Texas Capital Bancshares (TCBI) 10-Q 19 Jul 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Jul. 18, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	TEXAS CAPITAL BANCSHARES INC/TX
Entity Central Index Key	1,077,428
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		50,158,736

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Assets
Cash and due from banks	$ 174,687	$ 178,010
Interest-bearing deposits in other banks	3,249,107	2,697,581
Federal funds sold and securities purchased under resale agreements	39,000	30,000
Investment securities	24,408	23,511
Loans held for sale ($1,275.5 million and $1,007.7 million at June 30, 2018 and December 31, 2017, respectively, at fair value)	1,276,768	1,011,004
Loans held for investment, mortgage finance	5,923,058	5,308,160
Loans held for investment (net of unearned income)	16,536,721	15,366,252
Less: Allowance for loan losses	179,096	184,655
Loans held for investment, net	22,280,683	20,489,757
Mortgage servicing rights, net	82,776	85,327
Premises and equipment, net	26,175	25,176
Accrued interest receivable and other assets	609,501	516,239
Goodwill and intangible assets, net	18,805	19,040
Total assets	27,781,910	25,075,645
Non-interest-bearing
Non-interest-bearing	7,648,125	7,812,660
Interest-bearing	12,686,746	11,310,520
Total deposits	20,334,871	19,123,180
Accrued interest payable	11,268	7,680
Other liabilities	176,400	182,212
Federal funds purchased and repurchase agreements	520,849	365,040
Other borrowings	4,000,000	2,800,000
Subordinated notes, net	281,586	281,406
Trust preferred subordinated debentures	113,406	113,406
Total liabilities	25,438,380	22,872,924
Stockholders’ equity:
Preferred stock, $.01 par value, $1,000 liquidation value; Authorized shares - 10,000,000; Issued shares – 6,000,000 shares issued at June 30, 2017 and December 31, 2016, respectively	150,000	150,000
Common stock, $.01 par value; Authorized shares - 100,000,000; Issued shares – 45,595,669 and 49,504,079 at June 30, 2017 and December 31, 2016, respectively	502	496
Additional paid-in capital	963,732	961,305
Retained earnings	1,228,924	1,090,500
Treasury stock – shares at cost: 417 at June 30, 2018 and December 31, 2017	(8)	(8)
Accumulated other comprehensive income, net of taxes	380	428
Total stockholders’ equity	2,343,530	2,202,721
Total liabilities and stockholders’ equity	$ 27,781,910	$ 25,075,645

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Loans held for sale	$ 1,275,466	$ 1,007,695
Preferred stock, par value	$ 0.01	$ 0.01
Preferred Stock, shares authorized	10,000,000	10,000,000
Preferred Stock, shares issued	6,000,000	6,000,000
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	100,000,000	100,000,000
Common Stock, shares issued	50,151,481	49,643,761
Treasury Stock, shares	417	417

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME AND OTHER COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest income
Interest and fees on loans	$ 279,447	$ 201,646	$ 523,311	$ 378,270
Investment securities	193	287	399	512
Federal funds sold and securities purchased under resale agreements	745	434	1,790	964
Interest-bearing deposits in other banks	6,467	5,824	15,221	12,391
Total interest income	286,852	208,191	540,721	392,137
Interest expense
Deposits	39,607	16,533	71,309	29,826
Federal funds purchased	1,665	726	2,634	978
Other borrowings	8,484	2,901	14,164	4,922
Subordinated notes	4,191	4,191	8,382	8,382
Trust preferred subordinated debentures	1,193	881	2,220	1,711
Total interest expense	55,140	25,232	98,709	45,819
Net interest income	231,712	182,959	442,012	346,318
Provision for credit losses	27,000	13,000	39,000	22,000
Net interest income after provision for credit losses	204,712	169,959	403,012	324,318
Non-interest income
Service charges on deposit accounts	3,005	3,067	6,142	6,112
Wealth management and trust fee income	2,007	1,402	3,931	2,759
Bank owned life insurance (BOLI) income	657	481	1,316	947
Brokered loan fees	5,815	5,809	10,983	11,487
Servicing income	4,967	3,700	10,459	5,901
Swap fees	1,352	954	2,914	2,757
Other	(524)	3,356	1,481	5,916
Total non-interest income	17,279	18,769	37,226	35,879
Non-interest expense
Salaries and employee benefits	72,404	63,154	144,941	126,157
Net occupancy expense	7,356	6,515	14,590	12,626
Marketing	10,236	6,157	18,913	11,107
Legal and professional	11,654	7,127	19,184	14,580
Communications and technology	7,143	11,906	13,776	18,412
FDIC insurance assessment	6,257	4,603	12,360	10,597
Servicing related expenses	4,367	2,682	8,172	4,432
Allowance and other carrying costs for other real estate owned (OREO)	176	71	2,331	210
Other	12,538	9,599	24,824	19,787
Total non-interest expense	132,131	111,814	259,091	217,908
Income before income taxes	89,860	76,914	181,147	142,289
Income tax expense	18,424	25,819	37,766	48,652
Net income	71,436	51,095	143,381	93,637
Preferred stock dividends	2,437	2,437	4,875	4,875
Net income available to common stockholders	68,999	48,658	138,506	88,762
Other comprehensive income (loss)
Change in net unrealized gain on available-for-sale debt securities arising during period, before-tax	(104)	(33)	(167)	(30)
Income tax expense (benefit) related to net unrealized gain on available-for-sale debt securities	(22)	(11)	(35)	(10)
Other comprehensive income (loss), net of tax	(82)	(22)	(132)	(20)
Comprehensive income	$ 71,354	$ 51,073	$ 143,249	$ 93,617
Basic earnings per common share (usd per share)	$ 1.39	$ 0.98	$ 2.79	$ 1.79
Diluted earnings per common share (usd per share)	$ 1.38	$ 0.97	$ 2.76	$ 1.77

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss), Net of Taxes
Stockholders' equity, beginning balance at Dec. 31, 2016	$ 2,009,557	$ 150,000	$ 495	$ 955,468	$ 903,187	$ (8)	$ 415
Shares, outstanding, beginning balance at Dec. 31, 2016		6,000,000	49,504,079			417
Comprehensive income:
Net income	93,637				93,637
Change in unrealized gain on available-for-sale securities, net of taxes	(20)						(20)
Total comprehensive income	93,617
Stock-based compensation expense recognized in earnings	3,461			3,461
Preferred stock dividend	(4,875)				(4,875)
Issuance of common stock related to warrants - value			33,595
Issuance of stock related to stock-based awards - value	(1,207)		$ (1)	(1,208)
Issuance of stock related to stock-based awards - shares			57,995
Stockholders' equity, ending balance at Jun. 30, 2017	2,100,553	$ 150,000	$ 496	957,721	991,949	$ (8)	395
Shares, outstanding, ending balance at Jun. 30, 2017		6,000,000	49,595,669			417
Stockholders' equity, beginning balance at Dec. 31, 2017	2,202,721	$ 150,000	$ 496	961,305	1,090,500	$ (8)	428
Shares, outstanding, beginning balance at Dec. 31, 2017		6,000,000	49,643,761			417
Comprehensive income:
Net income	143,381				143,381
Change in unrealized gain on available-for-sale securities, net of taxes	(132)						(132)
Total comprehensive income	143,249
Stock-based compensation expense recognized in earnings	4,091			4,091
Preferred stock dividend	(4,875)				(4,875)
Issuance of common stock related to warrants - value			436,648
Issuance of common stock related to warrants - shares	0		$ (5)	(5)
Issuance of stock related to stock-based awards - value	(1,658)		$ (1)	(1,659)
Issuance of stock related to stock-based awards - shares			71,072
Stockholders' equity, ending balance at Jun. 30, 2018	2,343,530	$ 150,000	$ 502	$ 963,732	1,228,924	$ (8)	380
Shares, outstanding, ending balance at Jun. 30, 2018		6,000,000	50,151,481			417
Impact of adoption of new accounting standards	$ 2				$ (82)		$ 84

CONSOLIDATED STATEMENTS OF STO6

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parentheticals) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Stockholders' Equity [Abstract]
Income tax expense (benefit) related to net unrealized gain on available-for-sale debt securities	$ (22)	$ (11)	$ (35)	$ (10)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating activities
Income from continuing operations	$ 143,381	$ 93,637
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	39,000	22,000
Depreciation and amortization	16,214	12,346
Decrease in valuation allowance on mortgage servicing rights	(757)	0
Bank owned life insurance (BOLI) income	(1,316)	(947)
Stock-based compensation expense	11,197	8,954
Purchases and originations of loans held for sale	(3,205,483)	(2,843,690)
Proceeds from sales and repayments of loans held for sale	2,908,777	2,939,002
Proceeds from sale of MSRs	22,439	0
Net (gain) loss on sale of loans held for sale and other assets	7,648	93
Technology write-off	0	5,285
Increase in OREO valuation allowance	2,000	0
Changes in operating assets and liabilities:
Accrued interest receivable and other assets	(97,710)	(46,025)
Accrued interest payable and other liabilities	(14,289)	(488)
Net cash provided by (used in) operating activities	(168,899)	190,167
Investing activities
Purchases of investment securities	(3,323)	(96,871)
Maturities and calls of available-for-sale securities	349	275
Principal payments received on available-for-sale securities	1,644	2,397
Originations of mortgage finance loans	(45,661,608)	(37,251,933)
Proceeds from pay-offs of mortgage finance loans	45,046,710	36,565,671
Net increase in loans held for investment, excluding mortgage finance loans	(1,213,641)	(1,297,460)
Purchase of premises and equipment, net	(5,212)	(4,194)
Proceeds from sale of foreclosed assets	216	272
Net cash provided by investing activities	(1,834,865)	(2,081,843)
Financing activities
Net increase in deposits	1,211,691	275,392
Costs from issuance of stock related to stock-based awards and warrants	(1,658)	(1,207)
Preferred dividends paid	(4,875)	(4,875)
Net increase in other borrowings	1,200,000	700,000
Net increase in Federal funds purchased and repurchase agreements	155,809	352,649
Net cash provided by financing activities	2,560,967	1,321,959
Net increase (decrease) in cash and cash equivalents	557,203	(569,717)
Cash and cash equivalents at beginning of period	2,905,591	2,839,352
Cash and cash equivalents at end of period	3,462,794	2,269,635
Supplemental disclosures of cash flow information:
Cash paid during the period for interest	95,121	45,071
Cash paid during the period for income taxes	49,770	52,042
Transfers from loans/leases to OREO and other repossessed assets	$ 0	$ 0

OPERATIONS AND SUMMARY OF SIGNI

OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Operations and summary of significant accounting policies	OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Organization and Nature of Business Texas Capital Bancshares, Inc. (the “Company”), a Delaware corporation, was incorporated in November 1996 and commenced banking operations in December 1998. The consolidated financial statements of the Company include the accounts of Texas Capital Bancshares, Inc. and its wholly owned subsidiary, Texas Capital Bank, National Association (the “Bank”). We serve the needs of commercial businesses and successful professionals and entrepreneurs located in Texas as well as operate several lines of business serving a regional and national clientèle of commercial borrowers. We are primarily a secured lender with a majority of our loans being made to businesses headquartered or with operations in Texas. At the same time, our national lines of business continue to provide specialized lending products to businesses throughout the United States. Basis of Presentation Our accounting and reporting policies conform to accounting principles generally accepted in the United States (“GAAP”) and to generally accepted practices within the banking industry. Certain prior period balances have been reclassified to conform to the current period presentation. The consolidated interim financial statements are unaudited and certain information and footnote disclosures presented in accordance with GAAP have been condensed or omitted. In the opinion of management, the interim financial statements include all normal and recurring adjustments and the disclosures made are adequate to make the interim financial information not misleading. The consolidated financial statements have been prepared in accordance with GAAP for interim financial information and the instructions to Form 10-Q adopted by the Securities and Exchange Commission (“SEC”). Accordingly, the financial statements do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with our consolidated financial statements, and notes thereto, for the year ended December 31, 2017 , included in our Annual Report on Form 10-K filed with the SEC on February 14, 2018 (the “ 2017 Form 10-K”). Operating results for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for a full year or any future period. Accounting Changes ASU 2018-02 " Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income" ("ASU 2018-02") allows a reclassification from accumulated other comprehensive income (loss) ("AOCI") to retained earnings for the stranded tax effects caused by the revaluation of deferred taxes resulting from the newly enacted corporate tax rate in the Tax Cuts and Jobs Act. The ASU is effective in years beginning after December 15, 2018, but permits early adoption in a period for which financial statements have not yet been issued. We have elected to early adopt the ASU as of January 1, 2018. The adoption of the guidance resulted in an insignificant cumulative-effect adjustment that decreased retained earnings and increased AOCI in the first quarter of 2018. ASU 2016-15 "Statement of Cash Flows (Topic 230)" ("ASU 2016-15") is intended to reduce the diversity in practice around how certain transactions are classified within the statement of cash flows. ASU 2016-15 became effective for us on January 1, 2018 and did not have a significant impact on our financial statements. ASU 2016-01 "Financial Instruments - Overall (Subtopic 825-10): Recognition of Financial Assets and Financial Liabilities, ("ASU 2016-01") makes targeted amendments to the guidance for recognition, measurement, presentation and disclosure of financial instruments. ASU 2016-01 requires equity investments, other than equity method investments, to be measured at fair value with changes in fair value recognized in net income. The ASU requires a cumulative-effect adjustment to retained earnings as of the beginning of the reporting period of adoption to reclassify the cumulative change in fair value of equity securities previously recognized in AOCI. ASU 2016-01 became effective for us on January 1, 2018. The adoption of the guidance resulted in an insignificant cumulative-effect adjustment that increased retained earnings, with offsetting related adjustments to deferred taxes and AOCI. ASU 2016-01 also emphasizes the existing requirement to use exit prices to measure fair value for disclosure purposes and clarifies that entities should not make use of a practicability exception in determining the fair value of loans. Accordingly, we refined the calculation used to determine the disclosed fair value of our loans held for investment portfolio as part of adopting this standard. The refined calculation did not have a significant impact on our fair value disclosures. See Note 11 - Fair Value Disclosures. ASU 2014-09 "Revenue from Contracts with Customers (Topic 606)" ("ASU 2014-09") implements a common revenue standard that clarifies the principles for recognizing revenue. The core principle of ASU 2014-09 is 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. ASU 2014-09 establishes a five-step model which entities must follow to recognize revenue and removes inconsistencies and weaknesses in existing guidance. The guidance does not apply to revenue associated with financial instruments, including loans and investment securities that are accounted for under other GAAP, which comprises a significant portion of our revenue stream. ASU 2014-09 became effective for us on January 1, 2018 and had no material effect on how we recognize revenue or to our consolidated financial statements and disclosures. See below for additional information related to revenue generated from contracts with customers. Revenue Recognition Accounting Standards Codification ("ASC") 606, Revenue from Contracts with Customers ("ASC 606"), establishes principles for reporting information about the nature, amount, timing and uncertainty of revenue and cash flows arising from the entity's contracts to provide goods or services to customers. The core principle requires an entity to recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration that it expects to be entitled to receive in exchange for those goods or services recognized as performance obligations are satisfied. The majority of our revenue-generating transactions are not subject to ASC 606, including revenue generated from financial instruments, such as our loans, letters of credit, derivatives and investment securities, as well as revenue related to our mortgage servicing activities, as these activities are subject to other GAAP discussed elsewhere within our disclosures. Descriptions of our revenue-generating activities that are within the scope of ASC 606, which are presented in our income statements as components of non-interest income are as follows: • Service charges on deposit accounts - these represent general service fees for monthly account maintenance and activity- or transaction-based fees and consist of transaction-based revenue, time-based revenue (service period), item-based revenue or some other individual attribute-based revenue. Revenue is recognized when our performance obligation is completed which is generally monthly for account maintenance services or when a transaction has been completed (such as a wire transfer). Payments for such performance obligations are generally received at the time the performance obligations are satisfied. • Wealth management and trust fee income - this represents monthly fees due from wealth management customers as consideration for managing the customers' assets. Wealth management and trust services include custody of assets, investment management, escrow services, fees for trust services and similar fiduciary activities. Revenue is recognized when our performance obligation is completed each month, which is generally the time that payment is received. Also included are fees received from a third party broker-dealers as part of a revenue-sharing agreement for fees earned from customers that we refer to the third party. These fees are paid to us by the third party on a quarterly basis and recognized ratably throughout the quarter as our performance obligation is satisfied. • Brokered loan fees - these represent fees for the administration and funding of purchased mortgage loan interests as well as facility renewal and application fees received from mortgage originator customers in our warehouse lending business. Also included are fees received from independent correspondent mortgage lenders as consideration for our purchase of individual residential mortgage loans through our Mortgage Correspondent Aggregation ("MCA") business. Revenue related to the warehouse lending business is recognized when the related loan interest is disposed (i.e., through sale or payoff) or upon receipt of the facility renewal or application. Revenue related to our MCA business is recognized at the time a loan is purchased. • Other non-interest income primarily includes items such as letter of credit fees, gains on sale of loans held for sale and servicing fees related to the MCA program, none of which are subject to the requirements of ASC 606. Investment Securities Investment securities includes available-for-sale debt securities and equity securities at fair value. Debt Securities Debt securities are classified as trading, available-for-sale or held-to-maturity. Management classifies debt securities at the time of purchase and re-assesses such designation at each balance sheet date; however, transfers between categories from this re-assessment are rare. Trading Account Debt securities acquired for resale in anticipation of short-term market movements are classified as trading, with realized and unrealized gains and losses recognized in income. To date, we have not had any activity in our trading account. Held-to-Maturity Debt securities are classified as held to maturity when we have the positive intent and ability to hold the securities to maturity. Held-to-maturity securities are stated at amortized cost. Debt securities not classified as held-to-maturity or trading are classified as available-for-sale. Available-for-Sale Available-for-sale debt securities are stated at fair value, with the unrealized gains and losses reported as a separate component of AOCI, net of tax. The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity, or in the case of mortgage-backed securities, over the estimated life of the security. Such amortization and accretion is included in interest income from securities. Realized gains and losses and declines in value judged to be other-than-temporary are included in gain (loss) on sale of securities. The cost of securities sold is based on the specific identification method. All debt securities are available-for-sale as of June 30, 2018 and December 31, 2017. Equity Securities Beginning January 1, 2018, upon adoption of ASU 2016-01, equity securities with readily determinable fair values are stated at fair value with realized and unrealized gains and losses reported in other non-interest income in the consolidated statements of income and other comprehensive income. For periods prior to January 1, 2018, equity securities were classified as available-for-sale and stated at fair value with unrealized gains and losses reported as a separate component of AOCI, net of tax. Equity securities without readily determinable fair values are recorded at cost less any impairment, if any. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates. The allowance for loan losses, the fair value of stock-based compensation awards, the fair value of mortgage servicing rights ("MSRs") and the status of contingencies are particularly susceptible to significant change.

EARNINGS PER COMMON SHARE

EARNINGS PER COMMON SHARE	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
EARNINGS PER COMMON SHARE	EARNINGS PER COMMON SHARE The following table presents the computation of basic and diluted earnings per share (in thousands except share data): Three months ended Six months ended 2018 2017 2018 2017 Numerator: Net income $ 71,436 $ 51,095 $ 143,381 $ 93,637 Preferred stock dividends 2,437 2,437 4,875 4,875 Net income available to common stockholders 68,999 48,658 $ 138,506 88,762 Denominator: Denominator for basic earnings per share—weighted average shares 49,736,384 49,576,837 49,695,783 49,556,393 Effect of employee stock-based awards (1) 348,762 224,306 336,285 244,058 Effect of warrants to purchase common stock 10,869 428,527 112,884 432,660 Denominator for dilutive earnings per share—adjusted weighted average shares and assumed conversions 50,096,015 50,229,670 50,144,952 50,233,111 Basic earnings per common share $ 1.39 $ 0.98 $ 2.79 $ 1.79 Diluted earnings per common share $ 1.38 $ 0.97 $ 2.76 $ 1.77 (1) SARs and RSUs outstanding of 4,000 at June 30, 2018 and 6,200 at June 30, 2017 have not been included in diluted earnings per share because to do so would have been anti-dilutive for the periods presented.

