UMB Financial (UMBF) 10-K 27 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 20, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	UMBF
Entity Registrant Name	UMB FINANCIAL CORP
Entity Central Index Key	101382
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		45,748,796
Entity Public Float			$2,395,384,553

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
ASSETS
Loans	$7,465,794	$6,520,512
Allowance for loan losses	-76,140	-74,751
Net loans	7,389,654	6,445,761
Loans held for sale	624	1,357
Investment securities:
Available for sale	6,911,936	6,762,411
Held to maturity (fair value of $304,112 and $231,510, respectively)	278,054	209,770
Trading	27,203	28,464
Federal Reserve Bank stock and other	68,474	50,482
Total investment securities	7,285,667	7,051,127
Federal funds sold and securities purchased under agreements to resell	118,105	87,018
Interest-bearing due from banks	1,539,386	2,093,467
Cash and due from banks	444,299	521,001
Premises and equipment, net	257,835	249,689
Accrued income	79,297	78,216
Goodwill	209,758	209,758
Other intangibles, net	43,991	55,585
Other assets	132,344	118,873
Total assets	17,500,960	16,911,852
Deposits:
Noninterest-bearing demand	5,643,989	5,189,998
Interest-bearing demand and savings	6,709,281	7,001,126
Time deposits under $100,000	424,925	491,792
Time deposits of $100,000 or more	838,664	957,850
Total deposits	13,616,859	13,640,766
Federal funds purchased and repurchase agreements	2,025,132	1,583,218
Short-term debt		107
Long-term debt	8,810	5,055
Accrued expenses and taxes	180,074	153,450
Other liabilities	26,327	23,191
Total liabilities	15,857,202	15,405,787
SHAREHOLDERS' EQUITY
Common stock, $1.00 par value; 80,000,000 shares authorized, 55,056,730 shares issued and 45,532,188 and 45,221,237 shares outstanding, respectively	55,057	55,057
Capital surplus	894,602	882,407
Retained earnings	963,911	884,630
Accumulated other comprehensive income (loss), net	11,006	-32,640
Treasury stock, 9,524,542 and 9,835,493 shares, at cost, respectively	-280,818	-283,389
Total shareholders' equity	1,643,758	1,506,065
Total liabilities and shareholders' equity	$17,500,960	$16,911,852

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Held to Maturity, Fair value	$304,112	$231,510
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	45,532,188	45,221,237
Treasury stock, shares	9,524,542	9,835,493

CONSOLIDATED_STATEMENTS_OF_INC

CONSOLIDATED STATEMENTS OF INCOME (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
INTEREST INCOME
Loans	$245,278	$229,665	$217,391
Securities:
Taxable interest	76,204	75,202	81,013
Tax exempt interest	39,209	40,399	38,224
Total securities income	115,413	115,601	119,237
Federal funds sold and resell agreements	259	193	121
Interest-bearing due from banks	2,525	1,918	1,789
Trading securities	396	964	1,147
Total interest income	363,871	348,341	339,685
INTEREST EXPENSE
Deposits	12,242	13,183	17,416
Federal funds purchased and repurchase agreements	1,616	1,739	1,884
Other	-42	150	329
Total interest expense	13,816	15,072	19,629
Net interest income	350,055	333,269	320,056
Provision for loan losses	17,000	17,500	17,500
Net interest income after provision for loan losses	333,055	315,769	302,556
NONINTEREST INCOME
Trust and securities processing	288,054	265,948	225,094
Trading and investment banking	19,398	20,641	30,359
Service charges on deposit accounts	85,299	84,133	78,694
Insurance fees and commissions	3,011	3,727	4,095
Brokerage fees	10,761	11,470	11,105
Bankcard fees	67,250	62,031	60,567
Gains on sales of securities available for sale, net	4,127	8,542	20,232
Equity earnings on alternative investments	3,975	19,048	422
Other	16,813	16,293	27,554
Total noninterest income	498,688	491,833	458,122
NONINTEREST EXPENSE
Salaries and employee benefits	358,569	339,691	319,852
Occupancy, net	40,197	39,291	37,927
Equipment	53,609	49,207	43,465
Supplies and services	20,411	20,387	21,045
Marketing and business development	24,148	22,703	24,604
Processing fees	56,049	57,791	51,191
Legal and consulting	20,407	18,703	17,980
Bankcard	19,594	18,381	18,154
Amortization of other intangible assets	12,193	13,218	14,775
Regulatory fees	10,445	9,129	9,447
Contingency reserve	20,272
Other	31,032	35,677	32,014
Total noninterest expense	666,926	624,178	590,454
Income before income taxes	164,817	183,424	170,224
Income tax expense	44,162	49,459	47,507
Net income	$120,655	$133,965	$122,717
PER SHARE DATA
Net income-basic	$2.69	$3.25	$3.07
Net income-diluted	$2.65	$3.20	$3.04
Weighted average shares outstanding-basic	44,844,578	41,275,839	40,034,428
Weighted average shares outstanding-diluted	45,445,283	41,838,580	40,433,367

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$120,655	$133,965	$122,717
Unrealized gains (losses) on securities:
Change in unrealized holding gains (losses), net	74,147	-178,500	27,164
Less: Reclassifications adjustment for gains included in net income	-4,127	-8,542	-20,232
Change in unrealized gains (losses) on securities during the period	70,020	-187,042	6,932
Income tax (expense) benefit	-26,374	68,814	-2,443
Other comprehensive income (loss)	43,646	-118,228	4,489
Comprehensive income	$164,301	$15,737	$127,206

CONSOLIDATED_STATEMENTS_OF_CHA

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (USD $)	Total	Common Stock	Capital Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
In Thousands
Beginning Balance at Dec. 31, 2011	$1,191,132	$55,057	$723,299	$697,923	$81,099	($366,246)
Total comprehensive income	127,206			122,717	4,489
Cash dividends	-33,625			-33,625
Purchase of treasury stock	-20,419					-20,419
Issuance of equity awards	245		-1,911			2,156
Recognition of equity based compensation	6,917		6,917
Net tax benefit related to equity compensation plans	359		359
Sale of treasury stock	976		587			389
Exercise of stock options	6,554		2,818			3,736
Ending Balance at Dec. 31, 2012	1,279,345	55,057	732,069	787,015	85,588	-380,384
Total comprehensive income	15,737			133,965	-118,228
Cash dividends	-36,350			-36,350
Purchase of treasury stock	-3,501					-3,501
Issuance of equity awards	450		-1,651			2,101
Recognition of equity based compensation	7,936		7,936
Net tax benefit related to equity compensation plans	1,224		1,224
Sale of treasury stock	776		520			256
Exercise of stock options	9,018		3,986			5,032
Common stock issuance	231,430		138,323			93,107
Ending Balance at Dec. 31, 2013	1,506,065	55,057	882,407	884,630	-32,640	-283,389
Total comprehensive income	164,301			120,655	43,646
Cash dividends	-41,374			-41,374
Purchase of treasury stock	-5,741					-5,741
Issuance of equity awards	489		-2,338			2,827
Recognition of equity based compensation	9,172		9,172
Net tax benefit related to equity compensation plans	1,880		1,880
Sale of treasury stock	936		596			340
Exercise of stock options	8,030		2,885			5,145
Ending Balance at Dec. 31, 2014	$1,643,758	$55,057	$894,602	$963,911	$11,006	($280,818)

CONSOLIDATED_STATEMENTS_OF_CHA1

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Parenthetical) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Cash dividends, per share	$0.24	$0.23	$0.23	$0.23	$0.23	$0.22	$0.22	$0.22	$0.91	$0.87	$0.83

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
OPERATING ACTIVITIES
Net income	$120,655	$133,965	$122,717
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	17,000	17,500	17,500
Depreciation and amortization	46,355	44,221	40,847
Deferred income tax (benefit) expense	-11,456	-5,123	3,675
Net (increase) decrease in trading securities and other earning assets	-2,714	8,252	2,378
Gains on sales of securities available for sale	-4,127	-8,542	-20,232
Gains on sales of assets	-3,034	-1,431	-904
Amortization of securities premiums, net of discount accretion	51,542	53,248	50,435
Originations of loans held for sale	-71,598	-118,418	-237,997
Net gains on sales of loans held for sale	-1,137	-887	-2,010
Proceeds from sales of loans held for sale	73,468	121,825	246,345
Equity based compensation	9,661	8,386	7,162
Changes in:
Accrued income	-1,081	-8,467	6,248
Accrued expenses and taxes	40,345	61,092	8,376
Other assets and liabilities, net	-20,100	-10,423	-20,796
Net cash provided by operating activities	243,779	295,198	223,744
INVESTING ACTIVITIES
Proceeds from maturities of securities held to maturity	25,270	34,033	9,756
Proceeds from sales of securities available for sale	413,955	685,031	1,016,129
Proceeds from maturities of securities available for sale	1,321,135	1,495,867	1,691,293
Purchases of securities held to maturity	-109,308	-135,598	-39,642
Purchases of securities available for sale	-1,859,692	-2,238,238	-3,561,042
Net increase in loans	-963,028	-844,993	-738,343
Net (increase) decrease in fed funds sold and resell agreements	-31,087	2,850	-23,790
Net (increase) decrease in interest bearing balances due from other financial institutions	-164,415	-10,160	129,076
Purchases of premises and equipment	-44,790	-38,313	-44,038
Net cash activity from acquisitions and branch sales	-18,231	26,087	17,597
Proceeds from sales of premises and equipment	5,212	2,586	1,473
Increase in COLI cash surrender value	-6,000
Net cash used in investing activities	-1,430,979	-1,020,848	-1,541,531
FINANCING ACTIVITIES
Net increase in demand and savings deposits	174,718	1,800,207	1,737,072
Net (decrease) increase in time deposits	-178,294	159,639	-272,627
Net increase (decrease) in fed funds purchased and repurchase agreements	441,914	-204,052	-163,557
Net change in short-term debt	-107	-407	-12,000
Proceeds from long-term debt	5,320	1,000	1,029
Repayment of long-term debt	-1,565	-1,310	-1,679
Payment of contingent consideration on acquisitions	-13,725	-16,172	-17,371
Cash dividends paid	-41,364	-36,168	-33,787
Net tax benefit related to equity compensation plans	1,880	1,224	359
Common stock issuance		231,430
Proceeds from exercise of stock options and sales of treasury shares	8,966	9,794	7,530
Purchases of treasury stock	-5,741	-3,501	-20,419
Net cash provided by financing activities	392,002	1,941,684	1,224,550
(Decrease) increase in cash and cash equivalents	-795,198	1,216,034	-93,237
Cash and cash equivalents at beginning of year	2,582,428	1,366,394	1,459,631
Cash and cash equivalents at end of year	1,787,230	2,582,428	1,366,394
Supplemental disclosures:
Income taxes paid	61,228	46,445	44,074
Total interest paid	$13,958	$15,823	$20,975

SUMMARY_OF_SIGNIFICANT_ACCOUNT

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	1.  SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	UMB Financial Corporation (the Company) is a bank holding company, which offers a wide range of banking and other financial services to its customers through its branches and offices in the states of Missouri, Kansas, Colorado, Illinois, Oklahoma, Arizona, Nebraska, Pennsylvania, South Dakota, Indiana, Wisconsin, Utah, Texas, and Massachusetts. The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America 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 consolidated 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. Following is a summary of the more significant accounting policies to assist the reader in understanding the financial presentation.
	Consolidation
	The Company and its wholly owned subsidiaries are included in the consolidated financial statements (references hereinafter to the “Company” in these Notes to Consolidated Financial Statements include wholly owned subsidiaries). Intercompany accounts and transactions have been eliminated.
	Revenue Recognition
	Interest on loans and securities is recognized based on rate times the principal amount outstanding. This includes the impact of amortization of premiums and discounts. Interest accrual is discontinued when, in the opinion of management, the likelihood of collection becomes doubtful. Other noninterest income is recognized as services are performed or revenue-generating transactions are executed.
	Cash and cash equivalents
	Cash and cash equivalents include Cash and due from banks and amounts due from the Federal Reserve Bank. 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 Federal Reserve Bank 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 December 31, 2014 and 2013 (in thousands):
		Year Ended December 31
		2014		2013
	Due from the Federal Reserve	$	1,342,931	$	2,061,427
	Cash and due from banks		444,299		521,001
	Cash and cash equivalents at end of year	$	1,787,230	$	2,582,428
	Also included in the Interest-bearing due from banks line, but not considered cash and cash equivalents are interest-bearing accounts held at other financial institutions, which totaled $196.5 million and $32.0 million at December 31, 2014 and 2013, respectively.
	Loans and Loans Held for Sale
	Loans are classified by the portfolio segments of commercial, real estate, consumer, and leases. The portfolio segments are further disaggregated into the loan classes of commercial, commercial credit card, real estate—construction, real estate—commercial, real estate—residential, real estate—HELOC, consumer—credit card, consumer—other, and leases.
	A loan is considered to be impaired when management believes it is probable that it will be unable to collect all principal and interest due according to the contractual terms of the loan. If a loan is impaired, the Company records a valuation allowance equal to the carrying amount of the loan in excess of the present value of the estimated future cash flows discounted at the loan’s effective rate, based on the loan’s observable market price or the fair value of the collateral if the loan is collateral dependent.
	A loan is accounted for as a troubled debt restructuring when a concession had been granted to a debtor experiencing financial difficulties. The Company’s modifications generally include interest rate adjustments, and amortization and maturity date extensions. These modifications allow the debtor short-term cash relief to allow them to improve their financial condition. Restructured loans are individually evaluated for impairment as part of the allowance for loan loss analysis.
	Loans, including those that are considered to be impaired and restructured, are evaluated regularly by management. Loans are considered delinquent when payment has not been received within 30 days of its contractual due date. Loans are placed on non-accrual status when the collection of interest or principal is 90 days or more past due, unless the loan is adequately secured and in the process of collection. When a loan is placed on non-accrual status, any interest previously accrued but not collected is reversed against current income. Loans may be returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured. Interest payments received on non-accrual loans are applied to principal unless the remaining principal balance has been determined to be fully collectible.
	The adequacy of the allowance for loan losses is based on management’s continuing evaluation of the pertinent factors underlying the quality of the loan portfolio, including actual loan loss experience, current economic conditions, detailed analysis of individual loans for which full collectability may not be assured, determination of the existence and realizable value of the collateral and guarantees securing such loans. The actual losses, notwithstanding such considerations, however, could differ from the amounts estimated by management.
	The Company maintains a reserve, separate from the allowance for loan losses, to address the risk of loss associated with loan contingencies, which is included in the accrued expenses and taxes line item in the Consolidated Balance Sheets. In order to maintain the reserve for off-balance sheet items at an appropriate level, a provision to increase or reduce the reserve is included in the Company’s Consolidated Statements of Income. The level of the reserve will be adjusted as needed to maintain the reserve at a specified level in relation to contingent loan risk. The risk of loss arising from un-funded loan commitments has been assessed by dividing the contingencies into pools of similar loan commitments and by applying two factors to each pool. The gross amount of contingent exposure is first multiplied by a potential use factor to estimate the degree to which the unused commitments might reasonably be expected to be used in a time of high usage. The resultant figure is then multiplied by a factor to estimate the risk of loss assuming funding of these loans. The potential loss estimates for each segment of the portfolio are added to arrive at a total potential loss estimate that is used to set the reserve.
	Loans held for sale are carried at the lower of aggregate cost or market value. Loan fees (net of certain direct loan origination costs) on loans held for sale are deferred until the related loans are sold or repaid. Gains or losses on loan sales are recognized at the time of sale and determined using the specific identification method.
	Securities
	Debt securities available for sale principally include U.S. Treasury and agency securities, Government Sponsored Entity (GSE) mortgage-backed securities, certain securities of state and political subdivisions, and corporates. Securities classified as available for sale are measured at fair value. Unrealized holding gains and losses are excluded from earnings and reported in accumulated other comprehensive income (loss) until realized. Realized gains and losses on sales are computed by the specific identification method at the time of disposition and are shown separately as a component of noninterest income.
	Securities held to maturity are carried at amortized historical cost based on management’s intention, and the Company’s ability to hold them to maturity. The Company classifies certain securities of state and political subdivisions as held to maturity.
	Trading securities, acquired for subsequent sale to customers, are carried at fair value. Market adjustments, fees and gains or losses on the sale of trading securities are considered to be a normal part of operations and are included in trading and investment banking income.
	Equity-method investments
	The Company accounts for certain other investments using equity-method accounting. For non-marketable equity-method investments, the Company’s proportionate share of the income or loss is recognized on a one-quarter lag. When transparency in pricing exists, other investments are considered marketable equity-method investments. For marketable equity-method investments, the Company recognizes its proportionate share of income or loss as of the date of the Company’s consolidated financial statements.
	Goodwill and Other Intangibles
	Goodwill is tested for impairment annually and more frequently whenever events or changes in circumstance indicate that it is more likely than not that the fair value of a reporting unit is less than its carrying value.
	To test goodwill for impairment, the Company performs a qualitative assessment of each reporting unit. If the Company determines, on the basis of qualitative factors, that the fair value of the reporting unit is more likely than not greater than the carrying amount, the two-step impairment test is not required. Otherwise, the Company compares the fair value of its reporting units to their carrying amounts to determine if an impairment is indicated. If an impairment is indicated, the implied fair value of the reporting unit’s goodwill is compared to its carrying amount. An impairment loss is measured as the excess of the carrying value of a reporting unit’s goodwill over its implied fair value. As a result of such impairment tests, the Company has not recognized an impairment charge.
	No goodwill impairments were recognized in 2014, 2013, or 2012. Other intangible assets are amortized over a period of up to 17 years and are evaluated for impairment when events or circumstances dictate. No intangible asset impairments were recognized in 2014, 2013, or 2012. The Company does not have any indefinite lived intangible assets.
	Premises and Equipment
	Premises and equipment are stated at cost less accumulated depreciation, which is computed primarily on the straight line method. Premises are depreciated over 15 to 40 year lives, while equipment is depreciated over lives of 3 to 20 years. Gains and losses from the sale of Premises and equipment are included in other noninterest income.
	Impairment of Long-Lived Assets
	Long-lived assets, including premises and equipment, are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset or group of assets may not be recoverable. The impairment review includes a comparison of future cash flows expected to be generated by the asset or group of assets to their current carrying value. If the carrying value of the asset or group of assets exceeds expected cash flows (undiscounted and without interest charges), an impairment loss is recognized to the extent the carrying value exceeds fair value. No impairments were recognized in 2014, 2013, or 2012.
	Income Taxes
	The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Under this method, deferred tax assets and liabilities are measured based on the differences between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the periods in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The provision for deferred income taxes represents the change in the deferred income tax accounts during the year excluding the tax effect of the change in net unrealized gain (loss) on securities available for sale.
	The Company records deferred tax assets to the extent these assets will more likely than not be realized. All available evidence is considered in making such determination, including future reversals of existing taxable temporary differences, projected future taxable income, tax planning strategies and recent financial operations. A valuation allowance is recorded for the portion of deferred tax assets that do not meet the more-likely-than-not threshold, and any changes to the valuation allowance are recorded in income tax expense.
	The Company records the financial statement effects of an income tax position when it is more likely than not, based on the technical merits, that it will be sustained upon examination. A tax position that meets the more-likely-than-not recognition threshold is measured and recorded as the largest amount of tax benefit that is greater than 50 percent likely of being realized upon ultimate settlement with a taxing authority. Previously recognized tax positions are derecognized in the first period in which it is no longer more likely than not that the tax position will be sustained. The benefit associated with previously unrecognized tax positions are generally recognized in the first period in which the more-likely-than-not threshold is met at the reporting date, the tax matter is ultimately settled through negotiation or litigation or when the related statute of limitations for the relevant taxing authority to examine and challenge the tax position has expired. The recognition, derecognition and measurement of tax positions are based on management’s best judgment given the facts, circumstance and information available at the reporting date.
	The Company recognizes accrued interest related to unrecognized tax benefits in interest expense and penalties in other noninterest expense. Accrued interest and penalties are included within the related liability lines in the consolidated balance sheets. For the year ended December 31, 2014, the Company has recognized an immaterial amount in interest and penalties related to the unrecognized tax benefits.
	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, one of the Company’s derivatives is designated in a qualifying hedging relationship. 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 derivatives are recognized directly in earnings.
	Per Share Data
	Basic income per share is computed based on the weighted average number of shares of common stock outstanding during each period. Diluted year-to-date income per share includes the dilutive effect of 600,705; 562,741; and 398,939 shares issuable upon the exercise of stock options and nonvested restricted shares granted by the Company at December 31, 2014, 2013, and 2012, respectively.
	Options issued under employee benefit plans to purchase 249,368, and 504,938 shares of common stock were outstanding at December 31, 2014, and 2012, respectively, but were not included in the computation of diluted earnings per share because the options were anti-dilutive.
	Accounting for Stock-Based Compensation
	The Company measures the cost of employee services received in exchange for an award of equity instruments based on the fair value of the award on the date of the grant. The grant date fair value is estimated using either an option-pricing model which is consistent with the terms of the award or an observed market price, if such a price exists. Such cost is generally recognized over the vesting period during which an employee is required to provide service in exchange for the award and, in some cases, when performance metrics are met. The Company also estimates the number of instruments that will ultimately be issued by applying a forfeiture rate to each grant.

NEW_ACCOUNTING_PRONOUNCEMENTS

NEW ACCOUNTING PRONOUNCEMENTS	12 Months Ended
	Dec. 31, 2014
Accounting Changes and Error Corrections [Abstract]
NEW ACCOUNTING PRONOUNCEMENTS	2.  NEW ACCOUNTING PRONOUNCEMENTS
	Investment Companies    In June 2013, the FASB issued Accounting Standards Update (ASU) No. 2013-08, “Amendments to the Scope, Measurement, and Disclosure Requirements” for investment companies. The amendments changed the assessment of whether an entity is an investment company by requiring an entity to possess certain fundamental characteristics, while allowing judgment in assessing other typical characteristics. The ASU was effective January 1, 2014, and the Company did not change the status of any subsidiary, or the accounting applied to a subsidiary, under the new guidelines.
	Accounting for Investments in Qualified Affordable Housing Projects    In January 2014, the FASB issued ASU No. 2014-01, “Accounting for Investments in Qualified Affordable Housing Projects.” The amendments permit reporting entities to make an accounting policy election to account for their investments in qualified affordable housing projects using the proportional amortization method if certain conditions are met. Regardless of whether the reporting entity chooses to elect the proportional amortization method, this ASU introduces new recurring disclosures about all investments in qualified affordable housing projects. The ASU is effective for interim and annual reporting periods beginning after December 15, 2014. The adoption of this accounting pronouncement will not have a significant impact on the Company’s consolidated financial statements or financial statement disclosures.
	Reclassification of Residential Real Estate Loans    In January 2014, the FASB issued ASU No. 2014-04, “Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure.” The amendment is intended to reduce diversity in practice by clarifying when an in substance repossession or foreclosure occurs, that is, when a creditor should be considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loans such that the loan receivable should be derecognized and the real stated property recognized. The amendments in this update are effective for interim and annual periods beginning after December 15, 2014. The adoption of this accounting pronouncement will not have a significant impact on the Company’s consolidated financial statements.
	Revenue Recognition    In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers.” The issuance is part of a joint effort by the FASB and the International Accounting Standards Board (IASB) to enhance financial reporting by creating common revenue recognition guidance for U.S. Generally Accepted Accounting Principles (GAAP) and International Financial Reporting Standards (IFRS) and, thereby, improving the consistency of requirements, comparability of practices and usefulness of disclosures. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The amendments in this update are effective for interim and annual periods beginning after December 15, 2016. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is currently evaluating the effect that ASU 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting.
	Repurchase-to-Maturity Transactions    In June 2014, the FASB issued ASU No. 2014-11, “Repurchase-to-Maturity Transactions, Repurchased Financings, and Disclosures.” The amendment changes the accounting for repurchase-to-maturity transactions and linked repurchase financings to secured borrowing accounting, which is consistent with accounting for other repurchase agreements. Additionally, the amendment requires new disclosures on transfers accounted for as sales in transactions that are economically similar to repurchase agreements and requires increased transparency on collateral pledged in secured borrowings. The accounting changes in the standard and the disclosures for transactions accounted for as sales are effective for interim and annual periods beginning after December 15, 2014. The disclosures for repurchase agreements, securities lending transactions, and repos-to-maturity accounted for as secured borrowings are required for annual periods beginning after December 15, 2014, and interim periods beginning after March 15, 2015. Early application is not permitted. The adoption of this accounting pronouncement will have no impact on the Company’s consolidated financial statements except for additional financial statement disclosures.
	Stock Compensation    In June 2014, the FASB issued ASU No. 2014-12, “Accounting for Share-Based Payments When the Terms of an Award Provide that a Performance Target could be Achieved after the Requisite Service Period.” The amendment is intended to reduce diversity in practice by clarifying that a performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. The amendments in this update are effective for interim and annual periods beginning after December 15, 2015 with early adoption permitted. The adoption of this accounting pronouncement will not have a significant impact on the Company’s consolidated financial statements.
	Troubled Debt Restructurings by Creditors    In August 2014, the FASB issued ASU No. 2014-14, “Classification of Certain Government-Guaranteed Mortgage Loans upon Foreclosure.” The amendment is intended to reduce diversity in practice in the classification of mortgage loans extended under certain government-sponsored loan guarantee programs, such as those offered by the Federal Housing Administration (FHA) and the Department of Veterans Affairs (VA), that entitle the creditor to recover all or a portion of the unpaid principal balance from the government if a borrower defaults. This update requires government-guaranteed mortgage loans that meet certain criteria to be derecognized and a separate receivable be recognized upon foreclosure. The amendments in this update are effective for interim and annual periods beginning after December 15, 2014. The adoption of this accounting pronouncement will not have a significant impact on the Company’s consolidated financial statements.
	Going Concern    In August 2014, the FASB issued ASU No. 2014-15, “Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern.” The amendment addresses management’s responsibility in regularly evaluating whether there is substantial doubt about a company’s ability to continue as a going concern. The amendments in this update are effective for the annual period ending after December 15, 2016, and for annual and interim periods thereafter, although early adoption is permitted. The adoption of this accounting pronouncement will not have a significant impact on the Company’s consolidated financial statements.
	Derivatives and Hedging    In November 2014, the FASB issued ASU No. 2014-16, “Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share is More Akin to Debt or to Equity.” The amendment is intended to address how current U.S. GAAP should be interpreted in evaluating the economic characteristics and risks of a host contract in a hybrid financial instrument that is issued in the form of a share. The amendments in this update are effective for the annual period beginning after December 15, 2015, and for annual and interim periods thereafter, although early adoption is permitted. The adoption of this accounting pronouncement will not have a significant impact on the Company’s consolidated financial statements.

