 $ — $ — $ 5,113 Ending balance: collectively evaluated for impairment 76,071 9,611 9,460 47 95,189 Loans: Ending balance: loans $ 5,242,307 $ 5,764,398 $ 428,938 $ 23,151 $ 11,458,794 Ending balance: individually evaluated for impairment 48,190 15,344 — — 63,534 Ending balance: collectively evaluated for impairment 5,194,117 5,749,054 428,938 23,151 11,395,260 This table provides a rollforward of the allowance for loan losses by portfolio segment for the three months ended March 31, 2017 (in thousands): Three Months Ended March 31, 2017 Commercial Real estate Consumer Leases Total Allowance for loan losses: Beginning balance $ 71,657 $ 10,569 $ 9,311 $ 112 $ 91,649 Charge-offs (5,981 ) (186 ) (2,537 ) — (8,704 ) Recoveries 698 61 619 — 1,378 Provision 6,823 68 2,117 (8 ) 9,000 Ending balance $ 73,197 $ 10,512 $ 9,510 $ 104 $ 93,323 Ending balance: individually evaluated for impairment 8,173 67 $ — $ — 8,240 Ending balance: collectively evaluated for impairment 65,024 10,445 9,510 104 85,083 Loans: Ending balance: loans $ 5,100,988 $ 5,262,356 $ 355,209 $ 38,683 $ 10,757,236 Ending balance: individually evaluated for impairment 69,314 18,136 33 — 87,483 Ending balance: collectively evaluated for impairment 5,031,674 5,244,220 355,176 38,683 10,669,753 Impaired Loans This table provides an analysis of impaired loans by class at March 31, 2018 and December 31, 2017 (in thousands): As of March 31, 2018 Unpaid Principal Balance Recorded Investment with No Allowance Recorded Investment with Allowance Total Recorded Investment Related Allowance Average Recorded Investment Commercial: Commercial $ 69,419 $ 24,597 $ 23,049 $ 47,646 $ 4,986 $ 54,319 Asset-based — — — — — — Factoring — 544 — 544 — 687 Commercial – credit card — — — — — — Real estate: Real estate – construction 108 93 — 93 — 93 Real estate – commercial 20,727 10,679 4,361 15,040 52 13,742 Real estate – residential 219 114 97 211 75 314 Real estate – HELOC — — — — — — Consumer: Consumer – credit card — — — — — — Consumer – other — — — — — — Leases — — — — — — Total $ 90,473 $ 36,027 $ 27,507 $ 63,534 $ 5,113 $ 69,155 As of December 31, 2017 Unpaid Principal Balance Recorded Investment with No Allowance Recorded Investment with Allowance Total Recorded Investment Related Allowance Average Recorded Investment Commercial: Commercial $ 84,749 $ 44,525 $ 16,465 $ 60,990 $ 6,299 $ 65,385 Asset-based — — — — — — Factoring 830 — 830 830 306 207 Commercial – credit card — — — — — — Real estate: Real estate – construction 108 93 — 93 — 148 Real estate – commercial 16,284 7,968 4,477 12,445 3 10,506 Real estate – residential 427 321 97 418 75 221 Real estate – HELOC — — — — — — Consumer: Consumer – credit card — — — — — — Consumer – other — — — — — 8 Leases — — — — — — Total $ 102,398 $ 52,907 $ 21,869 $ 74,776 $ 6,683 $ 76,475 Troubled Debt Restructurings A loan modification is considered a troubled debt restructuring (TDR) when a concession has been granted to a debtor experiencing financial difficulties. The Company’s modifications generally include interest rate adjustments, principal reductions, and amortization and maturity date extensions. These modifications allow the debtor short-term cash relief to allow them to improve their financial condition. The Company’s restructured loans are individually evaluated for impairment and evaluated as part of the allowance for loan loss as described above in the Allowance for Loan Losses section of this note. The Company had no outstanding commitments to lend to borrowers with loan modifications classified as TDRs as of March 31, 2018. As of March 31, 2017 the company had $24 thousand in commitments to lend to borrowers with loan modifications classified as TDRs. The Company monitors loan payments on an on-going basis to determine if a loan is considered to have a payment default. Determination of payment default involves analyzing the economic conditions that exist for each customer and their ability to generate positive cash flows during the loan term. For the three month period ended March 31, 2018, the Company had no new TDRs. For the three month period ended March 31, 2017, the Company had one commercial TDR with a pre- and post-modification loan balance of $7.2 million.

Securities

Securities	3 Months Ended
	Mar. 31, 2018
Investments Debt And Equity Securities [Abstract]
Securities	5. Securities Securities Available for Sale This table provides detailed information about securities available for sale at March 31, 2018 and December 31, 2017 (in thousands): March 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury $ 40,095 $ — $ (1,899 ) $ 38,196 U.S. Agencies 3,774 — (5 ) 3,769 Mortgage-backed 3,835,039 1,019 (120,665 ) 3,715,393 State and political subdivisions 2,415,196 3,612 (38,299 ) 2,380,509 Corporates 1,485 — (6 ) 1,479 Total $ 6,295,589 $ 4,631 $ (160,874 ) $ 6,139,346 December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury $ 40,092 $ — $ (1,449 ) $ 38,643 U.S. Agencies 14,762 — (10 ) 14,752 Mortgage-backed 3,719,369 1,914 (72,040 ) 3,649,243 State and political subdivisions 2,546,517 11,965 (15,809 ) 2,542,673 Corporates 13,278 — (12 ) 13,266 Total $ 6,334,018 $ 13,879 $ (89,320 ) $ 6,258,577 The following table presents contractual maturity information for securities available for sale at March 31, 2018 (in thousands): Amortized Fair Cost Value Due in 1 year or less $ 306,247 $ 306,019 Due after 1 year through 5 years 1,064,499 1,056,930 Due after 5 years through 10 years 777,352 758,232 Due after 10 years 312,452 302,772 Total 2,460,550 2,423,953 Mortgage-backed securities 3,835,039 3,715,393 Total securities available for sale $ 6,295,589 $ 6,139,346 Securities may be disposed of before contractual maturities due to sales by the Company or because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. For the three months ended March 31, 2018, proceeds from the sales of securities available for sale were $41.3 million compared to $86.1 million for the same period in 2017. Securities transactions resulted in gross realized gains of $0.1 million and $0.5 million for the three months ended March 31, 2018 and 2017, respectively. Securities transactions resulted in gross realized losses of $3 thousand for the three months ended March 31, 2018 and there were no gross realized losses for the three months ended March 31, 2017. Securities available for sale with a fair value of $5.1 billion at March 31, 2018 and $5.7 billion at December 31, 2017 were pledged to secure U.S. Government deposits, other public deposits, certain trust deposits, derivative transactions, and repurchase agreements. Of this amount, securities with a market value of $1.7 billion and $1.8 billion at March 31, 2018 and The following table shows the Company’s available for sale investments’ gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at March 31, 2018 and December 31, 2017 (in thousands): Less than 12 months 12 months or more Total March 31, 2018 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Description of Securities U.S. Treasury $ 9,808 $ (117 ) $ 28,387 $ (1,782 ) $ 38,195 $ (1,899 ) U.S. Agencies 3,571 (5 ) — — 3,571 (5 ) Mortgage-backed 2,085,580 (47,831 ) 1,471,848 (72,834 ) 3,557,428 (120,665 ) State and political subdivisions 1,534,275 (21,958 ) 360,967 (16,341 ) 1,895,242 (38,299 ) Corporates 1,479 (6 ) — — 1,479 (6 ) Total temporarily-impaired debt securities available for sale $ 3,634,713 $ (69,917 ) $ 1,861,202 $ (90,957 ) $ 5,495,915 $ (160,874 ) Less than 12 months 12 months or more Total December 31, 2017 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Description of Securities U.S. Treasury $ 9,851 $ (64 ) $ 28,792 $ (1,385 ) $ 38,643 $ (1,449 ) U.S. Agencies 14,553 (10 ) — — 14,553 (10 ) Mortgage-backed 1,990,006 (19,980 ) 1,562,333 (52,060 ) 3,552,339 (72,040 ) State and political subdivisions 1,076,930 (7,325 ) 376,560 (8,484 ) 1,453,490 (15,809 ) Corporates 13,266 (12 ) — — 13,266 (12 ) Total temporarily-impaired debt securities available for sale $ 3,104,606 $ (27,391 ) $ 1,967,685 $ (61,929 ) $ 5,072,291 $ (89,320 ) The unrealized losses in the Company’s investments in U.S. Treasury obligations, U.S. government agencies, Government Sponsored Entity (GSE) mortgage-backed securities, municipal securities, and corporates were caused by changes in interest rates. The Company does not have the intent to sell these securities and does not believe it is more likely than not that the Company will be required to sell these securities before a recovery of amortized cost. The Company expects to recover its cost basis in the securities and does not consider these investments to be other-than-temporarily impaired at March 31, 2018. Securities Held to Maturity The following table shows the Company’s held to maturity investments’ amortized cost, fair value, and gross unrealized gains and losses at March 31, 2018 and December 31, 2017, respectively (in thousands): Gross Gross Amortized Unrealized Unrealized Fair March 31, 2018 Cost Gains Losses Value State and political subdivisions: Due in 1 year or less $ 3,883 $ — $ (105 ) $ 3,778 Due after 1 year through 5 years 106,522 258 (6,386 ) 100,394 Due after 5 years through 10 years 352,349 4,692 (17,169 ) 339,872 Due after 10 years 783,712 6,217 (76,346 ) 713,583 Total state and political subdivisions $ 1,246,466 $ 11,167 $ (100,006 ) $ 1,157,627 Gross Gross Amortized Unrealized Unrealized Fair December 31, 2017 Cost Gains Losses Value State and political subdivisions: Due in 1 year or less $ 2,275 $ 3 $ (24 ) $ 2,254 Due after 1 year through 5 years 100,648 3,111 (2,834 ) 100,925 Due after 5 years through 10 years 372,234 5,006 (14,117 ) 363,123 Due after 10 years 785,857 6,952 (51,664 ) 741,145 Total state and political subdivisions $ 1,261,014 $ 15,072 $ (68,639 ) $ 1,207,447 Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. There were no sales of securities held to maturity during the three months ended March 31, 2018 or 2017. Trading Securities The net unrealized losses on trading securities at March 31, 2018 were $123 thousand. There were no net unrealized gains or losses on trading securities at March 31, 2017. Net unrealized gains/losses are included in trading and investment banking income on the Consolidated Statements of Income. Securities sold not yet purchased totaled $9.5 million and $4.1 million at March 31, 2018 and December 31, 2017, respectively, and is classified within the Other liabilities line of the Company’s Consolidated Balance Sheets. Other Securities The table below provides detailed information for FRB stock and Federal Home Loan Bank (FHLB) stock and other securities at March 31, 2018 and December 31, 2017 (in thousands): Gross Gross Amortized Unrealized Unrealized Fair March 31, 2018 Cost Gains Losses Value FRB and FHLB stock $ 33,262 $ — $ — $ 33,262 Other securities – marketable 3 4,733 — 4,736 Other securities – non-marketable 25,888 3,522 — 29,410 Total Other securities $ 59,153 $ 8,255 $ — $ 67,408 Gross Gross Amortized Unrealized Unrealized Fair December 31, 2017 Cost Gains Losses Value FRB and FHLB stock $ 33,262 $ — $ — $ 33,262 Other securities – marketable 3 4,637 — 4,640 Other securities – non-marketable 26,606 1,389 — 27,995 Total Other securities $ 59,871 $ 6,026 $ — $ 65,897 Investment in FRB stock is based on the capital structure of the investing bank, and investment in FHLB stock is mainly tied to the level of borrowings from the FHLB. These holdings are carried at cost. Other marketable and non-marketable securities include Prairie Capital Management (PCM) alternative investments in hedge funds and private equity funds, which are accounted for as equity-method investments. The fair value of other marketable securities includes alternative investment securities of $4.7 million at March 31, 2018 and $4.6 million at December 31, 2017. The fair value of other non-marketable securities includes alternative investment securities of $5.5 million at March 31, 2018 and $3.4 million at December 31, 2017. Unrealized gains or losses on alternative investments are recognized in the Other noninterest income line on the Company’s Consolidated Statements of Income.

Goodwill and Other Intangibles

Goodwill and Other Intangibles	3 Months Ended
	Mar. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangibles	6. Goodwill and Other Intangibles Changes in the carrying amount of goodwill for the periods ended March 31, 2018 and December 31, 2017 by reportable segment are as follows (in thousands): Commercial Banking Institutional Banking Personal Banking Healthcare Services Total Balances as of January 1, 2018 $ 59,419 $ 51,332 $ 70,116 $ — $ 180,867 Balances as of March 31, 2018 $ 59,419 $ 51,332 $ 70,116 $ — $ 180,867 Balances as of January 1, 2017 $ 59,419 $ 98,861 $ 70,116 $ — $ 228,396 Discontinued assets ─ goodwill and other intangibles, net — (47,529 ) — — (47,529 ) Balances as of December 31, 2017 $ 59,419 $ 51,332 $ 70,116 $ — $ 180,867 The following table lists the finite-lived intangible assets that continue to be subject to amortization as of March 31, 2018 and December 31, 2017 (in thousands) As of March 31, 2018 Core Deposit Intangible Assets Customer Relationships Other Intangible Assets Total Gross carrying amount $ 50,059 $ 71,342 $ 3,254 $ 124,655 Accumulated amortization 42,990 59,716 3,254 105,960 Net carrying amount $ 7,069 $ 11,626 $ — $ 18,695 As of December 31, 2017 Core Deposit Intangible Assets Customer Relationships Other Intangible Assets Total Gross carrying amount $ 50,059 $ 71,342 $ 3,254 $ 124,655 Accumulated amortization 42,209 58,935 3,254 104,398 Net carrying amount $ 7,850 $ 12,407 $ — $ 20,257 The following table has the aggregate amortization expense recognized in each period (in thousands) Three Months Ended March 31, 2018 2017 Aggregate amortization expense $ 1,562 $ 2,046 The following table lists estimated amortization expense of intangible assets in future periods (in thousands): For the nine months ending December 31, 2018 $ 4,151 For the year ending December 31, 2019 4,714 For the year ending December 31, 2020 3,759 For the year ending December 31, 2021 2,755 For the year ending December 31, 2022 1,815 For the year ending December 31, 2023 1,097