SECURITIES

SECURITIES	6 Months Ended
	Jun. 30, 2018
Available-for-sale Securities [Abstract]
INVESTMENT SECURITIES	Available-for-Sale Debt Securities The following is a summary of available-for-sale debt securities (in thousands): June 30, 2018 Amortized Gross Gross Estimated Residential mortgage-backed securities $ 8,304 $ 481 $ — $ 8,785 December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Residential mortgage-backed securities $ 10,297 $ 648 $ — $ 10,945 The amortized cost and estimated fair value of available-for-sale debt securities are presented below by contractual maturity (in thousands, except percentage data): June 30, 2018 Less Than After One After Five After Ten Total Residential mortgage-backed securities: (1) Amortized cost 50 1,895 — 6,359 8,304 Estimated fair value 52 2,038 — 6,695 8,785 Weighted average yield (2) 5.24 % 5.55 % — % 3.75 % 4.17 % December 31, 2017 Less Than After One After Five After Ten Total Residential mortgage-backed securities:(1) Amortized cost $ 409 $ 819 $ 1,502 $ 7,567 $ 10,297 Estimated fair value 418 916 1,636 7,975 10,945 Weighted average yield(2) 4.59 % 6.02 % 5.32 % 3.45 % 3.97 % (1) Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without prepayment penalties. (2) Yields are calculated based on amortized cost. As of June 30, 2018 and December 31, 2017 , we did not have any available-for-sale debt securities in an unrealized loss position. At June 30, 2018 , available-for-sale debt securities with carrying values of $2.0 million and $5.8 million were pledged to secure certain deposits and repurchase agreements, respectively. Equity Securities Equity securities consist of Community Reinvestment Act funds and investments related to our non-qualified deferred compensation plan. At June 30, 2018 and December 31, 2017 , we had $15.6 million and $12.6 million , respectively, in equity securities recorded at fair value. Prior to January 1, 2018, equity securities were stated at fair value with unrealized gains and losses reported as a separate component of AOCI, net of tax. At December 31, 2017 , net unrealized gains of $10,000 had been recognized in AOCI. On January 1, 2018, these unrealized gains and losses were reclassified out of AOCI and into retained earnings with subsequent changes in fair value being recognized in other non-interest income. The following is a summary of unrealized and realized gains and losses recognized in net income on equity securities during the three and six months ended June 30, 2018 (in thousands): Three months ended Six months ended June 30, 2018 June 30, 2018 Net gains and (losses) recognized during the period on equity securities $ 108 $ (104 ) Less: Net gains and (losses) recognized during the period on equity securities sold during the period 162 162 Unrealized gains and (losses) recognized during the reporting period on equity securities still held at the reporting date $ (54 ) $ (266 )

LOANS AND ALLOWANCE FOR LOAN LO

LOANS AND ALLOWANCE FOR LOAN LOSSES	6 Months Ended
	Jun. 30, 2018
Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]
Loans and allowance for credit losses	LOANS HELD FOR INVESTMENT AND ALLOWANCE FOR LOAN LOSSES At June 30, 2018 and December 31, 2017 , loans held for investment were as follows (in thousands): June 30, December 31, Commercial $ 10,189,832 $ 9,189,811 Mortgage finance 5,923,058 5,308,160 Construction 2,226,590 2,166,208 Real estate 3,868,411 3,794,577 Consumer 46,652 48,684 Leases 314,575 264,903 Gross loans held for investment 22,569,118 20,772,343 Deferred income (net of direct origination costs) (109,339 ) (97,931 ) Allowance for loan losses (179,096 ) (184,655 ) Total loans held for investment, net $ 22,280,683 $ 20,489,757 Commercial Loans and Leases. Our commercial loan portfolio is comprised of lines of credit for working capital and term loans and leases to finance equipment and other business assets. Our energy production loans are generally collateralized with proven reserves based on appropriate valuation standards and take into account the risk of oil and gas price volatility. Our commercial loans and leases are underwritten after carefully evaluating and understanding the borrower’s ability to operate profitably. Our underwriting standards are designed to promote relationship banking rather than to make loans on a transaction basis. Our lines of credit typically are limited to a percentage of the value of the assets securing the line. Lines of credit and term loans typically are reviewed annually, or more frequently, as needed, and are supported by accounts receivable, inventory, equipment and other assets of our clients’ businesses. Mortgage Finance Loans. Our mortgage finance loans consist of ownership interests purchased in single-family residential mortgages funded through our mortgage finance group. We have agreements with mortgage lenders and purchase interests in individual loans they originate. The ownership interests collateralizing our mortgage finance loans are typically held on our balance sheet for 10 to 20 days, and substantially all loans are conforming loans. Substantially all mortgage loans are underwritten consistently with established programs for permanent financing with financially sound investors. Balances as of June 30, 2018 and December 31, 2017 are stated net of $242.7 million and $171.2 million of participations sold, respectively. Construction Loans. Our construction loan portfolio consists primarily of single- and multi-family residential properties and commercial projects used in manufacturing, warehousing, service or retail businesses. Our construction loans generally have terms of one to three years. We typically make construction loans to developers, builders and contractors that have an established record of successful project completion and loan repayment and have a substantial equity investment in the borrowers. Loan amounts are derived primarily from the Bank's evaluation of expected cash flows available to service debt from stabilized projects under hypothetically stressed conditions. Construction loans are also based in part upon estimates of costs and value associated with the completed project. Sources of repayment for these types of loans may be permanent loans from other lenders, sales of developed property, or an interim loan commitment from us until permanent financing is obtained. The nature of these loans makes ultimate repayment sensitive to overall economic conditions. Borrowers may not be able to correct conditions of loan defaults, increasing risk of exposure to classification, non-performing status, reserve allocation and actual credit loss and foreclosure. These loans typically have floating rates and require commitment fees. Real Estate Loans. A portion of our real estate loan portfolio is comprised of loans secured by properties other than market risk or investment-type real estate. Market risk loans are real estate loans where the primary source of repayment is expected to come from the sale, permanent financing or lease of the real property collateral. We generally provide temporary financing for commercial and residential property. These loans are viewed primarily as cash flow loans and secondarily as loans secured by real estate. Our real estate loans generally have maximum terms of five to seven years, and we provide loans with both floating and fixed rates. Real estate loans may be more adversely affected by conditions in the real estate markets or in the general economy. Appraised values may be highly variable due to market conditions and the impact of the inability of potential purchasers and lessees to obtain financing and a lack of transactions at comparable values. At June 30, 2018 and December 31, 2017 , we had a blanket floating lien on certain real estate-secured loans, mortgage finance loans and certain investment securities used as collateral for Federal Home Loan Bank borrowings. Summary of Loan Loss Experience The allowance for loan losses is comprised of general reserves, specific reserves for impaired loans and an additional qualitative reserve based on our estimate of losses inherent in the portfolio at the balance sheet date, but not yet identified with specified loans. We consider the allowance at June 30, 2018 to be appropriate, given management's assessment of losses inherent in the portfolio as of the evaluation date, the significant growth in the loan and lease portfolio, current economic conditions in our market areas and other factors. The following tables summarize the credit risk profile of our loan portfolio by internally assigned grades and non-accrual status as of June 30, 2018 and December 31, 2017 (in thousands): June 30, 2018 Commercial Mortgage Finance Construction Real Estate Consumer Leases Total Grade: Pass $ 9,945,020 $ 5,923,058 $ 2,211,981 $ 3,778,808 $ 46,493 $ 299,825 $ 22,205,185 Special mention 87,297 — 14,609 56,003 — — 157,909 Substandard-accruing 77,929 — — 31,057 93 13,650 122,729 Non-accrual 79,586 — — 2,543 66 1,100 83,295 Total loans held for investment $ 10,189,832 $ 5,923,058 $ 2,226,590 $ 3,868,411 $ 46,652 $ 314,575 $ 22,569,118 December 31, 2017 Commercial Mortgage Finance Construction Real Estate Consumer Leases Total Grade: Pass $ 8,967,471 $ 5,308,160 $ 2,152,654 $ 3,706,541 $ 48,591 $ 249,865 $ 20,433,282 Special mention 19,958 — 13,554 53,652 — 495 87,659 Substandard-accruing 102,651 — — 32,671 93 14,543 149,958 Non-accrual 99,731 — — 1,713 — — 101,444 Total loans held for investment $ 9,189,811 $ 5,308,160 $ 2,166,208 $ 3,794,577 $ 48,684 $ 264,903 $ 20,772,343 The following table details activity in the allowance for loan losses by portfolio segment for the six months ended June 30, 2018 and 2017 . Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. June 30, 2018 (in thousands) Commercial Mortgage Finance Construction Real Estate Consumer Leases Additional Qualitative Reserve Total Beginning balance $ 118,806 $ — $ 19,273 $ 34,287 $ 357 $ 3,542 $ 8,390 $ 184,655 Provision for loan losses 38,920 — 621 928 (205 ) 860 (3,511 ) 37,613 Charge-offs 43,972 — — — — — — 43,972 Recoveries 680 — — 32 68 20 — 800 Net charge-offs (recoveries) 43,292 — — (32 ) (68 ) (20 ) — 43,172 Ending balance $ 114,434 $ — $ 19,894 $ 35,247 $ 220 $ 4,422 $ 4,879 $ 179,096 Period end amount allocated to: Loans individually evaluated for impairment $ 11,772 $ — $ — $ 73 $ 11 $ 495 $ — $ 12,351 Loans collectively evaluated for impairment 102,662 — 19,894 35,174 209 3,927 4,879 166,745 Ending balance $ 114,434 $ — $ 19,894 $ 35,247 $ 220 $ 4,422 $ 4,879 $ 179,096 June 30, 2017 (in thousands) Commercial Mortgage Finance Construction Real Estate Consumer Leases Additional Qualitative Reserve Total Beginning balance $ 128,768 $ — $ 13,144 $ 19,149 $ 241 $ 1,124 $ 5,700 $ 168,126 Provision for loan losses 19,384 — 680 3,436 287 2,989 (2,559 ) 24,217 Charge-offs 21,543 — — 40 180 — — 21,763 Recoveries 3,442 — 101 53 41 8 — 3,645 Net charge-offs (recoveries) 18,101 — (101 ) (13 ) 139 (8 ) — 18,118 Ending balance $ 130,051 $ — $ 13,925 $ 22,598 $ 389 $ 4,121 $ 3,141 $ 174,225 Period end amount allocated to: Loans individually evaluated for impairment $ 28,382 $ — $ — $ 180 $ — $ — $ — $ 28,562 Loans collectively evaluated for impairment 101,669 — 13,925 22,418 389 4,121 3,141 145,663 Ending balance $ 130,051 $ — $ 13,925 $ 22,598 $ 389 $ 4,121 $ 3,141 $ 174,225 The table below presents the activity in the allowance for off-balance sheet credit losses related to unfunded commitments for the three and six months ended June 30, 2018 and 2017 (in thousands). This allowance is recorded in other liabilities in the consolidated balance sheet. Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Beginning balance $ 9,623 $ 10,847 $ 9,071 $ 11,422 Provision for off-balance sheet credit losses 835 (1,642 ) 1,387 (2,217 ) Ending balance $ 10,458 $ 9,205 $ 10,458 $ 9,205 We have traditionally maintained an additional qualitative reserve component to compensate for the uncertainty and complexity in estimating loan and lease losses including factors and conditions that may not be fully reflected in the determination and application of the allowance allocation percentages. The decrease in the additional qualitative reserve at June 30, 2018 as compared to December 31, 2017 was primarily related to the resolution of remaining uncertainty regarding the impact to our loan portfolio from Hurricanes Harvey and Irma. We believe the level of additional qualitative reserves at June 30, 2018 is warranted due to uncertainties and unpredictable factors that have produced losses, including those resulting from borrowers' misstatement of financial information or inaccurate certification of collateral values. Such losses are not necessarily correlated with historical loss trends or general economic conditions. Our methodology used to calculate the allowance considers historical losses; however, the historical loss rates for specific product types or credit risk grades may not fully incorporate the effects of uncertainties or unpredictable events. Our recorded investment in loans as of June 30, 2018 , December 31, 2017 and June 30, 2017 related to each balance in the allowance for loan losses by portfolio segment and disaggregated on the basis of our impairment methodology was as follows (in thousands): June 30, 2018 Commercial Mortgage Finance Construction Real Estate Consumer Leases Total Loans individually evaluated for impairment $ 80,171 $ — $ — $ 2,543 $ 66 $ 1,100 $ 83,880 Loans collectively evaluated for impairment 10,109,661 5,923,058 2,226,590 3,865,868 46,586 313,475 22,485,238 Total $ 10,189,832 $ 5,923,058 $ 2,226,590 $ 3,868,411 $ 46,652 $ 314,575 $ 22,569,118 December 31, 2017 Commercial Mortgage Finance Construction Real Estate Consumer Leases Total Loans individually evaluated for impairment $ 100,676 $ — $ — $ 2,008 $ — $ — $ 102,684 Loans collectively evaluated for impairment 9,089,135 5,308,160 2,166,208 3,792,569 48,684 264,903 20,669,659 Total $ 9,189,811 $ 5,308,160 $ 2,166,208 $ 3,794,577 $ 48,684 $ 264,903 $ 20,772,343 June 30, 2017 Commercial Mortgage Finance Construction Real Estate Consumer Leases Total Loans individually evaluated for impairment $ 120,770 $ — $ — $ 4,514 $ — $ — $ 125,284 Loans collectively evaluated for impairment 8,130,182 5,183,600 2,242,562 3,565,273 39,122 274,863 19,435,602 Total $ 8,250,952 $ 5,183,600 $ 2,242,562 $ 3,569,787 $ 39,122 $ 274,863 $ 19,560,886 We place loans on non-accrual when there is a clear indication that the borrower’s cash flow may not be sufficient to meet payments as they become due, generally when a loan is 90 days past due. When a loan is placed on non-accrual status, all previously accrued and unpaid interest is reversed. Interest income is subsequently recognized on a cash basis as long as the remaining unpaid principal amount of the loan is deemed to be fully collectible. If collectability is questionable, then cash payments are applied to principal. As of both June 30, 2018 and December 31, 2017 , none of our non-accrual loans were earning on a cash basis. A loan is placed back on accrual status when both principal and interest are current and it is probable that we will be able to collect all amounts due (both principal and interest) according to the terms of the loan agreement. A loan held for investment is considered impaired when, based on current information and events, it is probable that we will be unable to collect all amounts due (both principal and interest) according to the terms of the original loan agreement. In accordance with ASC 310, Receivables , we have also included all restructured and formerly restructured loans in our impaired loan totals. The following tables detail our impaired loans, by portfolio class, as of June 30, 2018 and December 31, 2017 (in thousands): June 30, 2018 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized With no related allowance recorded: Commercial Business loans $ 27,521 $ 52,966 $ — $ 12,449 $ 133 Energy 16,373 17,549 — 20,393 — Construction Market risk — — — — — Real estate Market risk — — — — — Commercial 1,042 1,042 — 1,074 — Secured by 1-4 family 1,263 1,263 — 211 — Consumer — — — — — Leases — — — — — Total impaired loans with no allowance recorded $ 46,199 $ 72,820 $ — $ 34,127 $ 133 With an allowance recorded: Commercial Business loans $ 19,038 $ 19,038 $ 5,597 $ 43,537 $ — Energy 17,239 18,500 6,175 32,145 — Construction Market risk — — — — — Real estate Market risk — — — 98 — Commercial — — — 166 — Secured by 1-4 family 238 238 73 138 — Consumer 66 71 11 47 — Leases 1,100 1,100 495 183 — Total impaired loans with an allowance recorded $ 37,681 $ 38,947 $ 12,351 $ 76,314 $ — Combined: Commercial Business loans $ 46,559 $ 72,004 $ 5,597 $ 55,986 $ 133 Energy 33,612 36,049 6,175 52,538 — Construction Market risk — — — — — Real estate Market risk — — — 98 — Commercial 1,042 1,042 — 1,240 — Secured by 1-4 family 1,501 1,501 73 349 — Consumer 66 71 11 47 — Leases 1,100 1,100 495 183 — Total impaired loans $ 83,880 $ 111,767 $ 12,351 $ 110,441 $ 133 December 31, 2017 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized With no related allowance recorded: Commercial Business loans $ 16,835 $ 18,257 $ — $ 22,964 $ — Energy 21,426 22,602 — 36,579 — Construction Market risk — — — — — Real estate Market risk — — — — — Commercial 1,096 1,096 — 2,166 — Secured by 1-4 family — — — — — Consumer — — — — — Leases — — — — — Total impaired loans with no allowance recorded $ 39,357 $ 41,955 $ — $ 61,709 $ — With an allowance recorded: Commercial Business loans $ 18,645 $ 19,020 $ 2,544 $ 16,960 $ — Energy 43,770 55,875 21,772 50,867 6 Construction Market risk — — — 27 — Real estate Market risk 295 295 6 485 — Commercial 499 499 75 166 — Secured by 1-4 family 118 118 20 516 — Consumer — — — 33 — Leases — — — 14 — Total impaired loans with an allowance recorded $ 63,327 $ 75,807 $ 24,417 $ 69,068 $ 6 Combined: Commercial Business loans $ 35,480 $ 37,277 $ 2,544 $ 39,924 $ — Energy 65,196 78,477 21,772 87,446 6 Construction Market risk — — — 27 — Real estate Market risk 295 295 6 485 — Commercial 1,595 1,595 75 2,332 — Secured by 1-4 family 118 118 20 516 — Consumer — — — 33 — Leases — — — 14 — Total impaired loans $ 102,684 $ 117,762 $ 24,417 $ 130,777 $ 6 Average impaired loans outstanding during the six months ended June 30, 2018 and 2017 totaled $110.4 million and $ 149.5 million , respectively. The table below provides an age analysis of our loans held for investment as of June 30, 2018 (in thousands): 30-59 Days Past Due 60-89 Days Past Due Greater Than 90 Days and Accruing(1) Total Past Due Non-accrual Current Total Commercial Business loans $ 14,114 $ 17,188 $ 6,203 $ 37,505 $ 45,974 $ 8,750,741 $ 8,834,220 Energy 24,900 — — 24,900 33,612 1,297,100 1,355,612 Mortgage finance loans — — — — — 5,923,058 5,923,058 Construction Market risk 489 — — 489 — 2,151,838 2,152,327 Commercial — — — — — 41,991 41,991 Secured by 1-4 family — 1,610 — 1,610 — 30,662 32,272 Real estate Market risk 1,337 — 661 1,998 — 2,728,753 2,730,751 Commercial 639 — — 639 1,042 814,188 815,869 Secured by 1-4 family 2,745 152 493 3,390 1,501 316,900 321,791 Consumer 2 — — 2 66 46,584 46,652 Leases — — — — 1,100 313,475 314,575 Total loans held for investment $ 44,226 $ 18,950 $ 7,357 $ 70,533 $ 83,295 $ 22,415,290 $ 22,569,118 (1) Loans past due 90 days and still accruing includes premium finance loans of $6.0 million . These loans are generally secured by obligations of insurance carriers to refund premiums on canceled insurance policies. The refund of premiums from the insurance carriers can take 180 days or longer from the cancellation date. Restructured loans are loans on which, due to the borrower’s financial difficulties, we have granted a concession that we would not otherwise consider for borrowers of similar credit quality. This may include a transfer of real estate or other assets from the borrower, a modification of loan terms, or a combination of the two. Modifications of terms that could potentially qualify as a restructuring include reduction of the contractual interest rate, extension of the maturity date at a contractual interest rate lower than the current rate for new debt with similar risk, a reduction of the face amount of debt or forgiveness of either principal or accrued interest. At June 30, 2018 and December 31, 2017 , we did not have any loans considered restructured that were not on non-accrual. Of the non-accrual loans at June 30, 2018 and December 31, 2017 , $9.0 million and $18.8 million , respectively, met the criteria for restructured. These loans had no unfunded commitments at their respective balance sheet dates. A loan continues to qualify as restructured until a consistent payment history or change in borrower’s financial condition has been evidenced, generally over no less than twelve months. Assuming that the restructuring agreement specifies an interest rate at the time of the restructuring that is greater than or equal to the rate that we are willing to accept for a new extension of credit with comparable risk, then the loan no longer has to be considered a restructuring if it is in compliance with the modified terms in calendar years after the year of the restructure. The following table summarizes the loans that were restructured during the six months ended June 30, 2018 and 2017 (in thousands): As of and for the six months ended June 30, 2018 Number of Restructured Loans Balance at Restructure Balance at Period-End Energy loans 1 $ 1,370 $ 1,370 Total new restructured loans 1 $ 1,370 $ 1,370 As of and for the six months ended June 30, 2017 Number of Restructured Loans Balance at Restructure Balance at Period-End Energy loans 1 $ 1,070 $ 700 Commercial business loans 1 599 672 Total new restructured loans 2 $ 1,669 $ 1,372 The restructured loans generally include terms to temporarily place loans on interest only, extend the payment terms or reduce the interest rate. We did not forgive any principal on the above loans. The restructuring of the loans did not have a significant impact on our allowance for loan losses at June 30, 2018 or 2017 . The following table provides information on how loans were modified as restructured during the six months ended June 30, 2018 and 2017 (in thousands): Six months ended June 30, 2018 2017 Extended maturity $ — $ 1,372 Adjusted payment schedule 1,370 — Total $ 1,370 $ 1,372 As of June 30, 2018 and 2017 , we did not have any loans that were restructured within the last 12 months that subsequently defaulted.

