Texas Capital Bancshares (TCBI) 10-Q 21 Oct 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 20, 2021
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-34657
Entity Registrant Name	TEXAS CAPITAL BANCSHARES INC/TX
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	75-2679109
Entity Address, Address Line One	2000 McKinney Avenue
Entity Address, Address Line Two	Suite 700
Entity Address, City or Town	Dallas
Entity Address, State or Province	TX
Entity Address, Country	US
Entity Address, Postal Zip Code	75201
City Area Code	214
Local Phone Number	932-6600
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0001077428
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus (Q1,Q2,Q3,FY)	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		50,607,526
Common Stock
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	TCBI
Security Exchange Name	NASDAQ
Series B Preferred Stock
Entity Information [Line Items]
Title of 12(b) Security	5.75% Non-Cumulative Perpetual Preferred Stock Series B, par value $0.01 per share
Trading Symbol	TCBIO
Security Exchange Name	NASDAQ

Operations and Summary of Signi

Operations and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
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 the Company and its wholly owned subsidiary, Texas Capital Bank (the “Bank”). We serve the needs of commercial businesses and professionals and entrepreneurs located in Texas as well as operate several lines of business serving a regional or national clientele of commercial borrowers. We are primarily a secured lender, with the majority of our loans held for investment, excluding mortgage finance loans and other national lines of business, being made to businesses headquartered or with operations in Texas. Our national lines of business provide specialized lending products to businesses throughout the United States. In May 2021 the Bank applied to the Texas Department of Banking to convert from a national association to a Texas state-chartered bank. The application was approved during the third quarter and the conversion was effective at open of business on September 15, 2021. Effective as of the date of conversion, the Texas Department of Banking is the Bank’s primary regulator, the FDIC is the Bank’s primary federal regulator, and the Federal Reserve will continue to be the Company’s primary federal regulator. 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 disclosures in the notes to consolidated financial statements that are 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 U.S. Securities and Exchange Commission (“SEC”). Accordingly, the financial statements do not include all of the information and notes to the consolidated financial statements required by GAAP for complete annual financial statements and should be read in conjunction with our consolidated financial statements, and notes thereto, for the year ended December 31, 2020, included in our Annual Report on Form 10-K for the year ended December 31, 2020 (the “2020 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 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 credit losses, the fair value of financial instruments and the status of contingencies are particularly susceptible to significant change.

New Accounting Standards

New Accounting Standards	9 Months Ended
	Sep. 30, 2021
Accounting Standards Update and Change in Accounting Principle [Abstract]
New Accounting Standards	New Accounting Standards ASU 2020-04, “ Reference Rate Reform (Topic 848)” (“ASU 2020-04”) provides optional expedients and exceptions for applying GAAP to loan and lease agreements, derivative contracts and other transactions affected by the anticipated transition away from LIBOR toward new interest rate benchmarks. For transactions that are modified because of reference rate reform and that meet certain scope guidance (i) modifications of loan agreements should be accounted for by prospectively adjusting the effective interest rate and the modification will be considered “minor” so that any existing unamortized origination fees/costs would carry forward and continue to be amortized and (ii) modifications of lease agreements should be accounted for as a continuation of the existing agreement with no reassessments of the lease classification and the discount rate or remeasurements of lease payments that otherwise would be required for modifications not accounted for as separate contracts. ASU 2020-04 also provides numerous optional expedients for derivative accounting. ASU 2020-04 is effective March 12, 2020 through December 31, 2022. An entity may elect to apply ASU 2020-04 for contract modifications as of January 1, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. Once elected for a Topic or an Industry Subtopic within the Codification, the amendments in this ASU must be applied prospectively for all eligible contract modifications for that Topic or Industry Subtopic. We anticipate this ASU will simplify any modifications we execute between the selected start date (yet to be determined) and December 31, 2022 that are directly related to LIBOR transition by allowing prospective recognition of the continuation of the contract, rather than extinguishment of the old contract resulting in writing off unamortized fees/costs. The adoption of this ASU did not significantly impact our consolidated financial statements. ASU 2021-05, “Leases (Topic 842) (“ASU 2021-05”) amends guidance to allow lessors to classify as an operating lease any lease that would otherwise be classified as a sales-type or direct financing lease and that would result in the recognition of a day-one loss at lease commencement, provided that the lease includes variable lease payments that does not depend on an index or rate. ASU 2021-05 will be effective for us on January 1, 2022 and is not expected to have an impact on our consolidated financial statements.