Securities Sold Under Agreement

Securities Sold Under Agreements to Repurchase	3 Months Ended
	Mar. 31, 2018
Banking And Thrift [Abstract]
Securities Sold Under Agreements to Repurchase	7. Securities Sold Under Agreements to Repurchase The Company utilizes repurchase agreements to facilitate the needs of customers and to facilitate secured short-term funding needs. Repurchase agreements are stated at the amount of cash received in connection with the transaction. The Company monitors collateral levels on a continuous basis and 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 the Company’s safekeeping agents. The table below presents the remaining contractual maturities of repurchase agreements outstanding at March 31, 2018, in addition to the various types of marketable securities that have been pledged as collateral for these borrowings (in thousands): As of March 31, 2018 Remaining Contractual Maturities of the Agreements Repurchase agreements, secured by: On Demand 2-29 Days Over 90 Days Total U.S. Treasury $ — $ 17,700 $ — $ 17,700 U.S. Agencies — 1,302,756 3,000 1,305,756 Total repurchase agreements $ — $ 1,320,456 $ 3,000 $ 1,323,456

Business Segment Reporting

Business Segment Reporting	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Business Segment Reporting	8. Business Segment Reporting The Company has strategically aligned its operations into the following four reportable segments: Commercial Banking, Institutional Banking, Personal Banking, and Healthcare Services (collectively, the Business Segments). Senior executive officers regularly evaluate Business Segment financial results produced by the Company’s internal reporting system in deciding how to allocate resources and assess performance for individual Business Segments. Previously, the Company had the following three Business Segments: Bank, Institutional Investment Management, and Asset Servicing. During 2017, the Company sold all of the outstanding stock of Scout, its institutional investment management subsidiary. As the operations of Scout are included in discontinued operations, the Company no longer presents such operations as one of its business segments. The Company’s reportable Business Segments include certain corporate overhead, technology and service costs that are allocated based on methodologies that are applied consistently between periods. For comparability purposes, amounts in all periods are based on methodologies in effect at March 31, 2018. Previously reported results have been reclassified in this filing to conform to the current organizational structure. The following summaries provide information about the activities of each segment: Commercial Banking serves the commercial lending and leasing, capital markets, and treasury management needs of the Company’s mid-market businesses and governmental entities by offering various products and services. Such services include commercial loans, commercial credit cards, letters of credit, loan syndication services, consultative services, and a variety of financial options for companies that need non-traditional banking services. Capital markets services include asset-based financing, asset securitization, equity and mezzanine financing, factoring, private and public placement of senior debt, as well as merger and acquisition consulting. Treasury management services include depository services, account reconciliation services, electronic fund transfer services, controlled disbursements, lockbox services, and remote deposit capture services. Institutional Banking is a combination of banking services, fund services, and asset management services provided to institutional clients. This segment also provides mutual fund cash management, international payments, corporate trust and escrow services, as well as correspondent banking and investment banking. Products and services include bond trading transactions, cash letter collections, investment portfolio accounting and safekeeping, reporting for asset/liability management, and Federal funds transactions. Institutional Banking also includes UMB Fund Services, which provides fund administration and accounting, investor services and transfer agency, marketing and distribution, custody and alternative investment services. Personal Banking combines consumer services and asset management provided to personal clients. This segment combines the Company’s consumer bank with the individual investment and wealth management solutions. The range of services offered to UMB clients extends from a basic checking account to estate planning and trust services. Products and services include the Company’s bank branches, call center, internet banking and ATM network, deposit accounts, retail credit cards, private banking, installment loans, home equity lines of credit, residential mortgages, small business loans, brokerage services, and insurance services in addition to a full spectrum of investment advisory, trust, and custody services. Healthcare Services provides healthcare payment solutions including custodial services for health savings accounts (HSAs) and private label, multipurpose debit cards to insurance carriers, third-party administrators, software companies, employers and financial institutions. Business Segment Information Business Segment financial results were as follows for the three months ended March 31, 2018 and March 31, 2017 (in thousands): Three Months Ended March 31, 2018 Commercial Banking Institutional Banking Personal Banking Healthcare Services Total Net interest income $ 91,968 $ 15,744 $ 30,920 $ 9,290 $ 147,922 Provision for loan losses 7,978 350 1,672 — 10,000 Noninterest income 20,598 45,419 30,714 8,794 105,525 Noninterest expense 62,246 46,833 54,994 11,803 175,876 Income before taxes 42,342 13,980 4,968 6,281 67,571 Income tax expense 6,284 2,080 738 936 10,038 Income from continuing operations $ 36,058 $ 11,900 $ 4,230 $ 5,345 $ 57,533 Average assets $ 9,785,000 $ 3,826,000 $ 4,982,000 $ 2,154,000 $ 20,747,000 Three Months Ended March 31, 2017 Commercial Banking Institutional Banking Personal Banking Healthcare Services Total Net interest income $ 85,390 $ 11,582 $ 30,075 $ 7,268 $ 134,315 Provision for loan losses 6,820 469 1,711 — 9,000 Noninterest income 19,206 45,666 28,536 9,509 102,917 Noninterest expense 62,750 44,778 55,997 10,285 173,810 Income before taxes 35,026 12,001 903 6,492 54,422 Income tax expense 8,007 2,734 224 1,481 12,446 Income from continuing operations $ 27,019 $ 9,267 $ 679 $ 5,011 $ 41,976 Average assets $ 9,611,000 $ 3,466,000 $ 5,347,000 $ 1,810,000 $ 20,234,000

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 31, 2018
Revenue From Contract With Customer [Abstract]
Revenue Recognition	9. Revenue Recognition As of January 1, 2018, the Company adopted ASU No. 2014-09, Revenue from Contracts with Customers The following is a description of the principal activities from which the Company generates revenue that are within the scope of ASC 606: Trust and securities processing - Trust and securities processing income consists of fees earned on personal and corporate trust accounts, custody of securities services, trust investments and wealth management services, and mutual fund and alternative asset servicing. The performance obligations related to this revenue include items such as performing full bond trustee service administration, investment advisory services, custody and record-keeping services, and fund administrative and accounting services. These fees are part of long-term contractual agreements and the performance obligations are satisfied upon completion of service and fees are generally a fixed flat monthly rate or based on a percentage of the account’s market value per the contract with the customer. These fees are primarily recorded within the Company’s Institutional and Personal Banking segments. Trading and investment banking Debt and Equity Securities Service charges on deposits Insurance fees and commissions Brokerage fees Bankcard fees Gains on sales of securities available for sale, net Debt and Equity Securities Other income – The Company had no material contract assets, contract liabilities, or remaining performance obligations as of March 31, 2018. Total receivables from revenue recognized under the scope of ASC 606 were $53.3 million and $53.5 million as of March 31, 2018 and December 31, 2017, respectively. These receivables are included as part of the Other assets line on the Company’s Consolidated Balance Sheets. The following table depicts the disaggregation of revenue according to revenue stream and Business Segment for the three months ended March 31, 2018 and March 31, 2017 (in thousands): Three Months Ended March 31, 2018 NONINTEREST INCOME Commercial Banking Institutional Banking Personal Banking Healthcare Services Revenue (Expense) out of Scope of ASU 606 Total Trust and securities processing $ — $ 27,696 $ 16,306 $ — $ — $ 44,002 Trading and investment banking — — — — 4,101 4,101 Service charges on deposit accounts 7,791 7,230 2,812 4,038 34 21,905 Insurance fees and commissions — — 301 — — 301 Brokerage fees 52 4,060 2,241 — — 6,353 Bankcard fees 14,797 1,635 5,313 4,304 (7,926 ) 18,123 Gains on sales of securities available for sale, net — — — — 139 139 Other 454 120 906 149 8,972 10,601 Total Noninterest income $ 23,094 $ 40,741 $ 27,879 $ 8,491 $ 5,320 $ 105,525 Three Months Ended March 31, 2017 NONINTEREST INCOME Commercial Banking Institutional Banking Personal Banking Healthcare Services Revenue (Expense) out of Scope of ASU 606 Total Trust and securities processing $ — $ 26,517 $ 16,024 $ — $ — $ 42,541 Trading and investment banking — 505 — — 7,037 7,542 Service charges on deposit accounts 8,021 7,355 2,865 3,804 30 22,075 Insurance fees and commissions — — 646 — — 646 Brokerage fees 40 3,256 2,081 — — 5,377 Bankcard fees 12,148 1,505 5,438 5,223 (6,562 ) 17,752 Gains on sales of securities available for sale, net — — — — 468 468 Other 489 163 764 76 5,024 6,516 Total Noninterest income $ 20,698 $ 39,301 $ 27,818 $ 9,103 $ 5,997 $ 102,917

Commitments, Contingencies and

Commitments, Contingencies and Guarantees	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments, Contingencies and Guarantees	10. Commitments, Contingencies and Guarantees In the normal course of business, the Company is party to financial instruments with off-balance-sheet risk in order to meet the financing needs of its customers and to reduce its own exposure to fluctuations in interest rates. These financial instruments include commitments to extend credit, commercial letters of credit, standby letters of credit, forward foreign exchange contracts and spot foreign exchange contracts. These instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amounts recognized in the Consolidated Balance Sheets. The contractual or notional amount of those instruments reflects the extent of involvement the Company has in particular classes of financial instruments. Many of the commitments expire without being drawn upon; therefore, the total amount of these commitments does not necessarily represent the future cash requirements of the Company. The Company’s exposure to credit loss in the event of nonperformance by the counterparty to the financial instruments for commitments to extend credit, commercial letters of credit, and standby letters of credit is represented by the contract or notional amount of those instruments. The Company uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments. The following table summarizes the Company’s off-balance sheet financial instruments (in thousands): Contract or Notional Amount March 31, December 31, 2018 2017 Commitments to extend credit for loans (excluding credit card loans) $ 6,245,306 $ 6,689,467 Commitments to extend credit under credit card loans 3,007,843 2,975,507 Commercial letters of credit 5,059 813 Standby letters of credit 321,748 316,054 Forward contracts 25,365 29,007 Spot foreign exchange contracts 4,575 628