OREO AND VALUATION ALLOWANCE FO

OREO AND VALUATION ALLOWANCE FOR LOSSES ON OREO	6 Months Ended
	Jun. 30, 2018
Real Estate Owned, Disclosure of Detailed Components [Abstract]
OREO AND VALUATION ALLOWANCE FOR LOSSES ON OREO	OREO AND VALUATION ALLOWANCE FOR LOSSES ON OREO The table below presents a summary of the activity related to OREO (in thousands): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Beginning balance $ 9,558 $ 18,833 $ 11,742 $ 18,961 Additions — — — — Sales (32 ) (144 ) (216 ) (272 ) Valuation allowance for OREO — — (2,000 ) — Ending balance $ 9,526 $ 18,689 $ 9,526 $ 18,689 When foreclosure occurs, the acquired asset is recorded at fair value less selling costs, generally based on appraised value, which may result in partial charge-off of the loan. Subsequent write-downs required for declines in value are recorded through a valuation allowance or taken directly against the asset and charged to other non-interest expense.

CERTAIN TRANSFERS OF FINANCIAL

CERTAIN TRANSFERS OF FINANCIAL ASSETS	6 Months Ended
	Jun. 30, 2018
Transfers and Servicing [Abstract]
CERTAIN TRANSFERS OF FINANCIAL ASSETS	CERTAIN TRANSFERS OF FINANCIAL ASSETS Through our MCA business, we commit to purchase residential mortgage loans from independent correspondent lenders and deliver those loans into the secondary market via whole loan sales to independent third parties or in securitization transactions to Ginnie Mae and government sponsored entities ("GSEs") such as Fannie Mae and Freddie Mac. We have elected to carry these loans at fair value based on sales commitments, market quotes or pricing models. Gains and losses on the sale of mortgage loans held for sale and changes in the fair value of the loans held for sale and related derivatives are included in other non-interest income on the consolidated statements of income and other comprehensive income. For the six months ended June 30, 2018 and 2017 , losses totaled $7.4 million and $93,000 , respectively. Residential mortgage loans held for sale are subject to both credit and interest rate risk. Credit risk is managed through underwriting policies and procedures, including collateral requirements, which are generally accepted by the secondary loan markets. Exposure to interest rate fluctuations is partially mitigated through forward sales contracts, which set the price for loans that will be delivered in the next 60 to 90 days. The table below presents the unpaid principal balance of loans held for sale and related fair values at June 30, 2018 and December 31, 2017 (in thousands): June 30, 2018 December 31, 2017 Outstanding balance(1) $ 1,273,889 $ 1,009,271 Fair value(1) 1,275,466 1,007,695 Fair value over/(under) outstanding balance $ 1,577 $ (1,576 ) (1) Does not include $1.3 million and $3.3 million of Small Business Administration ("SBA") loans held for sale carried at lower of cost or market as of June 30, 2018 and December 31, 2017 . No loans held for sale were on non-accrual as of June 30, 2018 or December 31, 2017 . At June 30, 2018 and December 31, 2017 , we had $27.9 million and $19.7 million , respectively, in outstanding balances of loans held for sale that were 90 days or more past due. The $27.9 million loans held for sale that were 90 days or more past due at June 30, 2018 included $24.1 million in loans guaranteed by U.S. government agencies that were repurchased out of Ginnie Mae securities and recorded as loans held for sale, at fair value, on the balance sheet. Interest on these past due loans accrues at the debenture rate guaranteed by the U.S. government. Also included in the $27.9 million were $3.1 million in loans that, pursuant to Ginnie Mae servicing guidelines, we have the unilateral right, but not the obligation, to repurchase if defined delinquent loan criteria are met, and therefore must record as loans held for sale on our balance sheet regardless of whether the repurchase option has been exercised. The comparable balances at December 31, 2017 were no loans repurchased and $19.0 million in loans for which we have the unilateral right but not the obligation to repurchase. The table below presents a reconciliation of the changes in loans held for sale for the six months ended June 30, 2018 and 2017 (in thousands): Six months ended June 30, 2018 2017 Beginning balance(1) $ 1,011,004 $ 968,929 Loans purchased 3,205,483 2,843,690 Payments and loans sold(1) (2,942,872 ) (2,976,523 ) Change in fair value 3,153 9,921 Ending balance $ 1,276,768 $ 846,017 (1) Includes $1.3 million and $3.3 million of SBA loans held for sale carried at lower of cost or market at June 30, 2018 and December 31, 2017 . We generally retain the right to service the loans sold, creating MSRs which are recorded as assets on our balance sheet. A summary of MSR activity for the six months ended June 30, 2018 and 2017 is as follows (in thousands): Six months ended June 30, 2018 2017 MSRs: Balance, beginning of year $ 88,150 $ 28,536 Capitalized servicing rights 26,656 37,343 Amortization (5,288 ) (2,856 ) Sales (26,742 ) — Balance, end of period $ 82,776 $ 63,023 Valuation allowance: Balance, beginning of year $ 2,823 $ — Increase (decrease) in valuation allowance (2,823 ) — Balance, end of period $ — $ — MSRs, net(1) $ 82,776 $ 63,023 MSRs, fair value $ 90,179 $ 64,889 (1) MSRs are reported on the consolidated balance sheets at amortized cost, less a valuation allowance if the fair value of identified strata, determined by interest rates, within the MSR portfolio are determined to have a fair value that is less than amortized cost. We completed a sale of Ginnie Mae MSRs in the first quarter of 2018. In anticipation of this sale, the fair value of the MSRs at December 31, 2017 was adjusted, resulting in a $2.8 million impairment charge taken in the fourth quarter of 2017. At June 30, 2018 and December 31, 2017 , our servicing portfolio of residential mortgage loans had an outstanding principal balance of $7.1 billion and $7.0 billion , respectively. In connection with the servicing of these loans, we hold deposits in the names of the investors who own the loans representing escrow funds for taxes and insurance, as well as collections in transit to the investors. These escrow funds are segregated and held in separate non-interest-bearing accounts at the Bank. These deposits, included in total non-interest-bearing deposits on the consolidated balance sheets, were $84.5 million at June 30, 2018 and $73.4 million at December 31, 2017 . The estimated fair value of the MSR assets is obtained from an independent third party and reviewed by management on a quarterly basis. MSRs typically do not trade in an active, open market with readily observable prices; as such, the fair value of MSRs is determined using a discounted cash flow model to calculate the present value of the estimated future net servicing income. The assumptions utilized in the discounted cash flow model are based on market data for comparable assets, where available. Each quarter, management and the independent third party discuss the key assumptions used in the discounted cash flow model and make adjustments as necessary to estimate the fair value of the MSRs. As of June 30, 2018 and December 31, 2017 , management used the following assumptions to determine the fair value of MSRs: June 30, 2018 December 31, 2017 Average discount rates 9.61 % 9.90 % Expected prepayment speeds 9.04 % 9.99 % Weighted average life, in years 7.5 7.0 A sensitivity analysis of changes in the fair value of our MSR portfolio resulting from certain key assumptions is presented in the following table (in thousands): June 30, 2018 December 31, 2017 50 bp adverse change in prepayment speed $ (12,184 ) $ (11,896 ) 100 bp adverse change in prepayment speed (24,683 ) (28,226 ) These sensitivities are hypothetical and actual results may differ materially due to a number of factors. The effect on fair value of a 10% variation in assumptions generally cannot be determined with confidence because the relationship of the change in assumptions to the fair value may not be linear. Additionally, the impact of a variation in a particular assumption on the fair value is calculated while holding other assumptions constant. In reality, changes in one factor may be correlated with changes in other factors, which could impact the sensitivity analysis as presented. In conjunction with the sale and securitization of loans held for sale, we may be exposed to liability resulting from recourse agreements and repurchase agreements. If it is determined subsequent to our sale of a loan that the loan sold is in breach of the representations or warranties made in the applicable sale agreement, we may have an obligation to either (a) repurchase the loan for the unpaid principal balance, accrued interest and related advances, (b) indemnify the purchaser against any loss it suffers or (c) make the purchaser whole for the economic benefits of the loan. Our repurchase, indemnification and make whole obligations vary based upon the terms of the applicable agreements, the nature of the asserted breach and the status of the mortgage loan at the time a claim is made. We establish reserves for estimated losses of this nature inherent in the origination of mortgage loans by estimating the losses inherent in the population of all loans sold based on trends in claims and actual loss severities experienced. The reserve includes accruals for probable contingent losses in addition to those identified in the pipeline of claims received. The estimation process is designed to include amounts based on any actual losses experienced from actual repurchase activity. Our estimated exposure related to loans previously sold and currently held for sale was $1.5 million at June 30, 2018 and $1.3 million at December 31, 2017 and is recorded in other liabilities in the consolidated balance sheets. We had $148,000 in losses due to repurchase, indemnification and make-whole obligations during the six months ended June 30, 2018 and $7,000 in losses during the six months ended June 30, 2017 .

FINANCIAL INSTRUMENTS WITH OFF-

FINANCIAL INSTRUMENTS WITH OFF-BALANCE SHEET RISK	6 Months Ended
	Jun. 30, 2018
Risks and Uncertainties [Abstract]
FINANCIAL INSTRUMENTS WITH OFF-BALANCE SHEET RISK	FINANCIAL INSTRUMENTS WITH OFF-BALANCE SHEET RISK The Bank is a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit that involve varying degrees of credit risk in excess of the amount recognized in the consolidated balance sheets. The Bank’s exposure to credit loss in the event of non-performance by the other party to the financial instrument for commitments to extend credit and standby letters of credit is represented by the contractual amount of these instruments. The Bank uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments. The amount of collateral obtained, if deemed necessary, is based on management’s credit evaluation of the borrower. Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the commitments may expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The Bank evaluates each customer’s credit-worthiness on a case-by-case basis. Standby letters of credit are conditional commitments issued by the Bank to guarantee the performance of a customer to a third party. Those guarantees are primarily issued to support public and private borrowing arrangements. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. The table below summarizes our off-balance sheet financial instruments whose contract amounts represented credit risk (in thousands): June 30, 2018 December 31, 2017 Commitments to extend credit $ 7,254,475 $ 6,957,847 Standby letters of credit 244,962 230,958 At June 30, 2018 and December 31, 2017 , we had $10.5 million and $9.1 million , respectively, in allowance for off-balance sheet credit losses related to these off-balance sheet commitments recorded in other liabilities in the consolidated balance sheets.

REGULATORY MATTERS

REGULATORY MATTERS	6 Months Ended
	Jun. 30, 2017
Regulatory Capital Requirements [Abstract]
REGULATORY MATTERS	REGULATORY MATTERS The Company and the Bank 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 adverse effect on the Company’s and the Bank’s financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company and the Bank must meet specific capital guidelines that involve quantitative measures of the Company’s and the Bank’s assets, liabilities, and certain off-balance sheet items as calculated under regulatory accounting practices. The Company’s and the Bank’s capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors. The Basel III regulatory capital framework (the "Basel III Capital Rules") adopted by U.S. federal regulatory authorities, among other things, (i) establishes the capital measure called "Common Equity Tier 1" ("CET1"), (ii) specifies that Tier 1 capital consist of CET1 and "Additional Tier 1 Capital" instruments meeting stated requirements, (iii) requires that most deductions/adjustments to regulatory capital measures be made to CET1 and not to other components of capital and (iv) defines the scope of the deductions/adjustments to the capital measures. The Basel III Capital Rules became effective for us on January 1, 2015 with certain transition provisions fully phasing in over a period ending on January 1, 2019. Additionally, the Basel III Capital Rules require that we maintain a capital conservation buffer with respect to each of CET1, Tier 1 and total capital to risk-weighted assets, which provides for capital levels that exceed the minimum risk-based capital adequacy requirements. The capital conservation buffer is subject to a three year phase-in period that began on January 1, 2016 and will be fully phased in on January 1, 2019 at 2.5%. The required phase-in capital conservation buffer during 2018 is 1.875% and was 1.25% during 2017 . A financial institution with a conservation buffer of less than the required amount is subject to limitations on capital distributions, including dividend payments and stock repurchases, and certain discretionary bonus payments to executive officers. Quantitative measures established by these regulations to ensure capital adequacy require the Company and the Bank to maintain minimum amounts and ratios of CET1, Tier 1 and total capital to risk-weighted assets, and of Tier 1 capital to average assets, each as defined in the regulations. Management believes, as of June 30, 2018 , that the Company and the Bank met all capital adequacy requirements to which they are subject. Financial institutions are categorized as well capitalized or adequately capitalized, based on minimum total risk-based, Tier 1 risk-based, CET1 and Tier 1 leverage ratios. As shown in the table below, the Company’s capital ratios exceeded the regulatory definition of adequately capitalized as of June 30, 2018 and December 31, 2017 . Based upon the information in its most recently filed call report, the Bank met the capital ratios necessary to be well capitalized. The regulatory authorities can apply changes in classification of assets and such changes may retroactively subject the Company to changes in capital ratios. Any such changes could result in reducing one or more capital ratios below well-capitalized status. In addition, a change may result in imposition of additional assessments by the FDIC or could result in regulatory actions that could have a material adverse effect on our financial condition and results of operations. Because our Bank had less than $15.0 billion in total consolidated assets as of December 31, 2009, we are allowed to continue to classify our trust preferred securities, all of which were issued prior to May 19, 2010, as Tier 1 capital. The table below summarizes our actual and required capital ratios under the Basel III Capital Rules: Actual Minimum Capital Required - Basel III Phase-In Schedule Minimum capital Required - Basel III Fully Phased-In Required to be Considered Well Capitalized Capital Amount Ratio Capital Amount Ratio Capital Amount Ratio Capital Amount Ratio As of June 30, 2018: CET1 Company $ 2,173,815 8.32 % $ 1,665,009 6.38 % $ 1,828,245 7.00 % N/A N/A Bank 2,178,607 8.35 % 1,662,918 6.38 % 1,825,950 7.00 % 1,695,525 6.50 % Total capital (to risk-weighted assets) Company 2,902,789 11.11 % 2,579,132 9.88 % 2,742,368 10.50 % N/A N/A Bank 2,749,018 10.54 % 2,575,893 9.88 % 2,738,925 10.50 % 2,608,500 10.00 % Tier 1 capital (to risk-weighted assets) Company 2,431,650 9.31 % 2,056,776 7.88 % 2,220,012 8.50 % N/A N/A Bank 2,336,442 8.96 % 2,054,193 7.88 % 2,217,225 8.50 % 2,086,800 8.00 % Tier 1 capital (to average assets)(1) Company 2,431,650 9.89 % 983,476 4.00 % 983,476 4.00 % N/A N/A Bank 2,336,442 9.51 % 982,989 4.00 % 982,989 4.00 % 1,228,736 5.00 % As of December 31, 2017: CET1 Company $ 2,033,830 8.45 % $ 1,384,448 5.75 % $ 1,685,464 7.00 % N/A N/A Bank 1,992,152 8.28 % 1,383,475 5.75 % 1,684,231 7.00 % 1,563,929 6.50 % Total capital (to risk-weighted assets) Company 2,768,153 11.50 % 2,227,221 9.25 % 2,528,196 10.50 % N/A N/A Bank 2,567,961 10.67 % 2,225,591 9.25 % 2,526,347 10.50 % 2,406,044 10.00 % Tier 1 capital (to risk-weighted assets) Company 2,293,016 9.52 % 1,745,659 7.25 % 2,046,635 8.50 % N/A N/A Bank 2,151,338 8.94 % 1,744,382 7.25 % 2,045,138 8.50 % 1,924,835 8.00 % Tier 1 capital (to average assets)(1) Company 2,293,016 9.15 % 1,002,494 4.00 % 1,002,494 4.00 % N/A N/A Bank 2,151,338 8.59 % 1,002,144 4.00 % 1,002,144 4.00 % 1,252,680 5.00 % (1) The Tier 1 capital ratio (to average assets) is not impacted by the Basel III Capital Rules; however, it should be noted that the Federal Reserve Board and the FDIC may require the Company and the Bank, respectively, to maintain a Tier 1 capital ratio (to average assets) above the required minimum. Our mortgage finance loan volumes can increase significantly at month end, causing a meaningful difference between ending balance and average balance for any period. At June 30, 2018 , our total mortgage finance loans were $5.9 billion compared to the average for the three months ended June 30, 2018 of $4.9 billion . As CET1, Tier 1 and total capital ratios are calculated using quarter-end risk-weighted assets and our mortgage finance loans are 100% risk-weighted (excluding MCA mortgage loans held for sale, which receive lower risk weights), the quarter-end fluctuation in these balances can significantly impact our reported ratios. Due to the actual risk profile and liquidity of this asset class, we manage capital allocated to mortgage finance loans based on changing trends in average balances and do not believe that the quarter-end balance is representative of risk characteristics that would justify higher allocations. However, we continue to monitor our capital allocation to confirm that all capital levels remain above well-capitalized levels. Dividends that may be paid by subsidiary banks are routinely restricted by various regulatory authorities. The amount that can be paid in any calendar year without prior approval of the Bank’s regulatory agencies cannot exceed the lesser of the net profits (as defined) for that year plus the net profits for the preceding two calendar years, or retained earnings. The Basel III Capital Rules further limit the amount of dividends that may be paid by our Bank. No dividends were declared or paid on our common stock during the six months ended June 30, 2018 or 2017 .