LOANS_AND_ALLOWANCE_FOR_LOAN_L

LOANS AND ALLOWANCE FOR LOAN LOSSES	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
LOANS AND ALLOWANCE FOR LOAN LOSSES	3.  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. The Company maintains an independent loan review department that reviews and validates the credit risk program 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.
	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 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.
	This table provides a summary of loan classes and an aging of past due loans as of December 31, 2014 (in thousands):
			As Of December 31, 2014
			30-89			Greater			Non-Accrual			Total		Current			Total Loans
			Days Past			than 90			Loans			Past Due
			Due and			Days Past
			Accruing			Due and
						Accruing
	Commercial:
	Commercial		$	2,509		$	363		$	13,114		$	15,986	$	3,798,023		$	3,814,009
	Commercial—credit card			267			147			37			451		115,258			115,709
	Real estate:
	Real estate—construction			1,244			—			983			2,227		253,779			256,006
	Real estate—commercial			1,727			61			12,037			13,825		1,852,476			1,866,301
	Real estate—residential			828			113			562			1,503		318,324			319,827
	Real estate—HELOC			1,371			—			19			1,390		642,196			643,586
	Consumer:
	Consumer—credit card			2,268			2,303			560			5,131		305,165			310,296
	Consumer—other			1,743			843			70			2,656		98,314			100,970
	Leases			—			—			—			—		39,090			39,090
	Total loans		$	11,957		$	3,830		$	27,382		$	43,169	$	7,422,625		$	7,465,794
	This table provides a summary of loan classes and an aging of past due loans as of December 31, 2013 (in thousands):
			As Of December 31, 2013
			30-89			Greater			Non-Accrual			Total		Current			Total Loans
			Days Past			than 90			Loans			Past Due
			Due and			Days Past
			Accruing			Due and
						Accruing
	Commercial:
	Commercial		$	2,107		$	135		$	8,042		$	10,284	$	3,291,219		$	3,301,503
	Commercial—credit card			362			82			38			482		102,788			103,270
	Real estate:
	Real estate—construction			186			—			934			1,120		151,755			152,875
	Real estate—commercial			3,611			344			19,213			23,168		1,678,983			1,702,151
	Real estate—residential			1,257			13			868			2,138		287,218			289,356
	Real estate—HELOC			880			6			210			1,096		565,032			566,128
	Consumer:
	Consumer—credit card			3,230			2,448			1,031			6,709		311,627			318,336
	Consumer—other			1,727			190			370			2,287		60,625			62,912
	Leases			—			—			—			—		23,981			23,981
	Total loans		$	13,360		$	3,218		$	30,706		$	47,284	$	6,473,228		$	6,520,512
	The Company sold $73.5 million, $121.8 million, and $246.3 million of residential real estate and student loans without recourse during the periods ended December 31, 2014, 2013, and 2012 respectively.
	The Company has ceased the recognition of interest on loans with a carrying value of $27.4 million and $30.7 million at December 31, 2014 and 2013, respectively. Restructured loans totaled $9.3 million and $12.1 million at December 31, 2014 and 2013, respectively. Loans 90 days past due and still accruing interest amounted to $3.8 million and $3.2 million at December 31, 2014 and 2013, respectively. There was an insignificant amount of interest recognized on impaired loans during 2014, 2013, and 2012.
	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 rankings 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 ranking 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 institution’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 bank 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 as of December 31, 2014 (in thousands):
	Credit Exposure
	Credit Risk Profile by Risk Rating
			Commercial			Real estate-			Real estate-
						construction			commercial
			2014			2014			2014
	Non-watch list		$	3,532,611		$	253,895		$	1,780,323
Watch			72,283			181			31,984
Special Mention			98,750			756			8,691
Substandard			110,365			1,174			45,303
Total		$	3,814,009		$	256,006		$	1,866,301
Credit Exposure
Credit Risk Profile Based on Payment Activity
		Commercial-			Real estate-			Real estate-
		credit card			residential			HELOC
		2014			2014			2014
Performing		$	115,672		$	319,265		$	643,567
Non-performing			37			562			19
Total		$	115,709		$	319,827		$	643,586
		Consumer-			Consumer-			Leases
		credit card			other
		2014			2014			2014
Performing		$	309,736		$	100,900		$	39,090
Non-performing			560			70			—
Total		$	310,296		$	100,970		$	39,090
This table provides an analysis of the credit risk profile of each loan class as of December 31, 2013 (in thousands):
Credit Exposure
Credit Risk Profile by Risk Rating
		Commercial			Real estate-			Real estate-
					construction			commercial
		2013			2013			2013
Non-watch list		$	3,041,224		$	151,359		$	1,565,894
Watch			110,932			210			76,647
Special Mention			78,064			—			19,876
Substandard			71,283			1,306			39,734
Total		$	3,301,503		$	152,875		$	1,702,151
Credit Exposure
Credit Risk Profile Based on Payment Activity
		Commercial-			Real estate-			Real estate-
		credit card			residential			HELOC
		2013			2013			2013
Performing		$	103,232		$	288,488		$	565,918
Non-performing			38			868			210
Total		$	103,270		$	289,356		$	566,128
		Consumer-			Consumer-			Leases
		credit card			other
		2013			2013			2013
Performing		$	317,305		$	62,542		$	23,981
Non-performing			1,031			370			—
Total		$	318,336		$	62,912		$	23,981
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 unidentified 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, 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 ranking 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 120 cumulative days and open-end retail loans (such as home equity lines of credit and consumer credit cards) that become past due 180 cumulative days are classified as a loss and charged-off.
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 year ended December 31, 2014 (in thousands):
		Year Ended December 31, 2014
		Commercial			Real estate			Consumer			Leases		Total
Allowance for loan losses:
Beginning balance		$	48,886		$	15,342		$	10,447		$	76	$	74,751
Charge-offs			(7,307	)		(259	)		(11,427	)		—		(18,993	)
Recoveries			848			44			2,490			—		3,382
Provision			12,922			(4,402	)		8,411			69		17,000
Ending Balance		$	55,349		$	10,725		$	9,921		$	145	$	76,140
Ending Balance: individually evaluated for impairment		$	972		$	935		$	—		$	—	$	1,907
Ending Balance: collectively evaluated for impairment			54,377			9,790			9,921			145		74,233
Loans:
Ending Balance: loans		$	3,929,718		$	3,085,720		$	411,266		$	39,090	$	7,465,794
Ending Balance: individually evaluated for impairment			17,060			10,243			1			—		27,304
Ending Balance: collectively evaluated for impairment			3,912,658			3,075,477			411,265			39,090		7,438,490
This table provides a rollforward of the allowance for loan losses by portfolio segment for the year ended December 31, 2013 (in thousands):
		Year Ended December 31, 2013
		Commercial			Real estate			Consumer			Leases		Total
Allowance for loan losses:
Beginning balance		$	43,390		$	15,506		$	12,470		$	60	$	71,426
Charge-offs			(4,748	)		(775	)		(12,131	)		—		(17,654	)
Recoveries			867			77			2,535			—		3,479
Provision			9,377			534			7,573			16		17,500
Ending Balance		$	48,886		$	15,342		$	10,447		$	76	$	74,751
Ending Balance: individually evaluated for impairment		$	2,882		$	1,370		$	—		$	—	$	4,252
Ending Balance: collectively evaluated for impairment			46,004			13,972			10,447			76		70,499
Loans:
Ending Balance: loans		$	3,404,773		$	2,710,510		$	381,248		$	23,981	$	6,520,512
Ending Balance: individually evaluated for impairment			14,635			15,543			11			—		30,189
Ending Balance: collectively evaluated for impairment			3,390,138			2,694,967			381,237			23,981		6,490,323
This table provides a rollforward of the allowance for loan losses by portfolio segment for the year ended December 31, 2012 (in thousands):
		Year Ended December 31, 2012
		Commercial			Real estate			Consumer			Leases		Total
Allowance for loan losses:
Beginning balance		$	37,927		$	20,486		$	13,593		$	11	$	72,017
Charge-offs			(8,446	)		(932	)		(12,678	)		—		(22,056	)
Recoveries			1,136			28			2,801			—		3,965
Provision			12,773			(4,076	)		8,754			49		17,500
Ending Balance		$	43,390		$	15,506		$	12,470		$	60	$	71,426
Ending Balance: individually evaluated for impairment		$	1,393		$	781		$	—		$	—	$	2,174
Ending Balance: collectively evaluated for impairment			41,977			14,725			12,470			60		69,252
Loans:
Ending Balance: loans		$	2,978,014		$	2,300,583		$	389,068		$	19,084	$	5,686,749
Ending Balance: individually evaluated for impairment			15,057			11,203			49			—		26,309
Ending Balance: collectively evaluated for impairment			2,962,957			2,289,380			389,019			19,084		5,660,440
Impaired Loans
This table provides an analysis of impaired loans by class for the year ended December 31, 2014 (in thousands):
		As Of December 31, 2014
		Unpaid			Recorded			Recorded			Total		Related			Average
		Principal			Investment			Investment			Recorded		Allowance			Recorded
		Balance			with No			with			Investment					Investment
					Allowance			Allowance
Commercial:
Commercial		$	21,758		$	13,928		$	3,132		$	17,060	$	972		$	16,022
Commercial—credit card			—			—			—			—		—			—
Real estate:
Real estate—construction			1,540			983			—			983		—			939
Real estate—commercial			9,546			4,454			3,897			8,351		935			11,298
Real estate—residential			1,083			909			—			909		—			1,006
Real estate—HELOC			—			—			—			—		—			—
Consumer:
Consumer—credit card			—			—			—			—		—			—
Consumer—other			1			1			—			1		—			12
Leases			—			—			—			—		—			—
Total		$	33,928		$	20,275		$	7,029		$	27,304	$	1,907		$	29,277
This table provides an analysis of impaired loans by class for the year ended December 31, 2013 (in thousands):
		As Of December 31, 2013
		Unpaid			Recorded			Recorded			Total		Related			Average
		Principal			Investment			Investment			Recorded		Allowance			Recorded
		Balance			with No			with			Investment					Investment
					Allowance			Allowance
Commercial:
Commercial		$	17,227		$	3,228		$	11,407		$	14,635	$	2,882		$	14,791
Commercial—credit card			—			—			—			—		—			—
Real estate:
Real estate—construction			1,408			810			123			933		—			1,186
Real estate—commercial			14,686			5,305			8,218			13,523		94			10,506
Real estate—residential			1,317			1,087			—			1,087		1,276			1,122
Real estate—HELOC			—			—			—			—		—			—
Consumer:
Consumer—credit card			—			—			—			—		—			—
Consumer—other			12			11			—			11		—			34
Leases			—			—			—			—		—			—
Total		$	34,650		$	10,441		$	19,748		$	30,189	$	4,252		$	27,639
This table provides an analysis of impaired loans by class for the year ended December 31, 2012 (in thousands):
		As Of December 31, 2012
		Unpaid			Recorded			Recorded			Total		Related			Average
		Principal			Investment			Investment			Recorded		Allowance			Recorded
		Balance			with No			with			Investment					Investment
					Allowance			Allowance
Commercial:
Commercial		$	22,453		$	12,119		$	2,938		$	15,057	$	1,393		$	13,287
Commercial—credit card			—			—			—			—		—			—
Real estate:
Real estate—construction			276			276			—			276		—			118
Real estate—commercial			9,334			6,777			2,213			8,990		733			9,925
Real estate—residential			2,357			1,714			223			1,937		48			2,622
Real estate—HELOC			—			—			—			—		—			—
Consumer:
Consumer—credit card			—			—			—			—		—			—
Consumer—other			51			49			—			49		—			43
Leases			—			—			—			—		—			—
Total		$	34,471		$	20,935		$	5,374		$	26,309	$	2,174		$	25,995
Troubled Debt Restructurings
A loan modification is considered a troubled debt restructuring (TDR) when a concession had 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 $477 thousand and $347 thousand in commitments to lend to borrowers with loan modifications classified as TDR’s as of December 31, 2014 and December 31, 2013, respectively. The Company made no TDR’s in the last 12 months that had payment defaults for the year ended December 31, 2014.
This table provides a summary of loans restructured by class during the years ended December 31, 2014 and 2013 (in thousands):
		Year Ended December 31, 2014									Year Ended December 31, 2013
		Number			Pre-Modification			Post-			Number		Pre-Modification			Post-
		of			Outstanding			Modification			of		Outstanding			Modification
		Contracts			Recorded			Outstanding			Contracts		Recorded			Outstanding
					Investment			Recorded					Investment			Recorded
								Investment								Investment
Troubled Debt Restructurings
Commercial:
Commercial			1		$	469		$	469			2	$	1,128		$	1,066
Commercial—credit card			—			—			—			—		—			—
Real estate:
Real estate—construction			—			—			—			—		—			—
Real estate—commercial			1			178			178			1		937			937
Real estate—residential			4			277			301			—		—			—
Real estate—HELOC			—			—			—			—		—			—
Consumer:
Consumer—credit card			—			—			—			—		—			—
Consumer—other			—			—			—			—		—			—
Leases			—			—			—			—		—			—
Total			6		$	924		$	948			3	$	2,065		$	2,003

SECURITIES

SECURITIES	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
SECURITIES	4.  SECURITIES
	Securities Available for Sale
	This table provides detailed information about securities available for sale at December 31, 2014 and 2013 (in thousands):
	2014	Amortized		Gross			Gross			Fair Value
		Cost		Unrealized			Unrealized
				Gains			Losses
	U.S. Treasury	$	519,484	$	501		$	(525	)	$	519,460
	U.S. Agencies		991,084		780			(1,175	)		990,689
	Mortgage-backed		3,276,009		28,470			(26,875	)		3,277,604
	State and political subdivisions		1,983,549		22,973			(5,165	)		2,001,357
	Corporates		124,096		—			(1,270	)		122,826
	Total	$	6,894,222	$	52,724		$	(35,010	)	$	6,911,936
	2013	Amortized		Gross			Gross			Fair Value
		Cost		Unrealized			Unrealized
				Gains			Losses
	U.S. Treasury	$	110,789	$	284		$	(873	)	$	110,200
	U.S. Agencies		1,258,176		2,793			(3,306	)		1,257,663
	Mortgage-backed		2,984,963		23,942			(64,339	)		2,944,566
	State and political subdivisions		2,003,509		23,493			(31,756	)		1,995,246
	Corporates		457,275		902			(3,441	)		454,736
	Total	$	6,814,712	$	51,414		$	(103,715	)	$	6,762,411
	The following table presents contractual maturity information for securities available for sale at December 31, 2014 (in thousands):
		Amortized		Fair Value
		Cost
	Due in 1 year or less	$	607,929	$	609,430
	Due after 1 year through 5 years		2,223,097		2,231,267
	Due after 5 years through 10 years		674,876		682,409
	Due after 10 years		112,311		111,226
	Total		3,618,213		3,634,332
	Mortgage-backed securities		3,276,009		3,277,604
	Total securities available for sale	$	6,894,222	$	6,911,936
	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.
	Proceeds from the sales of securities available for sale were $414.0 million, $685.0 million, and $1.0 billion for 2014, 2013, and 2012, respectively. Securities transactions resulted in gross realized gains of $4.1 million for 2014, $8.7 million for 2013, and $20.2 million for 2012. The gross realized losses were $11 thousand for 2014, $200 thousand for 2013, and $30 thousand for 2012.
	Securities available for sale with a market value of $5.7 billion at December 31, 2014, and $5.9 at December 31, 2013, were pledged to secure U.S. Government deposits, other public deposits and certain trust deposits as required by law. Of this amount, securities with a market value of $1.2 billion at December 31, 2014 and $1.7 billion at December 31, 2013 were pledged at the Federal Reserve Discount Window but were unencumbered as of those dates.
	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 December 31, 2014 and 2013 (in thousands).
	2014	Less than 12 months					12 months or more						Total
	Description of Securities	Fair Value		Unrealized			Fair Value			Unrealized			Fair Value		Unrealized
				Losses						Losses					Losses
	U.S. Treasury	$	236,591	$	(329	)	$	14,863		$	(196	)	$	251,454	$	(525	)
	U.S. Agencies		387,999		(689	)		81,593			(486	)		469,592		(1,175	)
	Mortgage-backed		727,142		(8,370	)		616,044			(18,504	)		1,343,186		(26,874	)
	State and political subdivisions		401,934		(1,406	)		226,678			(3,760	)		628,612		(5,166	)
	Corporates		36,655		(243	)		86,171			(1,027	)		122,826		(1,270	)
	Total temporarily- impaired debt securities available for sale	$	1,790,321	$	(11,037	)	$	1,025,349		$	(23,973	)	$	2,815,670	$	(35,010	)
	2013	Less than 12 months					12 months or more						Total
	Description of Securities	Fair Value		Unrealized			Fair Value			Unrealized			Fair Value		Unrealized
				Losses						Losses					Losses
	U.S. Treasury	$	39,822	$	(873	)	$	—		$	—		$	39,822	$	(873	)
	U.S. Agencies		675,509		(3,130	)		9,824			(176	)		685,333		(3,306	)
	Mortgage-backed		1,945,964		(60,719	)		89,147			(3,620	)		2,035,111		(64,339	)
	State and political subdivisions		662,225		(25,064	)		87,061			(6,692	)		749,286		(31,756	)
	Corporates		271,834		(2,458	)		41,522			(983	)		313,356		(3,441	)
	Total temporarily-impaired debt securities available for sale	$	3,595,354	$	(92,244	)	$	227,554		$	(11,471	)	$	3,822,908	$	(103,715	)
	The unrealized losses in the Company’s investments in U.S. treasury obligations, U.S. government agencies, GSE mortgage-backed securities, municipal securities, and corporates were caused by changes in the interest rate environment. 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 December 31, 2014.
	Securities Held to Maturity
	The table below provides detailed information for securities held to maturity at December 31, 2014 and 2013 (in thousands):
	2014	Amortized		Gross			Gross			Fair
		Cost		Unrealized			Unrealized			Value
				Gains			Losses
	State and political subdivisions	$	278,054	$	26,058		$	—		$	304,112
	2013
	State and political subdivisions	$	209,770	$	21,740		$	—		$	231,510
	The following table presents contractual maturity information for securities held to maturity at December 31, 2014 (in thousands):
		Amortized		Fair Value
Cost
Due in 1 year or less	$	15	$	16
Due after 1 year through 5 years		31,389		34,331
Due after 5 years through 10 years		165,062		180,531
Due after 10 years		81,588		89,234
Total securities held to maturity	$	278,054	$	304,112
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 2014, 2013, or 2012.
Trading Securities
The net unrealized gains on trading securities at December 31, 2014, 2013, and 2012 were $101 thousand, $151 thousand, and $403 thousand, respectively. Net unrealized gains/losses were included in trading and investment banking income on the Consolidated Statements of Income.
Federal Reserve Bank Stock and Other Securities
The table below provides detailed information for Federal Reserve Bank stock and other securities at December 31, 2014 and 2013 (in thousands):
2014	Amortized		Gross			Gross			Fair Value
	Cost		Unrealized			Unrealized
			Gains			Losses
FRB and FHLB stock	$	26,279	$	—		$	—		$	26,279
Other securities—marketable		—		16,668			—			16,668
Other securities—non-marketable		21,669		3,937			(79	)		25,527
Total Federal Reserve Bank stock and other	$	47,948	$	20,605		$	(79	)	$	68,474
2013
FRB stock	$	16,279	$	—		$	—		$	16,279
Other securities—marketable		20		16,612			—			16,632
Other securities—non-marketable		17,139		432			—			17,571
Total Federal Reserve Bank stock and other	$	33,438	$	17,044		$	—		$	50,482
Federal Reserve Bank stock is based on the capital structure of the investing bank and is carried at cost. Other marketable and non-marketable securities include 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 $16.7 million at December 31, 2014 and $16.6 million at December 31, 2013. The fair value of other non-marketable securities includes alternative investment securities of $8.5 million at December 31, 2014 and $4.7 million at December 31, 2013. Unrealized gains or losses on alternative investments are recognized in the Equity Earnings on Alternative Investments line of the Company’s Consolidated Statements of Income. Unrealized gains on alternative investments of $422 thousand were recorded in the other noninterest income line of the Company’s Consolidated Statements of Income in the previously filed Form 10-K for the year-ended December 31, 2012. This amount was reclassified to Equity Earnings on Alternative Investments line of the Company’s Consolidated Statements of Income within this filing to conform to the current year presentation.

SECURITIES_PURCHASED_UNDER_AGR

SECURITIES PURCHASED UNDER AGREEMENTS TO RESELL	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
SECURITIES PURCHASED UNDER AGREEMENTS TO RESELL	5.  SECURITIES PURCHASED UNDER AGREEMENTS TO RESELL
	The Company regularly enters into agreements for the purchase of securities with simultaneous agreements to resell (resell agreements). The agreements permit the Company to sell or repledge these securities. Resell agreements were $95.5 million and $75.2 million at December 31, 2014 and 2013, respectively. The Company obtains possession of collateral with a market value equal to or in excess of the principal amount loaned under resell agreements.

LOANS_TO_OFFICERS_AND_DIRECTOR

LOANS TO OFFICERS AND DIRECTORS	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
LOANS TO OFFICERS AND DIRECTORS	6.  LOANS TO OFFICERS AND DIRECTORS
	Certain Company and principal Bank executive officers and directors, including companies in which those persons are principal holders of equity securities or are general partners, borrow in the normal course of business from the Bank. All such loans have been made on the same terms, including interest rates and collateral, as those prevailing at the same time for comparable transactions with unrelated parties. In addition, all such loans are current as to repayment terms.
	For the years 2014 and 2013, an analysis of activity with respect to such aggregate loans to related parties appears below (in thousands):
		Year Ended December 31
		2014			2013
	Balance—beginning of year	$	493,373		$	480,291
	New loans		139,442			149,709
	Repayments		(91,308	)		(136,627	)
	Balance—end of year	$	541,507		$	493,373

GOODWILL_AND_OTHER_INTANGIBLES

GOODWILL AND OTHER INTANGIBLES	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND OTHER INTANGIBLES	7.  GOODWILL AND OTHER INTANGIBLES
	Changes in the carrying amount of goodwill for the years ended December 31, 2014 and December 31, 2013 by operating segment are as follows (in thousands):
		Bank		Institutional		Asset		Total
				Investment		Servicing
				Management
	Balances as of January 1, 2014	$	142,753	$	47,529	$	19,476	$	209,758
	Balances as of December 31, 2014	$	142,753	$	47,529	$	19,476	$	209,758
	Balances as of January 1, 2013	$	142,753	$	47,529	$	19,476	$	209,758
	Balances as of December 31, 2013	$	142,753	$	47,529	$	19,476	$	209,758
	Following are the intangible assets that continue to be subject to amortization as of December 31, 2014 and 2013 (in thousands):
		As of December 31, 2014
		Gross Carrying		Accumulated		Net Carrying
		Amount		Amortization		Amount
	Core deposit intangible assets	$	36,497	$	32,721	$	3,776
	Customer relationships		104,560		64,980		39,580
	Other intangible assets		3,247		2,612		635
	Total intangible assets	$	144,304	$	100,313	$	43,991
		As of December 31, 2013
	Core deposit intangible assets	$	36,497	$	31,674	$	4,823
	Customer relationships		103,960		54,062		49,898
	Other intangible assets		3,247		2,383		864
	Total intangible assets	$	143,704	$	88,119	$	55,585
	Amortization expense for the years ended December 31, 2014, 2013, and 2012 was $12.2 million, $13.2 million and $14.8 million, respectively. The following table discloses the estimated amortization expense of intangible assets in future years (in thousands):
	For the year ending December 31, 2015	$	9,636
	For the year ending December 31, 2016		8,428
	For the year ending December 31, 2017		7,185
	For the year ending December 31, 2018		4,994
	For the year ending December 31, 2019		4,204

PREMISES_AND_EQUIPMENT

PREMISES AND EQUIPMENT	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
PREMISES AND EQUIPMENT	8.  PREMISES AND EQUIPMENT
	Premises and equipment consisted of the following (in thousands):
		December 31
		2014			2013
	Land	$	43,798		$	44,731
	Buildings and leasehold improvements		301,687			300,175
	Equipment		120,745			124,992
	Software		132,265			121,974
			598,495			591,872
	Accumulated depreciation		(246,457	)		(247,519	)
	Accumulated amortization		(94,203	)		(94,664	)
	Premises and equipment, net	$	257,835		$	249,689
	Consolidated rental and operating lease expenses were $12.0 million in 2014, $10.9 million in 2013, and $10.8 million in 2012. Consolidated bank premises and equipment depreciation and amortization expenses were $34.2 million in 2014, $31.0 million in 2013, and $26.1 million in 2011.
	Minimum future rental commitments as of December 31, 2014, for all non-cancelable operating leases are as follows (in thousands):
	2015	$	9,325
	2016		8,626
	2017		8,335
	2018		7,903
	2019		7,668
	Thereafter		31,616
	Total	$	73,473

BORROWED_FUNDS

BORROWED FUNDS	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
BORROWED FUNDS	9.  BORROWED FUNDS
	The components of the Company’s short-term and long-term debt are as follows (in thousands):
		December 31
		2014		2013
	Short-term debt:
	Federal Home Loan Bank 5.89% due 2014	$	—	$	107
	Total short-term debt		—		107
	Long-term debt:
	Kansas Equity Fund IV, L.P. 0% due 2017		71		173
	Kansas Equity Fund V, L.P. 0% due 2017		119		176
	Kansas Equity Fund VI, L.P. 0% due 2017		239		369
	Kansas Equity Fund IX, L.P. 0% due 2023		341		408
	Kansas Equity Fund X, L.P. 0% due 2021		419		469
	Kansas City Equity Fund 2007, L.L.C. 0% due 2016		86		162
	Kansas City Equity Fund 2008, L.L.C. 0% due 2016		149		290
	Kansas City Equity Fund 2009, L.L.C. 0% due 2017		371		504
	St. Louis Equity Fund 2007 L.L.C. 0% due 2016		39		179
	St. Louis Equity Fund 2008 L.L.C. 0% due 2016		160		310
	St. Louis Equity Fund 2009 L.L.C. 0% due 2017		395		544
	St. Louis Equity Fund 2012 L.L.C. 0% due 2020		402		481
	St. Louis Equity Fund 2013 L.L.C. 0% due 2021		1,758		—
	St. Louis Equity Fund 2014 L.L.C. 0% due 2022		1,819		—
	MHEG Community Fund 41, L.P. 0% due 2024		957		990
	MHEG Community Fund 43, L.P. 0% due 2026		1,485		—
	Total long-term debt		8,810		5,055
	Total borrowed funds	$	8,810	$	5,162
	Aggregate annual repayments of long-term debt at December 31, 2014, are as follows (in thousands):
	2015	$	1,584
	2016		1,552
	2017		1,252
	2018		1,112
	2019		1,091
	Thereafter		2,219
	Total	$	8,810
	The Company became a member bank of the Federal Home Loan Bank (FHLB) of Des Moines in March 2014. Through this relationship, the Company purchased $10.0 million of FHLB stock and has access to additional liquidity and funding sources through FHLB advances. The Company’s borrowing capacity is dependent upon the amount of collateral the Company places at the FHLB. On December 24, 2014, the FHLB issued a 30-day letter of credit of $150.0 million on behalf of the Company to secure public fund deposits, which expired on January 23, 2015. The letter of credit reduced the Company’s borrowing capacity with the FHLB from $483 million to $333 million as of December 31, 2014. The Company had no outstanding FHLB advances as of December 31, 2014. All of the Federal Home Loan Bank notes are secured by investment securities of the Company. Federal Home Loan Bank notes require monthly principal and interest payments and may require a penalty for payoff prior to the maturity date.
	The Company has a revolving line of credit with Wells Fargo, N.A. which allows the Company to borrow up to $25.0 million for general working capital purposes. The interest rate applied to borrowed balances will be at the Company’s option either 1.00 percent above LIBOR or 1.75 percent below Prime on the date of an advance. The Company will also pay a 0.2 percent unused commitment fee for unused portions of the line of credit. The Company currently has no outstanding balance on this line of credit.
	The Company enters into sales of securities with simultaneous agreements to repurchase (repurchase agreements). The amounts received under these agreements represent short-term borrowings. The amount outstanding at December 31, 2014, was $2.0 billion (with accrued interest payable of $10 thousand). The amount outstanding at December 31, 2013, was $1.6 billion (with accrued interest payable of $8 thousand).
	The carrying amounts and market values of the securities and the related repurchase liabilities and weighted average interest rates of the repurchase liabilities (grouped by maturity of the repurchase agreements) were as follows as of December 31, 2014 (in thousands):
	Maturity of the Repurchase Liabilities	Securities Market		Repurchase		Weighted Average
		Value		Liabilities		Interest Rate
	On Demand	$	3,008	$	3,001		0.01	%
	2 to 30 days		2,003,126		1,979,783		0.19
	Over 90 Days		301		300		0
	Total	$	2,006,435	$	1,983,084		0.19	%

REGULATORY_REQUIREMENTS

REGULATORY REQUIREMENTS	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
REGULATORY REQUIREMENTS	10.  REGULATORY REQUIREMENTS
	Payment of dividends by the Bank to the parent company is subject to various regulatory restrictions. For national banks, the governing regulatory agency must approve the declaration of any dividends generally in excess of the sum of net income for that year and retained net income for the preceding two years.
	The Bank maintains a reserve balance with the Federal Reserve Bank as required by law. During 2014, this amount averaged $729.1 million, compared to $639.7 million in 2013.
	The Company is required to maintain minimum amounts of capital to total “risk weighted” assets, as defined by the banking regulators. At December 31, 2014, the Company is required to have minimum tier 1 and total capital ratios of 4.0% and 8.0%, respectively. The Company’s actual ratios at that date were 13.29% and 14.04%, respectively. The Company is required to have a minimum leverage ratio of 4.0%, and the leverage ratio at December 31, 2014, was 8.72%.
	As of December 31, 2014, the most recent notification from the Office of Comptroller of the Currency categorized the Bank as well capitalized under the regulatory framework for prompt corrective action. To be categorized as well-capitalized the Bank must maintain total risk-based, tier 1 risk-based and tier 1 leverage ratios of 10.0%, 6.0% and 5.0%, respectively. There are no conditions or events since that notification that management believes have changed the Bank’s category.
	In July 2013 the Federal Reserve approved a final rule to implement in the United States the Basel III regulatory capital reforms from the Basel Committee on Banking Supervision and certain changes required by the Dodd-Frank Act. The final rule increases minimum requirements for both the quantity and quality of capital held by banking organizations. The rule includes a new minimum ratio of common equity tier 1 capital to risk-weighted assets of 4.5% and a common equity tier 1 capital conservation buffer of 2.5% of risk-weighted assets. The final rule also adjusted the methodology for calculating risk-weighted assets to enhance risk sensitivity. Beginning January 1, 2015, the Company must be compliant with revised minimum regulatory capital ratios and will begin the transitional period for definitions of regulatory capital and regulatory capital adjustments and deductions established under the final rule. Compliance with the risk-weighted asset calculations will be required on January 1, 2015. The Company’s capital ratios are higher than those required in the final rule.
	In addition, under amendments to the BHCA effected by the Dodd-Frank Act and commonly known as the Volcker Rule, the Company and its subsidiaries are subject to extensive limits on proprietary trading and on owning or sponsoring hedge funds and private-equity funds. The limits on proprietary trading are largely focused on purchases or sales of financial instruments by a banking entity as principal primarily for the purpose of short-term resale, benefitting from actual or expected short-term price movements, or realizing short-term arbitrage profits. The limits on owning or sponsoring hedge funds and private-equity funds are designed to ensure that banking entities generally maintain only small positions in managed or advised funds and are not exposed to significant losses arising directly or indirectly from them. The Volcker Rule also provides for increased capital charges, quantitative limits, rigorous compliance programs, and other restrictions on permitted proprietary trading and fund activities, including a prohibition on transactions with a covered fund that would constitute a covered transaction under Sections 23A and 23B of the Federal Reserve Act. The Company is currently assessing the impact to its businesses of the final regulation implementing the Volcker Rule, which was issued in December 2013, and will have fully conformed its activities by July 21, 2015.
	Actual capital amounts as well as required and well-capitalized tier 1, total and tier 1 Leverage ratios as of December 31, for the Company and its banks are as follows (in thousands):
		2014
		Actual					For Capital					To Be Well
							Adequacy					Capitalized Under
							Purposes					Prompt Corrective
												Action Provisions
		Amount		Ratio			Amount		Ratio			Amount		Ratio
	Tier 1 Capital:
	UMB Financial Corporation	$	1,393,389		13.29	%	$	419,383		4	%	$	N/A		N/A	%
	UMB Bank, n. a.		1,209,096		11.68			414,135		4			621,202		6
	Total Capital:
	UMB Financial Corporation		1,471,631		14.04			838,766		8			N/A		N/A
	UMB Bank, n. a.		1,287,338		12.43			828,270		8			1,035,337		10
	Tier 1 Leverage:
	UMB Financial Corporation		1,393,389		8.72			639,476		4			N/A		N/A
	UMB Bank, n. a.		1,209,096		7.63			634,187		4			792,733		5
		2013
	Tier 1 Capital:
	UMB Financial Corporation	$	1,285,100		13.61	%	$	377,681		4	%	$	N/A		N/A	%
	UMB Bank, n. a.		1,095,446		11.73			373,509		4			560,264		6
	Total Capital:
	UMB Financial Corporation		1,362,015		14.43			755,361		8			N/A		N/A
	UMB Bank, n. a.		1,172,361		12.56			747,018		8			933,773		10
	Tier 1 Leverage:
	UMB Financial Corporation		1,285,100		8.41			611,206		4			N/A		N/A
	UMB Bank, n. a.		1,095,446		7.21			608,148		4			760,185		5