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Assets
Cash and due from banks	$ 217,125,000	$ 173,573,000
Interest-bearing deposits in other banks	8,317,926,000	9,032,807,000
Investment securities	3,663,874,000	3,196,970,000
Financing Receivable, Held-for-Sale	9,660,000	283,165,000
Loans held for investment, mortgage finance	8,528,313,000	9,079,409,000
Loans held for investment (net of unearned income)	15,221,404,000	15,351,451,000
Less: Allowance for credit losses on loans	(221,957,000)	(254,615,000)
Loans held for investment, net	23,527,760,000	24,176,245,000
Mortgage servicing rights, net	1,158,000	105,424,000
Premises and equipment, net	21,119,000	24,546,000
Accrued interest receivable and other assets	628,335,000	715,699,000
Goodwill and intangible assets, net	17,363,000	17,667,000
Total assets	36,404,320,000	37,726,096,000
Deposits:
Non-interest-bearing	14,970,462,000	12,740,947,000
Interest-bearing	14,843,206,000	18,255,642,000
Total deposits	29,813,668,000	30,996,589,000
Accrued interest payable	8,920,000	11,150,000
Other liabilities	302,448,000	339,486,000
Federal funds purchased and repurchase agreements	3,470,000	111,751,000
Other borrowings	2,200,000,000	3,000,000,000
Long-term Debt	928,062,000	395,896,000
Total liabilities	33,256,568,000	34,854,872,000
Comprehensive income:
Issued shares—300,000 and 6,000,000 at September 30, 2021 and December 31, 2020, respectively	300,000,000	150,000,000
Issued shares— 50,606,043 and 50,470,867 at September 30, 2021 and December 31, 2020, respectively	506,000	504,000
Additional paid-in capital	1,000,509,000	991,898,000
Retained earnings	1,887,457,000	1,713,056,000
Treasury stock (shares at cost: 417 at September 30, 2021 and December 31, 2020)	(8,000)	(8,000)
Accumulated other comprehensive income/(loss), net of taxes	(40,712,000)	15,774,000
Total stockholders’ equity	3,147,752,000	2,871,224,000
Total liabilities and stockholders’ equity	36,404,320,000	37,726,096,000
Loans held for sale ($8.4 million and $239.1 million at September 30, 2021 and December 31, 2020, respectively, at fair value)	$ 8,400,000	$ 239,100,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, Liquidation value	$ 1,000	$ 1,000
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred Stock, Shares Issued	300,000	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	50,606,043	50,470,867
Treasury stock, shares	417	417

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Loans held for sale ($8.4 million and $239.1 million at September 30, 2021 and December 31, 2020, respectively, at fair value)	$ 8,400,000	$ 239,100,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, Liquidation value	$ 1,000	$ 1,000
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	300,000	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	50,606,043	50,470,867
Treasury stock, shares	417	417