Derivatives and Hedging Activit

Derivatives and Hedging Activities	3 Months Ended
	Mar. 31, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	11. Derivatives and Hedging Activities Risk Management Objective of Using Derivatives The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk, primarily by managing the amount, sources, and duration of its assets and liabilities. Specifically, the Company enters into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. The Company’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Company’s known or expected cash receipts and its known or expected cash payments principally related to certain fixed-rate assets and liabilities. The Company also has interest rate derivatives that result from a service provided to certain qualifying customers and, therefore, are not used to manage interest rate risk of the Company’s assets or liabilities. The Company has entered into an offsetting position for each of these derivative instruments with a matching instrument from another financial institution in order to minimize its net risk exposure resulting from such transactions. Fair Values of Derivative Instruments on the Consolidated Balance Sheets The table below presents the fair value of the Company’s derivative financial instruments as of March 31, 2018 and December 31, 2017. The Company’s derivative assets and derivative liabilities are located within Other assets and Other liabilities, respectively, on the Company’s Consolidated Balance Sheets. Derivatives Fair values are determined using valuation techniques including discounted cash flow analysis on the expected cash flows from each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves, foreign exchange rates, and implied volatilities. The Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Company has considered the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees. This table provides a summary of the fair value of the Company’s derivative assets and liabilities as of March 31, 2018 and December 31, 2017 ( in thousands Derivative Assets Derivative Liabilities March 31, December 31, March 31, December 31, Fair Value 2018 2017 2018 2017 Interest Rate Products: Derivatives not designated as hedging instruments $ 7,424 $ 10,116 $ 6,347 $ 7,326 Derivatives designated as hedging instruments — 33 31 1,580 Total $ 7,424 $ 10,149 $ 6,378 $ 8,906 Fair Value Hedges of Interest Rate Risk The Company is exposed to changes in the fair value of certain of its fixed-rate assets and liabilities due to changes in the benchmark interest rate, London Interbank Offered Rate (LIBOR). Interest rate swaps designated as fair value hedges involve either making fixed rate payments to a counterparty in exchange for the Company receiving variable rate payments, or making variable rate payments to a counterparty in exchange for the Company receiving fixed rate payments, over the life of the agreements without the exchange of the underlying notional amount. As of March 31, 2018, the Company had one interest rate swap with a notional amount of $5.8 million that was designated as a fair value hedge of interest rate risk associated with the Company’s fixed rate loan assets. For derivatives designated and that qualify as fair value hedges, the gain or loss on the derivative as well as the offsetting loss or gain on the hedged item attributable to the hedged risk are recognized in earnings. Cash Flow Hedges of Interest Rate Risk The Company is exposed to changes in the fair value of certain of its variable-rate liabilities due to changes in the benchmark interest rate, LIBOR. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. As of March 31, 2018, the Company had two interest rate swaps with a notional amount of $51.5 million that were designated as cash flow hedges of interest rate risk associated with the Company’s variable-rate subordinated debentures issued by Marquette Capital Trusts III and IV. For derivatives designated and that qualify as cash flow hedges, the change in fair value is recorded in AOCI and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. During the three months ended March 31, 2018 and 2017, the Company recognized net gains of $2.2 million and $246 thousand, respectively, in AOCI for the change in fair value of these cash flow hedges. Amounts reported in AOCI related to derivatives will be reclassified to Interest expense as interest payments are received or paid on the Company’s derivatives. The Company does not expect to reclassify any amounts from AOCI to Interest expense during the next 12 months. As of March 31, 2018, the Company is hedging its exposure to the variability in future cash flows for forecasted transactions over a maximum period of 18.47 years. Non-designated Hedges The remainder of the Company’s derivatives are not designated in qualifying hedging relationships. Derivatives not designated as hedges are not speculative and result from a service the Company provides to certain customers. The Company executes interest rate swaps with commercial banking customers to facilitate their respective risk management strategies. Those interest rate swaps are simultaneously offset by interest rate swaps that the Company executes with a third party, such that the Company minimizes its net risk exposure resulting from such transactions. As the interest rate swaps associated with this program do not meet the strict hedge accounting requirements, changes in the fair value of both the customer swaps and the offsetting swaps are recognized directly in earnings. As of March 31, 2018, the Company had 88 interest rate swaps with an aggregate notional amount of $1.1 billion related to this program. During the three months ended March 31, 2018 and 2017, the Company recognized net gains of $336 thousand and net losses of $348 thousand, respectively, related to changes in fair value of these swaps. Effect of Derivative Instruments on the Consolidated Statements of Income This table provides a summary of the amount of gain or loss recognized in Other noninterest expense in the Consolidated Statements of Income related to the Company’s derivative assets and liabilities for the three months ended March 31, 2018 and March 31, 2017 (in thousands) Amount of Gain (Loss) Recognized For the Three Months Ended March 31, March 31, 2018 2017 Interest Rate Products Derivatives not designated as hedging instruments $ 336 $ (348 ) Total $ 336 $ (348 ) Interest Rate Products Derivatives designated as hedging instruments: Fair value adjustments on derivatives $ 81 $ (46 ) Fair value adjustments on hedged items (81 ) 46 Total $ — $ — This table provides a summary of the amount of gain or loss recognized in AOCI in the Consolidated Statements of Comprehensive Income related to the Company’s derivative assets and liabilities for the three months ended March 31, 2018 and March 31, 2017 (in thousands) Amount of Gain Recognized in Other Comprehensive Income on Derivatives For the Three Months Ended March 31, March 31, Derivatives in Cash Flow Hedging Relationships 2018 2017 Interest Rate Products Derivatives designated as cash flow hedging instruments $ 2,202 $ 246 Total $ 2,202 $ 246 Credit-risk-related Contingent Features The Company has agreements with certain of its derivative counterparties that contain a provision that if the Company defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then the Company could also be declared in default on its derivative obligations. As of March 31, 2018, the termination value of derivatives in a net liability position, which includes accrued interest, related to these agreements was $1.3 million. The Company has minimum collateral posting thresholds with certain of its derivative counterparties. At March 31, 2018, the Company had posted $1.0 million of collateral. If the Company had breached any of these provisions at March 31, 2018, it could have been required to settle its obligations under the agreements at the termination value.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	12. Fair Value Measurements The following table presents information about the Company’s assets measured at fair value on a recurring basis as of March 31, 2018, and indicates the fair value hierarchy of the valuation techniques utilized by the Company to determine such fair value. Fair values determined by Level 1 inputs utilize quoted prices in active markets for identical assets and liabilities that the Company has the ability to access. Fair values determined by Level 2 inputs utilize inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices for similar assets or liabilities in active markets, and inputs other than quoted prices that are observable for the asset or liability, such as interest rates and yield curves that are observable at commonly quoted intervals. Level 3 inputs are unobservable inputs for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability. In certain cases, the inputs used to measure fair value may fall into different levels of the hierarchy. In such cases, the fair value is determined based on the lowest level input that is significant to the fair value measurement in its entirety. Assets measured at fair value on a recurring basis as of March 31, 2018 and December 31, 2017 (in thousands): Fair Value Measurement at March 31, 2018 Description March 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets U.S. Treasury $ 497 $ 497 $ — $ — U.S. Agencies 5,188 — 5,188 — Mortgage-backed 634 — 634 — State and political subdivisions 36,386 — 36,386 — Corporates 8,517 8,517 — — Trading – other 14,167 12,262 1,905 — Trading securities 65,389 21,276 44,113 — U.S. Treasury 38,196 38,196 — — U.S. Agencies 3,769 — 3,769 — Mortgage-backed 3,715,393 — 3,715,393 — State and political subdivisions 2,380,509 — 2,380,509 — Corporates 1,479 1,479 — — Available for sale securities 6,139,346 39,675 6,099,671 — Company-owned life insurance 55,711 — 55,711 — Bank-owned life insurance 267,747 — 267,747 — Derivatives 7,424 — 7,424 — Total $ 6,535,617 $ 60,951 $ 6,474,666 $ — Liabilities Deferred compensation $ 53,125 $ 53,125 $ — $ — Derivatives 6,378 — 6,378 — Securities sold not yet purchased 9,507 — 9,507 — Total $ 69,010 $ 53,125 $ 15,885 $ — Fair Value Measurement at December 31, 2017 Description December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets U.S. Treasury $ 18 $ 18 $ — $ — U.S. Agencies 9,976 — 9,976 — Mortgage-backed 1,949 — 1,949 — State and political subdivisions 27,114 — 27,114 — Corporates 1,885 1,885 — — Trading – other 13,113 12,434 679 — Trading securities 54,055 14,337 39,718 — U.S. Treasury 38,643 38,643 — — U.S. Agencies 14,752 — 14,752 — Mortgage-backed 3,649,243 — 3,649,243 — State and political subdivisions 2,542,673 — 2,542,673 — Corporates 13,266 13,266 — — Available for sale securities 6,258,577 51,909 6,206,668 — Company-owned life insurance 53,577 — 53,577 — Bank-owned life insurance 265,823 — 265,823 — Derivatives 10,149 — 10,149 — Total $ 6,642,181 $ 66,246 $ 6,575,935 $ — Liabilities Deferred compensation $ 50,963 $ 50,963 $ — $ — Derivatives 8,906 — 8,906 — Securities sold not yet purchased 4,130 — 4,130 — Total $ 63,999 $ 50,963 $ 13,036 $ — Valuation methods for instruments measured at fair value on a recurring basis The following methods and assumptions were used to estimate the fair value of each class of financial instruments measured on a recurring basis: Trading Securities Fair values for trading securities (including financial futures), are based on quoted market prices where available. If quoted market prices are not available, fair values are based on quoted market prices for similar securities. Securities Available for Sale Fair values are based on quoted market prices or dealer quotes, if available. If a quoted market price is not available, fair value is estimated using quoted market prices for similar securities. Prices are provided by third-party pricing services and are based on observable market inputs. On an annual basis, the Company compares a sample of these prices to other independent sources for the same securities. Additionally, throughout the year, if securities are sold, comparisons are made between the pricing services prices and the market prices at which the securities were sold. Variances are analyzed, and, if appropriate, additional research is conducted with the third-party pricing services. Based on this research, the pricing services may affirm or revise their quoted price. No significant adjustments have been made to the prices provided by the pricing services. The pricing services also provide documentation on an ongoing basis that includes reference data, inputs and methodology by asset class, which is reviewed to ensure that security placement within the fair value hierarchy is appropriate. Company-owned Life Insurance Fair value is equal to the cash surrender value of the life insurance policies. Bank-owned Life Insurance Fair value is equal to the cash surrender value of the life insurance policies. Derivatives Fair values are determined using valuation techniques including discounted cash flow analysis on the expected cash flows from each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves, foreign exchange rates, and implied volatilities. The Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Company has considered the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts, and guarantees. Deferred Compensation Fair values are based on quoted market prices or dealer quotes. Securities sold not yet purchased Fair values are based on quoted market prices or dealer quotes, if available. If a quoted market price is not available, fair value is estimated using quoted market prices for similar securities. Prices are provided by third-party pricing services and are based on observable market inputs. Assets measured at fair value on a non-recurring basis as of March 31, 2018 and December 31, 2017 (in thousands): Fair Value Measurement at March 31, 2018 Using Description March 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Gains Recognized During the Three Months Ended March 31 Impaired loans $ 22,394 $ — $ — $ 22,394 $ 1,570 Other real estate owned 93 — — 93 — Total $ 22,487 $ — $ — $ 22,487 $ 1,570 Fair Value Measurement at December 31, 2017 Using Description December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Gains Recognized During the Twelve Months Ended December 31 Impaired loans $ 15,186 $ — $ — $ 15,186 $ 1,251 Other real estate owned 1,488 — — 1,488 13 Total $ 16,674 $ — $ — $ 16,674 $ 1,264 Valuation methods for instruments measured at fair value on a non-recurring basis The following methods and assumptions were used to estimate the fair value of each class of financial instruments measured on a non-recurring basis: Impaired loans While the overall loan portfolio is not carried at fair value, adjustments are recorded on certain loans to reflect write-downs that are based on the external appraised value of the underlying collateral. The external appraisals are generally based on recent sales of comparable properties which are then adjusted for the unique characteristics of the property being valued. In the case of non-real estate collateral, reliance is placed on a variety of sources, including external estimates of value and judgments based on the experience and expertise of internal specialists within the Company’s property management group and the Company’s credit department. The valuation of the impaired loans is reviewed on a quarterly basis. Because many of these inputs are not observable, the measurements are classified as Level 3. Other real estate owned Other real estate owned consists of loan collateral which has been repossessed through foreclosure. This collateral is comprised of commercial and residential real estate and other non-real estate property, including auto, recreational and marine vehicles. Other real estate owned is recorded as held for sale initially at the lower of the loan balance or fair value of the collateral. The initial valuation of the foreclosed property is obtained through an appraisal process similar to the process described in the impaired loans paragraph above. Subsequent to foreclosure, valuations are reviewed quarterly and updated periodically, and the assets may be marked down further, reflecting a new cost basis. Fair value measurements may be based upon appraisals, third-party price opinions, or internally developed pricing methods and those measurements are classified as Level 3. Goodwill Valuation of goodwill to determine impairment is performed annually, or more frequently if there is an event or circumstance that would indicate impairment may have occurred. The process involves calculations to determine the fair value of each reporting unit on a stand-alone basis. A combination of formulas using current market multiples, based on recent sales of financial institutions within the Company’s geographic marketplace, is used to estimate the fair value of each reporting unit. That fair value is compared to the carrying amount of the reporting unit, including its recorded goodwill. Impairment is considered to have occurred if the fair value of the reporting unit is lower than the carrying amount of the reporting unit. The fair value of the Company’s common stock relative to its computed book value per share is also considered as part of the overall evaluation. These measurements are classified as Level 3. Fair value disclosures require disclosure 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 non-recurring basis. The estimated fair value of the Company’s financial instruments at March 31, 2018 and December 31, 2017 are as follows (in thousands): Fair Value Measurement at March 31, 2018 Using Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Estimated Fair Value FINANCIAL ASSETS Cash and short-term investments $ 1,078,209 $ 965,247 $ 112,962 $ — $ 1,078,209 Securities available for sale 6,139,346 39,675 6,099,671 — 6,139,346 Securities held to maturity 1,246,466 — 1,157,627 — 1,157,627 Trading securities 65,389 21,276 44,113 — 65,389 Other securities 67,408 — 67,408 — 67,408 Loans (exclusive of allowance for loan loss) 11,463,380 — 11,460,851 — 11,460,851 Derivatives 7,424 — 7,424 — 7,424 FINANCIAL LIABILITIES Demand and savings deposits 16,231,085 16,231,085 — — 16,231,085 Time deposits 987,179 — 987,179 — 987,179 Other borrowings 1,354,615 31,159 1,323,456 — 1,354,615 Long-term debt 78,687 — 78,940 — 78,940 Derivatives 6,378 — 6,378 — 6,378 OFF-BALANCE SHEET ARRANGEMENTS Commitments to extend credit for loans 1,544 Commercial letters of credit 17 Standby letters of credit 647 Fair Value Measurement at December 31, 2017 Using Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Estimated Fair Value FINANCIAL ASSETS Cash and short-term investments $ 1,936,084 $ 1,749,618 $ 186,466 $ — $ 1,936,084 Securities available for sale 6,258,577 51,909 6,206,668 — 6,258,577 Securities held to maturity 1,261,014 — 1,207,447 — 1,207,447 Trading securities 54,055 14,337 39,718 — 54,055 Other securities 65,897 — 65,897 — 65,897 Loans (exclusive of allowance for loan loss) 11,281,973 — 11,318,764 — 11,318,764 Derivatives 10,149 — 10,149 — 10,149 FINANCIAL LIABILITIES Demand and savings deposits 16,742,736 16,742,736 — — 16,742,736 Time deposits 1,280,264 — 1,280,264 — 1,280,264 Other borrowings 1,260,704 11,334 1,249,370 — 1,260,704 Long-term debt 79,281 — 79,496 — 79,496 Derivatives 8,906 — 8,906 — 8,906 OFF-BALANCE SHEET ARRANGEMENTS Commitments to extend credit for loans 6,654 Commercial letters of credit 136 Standby letters of credit 2,514 Cash and short-term investments The carrying amounts of cash and due from banks, federal funds sold and resell agreements are reasonable estimates of their fair values. Securities held to maturity Fair value of held-to-maturity securities are estimated by discounting the future cash flows using current market rates. Other securities Amount consists of FRB and FHLB stock held by the Company, PCM equity-method investments, and other miscellaneous investments. The carrying amount of the FRB and FHLB stock equals its fair value because the shares can only be redeemed by the FRB and FHLB at their carrying amount. The fair value of PCM marketable equity-method investments are based on quoted market prices used to estimate the value of the underlying investment. For non-marketable equity-method investments, the Company’s proportionate share of the income or loss is recognized on a one-quarter lag based on the valuation of the underlying investment(s). Loans Fair values are estimated for portfolios with similar financial characteristics. Loans are segregated by type, such as commercial, real estate, consumer, and credit card. Each loan category is further segmented into fixed and variable interest rate categories. The fair value of loans are based on quoted market prices for similar instruments or estimated by discounting the future cash flows. The discount rates used are estimated using comparable market rates for similar types of instruments adjusted to be commensurate with the credit risk, overhead costs, and optionality of such instruments. Demand and savings deposits The fair value of demand deposits and savings accounts was the amount payable on demand at March 31, 2018 and December 31, 2017. Time deposits The fair value of fixed-maturity certificates of deposit is estimated by discounting the future cash flows using the rates that are currently offered for deposits of similar remaining maturities. Other borrowings The carrying amounts of federal funds purchased, repurchase agreements and other short-term debt are reasonable estimates of their fair value because of the short-term nature of their maturities. Long-term debt Rates currently available to the Company for debt with similar terms and remaining maturities are used to estimate fair value of existing debt. Other off-balance sheet instruments The fair value of loan commitments and letters of credit are determined based on the fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreement and the present creditworthiness of the counterparties. Neither the fees earned during the year on these instruments nor their fair value at period-end are significant to the Company’s consolidated financial position.

