International Bancshares (IBOC) 10-K 26 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 22, 2016	Jun. 30, 2015
Document and Entity Information
Entity Registrant Name	INTERNATIONAL BANCSHARES CORP
Entity Central Index Key	315,709
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 1,785,409,000
Entity Common Stock, Shares Outstanding		65,933,477
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY

Consolidated Statements of Cond

Consolidated Statements of Condition - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 273,053	$ 255,146
Investment securities:
Held-to-maturity (Market value of $2,400 on December 31, 2015 and $2,400 on December 31, 2014)	2,400	2,400
Available-for-sale (Amortized cost of $4,196,034 on December 31, 2015 and $4,894,428 on December 31, 2014)	4,199,372	4,911,963
Total investment securities	4,201,772	4,914,363
Loans	5,950,914	5,679,245
Less allowance for probable loan losses	(66,988)	(64,828)
Net loans	5,883,926	5,614,417
Bank premises and equipment, net	516,716	526,423
Accrued interest receivable	31,572	31,461
Other investments	468,791	440,670
Identified intangible assets, net	153	797
Goodwill	282,532	282,532
Other assets	114,354	130,711
Total assets	11,772,869	12,196,520
Deposits:
Demand - non-interest bearing	3,149,618	2,930,253
Savings and interest bearing demand	3,020,222	3,025,680
Time	2,366,413	2,482,692
Total deposits	8,536,253	8,438,625
Securities sold under repurchase agreements	827,772	858,350
Other borrowed funds	505,750	1,073,944
Junior subordinated deferrable interest debentures	161,416	175,416
Other liabilities	76,175	69,527
Total liabilities	10,107,366	10,615,862
Shareholders' equity:
Common shares of $1.00 par value. Authorized 275,000,000 shares; issued 95,866,218 shares on December 31, 2015 and 95,783,977 shares on December 31, 2014	95,866	95,784
Surplus	167,980	165,520
Retained earnings	1,683,600	1,585,389
Accumulated other comprehensive income (including $(4,026) on December 31, 2015 and $(4,881) on December 31, 2014 of comprehensive loss related to other-than-temporary impairment for non-credit related issues)	2,167	11,397
Total shareholders' equity before treasury stock	1,949,613	1,858,090
Less cost of shares in treasury, 29,585,646 shares on December 31, 2015 and 29,324,567 December 31, 2014	(284,110)	(277,432)
Total shareholders' equity	1,665,503	1,580,658
Total liabilities and shareholders' equity	$ 11,772,869	$ 12,196,520

Consolidated Statements of Con3

Consolidated Statements of Condition (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Consolidated Statements of Condition
Held to maturity, Market value (in dollars)	$ 2,400	$ 2,400
Available for sale, Amortized cost (in dollars)	$ 4,196,034	$ 4,894,428
Common shares, par value (in dollars per share)	$ 1	$ 1
Common shares, Authorized shares	275,000,000	275,000,000
Common shares, issued shares	95,866,218	95,783,977
Comprehensive (loss) related to other-than-temporary impairment for non-credit related issues (in dollars)	$ (4,026)	$ (4,881)
Treasury, shares	29,585,646	29,324,567

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest income:
Loans, including fees	$ 297,283	$ 281,546	$ 263,027
Investment securities:
Taxable	88,008	100,095	87,198
Tax-exempt	11,319	11,767	12,877
Other interest income	144	191	115
Total interest income	396,754	393,599	363,217
Interest expense:
Savings and interest bearing demand deposits	3,593	3,597	3,762
Time deposits	11,233	12,033	15,444
Securities sold under repurchase agreements	23,777	24,616	29,171
Other borrowings	1,615	2,033	1,590
Junior subordinated deferrable interest debentures	4,099	4,264	4,665
Total interest expense	44,317	46,543	54,632
Net interest income	352,437	347,056	308,585
Provision for probable loan losses	24,405	14,423	22,968
Net interest income after provision for probable loan losses	328,032	332,633	285,617
Non-interest income:
Service charges on deposit accounts	78,825	88,586	97,087
Other service charges, commissions and fees
Banking	44,971	44,435	41,075
Non-banking	7,223	7,463	7,116
Investment securities transactions, net	(3,682)	1,283	9,601
Other investments, net	16,969	22,023	22,383
Other income	11,428	14,558	12,343
Total non-interest income	155,734	178,348	189,605
Non-interest expense:
Employee compensation and benefits	125,135	121,511	119,845
Occupancy	28,019	32,530	31,766
Depreciation of bank premises and equipment	25,009	24,013	26,017
Professional fees	12,278	10,925	13,146
Deposit insurance assessments	5,938	6,082	6,737
Net expense, other real estate owned	5,695	2,358	6,896
Amortization of identified intangible assets	644	2,389	4,633
Advertising	7,585	7,742	7,034
Early termination fee - securities sold under repurchase agreements	3,510	11,000	12,303
Impairment charges (Total other-than-temporary impairment charges, $1,325 less gain of $(371), $(366) less loss of $1,183, and $(431) less loss of $(1,805), included in other comprehensive income)	954	817	1,374
Other	62,157	61,676	62,881
Total non-interest expense	276,924	281,043	292,632
Income before income taxes	206,842	229,938	182,590
Provision for income taxes	70,116	76,787	56,239
Net income	136,726	153,151	126,351
Net income available to common shareholders	$ 136,726	$ 153,151	$ 126,351
Basic earnings per common share:
Weighted average number of shares outstanding (in shares)	66,411,193	66,872,500	67,195,180
Net income (in dollars per share)	$ 2.06	$ 2.29	$ 1.88
Fully diluted earnings per common share:
Weighted average number of shares outstanding (in shares)	66,636,353	67,056,456	67,314,859
Net income (in dollars per share)	$ 2.05	$ 2.28	$ 1.88

Consolidated Statements of Inc5

Consolidated Statements of Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Income
Impairment charges, other-than-temporary impairment charges	$ 1,325	$ (366)	$ (431)
Impairment charges, other comprehensive (income) loss	$ (371)	$ 1,183	$ (1,805)

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Comprehensive Income
Net income	$ 136,726	$ 153,151	$ 126,351
Other comprehensive (loss) income, net of tax:
Net unrealized holding (losses) gains on securities available for sale arising during period (net of tax effects of $(6,593), $29,870, and $(56,048))	(12,243)	55,474	(104,088)
Reclassification adjustment for losses (gains) on securities available for sale included in net income (net of tax effects of $1,289, $(449), and $(3,360))	2,393	(834)	(6,241)
Reclassification adjustment for impairment charges on available for sale securities included in net income (net of tax effects of $334, $286, and $481)	620	531	893
Other comprehensive (loss) income, net of tax	(9,230)	55,171	(109,436)
Comprehensive income	$ 127,496	$ 208,322	$ 16,915

Consolidated Statements of Com7

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Comprehensive Income
Net unrealized holding (losses) gains on securities available for sale arising during period, tax effects	$ (6,593)	$ 29,870	$ (56,048)
Reclassification adjustment for losses (gains) on securities available for sale included in net income, tax effects	1,289	(449)	(3,360)
Reclassification adjustment for impairment charges on available for sale securities included in net income, tax effects	$ 334	$ 286	$ 481

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Preferred Stock	Common Stock	Surplus	Retained Earnings	Other Comprehensive Income (Loss)	Treasury Stock	Total
Balance at Dec. 31, 2012		$ 95,725	$ 163,287	$ 1,369,543	$ 65,662	$ (258,509)	$ 1,435,708
Balance (in shares) at Dec. 31, 2012	95,725
Increase (decrease) in shareholders' equity
Net Income				126,351			126,351
Dividends:
Cash ($.58, $.43 and $.40 per share) for the year ended December 31, 2015, 2014 and 2013, respectively)				(28,894)			(28,894)
Exercise of stock options		19	246				265
Options exercised (in shares)	19
Stock compensation expense recognized in earnings			414				414
Other comprehensive income (loss), net of tax:
Net change in unrealized gains and losses on available for sale securities, net of reclassification adjustments					(109,436)		(109,436)
Balance at Dec. 31, 2013		95,744	163,947	1,467,000	(43,774)	(258,509)	1,424,408
Balance (in shares) at Dec. 31, 2013	95,744
Increase (decrease) in shareholders' equity
Net Income				153,151			153,151
Dividends:
Cash ($.58, $.43 and $.40 per share) for the year ended December 31, 2015, 2014 and 2013, respectively)				(34,762)			(34,762)
Purchase of treasury stock (261,079, 787,387 and 95,466 shares) for the years ended December 31, 2015, 2014 and 2013, respectively)						(18,923)	(18,923)
Exercise of stock options		40	515				555
Options exercised (in shares)	40
Stock compensation expense recognized in earnings			1,058				1,058
Other comprehensive income (loss), net of tax:
Net change in unrealized gains and losses on available for sale securities, net of reclassification adjustments					55,171		55,171
Balance at Dec. 31, 2014		95,784	165,520	1,585,389	11,397	(277,432)	1,580,658
Balance (in shares) at Dec. 31, 2014	95,784
Increase (decrease) in shareholders' equity
Net Income				136,726			136,726
Dividends:
Cash ($.58, $.43 and $.40 per share) for the year ended December 31, 2015, 2014 and 2013, respectively)				(38,515)			(38,515)
Purchase of treasury stock (261,079, 787,387 and 95,466 shares) for the years ended December 31, 2015, 2014 and 2013, respectively)						(6,678)	(6,678)
Exercise of stock options		82	1,288				1,370
Options exercised (in shares)	82
Stock compensation expense recognized in earnings			1,172				1,172
Other comprehensive income (loss), net of tax:
Net change in unrealized gains and losses on available for sale securities, net of reclassification adjustments					(9,230)		(9,230)
Balance at Dec. 31, 2015		$ 95,866	$ 167,980	$ 1,683,600	$ 2,167	$ (284,110)	$ 1,665,503
Balance (in shares) at Dec. 31, 2015	95,866

Consolidated Statements of Sha9

Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Shareholders' Equity
Cash Dividends (in dollars per share)	$ 0.58	$ 0.43	$ 0.40
Purchase of treasury stock (in shares)	261,079	787,387	95,466

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities:
Net income	$ 136,726,000	$ 153,151,000	$ 126,351,000
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for probable loan losses	24,405,000	14,423,000	22,968,000
Specific reserve, other real estate owned	1,023,000	779,000	1,204,000
Depreciation of bank premises and equipment	25,009,000	24,013,000	26,017,000
Loss (gain) on sale of bank premises and equipment	14,000	(3,658,000)	(2,089,000)
Gain on sale of other real estate owned	(57,000)	(933,000)	(460,000)
Accretion of investment securities discounts	(1,704,000)	(2,608,000)	(4,025,000)
Amortization of investment securities premiums	28,000,000	26,729,000	44,245,000
Investment securities transactions, net	3,682,000	(1,283,000)	(9,601,000)
Impairment charges on available for sale securities	954,000	817,000	1,374,000
Amortization of identified intangible assets	644,000	2,389,000	4,633,000
Stock based compensation expense	1,172,000	1,058,000	414,000
Earnings from affiliates and other investments	(12,176,000)	(10,903,000)	(18,806,000)
Deferred tax benefit	(332,000)	(1,027,000)	(1,817,000)
(Increase) decrease in accrued interest receivable	(111,000)	(807,000)	380,000
Decrease (increase) in other assets	2,967,000	(1,621,000)	20,612,000
Decrease in other liabilities	(6,567,000)	(7,482,000)	(2,274,000)
Net cash provided by operating activities	203,649,000	193,037,000	209,126,000
Investing activities:
Proceeds from maturities of securities	1,075,000		1,200,000
Proceeds from sales and calls of available for sale securities	164,163,000	621,588,000	178,123,000
Purchases of available for sale securities	(352,513,000)	(971,358,000)	(1,384,254,000)
Principal collected on mortgage-backed securities	854,736,000	787,361,000	1,223,532,000
Net increase in loans	(297,689,000)	(502,129,000)	(444,919,000)
Purchases of other investments	(16,355,000)	(20,602,000)	(2,475,000)
Distributions from other investments	18,293,000	18,152,000	5,457,000
Purchases of bank premises and equipment	(19,831,000)	(50,360,000)	(50,016,000)
Proceeds from sales of bank premises and equipment	4,515,000	8,424,000	2,533,000
Proceeds from sales of other real estate owned	16,831,000	18,525,000	23,170,000
Net cash provided by (used in) investing activities	373,225,000	(90,399,000)	(447,649,000)
Financing activities:
Net increase in non-interest bearing demand deposits	219,365,000	263,743,000	200,760,000
Net (decrease) increase in savings and interest bearing demand deposits	(5,458,000)	100,068,000	58,461,000
Net decrease in time deposits	(116,279,000)	(168,611,000)	(303,009,000)
Net decrease in securities sold under repurchase agreements	(30,578,000)	(99,031,000)	(172,298,000)
Other borrowed funds, net	(568,194,000)	(150,006,000)	474,923,000
Repayment of long-term debt	(14,000,000)	(15,310,000)
Purchase of treasury stock	(6,678,000)	(18,923,000)
Proceeds from stock transactions	1,370,000	555,000	265,000
Payments of cash dividends - common	(38,515,000)	(34,762,000)	(28,894,000)
Net cash (used in) provided by financing activities	(558,967,000)	(122,277,000)	230,208,000
Increase (decrease) in cash and cash equivalents	17,907,000	(19,639,000)	(8,315,000)
Cash and cash equivalents at beginning of period	255,146,000	274,785,000	283,100,000
Cash and cash equivalents at end of period	273,053,000	255,146,000	274,785,000
Supplemental cash flow information:
Interest paid	44,560,000	47,273,000	56,818,000
Income taxes paid	65,234,000	80,374,000	60,532,000
Non-cash investing and financing activities:
Net transfer from loans to other real estate owned	$ 3,775,000	$ 2,363,000	$ 9,688,000

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	(1) Summary of Significant Accounting Policies The accounting and reporting policies of International Bancshares Corporation (“Corporation”) and Subsidiaries (the Corporation and Subsidiaries collectively referred to herein as the “Company”) conform to accounting principles generally accepted in the United States of America and to general practices within the banking industry. The following is a description of the more significant of those policies. Consolidation and Basis of Presentation The consolidated financial statements include the accounts of the Corporation and its wholly-owned bank subsidiaries, International Bank of Commerce, Laredo ("IBC"), Commerce Bank, International Bank of Commerce, Zapata, International Bank of Commerce, Brownsville, and the Corporation's wholly-owned non-bank subsidiaries, IBC Subsidiary Corporation, IBC Life Insurance Company, IBC Trading Company, Premier Tierra Holdings, Inc., IBC Charitable and Community Development Corporation, and IBC Capital Corporation. All significant inter-company balances and transactions have been eliminated in consolidation. The Company, through its subsidiaries, is primarily engaged in the business of banking, including the acceptance of checking and savings deposits and the making of commercial, real estate, personal, home improvement, automobile and other installment and term loans. The primary markets of the Company are South, Central, and Southeast Texas and the state of Oklahoma. Each bank subsidiary is very active in facilitating international trade along the United States border with Mexico and elsewhere. Although the Company’s loan portfolio is diversified, the ability of the Company’s debtors to honor their contracts is primarily dependent upon the economic conditions in the Company’s trade area. In addition, the investment portfolio is directly impacted by fluctuations in market interest rates. The Company and its bank subsidiaries are subject to the regulations of certain Federal agencies as well as the Texas Department of Banking and undergo periodic examinations by those regulatory authorities. Such agencies may require certain standards or impose certain limitations based on their judgments or changes in law and regulations. The Company owns two insurance ‑related subsidiaries, IBC Life Insurance Company and IBC Insurance Agency, Inc., a wholly owned subsidiary of IBC, the bank subsidiary. Neither of the insurance ‑related subsidiaries conducts underwriting activities. The IBC Life Insurance Company is in the business of reinsuring credit life and credit accident and health insurance. The business is assumed from an unaffiliated insurer and the only business written is generated by the bank subsidiaries of the Company. The risk assumed on each of the policies is not significant to the consolidated financial statements. The preparation of the 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 amounts of assets and liabilities as of the dates of the statement of condition and income and expenses for the periods. Actual results could differ significantly from those estimates. Material estimates that are particularly susceptible to significant changes in the near ‑term relate to the determination of the allowance for probable loan losses. Subsequent Events The Company has evaluated all events or transactions that occurred through the date the Company issued these financial statements. During this period, the Company did not have any material recognizable or non ‑recognizable subsequent events. Investment Securities The Company classifies debt and equity securities into one of these categories: held ‑to ‑maturity, available ‑for ‑sale, or trading. Such classifications are reassessed for appropriate classification at each reporting date. Securities that are intended and expected to be held until maturity are classified as “held ‑to ‑maturity” and are carried at amortized cost for financial statement reporting. Securities that are not positively expected to be held until maturity, but are intended to be held for an indefinite period of time are classified as “available ‑for ‑sale” or “trading” and are carried at their fair value. Unrealized holding gains and losses are included in net income for those securities classified as “trading”, while unrealized holding gains and losses related to those securities classified as “available ‑for ‑sale” are excluded from net income and reported net of tax as other comprehensive income and in shareholders’ equity as accumulated other comprehensive income until realized. The Company did not maintain any trading securities during the three year period ended December 31, 2015. Mortgage ‑backed securities held at December 31, 2015 and 2014 represent participating interests in pools of long ‑term first mortgage loans originated and serviced by the issuers of the securities. Mortgage ‑backed securities are either issued or guaranteed by the U.S. government or its agencies including the Federal Home Loan Mortgage Corporation (“Freddie Mac”), the Federal National Mortgage Association (“Fannie Mae”), the Government National Mortgage Association (“Ginnie Mae”) or other non ‑government entities. Investments in residential mortgage ‑backed securities issued by Ginnie Mae are fully guaranteed by the U. S. government. Investments in residential mortgage ‑backed securities issued by Freddie Mac and Fannie Mae are not fully guaranteed by the U.S. government, however, the Company believes that the quality of the bonds is similar to other AAA rated bonds with limited credit risk, particularly given the placement of Fannie Mae and Freddie Mac into conservatorship by the federal government in 2008 and because securities issued by others that are collateralized by residential mortgage ‑backed securities issued by Fannie Mae or Freddie Mac are rated consistently as AAA rated securities. Market interest rate fluctuations can affect the prepayment speed of principal and the yield on the security. Premiums and discounts are amortized using the level yield or “interest method” over the terms of the securities. Declines in the fair value of held ‑to ‑maturity and available ‑for sale ‑securities below their cost that are deemed to be other than temporary are reflected in earnings as realized losses. In determining whether other ‑than ‑temporary impairment exists, management considers many factors, including (1) the length of time and the extent to which the fair value has been less than cost, (2) the financial condition and near ‑term prospects of the issuer, and (3) the intent of the Company to hold and the determination of whether the Company will more likely than not be required to sell the security prior to a recovery in fair value. If the Company determines that (1) it intends to sell the security or (2) it is more likely than not that it will be required to sell the security before it’s anticipated recovery, the other ‑than ‑temporary impairment that is recognized in earnings is equal to the difference between the fair value of the security and the Company’s amortized cost in the security. If the Company determines that it (1) does not intend to sell the security and (2) it will not be more likely than not required to sell the security before it’s anticipated recovery, the other ‑than ‑temporary impairment is segregated into its two components (1) the amount of impairment related to credit loss and (2) the amount of impairment related to other factors. The difference between the present value of the cash flows expected to be collected and the amortized cost is the credit loss recognized through earnings and an adjustment to the cost basis of the security. The amount of impairment related to other factors is included in other comprehensive income (loss). Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method. Provision and Allowance for Probable Loan Losses The allowance for probable loan losses is maintained at a level considered adequate by management to provide for probable loan losses. The allowance is increased by provisions charged to operating expense and reduced by net charge ‑offs. The provision for probable loan losses is the amount, which, in the judgment of management, is necessary to establish the allowance for probable loan losses at a level that is adequate to absorb known and inherent risks in the loan portfolio. Management believes that the allowance for probable loan losses is adequate. While management uses available information to recognize losses on loans, future additions to the allowance may be necessary based on changes in economic conditions. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Company’s bank subsidiaries’ allowances for probable loan losses. Such agencies may require the Company’s bank subsidiaries to make additions or reductions to their U.S. generally accepted accounting principles (“GAAP”) allowances based on their judgments of information available to them at the time of their examination. The bank subsidiaries charge off that portion of any loan which management considers to represent a loss as well as that portion of any other loan which is classified as a “loss” by bank examiners. Commercial, financial and agricultural or real estate loans are generally considered by management to represent a loss, in whole or part, (i) when an exposure beyond any collateral coverage is apparent, (ii) when no further collection of the portion of the loan so exposed is anticipated based on actual results, (iii) when the credit enhancements, if any, are not adequate, and (iv) when the borrower’s financial condition would indicate so. Generally, unsecured consumer loans are charged off when 90 days past due. Loans Loans are reported at the principal balance outstanding, net of unearned discounts. Interest income on loans is reported on an accrual basis. Loan fees and costs associated with originating the loans are amortized over the life of the loan using the interest method. The Company originates mortgage loans that may subsequently be sold to an unaffiliated third party. The loans are not securitized and if sold, are sold without recourse. Loans held for sale are carried at cost and the principal amount outstanding is not significant to the consolidated financial statements. Impaired Loans Impaired loans are those loans where it is probable that all amounts due according to contractual terms of the loan agreement will not be collected. Impaired loans are measured based on (1) the present value of expected future cash flows discounted at the loan’s effective interest rate; (2) the loan’s observable market price; or (3) the fair value of the collateral if the loan is collateral dependent. Substantially all of the Company’s impaired loans are measured at the fair value of the collateral. In limited cases the Company may use other methods to determine the level of impairment of a loan if such loan is not collateral dependent. Troubled Debt Restructured Loans Troubled debt restructured loans (“TDR”) are those loans where, for reasons related to a borrower’s difficulty to repay a loan, the company grants a concession to the borrower that the company would not normally consider in the normal course of business. The original terms of the loan are modified or restructured. The terms that may be modified include a reduction in the original stated interest rate, an extension of the original maturity of the loan, a renewal of the loan at an interest rate below current market rates, a reduction in the principal amount of debt outstanding, a reduction in accrued interest or deferral of interest payments. A loan classified as a TDR is classified as an impaired loan and included in the impaired loan totals. A TDR loan may be returned to accrual status when the loan is brought current, has performed in accordance with the restructured terms for a reasonable period of time, is at the current market rate, and the ultimate collectability of the outstanding principal and interest is no longer questionable, however, although those loans may be placed back on accrual status, they will continue to be classified as impaired. Consistent with regulatory guidance, a TDR loan that is subsequently modified, but has shown sustained performance and classification as a TDR, will be removed from TDR status provided that the modified terms were market-based at the time of modification. Non ‑Accrual Loans The non ‑accrual loan policy of the Company’s bank subsidiaries is to discontinue the accrual of interest on loans when management determines that it is probable that future interest accruals will be un ‑collectible. As it relates to consumer loans, management charges off those loans when the loan is contractually 90 days past due. Under special circumstances, a consumer or non ‑consumer loan may be more than 90 days delinquent as to interest or principal and not be placed on non ‑accrual status. This situation generally results when a bank subsidiary has a borrower who is experiencing financial difficulties, but not to the extent that requires a restructuring of indebtedness. The majority of this category is composed of loans that are considered to be adequately secured and/or for which there are expected future payments. When a loan is placed on non ‑accrual status, any interest accrued, not paid is reversed and charged to operations against interest income. As it relates to non ‑consumer loans that are not 90 days past due, management will evaluate each of these loans to determine if placing the loan on non ‑accrual status is warranted. Interest income on non ‑accrual loans is recognized only to the extent payments are received or when, in management’s opinion, the debtor’s financial condition warrants reestablishment of interest accruals. Other Real Estate Owned Other real estate owned is comprised of real estate acquired by foreclosure and deeds in lieu of foreclosure. Other real estate is carried at the lower of the recorded investment in the property or its fair value less estimated costs to sell such property (as determined by independent appraisal). Prior to foreclosure, the value of the underlying loan is written down to the fair value of the real estate to be acquired by a charge to the allowance for probable loan losses, if necessary. Any subsequent write ‑downs are charged against other non ‑interest expense through a valuation allowance. Other real estate owned totaled approximately $55,850,000 and $69,872,000 at December 31, 2015 and 2014, respectively. Other real estate owned is included in other assets. Bank Premises and Equipment Bank premises and equipment are stated at cost less accumulated depreciation. Depreciation is computed on straight ‑line and accelerated methods over the estimated useful lives of the assets. Repairs and maintenance are charged to operations as incurred and expenditures for renewals and betterments are capitalized. Other Investments Other investments include equity investments in non ‑financial companies, bank owned life insurance, as well as equity securities with no readily determinable fair market value. Equity investments are accounted for using the equity method of accounting. Equity securities with no readily determinable fair value are accounted for using the cost method. Income Taxes Deferred income tax assets and liabilities are determined using the asset and liability method. Under this method, the net deferred tax asset or liability is determined based on the tax effects of the differences between the book and tax basis of the various balance sheet assets and liabilities and gives current recognition to changes in tax rates and laws. The Company files a consolidated federal income tax return with its subsidiaries. Recognition of deferred tax assets is based on management’s assessment that the benefit related to certain temporary differences, tax operating loss carry forwards, and tax credits are more likely than not to be realized. A valuation allowance is recorded for the amount of the deferred tax items for which it is more likely than not that the tax benefits will not be realized. The Company evaluates uncertain tax positions at the end of each reporting period. The Company may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefit recognized in the financial statements from any such a position is measured based on the largest benefit that has a greater than fifty percent likelihood of being realized upon ultimate settlement. As of December 31, 2015 and 2014, respectively, after evaluating all uncertain tax positions, the Company has recorded no liability for unrecognized tax benefits at the end of the reporting period. The Company would recognize any interest accrued on unrecognized tax benefits as other interest expense and penalties as other non ‑interest expense. During the years ended December 31, 2015, 2014 and 2013, the Company recognized no interest expense or penalties related to uncertain tax positions. The Company files consolidated tax returns in the U.S. Federal jurisdiction and various state jurisdictions. The Company is no longer subject to U.S. federal or state income tax examinations by tax authorities for years before 2012. Stock Options Compensation expense for stock awards is based on the market price of the stock on the measurement date, which is generally the date of grant, and is recognized ratably over the service period of the award. The fair value of stock options granted was estimated, using the Black ‑Sholes ‑Merton option ‑pricing model. This model was developed for use in estimating the fair value of publicly traded options that have no vesting restrictions and are fully transferable. Additionally, the model requires the input of highly subjective assumptions. Because the Company’s employee stock options have characteristics significantly different from those of publicly traded options, and because changes in the subjective input assumptions can materially affect the fair value estimate, in management’s opinion, the Black ‑Scholes ‑Merton option ‑pricing model does not necessarily provide a reliable single measure of the fair value of the Company’s stock options. Net Income Per Share Basic Earnings Per Share (“EPS”) is calculated by dividing net income by the weighted average number of common shares outstanding. The computation of diluted EPS assumes the issuance of common shares for all dilutive potential common shares outstanding during the reporting period. The dilutive effect of stock options is considered in earnings per share calculations, if dilutive, using the treasury stock method. Goodwill and Identified Intangible Assets Goodwill represents the excess of costs over fair value of assets of businesses acquired. Goodwill is tested for impairment at least annually or on an interim basis if an event triggering impairment may have occurred. As of October 1, 2015, after completing goodwill testing, the Company has determined that no goodwill impairment exists. Identified intangible assets are acquired assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights or because the asset is capable of being sold or exchanged either on its own or in combination with a related contract, asset, or liability. The Company’s identified intangible assets relate to core deposits and contract rights. As of December 31, 2015, the Company has determined that no impairment of identified intangibles exists. Identified intangible assets with definite useful lives are amortized on an accelerated basis over their estimated life. See Note 6—Goodwill and Other Intangible Assets. Impairment of Long ‑Lived Assets Long ‑lived assets, such as property, plant and equipment, and purchased intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying value of the asset to the estimated undiscounted future cash flows expected to be generated by the asset. If the carrying value of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying value of the asset exceeds the fair value of the asset. Assets to be disposed of would be separately presented in the statement of condition and reported at the lower of the carrying value or fair value less costs to sell, and are no longer depreciated. The assets and liabilities of a disposed group classified as held for sale would be presented separately in the appropriate asset and liability sections of the statement of condition. Consolidated Statements of Cash Flows For purposes of the consolidated statements of cash flows, the Company considers all short ‑term investments with a maturity at date of purchase of three months or less to be cash equivalents. Also, the Company reports transactions related to deposits and loans to customers on a net basis. Accounting for Transfers and Servicing of Financial Assets The Company accounts for transfers and servicing of financial assets and extinguishments of liabilities based on the application of a financial ‑components approach that focuses on control. After a transfer of financial assets, the Company recognizes the financial and servicing assets it controls and liabilities it has incurred, derecognizes financial assets when control has been surrendered and derecognizes liabilities when extinguished. The Company has retained mortgage servicing rights in connection with the sale of mortgage loans. Because the Company may not initially identify loans as originated for resale, all loans are initially treated as held for investment. The value of the mortgage servicing rights are reviewed periodically for impairment and are amortized in proportion to, and over the period of estimated net servicing income or net servicing losses. The value of the mortgage servicing rights is not significant to the consolidated statements of condition. Segments of an Enterprise and Related Information The Company operates as one segment. The operating information used by the Company’s chief executive officer for purposes of assessing performance and making operating decisions about the Company is the consolidated financial statements presented in this report. The Company has four active operating subsidiaries, namely, the bank subsidiaries, otherwise known as International Bank of Commerce, Laredo, Commerce Bank, International Bank of Commerce, Zapata and International Bank of Commerce, Brownsville. The Company applies the provisions of ASC Topic 280, “Segment Reporting,” in determining its reportable segments and related disclosures. Comprehensive Income (Loss) Comprehensive income (loss) consists of net income and other comprehensive income (loss). Other comprehensive income (loss) includes unrealized gains and losses on securities available for sale. Advertising Advertising costs are expensed as incurred. Reclassifications Certain amounts in the prior year’s presentations have been reclassified to conform to the current presentation. These reclassifications had no effect on previously reported net income or shareholders’ equity. New Accounting Standards In July 2013, the Financial Accounting Standards Board issued Accounting Standards Update No. 2013 ‑11 to ASC 740, “Income Taxes.” The update amends existing literature to eliminate diversity in practice in the presentation of unrecognized tax benefits in instances where a net operating loss carryforward, a similar tax loss or a tax credit carryforward also exist. The update clarifies how the unrecognized tax benefit should be presented in those situations where other tax losses or tax credit carryforwards exist. The update does not change the currently required disclosures for unrecognized tax benefits under current ASC 740 guidance. The update is effective for fiscal years and interim periods within those years beginning after December 15, 2013. The adoption of the update to existing standards did not have a significant impact to the Company’s consolidated financial statements. In January 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-01 to ASC 323-70, “Investments – Equity Method and Joint Ventures – Accounting for Investments in Qualified Affordable Housing Project.” The update issues new guidance for investments in qualified affordable housing projects which permits entities to elect to apply the proportional amortization method to account for the investment when certain conditions are met. The update is effective for public entities for annual and interim periods beginning after December 15, 2014 and is able to be applied retrospectively. The adoption of the update did not have a significant impact to the Company’s consolidated financial statements. In January 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014 ‑04 to ASC 310 ‑40, “Receivables—Troubled Debt Restructurings by Creditors.” The update amends existing literature to eliminate diversity in practice by clarifying and defining when an in substance repossession or foreclosure occurs. The terms “in substance repossession or foreclosure” and “physical possession” are not currently defined in the accounting literature, resulting in diversity in practice when a creditor derecognizes a loan receivable and recognizes the real estate property collateralizing the loan receivable as an asset. Additionally, the update requires interim and annual disclosures of both the amount of foreclosed residential real estate property and the recorded investment in consumer mortgage loans collateralized by residential real estate property that are in the process of foreclosure. The update is effective for annual periods and the interim periods within those annual periods beginning after December 15, 2014. The adoption of the update to existing standards did not have a significant impact to the Company’s consolidated financial statements. In April 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-08 to ASC 205, “Presentation of Financial Statements,” and ASC 360, “Property, Plant and Equipment.” The update to existing standards change the requirements for reporting discontinued operations, primarily by clarifying that the disposal of a component or group of components of an entity could constitute discontinued operations under certain circumstances. The update also defines required information in disclosures about discontinued operations, including a discussion of the entity’s continued involvement in the discontinued operation, if any. The update is applicable to all disposals of components of an entity that occurred within interim and annual periods beginning after December 15, 2014 and for acquisitions that are classified as held for sale for interim and annual periods beginning after December 15, 2014. The adoption of the update did not have a significant impact to the Company’s consolidated financial statements. In May 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-09 to ASC 606, “Revenue from Contracts with Customers.” The update sets a common standard that defines revenue and the principles for recognizing revenue. The update outlines when an entity should recognize revenue, among other matters. At its core, the update states that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The update also outlines the steps that entities should take to determine and record the correct revenue number. The update was originally effective for annual periods beginning after December 15, 2016 and the interim periods within that reporting period. In August 2015, the Financial Accounting Standards Board issued Accounting Standards Update No 2015-14 which deferred the effective date of Accounting Standards Update No. 2014-019 by one year to annual and interim periods beginning after December 15, 2017. The Company is evaluating the potential impact to the Company’s consolidated financial statements. In June 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-11 to ASC 860, “Transfers and Servicing.” The update amended existing standards to require that repurchase-to-maturity transactions be accounted for as secured borrowings, in line with accounting standards for other similar instruments. Additionally, the update requires various disclosures including information regarding transfers accounted for as sales in transactions that are economically similar as repurchase agreements, in addition to disclosures related to collateral, remaining contractual tenor and a discussion of the potential risks associated with repurchase agreements, securities lending transactions and repurchase-to-maturity transactions. The update is effective for interim and annual periods beginning after December 15, 2014. The adoption of the update to existing standards did not have a significant impact to the Company’s consolidated financial statements. In August 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-14 to ASC 310-40, “Receivables – Troubled Debt Restructurings by Creditors.” The update is guidance regarding classification and measurement of foreclosed mortgage loans that are government guaranteed. The update specifies that government secured mortgage loans foreclosed upon should be classified as other assets and measured based on the amount of the loan balance that is expected to be recovered from the guarantor. The new guidance is effective for interim and annual periods after December 15, 2014. The adoption of the update did not have a significant impact to the Company’s consolidated financial statements. In January 2015, the Financial Accounting Standards Board issued Accounting Standards Update No. 2015-01 to ASC 225-20, “Income Statement- Extraordinary and Unusual Items.” The update amends existing standards and is being issued as part of the FASB’s initiative to reduce complexity in accounting standards. The update eliminates the concept of extraordinary items. The update is effective for interim and annual periods after December 15, 2015. The adoption of the update to existing standards is not expected to have a significant impact to the Company’s consolidated financial statements. In February 2015, the Financial Accounting Standards Board issued Accounting Standards Update No. 2015-02 to ASC 810, “Consolidation.” The update amends existing standards regarding the evaluation of certain legal entities and their consolidation in the financial statements. The amendments modify the evaluation process to assess whether limited partnerships and similar legal entities are variable interest entities or voting interest entities, eliminate the presumption that a general partner should consolidate a limited partnership, affect the consolidation analysis of entities that are involved in variable interest entities, particularly those that have fee arrangements and related party relationships and provides a scope exception for reporting entities with legal interests that are required to comply with or operate in accordance with requirements that are similar to those in Rule 2a-7 of the Investment Company Act of 1940 for registered money market funds. The update is effective for interim and annual periods after December 15, 2015. The adoption of the update to existing standards is not expected to have a significant impact to the Company’s consolidated financial statements. In September 2015, the Financial Accounting Standards Board issued Accounting Standards Update No. 2015-16 to ASC 805, “Business Combinations.” The update amends existing standards regarding the methodology used to recognize adjustments related to provisional amounts that are identified during the measurement period of a business combination. The update requires that adjustments to provisional amou