EMPLOYEE_BENEFITS

EMPLOYEE BENEFITS	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
EMPLOYEE BENEFITS	11.  EMPLOYEE BENEFITS
	The Company has a discretionary noncontributory profit sharing plan, which features an employee stock ownership plan. This plan is for the benefit of substantially all eligible officers and employees of the Company and its subsidiaries. The Company has accrued and anticipates making a discretionary payment of $2.0 million in March 2015, for 2014. A $2.9 million contribution was paid in 2014, for 2013. A $2.5 million contribution was paid in 2013, for 2012.
	The Company has a qualified 401(k) profit sharing plan that permits participants to make contributions by salary deduction. The Company made a matching contribution to this plan of $5.2 million in 2014, for 2013 and $5.1 million in 2013, for 2012. The Company anticipates making a matching contribution of $5.9 million in March 2015, for 2014.
	The Company recognized $2.0 million, $2.0 million, and $2.3 million in expense related to outstanding stock options and $7.2 million, $5.9 million, and $4.6 million in expense related to outstanding restricted stock grants for the years ended December 31, 2014, 2013, and 2012, respectively. The Company has $5.2 million of unrecognized compensation expense related to the outstanding options and $14.2 million of unrecognized compensation expense related to outstanding restricted stock grants at December 31, 2014.
	2002 Incentive Stock Option Plan
	On April 18, 2002, the shareholders of the Company approved the 2002 Incentive Stock Options Plan (the 2002 Plan), which provides incentive options to certain key employees to receive up to 2 million common shares of the Company. All options that are issued under the 2002 Plan are in effect for 10 years (except for any option granted to a person holding more than 10 percent of the Company’s stock, in which case the option is in effect for five years). All options issued prior to 2005, under the 2002 Plan, could not be exercised until at least four years 11 months after the date they are granted. Options issued in 2006, 2007, and 2008 under the 2002 Plan, have a vesting schedule of 50 percent after three years; 75 percent after four years and 100 percent after four years and eleven months. Except under circumstances of death, disability or certain retirements, the options cannot be exercised after the grantee has left the employment of the Company or its subsidiaries. The exercise period for an option may be accelerated upon the optionee’s qualified disability, retirement or death. All options expire at the end of the exercise period. Prior to 2006, the Company made no recognition in the balance sheet of the options until such options were exercised and no amounts applicable thereto were reflected in net income as all options were granted at strike prices at the then current fair value of the underlying shares. For options granted after January 1, 2006, compensation expense is recognized on unvested options outstanding. Options are granted at exercise prices of no less than 100 percent of the fair market value of the underlying shares based on the fair value of the option at date of grant. On January 25, 2011, the Board of Directors amended and froze the 2002 Plan such that no shares of Company stock shall thereafter be available for grants under the 2002 Plan. Existing awards granted under the 2002 Plan will continue in accordance with their terms under the 2002 Plan. The plan expired without modification on April 17, 2012.
	The table below discloses the information relating to option activity in 2014, under the 2002 Plan:
	Stock Options Under the 2002 Plan	Number			Weighted Average			Weighted Average			Aggregate
		of Shares			Price Per Share			Remaining			Intrinsic
								Contractual Term			Value
	Outstanding—December 31, 2013		341,491		$	36.05
	Granted		—			—
	Canceled		(7,673	)		32.68
	Exercised		(75,343	)		31.52
	Outstanding—December 31, 2014		258,475			37.47			2.5		$	5,020,538
	Exercisable—December 31, 2014		258,475			37.47
	Exercisable and expected to be exercisable— December 31, 2014		258,475		$	37.47			2.5		$	5,020,538
	No options were granted under the 2002 Plan during 2014, 2013, or 2012. The total intrinsic value of options exercised during the year ended December 31, 2014, 2013, and 2012 was $2.0 million, $3.4 million, and $2.0 million, respectively. As of December 31, 2014, there was no unrecognized compensation cost related to the nonvested options.
	Long-Term Incentive Compensation Plan
	At the April 26, 2005, shareholders’ meeting, the shareholders approved the UMB Financial Corporation Long-Term Incentive Compensation Plan (LTIP) which became effective as of January 1, 2005. The LTIP permits the issuance to selected officers of the Company service-based restricted stock grants, performance-based restricted stock grants and non-qualified stock options. Service-based restricted stock grants contain a service requirement. The performance-based restricted grants contain performance and service requirements. The non-qualified stock options contains a service requirement.
	At the April 23, 2013 shareholders’ meeting, the shareholders approved amendments to the LTIP Plan, including increasing the shares of the Company’s stock reserved under the Plan from 5.25 million shares to 7.44 million shares. Additionally, the shareholders approved increasing the maximum benefits any one eligible employee may receive under the plan during any one fiscal year from $1 million to $2 million taking into account the value of all stock options and restricted stock received.
	The service-based restricted stock grants contain a service requirement with varying vesting schedules. The majority of these grants utilize a vesting schedule in which 50 percent of the shares vest after three years of service, 75 percent after four years of service and 100 percent after five years of service. The remainder of these grants utilize vesting schedules in which the grants vest ratably over three years or contain a three-year cliff vesting.
	The performance-based restricted stock grants contain a service and a performance requirement. The performance requirement is based on a predetermined performance requirement over a three year period. The service requirement portion is a three year cliff vesting. If the performance requirement is not met, the executives do not receive the shares.
	The dividends on service and performance-based restricted stock grants are treated as two separate transactions. First, cash dividends are paid on the restricted stock. Those cash dividends are then paid to purchase additional shares of restricted stock. Dividends earned as additional shares of restricted stock have the same terms as the associated grant. The dividends paid on the stock are recorded as a reduction to retained earnings (similar to all dividend transactions).
	The table below discloses the status of the service-based restricted shares during 2014:
	Service-Based Restricted Stock	Number			Weighted Average
		of Shares			Grant Date Fair
					Value
	Nonvested—December 31, 2013		426,922		$	43.58
	Granted		153,721			57.42
	Canceled		(27,856	)		45.07
	Vested		(96,156	)		41.58
	Nonvested—December 31, 2014		456,631		$	48.57
	As of December 31, 2014, there was $12.6 million of unrecognized compensation cost related to the nonvested shares. The cost is expected to be recognized over a period of 2.8 years. Total fair value of shares vested during the year ended December 31, 2014, 2013, and 2012 was $5.6 million, $4.3 million, and $2.3 million respectively.
	The table below discloses the status of the performance-based restricted shares during 2014:
	Performance-Based Restricted Stock	Number			Weighted Average
		of Shares			Grant Date Fair
					Value
	Nonvested—December 31, 2013		112,197		$	42.46
	Granted		31,590			57.4
	Canceled		(6,443	)		44.44
	Vested		(36,075	)		41.71
	Nonvested—December 31, 2014		101,269		$	47.26
	As of December 31, 2014, there was $1.6 million of unrecognized compensation cost related to the nonvested shares. The cost is expected to be recognized over a period of 1.7 years. Total fair value of shares vested during the years ended December 31, 2014, 2013 and 2012, was $2.3 million, $1.6 million and $1.3 million, respectively.
	The non-qualified stock options carry a service requirement and will vest 50 percent after three years, 75 percent after four years and 100 percent after five years.
	The table below discloses the information relating to non-qualified option activity in 2014 under the LTIP:
	Stock Options Under the LTIP	Number of			Weighted Average			Weighted Average			Aggregate
		Shares			Price Per Share			Remaining			Intrinsic
								Contractual Term			Value
	Outstanding—December 31, 2013		1,342,025		$	40.45
	Granted		259,158			57.4
	Canceled		(60,373	)		44.18
	Exercised		(156,775	)		36.08
	Outstanding—December 31, 2014		1,384,035			44.03			6.3		$	17,801,893
	Exercisable—December 31, 2014		525,298			39.43
	Exercisable and expected to be exercisable—December 31, 2014		1,328,241		$	43.76			6.2		$	17,440,423
	The Company uses the Black-Scholes pricing model to determine the fair value of its options. The assumptions for stock-based awards in the past three years utilized in the model are shown in the table below.
	Black-Scholes pricing model:	2014			2013			2012
	Weighted average fair value of the granted options	$	13.03		$	10.18		$	8.83
	Weighted average risk-free interest rate		1.77	%		1.49	%		1.14	%
	Expected option life in years		6.25			6.25			6.25
	Expected volatility		24.87	%		26.36	%		27.02	%
	Expected dividend yield		1.53	%		1.83	%		1.95	%
	The expected option life is derived from historical exercise patterns and represents the amount of time that options granted are expected to be outstanding. The expected volatility is based on historical volatilities of the Company’s stock. The risk-free interest rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant.
The weighted average grant-date fair value of options granted during the years 2014, 2013, and 2012 was $13.03, $10.18, and $8.83. The total intrinsic value of options exercised during the years ended December 31, 2014, 2013 and 2012, was $3.7 million, $2.4 million and $1.3 million, respectively. As of December 31, 2014, there was $5.2 million of unrecognized compensation cost related to the nonvested options. The cost is expected to be recognized over a period of 3.1 years.
Cash received from options exercised under all share based compensation plans was $8.0 million, $9.0 million, and $6.6 million for the years ended December 31, 2014, 2013, and 2012, respectively. The tax benefit realized for stock options exercised was $1.9 million in 2014, $1.2 million in 2013 and $359 thousand in 2012.
The Company has no specific policy to repurchase common shares to mitigate the dilutive impact of options; however, the Company has historically made adequate discretionary purchases to satisfy stock option exercise activity. See a description of the Company’s share repurchase plan in Note 13, “Common Stock and Earnings Per Share,” to the Consolidated Financial Statements provided in Item 8, page 94 of this report.

BUSINESS_SEGMENT_REPORTING

BUSINESS SEGMENT REPORTING	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
BUSINESS SEGMENT REPORTING	12.  BUSINESS SEGMENT REPORTING
	The Company has strategically aligned its operations into the following four reportable segments (collectively, “Business Segments”): Bank, Payment Solutions, Institutional Investment Management, and Asset Servicing. Business segment financial results produced by the Company’s internal management reporting system are evaluated regularly by senior executive officers in deciding how to allocate resources and assess performance for individual Business Segments. The management reporting system assigns balance sheet and income statement items to each business segment using methodologies that are refined on an ongoing basis. For comparability purposes, amounts in all periods presented are based on methodologies in effect at December 31, 2014. Previously reported results have been reclassified to conform to the current organizational structure.
	The following summaries provide information about the activities of each segment:
	The Bank provides a full range of banking services to commercial, retail, government and correspondent bank customers through the Company’s branches, call center, internet banking, and ATM network. Services include traditional commercial and consumer banking, treasury management, leasing, foreign exchange, merchant bankcard, wealth management, brokerage, insurance, capital markets, investment banking, corporate trust, and correspondent banking.
	Payment Solutions provides consumer and commercial credit and debit card, prepaid debit card solutions, healthcare services, and institutional cash management. Healthcare services include health savings account and flexible savings account products for healthcare providers, third-party administrators and large employers.
	Institutional Investment Management provides equity and fixed income investment strategies in the intermediary and institutional markets via mutual funds, traditional separate accounts and sub-advisory relationships.
	Asset Servicing provides services to the asset management industry, supporting a range of investment products, including mutual funds, alternative investments and managed accounts. Services include fund administration, fund accounting, investor services, transfer agency, distribution, marketing, custody, alternative investment services, managed account services, and collective and multiple-series trust services.
	BUSINESS SEGMENT INFORMATION
	Line of business/segment financial results were as follows (in thousands):
		Year Ended December 31, 2014
		Bank		Payment		Institutional			Asset		Total
				Solutions		Investment			Servicing
						Management
	Net interest income	$	292,357	$	52,251	$	(3	)	$	5,450	$	350,055
	Provision for loan losses		9,175		7,825		—			—		17,000
	Noninterest income		194,223		84,477		131,226			88,762		498,688
	Noninterest expense		405,065		94,177		92,008			75,676		666,926
	Income before taxes		72,340		34,726		39,215			18,536		164,817
	Income tax expense		19,487		9,311		10,331			5,033		44,162
	Net income	$	52,853	$	25,415	$	28,884		$	13,503	$	120,655
	Average assets	$	12,099,000	$	2,456,000	$	72,000		$	1,372,000	$	15,999,000
		Year Ended December 31, 2013
		Bank		Payment		Institutional			Asset		Total
				Solutions		Investment			Servicing
						Management
	Net interest income	$	285,112	$	45,832	$	(32	)	$	2,357	$	333,269
	Provision for loan losses		5,535		11,965		—			—		17,500
	Noninterest income		210,535		74,223		126,442			80,633		491,833
	Noninterest expense		376,307		86,746		88,336			72,789		624,178
	Income before taxes		113,805		21,344		38,074			10,201		183,424
	Income tax expense		28,548		6,739		10,002			4,170		49,459
	Net income	$	85,257	$	14,605	$	28,072		$	6,031	$	133,965
	Average assets	$	11,255,000	$	1,736,000	$	77,000		$	1,963,000	$	15,031,000
		Year Ended December 31, 2012
		Bank		Payment		Institutional			Asset		Total
				Solutions		Investment			Servicing
						Management
	Net interest income	$	274,843	$	43,351	$	2		$	1,860	$	320,056
	Provision for loan losses		9,267		8,233		—			—		17,500
	Noninterest income		214,595		67,887		100,051			75,589		458,122
	Noninterest expense		381,273		69,205		71,053			68,923		590,454
	Income before taxes		98,898		33,800		29,000			8,526		170,224
	Income tax expense		26,543		9,523		8,098			3,343		47,507
	Net income	$	72,355	$	24,277	$	20,902		$	5,183	$	122,717
	Average assets	$	10,864,000	$	1,282,000	$	79,000		$	1,164,000	$	13,389,000

COMMON_STOCK_AND_EARNINGS_PER_

COMMON STOCK AND EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
COMMON STOCK AND EARNINGS PER SHARE	13.  COMMON STOCK AND EARNINGS PER SHARE
	The following table summarizes the share transactions for the three years ended December 31, 2014:
		Shares		Shares in
		Issued		Treasury
	Balance December 31, 2011		55,056,730		(14,630,388	)
	Purchase of Treasury Stock		—		(514,824	)
	Sale of Treasury Stock		—		21,950
	Issued for stock options & restricted stock		—		407,410
	Balance December 31, 2012		55,056,730		(14,715,852	)
	Common stock issuance				4,485,000
	Purchase of Treasury Stock		—		(99,402	)
	Sale of Treasury Stock		—		14,661
	Issued for stock options & restricted stock		—		480,100
	Balance December 31, 2013		55,056,730		(9,835,493	)
	Purchase of Treasury Stock		—		(130,197	)
	Sale of Treasury Stock		—		15,320
	Issued for stock options & restricted stock		—		425,828
	Balance December 31, 2014		55,056,730		(9,524,542	)
	In 2013, the Company completed the issuance of 4.5 million shares of common stock with net proceeds of $231.4 million to be used for strategic growth purposes. The Company’s Board of Directors approved a plan to repurchase up to 2 million shares of common stock annually at its 2011, 2012, 2013 and 2014 meetings. All open market share purchases under the share repurchase plans are intended to be within the scope of Rule 10b-18 promulgated under the Exchange Act. Rule 10b-18 provides a safe harbor for purchases in a given day if the Company satisfies the manner, timing and volume conditions of the rule when purchasing its own common shares. The Company has not made any repurchases other than through these plans.
	Basic earnings per share are computed by dividing income available to common shareholders by the weighted average number of shares outstanding during the year. Diluted earnings per share gives effect to all potential common shares that were outstanding during the year.
	The shares used in the calculation of basic and diluted earnings per share, are shown below:
		For the Years Ended December 31
		2014		2013			2012
	Weighted average basic common shares outstanding		44,844,578		41,275,839			40,034,428
	Dilutive effect of stock options and restricted stock		600,705		562,741			398,939
	Weighted average diluted common shares outstanding		45,445,283		41,838,580			40,433,367

COMMITMENTS_CONTINGENCIES_AND_

COMMITMENTS, CONTINGENCIES AND GUARANTEES	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS, CONTINGENCIES AND GUARANTEES	14.  COMMITMENTS, CONTINGENCIES AND GUARANTEES
	In the normal course of business, the Company is a 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, and futures contracts. These instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the consolidated balance sheet. The contract or notional amount of those instruments reflects the extent of involvement the Company has in particular classes of financial instruments.
	The Company’s exposure to credit loss in the event of nonperformance by the other party 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.
	Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the agreement. These conditions generally include, but are not limited to, each customer being current as to repayment terms of existing loans and no deterioration in the customer’s financial condition. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. The interest rate is generally a variable rate. If the commitment has a fixed interest rate, the rate is generally not set until such time as credit is extended. For credit card customers, the Company has the right to change or terminate terms or conditions of the credit card account at any time. Since a large portion of the commitments and unused credit card lines are never actually drawn upon, the total commitment amount does not necessarily represent future cash requirements. The Company evaluates each customer’s creditworthiness on an individual basis. The amount of collateral obtained, if deemed necessary by the Company upon extension of credit, is based on management’s credit evaluation. Collateral pledged by customers varies but may include accounts receivable, inventory, real estate, plant and equipment, stock, securities and certificates of deposit.
	Commercial letters of credit are issued specifically to facilitate trade or commerce. Under the terms of a commercial letter of credit, as a general rule, drafts will be drawn when the underlying transaction is consummated as intended.
	Standby letters of credit are conditional commitments issued by the Company payable upon the non-performance of a customer’s obligation to a third party. The Company issues standby letters of credit for terms ranging from three months to five years. The Company generally requires the customer to pledge collateral to support the letter of credit. The maximum liability to the Company under standby letters of credit at December 31, 2014 and 2013, was $375.0 million and $356.1 million, respectively. As of December 31, 2014 and 2013, standby letters of credit totaling $54.6 million and $51.8 million, respectively, were with related parties to the Company.
	The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities. The Company holds collateral supporting those commitments when deemed necessary. Collateral varies but may include such items as those described for commitments to extend credit.
	Futures contracts are contracts for delayed delivery of securities or money market instruments in which the seller agrees to make delivery at a specified future date, of a specified instrument, at a specified yield. Risks arise from the possible inability of counterparties to meet the terms of their contracts and from movement in securities values and interest rates. Instruments used in trading activities are carried at market value and gains and losses on futures contracts are settled in cash daily. Any changes in the market value are recognized in trading and investment banking income.
	The Company uses contracts to offset interest rate risk on specific securities held in the trading portfolio. As of December 31, 2014 and 2013, there were no notional amounts outstanding for these contracts. Open futures contract positions average notional amount was $0.9 million and $11.4 million during the years ended December 31, 2014 and 2013, respectively. Net futures activity resulted in losses of $319 thousand, $131 thousand and $598 thousand for 2014, 2013, and 2012, respectively. The Company controls the credit risk of its futures contracts through credit approvals, limits and monitoring procedures.
	The Company also enters into foreign exchange contracts on a limited basis. For operating purposes, the Company maintains certain balances in foreign banks. Foreign exchange contracts are purchased on a monthly basis to avoid foreign exchange risk on these foreign balances. The Company will also enter into foreign exchange contracts to facilitate foreign exchange needs of customers. The Company will enter into a contract to buy or sell a foreign currency at a future date only as part of a contract to sell or buy the foreign currency at the same future date to a customer. During 2014, contracts to purchase and to sell foreign currency averaged approximately $51.8 million compared to $12.4 million during 2013. The net gains on these foreign exchange contracts for 2014, 2013 and 2012 were $1.7 million, $2.2 million and $2.3 million, respectively.
	With respect to group concentrations of credit risk, most of the Company’s business activity is with customers in the states of Missouri, Kansas, Colorado, Oklahoma, Nebraska, Arizona, Illinois, and Texas. At December 31, 2014, the Company did not have any significant credit concentrations in any particular industry.
	The following table summarizes the Company’s off-balance sheet financial instruments as described above.
		Contract or Notional
		Amount December 31
	(in thousands)	2014		2013
	Commitments to extend credit for loans (excluding credit card loans)	$	3,509,841	$	2,690,268
	Commitments to extend credit under credit card loans		2,690,752		2,215,278
	Commercial letters of credit		1,334		5,949
	Standby letters of credit		375,003		356,054
	Forward contracts		144,950		21,525
	Spot foreign exchange contracts		14,721		8,001

ACQUISITIONS

ACQUISITIONS	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
ACQUISITIONS	15.  ACQUISITIONS
	The following two acquisitions were completed during the third and fourth quarters of 2010. The pro-forma impact of these transactions was not material. Each of these acquisitions has a contingent consideration liability measured at fair value through earnings which has had payments and valuation adjustments applied since the acquisition date. A rollforward of these changes is included in Note 18, “Disclosures about Fair Value of Financial Instruments,” to the Consolidated Financial Statements under Item 8 on pages 101 through 108.
	On July 30, 2010, UMB Advisors, LLC (UMB Advisors) and UMB Merchant Banc, LLC (UMBMB), subsidiaries of UMB Financial Corporation, completed the purchase of substantially all of the assets of Prairie Capital Management LLC (Prairie Capital) and PCM LLC for cash of $25.9 million and future consideration. After the completion of the transaction, UMB Advisors name was changed to Prairie Capital Management, LLC. PCM is in the business of providing investment management services, and is the general partner of various PCM investment funds. UMB Advisors purchased substantially all of the assets of Prairie Capital’s business, and UMBMB purchased substantially all of the assets of PCM LLC’s business. As of the date of acquisition, this acquisition increased the Company’s assets under management base by $2.2 billion and increased the Company’s servicing assets by $2.6 billion. Goodwill amounted to $32.2 million with the remaining purchase price allocated to cash, furniture, fixtures, prepaid assets, and unearned income. Identifiable intangible assets amounted to $19.4 million. Total goodwill and intangible assets are inclusive of contingent earn-out payments based on revenue targets over five years. This earn-out liability was estimated to be $26.0 million at the purchase date. Since the date of acquisition, earn-out payments and valuation adjustments have been made resulting in a contingent earn-out liability of $9.4 million at December 31, 2014.
	On June 30, 2014, the Company entered into a settlement agreement to resolve objections to its calculation of the earn-out amount owed to the sellers of PCM and a related incentive bonus calculation for the employees of PCM. As of March 31, 2014, $15.0 million of contingency reserve expense had been accrued related to this dispute. An additional $5.3 million of contingency reserve expense was recorded during the second quarter for a total estimated settlement liability of $20.3 million. On June 30, 2014, the Company made payment of $6.0 million, reducing the remaining contingency reserve to $14.3 million. Since the date of settlement, valuation adjustments have been made resulting in a post-settlement contingent earn-out liability of $12.2 million at December 31, 2014.
	On September 1, 2010, Scout Investments, Inc. (Scout), a wholly-owned subsidiary of UMB Financial Corporation, completed the purchase of substantially all of the assets of Reams Asset Management Company, LLC (Reams) for cash of $44.7 million and future consideration. Reams is a provider of investment management services to institutional clients and a manager of over $9.8 billion in fixed income assets. Reams is now operated as a division of Scout Investments, Inc. Goodwill amounted to $47.5 million with the remaining purchase price allocated to cash, furniture, fixtures, prepaid assets, and unearned income. Identifiable intangible assets totaled $26.0 million. Total goodwill and intangible assets are inclusive of contingent earn-out payments based on revenue and expense targets over five years. This earn-out liability was estimated to be $32.5 million at the purchase date. Since the date of acquisition, earn-out payments and valuation adjustments have been made resulting in a contingent earn-out liability of $31.8 million at December 31, 2014.
	On December 15, 2014, the Company entered into an Agreement and Plan of Merger with Marquette Financial Companies, the beneficial owners of all of the outstanding shares of Marquette, and Lakes Merger Sub LLC, a Missouri limited liability company and wholly owned subsidiary of the Company. The Merger Agreement and the merger were unanimously approved by the boards of directors of the Company and Marquette. Pending regulatory approval, the merger is expected to close in mid-2015, and subject to the terms and conditions of the Merger Agreement, each share of Marquette common stock issued and outstanding immediately prior to the effective time of the merger will be converted into the right to receive 9.131 shares of the Company’s common stock, or approximately 3.4 million shares of the Company’s common stock in the aggregate, subject to an adjustment as provided in the Merger Agreement. The market value of the shares to be issued in connection with the Merger was approximately $182.5 million, based on the Company’s closing stock price of $53.16 on December 12, 2014.

INCOME_TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
INCOME TAXES	16.  INCOME TAXES
	Income taxes as set forth below produce effective income tax rates of 26.8 percent in 2014, 27.0 percent in 2013, and 27.9 percent in 2012. These percentages are computed by dividing total income tax by income before income taxes.
	Income tax expense includes the following components (in thousands):
		Year Ended December 31
		2014			2013			2012
	Current tax
	Federal	$	53,314		$	50,832		$	40,837
	State		2,304			3,750			2,995
	Total current tax expense		55,618			54,582			43,832
	Deferred tax
	Federal		(11,448	)		(4,278	)		2,862
	State		(8	)		(845	)		813
	Total deferred tax (benefit) expense		(11,456	)		(5,123	)		3,675
	Total tax expense	$	44,162		$	49,459		$	47,507
	The reconciliation between the income tax expense and the amount computed by applying the statutory federal tax rate of 35% to income before income taxes is as follows (in thousands):
		Year Ended December 31
		2014			2013			2012
	Statutory federal income tax expense	$	57,686		$	64,199		$	59,578
	Tax-exempt interest income		(13,861	)		(14,146	)		(13,480	)
	State and local income taxes, net of federal tax benefits		1,403			1,887			2,475
	Federal tax credits		(1,433	)		(2,338	)		(1,090	)
	Other		367			(143	)		24
	Total tax expense	$	44,162		$	49,459		$	47,507
	In preparing its tax returns, the Company is required to interpret tax laws and regulations to determine its taxable income. Periodically, the Company is subject to examinations by various taxing authorities that may give rise to differing interpretations of these laws. Upon examination, agreement of tax liabilities between the Company and the multiple tax jurisdictions in which the Company files tax returns may ultimately be different. The Company is in the examination process with the Internal Revenue Service for tax year 2012. The Company believes the aggregate amount of any additional liabilities that may result from this examination, if any, will not have a material adverse effect on the financial condition, results of operations, or cash flows of the Company.
	Deferred income taxes result from differences between the carrying value of assets and liabilities measured for financial reporting and the tax basis of assets and liabilities for income tax return purposes.
	The significant components of deferred tax assets and liabilities are reflected in the following table (in thousands):
		December 31,
		2014			2013
	Deferred tax assets:
	Net unrealized loss on securities available for sale	$	—		$	19,495
	Loans, principally due to allowance for loan losses		28,924			28,367
	Stock-based compensation		7,109			6,302
	Accrued expenses		24,747			19,943
	Intangibles		7,254			—
	Miscellaneous		3,551			4,474
	Total deferred tax assets before valuation allowance		71,585			78,581
	Valuation allowance		(3,417	)		(2,680	)
	Total deferred tax assets		68,168			75,901
	Deferred tax liabilities:
	Net unrealized gain on securities available for sale		(6,879	)		—
	Land, buildings and equipment		(24,002	)		(25,403	)
	Original issue discount		(4,311	)		(4,439	)
	Partnership investments		(7,838	)		(6,540	)
	Intangibles		—			(238	)
	Miscellaneous		(6,183	)		(5,408	)
	Total deferred tax liabilities		(49,213	)		(42,028	)
	Net deferred tax asset	$	18,955		$	33,873
	The Company has various state net operating loss carryforwards of approximately $0.6 million as of December 31, 2014. These net operating losses expire at various times between 2015 and 2034. The Company has a full valuation allowance for these state net operating losses as they are not expected to be realized. In addition, the Company has a valuation allowance of $2.8 million to reduce certain other state deferred tax assets to the amount of tax benefit management believes it will more likely than not realize.
	The net deferred tax asset at December 31, 2014 and December 31, 2013 is included in the Other assets line of the Company’s Consolidated Balance Sheets.
	Liabilities Associated With Unrecognized Tax Benefits
	The Company and its subsidiaries file income tax returns in the U.S. federal jurisdiction and various states. With few exceptions, the Company is no longer subject to U.S. federal, state and local income tax examinations by tax authorities for tax years prior to 2011 in the jurisdictions in which it files.
	The gross amount of unrecognized tax benefits totaled $4.0 million and $5.0 million at December 31, 2014 and 2013, respectively. The total amount of unrecognized tax benefits, net of associated deferred tax benefit, that would impact the effective tax rate, if recognized, would be $2.6 million and $3.3 million at December 31, 2014 and December 31, 2013, respectively. The unrecognized tax benefit relates to state tax positions that have a corresponding federal tax benefit. While it is expected that the amount of unrecognized tax benefits will change in the next twelve months, the Company does not expect this change to have a material impact on the results of operations or the financial position of the Company.
	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands):
		December 31,
		2014			2013
	Unrecognized tax benefits—opening balance	$	4,997		$	4,347
	Gross decreases—tax positions in prior period		(444	)		(80	)
	Gross increases—current-period tax positions		964			1,049
	Lapse of statute of limitations		(1,492	)		(319	)
	Unrecognized tax benefits—ending balance	$	4,025		$	4,997

DERIVATIVES_AND_HEDGING_ACTIVI

DERIVATIVES AND HEDGING ACTIVITIES	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVES AND HEDGING ACTIVITIES	17.  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. 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 Value of Derivative Instruments on the Balance Sheet
	The table below presents the fair value of the Company’s derivative financial instruments as of December 31, 2014 and 2013. The Company’s derivative asset and derivative liability are located within Other Assets and Other Liabilities, respectively, on the Company’s Consolidated Balance Sheets.
	This table provides a summary of the fair value of the Company’s derivative assets and liabilities as of December 31, 2014 and December 31, 2013 (in thousands):
		Asset Derivatives						Liability Derivatives
		December 31,						December 31,
		2014			2013			2014		2013
	Fair value
	Interest Rate Products:
	Derivatives not designated as hedging instruments	$	7,138		$	2,442		$	7,250	$	2,346
	Derivatives designated as hedging instruments		—			76			285		—
	Total	$	7,138		$	2,518		$	7,535	$	2,346
	Fair Value Hedges of Interest Rate Risk
	The Company is exposed to changes in the fair value of certain of its fixed-rate assets due to changes in the benchmark interest rate, LIBOR. Interest rate swaps designated as fair value hedges involve making fixed-rate payments to a counterparty in exchange for the Company receiving variable-rate payments over the life of the agreements without the exchange of the underlying notional amount. As of December 31, 2014, the Company had one interest rate swap with a notional amount of $6.7 million that was designated as a fair value hedge of interest rate risk associated with the Company’s fixed rate loan assets.
	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, which the Company implemented in 2010. 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 December 31, 2014, the Company had 30 interest rate swaps with an aggregate notional amount of $382.8 million related to this program. During the years ended December 31, 2014 and 2013, the Company recognized net losses of $207 thousand and net gains of $217 thousand, respectively, related to changes in the fair value of these swaps.
	Designated Hedges
	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. The Company includes the gain or loss on the hedged items in the same line item as the offsetting loss or gain on the related derivatives. During the years ended December 31, 2014 and 2013, the Company recognized net losses of $27 thousand and net gains of $2 thousand, respectively, in other noninterest expense related to hedge ineffectiveness.
	Effect of Derivative Instruments on the Income Statement
	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 asset and liability as of December 31, 2014 and December 31, 2013 (in thousands):
		Amount of Gain (Loss) Recognized
		For the Year Ended
		December 31,
		2014			2013
	Interest Rate Products
	Derivatives not designated as hedging instruments	$	(207	)	$	217
	Total	$	(207	)	$	217
	Interest Rate Products
	Derivatives designated as hedging instruments
	Fair value adjustments on derivatives	$	(361	)	$	76
	Fair value adjustments on hedged items		334			(74	)
	Total	$	(27	)	$	2
	Credit-risk-related Contingent Features
	The Company has agreements with certain of its derivative counterparties that contain a provision where 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 December 31, 2014 the termination value of derivatives in a net liability position, which includes accrued interest, related to these agreements was $675 thousand. The Company has minimum collateral posting thresholds with certain of its derivative counterparties and has not yet reached its minimum collateral posting threshold under these agreements. If the Company had breached any of these provisions at December 31, 2014, it could have been required to settle its obligations under the agreements at the termination value.