Divestitures

Divestitures	3 Months Ended
	Mar. 31, 2018
Discontinued Operations And Disposal Groups [Abstract]
Divestitures	13. Divestitures On November 17, 2017, the Company closed on the sale of all of the outstanding stock of Scout, an institutional investment management subsidiary, for $172.5 million in cash. The gain recorded on the disposal of Scout was $103.6 million. This table summarizes the components of (loss) income from discontinued operations, net of taxes, for the three months ended March 31, 2018 and March 31, 2017 presented in the Consolidated Statements of Income (in thousands) For the Three Months Ended March 31, 2018 March 31, 2017 Total noninterest income $ — $ 17,863 Total noninterest expense 917 14,956 (Loss) income from discontinued operations (917 ) 2,907 Income tax (benefit) expense (170 ) 702 Net (loss) income on discontinued operations $ (747 ) $ 2,205 The components of net cash provided by operating activities of discontinued operations included in the Consolidated Statements of Cash Flows are as follows (in thousands) Three Months Ended March 31, 2018 2017 (Loss) income from discontinued operations $ (747 ) $ 2,205 Depreciation and amortization — 824 Net cash provided by operating activities of discontinued operations $ (747 ) $ 3,029

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Nature Of Operations	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP) requires management to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. These estimates and assumptions also impact reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. A summary of the significant accounting policies to assist the reader in understanding the financial presentation is provided in the Notes to Consolidated Financial Statements in the Form 10-K.
Cash and cash equivalents	Cash and cash equivalents Cash and cash equivalents include Cash and due from banks and amounts due from the Federal Reserve Bank (FRB). Cash on hand, cash items in the process of collection, and amounts due from correspondent banks are included in Cash and due from banks. Amounts due from the FRB are interest-bearing for all periods presented and are included in the Interest-bearing due from banks line on the Company’s Consolidated Balance Sheets. This table provides a summary of cash and cash equivalents as presented on the Consolidated Statements of Cash Flows as of March 31, 2018 and March 31, 2017 (in thousands) March 31, 2018 2017 Due from the FRB $ 649,616 $ 322,959 Cash and due from banks 279,838 373,671 Cash and cash equivalents at end of period $ 929,454 $ 696,630 Also included in the Interest-bearing due from banks, but not considered cash and cash equivalents, are interest-bearing accounts held at other financial institutions, which totaled $21.5 million and $51.6 million at March 31, 2018 and March 31, 2017, respectively.
Per Share Data	Per Share Data Basic net income per share is computed based on the weighted average number of shares of common stock outstanding during each period. Diluted net income per share includes the dilutive effect of 496,848 and 719,637 shares issuable upon the exercise of options granted by the Company and outstanding at March 31, 2018 and 2017, respectively. Options issued under employee benefits plans to purchase 141,870 and 151,002 shares of common stock were outstanding at March 31, 2018 and 2017, respectively, but were not included in the computation of diluted earnings per share because the options were anti-dilutive.
Derivatives	Derivatives The Company records all derivatives on the Consolidated Balance Sheets at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Currently, three of the Company’s derivatives are designated in qualifying hedging relationships. However, the remainder of the Company’s derivatives are not designated in qualifying hedging relationships, as the derivatives are not used to manage risks within the Company’s assets or liabilities. All changes in fair value of the Company’s non-designated derivatives are recognized directly in earnings. Changes in fair value of the Company’s fair value hedges are recognized directly in earnings. Changes in fair value of the Company’s cash flow hedges are recognized in accumulated other comprehensive income (AOCI).

Summary of Significant Accoun23

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Summary of Cash and Cash Equivalents	This table provides a summary of cash and cash equivalents as presented on the Consolidated Statements of Cash Flows as of March 31, 2018 and March 31, 2017 (in thousands) March 31, 2018 2017 Due from the FRB $ 649,616 $ 322,959 Cash and due from banks 279,838 373,671 Cash and cash equivalents at end of period $ 929,454 $ 696,630

Loans and Allowance for Loan 24

Loans and Allowance for Loan Losses (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Summary of Loan Classes and Aging of Past Due Loans	This table provides a summary of loan classes and an aging of past due loans at March 31, 2018 and December 31, 2017 (in thousands): March 31, 2018 30-89 Days Past Due and Accruing Greater than 90 Days Past Due and Accruing Non- Accrual Loans Total Past Due Current Total Loans Loans Commercial: Commercial $ 7,988 $ 1,508 $ 44,253 $ 53,749 $ 4,415,694 $ 4,469,443 Asset-based — — — — 345,980 345,980 Factoring — — — — 234,148 234,148 Commercial – credit card 640 54 — 694 192,042 192,736 Real estate: Real estate – construction 195 — — 195 789,650 789,845 Real estate – commercial 2,294 1,908 18,816 23,018 3,687,450 3,710,468 Real estate – residential 32 — 686 718 649,630 650,348 Real estate – HELOC 87 — 3,434 3,521 610,216 613,737 Consumer: Consumer – credit card 1,914 2,138 393 4,445 225,169 229,614 Consumer – other 266 42 22 330 198,994 199,324 Leases — — — — 23,151 23,151 Total loans $ 13,416 $ 5,650 $ 67,604 $ 86,670 $ 11,372,124 $ 11,458,794 December 31, 2017 30-89 Days Past Due and Accruing Greater than 90 Days Past Due and Accruing Non- Accrual Loans Total Past Due Current Total Loans Loans Commercial: Commercial $ 11,216 $ 672 $ 38,644 $ 50,532 $ 4,502,508 $ 4,553,040 Asset-based — — — — 336,614 336,614 Factoring — — — — 221,672 221,672 Commercial – credit card 387 79 — 466 171,825 172,291 Real estate: Real estate – construction 6,666 243 93 7,002 710,847 717,849 Real estate – commercial 832 — 16,115 16,947 3,546,683 3,563,630 Real estate – residential 791 — 929 1,720 636,871 638,591 Real estate – HELOC 1,254 — 3,013 4,267 644,112 648,379 Consumer: Consumer – credit card 2,155 2,057 312 4,524 248,173 252,697 Consumer – other 835 40 36 911 150,872 151,783 Leases — — — — 23,967 23,967 Total loans $ 24,136 $ 3,091 $ 59,142 $ 86,369 $ 11,194,144 $ 11,280,513
Credit Risk Profile by Risk Rating and Based on Payment Activity	This table provides an analysis of the credit risk profile of each loan class excluded from ASC 310-30, Loans and Debt Securities Purchased with Deteriorated Credit Quality (in thousands) Credit Exposure Credit Risk Profile by Risk Rating Commercial Asset-based Factoring March 31, December 31, March 31, December 31, March 31, December 31, 2018 2017 2018 2017 2018 2017 Non-watch list $ 3,914,518 $ 4,048,238 $ 287,754 $ 306,899 $ 233,291 $ 220,795 Watch 206,883 162,788 — — — — Special Mention 128,015 106,638 58,226 29,715 282 47 Substandard 220,027 235,376 — — 575 830 Total $ 4,469,443 $ 4,553,040 $ 345,980 $ 336,614 $ 234,148 $ 221,672 Real estate – construction Real estate – commercial March 31, December 31, March 31, December 31, 2018 2017 2018 2017 Non-watch list $ 787,898 $ 716,830 $ 3,562,117 $ 3,434,982 Watch 1,725 631 74,060 50,715 Special Mention — — 27,843 35,940 Substandard 222 388 46,448 41,993 Total $ 789,845 $ 717,849 $ 3,710,468 $ 3,563,630 Credit Exposure Credit Risk Profile Based on Payment Activity Commercial – credit card Real estate – residential Real estate – HELOC March 31, December 31, March 31, December 31, March 31, December 31, 2018 2017 2018 2017 2018 2017 Performing $ 192,736 $ 172,291 $ 649,662 $ 637,662 $ 610,303 $ 645,366 Non-performing — — 686 929 3,434 3,013 Total $ 192,736 $ 172,291 $ 650,348 $ 638,591 $ 613,737 $ 648,379 Consumer – credit card Consumer – other Leases March 31, December 31, March 31, December 31, March 31, December 31, 2018 2017 2018 2017 2018 2017 Performing $ 229,221 $ 252,385 $ 199,302 $ 151,747 $ 23,151 $ 23,967 Non-performing 393 312 22 36 — — Total $ 229,614 $ 252,697 $ 199,324 $ 151,783 $ 23,151 $ 23,967
Rollforward of Allowance for Loan Losses by Portfolio Segment	This table provides a rollforward of the allowance for loan losses by portfolio segment for the three months ended March 31, 2018 (in thousands): Three Months Ended March 31, 2018 Commercial Real estate Consumer Leases Total Allowance for loan losses: Beginning balance $ 81,156 $ 9,312 $ 10,083 $ 53 $ 100,604 Charge-offs (7,318 ) (1,742 ) (2,700 ) — (11,760 ) Recoveries 471 230 757 — 1,458 Provision 6,748 1,938 1,320 (6 ) 10,000 Ending balance $ 81,057 $ 9,738 $ 9,460 $ 47 $ 100,302 Ending balance: individually evaluated for impairment $ 4,986 $ 127 $ — $ — $ 5,113 Ending balance: collectively evaluated for impairment 76,071 9,611 9,460 47 95,189 Loans: Ending balance: loans $ 5,242,307 $ 5,764,398 $ 428,938 $ 23,151 $ 11,458,794 Ending balance: individually evaluated for impairment 48,190 15,344 — — 63,534 Ending balance: collectively evaluated for impairment 5,194,117 5,749,054 428,938 23,151 11,395,260 This table provides a rollforward of the allowance for loan losses by portfolio segment for the three months ended March 31, 2017 (in thousands): Three Months Ended March 31, 2017 Commercial Real estate Consumer Leases Total Allowance for loan losses: Beginning balance $ 71,657 $ 10,569 $ 9,311 $ 112 $ 91,649 Charge-offs (5,981 ) (186 ) (2,537 ) — (8,704 ) Recoveries 698 61 619 — 1,378 Provision 6,823 68 2,117 (8 ) 9,000 Ending balance $ 73,197 $ 10,512 $ 9,510 $ 104 $ 93,323 Ending balance: individually evaluated for impairment 8,173 67 $ — $ — 8,240 Ending balance: collectively evaluated for impairment 65,024 10,445 9,510 104 85,083 Loans: Ending balance: loans $ 5,100,988 $ 5,262,356 $ 355,209 $ 38,683 $ 10,757,236 Ending balance: individually evaluated for impairment 69,314 18,136 33 — 87,483 Ending balance: collectively evaluated for impairment 5,031,674 5,244,220 355,176 38,683 10,669,753
Analysis of Impaired Loans	This table provides an analysis of impaired loans by class at March 31, 2018 and December 31, 2017 (in thousands): As of March 31, 2018 Unpaid Principal Balance Recorded Investment with No Allowance Recorded Investment with Allowance Total Recorded Investment Related Allowance Average Recorded Investment Commercial: Commercial $ 69,419 $ 24,597 $ 23,049 $ 47,646 $ 4,986 $ 54,319 Asset-based — — — — — — Factoring — 544 — 544 — 687 Commercial – credit card — — — — — — Real estate: Real estate – construction 108 93 — 93 — 93 Real estate – commercial 20,727 10,679 4,361 15,040 52 13,742 Real estate – residential 219 114 97 211 75 314 Real estate – HELOC — — — — — — Consumer: Consumer – credit card — — — — — — Consumer – other — — — — — — Leases — — — — — — Total $ 90,473 $ 36,027 $ 27,507 $ 63,534 $ 5,113 $ 69,155 As of December 31, 2017 Unpaid Principal Balance Recorded Investment with No Allowance Recorded Investment with Allowance Total Recorded Investment Related Allowance Average Recorded Investment Commercial: Commercial $ 84,749 $ 44,525 $ 16,465 $ 60,990 $ 6,299 $ 65,385 Asset-based — — — — — — Factoring 830 — 830 830 306 207 Commercial – credit card — — — — — — Real estate: Real estate – construction 108 93 — 93 — 148 Real estate – commercial 16,284 7,968 4,477 12,445 3 10,506 Real estate – residential 427 321 97 418 75 221 Real estate – HELOC — — — — — — Consumer: Consumer – credit card — — — — — — Consumer – other — — — — — 8 Leases — — — — — — Total $ 102,398 $ 52,907 $ 21,869 $ 74,776 $ 6,683 $ 76,475

Securities (Tables)