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME AND OTHER COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Interest income
Interest and fees on loans	$ 206,307	$ 237,179	$ 632,510	$ 768,399
Investment securities	10,235	3,674	31,040	7,881
Federal funds sold and securities purchased under resale agreements	0	1	1	692
Interest-bearing deposits in other banks	3,606	2,877	9,499	24,777
Total interest income	220,148	243,731	673,050	801,749
Interest expense
Deposits	14,719	27,830	50,994	122,298
Federal funds purchased	5	128	131	973
Other borrowings	743	3,365	3,711	17,516
Long-term debt	10,586	4,839	27,052	15,146
Total interest expense	26,053	36,162	81,888	155,933
Net interest income	194,095	207,569	591,162	645,816
Provision for credit losses	5,000	30,000	(20,000)	226,000
Net interest income after provision for credit losses	189,095	177,569	611,162	419,816
Non-interest income
Service charges on deposit accounts	4,622	2,864	13,972	8,616
Wealth management and trust fee income	3,382	2,502	9,380	7,317
Brokered loan fees	6,032	15,034	22,276	33,813
Servicing income	292	7,329	15,236	18,195
Swap fees	568	484	1,628	4,709
Net gain/(loss) on sale of loans held for sale	(1,185)	25,242	1,317	51,265
Other	7,509	6,893	26,605	18,698
Total non-interest income	21,220	60,348	90,414	142,613
Non-interest expense
Salaries and employee benefits	87,503	84,096	261,855	262,080
Net occupancy expense	8,324	8,736	24,463	26,582
Marketing	2,123	3,636	5,720	20,146
Legal and professional	11,055	11,207	28,479	40,003
Communications and technology	28,374	31,098	58,695	87,649
Federal Deposit Insurance Corporation (“FDIC”) insurance assessment	4,500	6,374	16,339	19,363
Servicing-related expenses	2,396	12,287	27,740	48,741
Merger-related expenses	0	0	0	17,756
Other	8,712	8,307	29,072	31,173
Total non-interest expense	152,987	165,741	452,363	553,493
Income before income taxes	57,328	72,176	249,213	8,936
Income tax expense	13,938	15,060	60,404	2,823
Net income	43,390	57,116	188,809	6,113
Preferred Stock Dividends and Other Adjustments [Abstract]
Preferred stock dividends	4,312	2,438	14,408	7,313
Net income/(loss) available to common stockholders	39,078	54,678	174,401	(1,200)
Other comprehensive loss
Change in unrealized gain/(loss) on available-for-sale debt securities, before tax	(18,131)	8,053	(71,501)	(2,674)
Income tax expense/(benefit)	(3,808)	1,692	(15,015)	(561)
Other comprehensive income/(loss), net of tax	(14,323)	6,361	(56,486)	(2,113)
Comprehensive income	$ 29,067	$ 63,477	$ 132,323	$ 4,000
Basic earnings/(loss) per common share
Basic earnings/(loss) per common share	$ 0.77	$ 1.08	$ 3.45	$ (0.02)
Diluted earnings/(loss) per common share
Diluted earnings/(loss) per common share	$ 0.76	$ 1.08	$ 3.41	$ (0.02)