DISCLOSURES_ABOUT_FAIR_VALUE_O

DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS	18.  DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS
	The following table presents information about the Company’s assets measured at fair value on a recurring basis as of December 31, 2014, 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 and liabilities measured at fair value on a recurring basis as of December 31, 2014 and 2013 (in thousands):
					Fair Value Measurement at Reporting Date Using
	Description	December 31,			Quoted Prices in			Significant Other		Significant
		2014			Active Markets			Observable		Unobservable
					for Identical			Inputs (Level 2)		Inputs (Level 3)
					Assets (Level 1)
	Assets
	U.S. Treasury	$	400		$	400		$	—	$	—
	U.S. Agencies		1,315			—			1,315		—
	Mortgage-backed		—			—			—		—
	State and political subdivisions		7,381			—			7,381		—
	Trading—other		18,107			18,106			1		—
	Trading securities		27,203			18,506			8,697		—
	U.S. Treasury		519,460			519,460			—		—
	U.S. Agencies		990,689			—			990,689		—
	Mortgage-backed		3,277,604			—			3,277,604		—
	State and political subdivisions		2,001,357			—			2,001,357		—
	Corporates		122,826			122,826			—		—
	Available for sale securities		6,911,936			642,286			6,269,650		—
	Company-owned life insurance		26,886			—			26,886		—
	Derivatives		7,138			—			7,138		—
	Total	$	6,973,163		$	660,792		$	6,312,371	$	—
	Liabilities
	Deferred compensation	$	26,885		$	26,885		$	—	$	—
	Contingent consideration liability		53,411			—			—		53,411
	Derivatives		7,535			—			7,535		—
	Total	$	87,831		$	26,885		$	7,535	$	53,411
					Fair Value Measurement at Reporting Date Using
	Description	December 31,			Quoted Prices in			Significant Other		Significant
		2013			Active Markets			Observable		Unobservable
					for Identical			Inputs (Level 2)		Inputs (Level 3)
					Assets (Level 1)
	Assets
	U.S. Treasury	$	400		$	400		$	—	$	—
	U.S. Agencies		—			—			—		—
	Mortgage-backed		515			—			515		—
	State and political subdivisions		3,072			—			3,072		—
	Trading—other		24,477			24,477			—		—
	Trading securities		28,464			24,877			3,587		—
	U.S. Treasury		110,200			110,200			—		—
	U.S. Agencies		1,257,663			—			1,257,663		—
	Mortgage-backed		2,944,566			—			2,944,566		—
	State and political subdivisions		1,995,246			—			1,995,246		—
	Corporates		454,736			454,736			—		—
	Available for sale securities		6,762,411			564,936			6,197,475		—
	Company-owned life insurance		19,619			—			19,619		—
	Derivatives		2,518			—			2,518		—
	Total	$	6,813,012		$	589,813		$	6,223,199	$	—
	Liabilities
	Deferred compensation	$	19,825		$	19,825		$	—	$	—
	Contingent consideration liability		46,201			—			—		46,201
	Derivatives		2,346			—			2,346		—
	Total	$	68,372		$	19,825		$	2,346	$	46,201
	The following table reconciles the beginning and ending fair value of balances of the contingent consideration liability:
		December 31,
		2014			2013
	Beginning balance	$	46,201		$	51,163
	Contingency reserve		14,272			—
	Payment of contingent consideration on acquisitions		(13,725	)		(16,172	)
	Income from fair value adjustments		—			(138	)
	Expense from fair value adjustments		6,663			11,348
Ending balance	$	53,411		$	46,201
During the year ended December 31, 2014, the Company recorded contingency reserve expense of $20.3 million in its Consolidated Statements of Income related to the resolution of the PCM dispute. On June 30, 2014, the Company made a payment of $6.0 million, reducing the remaining contingency reserve to $14.3 million. The settlement agreement amends the original asset purchase agreement dated June 27, 2010, and subsequent to the settlement, the remaining contingency reserve liability has been included in the table above as additional contingent consideration recorded at fair value. Fair value adjustments made subsequent to settlement are included in the table above as expense from fair value adjustments.
The following table presents certain quantitative information about the significant unobservable input used in the fair value measurement for the contingent consideration liability measured at fair value on a recurring basis using significant unobservable inputs (Level 3):
Description	Valuation Techniques		Significant	Range
			Unobservable Inputs
Liabilities
Contingent consideration liability	Discounted cash flows		Revenue and expense growth percentage		1% - 102%
An increase in the revenue growth percentage may result in a significantly higher estimated fair value of the contingent consideration liability. Alternatively, a decrease in the revenue growth percentage may result in a significantly lower estimated fair value of the contingent consideration liability.
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:
Securities Available for Sale and Investment Securities    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.
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.
Company-owned Life Insurance    Fair values are based on quoted market prices or dealer quotes with adjustments for dividends, capital gains, and administrative charges.
Derivatives    Fair values are determined using valuation techniques including discounted cash flow analysis on the expected cash flows of 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.
Contingent Consideration    The fair value of contingent consideration liabilities are derived from a discounted cash flow model of future contingent payments. The valuation of these liabilities are estimated by a collaborative effort of the Company’s mergers and acquisitions group, business unit management, and the corporate accounting group. These future contingent payments are calculated based on estimates of future income and expense from each acquisition. These estimated cash flows are projected by the business unit management and reviewed by the mergers and acquisitions group. To obtain a current valuation of these projected cash flows, an expected present value technique is utilized to calculate a discount rate. The cash flow projections and discount rates are reviewed quarterly and updated as market conditions necessitate. Potential valuation adjustments are made as future income and expense projections for each acquisition are made which affect the calculation of the related contingent consideration payment. These adjustments are recorded through noninterest income and expense.
Assets measured at fair value on a non-recurring basis as of December 31, 2014 and 2013 (in thousands):
				Fair Value Measurement at December 31, 2014 Using
Description	December 31,			Quoted Prices in			Significant Other		Significant		Total
	2014			Active Markets			Observable Inputs		Unobservable		Gains
				for Identical			(Level 2)		Inputs (Level 3)		Recognized
				Assets (Level 1)							During the
											Twelve
											Months
											Ended
											December 31
Impaired loans	$	5,122		$	—		$	—	$	5,122	$	2,345
Other real estate owned		208			—			—		208		—
Total	$	5,330		$	—		$	—	$	5,330	$	2,345
				Fair Value Measurement at December 31, 2013 Using
Description	December 31,			Quoted Prices in			Significant Other		Significant		Total
	2013			Active Markets			Observable Inputs		Unobservable		(Losses)
				for Identical			(Level 2)		Inputs (Level 3)		Recognized
				Assets (Level 1)							During the
											Twelve
											Months
											Ended
											December 31
Impaired loans	$	15,496		$	—		$	—	$	15,496	$	(2,496	)
Other real estate owned		329			—			—		329		(125	)
Total	$	15,825		$	—		$	—	$	15,825	$	(2,621	)
Valuation methods for instruments measured at fair value on a nonrecurring 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 appraisal 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 December, 31, 2014 and 2013 are as follows (in millions):
	Fair Value Measurement at December 31, 2014 Using
	Carrying			Quoted Prices in			Significant Other		Significant		Total
	Amount			Active Markets			Observable		Unobservable		Estimated
				for Identical			Inputs (Level 2)		Inputs (Level 3)		Fair Value
				Assets (Level 1)
FINANCIAL ASSETS
Cash and short-term investments	$	2,101.80		$	2,006.30		$	95.5	$	—	$	2,101.80
Securities available for sale		6,911.90			642.3			6,269.60		—		6,911.90
Securities held to maturity		278.1			—			304.1		—		304.1
Federal Reserve Bank stock and other		68.5			—			68.5		—		68.5
Trading securities		27.2			18.5			8.7		—		27.2
Loans (exclusive of allowance for loan loss)		7,466.40			—			7,483.30		—		7,483.30
Derivatives		7.1			—			7.1		—		7.1
FINANCIAL LIABILITIES
Demand and savings deposits		12,353.30			12,353.30			—		—		12,353.30
Time deposits		1,263.60			—			1,263.60		—		1,263.60
Other borrowings		2,025.10			42			1,983.10		—		2,025.10
Long-term debt		8.8			—			9.1		—		9.1
Derivatives		7.5			—			7.5		—		7.5
OFF-BALANCE SHEET ARRANGEMENTS
Commitments to extend credit for loans												5.7
Commercial letters of credit												0.2
Standby letters of credit												2.4
	Fair Value Measurement at December 31, 2013 Using
	Carrying			Quoted Prices in			Significant Other		Significant		Total
	Amount			Active Markets			Observable		Unobservable		Estimated
				for Identical			Inputs (Level 2)		Inputs (Level 3)		Fair Value
				Assets (Level 1)
FINANCIAL ASSETS
Cash and short-term investments	$	2,701.50		$	2,626.30		$	75.2	$	—	$	2,701.50
Securities available for sale		6,762.40			564.9			6,197.50		—		6,762.40
Securities held to maturity		209.8			—			231.5		—		231.5
Federal Reserve Bank stock and other		50.5			—			50.5		—		50.5
Trading securities		28.5			24.9			3.6		—		28.5
Loans (exclusive of allowance for loan loss)		6,521.90			—			6,571.60		—		6,571.60
Derivatives		2.5			—			2.5		—		2.5
FINANCIAL LIABILITIES
Demand and savings deposits		12,191.10			12,191.10			—		—		12,191.10
Time deposits		1,449.60			—			1,449.40		—		1,449.40
Other borrowings		1,583.30			12.8			1,570.50		—		1,583.30
Long-term debt		5.1			—			4.5		—		4.5
Derivatives		2.3			—			2.3		—		2.3
OFF-BALANCE SHEET ARRANGEMENTS
Commitments to extend credit for loans												6
Commercial letters of credit												0.1
Standby letters of credit												2
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 the current rates at which similar investments would be made to borrowers with similar credit ratings and for the same remaining maturities.
Federal Reserve Bank stock and Other    Amount consists of FRB and FHLB stock held by the Bank, PCM equity-method investments, and other miscellaneous investments. The fair value of FRB and FHLB stock is considered to be the carrying value as no readily determinable market exists for these investments because they can only be redeemed with the FRB. 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 investments.
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 is estimated by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities.
Demand and savings deposits    The fair value of demand deposits and savings accounts is the amount payable on demand at December 31, 2014 and 2013.
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 year-end are significant to the Company’s consolidated financial position.

PARENT_COMPANY_FINANCIAL_INFOR

PARENT COMPANY FINANCIAL INFORMATION	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
PARENT COMPANY FINANCIAL INFORMATION	19.  PARENT COMPANY FINANCIAL INFORMATION
	UMB FINANCIAL CORPORATION
		December 31
			2014			2013
	BALANCE SHEETS (in thousands)
	ASSETS
	Investment in subsidiaries:
	Banks	$	1,312,575		$	1,159,098
	Non-banks		187,329			175,650
	Total investment in subsidiaries		1,499,904			1,334,748
	Goodwill on purchased affiliates		5,011			5,011
	Cash		80,958			110,932
	Securities available for sale and other		65,628			61,685
	Total assets	$	1,651,501		$	1,512,376
	LIABILITIES AND SHAREHOLDERS’ EQUITY
	Short-term debt	$	—		$	—
	Accrued expenses and other		7,743			6,311
	Total liabilities		7,743			6,311
	Shareholders’ equity		1,643,758			1,506,065
	Total liabilities and shareholders’ equity	$	1,651,501		$	1,512,376
		Year Ended December 31
		2014			2013			2012
	STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (in thousands)
	INCOME
	Dividends and income received from subsidiary banks	$	31,000		$	54,750		$	78,000
	Service fees from subsidiaries		35,206			33,443			27,821
	Other		2,504			387			1,012
	Total income		68,710			88,580			106,833
	EXPENSE
	Salaries and employee benefits		33,556			32,223			30,683
	Other		17,037			9,198			9,428
	Total expense		50,593			41,421			40,111
	Income before income taxes and equity in undistributed earnings of subsidiaries		18,117			47,159			66,722
	Income tax benefit		(5,227	)		(4,307	)		(4,248	)
	Income before equity in undistributed earnings of subsidiaries		23,344			51,466			70,970
	Equity in undistributed earnings of subsidiaries:
	Banks		94,833			64,674			44,797
	Non-Banks		2,478			17,825			6,950
	Net income	$	120,655		$	133,965		$	122,717
	Other comprehensive income (loss)		43,646			(118,228	)		4,489
	Comprehensive income	$	164,301		$	15,737		$	127,206
		Year Ended December 31
		2014			2013			2012
	STATEMENTS OF CASH FLOWS (in thousands)
	OPERATING ACTIVITIES
	Net income	$	120,655		$	133,965		$	122,717
	Adjustments to reconcile net income to cash used in operating
	activities:
	Equity in earnings of subsidiaries		(128,311	)		(137,249	)		(129,747	)
	Dividends received from subsidiaries		31,000			—			—
	Net decrease (increase) in trading securities		6,397			6,181			(11,380	)
	Equity based compensation		9,661			—			—
	Other		(9,071	)		(8,467	)		(16,812	)
	Net cash provided by operating activities		30,331			(5,570	)		(35,222	)
	INVESTING ACTIVITIES
	Net capital investment in subsidiaries		(24,200	)		(156,000	)		(3,000	)
	Dividends received from subsidiaries		—			54,750			78,000
	Net capital proceeds (expenditures) for premises and equipment		154			(406	)		466
	Net cash used in investing activities		(24,046	)		(101,656	)		75,466
	FINANCING ACTIVITIES
	Proceeds from short-term debt		—			—			—
	Cash dividends paid		(41,364	)		(36,168	)		(33,787	)
	Common stock issuance		—			231,430			—
	Other		5,105			15,903			(5,368	)
Net cash (used in) provided by financing activities		(36,259	)		211,165			(39,155	)
Net (decrease) increase in cash		(29,974	)		103,939			1,089
Cash and cash equivalents at beginning of period		110,932			6,993			5,904
Cash and cash equivalents at end of period	$	80,958		$	110,932		$	6,993

SUMMARY_OF_OPERATING_RESULTS_B

SUMMARY OF OPERATING RESULTS BY QUARTER	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
SUMMARY OF OPERATING RESULTS BY QUARTER	20.  SUMMARY OF OPERATING RESULTS BY QUARTER (unaudited) (in thousands except per share data)
		Three Months Ended
	2014	March 31		June 30		30-Sep		31-Dec
	Interest income	$	89,047	$	89,789	$	90,817	$	94,218
	Interest expense		3,602		3,619		3,291		3,304
	Net interest income		85,445		86,170		87,526		90,914
	Provision for loan losses		4,500		5,000		4,500		3,000
	Noninterest income		122,964		134,001		126,475		115,248
	Noninterest expense		172,241		166,511		161,461		166,713
	Income tax expense		8,255		13,988		12,410		9,509
	Net income	$	23,413	$	34,672	$	35,630	$	26,940
	2013	31-Mar		30-Jun		30-Sep		31-Dec
	Interest income	$	83,902	$	86,212	$	89,096	$	89,131
	Interest expense		4,419		3,885		3,551		3,217
	Net interest income		79,483		82,327		85,545		85,914
	Provision for loan losses		2,000		5,000		6,500		4,000
	Noninterest income		121,016		113,585		121,625		135,607
	Noninterest expense		150,378		150,311		153,063		170,426
	Income tax expense		13,180		10,672		13,175		12,432
	Net income	$	34,941	$	29,929	$	34,432	$	34,663
	Per Share	Three Months Ended
	2014	March 31		30-Jun		30-Sep		31-Dec
	Net income—basic	$	0.52	$	0.77	$	0.79	$	0.6
	Net income—diluted		0.52		0.76		0.78		0.59
	Dividend		0.225		0.225		0.225		0.235
	Book value		33.94		35.21		35.51		36.1
	Per Share	31-Mar		30-Jun		30-Sep		31-Dec
	2013
	Net income—basic	$	0.88	$	0.75	$	0.85	$	0.78
	Net income—diluted		0.87		0.74		0.83		0.77
	Dividend		0.215		0.215		0.215		0.225
	Book value		31.73		30.2		32.85		33.3

SUMMARY_OF_SIGNIFICANT_ACCOUNT1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Nature of Operations	UMB Financial Corporation (the Company) is a bank holding company, which offers a wide range of banking and other financial services to its customers through its branches and offices in the states of Missouri, Kansas, Colorado, Illinois, Oklahoma, Arizona, Nebraska, Pennsylvania, South Dakota, Indiana, Wisconsin, Utah, Texas, and Massachusetts. The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America 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 consolidated 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. Following is a summary of the more significant accounting policies to assist the reader in understanding the financial presentation.
Consolidation	Consolidation
	The Company and its wholly owned subsidiaries are included in the consolidated financial statements (references hereinafter to the “Company” in these Notes to Consolidated Financial Statements include wholly owned subsidiaries). Intercompany accounts and transactions have been eliminated.
Revenue Recognition	Revenue Recognition
	Interest on loans and securities is recognized based on rate times the principal amount outstanding. This includes the impact of amortization of premiums and discounts. Interest accrual is discontinued when, in the opinion of management, the likelihood of collection becomes doubtful. Other noninterest income is recognized as services are performed or revenue-generating transactions are executed.
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. 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 Federal Reserve Bank 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 December 31, 2014 and 2013 (in thousands):
		Year Ended December 31
		2014		2013
	Due from the Federal Reserve	$	1,342,931	$	2,061,427
	Cash and due from banks		444,299		521,001
	Cash and cash equivalents at end of year	$	1,787,230	$	2,582,428
	Also included in the Interest-bearing due from banks line, but not considered cash and cash equivalents are interest-bearing accounts held at other financial institutions, which totaled$196.5 million and $32.0 million at December 31, 2014 and 2013, respectively.
Loans and Loans Held for Sale	Loans and Loans Held for Sale
	Loans are classified by the portfolio segments of commercial, real estate, consumer, and leases. The portfolio segments are further disaggregated into the loan classes of commercial, commercial credit card, real estate—construction, real estate—commercial, real estate—residential, real estate—HELOC, consumer—credit card, consumer—other, and leases.
	A loan is considered to be impaired when management believes it is probable that it will be unable to collect all principal and interest due according to the contractual terms of the loan. If a loan is impaired, the Company records a valuation allowance equal to the carrying amount of the loan in excess of the present value of the estimated future cash flows discounted at the loan’s effective rate, based on the loan’s observable market price or the fair value of the collateral if the loan is collateral dependent.
	A loan is accounted for as a troubled debt restructuring when a concession had been granted to a debtor experiencing financial difficulties. The Company’s modifications generally include interest rate adjustments, and amortization and maturity date extensions. These modifications allow the debtor short-term cash relief to allow them to improve their financial condition. Restructured loans are individually evaluated for impairment as part of the allowance for loan loss analysis.
	Loans, including those that are considered to be impaired and restructured, are evaluated regularly by management. Loans are considered delinquent when payment has not been received within 30 days of its contractual due date. Loans are placed on non-accrual status when the collection of interest or principal is 90 days or more past due, unless the loan is adequately secured and in the process of collection. When a loan is placed on non-accrual status, any interest previously accrued but not collected is reversed against current income. Loans may be returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured. Interest payments received on non-accrual loans are applied to principal unless the remaining principal balance has been determined to be fully collectible.
	The adequacy of the allowance for loan losses is based on management’s continuing evaluation of the pertinent factors underlying the quality of the loan portfolio, including actual loan loss experience, current economic conditions, detailed analysis of individual loans for which full collectability may not be assured, determination of the existence and realizable value of the collateral and guarantees securing such loans. The actual losses, notwithstanding such considerations, however, could differ from the amounts estimated by management.
	The Company maintains a reserve, separate from the allowance for loan losses, to address the risk of loss associated with loan contingencies, which is included in the accrued expenses and taxes line item in the Consolidated Balance Sheets. In order to maintain the reserve for off-balance sheet items at an appropriate level, a provision to increase or reduce the reserve is included in the Company’s Consolidated Statements of Income. The level of the reserve will be adjusted as needed to maintain the reserve at a specified level in relation to contingent loan risk. The risk of loss arising from un-funded loan commitments has been assessed by dividing the contingencies into pools of similar loan commitments and by applying two factors to each pool. The gross amount of contingent exposure is first multiplied by a potential use factor to estimate the degree to which the unused commitments might reasonably be expected to be used in a time of high usage. The resultant figure is then multiplied by a factor to estimate the risk of loss assuming funding of these loans. The potential loss estimates for each segment of the portfolio are added to arrive at a total potential loss estimate that is used to set the reserve.
	Loans held for sale are carried at the lower of aggregate cost or market value. Loan fees (net of certain direct loan origination costs) on loans held for sale are deferred until the related loans are sold or repaid. Gains or losses on loan sales are recognized at the time of sale and determined using the specific identification method.
Securities	Securities
	Debt securities available for sale principally include U.S. Treasury and agency securities, Government Sponsored Entity (GSE) mortgage-backed securities, certain securities of state and political subdivisions, and corporates. Securities classified as available for sale are measured at fair value. Unrealized holding gains and losses are excluded from earnings and reported in accumulated other comprehensive income (loss) until realized. Realized gains and losses on sales are computed by the specific identification method at the time of disposition and are shown separately as a component of noninterest income.
	Securities held to maturity are carried at amortized historical cost based on management’s intention, and the Company’s ability to hold them to maturity. The Company classifies certain securities of state and political subdivisions as held to maturity.
	Trading securities, acquired for subsequent sale to customers, are carried at fair value. Market adjustments, fees and gains or losses on the sale of trading securities are considered to be a normal part of operations and are included in trading and investment banking income.
Equity-method investments	Equity-method investments
	The Company accounts for certain other investments using equity-method accounting. For non-marketable equity-method investments, the Company’s proportionate share of the income or loss is recognized on a one-quarter lag. When transparency in pricing exists, other investments are considered marketable equity-method investments. For marketable equity-method investments, the Company recognizes its proportionate share of income or loss as of the date of the Company’s consolidated financial statements.
Goodwill and Other Intangibles	Goodwill and Other Intangibles
	Goodwill is tested for impairment annually and more frequently whenever events or changes in circumstance indicate that it is more likely than not that the fair value of a reporting unit is less than its carrying value.
	To test goodwill for impairment, the Company performs a qualitative assessment of each reporting unit. If the Company determines, on the basis of qualitative factors, that the fair value of the reporting unit is more likely than not greater than the carrying amount, the two-step impairment test is not required. Otherwise, the Company compares the fair value of its reporting units to their carrying amounts to determine if an impairment is indicated. If an impairment is indicated, the implied fair value of the reporting unit’s goodwill is compared to its carrying amount. An impairment loss is measured as the excess of the carrying value of a reporting unit’s goodwill over its implied fair value. As a result of such impairment tests, the Company has not recognized an impairment charge.
	No goodwill impairments were recognized in 2014, 2013, or 2012. Other intangible assets are amortized over a period of up to 17 years and are evaluated for impairment when events or circumstances dictate. No intangible asset impairments were recognized in 2014, 2013, or 2012. The Company does not have any indefinite lived intangible assets.
Premises and Equipment	Premises and Equipment
	Premises and equipment are stated at cost less accumulated depreciation, which is computed primarily on the straight line method. Premises are depreciated over 15 to 40 year lives, while equipment is depreciated over lives of 3 to 20 years. Gains and losses from the sale of Premises and equipment are included in other noninterest income.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets
	Long-lived assets, including premises and equipment, are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset or group of assets may not be recoverable. The impairment review includes a comparison of future cash flows expected to be generated by the asset or group of assets to their current carrying value. If the carrying value of the asset or group of assets exceeds expected cash flows (undiscounted and without interest charges), an impairment loss is recognized to the extent the carrying value exceeds fair value. No impairments were recognized in 2014, 2013, or 2012.
Income Taxes	Income Taxes
	The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Under this method, deferred tax assets and liabilities are measured based on the differences between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the periods in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The provision for deferred income taxes represents the change in the deferred income tax accounts during the year excluding the tax effect of the change in net unrealized gain (loss) on securities available for sale.
	The Company records deferred tax assets to the extent these assets will more likely than not be realized. All available evidence is considered in making such determination, including future reversals of existing taxable temporary differences, projected future taxable income, tax planning strategies and recent financial operations. A valuation allowance is recorded for the portion of deferred tax assets that do not meet the more-likely-than-not threshold, and any changes to the valuation allowance are recorded in income tax expense.
	The Company records the financial statement effects of an income tax position when it is more likely than not, based on the technical merits, that it will be sustained upon examination. A tax position that meets the more-likely-than-not recognition threshold is measured and recorded as the largest amount of tax benefit that is greater than 50 percent likely of being realized upon ultimate settlement with a taxing authority. Previously recognized tax positions are derecognized in the first period in which it is no longer more likely than not that the tax position will be sustained. The benefit associated with previously unrecognized tax positions are generally recognized in the first period in which the more-likely-than-not threshold is met at the reporting date, the tax matter is ultimately settled through negotiation or litigation or when the related statute of limitations for the relevant taxing authority to examine and challenge the tax position has expired. The recognition, derecognition and measurement of tax positions are based on management’s best judgment given the facts, circumstance and information available at the reporting date.
	The Company recognizes accrued interest related to unrecognized tax benefits in interest expense and penalties in other noninterest expense. Accrued interest and penalties are included within the related liability lines in the consolidated balance sheets. For the year ended December 31, 2014, the Company has recognized an immaterial amount in interest and penalties related to the unrecognized tax benefits.
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, one of the Company’s derivatives is designated in a qualifying hedging relationship. 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 derivatives are recognized directly in earnings.
Per Share Data	Per Share Data
	Basic income per share is computed based on the weighted average number of shares of common stock outstanding during each period. Diluted year-to-date income per share includes the dilutive effect of 600,705; 562,741; and 398,939 shares issuable upon the exercise of stock options and nonvested restricted shares granted by the Company at December 31, 2014, 2013, and 2012, respectively.
	Options issued under employee benefit plans to purchase 249,368, and 504,938 shares of common stock were outstanding at December 31, 2014, and 2012, respectively, but were not included in the computation of diluted earnings per share because the options were anti-dilutive.
Accounting for Stock-Based Compensation	Accounting for Stock-Based Compensation
	The Company measures the cost of employee services received in exchange for an award of equity instruments based on the fair value of the award on the date of the grant. The grant date fair value is estimated using either an option-pricing model which is consistent with the terms of the award or an observed market price, if such a price exists. Such cost is generally recognized over the vesting period during which an employee is required to provide service in exchange for the award and, in some cases, when performance metrics are met. The Company also estimates the number of instruments that will ultimately be issued by applying a forfeiture rate to each grant.