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	6 Months Ended
	Jun. 30, 2018
Compensation Related Costs [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION We have long-term incentive plans under which stock-based compensation awards are granted to employees and directors by the board of directors, or its designated committee. Grants are subject to vesting requirements and may include, among other things, nonqualified stock options, stock appreciation rights ("SARs"), restricted stock units ("RSUs"), restricted stock and performance units, or any combination thereof. There are 2,550,000 total shares authorized for grant under the plans. The table below summarizes our stock-based compensation expense for the three and six months ended June 30, 2018 and 2017 (in thousands): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Stock-settled awards: SARs $ 43 $ 74 $ 93 $ 146 RSUs 2,078 1,714 3,974 3,307 Restricted stock 13 4 24 8 Cash-settled performance units 3,092 2,603 7,106 5,493 Total $ 5,226 $ 4,395 $ 11,197 $ 8,954 (in thousands) June 30, 2018 Unrecognized compensation expense related to unvested stock-settled awards $ 15,335 Weighted average period over which expense is expected to be recognized, in years 2.9

INCOME TAXES (Notes)

INCOME TAXES (Notes)	6 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Tax Cuts and Jobs Act (the "Tax Act") enacted in December 2017 reduced the federal corporate income tax rate from 35% to 21% effective January 1, 2018. As a result of the Tax Act, we re-measured certain deferred tax assets and liabilities based on the rates at which they are expected to reverse in the future, which is generally 21%. However, we are still analyzing certain aspects of the Tax Act and refining our calculations, which could potentially affect the measurement of these balances or potentially give rise to new deferred tax amounts. The provisional amount recorded in 2017 related to the re-measurement of our deferred tax asset was $17.6 million , and no further adjustments were made during the six months ended June 30, 2018 . The reconciliation of our total effective income tax rate to the U.S. federal statutory tax rate for the six months ended June 30, 2018 and 2017 is as follows: Six months ended June 30, 2018 2017 U.S. statutory rate 21 % 35 % State taxes 1 % 1 % Non-deductible expenses 1 % — % Non-taxable income (1 )% (1 )% Other (1 )% (1 )% Effective tax rate 21 % 34 %

FAIR VALUE DISCLOSURES

FAIR VALUE DISCLOSURES	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
FAIR VALUE DISCLOSURES	FAIR VALUE DISCLOSURES We determine the fair market values of our assets and liabilities measured at fair value on a recurring and nonrecurring basis using the fair value hierarchy as prescribed in ASC 820, Fair Value Measurements and Disclosures . The standard describes three levels of inputs that may be used to measure fair value as provided below. Level 1 Quoted prices in active markets for identical assets or liabilities. This category includes the assets and liabilities related to our non-qualified deferred compensation plan where values are based on quoted market prices for identical equity securities in an active market. Level 2 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 2 assets include agency mortgage-backed debt securities and Community Reinvestment Act funds. This category also includes loans held for sale and derivative assets and liabilities where values are obtained from independent pricing services using observable market data. Level 3 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 similar techniques, as well as instruments for which the determination of fair values requires significant management judgment or estimation. This category includes certain loans held for sale for which fair values are determined using third party pricing models. This category also includes impaired loans and OREO where collateral values have been based on third party appraisals; however, comparative sales data typically used in appraisals may be unavailable or more subjective in certain markets due to lack of market activity. Assets and liabilities measured at fair value at June 30, 2018 and December 31, 2017 are as follows (in thousands): Fair Value Measurements Using June 30, 2018 Level 1 Level 2 Level 3 Available-for-sale debt securities:(1) Residential mortgage-backed securities $ — $ 8,785 $ — Equity securities(1)(2) 8,711 6,912 — Loans held for sale (3) — 1,247,537 27,929 Loans held for investment(4)(6) — — 22,165 OREO(5)(6) — — 9,526 Derivative assets(7) — 21,740 — Derivative liabilities(7) — 25,516 — Non-qualified deferred compensation plan liabilities (8) 9,192 — — December 31, 2017 Available-for-sale debt securities:(1) Residential mortgage-backed securities $ — $ 10,945 $ — Equity securities(1)(2) 5,460 7,106 — Loans held for sale(3) — 1,007,695 — Loans held for investment(4)(6) — — 21,216 OREO(5)(6) — — 11,742 Derivative assets(7) — 16,719 — Derivative liabilities(7) — 17,377 — Non-qualified deferred compensation plan liabilities (8) 5,587 — — (1) Securities are measured at fair value on a recurring basis, generally monthly. (2) Equity securities consist of Community Reinvestment Act funds and investments related to our non-qualified deferred compensation plan. (3) Loans held for sale, excluding SBA loans which are carried at lower of cost or market, are measured at fair value on a recurring basis, generally monthly. (4) Includes impaired loans that have been measured for impairment at the fair value of the loan’s collateral. (5) OREO is transferred from loans to OREO at fair value less selling costs. (6) Loans held for investment and OREO are measured on a nonrecurring basis, generally annually or more often as warranted by market and economic conditions. (7) Derivative assets and liabilities are measured at fair value on a recurring basis, generally quarterly. (8) Non-qualified deferred compensation plan liabilities represent the fair value of the obligation to the employee, which corresponds to the fair value of the invested assets, and are measured at fair value on a recurring basis, generally monthly. Level 3 Valuations Financial instruments are considered Level 3 when their values are determined using pricing models, discounted cash flow methodologies or similar techniques and at least one significant model assumption or input is unobservable. Level 3 financial instruments include those for which the determination of fair value requires significant management judgment or estimation. Currently, we measure the fair value of certain loans held for sale using third party pricing models on a recurring basis, and measure certain collateral dependent impaired loans and OREO on a nonrecurring basis as described below. Loans held for sale The following table presents a reconciliation for the three and six months ended June 30, 2018 of loans held for sale measured at fair value on a recurring basis using Level 3 inputs (in thousands): Net Realized/Unrealized Gains (Losses) Recorded in Earnings(1) Balance at Beginning of Period Purchases / Additions Sales / Reductions Realized Unrealized Balance at End of Period Three months ended June 30, 2018 Loans held for sale $ 34,251 $ 1,437 $ (7,988 ) $ 161 $ 68 $ 27,929 Six months ended June 30, 2018 Loans held for sale $ — $ 37,529 $ (7,988 ) $ (1,680 ) $ 68 $ 27,929 (1) Recorded in other non-interest income. The fair value of loans held for sale using Level 3, or unobservable inputs, include loans that cannot be sold through normal sale channels and thus require significant management judgment or estimation when determining the fair value. The fair value of such loans is generally based upon quoted prices of comparable loans with a liquidity discount applied. At June 30, 2018 , the fair value of these loans was calculated using a weighted-average discounted price of 94.3% . Loans held for investment At June 30, 2018 and December 31, 2017 , certain impaired loans held for investment were reported at fair value through a specific allocation of the allowance for loan losses based upon the fair value of the underlying collateral. The $22.2 million fair value of loans held for investment at June 30, 2018 reported above includes impaired loans held for investment with a carrying value of $30.1 million that were reduced by specific allowance allocations totaling $7.9 million based on collateral valuations utilizing Level 3 valuation inputs. The $21.2 million fair value of loans held for investment at December 31, 2017 reported above includes impaired loans with a carrying value of $32.2 million that were reduced by specific valuation allowance allocations totaling $11.0 million based on collateral valuations utilizing Level 3 valuation inputs. Fair values were based on third party appraisals, which are Level 3 valuation inputs. OREO Certain foreclosed assets, upon initial recognition, are recorded at fair value less estimated selling costs. At June 30, 2018 and December 31, 2017 , OREO had a carrying value of $11.5 million and $11.7 million , respectively, net of a $2.0 million specific valuation allowance at June 30, 2018 and no valuation allowance at December 31, 2017 . The fair value of OREO was computed based on third party appraisals, which are Level 3 valuation inputs. Fair Value of Financial Instruments GAAP requires disclosure of fair value information about financial instruments, whether or not recognized on the balance sheet, for which it is practical to estimate that value. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. This disclosure does not and is not intended to represent the fair value of the Company. A summary of the carrying amounts and estimated fair values of financial instruments is as follows (in thousands): June 30, 2018 December 31, 2017 Carrying Amount Estimated Fair Value Carrying Estimated Financial assets: Level 1 inputs: Cash and cash equivalents $ 3,462,794 $ 3,462,794 $ 2,905,591 $ 2,905,591 Investment securities 8,711 8,711 5,460 5,460 Level 2 inputs: Investment securities 15,697 15,697 18,051 18,051 Loans held for sale 1,248,839 1,248,839 1,011,004 1,011,004 Derivative assets 21,740 21,740 16,719 16,719 Level 3 inputs: Loans held for sale 27,929 27,929 — — Loans held for investment, net 22,280,683 22,258,008 20,489,757 20,480,802 Financial liabilities: Level 2 inputs: Federal funds purchased 510,221 510,221 359,338 359,338 Customer repurchase agreements 10,628 10,628 5,702 5,702 Other borrowings 4,000,000 4,000,000 2,800,000 2,800,000 Subordinated notes 281,586 283,268 281,406 285,485 Derivative liabilities 25,516 25,516 17,377 17,377 Level 3 inputs: Deposits 20,334,871 21,258,150 19,123,180 19,124,121 Trust preferred subordinated debentures 113,406 113,406 113,406 113,406 The following methods and assumptions were used by the Company in estimating its fair value disclosures for financial instruments: Investment Securities Within the investment securities portfolio, we hold equity securities related to our non-qualified deferred compensation plan which are valued using quoted market prices for identical equity securities in an active market. These financial instruments are classified as Level 1 assets in the fair value hierarchy. The fair value of the remaining investment portfolio is based on prices obtained from independent pricing services which are based on quoted market prices for the same or similar securities, and these financial instruments are characterized as Level 2 assets in the fair value hierarchy. We have obtained documentation from our primary pricing service regarding their processes and controls applicable to pricing investment securities. In addition, on a quarterly basis we independently verify the prices that we receive from the service provider using two additional independent pricing sources. Any significant differences are investigated and resolved. Loans Held for Sale Fair value for loans held for sale is derived from quoted market prices for similar loans, in which case they are characterized as Level 2 assets in the fair value hierarchy, or is derived from third party pricing models, in which case they are characterized as Level 3 assets in the fair value hierarchy. Derivatives The estimated fair value of interest rate swaps and caps is obtained from independent pricing services based on quoted market prices for similar derivative contracts and these financial instruments are characterized as Level 2 assets and liabilities in the fair value hierarchy. On a quarterly basis, we independently verify the fair value using an additional independent pricing source. Any significant differences are investigated and resolved. Foreign currency forward contracts are valued based upon quoted market prices obtained from independent pricing services for similar derivative contracts. As such, these financial instruments are characterized as Level 2 assets and liabilities in the fair value hierarchy. The derivative instruments related to the loans held for sale portfolio include loan purchase commitments and forward sales commitments. Loan purchase commitments are valued based upon the fair value of the underlying mortgage loans to be purchased, which is based on observable market data for similar loans. Forward sales commitments are valued based upon quoted market prices from brokers. As such, these loan purchase commitments and forward sales commitments are characterized as Level 2 assets or liabilities in the fair value hierarchy.

DERIVATIVE FINANCIAL INSTRUMENT

DERIVATIVE FINANCIAL INSTRUMENTS	6 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE FINANCIAL INSTRUMENTS	DERIVATIVE FINANCIAL INSTRUMENTS The fair value of derivative positions outstanding is included in accrued interest receivable and other assets and other liabilities in the accompanying consolidated balance sheets on a net basis when a right of offset exists, based on transactions with a single counterparty that are subject to a legally enforceable master netting agreement. We enter into interest rate derivative positions that are not designated as hedging instruments. These derivative positions relate to transactions in which we enter into an interest rate swap, cap and/or floor with a customer while at the same time entering into an offsetting interest rate swap, cap and/or floor with another financial institution. In connection with each swap transaction, we agree to pay interest to the customer on a notional amount at a variable interest rate and receive interest from the customer on a similar notional amount at a fixed interest rate. At the same time, we agree to pay another financial institution the same fixed interest rate on the same notional amount and receive the same variable interest rate on the same notional amount. The transaction allows our customer to effectively convert a variable rate loan to a fixed rate. Because we act as an intermediary for our customer, changes in the fair value of the underlying derivative contracts substantially offset each other and do not have a material impact on our results of operations. We also enter into foreign currency forward contracts that are not designated as hedging instruments. These derivative instruments relate to transactions in which we enter into a contract with a customer to buy or sell a foreign currency at a future date for a specified price while at the same time entering into an offsetting contract with a financial institution to buy or sell the same currency at the same future date for a specified price. These transactions allow our customers to manage their exposure to foreign currency exchange rate fluctuations. Because we act as an intermediary for our customer, changes in the fair value of the underlying derivative instruments substantially offset each other and do not have a material impact on our results of operations. We also enter into loan purchase commitment contracts with mortgage originators to purchase residential mortgage loans at a future date, as well as forward sales commitment contracts to sell residential mortgage loans at a future date as part of our MCA program. The objective of these transactions is to mitigate our exposure to interest rate risk associated with the purchase of mortgage loans held for sale. Any changes in fair value are recorded in other non-interest expense in the consolidated statements of income and other comprehensive income. The notional amounts and estimated fair values of interest rate derivative positions outstanding at June 30, 2018 and December 31, 2017 are presented in the following tables (in thousands): June 30, 2018 December 31, 2017 Estimated Fair Value Estimated Fair Value Notional Amount Asset Derivative Liability Derivative Notional Amount Asset Derivative Liability Derivative Non-hedging interest rate derivatives: Financial institution counterparties: Commercial loan/lease interest rate swaps $ 1,514,867 $ 17,079 $ 6,239 $ 1,393,764 $ 4,736 $ 15,482 Commercial loan/lease interest rate caps 245,667 992 18 242,700 421 7 Foreign currency forward contracts 53,871 1,794 58 2,466 4 69 Customer counterparties: Commercial loan/lease interest rate swaps 1,514,867 6,239 17,079 1,393,764 15,482 4,736 Commercial loan/lease interest rate caps 245,667 18 992 242,700 7 421 Foreign currency forward contracts 53,871 58 1,794 2,466 69 4 Economic hedging interest rate derivatives: Loan purchase commitments 204,057 1,089 21 253,815 635 190 Forward sales commitments 1,361,500 — 4,844 1,086,224 — 1,103 Gross derivatives 27,269 31,045 21,354 22,012 Offsetting derivative assets/liabilities (5,529 ) (5,529 ) (4,635 ) (4,635 ) Net derivatives included in the consolidated balance sheets $ 21,740 $ 25,516 $ 16,719 $ 17,377 The weighted average received and paid interest rates for interest rate swaps outstanding at June 30, 2018 and December 31, 2017 were as follows: June 30, 2018 December 31, 2017 Received Paid Received Paid Non-hedging interest rate swaps 3.85 % 4.17 % 3.59 % 4.34 % The weighted average strike rate for outstanding interest rate caps was 2.38% at June 30, 2018 and 2.40% at December 31, 2017 . Our credit exposure on derivative instruments is limited to the net favorable value and interest payments by each counterparty. In some cases collateral may be required from the counterparties involved if the net value of the derivative instruments exceeds a nominal amount . Our credit exposure associated with these instruments, net of any collateral pledged, was approximately $12.9 million at June 30, 2018 and approximately $16.7 million at December 31, 2017 . Collateral levels are monitored and adjusted on a regular basis for changes in interest rate swap and cap values, as well as for changes in the value of forward sales commitments. At June 30, 2018 , we had pledged to counterparties $6.7 million in cash collateral for these derivatives, of which $2.8 million was included in interest-bearing deposits in other banks and $3.9 million was included in accrued interest receivable and other assets, and counterparties had pledged to us $11.1 million in cash collateral included in interest-bearing deposit liabilities. At December 31, 2017 , we had pledged to counterparties $15.2 million in cash collateral for these derivatives, of which $14.0 million was included in interest-bearing deposits in other banks and $1.2 million was included in accrued interest receivable and other assets. We also enter into credit risk participation agreements with financial institution counterparties for interest rate swaps related to loans in which we are either a participant or a lead bank. The risk participation agreements entered into by us as a participant bank provide credit protection to the financial institution counterparty should the borrower fail to perform on its interest rate derivative contract with that financial institution. We are party to 14 risk participation agreements where we are a participant bank having a notional amount of $130.2 million at June 30, 2018 , compared to 15 risk participation agreements having a notional amount of $157.1 million at December 31, 2017 . The maximum estimated exposure to these agreements, assuming 100% default by all obligors, was approximately $157,000 at June 30, 2018 and $221,000 at December 31, 2017 . The fair value of these exposures was insignificant to the consolidated financial statements at both June 30, 2018 and December 31, 2017 . Risk participation agreements entered into by us as the lead bank provide credit protection to us should the borrower fail to perform on its interest rate derivative contract with us. We are party to 11 risk participation agreements where we are the lead bank having a notional amount of $126.5 million at June 30, 2018 , compared to 10 agreements having a notional amount of $86.3 million at December 31, 2017 .

NEW ACCOUNTING PRONOUNCEMENTS

NEW ACCOUNTING PRONOUNCEMENTS	6 Months Ended
	Jun. 30, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
NEW ACCOUNTING PRONOUNCEMENTS	NEW ACCOUNTING PRONOUNCEMENTS ASU 2016-13 "Financial Instruments - Credit Losses (Topic 326)" ("ASU 2016-13") requires an entity to utilize a new impairment model known as the current expected credit loss ("CECL") model to estimate its lifetime "expected credit loss" and record an allowance that, when deducted from the amortized cost basis of the financial asset, presents the net amount expected to be collected on the financial asset. The CECL model is expected to result in more timely recognition of credit losses. ASU 2016-13 also requires new disclosures for financial assets measured at amortized cost, loans and available-for-sale debt securities. Entities will apply the standard's provisions as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. ASU 2016-13 will be effective for us on January 1, 2020. We are evaluating the impact adoption of ASU 2016-13 will have on our consolidated financial statements and disclosures. While we are currently unable to reasonably estimate the impact of adopting ASU 2016-13, we expect that the impact of adoption could be significantly influenced by the composition, characteristics and quality of our loan portfolio as well as the prevailing economic conditions and forecasts as of the adoption date. As part of our evaluation process, we have established a steering committee and working group that includes individuals from various functional areas to assess processes, portfolio segmentation, systems requirements and needed resources to implement this new accounting standard. ASU 2016-02 " Leases (Topic 842) " ("ASU 2016-02") requires that lessees and lessors recognize lease assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. ASU 2016-02 will be effective for us on January 1, 2019. ASU 2016-02 provides for a modified retrospective transition approach requiring lessees to recognize and measure leases on the balance sheet at the beginning of the earliest period presented with the option to elect certain practical expedients. We are currently implementing a third party software solution to assist with the accounting under the new standard. Our operating leases relate primarily to office space and bank branches. We expect recorded assets and liabilities to increase upon adoption of the standard as it relates to operating leases in which we are the lessee.