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2015
Investment Securities
Investment Securities	(2) Investment Securities The amortized cost and estimated fair value by type of investment security at December 31, 2015 are as follows: Held to Maturity Gross Gross Amortized unrealized unrealized Estimated Carrying cost gains losses fair value value (Dollars in Thousands) Other securities $ $ — $ — $ $ Total investment securities $ $ — $ — $ $ Available for Sale Gross Gross Amortized unrealized unrealized Estimated Carrying cost gains losses fair value value (1) (Dollars in Thousands) Residential mortgage-backed securities $ $ $ $ $ Obligations of states and political subdivisions Equity securities Total investment securities $ $ $ $ $ (1) Included in the carrying value of residential mortgage ‑ backed securities are $1,147,143 of mortgage ‑backed securities issued by Ginnie Mae, $2,724,83 9 of mortgage ‑backed securities issued by Fannie Mae and Freddie Mac and $21,229 issued by non ‑government entities The amortized cost and estimated fair value of investment securities at December 31, 2015, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties. Held to Maturity Available for Sale Amortized Estimated Amortized Estimated Cost fair value Cost fair value (Dollars in Thousands) Due in one year or less $ $ $ — $ — Due after one year through five years — — Due after five years through ten years — — — — Due after ten years — — Residential mortgage-backed securities — — Equity securities — — Total investment securities $ $ $ $ The amortized cost and estimated fair value by type of investment security at December 31, 2014 are as follows: Held to Maturity Gross Gross Amortized unrealized unrealized Estimated Carrying cost gains losses fair value value (Dollars in Thousands) Other securities $ $ — $ — $ $ Total investment securities $ $ — $ — $ $ Available for Sale Gross Gross Estimated Amortized unrealized unrealized fair Carrying cost gains losses value value (1) (Dollars in Thousands) Residential mortgage-backed securities $ $ $ $ $ Obligations of states and political subdivisions Equity securities Total investment securities $ $ $ $ $ (1) Included in the carrying value of residential mortgage ‑ backed securities are $1,503,774 of mortgage ‑backed securities issued by Ginnie Mae, $3,072,535 of mortgage ‑backed securities issued by Fannie Mae and Freddie Mac and $24,063 issued by non ‑government entities Residential mortgage ‑backed securities are securities issued by Freddie Mac, Fannie Mae, Ginnie Mae or non ‑government entities. Investments in residential mortgage ‑backed securities issued by Ginnie Mae are fully guaranteed by the U.S. government. Investments in mortgage ‑backed securities issued by Freddie Mac and Fannie Mae are not fully guaranteed by the U.S. government, however, the Company believes that the quality of the bonds is similar to other AAA rated bonds with limited credit risk, particularly given the placement of Fannie Mae and Freddie Mac into conservatorship by the federal government in early September 2008 and because securities issued by others that are collateralized by residential mortgage ‑backed securities issued by Fannie Mae and Freddie Mac are rated consistently as AAA rated securities. The amortized cost and fair value of available for sale investment securities pledged to qualify for fiduciary powers, to secure public monies as required by law, repurchase agreements and short ‑term fixed borrowings was $1,908,680,000 and $1,903,734,000 , respectively, at December 31, 2015. Proceeds from the sale and call of securities available ‑for ‑sale were $164,163,000 , $621,588,000 and $178,123,000 during 2015, 2014 and 2013, respectively, which amounts included $128,444,000 , $620,933,000 and $177,623,000 of mortgage ‑backed securities. Gross gains of $2,450,000 , $9,479,000 and $9,601,000 and gross losses of $6,132,000 , $8,196,000 and $0 were realized on the sales in 2015, 2014 and 2013, respectively. Gross unrealized losses on investment securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at December 31, 2015 were as follows: Less than 12 months 12 months or more Total Unrealized Unrealized Unrealized Fair Value Losses Fair Value Losses Fair Value Losses (Dollars in Thousands) Available for sale: Residential mortgage-backed securities $ $ $ $ $ $ Obligations of states and political subdivisions Equity securities $ $ $ $ $ $ Gross unrealized losses on investment securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous loss position, at December 31, 2014 were as follows: Less than 12 months 12 months or more Total Unrealized Unrealized Unrealized Fair Value Losses Fair Value Losses Fair Value Losses (Dollars in Thousands) Available for sale: Residential mortgage-backed securities $ $ $ $ $ $ Obligations of states and political subdivisions Equity securities $ $ $ $ $ $ The unrealized losses on investments in residential mortgage ‑backed securities are primarily caused by changes in market interest rates. Residential mortgage ‑backed securities are primarily securities issued by Freddie Mac, Fannie Mae and Ginnie Mae. The contractual cash obligations of the securities issued by Ginnie Mae are fully guaranteed by the U.S. government. The contractual cash obligations of the securities issued by Freddie Mac and Fannie Mae are not fully guaranteed by the U.S. government; however, the Company believes that the quality of the bonds is similar to other AAA rated bonds with limited credit risk, particularly given the placement of Fannie Mae and Freddie Mac into conservatorship by the federal government in early September 2008 and because securities issued by others that are collateralized by residential mortgage ‑backed securities issued by Fannie Mae and Freddie Mac are rated consistently as AAA rated securities. The decrease in fair value on residential mortgage ‑backed securities issued by Freddie Mac, Fannie Mae and Ginnie Mae is due to market interest rates. The Company has no intent to sell and will more than likely not be required to sell before a market price recovery or maturity of the securities; therefore, it is the conclusion of the Company that the investments in residential mortgage ‑backed securities issued by Freddie Mac, Fannie Mae and Ginnie Mae are not considered other ‑than ‑temporarily impaired. In addition, the Company has a small investment in non ‑agency residential mortgage ‑backed securities that have strong credit backgrounds and include additional credit enhancements to protect the Company from losses arising from high foreclosure rates. These securities have additional market volatility beyond economically induced interest rate events. It is the conclusion of the Company that the investments in non ‑agency residential mortgage ‑backed securities are other ‑than ‑temporarily impaired due to both credit and other than credit issues. An impairment charge of $954,000 ( $620,100 , after tax), was recorded in 2015 on the non ‑agency residential mortgage backed securities. Impairment charges of $817,000 ( $531,050 , after tax) and $1,374,000 ( $893,100 , after tax) were recorded in 2014 and 2013, respectively on the non ‑agency residential mortgage backed securities. The impairment charges represent the credit related impairment on the securities. The unrealized losses on investments in other securities are caused by fluctuations in market interest rates. The underlying cash obligations of the securities are guaranteed by the entity underwriting the debt instrument. It is the belief of the Company that the entity issuing the debt will honor its interest payment schedule, as well as the full debt at maturity. The securities are purchased by the Company for their economic value. The decrease in fair value is primarily due to market interest rates and not other factors, and because the Company has no intent to sell and will more than likely not be required to sell before a market price recovery or maturity of the securities, it is the conclusion of the Company that the investments are not considered other ‑than ‑temporarily impaired. The following table presents a reconciliation of credit ‑related impairment charges on available ‑for ‑sale investments recognized in earnings for the twelve months ended December 31, 2015 (in Thousands): Balance at December 31, 2014 $ Impairment charges recognized during period Balance at December 31, 2015 $ The following table presents a reconciliation of credit ‑related impairment charges on available ‑for ‑sale investments recognized in earnings for the twelve months ended December 31, 2014 (in Thousands): Balance at December 31, 2013 $ Impairment charges recognized during period Balance at December 31, 2014 $ The following table presents a reconciliation of credit ‑related impairment charges on available ‑for ‑sale investments recognized in earnings for the twelve months ended December 31, 2013 (in Thousands): Balance at December 31, 2012 $ Impairment charges recognized during period Balance at December 31, 2013 $

Loans

Loans	12 Months Ended
	Dec. 31, 2015
Loans
Loans	(3) Loans A summary of loans, by loan type at December 31, 2015 and 2014 is as follows: December 31, December 31, 2015 2014 (Dollars in Thousands) Commercial, financial and agricultural $ $ Real estate - mortgage Real estate - construction Consumer Foreign Total loans $ $

Allowance for Probable Loan Los

Allowance for Probable Loan Losses	12 Months Ended
	Dec. 31, 2015
Allowance for Probable Loan Losses
Allowance for Probable Loan Losses	(4) Allowance for Probable Loan Losses The allowance for probable loan losses primarily consists of the aggregate loan loss allowances of the bank subsidiaries. The allowances are established through charges to operations in the form of provisions for probable loan losses. Loan losses or recoveries are charged or credited directly to the allowances. The allowance for probable loan losses of each bank subsidiary is maintained at a level considered appropriate by management, based on estimated probable losses in the loan portfolio. The allowance for probable loan losses is derived from the following elements: (i) allowances established on specific impaired loans, which are based on a review of the individual characteristics of each loan, including the customer’s ability to repay the loan, the underlying collateral values, and the industry in which the customer operates, (ii) allowances based on actual historical loss experience for similar types of loans in the Company’s loan portfolio, and (iii) allowances based on general economic conditions, changes in the mix of loans, company resources, border risk and credit quality indicators, among other things. All segments of the loan portfolio continue to be impacted by the prolonged economic downturn. Loans secured by real estate could be impacted negatively by the continued economic environment and resulting decrease in collateral values. Consumer loans may be impacted by continued and prolonged unemployment rates. The Company’s management continually reviews the allowance for loan losses of the bank subsidiaries using the amounts determined from the allowances established on specific impaired loans, the allowance established on quantitative historical loss percentages, and the allowance based on qualitative data to establish an appropriate amount to maintain in the Company’s allowance for loan losses. Should any of the factors considered by management in evaluating the adequacy of the allowance for probable loan losses change, the Company’s estimate of probable loan losses could also change, which could affect the level of future provisions for probable loan losses. While the calculation of the allowance for probable loan losses utilizes management’s best judgment and all information available, the adequacy of the allowance is dependent on a variety of factors beyond the Company’s control, including, among other things, the performance of the entire loan portfolio, the economy, changes in interest rates and the view of regulatory authorities towards loan classifications. The loan loss provision is determined using the following methods. On a weekly basis, loan past due reports are reviewed by the credit quality committee to determine if a loan has any potential problems and if a loan should be placed on the Company’s internal classified report. Additionally, the Company’s credit department reviews the majority of the Company’s loans for proper internal classification purposes regardless of whether they are past due and segregates any loans with potential problems for further review. The credit department will discuss the potential problem loans with the servicing loan officers to determine any relevant issues that were not discovered in the evaluation. Also, an analysis of loans that is provided through examinations by regulatory authorities is considered in the review process. After the above analysis is completed, the Company will determine if a loan should be placed on an internal classified report because of issues related to the analysis of the credit, credit documents, collateral and/or payment history. While the Texas and Oklahoma economies are performing better than other parts of the country, Texas and Oklahoma are not completely immune to the problems associated with the U.S. economy. The increase in income and capital gains taxes on certain individuals, the increase in payroll taxes, the substantial decrease in oil and gas prices, and the unprecedented debt and deficit of the United States not yet resolved, adds uncertainty to the possibility of robust economic growth and may create an adverse effect on the economies of Texas and Oklahoma. Thus, the risk of loss associated with all segments of the loan portfolio in these markets continues to be impacted by the prolonged economic uncertainty. Economic risk factors are minimized by the underwriting standards of the bank subsidiaries. The general underwriting standards encompass the following principles: (i) the financial strength of the borrower including strong earnings, a high net worth, significant liquidity and an acceptable debt to worth ratio, (ii) managerial and business competence, (iii) the ability to repay, (iv) for a new business, projected cash flows, (v) loan to value, (vi) in the case of a secondary guarantor, a guarantor financial statement, and (vii) financial and/or other character references. Although the underwriting standards reduce the risk of loss, unique risk factors exist in each type of loan in which the bank subsidiaries invest. Commercial and industrial loans are mostly secured by the collateral pledged by the borrower that is directly related to the business activities of the company such as accounts receivable and inventory. The ability of the borrower to collect accounts receivable, and to turn inventory into sales are risk factors in the repayment of the loan. Construction and land development loans can carry risk of repayment when projects incur cost overruns, have an increase in the price of building materials, encounter zoning and environmental issues, or encounter other factors that may affect the completion of a project on time and on budget. Additionally, repayment risk may be negatively impacted when the market experiences a deterioration in the value of real estate. Risks specifically related to 1 ‑4 family development loans also include the practice by the mortgage industry of more restrictive underwriting standards, which inhibits the buyer from obtaining long term financing and excessive housing and lot inventory in the market. Commercial real estate loans demonstrate a risk of repayment when market values deteriorate, the business experiences turnover in key management, the business has an inability to attract or keep occupancy levels stable, or when the market experiences an exit of a specific business industry that is significant to the local economy, such as a manufacturing plant. First and second lien residential 1 - 4 family mortgage and consumer loan repayments may be affected by unemployment or underemployment and deteriorating market values of real estate. A summary of the changes in the allowance for probable loan losses by loan class is as follows: December 31, 2015 Domestic Foreign Commercial real estate: other Commercial construction & real estate: Commercial land farmland & real estate: Residential: Residential: Commercial development commercial multifamily first lien junior lien Consumer Foreign Total (Dollars in Thousands) Balance at December 31, $ $ $ $ $ $ $ $ $ Losses charge to allowance — — Recoveries credited to allowance — Net losses charged to allowance — Provision (credit) charged to operations Balance at December 31, $ $ $ $ $ $ $ $ $ December 31, 2014 Domestic Foreign Commercial real estate: other Commercial construction & real estate: Commercial land farmland & real estate: Residential: Residential: Commercial development commercial multifamily first lien junior lien Consumer Foreign Total (Dollars in Thousands) Balance at December 31, $ $ $ $ $ $ $ $ $ Losses charge to allowance — Recoveries credited to allowance — Net losses charged to allowance — Provision (credit) charged to operations Balance at December 31, $ $ $ $ $ $ $ $ $ December 31, 2013 Domestic Foreign Commercial real estate: other Commercial construction & real estate: Commercial land farmland & real estate: Residential: Residential: Commercial development commercial multifamily first lien junior lien Consumer Foreign Total (Dollars in Thousands) Balance at December 31, $ $ $ $ $ $ $ $ $ Losses charge to allowance Recoveries credited to allowance — Net losses charged to allowance Provision (credit) charged to operations Balance at December 31, $ $ $ $ $ $ $ $ $ The allowance for probable loan losses is a reserve established through a provision for probable loan losses charged to expense, which represents management’s best estimate of probable loan losses when evaluating loans (i) individually or (ii) collectively. The Company’s allowance for probable loan losses decreased for the year ended December 31, 2014 mainly due to a charge down of a relationship that is mainly secured by multiple pieces of transportation equipment. The relationship also contributed to the increase in net losses charged against the allowance for probable loan losses The table below provides additional information on the balance of loans individually or collectively evaluated for impairment and their related allowance, by loan class: December 31, 2015 Loans individually Loans collectively evaluated for evaluated for impairment impairment Recorded Recorded Investment Allowance Investment Allowance (Dollars in Thousands) Domestic Commercial $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Commercial real estate: multifamily Residential: first lien — Residential: junior lien — Consumer — Foreign — Total $ $ $ $ December 31, 2014 Loans individually Loans collectively evaluated for evaluated for impairment impairment Recorded Recorded Investment Allowance Investment Allowance (Dollars in Thousands) Domestic Commercial $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Commercial real estate: multifamily — Residential: first lien — Residential: junior lien — Consumer — Foreign — — Total $ $ $ $ During the second quarter of 2015, the Company charged down a portion of an impaired loan relationship that is mainly secured by multiple pieces of transportation equipment, the value of which fluctuates due to market factors. The Company also foreclosed upon two other real-estate secured commercial impaired loans. The transactions and their impact to the Company’s loan portfolio, including the allowance for probable loan losses, non-accrual loans and impaired loans with a related allowance for December 31, 2015 compared to December 31, 2014 are illustrated in the various associated tables on the following pages. Loans accounted for on a non ‑accrual basis at December 31, 2015, 2014 and 2013 amounted to $47,685,000 , $63,559,000 and $62,823,000 , respectively. The effect of such non ‑accrual loans reduced interest income by approximately $3,298,000 , $4,013,000 and $4,088,000 for the years ended December 31, 2015, 2014 and 2013, respectively. Amounts received on non ‑accruals are applied, for financial accounting purposes, first to principal and then to interest after all principal has been collected. Accruing loans contractually past due 90 days or more as to principal or interest payments at December 31, 2014, 2013 and 2012 amounted to approximately $11,616,000 , $9,988,000 and $7,197,000 , respectively. The table below provides additional information on loans accounted for on a non ‑accrual basis by loan class: 2015 2014 (Dollars in Thousands) Domestic Commercial $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Commercial real estate: multifamily Residential: first lien Residential: junior lien Consumer Foreign — Total non-accrual loans $ $ Impaired loans are those loans where it is probable that all amounts due according to contractual terms of the loan agreement will not be collected. The Company has identified these loans through its normal loan review procedures. Impaired loans are measured based on (1) the present value of expected future cash flows discounted at the loan’s effective interest rate; (2) the loan’s observable market price; or (3) the fair value of the collateral if the loan is collateral dependent. Substantially all of the Company’s impaired loans are measured at the fair value of the collateral. In limited cases the Company may use other methods to determine the level of impairment of a loan if such loan is not collateral dependent. The following tables detail key information regarding the Company’s impaired loans by loan class for the year ended December 31, 2015: December 31, 2015 Unpaid Average Recorded Principal Related Recorded Interest Investment Balance Allowance Investment Recognized (Dollars in Thousands) Loans with Related Allowance Domestic Commercial $ $ $ $ $ — Commercial real estate: other construction & land development — Commercial real estate: farmland & commercial Commercial real estate: multifamily — Total impaired loans with related allowance $ $ $ $ $ December 31, 2015 Unpaid Average Recorded Principal Recorded Interest Investment Balance Investment Recognized (Dollars in Thousands) Loans with No Related Allowance Domestic Commercial $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial — Commercial real estate: multifamily — Residential: first lien Residential: junior lien Consumer Foreign Total impaired loans with no related allowance $ $ $ $ The following tables detail key information regarding the Company’s impaired loans by loan class for the year ended December 31, 2014: December 31, 2014 Unpaid Average Recorded Principal Related Recorded Interest Investment Balance Allowance Investment Recognized (Dollars in Thousands) Loans with Related Allowance Domestic Commercial $ $ $ $ $ — Commercial real estate: other construction & land development — Commercial real estate: farmland & commercial Total impaired loans with related allowance $ $ $ $ $ December 31, 2014 Unpaid Average Recorded Principal Recorded Interest Investment Balance Investment Recognized (Dollars in Thousands) Loans with No Related Allowance Domestic Commercial $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial — Commercial real estate: multifamily — Residential: first lien Residential: junior lien Consumer Foreign — — — — Total impaired loans with no related allowance $ $ $ $ A portion of the impaired loans have adequate collateral and credit enhancements not requiring a related allowance for loan loss. The level of impaired loans is reflective of the economic weakness that has been created by the financial crisis and the subsequent economic downturn. Management is confident the Company’s loss exposure regarding these credits will be significantly reduced due to the Company’s long ‑standing practices that emphasize secured lending with strong collateral positions and guarantor support. Management is likewise confident the reserve for probable loan losses is adequate. Management of the Company recognizes the risks associated with these impaired loans. However, management's decision to place loans in this category does not necessarily mean that losses will occur. In the current environment, troubled loan management can be protracted because of the legal and process problems that delay the collection of an otherwise collectable loan. Additionally, management believes that the collateral related to these impaired loans and/or the secondary support from guarantors mitigates the potential for losses from impaired loans. It is also important to note that even though the economic conditions in Texas and Oklahoma are weakened, we believe these markets continue to improve and continue to be in a position to recover better than many other areas of the country. The following table details loans accounted for as “troubled debt restructuring,” segregated by loan class. Loans accounted for as troubled debt restructuring are included in impaired loans. December 31, 2015 December 31, 2014 (Dollars in Thousands) Domestic Commercial $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Residential: first lien Residential: junior lien Consumer Foreign — Total troubled debt restructuring $ $ The bank subsidiaries charge off that portion of any loan which management considers to represent a loss, as well as that portion of any other loan which is classified as a “loss” by bank examiners. Commercial and industrial or real estate loans are generally considered by management to represent a loss, in whole or part, when an exposure beyond any collateral coverage is apparent and when no further collection of the loss portion is anticipated based on the borrower’s financial condition and general economic conditions in the borrower’s industry. Generally, unsecured consumer loans are charged ‑off when 90 days past due. While management of the Company considers that it is generally able to identify borrowers with financial problems reasonably early and to monitor credit extended to such borrowers carefully, there is no precise method of predicting loan losses. The determination that a loan is likely to be uncollectible and that it should be wholly or partially charged ‑off as a loss is an exercise of judgment. Similarly, the determination of the adequacy of the allowance for probable loan losses can be made only on a subjective basis. It is the judgment of the Company’s management that the allowance for probable loan losses at December 31, 2015 and December 31, 2014, was adequate to absorb probable losses from loans in the portfolio at that date. The following table presents information regarding the aging of past due loans by loan class: December 31, 2015 90 Days or 30 - 59 60 - 89 90 Days or greater & Total Total Days Days Greater still accruing Past due Current Portfolio (Dollars in Thousands) Domestic Commercial $ $ $ $ $ $ $ Commercial real estate: other construction & land development — Commercial real estate: farmland & commercial Commercial real estate: multifamily Residential: first lien Residential: junior lien Consumer Foreign Total past due loans $ $ $ $ $ $ $ December 31, 2014 90 Days or 30 - 59 60 - 89 90 Days or greater & Total Total Days Days Greater still accruing Past due Current Portfolio (Dollars in Thousands) Domestic Commercial $ $ $ $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Commercial real estate: multifamily — Residential: first lien Residential: junior lien Consumer Foreign Total past due loans $ $ $ $ $ $ $ The Company’s internal classified report is segregated into the following categories: (i) “Special Review Credits,” (ii) “Watch List—Pass Credits,” or (iii) “Watch List—Substandard Credits.” The loans placed in the “Special Review Credits” category reflect the Company’s opinion that the loans reflect potential weakness which require monitoring on a more frequent basis. The “Special Review Credits” are reviewed and discussed on a regular basis with the credit department and the lending staff to determine if a change in category is warranted. The loans placed in the “Watch List—Pass Credits” category reflect the Company’s opinion that the credit contains weaknesses which represent a greater degree of risk, which warrant “extra attention.” The “Watch List—Pass Credits” are reviewed and discussed on a regular basis with the credit department and the lending staff to determine if a change in category is warranted. The loans placed in the “Watch List—Substandard Credits” classification are considered to be potentially inadequately protected by the current sound worth and debt service capacity of the borrower or of any pledged collateral. These credit obligations, even if apparently protected by collateral value, have shown defined weaknesses related to adverse financial, managerial, economic, market or political conditions which may jeopardize repayment of principal and interest. Furthermore, there is the possibility that some future loss could be sustained by the Company if such weaknesses are not corrected. For loans that are classified as impaired, management evaluates these credits in accordance with the provision of. ASC 310 ‑10, “Receivables,” and, if deemed necessary, a specific reserve is allocated to the credit. The specific reserve allocated under ASC 310 ‑10, is based on (i) the present value of expected future cash flows discounted at the loan’s effective interest rate; (ii) the loan’s observable market price; or (iii) the fair value of the collateral if the loan is collateral dependent. Substantially all of the Company’s loans evaluated as impaired under ASC 310 ‑10 are measured using the fair value of collateral method. In limited cases, the Company may use other methods to determine the specific reserve of a loan under ASC 310 ‑10 if such loan is not collateral dependent. The allowance based on historical loss experience on the Company’s remaining loan portfolio, which includes the “Special Review Credits,” “Watch List—Pass Credits,” and “Watch List—Substandard Credits” is determined by segregating the remaining loan portfolio into certain categories such as commercial loans, installment loans, international loans, loan concentrations and overdrafts. Installment loans are then further segregated by number of days past due. A historical loss percentage, adjusted for (i) management’s evaluation of changes in lending policies and procedures, (ii) current economic conditions in the market area served by the Company, (iii) other risk factors, (iv) the effectiveness of the internal loan review function, (v) changes in loan portfolios, and (vi) the composition and concentration of credit volume is applied to each category. Each category is then added together to determine the allowance allocated under ASC 450 ‑20. The decrease in Special Review credits for December 31, 2015 compared to December 31, 2014 can be attributed to the reclassification of a commercial loan relationship secured mainly by all assets, including contract rights of the borrower, to the Watch-List Substandard category, offset by the reclassification of a commercial loan relationship that is mainly secured by all assets, including contract rights and oil and gas leases to the Special Review category from the Pass category. The decrease in Watch-List Impaired loans at December 31, 2015 compared to December 31, 2014 can be attributed to the charge down of a loan relationship that is mainly secured by multiple pieces of transportation equipment, the value of which fluctuates due to market factors, and the foreclosure of two other real estate secured commercial impaired loans. The increase in Watch-List Pass loans at December 31, 2015 compared to December 31, 2014 can be attributed to a commercial loan relationship that is mainly secured by all assets, including contract rights and oil and gas leases and a commercial secured by a retail shopping center moved to that category from Pass loans. A summary of the loan portfolio by credit quality indicator by loan class is as follows: December 31, 2015 Special Watch Watch List— Watch List— Pass Review List—Pass Substandard Impaired (Dollars in Thousands) Domestic Commercial $ $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Commercial real estate: multifamily — — Residential: first lien — — Residential: junior lien — — Consumer — — Foreign — — — Total $ $ $ $ $ December 31, 2014 Special Watch Watch List— Watch List— Pass Review List—Pass Substandard Impaired (Dollars in Thousands) Domestic Commercial $ $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Commercial real estate: multifamily — — Residential: first lien — Residential: junior lien — — Consumer — — Foreign — — — — Total $ $ $ $ $