Securities (Tables)	3 Months Ended
	Mar. 31, 2018
Securities Available for Sale	This table provides detailed information about securities available for sale at March 31, 2018 and December 31, 2017 (in thousands): March 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury $ 40,095 $ — $ (1,899 ) $ 38,196 U.S. Agencies 3,774 — (5 ) 3,769 Mortgage-backed 3,835,039 1,019 (120,665 ) 3,715,393 State and political subdivisions 2,415,196 3,612 (38,299 ) 2,380,509 Corporates 1,485 — (6 ) 1,479 Total $ 6,295,589 $ 4,631 $ (160,874 ) $ 6,139,346 December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury $ 40,092 $ — $ (1,449 ) $ 38,643 U.S. Agencies 14,762 — (10 ) 14,752 Mortgage-backed 3,719,369 1,914 (72,040 ) 3,649,243 State and political subdivisions 2,546,517 11,965 (15,809 ) 2,542,673 Corporates 13,278 — (12 ) 13,266 Total $ 6,334,018 $ 13,879 $ (89,320 ) $ 6,258,577
Gross Unrealized Losses and Fair Value of Investment Securities Available for Sale	The following table shows the Company’s available for sale investments’ gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at March 31, 2018 and December 31, 2017 (in thousands): Less than 12 months 12 months or more Total March 31, 2018 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Description of Securities U.S. Treasury $ 9,808 $ (117 ) $ 28,387 $ (1,782 ) $ 38,195 $ (1,899 ) U.S. Agencies 3,571 (5 ) — — 3,571 (5 ) Mortgage-backed 2,085,580 (47,831 ) 1,471,848 (72,834 ) 3,557,428 (120,665 ) State and political subdivisions 1,534,275 (21,958 ) 360,967 (16,341 ) 1,895,242 (38,299 ) Corporates 1,479 (6 ) — — 1,479 (6 ) Total temporarily-impaired debt securities available for sale $ 3,634,713 $ (69,917 ) $ 1,861,202 $ (90,957 ) $ 5,495,915 $ (160,874 ) Less than 12 months 12 months or more Total December 31, 2017 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Description of Securities U.S. Treasury $ 9,851 $ (64 ) $ 28,792 $ (1,385 ) $ 38,643 $ (1,449 ) U.S. Agencies 14,553 (10 ) — — 14,553 (10 ) Mortgage-backed 1,990,006 (19,980 ) 1,562,333 (52,060 ) 3,552,339 (72,040 ) State and political subdivisions 1,076,930 (7,325 ) 376,560 (8,484 ) 1,453,490 (15,809 ) Corporates 13,266 (12 ) — — 13,266 (12 ) Total temporarily-impaired debt securities available for sale $ 3,104,606 $ (27,391 ) $ 1,967,685 $ (61,929 ) $ 5,072,291 $ (89,320 )
Schedule of Federal Reserve Bank Stock and Federal Home Loan Bank Stock and Other Securities	The table below provides detailed information for FRB stock and Federal Home Loan Bank (FHLB) stock and other securities at March 31, 2018 and December 31, 2017 (in thousands): Gross Gross Amortized Unrealized Unrealized Fair March 31, 2018 Cost Gains Losses Value FRB and FHLB stock $ 33,262 $ — $ — $ 33,262 Other securities – marketable 3 4,733 — 4,736 Other securities – non-marketable 25,888 3,522 — 29,410 Total Other securities $ 59,153 $ 8,255 $ — $ 67,408 Gross Gross Amortized Unrealized Unrealized Fair December 31, 2017 Cost Gains Losses Value FRB and FHLB stock $ 33,262 $ — $ — $ 33,262 Other securities – marketable 3 4,637 — 4,640 Other securities – non-marketable 26,606 1,389 — 27,995 Total Other securities $ 59,871 $ 6,026 $ — $ 65,897
Available-for-sale Securities [Member]
Contractual Maturity Information	The following table presents contractual maturity information for securities available for sale at March 31, 2018 (in thousands): Amortized Fair Cost Value Due in 1 year or less $ 306,247 $ 306,019 Due after 1 year through 5 years 1,064,499 1,056,930 Due after 5 years through 10 years 777,352 758,232 Due after 10 years 312,452 302,772 Total 2,460,550 2,423,953 Mortgage-backed securities 3,835,039 3,715,393 Total securities available for sale $ 6,295,589 $ 6,139,346
Held-to-maturity Securities [Member]
Contractual Maturity Information	The following table shows the Company’s held to maturity investments’ amortized cost, fair value, and gross unrealized gains and losses at March 31, 2018 and December 31, 2017, respectively (in thousands): Gross Gross Amortized Unrealized Unrealized Fair March 31, 2018 Cost Gains Losses Value State and political subdivisions: Due in 1 year or less $ 3,883 $ — $ (105 ) $ 3,778 Due after 1 year through 5 years 106,522 258 (6,386 ) 100,394 Due after 5 years through 10 years 352,349 4,692 (17,169 ) 339,872 Due after 10 years 783,712 6,217 (76,346 ) 713,583 Total state and political subdivisions $ 1,246,466 $ 11,167 $ (100,006 ) $ 1,157,627 Gross Gross Amortized Unrealized Unrealized Fair December 31, 2017 Cost Gains Losses Value State and political subdivisions: Due in 1 year or less $ 2,275 $ 3 $ (24 ) $ 2,254 Due after 1 year through 5 years 100,648 3,111 (2,834 ) 100,925 Due after 5 years through 10 years 372,234 5,006 (14,117 ) 363,123 Due after 10 years 785,857 6,952 (51,664 ) 741,145 Total state and political subdivisions $ 1,261,014 $ 15,072 $ (68,639 ) $ 1,207,447

Goodwill and Other Intangibles

Goodwill and Other Intangibles (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill	Changes in the carrying amount of goodwill for the periods ended March 31, 2018 and December 31, 2017 by reportable segment are as follows (in thousands): Commercial Banking Institutional Banking Personal Banking Healthcare Services Total Balances as of January 1, 2018 $ 59,419 $ 51,332 $ 70,116 $ — $ 180,867 Balances as of March 31, 2018 $ 59,419 $ 51,332 $ 70,116 $ — $ 180,867 Balances as of January 1, 2017 $ 59,419 $ 98,861 $ 70,116 $ — $ 228,396 Discontinued assets ─ goodwill and other intangibles, net — (47,529 ) — — (47,529 ) Balances as of December 31, 2017 $ 59,419 $ 51,332 $ 70,116 $ — $ 180,867
Changes in Intangible Assets	The following table lists the finite-lived intangible assets that continue to be subject to amortization as of March 31, 2018 and December 31, 2017 (in thousands) As of March 31, 2018 Core Deposit Intangible Assets Customer Relationships Other Intangible Assets Total Gross carrying amount $ 50,059 $ 71,342 $ 3,254 $ 124,655 Accumulated amortization 42,990 59,716 3,254 105,960 Net carrying amount $ 7,069 $ 11,626 $ — $ 18,695 As of December 31, 2017 Core Deposit Intangible Assets Customer Relationships Other Intangible Assets Total Gross carrying amount $ 50,059 $ 71,342 $ 3,254 $ 124,655 Accumulated amortization 42,209 58,935 3,254 104,398 Net carrying amount $ 7,850 $ 12,407 $ — $ 20,257
Aggregate Amortization Expense Recognized	The following table has the aggregate amortization expense recognized in each period (in thousands) Three Months Ended March 31, 2018 2017 Aggregate amortization expense $ 1,562 $ 2,046
Estimated Amortization Expense of Intangible Assets	The following table lists estimated amortization expense of intangible assets in future periods (in thousands): For the nine months ending December 31, 2018 $ 4,151 For the year ending December 31, 2019 4,714 For the year ending December 31, 2020 3,759 For the year ending December 31, 2021 2,755 For the year ending December 31, 2022 1,815 For the year ending December 31, 2023 1,097

Securities Sold Under Agreeme27

Securities Sold Under Agreements to Repurchase (Tables)	3 Months Ended
	Mar. 31, 2018
Repurchase Agreements
Remaining Contractual Maturities Of Repurchase Agreements	The table below presents the remaining contractual maturities of repurchase agreements outstanding at March 31, 2018, in addition to the various types of marketable securities that have been pledged as collateral for these borrowings (in thousands): As of March 31, 2018 Remaining Contractual Maturities of the Agreements Repurchase agreements, secured by: On Demand 2-29 Days Over 90 Days Total U.S. Treasury $ — $ 17,700 $ — $ 17,700 U.S. Agencies — 1,302,756 3,000 1,305,756 Total repurchase agreements $ — $ 1,320,456 $ 3,000 $ 1,323,456

Business Segment Reporting (Tab

Business Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Line of Business Segment Financial Results	Business Segment financial results were as follows for the three months ended March 31, 2018 and March 31, 2017 (in thousands): Three Months Ended March 31, 2018 Commercial Banking Institutional Banking Personal Banking Healthcare Services Total Net interest income $ 91,968 $ 15,744 $ 30,920 $ 9,290 $ 147,922 Provision for loan losses 7,978 350 1,672 — 10,000 Noninterest income 20,598 45,419 30,714 8,794 105,525 Noninterest expense 62,246 46,833 54,994 11,803 175,876 Income before taxes 42,342 13,980 4,968 6,281 67,571 Income tax expense 6,284 2,080 738 936 10,038 Income from continuing operations $ 36,058 $ 11,900 $ 4,230 $ 5,345 $ 57,533 Average assets $ 9,785,000 $ 3,826,000 $ 4,982,000 $ 2,154,000 $ 20,747,000 Three Months Ended March 31, 2017 Commercial Banking Institutional Banking Personal Banking Healthcare Services Total Net interest income $ 85,390 $ 11,582 $ 30,075 $ 7,268 $ 134,315 Provision for loan losses 6,820 469 1,711 — 9,000 Noninterest income 19,206 45,666 28,536 9,509 102,917 Noninterest expense 62,750 44,778 55,997 10,285 173,810 Income before taxes 35,026 12,001 903 6,492 54,422 Income tax expense 8,007 2,734 224 1,481 12,446 Income from continuing operations $ 27,019 $ 9,267 $ 679 $ 5,011 $ 41,976 Average assets $ 9,611,000 $ 3,466,000 $ 5,347,000 $ 1,810,000 $ 20,234,000

Revenue Recognition (Tables)

Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue From Contract With Customer [Abstract]
Summary of Disaggregation of Revenue According to Revenue Stream and Business Segment	The following table depicts the disaggregation of revenue according to revenue stream and Business Segment for the three months ended March 31, 2018 and March 31, 2017 (in thousands): Three Months Ended March 31, 2018 NONINTEREST INCOME Commercial Banking Institutional Banking Personal Banking Healthcare Services Revenue (Expense) out of Scope of ASU 606 Total Trust and securities processing $ — $ 27,696 $ 16,306 $ — $ — $ 44,002 Trading and investment banking — — — — 4,101 4,101 Service charges on deposit accounts 7,791 7,230 2,812 4,038 34 21,905 Insurance fees and commissions — — 301 — — 301 Brokerage fees 52 4,060 2,241 — — 6,353 Bankcard fees 14,797 1,635 5,313 4,304 (7,926 ) 18,123 Gains on sales of securities available for sale, net — — — — 139 139 Other 454 120 906 149 8,972 10,601 Total Noninterest income $ 23,094 $ 40,741 $ 27,879 $ 8,491 $ 5,320 $ 105,525 Three Months Ended March 31, 2017 NONINTEREST INCOME Commercial Banking Institutional Banking Personal Banking Healthcare Services Revenue (Expense) out of Scope of ASU 606 Total Trust and securities processing $ — $ 26,517 $ 16,024 $ — $ — $ 42,541 Trading and investment banking — 505 — — 7,037 7,542 Service charges on deposit accounts 8,021 7,355 2,865 3,804 30 22,075 Insurance fees and commissions — — 646 — — 646 Brokerage fees 40 3,256 2,081 — — 5,377 Bankcard fees 12,148 1,505 5,438 5,223 (6,562 ) 17,752 Gains on sales of securities available for sale, net — — — — 468 468 Other 489 163 764 76 5,024 6,516 Total Noninterest income $ 20,698 $ 39,301 $ 27,818 $ 9,103 $ 5,997 $ 102,917

Commitments, Contingencies an30

Commitments, Contingencies and Guarantees (Tables)	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Notional Amount of Off-Balance Sheet Financial Instruments	The following table summarizes the Company’s off-balance sheet financial instruments (in thousands) : Contract or Notional Amount March 31, December 31, 2018 2017 Commitments to extend credit for loans (excluding credit card loans) $ 6,245,306 $ 6,689,467 Commitments to extend credit under credit card loans 3,007,843 2,975,507 Commercial letters of credit 5,059 813 Standby letters of credit 321,748 316,054 Forward contracts 25,365 29,007 Spot foreign exchange contracts 4,575 628

Derivatives and Hedging Activ31

Derivatives and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Summary of Fair Value of Derivative Assets and Liabilities	This table provides a summary of the fair value of the Company’s derivative assets and liabilities as of March 31, 2018 and December 31, 2017 ( in thousands Derivative Assets Derivative Liabilities March 31, December 31, March 31, December 31, Fair Value 2018 2017 2018 2017 Interest Rate Products: Derivatives not designated as hedging instruments $ 7,424 $ 10,116 $ 6,347 $ 7,326 Derivatives designated as hedging instruments — 33 31 1,580 Total $ 7,424 $ 10,149 $ 6,378 $ 8,906
Summary of Amount of Gain (Loss) Recognized in Other Non-Interest Expense in Consolidated Statements of Income Related to Derivative Assets and Liabilities	This table provides a summary of the amount of gain or loss recognized in Other noninterest expense in the Consolidated Statements of Income related to the Company’s derivative assets and liabilities for the three months ended March 31, 2018 and March 31, 2017 (in thousands) Amount of Gain (Loss) Recognized For the Three Months Ended March 31, March 31, 2018 2017 Interest Rate Products Derivatives not designated as hedging instruments $ 336 $ (348 ) Total $ 336 $ (348 ) Interest Rate Products Derivatives designated as hedging instruments: Fair value adjustments on derivatives $ 81 $ (46 ) Fair value adjustments on hedged items (81 ) 46 Total $ — $ —
Summary of Amount of Loss Recognized in AOCI in Consolidated Statements of Comprehensive Income Related to Company's Derivative Assets and Liabilities	This table provides a summary of the amount of gain or loss recognized in AOCI in the Consolidated Statements of Comprehensive Income related to the Company’s derivative assets and liabilities for the three months ended March 31, 2018 and March 31, 2017 (in thousands) Amount of Gain Recognized in Other Comprehensive Income on Derivatives For the Three Months Ended March 31, March 31, Derivatives in Cash Flow Hedging Relationships 2018 2017 Interest Rate Products Derivatives designated as cash flow hedging instruments $ 2,202 $ 246 Total $ 2,202 $ 246