SUMMARY_OF_SIGNIFICANT_ACCOUNT2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2014
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 December 31, 2014 and 2013 (in thousands):
		Year Ended December 31
		2014		2013
	Due from the Federal Reserve	$	1,342,931	$	2,061,427
	Cash and due from banks		444,299		521,001
	Cash and cash equivalents at end of year	$	1,787,230	$	2,582,428

LOANS_AND_ALLOWANCE_FOR_LOAN_L1

LOANS AND ALLOWANCE FOR LOAN LOSSES (Tables)	12 Months Ended
	Dec. 31, 2014
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 as of December 31, 2014 (in thousands):
		As Of December 31, 2014
		30-89			Greater			Non-Accrual			Total		Current			Total Loans
		Days Past			than 90			Loans			Past Due
		Due and			Days Past
		Accruing			Due and
					Accruing
	Commercial:
	Commercial	$	2,509		$	363		$	13,114		$	15,986	$	3,798,023		$	3,814,009
	Commercial—credit card		267			147			37			451		115,258			115,709
	Real estate:
	Real estate—construction		1,244			—			983			2,227		253,779			256,006
	Real estate—commercial		1,727			61			12,037			13,825		1,852,476			1,866,301
	Real estate—residential		828			113			562			1,503		318,324			319,827
	Real estate—HELOC		1,371			—			19			1,390		642,196			643,586
	Consumer:
	Consumer—credit card		2,268			2,303			560			5,131		305,165			310,296
	Consumer—other		1,743			843			70			2,656		98,314			100,970
	Leases		—			—			—			—		39,090			39,090
	Total loans	$	11,957		$	3,830		$	27,382		$	43,169	$	7,422,625		$	7,465,794
	This table provides a summary of loan classes and an aging of past due loans as of December 31, 2013 (in thousands):
		As Of December 31, 2013
		30-89			Greater			Non-Accrual			Total		Current			Total Loans
		Days Past			than 90			Loans			Past Due
		Due and			Days Past
		Accruing			Due and
					Accruing
	Commercial:
	Commercial	$	2,107		$	135		$	8,042		$	10,284	$	3,291,219		$	3,301,503
	Commercial—credit card		362			82			38			482		102,788			103,270
	Real estate:
	Real estate—construction		186			—			934			1,120		151,755			152,875
	Real estate—commercial		3,611			344			19,213			23,168		1,678,983			1,702,151
	Real estate—residential		1,257			13			868			2,138		287,218			289,356
	Real estate—HELOC		880			6			210			1,096		565,032			566,128
	Consumer:
	Consumer—credit card		3,230			2,448			1,031			6,709		311,627			318,336
	Consumer—other		1,727			190			370			2,287		60,625			62,912
	Leases		—			—			—			—		23,981			23,981
	Total loans	$	13,360		$	3,218		$	30,706		$	47,284	$	6,473,228		$	6,520,512
Credit Risk Profile by Risk Rating	Credit Exposure
	Credit Risk Profile by Risk Rating
		Commercial			Real estate-			Real estate-
					construction			commercial
		2014			2014			2014
	Non-watch list	$	3,532,611		$	253,895		$	1,780,323
	Watch		72,283			181			31,984
	Special Mention		98,750			756			8,691
	Substandard		110,365			1,174			45,303
	Total	$	3,814,009		$	256,006		$	1,866,301
	Credit Exposure
	Credit Risk Profile by Risk Rating
		Commercial			Real estate-			Real estate-
					construction			commercial
		2013			2013			2013
	Non-watch list	$	3,041,224		$	151,359		$	1,565,894
	Watch		110,932			210			76,647
	Special Mention		78,064			—			19,876
	Substandard		71,283			1,306			39,734
	Total	$	3,301,503		$	152,875		$	1,702,151
Credit Risk Profile Based on Payment Activity	Credit Exposure
	Credit Risk Profile Based on Payment Activity
		Commercial-			Real estate-			Real estate-
		credit card			residential			HELOC
		2014			2014			2014
	Performing	$	115,672		$	319,265		$	643,567
	Non-performing		37			562			19
	Total	$	115,709		$	319,827		$	643,586
		Consumer-			Consumer-			Leases
		credit card			other
		2014			2014			2014
	Performing	$	309,736		$	100,900		$	39,090
	Non-performing		560			70			—
	Total	$	310,296		$	100,970		$	39,090
	Credit Exposure
	Credit Risk Profile Based on Payment Activity
		Commercial-			Real estate-			Real estate-
		credit card			residential			HELOC
		2013			2013			2013
	Performing	$	103,232		$	288,488		$	565,918
	Non-performing		38			868			210
	Total	$	103,270		$	289,356		$	566,128
		Consumer-			Consumer-			Leases
		credit card			other
		2013			2013			2013
	Performing	$	317,305		$	62,542		$	23,981
	Non-performing		1,031			370			—
	Total	$	318,336		$	62,912		$	23,981
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 year ended December 31, 2014 (in thousands):
		Year Ended December 31, 2014
		Commercial			Real estate			Consumer			Leases		Total
	Allowance for loan losses:
	Beginning balance	$	48,886		$	15,342		$	10,447		$	76	$	74,751
	Charge-offs		(7,307	)		(259	)		(11,427	)		—		(18,993	)
	Recoveries		848			44			2,490			—		3,382
	Provision		12,922			(4,402	)		8,411			69		17,000
	Ending Balance	$	55,349		$	10,725		$	9,921		$	145	$	76,140
	Ending Balance: individually evaluated for impairment	$	972		$	935		$	—		$	—	$	1,907
	Ending Balance: collectively evaluated for impairment		54,377			9,790			9,921			145		74,233
	Loans:
	Ending Balance: loans	$	3,929,718		$	3,085,720		$	411,266		$	39,090	$	7,465,794
	Ending Balance: individually evaluated for impairment		17,060			10,243			1			—		27,304
	Ending Balance: collectively evaluated for impairment		3,912,658			3,075,477			411,265			39,090		7,438,490
	This table provides a rollforward of the allowance for loan losses by portfolio segment for the year ended December 31, 2013 (in thousands):
		Year Ended December 31, 2013
		Commercial			Real estate			Consumer			Leases		Total
	Allowance for loan losses:
	Beginning balance	$	43,390		$	15,506		$	12,470		$	60	$	71,426
	Charge-offs		(4,748	)		(775	)		(12,131	)		—		(17,654	)
	Recoveries		867			77			2,535			—		3,479
	Provision		9,377			534			7,573			16		17,500
	Ending Balance	$	48,886		$	15,342		$	10,447		$	76	$	74,751
	Ending Balance: individually evaluated for impairment	$	2,882		$	1,370		$	—		$	—	$	4,252
	Ending Balance: collectively evaluated for impairment		46,004			13,972			10,447			76		70,499
	Loans:
	Ending Balance: loans	$	3,404,773		$	2,710,510		$	381,248		$	23,981	$	6,520,512
	Ending Balance: individually evaluated for impairment		14,635			15,543			11			—		30,189
	Ending Balance: collectively evaluated for impairment		3,390,138			2,694,967			381,237			23,981		6,490,323
	This table provides a rollforward of the allowance for loan losses by portfolio segment for the year ended December 31, 2012 (in thousands):
		Year Ended December 31, 2012
		Commercial			Real estate			Consumer			Leases		Total
	Allowance for loan losses:
	Beginning balance	$	37,927		$	20,486		$	13,593		$	11	$	72,017
	Charge-offs		(8,446	)		(932	)		(12,678	)		—		(22,056	)
	Recoveries		1,136			28			2,801			—		3,965
	Provision		12,773			(4,076	)		8,754			49		17,500
	Ending Balance	$	43,390		$	15,506		$	12,470		$	60	$	71,426
	Ending Balance: individually evaluated for impairment	$	1,393		$	781		$	—		$	—	$	2,174
	Ending Balance: collectively evaluated for impairment		41,977			14,725			12,470			60		69,252
	Loans:
	Ending Balance: loans	$	2,978,014		$	2,300,583		$	389,068		$	19,084	$	5,686,749
	Ending Balance: individually evaluated for impairment		15,057			11,203			49			—		26,309
	Ending Balance: collectively evaluated for impairment		2,962,957			2,289,380			389,019			19,084		5,660,440
Analysis of Impaired Loans	This table provides an analysis of impaired loans by class for the year ended December 31, 2014 (in thousands):
		As Of December 31, 2014
		Unpaid			Recorded			Recorded			Total		Related			Average
		Principal			Investment			Investment			Recorded		Allowance			Recorded
		Balance			with No			with			Investment					Investment
					Allowance			Allowance
	Commercial:
	Commercial	$	21,758		$	13,928		$	3,132		$	17,060	$	972		$	16,022
	Commercial—credit card		—			—			—			—		—			—
	Real estate:
	Real estate—construction		1,540			983			—			983		—			939
	Real estate—commercial		9,546			4,454			3,897			8,351		935			11,298
	Real estate—residential		1,083			909			—			909		—			1,006
	Real estate—HELOC		—			—			—			—		—			—
	Consumer:
	Consumer—credit card		—			—			—			—		—			—
	Consumer—other		1			1			—			1		—			12
	Leases		—			—			—			—		—			—
	Total	$	33,928		$	20,275		$	7,029		$	27,304	$	1,907		$	29,277
	This table provides an analysis of impaired loans by class for the year ended December 31, 2013 (in thousands):
		As Of December 31, 2013
		Unpaid			Recorded			Recorded			Total		Related			Average
		Principal			Investment			Investment			Recorded		Allowance			Recorded
		Balance			with No			with			Investment					Investment
					Allowance			Allowance
	Commercial:
	Commercial	$	17,227		$	3,228		$	11,407		$	14,635	$	2,882		$	14,791
	Commercial—credit card		—			—			—			—		—			—
	Real estate:
	Real estate—construction		1,408			810			123			933		—			1,186
	Real estate—commercial		14,686			5,305			8,218			13,523		94			10,506
	Real estate—residential		1,317			1,087			—			1,087		1,276			1,122
	Real estate—HELOC		—			—			—			—		—			—
	Consumer:
	Consumer—credit card		—			—			—			—		—			—
	Consumer—other		12			11			—			11		—			34
	Leases		—			—			—			—		—			—
	Total	$	34,650		$	10,441		$	19,748		$	30,189	$	4,252		$	27,639
	This table provides an analysis of impaired loans by class for the year ended December 31, 2012 (in thousands):
		As Of December 31, 2012
		Unpaid			Recorded			Recorded			Total		Related			Average
		Principal			Investment			Investment			Recorded		Allowance			Recorded
		Balance			with No			with			Investment					Investment
					Allowance			Allowance
	Commercial:
	Commercial	$	22,453		$	12,119		$	2,938		$	15,057	$	1,393		$	13,287
	Commercial—credit card		—			—			—			—		—			—
	Real estate:
	Real estate—construction		276			276			—			276		—			118
	Real estate—commercial		9,334			6,777			2,213			8,990		733			9,925
	Real estate—residential		2,357			1,714			223			1,937		48			2,622
	Real estate—HELOC		—			—			—			—		—			—
	Consumer:
	Consumer—credit card		—			—			—			—		—			—
	Consumer—other		51			49			—			49		—			43
	Leases		—			—			—			—		—			—
	Total	$	34,471		$	20,935		$	5,374		$	26,309	$	2,174		$	25,995
Summary of Loans Restructured by Class	This table provides a summary of loans restructured by class during the years ended December 31, 2014 and 2013 (in thousands):
		Year Ended December 31, 2014									Year Ended December 31, 2013
		Number			Pre-Modification			Post-			Number		Pre-Modification			Post-
		of			Outstanding			Modification			of		Outstanding			Modification
		Contracts			Recorded			Outstanding			Contracts		Recorded			Outstanding
					Investment			Recorded					Investment			Recorded
								Investment								Investment
	Troubled Debt Restructurings
	Commercial:
	Commercial		1		$	469		$	469			2	$	1,128		$	1,066
	Commercial—credit card		—			—			—			—		—			—
	Real estate:
	Real estate—construction		—			—			—			—		—			—
	Real estate—commercial		1			178			178			1		937			937
	Real estate—residential		4			277			301			—		—			—
	Real estate—HELOC		—			—			—			—		—			—
	Consumer:
	Consumer—credit card		—			—			—			—		—			—
	Consumer—other		—			—			—			—		—			—
	Leases		—			—			—			—		—			—
	Total		6		$	924		$	948			3	$	2,065		$	2,003

SECURITIES_Tables

SECURITIES (Tables)	12 Months Ended
	Dec. 31, 2014
Securities Available for Sale	This table provides detailed information about securities available for sale at December 31, 2014 and 2013 (in thousands):
	2014	Amortized		Gross			Gross			Fair
		Cost		Unrealized			Unrealized			Value
				Gains			Losses
	U.S. Treasury	$	519,484	$	501		$	(525	)	$	519,460
	U.S. Agencies		991,084		780			(1,175	)		990,689
	Mortgage-backed		3,276,009		28,470			(26,875	)		3,277,604
	State and political subdivisions		1,983,549		22,973			(5,165	)		2,001,357
	Corporates		124,096		—			(1,270	)		122,826
	Total	$	6,894,222	$	52,724		$	(35,010	)	$	6,911,936
	2013	Amortized		Gross			Gross			Fair
		Cost		Unrealized			Unrealized			Value
				Gains			Losses
	U.S. Treasury	$	110,789	$	284		$	(873	)	$	110,200
	U.S. Agencies		1,258,176		2,793			(3,306	)		1,257,663
	Mortgage-backed		2,984,963		23,942			(64,339	)		2,944,566
	State and political subdivisions		2,003,509		23,493			(31,756	)		1,995,246
	Corporates		457,275		902			(3,441	)		454,736
	Total	$	6,814,712	$	51,414		$	(103,715	)	$	6,762,411
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 December 31, 2014 and 2013 (in thousands).
	2014	Less than 12 months					12 months or more						Total
	Description of Securities	Fair Value		Unrealized			Fair Value			Unrealized			Fair Value		Unrealized
				Losses						Losses					Losses
	U.S. Treasury	$	236,591	$	(329	)	$	14,863		$	(196	)	$	251,454	$	(525	)
	U.S. Agencies		387,999		(689	)		81,593			(486	)		469,592		(1,175	)
	Mortgage-backed		727,142		(8,370	)		616,044			(18,504	)		1,343,186		(26,874	)
	State and political subdivisions		401,934		(1,406	)		226,678			(3,760	)		628,612		(5,166	)
	Corporates		36,655		(243	)		86,171			(1,027	)		122,826		(1,270	)
	Total temporarily-impaired debt securities available for sale	$	1,790,321	$	(11,037	)	$	1,025,349		$	(23,973	)	$	2,815,670	$	(35,010	)
	2013	Less than 12 months					12 months or more						Total
	Description of Securities	Fair Value		Unrealized			Fair Value			Unrealized			Fair Value		Unrealized
				Losses						Losses					Losses
	U.S. Treasury	$	39,822	$	(873	)	$	—		$	—		$	39,822	$	(873	)
	U.S. Agencies		675,509		(3,130	)		9,824			(176	)		685,333		(3,306	)
	Mortgage-backed		1,945,964		(60,719	)		89,147			(3,620	)		2,035,111		(64,339	)
	State and political subdivisions		662,225		(25,064	)		87,061			(6,692	)		749,286		(31,756	)
	Corporates		271,834		(2,458	)		41,522			(983	)		313,356		(3,441	)
	Total temporarily-impaired debt securities available for sale	$	3,595,354	$	(92,244	)	$	227,554		$	(11,471	)	$	3,822,908	$	(103,715	)
Securities Held to Maturity	The table below provides detailed information for securities held to maturity at December 31, 2014 and 2013 (in thousands):
	2014	Amortized		Gross			Gross			Fair
		Cost		Unrealized			Unrealized			Value
				Gains			Losses
	State and political subdivisions	$	278,054	$	26,058		$	—		$	304,112
	2013
	State and political subdivisions	$	209,770	$	21,740		$	—		$	231,510
Schedule of Federal Reserve Bank Stock and Other Securities	The table below provides detailed information for Federal Reserve Bank stock and other securities at December 31, 2014 and 2013 (in thousands):
	2014	Amortized		Gross			Gross			Fair Value
		Cost		Unrealized			Unrealized
				Gains			Losses
	FRB and FHLB stock	$	26,279	$	—		$	—		$	26,279
	Other securities—marketable		—		16,668			—			16,668
	Other securities—non-marketable		21,669		3,937			(79	)		25,527
	Total Federal Reserve Bank stock and other	$	47,948	$	20,605		$	(79	)	$	68,474
	2013
	FRB stock	$	16,279	$	—		$	—		$	16,279
	Other securities—marketable		20		16,612			—			16,632
	Other securities—non-marketable		17,139		432			—			17,571
	Total Federal Reserve Bank stock and other	$	33,438	$	17,044		$	—		$	50,482
Available-for-sale Securities [Member]
Contractual Maturity Information	The following table presents contractual maturity information for securities available for sale at December 31, 2014 (in thousands):
		Amortized		Fair
		Cost		Value
	Due in 1 year or less	$	607,929	$	609,430
	Due after 1 year through 5 years		2,223,097		2,231,267
	Due after 5 years through 10 years		674,876		682,409
	Due after 10 years		112,311		111,226
	Total		3,618,213		3,634,332
	Mortgage-backed securities		3,276,009		3,277,604
	Total securities available for sale	$	6,894,222	$	6,911,936
Held-to-maturity Securities [Member]
Contractual Maturity Information	The following table presents contractual maturity information for securities held to maturity at December 31, 2014 (in thousands):
		Amortized		Fair
		Cost		Value
	Due in 1 year or less	$	15	$	16
	Due after 1 year through 5 years		31,389		34,331
	Due after 5 years through 10 years		165,062		180,531
	Due after 10 years		81,588		89,234
	Total securities held to maturity	$	278,054	$	304,112

LOANS_TO_OFFICERS_AND_DIRECTOR1

LOANS TO OFFICERS AND DIRECTORS (Tables)	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Activity with Respect to Aggregate Loans to Related Parties	For the years 2014 and 2013, an analysis of activity with respect to such aggregate loans to related parties appears below (in thousands):
		Year Ended December 31
		2014			2013
	Balance—beginning of year	$	493,373		$	480,291
	New loans		139,442			149,709
	Repayments		(91,308	)		(136,627	)
	Balance—end of year	$	541,507		$	493,373

GOODWILL_AND_OTHER_INTANGIBLES1

GOODWILL AND OTHER INTANGIBLES (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill	Changes in the carrying amount of goodwill for the years ended December 31, 2014 and December 31, 2013 by operating segment are as follows (in thousands):
		Bank		Institutional		Asset		Total
				Investment		Servicing
				Management
	Balances as of January 1, 2014	$	142,753	$	47,529	$	19,476	$	209,758
	Balances as of December 31, 2014	$	142,753	$	47,529	$	19,476	$	209,758
	Balances as of January 1, 2013	$	142,753	$	47,529	$	19,476	$	209,758
	Balances as of December 31, 2013	$	142,753	$	47,529	$	19,476	$	209,758
Changes in Intangible Assets	Following are the intangible assets that continue to be subject to amortization as of December 31, 2014 and 2013 (in thousands):
		As of December 31, 2014
		Gross Carrying		Accumulated		Net Carrying
		Amount		Amortization		Amount
	Core deposit intangible assets	$	36,497	$	32,721	$	3,776
	Customer relationships		104,560		64,980		39,580
	Other intangible assets		3,247		2,612		635
	Total intangible assets	$	144,304	$	100,313	$	43,991
		As of December 31, 2013
	Core deposit intangible assets	$	36,497	$	31,674	$	4,823
	Customer relationships		103,960		54,062		49,898
	Other intangible assets		3,247		2,383		864
	Total intangible assets	$	143,704	$	88,119	$	55,585
Estimated Amortization Expense of Intangible Assets	The following table discloses the estimated amortization expense of intangible assets in future years (in thousands):
	For the year ending December 31, 2015	$	9,636
	For the year ending December 31, 2016		8,428
	For the year ending December 31, 2017		7,185
	For the year ending December 31, 2018		4,994
	For the year ending December 31, 2019		4,204

PREMISES_AND_EQUIPMENT_Tables

PREMISES AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Components of Premises and Equipment	Premises and equipment consisted of the following (in thousands):
		December 31
		2014			2013
	Land	$	43,798		$	44,731
	Buildings and leasehold improvements		301,687			300,175
	Equipment		120,745			124,992
	Software		132,265			121,974
			598,495			591,872
	Accumulated depreciation		(246,457	)		(247,519	)
	Accumulated amortization		(94,203	)		(94,664	)
	Premises and equipment, net	$	257,835		$	249,689
Minimum Future Rental Commitments for all Non-cancelable Operating Leases	Minimum future rental commitments as of December 31, 2014, for all non-cancelable operating leases are as follows (in thousands):
	2015	$	9,325
	2016		8,626
	2017		8,335
	2018		7,903
	2019		7,668
	Thereafter		31,616
	Total	$	73,473

BORROWED_FUNDS_Tables

BORROWED FUNDS (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Components of Short-Term and Long Term Debt	The components of the Company’s short-term and long-term debt are as follows (in thousands):
		December 31
		2014		2013
	Short-term debt:
	Federal Home Loan Bank 5.89% due 2014	$	—	$	107
	Total short-term debt		—		107
	Long-term debt:
	Kansas Equity Fund IV, L.P. 0% due 2017		71		173
	Kansas Equity Fund V, L.P. 0% due 2017		119		176
	Kansas Equity Fund VI, L.P. 0% due 2017		239		369
	Kansas Equity Fund IX, L.P. 0% due 2023		341		408
	Kansas Equity Fund X, L.P. 0% due 2021		419		469
	Kansas City Equity Fund 2007, L.L.C. 0% due 2016		86		162
	Kansas City Equity Fund 2008, L.L.C. 0% due 2016		149		290
	Kansas City Equity Fund 2009, L.L.C. 0% due 2017		371		504
	St. Louis Equity Fund 2007 L.L.C. 0% due 2016		39		179
	St. Louis Equity Fund 2008 L.L.C. 0% due 2016		160		310
	St. Louis Equity Fund 2009 L.L.C. 0% due 2017		395		544
	St. Louis Equity Fund 2012 L.L.C. 0% due 2020		402		481
	St. Louis Equity Fund 2013 L.L.C. 0% due 2021		1,758		—
	St. Louis Equity Fund 2014 L.L.C. 0% due 2022		1,819		—
	MHEG Community Fund 41, L.P. 0% due 2024		957		990
	MHEG Community Fund 43, L.P. 0% due 2026		1,485		—
	Total long-term debt		8,810		5,055
	Total borrowed funds	$	8,810	$	5,162
Aggregate Annual Repayments of Long-Term Debt	Aggregate annual repayments of long-term debt at December 31, 2014, are as follows (in thousands):
	2015	$	1,584
	2016		1,552
	2017		1,252
	2018		1,112
	2019		1,091
	Thereafter		2,219
	Total	$	8,810
Carrying Amounts and Market Values of Securities and Related Repurchase Liabilities and Weighted Average Interest Rates of Repurchase Liabilities	The carrying amounts and market values of the securities and the related repurchase liabilities and weighted average interest rates of the repurchase liabilities (grouped by maturity of the repurchase agreements) were as follows as of December 31, 2014 (in thousands):
	Maturity of the Repurchase Liabilities	Securities Market		Repurchase		Weighted Average
		Value		Liabilities		Interest Rate
	On Demand	$	3,008	$	3,001		0.01	%
	2 to 30 days		2,003,126		1,979,783		0.19
	Over 90 Days		301		300		0
	Total	$	2,006,435	$	1,983,084		0.19	%

REGULATORY_REQUIREMENTS_Tables

REGULATORY REQUIREMENTS (Tables)	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Actual Capital Amounts as well as Required and Well-Capitalized Tier One, Total and Tier One Leverage Ratios	Actual capital amounts as well as required and well-capitalized tier 1, total and tier 1 Leverage ratios as of December 31, for the Company and its banks are as follows (in thousands):
		2014
		Actual					For Capital					To Be Well
							Adequacy					Capitalized Under
							Purposes					Prompt Corrective
												Action Provisions
		Amount		Ratio			Amount		Ratio			Amount		Ratio
	Tier 1 Capital:
	UMB Financial Corporation	$	1,393,389		13.29	%	$	419,383		4	%	$	N/A		N/A	%
	UMB Bank, n. a.		1,209,096		11.68			414,135		4			621,202		6
	Total Capital:
	UMB Financial Corporation		1,471,631		14.04			838,766		8			N/A		N/A
	UMB Bank, n. a.		1,287,338		12.43			828,270		8			1,035,337		10
	Tier 1 Leverage:
	UMB Financial Corporation		1,393,389		8.72			639,476		4			N/A		N/A
	UMB Bank, n. a.		1,209,096		7.63			634,187		4			792,733		5
		2013
	Tier 1 Capital:
	UMB Financial Corporation	$	1,285,100		13.61	%	$	377,681		4	%	$	N/A		N/A	%
	UMB Bank, n. a.		1,095,446		11.73			373,509		4			560,264		6
	Total Capital:
	UMB Financial Corporation		1,362,015		14.43			755,361		8			N/A		N/A
	UMB Bank, n. a.		1,172,361		12.56			747,018		8			933,773		10
	Tier 1 Leverage:
	UMB Financial Corporation		1,285,100		8.41			611,206		4			N/A		N/A
	UMB Bank, n. a.		1,095,446		7.21			608,148		4			760,185		5

EMPLOYEE_BENEFITS_Tables

EMPLOYEE BENEFITS (Tables)	12 Months Ended
	Dec. 31, 2014
Status of Service Based Restricted Shares	The table below discloses the status of the service-based restricted shares during 2014:
	Service-Based Restricted Stock	Number			Weighted Average
		of Shares			Grant Date Fair
					Value
	Nonvested—December 31, 2013		426,922		$	43.58
	Granted		153,721			57.42
	Canceled		(27,856	)		45.07
	Vested		(96,156	)		41.58
	Nonvested—December 31, 2014		456,631		$	48.57
Status of Performance Based Restricted Shares	The table below discloses the status of the performance-based restricted shares during 2014:
	Performance-Based Restricted Stock	Number			Weighted Average
		of Shares			Grant Date Fair
					Value
	Nonvested—December 31, 2013		112,197		$	42.46
	Granted		31,590			57.4
	Canceled		(6,443	)		44.44
	Vested		(36,075	)		41.71
	Nonvested—December 31, 2014		101,269		$	47.26
Assumptions for Stock-Based Awards	The Company uses the Black-Scholes pricing model to determine the fair value of its options. The assumptions for stock-based awards in the past three years utilized in the model are shown in the table below.
	Black-Scholes pricing model:	2014			2013			2012
	Weighted average fair value of the granted options	$	13.03		$	10.18		$	8.83
	Weighted average risk-free interest rate		1.77	%		1.49	%		1.14	%
	Expected option life in years		6.25			6.25			6.25
	Expected volatility		24.87	%		26.36	%		27.02	%
	Expected dividend yield		1.53	%		1.83	%		1.95	%
2002 Plan [Member]
Information Relating to Option Activity	The table below discloses the information relating to option activity in 2014, under the 2002 Plan:
	Stock Options Under the 2002 Plan	Number			Weighted Average			Weighted Average			Aggregate
		of Shares			Price Per Share			Remaining			Intrinsic
								Contractual Term			Value
	Outstanding—December 31, 2013		341,491		$	36.05
	Granted		—			—
	Canceled		(7,673	)		32.68
	Exercised		(75,343	)		31.52
	Outstanding—December 31, 2014		258,475			37.47			2.5		$	5,020,538
	Exercisable—December 31, 2014		258,475			37.47
	Exercisable and expected to be exercisable— December 31, 2014		258,475		$	37.47			2.5		$	5,020,538
Long-Term Incentive Compensation Plan (LTIP) [Member]
Information Relating to Option Activity	The table below discloses the information relating to non-qualified option activity in 2014 under the LTIP:
	Stock Options Under the LTIP	Number of			Weighted Average			Weighted Average			Aggregate
		Shares			Price Per Share			Remaining			Intrinsic
								Contractual Term			Value
	Outstanding—December 31, 2013		1,342,025		$	40.45
	Granted		259,158			57.4
	Canceled		(60,373	)		44.18
	Exercised		(156,775	)		36.08
	Outstanding—December 31, 2014		1,384,035			44.03			6.3		$	17,801,893
	Exercisable—December 31, 2014		525,298			39.43
	Exercisable and expected to be exercisable—December 31, 2014		1,328,241		$	43.76			6.2		$	17,440,423

BUSINESS_SEGMENT_REPORTING_Tab

BUSINESS SEGMENT REPORTING (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Line of Business Segment Financial Results	Line of business/segment financial results were as follows (in thousands):
		Year Ended December 31, 2014
		Bank		Payment		Institutional			Asset		Total
				Solutions		Investment			Servicing
						Management
	Net interest income	$	292,357	$	52,251	$	(3	)	$	5,450	$	350,055
	Provision for loan losses		9,175		7,825		—			—		17,000
	Noninterest income		194,223		84,477		131,226			88,762		498,688
	Noninterest expense		405,065		94,177		92,008			75,676		666,926
	Income before taxes		72,340		34,726		39,215			18,536		164,817
	Income tax expense		19,487		9,311		10,331			5,033		44,162
	Net income	$	52,853	$	25,415	$	28,884		$	13,503	$	120,655
	Average assets	$	12,099,000	$	2,456,000	$	72,000		$	1,372,000	$	15,999,000
		Year Ended December 31, 2013
		Bank		Payment		Institutional			Asset		Total
				Solutions		Investment			Servicing
						Management
	Net interest income	$	285,112	$	45,832	$	(32	)	$	2,357	$	333,269
	Provision for loan losses		5,535		11,965		—			—		17,500
	Noninterest income		210,535		74,223		126,442			80,633		491,833
	Noninterest expense		376,307		86,746		88,336			72,789		624,178
	Income before taxes		113,805		21,344		38,074			10,201		183,424
	Income tax expense		28,548		6,739		10,002			4,170		49,459
	Net income	$	85,257	$	14,605	$	28,072		$	6,031	$	133,965
	Average assets	$	11,255,000	$	1,736,000	$	77,000		$	1,963,000	$	15,031,000
		Year Ended December 31, 2012
		Bank		Payment		Institutional			Asset		Total
				Solutions		Investment			Servicing
						Management
	Net interest income	$	274,843	$	43,351	$	2		$	1,860	$	320,056
	Provision for loan losses		9,267		8,233		—			—		17,500
	Noninterest income		214,595		67,887		100,051			75,589		458,122
	Noninterest expense		381,273		69,205		71,053			68,923		590,454
	Income before taxes		98,898		33,800		29,000			8,526		170,224
	Income tax expense		26,543		9,523		8,098			3,343		47,507
	Net income	$	72,355	$	24,277	$	20,902		$	5,183	$	122,717
	Average assets	$	10,864,000	$	1,282,000	$	79,000		$	1,164,000	$	13,389,000