Summary of Significant Accounti

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Nature of Business	Organization and Nature of Business Texas Capital Bancshares, Inc. (the “Company”), a Delaware corporation, was incorporated in November 1996 and commenced banking operations in December 1998. The consolidated financial statements of the Company include the accounts of Texas Capital Bancshares, Inc. and its wholly owned subsidiary, Texas Capital Bank, National Association (the “Bank”). We serve the needs of commercial businesses and successful professionals and entrepreneurs located in Texas as well as operate several lines of business serving a regional and national clientèle of commercial borrowers. We are primarily a secured lender with a majority of our loans being made to businesses headquartered or with operations in Texas. At the same time, our national lines of business continue to provide specialized lending products to businesses throughout the United States.
Basis of Presentation	Basis of Presentation Our accounting and reporting policies conform to accounting principles generally accepted in the United States (“GAAP”) and to generally accepted practices within the banking industry. Certain prior period balances have been reclassified to conform to the current period presentation. The consolidated interim financial statements are unaudited and certain information and footnote disclosures presented in accordance with GAAP have been condensed or omitted. In the opinion of management, the interim financial statements include all normal and recurring adjustments and the disclosures made are adequate to make the interim financial information not misleading. The consolidated financial statements have been prepared in accordance with GAAP for interim financial information and the instructions to Form 10-Q adopted by the Securities and Exchange Commission (“SEC”). Accordingly, the financial statements do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with our consolidated financial statements, and notes thereto, for the year ended December 31, 2017 , included in our Annual Report on Form 10-K filed with the SEC on February 14, 2018 (the “ 2017 Form 10-K”). Operating results for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for a full year or any future period.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates. The allowance for loan losses, the fair value of stock-based compensation awards, the fair value of mortgage servicing rights ("MSRs") and the status of contingencies are particularly susceptible to significant change.

EARNINGS PER COMMON SHARE (Tabl

EARNINGS PER COMMON SHARE (Tables)	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted earnings per share	The following table presents the computation of basic and diluted earnings per share (in thousands except share data): Three months ended Six months ended 2018 2017 2018 2017 Numerator: Net income $ 71,436 $ 51,095 $ 143,381 $ 93,637 Preferred stock dividends 2,437 2,437 4,875 4,875 Net income available to common stockholders 68,999 48,658 $ 138,506 88,762 Denominator: Denominator for basic earnings per share—weighted average shares 49,736,384 49,576,837 49,695,783 49,556,393 Effect of employee stock-based awards (1) 348,762 224,306 336,285 244,058 Effect of warrants to purchase common stock 10,869 428,527 112,884 432,660 Denominator for dilutive earnings per share—adjusted weighted average shares and assumed conversions 50,096,015 50,229,670 50,144,952 50,233,111 Basic earnings per common share $ 1.39 $ 0.98 $ 2.79 $ 1.79 Diluted earnings per common share $ 1.38 $ 0.97 $ 2.76 $ 1.77 (1) SARs and RSUs outstanding of 4,000 at June 30, 2018 and 6,200 at June 30, 2017 have not been included in diluted earnings per share because to do so would have been anti-dilutive for the periods presented.

INVESTMENT SECURITIES (Tables)

INVESTMENT SECURITIES (Tables)	6 Months Ended
	Jun. 30, 2018
Available-for-sale Securities [Abstract]
Schedule of summary of securities	The following is a summary of available-for-sale debt securities (in thousands): June 30, 2018 Amortized Gross Gross Estimated Residential mortgage-backed securities $ 8,304 $ 481 $ — $ 8,785 December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Residential mortgage-backed securities $ 10,297 $ 648 $ — $ 10,945
Schedule of amortized cost and estimated fair value of securities	The amortized cost and estimated fair value of available-for-sale debt securities are presented below by contractual maturity (in thousands, except percentage data): June 30, 2018 Less Than After One After Five After Ten Total Residential mortgage-backed securities: (1) Amortized cost 50 1,895 — 6,359 8,304 Estimated fair value 52 2,038 — 6,695 8,785 Weighted average yield (2) 5.24 % 5.55 % — % 3.75 % 4.17 % December 31, 2017 Less Than After One After Five After Ten Total Residential mortgage-backed securities:(1) Amortized cost $ 409 $ 819 $ 1,502 $ 7,567 $ 10,297 Estimated fair value 418 916 1,636 7,975 10,945 Weighted average yield(2) 4.59 % 6.02 % 5.32 % 3.45 % 3.97 % (1) Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without prepayment penalties. (2) Yields are calculated based on amortized cost.
Summary of unrealized and realized gains and losses recognized on equity securities	The following is a summary of unrealized and realized gains and losses recognized in net income on equity securities during the three and six months ended June 30, 2018 (in thousands): Three months ended Six months ended June 30, 2018 June 30, 2018 Net gains and (losses) recognized during the period on equity securities $ 108 $ (104 ) Less: Net gains and (losses) recognized during the period on equity securities sold during the period 162 162 Unrealized gains and (losses) recognized during the reporting period on equity securities still held at the reporting date $ (54 ) $ (266 )

LOANS AND ALLOWANCE FOR LOAN 24

LOANS AND ALLOWANCE FOR LOAN LOSSES (Tables)	6 Months Ended
	Jun. 30, 2018
Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]
Schedule of loans held for investments	At June 30, 2018 and December 31, 2017 , loans held for investment were as follows (in thousands): June 30, December 31, Commercial $ 10,189,832 $ 9,189,811 Mortgage finance 5,923,058 5,308,160 Construction 2,226,590 2,166,208 Real estate 3,868,411 3,794,577 Consumer 46,652 48,684 Leases 314,575 264,903 Gross loans held for investment 22,569,118 20,772,343 Deferred income (net of direct origination costs) (109,339 ) (97,931 ) Allowance for loan losses (179,096 ) (184,655 ) Total loans held for investment, net $ 22,280,683 $ 20,489,757
Schedule of the credit risk profile of loan portfolio by internally assigned grades and non-accrual status	The following tables summarize the credit risk profile of our loan portfolio by internally assigned grades and non-accrual status as of June 30, 2018 and December 31, 2017 (in thousands): June 30, 2018 Commercial Mortgage Finance Construction Real Estate Consumer Leases Total Grade: Pass $ 9,945,020 $ 5,923,058 $ 2,211,981 $ 3,778,808 $ 46,493 $ 299,825 $ 22,205,185 Special mention 87,297 — 14,609 56,003 — — 157,909 Substandard-accruing 77,929 — — 31,057 93 13,650 122,729 Non-accrual 79,586 — — 2,543 66 1,100 83,295 Total loans held for investment $ 10,189,832 $ 5,923,058 $ 2,226,590 $ 3,868,411 $ 46,652 $ 314,575 $ 22,569,118 December 31, 2017 Commercial Mortgage Finance Construction Real Estate Consumer Leases Total Grade: Pass $ 8,967,471 $ 5,308,160 $ 2,152,654 $ 3,706,541 $ 48,591 $ 249,865 $ 20,433,282 Special mention 19,958 — 13,554 53,652 — 495 87,659 Substandard-accruing 102,651 — — 32,671 93 14,543 149,958 Non-accrual 99,731 — — 1,713 — — 101,444 Total loans held for investment $ 9,189,811 $ 5,308,160 $ 2,166,208 $ 3,794,577 $ 48,684 $ 264,903 $ 20,772,343
Schedule of activity in the reserve for loan losses by portfolio segment	The following table details activity in the allowance for loan losses by portfolio segment for the six months ended June 30, 2018 and 2017 . Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. June 30, 2018 (in thousands) Commercial Mortgage Finance Construction Real Estate Consumer Leases Additional Qualitative Reserve Total Beginning balance $ 118,806 $ — $ 19,273 $ 34,287 $ 357 $ 3,542 $ 8,390 $ 184,655 Provision for loan losses 38,920 — 621 928 (205 ) 860 (3,511 ) 37,613 Charge-offs 43,972 — — — — — — 43,972 Recoveries 680 — — 32 68 20 — 800 Net charge-offs (recoveries) 43,292 — — (32 ) (68 ) (20 ) — 43,172 Ending balance $ 114,434 $ — $ 19,894 $ 35,247 $ 220 $ 4,422 $ 4,879 $ 179,096 Period end amount allocated to: Loans individually evaluated for impairment $ 11,772 $ — $ — $ 73 $ 11 $ 495 $ — $ 12,351 Loans collectively evaluated for impairment 102,662 — 19,894 35,174 209 3,927 4,879 166,745 Ending balance $ 114,434 $ — $ 19,894 $ 35,247 $ 220 $ 4,422 $ 4,879 $ 179,096 June 30, 2017 (in thousands) Commercial Mortgage Finance Construction Real Estate Consumer Leases Additional Qualitative Reserve Total Beginning balance $ 128,768 $ — $ 13,144 $ 19,149 $ 241 $ 1,124 $ 5,700 $ 168,126 Provision for loan losses 19,384 — 680 3,436 287 2,989 (2,559 ) 24,217 Charge-offs 21,543 — — 40 180 — — 21,763 Recoveries 3,442 — 101 53 41 8 — 3,645 Net charge-offs (recoveries) 18,101 — (101 ) (13 ) 139 (8 ) — 18,118 Ending balance $ 130,051 $ — $ 13,925 $ 22,598 $ 389 $ 4,121 $ 3,141 $ 174,225 Period end amount allocated to: Loans individually evaluated for impairment $ 28,382 $ — $ — $ 180 $ — $ — $ — $ 28,562 Loans collectively evaluated for impairment 101,669 — 13,925 22,418 389 4,121 3,141 145,663 Ending balance $ 130,051 $ — $ 13,925 $ 22,598 $ 389 $ 4,121 $ 3,141 $ 174,225
Schedule of allowance for credit losses related to unfunded commitments	The table below presents the activity in the allowance for off-balance sheet credit losses related to unfunded commitments for the three and six months ended June 30, 2018 and 2017 (in thousands). This allowance is recorded in other liabilities in the consolidated balance sheet. Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Beginning balance $ 9,623 $ 10,847 $ 9,071 $ 11,422 Provision for off-balance sheet credit losses 835 (1,642 ) 1,387 (2,217 ) Ending balance $ 10,458 $ 9,205 $ 10,458 $ 9,205
Schedule of recorded investment in loans related to each balance in the allowance for loan losses	Our recorded investment in loans as of June 30, 2018 , December 31, 2017 and June 30, 2017 related to each balance in the allowance for loan losses by portfolio segment and disaggregated on the basis of our impairment methodology was as follows (in thousands): June 30, 2018 Commercial Mortgage Finance Construction Real Estate Consumer Leases Total Loans individually evaluated for impairment $ 80,171 $ — $ — $ 2,543 $ 66 $ 1,100 $ 83,880 Loans collectively evaluated for impairment 10,109,661 5,923,058 2,226,590 3,865,868 46,586 313,475 22,485,238 Total $ 10,189,832 $ 5,923,058 $ 2,226,590 $ 3,868,411 $ 46,652 $ 314,575 $ 22,569,118 December 31, 2017 Commercial Mortgage Finance Construction Real Estate Consumer Leases Total Loans individually evaluated for impairment $ 100,676 $ — $ — $ 2,008 $ — $ — $ 102,684 Loans collectively evaluated for impairment 9,089,135 5,308,160 2,166,208 3,792,569 48,684 264,903 20,669,659 Total $ 9,189,811 $ 5,308,160 $ 2,166,208 $ 3,794,577 $ 48,684 $ 264,903 $ 20,772,343 June 30, 2017 Commercial Mortgage Finance Construction Real Estate Consumer Leases Total Loans individually evaluated for impairment $ 120,770 $ — $ — $ 4,514 $ — $ — $ 125,284 Loans collectively evaluated for impairment 8,130,182 5,183,600 2,242,562 3,565,273 39,122 274,863 19,435,602 Total $ 8,250,952 $ 5,183,600 $ 2,242,562 $ 3,569,787 $ 39,122 $ 274,863 $ 19,560,886
Schedule of impaired loans, by portfolio class	The following tables detail our impaired loans, by portfolio class, as of June 30, 2018 and December 31, 2017 (in thousands): June 30, 2018 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized With no related allowance recorded: Commercial Business loans $ 27,521 $ 52,966 $ — $ 12,449 $ 133 Energy 16,373 17,549 — 20,393 — Construction Market risk — — — — — Real estate Market risk — — — — — Commercial 1,042 1,042 — 1,074 — Secured by 1-4 family 1,263 1,263 — 211 — Consumer — — — — — Leases — — — — — Total impaired loans with no allowance recorded $ 46,199 $ 72,820 $ — $ 34,127 $ 133 With an allowance recorded: Commercial Business loans $ 19,038 $ 19,038 $ 5,597 $ 43,537 $ — Energy 17,239 18,500 6,175 32,145 — Construction Market risk — — — — — Real estate Market risk — — — 98 — Commercial — — — 166 — Secured by 1-4 family 238 238 73 138 — Consumer 66 71 11 47 — Leases 1,100 1,100 495 183 — Total impaired loans with an allowance recorded $ 37,681 $ 38,947 $ 12,351 $ 76,314 $ — Combined: Commercial Business loans $ 46,559 $ 72,004 $ 5,597 $ 55,986 $ 133 Energy 33,612 36,049 6,175 52,538 — Construction Market risk — — — — — Real estate Market risk — — — 98 — Commercial 1,042 1,042 — 1,240 — Secured by 1-4 family 1,501 1,501 73 349 — Consumer 66 71 11 47 — Leases 1,100 1,100 495 183 — Total impaired loans $ 83,880 $ 111,767 $ 12,351 $ 110,441 $ 133 December 31, 2017 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized With no related allowance recorded: Commercial Business loans $ 16,835 $ 18,257 $ — $ 22,964 $ — Energy 21,426 22,602 — 36,579 — Construction Market risk — — — — — Real estate Market risk — — — — — Commercial 1,096 1,096 — 2,166 — Secured by 1-4 family — — — — — Consumer — — — — — Leases — — — — — Total impaired loans with no allowance recorded $ 39,357 $ 41,955 $ — $ 61,709 $ — With an allowance recorded: Commercial Business loans $ 18,645 $ 19,020 $ 2,544 $ 16,960 $ — Energy 43,770 55,875 21,772 50,867 6 Construction Market risk — — — 27 — Real estate Market risk 295 295 6 485 — Commercial 499 499 75 166 — Secured by 1-4 family 118 118 20 516 — Consumer — — — 33 — Leases — — — 14 — Total impaired loans with an allowance recorded $ 63,327 $ 75,807 $ 24,417 $ 69,068 $ 6 Combined: Commercial Business loans $ 35,480 $ 37,277 $ 2,544 $ 39,924 $ — Energy 65,196 78,477 21,772 87,446 6 Construction Market risk — — — 27 — Real estate Market risk 295 295 6 485 — Commercial 1,595 1,595 75 2,332 — Secured by 1-4 family 118 118 20 516 — Consumer — — — 33 — Leases — — — 14 — Total impaired loans $ 102,684 $ 117,762 $ 24,417 $ 130,777 $ 6
Schedule of an age analysis of accruing past due loans	The table below provides an age analysis of our loans held for investment as of June 30, 2018 (in thousands): 30-59 Days Past Due 60-89 Days Past Due Greater Than 90 Days and Accruing(1) Total Past Due Non-accrual Current Total Commercial Business loans $ 14,114 $ 17,188 $ 6,203 $ 37,505 $ 45,974 $ 8,750,741 $ 8,834,220 Energy 24,900 — — 24,900 33,612 1,297,100 1,355,612 Mortgage finance loans — — — — — 5,923,058 5,923,058 Construction Market risk 489 — — 489 — 2,151,838 2,152,327 Commercial — — — — — 41,991 41,991 Secured by 1-4 family — 1,610 — 1,610 — 30,662 32,272 Real estate Market risk 1,337 — 661 1,998 — 2,728,753 2,730,751 Commercial 639 — — 639 1,042 814,188 815,869 Secured by 1-4 family 2,745 152 493 3,390 1,501 316,900 321,791 Consumer 2 — — 2 66 46,584 46,652 Leases — — — — 1,100 313,475 314,575 Total loans held for investment $ 44,226 $ 18,950 $ 7,357 $ 70,533 $ 83,295 $ 22,415,290 $ 22,569,118 (1) Loans past due 90 days and still accruing includes premium finance loans of $6.0 million . These loans are generally secured by obligations of insurance carriers to refund premiums on canceled insurance policies. The refund of premiums from the insurance carriers can take 180 days or longer from the cancellation date.
Schedule of loans that have been restructured	The following table summarizes the loans that were restructured during the six months ended June 30, 2018 and 2017 (in thousands): As of and for the six months ended June 30, 2018 Number of Restructured Loans Balance at Restructure Balance at Period-End Energy loans 1 $ 1,370 $ 1,370 Total new restructured loans 1 $ 1,370 $ 1,370 As of and for the six months ended June 30, 2017 Number of Restructured Loans Balance at Restructure Balance at Period-End Energy loans 1 $ 1,070 $ 700 Commercial business loans 1 599 672 Total new restructured loans 2 $ 1,669 $ 1,372 The following table provides information on how loans were modified as restructured during the six months ended June 30, 2018 and 2017 (in thousands): Six months ended June 30, 2018 2017 Extended maturity $ — $ 1,372 Adjusted payment schedule 1,370 — Total $ 1,370 $ 1,372

OREO AND VALUATION ALLOWANCE 25

OREO AND VALUATION ALLOWANCE FOR LOSSES ON OREO (Tables)	6 Months Ended
	Jun. 30, 2018
Real Estate Owned, Disclosure of Detailed Components [Abstract]
Schedule of the activity related to OREO	The table below presents a summary of the activity related to OREO (in thousands): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Beginning balance $ 9,558 $ 18,833 $ 11,742 $ 18,961 Additions — — — — Sales (32 ) (144 ) (216 ) (272 ) Valuation allowance for OREO — — (2,000 ) — Ending balance $ 9,526 $ 18,689 $ 9,526 $ 18,689

CERTAIN TRANSFERS OF FINANCIA26

CERTAIN TRANSFERS OF FINANCIAL ASSETS (Tables)	6 Months Ended
	Jun. 30, 2018
Transfers and Servicing [Abstract]
Schedule of Loans Held for Sale	The table below presents the unpaid principal balance of loans held for sale and related fair values at June 30, 2018 and December 31, 2017 (in thousands): June 30, 2018 December 31, 2017 Outstanding balance(1) $ 1,273,889 $ 1,009,271 Fair value(1) 1,275,466 1,007,695 Fair value over/(under) outstanding balance $ 1,577 $ (1,576 ) The table below presents a reconciliation of the changes in loans held for sale for the six months ended June 30, 2018 and 2017 (in thousands): Six months ended June 30, 2018 2017 Beginning balance(1) $ 1,011,004 $ 968,929 Loans purchased 3,205,483 2,843,690 Payments and loans sold(1) (2,942,872 ) (2,976,523 ) Change in fair value 3,153 9,921 Ending balance $ 1,276,768 $ 846,017 (1) Includes $1.3 million and $3.3 million of SBA loans held for sale carried at lower of cost or market at June 30, 2018 and December 31, 2017 .
Servicing Asset at Amortized Cost	We generally retain the right to service the loans sold, creating MSRs which are recorded as assets on our balance sheet. A summary of MSR activity for the six months ended June 30, 2018 and 2017 is as follows (in thousands): Six months ended June 30, 2018 2017 MSRs: Balance, beginning of year $ 88,150 $ 28,536 Capitalized servicing rights 26,656 37,343 Amortization (5,288 ) (2,856 ) Sales (26,742 ) — Balance, end of period $ 82,776 $ 63,023 Valuation allowance: Balance, beginning of year $ 2,823 $ — Increase (decrease) in valuation allowance (2,823 ) — Balance, end of period $ — $ — MSRs, net(1) $ 82,776 $ 63,023 MSRs, fair value $ 90,179 $ 64,889 (1) MSRs are reported on the consolidated balance sheets at amortized cost
Schedule of Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities	As of June 30, 2018 and December 31, 2017 , management used the following assumptions to determine the fair value of MSRs: June 30, 2018 December 31, 2017 Average discount rates 9.61 % 9.90 % Expected prepayment speeds 9.04 % 9.99 % Weighted average life, in years 7.5 7.0
Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets	A sensitivity analysis of changes in the fair value of our MSR portfolio resulting from certain key assumptions is presented in the following table (in thousands): June 30, 2018 December 31, 2017 50 bp adverse change in prepayment speed $ (12,184 ) $ (11,896 ) 100 bp adverse change in prepayment speed (24,683 ) (28,226 )

FINANCIAL INSTRUMENTS WITH OF27

FINANCIAL INSTRUMENTS WITH OFF-BALANCE SHEET RISK (Tables)	6 Months Ended
	Jun. 30, 2018
Risks and Uncertainties [Abstract]
Schedule of financial instruments with off-balance sheet risk	The table below summarizes our off-balance sheet financial instruments whose contract amounts represented credit risk (in thousands): June 30, 2018 December 31, 2017 Commitments to extend credit $ 7,254,475 $ 6,957,847 Standby letters of credit 244,962 230,958 At June 30, 2018 and December 31, 2017 , we had $10.5 million and $9.1 million , respectively, in allowance for off-balance sheet credit losses related to these off-balance sheet commitments recorded in other liabilities in the consolidated balance sheets.