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	Assets measured at fair value on a recurring basis as of March 31, 2018 and December 31, 2017 (in thousands): Fair Value Measurement at March 31, 2018 Description March 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets U.S. Treasury $ 497 $ 497 $ — $ — U.S. Agencies 5,188 — 5,188 — Mortgage-backed 634 — 634 — State and political subdivisions 36,386 — 36,386 — Corporates 8,517 8,517 — — Trading – other 14,167 12,262 1,905 — Trading securities 65,389 21,276 44,113 — U.S. Treasury 38,196 38,196 — — U.S. Agencies 3,769 — 3,769 — Mortgage-backed 3,715,393 — 3,715,393 — State and political subdivisions 2,380,509 — 2,380,509 — Corporates 1,479 1,479 — — Available for sale securities 6,139,346 39,675 6,099,671 — Company-owned life insurance 55,711 — 55,711 — Bank-owned life insurance 267,747 — 267,747 — Derivatives 7,424 — 7,424 — Total $ 6,535,617 $ 60,951 $ 6,474,666 $ — Liabilities Deferred compensation $ 53,125 $ 53,125 $ — $ — Derivatives 6,378 — 6,378 — Securities sold not yet purchased 9,507 — 9,507 — Total $ 69,010 $ 53,125 $ 15,885 $ — Fair Value Measurement at December 31, 2017 Description December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets U.S. Treasury $ 18 $ 18 $ — $ — U.S. Agencies 9,976 — 9,976 — Mortgage-backed 1,949 — 1,949 — State and political subdivisions 27,114 — 27,114 — Corporates 1,885 1,885 — — Trading – other 13,113 12,434 679 — Trading securities 54,055 14,337 39,718 — U.S. Treasury 38,643 38,643 — — U.S. Agencies 14,752 — 14,752 — Mortgage-backed 3,649,243 — 3,649,243 — State and political subdivisions 2,542,673 — 2,542,673 — Corporates 13,266 13,266 — — Available for sale securities 6,258,577 51,909 6,206,668 — Company-owned life insurance 53,577 — 53,577 — Bank-owned life insurance 265,823 — 265,823 — Derivatives 10,149 — 10,149 — Total $ 6,642,181 $ 66,246 $ 6,575,935 $ — Liabilities Deferred compensation $ 50,963 $ 50,963 $ — $ — Derivatives 8,906 — 8,906 — Securities sold not yet purchased 4,130 — 4,130 — Total $ 63,999 $ 50,963 $ 13,036 $ —
Assets Measured at Fair Value on Non-Recurring Basis	Assets measured at fair value on a non-recurring basis as of March 31, 2018 and December 31, 2017 (in thousands): Fair Value Measurement at March 31, 2018 Using Description March 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Gains Recognized During the Three Months Ended March 31 Impaired loans $ 22,394 $ — $ — $ 22,394 $ 1,570 Other real estate owned 93 — — 93 — Total $ 22,487 $ — $ — $ 22,487 $ 1,570 Fair Value Measurement at December 31, 2017 Using Description December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Gains Recognized During the Twelve Months Ended December 31 Impaired loans $ 15,186 $ — $ — $ 15,186 $ 1,251 Other real estate owned 1,488 — — 1,488 13 Total $ 16,674 $ — $ — $ 16,674 $ 1,264
Estimated Fair Value of Financial Instruments	The estimated fair value of the Company’s financial instruments at March 31, 2018 and December 31, 2017 are as follows (in thousands): Fair Value Measurement at March 31, 2018 Using Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Estimated Fair Value FINANCIAL ASSETS Cash and short-term investments $ 1,078,209 $ 965,247 $ 112,962 $ — $ 1,078,209 Securities available for sale 6,139,346 39,675 6,099,671 — 6,139,346 Securities held to maturity 1,246,466 — 1,157,627 — 1,157,627 Trading securities 65,389 21,276 44,113 — 65,389 Other securities 67,408 — 67,408 — 67,408 Loans (exclusive of allowance for loan loss) 11,463,380 — 11,460,851 — 11,460,851 Derivatives 7,424 — 7,424 — 7,424 FINANCIAL LIABILITIES Demand and savings deposits 16,231,085 16,231,085 — — 16,231,085 Time deposits 987,179 — 987,179 — 987,179 Other borrowings 1,354,615 31,159 1,323,456 — 1,354,615 Long-term debt 78,687 — 78,940 — 78,940 Derivatives 6,378 — 6,378 — 6,378 OFF-BALANCE SHEET ARRANGEMENTS Commitments to extend credit for loans 1,544 Commercial letters of credit 17 Standby letters of credit 647 Fair Value Measurement at December 31, 2017 Using Carrying Amount Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Estimated Fair Value FINANCIAL ASSETS Cash and short-term investments $ 1,936,084 $ 1,749,618 $ 186,466 $ — $ 1,936,084 Securities available for sale 6,258,577 51,909 6,206,668 — 6,258,577 Securities held to maturity 1,261,014 — 1,207,447 — 1,207,447 Trading securities 54,055 14,337 39,718 — 54,055 Other securities 65,897 — 65,897 — 65,897 Loans (exclusive of allowance for loan loss) 11,281,973 — 11,318,764 — 11,318,764 Derivatives 10,149 — 10,149 — 10,149 FINANCIAL LIABILITIES Demand and savings deposits 16,742,736 16,742,736 — — 16,742,736 Time deposits 1,280,264 — 1,280,264 — 1,280,264 Other borrowings 1,260,704 11,334 1,249,370 — 1,260,704 Long-term debt 79,281 — 79,496 — 79,496 Derivatives 8,906 — 8,906 — 8,906 OFF-BALANCE SHEET ARRANGEMENTS Commitments to extend credit for loans 6,654 Commercial letters of credit 136 Standby letters of credit 2,514

Divestitures (Tables)

Divestitures (Tables)	3 Months Ended
	Mar. 31, 2018
Discontinued Operations And Disposal Groups [Abstract]
Schedule of Components of (Loss) Income from Discontinued Operations, Net of Taxes and Consolidated Statements of Cash Flows	This table summarizes the components of (loss) income from discontinued operations, net of taxes, for the three months ended March 31, 2018 and March 31, 2017 presented in the Consolidated Statements of Income (in thousands) For the Three Months Ended March 31, 2018 March 31, 2017 Total noninterest income $ — $ 17,863 Total noninterest expense 917 14,956 (Loss) income from discontinued operations (917 ) 2,907 Income tax (benefit) expense (170 ) 702 Net (loss) income on discontinued operations $ (747 ) $ 2,205 The components of net cash provided by operating activities of discontinued operations included in the Consolidated Statements of Cash Flows are as follows (in thousands) Three Months Ended March 31, 2018 2017 (Loss) income from discontinued operations $ (747 ) $ 2,205 Depreciation and amortization — 824 Net cash provided by operating activities of discontinued operations $ (747 ) $ 3,029

Financial Statement Presentat34

Financial Statement Presentation - Additional Information (Detail) $ in Millions	Nov. 17, 2017USD ($)
Scout Investments Inc [Member]
Consideration received on sale of stock of subsidiaries	$ 172.5

Summary of Cash and Cash Equiva

Summary of Cash and Cash Equivalents (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Due from the FRB	$ 649,616		$ 322,959
Cash and due from banks	279,838	$ 392,723	373,671
Cash and cash equivalents at end of period	$ 929,454	$ 1,716,262	$ 696,630	$ 1,063,967

Summary of Significant Accoun36

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accounting Policies [Abstract]
Interest bearing amounts held at other financial institutions	$ 21.5	$ 51.6
Dilutive effect of common stock issuable upon exercise of options and nonvested restricted shares	496,848	719,637
Anti-dilutive shares	141,870	151,002

New Accounting Pronouncements -

New Accounting Pronouncements - Additional Information (Detail) - USD ($) $ in Thousands	Jan. 01, 2018	Feb. 28, 2018
Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment	$ 132
Accounting Standards Update 2017-12 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment	$ 13
Accounting Standards Update 2018-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassified stranded tax effects from AOCI to retained earnings		$ 12,900

Summary of Loan Classes and Agi

Summary of Loan Classes and Aging of Past Due Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	$ 86,670	$ 86,369
Non- Accrual Loans	67,604	59,142
Current	11,372,124	11,194,144
Total Loans	11,458,794	11,280,513	$ 10,757,236
30-89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	13,416	24,136
Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	5,650	3,091
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	428,938		355,209
Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	23,151	23,967
Total Loans	23,151	23,967	$ 38,683
Prime [Member] | Real estate - residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	718	1,720
Non- Accrual Loans	686	929
Current	649,630	636,871
Total Loans	650,348	638,591
Prime [Member] | Real estate - residential [Member] | 30-89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	32	791
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	53,749	50,532
Non- Accrual Loans	44,253	38,644
Current	4,415,694	4,502,508
Total Loans	4,469,443	4,553,040
Commercial [Member] | 30-89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	7,988	11,216
Commercial [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	1,508	672
Asset-based [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	345,980	336,614
Total Loans	345,980	336,614
Factoring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	234,148	221,672
Total Loans	234,148	221,672
Commercial - credit card [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	694	466
Current	192,042	171,825
Total Loans	192,736	172,291
Commercial - credit card [Member] | 30-89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	640	387
Commercial - credit card [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	54	79
Construction [Member] | Real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	195	7,002
Non- Accrual Loans		93
Current	789,650	710,847
Total Loans	789,845	717,849
Construction [Member] | Real estate [Member] | 30-89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	195	6,666
Construction [Member] | Real estate [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		243
Real estate - commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	23,018	16,947
Non- Accrual Loans	18,816	16,115
Current	3,687,450	3,546,683
Total Loans	3,710,468	3,563,630
Real estate - commercial [Member] | 30-89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	2,294	832
Real estate - commercial [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	1,908
Real estate - HELOC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	3,521	4,267
Non- Accrual Loans	3,434	3,013
Current	610,216	644,112
Total Loans	613,737	648,379
Real estate - HELOC [Member] | 30-89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	87	1,254
Credit card [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	4,445	4,524
Non- Accrual Loans	393	312
Current	225,169	248,173
Total Loans	229,614	252,697
Credit card [Member] | Consumer [Member] | 30-89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	1,914	2,155
Credit card [Member] | Consumer [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	2,138	2,057
Other [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	330	911
Non- Accrual Loans	22	36
Current	198,994	150,872
Total Loans	199,324	151,783
Other [Member] | Consumer [Member] | 30-89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	266	835
Other [Member] | Consumer [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due	$ 42	$ 40

Loans and Allowance for Loan 39

Loans and Allowance for Loan Losses - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)
Financing Receivable, Allowance for Credit Losses [Line Items]
Proceeds from sales of loans held for sale	$ 9,664,000	$ 14,462,000
Non- Accrual Loans	67,604,000		$ 59,142,000
Restructured loans	20,700,000		41,000,000
Total Past Due	86,670,000		86,369,000
Commitments to lend to borrowers with loan modifications classified as TDR's	$ 0	$ 24,000
Number of Contracts	0
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Non- Accrual Loans	$ 44,253,000		38,644,000
Total Past Due	$ 53,749,000		50,532,000
Number of Contracts		1
Pre-Modification Outstanding Recorded Investment		$ 7,200,000
Post-Modification Outstanding Recorded Investment		$ 7,200,000
Revolving Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of days past due to consider loan as a loss and charged off	90 days
Closed-End Retail Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of days past due to consider loan as a loss and charged off	120 days
Open-End Retail Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of days past due to consider loan as a loss and charged off	180 days
Greater than 90 days Past Due and Accruing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total Past Due	$ 5,650,000		3,091,000
Greater than 90 days Past Due and Accruing [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total Past Due	$ 1,508,000		$ 672,000

Credit Risk Profile by Risk Rat

Credit Risk Profile by Risk Rating - Originated and Non-PCI Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	$ 11,458,794	$ 11,280,513	$ 10,757,236
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	4,469,443	4,553,040
Commercial [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	4,469,443	4,553,040
Asset-based [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	345,980	336,614
Asset-based [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	345,980	336,614
Factoring [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	234,148	221,672
Factoring [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	234,148	221,672
Real estate - construction [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	789,845	717,849
Real estate - commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	3,710,468	3,563,630
Real estate - commercial [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	3,710,468	3,563,630
Non-watch list [Member] | Commercial [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	3,914,518	4,048,238
Non-watch list [Member] | Asset-based [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	287,754	306,899
Non-watch list [Member] | Factoring [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	233,291	220,795
Non-watch list [Member] | Real estate - construction [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	787,898	716,830
Non-watch list [Member] | Real estate - commercial [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	3,562,117	3,434,982
Watch [Member] | Commercial [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	206,883	162,788
Watch [Member] | Real estate - construction [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	1,725	631
Watch [Member] | Real estate - commercial [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	74,060	50,715
Special Mention [Member] | Commercial [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	128,015	106,638
Special Mention [Member] | Asset-based [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	58,226	29,715
Special Mention [Member] | Factoring [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	282	47
Special Mention [Member] | Real estate - commercial [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	27,843	35,940
Substandard [Member] | Commercial [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	220,027	235,376
Substandard [Member] | Factoring [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	575	830
Substandard [Member] | Real estate - construction [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	222	388
Substandard [Member] | Real estate - commercial [Member] | Originated and Non-PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	$ 46,448	$ 41,993

Credit Risk Profile Based on Pa

Credit Risk Profile Based on Payment Activity - Originated and Non-PCI Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	$ 11,458,794	$ 11,280,513	$ 10,757,236
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	428,938		355,209
Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	23,151	23,967	$ 38,683
Commercial - credit card [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	192,736	172,291
Real estate - HELOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	613,737	648,379
Credit card [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	229,614	252,697
Other [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	199,324	151,783
Originated and Non-PCI Loans [Member] | Real estate - residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	650,348	638,591
Originated and Non-PCI Loans [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	23,151	23,967
Originated and Non-PCI Loans [Member] | Commercial - credit card [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	192,736	172,291
Originated and Non-PCI Loans [Member] | Real estate - HELOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	613,737	648,379
Originated and Non-PCI Loans [Member] | Credit card [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	229,614	252,697
Originated and Non-PCI Loans [Member] | Other [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	199,324	151,783
Originated and Non-PCI Loans [Member] | Performing [Member] | Real estate - residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	649,662	637,662
Originated and Non-PCI Loans [Member] | Performing [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	23,151	23,967
Originated and Non-PCI Loans [Member] | Performing [Member] | Commercial - credit card [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	192,736	172,291
Originated and Non-PCI Loans [Member] | Performing [Member] | Real estate - HELOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	610,303	645,366
Originated and Non-PCI Loans [Member] | Performing [Member] | Credit card [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	229,221	252,385
Originated and Non-PCI Loans [Member] | Performing [Member] | Other [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	199,302	151,747
Originated and Non-PCI Loans [Member] | Non-performing [Member] | Real estate - residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	686	929
Originated and Non-PCI Loans [Member] | Non-performing [Member] | Real estate - HELOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	3,434	3,013
Originated and Non-PCI Loans [Member] | Non-performing [Member] | Credit card [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	393	312
Originated and Non-PCI Loans [Member] | Non-performing [Member] | Other [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	$ 22	$ 36

Rollforward of Allowance for Lo

Rollforward of Allowance for Loan Losses by Portfolio Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	$ 100,604	$ 91,649
Charge-offs	(11,760)	(8,704)
Recoveries	1,458	1,378
Provision	10,000	9,000
Ending balance	100,302	93,323
Ending balance: individually evaluated for impairment	5,113	8,240	$ 6,683
Ending balance: collectively evaluated for impairment	95,189	85,083
Ending balance: loans	11,458,794	10,757,236
Ending balance: individually evaluated for impairment	63,534	87,483
Ending balance: collectively evaluated for impairment	11,395,260	10,669,753
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	81,156	71,657
Charge-offs	(7,318)	(5,981)
Recoveries	471	698
Provision	6,748	6,823
Ending balance	81,057	73,197
Ending balance: individually evaluated for impairment	4,986	8,173
Ending balance: collectively evaluated for impairment	76,071	65,024
Ending balance: loans	5,242,307	5,100,988
Ending balance: individually evaluated for impairment	48,190	69,314
Ending balance: collectively evaluated for impairment	5,194,117	5,031,674
Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	9,312	10,569
Charge-offs	(1,742)	(186)
Recoveries	230	61
Provision	1,938	68
Ending balance	9,738	10,512
Ending balance: individually evaluated for impairment	127	67
Ending balance: collectively evaluated for impairment	9,611	10,445
Ending balance: loans	5,764,398	5,262,356
Ending balance: individually evaluated for impairment	15,344	18,136
Ending balance: collectively evaluated for impairment	5,749,054	5,244,220
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	10,083	9,311
Charge-offs	(2,700)	(2,537)
Recoveries	757	619
Provision	1,320	2,117
Ending balance	9,460	9,510
Ending balance: collectively evaluated for impairment	9,460	9,510
Ending balance: loans	428,938	355,209
Ending balance: individually evaluated for impairment		33
Ending balance: collectively evaluated for impairment	428,938	355,176
Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	53	112
Provision	(6)	(8)
Ending balance	47	104
Ending balance: collectively evaluated for impairment	47	104
Ending balance: loans	23,151	38,683
Ending balance: collectively evaluated for impairment	$ 23,151	$ 38,683