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Cumulative Effect, Period Of Adoption, Adjustment	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Retained EarningsCumulative Effect, Period Of Adoption, Adjustment	Treasury Stock	Accumulated Other Comprehensive Income
Beginning balance - Shares at Dec. 31, 2019			(6,000,000)	(50,338,158)				(417)
Beginning balance - Amount at Dec. 31, 2019	$ 2,801,321	$ (7,154)	$ 150,000	$ 503	$ 978,205	$ 1,663,671	$ (7,154)	$ (8)	$ 8,950
Comprehensive income:
Net income	6,113					6,113
Change in unrealized gain (loss) on available-for-sale securities, net of taxes	(2,113)								(2,113)
Comprehensive income	4,000
Stock-based compensation expense recognized in earnings	11,348				11,348
Preferred stock dividend	(7,313)					(7,313)
Issuance of stock related to stock-based awards - Shares				117,811
Issuance of stock related to stock-based awards - Amount	(1,798)			$ 1	(1,799)
Ending balance - Amount at Sep. 30, 2020	2,800,404		$ 150,000	$ 504	987,754	1,655,317		$ (8)	6,837
Ending balance - Shares at Sep. 30, 2020			(6,000,000)	(50,455,969)				(417)
Beginning balance - Shares at Jun. 30, 2020			(6,000,000)	(50,436,089)				(417)
Beginning balance - Amount at Jun. 30, 2020	2,734,755		$ 150,000	$ 504	983,144	1,600,639		$ (8)	476
Comprehensive income:
Net income	57,116					57,116
Change in unrealized gain (loss) on available-for-sale securities, net of taxes	6,361								6,361
Comprehensive income	63,477
Stock-based compensation expense recognized in earnings	4,799				4,799
Preferred stock dividend	(2,438)					(2,438)
Issuance of stock related to stock-based awards - Shares				19,880
Issuance of stock related to stock-based awards - Amount	(189)				(189)
Ending balance - Amount at Sep. 30, 2020	2,800,404		$ 150,000	$ 504	987,754	1,655,317		$ (8)	6,837
Ending balance - Shares at Sep. 30, 2020			(6,000,000)	(50,455,969)				(417)
Beginning balance - Shares at Dec. 31, 2020			(6,000,000)	(50,470,867)				(417)
Beginning balance - Amount at Dec. 31, 2020	2,871,224		$ 150,000	$ 504	991,898	1,713,056		$ (8)	15,774
Comprehensive income:
Net income	188,809					188,809
Change in unrealized gain (loss) on available-for-sale securities, net of taxes	(56,486)								(56,486)
Comprehensive income	132,323
Stock-based compensation expense recognized in earnings	22,100				22,100
Issuance of preferred stock - Amount			$ 300,000
Preferred stock dividend	(14,408)					(14,408)
Issuance of stock related to stock-based awards - Shares				135,176
Issuance of stock related to stock-based awards - Amount	(3,210)			$ 2	(3,212)
Redemption of preferred stock - shares			(6,000,000)
Redemption of preferred stock	(150,000)		$ (150,000)
Ending balance - Amount at Sep. 30, 2021	3,147,752		$ 300,000	$ 506	1,000,509	1,887,457		$ (8)	(40,712)
Ending balance - Shares at Sep. 30, 2021			(300,000)	(50,606,043)				(417)
Beginning balance - Shares at Jun. 30, 2021			(300,000)	(50,592,618)				(417)
Beginning balance - Amount at Jun. 30, 2021	3,114,957		$ 300,000	$ 506	992,469	1,848,379		$ (8)	(26,389)
Comprehensive income:
Net income	43,390					43,390
Change in unrealized gain (loss) on available-for-sale securities, net of taxes	(14,323)								(14,323)
Comprehensive income	29,067
Stock-based compensation expense recognized in earnings	$ 8,324				8,324
Issuance of preferred stock - Shares	300,000
Issuance of preferred stock - Amount	$ 289,723				(10,277)
Preferred stock dividend	(4,312)					(4,312)
Issuance of stock related to stock-based awards - Shares				13,425
Issuance of stock related to stock-based awards - Amount	(284)			$ 0	(284)
Ending balance - Amount at Sep. 30, 2021	$ 3,147,752		$ 300,000	$ 506	$ 1,000,509	$ 1,887,457		$ (8)	$ (40,712)
Ending balance - Shares at Sep. 30, 2021			(300,000)	(50,606,043)				(417)