Bank Premises and Equipment

Bank Premises and Equipment	12 Months Ended
	Dec. 31, 2015
Bank Premises and Equipment
Bank Premises and Equipment	(5) Bank Premises and Equipment A summary of bank premises and equipment, by asset classification, at December 31, 2015 and 2014 were as follows: Estimated useful lives 2015 2014 (Dollars in Thousands) Bank buildings and improvements 5 - 40 years $ $ Furniture, equipment and vehicles 1 - 20 years Land Real estate held for future expansion: Land, building, furniture, fixture and equipment 7 - 27 years — — Less: accumulated depreciation Bank premises and equipment, net $ $

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2015
Goodwill and Other Intangible Assets
Goodwill and Other Intangible Assets	(6) Goodwill and Other Intangible Assets The majority of the Company’s identified intangibles are in the form of amortizable core deposit premium. A small portion of the fully amortized identified intangibles represent identified intangibles in the acquisition of the rights to the insurance agency contracts of InsCorp, Inc., acquired in 2008. Information on the Company’s identified intangible assets follows: Carrying Accumulated Amount Amortization Net (Dollars in Thousands) December 31, 2015: Core deposit premium $ $ $ Identified intangible (contract rights) — Total identified intangibles $ $ $ December 31, 2014: Core deposit premium $ $ $ Identified intangible (contract rights) Total identified intangibles $ $ $ Amortization expense of intangible assets for the years ended December 31, 2015, 2014 and 2013, was $644,000 , $2,389,000 and $4,633,000 , respectively. Estimated amortization expense for each of the five succeeding fiscal years, and thereafter, is as follows: Fiscal year ending December 31: Total (in thousands) 2016 2017 2018 — 2019 — 2020 — Thereafter Total $ There were no changes in the carrying amount of goodwill for the years ended December 31, 2015 and 2014.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2015
Deposits.
Deposits	(7) Deposits Deposits as of December 31, 2015 and 2014 and related interest expense for the years ended December 31, 2015, 2014 and 2013 were as follows: 2015 2014 (Dollars in Thousands) Deposits: Demand - non-interest bearing Domestic $ $ Foreign Total demand non-interest bearing Savings and interest bearing demand Domestic Foreign Total savings and interest bearing demand Time, certificates of deposit $100,000 or more Domestic Foreign Less than $100,000 Domestic Foreign Total time, certificates of deposit Total deposits $ $ 2015 2014 2013 (Dollars in Thousands) Interest expense: Savings and interest bearing demand Domestic $ $ $ Foreign Total savings and interest bearing demand Time, certificates of deposit $100,000 or more Domestic Foreign Less than $100,000 Domestic Foreign Total time, certificates of deposit Total interest expense on deposits $ $ $ Scheduled maturities of time deposits as of December 31, 2015 were as follows: Total (in thousands) 2016 $ 2017 2018 2019 2020 Thereafter Total $ Scheduled maturities of time deposits in amounts of $100,000 or more at December 31, 2015, were as follows: Total (in thousands) Due within 3 months or less $ Due after 3 months and within 6 months Due after 6 months and within 12 months Due after 12 months $ Time deposits that meet or exceed the FDIC insurance limit of $250,000 at December 31, 2015 and December 31, 2014 were $1,021,000 and $1,027,000 , respectively.

Securities Sold Under Repurchas

Securities Sold Under Repurchase Agreements	12 Months Ended
	Dec. 31, 2015
Securities Sold Under Repurchase Agreements
Securities Sold Under Repurchase Agreements	(8) Securities Sold Under Repurchase Agreements The Company’s bank subsidiaries have entered into repurchase agreements with an investment banking firm and individual customers of the bank subsidiaries. The purchasers have agreed to resell to the bank subsidiaries identical securities upon the maturities of the agreements. Securities sold under repurchase agreements were mortgage ‑backed book entry securities and averaged $872,611,000 and $893,830,000 during 2015 and 2014, respectively, and the maximum amount outstanding at any month end during 2015 and 2014 was $907,211,000 and $892,341,000 respectively. Further information related to repurchase agreements at December 31, 2015 and 2014 is set forth in the following table: Collateral Securities Repurchase Borrowing Book Value of Fair Value of Balance of Weighted Average Securities Sold Securities Sold Liability Interest Rate (Dollars in Thousands) December 31, 2015 term: Overnight agreements $ $ $ % 1 to 29 days 30 to 90 days Over 90 days Total $ $ $ % December 31, 2014 term: Overnight agreements $ $ $ % 1 to 29 days 30 to 90 days Over 90 days Total $ $ $ % The book value and fair value of securities sold includes the entire book value and fair value of securities partially or fully pledged under repurchase agreements.

Other Borrowed Funds

Other Borrowed Funds	12 Months Ended
	Dec. 31, 2015
Other Borrowed Funds
Other Borrowed Funds	(9) Other Borrowed Funds Other borrowed funds include Federal Home Loan Bank borrowings, which are short and long ‑term fixed borrowings issued by the Federal Home Loan Bank of Dallas at the market price offered at the time of funding. These borrowings are secured by mortgage ‑backed investment securities and a portion of the Company’s loan portfolio. The increase in other borrowed funds is a result of purchases of available ‑for ‑sale securities. Further information regarding the Company’s other borrowed funds at December 31, 2015 and 2014 is set forth in the following table: December 31, 2015 2014 (Dollars in Thousands) Federal Home Loan Bank advances—short-term Balance at year end $ $ Rate on balance outstanding at year end % % Average daily balance $ $ Average rate % % Maximum amount outstanding at any month end $ $ Federal Home Loan Bank advances—long-term(1) Balance at year end $ $ Rate on balance outstanding at year end % % Average daily balance $ $ Average rate % % Maximum amount outstanding at any month end $ $ (1) The long ‑term advances are not amortizable and consist of two advances in the amount of $75,000,000 each. The advances mature on January 13, 2017 and January 25, 2017 , respectively.

Junior Subordinated Deferrable

Junior Subordinated Deferrable Interest Debentures	12 Months Ended
	Dec. 31, 2015
Junior Subordinated Interest Deferrable Debentures
Junior Subordinated Interest Deferrable Debentures	(10) Junior Subordinated Deferrable Interest Debentures The Company has formed six statutory business trusts under the laws of the State of Delaware, for the purpose of issuing trust preferred securities. The statutory business trusts formed by the Company (the “Trusts”) have each issued Capital and Common Securities and invested the proceeds thereof in an equivalent amount of junior subordinated debentures (the “Debentures”) issued by the Company. As of December 31, 2015 and December 31, 2014, the principal amount of debentures outstanding totaled $161,416,000 and $ 175,416,000 , respectively. On February 11, 2014, the Company bought back all of the Capital and Common Securities of IB Capital Trust VII from the holder of the securities for a price that reflected an approximate six percent discount from the redemption price of the securities and thereby retired the $10,310,000 of related Junior Subordinated Deferrable Interest Debentures related to IB Capital Trust VII. On December 24, 2014, the Company bought back a portion of the Capital Securities of IB Capital Trust XI from the holder of the securities for a price that reflected an approximate 23.6% discount from the redemption price of the securities and thereby retired $5,000,000 of the tota l $32,900,00 0 of related Junior Subordinated Deferrable Interest Debentures related to IB Capital Trust XI. On July 29, 2015, the Company bought back a portion of the Capital securities of IBC Capital Trusts X and XI from the holder of the securities for a price that reflected an approximate 24.5% discount from the redemption price of the securities. The Company thereby retired $13,000,000 of the total $34,021,000 of related Junior Subordinated Deferrable Interest Debentures related to IBC Capital Trust X and $1,000,000 of the total $27,900,000 of related Junior Subordinated Deferrable Interest Debentures related to IB Capital Trust XI. The discounts recorded in connection with the repurchases of the outstanding Capital Securities are included in other income on the consolidated financial statements. The Debentures are subordinated and junior in right of payment to all present and future senior indebtedness (as defined in the respective indentures) of the Company, and are pari passu with one another. The interest rate payable on, and the payment terms of the Debentures are the same as the distribution rate and payment terms of the respective issues of Capital and Common Securities issued by the Trusts. The Company has fully and unconditionally guaranteed the obligations of each of the Trusts with respect to the Capital and Common Securities. The Company has the right, unless an Event of Default (as defined in the Indentures) has occurred and is continuing, to defer payment of interest on the Debentures for up to twenty consecutive quarterly periods on Trusts VI, VIII, IX, X, XI and XII. If interest payments on any of the Debentures are deferred, distributions on both the Capital and Common Securities related to that Debenture would also be deferred. The redemption prior to maturity of any of the Debentures may require the prior approval of the Federal Reserve and/or other regulatory bodies. For financial reporting purposes, the Trusts are treated as investments of the Company and not consolidated in the consolidated financial statements. Although the Capital Securities issued by each of the Trusts are not included as a component of shareholders’ equity on the consolidated statement of condition, the Capital Securities are treated as capital for regulatory purposes. Specifically, under applicable regulatory guidelines, the Capital Securities issued by the Trusts qualify as Tier 1 capital up to a maximum of 25% of Tier 1 capital on an aggregate basis. Any amount that exceeds the 25% threshold would qualify as Tier 2 capital. At December 31, 2015 and December 31, 2014, the total $161,416,000 and $175,416,000 , respectively, of the Capital Securities outstanding qualified as Tier 1 capital. The following table illustrates key information about each of the Debentures and their interest rates at December 31, 2015: Junior Subordinated Deferrable Interest Repricing Interest Interest Optional Debentures Frequency Rate Rate Index(1) Maturity Date Redemption Date (1) (in thousands) Trust VI $ Quarterly % LIBOR + 3.45 November 2032 February 2008 Trust VIII Quarterly % LIBOR + 3.05 October 2033 October 2008 Trust IX Quarterly % LIBOR + 1.62 October 2036 October 2011 Trust X Quarterly % LIBOR + 1.65 February 2037 February 2012 Trust XI Quarterly % LIBOR + 1.62 July 2037 July 2012 Trust XII Quarterly % LIBOR + 1.45 September 2037 September 2012 $ (1) The Capital Securities may be redeemed in whole or in part on any interest payment date after the Optional Redemption Date.

Earnings per Share ("EPS")

Earnings per Share ("EPS")	12 Months Ended
	Dec. 31, 2015
Earnings per Share ("EPS")
Earnings per Share ("EPS")	(11) Earnings per Share (“EPS”) Basic EPS is calculated by dividing net income by the weighted average number of common shares outstanding. The computation of diluted EPS assumes the issuance of common shares for all dilutive potential common shares outstanding during the reporting period. The calculation of the basic EPS and the diluted EPS for the years ended December 31, 2015, 2014, and 2013 is set forth in the following table: Net Income Shares Per Share (Numerator) (Denominator) Amount (Dollars in Thousands, Except Per Share Amounts) December 31, 2015: Basic EPS Net income available to common shareholders $ $ Potential dilutive common shares and warrants — Diluted EPS $ $ December 31, 2014: Basic EPS Net income available to common shareholders $ $ Potential dilutive common shares — Diluted EPS $ $ December 31, 2013: Basic EPS Net income available to common shareholders $ $ Potential dilutive common shares — Diluted EPS $ $

Employees' Profit Sharing Plan

Employees' Profit Sharing Plan	12 Months Ended
	Dec. 31, 2015
Employees' Profit Sharing Plan
Employees' Profit Sharing Plan	(12) Employees’ Profit Sharing Plan The Company has a deferred profit sharing plan for full ‑time employees with a minimum of one year of continuous employment. The Company’s annual contribution to the plan is based on a percentage, as determined by the Board of Directors, of income before income taxes, as defined, for the year. Allocation of the contribution among officers and employees’ accounts is based on length of service and amount of salary earned. Profit sharing costs of $3,525,000 , $3,510,000 and $3,500,000 were charged to income for the years ended December 31, 2015, 2014, and 2013, respectively.

International Operations

International Operations	12 Months Ended
	Dec. 31, 2015
International Operations
International Operations	(13) International Operations The Company provides international banking services for its customers through its bank subsidiaries. Neither the Company nor its bank subsidiaries have facilities located outside the United States. International operations are distinguished from domestic operations based upon the domicile of the customer. Because the resources employed by the Company are common to both international and domestic operations, it is not practical to determine net income generated exclusively from international activities. A summary of assets attributable to international operations at December 31, 2015 and 2014 are as follows: 2015 2014 (Dollars in Thousands) Loans: Commercial $ $ Others Less allowance for probable loan losses Net loans $ $ Accrued interest receivable $ $ At December 31, 2015, the Company had $116,905,000 in outstanding standby and commercial letters of credit to facilitate trade activities. Revenues directly attributable to international operations were approximately $6,113,000 , $6,034,000 and $6,085,000 for the years ended December 31, 2015, 2014 and 2013, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Taxes
Income Taxes	(14) Income Taxes The Company files a consolidated U.S. Federal and State income tax return. The current and deferred portions of net income tax expense included in the consolidated statements of income are presented below for the years ended December 31: 2015 2014 2013 (Dollars in Thousands) Current U.S. $ $ $ State Foreign Total current taxes Deferred U.S. State Total deferred taxes Total income taxes $ $ $ Total income tax expense differs from the amount computed by applying the U.S. Federal income tax rate of 35% for 2015, 2014 and 2013 to income before income taxes. The reasons for the differences for the years ended December 31 are as follows: 2015 2014 2013 (Dollars in Thousands) Computed expected tax expense $ $ $ Change in taxes resulting from: Tax-exempt interest income State tax, net of federal income taxes and tax credit Tax refunds — — Other investment income Other Actual tax expense $ $ $ The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities at December 31, 2015 and 2014 are reflected below: 2015 2014 (Dollars in Thousands) Deferred tax assets: Loans receivable, principally due to the allowance for probable loan losses $ $ Other real estate owned Impairment charges on available-for-sale securities Accrued expenses Other Total deferred tax assets Deferred tax liabilities: Bank premises and equipment, principally due to differences on depreciation Net unrealized gains on available for sale investment securities Identified intangible assets and goodwill Other Total deferred tax liabilities Net deferred tax asset (liability) $ $ The net deferred tax liability of $10,285,000 at December 31, 2015 and $15,589,000 at December 31, 2014 is included in other liabilities in the consolidated statements of condition .

Stock Options

Stock Options	12 Months Ended
	Dec. 31, 2015
Stock Options
Stock Options	(15) Stock Options On April 5, 2012, the Board of Directors adopted the 2012 International Bancshares Corporation Stock Option Plan (the “2012 Plan”). There are 800,000 shares available for stock option grants under the 2012 Plan. Under the 2012 Plan, both qualified incentive stock options (“ISOs”) and non ‑qualified stock options (“NQSOs”) may be granted. Options granted may be exercisable for a period of up to 10 years from the date of grant, excluding ISOs granted to 10% shareholders, which may be exercisable for a period of up to only five years. As of December 31, 2015, 178,250 shares were available for future grants under the 2012 Plan. The fair value of each option award granted under the plan is estimated on the date of grant using a Black ‑Scholes ‑Merton option valuation model that uses the assumptions noted in the following table. Expected volatility is based on the historical volatility of the price of the Company’s stock. The Company uses historical data to estimate the expected dividend yield and employee termination rates within the valuation model. The expected term of options is derived from historical exercise behavior. The risk ‑free 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. 2015 2014 Expected Life (Years) Dividend yield % % Interest rate % % Volatility % % A summary of option activity under the stock option plans for the twelve months ended December 31, 2015 is as follows: Weighted Weighted average average remaining Aggregate Number of exercise contractual intrinsic options price term (years) value ($) (in Thousands) Options outstanding at December 31, 2014 $ Plus: Options granted Less: Options exercised Options expired Options forfeited Options outstanding at December 31, 2015 $ Options fully vested and exercisable at December 31, 2015 $ $ Stock ‑based compensation expense included in the consolidated statements of income for the years ended December 31, 2015, 2014 and 2013 was approximately $1,172,000 , $1,058,000 and $414,000 , respectively. As of December 31, 2015, there was approximately $3,334,000 of total unrecognized stock ‑based compensation cost related to non ‑vested options granted under the Company plans that will be recognized over a weighted average period of 2.0 years. Other information pertaining to option activity during the twelve month period ending December 31, 2015, 2014 and 2013 is as follows: Twelve Months Ended December 31, 2015 2014 2013 Weighted average grant date fair value of stock options granted $ $ $ Total fair value of stock options vested $ $ $ Total intrinsic value of stock options exercised $ $ $

Long Term Restricted Stock Unit

Long Term Restricted Stock Units	12 Months Ended
	Dec. 31, 2015
Long Term Restricted Stock Units
Long Term Restricted Stock Units	(16) Long Term Restricted Stock Units As a participant in the Troubled Asset Relief Program Capital Purchase Program (the “CPP”) until November 28, 2012, the Company was subject to certain compensation restrictions, which included a prohibition on the payment or accrual of any bonuses (including equity ‑based incentive compensation) to certain officers and employees except for awards of CPP ‑compliant long ‑ term restricted stock and stock units. On December 18, 2009, the Company’s board of directors (the “Board”) adopted the 2009 International Bancshares Corporation Long ‑Term Restricted Stock Unit Plan (the “Plan”) to give the Company additional flexibility in the compensation of its officers, employees, consultants and advisors in compliance with all applicable laws and restrictions. The Plan authorizes the Company to issue Restricted Stock Units (“RSUs”) to officers, employees, consultants and advisors of the Company and its subsidiaries. The Plan provides that RSUs shall be issued by a committee of the Board appointed by the Board from time to time consisting of at least two (2) members of the Board, each of whom is both a non ‑employee director and an outside director. On December 18, 2009, the Board adopted resolutions creating the Long ‑Term Restricted Stock Unit Plan Committee to administer the Plan. RSUs issued under the Plan are not equity and are payable only in cash. The Plan provides for both the issuance of CPP ‑compliant long ‑term RSUs as well as RSUs that are not CPP ‑compliant. Dennis E. Nixon, the Company’s President, Chairman of the Board and a director of the Company, was awarded CPP ‑compliant RSU’s granted as of December 19, 2012, December 16, 2011, December 15, 2010 and December 18, 2009 of $425,000 , $400,000 , $400,000 and $250,000 for his performance in 2012, 2011, 2010 and 2009, respectively. In order to meet the requirements of a CPP ‑compliant RSU, Mr. Nixon’s RSUs do not exceed one ‑third of his total annual compensation in the respective year. Mr. Nixon’s 2009 and 2010 RSU’s vested and were paid in December 2012 in the respective cash amounts of $262,842 and $358,782 . The 2011 RSU vested and was paid in December 2013 in the cash amount of $591,344 . The 2012 RSU vested and was paid in December 2014 in the cash amount of $572,746 .

Commitments, Contingent Liabili

Commitments, Contingent Liabilities and Other Matters	12 Months Ended
	Dec. 31, 2015
Commitments, Contingent Liabilities and Other Matters
Commitments, Contingent Liabilities and Other Matters	(17) Commitments, Contingent Liabilities and Other Matters The Company leases portions of its banking premises and equipment under operating leases. Total rental expense for the years ended December 31, 2015, 2014 and 2013 were approximately $6,200,000 , $7,200,000 and $7,300,000 , respectively. Future minimum lease payments due under non ‑cancellable operating leases at December 31, 2015 were as follows: Fiscal year ending: Total (in thousands) 2016 $ 2017 2018 2019 2020 Thereafter Total $ It is expected that certain leases will be renewed, as these leases expire. Aggregate future minimum rentals to be received under non ‑cancellable sub ‑leases greater than one year at December 31, 2015 were $107,193,000 . Cash of approximately $104,684,000 and $106,841,000 at December 31, 2015 and 2014, respectively, was maintained to satisfy regulatory reserve requirements. The Company is involved in various legal proceedings that are in various stages of litigation. Some of these actions allege “lender liability” claims on a variety of theories and claim substantial actual and punitive damages. The Company has determined, based on discussions with its counsel that any material loss in such actions, individually or in the aggregate, is remote or the damages sought, even if fully recovered, would not be considered material to the consolidated statements of condition and related statements of income, comprehensive income, shareholders’ equity and cash flows of the Company. However, many of these matters are in various stages of proceedings and further developments could cause management to revise its assessment of these matters.

Transactions with Related Parti

Transactions with Related Parties	12 Months Ended
	Dec. 31, 2015
Transactions with Related Parties
Transactions with Related Parties	(18) Transactions with Related Parties In the ordinary course of business, the subsidiaries of the Company make loans to directors and executive officers of the Corporation, including their affiliates, families and companies in which they are principal owners. In the opinion of management, these loans are made on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with other persons and do not involve more than normal risk of collectability or present other unfavorable features. The aggregate amounts receivable from such related parties amounted to approximately $31,975,000 and $26,382,000 at December 31, 2015 and 2014, respectively.

Financial Instruments with Off-

Financial Instruments with Off-Statement of Condition Risk and Concentrations of Credit Risk	12 Months Ended
	Dec. 31, 2015
Financial Instruments with Off-Statement of Condition Risk and Concentrations of Credit Risk
Financial Instruments with Off-Statement of Condition Risk and Concentrations of Credit Risk	(19) Financial Instruments with Off ‑Statement of Condition Risk and Concentrations of Credit Risk In the normal course of business, the bank subsidiaries are party to financial instruments with off ‑statement of condition risk to meet the financing needs of their customers. These financial instruments include commitments to their customers. These financial instruments involve, to varying degrees, elements of credit risk in excess of the amounts recognized in the consolidated statement of condition. The contract amounts of these instruments reflect the extent of involvement the bank subsidiaries have in particular classes of financial instruments. At December 31, 2015, the following financial amounts of instruments, whose contract amounts represent credit risks, were outstanding: Commitments to extend credit $ Credit card lines Standby letters of credit Commercial letters of credit The Company enters into a standby letter of credit to guarantee performance of a customer to a third party. These guarantees are primarily issued to support public and private borrowing arrangements. The credit risk involved is represented by the contractual amounts of those instruments. Under the standby letters of credit, the Company is required to make payments to the beneficiary of the letters of credit upon request by the beneficiary so long as all performance criteria have been met. At December 31, 2015, the maximum potential amount of future payments is approximately $111,347,000 . At December 31, 2015, the fair value of these guarantees is not significant. Unsecured letters of credit totaled approximately $37,454,000 and $40,875,000 at December 31, 2015 and 2014, respectively. The Company enters into commercial letters of credit on behalf of its customers which authorize a third party to draw drafts on the Company up to a stipulated amount and with specific terms and conditions. A commercial letter of credit is a conditional commitment on the part of the Company to provide payment on drafts drawn in accordance with the terms of the commercial letter of credit. The bank subsidiaries’ exposure to credit loss in the event of nonperformance by the other party to the above financial instruments is represented by the contractual amounts of the instruments. The bank subsidiaries use the same credit policies in making commitments and conditional obligations as they do for on ‑statement of condition instruments. The bank subsidiaries control the credit risk of these transactions through credit approvals, limits and monitoring procedures. Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates normally less than one year or other termination clauses and may require the payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The bank subsidiaries evaluate each customer’s credit ‑worthiness on a case ‑by ‑case basis. The amount of collateral obtained, if deemed necessary by the subsidiary banks upon extension of credit, is based on management’s credit evaluation of the customer. Collateral held varies, but may include residential and commercial real estate, bank certificates of deposit, accounts receivable and inventory. The bank subsidiaries make commercial, real estate and consumer loans to customers principally located in South, Central and Southeast Texas and the State of Oklahoma. Although the loan portfolio is diversified, a substantial portion of its debtors’ ability to honor their contracts is dependent upon the economic conditions in these areas, especially in the real estate and commercial business sectors.