COMMON_STOCK_AND_EARNINGS_PER_1

COMMON STOCK AND EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Summary of Share Transactions	The following table summarizes the share transactions for the three years ended December 31, 2014:
		Shares		Shares in
		Issued		Treasury
	Balance December 31, 2011		55,056,730		(14,630,388	)
	Purchase of Treasury Stock		—		(514,824	)
	Sale of Treasury Stock		—		21,950
	Issued for stock options & restricted stock		—		407,410
	Balance December 31, 2012		55,056,730		(14,715,852	)
	Common stock issuance				4,485,000
	Purchase of Treasury Stock		—		(99,402	)
	Sale of Treasury Stock		—		14,661
	Issued for stock options & restricted stock		—		480,100
	Balance December 31, 2013		55,056,730		(9,835,493	)
	Purchase of Treasury Stock		—		(130,197	)
	Sale of Treasury Stock		—		15,320
	Issued for stock options & restricted stock		—		425,828
	Balance December 31, 2014		55,056,730		(9,524,542	)
Shares Used in Calculation of Basic and Diluted Earnings	The shares used in the calculation of basic and diluted earnings per share, are shown below:
		For the Years Ended December 31
		2014		2013			2012
	Weighted average basic common shares outstanding		44,844,578		41,275,839			40,034,428
	Dilutive effect of stock options and restricted stock		600,705		562,741			398,939
	Weighted average diluted common shares outstanding		45,445,283		41,838,580			40,433,367

COMMITMENTS_CONTINGENCIES_AND_1

COMMITMENTS, CONTINGENCIES AND GUARANTEES (Tables)	12 Months Ended
	Dec. 31, 2014
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 as described above.
		Contract or Notional Amount
		December 31
	(in thousands)	2014		2013
	Commitments to extend credit for loans (excluding credit card loans)	$	3,509,841	$	2,690,268
	Commitments to extend credit under credit card loans		2,690,752		2,215,278
	Commercial letters of credit		1,334		5,949
	Standby letters of credit		375,003		356,054
	Forward contracts		144,950		21,525
	Spot foreign exchange contracts		14,721		8,001

INCOME_TAXES_Tables

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Components of Income Tax Expense (Benefit)	Income tax expense includes the following components (in thousands):
		Year Ended December 31
		2014			2013			2012
	Current tax
	Federal	$	53,314		$	50,832		$	40,837
	State		2,304			3,750			2,995
	Total current tax expense		55,618			54,582			43,832
	Deferred tax
	Federal		(11,448	)		(4,278	)		2,862
	State		(8	)		(845	)		813
	Total deferred tax (benefit) expense		(11,456	)		(5,123	)		3,675
	Total tax expense	$	44,162		$	49,459		$	47,507
Reconciliation Between Income Tax Expense and Amount Computed by Applying Federal Statutory Tax Rate	The reconciliation between the income tax expense and the amount computed by applying the statutory federal tax rate of 35% to income before income taxes is as follows (in thousands):
		Year Ended December 31
		2014			2013			2012
	Statutory federal income tax expense	$	57,686		$	64,199		$	59,578
	Tax-exempt interest income		(13,861	)		(14,146	)		(13,480	)
	State and local income taxes, net of federal tax benefits		1,403			1,887			2,475
	Federal tax credits		(1,433	)		(2,338	)		(1,090	)
	Other		367			(143	)		24
	Total tax expense	$	44,162		$	49,459		$	47,507
Components of Deferred Tax Assets and Liabilities	The significant components of deferred tax assets and liabilities are reflected in the following table (in thousands):
		December 31,
		2014			2013
	Deferred tax assets:
	Net unrealized loss on securities available for sale	$	—		$	19,495
	Loans, principally due to allowance for loan losses		28,924			28,367
	Stock-based compensation		7,109			6,302
	Accrued expenses		24,747			19,943
	Intangibles		7,254			—
	Miscellaneous		3,551			4,474
	Total deferred tax assets before valuation allowance		71,585			78,581
	Valuation allowance		(3,417	)		(2,680	)
	Total deferred tax assets		68,168			75,901
	Deferred tax liabilities:
	Net unrealized gain on securities available for sale		(6,879	)		—
	Land, buildings and equipment		(24,002	)		(25,403	)
	Original issue discount		(4,311	)		(4,439	)
	Partnership investments		(7,838	)		(6,540	)
	Intangibles		—			(238	)
	Miscellaneous		(6,183	)		(5,408	)
	Total deferred tax liabilities		(49,213	)		(42,028	)
	Net deferred tax asset	$	18,955		$	33,873
Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands):
		December 31,
		2014			2013
	Unrecognized tax benefits—opening balance	$	4,997		$	4,347
	Gross decreases—tax positions in prior period		(444	)		(80	)
	Gross increases—current-period tax positions		964			1,049
	Lapse of statute of limitations		(1,492	)		(319	)
	Unrecognized tax benefits—ending balance	$	4,025		$	4,997

DERIVATIVES_AND_HEDGING_ACTIVI1

DERIVATIVES AND HEDGING ACTIVITIES (Tables)	12 Months Ended
	Dec. 31, 2014
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 December 31, 2014 and December 31, 2013 (in thousands):
		Asset Derivatives						Liability Derivatives
		December 31,						December 31,
		2014			2013			2014		2013
	Fair value
	Interest Rate Products:
	Derivatives not designated as hedging instruments	$	7,138		$	2,442		$	7,250	$	2,346
	Derivatives designated as hedging instruments		—			76			285		—
	Total	$	7,138		$	2,518		$	7,535	$	2,346
Summary of Amount of Gain (Loss) Recognized in Other Non-Interest Expense in Consolidated Statements of Income Related to Derivative Asset and Liability	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 asset and liability as of December 31, 2014 and December 31, 2013 (in thousands):
		Amount of Gain (Loss) Recognized
		For the Year Ended
		December 31,
		2014			2013
	Interest Rate Products
	Derivatives not designated as hedging instruments	$	(207	)	$	217
	Total	$	(207	)	$	217
	Interest Rate Products
	Derivatives designated as hedging instruments
	Fair value adjustments on derivatives	$	(361	)	$	76
	Fair value adjustments on hedged items		334			(74	)
	Total	$	(27	)	$	2

DISCLOSURES_ABOUT_FAIR_VALUE_O1

DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis as of December 31, 2014 and 2013 (in thousands):
					Fair Value Measurement at Reporting Date Using
	Description	December 31,			Quoted Prices in			Significant Other		Significant
		2014			Active Markets			Observable		Unobservable
					for Identical			Inputs (Level 2)		Inputs (Level 3)
					Assets (Level 1)
	Assets
	U.S. Treasury	$	400		$	400		$	—	$	—
	U.S. Agencies		1,315			—			1,315		—
	Mortgage-backed		—			—			—		—
	State and political subdivisions		7,381			—			7,381		—
	Trading—other		18,107			18,106			1		—
	Trading securities		27,203			18,506			8,697		—
	U.S. Treasury		519,460			519,460			—		—
	U.S. Agencies		990,689			—			990,689		—
	Mortgage-backed		3,277,604			—			3,277,604		—
	State and political subdivisions		2,001,357			—			2,001,357		—
	Corporates		122,826			122,826			—		—
	Available for sale securities		6,911,936			642,286			6,269,650		—
	Company-owned life insurance		26,886			—			26,886		—
	Derivatives		7,138			—			7,138		—
	Total	$	6,973,163		$	660,792		$	6,312,371	$	—
	Liabilities
	Deferred compensation	$	26,885		$	26,885		$	—	$	—
	Contingent consideration liability		53,411			—			—		53,411
	Derivatives		7,535			—			7,535		—
	Total	$	87,831		$	26,885		$	7,535	$	53,411
					Fair Value Measurement at Reporting Date Using
	Description	December 31,			Quoted Prices in			Significant Other		Significant
		2013			Active Markets			Observable		Unobservable
					for Identical			Inputs (Level 2)		Inputs (Level 3)
					Assets (Level 1)
	Assets
	U.S. Treasury	$	400		$	400		$	—	$	—
	U.S. Agencies		—			—			—		—
	Mortgage-backed		515			—			515		—
	State and political subdivisions		3,072			—			3,072		—
	Trading—other		24,477			24,477			—		—
	Trading securities		28,464			24,877			3,587		—
	U.S. Treasury		110,200			110,200			—		—
	U.S. Agencies		1,257,663			—			1,257,663		—
	Mortgage-backed		2,944,566			—			2,944,566		—
	State and political subdivisions		1,995,246			—			1,995,246		—
	Corporates		454,736			454,736			—		—
	Available for sale securities		6,762,411			564,936			6,197,475		—
	Company-owned life insurance		19,619			—			19,619		—
	Derivatives		2,518			—			2,518		—
	Total	$	6,813,012		$	589,813		$	6,223,199	$	—
	Liabilities
	Deferred compensation	$	19,825		$	19,825		$	—	$	—
	Contingent consideration liability		46,201			—			—		46,201
	Derivatives		2,346			—			2,346		—
	Total	$	68,372		$	19,825		$	2,346	$	46,201
Reconciliation of Beginning and Ending Balances of Contingent Consideration Liability	The following table reconciles the beginning and ending fair value of balances of the contingent consideration liability:
		December 31,
		2014			2013
	Beginning balance	$	46,201		$	51,163
	Contingency reserve		14,272			—
	Payment of contingent consideration on acquisitions		(13,725	)		(16,172	)
	Income from fair value adjustments		—			(138	)
	Expense from fair value adjustments		6,663			11,348
	Ending balance	$	53,411		$	46,201
Quantitative Information about Significant Unobservable Input used in Fair Value Measurement for Contingent Consideration Liability Measured at Fair Value on Recurring Basis	The following table presents certain quantitative information about the significant unobservable input used in the fair value measurement for the contingent consideration liability measured at fair value on a recurring basis using significant unobservable inputs (Level 3):
	Description	Valuation Techniques		Significant	Range
				Unobservable Inputs
	Liabilities
	Contingent consideration liability	Discounted cash flows		Revenue and expense growth percentage		1% - 102%
Assets Measured at Fair Value on Non-Recurring Basis	Assets measured at fair value on a non-recurring basis as of December 31, 2014 and 2013 (in thousands):
					Fair Value Measurement at December 31, 2014 Using
	Description	December 31,			Quoted Prices in			Significant Other		Significant		Total
		2014			Active Markets			Observable Inputs		Unobservable		Gains
					for Identical			(Level 2)		Inputs (Level 3)		Recognized
					Assets (Level 1)							During the
												Twelve
												Months
												Ended
												December 31
	Impaired loans	$	5,122		$	—		$	—	$	5,122	$	2,345
	Other real estate owned		208			—			—		208		—
	Total	$	5,330		$	—		$	—	$	5,330	$	2,345
					Fair Value Measurement at December 31, 2013 Using
	Description	December 31,			Quoted Prices in			Significant Other		Significant		Total
		2013			Active Markets			Observable Inputs		Unobservable		(Losses)
					for Identical			(Level 2)		Inputs (Level 3)		Recognized
					Assets (Level 1)							During the
												Twelve
												Months
												Ended
												December 31
	Impaired loans	$	15,496		$	—		$	—	$	15,496	$	(2,496	)
	Other real estate owned		329			—			—		329		(125	)
	Total	$	15,825		$	—		$	—	$	15,825	$	(2,621	)
Estimated Fair Value of Financial Instruments	fair value on a recurring basis or non-recurring basis. The estimated fair value of the Company’s financial instruments at December, 31, 2014 and 2013 are as follows (in millions):
		Fair Value Measurement at December 31, 2014 Using
		Carrying			Quoted Prices in			Significant Other		Significant		Total
		Amount			Active Markets			Observable		Unobservable		Estimated
					for Identical			Inputs (Level 2)		Inputs (Level 3)		Fair Value
					Assets (Level 1)
	FINANCIAL ASSETS
	Cash and short-term investments	$	2,101.80		$	2,006.30		$	95.5	$	—	$	2,101.80
	Securities available for sale		6,911.90			642.3			6,269.60		—		6,911.90
	Securities held to maturity		278.1			—			304.1		—		304.1
	Federal Reserve Bank stock and other		68.5			—			68.5		—		68.5
	Trading securities		27.2			18.5			8.7		—		27.2
	Loans (exclusive of allowance for loan loss)		7,466.40			—			7,483.30		—		7,483.30
	Derivatives		7.1			—			7.1		—		7.1
	FINANCIAL LIABILITIES
	Demand and savings deposits		12,353.30			12,353.30			—		—		12,353.30
	Time deposits		1,263.60			—			1,263.60		—		1,263.60
	Other borrowings		2,025.10			42			1,983.10		—		2,025.10
	Long-term debt		8.8			—			9.1		—		9.1
	Derivatives		7.5			—			7.5		—		7.5
	OFF-BALANCE SHEET ARRANGEMENTS
	Commitments to extend credit for loans												5.7
	Commercial letters of credit												0.2
	Standby letters of credit												2.4
		Fair Value Measurement at December 31, 2013 Using
		Carrying			Quoted Prices in			Significant Other		Significant		Total
		Amount			Active Markets			Observable		Unobservable		Estimated
					for Identical			Inputs (Level 2)		Inputs (Level 3)		Fair Value
					Assets (Level 1)
	FINANCIAL ASSETS
	Cash and short-term investments	$	2,701.50		$	2,626.30		$	75.2	$	—	$	2,701.50
	Securities available for sale		6,762.40			564.9			6,197.50		—		6,762.40
	Securities held to maturity		209.8			—			231.5		—		231.5
	Federal Reserve Bank stock and other		50.5			—			50.5		—		50.5
	Trading securities		28.5			24.9			3.6		—		28.5
	Loans (exclusive of allowance for loan loss)		6,521.90			—			6,571.60		—		6,571.60
	Derivatives		2.5			—			2.5		—		2.5
	FINANCIAL LIABILITIES
	Demand and savings deposits		12,191.10			12,191.10			—		—		12,191.10
	Time deposits		1,449.60			—			1,449.40		—		1,449.40
	Other borrowings		1,583.30			12.8			1,570.50		—		1,583.30
	Long-term debt		5.1			—			4.5		—		4.5
	Derivatives		2.3			—			2.3		—		2.3
	OFF-BALANCE SHEET ARRANGEMENTS
	Commitments to extend credit for loans												6
	Commercial letters of credit												0.1
	Standby letters of credit												2

PARENT_COMPANY_FINANCIAL_INFOR1

PARENT COMPANY FINANCIAL INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule of Parent Company Balance Sheets		December 31
			2014			2013
	BALANCE SHEETS (in thousands)
	ASSETS
	Investment in subsidiaries:
	Banks	$	1,312,575		$	1,159,098
	Non-banks		187,329			175,650
	Total investment in subsidiaries		1,499,904			1,334,748
	Goodwill on purchased affiliates		5,011			5,011
	Cash		80,958			110,932
	Securities available for sale and other		65,628			61,685
	Total assets	$	1,651,501		$	1,512,376
	LIABILITIES AND SHAREHOLDERS’ EQUITY
	Short-term debt	$	—		$	—
	Accrued expenses and other		7,743			6,311
	Total liabilities		7,743			6,311
	Shareholders’ equity		1,643,758			1,506,065
	Total liabilities and shareholders’ equity	$	1,651,501		$	1,512,376
Schedule of Parent Company Statements of Income and Comprehensive Income
		Year Ended December 31
		2014			2013			2012
	STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (in thousands)
	INCOME
	Dividends and income received from subsidiary banks	$	31,000		$	54,750		$	78,000
	Service fees from subsidiaries		35,206			33,443			27,821
	Other		2,504			387			1,012
	Total income		68,710			88,580			106,833
	EXPENSE
	Salaries and employee benefits		33,556			32,223			30,683
	Other		17,037			9,198			9,428
	Total expense		50,593			41,421			40,111
	Income before income taxes and equity in undistributed earnings of subsidiaries		18,117			47,159			66,722
	Income tax benefit		(5,227	)		(4,307	)		(4,248	)
	Income before equity in undistributed earnings of subsidiaries		23,344			51,466			70,970
	Equity in undistributed earnings of subsidiaries:
	Banks		94,833			64,674			44,797
	Non-Banks		2,478			17,825			6,950
	Net income	$	120,655		$	133,965		$	122,717
	Other comprehensive income (loss)		43,646			(118,228	)		4,489
	Comprehensive income	$	164,301		$	15,737		$	127,206
Schedule of Parent Company Statements of Cash Flows		Year Ended December 31
		2014			2013			2012
	STATEMENTS OF CASH FLOWS (in thousands)
	OPERATING ACTIVITIES
	Net income	$	120,655		$	133,965		$	122,717
	Adjustments to reconcile net income to cash used in operating
	activities:
	Equity in earnings of subsidiaries		(128,311	)		(137,249	)		(129,747	)
	Dividends received from subsidiaries		31,000			—			—
	Net decrease (increase) in trading securities		6,397			6,181			(11,380	)
	Equity based compensation		9,661			—			—
	Other		(9,071	)		(8,467	)		(16,812	)
	Net cash provided by operating activities		30,331			(5,570	)		(35,222	)
	INVESTING ACTIVITIES
	Net capital investment in subsidiaries		(24,200	)		(156,000	)		(3,000	)
	Dividends received from subsidiaries		—			54,750			78,000
	Net capital proceeds (expenditures) for premises and equipment		154			(406	)		466
	Net cash used in investing activities		(24,046	)		(101,656	)		75,466
	FINANCING ACTIVITIES
	Proceeds from short-term debt		—			—			—
	Cash dividends paid		(41,364	)		(36,168	)		(33,787	)
	Common stock issuance		—			231,430			—
	Other		5,105			15,903			(5,368	)
	Net cash (used in) provided by financing activities		(36,259	)		211,165			(39,155	)
	Net (decrease) increase in cash		(29,974	)		103,939			1,089
	Cash and cash equivalents at beginning of period		110,932			6,993			5,904
	Cash and cash equivalents at end of period	$	80,958		$	110,932		$	6,993

SUMMARY_OF_OPERATING_RESULTS_B1

SUMMARY OF OPERATING RESULTS BY QUARTER (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Summary of Operating Results By Quarter	SUMMARY OF OPERATING RESULTS BY QUARTER (unaudited) (in thousands except per share data)
		Three Months Ended
		March 31		June 30		30-Sep		31-Dec
	2014
	Interest income	$	89,047	$	89,789	$	90,817	$	94,218
	Interest expense		3,602		3,619		3,291		3,304
	Net interest income		85,445		86,170		87,526		90,914
	Provision for loan losses		4,500		5,000		4,500		3,000
	Noninterest income		122,964		134,001		126,475		115,248
	Noninterest expense		172,241		166,511		161,461		166,713
	Income tax expense		8,255		13,988		12,410		9,509
	Net income	$	23,413	$	34,672	$	35,630	$	26,940
		31-Mar		30-Jun		30-Sep		31-Dec
	2013
	Interest income	$	83,902	$	86,212	$	89,096	$	89,131
	Interest expense		4,419		3,885		3,551		3,217
	Net interest income		79,483		82,327		85,545		85,914
	Provision for loan losses		2,000		5,000		6,500		4,000
	Noninterest income		121,016		113,585		121,625		135,607
	Noninterest expense		150,378		150,311		153,063		170,426
	Income tax expense		13,180		10,672		13,175		12,432
	Net income	$	34,941	$	29,929	$	34,432	$	34,663
		Three Months Ended
	Per Share	31-Mar		30-Jun		30-Sep		31-Dec
	2014
	Net income - basic	$	0.52	$	0.77	$	0.79	$	0.6
	Net income - diluted		0.52		0.76		0.78		0.59
	Dividend		0.225		0.225		0.225		0.235
	Book value		33.94		35.21		35.51		36.1
	Per Share	31-Mar		30-Jun		30-Sep		31-Dec
	2013
	Net income - basic	$	0.88	$	0.75	$	0.85	$	0.78
	Net income - diluted		0.87		0.74		0.83		0.77
	Dividend		0.215		0.215		0.215		0.225
	Book value		31.73		30.2		32.85		33.3

Summary_of_Cash_and_Cash_Equiv

Summary of Cash and Cash Equivalents (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Accounting Policies [Abstract]
Due from the Federal Reserve	$1,342,931	$2,061,427
Cash and due from banks	444,299	521,001
Cash and cash equivalents at end of year	$1,787,230	$2,582,428	$1,366,394	$1,459,631

Recovered_Sheet1

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary Of Significant Accounting Policies [Line Items]
Interest bearing amounts held at other financial institutions	$196,500,000	$32,000,000
Days loan should be past due after contractual due date to be considered as delinquent loan	30 days
Days in which collection of interest or principal should be past to be placed on non-accrual status	90 days
Goodwill impairment	0	0	0
Impairment of intangible assets	0	0	0
Impairment charges	$0	$0	$0
Dilutive effect of common stock issuable upon exercise of options and nonvested restricted shares	600,705	562,741	398,939
Anti-dilutive shares	249,368		504,938
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Tax benefit, Percentage	50.00%
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortizable intangible assets, amortization period	17 years
Premises [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, depreciation period	15 years
Premises [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, depreciation period	40 years
Equipment [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, depreciation period	3 years
Equipment [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, depreciation period	20 years

Summary_of_Loan_Classes_and_Ag

Summary of Loan Classes and Aging of Past Due Loans (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due and Accruing	$11,957	$13,360
Greater than 90 Days Past Due and Accruing	3,830	3,218
Non- Accrual Loans	27,382	30,706
Total Past Due	43,169	47,284
Current	7,422,625	6,473,228
Total Loans	7,465,794	6,520,512	5,686,749
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due and Accruing	2,509	2,107
Greater than 90 Days Past Due and Accruing	363	135
Non- Accrual Loans	13,114	8,042
Total Past Due	15,986	10,284
Current	3,798,023	3,291,219
Total Loans	3,814,009	3,301,503
Commercial - credit card [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due and Accruing	267	362
Greater than 90 Days Past Due and Accruing	147	82
Non- Accrual Loans	37	38
Total Past Due	451	482
Current	115,258	102,788
Total Loans	115,709	103,270
Real estate - construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due and Accruing	1,244	186
Greater than 90 Days Past Due and Accruing	0	0
Non- Accrual Loans	983	934
Total Past Due	2,227	1,120
Current	253,779	151,755
Total Loans	256,006	152,875
Real estate - commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due and Accruing	1,727	3,611
Greater than 90 Days Past Due and Accruing	61	344
Non- Accrual Loans	12,037	19,213
Total Past Due	13,825	23,168
Current	1,852,476	1,678,983
Total Loans	1,866,301	1,702,151
Real estate - residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due and Accruing	828	1,257
Greater than 90 Days Past Due and Accruing	113	13
Non- Accrual Loans	562	868
Total Past Due	1,503	2,138
Current	318,324	287,218
Total Loans	319,827	289,356
Real estate - Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due and Accruing	1,371	880
Greater than 90 Days Past Due and Accruing	0	6
Non- Accrual Loans	19	210
Total Past Due	1,390	1,096
Current	642,196	565,032
Total Loans	643,586	566,128
Consumer - credit card [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due and Accruing	2,268	3,230
Greater than 90 Days Past Due and Accruing	2,303	2,448
Non- Accrual Loans	560	1,031
Total Past Due	5,131	6,709
Current	305,165	311,627
Total Loans	310,296	318,336
Consumer - other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due and Accruing	1,743	1,727
Greater than 90 Days Past Due and Accruing	843	190
Non- Accrual Loans	70	370
Total Past Due	2,656	2,287
Current	98,314	60,625
Total Loans	100,970	62,912
Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-89 Days Past Due and Accruing	0	0
Greater than 90 Days Past Due and Accruing	0	0
Non- Accrual Loans	0	0
Total Past Due	0	0
Current	39,090	23,981
Total Loans	$39,090	$23,981	$19,084

Recovered_Sheet2

Loans and Allowance for Loan Losses - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Proceeds from sales of loans held for sale	$73,468,000	$121,825,000	$246,345,000
Non-accrual loans	27,382,000	30,706,000
Restructured loans	9,300,000	12,100,000
Loans 90 days past due and accruing	3,830,000	3,218,000
Commitments to lend to borrowers with loan modifications classified as TDR's	$477,000	$347,000
Revolving Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [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, Recorded Investment, Past Due [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, Recorded Investment, Past Due [Line Items]
Number of days past due to consider loan as a loss and charged off	180 days

Credit_Risk_Profile_by_Risk_Ra

Credit Risk Profile by Risk Rating (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	$7,465,794	$6,520,512	$5,686,749
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	3,814,009	3,301,503
Commercial [Member] | Non-watch list [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	3,532,611	3,041,224
Commercial [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	72,283	110,932
Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	98,750	78,064
Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	110,365	71,283
Real estate - construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	256,006	152,875
Real estate - construction [Member] | Non-watch list [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	253,895	151,359
Real estate - construction [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	181	210
Real estate - construction [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	756	0
Real estate - construction [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	1,174	1,306
Real estate - commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	1,866,301	1,702,151
Real estate - commercial [Member] | Non-watch list [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	1,780,323	1,565,894
Real estate - commercial [Member] | Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	31,984	76,647
Real estate - commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	8,691	19,876
Real estate - commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile by Risk Rating	$45,303	$39,734

Credit_Risk_Profile_Based_on_P

Credit Risk Profile Based on Payment Activity (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	$7,465,794	$6,520,512	$5,686,749
Commercial - credit card [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	115,709	103,270
Commercial - credit card [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	115,672	103,232
Commercial - credit card [Member] | Non-performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	37	38
Real estate - residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	319,827	289,356
Real estate - residential [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	319,265	288,488
Real estate - residential [Member] | Non-performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	562	868
Real estate - Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	643,586	566,128
Real estate - Home Equity Line of Credit [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	643,567	565,918
Real estate - Home Equity Line of Credit [Member] | Non-performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	19	210
Consumer - credit card [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	310,296	318,336
Consumer - credit card [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	309,736	317,305
Consumer - credit card [Member] | Non-performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	560	1,031
Consumer - other [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	100,970	62,912
Consumer - other [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	100,900	62,542
Consumer - other [Member] | Non-performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	70	370
Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	39,090	23,981	19,084
Leases [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	39,090	23,981
Leases [Member] | Non-performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Credit Risk Profile Based on Payment Activity	$0	$0

Rollforward_of_Allowance_for_L

Rollforward of Allowance for Loan Losses by Portfolio Segment (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance				$74,751				$71,426	$74,751	$71,426	$72,017
Charge-offs									-18,993	-17,654	-22,056
Recoveries									3,382	3,479	3,965
Provision	3,000	4,500	5,000	4,500	4,000	6,500	5,000	2,000	17,000	17,500	17,500
Ending Balance	76,140				74,751				76,140	74,751	71,426
Ending Balance: individually evaluated for impairment, allowances	1,907				4,252				1,907	4,252	2,174
Ending Balance: collectively evaluated for impairment, allowances	74,233				70,499				74,233	70,499	69,252
Total Loans	7,465,794				6,520,512				7,465,794	6,520,512	5,686,749
Ending Balance: individually evaluated for impairment, loans	27,304				30,189				27,304	30,189	26,309
Ending Balance: collectively evaluated for impairment, loans	7,438,490				6,490,323				7,438,490	6,490,323	5,660,440
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance				48,886				43,390	48,886	43,390	37,927
Charge-offs									-7,307	-4,748	-8,446
Recoveries									848	867	1,136
Provision									12,922	9,377	12,773
Ending Balance	55,349				48,886				55,349	48,886	43,390
Ending Balance: individually evaluated for impairment, allowances	972				2,882				972	2,882	1,393
Ending Balance: collectively evaluated for impairment, allowances	54,377				46,004				54,377	46,004	41,977
Total Loans	3,929,718				3,404,773				3,929,718	3,404,773	2,978,014
Ending Balance: individually evaluated for impairment, loans	17,060				14,635				17,060	14,635	15,057
Ending Balance: collectively evaluated for impairment, loans	3,912,658				3,390,138				3,912,658	3,390,138	2,962,957
Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance				15,342				15,506	15,342	15,506	20,486
Charge-offs									-259	-775	-932
Recoveries									44	77	28
Provision									-4,402	534	-4,076
Ending Balance	10,725				15,342				10,725	15,342	15,506
Ending Balance: individually evaluated for impairment, allowances	935				1,370				935	1,370	781
Ending Balance: collectively evaluated for impairment, allowances	9,790				13,972				9,790	13,972	14,725
Total Loans	3,085,720				2,710,510				3,085,720	2,710,510	2,300,583
Ending Balance: individually evaluated for impairment, loans	10,243				15,543				10,243	15,543	11,203
Ending Balance: collectively evaluated for impairment, loans	3,075,477				2,694,967				3,075,477	2,694,967	2,289,380
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance				10,447				12,470	10,447	12,470	13,593
Charge-offs									-11,427	-12,131	-12,678
Recoveries									2,490	2,535	2,801
Provision									8,411	7,573	8,754
Ending Balance	9,921				10,447				9,921	10,447	12,470
Ending Balance: individually evaluated for impairment, allowances	0				0				0	0	0
Ending Balance: collectively evaluated for impairment, allowances	9,921				10,447				9,921	10,447	12,470
Total Loans	411,266				381,248				411,266	381,248	389,068
Ending Balance: individually evaluated for impairment, loans	1				11				1	11	49
Ending Balance: collectively evaluated for impairment, loans	411,265				381,237				411,265	381,237	389,019
Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance				76				60	76	60	11
Charge-offs									0	0	0
Recoveries									0	0	0
Provision									69	16	49
Ending Balance	145				76				145	76	60
Ending Balance: individually evaluated for impairment, allowances	0				0				0	0	0
Ending Balance: collectively evaluated for impairment, allowances	145				76				145	76	60
Total Loans	39,090				23,981				39,090	23,981	19,084
Ending Balance: individually evaluated for impairment, loans	0				0				0	0
Ending Balance: collectively evaluated for impairment, loans	$39,090				$23,981				$39,090	$23,981	$19,084