Analysis of Impaired Loans by C

Analysis of Impaired Loans by Class (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	$ 90,473	$ 102,398
Recorded Investment with No Allowance	36,027	52,907
Recorded Investment with Allowance	27,507	21,869
Total Recorded Investment	63,534	74,776
Related Allowance	5,113	6,683	$ 8,240
Average Recorded Investment	69,155	76,475
Real estate - residential [Member] | Prime [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	219	427
Recorded Investment with No Allowance	114	321
Recorded Investment with Allowance	97	97
Total Recorded Investment	211	418
Related Allowance	75	75
Average Recorded Investment	314	221
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	69,419	84,749
Recorded Investment with No Allowance	24,597	44,525
Recorded Investment with Allowance	23,049	16,465
Total Recorded Investment	47,646	60,990
Related Allowance	4,986	6,299
Average Recorded Investment	54,319	65,385
Factoring [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		830
Recorded Investment with No Allowance	544
Recorded Investment with Allowance		830
Total Recorded Investment	544	830
Related Allowance		306
Average Recorded Investment	687	207
Construction [Member] | Real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	108	108
Recorded Investment with No Allowance	93	93
Total Recorded Investment	93	93
Average Recorded Investment	93	148
Real estate - commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	20,727	16,284
Recorded Investment with No Allowance	10,679	7,968
Recorded Investment with Allowance	4,361	4,477
Total Recorded Investment	15,040	12,445
Related Allowance	52	3
Average Recorded Investment	$ 13,742	10,506
Other [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment		$ 8

Securities Available for Sale (

Securities Available for Sale (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 6,295,589	$ 6,334,018
Gross Unrealized Gains	4,631	13,879
Gross Unrealized Losses	(160,874)	(89,320)
Available for sale	6,139,346	6,258,577
U.S. Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	40,095	40,092
Gross Unrealized Losses	(1,899)	(1,449)
Available for sale	38,196	38,643
U.S. Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,774	14,762
Gross Unrealized Losses	(5)	(10)
Available for sale	3,769	14,752
Mortgage-backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,835,039	3,719,369
Gross Unrealized Gains	1,019	1,914
Gross Unrealized Losses	(120,665)	(72,040)
Available for sale	3,715,393	3,649,243
State and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,415,196	2,546,517
Gross Unrealized Gains	3,612	11,965
Gross Unrealized Losses	(38,299)	(15,809)
Available for sale	2,380,509	2,542,673
Corporates [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,485	13,278
Gross Unrealized Losses	(6)	(12)
Available for sale	$ 1,479	$ 13,266

Summary of Contractual Maturity

Summary of Contractual Maturity Information for Securities Available for Sale (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Due in 1 year or less, Amortized Cost	$ 306,247
Due after 1 year through 5 years, Amortized Cost	1,064,499
Due after 5 years through 10 years, Amortized Cost	777,352
Due after 10 years, Amortized Cost	312,452
Total, Amortized Cost	2,460,550
Mortgage-backed securities, Amortized Cost	3,835,039
Amortized Cost	6,295,589	$ 6,334,018
Due in 1 year or less, Fair Value	306,019
Due after 1 year through 5 years, Fair Value	1,056,930
Due after 5 years through 10 years, Fair Value	758,232
Due after 10 years, Fair Value	302,772
Total, Fair Value	2,423,953
Mortgage-backed securities, Fair Value	3,715,393
Total securities available for sale, Fair Value	$ 6,139,346	$ 6,258,577

Securities - Additional Informa

Securities - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Schedule of Trading Securities and Other Trading Assets [Line Items]
Proceeds from sales of securities available for sale	$ 41,273,000	$ 86,069,000
Gross realized gains from securities	100,000	500,000
Gross realized losses from securities	3,000	0
Sales of securities held to maturity	0	0
Unrealized (loss) gain on trading securities	(123,000)	$ 0
Securities sold not yet purchased	9,500,000		$ 4,100,000
Other securities - marketable [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fair value of securities including alternative investment securities	4,700,000		4,600,000
Other Non-marketable Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Fair value of securities including alternative investment securities	5,500,000		3,400,000
U.S. Government and Other Public Deposit [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Pledged securities for deposits	5,100,000,000		5,700,000,000
Federal Reserve Discount Window [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Pledged securities for deposits	$ 1,700,000,000		$ 1,800,000,000

Gross Unrealized Losses and Fai

Gross Unrealized Losses and Fair Value of Investment Securities Available for Sale (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Gain (Loss) on Investments [Line Items]
Less than 12 months, Fair Value	$ 3,634,713	$ 3,104,606
Less than 12 months, Unrealized Losses	(69,917)	(27,391)
12 months or more, Fair Value	1,861,202	1,967,685
12 months or more, Unrealized Losses	(90,957)	(61,929)
Total Fair Value	5,495,915	5,072,291
Total Unrealized Losses	(160,874)	(89,320)
U.S. Treasury [Member]
Gain (Loss) on Investments [Line Items]
Less than 12 months, Fair Value	9,808	9,851
Less than 12 months, Unrealized Losses	(117)	(64)
12 months or more, Fair Value	28,387	28,792
12 months or more, Unrealized Losses	(1,782)	(1,385)
Total Fair Value	38,195	38,643
Total Unrealized Losses	(1,899)	(1,449)
U.S. Agencies [Member]
Gain (Loss) on Investments [Line Items]
Less than 12 months, Fair Value	3,571	14,553
Less than 12 months, Unrealized Losses	(5)	(10)
Total Fair Value	3,571	14,553
Total Unrealized Losses	(5)	(10)
Mortgage-backed [Member]
Gain (Loss) on Investments [Line Items]
Less than 12 months, Fair Value	2,085,580	1,990,006
Less than 12 months, Unrealized Losses	(47,831)	(19,980)
12 months or more, Fair Value	1,471,848	1,562,333
12 months or more, Unrealized Losses	(72,834)	(52,060)
Total Fair Value	3,557,428	3,552,339
Total Unrealized Losses	(120,665)	(72,040)
State and political subdivisions [Member]
Gain (Loss) on Investments [Line Items]
Less than 12 months, Fair Value	1,534,275	1,076,930
Less than 12 months, Unrealized Losses	(21,958)	(7,325)
12 months or more, Fair Value	360,967	376,560
12 months or more, Unrealized Losses	(16,341)	(8,484)
Total Fair Value	1,895,242	1,453,490
Total Unrealized Losses	(38,299)	(15,809)
Corporates [Member]
Gain (Loss) on Investments [Line Items]
Less than 12 months, Fair Value	1,479	13,266
Less than 12 months, Unrealized Losses	(6)	(12)
Total Fair Value	1,479	13,266
Total Unrealized Losses	$ (6)	$ (12)

Contractual Maturity Informatio

Contractual Maturity Information for Securities Held to Maturity (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Due in 1 year or less, Amortized Cost	$ 3,883	$ 2,275
Due after 1 year through 5 years, Amortized Cost	106,522	100,648
Due after 5 years through 10 years, Amortized Cost	352,349	372,234
Due after 10 years, Amortized Cost	783,712	785,857
Total state and political subdivisions, Amortized Cost	1,246,466	1,261,014
Due in 1 year or less, Gross Unrealized Gains		3
Due after 1 year through 5 years, Gross Unrealized Gains	258	3,111
Due after 5 years through 10 years, Gross Unrealized Gains	4,692	5,006
Due after 10 years, Gross Unrealized Gains	6,217	6,952
Total state and political subdivisions, Gross Unrealized Gains	11,167	15,072
Due in 1 year or less, Gross Unrealized Losses	(105)	(24)
Due after 1 year through 5 years, Gross Unrealized Losses	(6,386)	(2,834)
Due after 5 years through 10 years, Gross Unrealized Losses	(17,169)	(14,117)
Due after 10 years, Gross Unrealized Losses	(76,346)	(51,664)
Total state and political subdivisions, Gross Unrealized Losses	(100,006)	(68,639)
Due in 1 year or less, Fair Value	3,778	2,254
Due after 1 year through 5 years, Fair Value	100,394	100,925
Due after 5 years through 10 years, Fair Value	339,872	363,123
Due after 10 years, Fair Value	713,583	741,145
Total state and political subdivisions, Fair Value	$ 1,157,627	$ 1,207,447

Schedule of Federal Reserve Ban

Schedule of Federal Reserve Bank Stock and Federal Home Loan Bank Stock and Other Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Other Securities [Line Items]
Fair Value	$ 67,408	$ 65,897
Federal Reserve Bank Stock and Other Securities [Member]
Schedule of Other Securities [Line Items]
Amortized Cost	59,153	59,871
Gross Unrealized Gains	8,255	6,026
Gross Unrealized Losses	0	0
Fair Value	67,408	65,897
FRB and FHLB stock [Member] | Federal Reserve Bank Stock and Other Securities [Member]
Schedule of Other Securities [Line Items]
Amortized Cost	33,262	33,262
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	33,262	33,262
Other securities - marketable [Member] | Federal Reserve Bank Stock and Other Securities [Member]
Schedule of Other Securities [Line Items]
Amortized Cost	3	3
Gross Unrealized Gains	4,733	4,637
Gross Unrealized Losses	0	0
Fair Value	4,736	4,640
Other securities - non-marketable [Member] | Federal Reserve Bank Stock and Other Securities [Member]
Schedule of Other Securities [Line Items]
Amortized Cost	25,888	26,606
Gross Unrealized Gains	3,522	1,389
Gross Unrealized Losses	0	0
Fair Value	$ 29,410	$ 27,995

Changes in Carrying Amount of G

Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	$ 180,867
Discontinued assets ─ goodwill and other intangibles, net	0	$ (47,529)
Ending Balance	180,867	180,867
Segment, Continuing and Discontinued Operations [Member]
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	180,867	228,396
Ending Balance		180,867
Continuing Operations [Member]
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	180,867
Ending Balance	180,867	180,867
Commercial Banking [Member]
Goodwill And Other Intangible Assets [Line Items]
Discontinued assets ─ goodwill and other intangibles, net	0	0
Commercial Banking [Member] | Segment, Continuing and Discontinued Operations [Member]
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	59,419	59,419
Ending Balance		59,419
Commercial Banking [Member] | Continuing Operations [Member]
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	59,419
Ending Balance	59,419	59,419
Institutional Banking [Member]
Goodwill And Other Intangible Assets [Line Items]
Discontinued assets ─ goodwill and other intangibles, net	0	(47,529)
Institutional Banking [Member] | Segment, Continuing and Discontinued Operations [Member]
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	51,332	98,861
Ending Balance		51,332
Institutional Banking [Member] | Continuing Operations [Member]
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	51,332
Ending Balance	51,332	51,332
Personal Banking [Member]
Goodwill And Other Intangible Assets [Line Items]
Discontinued assets ─ goodwill and other intangibles, net	0	0
Personal Banking [Member] | Segment, Continuing and Discontinued Operations [Member]
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	70,116	70,116
Ending Balance		70,116
Personal Banking [Member] | Continuing Operations [Member]
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	70,116
Ending Balance	70,116	70,116
Healthcare Services [Member]
Goodwill And Other Intangible Assets [Line Items]
Discontinued assets ─ goodwill and other intangibles, net	0	0
Healthcare Services [Member] | Segment, Continuing and Discontinued Operations [Member]
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	0	0
Ending Balance		0
Healthcare Services [Member] | Continuing Operations [Member]
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	0
Ending Balance	$ 0	$ 0

Changes In Intangible Assets (D

Changes In Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	$ 124,655	$ 124,655
Accumulated amortization	105,960	104,398
Net carrying amount	18,695	20,257
Core deposit intangible assets [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	50,059	50,059
Accumulated amortization	42,990	42,209
Net carrying amount	7,069	7,850
Customer relationships [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	71,342	71,342
Accumulated amortization	59,716	58,935
Net carrying amount	11,626	12,407
Other intangible assets [Member]
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	3,254	3,254
Accumulated amortization	$ 3,254	$ 3,254

Aggregate Amortization Expense

Aggregate Amortization Expense Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Aggregate amortization expense	$ 1,562	$ 2,046

Estimated Amortization Expense

Estimated Amortization Expense of Intangible Assets (Detail) $ in Thousands	Mar. 31, 2018USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
For the nine months ending December 31, 2018	$ 4,151
For the year ending December 31, 2019	4,714
For the year ending December 31, 2020	3,759
For the year ending December 31, 2021	2,755
For the year ending December 31, 2022	1,815
For the year ending December 31, 2023	$ 1,097

Remaining Contractual Maturitie

Remaining Contractual Maturities Of Repurchase Agreements (Detail) $ in Thousands	Mar. 31, 2018USD ($)
Assets Sold under Agreements to Repurchase [Line Items]
Total repurchase agreements	$ 1,323,456
2 to 29 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Total repurchase agreements	1,320,456
Over 90 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Total repurchase agreements	3,000
U.S. Treasury [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Total repurchase agreements	17,700
U.S. Treasury [Member] | 2 to 29 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Total repurchase agreements	17,700
U.S. Agencies [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Total repurchase agreements	1,305,756
U.S. Agencies [Member] | 2 to 29 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Total repurchase agreements	1,302,756
U.S. Agencies [Member] | Over 90 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Total repurchase agreements	$ 3,000

Business Segment Reporting - Ad

Business Segment Reporting - Additional Information (Detail) - Segment	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Segment Reporting [Abstract]
Number of reportable segments	4	3