Capital Requirements

Capital Requirements	12 Months Ended
	Dec. 31, 2015
Capital Requirements
Capital Requirements	(20) Capital Requirements On December 23, 3008, as part of the Troubled Asset Relief Program Capital Purchase Program (the “TARP Capital Purchase Program”) of the United States Department of the Treasury (“Treasury”), the Company issued to the Treasury, in exchange for aggregate consideration of $216 million, (i) 216,000 shares of the Company’s fixed ‑rate cumulative perpetual preferred stock, Series A, par value $.01 per share (the “Senior Preferred Stock”), having a liquidation preference of $1,000 per share and (ii) a warrant to purchase 1,326,238 shares of the Company’s common stock at a price per share of $24.43 and with a term of ten years (the “Warrant”). The Senior Preferred Stock paid a coupon rate of 5% of the first five years and 9% per year thereafter. On November 28, 2012, the Company completed the repurchase of all of the 216,000 shares of the Senior Preferred Stock held by Treasury. The Company commenced the $216 million r epayment during the third quarter of 2012 and completed the final payment in the fourth quarter of 2012. The Company paid a total of $41,520,139 in preferred stock dividends to the U.S. Treasury from December of 2008 to November 28, 2012. On June 12, 2013, the U.S. Treasury sold the Warrant to a third party. As of February 20, 2016, the Warrant is still outstanding. Adjustments to the $24.43 per share Exercise Price of the Warrant will be made if the Company pays cash dividends in excess of 33 cents per semi-annual period or makes certain other shareholder distributions before the Warrants expires on December 23, 2018. Bank regulatory agencies limit the amount of dividends, which the bank subsidiaries can pay the Corporation, through IBC Subsidiary Corporation, without obtaining prior approval from such agencies. At December 31, 2015, the subsidiary banks could pay dividends of up to $776,750,000 to the Corporation without prior regulatory approval and without adversely affecting their “well ‑capitalized” status under regulatory capital rules in effect at December 31, 2015. In addition to legal requirements, regulatory authorities also consider the adequacy of the bank subsidiaries’ total capital in relation to their deposits and other factors. These capital adequacy considerations also limit amounts available for payment of dividends. The Company historically has not allowed any subsidiary bank to pay dividends in such a manner as to impair its capital adequacy. The Company and the bank subsidiaries are subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company’s consolidated financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company must meet specific capital guidelines that involve quantitative measures of the Company’s assets, liabilities, and certain off ‑statement of condition items as calculated under regulatory accounting practices. The Company’s capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings, and other factors. Current quantitative measures established by regulation to ensure capital adequacy require the Company to maintain minimum amounts and ratios (set forth in the table on the following page) of Total and Tier 1 capital to risk ‑weighted assets and of Tier 1 capital to average assets. Management believes, as of December 31, 2015, that the Company and each of the bank subsidiaries met all capital adequacy requirements to which they are subject. In July 2013, the Federal Deposit Insurance Corporation (“FDIC”) and other regulatory bodies established a new, comprehensive capital framework for U.S. banking organizations, consisting of minimum requirements that increase both the quantity and quality of capital held by banking organizations. The final rules are a result of the implementation of the BASEL III capital reforms and various Dodd-Frank Act related capital provisions. Consistent with the Basel international framework, the rules include a new minimum ratio of Common Equity Tier 1 (“CET1”) to risk-weighted assets of 4.5 percent and a CET1 capital conservation buffer of 2.5 percent of risk-weighted assets. The capital conservation buffer began phasing-in on January 1, 2016 at .625% and will increase each year until January 1, 2019, when the Company will be required to have a 2.5% capital conservation buffer, effectively resulting in a minimum ratio of CET1 capital to risk-weighted assets of at least 7% upon full implementation. The rules also raised the minimum ratio of Tier 1 capital to risk-weighted assets from 4% to 6% and include a minimum leverage ratio of 4% for all banking organizations. Regarding the quality of capital, the new rules emphasize CET1 capital and implements strict eligibility criteria for regulatory capital instruments. The new rules also improve the methodology for calculating risk-weighted assets to enhance risk sensitivity. The new rules are subject to a four year phase in period for mandatory compliance and the Company was required to begin to phase in the new rules beginning on January 1, 2015. The CET1 (beginning in 2015), Tier 1 and Total capital ratios are calculated by dividing the respective capital amounts by risk-weighted assets. Risk-weighted assets are calculated based on regulatory requirements and include total assets, excluding goodwill and other intangible assets, allocated by risk weight category, and certain off-balance-sheet items, among other things. The leverage ratio is calculated by dividing Tier 1 capital by adjusted quarterly average total assets, which exclude goodwill and other intangible assets, among other things. The aforementioned capital conservation buffer is designed to absorb losses during periods of economic stress. Banking institutions with a ratio of CET1 capital to risk-weighted assets above the minimum but below the conservation buffer will face constraints on dividends, equity repurchases and compensation based on the amount of the shortfall. As of December 31, 2015, capital levels at the Company exceed all capital adequacy requirements under the Basel III Capital Rules as currently applicable to the Company. Based on the ratios presented below, capital levels as of December 31, 2015 at the Company exceed the minimum levels necessary to be considered “well capitalized.” As of December 31, 2015, the most recent notification from the Federal Deposit Insurance Corporation categorized all the bank subsidiaries as well ‑capitalized under the regulatory framework for prompt corrective action. To be categorized as “well ‑capitalized,” the Company and the bank subsidiaries must maintain minimum Total risk ‑based, Tier 1 risk based, and Tier 1 leverage ratios as set forth in the table. There are no conditions or events since that notification that management believes have changed the categorization of the Company or any of the bank subsidiaries as well ‑capitalized. The Company’s and the bank subsidiaries’ actual capital amounts and ratios for 2015 under current guidelines are presented in the following table: To Be Well-Capitalized For Capital Adequacy Under Prompt Corrective Actual Purposes Action Provisions Amount Ratio Amount Ratio Amount Ratio (greater than (greater than (greater than (greater than or equal to) or equal to) or equal to) or equal to) (Dollars in Thousands) As of December 31, 2015: Common Equity Tier 1 (to Risk Weighted Assets): Consolidated $ % $ % N/A N/A International Bank of Commerce, Laredo $ % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank Total Capital (to Risk Weighted Assets): Consolidated $ % $ % N/A N/A International Bank of Commerce, Laredo $ % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank Tier 1 Capital (to Risk Weighted Assets): Consolidated $ % $ % N/A N/A International Bank of Commerce, Laredo $ % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank Tier 1 Capital (to Average Assets): Consolidated $ % $ % $ N/A N/A International Bank of Commerce, Laredo % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank The Company’s and the bank subsidiaries’ actual capital amounts and ratios for 2014 are also presented in the following table: To Be Well-Capitalized For Capital Adequacy Under Prompt Corrective Actual Purposes Action Provisions Amount Ratio Amount Ratio Amount Ratio (greater than (greater than (greater than (greater than or equal to) or equal to) or equal to) or equal to) (Dollars in Thousands) As of December 31, 2014: Total Capital (to Risk Weighted Assets): Consolidated $ % $ % N/A N/A International Bank of Commerce, Laredo $ % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank Tier 1 Capital (to Risk Weighted Assets): Consolidated $ % $ % N/A N/A International Bank of Commerce, Laredo $ % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank Tier 1 Capital (to Average Assets): Consolidated $ % $ % $ N/A N/A International Bank of Commerce, Laredo % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2015
Fair Value
Fair Value	(21) Fair Value ASC Topic 820,”Fair Value Measurements and Disclosures” (“ASC 820”) defines fair value, establishes a framework for measuring fair value in generally accepted accounting principles, and expands disclosures about fair value measurements. ASC 820 applies to all financial instruments that are being measured and reported on a fair value basis. ASC 820 defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date; it also establishes a fair value hierarchy that prioritizes the inputs used in valuation methodologies into the following three levels: · Level 1 Inputs—Unadjusted quoted prices in active markets for identical assets or liabilities. · Level 2 Inputs—Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. · Level 3 Inputs—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or other valuation techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. A description of the valuation methodologies used for instruments measured at fair value, as well as the general classification of such instruments pursuant to the valuation hierarchy is set forth below. The following table represents financial instruments reported on the consolidated statements of condition at their fair value as of December 31, 2015 by level within the fair value measurement hierarchy. Fair Value Measurements at Reporting Date Using (in thousands) Quoted Prices in Assets/Liabilities Active Significant Measured at Markets for Other Significant Fair Value Identical Observable Unobservable December 31, Assets Inputs Inputs 2015 (Level 1) (Level 2) (Level 3) Measured on a recurring basis: Assets: Available for sale securities Residential mortgage-backed securities $ $ — $ $ States and political subdivisions — — Other — — $ $ $ $ The following table represents financial instruments reported on the consolidated balance sheets at their fair value as of December 31, 2014 by level within the fair value measurement hierarchy. Fair Value Measurements at Reporting Date Using (in thousands) Quoted Prices in Assets/Liabilities Active Significant Measured at Markets for Other Significant Fair Value Identical Observable Unobservable December 31, Assets Inputs Inputs 2014 (Level 1) (Level 2) (Level 3) Measured on a recurring basis: Assets: Available for sale securities Residential mortgage - backed securities $ $ — $ $ States and political subdivisions — — Other — — $ $ $ $ Investment securities available ‑for ‑sale are classified within level 2 and level 3 of the valuation hierarchy, with the exception of certain equity investments that are classified within level 1. For investments classified as level 2 in the fair value hierarchy, the Company obtains fair value measurements for investment securities from an independent pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. Investment securities classified as level 3 are non ‑agency mortgage ‑backed securities. The non ‑agency mortgage ‑backed securities held by the Company are traded in inactive markets and markets that have experienced significant decreases in volume and level of activity, as evidenced by few recent transactions, a significant decline or absence of new issuances, price quotations that are not based on comparable securities transactions and wide bid ‑ask spreads among other factors. As a result of the inability to use quoted market prices to determine fair value for these securities, the Company determined that fair value, as determined by level 3 inputs in the fair value hierarchy, is more appropriate for financial reporting and more consistent with the expected performance of the investments. For the investments classified within level 3 of the fair value hierarchy, the Company used a discounted cash flow model to determine fair value. Inputs in the model included both historical performance and expected future performance based on information currently available. Assumptions used in the discounted cash flow model as of December 31, 2015 and December 31, 2014 were applied separately to those portions of the bond where the underlying residential mortgage loans had been performing under original contract terms for at least the prior 24 months and those where the underlying residential mortgages had not been meeting the original contractual obligation for the same period. Unobservable inputs included in the model are estimates on future principal prepayment rates, and default and loss severity rates. For that portion of the bond where the underlying residential mortgage had been meeting the original contract terms for at least 24 months, the Company used the following estimates in the model: (i) a voluntary prepayment rate of 7% , (ii) a 1% default rate, (iii) a loss severity rate of 25% , and (iv) a discount rate of 13% . The assumptions used in the model for the rest of the bond included the following estimates: (i) a voluntary prepayment rate of 2% , (ii) a default rate of 4.5% , (iii) a loss severity rate that started at 60% for the first year (2012) then declines by 5% for the following five years (2013, 2014, 2015, 2016 and 2017) and remains at 25% thereafter (2018 and beyond), and (iv) a discount rate of 13% . The estimates used in the model to determine fair value are based on observable historical data of the underlying collateral. The model anticipates that the housing market will gradually improve and that the underlying collateral will eventually all perform in accordance with the original contract terms on the bond. Should the number of loans in the underlying collateral that default and go into foreclosure or the severity of the losses in the underlying collateral significantly change, the results of the model would be impacted. The Company will continue to evaluate the actual historical performance of the underlying collateral and will modify the assumptions used in the model as necessary. The following table presents a reconciliation of activity for such mortgage ‑backed securities on a net basis (Dollars in thousands): Balance at December 31, 2014 $ Principal paydowns Total unrealized gains (losses) included in: Other comprehensive income Impairment realized in earnings Balance at December 31, 2015 $ Certain financial instruments are measured at fair value on a nonrecurring basis. They are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment). The following table represents financial instruments measured at fair value on a non ‑recurring basis as of and for the period ended December 31, 2015 by level within the fair value measurement hierarchy: Fair Value Measurements at Reporting Date Using (in thousands) Quoted Assets/Liabilities Prices in Measured at Active Significant Fair Value Markets for Other Significant Net (credit) Year ended Identical Observable Unobservable Provision December 31, Assets Inputs Inputs During 2015 (Level 1) (Level 2) (Level 3) Period Measured on a non-recurring basis: Assets: Impaired loans $ $ — $ — $ $ Other real estate owned — — The following table represents financial instruments measured at fair value on a non ‑recurring basis as of and for the year ended December 31, 2014 by level within the fair value measurement hierarchy: Fair Value Measurements at Reporting Date Using (in thousands) Quoted Assets/Liabilities Prices in Measured at Active Significant Fair Value Markets Other Significant Net (credit) Year ended for Identical Observable Unobservable Provision December 31, Assets Inputs Inputs During 2014 (Level 1) (Level 2) (Level 3) Period Measured on a non-recurring basis: Assets: Impaired loans $ $ — $ — $ $ Other real estate owned — — The Company’s assets measured at fair value on a non-recurring basis are limited to impaired loans and other real estate owned. Impaired loans are classified within level 3 of the valuation hierarchy. The fair value of impaired loans is derived in accordance with FASB ASC 310, “Receivables”. Impaired loans are primarily comprised of collateral-dependent commercial loans. Understanding that as the primary sources of loan repayments decline, the secondary repayment source comes into play and correctly evaluating the fair value of that secondary source, the collateral, becomes even more important. Re-measurement of the impaired loan to fair value is done through a specific valuation allowance included in the allowance for probable loan losses. The fair value of impaired loans is based on the fair value of the collateral, as determined through either an appraisal or evaluation process. The basis for the Company’s appraisal and appraisal review process is based on regulatory guidelines and strives to comply with all regulatory appraisal laws, regulations and the Uniform Standards of Professional Appraisal Practice. All appraisals and evaluations are “as is” (the property’s highest and best use) valuations based on the current conditions of the property/project at that point in time. The determination of the fair value of the collateral is based on the net realizable value, which is the appraised value less any closing costs, when applicable. As of December 31, 2015, the Company had approximately $51,021,000 of impaired commercial collateral dependent loans, of which a pproximately $39,520,000 had an appraisal performed within the immediately preceding twelve months and of which approximately $2,958,000 had an evaluation performed within the immediately preceding twelve months. As of December 31, 2014, the Company had approximately $65,551,000 of impaired commercial collateral dependent loans, of which approximately $52,092,000 had an appraisal performed within the immediately preceding twelve months and of which approximately $5,307,000 had an evaluation performed within the immediately preceding twelve months. The determination to either seek an appraisal or to perform an evaluation begins in weekly credit quality meetings, where the committee analyzes the existing collateral values of the impaired loans and where obsolete appraisals are identified. In order to determine whether the Company would obtain a new appraisal or perform an internal evaluation to determine the fair value of the collateral, the credit committee reviews the existing appraisal to determine if the collateral value is reasonable in view of the current use of the collateral and the economic environment related to the collateral. If the analysis of the existing appraisal does not find that the collateral value is reasonable under the current circumstances, the Company would obtain a new appraisal on the collateral or perform an internal evaluation of the collateral. The ultimate decision to get a new appraisal rests with the independent credit administration group. A new appraisal is not required if an internal evaluation, as performed by in-house experts, is able to appropriately update the original appraisal assumptions to reflect current market conditions and provide an estimate of the collateral’s market value for impairment analysis. The internal evaluations must be in writing and contain sufficient information detailing the analysis, assumptions and conclusions and they must support performing an evaluation in lieu of ordering a new appraisal. Other real estate owned is comprised of real estate acquired by foreclosure and deeds in lieu of foreclosure. Other real estate owned is carried at the lower of the recorded investment in the property or its fair value less estimated costs to sell such property (as determined by independent appraisal) within level 3 of the fair value hierarchy. Prior to foreclosure, the value of the underlying loan is written down to the fair value of the real estate to be acquired by a charge to the allowance for probable loan losses, if necessary. The fair value is reviewed periodically and subsequent write downs are made accordingly through a charge to operations. Other real estate owned is included in other assets on the consolidated financial statements. For the twelve months ended December 31, 2015 and December 31, 2014, respectively the Company recorded approximately $696,000 and $367,000 in charges to the allowance for probable loan losses in connection with loans transferred to other real estate owned. For the twelve months ended December 31, 2015 and December 31, 2014, respectively, the Company recorded approximately $1,023,000 and $597,000 in adjustments to fair value in connection with other real estate owned. The fair value estimates, methods, and assumptions for the Company’s financial instruments at December 31, 2015 and December 31, 2014 are outlined below. Cash and Cash Equivalents For these short ‑term instruments, the carrying amount is a reasonable estimate of fair value. Investment securities held ‑to ‑maturity The carrying amounts of investments held ‑to ‑maturity approximate fair value. Investment Securities For investment securities, which include U.S. Treasury securities, obligations of other U.S. government agencies, obligations of states and political subdivisions and mortgage pass through and related securities, fair values are from an independent pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. See disclosures of fair value of investment securities in Note 2. Loans Fair values are estimated for portfolios of loans with similar financial characteristics. Loans are segregated by type such as commercial, real estate and consumer loans as outlined by regulatory reporting guidelines. Each category is segmented into fixed and variable interest rate terms and by performing and non ‑performing categories. For variable rate performing loans, the carrying amount approximates the fair value. For fixed rate performing loans, except residential mortgage loans, the fair value is calculated by discounting scheduled cash flows through the estimated maturity using estimated market discount rates that reflect the credit and interest rate risk inherent in the loan. For performing residential mortgage loans, fair value is estimated by discounting contractual cash flows adjusted for prepayment estimates using discount rates based on secondary market sources or the primary origination market. Fixed rate performing loans are within Level 3 of the fair value hierarchy. At December 31, 2015, and December 31, 2014, the carrying amount of fixed rate performing loans was $1,383,836,000 and $1,352,147,000 , respectively, and the estimated fair value was $1,362,248,000 and $1,285,648,000 , respectively. Accrued Interest The carrying amounts of accrued interest approximate fair value. Deposits The fair value of deposits with no stated maturity, such as non ‑interest bearing demand deposit accounts, savings accounts and interest bearing demand deposit accounts, was equal to the amount payable on demand as of December 31, 2015 and December 31, 2014. The fair value of time deposits is based on the discounted value of contractual cash flows. The discount rate is based on currently offered rates. Time deposits are within Level 3 of the fair value hierarchy. At December 31, 2015 and December 31, 2014, the carrying amount of time deposits was $2,366,413,000 and $2,482,692,000 , respectively, and the estimated fair value was $2,365,390,000 and $2,480,390,000 , respectively. Securities Sold Under Repurchase Agreements Securities sold under repurchase agreements include both short and long ‑term maturities. Due to the contractual terms of the short ‑term instruments, the carrying amounts approximated fair value at December 31, 2015 and December 31, 2014. The fair value of the long ‑term instruments is based on established market spread using option adjusted spreads methodology. Long ‑term repurchase agreements are within level 3 of the fair value hierarchy. At December 31, 2015 and December 31, 2014, respectively, the carrying amount of long ‑term repurchase agreements was $560,000,000 and $610,000,000 and the estimated fair value was $527,198,600 and $558,097,500 , respectively. Junior Subordinated Deferrable Interest Debentures The company currently has floating rate junior subordinated deferrable interest debentures outstanding. Due to the contractual terms of the floating rate junior subordinated deferrable interest debentures, the carrying amounts approximated fair value at December 31, 2015 and December 31, 2016. Other Borrowed Funds The company currently has short and long ‑term borrowings issued from the Federal Home Loan Bank (“FHLB”). Due to the contractual terms of the short ‑term borrowings, the carrying amounts approximated fair value at December 31, 2015 and December 31, 2014. The long-term borrowings outstanding at December 31, 2015 are variable rate borrowings and re-price on a monthly basis. The long-term borrowings outstanding at December 31, 2014 are fixed rate and the fair value of the fixed-rate long ‑term borrowings is based on established market spreads for similar types of borrowings. The fixed rate long ‑term borrowings are included in Level 2 of the fair value hierarchy. At December 31, 2014 the carrying amount of the fixed rate long ‑term FHLB borrowings was $6,244,000 and the estimated fair value was $6,645,000 . Commitments to Extend Credit and Letters of Credit Commitments to extend credit and fund letters of credit are principally at current interest rates and therefore the carrying amount approximates fair value. Limitations Fair value estimates are made at a point in time, based on relevant market information and information about the financial instrument. These estimates do not reflect any premium or discount that could result from offering for sale at one time the Company’s entire holdings of a particular financial instrument. Because no market exists for a significant portion of the Company’s financial instruments, fair value estimates are based on judgments regarding future expected loss experience, current economic conditions, risk characteristics of various financial instruments and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. Changes in assumptions could significantly affect the estimates. Fair value estimates are based on existing on ‑and off ‑statement of condition financial instruments without attempting to estimate the value of anticipated future business and the value of assets and liabilities that are not considered financial instruments. Other significant assets and liabilities that are not considered financial assets or liabilities include the bank premises and equipment and core deposit value. In addition, the tax ramifications related to the effect of fair value estimates have not been considered in the above estimates.

International Bancshares Corpor

International Bancshares Corporation (Parent Company Only) Financial Information Statements of Condition	12 Months Ended
	Dec. 31, 2015
International Bancshares Corporation (Parent Company Only) Financial Information Statements of Condition
International Bancshares Corporation (Parent Company Only) Financial Information Statements of Condition	(22) International Bancshares Corporation (Parent Company Only) Financial Information Statements of Condition (Parent Company Only) December 31, 2015 and 2014 (Dollars in Thousands) 2015 2014 ASSETS Cash $ $ Other investments Notes receivable Investment in subsidiaries Other assets Total assets $ $ LIABILITIES AND SHAREHOLDERS’ EQUITY Liabilities: Junior subordinated deferrable interest debentures $ $ Due to IBC Trading Other liabilities Total liabilities Shareholders’ equity: Common shares Surplus Retained earnings Accumulated other comprehensive income (loss) Less cost of shares in treasury Total shareholders’ equity Total liabilities and shareholders’ equity $ $

International Bancshares Corp33

International Bancshares Corporation (Parent Company Only) Financial Information Statements of Income	12 Months Ended
	Dec. 31, 2015
International Bancshares Corporation (Parent Company Only) Financial Information Statements of Income
International Bancshares Corporation (Parent Company Only) Financial Information Statements of Income	(23) International Bancshares Corporation (Parent Company Only) Financial Information Statements of Income (Parent Company Only) Years ended December 31, 2015, 2014 and 2013 (Dollars in Thousands) 2015 2014 2013 Income: Dividends from subsidiaries $ $ $ Interest income on notes receivable Interest income on other investments Other Total income Expenses: Interest expense (Debentures) Other Total expenses Income before federal income taxes and equity in undistributed net income of subsidiaries Income tax expense (benefit) Income before equity in undistributed net income of subsidiaries Equity in undistributed (distributed) net income of subsidiaries Net income $ $ $

International Bancshares Corp34

International Bancshares Corporation (Parent Company Only) Financial Information Statements of Cash Flows	12 Months Ended
	Dec. 31, 2015
International Bancshares Corporation (Parent Company Only) Financial Information Statements of Cash Flows
International Bancshares Corporation (Parent Company Only) Financial Information Statements of Cash Flows	(24) International Bancshares Corporation (Parent Company Only) Financial Information Statements of Cash Flows (Parent Company Only) Years ended December 31, 2015, 2014 and 2013 (Dollars in Thousands) 2015 2014 2013 Operating activities: Net income $ $ $ Adjustments to reconcile net income to net cash provided by operating activities: Impairment charges on available for sale securities Stock compensation expense (Decrease) increase in other liabilities Equity in (undistributed) distributed net income of subsidiaries Net cash provided by operating activities Investing activities: Principal collected on mortgage-backed securities Net decrease in notes receivable (Increase) decrease in other assets and other investments Net cash (used in) provided by investing activities Financing activities: Repayment of trust preferred securities — Proceeds from stock transactions Payments of cash dividends - common Purchase of treasury stock — Net cash used in financing activities Increase (decrease) in cash Cash at beginning of year Cash at end of year $ $ $