Analysis_of_Impaired_Loans_by_

Analysis of Impaired Loans by Class (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	$33,928	$34,650	$34,471
Recorded Investment with No Allowance	20,275	10,441	20,935
Recorded Investment with Allowance	7,029	19,748	5,374
Total Recorded Investment	27,304	30,189	26,309
Related Allowance	1,907	4,252	2,174
Average Recorded Investment	29,277	27,639	25,995
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	21,758	17,227	22,453
Recorded Investment with No Allowance	13,928	3,228	12,119
Recorded Investment with Allowance	3,132	11,407	2,938
Total Recorded Investment	17,060	14,635	15,057
Related Allowance	972	2,882	1,393
Average Recorded Investment	16,022	14,791	13,287
Commercial - credit card [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	0	0	0
Recorded Investment with No Allowance	0	0	0
Recorded Investment with Allowance	0	0	0
Total Recorded Investment	0	0	0
Related Allowance	0	0	0
Average Recorded Investment	0	0	0
Real estate - construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	1,540	1,408	276
Recorded Investment with No Allowance	983	810	276
Recorded Investment with Allowance	0	123
Total Recorded Investment	983	933	276
Related Allowance	0
Average Recorded Investment	939	1,186	118
Real estate - commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	9,546	14,686	9,334
Recorded Investment with No Allowance	4,454	5,305	6,777
Recorded Investment with Allowance	3,897	8,218	2,213
Total Recorded Investment	8,351	13,523	8,990
Related Allowance	935	94	733
Average Recorded Investment	11,298	10,506	9,925
Real estate - residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	1,083	1,317	2,357
Recorded Investment with No Allowance	909	1,087	1,714
Recorded Investment with Allowance	0		223
Total Recorded Investment	909	1,087	1,937
Related Allowance	0	1,276	48
Average Recorded Investment	1,006	1,122	2,622
Real estate - Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	0	0	0
Recorded Investment with No Allowance	0	0	0
Recorded Investment with Allowance	0	0	0
Total Recorded Investment	0	0	0
Related Allowance	0	0	0
Average Recorded Investment	0	0	0
Consumer - credit card [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	0	0	0
Recorded Investment with No Allowance	0	0	0
Recorded Investment with Allowance	0	0	0
Total Recorded Investment	0	0	0
Related Allowance	0	0	0
Average Recorded Investment	0	0	0
Consumer - other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	1	12	51
Recorded Investment with No Allowance	1	11	49
Recorded Investment with Allowance	0
Total Recorded Investment	1	11	49
Related Allowance	0
Average Recorded Investment	12	34	43
Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	0	0	0
Recorded Investment with No Allowance	0	0	0
Recorded Investment with Allowance	0	0	0
Total Recorded Investment	0	0	0
Related Allowance	0	0	0
Average Recorded Investment	$0	$0	$0

Summary_of_Loans_Restructured_

Summary of Loans Restructured by Class (Detail) (Troubled Debt Restructuring [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
	Contract	Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts	6	3
Pre-Modification Outstanding Recorded Investment	$924	$2,065
Post-Modification Outstanding Recorded Investment	948	2,003
Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	1	2
Pre-Modification Outstanding Recorded Investment	469	1,128
Post-Modification Outstanding Recorded Investment	469	1,066
Commercial - credit card [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	0	0
Pre-Modification Outstanding Recorded Investment	0	0
Post-Modification Outstanding Recorded Investment	0	0
Real estate - construction [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	0	0
Pre-Modification Outstanding Recorded Investment	0	0
Post-Modification Outstanding Recorded Investment	0	0
Real estate - commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	1	1
Pre-Modification Outstanding Recorded Investment	178	937
Post-Modification Outstanding Recorded Investment	178	937
Real estate - residential [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	4	0
Pre-Modification Outstanding Recorded Investment	277	0
Post-Modification Outstanding Recorded Investment	301	0
Real estate - Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	0	0
Pre-Modification Outstanding Recorded Investment	0	0
Post-Modification Outstanding Recorded Investment	0	0
Consumer - credit card [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	0	0
Pre-Modification Outstanding Recorded Investment	0	0
Post-Modification Outstanding Recorded Investment	0	0
Consumer - other [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	0	0
Pre-Modification Outstanding Recorded Investment	0	0
Post-Modification Outstanding Recorded Investment	0	0
Leases [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	0	0
Pre-Modification Outstanding Recorded Investment	0	0
Post-Modification Outstanding Recorded Investment	$0	$0

Securities_Available_for_Sale_

Securities Available for Sale (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	$6,894,222	$6,814,712
Securities available for sale, Gross Unrealized Gains	52,724	51,414
Securities available for sale, Gross Unrealized Losses	-35,010	-103,715
Total securities available for sale, Fair Value	6,911,936	6,762,411
U.S. Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	519,484	110,789
Securities available for sale, Gross Unrealized Gains	501	284
Securities available for sale, Gross Unrealized Losses	-525	-873
Total securities available for sale, Fair Value	519,460	110,200
U.S. Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	991,084	1,258,176
Securities available for sale, Gross Unrealized Gains	780	2,793
Securities available for sale, Gross Unrealized Losses	-1,175	-3,306
Total securities available for sale, Fair Value	990,689	1,257,663
Mortgage-backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	3,276,009	2,984,963
Securities available for sale, Gross Unrealized Gains	28,470	23,942
Securities available for sale, Gross Unrealized Losses	-26,875	-64,339
Total securities available for sale, Fair Value	3,277,604	2,944,566
State and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	1,983,549	2,003,509
Securities available for sale, Gross Unrealized Gains	22,973	23,493
Securities available for sale, Gross Unrealized Losses	-5,165	-31,756
Total securities available for sale, Fair Value	2,001,357	1,995,246
Corporates [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	124,096	457,275
Securities available for sale, Gross Unrealized Gains	0	902
Securities available for sale, Gross Unrealized Losses	-1,270	-3,441
Total securities available for sale, Fair Value	$122,826	$454,736

Summary_of_Contractual_Maturit

Summary of Contractual Maturity Information for Securities Available for Sale (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]
Due in 1 year or less, Amortized Cost	$607,929
Due after 1 year through 5 years, Amortized Cost	2,223,097
Due after 5 years through 10 years, Amortized Cost	674,876
Due after 10 years, Amortized Cost	112,311
Total, Amortized Cost	3,618,213
Mortgage-backed securities, Amortized Cost	3,276,009
Securities available for sale, Amortized Cost	6,894,222	6,814,712
Due in 1 year or less, Fair Value	609,430
Due after 1 year through 5 years, Fair Value	2,231,267
Due after 5 years through 10 years, Fair Value	682,409
Due after 10 years, Fair Value	111,226
Total, Fair Value	3,634,332
Mortgage-backed securities, Fair Value	3,277,604
Total securities available for sale, Fair Value	$6,911,936	$6,762,411

Securities_Additional_Informat

Securities - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Trading Securities and Other Trading Assets [Line Items]
Proceeds from sales of securities available for sale	$413,955,000	$685,031,000	$1,016,129,000
Gross realized gains from securities	4,100,000	8,700,000	20,200,000
Gross realized losses from securities	11,000	200,000	30,000
Sales of securities held to maturity	0	0	0
Unrealized gains on trading securities	101,000	151,000	403,000
Fair value of marketable securities	16,700,000	16,600,000
Fair value of non-marketable securities	8,500,000	4,700,000
Unrealized gains on alternative investments			422,000
U.S. Government and Other Public Deposit [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Pledged securities for deposits	5,700,000,000	5,900,000,000
Federal Reserve Discount Window [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Pledged securities for deposits	$1,200,000,000	$1,700,000,000

Gross_Unrealized_Losses_and_Fa

Gross Unrealized Losses and Fair Value of Investment Securities Available for Sale (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Gain (Loss) on Investments [Line Items]
Less than 12 months, Fair Value	$1,790,321	$3,595,354
Less than 12 months, Unrealized Losses	-11,037	-92,244
12 months or more, Fair Value	1,025,349	227,554
12 months or more, Unrealized Losses	-23,973	-11,471
Total Fair Value	2,815,670	3,822,908
Total Unrealized Losses	-35,010	-103,715
U.S. Treasury [Member]
Gain (Loss) on Investments [Line Items]
Less than 12 months, Fair Value	236,591	39,822
Less than 12 months, Unrealized Losses	-329	-873
12 months or more, Fair Value	14,863	0
12 months or more, Unrealized Losses	-196	0
Total Fair Value	251,454	39,822
Total Unrealized Losses	-525	-873
U.S. Agencies [Member]
Gain (Loss) on Investments [Line Items]
Less than 12 months, Fair Value	387,999	675,509
Less than 12 months, Unrealized Losses	-689	-3,130
12 months or more, Fair Value	81,593	9,824
12 months or more, Unrealized Losses	-486	-176
Total Fair Value	469,592	685,333
Total Unrealized Losses	-1,175	-3,306
Mortgage-backed [Member]
Gain (Loss) on Investments [Line Items]
Less than 12 months, Fair Value	727,142	1,945,964
Less than 12 months, Unrealized Losses	-8,370	-60,719
12 months or more, Fair Value	616,044	89,147
12 months or more, Unrealized Losses	-18,504	-3,620
Total Fair Value	1,343,186	2,035,111
Total Unrealized Losses	-26,874	-64,339
State and political subdivisions [Member]
Gain (Loss) on Investments [Line Items]
Less than 12 months, Fair Value	401,934	662,225
Less than 12 months, Unrealized Losses	-1,406	-25,064
12 months or more, Fair Value	226,678	87,061
12 months or more, Unrealized Losses	-3,760	-6,692
Total Fair Value	628,612	749,286
Total Unrealized Losses	-5,166	-31,756
Corporates [Member]
Gain (Loss) on Investments [Line Items]
Less than 12 months, Fair Value	36,655	271,834
Less than 12 months, Unrealized Losses	-243	-2,458
12 months or more, Fair Value	86,171	41,522
12 months or more, Unrealized Losses	-1,027	-983
Total Fair Value	122,826	313,356
Total Unrealized Losses	($1,270)	($3,441)

Securities_Held_to_Maturity_De

Securities Held to Maturity (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	$278,054	$209,770
Held to Maturity, Fair value	304,112	231,510
State and political subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	278,054	209,770
Held to Maturity, Gross Unrealized Gains	26,058	21,740
Held to Maturity, Gross Unrealized Losses	0	0
Held to Maturity, Fair value	$304,112	$231,510

Contractual_Maturity_Informati

Contractual Maturity Information for Securities Held to Maturity (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]
Due in 1 year or less, Amortized Cost	$15
Due after 1 year through 5 years, Amortized Cost	31,389
Due after 5 years through 10 years, Amortized Cost	165,062
Due after 10 years, Amortized Cost	81,588
Total securities held to maturity, Amortized Cost	278,054	209,770
Due in 1 year or less, Fair Value	16
Due after 1 year through 5 years, Fair Value	34,331
Due after 5 years through 10 years, Fair Value	180,531
Due after 10 years, Fair Value	89,234
Total securities held to maturity, Fair Value	$304,112	$231,510

Schedule_of_Federal_Reserve_Ba

Schedule of Federal Reserve Bank Stock and Other Securities (Detail) (Federal Reserve Bank Stock and Other Securities [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Other Securities [Line Items]
Amortized Cost	$47,948	$33,438
Gross Unrealized Gains	20,605	17,044
Gross Unrealized Losses	-79	0
Fair Value	68,474	50,482
FRB and FHLB stock [Member]
Schedule of Other Securities [Line Items]
Amortized Cost	26,279
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	26,279
Federal Reserve Bank Stock [Member]
Schedule of Other Securities [Line Items]
Amortized Cost		16,279
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Fair Value		16,279
Other securities - marketable [Member]
Schedule of Other Securities [Line Items]
Amortized Cost		20
Gross Unrealized Gains	16,668	16,612
Gross Unrealized Losses	0	0
Fair Value	16,668	16,632
Other securities - non-marketable [Member]
Schedule of Other Securities [Line Items]
Amortized Cost	21,669	17,139
Gross Unrealized Gains	3,937	432
Gross Unrealized Losses	-79	0
Fair Value	$25,527	$17,571

Recovered_Sheet3

Securities Purchased Under Agreements to Resell - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Disclosure of Repurchase Agreements [Abstract]
Securities purchased under agreements to resell	$95.50	$75.20

Recovered_Sheet4

Loans to Officers and Directors - Activity with Respect to Aggregate Loans to Related Parties (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Related Party Transactions [Abstract]
Balance-beginning of year	$493,373	$480,291
New loans	139,442	149,709
Repayments	-91,308	-136,627
Balance-end of year	$541,507	$493,373

Changes_in_Carrying_Amount_of_

Changes in Carrying Amount of Goodwill (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	$209,758	$209,758	$209,758
Ending Balance	209,758	209,758	209,758
Bank [Member]
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	142,753	142,753	142,753
Ending Balance	142,753	142,753	142,753
Institutional Investment Management [Member]
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	47,529	47,529	47,529
Ending Balance	47,529	47,529	47,529
Asset Servicing [Member]
Goodwill And Other Intangible Assets [Line Items]
Beginning Balance	19,476	19,476	19,476
Ending Balance	$19,476	$19,476	$19,476

Changes_In_Intangible_Assets_D

Changes In Intangible Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$144,304	$143,704
Accumulated Amortization	100,313	88,119
Net Carrying Amount	43,991	55,585
Core deposit intangible assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	36,497	36,497
Accumulated Amortization	32,721	31,674
Net Carrying Amount	3,776	4,823
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	104,560	103,960
Accumulated Amortization	64,980	54,062
Net Carrying Amount	39,580	49,898
Other intangible assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,247	3,247
Accumulated Amortization	2,612	2,383
Net Carrying Amount	$635	$864

Recovered_Sheet5

Goodwill and Other Intangibles - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$12,193	$13,218	$14,775

Estimated_Amortization_Expense

Estimated Amortization Expense of Intangible Assets (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]
For the year ending December 31, 2015	$9,636
For the year ending December 31, 2016	8,428
For the year ending December 31, 2017	7,185
For the year ending December 31, 2018	4,994
For the year ending December 31, 2019	$4,204

Components_of_Premises_and_Equ

Components of Premises and Equipment (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment [Abstract]
Land	$43,798	$44,731
Buildings and leasehold improvements	301,687	300,175
Equipment	120,745	124,992
Software	132,265	121,974
Premises and equipment, gross	598,495	591,872
Accumulated depreciation	-246,457	-247,519
Accumulated amortization	-94,203	-94,664
Premises and equipment, net	$257,835	$249,689

Premises_and_Equipment_Additio

Premises and Equipment - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Abstract]
Consolidated rental and operating lease expenses	$12	$10.90	$10.80
Consolidated bank premises and equipment depreciation and amortization expenses	$34.20	$31	$26.10

Minimum_Future_Rental_Commitme

Minimum Future Rental Commitments for all Non-cancelable Operating Leases (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Property, Plant and Equipment [Abstract]
2015	$9,325
2016	8,626
2017	8,335
2018	7,903
2019	7,668
Thereafter	31,616
Total	$73,473

Components_of_ShortTerm_and_Lo

Components of Short-Term and Long-Term Debt (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Short-term debt		$107
Long-term debt	8,810	5,055
Total borrowed funds	8,810	5,162
Federal Home Loan Bank 5.89% due 2014 [Member]
Debt Instrument [Line Items]
Short-term debt	0	107
Kansas Equity Fund IV, L.P. 0% due 2017 [Member]
Debt Instrument [Line Items]
Long-term debt	71	173
Kansas Equity Fund V, L.P. 0% due 2017 [Member]
Debt Instrument [Line Items]
Long-term debt	119	176
Kansas Equity Fund VI, L.P. 0% due 2017 [Member]
Debt Instrument [Line Items]
Long-term debt	239	369
Kansas Equity Fund IX, L.P. 0% due 2023 [Member]
Debt Instrument [Line Items]
Long-term debt	341	408
Kansas Equity Fund X, L.P. 0% due 2021 [Member]
Debt Instrument [Line Items]
Long-term debt	419	469
Kansas City Equity Fund 2007, L.L.C. 0% due 2016 [Member]
Debt Instrument [Line Items]
Long-term debt	86	162
Kansas City Equity Fund 2008, L.L.C. 0% due 2016 [Member]
Debt Instrument [Line Items]
Long-term debt	149	290
Kansas City Equity Fund 2009, L.L.C. 0% due 2017 [Member]
Debt Instrument [Line Items]
Long-term debt	371	504
St. Louis Equity Fund 2007 L.L.C. 0% due 2016 [Member]
Debt Instrument [Line Items]
Long-term debt	39	179
St. Louis Equity Fund 2008 L.L.C. 0% due 2016 [Member]
Debt Instrument [Line Items]
Long-term debt	160	310
St. Louis Equity Fund 2009 L.L.C. 0% due 2017 [Member]
Debt Instrument [Line Items]
Long-term debt	395	544
St. Louis Equity Fund 2012 L.L.C. 0% due 2020 [Member]
Debt Instrument [Line Items]
Long-term debt	402	481
St. Louis Equity Fund 2013 L.L.C. 0% due 2021 [Member]
Debt Instrument [Line Items]
Long-term debt	1,758
St. Louis Equity Fund 2014 L.L.C. 0% due 2022 [Member]
Debt Instrument [Line Items]
Long-term debt	1,819
MHEG Community Fund 41, L.P. 0% due 2024 [Member]
Debt Instrument [Line Items]
Long-term debt	957	990
MHEG Community Fund 43, L.P. 0% due 2026 [Member]
Debt Instrument [Line Items]
Long-term debt	$1,485

Components_of_ShortTerm_and_Lo1

Components of Short-Term and Long-Term Debt (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Federal Home Loan Bank 5.89% due 2014 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	5.89%	5.89%
Debt instrument, maturity year	2014	2014
Kansas Equity Fund IV, L.P. 0% due 2017 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2017	2017
Kansas Equity Fund V, L.P. 0% due 2017 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2017	2017
Kansas Equity Fund VI, L.P. 0% due 2017 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2017	2017
Kansas Equity Fund IX, L.P. 0% due 2023 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2023	2023
Kansas Equity Fund X, L.P. 0% due 2021 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2021	2021
Kansas City Equity Fund 2007, L.L.C. 0% due 2016 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2016	2016
Kansas City Equity Fund 2008, L.L.C. 0% due 2016 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2016	2016
Kansas City Equity Fund 2009, L.L.C. 0% due 2017 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2017	2017
St. Louis Equity Fund 2007 L.L.C. 0% due 2016 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2016	2016
St. Louis Equity Fund 2008 L.L.C. 0% due 2016 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2016	2016
St. Louis Equity Fund 2009 L.L.C. 0% due 2017 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2017	2017
St. Louis Equity Fund 2012 L.L.C. 0% due 2020 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2020	2020
St. Louis Equity Fund 2013 L.L.C. 0% due 2021 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2021	2021
St. Louis Equity Fund 2014 L.L.C. 0% due 2022 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2022	2022
MHEG Community Fund 41, L.P. 0% due 2024 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2024	2024
MHEG Community Fund 43, L.P. 0% due 2026 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate	0.00%	0.00%
Debt instrument, maturity year	2026	2026

Aggregate_Annual_Repayments_of

Aggregate Annual Repayments of Long-Term Debt (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Maturities of Long-term Debt [Abstract]
2015	$1,584
2016	1,552
2017	1,252
2018	1,112
2019	1,091
Thereafter	2,219
Total	$8,810	$5,055

Borrowed_Funds_Additional_Info

Borrowed Funds - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 24, 2014
Debt Instrument [Line Items]
Payments to acquire federal home loan bank stock	$10,000,000
Federal home loan bank maturity period	30 days
Securities sold under agreements to repurchase	1,983,084,000	1,600,000,000
Accrued interest payable	10,000	8,000
FHLB [Member]
Debt Instrument [Line Items]
Issuance of letter of credit			150,000,000
Federal home loan bank amount outstanding	0
Wells Fargo Bank 1.25% due 2012 [Member]
Debt Instrument [Line Items]
Borrowing capacity	25,000,000
Interest rate based on LIBOR	1.00 percent above LIBOR
Debt instrument, interest rate based on prime lending rate	1.75 percent below Prime
Revolving line of credit, commitment fee for unused portion	0.20%
Letter of Credit [Member] | Maximum [Member] | FHLB [Member]
Debt Instrument [Line Items]
Borrowing capacity	483,000,000
Letter of Credit [Member] | Reduced Borrowing Limit [Member] | FHLB [Member]
Debt Instrument [Line Items]
Borrowing capacity	$333,000,000

Carrying_Amounts_and_Market_Va

Carrying Amounts and Market Values of Securities and Related Repurchase Liabilities and Weighted Average Interest Rates of Repurchase Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets Sold under Agreements to Repurchase [Line Items]
Securities Market Value	$2,006,435
Repurchase Liabilities	1,983,084	1,600,000
Weighted Average Interest Rate	0.19%
On Demand [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Market Value	3,008
Repurchase Liabilities	3,001
Weighted Average Interest Rate	0.01%
2 to 30 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Market Value	2,003,126
Repurchase Liabilities	1,979,783
Weighted Average Interest Rate	0.19%
Over 90 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Market Value	301
Repurchase Liabilities	$300
Weighted Average Interest Rate	0.00%

Regulatory_Requirements_Additi

Regulatory Requirements - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Regulatory Requirements [Line Items]
Reserve balance with Federal Reserve Bank maintained by affiliate bank	$729.10	$639.70
Tier 1 Capital For Capital Adequacy Purposes, Ratio	4.00%
Total Capital For Capital Adequacy Purposes, Ratio	8.00%
Tier 1 Capital, Actual Ratio	13.29%
Common equity capital to risk weighted asset	14.04%
Tier 1 Leverage for Capital Adequacy Purposes, Ratio	4.00%
Tier 1 Leverage, Actual Ratio	8.72%
Tier 1 Capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%
Total Capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.00%
Tier 1 Leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	5.00%
Common Equity Tier One Capital [Member]
Regulatory Requirements [Line Items]
Common equity capital to risk weighted asset	4.50%
Common equity capital conservation buffer to risk weighted asset	2.50%

Actual_Capital_Amounts_as_well

Actual Capital Amounts as well as Required and Well-Capitalized Tier One, Total and Tier One Leverage Ratios (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Capital, Actual Ratio	13.29%
Tier 1 Capital For Capital Adequacy Purposes, Ratio	4.00%
Tier 1 Capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.00%
Total Capital, Actual Ratio	14.04%
Total Capital For Capital Adequacy Purposes, Ratio	8.00%
Total Capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%
Tier 1 Leverage, Actual Ratio	8.72%
Tier 1 Leverage for Capital Adequacy Purposes, Ratio	4.00%
Tier 1 Leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	5.00%
Umb Financial Corporation [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Capital, Actual Amount	$1,393,389	$1,285,100
Tier 1 Capital, Actual Ratio	13.29%	13.61%
Tier 1 Capital For Capital Adequacy Purposes, Amount	419,383	377,681
Tier 1 Capital For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Total Capital, Actual Amount	1,471,631	1,362,015
Total Capital, Actual Ratio	14.04%	14.43%
Total Capital For Capital Adequacy Purposes, Amount	838,766	755,361
Total Capital For Capital Adequacy Purposes, Ratio	8.00%	8.00%
Tier 1 Leverage, Actual Amount	1,393,389	1,285,100
Tier 1 Leverage, Actual Ratio	8.72%	8.41%
Tier 1 Leverage For Capital Adequacy Purposes, Amount	639,476	611,206
Tier 1 Leverage for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Umb Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Capital, Actual Amount	1,209,096	1,095,446
Tier 1 Capital, Actual Ratio	11.68%	11.73%
Tier 1 Capital For Capital Adequacy Purposes, Amount	414,135	373,509
Tier 1 Capital For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 Capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	621,202	560,264
Tier 1 Capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.00%	6.00%
Total Capital, Actual Amount	1,287,338	1,172,361
Total Capital, Actual Ratio	12.43%	12.56%
Total Capital For Capital Adequacy Purposes, Amount	828,270	747,018
Total Capital For Capital Adequacy Purposes, Ratio	8.00%	8.00%
Total Capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	1,035,337	933,773
Total Capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%	10.00%
Tier 1 Leverage, Actual Amount	1,209,096	1,095,446
Tier 1 Leverage, Actual Ratio	7.63%	7.21%
Tier 1 Leverage For Capital Adequacy Purposes, Amount	634,187	608,148
Tier 1 Leverage for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 Leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$792,733	$760,185
Tier 1 Leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	5.00%	5.00%

Employee_Benefits_Additional_I

Employee Benefits - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 23, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accrued contributions related to discretionary noncontributory profit sharing plan	$2,000,000
Contributions paid related to discretionary noncontributory profit sharing plan	2,900,000	2,500,000
401(k) profit sharing contributions paid	5,200,000	5,100,000
Accrued 401(k) profit sharing contribution	5,900,000
Weighted average grant-date fair value of options granted	$13.03	$10.18	$8.83
2002 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	0
Common shares authorized for grant to employees	2,000,000
Plan effective period, in years	10 years
Exercise price of options as percentage of fair market value at grant date, minimum	100.00%
Plan expiration date	17-Apr-12
Total intrinsic value of options exercised	2,000,000	3,400,000	2,000,000
Options granted	0	0	0
Long-Term Incentive Compensation Plan (LTIP) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	5,200,000
Total intrinsic value of options exercised	3,700,000	2,400,000	1,300,000
Options granted	259,158
Cost is expected to be recognized, (in years)	3 years 1 month 6 days
Weighted average grant-date fair value of options granted	$13.03	$10.18	$8.83
Cash received from options exercised	8,000,000	9,000,000	6,600,000
Tax benefit realized for stock options exercised	1,900,000	1,200,000	359,000
Long-Term Incentive Compensation Plan (LTIP) [Member] | Prior Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of stock reserved				5,250,000
Benefits received by eligible employee				1,000,000
Long-Term Incentive Compensation Plan (LTIP) [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of stock reserved				7,440,000
Benefits received by eligible employee				2,000,000
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized expense	2,000,000	2,000,000	2,300,000
Unrecognized compensation expense	5,200,000
Options Granted to Person Holding More Than 10 Percent of Stock [Member] | 2002 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Plan effective period, in years	5 years
Options issued prior to 2005 [Member] | 2002 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Time Period for 100% Vesting	4 years 11 months
Options Issued in 2006, 2007 and 2008 [Member] | 2002 Plan [Member] | After Three Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting schedule	Options issued in 2006, 2007, and 2008 under the 2002 Plan, have a vesting schedule of 50 percent after three years
Options Issued in 2006, 2007 and 2008 [Member] | 2002 Plan [Member] | After Four Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting schedule	75 percent after four years
Options Issued in 2006, 2007 and 2008 [Member] | 2002 Plan [Member] | Four Years And Eleven Months [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting schedule	100 percent after four years and eleven months
Service Based Restricted Stock [Member] | After Three Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting schedule	50 percent of the shares vest after three years of service
Service Based Restricted Stock [Member] | After Four Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting schedule	75 percent after four years of service
Service Based Restricted Stock [Member] | After Five Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting schedule	100 percent after five years of service
Service Based Restricted Stock [Member] | Long-Term Incentive Compensation Plan (LTIP) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	12,600,000
Cost is expected to be recognized, (in years)	2 years 9 months 18 days
Total fair value of shares vested	5,600,000	4,300,000	2,300,000
Performance Based Restricted Stock Unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance requirement period	3 years
Nonqualified Stock Option Plan [Member] | Long-Term Incentive Compensation Plan (LTIP) [Member] | After Three Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting schedule	50 percent after three years
Nonqualified Stock Option Plan [Member] | Long-Term Incentive Compensation Plan (LTIP) [Member] | After Four Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting schedule	75 percent after four years
Nonqualified Stock Option Plan [Member] | Long-Term Incentive Compensation Plan (LTIP) [Member] | After Five Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting schedule	100 percent after five years
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized expense	7,200,000	5,900,000	4,600,000
Unrecognized compensation expense	14,200,000
Performance Based Restricted Stock [Member] | Long-Term Incentive Compensation Plan (LTIP) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	1,600,000
Cost is expected to be recognized, (in years)	1 year 8 months 12 days
Total fair value of shares vested	$2,300,000	$1,600,000	$1,300,000