REGULATORY MATTERS (Tables)

REGULATORY MATTERS (Tables)	6 Months Ended
	Jun. 30, 2018
Regulatory Capital Requirements [Abstract]
Schedule of capital ratios	The table below summarizes our actual and required capital ratios under the Basel III Capital Rules: Actual Minimum Capital Required - Basel III Phase-In Schedule Minimum capital Required - Basel III Fully Phased-In Required to be Considered Well Capitalized Capital Amount Ratio Capital Amount Ratio Capital Amount Ratio Capital Amount Ratio As of June 30, 2018: CET1 Company $ 2,173,815 8.32 % $ 1,665,009 6.38 % $ 1,828,245 7.00 % N/A N/A Bank 2,178,607 8.35 % 1,662,918 6.38 % 1,825,950 7.00 % 1,695,525 6.50 % Total capital (to risk-weighted assets) Company 2,902,789 11.11 % 2,579,132 9.88 % 2,742,368 10.50 % N/A N/A Bank 2,749,018 10.54 % 2,575,893 9.88 % 2,738,925 10.50 % 2,608,500 10.00 % Tier 1 capital (to risk-weighted assets) Company 2,431,650 9.31 % 2,056,776 7.88 % 2,220,012 8.50 % N/A N/A Bank 2,336,442 8.96 % 2,054,193 7.88 % 2,217,225 8.50 % 2,086,800 8.00 % Tier 1 capital (to average assets)(1) Company 2,431,650 9.89 % 983,476 4.00 % 983,476 4.00 % N/A N/A Bank 2,336,442 9.51 % 982,989 4.00 % 982,989 4.00 % 1,228,736 5.00 % As of December 31, 2017: CET1 Company $ 2,033,830 8.45 % $ 1,384,448 5.75 % $ 1,685,464 7.00 % N/A N/A Bank 1,992,152 8.28 % 1,383,475 5.75 % 1,684,231 7.00 % 1,563,929 6.50 % Total capital (to risk-weighted assets) Company 2,768,153 11.50 % 2,227,221 9.25 % 2,528,196 10.50 % N/A N/A Bank 2,567,961 10.67 % 2,225,591 9.25 % 2,526,347 10.50 % 2,406,044 10.00 % Tier 1 capital (to risk-weighted assets) Company 2,293,016 9.52 % 1,745,659 7.25 % 2,046,635 8.50 % N/A N/A Bank 2,151,338 8.94 % 1,744,382 7.25 % 2,045,138 8.50 % 1,924,835 8.00 % Tier 1 capital (to average assets)(1) Company 2,293,016 9.15 % 1,002,494 4.00 % 1,002,494 4.00 % N/A N/A Bank 2,151,338 8.59 % 1,002,144 4.00 % 1,002,144 4.00 % 1,252,680 5.00 % (1) The Tier 1 capital ratio (to average assets) is not impacted by the Basel III Capital Rules; however, it should be noted that the Federal Reserve Board and the FDIC may require the Company and the Bank, respectively, to maintain a Tier 1 capital ratio (to average assets) above the required minimum.

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	6 Months Ended
	Jun. 30, 2018
Compensation Related Costs [Abstract]
Schedule of stock-based compensation costs	tock-based compensation expense for the three and six months ended June 30, 2018 and 2017 (in thousands): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Stock-settled awards: SARs $ 43 $ 74 $ 93 $ 146 RSUs 2,078 1,714 3,974 3,307 Restricted stock 13 4 24 8 Cash-settled performance units 3,092 2,603 7,106 5,493 Total $ 5,226 $ 4,395 $ 11,197 $ 8,954
Schedule of unrecognized compensation costs	(in thousands) June 30, 2018 Unrecognized compensation expense related to unvested stock-settled awards $ 15,335 Weighted average period over which expense is expected to be recognized, in years 2.9

INCOME TAXES (Tables)

INCOME TAXES (Tables)	6 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation	The reconciliation of our total effective income tax rate to the U.S. federal statutory tax rate for the six months ended June 30, 2018 and 2017 is as follows: Six months ended June 30, 2018 2017 U.S. statutory rate 21 % 35 % State taxes 1 % 1 % Non-deductible expenses 1 % — % Non-taxable income (1 )% (1 )% Other (1 )% (1 )% Effective tax rate 21 % 34 %

FAIR VALUE DISCLOSURES (Tables)

FAIR VALUE DISCLOSURES (Tables)	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of assets and liabilities measured at fair value	Assets and liabilities measured at fair value at June 30, 2018 and December 31, 2017 are as follows (in thousands): Fair Value Measurements Using June 30, 2018 Level 1 Level 2 Level 3 Available-for-sale debt securities:(1) Residential mortgage-backed securities $ — $ 8,785 $ — Equity securities(1)(2) 8,711 6,912 — Loans held for sale (3) — 1,247,537 27,929 Loans held for investment(4)(6) — — 22,165 OREO(5)(6) — — 9,526 Derivative assets(7) — 21,740 — Derivative liabilities(7) — 25,516 — Non-qualified deferred compensation plan liabilities (8) 9,192 — — December 31, 2017 Available-for-sale debt securities:(1) Residential mortgage-backed securities $ — $ 10,945 $ — Equity securities(1)(2) 5,460 7,106 — Loans held for sale(3) — 1,007,695 — Loans held for investment(4)(6) — — 21,216 OREO(5)(6) — — 11,742 Derivative assets(7) — 16,719 — Derivative liabilities(7) — 17,377 — Non-qualified deferred compensation plan liabilities (8) 5,587 — — (1) Securities are measured at fair value on a recurring basis, generally monthly. (2) Equity securities consist of Community Reinvestment Act funds and investments related to our non-qualified deferred compensation plan. (3) Loans held for sale, excluding SBA loans which are carried at lower of cost or market, are measured at fair value on a recurring basis, generally monthly. (4) Includes impaired loans that have been measured for impairment at the fair value of the loan’s collateral. (5) OREO is transferred from loans to OREO at fair value less selling costs. (6) Loans held for investment and OREO are measured on a nonrecurring basis, generally annually or more often as warranted by market and economic conditions. (7) Derivative assets and liabilities are measured at fair value on a recurring basis, generally quarterly. (8) Non-qualified deferred compensation plan liabilities represent the fair value of the obligation to the employee, which corresponds to the fair value of the invested assets, and are measured at fair value on a recurring basis, generally monthly.
Summary of the carrying amounts and estimated fair values of financial instruments	A summary of the carrying amounts and estimated fair values of financial instruments is as follows (in thousands): June 30, 2018 December 31, 2017 Carrying Amount Estimated Fair Value Carrying Estimated Financial assets: Level 1 inputs: Cash and cash equivalents $ 3,462,794 $ 3,462,794 $ 2,905,591 $ 2,905,591 Investment securities 8,711 8,711 5,460 5,460 Level 2 inputs: Investment securities 15,697 15,697 18,051 18,051 Loans held for sale 1,248,839 1,248,839 1,011,004 1,011,004 Derivative assets 21,740 21,740 16,719 16,719 Level 3 inputs: Loans held for sale 27,929 27,929 — — Loans held for investment, net 22,280,683 22,258,008 20,489,757 20,480,802 Financial liabilities: Level 2 inputs: Federal funds purchased 510,221 510,221 359,338 359,338 Customer repurchase agreements 10,628 10,628 5,702 5,702 Other borrowings 4,000,000 4,000,000 2,800,000 2,800,000 Subordinated notes 281,586 283,268 281,406 285,485 Derivative liabilities 25,516 25,516 17,377 17,377 Level 3 inputs: Deposits 20,334,871 21,258,150 19,123,180 19,124,121 Trust preferred subordinated debentures 113,406 113,406 113,406 113,406
Reconciliation of loans held for sale	The following table presents a reconciliation for the three and six months ended June 30, 2018 of loans held for sale measured at fair value on a recurring basis using Level 3 inputs (in thousands): Net Realized/Unrealized Gains (Losses) Recorded in Earnings(1) Balance at Beginning of Period Purchases / Additions Sales / Reductions Realized Unrealized Balance at End of Period Three months ended June 30, 2018 Loans held for sale $ 34,251 $ 1,437 $ (7,988 ) $ 161 $ 68 $ 27,929 Six months ended June 30, 2018 Loans held for sale $ — $ 37,529 $ (7,988 ) $ (1,680 ) $ 68 $ 27,929

DERIVATIVE FINANCIAL INSTRUME32

DERIVATIVE FINANCIAL INSTRUMENTS (Tables)	6 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of notional amounts and estimated fair values of interest rate derivative positions	The notional amounts and estimated fair values of interest rate derivative positions outstanding at June 30, 2018 and December 31, 2017 are presented in the following tables (in thousands): June 30, 2018 December 31, 2017 Estimated Fair Value Estimated Fair Value Notional Amount Asset Derivative Liability Derivative Notional Amount Asset Derivative Liability Derivative Non-hedging interest rate derivatives: Financial institution counterparties: Commercial loan/lease interest rate swaps $ 1,514,867 $ 17,079 $ 6,239 $ 1,393,764 $ 4,736 $ 15,482 Commercial loan/lease interest rate caps 245,667 992 18 242,700 421 7 Foreign currency forward contracts 53,871 1,794 58 2,466 4 69 Customer counterparties: Commercial loan/lease interest rate swaps 1,514,867 6,239 17,079 1,393,764 15,482 4,736 Commercial loan/lease interest rate caps 245,667 18 992 242,700 7 421 Foreign currency forward contracts 53,871 58 1,794 2,466 69 4 Economic hedging interest rate derivatives: Loan purchase commitments 204,057 1,089 21 253,815 635 190 Forward sales commitments 1,361,500 — 4,844 1,086,224 — 1,103 Gross derivatives 27,269 31,045 21,354 22,012 Offsetting derivative assets/liabilities (5,529 ) (5,529 ) (4,635 ) (4,635 ) Net derivatives included in the consolidated balance sheets $ 21,740 $ 25,516 $ 16,719 $ 17,377
Schedule of the weighted-average receive and pay interest rate swaps	The weighted average received and paid interest rates for interest rate swaps outstanding at June 30, 2018 and December 31, 2017 were as follows: June 30, 2018 December 31, 2017 Received Paid Received Paid Non-hedging interest rate swaps 3.85 % 4.17 % 3.59 % 4.34 %

EARNINGS PER COMMON SHARE (Deta

EARNINGS PER COMMON SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Numerator:
Net income		$ 71,436	$ 51,095	$ 143,381	$ 93,637
Preferred stock dividends		2,437	2,437	4,875	4,875
Net income available to common stockholders		$ 68,999	$ 48,658	$ 138,506	$ 88,762
Denominator:
Denominator for basic earnings per share—weighted average shares		49,736,384	49,576,837	49,695,783	49,556,393
Effect of employee stock-based awards	[1]	348,762	224,306	336,285	244,058
Effect of warrants to purchase common stock		10,869	428,527	112,884	432,660
Denominator for dilutive earnings per share—adjusted weighted average shares and assumed conversions		50,096,015	50,229,670	50,144,952	50,233,111
Basic earnings per common share (usd per share)		$ 1.39	$ 0.98	$ 2.79	$ 1.79
Diluted earnings per common share (usd per share)		$ 1.38	$ 0.97	$ 2.76	$ 1.77
Stock options, SARs and RSUs excluded from computation of diluted EPS				4,000	6,200
[1]	SARs and RSUs outstanding of 4,000 at June 30, 2018 and 6,200 at June 30, 2017 have not been included in diluted earnings per share because to do so would have been anti-dilutive for the periods presented.

INVESTMENT SECURITIES (Details)

INVESTMENT SECURITIES (Details) - USD ($) $ in Thousands		Jun. 30, 2018	Dec. 31, 2017
Summary of Available-for-Sale Securities
Estimated Fair Value		$ 24,408	$ 23,511
Residential mortgage-backed securities
Summary of Available-for-Sale Securities
Amortized Cost	[1]	8,304	10,297
Gross Unrealized Gains		481	648
Gross Unrealized Losses		0	0
Estimated Fair Value	[1]	$ 8,785	$ 10,945
[1]	Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without prepayment penalties.

INVESTMENT SECURITIES (Details

INVESTMENT SECURITIES (Details 1) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Jun. 30, 2018
The amortized cost and fair value of available-for-sale securites by maturity
Estimated Fair Value		$ 12,600	$ 15,600
Residential mortgage-backed securities
The amortized cost and fair value of available-for-sale securites by maturity
Amortized cost, Less Than One Year	[1]	409	50
Amortized cost, After One Through Five Years	[1]	819	1,895
Amortized cost, After Five Through Ten Years	[1]	1,502	0
Amortized cost, After Ten Years	[1]	7,567	6,359
Amortized Cost	[1]	10,297	8,304
Estimated fair value, Less Than One Year	[1]	418	52
Estimated fair value, After One Through Five Years	[1]	916	2,038
Estimated fair value, After Five Through Ten Years	[1]	1,636	0
Estimated fair value, After Ten Years	[1]	$ 7,975	$ 6,695
Weighted average yield, Less Than One Year	[1]	4.59%	5.24%
Weighted average yield, After One Through Five Years	[1]	6.02%	5.55%
Weighted average yield, After Five Through Ten Years	[1]	5.32%	0.00%
Weighted average yield, After Ten Years	[1]	3.45%	3.75%
Weighted average yield, Total	[1]	3.97%	4.17%
Deposits
Available-for-sale Securities, Other Disclosure Items
Available-for-sale securities pledged as collateral			$ 2,000
Repurchase agreements
Available-for-sale Securities, Other Disclosure Items
Available-for-sale securities pledged as collateral			$ 5,800
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Available-for-sale Securities, Other Disclosure Items
Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent		$ 10
[1]	Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without prepayment penalties.

INVESTMENT SECURITIES (Detail36

INVESTMENT SECURITIES (Details 3) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Available-for-sale Securities [Abstract]
Realized Investment Gains (Losses)	$ 108	$ (104)
Gain (Loss) on Sale of Equity Investments	162	162
Unrealized Gain (Loss) on Investments	$ (54)	$ (266)

LOANS AND ALLOWANCE FOR LOAN 37

LOANS AND ALLOWANCE FOR LOAN LOSSES (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Loans and Leases Receivable, Net Reported Amount
Commercial	$ 10,189,832	$ 9,189,811
Mortgage finance	5,923,058	5,308,160
Construction	2,226,590	2,166,208
Real estate	3,868,411	3,794,577
Consumer	46,652	48,684
Leases	314,575	264,903
Gross loans held for investment	22,569,118	20,772,343	$ 19,560,886
Deferred income (net of direct origination costs)	(109,339)	(97,931)
Allowance for loan losses	(179,096)	(184,655)	$ (174,225)	$ (168,126)
Loans held for investment, net	22,280,683	20,489,757
Participating mortgage finance loans	$ 242,700	$ 171,200

LOANS AND ALLOWANCE FOR LOAN 38

LOANS AND ALLOWANCE FOR LOAN LOSSES - Credit Risk Profile (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Financing Receivable, Recorded Investment [Line Items]
Commercial	$ 10,189,832	$ 9,189,811
Mortgage finance	5,923,058	5,308,160
Construction	2,226,590	2,166,208
Real estate	3,868,411	3,794,577
Consumer	46,652	48,684
Leases	314,575	264,903
Gross loans held for investment	22,569,118	20,772,343	$ 19,560,886
Pass
Financing Receivable, Recorded Investment [Line Items]
Commercial	9,945,020	8,967,471
Mortgage finance	5,923,058	5,308,160
Construction	2,211,981	2,152,654
Real estate	3,778,808	3,706,541
Consumer	46,493	48,591
Leases	299,825	249,865
Gross loans held for investment	22,205,185	20,433,282
Special mention
Financing Receivable, Recorded Investment [Line Items]
Commercial	87,297	19,958
Mortgage finance	0	0
Construction	14,609	13,554
Real estate	56,003	53,652
Consumer	0	0
Leases	0	495
Gross loans held for investment	157,909	87,659
Substandard-accruing
Financing Receivable, Recorded Investment [Line Items]
Commercial	77,929	102,651
Mortgage finance	0	0
Construction	0	0
Real estate	31,057	32,671
Consumer	93	93
Leases	13,650	14,543
Gross loans held for investment	122,729	149,958
Non-accrual
Financing Receivable, Recorded Investment [Line Items]
Commercial	79,586	99,731
Mortgage finance	0	0
Construction	0	0
Real estate	2,543	1,713
Consumer	66	0
Leases	1,100	0
Gross loans held for investment	$ 83,295	$ 101,444

LOANS AND ALLOWANCE FOR LOAN 39

LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 2) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable Modifications Non Accrual Loans Met Criteria For Restrucutred			$ 9,000	$ 18,800
Reserve for loan losses:
Beginning balance	$ 184,655	$ 168,126
Provision for loan losses	37,613	24,217
Charge-offs	43,972	21,763
Recoveries	800	3,645
Net charge-offs (recoveries)	43,172	18,118
Period end amount allocated to:
Loans individually evaluated for impairment			12,351		$ 28,562
Loans collectively evaluated for impairment			166,745		145,663
Ending balance	184,655	168,126	179,096	184,655	174,225
Commercial
Reserve for loan losses:
Beginning balance	118,806	128,768
Provision for loan losses	38,920	19,384
Charge-offs	43,972	21,543
Recoveries	680	3,442
Net charge-offs (recoveries)	43,292	18,101
Period end amount allocated to:
Loans individually evaluated for impairment			11,772		28,382
Loans collectively evaluated for impairment			102,662		101,669
Ending balance	118,806	128,768	114,434	118,806	130,051
Mortgage finance loans
Reserve for loan losses:
Beginning balance	0	0
Provision for loan losses	0	0
Charge-offs	0	0
Recoveries	0	0
Net charge-offs (recoveries)	0	0
Period end amount allocated to:
Loans individually evaluated for impairment			0		0
Loans collectively evaluated for impairment			0		0
Ending balance	0	0	0	0	0
Construction
Reserve for loan losses:
Beginning balance	19,273	13,144
Provision for loan losses	621	680
Charge-offs	0	0
Recoveries	0	101
Net charge-offs (recoveries)	0	(101)
Period end amount allocated to:
Loans individually evaluated for impairment			0		0
Loans collectively evaluated for impairment			19,894		13,925
Ending balance	19,273	13,144	19,894	19,273	13,925
Real Estate
Reserve for loan losses:
Beginning balance	34,287	19,149
Provision for loan losses	928	3,436
Charge-offs	0	40
Recoveries	32	53
Net charge-offs (recoveries)	(32)	(13)
Period end amount allocated to:
Loans individually evaluated for impairment			73		180
Loans collectively evaluated for impairment			35,174		22,418
Ending balance	34,287	19,149	35,247	34,287	22,598
Consumer
Reserve for loan losses:
Beginning balance	357	241
Provision for loan losses	(205)	287
Charge-offs	0	180
Recoveries	68	41
Net charge-offs (recoveries)	(68)	139
Period end amount allocated to:
Loans individually evaluated for impairment			11		0
Loans collectively evaluated for impairment			209		389
Ending balance	357	241	220	357	389
Leases
Reserve for loan losses:
Beginning balance	3,542	1,124
Provision for loan losses	860	2,989
Charge-offs	0	0
Recoveries	20	8
Net charge-offs (recoveries)	(20)	(8)
Period end amount allocated to:
Loans individually evaluated for impairment			495		0
Loans collectively evaluated for impairment			3,927		4,121
Ending balance	3,542	1,124	4,422	3,542	4,121
Unallocated
Reserve for loan losses:
Beginning balance	8,390	5,700
Provision for loan losses	(3,511)	(2,559)
Charge-offs	0	0
Recoveries	0	0
Net charge-offs (recoveries)	0	0
Period end amount allocated to:
Loans individually evaluated for impairment			0		0
Loans collectively evaluated for impairment			4,879		3,141
Ending balance	$ 8,390	$ 5,700	$ 4,879	$ 8,390	$ 3,141