Summary of Significant Accoun35

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Summary of Significant Accounting Policies
Consolidation and Basis of Presentation	Consolidation and Basis of Presentation The consolidated financial statements include the accounts of the Corporation and its wholly-owned bank subsidiaries, International Bank of Commerce, Laredo ("IBC"), Commerce Bank, International Bank of Commerce, Zapata, International Bank of Commerce, Brownsville, and the Corporation's wholly-owned non-bank subsidiaries, IBC Subsidiary Corporation, IBC Life Insurance Company, IBC Trading Company, Premier Tierra Holdings, Inc., IBC Charitable and Community Development Corporation, and IBC Capital Corporation. All significant inter-company balances and transactions have been eliminated in consolidation. The Company, through its subsidiaries, is primarily engaged in the business of banking, including the acceptance of checking and savings deposits and the making of commercial, real estate, personal, home improvement, automobile and other installment and term loans. The primary markets of the Company are South, Central, and Southeast Texas and the state of Oklahoma. Each bank subsidiary is very active in facilitating international trade along the United States border with Mexico and elsewhere. Although the Company’s loan portfolio is diversified, the ability of the Company’s debtors to honor their contracts is primarily dependent upon the economic conditions in the Company’s trade area. In addition, the investment portfolio is directly impacted by fluctuations in market interest rates. The Company and its bank subsidiaries are subject to the regulations of certain Federal agencies as well as the Texas Department of Banking and undergo periodic examinations by those regulatory authorities. Such agencies may require certain standards or impose certain limitations based on their judgments or changes in law and regulations. The Company owns two insurance ‑related subsidiaries, IBC Life Insurance Company and IBC Insurance Agency, Inc., a wholly owned subsidiary of IBC, the bank subsidiary. Neither of the insurance ‑related subsidiaries conducts underwriting activities. The IBC Life Insurance Company is in the business of reinsuring credit life and credit accident and health insurance. The business is assumed from an unaffiliated insurer and the only business written is generated by the bank subsidiaries of the Company. The risk assumed on each of the policies is not significant to the consolidated financial statements. The preparation of the 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 amounts of assets and liabilities as of the dates of the statement of condition and income and expenses for the periods. Actual results could differ significantly from those estimates. Material estimates that are particularly susceptible to significant changes in the near ‑term relate to the determination of the allowance for probable loan losses.
Subsequent Events	Subsequent Events The Company has evaluated all events or transactions that occurred through the date the Company issued these financial statements. During this period, the Company did not have any material recognizable or non ‑recognizable subsequent events.
Investment Securities	Investment Securities The Company classifies debt and equity securities into one of these categories: held ‑to ‑maturity, available ‑for ‑sale, or trading. Such classifications are reassessed for appropriate classification at each reporting date. Securities that are intended and expected to be held until maturity are classified as “held ‑to ‑maturity” and are carried at amortized cost for financial statement reporting. Securities that are not positively expected to be held until maturity, but are intended to be held for an indefinite period of time are classified as “available ‑for ‑sale” or “trading” and are carried at their fair value. Unrealized holding gains and losses are included in net income for those securities classified as “trading”, while unrealized holding gains and losses related to those securities classified as “available ‑for ‑sale” are excluded from net income and reported net of tax as other comprehensive income and in shareholders’ equity as accumulated other comprehensive income until realized. The Company did not maintain any trading securities during the three year period ended December 31, 2015. Mortgage ‑backed securities held at December 31, 2015 and 2014 represent participating interests in pools of long ‑term first mortgage loans originated and serviced by the issuers of the securities. Mortgage ‑backed securities are either issued or guaranteed by the U.S. government or its agencies including the Federal Home Loan Mortgage Corporation (“Freddie Mac”), the Federal National Mortgage Association (“Fannie Mae”), the Government National Mortgage Association (“Ginnie Mae”) or other non ‑government entities. Investments in residential mortgage ‑backed securities issued by Ginnie Mae are fully guaranteed by the U. S. government. Investments in residential mortgage ‑backed securities issued by Freddie Mac and Fannie Mae are not fully guaranteed by the U.S. government, however, the Company believes that the quality of the bonds is similar to other AAA rated bonds with limited credit risk, particularly given the placement of Fannie Mae and Freddie Mac into conservatorship by the federal government in 2008 and because securities issued by others that are collateralized by residential mortgage ‑backed securities issued by Fannie Mae or Freddie Mac are rated consistently as AAA rated securities. Market interest rate fluctuations can affect the prepayment speed of principal and the yield on the security. Premiums and discounts are amortized using the level yield or “interest method” over the terms of the securities. Declines in the fair value of held ‑to ‑maturity and available ‑for sale ‑securities below their cost that are deemed to be other than temporary are reflected in earnings as realized losses. In determining whether other ‑than ‑temporary impairment exists, management considers many factors, including (1) the length of time and the extent to which the fair value has been less than cost, (2) the financial condition and near ‑term prospects of the issuer, and (3) the intent of the Company to hold and the determination of whether the Company will more likely than not be required to sell the security prior to a recovery in fair value. If the Company determines that (1) it intends to sell the security or (2) it is more likely than not that it will be required to sell the security before it’s anticipated recovery, the other ‑than ‑temporary impairment that is recognized in earnings is equal to the difference between the fair value of the security and the Company’s amortized cost in the security. If the Company determines that it (1) does not intend to sell the security and (2) it will not be more likely than not required to sell the security before it’s anticipated recovery, the other ‑than ‑temporary impairment is segregated into its two components (1) the amount of impairment related to credit loss and (2) the amount of impairment related to other factors. The difference between the present value of the cash flows expected to be collected and the amortized cost is the credit loss recognized through earnings and an adjustment to the cost basis of the security. The amount of impairment related to other factors is included in other comprehensive income (loss). Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method.
Provision and Allowance for Probable Loan Losses	Provision and Allowance for Probable Loan Losses The allowance for probable loan losses is maintained at a level considered adequate by management to provide for probable loan losses. The allowance is increased by provisions charged to operating expense and reduced by net charge ‑offs. The provision for probable loan losses is the amount, which, in the judgment of management, is necessary to establish the allowance for probable loan losses at a level that is adequate to absorb known and inherent risks in the loan portfolio. Management believes that the allowance for probable loan losses is adequate. While management uses available information to recognize losses on loans, future additions to the allowance may be necessary based on changes in economic conditions. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Company’s bank subsidiaries’ allowances for probable loan losses. Such agencies may require the Company’s bank subsidiaries to make additions or reductions to their U.S. generally accepted accounting principles (“GAAP”) allowances based on their judgments of information available to them at the time of their examination. The bank subsidiaries charge off that portion of any loan which management considers to represent a loss as well as that portion of any other loan which is classified as a “loss” by bank examiners. Commercial, financial and agricultural or real estate loans are generally considered by management to represent a loss, in whole or part, (i) when an exposure beyond any collateral coverage is apparent, (ii) when no further collection of the portion of the loan so exposed is anticipated based on actual results, (iii) when the credit enhancements, if any, are not adequate, and (iv) when the borrower’s financial condition would indicate so. Generally, unsecured consumer loans are charged off when 90 days past due.
Loans	Loans Loans are reported at the principal balance outstanding, net of unearned discounts. Interest income on loans is reported on an accrual basis. Loan fees and costs associated with originating the loans are amortized over the life of the loan using the interest method. The Company originates mortgage loans that may subsequently be sold to an unaffiliated third party. The loans are not securitized and if sold, are sold without recourse. Loans held for sale are carried at cost and the principal amount outstanding is not significant to the consolidated financial statements.
Impaired Loans	Impaired Loans Impaired loans are those loans where it is probable that all amounts due according to contractual terms of the loan agreement will not be collected. Impaired loans are measured based on (1) the present value of expected future cash flows discounted at the loan’s effective interest rate; (2) the loan’s observable market price; or (3) the fair value of the collateral if the loan is collateral dependent. Substantially all of the Company’s impaired loans are measured at the fair value of the collateral. In limited cases the Company may use other methods to determine the level of impairment of a loan if such loan is not collateral dependent.
Troubled Debt Restructured Loans	Troubled Debt Restructured Loans Troubled debt restructured loans (“TDR”) are those loans where, for reasons related to a borrower’s difficulty to repay a loan, the company grants a concession to the borrower that the company would not normally consider in the normal course of business. The original terms of the loan are modified or restructured. The terms that may be modified include a reduction in the original stated interest rate, an extension of the original maturity of the loan, a renewal of the loan at an interest rate below current market rates, a reduction in the principal amount of debt outstanding, a reduction in accrued interest or deferral of interest payments. A loan classified as a TDR is classified as an impaired loan and included in the impaired loan totals. A TDR loan may be returned to accrual status when the loan is brought current, has performed in accordance with the restructured terms for a reasonable period of time, is at the current market rate, and the ultimate collectability of the outstanding principal and interest is no longer questionable, however, although those loans may be placed back on accrual status, they will continue to be classified as impaired. Consistent with regulatory guidance, a TDR loan that is subsequently modified, but has shown sustained performance and classification as a TDR, will be removed from TDR status provided that the modified terms were market-based at the time of modification.
Non-Accrual Loans	Non ‑Accrual Loans The non ‑accrual loan policy of the Company’s bank subsidiaries is to discontinue the accrual of interest on loans when management determines that it is probable that future interest accruals will be un ‑collectible. As it relates to consumer loans, management charges off those loans when the loan is contractually 90 days past due. Under special circumstances, a consumer or non ‑consumer loan may be more than 90 days delinquent as to interest or principal and not be placed on non ‑accrual status. This situation generally results when a bank subsidiary has a borrower who is experiencing financial difficulties, but not to the extent that requires a restructuring of indebtedness. The majority of this category is composed of loans that are considered to be adequately secured and/or for which there are expected future payments. When a loan is placed on non ‑accrual status, any interest accrued, not paid is reversed and charged to operations against interest income. As it relates to non ‑consumer loans that are not 90 days past due, management will evaluate each of these loans to determine if placing the loan on non ‑accrual status is warranted. Interest income on non ‑accrual loans is recognized only to the extent payments are received or when, in management’s opinion, the debtor’s financial condition warrants reestablishment of interest accruals.
Other Real Estate Owned	Other Real Estate Owned Other real estate owned is comprised of real estate acquired by foreclosure and deeds in lieu of foreclosure. Other real estate is carried at the lower of the recorded investment in the property or its fair value less estimated costs to sell such property (as determined by independent appraisal). Prior to foreclosure, the value of the underlying loan is written down to the fair value of the real estate to be acquired by a charge to the allowance for probable loan losses, if necessary. Any subsequent write ‑downs are charged against other non ‑interest expense through a valuation allowance. Other real estate owned totaled approximately $55,850,000 and $69,872,000 at December 31, 2015 and 2014, respectively. Other real estate owned is included in other assets.
Bank Premises and Equipment	Bank Premises and Equipment Bank premises and equipment are stated at cost less accumulated depreciation. Depreciation is computed on straight ‑line and accelerated methods over the estimated useful lives of the assets. Repairs and maintenance are charged to operations as incurred and expenditures for renewals and betterments are capitalized.
Other Investments	Other Investments Other investments include equity investments in non ‑financial companies, bank owned life insurance, as well as equity securities with no readily determinable fair market value. Equity investments are accounted for using the equity method of accounting. Equity securities with no readily determinable fair value are accounted for using the cost method.
Income Taxes	Income Taxes Deferred income tax assets and liabilities are determined using the asset and liability method. Under this method, the net deferred tax asset or liability is determined based on the tax effects of the differences between the book and tax basis of the various balance sheet assets and liabilities and gives current recognition to changes in tax rates and laws. The Company files a consolidated federal income tax return with its subsidiaries. Recognition of deferred tax assets is based on management’s assessment that the benefit related to certain temporary differences, tax operating loss carry forwards, and tax credits are more likely than not to be realized. A valuation allowance is recorded for the amount of the deferred tax items for which it is more likely than not that the tax benefits will not be realized. The Company evaluates uncertain tax positions at the end of each reporting period. The Company may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefit recognized in the financial statements from any such a position is measured based on the largest benefit that has a greater than fifty percent likelihood of being realized upon ultimate settlement. As of December 31, 2015 and 2014, respectively, after evaluating all uncertain tax positions, the Company has recorded no liability for unrecognized tax benefits at the end of the reporting period. The Company would recognize any interest accrued on unrecognized tax benefits as other interest expense and penalties as other non ‑interest expense. During the years ended December 31, 2015, 2014 and 2013, the Company recognized no interest expense or penalties related to uncertain tax positions. The Company files consolidated tax returns in the U.S. Federal jurisdiction and various state jurisdictions. The Company is no longer subject to U.S. federal or state income tax examinations by tax authorities for years before 2012.
Stock Options	Stock Options Compensation expense for stock awards is based on the market price of the stock on the measurement date, which is generally the date of grant, and is recognized ratably over the service period of the award. The fair value of stock options granted was estimated, using the Black ‑Sholes ‑Merton option ‑pricing model. This model was developed for use in estimating the fair value of publicly traded options that have no vesting restrictions and are fully transferable. Additionally, the model requires the input of highly subjective assumptions. Because the Company’s employee stock options have characteristics significantly different from those of publicly traded options, and because changes in the subjective input assumptions can materially affect the fair value estimate, in management’s opinion, the Black ‑Scholes ‑Merton option ‑pricing model does not necessarily provide a reliable single measure of the fair value of the Company’s stock options.
Net Income Per Share	Net Income Per Share Basic Earnings Per Share (“EPS”) is calculated by dividing net income by the weighted average number of common shares outstanding. The computation of diluted EPS assumes the issuance of common shares for all dilutive potential common shares outstanding during the reporting period. The dilutive effect of stock options is considered in earnings per share calculations, if dilutive, using the treasury stock method.
Goodwill and Identified Intangible Assets	Goodwill and Identified Intangible Assets Goodwill represents the excess of costs over fair value of assets of businesses acquired. Goodwill is tested for impairment at least annually or on an interim basis if an event triggering impairment may have occurred. As of October 1, 2015, after completing goodwill testing, the Company has determined that no goodwill impairment exists. Identified intangible assets are acquired assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights or because the asset is capable of being sold or exchanged either on its own or in combination with a related contract, asset, or liability. The Company’s identified intangible assets relate to core deposits and contract rights. As of December 31, 2015, the Company has determined that no impairment of identified intangibles exists. Identified intangible assets with definite useful lives are amortized on an accelerated basis over their estimated life. See Note 6—Goodwill and Other Intangible Assets.
Impairment of Long-Lived Assets	Impairment of Long ‑Lived Assets Long ‑lived assets, such as property, plant and equipment, and purchased intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying value of the asset to the estimated undiscounted future cash flows expected to be generated by the asset. If the carrying value of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying value of the asset exceeds the fair value of the asset. Assets to be disposed of would be separately presented in the statement of condition and reported at the lower of the carrying value or fair value less costs to sell, and are no longer depreciated. The assets and liabilities of a disposed group classified as held for sale would be presented separately in the appropriate asset and liability sections of the statement of condition.
Consolidated Statements of Cash Flows	Consolidated Statements of Cash Flows For purposes of the consolidated statements of cash flows, the Company considers all short ‑term investments with a maturity at date of purchase of three months or less to be cash equivalents. Also, the Company reports transactions related to deposits and loans to customers on a net basis.
Accounting for Transfers and Servicing of Financial Assets	Accounting for Transfers and Servicing of Financial Assets The Company accounts for transfers and servicing of financial assets and extinguishments of liabilities based on the application of a financial ‑components approach that focuses on control. After a transfer of financial assets, the Company recognizes the financial and servicing assets it controls and liabilities it has incurred, derecognizes financial assets when control has been surrendered and derecognizes liabilities when extinguished. The Company has retained mortgage servicing rights in connection with the sale of mortgage loans. Because the Company may not initially identify loans as originated for resale, all loans are initially treated as held for investment. The value of the mortgage servicing rights are reviewed periodically for impairment and are amortized in proportion to, and over the period of estimated net servicing income or net servicing losses. The value of the mortgage servicing rights is not significant to the consolidated statements of condition.
Segments of an Enterprise and Related Information	Segments of an Enterprise and Related Information The Company operates as one segment. The operating information used by the Company’s chief executive officer for purposes of assessing performance and making operating decisions about the Company is the consolidated financial statements presented in this report. The Company has four active operating subsidiaries, namely, the bank subsidiaries, otherwise known as International Bank of Commerce, Laredo, Commerce Bank, International Bank of Commerce, Zapata and International Bank of Commerce, Brownsville. The Company applies the provisions of ASC Topic 280, “Segment Reporting,” in determining its reportable segments and related disclosures.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) consists of net income and other comprehensive income (loss). Other comprehensive income (loss) includes unrealized gains and losses on securities available for sale.
Advertising	Advertising Advertising costs are expensed as incurred.
Reclassifications	Reclassifications Certain amounts in the prior year’s presentations have been reclassified to conform to the current presentation. These reclassifications had no effect on previously reported net income or shareholders’ equity.
New Accounting Standards	New Accounting Standards In July 2013, the Financial Accounting Standards Board issued Accounting Standards Update No. 2013 ‑11 to ASC 740, “Income Taxes.” The update amends existing literature to eliminate diversity in practice in the presentation of unrecognized tax benefits in instances where a net operating loss carryforward, a similar tax loss or a tax credit carryforward also exist. The update clarifies how the unrecognized tax benefit should be presented in those situations where other tax losses or tax credit carryforwards exist. The update does not change the currently required disclosures for unrecognized tax benefits under current ASC 740 guidance. The update is effective for fiscal years and interim periods within those years beginning after December 15, 2013. The adoption of the update to existing standards did not have a significant impact to the Company’s consolidated financial statements. In January 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-01 to ASC 323-70, “Investments – Equity Method and Joint Ventures – Accounting for Investments in Qualified Affordable Housing Project.” The update issues new guidance for investments in qualified affordable housing projects which permits entities to elect to apply the proportional amortization method to account for the investment when certain conditions are met. The update is effective for public entities for annual and interim periods beginning after December 15, 2014 and is able to be applied retrospectively. The adoption of the update did not have a significant impact to the Company’s consolidated financial statements. In January 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014 ‑04 to ASC 310 ‑40, “Receivables—Troubled Debt Restructurings by Creditors.” The update amends existing literature to eliminate diversity in practice by clarifying and defining when an in substance repossession or foreclosure occurs. The terms “in substance repossession or foreclosure” and “physical possession” are not currently defined in the accounting literature, resulting in diversity in practice when a creditor derecognizes a loan receivable and recognizes the real estate property collateralizing the loan receivable as an asset. Additionally, the update requires interim and annual disclosures of both the amount of foreclosed residential real estate property and the recorded investment in consumer mortgage loans collateralized by residential real estate property that are in the process of foreclosure. The update is effective for annual periods and the interim periods within those annual periods beginning after December 15, 2014. The adoption of the update to existing standards did not have a significant impact to the Company’s consolidated financial statements. In April 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-08 to ASC 205, “Presentation of Financial Statements,” and ASC 360, “Property, Plant and Equipment.” The update to existing standards change the requirements for reporting discontinued operations, primarily by clarifying that the disposal of a component or group of components of an entity could constitute discontinued operations under certain circumstances. The update also defines required information in disclosures about discontinued operations, including a discussion of the entity’s continued involvement in the discontinued operation, if any. The update is applicable to all disposals of components of an entity that occurred within interim and annual periods beginning after December 15, 2014 and for acquisitions that are classified as held for sale for interim and annual periods beginning after December 15, 2014. The adoption of the update did not have a significant impact to the Company’s consolidated financial statements. In May 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-09 to ASC 606, “Revenue from Contracts with Customers.” The update sets a common standard that defines revenue and the principles for recognizing revenue. The update outlines when an entity should recognize revenue, among other matters. At its core, the update states that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The update also outlines the steps that entities should take to determine and record the correct revenue number. The update was originally effective for annual periods beginning after December 15, 2016 and the interim periods within that reporting period. In August 2015, the Financial Accounting Standards Board issued Accounting Standards Update No 2015-14 which deferred the effective date of Accounting Standards Update No. 2014-019 by one year to annual and interim periods beginning after December 15, 2017. The Company is evaluating the potential impact to the Company’s consolidated financial statements. In June 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-11 to ASC 860, “Transfers and Servicing.” The update amended existing standards to require that repurchase-to-maturity transactions be accounted for as secured borrowings, in line with accounting standards for other similar instruments. Additionally, the update requires various disclosures including information regarding transfers accounted for as sales in transactions that are economically similar as repurchase agreements, in addition to disclosures related to collateral, remaining contractual tenor and a discussion of the potential risks associated with repurchase agreements, securities lending transactions and repurchase-to-maturity transactions. The update is effective for interim and annual periods beginning after December 15, 2014. The adoption of the update to existing standards did not have a significant impact to the Company’s consolidated financial statements. In August 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-14 to ASC 310-40, “Receivables – Troubled Debt Restructurings by Creditors.” The update is guidance regarding classification and measurement of foreclosed mortgage loans that are government guaranteed. The update specifies that government secured mortgage loans foreclosed upon should be classified as other assets and measured based on the amount of the loan balance that is expected to be recovered from the guarantor. The new guidance is effective for interim and annual periods after December 15, 2014. The adoption of the update did not have a significant impact to the Company’s consolidated financial statements. In January 2015, the Financial Accounting Standards Board issued Accounting Standards Update No. 2015-01 to ASC 225-20, “Income Statement- Extraordinary and Unusual Items.” The update amends existing standards and is being issued as part of the FASB’s initiative to reduce complexity in accounting standards. The update eliminates the concept of extraordinary items. The update is effective for interim and annual periods after December 15, 2015. The adoption of the update to existing standards is not expected to have a significant impact to the Company’s consolidated financial statements. In February 2015, the Financial Accounting Standards Board issued Accounting Standards Update No. 2015-02 to ASC 810, “Consolidation.” The update amends existing standards regarding the evaluation of certain legal entities and their consolidation in the financial statements. The amendments modify the evaluation process to assess whether limited partnerships and similar legal entities are variable interest entities or voting interest entities, eliminate the presumption that a general partner should consolidate a limited partnership, affect the consolidation analysis of entities that are involved in variable interest entities, particularly those that have fee arrangements and related party relationships and provides a scope exception for reporting entities with legal interests that are required to comply with or operate in accordance with requirements that are similar to those in Rule 2a-7 of the Investment Company Act of 1940 for registered money market funds. The update is effective for interim and annual periods after December 15, 2015. The adoption of the update to existing standards is not expected to have a significant impact to the Company’s consolidated financial statements. In September 2015, the Financial Accounting Standards Board issued Accounting Standards Update No. 2015-16 to ASC 805, “Business Combinations.” The update amends existing standards regarding the methodology used to recognize adjustments related to provisional amounts that are identified during the measurement period of a business combination. The update requires that adjustments to provisional amounts be recognized in the reporting period in which the adjustment amounts are determined. The update requires that the reporting entity disclose on the face of the income statement or in the notes, the portion of the amount recorded in current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the provisional amounts had been recognized as of the acquisition date. The update is effective for interim and annual periods after December 15, 2015. The adoption of the update to existing standards is not expected to have a significant impact to the Company’s consolidated financial statements. In January 2016, the Financial Accounting Standards Board issued Accounting Standards Update No. 2016-01 to ASC 825-10, “Financial Instruments – Overall.” The update amends existing standards regarding certain aspects of recognition and measurement of financial assets and financial liabilities. The amendments in the update establish the following guidance: (i) requires equity investments, except those accounted for under the equity method of accounting or those that result in consolidation of the investee, to be measured at fair value with changes in fair value recognized in net income, (ii) simplifies the impairment assessment of equity securities without readily determinable fair values by requiring a qualitative assessment, (iii) eliminates the requirement to disclose the fair value of financial instruments measured at amortized cost for entities that are not public business entities, (iv) eliminates the requirement for public business entities to disclose the methods and significant assumptions used to estimate fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet, (v) requires public business entities to use the exit price notion when measuring fair value for disclosure purposes, (vi) requires an entity to present separately, in other comprehensive income, the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option, (vii) requires separate presentation of financial assets and liabilities by measurement category and form of financial assets on the balance sheet or in the accompanying notes to the financial statements, and (viii) clarifies that an entity should evaluate the need to a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity’s other deferred tax assets. The update is effective for interim and annual periods beginning after December 15, 2017. The adoption of the update is not expected to have a significant impact to the Company’s consolidated financial statements. In February 2016, the Financial Accounting Standards Board issued Accounting Standards Update No. 2016-02 to ASC 820, “Leases.” The update amends existing standards for accounting for leases by lessees, with accounting for leases by lessors remaining mainly unchanged from current guidance. The update requires that lessees recognize a lease liability and a right of use asset for all leases (with the exception of short-term leases) at the commencement date of the lease and disclose key information about leasing arrangements. The update is effective for interim and annual periods beginning after December 15, 2015 and is to be applied on a modified retrospective basis. The Company is evaluating the potential impact to the Company’s consolidated financial statements .

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2015
Investment Securities
Amortized cost and estimated fair value by type of investment security	Held to Maturity Gross Gross Amortized unrealized unrealized Estimated Carrying cost gains losses fair value value (Dollars in Thousands) Other securities $ $ — $ — $ $ Total investment securities $ $ — $ — $ $ Available for Sale Gross Gross Amortized unrealized unrealized Estimated Carrying cost gains losses fair value value (1) (Dollars in Thousands) Residential mortgage-backed securities $ $ $ $ $ Obligations of states and political subdivisions Equity securities Total investment securities $ $ $ $ $ Held to Maturity Gross Gross Amortized unrealized unrealized Estimated Carrying cost gains losses fair value value (Dollars in Thousands) Other securities $ $ — $ — $ $ Total investment securities $ $ — $ — $ $ Available for Sale Gross Gross Estimated Amortized unrealized unrealized fair Carrying cost gains losses value value (1) (Dollars in Thousands) Residential mortgage-backed securities $ $ $ $ $ Obligations of states and political subdivisions Equity securities Total investment securities $ $ $ $ $
Amortized cost and fair value of investment securities, by contractual maturity	Held to Maturity Available for Sale Amortized Estimated Amortized Estimated Cost fair value Cost fair value (Dollars in Thousands) Due in one year or less $ $ $ — $ — Due after one year through five years — — Due after five years through ten years — — — — Due after ten years — — Residential mortgage-backed securities — — Equity securities — — Total investment securities $ $ $ $
Gross unrealized losses on investment securities and the related fair value	Gross unrealized losses on investment securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at December 31, 2015 were as follows: Less than 12 months 12 months or more Total Unrealized Unrealized Unrealized Fair Value Losses Fair Value Losses Fair Value Losses (Dollars in Thousands) Available for sale: Residential mortgage-backed securities $ $ $ $ $ $ Obligations of states and political subdivisions Equity securities $ $ $ $ $ $ Gross unrealized losses on investment securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous loss position, at December 31, 2014 were as follows: Less than 12 months 12 months or more Total Unrealized Unrealized Unrealized Fair Value Losses Fair Value Losses Fair Value Losses (Dollars in Thousands) Available for sale: Residential mortgage-backed securities $ $ $ $ $ $ Obligations of states and political subdivisions Equity securities $ $ $ $ $ $
Reconciliation of credit-related impairment charges on available-for-sale investment	The following table presents a reconciliation of credit ‑related impairment charges on available ‑for ‑sale investments recognized in earnings for the twelve months ended December 31, 2015 (in Thousands): Balance at December 31, 2014 $ Impairment charges recognized during period Balance at December 31, 2015 $ The following table presents a reconciliation of credit ‑related impairment charges on available ‑for ‑sale investments recognized in earnings for the twelve months ended December 31, 2014 (in Thousands): Balance at December 31, 2013 $ Impairment charges recognized during period Balance at December 31, 2014 $ The following table presents a reconciliation of credit ‑related impairment charges on available ‑for ‑sale investments recognized in earnings for the twelve months ended December 31, 2013 (in Thousands): Balance at December 31, 2012 $ Impairment charges recognized during period Balance at December 31, 2013 $

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2015
Loans
Summary of loans, by loan type	December 31, December 31, 2015 2014 (Dollars in Thousands) Commercial, financial and agricultural $ $ Real estate - mortgage Real estate - construction Consumer Foreign Total loans $ $

Allowance for Probable Loan L38

Allowance for Probable Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2015
Allowance for Probable Loan Losses
Summary of the transactions in the allowance for probable loan losses by loan class	December 31, 2015 Domestic Foreign Commercial real estate: other Commercial construction & real estate: Commercial land farmland & real estate: Residential: Residential: Commercial development commercial multifamily first lien junior lien Consumer Foreign Total (Dollars in Thousands) Balance at December 31, $ $ $ $ $ $ $ $ $ Losses charge to allowance — — Recoveries credited to allowance — Net losses charged to allowance — Provision (credit) charged to operations Balance at December 31, $ $ $ $ $ $ $ $ $ December 31, 2014 Domestic Foreign Commercial real estate: other Commercial construction & real estate: Commercial land farmland & real estate: Residential: Residential: Commercial development commercial multifamily first lien junior lien Consumer Foreign Total (Dollars in Thousands) Balance at December 31, $ $ $ $ $ $ $ $ $ Losses charge to allowance — Recoveries credited to allowance — Net losses charged to allowance — Provision (credit) charged to operations Balance at December 31, $ $ $ $ $ $ $ $ $ December 31, 2013 Domestic Foreign Commercial real estate: other Commercial construction & real estate: Commercial land farmland & real estate: Residential: Residential: Commercial development commercial multifamily first lien junior lien Consumer Foreign Total (Dollars in Thousands) Balance at December 31, $ $ $ $ $ $ $ $ $ Losses charge to allowance Recoveries credited to allowance — Net losses charged to allowance Provision (credit) charged to operations Balance at December 31, $ $ $ $ $ $ $ $ $
Loans individually or collectively evaluated for their impairment and related allowance, by loan class	December 31, 2015 Loans individually Loans collectively evaluated for evaluated for impairment impairment Recorded Recorded Investment Allowance Investment Allowance (Dollars in Thousands) Domestic Commercial $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Commercial real estate: multifamily Residential: first lien — Residential: junior lien — Consumer — Foreign — Total $ $ $ $ December 31, 2014 Loans individually Loans collectively evaluated for evaluated for impairment impairment Recorded Recorded Investment Allowance Investment Allowance (Dollars in Thousands) Domestic Commercial $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Commercial real estate: multifamily — Residential: first lien — Residential: junior lien — Consumer — Foreign — — Total $ $ $ $
Loans accounted on non-accrual basis, by loan class	2015 2014 (Dollars in Thousands) Domestic Commercial $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Commercial real estate: multifamily Residential: first lien Residential: junior lien Consumer Foreign — Total non-accrual loans $ $
Impaired loans, by loan class	December 31, 2015 Unpaid Average Recorded Principal Related Recorded Interest Investment Balance Allowance Investment Recognized (Dollars in Thousands) Loans with Related Allowance Domestic Commercial $ $ $ $ $ — Commercial real estate: other construction & land development — Commercial real estate: farmland & commercial Commercial real estate: multifamily — Total impaired loans with related allowance $ $ $ $ $ December 31, 2015 Unpaid Average Recorded Principal Recorded Interest Investment Balance Investment Recognized (Dollars in Thousands) Loans with No Related Allowance Domestic Commercial $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial — Commercial real estate: multifamily — Residential: first lien Residential: junior lien Consumer Foreign Total impaired loans with no related allowance $ $ $ $ The following tables detail key information regarding the Company’s impaired loans by loan class for the year ended December 31, 2014: December 31, 2014 Unpaid Average Recorded Principal Related Recorded Interest Investment Balance Allowance Investment Recognized (Dollars in Thousands) Loans with Related Allowance Domestic Commercial $ $ $ $ $ — Commercial real estate: other construction & land development — Commercial real estate: farmland & commercial Total impaired loans with related allowance $ $ $ $ $ December 31, 2014 Unpaid Average Recorded Principal Recorded Interest Investment Balance Investment Recognized (Dollars in Thousands) Loans with No Related Allowance Domestic Commercial $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial — Commercial real estate: multifamily — Residential: first lien Residential: junior lien Consumer Foreign — — — — Total impaired loans with no related allowance $ $ $ $
Loans accounted for as trouble debt restructuring, by loan class	December 31, 2015 December 31, 2014 (Dollars in Thousands) Domestic Commercial $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Residential: first lien Residential: junior lien Consumer Foreign — Total troubled debt restructuring $ $
Information regarding the aging of past due loans, by loan class	December 31, 2015 90 Days or 30 - 59 60 - 89 90 Days or greater & Total Total Days Days Greater still accruing Past due Current Portfolio (Dollars in Thousands) Domestic Commercial $ $ $ $ $ $ $ Commercial real estate: other construction & land development — Commercial real estate: farmland & commercial Commercial real estate: multifamily Residential: first lien Residential: junior lien Consumer Foreign Total past due loans $ $ $ $ $ $ $ December 31, 2014 90 Days or 30 - 59 60 - 89 90 Days or greater & Total Total Days Days Greater still accruing Past due Current Portfolio (Dollars in Thousands) Domestic Commercial $ $ $ $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Commercial real estate: multifamily — Residential: first lien Residential: junior lien Consumer Foreign Total past due loans $ $ $ $ $ $ $
Summary of the loan portfolio by credit quality indicator, by loan class	December 31, 2015 Special Watch Watch List— Watch List— Pass Review List—Pass Substandard Impaired (Dollars in Thousands) Domestic Commercial $ $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Commercial real estate: multifamily — — Residential: first lien — — Residential: junior lien — — Consumer — — Foreign — — — Total $ $ $ $ $ December 31, 2014 Special Watch Watch List— Watch List— Pass Review List—Pass Substandard Impaired (Dollars in Thousands) Domestic Commercial $ $ $ $ $ Commercial real estate: other construction & land development Commercial real estate: farmland & commercial Commercial real estate: multifamily — — Residential: first lien — Residential: junior lien — — Consumer — — Foreign — — — — Total $ $ $ $ $

Bank Premises and Equipment (Ta

Bank Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Bank Premises and Equipment
Summary of bank premises and equipment, by asset classification	Estimated useful lives 2015 2014 (Dollars in Thousands) Bank buildings and improvements 5 - 40 years $ $ Furniture, equipment and vehicles 1 - 20 years Land Real estate held for future expansion: Land, building, furniture, fixture and equipment 7 - 27 years — — Less: accumulated depreciation Bank premises and equipment, net $ $

Goodwill and Other Intangible40

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill and Other Intangible Assets
Schedule of the entity's identified intangible assets	Carrying Accumulated Amount Amortization Net (Dollars in Thousands) December 31, 2015: Core deposit premium $ $ $ Identified intangible (contract rights) — Total identified intangibles $ $ $ December 31, 2014: Core deposit premium $ $ $ Identified intangible (contract rights) Total identified intangibles $ $ $
Schedule of estimated amortization expense for each of the five succeeding fiscal years and thereafter	Total (in thousands) 2016 2017 2018 — 2019 — 2020 — Thereafter Total $

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2015
Deposits.
Schedule of deposits and related interest expense	2015 2014 (Dollars in Thousands) Deposits: Demand - non-interest bearing Domestic $ $ Foreign Total demand non-interest bearing Savings and interest bearing demand Domestic Foreign Total savings and interest bearing demand Time, certificates of deposit $100,000 or more Domestic Foreign Less than $100,000 Domestic Foreign Total time, certificates of deposit Total deposits $ $ 2015 2014 2013 (Dollars in Thousands) Interest expense: Savings and interest bearing demand Domestic $ $ $ Foreign Total savings and interest bearing demand Time, certificates of deposit $100,000 or more Domestic Foreign Less than $100,000 Domestic Foreign Total time, certificates of deposit Total interest expense on deposits $ $ $
Scheduled maturities of time deposits	Total (in thousands) 2016 $ 2017 2018 2019 2020 Thereafter Total $
Scheduled maturities of time deposits in amounts of $100,000 or more	Total (in thousands) Due within 3 months or less $ Due after 3 months and within 6 months Due after 6 months and within 12 months Due after 12 months $

Securities Sold Under Repurch42

Securities Sold Under Repurchase Agreements (Tables)	12 Months Ended
	Dec. 31, 2015
Securities Sold Under Repurchase Agreements
Schedule of repurchase agreements	Collateral Securities Repurchase Borrowing Book Value of Fair Value of Balance of Weighted Average Securities Sold Securities Sold Liability Interest Rate (Dollars in Thousands) December 31, 2015 term: Overnight agreements $ $ $ % 1 to 29 days 30 to 90 days Over 90 days Total $ $ $ % December 31, 2014 term: Overnight agreements $ $ $ % 1 to 29 days 30 to 90 days Over 90 days Total $ $ $ %

Other Borrowed Funds (Tables)

Other Borrowed Funds (Tables)	12 Months Ended
	Dec. 31, 2015
Other Borrowed Funds
Schedule of other borrowed funds	December 31, 2015 2014 (Dollars in Thousands) Federal Home Loan Bank advances—short-term Balance at year end $ $ Rate on balance outstanding at year end % % Average daily balance $ $ Average rate % % Maximum amount outstanding at any month end $ $ Federal Home Loan Bank advances—long-term(1) Balance at year end $ $ Rate on balance outstanding at year end % % Average daily balance $ $ Average rate % % Maximum amount outstanding at any month end $ $ The long ‑term advances are not amortizable and consist of two advances in the amount of $75,000,000 each. The advances mature on January 13, 2017 and January 25, 2017 , respectively.