Information_Relating_to_Option

Information Relating to Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014
Long-Term Incentive Compensation Plan (LTIP) [Member]
Number of Shares
Outstanding, Beginning Balance	1,342,025
Granted	259,158
Canceled	-60,373
Exercised	-156,775
Outstanding, Ending Balance	1,384,035
Exercisable	525,298
Exercisable and expected to be exercisable	1,328,241
Weighted Average Price Per Share
Outstanding, Beginning Balance	$40.45
Granted	$57.40
Canceled	$44.18
Exercised	$36.08
Outstanding, Ending Balance	$44.03
Exercisable	$39.43
Exercisable and expected to be exercisable	$43.76
Weighted Average Remaining Contractual Term
Outstanding	6 years 3 months 18 days
Exercisable and expected to be exercisable	6 years 2 months 12 days
Aggregate Intrinsic Value
Outstanding	$17,801,893
Exercisable and expected to be exercisable	17,440,423
2002 Plan [Member]
Number of Shares
Outstanding, Beginning Balance	341,491
Canceled	-7,673
Exercised	-75,343
Outstanding, Ending Balance	258,475
Exercisable	258,475
Exercisable and expected to be exercisable	258,475
Weighted Average Price Per Share
Outstanding, Beginning Balance	$36.05
Canceled	$32.68
Exercised	$31.52
Outstanding, Ending Balance	$37.47
Exercisable	$37.47
Exercisable and expected to be exercisable	$37.47
Weighted Average Remaining Contractual Term
Outstanding	2 years 6 months
Exercisable and expected to be exercisable	2 years 6 months
Aggregate Intrinsic Value
Outstanding	5,020,538
Exercisable and expected to be exercisable	$5,020,538

Status_of_Service_Based_Restri

Status of Service Based Restricted Shares (Detail) (Service Based Restricted Stock [Member], USD $)	12 Months Ended
	Dec. 31, 2014
Service Based Restricted Stock [Member]
Number of Shares
Nonvested, Beginning Balance	426,922
Granted	153,721
Canceled	-27,856
Vested	-96,156
Nonvested, Ending Balance	456,631
Weighted Average Grant Date Fair Value
Nonvested, Beginning Balance	$43.58
Granted	$57.42
Canceled	$45.07
Vested	$41.58
Nonvested, Ending Balance	$48.57

Status_of_Performance_Based_Re

Status of Performance Based Restricted Shares (Detail) (Performance Based Restricted Stock Unit [Member], USD $)	12 Months Ended
	Dec. 31, 2014
Performance Based Restricted Stock Unit [Member]
Number of Shares
Nonvested, Beginning Balance	112,197
Granted	31,590
Canceled	-6,443
Vested	-36,075
Nonvested, Ending Balance	101,269
Weighted Average Grant Date Fair Value
Nonvested, Beginning Balance	$42.46
Granted	$57.40
Canceled	$44.44
Vested	$41.71
Nonvested, Ending Balance	$47.26

Assumptions_for_StockBased_Awa

Assumptions for Stock-Based Awards (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted average fair value of the granted options	$13.03	$10.18	$8.83
Weighted average risk-free interest rate	1.77%	1.49%	1.14%
Expected option life in years	6 years 3 months	6 years 3 months	6 years 3 months
Expected volatility	24.87%	26.36%	27.02%
Expected dividend yield	1.53%	1.83%	1.95%

Business_Segment_Reporting_Add

Business Segment Reporting - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
	Segment
Segment Reporting [Abstract]
Number of reportable segments	4

Schedule_of_Segment_Financial_

Schedule of Segment Financial Results (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Net interest income	$90,914	$87,526	$86,170	$85,445	$85,914	$85,545	$82,327	$79,483	$350,055	$333,269	$320,056
Provision for loan losses	3,000	4,500	5,000	4,500	4,000	6,500	5,000	2,000	17,000	17,500	17,500
Noninterest income	115,248	126,475	134,001	122,964	135,607	121,625	113,585	121,016	498,688	491,833	458,122
Noninterest expense	166,713	161,461	166,511	172,241	170,426	153,063	150,311	150,378	666,926	624,178	590,454
Income before income taxes									164,817	183,424	170,224
Income tax expense	9,509	12,410	13,988	8,255	12,432	13,175	10,672	13,180	44,162	49,459	47,507
Net income	26,940	35,630	34,672	23,413	34,663	34,432	29,929	34,941	120,655	133,965	122,717
Average assets									15,999,000	15,031,000	13,389,000
Bank [Member]
Segment Reporting Information [Line Items]
Net interest income									292,357	285,112	274,843
Provision for loan losses									9,175	5,535	9,267
Noninterest income									194,223	210,535	214,595
Noninterest expense									405,065	376,307	381,273
Income before income taxes									72,340	113,805	98,898
Income tax expense									19,487	28,548	26,543
Net income									52,853	85,257	72,355
Average assets									12,099,000	11,255,000	10,864,000
Payment Solutions [Member]
Segment Reporting Information [Line Items]
Net interest income									52,251	45,832	43,351
Provision for loan losses									7,825	11,965	8,233
Noninterest income									84,477	74,223	67,887
Noninterest expense									94,177	86,746	69,205
Income before income taxes									34,726	21,344	33,800
Income tax expense									9,311	6,739	9,523
Net income									25,415	14,605	24,277
Average assets									2,456,000	1,736,000	1,282,000
Institutional Investment Management [Member]
Segment Reporting Information [Line Items]
Net interest income									-3	-32	2
Provision for loan losses									0	0	0
Noninterest income									131,226	126,442	100,051
Noninterest expense									92,008	88,336	71,053
Income before income taxes									39,215	38,074	29,000
Income tax expense									10,331	10,002	8,098
Net income									28,884	28,072	20,902
Average assets									72,000	77,000	79,000
Asset Servicing [Member]
Segment Reporting Information [Line Items]
Net interest income									5,450	2,357	1,860
Provision for loan losses									0	0	0
Noninterest income									88,762	80,633	75,589
Noninterest expense									75,676	72,789	68,923
Income before income taxes									18,536	10,201	8,526
Income tax expense									5,033	4,170	3,343
Net income									13,503	6,031	5,183
Average assets									$1,372,000	$1,963,000	$1,164,000

Summary_of_Share_Transactions_

Summary of Share Transactions (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Shares in Treasury, Beginning Balance	-9,835,493	-14,715,852	-14,630,388
Common stock issuance		4,485,000
Purchase of Treasury Stock	-130,197	-99,402	-514,824
Sale of Treasury Stock	15,320	14,661	21,950
Issued for stock options & restricted stock	425,828	480,100	407,410
Shares in Treasury, Ending Balance	-9,524,542	-9,835,493	-14,715,852
Shares Issued, Beginning Balance	55,056,730	55,056,730	55,056,730
Shares Issued, Ending Balance	55,056,730	55,056,730	55,056,730

Recovered_Sheet6

Common Stock and Earnings Per Share - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Share [Abstract]
Common stock, issuance shares	4,485,000
Common stock with net proceeds	$231,430
Common stock share repurchase program, number of shares authorized to be repurchased	2,000,000	2,000,000	2,000,000	2,000,000

Shares_Used_in_Calculation_of_

Shares Used in Calculation of Basic and Diluted Earnings (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Weighted average basic common shares outstanding	44,844,578	41,275,839	40,034,428
Dilutive effect of stock options and restricted stock	600,705	562,741	398,939
Weighted average diluted common shares outstanding	45,445,283	41,838,580	40,433,367

Recovered_Sheet7

Commitments, Contingencies and Guarantees - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies Disclosure [Line Items]
Average notional amount of open futures contract	$900,000	$11,400,000
Net futures activity resulted in losses	319,000	131,000	598,000
Notional amount outstanding	0	0
Average of contracts to purchase and to sell foreign currency	51,800,000	12,400,000
Net gains on foreign exchange contracts	1,700,000	2,200,000	2,300,000
Maximum [Member]
Commitments and Contingencies Disclosure [Line Items]
Standby letters of credit	375,000,000	356,100,000
Standby letters of credit term	5 years
Minimum [Member]
Commitments and Contingencies Disclosure [Line Items]
Standby letters of credit term	3 months
Related Parties [Member]
Commitments and Contingencies Disclosure [Line Items]
Standby letters of credit	$54,600,000	$51,800,000

Notional_Amount_of_OffBalance_

Notional Amount of Off-Balance Sheet Financial Instruments (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
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	$3,509,841	$2,690,268
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	2,690,752	2,215,278
Commercial letters of credit [Member]
Commitments and Contingencies Disclosure [Line Items]
Contract or notional amount of off-balance sheet financial instruments	1,334	5,949
Standby letters of credit [Member]
Commitments and Contingencies Disclosure [Line Items]
Contract or notional amount of off-balance sheet financial instruments	375,003	356,054
Forward contracts [Member]
Commitments and Contingencies Disclosure [Line Items]
Contract or notional amount of off-balance sheet financial instruments	144,950	21,525
Spot foreign exchange contracts [Member]
Commitments and Contingencies Disclosure [Line Items]
Contract or notional amount of off-balance sheet financial instruments	$14,721	$8,001

Acquisitions_Additional_Inform

Acquisitions - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended	12 Months Ended	0 Months Ended
	Jun. 30, 2014	Jun. 30, 2014	Dec. 31, 2014	Jul. 30, 2010	Sep. 01, 2010	Dec. 15, 2014	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 12, 2014
Business Acquisition [Line Items]
Business acquisition, goodwill amount			$209,758,000					$209,758,000	$209,758,000
Estimated earn-out liability			53,411,000					46,201,000	51,163,000
Contingency reserve expense accrued							15,000,000
Additional contingency reserve expense		5,300,000
Total estimated settlement liability		20,300,000	20,272,000
Payment made for reducing contingency reserve	6,000,000	6,000,000
Contingency reserve, reduction amount	14,300,000	14,300,000	14,272,000					0
Contingent earn-out liability			12,200,000
Prairie Capital Management LLC and PCM LLC [Member]
Business Acquisition [Line Items]
Cash payment of acquisition				25,900,000
Assets under management base				2,200,000,000
Servicing assets				2,600,000,000
Business acquisition, goodwill amount				32,200,000
Identifiable intangible assets				19,400,000
Estimated earn-out liability			9,400,000	26,000,000
Reams Asset Management Company, LLC [Member]
Business Acquisition [Line Items]
Cash payment of acquisition					44,700,000
Assets under management base					9,800,000,000
Business acquisition, goodwill amount					47,500,000
Identifiable intangible assets					26,000,000
Estimated earn-out liability			31,800,000		32,500,000
Marquette [Member]
Business Acquisition [Line Items]
Conversion of Company's common stock due to merger						9.131
Aggregate common stock amount						3,400,000
Market value of shares in connection with merger						$182,500,000
Closing stock price										$53.16

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Line Items]
Effective income tax rates	26.80%	27.00%	27.90%
Statutory federal tax rate	35.00%
State net operating loss carry forwards	$600,000
Change in valuation allowance, unrealized deferred tax assets	2,800,000
Gross amount of unrecognized tax benefits	4,025,000	4,997,000	4,347,000
Total amount of unrecognized tax benefits, net of associated deferred tax benefit that would impact effective tax rate, if recognized	$2,600,000	$3,300,000
Minimum [Member]
Income Taxes [Line Items]
State net operating loss carry forwards, expiration year	2015
Maximum [Member]
Income Taxes [Line Items]
State net operating loss carry forwards, expiration year	2034

Components_of_Income_Tax_Expen

Components of Income Tax Expense (Benefit) (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current tax
Federal									$53,314	$50,832	$40,837
State									2,304	3,750	2,995
Total current tax expense									55,618	54,582	43,832
Deferred tax
Federal									-11,448	-4,278	2,862
State									-8	-845	813
Total deferred tax (benefit) expense									-11,456	-5,123	3,675
Total tax expense	$9,509	$12,410	$13,988	$8,255	$12,432	$13,175	$10,672	$13,180	$44,162	$49,459	$47,507

Reconciliation_Between_Income_

Reconciliation Between Income Tax Expense and Amount Computed by Applying Federal Statutory Tax Rate (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Statutory federal income tax expense									$57,686	$64,199	$59,578
Tax-exempt interest income									-13,861	-14,146	-13,480
State and local income taxes, net of federal tax benefits									1,403	1,887	2,475
Federal tax credits									-1,433	-2,338	-1,090
Other									367	-143	24
Total tax expense	$9,509	$12,410	$13,988	$8,255	$12,432	$13,175	$10,672	$13,180	$44,162	$49,459	$47,507

Components_of_Deferred_Tax_Ass

Components of Deferred Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred tax assets:
Net unrealized loss on securities available for sale	$0	$19,495
Loans, principally due to allowance for loan losses	28,924	28,367
Stock-based compensation	7,109	6,302
Accrued expenses	24,747	19,943
Intangibles	7,254	0
Miscellaneous	3,551	4,474
Total deferred tax assets before valuation allowance	71,585	78,581
Valuation allowance	-3,417	-2,680
Total deferred tax assets	68,168	75,901
Deferred tax liabilities:
Net unrealized gain on securities available for sale	-6,879	0
Land, buildings and equipment	-24,002	-25,403
Original issue discount	-4,311	-4,439
Partnership investments	-7,838	-6,540
Intangibles	0	-238
Miscellaneous	-6,183	-5,408
Total deferred tax liabilities	-49,213	-42,028
Net deferred tax asset	$18,955	$33,873

Reconciliation_of_Unrecognized

Reconciliation of Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Unrecognized tax benefits-opening balance	$4,997	$4,347
Gross decreases-tax positions in prior period	-444	-80
Gross increases-current-period tax positions	964	1,049
Lapse of statute of limitations	-1,492	-319
Unrecognized tax benefits-ending balance	$4,025	$4,997

Summary_of_Fair_Value_of_Deriv

Summary of Fair Value of Derivative Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair value	$7,138	$2,518
Liability Derivatives, Fair value	7,535	2,346
Derivatives not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair value	7,138	2,442
Liability Derivatives, Fair value	7,250	2,346
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair value	0	76
Liability Derivatives, Fair value	$285	$0

Recovered_Sheet8

Derivatives and Hedging Activities - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Termination value of derivatives in net liability position	$675,000
Derivatives Designated as Hedging Instruments [Member]
Derivative [Line Items]
Net gain (loss) in other noninterest expense related to hedge ineffectiveness	-27,000	2,000
Interest Rate Swap [Member] | Derivatives Designated as Hedging Instruments [Member]
Derivative [Line Items]
Notional amount of interest rate swaps	6,700,000
Number of interest rate swaps	1
Interest Rate Swap [Member] | Derivatives not Designated as Hedging Instruments [Member]
Derivative [Line Items]
Notional amount of interest rate swaps	382,800,000
Number of interest rate swaps	30
Gain (loss) related to changes in fair value of swaps	($207,000)	$217,000

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 Asset and Liability (Detail) (Interest rate products [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Derivatives not Designated as Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments	($207)	$217
Derivatives Designated as Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments	-27	2
Derivatives Designated as Hedging Instruments [Member] | Fair value adjustments on derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments	-361	76
Derivatives Designated as Hedging Instruments [Member] | Fair value adjustments on hedged items [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments	$334	($74)

Assets_and_Liabilities_Measure

Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	$27,203	$28,464
Available for sale securities	6,911,936	6,762,411
Derivatives	7,138	2,518
Contingent consideration liability	53,411	46,201	51,163
Derivatives	7,535	2,346
Fair Value Measurement, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	27,203	28,464
Available for sale securities	6,911,936	6,762,411
Company-owned life insurance	26,886	19,619
Derivatives	7,138	2,518
Total	6,973,163	6,813,012
Deferred compensation	26,885	19,825
Contingent consideration liability	53,411	46,201
Derivatives	7,535	2,346
Total	87,831	68,372
Fair Value Measurement, Recurring [Member] | Trading - other [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	18,107	24,477
Fair Value Measurement, Recurring [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	400	400
Available for sale securities	519,460	110,200
Fair Value Measurement, Recurring [Member] | U.S. Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	1,315	0
Available for sale securities	990,689	1,257,663
Fair Value Measurement, Recurring [Member] | Mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	0	515
Available for sale securities	3,277,604	2,944,566
Fair Value Measurement, Recurring [Member] | State and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	7,381	3,072
Available for sale securities	2,001,357	1,995,246
Fair Value Measurement, Recurring [Member] | Corporates [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale securities	122,826	454,736
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	18,500	24,900
Available for sale securities	642,300	564,900
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value Measurement, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	18,506	24,877
Available for sale securities	642,286	564,936
Company-owned life insurance	0	0
Derivatives	0	0
Total	660,792	589,813
Deferred compensation	26,885	19,825
Contingent consideration liability	0	0
Derivatives	0	0
Total	26,885	19,825
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value Measurement, Recurring [Member] | Trading - other [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	18,106	24,477
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value Measurement, Recurring [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	400	400
Available for sale securities	519,460	110,200
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value Measurement, Recurring [Member] | U.S. Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	0	0
Available for sale securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value Measurement, Recurring [Member] | Mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	0	0
Available for sale securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value Measurement, Recurring [Member] | State and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	0	0
Available for sale securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value Measurement, Recurring [Member] | Corporates [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale securities	122,826	454,736
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	8,697	3,587
Available for sale securities	6,269,650	6,197,475
Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurement, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	8,697	3,587
Available for sale securities	6,269,650	6,197,475
Company-owned life insurance	26,886	19,619
Derivatives	7,138	2,518
Total	6,312,371	6,223,199
Deferred compensation	0	0
Contingent consideration liability	0	0
Derivatives	7,535	2,346
Total	7,535	2,346
Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurement, Recurring [Member] | Trading - other [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	1	0
Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurement, Recurring [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	0	0
Available for sale securities	0	0
Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurement, Recurring [Member] | U.S. Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	1,315	0
Available for sale securities	990,689	1,257,663
Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurement, Recurring [Member] | Mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	0	515
Available for sale securities	3,277,604	2,944,566
Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurement, Recurring [Member] | State and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	7,381	3,072
Available for sale securities	2,001,357	1,995,246
Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurement, Recurring [Member] | Corporates [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale securities	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	0	0
Available for sale securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value Measurement, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	0	0
Available for sale securities	0	0
Company-owned life insurance	0	0
Derivatives	0	0
Total	0	0
Deferred compensation	0	0
Contingent consideration liability	53,411	46,201
Derivatives	0	0
Total	53,411	46,201
Significant Unobservable Inputs (Level 3) [Member] | Fair Value Measurement, Recurring [Member] | Trading - other [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value Measurement, Recurring [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	0	0
Available for sale securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value Measurement, Recurring [Member] | U.S. Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	0	0
Available for sale securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value Measurement, Recurring [Member] | Mortgage-backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	0	0
Available for sale securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value Measurement, Recurring [Member] | State and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading securities	0	0
Available for sale securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value Measurement, Recurring [Member] | Corporates [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale securities	$0	$0

Reconciliation_of_Beginning_an

Reconciliation of Beginning and Ending Balances of Contingent Consideration Liability (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2014
Fair Value Disclosures [Abstract]
Beginning balance	$46,201	$51,163
Contingency reserve	14,272	0		14,300
Payment of contingent consideration on acquisitions	-13,725	-16,172	-17,371
Income from fair value adjustments	0	-138
Expense from fair value adjustments	6,663	11,348
Ending balance	$53,411	$46,201	$51,163

Recovered_Sheet9

Disclosures about Fair Value of Financial Instruments - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended	12 Months Ended
	Jun. 30, 2014	Jun. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Fair Value Disclosures [Abstract]
Contingency reserve expense		$20,300,000	$20,272,000
Payment made for reducing contingency reserve	6,000,000	6,000,000
Remaining contingency reserve		$14,300,000	$14,272,000	$0

Quantitative_Information_about

Quantitative Information about Significant Unobservable Input used in Fair Value Measurement for Contingent Consideration Liability Measured at Fair Value on Recurring Basis (Detail) (Significant Unobservable Inputs (Level 3) [Member])	12 Months Ended
	Dec. 31, 2014
Minimum [Member]
Business Acquisition, Contingent Consideration [Line Items]
Revenue and expense growth percentage	1.00%
Maximum [Member]
Business Acquisition, Contingent Consideration [Line Items]
Revenue and expense growth percentage	102.00%

Assets_Measured_at_Fair_Value_

Assets Measured at Fair Value on Non-Recurring Basis (Detail) (Fair Value, Measurements, Non-Recurring [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	$5,330	$15,825
Impaired loans [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	5,122	15,496
Other real estate owned [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	208	329
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Impaired loans [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other real estate owned [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	0	0
Significant Other Observable Inputs (Level 2) [Member] | Impaired loans [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	0	0
Significant Other Observable Inputs (Level 2) [Member] | Other real estate owned [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	5,330	15,825
Significant Unobservable Inputs (Level 3) [Member] | Impaired loans [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	5,122	15,496
Significant Unobservable Inputs (Level 3) [Member] | Other real estate owned [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	208	329
Total Gains (Losses) Recognized [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	2,345	-2,621
Total Gains (Losses) Recognized [Member] | Impaired loans [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	2,345	-2,496
Total Gains (Losses) Recognized [Member] | Other real estate owned [Member]
Fair Value Of Assets And Liabilities Measured At Non Recurring Basis [Line Items]
Assets measured at fair value	$0	($125)

Estimated_Fair_Value_of_Financ

Estimated Fair Value of Financial Instruments (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and short-term investments	$2,101,800,000	$2,701,500,000
Securities available for sale	6,911,936,000	6,762,411,000
Securities held to maturity	278,054,000	209,770,000
Federal Reserve Bank stock and other	68,474,000	50,482,000
Trading securities	27,203,000	28,464,000
Loans (exclusive of allowance for loan loss)	7,466,400,000	6,521,900,000
Derivatives	7,100,000	2,500,000
Demand and savings deposits	12,353,300,000	12,191,100,000
Time deposits	1,263,600,000	1,449,600,000
Other borrowings	2,025,100,000	1,583,300,000
Long-term debt	8,810,000	5,055,000
Derivatives	7,500,000	2,300,000
Total Estimated Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and short-term investments	2,101,800,000	2,701,500,000
Securities available for sale	6,911,900,000	6,762,400,000
Securities held to maturity	304,100,000	231,500,000
Federal Reserve Bank stock and other	68,500,000	50,500,000
Trading securities	27,200,000	28,500,000
Loans (exclusive of allowance for loan loss)	7,483,300,000	6,571,600,000
Derivatives	7,100,000	2,500,000
Demand and savings deposits	12,353,300,000	12,191,100,000
Time deposits	1,263,600,000	1,449,400,000
Other borrowings	2,025,100,000	1,583,300,000
Long-term debt	9,100,000	4,500,000
Derivatives	7,500,000	2,300,000
Commitments to extend credit for loans	5,700,000	6,000,000
Commercial letters of credit	200,000	100,000
Standby letters of credit	2,400,000	2,000,000
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	2,006,300,000	2,626,300,000
Securities available for sale	642,300,000	564,900,000
Securities held to maturity	0	0
Federal Reserve Bank stock and other	0	0
Trading securities	18,500,000	24,900,000
Loans (exclusive of allowance for loan loss)	0	0
Derivatives	0	0
Demand and savings deposits	12,353,300,000	12,191,100,000
Time deposits	0	0
Other borrowings	42,000,000	12,800,000
Long-term debt	0	0
Derivatives	0	0
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	95,500,000	75,200,000
Securities available for sale	6,269,650,000	6,197,475,000
Securities held to maturity	304,100,000	231,500,000
Federal Reserve Bank stock and other	68,500,000	50,500,000
Trading securities	8,697,000	3,587,000
Loans (exclusive of allowance for loan loss)	7,483,300,000	6,571,600,000
Derivatives	7,100,000	2,500,000
Demand and savings deposits	0	0
Time deposits	1,263,600,000	1,449,400,000
Other borrowings	1,983,100,000	1,570,500,000
Long-term debt	9,100,000	4,500,000
Derivatives	7,500,000	2,300,000
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and short-term investments	0	0
Securities available for sale	0	0
Securities held to maturity	0	0
Federal Reserve Bank stock and other	0	0
Trading securities	0	0
Loans (exclusive of allowance for loan loss)	0	0
Derivatives	0	0
Demand and savings deposits	0	0
Time deposits	0	0
Other borrowings	0	0
Long-term debt	0	0
Derivatives	$0	$0

Schedule_of_Parent_Company_Bal

Schedule of Parent Company Balance Sheets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
ASSETS
Goodwill on purchased affiliates	$209,758	$209,758	$209,758
Securities available for sale and other	7,285,667	7,051,127
Total assets	17,500,960	16,911,852
LIABILITIES AND SHAREHOLDERS' EQUITY
Short-term debt		107
Total liabilities	15,857,202	15,405,787
Shareholders' equity	1,643,758	1,506,065	1,279,345	1,191,132
Total liabilities and shareholders' equity	17,500,960	16,911,852
Parent Company [Member]
ASSETS
Investment in subsidiaries: Banks	1,312,575	1,159,098
Investment in subsidiaries: Non-banks	187,329	175,650
Total investment in subsidiaries	1,499,904	1,334,748
Goodwill on purchased affiliates	5,011	5,011
Cash	80,958	110,932
Securities available for sale and other	65,628	61,685
Total assets	1,651,501	1,512,376
LIABILITIES AND SHAREHOLDERS' EQUITY
Short-term debt	0	0
Accrued expenses and other	7,743	6,311
Total liabilities	7,743	6,311
Shareholders' equity	1,643,758	1,506,065
Total liabilities and shareholders' equity	$1,651,501	$1,512,376

Schedule_of_Parent_Company_Sta

Schedule of Parent Company Statements of Income and Comprehensive Income (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
EXPENSE
Salaries and employee benefits									$358,569	$339,691	$319,852
Income before income taxes and equity in undistributed earnings of subsidiaries									164,817	183,424	170,224
Income tax benefit	9,509	12,410	13,988	8,255	12,432	13,175	10,672	13,180	44,162	49,459	47,507
Net income	26,940	35,630	34,672	23,413	34,663	34,432	29,929	34,941	120,655	133,965	122,717
Comprehensive income									164,301	15,737	127,206
Parent Company [Member]
INCOME
Dividends and income received from subsidiary banks									31,000	54,750	78,000
Service fees from subsidiaries									35,206	33,443	27,821
Other									2,504	387	1,012
Total income									68,710	88,580	106,833
EXPENSE
Salaries and employee benefits									33,556	32,223	30,683
Other									17,037	9,198	9,428
Total expense									50,593	41,421	40,111
Income before income taxes and equity in undistributed earnings of subsidiaries									18,117	47,159	66,722
Income tax benefit									-5,227	-4,307	-4,248
Income before equity in undistributed earnings of subsidiaries									23,344	51,466	70,970
Banks									94,833	64,674	44,797
Non-Banks									2,478	17,825	6,950
Net income									120,655	133,965	122,717
Other comprehensive income (loss)									43,646	-118,228	4,489
Comprehensive income									$164,301	$15,737	$127,206

Schedule_of_Parent_Company_Sta1

Schedule of Parent Company Statements of Cash Flows (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
OPERATING ACTIVITIES
Net income	$120,655	$133,965	$122,717
Net decrease (increase) in trading securities	-2,714	8,252	2,378
Equity based compensation	9,661	8,386	7,162
Other	-20,100	-10,423	-20,796
INVESTING ACTIVITIES
Net capital proceeds (expenditures) for premises and equipment	-44,790	-38,313	-44,038
FINANCING ACTIVITIES
Cash dividends paid	-41,364	-36,168	-33,787
Common stock issuance		231,430
(Decrease) increase in cash and cash equivalents	-795,198	1,216,034	-93,237
Parent Company [Member]
OPERATING ACTIVITIES
Net income	120,655	133,965	122,717
Equity in earnings of subsidiaries	-128,311	-137,249	-129,747
Dividends received from subsidiaries	31,000	0	0
Net decrease (increase) in trading securities	6,397	6,181	-11,380
Equity based compensation	9,661	0	0
Other	-9,071	-8,467	-16,812
Net cash provided by operating activities	30,331	-5,570	-35,222
INVESTING ACTIVITIES
Net capital investment in subsidiaries	-24,200	-156,000	-3,000
Dividends received from subsidiaries	0	54,750	78,000
Net capital proceeds (expenditures) for premises and equipment	154	-406	466
Net cash used in investing activities	-24,046	-101,656	75,466
FINANCING ACTIVITIES
Proceeds from short-term debt	0	0	0
Cash dividends paid	-41,364	-36,168	-33,787
Common stock issuance	0	231,430	0
Other	5,105	15,903	-5,368
Net cash (used in) provided by financing activities	-36,259	211,165	-39,155
(Decrease) increase in cash and cash equivalents	-29,974	103,939	1,089
Cash and cash equivalents at beginning of period	110,932	6,993	5,904
Cash and cash equivalents at end of period	$80,958	$110,932	$6,993

Recovered_Sheet10

Summary of Operating Results by Quarter (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Interest income	$94,218	$90,817	$89,789	$89,047	$89,131	$89,096	$86,212	$83,902	$363,871	$348,341	$339,685
Interest expense	3,304	3,291	3,619	3,602	3,217	3,551	3,885	4,419	13,816	15,072	19,629
Net interest income	90,914	87,526	86,170	85,445	85,914	85,545	82,327	79,483	350,055	333,269	320,056
Provision for loan losses	3,000	4,500	5,000	4,500	4,000	6,500	5,000	2,000	17,000	17,500	17,500
Noninterest income	115,248	126,475	134,001	122,964	135,607	121,625	113,585	121,016	498,688	491,833	458,122
Noninterest expense	166,713	161,461	166,511	172,241	170,426	153,063	150,311	150,378	666,926	624,178	590,454
Income tax expense	9,509	12,410	13,988	8,255	12,432	13,175	10,672	13,180	44,162	49,459	47,507
Net income	$26,940	$35,630	$34,672	$23,413	$34,663	$34,432	$29,929	$34,941	$120,655	$133,965	$122,717
Net income-basic	$0.60	$0.79	$0.77	$0.52	$0.78	$0.85	$0.75	$0.88	$2.69	$3.25	$3.07
Net income-diluted	$0.59	$0.78	$0.76	$0.52	$0.77	$0.83	$0.74	$0.87	$2.65	$3.20	$3.04
Dividend	$0.24	$0.23	$0.23	$0.23	$0.23	$0.22	$0.22	$0.22	$0.91	$0.87	$0.83
Book value	$36.10	$35.51	$35.21	$33.94	$33.30	$32.85	$30.20	$31.73