LOANS AND ALLOWANCE FOR LOAN 40

LOANS AND ALLOWANCE FOR LOAN LOSSES - Allowance for Credit Losses Related to Unfunded Commitments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Provision for off-balance sheet credit losses	$ 27,000	$ 13,000	$ 39,000	$ 22,000
Unfunded Loan Commitment
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	9,623	10,847	9,071	11,422
Provision for off-balance sheet credit losses	835	(1,642)	1,387	(2,217)
Ending balance	$ 10,458	$ 9,205	$ 10,458	$ 9,205

LOANS AND ALLOWANCE FOR LOAN 41

LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 3) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans individually evaluated for impairment	$ 83,880	$ 102,684	$ 125,284
Loans collectively evaluated for impairment	22,485,238	20,669,659	19,435,602
Gross loans held for investment	22,569,118	20,772,343	19,560,886
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans individually evaluated for impairment	80,171	100,676	120,770
Loans collectively evaluated for impairment	10,109,661	9,089,135	8,130,182
Gross loans held for investment	10,189,832	9,189,811	8,250,952
Mortgage finance loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans individually evaluated for impairment	0	0	0
Loans collectively evaluated for impairment	5,923,058	5,308,160	5,183,600
Gross loans held for investment	5,923,058	5,308,160	5,183,600
Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans individually evaluated for impairment	0	0	0
Loans collectively evaluated for impairment	2,226,590	2,166,208	2,242,562
Gross loans held for investment	2,226,590	2,166,208	2,242,562
Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans individually evaluated for impairment	2,543	2,008	4,514
Loans collectively evaluated for impairment	3,865,868	3,792,569	3,565,273
Gross loans held for investment	3,868,411	3,794,577	3,569,787
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans individually evaluated for impairment	66	0	0
Loans collectively evaluated for impairment	46,586	48,684	39,122
Gross loans held for investment	46,652	48,684	39,122
Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans individually evaluated for impairment	1,100	0	0
Loans collectively evaluated for impairment	313,475	264,903	274,863
Gross loans held for investment	$ 314,575	$ 264,903	$ 274,863

LOANS AND ALLOWANCE FOR LOAN 42

LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 4) $ in Millions	Jun. 30, 2018USD ($)
Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]
Non-accrual loans earning on a cash basis	$ 0

LOANS AND ALLOWANCE FOR LOAN 43

LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 5) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Commercial business loans | Energy
Financing Receivable, Impaired [Line Items]
Recorded investment			$ 21,426
With no related allowance recorded:
Financing Receivable, Impaired [Line Items]
Recorded investment	$ 46,199		39,357
Unpaid principal balance	72,820		41,955
Related allowance	0		0
Average recorded investment	34,127		61,709
Interest income recognized	133		0
With no related allowance recorded: | Commercial business loans | Business loans
Financing Receivable, Impaired [Line Items]
Recorded investment	27,521		16,835
Unpaid principal balance	52,966		18,257
Related allowance	0		0
Average recorded investment	12,449		22,964
Interest income recognized	133		0
With no related allowance recorded: | Commercial business loans | Energy
Financing Receivable, Impaired [Line Items]
Recorded investment	16,373
Unpaid principal balance	17,549		22,602
Related allowance	0		0
Average recorded investment	20,393		36,579
Interest income recognized	0		0
With no related allowance recorded: | Construction | Market risk
Financing Receivable, Impaired [Line Items]
Recorded investment	0		0
Unpaid principal balance	0		0
Related allowance	0		0
Average recorded investment	0		0
Interest income recognized	0		0
With no related allowance recorded: | Real estate | Market risk
Financing Receivable, Impaired [Line Items]
Recorded investment	0		0
Unpaid principal balance	0		0
Related allowance	0		0
Average recorded investment	0		0
Interest income recognized	0		0
With no related allowance recorded: | Real estate | Commercial
Financing Receivable, Impaired [Line Items]
Recorded investment	1,042		1,096
Unpaid principal balance	1,042		1,096
Related allowance	0		0
Average recorded investment	1,074		2,166
Interest income recognized	0		0
With no related allowance recorded: | Real estate | Secured by 1-4 family
Financing Receivable, Impaired [Line Items]
Recorded investment	1,263		0
Unpaid principal balance	1,263		0
Related allowance	0		0
Average recorded investment	211		0
Interest income recognized	0		0
With no related allowance recorded: | Consumer
Financing Receivable, Impaired [Line Items]
Recorded investment	0		0
Unpaid principal balance	0		0
Related allowance	0		0
Average recorded investment	0		0
Interest income recognized	0		0
With no related allowance recorded: | Leases
Financing Receivable, Impaired [Line Items]
Recorded investment	0		0
Unpaid principal balance	0		0
Related allowance	0		0
Average recorded investment	0		0
Interest income recognized	0		0
With an allowance recorded:
Financing Receivable, Impaired [Line Items]
Recorded investment	37,681		63,327
Unpaid principal balance	38,947		75,807
Related allowance	12,351		24,417
Average recorded investment	76,314		69,068
Interest income recognized	0		6
With an allowance recorded: | Commercial business loans | Business loans
Financing Receivable, Impaired [Line Items]
Recorded investment	19,038		18,645
Unpaid principal balance	19,038		19,020
Related allowance	5,597		2,544
Average recorded investment	43,537		16,960
Interest income recognized	0		0
With an allowance recorded: | Commercial business loans | Energy
Financing Receivable, Impaired [Line Items]
Recorded investment	17,239		43,770
Unpaid principal balance	18,500		55,875
Related allowance	6,175		21,772
Average recorded investment	32,145		50,867
Interest income recognized	0		6
With an allowance recorded: | Construction | Market risk
Financing Receivable, Impaired [Line Items]
Recorded investment	0		0
Unpaid principal balance	0		0
Related allowance	0		0
Average recorded investment	0		27
Interest income recognized	0		0
With an allowance recorded: | Real estate | Market risk
Financing Receivable, Impaired [Line Items]
Recorded investment	0		295
Unpaid principal balance	0		295
Related allowance	0		6
Average recorded investment	98		485
Interest income recognized	0		0
With an allowance recorded: | Real estate | Commercial
Financing Receivable, Impaired [Line Items]
Recorded investment	0		499
Unpaid principal balance	0		499
Related allowance	0		75
Average recorded investment	166		166
Interest income recognized	0		0
With an allowance recorded: | Real estate | Secured by 1-4 family
Financing Receivable, Impaired [Line Items]
Recorded investment	238		118
Unpaid principal balance	238		118
Related allowance	73		20
Average recorded investment	138		516
Interest income recognized	0		0
With an allowance recorded: | Consumer
Financing Receivable, Impaired [Line Items]
Recorded investment	66		0
Unpaid principal balance	71		0
Related allowance	11		0
Average recorded investment	47		33
Interest income recognized	0		0
With an allowance recorded: | Leases
Financing Receivable, Impaired [Line Items]
Recorded investment	1,100		0
Unpaid principal balance	1,100		0
Related allowance	495		0
Average recorded investment	183		14
Interest income recognized	0		0
Combined:
Financing Receivable, Impaired [Line Items]
Recorded investment	83,880		102,684
Unpaid principal balance	111,767		117,762
Related allowance	12,351		24,417
Average recorded investment	110,441	$ 149,500	130,777
Interest income recognized	133		6
Combined: | Commercial business loans | Business loans
Financing Receivable, Impaired [Line Items]
Recorded investment	46,559		35,480
Unpaid principal balance	72,004		37,277
Related allowance	5,597		2,544
Average recorded investment	55,986		39,924
Interest income recognized	133		0
Combined: | Commercial business loans | Energy
Financing Receivable, Impaired [Line Items]
Recorded investment	33,612		65,196
Unpaid principal balance	36,049		78,477
Related allowance	6,175		21,772
Average recorded investment	52,538		87,446
Interest income recognized	0		6
Combined: | Construction | Market risk
Financing Receivable, Impaired [Line Items]
Recorded investment	0		0
Unpaid principal balance	0		0
Related allowance	0		0
Average recorded investment	0		27
Interest income recognized	0		0
Combined: | Real estate | Market risk
Financing Receivable, Impaired [Line Items]
Recorded investment	0		295
Unpaid principal balance	0		295
Related allowance	0		6
Average recorded investment	98		485
Interest income recognized	0		0
Combined: | Real estate | Commercial
Financing Receivable, Impaired [Line Items]
Recorded investment	1,042		1,595
Unpaid principal balance	1,042		1,595
Related allowance	0		75
Average recorded investment	1,240		2,332
Interest income recognized	0		0
Combined: | Real estate | Secured by 1-4 family
Financing Receivable, Impaired [Line Items]
Recorded investment	1,501		118
Unpaid principal balance	1,501		118
Related allowance	73		20
Average recorded investment	349		516
Interest income recognized	0		0
Combined: | Consumer
Financing Receivable, Impaired [Line Items]
Recorded investment	66		0
Unpaid principal balance	71		0
Related allowance	11		0
Average recorded investment	47		33
Interest income recognized	0		0
Combined: | Leases
Financing Receivable, Impaired [Line Items]
Recorded investment	1,100		0
Unpaid principal balance	1,100		0
Related allowance	495		0
Average recorded investment	183		14
Interest income recognized	$ 0		$ 0

LOANS AND ALLOWANCE FOR LOAN 44

LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 6) $ in Thousands	Jun. 30, 2018USD ($)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	$ 70,533
Non-accrual	83,295
Current	22,415,290
Total	22,569,118
Premium finance loans past due 90 days and still accruing	6,000
Commercial business loans | Business loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	37,505
Non-accrual	45,974
Current	8,750,741
Total	8,834,220
Commercial business loans | Energy
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	24,900
Non-accrual	33,612
Current	1,297,100
Total	1,355,612
Mortgage finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
Non-accrual	0
Current	5,923,058
Total	5,923,058
Construction | Market risk
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	489
Non-accrual	0
Current	2,151,838
Total	2,152,327
Construction | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
Non-accrual	0
Current	41,991
Total	41,991
Construction | Secured by 1-4 family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	1,610
Non-accrual	0
Current	30,662
Total	32,272
Real estate | Market risk
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	1,998
Non-accrual	0
Current	2,728,753
Total	2,730,751
Real estate | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	639
Non-accrual	1,042
Current	814,188
Total	815,869
Real estate | Secured by 1-4 family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	3,390
Non-accrual	1,501
Current	316,900
Total	321,791
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	2
Non-accrual	66
Current	46,584
Total	46,652
Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
Non-accrual	1,100
Current	313,475
Total	314,575
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	44,226
30-59 Days Past Due | Commercial business loans | Business loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	14,114
30-59 Days Past Due | Commercial business loans | Energy
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	24,900
30-59 Days Past Due | Mortgage finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
30-59 Days Past Due | Construction | Market risk
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	489
30-59 Days Past Due | Construction | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
30-59 Days Past Due | Construction | Secured by 1-4 family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
30-59 Days Past Due | Real estate | Market risk
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	1,337
30-59 Days Past Due | Real estate | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	639
30-59 Days Past Due | Real estate | Secured by 1-4 family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	2,745
30-59 Days Past Due | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	2
30-59 Days Past Due | Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	18,950
60-89 Days Past Due | Commercial business loans | Business loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	17,188
60-89 Days Past Due | Commercial business loans | Energy
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
60-89 Days Past Due | Mortgage finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
60-89 Days Past Due | Construction | Market risk
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
60-89 Days Past Due | Construction | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
60-89 Days Past Due | Construction | Secured by 1-4 family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	1,610
60-89 Days Past Due | Real estate | Market risk
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
60-89 Days Past Due | Real estate | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
60-89 Days Past Due | Real estate | Secured by 1-4 family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	152
60-89 Days Past Due | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
60-89 Days Past Due | Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0
Greater Than 90 Days and Accruing(1)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	7,357	[1]
Greater Than 90 Days and Accruing(1) | Commercial business loans | Business loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	6,203	[1]
Greater Than 90 Days and Accruing(1) | Commercial business loans | Energy
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	[1]
Greater Than 90 Days and Accruing(1) | Mortgage finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	[1]
Greater Than 90 Days and Accruing(1) | Construction | Market risk
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	[1]
Greater Than 90 Days and Accruing(1) | Construction | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	[1]
Greater Than 90 Days and Accruing(1) | Construction | Secured by 1-4 family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	[1]
Greater Than 90 Days and Accruing(1) | Real estate | Market risk
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	661	[1]
Greater Than 90 Days and Accruing(1) | Real estate | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	[1]
Greater Than 90 Days and Accruing(1) | Real estate | Secured by 1-4 family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	493	[1]
Greater Than 90 Days and Accruing(1) | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	0	[1]
Greater Than 90 Days and Accruing(1) | Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due	$ 0	[1]
[1]	Loans past due 90 days and still accruing includes premium finance loans of $6.0 million. These loans are generally secured by obligations of insurance carriers to refund premiums on canceled insurance policies. The refund of premiums from the insurance carriers can take 180 days or longer from the cancellation date.

LOANS AND ALLOWANCE FOR LOAN 45

LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 7) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)
Financing Receivable, Modifications [Line Items]
Number of restructured loans	1	2
Pre-restructuring outstanding recorded investment	$ 1,370	$ 1,669
Post-restructuring outstanding recorded investment	$ 1,370	$ 1,372
Energy loans
Financing Receivable, Modifications [Line Items]
Number of restructured loans	1	1
Pre-restructuring outstanding recorded investment	$ 1,370	$ 1,070
Post-restructuring outstanding recorded investment	$ 1,370	$ 700
Commercial business loans
Financing Receivable, Modifications [Line Items]
Number of restructured loans		1
Pre-restructuring outstanding recorded investment		$ 599
Post-restructuring outstanding recorded investment		$ 672

LOANS AND ALLOWANCE FOR LOAN 46

LOANS AND ALLOWANCE FOR LOAN LOSSES - TDR Summary (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017
Financing Receivable, Modifications [Line Items]
Details of how restructured loans were modified	$ 1,370	$ 1,372
Extended maturity
Financing Receivable, Modifications [Line Items]
Details of how restructured loans were modified	0	1,372
Adjusted payment schedule
Financing Receivable, Modifications [Line Items]
Details of how restructured loans were modified	$ 1,370	$ 0

OREO AND VALUATION ALLOWANCE 47

OREO AND VALUATION ALLOWANCE FOR LOSSES ON OREO (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Real Estate Acquired Through Foreclosure [Roll Forward]
Beginning balance	$ 9,558	$ 18,833	$ 11,742	$ 18,961
Additions	0	0	0	0
Sales	(32)	(144)	(216)	(272)
Valuation allowance for OREO	0	0	2,000	0
Ending balance	$ 9,526	$ 18,689	$ 9,526	$ 18,689

CERTAIN TRANSFERS OF FINANCIA48

CERTAIN TRANSFERS OF FINANCIAL ASSETS (Details) - USD ($)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Loans and Leases Receivable Disclosure [Line Items]
Fair value over/(under) outstanding balance	$ 1,577,000		$ (1,576,000)
Outstanding principal balance of loans in servicing portfolio Financial Assets, Principal Amount Outstanding	7,100,000,000		7,000,000,000
Escrow fund deposits related to servicing assets	84,500,000		73,400,000
Estimated exposure related to servicing assets	1,500,000	$ 1,300,000
Loss Contingency Accrual, Payments	148,000
Losses due to repurchase, indemnification or make-whole obligations		$ 7,000
Total past due	70,533,000
Loans held for sale, at fair value	1,276,768,000		1,011,004,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Maturity Greater than 90 Days [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total past due	27,900,000		19,700,000
Government Guaranteed Mortgage Loans upon Foreclosure Receivable [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Maturity Greater than 90 Days [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total past due	3,100,000		19,000,000
Loans held for sale, at fair value	24,100,000
Small Business Administration Loans [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Loans and Leases Receivable Disclosure [Line Items]
Fair value over/(under) outstanding balance	$ 1,300,000		$ 3,300,000

CERTAIN TRANSFERS OF FINANCIA49

CERTAIN TRANSFERS OF FINANCIAL ASSETS (Details 1) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Transfers and Servicing [Abstract]
Unpaid principal balance	$ 1,273,889	$ 1,009,271
Fair value	1,275,466	1,007,695
Fair value over/(under) outstanding balance	$ 1,577	(1,576)
Loans held for sale carried at lower of cost or market		$ 0

CERTAIN TRANSFERS OF FINANCIA50

CERTAIN TRANSFERS OF FINANCIAL ASSETS (Details 2) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Transfers and Servicing [Abstract]
Gain (Loss) on Sale of Notes Receivable	$ 7,400	$ 100
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Beginning balance(1)	1,011,004	968,929
Loans purchased	3,205,483	2,843,690
Payments and loans sold(1)(2)	(2,942,872)	(2,976,523)
Change in fair value	3,153	9,921
Ending balance	$ 1,276,768	$ 846,017
Loans held for sale carried at lower of cost or market			$ 0

CERTAIN TRANSFERS OF FINANCIA51

CERTAIN TRANSFERS OF FINANCIAL ASSETS (Details 3) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Valuation allowance:
MSRs, net(1)	$ 82,776	$ 63,023
MSR
MSRs:
Balance, beginning of year	88,150	28,536
Capitalized servicing rights	26,656	37,343
Amortization	(5,288)	(2,856)
Sales	(26,742)	0
Balance, end of period	82,776	63,023
Valuation allowance:
Balance, beginning of year	2,823	0
Increase (decrease) in valuation allowance	(2,823)	0
Balance, end of period	0	0
MSRs, net(1)	$ 90,179	$ 64,889

CERTAIN TRANSFERS OF FINANCIA52

CERTAIN TRANSFERS OF FINANCIAL ASSETS (Details 4) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended		12 Months Ended
	Dec. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Servicing Assets at Fair Value [Line Items]
Impairment charges		$ 0	$ 5,285
Average discount rates (percent)		9.61%		9.90%
Expected prepayment speeds (percent)		9.04%		9.99%
Weighted average life, in years		7 years 6 months		7 years
Servicing Asset [Member]
Servicing Assets at Fair Value [Line Items]
Impairment charges	$ 2,800