Junior Subordinated Deferrabl44

Junior Subordinated Deferrable Interest Debentures (Tables)	12 Months Ended
	Dec. 31, 2015
Junior Subordinated Interest Deferrable Debentures
Junior subordinated deferrable interest debentures, major types of business trusts	The following table illustrates key information about each of the Debentures and their interest rates at December 31, 2015: Junior Subordinated Deferrable Interest Repricing Interest Interest Optional Debentures Frequency Rate Rate Index(1) Maturity Date Redemption Date (1) (in thousands) Trust VI $ Quarterly % LIBOR + 3.45 November 2032 February 2008 Trust VIII Quarterly % LIBOR + 3.05 October 2033 October 2008 Trust IX Quarterly % LIBOR + 1.62 October 2036 October 2011 Trust X Quarterly % LIBOR + 1.65 February 2037 February 2012 Trust XI Quarterly % LIBOR + 1.62 July 2037 July 2012 Trust XII Quarterly % LIBOR + 1.45 September 2037 September 2012 $ The Capital Securities may be redeemed in whole or in part on any interest payment date after the Optional Redemption Date.

Earnings per Share ("EPS") (Tab

Earnings per Share ("EPS") (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings per Share ("EPS")
Schedule of calculation of the basic EPS and the diluted EPS	Net Income Shares Per Share (Numerator) (Denominator) Amount (Dollars in Thousands, Except Per Share Amounts) December 31, 2015: Basic EPS Net income available to common shareholders $ $ Potential dilutive common shares and warrants — Diluted EPS $ $ December 31, 2014: Basic EPS Net income available to common shareholders $ $ Potential dilutive common shares — Diluted EPS $ $ December 31, 2013: Basic EPS Net income available to common shareholders $ $ Potential dilutive common shares — Diluted EPS $ $

International Operations (Table

International Operations (Tables)	12 Months Ended
	Dec. 31, 2015
International Operations
Summary of assets attributable to international operations	2015 2014 (Dollars in Thousands) Loans: Commercial $ $ Others Less allowance for probable loan losses Net loans $ $ Accrued interest receivable $ $

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Taxes
Schedule of current and deferred portions of net income tax expense	2015 2014 2013 (Dollars in Thousands) Current U.S. $ $ $ State Foreign Total current taxes Deferred U.S. State Total deferred taxes Total income taxes $ $ $
Schedule of income tax expense differences from the amount computed by applying the U.S. Federal income tax rate to income before income taxes	2015 2014 2013 (Dollars in Thousands) Computed expected tax expense $ $ $ Change in taxes resulting from: Tax-exempt interest income State tax, net of federal income taxes and tax credit Tax refunds — — Other investment income Other Actual tax expense $ $ $
Schedule of tax effects of temporary difference that give rise to significant portions of the deferred tax assets and deferred tax liabilities	2015 2014 (Dollars in Thousands) Deferred tax assets: Loans receivable, principally due to the allowance for probable loan losses $ $ Other real estate owned Impairment charges on available-for-sale securities Accrued expenses Other Total deferred tax assets Deferred tax liabilities: Bank premises and equipment, principally due to differences on depreciation Net unrealized gains on available for sale investment securities Identified intangible assets and goodwill Other Total deferred tax liabilities Net deferred tax asset (liability) $ $

Stock Options (Tables)

Stock Options (Tables)	12 Months Ended
	Dec. 31, 2015
Stock Options
Schedule of Black-Scholes-Merton option valuation model assumptions	2015 2014 Expected Life (Years) Dividend yield % % Interest rate % % Volatility % %
Summary of option activity under stock option plans	Weighted Weighted average average remaining Aggregate Number of exercise contractual intrinsic options price term (years) value ($) (in Thousands) Options outstanding at December 31, 2014 $ Plus: Options granted Less: Options exercised Options expired Options forfeited Options outstanding at December 31, 2015 $ Options fully vested and exercisable at December 31, 2015 $ $
Schedule of other information pertaining to option activity	Twelve Months Ended December 31, 2015 2014 2013 Weighted average grant date fair value of stock options granted $ $ $ Total fair value of stock options vested $ $ $ Total intrinsic value of stock options exercised $ $ $

Commitments, Contingent Liabi49

Commitments, Contingent Liabilities and Other Matters (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments, Contingent Liabilities and Other Matters
Schedule of future minimum lease payments due under non-cancellable operating leases	Total (in thousands) 2016 $ 2017 2018 2019 2020 Thereafter Total $

Financial Instruments with Of50

Financial Instruments with Off-Statement of Condition Risk and Concentrations of Credit Risk (Tables)	12 Months Ended
	Dec. 31, 2015
Financial Instruments with Off-Statement of Condition Risk and Concentrations of Credit Risk
Schedule of financial amounts of instruments, whose contract amounts represent credit risks	Commitments to extend credit $ Credit card lines Standby letters of credit Commercial letters of credit

Capital Requirements (Tables)

Capital Requirements (Tables)	12 Months Ended
	Dec. 31, 2015
Capital Requirements
Schedule of the Company's and the bank subsidiaries' actual capital amounts and ratios	The Company’s and the bank subsidiaries’ actual capital amounts and ratios for 2015 under current guidelines are presented in the following table: To Be Well-Capitalized For Capital Adequacy Under Prompt Corrective Actual Purposes Action Provisions Amount Ratio Amount Ratio Amount Ratio (greater than (greater than (greater than (greater than or equal to) or equal to) or equal to) or equal to) (Dollars in Thousands) As of December 31, 2015: Common Equity Tier 1 (to Risk Weighted Assets): Consolidated $ % $ % N/A N/A International Bank of Commerce, Laredo $ % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank Total Capital (to Risk Weighted Assets): Consolidated $ % $ % N/A N/A International Bank of Commerce, Laredo $ % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank Tier 1 Capital (to Risk Weighted Assets): Consolidated $ % $ % N/A N/A International Bank of Commerce, Laredo $ % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank Tier 1 Capital (to Average Assets): Consolidated $ % $ % $ N/A N/A International Bank of Commerce, Laredo % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank The Company’s and the bank subsidiaries’ actual capital amounts and ratios for 2014 are also presented in the following table: To Be Well-Capitalized For Capital Adequacy Under Prompt Corrective Actual Purposes Action Provisions Amount Ratio Amount Ratio Amount Ratio (greater than (greater than (greater than (greater than or equal to) or equal to) or equal to) or equal to) (Dollars in Thousands) As of December 31, 2014: Total Capital (to Risk Weighted Assets): Consolidated $ % $ % N/A N/A International Bank of Commerce, Laredo $ % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank Tier 1 Capital (to Risk Weighted Assets): Consolidated $ % $ % N/A N/A International Bank of Commerce, Laredo $ % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank Tier 1 Capital (to Average Assets): Consolidated $ % $ % $ N/A N/A International Bank of Commerce, Laredo % International Bank of Commerce, Brownsville International Bank of Commerce, Zapata Commerce Bank

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value
Assets and liabilities measured at fair value on a recurring basis	The following table represents financial instruments reported on the consolidated statements of condition at their fair value as of December 31, 2015 by level within the fair value measurement hierarchy. Fair Value Measurements at Reporting Date Using (in thousands) Quoted Prices in Assets/Liabilities Active Significant Measured at Markets for Other Significant Fair Value Identical Observable Unobservable December 31, Assets Inputs Inputs 2015 (Level 1) (Level 2) (Level 3) Measured on a recurring basis: Assets: Available for sale securities Residential mortgage-backed securities $ $ — $ $ States and political subdivisions — — Other — — $ $ $ $ The following table represents financial instruments reported on the consolidated balance sheets at their fair value as of December 31, 2014 by level within the fair value measurement hierarchy. Fair Value Measurements at Reporting Date Using (in thousands) Quoted Prices in Assets/Liabilities Active Significant Measured at Markets for Other Significant Fair Value Identical Observable Unobservable December 31, Assets Inputs Inputs 2014 (Level 1) (Level 2) (Level 3) Measured on a recurring basis: Assets: Available for sale securities Residential mortgage - backed securities $ $ — $ $ States and political subdivisions — — Other — — $ $ $ $
Reconciliation of activity for mortgage-backed securities on a net basis	Balance at December 31, 2014 $ Principal paydowns Total unrealized gains (losses) included in: Other comprehensive income Impairment realized in earnings Balance at December 31, 2015 $
Assets measured at fair value on a non-recurring basis	The following table represents financial instruments measured at fair value on a non ‑recurring basis as of and for the period ended December 31, 2015 by level within the fair value measurement hierarchy: Fair Value Measurements at Reporting Date Using (in thousands) Quoted Assets/Liabilities Prices in Measured at Active Significant Fair Value Markets for Other Significant Net (credit) Year ended Identical Observable Unobservable Provision December 31, Assets Inputs Inputs During 2015 (Level 1) (Level 2) (Level 3) Period Measured on a non-recurring basis: Assets: Impaired loans $ $ — $ — $ $ Other real estate owned — — The following table represents financial instruments measured at fair value on a non ‑recurring basis as of and for the year ended December 31, 2014 by level within the fair value measurement hierarchy: Fair Value Measurements at Reporting Date Using (in thousands) Quoted Assets/Liabilities Prices in Measured at Active Significant Fair Value Markets Other Significant Net (credit) Year ended for Identical Observable Unobservable Provision December 31, Assets Inputs Inputs During 2014 (Level 1) (Level 2) (Level 3) Period Measured on a non-recurring basis: Assets: Impaired loans $ $ — $ — $ $ Other real estate owned — —

International Bancshares Corp53

International Bancshares Corporation (Parent Company Only) Financial Information Statements of Condition (Tables)	12 Months Ended
	Dec. 31, 2015
International Bancshares Corporation (Parent Company Only) Financial Information Statements of Condition
Schedule of condensed statements of condition of Parent Company	(Dollars in Thousands) 2015 2014 ASSETS Cash $ $ Other investments Notes receivable Investment in subsidiaries Other assets Total assets $ $ LIABILITIES AND SHAREHOLDERS’ EQUITY Liabilities: Junior subordinated deferrable interest debentures $ $ Due to IBC Trading Other liabilities Total liabilities Shareholders’ equity: Common shares Surplus Retained earnings Accumulated other comprehensive income (loss) Less cost of shares in treasury Total shareholders’ equity Total liabilities and shareholders’ equity $ $

International Bancshares Corp54

International Bancshares Corporation (Parent Company Only) Financial Information Statements of Income (Tables)	12 Months Ended
	Dec. 31, 2015
International Bancshares Corporation (Parent Company Only) Financial Information Statements of Income
Schedule of condensed statements of income of Parent Company	(Dollars in Thousands) 2015 2014 2013 Income: Dividends from subsidiaries $ $ $ Interest income on notes receivable Interest income on other investments Other Total income Expenses: Interest expense (Debentures) Other Total expenses Income before federal income taxes and equity in undistributed net income of subsidiaries Income tax expense (benefit) Income before equity in undistributed net income of subsidiaries Equity in undistributed (distributed) net income of subsidiaries Net income $ $ $

International Bancshares Corp55

International Bancshares Corporation (Parent Company Only) Financial Information Statements of Cash Flows (Tables)	12 Months Ended
	Dec. 31, 2015
International Bancshares Corporation (Parent Company Only) Financial Information Statements of Cash Flows
Schedule of condensed statements of cash flows of Parent Company	(Dollars in Thousands) 2015 2014 2013 Operating activities: Net income $ $ $ Adjustments to reconcile net income to net cash provided by operating activities: Impairment charges on available for sale securities Stock compensation expense (Decrease) increase in other liabilities Equity in (undistributed) distributed net income of subsidiaries Net cash provided by operating activities Investing activities: Principal collected on mortgage-backed securities Net decrease in notes receivable (Increase) decrease in other assets and other investments Net cash (used in) provided by investing activities Financing activities: Repayment of trust preferred securities — Proceeds from stock transactions Payments of cash dividends - common Purchase of treasury stock — Net cash used in financing activities Increase (decrease) in cash Cash at beginning of year Cash at end of year $ $ $

International Bancshares Corp56

International Bancshares Corporation (Parent Company Only) Financial Information Quarterly (Tables)	12 Months Ended
	Dec. 31, 2015
Consolidated Statements of Income
Condensed Quarterly Income Statements	Condensed Quarterly Income Statements (Dollars in Thousands, Except Per Share Amounts) (Unaudited) Fourth Third Second First Quarter Quarter Quarter Quarter 2015 Interest income $ $ $ $ Interest expense Net interest income Provision for probable loan losses Non-interest income Non-interest expense Income before income taxes Income taxes Net income $ $ $ $ Per common share: Basic Net income $ $ $ $ Diluted Net income $ $ $ $ Condensed Quarterly Income Statements (Dollars in Thousands, Except Per Share Amounts) (Unaudited) Fourth Third Second First Quarter Quarter Quarter Quarter 2014 Interest income $ $ $ $ Interest expense Net interest income Provision for probable loan losses Non-interest income Non-interest expense Income before income taxes Income taxes Net income $ $ $ $ Per common share: Basic Net income $ $ $ $ Diluted Net income $ $ $ $

Summary of Significant Accoun57

Summary of Significant Accounting Policies (Details)	Oct. 01, 2015USD ($)	Dec. 31, 2015USD ($)item	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Summary of Significant Accounting Policies
Number of insurance-related subsidiaries | item		2
Investment Securities
Number of components in which other-than-temporary impairment is segregated | item		2
Non-Accrual Loans
Period of charge off for past due unsecured consumer loans		90 days
Minimum period that past due unsecured loans outstanding may not be placed on nonaccrual status under special circumstances		90 days
Maximum period of non-consumer loans outstanding that is used to evaluate whether loans should be placed on non-accrual status		90 days
Other Real Estate Owned
Other real estate owned		$ 55,850,000	$ 69,872,000
Income Taxes
Percentage of likelihood of realization of recognized tax benefit		50.00%
Liability for unrecognized tax benefits		$ 0	0
Interest expense related to uncertain tax positions		0	0	$ 0
Penalties related to uncertain tax positions		0	$ 0	$ 0
Goodwill and Identified Intangible Assets
Goodwill impairment loss	$ 0
Impairment of identified intangible assets		$ 0
Segments of an Enterprise and Related Information
Number of operating segments | item		1
Number of active operating bank subsidiaries | item		4

Investment Securities (Amortize

Investment Securities (Amortized Cost and Estimated Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Held-to-maturity securities
Amortized Cost	$ 2,400	$ 2,400
Estimated Fair Value	2,400	2,400
Carrying Value	2,400	2,400
Available-for-sale securities
Amortized Cost	4,196,034	4,894,428
Gross unrealized gains	50,165	68,516
Gross unrealized losses	(46,827)	(50,981)
Total investment securities	4,199,372	4,911,963
Assets/Liabilities Measured at Fair Value
Available-for-sale securities
Total investment securities	4,199,372	4,911,963
Carrying Value
Available-for-sale securities
Total investment securities	4,199,372	4,911,963
Other securities
Held-to-maturity securities
Amortized Cost	2,400	2,400
Estimated Fair Value	2,400	2,400
Carrying Value	2,400	2,400
Residential mortgage-backed securities
Available-for-sale securities
Amortized Cost	3,908,809	4,597,590
Gross unrealized gains	30,959	47,960
Gross unrealized losses	(46,557)	(45,178)
Residential mortgage-backed securities | Assets/Liabilities Measured at Fair Value
Available-for-sale securities
Total investment securities	3,893,211	4,600,372
Residential mortgage-backed securities | Carrying Value
Available-for-sale securities
Total investment securities	3,893,211	4,600,372
Mortgage-backed securities by Ginnie Mae
Available-for-sale securities
Total investment securities	1,147,143	1,503,774
Mortgage-backed securities by Fannie Mae and Freddie Mac
Available-for-sale securities
Total investment securities	2,724,839	3,072,535
Mortgage-backed securities by non-government entities
Available-for-sale securities
Total investment securities	21,229	24,063
States and political subdivisions
Available-for-sale securities
Amortized Cost	259,150	268,763
Gross unrealized gains	18,579	19,131
Gross unrealized losses	(25)	(5,618)
States and political subdivisions | Assets/Liabilities Measured at Fair Value
Available-for-sale securities
Total investment securities	277,704	282,276
States and political subdivisions | Carrying Value
Available-for-sale securities
Total investment securities	277,704	282,276
Other
Available-for-sale securities
Amortized Cost	28,075	28,075
Gross unrealized gains	627	1,425
Gross unrealized losses	(245)	(185)
Other | Assets/Liabilities Measured at Fair Value
Available-for-sale securities
Total investment securities	28,457	29,315
Other | Carrying Value
Available-for-sale securities
Total investment securities	$ 28,457	$ 29,315

Investment Securities (Contract

Investment Securities (Contractual Maturities and Estimated Fair Values) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Held-to-maturity debt securities amortized cost disclosures
Due in one year or less, held-to-maturity debt securities amortized cost	$ 1,200,000
Due after one year through five years, held-to-maturity debt securities amortized cost	1,200,000
Amortized cost, held-to-maturity debt securities	2,400,000	$ 2,400,000
Held-to-maturity debt securities, Estimated fair value disclosures
Due in one year or less, held-to-maturity debt securities, Estimated fair value	1,200,000
Due after one year through five years, held-to-maturity debt securities, Estimated fair value	1,200,000
Estimated Fair Value	2,400,000	2,400,000
Available-for-sale debt securities amortized cost disclosures
Due after ten years, available-for-sale debt securities amortized cost	259,150,000
Residential mortgage-backed securities, amortized cost	3,908,809,000
Equity securities, amortized cost	28,075,000
Amortized cost, Available for sale securities	4,196,034,000	4,894,428,000
Available for sale debt securities, Estimated Fair Value Disclosures
Due after ten years, available-for-sale debt securities, Estimated Fair Value	277,704,000
Residential mortgage-backed securities, Estimated Fair Value	3,893,211,000
Equity securities, Estimated Fair Value	28,457,000
Estimated fair value, Available for sale securities	4,199,372,000	4,911,963,000
Amortized cost of available for sale investment securities pledged	1,908,680,000
Fair value of available for sale investment securities pledged	1,903,734,000
Proceeds from sales and calls of available for sale securities	164,163,000	621,588,000	$ 178,123,000
Proceeds from sales of mortgage-backed securities	128,444,000	620,933,000	177,623,000
Gross gains realized on sales	2,450,000	9,479,000	9,601,000
Gross losses realized on sales	6,132,000	8,196,000	0
Impairment charges on available for sale securities	954,000	817,000	1,374,000
Impairment charges on available-for-sale investment securities, after tax	$ 620,100	$ 531,050	$ 893,100

Investment Securities (Fair Val

Investment Securities (Fair Value and Gross Unrealized Loss) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Available for sale:
Fair value, less than 12 months	$ 1,094,992	$ 816,979
Unrealized losses, less than 12 months	(9,387)	(5,008)
Fair value, 12 months or more	1,460,634	1,872,077
Unrealized losses, 12 months or more	(37,440)	(45,973)
Fair value, total	2,555,626	2,689,056
Unrealized losses, total	(46,827)	(50,981)
Residential mortgage-backed securities
Available for sale:
Fair value, less than 12 months	1,083,137	808,072
Unrealized losses, less than 12 months	(9,333)	(4,910)
Fair value, 12 months or more	1,454,550	1,836,218
Unrealized losses, 12 months or more	(37,224)	(40,268)
Fair value, total	2,537,687	2,644,290
Unrealized losses, total	(46,557)	(45,178)
States and political subdivisions
Available for sale:
Fair value, less than 12 months	6,814	8,833
Unrealized losses, less than 12 months	(19)	(97)
Fair value, 12 months or more	544	27,793
Unrealized losses, 12 months or more	(6)	(5,521)
Fair value, total	7,358	36,626
Unrealized losses, total	(25)	(5,618)
Other
Available for sale:
Fair value, less than 12 months	5,041	74
Unrealized losses, less than 12 months	(35)	(1)
Fair value, 12 months or more	5,540	8,066
Unrealized losses, 12 months or more	(210)	(184)
Fair value, total	10,581	8,140
Unrealized losses, total	$ (245)	$ (185)

Investment Securities (Reconcil

Investment Securities (Reconciliation of Credit Related Impairment Charges ) (Details) - Available for sale investments - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of credit-related impairment charges on investments recognized in earnings
Balance at the beginning	$ 12,623	$ 11,806	$ 10,432
Impairment charges recognized during period	954	817	1,374
Balance at the end	$ 13,577	$ 12,623	$ 11,806

Loans (Details)

Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Summary of loans, by loan type
Total loans	$ 5,950,914	$ 5,679,245
Commercial, financial and agricultural
Summary of loans, by loan type
Total loans	3,101,748	3,107,584
Real estate - mortgage
Summary of loans, by loan type
Total loans	962,582	910,326
Commercial Real Estate: Other Construction and Land Development
Summary of loans, by loan type
Total loans	1,649,827	1,414,977
Consumer
Summary of loans, by loan type
Total loans	57,744	61,137
Foreign
Summary of loans, by loan type
Total loans	$ 179,013	$ 185,221

Allowance for Probable Loan L63

Allowance for Probable Loan Losses (Changes by Loan Class) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for probable loan losses
Balance at the beginning of the period				$ 64,828				$ 70,161	$ 64,828	$ 70,161	$ 58,193
Losses charged to allowance									(27,125)	(23,465)	(14,455)
Recoveries credited to allowance									4,880	3,709	3,455
Net (losses) recoveries charged to allowance									(22,245)	(19,756)	(11,000)
Provision (credit) charged to operations	$ 5,429	$ 8,832	$ 7,767	2,377	$ 5,884	$ 2,816	$ 3,645	2,078	24,405	14,423	22,968
Balance at the end of the period	66,988				64,828				66,988	64,828	70,161
Commercial
Allowance for probable loan losses
Balance at the beginning of the period				22,352				22,433	22,352	22,433	11,632
Losses charged to allowance									(24,802)	(19,110)	(11,737)
Recoveries credited to allowance									3,135	2,979	2,690
Net (losses) recoveries charged to allowance									(21,667)	(16,131)	(9,047)
Provision (credit) charged to operations									20,746	16,050	19,848
Balance at the end of the period	21,431				22,352				21,431	22,352	22,433
Commercial Real Estate: Other Construction and Land Development
Allowance for probable loan losses
Balance at the beginning of the period				12,955				12,541	12,955	12,541	12,720
Losses charged to allowance									(695)	(680)	(278)
Recoveries credited to allowance									141	72	87
Net (losses) recoveries charged to allowance									(554)	(608)	(191)
Provision (credit) charged to operations									1,519	1,022	12
Balance at the end of the period	13,920				12,955				13,920	12,955	12,541
Commercial real estate: farmland and commercial
Allowance for probable loan losses
Balance at the beginning of the period				18,683				24,467	18,683	24,467	21,880
Losses charged to allowance									(492)	(1,893)	(600)
Recoveries credited to allowance									963	107	152
Net (losses) recoveries charged to allowance									471	(1,786)	(448)
Provision (credit) charged to operations									615	(3,998)	3,035
Balance at the end of the period	19,769				18,683				19,769	18,683	24,467
Commercial real estate: multifamily
Allowance for probable loan losses
Balance at the beginning of the period				846				776	846	776	694
Losses charged to allowance											(5)
Net (losses) recoveries charged to allowance											(5)
Provision (credit) charged to operations									402	70	87
Balance at the end of the period	1,248				846				1,248	846	776
Residential: first lien
Allowance for probable loan losses
Balance at the beginning of the period				3,589				3,812	3,589	3,812	4,390
Losses charged to allowance									(157)	(351)	(632)
Recoveries credited to allowance									30	49	61
Net (losses) recoveries charged to allowance									(127)	(302)	(571)
Provision (credit) charged to operations									47	79	(7)
Balance at the end of the period	3,509				3,589				3,509	3,589	3,812
Residential: junior lien
Allowance for probable loan losses
Balance at the beginning of the period				4,683				4,249	4,683	4,249	4,448
Losses charged to allowance									(275)	(661)	(620)
Recoveries credited to allowance									431	242	298
Net (losses) recoveries charged to allowance									156	(419)	(322)
Provision (credit) charged to operations									482	853	123
Balance at the end of the period	5,321				4,683				5,321	4,683	4,249
Consumer
Allowance for probable loan losses
Balance at the beginning of the period				660				750	660	750	1,289
Losses charged to allowance									(704)	(719)	(561)
Recoveries credited to allowance									170	210	162
Net (losses) recoveries charged to allowance									(534)	(509)	(399)
Provision (credit) charged to operations									512	419	(140)
Balance at the end of the period	638				660				638	660	750
Foreign
Allowance for probable loan losses
Balance at the beginning of the period				$ 1,060				$ 1,133	1,060	1,133	1,140
Losses charged to allowance										(51)	(22)
Recoveries credited to allowance									10	50	5
Net (losses) recoveries charged to allowance									10	(1)	(17)
Provision (credit) charged to operations									82	(72)	10
Balance at the end of the period	$ 1,152				$ 1,060				$ 1,152	$ 1,060	$ 1,133

Allowance for Probable Loan L64

Allowance for Probable Loan Losses (Additional Information) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Loan loss allowances, impaired financing receivable, evaluated individually or collectively
Loans Individually Evaluated for Impairment, Recorded Investment	$ 60,448	$ 76,171
Loans Individually Evaluated for Impairment, Allowance	2,206	12,221
Loans Collectively Evaluated for Impairment, Recorded Investment	5,890,466	5,603,074
Loans Collectively Evaluated for Impairment, Allowance	64,782	52,607
Commercial
Loan loss allowances, impaired financing receivable, evaluated individually or collectively
Loans Individually Evaluated for Impairment, Recorded Investment	30,946	40,175
Loans Individually Evaluated for Impairment, Allowance	1,704	9,112
Loans Collectively Evaluated for Impairment, Recorded Investment	935,905	1,049,311
Loans Collectively Evaluated for Impairment, Allowance	19,727	13,240
Commercial Real Estate: Other Construction and Land Development
Loan loss allowances, impaired financing receivable, evaluated individually or collectively
Loans Individually Evaluated for Impairment, Recorded Investment	6,221	10,876
Loans Individually Evaluated for Impairment, Allowance	100	1,890
Loans Collectively Evaluated for Impairment, Recorded Investment	1,643,606	1,404,101
Loans Collectively Evaluated for Impairment, Allowance	13,820	11,065
Commercial real estate: farmland and commercial
Loan loss allowances, impaired financing receivable, evaluated individually or collectively
Loans Individually Evaluated for Impairment, Recorded Investment	13,806	14,166
Loans Individually Evaluated for Impairment, Allowance	202	1,219
Loans Collectively Evaluated for Impairment, Recorded Investment	1,981,643	1,887,233
Loans Collectively Evaluated for Impairment, Allowance	19,567	17,464
Commercial real estate: multifamily
Loan loss allowances, impaired financing receivable, evaluated individually or collectively
Loans Individually Evaluated for Impairment, Recorded Investment	777	835
Loans Individually Evaluated for Impairment, Allowance	200
Loans Collectively Evaluated for Impairment, Recorded Investment	138,671	115,864
Loans Collectively Evaluated for Impairment, Allowance	1,048	846
Residential: first lien
Loan loss allowances, impaired financing receivable, evaluated individually or collectively
Loans Individually Evaluated for Impairment, Recorded Investment	5,699	5,840
Loans Collectively Evaluated for Impairment, Recorded Investment	404,545	416,186
Loans Collectively Evaluated for Impairment, Allowance	3,509	3,589
Residential: junior lien
Loan loss allowances, impaired financing receivable, evaluated individually or collectively
Loans Individually Evaluated for Impairment, Recorded Investment	950	2,895
Loans Collectively Evaluated for Impairment, Recorded Investment	551,388	485,405
Loans Collectively Evaluated for Impairment, Allowance	5,321	4,683
Consumer
Loan loss allowances, impaired financing receivable, evaluated individually or collectively
Loans Individually Evaluated for Impairment, Recorded Investment	1,297	1,384
Loans Collectively Evaluated for Impairment, Recorded Investment	56,447	59,753
Loans Collectively Evaluated for Impairment, Allowance	638	660
Foreign
Loan loss allowances, impaired financing receivable, evaluated individually or collectively
Loans Individually Evaluated for Impairment, Recorded Investment	752
Loans Collectively Evaluated for Impairment, Recorded Investment	178,261	185,221
Loans Collectively Evaluated for Impairment, Allowance	$ 1,152	$ 1,060