Schedule of Business Segment Fi

Schedule of Business Segment Financial Results (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Net interest income	$ 147,922	$ 134,315
Provision for loan losses	10,000	9,000
Noninterest income	105,525	102,917
Noninterest expense	175,876	173,810
Income before taxes	67,571	54,422
Income tax expense	10,038	12,446
Income from continuing operations	57,533	41,976
Average assets	20,747,000	20,234,000
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	91,968	85,390
Provision for loan losses	7,978	6,820
Noninterest income	20,598	19,206
Noninterest expense	62,246	62,750
Income before taxes	42,342	35,026
Income tax expense	6,284	8,007
Income from continuing operations	36,058	27,019
Average assets	9,785,000	9,611,000
Personal Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	30,920	30,075
Provision for loan losses	1,672	1,711
Noninterest income	30,714	28,536
Noninterest expense	54,994	55,997
Income before taxes	4,968	903
Income tax expense	738	224
Income from continuing operations	4,230	679
Average assets	4,982,000	5,347,000
Institutional Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	15,744	11,582
Provision for loan losses	350	469
Noninterest income	45,419	45,666
Noninterest expense	46,833	44,778
Income before taxes	13,980	12,001
Income tax expense	2,080	2,734
Income from continuing operations	11,900	9,267
Average assets	3,826,000	3,466,000
Healthcare Services [Member]
Segment Reporting Information [Line Items]
Net interest income	9,290	7,268
Noninterest income	8,794	9,509
Noninterest expense	11,803	10,285
Income before taxes	6,281	6,492
Income tax expense	936	1,481
Income from continuing operations	5,345	5,011
Average assets	$ 2,154,000	$ 1,810,000

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Detail) - ASC 606 [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Total receivables of revenue recognized	$ 53.3		$ 53.5
Bankcard Fees [Member]
Disaggregation Of Revenue [Line Items]
Bankcard expenses	$ 8.1	$ 6.8

Revenue Recognition - Summary o

Revenue Recognition - Summary of Disaggregation of Revenue According to Revenue Stream and Business Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation Of Revenue [Line Items]
Trust and securities processing	$ 44,002	$ 42,541
Trading and investment banking	4,101	7,542
Service charges on deposit accounts	21,905	22,075
Insurance fees and commissions	301	646
Brokerage fees	6,353	5,377
Bankcard fees	18,123	17,752
Gains on sales of securities available for sale, net	139	468
Other	10,601	6,516
Total noninterest income	105,525	102,917
Revenue (Expense) out of Scope of ASU 606 [Member] | ASC 606 [Member]
Disaggregation Of Revenue [Line Items]
Trading and investment banking	4,101	7,037
Service charges on deposit accounts	34	30
Bankcard fees	(7,926)	(6,562)
Gains on sales of securities available for sale, net	139	468
Other	8,972	5,024
Total noninterest income	5,320	5,997
Commercial Banking [Member]
Disaggregation Of Revenue [Line Items]
Total noninterest income	20,598	19,206
Commercial Banking [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] | ASC 606 [Member]
Disaggregation Of Revenue [Line Items]
Service charges on deposit accounts	7,791	8,021
Brokerage fees	52	40
Bankcard fees	14,797	12,148
Other	454	489
Total noninterest income	23,094	20,698
Institutional Banking [Member]
Disaggregation Of Revenue [Line Items]
Total noninterest income	45,419	45,666
Institutional Banking [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] | ASC 606 [Member]
Disaggregation Of Revenue [Line Items]
Trust and securities processing	27,696	26,517
Trading and investment banking		505
Service charges on deposit accounts	7,230	7,355
Brokerage fees	4,060	3,256
Bankcard fees	1,635	1,505
Other	120	163
Total noninterest income	40,741	39,301
Personal Banking [Member]
Disaggregation Of Revenue [Line Items]
Total noninterest income	30,714	28,536
Personal Banking [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] | ASC 606 [Member]
Disaggregation Of Revenue [Line Items]
Trust and securities processing	16,306	16,024
Service charges on deposit accounts	2,812	2,865
Insurance fees and commissions	301	646
Brokerage fees	2,241	2,081
Bankcard fees	5,313	5,438
Other	906	764
Total noninterest income	27,879	27,818
Healthcare Services [Member]
Disaggregation Of Revenue [Line Items]
Total noninterest income	8,794	9,509
Healthcare Services [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] | ASC 606 [Member]
Disaggregation Of Revenue [Line Items]
Service charges on deposit accounts	4,038	3,804
Bankcard fees	4,304	5,223
Other	149	76
Total noninterest income	$ 8,491	$ 9,103

Notional Amount of Off-Balance

Notional Amount of Off-Balance Sheet Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Commitments to extend credit for loans (excluding credit card loans) [Member]
Commitments and Contingencies Disclosure [Line Items]
Contract or notional amount of off-balance sheet financial instruments	$ 6,245,306	$ 6,689,467
Commitments to extend credit under credit card loans [Member]
Commitments and Contingencies Disclosure [Line Items]
Contract or notional amount of off-balance sheet financial instruments	3,007,843	2,975,507
Commercial letters of credit [Member]
Commitments and Contingencies Disclosure [Line Items]
Contract or notional amount of off-balance sheet financial instruments	5,059	813
Standby letters of credit [Member]
Commitments and Contingencies Disclosure [Line Items]
Contract or notional amount of off-balance sheet financial instruments	321,748	316,054
Forward contracts [Member]
Commitments and Contingencies Disclosure [Line Items]
Contract or notional amount of off-balance sheet financial instruments	25,365	29,007
Spot foreign exchange contracts [Member]
Commitments and Contingencies Disclosure [Line Items]
Contract or notional amount of off-balance sheet financial instruments	$ 4,575	$ 628

Summary of Fair Value of Deriva

Summary of Fair Value of Derivative Assets and Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	$ 7,424	$ 10,149
Derivative Liabilities, Fair Value	6,378	8,906
Derivatives not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	7,424	10,116
Derivative Liabilities, Fair Value	6,347	7,326
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value		33
Derivative Liabilities, Fair Value	$ 31	$ 1,580

Derivatives and Hedging Activ61

Derivatives and Hedging Activities - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018USD ($)Derivative	Mar. 31, 2017USD ($)
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Termination value of derivatives in net liability position	$ 1,300,000
Collateral posted for derivative instruments	1,000,000
Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedging [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Effective portion of change in fair value of cash flow hedges	$ 2,202,000	$ 246,000
Interest rate hedging exposure to variability in future cash flows for forecasted transactions, maximum period	18 years 5 months 19 days
Interest Rate Swap [Member] | Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedging [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional amount of interest rate swaps	$ 5,800,000
Number of interest rate swaps | Derivative	1
Gain (Loss) related to changes in fair value of swaps	$ (81,000)	46,000
Interest Rate Swap [Member] | Derivatives Designated as Hedging Instruments [Member] | Cash Flow Hedging [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional amount of interest rate swaps	$ 51,500,000
Number of interest rate swaps | Derivative	2
Effective portion of change in fair value of cash flow hedges	$ 2,202,000	246,000
Interest Rate Swap [Member] | Derivatives not Designated as Hedging Instruments [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional amount of interest rate swaps	$ 1,100,000,000
Number of interest rate swaps | Derivative	88
Gain (Loss) related to changes in fair value of swaps	$ 336,000	$ (348,000)

Summary of Amount of Gain (Loss

Summary of Amount of Gain (Loss) Recognized in Other Non-Interest Expense in Consolidated Statements of Income Related to Derivative Assets and Liabilities (Detail) - Interest Rate Swap [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivatives not Designated as Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized	$ 336	$ (348)
Derivatives Designated as Hedging Instruments [Member] | Fair value adjustments on derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized	81	(46)
Derivatives Designated as Hedging Instruments [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized	$ (81)	$ 46

Summary of Amount of Gain (Lo63

Summary of Amount of Gain (Loss) Recognized in AOCI in Consolidated Statements of Comprehensive Income Related to Company's Derivative Assets and Liabilities (Detail) - Derivatives Designated as Hedging Instruments [Member] - Cash Flow Hedging [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain Recognized in Other Comprehensive Income on Derivatives	$ 2,202	$ 246
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain Recognized in Other Comprehensive Income on Derivatives	$ 2,202	$ 246

Assets and Liabilities Measured

Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	$ 65,389	$ 54,055
Available for sale	6,139,346	6,258,577
Derivative Assets, Fair Value	7,424	10,149
Derivative Liabilities, Fair Value	6,378	8,906
Securities sold not yet purchased	9,500	4,100
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	21,276	14,337
Available for sale	39,675	51,909
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	44,113	39,718
Available for sale	6,099,671	6,206,668
U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale	38,196	38,643
U.S. Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale	3,769	14,752
Mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale	3,715,393	3,649,243
State and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale	2,380,509	2,542,673
Corporates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale	1,479	13,266
Fair Value Measurement, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	65,389	54,055
Available for sale	6,139,346	6,258,577
Company-owned life insurance	55,711	53,577
Bank-owned life insurance	267,747	265,823
Derivative Assets, Fair Value	7,424	10,149
Total	6,535,617	6,642,181
Deferred compensation	53,125	50,963
Derivative Liabilities, Fair Value	6,378	8,906
Securities sold not yet purchased	9,507	4,130
Total	69,010	63,999
Fair Value Measurement, Recurring [Member] | Trading - other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	14,167	13,113
Fair Value Measurement, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	21,276	14,337
Available for sale	39,675	51,909
Total	60,951	66,246
Deferred compensation	53,125	50,963
Total	53,125	50,963
Fair Value Measurement, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Trading - other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	12,262	12,434
Fair Value Measurement, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	44,113	39,718
Available for sale	6,099,671	6,206,668
Company-owned life insurance	55,711	53,577
Bank-owned life insurance	267,747	265,823
Derivative Assets, Fair Value	7,424	10,149
Total	6,474,666	6,575,935
Derivative Liabilities, Fair Value	6,378	8,906
Securities sold not yet purchased	9,507	4,130
Total	15,885	13,036
Fair Value Measurement, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Trading - other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	1,905	679
Fair Value Measurement, Recurring [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	497	18
Available for sale	38,196	38,643
Fair Value Measurement, Recurring [Member] | U.S. Treasury [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	497	18
Available for sale	38,196	38,643
Fair Value Measurement, Recurring [Member] | U.S. Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	5,188	9,976
Available for sale	3,769	14,752
Fair Value Measurement, Recurring [Member] | U.S. Agencies [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	5,188	9,976
Available for sale	3,769	14,752
Fair Value Measurement, Recurring [Member] | Mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	634	1,949
Available for sale	3,715,393	3,649,243
Fair Value Measurement, Recurring [Member] | Mortgage-backed [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	634	1,949
Available for sale	3,715,393	3,649,243
Fair Value Measurement, Recurring [Member] | State and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	36,386	27,114
Available for sale	2,380,509	2,542,673
Fair Value Measurement, Recurring [Member] | State and political subdivisions [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	36,386	27,114
Available for sale	2,380,509	2,542,673
Fair Value Measurement, Recurring [Member] | Corporates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	8,517	1,885
Available for sale	1,479	13,266
Fair Value Measurement, Recurring [Member] | Corporates [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	8,517	1,885
Available for sale	$ 1,479	$ 13,266

Assets Measured at Fair Value o

Assets Measured at Fair Value on Non-Recurring Basis (Detail) - Fair Value, Measurements, Non-Recurring [Member] - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	$ 22,487	$ 16,674
Total Gains (Losses) Recognized	1,570	1,264
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	22,487	16,674
Impaired loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	22,394	15,186
Total Gains (Losses) Recognized	1,570	1,251
Impaired loans [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	22,394	15,186
Other real estate owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	93	1,488
Total Gains (Losses) Recognized		13
Other real estate owned [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	$ 93	$ 1,488

Estimated Fair Value of Financi

Estimated Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and short-term investments	$ 1,078,209	$ 1,936,084
Securities available for sale	6,139,346	6,258,577
Securities held to maturity	1,246,466	1,261,014
Trading securities	65,389	54,055
Other securities	67,408	65,897
Loans (exclusive of allowance for loan loss)	11,463,380	11,281,973
Derivatives	7,424	10,149
Demand and savings deposits	16,231,085	16,742,736
Time deposits	987,179	1,280,264
Other borrowings	1,354,615	1,260,704
Long-term debt	78,687	79,281
Derivatives	6,378	8,906
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and short-term investments	1,078,209	1,936,084
Securities available for sale	6,139,346	6,258,577
Securities held to maturity	1,157,627	1,207,447
Trading securities	65,389	54,055
Other securities	67,408	65,897
Loans (exclusive of allowance for loan loss)	11,460,851	11,318,764
Derivatives	7,424	10,149
Demand and savings deposits	16,231,085	16,742,736
Time deposits	987,179	1,280,264
Other borrowings	1,354,615	1,260,704
Long-term debt	78,940	79,496
Derivatives	6,378	8,906
Commitments to extend credit for loans	1,544	6,654
Commercial letters of credit	17	136
Standby letters of credit	647	2,514
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and short-term investments	965,247	1,749,618
Securities available for sale	39,675	51,909
Trading securities	21,276	14,337
Demand and savings deposits	16,231,085	16,742,736
Other borrowings	31,159	11,334
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and short-term investments	112,962	186,466
Securities available for sale	6,099,671	6,206,668
Securities held to maturity	1,157,627	1,207,447
Trading securities	44,113	39,718
Other securities	67,408	65,897
Loans (exclusive of allowance for loan loss)	11,460,851	11,318,764
Derivatives	7,424	10,149
Time deposits	987,179	1,280,264
Other borrowings	1,323,456	1,249,370
Long-term debt	78,940	79,496
Derivatives	$ 6,378	$ 8,906

Divestitures - Additional Infor

Divestitures - Additional Information (Detail) $ in Millions	Nov. 17, 2017USD ($)
Discontinued Operations And Disposal Groups [Abstract]
Sale of outstanding stock of subsidiary in cash	$ 172.5
Gain on the disposal of discontinued operations	$ 103.6

Schedule of Components of (Loss

Schedule of Components of (Loss) Income from Discontinued Operations, Net of Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Discontinued Operations And Disposal Groups [Abstract]
Total noninterest income		$ 17,863
Total noninterest expense	$ 917	14,956
(Loss) income from discontinued operations	(917)	2,907
Income tax (benefit) expense	(170)	702
(Loss) income from discontinued operations	$ (747)	$ 2,205

Schedule of Components of Net C

Schedule of Components of Net Cash Provided by Operating Activities of Discontinued Operations Consolidated Statements of Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Discontinued Operations And Disposal Groups [Abstract]
(Loss) income from discontinued operations	$ (747)	$ 2,205
Depreciation and amortization		824
Net cash provided by operating activities of discontinued operations	$ (747)	$ 3,029