CERTAIN TRANSFERS OF FINANCIA53

CERTAIN TRANSFERS OF FINANCIAL ASSETS (Details 5) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Transfers and Servicing [Abstract]
50 bp adverse change in prepayment speed	$ (12,184)	$ (11,896)
100 bp adverse change in prepayment speed	$ (24,683)	$ (28,226)

FINANCIAL INSTRUMENTS WITH OF54

FINANCIAL INSTRUMENTS WITH OFF-BALANCE SHEET RISK (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financing receivable allowance for credit losses off balance sheet liability	$ 10,500	$ 9,100
Commitments to extend credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet financial instruments whose contract amounts represented credit risk	7,254,475	6,957,847
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet financial instruments whose contract amounts represented credit risk	$ 244,962	$ 230,958

REGULATORY MATTERS (Details)

REGULATORY MATTERS (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2009
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Assets	$ 27,781,910		$ 25,075,645	$ 15,000,000
Common Equity Tier 1 Capital	$ 2,173,815		$ 2,033,830
Tier 1 capital	9.31%		9.52%
Total capital	11.11%		11.50%
Tier 1 leverage	9.89%		9.15%
Mortgage finance	$ 5,923,058		$ 5,308,160
Mortgage finance, average balance	$ 4,900,000
Common Equity Tier 1, Capital to Risk Weighted Assets	8.32%		8.45%
Capital	$ 2,902,789		$ 2,768,153
Tier One Risk Based Capital	2,431,650		2,293,016
Tier One Leverage Capital	$ 2,431,650		2,293,016
Common Stock, Dividends, Per Share, Declared	$ 0	$ 0
Common Stock, Dividends, Per Share, Cash Paid	$ 0	$ 0
Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Capital	$ 2,178,607		$ 1,992,152
Tier 1 capital	8.96%		8.94%
Total capital	10.54%		10.67%
Tier 1 leverage	9.51%		8.59%
Common Equity Tier 1, Capital to Risk Weighted Assets	8.35%		8.28%
Common Equity Tier 1, Capital Required to be Well Capitalized	$ 1,695,525		$ 1,563,929
Common Equity Tier 1, Capital Required to be Well Capitalized to Risk Weighted Assets	6.50%		6.50%
Capital	$ 2,749,018		$ 2,567,961
Capital Required to be Well Capitalized	$ 2,608,500		$ 2,406,044
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00%		10.00%
Tier One Risk Based Capital	$ 2,336,442		$ 2,151,338
Tier One Risk Based Capital Required to be Well Capitalized	$ 2,086,800		$ 1,924,835
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	8.00%		8.00%
Tier One Leverage Capital	$ 2,336,442		$ 2,151,338
Tier One Leverage Capital Required to be Well Capitalized	$ 1,228,736		$ 1,252,680
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	5.00%		5.00%
Advanced Approach, Phase-In Schedule [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1, Capital Required for Capital Adequacy	$ 1,665,009		$ 1,384,448
Common Equity Tier 1, Capital Required for Capital Adequacy to Risk Weighted Assets	6.375%		5.75%
Capital Required for Capital Adequacy	$ 2,579,132		$ 2,227,221
Capital Required for Capital Adequacy to Risk Weighted Assets	9.875%		9.25%
Tier One Risk Based Capital Required for Capital Adequacy	$ 2,056,776		$ 1,745,659
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	7.875%		7.25%
Tier One Leverage Capital Required for Capital Adequacy	$ 983,476		$ 1,002,494
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%		4.00%
Advanced Approach, Phase-In Schedule [Member] | Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1, Capital Required for Capital Adequacy	$ 1,662,918		$ 1,383,475
Common Equity Tier 1, Capital Required for Capital Adequacy to Risk Weighted Assets	6.375%		5.75%
Capital Required for Capital Adequacy	$ 2,575,893		$ 2,225,591
Capital Required for Capital Adequacy to Risk Weighted Assets	9.875%		9.25%
Tier One Risk Based Capital Required for Capital Adequacy	$ 2,054,193		$ 1,744,382
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	7.875%		7.25%
Tier One Leverage Capital Required for Capital Adequacy	$ 982,989		$ 1,002,144
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%		4.00%
Advanced Approach, Phased-In [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1, Capital Required for Capital Adequacy	$ 1,828,245		$ 1,685,464
Common Equity Tier 1, Capital Required for Capital Adequacy to Risk Weighted Assets	7.00%		7.00%
Capital Required for Capital Adequacy	$ 2,742,368		$ 2,528,196
Capital Required for Capital Adequacy to Risk Weighted Assets	10.50%		10.50%
Tier One Risk Based Capital Required for Capital Adequacy	$ 2,220,012		$ 2,046,635
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	8.50%		8.50%
Tier One Leverage Capital Required for Capital Adequacy	$ 983,476		$ 1,002,494
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%		4.00%
Advanced Approach, Phased-In [Member] | Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1, Capital Required for Capital Adequacy	$ 1,825,950		$ 1,684,231
Common Equity Tier 1, Capital Required for Capital Adequacy to Risk Weighted Assets	7.00%		7.00%
Capital Required for Capital Adequacy	$ 2,738,925		$ 2,526,347
Capital Required for Capital Adequacy to Risk Weighted Assets	10.50%		10.50%
Tier One Risk Based Capital Required for Capital Adequacy	$ 2,217,225		$ 2,045,138
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	8.50%		8.50%
Tier One Leverage Capital Required for Capital Adequacy	$ 982,989		$ 1,002,144
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%		4.00%

STOCK-BASED COMPENSATION (Detai

STOCK-BASED COMPENSATION (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	May 19, 2015
Restricted stock units, additional disclosures
Compensation expense	$ 5,226	$ 4,395	$ 11,197	$ 8,954
Unrecognized compensation expense related to unvested stock-settled awards	15,335		$ 15,335
Weighted average period over which expense is expected to be recognized, in years			2 years 11 months
SARs
Restricted stock units, additional disclosures
Compensation expense	43	74	$ 93	146
RSUs
Restricted stock units, additional disclosures
Compensation expense	2,078	1,714	3,974	3,307
Restricted stock
Restricted stock units, additional disclosures
Compensation expense	13	4	24	8
Cash-settled performance units
Restricted stock units, additional disclosures
Compensation expense	$ 3,092	$ 2,603	$ 7,106	$ 5,493
2015 Long-Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common stock shares that can be issued for compensation under the Plan					2,550,000

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Tax Cuts And Jobs Act Of 2017, change in tax rate, income tax expense (benefit)			$ 17.6
U.S. statutory rate	21.00%	35.00%
State taxes	1.00%	1.00%
Non-deductible expenses	1.00%	0.00%
Non-taxable income	(1.00%)	(1.00%)
Other	(1.00%)	(1.00%)
Effective tax rate	21.00%	34.00%

FAIR VALUE DISCLOSURES (Assets

FAIR VALUE DISCLOSURES (Assets and Liabilities) (Details) - USD ($)		Jun. 30, 2018		Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value		$ 24,408,000		$ 23,511,000
Loans held for sale		1,275,466,000		1,007,695,000
OREO	[1],[2]	11,526,000		11,742,000
Derivative assets		21,740,000		16,719,000
Derivative liabilities		25,516,000		17,377,000
Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	[3]	8,785,000		10,945,000
Fair value measurements, recurring basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	[4]	0		0
Derivative assets	[4]	0		0
Derivative liabilities	[4]	0		0
Non-qualified deferred compensation plan liabilities		9,192,000	[4]	5,587,000	[5]
Fair value measurements, recurring basis | Level 1 | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	[6]	0		0
Fair value measurements, recurring basis | Level 1 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	[6],[7]	8,711,000		5,460,000
Fair value measurements, recurring basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	[4]	1,247,537,000		1,007,695,000
Derivative assets	[4]	21,740,000		16,719,000
Derivative liabilities	[4]	25,516,000		17,377,000
Non-qualified deferred compensation plan liabilities		0	[4]	0	[5]
Fair value measurements, recurring basis | Level 2 | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	[6]	8,785,000		10,945,000
Fair value measurements, recurring basis | Level 2 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	[6],[7]	6,912,000		7,106,000
Fair value measurements, recurring basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	[4]	27,929,000		0
Derivative assets	[4]	0		0
Derivative liabilities	[4]	0		0
Non-qualified deferred compensation plan liabilities		0	[4]	0	[5]
Fair value measurements, recurring basis | Level 3 | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	[6]	0		0
Fair value measurements, recurring basis | Level 3 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	[6],[7]	0		0
Fair value measurements, nonrecurring basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for investment	[1],[8]	0		0
OREO	[1],[2]	0		0
Fair value measurements, nonrecurring basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for investment	[1],[8]	0		0
OREO	[1],[2]	0		0
Fair value measurements, nonrecurring basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for investment	[1],[8]	22,165,000		21,216,000
OREO	[1],[2]	$ 9,526,000		$ 11,742,000
[1]	Loans held for investment and OREO are measured on a nonrecurring basis, generally annually or more often as warranted by market and economic conditions.
[2]	OREO is transferred from loans to OREO at fair value less selling costs.
[3]	Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without prepayment penalties.
[4]	Derivative assets and liabilities are measured at fair value on a recurring basis, generally quarterly.
[5]	Non-qualified deferred compensation plan liabilities represent the fair value of the obligation to the employee, which corresponds to the fair value of the invested assets, and are measured at fair value on a recurring basis, generally monthly.
[6]	Securities are measured at fair value on a recurring basis, generally monthly.
[7]	Equity securities consist of Community Reinvestment Act funds and investments related to our non-qualified deferred compensation plan.
[8]	Includes impaired loans that have been measured for impairment at the fair value of the loan’s collateral.

FAIR VALUE DISCLOSURES (Financi

FAIR VALUE DISCLOSURES (Financial Instruments) (Details)		3 Months Ended	6 Months Ended
		Jun. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at Beginning of Period			$ 1,007,695,000
Balance at End of Period		$ 1,275,466,000	1,275,466,000
Fair Value Inputs, Projected Price				0.943
OREO	[1],[2]			$ 11,526,000	$ 11,742,000
Real Estate Owned, Valuation Allowance				2,000,000	0
Estimated Fair Value				24,408,000	23,511,000
Loans held for sale		1,275,466,000	1,007,695,000	1,275,466,000	1,007,695,000
Derivative assets				21,740,000	16,719,000
Senior Notes				281,586,000	281,406,000
Derivative liabilities				25,516,000	17,377,000
Level 1 | Carrying amount
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Cash and cash equivalents				3,462,794,000	2,905,591,000
Estimated Fair Value				8,711,000	5,460,000
Level 1 | Estimated fair value
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Cash and cash equivalents				3,462,794,000	2,905,591,000
Estimated Fair Value				8,711,000	5,460,000
Level 1 | Fair value measurements, recurring basis
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at Beginning of Period	[3]		0
Balance at End of Period	[3]	0	0
Loans held for sale	[3]	0	0	0	0
Derivative assets	[3]			0	0
Derivative liabilities	[3]			0	0
Level 1 | Fair value measurements, nonrecurring basis
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
OREO	[1],[2]			0	0
Loans held for investment, net	[1],[4]			0	0
Level 2 | Carrying amount
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at Beginning of Period			1,011,004,000
Balance at End of Period		1,248,839,000	1,248,839,000
Estimated Fair Value				15,697,000	18,051,000
Loans held for sale		1,248,839,000	1,011,004,000	1,248,839,000	1,011,004,000
Derivative assets				21,740,000	16,719,000
Federal funds purchased				510,221,000	359,338,000
Customer repurchase agreements				10,628,000	5,702,000
Other borrowings				4,000,000,000	2,800,000,000
Senior Notes				281,586,000	281,406,000
Derivative liabilities				25,516,000	17,377,000
Level 2 | Estimated fair value
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at Beginning of Period			1,011,004,000
Balance at End of Period		1,248,839,000	1,248,839,000
Estimated Fair Value				15,697,000	18,051,000
Loans held for sale		1,248,839,000	1,011,004,000	1,248,839,000	1,011,004,000
Derivative assets				21,740,000	16,719,000
Federal funds purchased				510,221,000	359,338,000
Customer repurchase agreements				10,628,000	5,702,000
Other borrowings				4,000,000,000	2,800,000,000
Senior Notes				283,268,000	285,485,000
Derivative liabilities				25,516,000	17,377,000
Level 2 | Fair value measurements, recurring basis
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at Beginning of Period	[3]		1,007,695,000
Balance at End of Period	[3]	1,247,537,000	1,247,537,000
Loans held for sale	[3]	1,247,537,000	1,007,695,000	1,247,537,000	1,007,695,000
Derivative assets	[3]			21,740,000	16,719,000
Derivative liabilities	[3]			25,516,000	17,377,000
Level 2 | Fair value measurements, nonrecurring basis
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
OREO	[1],[2]			0	0
Loans held for investment, net	[1],[4]			0	0
Level 3 | Carrying amount
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at Beginning of Period			0
Balance at End of Period		27,929,000	27,929,000
Loans held for sale		27,929,000	0	27,929,000	0
Loans held for investment, net				22,280,683,000	20,489,757,000
Deposits				20,334,871,000	19,123,180,000
Trust preferred subordinated debentures				113,406,000	113,406,000
Level 3 | Estimated fair value
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at Beginning of Period			0
Balance at End of Period		27,929,000	27,929,000
Loans held for sale		27,929,000	0	27,929,000	0
Loans held for investment, net				22,258,008,000	20,480,802,000
Deposits				21,258,150,000	19,124,121,000
Trust preferred subordinated debentures				113,406,000	113,406,000
Level 3 | Fair value measurements, recurring basis
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at Beginning of Period	[3]		0
Balance at End of Period	[3]	27,929,000	27,929,000
Loans held for sale	[3]	27,929,000	0	27,929,000	0
Derivative assets	[3]			0	0
Derivative liabilities	[3]			0	0
Level 3 | Fair value measurements, recurring basis | Estimated fair value
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at Beginning of Period		34,251,000	0
Purchases / Additions		1,437,000	37,529,000
Sales / Reductions		(7,988,000)	(7,988,000)
Realized		161,000	(1,680,000)
Unrealized		68,000	68,000
Balance at End of Period		27,929,000	27,929,000
Loans held for sale		$ 34,251,000	$ 0	27,929,000	0
Level 3 | Fair value measurements, nonrecurring basis
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Carrying value of impaired loans				30,100,000	32,200,000
Allowance allocation of impaired loans				7,900,000	11,000,000
OREO	[1],[2]			9,526,000	11,742,000
Loans held for investment, net	[1],[4]			$ 22,165,000	$ 21,216,000
[1]	Loans held for investment and OREO are measured on a nonrecurring basis, generally annually or more often as warranted by market and economic conditions.
[2]	OREO is transferred from loans to OREO at fair value less selling costs.
[3]	Derivative assets and liabilities are measured at fair value on a recurring basis, generally quarterly.
[4]	Includes impaired loans that have been measured for impairment at the fair value of the loan’s collateral.

DERIVATIVE FINANCIAL INSTRUME60

DERIVATIVE FINANCIAL INSTRUMENTS (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)instrument	Dec. 31, 2017USD ($)instrument
Derivatives, Fair Value [Line Items]
Asset Derivative	$ 27,269	$ 21,354
Liability Derivative	31,045	22,012
Offsetting derivative asset	(5,529)	(4,635)
Offsetting derivative liability	(5,529)	(4,635)
Derivative asset, net	21,740	16,719
Derivative liability, net	$ 25,516	17,377
Description of credit risk exposure on interest rate swaps and caps	Our credit exposure on derivative instruments is limited to the net favorable value and interest payments by each counterparty. In some cases collateral may be required from the counterparties involved if the net value of the derivative instruments exceeds a nominal amount
Credit exposure relating to interest rate swaps and caps	$ 12,900	16,700
Cash collateral pledge for derivatives	6,700	15,200
Interest-bearing deposits
Derivatives, Fair Value [Line Items]
Cash collateral pledge for derivatives	2,800	14,000
Accrued interest receivable and other assets
Derivatives, Fair Value [Line Items]
Cash collateral pledge for derivatives	3,900	$ 1,200
Interest-bearing Deposit Liability
Derivatives, Fair Value [Line Items]
Cash collateral pledge for derivatives	$ 11,100
Commercial loan/lease interest rate swaps | Non-hedging interest rate derivatives/swaps | Commercial loan/lease | Weighted-average interest rate received
Derivatives, Fair Value [Line Items]
Weighted-average interest rate received and paid	3.85%	3.59%
Commercial loan/lease interest rate swaps | Non-hedging interest rate derivatives/swaps | Commercial loan/lease | Weighted-average interest rate paid
Derivatives, Fair Value [Line Items]
Weighted-average interest rate received and paid	4.17%	4.34%
Commercial loan/lease interest rate caps
Derivatives, Fair Value [Line Items]
Weighted-average interest rate received and paid	2.38%	2.40%
Risk Participation Agreement - Participant Bank [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	$ 130,200	$ 157,100
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 157	$ 221
Derivative, number of instruments held | instrument	14	15
Risk Participation Agreements - Lead Bank [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	$ 126,500	$ 86,300
Derivative, number of instruments held | instrument	11	10
Financial institution counterparties: | Commercial loan/lease interest rate swaps | Non-hedging interest rate derivatives/swaps | Commercial loan/lease
Derivatives, Fair Value [Line Items]
Notional Amount	$ 1,514,867	$ 1,393,764
Asset Derivative	17,079	4,736
Liability Derivative	6,239	15,482
Financial institution counterparties: | Commercial loan/lease interest rate caps | Non-hedging interest rate derivatives/swaps | Commercial loan/lease
Derivatives, Fair Value [Line Items]
Notional Amount	245,667	242,700
Asset Derivative	992	421
Liability Derivative	18	7
Financial institution counterparties: | Foreign Exchange Forward [Member] | Non-hedging interest rate derivatives/swaps | Commercial loan/lease
Derivatives, Fair Value [Line Items]
Notional Amount	53,871	2,466
Asset Derivative	1,794	4
Liability Derivative	58	69
Customer counterparties: | Commercial loan/lease interest rate swaps | Non-hedging interest rate derivatives/swaps | Commercial loan/lease
Derivatives, Fair Value [Line Items]
Notional Amount	1,514,867	1,393,764
Asset Derivative	6,239	15,482
Liability Derivative	17,079	4,736
Customer counterparties: | Commercial loan/lease interest rate caps | Non-hedging interest rate derivatives/swaps | Commercial loan/lease
Derivatives, Fair Value [Line Items]
Notional Amount	245,667	242,700
Asset Derivative	18	7
Liability Derivative	992	421
Customer counterparties: | Foreign Exchange Forward [Member] | Non-hedging interest rate derivatives/swaps | Commercial loan/lease
Derivatives, Fair Value [Line Items]
Notional Amount	53,871	2,466
Asset Derivative	58	69
Liability Derivative	1,794	4
Loan purchase commitments | Interest rate derivative | Economic hedging interest rate derivatives
Derivatives, Fair Value [Line Items]
Asset Derivative	1,089	635
Liability Derivative	21	190
Forward sales commitments | Interest rate derivative | Economic hedging interest rate derivatives
Derivatives, Fair Value [Line Items]
Asset Derivative	0	0
Liability Derivative	4,844	1,103
Loan Purchase Commitments [Member] | Interest rate derivative | Non-hedging interest rate derivatives/swaps
Derivatives, Fair Value [Line Items]
Notional Amount	204,057	253,815
Forward Contracts [Member] | Interest rate derivative | Non-hedging interest rate derivatives/swaps
Derivatives, Fair Value [Line Items]
Notional Amount	$ 1,361,500	$ 1,086,224