Allowance for Probable Loan L65

Allowance for Probable Loan Losses (Non-Accrual) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Loan loss allowances, financing receivable past due
Non-accrual loans, total	$ 47,685,000	$ 63,559,000	$ 62,823,000
Reduced interest income on non-accrual loans	3,298,000	4,013,000	4,088,000
Accruing loans contractually past due 90 days or more as to principal or interest payments	11,616,000	9,988,000	$ 7,197,000
Commercial
Loan loss allowances, financing receivable past due
Non-accrual loans, total	30,894,000	40,121,000
Accruing loans contractually past due 90 days or more as to principal or interest payments	2,566,000	2,890,000
Commercial Real Estate: Other Construction and Land Development
Loan loss allowances, financing receivable past due
Non-accrual loans, total	3,668,000	8,621,000
Accruing loans contractually past due 90 days or more as to principal or interest payments		439,000
Commercial real estate: farmland and commercial
Loan loss allowances, financing receivable past due
Non-accrual loans, total	11,543,000	11,903,000
Accruing loans contractually past due 90 days or more as to principal or interest payments	3,373,000	1,711,000
Commercial real estate: multifamily
Loan loss allowances, financing receivable past due
Non-accrual loans, total	777,000	835,000
Accruing loans contractually past due 90 days or more as to principal or interest payments	49,000	21,000
Residential: first lien
Loan loss allowances, financing receivable past due
Non-accrual loans, total	383,000	527,000
Accruing loans contractually past due 90 days or more as to principal or interest payments	4,093,000	3,901,000
Residential: junior lien
Loan loss allowances, financing receivable past due
Non-accrual loans, total	21,000	1,523,000
Accruing loans contractually past due 90 days or more as to principal or interest payments	640,000	431,000
Consumer
Loan loss allowances, financing receivable past due
Non-accrual loans, total	34,000	29,000
Accruing loans contractually past due 90 days or more as to principal or interest payments	453,000	482,000
Foreign
Loan loss allowances, financing receivable past due
Non-accrual loans, total	365,000
Accruing loans contractually past due 90 days or more as to principal or interest payments	$ 442,000	$ 113,000

Allowance for Probable Loan L66

Allowance for Probable Loan Losses (Impaired Loans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Interest Recognized
Loans accounted for as troubled debt restructuring	$ 15,719	$ 15,653
Period of charge off for past due unsecured commercial loans	90 days
Total troubled debt restructuring	$ 15,719	15,653
Class of financing receivable
Recorded investment:
Total impaired loans with related allowance	8,785	31,765
Total impaired loans with no related allowance	51,663	44,406
Unpaid principal balance:
Total impaired loans with an allowance recorded	9,233	32,232
Total impaired loans with no related allowance recorded	64,788	46,262
Related Allowance	2,206	12,221
Average recorded investment:
Total impaired loans with an allowance recorded	9,694	33,286
Total impaired loans with no related allowance recorded	53,575	43,202
Interest Recognized
Total impaired loans with an allowance recorded	92	92
Total impaired loans with no related allowance recorded	441	444
Commercial
Interest Recognized
Loans accounted for as troubled debt restructuring	2,419	2,500
Total troubled debt restructuring	2,419	2,500
Commercial | Class of financing receivable
Recorded investment:
Total impaired loans with related allowance	4,016	19,944
Total impaired loans with no related allowance	26,930	20,231
Unpaid principal balance:
Total impaired loans with an allowance recorded	4,156	20,026
Total impaired loans with no related allowance recorded	38,845	20,260
Related Allowance	1,704	9,112
Average recorded investment:
Total impaired loans with an allowance recorded	3,758	19,313
Total impaired loans with no related allowance recorded	30,847	18,563
Interest Recognized
Total impaired loans with no related allowance recorded	4	4
Commercial Real Estate: Other Construction and Land Development
Interest Recognized
Loans accounted for as troubled debt restructuring	2,553	2,254
Total troubled debt restructuring	2,553	2,254
Commercial Real Estate: Other Construction and Land Development | Class of financing receivable
Recorded investment:
Total impaired loans with related allowance	167	6,714
Total impaired loans with no related allowance	6,054	4,162
Unpaid principal balance:
Total impaired loans with an allowance recorded	169	6,949
Total impaired loans with no related allowance recorded	6,204	4,270
Related Allowance	100	1,890
Average recorded investment:
Total impaired loans with an allowance recorded	893	7,183
Total impaired loans with no related allowance recorded	6,455	4,882
Interest Recognized
Total impaired loans with no related allowance recorded	85	74
Commercial real estate: farmland and commercial
Interest Recognized
Loans accounted for as troubled debt restructuring	2,853	2,861
Total troubled debt restructuring	2,853	2,861
Commercial real estate: farmland and commercial | Class of financing receivable
Recorded investment:
Total impaired loans with related allowance	4,003	5,107
Total impaired loans with no related allowance	9,803	9,059
Unpaid principal balance:
Total impaired loans with an allowance recorded	4,309	5,257
Total impaired loans with no related allowance recorded	10,717	10,562
Related Allowance	202	1,219
Average recorded investment:
Total impaired loans with an allowance recorded	4,444	6,790
Total impaired loans with no related allowance recorded	7,258	8,664
Interest Recognized
Total impaired loans with an allowance recorded	92	92
Commercial real estate: multifamily | Class of financing receivable
Recorded investment:
Total impaired loans with related allowance	599
Total impaired loans with no related allowance	178	835
Unpaid principal balance:
Total impaired loans with an allowance recorded	599
Total impaired loans with no related allowance recorded	178	835
Related Allowance	200
Average recorded investment:
Total impaired loans with an allowance recorded	599
Total impaired loans with no related allowance recorded	205	363
Residential: first lien
Interest Recognized
Loans accounted for as troubled debt restructuring	5,316	5,313
Total troubled debt restructuring	5,316	5,313
Residential: first lien | Class of financing receivable
Recorded investment:
Total impaired loans with no related allowance	5,699	5,840
Unpaid principal balance:
Total impaired loans with no related allowance recorded	5,822	6,034
Average recorded investment:
Total impaired loans with no related allowance recorded	5,853	6,293
Interest Recognized
Total impaired loans with no related allowance recorded	264	273
Residential: junior lien
Interest Recognized
Loans accounted for as troubled debt restructuring	929	1,371
Total troubled debt restructuring	929	1,371
Residential: junior lien | Class of financing receivable
Recorded investment:
Total impaired loans with no related allowance	950	2,895
Unpaid principal balance:
Total impaired loans with no related allowance recorded	972	2,915
Average recorded investment:
Total impaired loans with no related allowance recorded	1,182	3,035
Interest Recognized
Total impaired loans with no related allowance recorded	68	90
Consumer
Interest Recognized
Loans accounted for as troubled debt restructuring	1,263	1,354
Total troubled debt restructuring	1,263	1,354
Consumer | Class of financing receivable
Recorded investment:
Total impaired loans with no related allowance	1,297	1,384
Unpaid principal balance:
Total impaired loans with no related allowance recorded	1,298	1,386
Average recorded investment:
Total impaired loans with no related allowance recorded	1,227	1,402
Interest Recognized
Total impaired loans with no related allowance recorded	3	$ 3
Foreign
Interest Recognized
Loans accounted for as troubled debt restructuring	386
Total troubled debt restructuring	386
Foreign | Class of financing receivable
Recorded investment:
Total impaired loans with no related allowance	752
Unpaid principal balance:
Total impaired loans with no related allowance recorded	752
Average recorded investment:
Total impaired loans with no related allowance recorded	548
Interest Recognized
Total impaired loans with no related allowance recorded	$ 17

Allowance for Probable Loan L67

Allowance for Probable Loan Losses (Aging) (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing receivable recorded investment
Past due 30-59 days	$ 15,584,000	$ 17,261,000
Past due 60-89 days	5,219,000	12,215,000
Past due 90 days or greater	47,470,000	67,770,000
Past due 90 days or greater and still accruing	11,616,000	9,988,000	$ 7,197,000
Past due, total	68,273,000	97,246,000
Loans, current	5,882,641,000	5,581,999,000
Total loans	5,950,914,000	5,679,245,000
Commercial
Financing receivable recorded investment
Past due 30-59 days	3,361,000	4,103,000
Past due 60-89 days	940,000	2,665,000
Past due 90 days or greater	28,615,000	40,665,000
Past due 90 days or greater and still accruing	2,566,000	2,890,000
Past due, total	32,916,000	47,433,000
Loans, current	933,936,000	1,042,053,000
Total loans	966,852,000	1,089,486,000
Commercial Real Estate: Other Construction and Land Development
Financing receivable recorded investment
Past due 30-59 days	193,000	596,000
Past due 60-89 days	293,000	10,000
Past due 90 days or greater	3,502,000	8,707,000
Past due 90 days or greater and still accruing		439,000
Past due, total	3,988,000	9,313,000
Loans, current	1,645,839,000	1,405,664,000
Total loans	1,649,827,000	1,414,977,000
Commercial real estate: farmland and commercial
Financing receivable recorded investment
Past due 30-59 days	2,684,000	2,905,000
Past due 60-89 days	1,328,000	7,131,000
Past due 90 days or greater	8,292,000	10,724,000
Past due 90 days or greater and still accruing	3,373,000	1,711,000
Past due, total	12,304,000	20,760,000
Loans, current	1,983,144,000	1,880,639,000
Total loans	1,995,448,000	1,901,399,000
Commercial real estate: multifamily
Financing receivable recorded investment
Past due 30-59 days	49,000	351,000
Past due 60-89 days	442,000
Past due 90 days or greater	826,000	856,000
Past due 90 days or greater and still accruing	49,000	21,000
Past due, total	1,317,000	1,207,000
Loans, current	138,131,000	115,492,000
Total loans	139,448,000	116,699,000
Residential: first lien
Financing receivable recorded investment
Past due 30-59 days	5,299,000	5,895,000
Past due 60-89 days	1,545,000	1,864,000
Past due 90 days or greater	4,295,000	4,267,000
Past due 90 days or greater and still accruing	4,093,000	3,901,000
Past due, total	11,139,000	12,026,000
Loans, current	399,105,000	410,000,000
Total loans	410,244,000	422,026,000
Residential: junior lien
Financing receivable recorded investment
Past due 30-59 days	713,000	899,000
Past due 60-89 days	413,000	231,000
Past due 90 days or greater	646,000	1,931,000
Past due 90 days or greater and still accruing	640,000	431,000
Past due, total	1,772,000	3,061,000
Loans, current	550,566,000	485,239,000
Total loans	552,338,000	488,300,000
Consumer
Financing receivable recorded investment
Past due 30-59 days	646,000	896,000
Past due 60-89 days	175,000	216,000
Past due 90 days or greater	487,000	507,000
Past due 90 days or greater and still accruing	453,000	482,000
Past due, total	1,308,000	1,619,000
Loans, current	56,436,000	59,518,000
Total loans	57,744,000	61,137,000
Foreign
Financing receivable recorded investment
Past due 30-59 days	2,639,000	1,616,000
Past due 60-89 days	83,000	98,000
Past due 90 days or greater	807,000	113,000
Past due 90 days or greater and still accruing	442,000	113,000
Past due, total	3,529,000	1,827,000
Loans, current	175,484,000	183,394,000
Total loans	$ 179,013,000	$ 185,221,000

Allowance for Probable Loan L68

Allowance for Probable Loan Losses (Credit Quality Indicator) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Loan portfolio by credit quality indicator
Portfolio, total	$ 5,950,914	$ 5,679,245
Pass
Loan portfolio by credit quality indicator
Portfolio, total	5,529,707	5,328,410
Special Review
Loan portfolio by credit quality indicator
Portfolio, total	45,599	54,561
Watch List - Pass
Loan portfolio by credit quality indicator
Portfolio, total	83,069	37,674
Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	232,091	182,429
Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	60,448	76,171
Commercial
Loan portfolio by credit quality indicator
Portfolio, total	966,852	1,089,486
Commercial | Pass
Loan portfolio by credit quality indicator
Portfolio, total	771,999	961,490
Commercial | Special Review
Loan portfolio by credit quality indicator
Portfolio, total	42,152	38,382
Commercial | Watch List - Pass
Loan portfolio by credit quality indicator
Portfolio, total	31,539	3,793
Commercial | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	90,215	45,646
Commercial | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	30,946	40,175
Commercial Real Estate: Other Construction and Land Development
Loan portfolio by credit quality indicator
Portfolio, total	1,649,827	1,414,977
Commercial Real Estate: Other Construction and Land Development | Pass
Loan portfolio by credit quality indicator
Portfolio, total	1,582,683	1,353,971
Commercial Real Estate: Other Construction and Land Development | Special Review
Loan portfolio by credit quality indicator
Portfolio, total	1,164	1,005
Commercial Real Estate: Other Construction and Land Development | Watch List - Pass
Loan portfolio by credit quality indicator
Portfolio, total	13,765	10,428
Commercial Real Estate: Other Construction and Land Development | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	45,994	38,697
Commercial Real Estate: Other Construction and Land Development | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	6,221	10,876
Commercial real estate: farmland and commercial
Loan portfolio by credit quality indicator
Portfolio, total	1,995,448	1,901,399
Commercial real estate: farmland and commercial | Pass
Loan portfolio by credit quality indicator
Portfolio, total	1,849,587	1,754,741
Commercial real estate: farmland and commercial | Special Review
Loan portfolio by credit quality indicator
Portfolio, total	2,283	11,674
Commercial real estate: farmland and commercial | Watch List - Pass
Loan portfolio by credit quality indicator
Portfolio, total	37,765	23,453
Commercial real estate: farmland and commercial | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	92,008	97,365
Commercial real estate: farmland and commercial | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	13,806	14,166
Commercial real estate: multifamily
Loan portfolio by credit quality indicator
Portfolio, total	139,448	116,699
Commercial real estate: multifamily | Pass
Loan portfolio by credit quality indicator
Portfolio, total	138,546	115,729
Commercial real estate: multifamily | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	125	135
Commercial real estate: multifamily | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	777	835
Residential: first lien
Loan portfolio by credit quality indicator
Portfolio, total	410,244	422,026
Residential: first lien | Pass
Loan portfolio by credit quality indicator
Portfolio, total	401,053	412,668
Residential: first lien | Special Review
Loan portfolio by credit quality indicator
Portfolio, total		3,500
Residential: first lien | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	3,492	18
Residential: first lien | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	5,699	5,840
Residential: junior lien
Loan portfolio by credit quality indicator
Portfolio, total	552,338	488,300
Residential: junior lien | Pass
Loan portfolio by credit quality indicator
Portfolio, total	551,138	484,968
Residential: junior lien | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	250	437
Residential: junior lien | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	950	2,895
Consumer
Loan portfolio by credit quality indicator
Portfolio, total	57,744	61,137
Consumer | Pass
Loan portfolio by credit quality indicator
Portfolio, total	56,440	59,622
Consumer | Watch List - Substandard
Loan portfolio by credit quality indicator
Portfolio, total	7	131
Consumer | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	1,297	1,384
Foreign
Loan portfolio by credit quality indicator
Portfolio, total	179,013	185,221
Foreign | Pass
Loan portfolio by credit quality indicator
Portfolio, total	178,261	$ 185,221
Foreign | Watch List - Impaired
Loan portfolio by credit quality indicator
Portfolio, total	$ 752

Bank Premises and Equipment (De

Bank Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Bank premises and equipment
Less: accumulated depreciation	$ (403,165)	$ (378,682)
Bank premises and equipment, net	516,716	526,423
Bank buildings and improvements
Bank premises and equipment
Bank premises and equipment, gross	$ 523,022	509,830
Bank buildings and improvements | Minimum
Bank premises and equipment
Estimated useful lives	5 years
Bank buildings and improvements | Maximum
Bank premises and equipment
Estimated useful lives	40 years
Furniture, equipment and vehicles
Bank premises and equipment
Bank premises and equipment, gross	$ 274,923	269,861
Furniture, equipment and vehicles | Minimum
Bank premises and equipment
Estimated useful lives	1 year
Furniture, equipment and vehicles | Maximum
Bank premises and equipment
Estimated useful lives	20 years
Land
Bank premises and equipment
Bank premises and equipment, gross	$ 121,936	$ 125,414
Land, building, furniture, fixture and equipment | Minimum
Bank premises and equipment
Estimated useful lives	7 years
Land, building, furniture, fixture and equipment | Maximum
Bank premises and equipment
Estimated useful lives	27 years

Goodwill and Other Intangible70

Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Identified intangible assets
Carrying Amount	$ 60,697	$ 60,697
Accumulated Amortization	60,544	59,900
Total identified intangibles, Net	153	797
Amortization expense	644	2,389	$ 4,633
Estimated amortization expense for each of the five succeeding fiscal years and thereafter
2,016	128
2,017	25
Total	153
Changes in carrying amount of goodwill	0	0
Core deposit premium
Identified intangible assets
Carrying Amount	58,675	58,675
Accumulated Amortization	58,522	58,379
Total identified intangibles, Net	153	296
Identified intangible (contract rights)
Identified intangible assets
Carrying Amount	2,022	2,022
Accumulated Amortization	$ 2,022	1,521
Total identified intangibles, Net		$ 501

Deposits (Details)

Deposits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Demand non-interest bearing
Domestic	$ 2,536,192	$ 2,382,935
Foreign	613,426	547,318
Total demand non-interest bearing	3,149,618	2,930,253
Savings and interest bearing demand
Domestic	2,450,102	2,488,458
Foreign	570,120	537,222
Total savings and interest bearing demand	3,020,222	3,025,680
$100,000 or more
Domestic	800,393	835,792
Foreign	848,355	864,346
Less than $100,000
Domestic	430,102	482,089
Foreign	287,563	300,465
Total time, certificates of deposit	2,366,413	2,482,692
Total deposits	8,536,253	8,438,625
Savings and interest bearing demand
Domestic	3,026	2,998	$ 3,182
Foreign	567	599	580
Total savings and interest bearing demand	3,593	3,597	3,762
$100,000 or more
Domestic	4,693	4,615	5,761
Foreign	4,116	4,529	5,590
Less than $100,000
Domestic	1,680	2,074	3,065
Foreign	744	815	1,028
Total time, certificates of deposit	11,233	12,033	15,444
Total interest expense on deposits	$ 14,826	$ 15,630	$ 19,206

Deposits (Scheduled Maturities)

Deposits (Scheduled Maturities) (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Scheduled maturities of time deposits
2,016	$ 2,127,790,000
2,017	170,950,000
2,018	46,317,000
2,019	19,305,000
2,020	1,986,000
Thereafter	65,000
Total time, certificates of deposit	2,366,413,000	$ 2,482,692,000
Time Deposits 250,000 or exceed	1,021,000	$ 1,027,000
Scheduled maturities of time deposits in amounts of $100,000 or more
Due within 3 months or less	682,567,000
Due after 3 months and within 6 months	416,167,000
Due after 6 months and within 12 months	398,985,000
Due after 12 months	151,985,000
Total	$ 1,649,704,000

Securities Sold Under Repurch73

Securities Sold Under Repurchase Agreements (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Collateral Securities and Repurchase Borrowing agreements
Collateralized Securities, Book Value of Securities Sold	$ 977,714,000	$ 1,127,170,000
Collateralized securities, Fair Value of Securities Sold	976,400,000	1,134,418,000
Repurchase Borrowing, Balance of Liability	$ 827,772,000	$ 858,350,000
Repurchase Borrowing, Weighted Average Interest Rate (as a percent)	2.66%	2.79%
Average outstanding amount	$ 872,611,000	$ 893,830,000
Maximum amount outstanding at any month end	907,211,000	892,341,000
Overnight agreements
Collateral Securities and Repurchase Borrowing agreements
Collateralized Securities, Book Value of Securities Sold	316,041,000	366,731,000
Collateralized securities, Fair Value of Securities Sold	317,799,000	370,704,000
Repurchase Borrowing, Balance of Liability	$ 250,702,000	$ 236,077,000
Repurchase Borrowing, Weighted Average Interest Rate (as a percent)	0.15%	0.16%
1 to 29 days
Collateral Securities and Repurchase Borrowing agreements
Collateralized Securities, Book Value of Securities Sold	$ 10,199,000	$ 3,717,000
Collateralized securities, Fair Value of Securities Sold	10,114,000	3,781,000
Repurchase Borrowing, Balance of Liability	$ 9,798,000	$ 1,016,000
Repurchase Borrowing, Weighted Average Interest Rate (as a percent)	0.50%	0.45%
30 to 90 days
Collateral Securities and Repurchase Borrowing agreements
Collateralized Securities, Book Value of Securities Sold	$ 4,388,000	$ 13,399,000
Collateralized securities, Fair Value of Securities Sold	4,356,000	13,628,000
Repurchase Borrowing, Balance of Liability	$ 4,320,000	$ 6,705,000
Repurchase Borrowing, Weighted Average Interest Rate (as a percent)	0.31%	0.38%
Over 90 days
Collateral Securities and Repurchase Borrowing agreements
Collateralized Securities, Book Value of Securities Sold	$ 647,086,000	$ 743,323,000
Collateralized securities, Fair Value of Securities Sold	644,131,000	746,305,000
Repurchase Borrowing, Balance of Liability	$ 562,952,000	$ 614,552,000
Repurchase Borrowing, Weighted Average Interest Rate (as a percent)	3.84%	3.83%

Other Borrowed Funds (Details)

Other Borrowed Funds (Details)	12 Months Ended
	Dec. 31, 2015USD ($)loan	Dec. 31, 2014USD ($)
Federal Home Loan Bank advances
Balance at year end	$ 505,750,000	$ 1,073,944,000
Federal Home Loan Bank advances short-term
Federal Home Loan Bank advances
Balance at year end	$ 355,750,000	$ 1,067,700,000
Rate on balance outstanding at year end (as a percent)	0.37%	0.15%
Average daily balance	$ 859,220,000	$ 1,077,973,000
Average rate (as a percent)	0.19%	0.16%
Maximum amount outstanding at any month end	$ 1,239,200,000	$ 1,352,500,000
Federal Home Loan Bank advances long-term
Federal Home Loan Bank advances
Balance at year end	$ 150,000,000	$ 6,244,000
Rate on balance outstanding at year end (as a percent)	0.31%	3.51%
Average daily balance	$ 5,314,000	$ 7,338,000
Average rate (as a percent)	0.31%	3.51%
Maximum amount outstanding at any month end	$ 150,000,000	$ 8,934,000
Federal Home Loan Bank advances long-term | Federal Home Loan Bank advances maturing January 2017
Federal Home Loan Bank advances
Number of long-term advances | loan	2
Federal Home Loan Bank advances long-term | Federal Home Loan Bank Advances Maturing January 13 2017
Federal Home Loan Bank advances
Balance at year end	$ 75,000,000
Federal Home Loan Bank advances long-term | Federal Home Loan Bank Advances Maturing January 25 2017
Federal Home Loan Bank advances
Balance at year end	$ 75,000,000

Junior Subordinated Deferrabl75

Junior Subordinated Deferrable Interest Debentures (Details)	Jul. 29, 2015USD ($)	Dec. 24, 2014USD ($)	Feb. 11, 2014USD ($)	Dec. 31, 2015USD ($)item	Dec. 31, 2014USD ($)
Junior subordinated deferrable interest debentures, major types of business trusts
Number of statutory business trusts issuing trust preferred securities | item				6
Junior subordinated deferrable interest debentures				$ 161,416,000	$ 175,416,000
Maximum number of consecutive quarterly period available for deferral of interest payment on Trusts VI, VII, VIII, IX, X, XI and XII | item				20
Percentage of capital securities issued by trust qualifying as Tier I capital, maximum				25.00%
Percentage of capital securities issued by trust qualifying as Tier II capital, minimum				25.00%
Capital securities issued by the trust, qualifying as Tier I capital				$ 161,416,000	$ 175,416,000
Trust VI
Junior subordinated deferrable interest debentures, major types of business trusts
Junior subordinated deferrable interest debentures				25,774,000
Trust VII
Junior subordinated deferrable interest debentures, major types of business trusts
Redemption price discount (as a percent)			6.00%
Retirement of capital securities			$ 10,310,000
Trust VIII
Junior subordinated deferrable interest debentures, major types of business trusts
Junior subordinated deferrable interest debentures				25,774,000
Trust IX
Junior subordinated deferrable interest debentures, major types of business trusts
Junior subordinated deferrable interest debentures				41,238,000
Trust X
Junior subordinated deferrable interest debentures, major types of business trusts
Retirement of capital securities	$ 13,000,000
Junior subordinated deferrable interest debentures	34,021,000			$ 21,021,000
Trust X and XI
Junior subordinated deferrable interest debentures, major types of business trusts
Redemption price discount (as a percent)				24.50%
Trust XI
Junior subordinated deferrable interest debentures, major types of business trusts
Redemption price discount (as a percent)		23.60%
Retirement of capital securities	1,000,000	$ 5,000,000
Junior subordinated deferrable interest debentures	$ 27,900,000	$ 32,900,000		$ 26,990,000
Trust XII
Junior subordinated deferrable interest debentures, major types of business trusts
Junior subordinated deferrable interest debentures				$ 20,619,000

Junior Subordinated Deferrabl76

Junior Subordinated Deferrable Interest Debentures (Key Information) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Jul. 29, 2015	Dec. 31, 2014	Dec. 24, 2014
Junior subordinated deferrable interest debentures, major types of business trusts
Junior subordinated deferrable interest debentures	$ 161,416,000		$ 175,416,000
Trust VI
Junior subordinated deferrable interest debentures, major types of business trusts
Junior subordinated deferrable interest debentures	$ 25,774,000
Interest rate (as a percent)	3.81%
Interest rate index	LIBOR
Spread on interest rate index (as a percent)	3.45%
Trust VIII
Junior subordinated deferrable interest debentures, major types of business trusts
Junior subordinated deferrable interest debentures	$ 25,774,000
Interest rate (as a percent)	3.37%
Interest rate index	LIBOR
Spread on interest rate index (as a percent)	3.05%
Trust IX
Junior subordinated deferrable interest debentures, major types of business trusts
Junior subordinated deferrable interest debentures	$ 41,238,000
Interest rate (as a percent)	1.95%
Interest rate index	LIBOR
Spread on interest rate index (as a percent)	1.62%
Trust X
Junior subordinated deferrable interest debentures, major types of business trusts
Junior subordinated deferrable interest debentures	$ 21,021,000	$ 34,021,000
Interest rate (as a percent)	1.98%
Interest rate index	LIBOR
Spread on interest rate index (as a percent)	1.65%
Trust XI
Junior subordinated deferrable interest debentures, major types of business trusts
Junior subordinated deferrable interest debentures	$ 26,990,000	$ 27,900,000		$ 32,900,000
Interest rate (as a percent)	1.95%
Interest rate index	LIBOR
Spread on interest rate index (as a percent)	1.62%
Trust XII
Junior subordinated deferrable interest debentures, major types of business trusts
Junior subordinated deferrable interest debentures	$ 20,619,000
Interest rate (as a percent)	1.86%
Interest rate index	LIBOR
Spread on interest rate index (as a percent)	1.45%

Earnings per Share ("EPS") (Det

Earnings per Share ("EPS") (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Basic EPS
Net Income (Numerator)	$ 34,973	$ 32,019	$ 33,875	$ 35,859	$ 38,553	$ 33,233	$ 37,719	$ 43,646	$ 136,726	$ 153,151	$ 126,351
Shares (Denominator)									66,411,193	66,872,500	67,195,180
Per Share Amount	$ 0.53	$ 0.48	$ 0.51	$ 0.54	$ 0.58	$ 0.50	$ 0.56	$ 0.65	$ 2.06	$ 2.29	$ 1.88
Diluted EPS
Net Income (Numerator)	$ 34,973	$ 32,019	$ 33,875	$ 35,859	$ 38,553	$ 33,233	$ 37,719	$ 43,646	$ 136,726	$ 153,151	$ 126,351
Potential dilutive common shares and warrants									225,160	183,956	119,679
Shares (Denominator)									66,636,353	67,056,456	67,314,859
Per Share Amount (in dollars per share)	$ 0.52	$ 0.48	$ 0.51	$ 0.54	$ 0.57	$ 0.50	$ 0.56	$ 0.65	$ 2.05	$ 2.28	$ 1.88

Employees' Profit Sharing Plan

Employees' Profit Sharing Plan (Details) - Deferred profit sharing plan - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employees' profit sharing plan
Minimum period of continuous employment to be fully vested	1 year
Profit sharing costs	$ 3,525,000	$ 3,510,000	$ 3,500,000

International Operations (Detai

International Operations (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Loans:
Accrued interest receivable	$ 31,572,000	$ 31,461,000
International banking services
Loans:
Commercial	138,125,000	150,078,000
Others	40,888,000	35,143,000
Total loans	179,013,000	185,221,000
Less allowance for probable loan losses	(1,152,000)	(1,060,000)
Net loans	177,861,000	184,161,000
Accrued interest receivable	697,000	702,000
Outstanding standby and commercial letters of credit	116,905,000
Revenues	$ 6,113,000	$ 6,034,000	$ 6,085,000

Income Taxes (Current and Defer

Income Taxes (Current and Deferred Portions of Net Income Tax Expense) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current
U.S.									$ 65,196	$ 72,561	$ 59,583
State									5,258	5,252	(1,530)
Foreign									(6)	1	3
Total current taxes									70,448	77,814	58,056
Deferred
U.S.									(261)	(969)	(1,692)
State									(71)	(58)	(125)
Total deferred taxes									(332)	(1,027)	(1,817)
Total income taxes	$ 16,393	$ 16,864	$ 17,996	$ 18,863	$ 20,432	$ 16,660	$ 19,165	$ 20,530	$ 70,116	$ 76,787	$ 56,239

Income Taxes (Income Tax Expens

Income Taxes (Income Tax Expense Differences from the Amount Computed by Applying the U.S. Federal Income Tax Rate) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes
Income tax expense differences from the amount computed by applying the U.S. Federal income tax rate to income before income taxes (as a percent)									35.00%	35.00%	35.00%
Reasons for the difference of income tax expense
Computed expected tax expense									$ 72,389	$ 80,560	$ 64,183
Change in taxes resulting from:
Tax-exempt interest income									(3,910)	(4,554)	(4,828)
State tax, net of federal income taxes and tax credit									3,371	3,377	(110)
Tax refunds											(966)
Other investment income									(3,540)	(3,615)	(2,656)
Other									1,806	1,019	616
Total income taxes	$ 16,393	$ 16,864	$ 17,996	$ 18,863	$ 20,432	$ 16,660	$ 19,165	$ 20,530	$ 70,116	$ 76,787	$ 56,239

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets and Deferred Tax Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Loans receivable, principally due to the allowance for probable loan losses	$ 25,689	$ 24,849
Other real estate owned	3,224	3,453
Impairment charges on available-for-sale securities	5,959	5,618
Accrued expenses	137	268
Other	7,411	5,809
Total deferred tax assets	42,420	39,997
Deferred tax liabilities:
Bank premises and equipment, principally due to differences on depreciation	(18,266)	(18,314)
Net unrealized gains on available for sale investment securities	(1,171)	(6,182)
Identified intangible assets and goodwill	(20,169)	(18,787)
Other	(13,099)	(12,303)
Total deferred tax liabilities	52,705	55,586
Total deferred tax liabilities	$ (10,285)	$ (15,589)

Stock Options (Details)

Stock Options (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 05, 2012
Stock options under 2012 Plan
Stock option details
Shares available for future grants	178,250			800,000
Maximum exercisable period for options granted	10 years
Black-Scholes-Merton option valuation model assumptions
Expected Life	7 years 7 months 10 days	7 years 7 months 17 days
Dividend yield (as a percent)	2.36%	2.01%
Interest rate (as a percent)	1.91%	2.28%
Volatility (as a percent)	46.52%	47.36%
Stock option activity
Options outstanding at the beginning of the period (in shares)	993,889
Plus: Options granted (in shares)	56,500
Less:
Options exercised (in shares)	82,241
Options expired (in shares)	44,075
Options forfeited (in shares)	52,346
Options outstanding at the end of the period (in shares)	871,727	993,889
Options fully vested and exercisable at the end of the period (in shares)	212,821
Stock options, weighted average exercise price
Options outstanding at the beginning, weighted average exercise price (in dollars per share)	$ 18.94
Plus: Options granted, weighted average exercise price (in dollars per share)	24.24
Less:
Options exercised, weighted average exercise price (in dollars per share)	17.15
Options expired, weighted average exercise price (in dollars per share)	26.73
Options forfeited, weighted average exercise price (in dollars per share)	18.52
Options outstanding at the end, weighted average exercise price (in dollars per share)	19.08	$ 18.94
Options fully vested and exercisable at the end, weighted average exercise price (in dollars per share)	$ 13.99
Stock options, weighted average remaining contractual term
Options outstanding at the end, weighted average remaining contractual term	6 years 7 months 28 days
Options fully vested and exercisable at the end, weighted average remaining contractual term	3 years 4 months 17 days
Stock options, aggregate intrinsic value
Options outstanding at the end, aggregate intrinsic value	$ 5,769,000
Options fully vested and exercisable at the end, aggregate intrinsic value	2,492,000
Stock-based compensation expense	1,172,000	$ 1,058,000	$ 414,000
Stock-based compensation cost, unrecognized, related to non-vested options	$ 3,334,000
Stock-based compensation cost, unrecognized, related to non-vested options, weighted-average period of recognition	2 years
Other information pertaining to option activity
Weighted average grant date fair value of stock options granted (in dollars per share)	$ 9.42	$ 9.07	$ 9.05
Total fair value of stock options vested	$ 872,000	$ 376,000	$ 480,000
Total intrinsic value of stock options exercised	$ 781,000	$ 468,000	$ 171,000
Incentive stock options granted to 10% shareholders
Stock option details
Maximum exercisable period for options granted	5 years

Long Term Restricted Stock Un84

Long Term Restricted Stock Units (Details) - 2009 International Bancshares Corporation Long-Term Restricted Stock Unit Plan	1 Months Ended	12 Months Ended
	Dec. 31, 2009item	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2012USD ($)	Dec. 31, 2011USD ($)	Dec. 31, 2010USD ($)	Dec. 31, 2009USD ($)
CPP-compliant long-term RSUs
Long-Term Restricted Stock Units
Restricted stock compensation limit as a percentage to the total annual compensation of the President			33.00%
CPP-compliant long-term RSUs granted for performance in 2012
Long-Term Restricted Stock Units
Compensation cost				$ 425,000
CPP-compliant long-term RSUs granted for performance in 2011
Long-Term Restricted Stock Units
Compensation cost					$ 400,000
Cash amounts paid on vesting of awards		$ 572,746
CPP-compliant long-term RSUs granted for performance in 2010
Long-Term Restricted Stock Units
Compensation cost						$ 400,000
Cash amounts paid on vesting of awards				358,782
CPP-compliant long-term RSUs granted for performance in 2009
Long-Term Restricted Stock Units
Compensation cost							$ 250,000
Cash amounts paid on vesting of awards			$ 591,344	$ 262,842
Restricted Stock Units (RSUs)
Long-Term Restricted Stock Units
Minimum number of non-employee members of the Board needed to authorize restricted stock units | item	2

Commitments, Contingent Liabi85

Commitments, Contingent Liabilities and Other Matters (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments, Contingent Liabilities and Other Matters
Total rental expense	$ 6,200,000	$ 7,200,000	$ 7,300,000
Minimum period for non-cancellable sub-leases	1 year
Aggregate future minimum rentals to be received under non-cancellable sub-leases	$ 107,193,000
Approximate cash maintained to satisfy regulatory reserve requirements	104,684,000	$ 106,841,000
Future minimum lease payments due under non-cancellable operating leases
2,016	3,762,000
2,017	1,948,000
2,018	1,076,000
2,019	600,000
2,020	250,000
Thereafter	254,000
Total	$ 7,890,000

Transactions with Related Par86

Transactions with Related Parties (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Transactions with Related Parties
Aggregate amount receivable from related parties	$ 31,975,000	$ 26,382,000

Financial Instruments with Of87

Financial Instruments with Off-Statement of Condition Risk and Concentrations of Credit Risk (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Maximum
Financial amounts of instruments, whose contract amounts represent credit risks
Credit risk commitment, maximum expiration date	1 year
Commitments to extend credit
Financial amounts of instruments, whose contract amounts represent credit risks
Outstanding amount of financial instruments whose, contract amounts represent credit risks	$ 1,648,353,000
Credit card lines
Financial amounts of instruments, whose contract amounts represent credit risks
Outstanding amount of financial instruments whose, contract amounts represent credit risks	16,701,000
Standby letters of credit
Financial amounts of instruments, whose contract amounts represent credit risks
Outstanding amount of financial instruments whose, contract amounts represent credit risks	111,347,000
Commercial letters of credit
Financial amounts of instruments, whose contract amounts represent credit risks
Outstanding amount of financial instruments whose, contract amounts represent credit risks	5,558,000
Unsecured letters of credit
Financial amounts of instruments, whose contract amounts represent credit risks
Guarantee obligations, maximum exposure	111,347,000
Unsecured letters of credit	$ 37,454,000	$ 40,875,000

Capital Requirements (Details)

Capital Requirements (Details) - USD ($)	Nov. 28, 2012	Dec. 31, 2015	Nov. 28, 2012
Capital Requirements
Series A cumulative perpetual preferred shares, aggregate liquidation value		$ 216,000,000
Series A cumulative perpetual preferred shares, issued		216,000
Series A cumulative perpetual preferred shares, par value (in dollars per share)		$ 0.01
Series A cumulative perpetual preferred shares, per share liquidation value (in dollars per share)		$ 1,000
Warrants to purchase entity's common stock (in shares)		1,326,238
Warrants, exercise price (in dollars per share)		$ 24.43
Cash dividends (as a percent)		33.00%
Warrants, term		10 years
Senior preferred stock, dividend rate for first five years (as a percent)		5.00%
Senior preferred stock, dividend rate thereafter (as a percent)		9.00%
Senior Preferred Stock held by Treasury repurchased (in shares)	216,000
Preferred stock dividends to the U.S. Treasury			$ 41,520,139
Dividend payable by subsidiaries, maximum		$ 776,750,000

Capital Requirements (Capital A

Capital Requirements (Capital Amounts and Ratios) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Capital Requirements
Total Capital (to Risk Weighted Assets), Actual Ratio (as a percent)		20.24%
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent)		19.34%
Tier 1 capital (to Average Assets), Actual Ratio (as a percent)		12.33%
Minimum
Capital Requirements
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount		$ 602,847
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount		301,424
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Amount		$ 472,864
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)		8.00%
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)		4.00%
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Ratio (as a percent)		4.00%
Parent Company
Capital Requirements
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Amount	$ 1,380,801
Common Equity Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent)	16.81%
Total Capital (to Risk Weighted Assets), Actual Amount	$ 1,605,419	$ 1,524,998
Tier 1 Capital (to Risk Weighted Assets), Actual Amount	1,535,443	1,457,068
Tier 1 Capital (to Average Assets), Actual Amount	$ 1,535,443	1,457,068
Total Capital (to Risk Weighted Assets), Actual Ratio (as a percent)	19.54%
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent)	18.69%
Tier 1 capital (to Average Assets), Actual Ratio (as a percent)	13.15%
Parent Company | Minimum
Capital Requirements
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	$ 369,726
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	4.50%
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	$ 657,291
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	492,968
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Amount	$ 466,897
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	8.00%
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	6.00%
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Ratio (as a percent)	4.00%
International Bank of Commerce, Laredo
Capital Requirements
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Amount	$ 1,151,812
Common Equity Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent)	16.42%
Total Capital (to Risk Weighted Assets), Actual Amount	$ 1,213,377	1,131,528
Tier 1 Capital (to Risk Weighted Assets), Actual Amount	1,151,812	1,071,360
Tier 1 Capital (to Average Assets), Actual Amount	$ 1,151,812	$ 1,071,360
Total Capital (to Risk Weighted Assets), Actual Ratio (as a percent)	17.30%	17.31%
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent)	16.42%	16.39%
Tier 1 capital (to Average Assets), Actual Ratio (as a percent)	12.09%	11.22%
International Bank of Commerce, Laredo | Minimum
Capital Requirements
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	$ 315,707
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 456,022
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	4.50%
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	6.50%
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	$ 561,258	$ 523,006
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	701,572	653,757
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	420,943	261,503
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	561,258	392,254
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Amount	381,105	381,804
Tier 1 Capital (to Average Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 476,381	$ 477,255
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	8.00%	8.00%
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	10.00%	10.00%
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	6.00%	4.00%
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	8.00%	6.00%
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Ratio (as a percent)	4.00%	4.00%
Tier 1 Capital (to Average Assets), To Be well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	5.00%	5.00%
International Bank of Commerce, Brownsville
Capital Requirements
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Amount	$ 154,141
Common Equity Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent)	26.26%
Total Capital (to Risk Weighted Assets), Actual Amount	$ 159,913	$ 151,489
Tier 1 Capital (to Risk Weighted Assets), Actual Amount	154,141	145,584
Tier 1 Capital (to Average Assets), Actual Amount	$ 154,141	$ 145,584
Total Capital (to Risk Weighted Assets), Actual Ratio (as a percent)	27.24%	28.60%
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent)	26.26%	27.48%
Tier 1 capital (to Average Assets), Actual Ratio (as a percent)	15.03%	13.96%
International Bank of Commerce, Brownsville | Minimum
Capital Requirements
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	$ 26,418
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 38,159
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	4.50%
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	6.50%
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	$ 46,965	$ 42,381
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	58,706	52,976
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	35,224	21,190
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	46,965	31,785
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Amount	41,034	41,717
Tier 1 Capital (to Average Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 51,293	$ 52,146
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	8.00%	8.00%
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	10.00%	10.00%
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	6.00%	4.00%
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	8.00%	6.00%
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Ratio (as a percent)	4.00%	4.00%
Tier 1 Capital (to Average Assets), To Be well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	5.00%	5.00%
International Bank of Commerce, Zapata
Capital Requirements
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Amount	$ 66,153
Common Equity Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent)	35.71%
Total Capital (to Risk Weighted Assets), Actual Amount	$ 67,470	$ 60,946
Tier 1 Capital (to Risk Weighted Assets), Actual Amount	66,153	60,035
Tier 1 Capital (to Average Assets), Actual Amount	$ 66,153	$ 60,035
Total Capital (to Risk Weighted Assets), Actual Ratio (as a percent)	36.42%	33.83%
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent)	35.71%	33.33%
Tier 1 capital (to Average Assets), Actual Ratio (as a percent)	13.15%	10.88%
International Bank of Commerce, Zapata | Minimum
Capital Requirements
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	$ 8,336
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 12,042
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	4.50%
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	6.50%
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	$ 14,820	$ 14,412
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	18,525	18,041
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	11,115	7,206
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	14,820	10,809
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Amount	20,129	22,081
Tier 1 Capital (to Average Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 25,161	$ 27,602
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	8.00%	8.00%
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	10.00%	10.00%
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	6.00%	4.00%
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	8.00%	6.00%
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Ratio (as a percent)	4.00%	4.00%
Tier 1 Capital (to Average Assets), To Be well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	5.00%	5.00%
Commerce Bank
Capital Requirements
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Amount	$ 72,882
Common Equity Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent)	36.17%
Total Capital (to Risk Weighted Assets), Actual Amount	$ 74,204	$ 68,291
Tier 1 Capital (to Risk Weighted Assets), Actual Amount	72,882	67,347
Tier 1 Capital (to Average Assets), Actual Amount	$ 72,882	$ 67,347
Total Capital (to Risk Weighted Assets), Actual Ratio (as a percent)	36.83%	37.42%
Tier 1 capital (to Risk Weighted Assets), Actual Ratio (as a percent)	36.17%	36.90%
Tier 1 capital (to Average Assets), Actual Ratio (as a percent)	12.94%	12.04%
Commerce Bank | Minimum
Capital Requirements
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	$ 9,067
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 13,097
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	4.50%
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	6.50%
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	$ 16,119	$ 14,600
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	20,149	18,251
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Amount	12,089	7,300
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	16,119	10,950
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Amount	22,521	22,373
Tier 1 Capital (to Average Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 28,151	$ 27,966
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	8.00%	8.00%
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	10.00%	10.00%
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Ratio (as a percent)	6.00%	4.00%
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	8.00%	6.00%
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes Ratio (as a percent)	4.00%	4.00%
Tier 1 Capital (to Average Assets), To Be well Capitalized Under Prompt Corrective Action Provisions Ratio (as a percent)	5.00%	5.00%

Fair Value (Statements of Condi

Fair Value (Statements of Condition) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets:
Available for sale securities	$ 4,199,372	$ 4,911,963
Measured on a recurring basis:
Assets:
Available for sale securities	4,199,372	4,911,963
Measured on a recurring basis: | Residential mortgage-backed securities
Assets:
Available for sale securities	3,893,210	4,600,372
Measured on a recurring basis: | States and political subdivisions
Assets:
Available for sale securities	277,705	282,276
Measured on a recurring basis: | Other
Assets:
Available for sale securities	28,457	29,315
Measured on a recurring basis: | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Available for sale securities	28,457	29,315
Measured on a recurring basis: | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other
Assets:
Available for sale securities	28,457	29,315
Measured on a recurring basis: | Significant Other Observable Inputs (Level 2)
Assets:
Available for sale securities	4,149,686	4,858,585
Measured on a recurring basis: | Significant Other Observable Inputs (Level 2) | Residential mortgage-backed securities
Assets:
Available for sale securities	3,871,981	4,576,309
Measured on a recurring basis: | Significant Other Observable Inputs (Level 2) | States and political subdivisions
Assets:
Available for sale securities	277,705	282,276
Measured on a recurring basis: | Significant Unobservable Inputs (Level 3)
Assets:
Available for sale securities	21,229	24,063
Measured on a recurring basis: | Significant Unobservable Inputs (Level 3) | Residential mortgage-backed securities
Assets:
Available for sale securities	$ 21,229	$ 24,063

Fair Value (Mortgage-backed Sec

Fair Value (Mortgage-backed Securities Activity) (Details) - Residential mortgage-backed securities $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Reconciliation of activity for mortgage-backed securities on a net basis
Balance at the beginning of the period	$ 24,063
Principal paydowns	(3,205)
Total unrealized gains (losses) included in:
Other comprehensive income	1,325
Impairment realized in earnings	(954)
Balance at the end of the period	$ 21,229

Fair Value (Fair Value Measurem

Fair Value (Fair Value Measurement and Assumptions) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Assets:
Impaired Loans	$ 51,021,000	$ 65,551,000
Non-financial assets:
Other real estate owned	55,850,000	69,872,000
Assumptions used in discounted cash flow model to determine fair value of investments classified within level 3
Charges to allowance for probable loan losses in connection with other real estate owned	696,000	367,000
Adjustment to fair value in connection with other real estate owned	1,023,000	597,000
Impaired commercial collateral dependent loans	51,021,000	65,551,000
Impaired commercial collateral dependent receivables appraisals to determine fair value within immediately preceding twelve months	39,520,000	52,092,000
Impaired collateral dependent commercial loans with an internal evaluation completed in the last twelve months	$ 2,958,000	$ 5,307,000
Significant Unobservable Inputs (Level 3) | Bond meeting the original contract terms
Assumptions used in discounted cash flow model to determine fair value of investments classified within level 3
Minimum period of residential mortgage loan performance under original contract terms	24 months	24 months
Estimated future principal prepayment rate assumption, low end of range (as a percent)	7.00%	7.00%
Default rate assumptions (as a percent)	1.00%	1.00%
Loss severity rate assumptions, first year (as a percent)	25.00%	25.00%
Estimated future principal prepayment rate assumption, discount rate (as a percent)	13.00%	13.00%
Significant Unobservable Inputs (Level 3) | Bond not meeting the original contract terms
Assumptions used in discounted cash flow model to determine fair value of investments classified within level 3
Estimated future principal prepayment rate assumption, low end of range (as a percent)	2.00%	2.00%
Default rate assumptions (as a percent)	4.50%	4.50%
Loss severity rate assumptions, first year (as a percent)	60.00%
Decrease in loss severity rates, following five years (as a percent)	5.00%
Loss severity rate, thereafter (as a percent)	25.00%
Estimated future principal prepayment rate assumption, discount rate (as a percent)	13.00%
Measured on a non-recurring basis:
Assets:
Impaired Loans	$ 18,033,000	$ 29,501,000
Non-financial assets:
Other real estate owned	12,705,000	6,112,000
Assumptions used in discounted cash flow model to determine fair value of investments classified within level 3
Change in net provision, impaired loans	(8,589,000)	(1,557,000)
Change in net provision, other real estate owned	1,023,000	597,000
Impaired commercial collateral dependent loans	18,033,000	29,501,000
Measured on a non-recurring basis: | Significant Unobservable Inputs (Level 3)
Assets:
Impaired Loans	18,033,000	29,501,000
Non-financial assets:
Other real estate owned	12,705,000	6,112,000
Assumptions used in discounted cash flow model to determine fair value of investments classified within level 3
Impaired commercial collateral dependent loans	$ 18,033,000	$ 29,501,000

Fair Value (Details)

Fair Value (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Deposits
Carrying amount of time deposits	$ 2,366,413,000	$ 2,482,692,000
Significant Other Observable Inputs (Level 2)
Other borrowed funds
Carrying amount of the long-term FHLB borrowings	6,244,000
Estimated fair value of long-term FHLB borrowings	6,645,000
Significant Unobservable Inputs (Level 3)
Loans
Carrying amount of fixed rate performing loans	1,383,836,000	1,352,147,000
Estimated fair value of fixed rate performing loans	1,362,248,000	1,285,648,000
Deposits
Carrying amount of time deposits	2,366,413,000	2,482,692,000
Estimated fair value of time deposits	2,365,390,000	2,480,390,000
Securities Sold Under Repurchase Agreements
Carrying amount of long-term repurchase agreements	560,000,000	610,000,000
Estimated fair value of long-term repurchase agreements	$ 527,198,600	$ 558,097,500

International Bancshares Corp94

International Bancshares Corporation (Parent Company Only) Financial Information Statements of Condition (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
ASSETS
Other investments	$ 468,791	$ 440,670
Other assets	114,354	130,711
Total assets	11,772,869	12,196,520
Liabilities:
Junior subordinated deferrable interest debentures	161,416	175,416
Other liabilities	76,175	69,527
Total liabilities	10,107,366	10,615,862
Shareholders' equity:
Common shares	95,866	95,784
Surplus	167,980	165,520
Retained earnings	1,683,600	1,585,389
Accumulated other comprehensive income (loss)	2,167	11,397
Total shareholders' equity before treasury stock	1,949,613	1,858,090
Less cost of shares in treasury	(284,110)	(277,432)
Total shareholders' equity	1,665,503	1,580,658	$ 1,424,408	$ 1,435,708
Total liabilities and shareholders' equity	11,772,869	12,196,520
Parent Company
ASSETS
Cash	2,977	9,252
Other investments	69,160	69,042
Notes receivable	99	204
Investment in subsidiaries	1,766,592	1,691,553
Other assets	45	50
Total assets	1,838,873	1,770,101
Liabilities:
Junior subordinated deferrable interest debentures	161,416	175,416
Due to IBC Trading	21	21
Other liabilities	11,933	14,006
Total liabilities	173,370	189,443
Shareholders' equity:
Common shares	95,866	95,784
Surplus	167,980	165,520
Retained earnings	1,683,600	1,585,389
Accumulated other comprehensive income (loss)	2,167	11,397
Total shareholders' equity before treasury stock	1,949,613	1,858,090
Less cost of shares in treasury	(284,110)	(277,432)
Total shareholders' equity	1,665,503	1,580,658
Total liabilities and shareholders' equity	$ 1,838,873	$ 1,770,101

International Bancshares Corp95

International Bancshares Corporation (Parent Company Only) Financial Information Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Expenses:
Interest expense (Debentures)									$ 4,099	$ 4,264	$ 4,665
Income before federal income taxes and equity in undistributed net income of subsidiaries	$ 51,366	$ 48,883	$ 51,871	$ 54,722	$ 58,985	$ 49,893	$ 56,884	$ 64,176	206,842	229,938	182,590
Income tax expense (benefit)	$ 16,393	$ 16,864	$ 17,996	$ 18,863	$ 20,432	$ 16,660	$ 19,165	$ 20,530	70,116	76,787	56,239
Net income									136,726	153,151	126,351
Parent Company
Income:
Dividends from subsidiaries									51,575	71,389	30,000
Interest income on notes receivable									7	15	18
Interest income on other investments									5,738	6,862	12,301
Other									3,442	1,923	26
Total income									60,762	80,189	42,345
Expenses:
Interest expense (Debentures)									4,099	4,264	4,665
Other									3,037	1,099	1,889
Total expenses									7,136	5,363	6,554
Income before federal income taxes and equity in undistributed net income of subsidiaries									53,626	74,826	35,791
Income tax expense (benefit)									386	1,370	2,529
Income before equity in undistributed net income of subsidiaries									53,240	73,456	33,262
Equity in undistributed (distributed) net income of subsidiaries									83,486	79,695	93,089
Net income									$ 136,726	$ 153,151	$ 126,351

International Bancshares Corp96

International Bancshares Corporation (Parent Company Only) Financial Information Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities:
Net income	$ 136,726	$ 153,151	$ 126,351
Adjustments to reconcile net income to net cash provided by operating activities:
Impairment charges on available for sale securities	954	817	1,374
Stock compensation expense	1,172	1,058	414
(Decrease) increase in other liabilities	(6,567)	(7,482)	(2,274)
Net cash provided by operating activities	203,649	193,037	209,126
Investing activities:
Principal collected on mortgage-backed securities	854,736	787,361	1,223,532
Net cash provided by (used in) investing activities	373,225	(90,399)	(447,649)
Financing activities:
Proceeds from stock transactions	1,370	555	265
Payments of cash dividends - common	(38,515)	(34,762)	(28,894)
Purchase of treasury stock	(6,678)	(18,923)
Net cash (used in) provided by financing activities	(558,967)	(122,277)	230,208
Increase (decrease) in cash and cash equivalents	17,907	(19,639)	(8,315)
Cash and cash equivalents at beginning of period	255,146	274,785	283,100
Cash and cash equivalents at end of period	273,053	255,146	274,785
Parent Company
Operating activities:
Net income	136,726	153,151	126,351
Adjustments to reconcile net income to net cash provided by operating activities:
Impairment charges on available for sale securities	385	254	754
Stock compensation expense	1,172	1,058	414
(Decrease) increase in other liabilities	(1,998)	416	(969)
Equity in (undistributed) distributed net income of subsidiaries	(83,486)	(79,695)	(93,089)
Net cash provided by operating activities	52,799	75,184	33,461
Investing activities:
Principal collected on mortgage-backed securities	474	1,301	1,207
Net decrease in notes receivable	105	109	96
(Increase) decrease in other assets and other investments	(1,830)	(7,008)	432
Net cash provided by (used in) investing activities	(1,251)	(5,598)	1,735
Financing activities:
Repayment of trust preferred securities	(14,000)	(15,310)
Proceeds from stock transactions	1,370	555	265
Payments of cash dividends - common	(38,515)	(34,762)	(28,894)
Purchase of treasury stock	(6,678)	(18,923)
Net cash (used in) provided by financing activities	(57,823)	(68,440)	(28,629)
Increase (decrease) in cash and cash equivalents	(6,275)	1,146	6,567
Cash and cash equivalents at beginning of period	9,252	8,106	1,539
Cash and cash equivalents at end of period	$ 2,977	$ 9,252	$ 8,106

International Bancshares Corp97

International Bancshares Corporation (Parent Company Only) Financial Information Quarterly (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements of Income
Total interest income	$ 97,923	$ 100,724	$ 98,975	$ 99,132	$ 98,664	$ 97,958	$ 99,340	$ 97,637	$ 396,754	$ 393,599	$ 363,217
Total interest expense	10,730	11,133	11,210	11,244	11,461	11,575	11,634	11,873	44,317	46,543	54,632
Net interest income	87,193	89,591	87,765	87,888	87,203	86,383	87,706	85,764	352,437	347,056	308,585
Provision for probable loan losses	5,429	8,832	7,767	2,377	5,884	2,816	3,645	2,078	24,405	14,423	22,968
Total non-interest income	35,734	43,022	40,144	36,834	42,226	36,483	41,453	58,186	155,734	178,348	189,605
Total non-interest expense	66,132	74,898	68,271	67,623	64,560	70,157	68,630	77,696	276,924	281,043	292,632
Income before income taxes	51,366	48,883	51,871	54,722	58,985	49,893	56,884	64,176	206,842	229,938	182,590
Provision for income taxes	16,393	16,864	17,996	18,863	20,432	16,660	19,165	20,530	70,116	76,787	56,239
Net income available to common shareholders	$ 34,973	$ 32,019	$ 33,875	$ 35,859	$ 38,553	$ 33,233	$ 37,719	$ 43,646	$ 136,726	$ 153,151	$ 126,351
Basic EPS
Net income (in dollars per share)	$ 0.53	$ 0.48	$ 0.51	$ 0.54	$ 0.58	$ 0.50	$ 0.56	$ 0.65	$ 2.06	$ 2.29	$ 1.88
Diluted EPS
Net income (in dollars per share)	$ 0.52	$ 0.48	$ 0.51	$ 0.54	$ 0.57	$ 0.50	$ 0.56	$ 0.65	$ 2.05	$ 2.28	$ 1.88