CONSOLIDATED STATEMENTS OF ST_2

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Stockholders' Equity [Abstract]
Income tax expense (benefit) related to unrealized loss on available-for-sale securities	$ (3,808)	$ 1,692	$ (15,015)	$ (561)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating activities
Net income	$ 188,809	$ 6,113
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	(20,000)	226,000
Depreciation and amortization	65,943	51,716
Net (gain)/loss on sale of loans held for sale	(1,317)	(51,265)
Increase/(decrease) in valuation allowance on mortgage servicing rights	(16,448)	20,933
Stock-based compensation expense	23,192	12,064
Purchases and originations of loans held for sale	(1,413,899)	(8,963,499)
Proceeds from sales and repayments of loans held for sale	1,675,246	10,859,458
Changes in operating assets and liabilities:
Accrued interest receivable and other assets	86,707	(16,912)
Accrued interest payable and other liabilities	(41,920)	25,222
Net cash provided by operating activities	546,313	2,169,830
Investing activities
Purchases of investment securities	(952,982)	(1,140,935)
Principal payments received on investment securities	400,429	12,042
Originations of mortgage finance loans	(128,503,055)	(157,016,926)
Proceeds from pay-offs of mortgage finance loans	129,054,151	155,808,671
Proceeds from Sale of Mortgage Servicing Rights (MSR)	108,925	0
Net increase/(decrease) in loans held for investment, excluding mortgage finance loans	118,166	553,026
Purchase of premises and equipment, net	(2,619)	(2,705)
Net cash provided by/(used in) investing activities	223,015	(1,786,827)
Financing activities
Net increase/(decrease) in deposits	(1,182,921)	5,480,894
Costs from issuance of stock related to stock-based awards and warrants	(3,210)	(1,798)
Net proceeds from issuance of preferred stock	289,723	0
Payments for Repurchase of Preferred Stock and Preference Stock	(150,000)	0
Preferred dividends paid	(14,408)	(7,313)
Net increase/(decrease) in other borrowings		300,000
Net increase/(decrease) in other borrowings	(800,000)
Net increase/(decrease) in federal funds purchased and repurchase agreements	(108,281)	66,417
Net proceeds from issuance of long-term debt	639,440	0
Repayments of Long-term Debt	(111,000)	0
Net cash provided by/(used in) financing activities	(1,440,657)	5,838,200
Net increase/(decrease) in cash and cash equivalents	(671,329)	6,221,203
Cash and cash equivalents at beginning of period	9,206,380	4,425,583
Cash and cash equivalents at end of period	8,535,051	10,646,786
Supplemental disclosures of cash flow information:
Cash paid during the period for interest	84,118	154,019
Cash paid during the period for income taxes	$ 99,915	$ 21,747

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2021
Debt Securities, Available-for-sale [Abstract]
Investment Securities	Investment Securities Available-for-Sale Debt Securities The following is a summary of available-for-sale debt securities: (in thousands) Amortized Gross Gross Estimated September 30, 2021 Available-for-sale debt securities: U.S. government agency securities $ 125,000 $ — $ (3,080) $ 121,920 Residential mortgage-backed securities 3,363,930 331 (59,539) 3,304,722 Tax-exempt asset-backed securities 171,157 13,663 — 184,820 Credit risk transfer (“CRT”) securities 14,713 — (2,909) 11,804 Total $ 3,674,800 $ 13,994 $ (65,528) $ 3,623,266 December 31, 2020 Available-for-sale debt securities: U.S. government agency securities $ 125,000 $ 1 $ (1,412) $ 123,589 Residential mortgage-backed securities 2,818,518 11,566 (1,128) 2,828,956 Tax-exempt asset-backed securities 184,940 14,236 — 199,176 CRT securities 14,713 — (3,296) 11,417 Total $ 3,143,171 $ 25,803 $ (5,836) $ 3,163,138 (1) Excludes accrued interest receivable of $6.7 million and $6.0 million at September 30, 2021 and December 31, 2020, respectively, that is recorded in accrued interest receivable and other assets on the consolidated balance sheets. The amortized cost and estimated fair value, excluding accrued interest receivable, and weighted average yield of available-for-sale debt securities are presented below by contractual maturity: (in thousands, except percentage data) Less Than After One After Five After Ten Total September 30, 2021 Available-for-sale: U.S. government agency securities:(1) Amortized cost $ — $ — $ 125,000 $ — $ 125,000 Estimated fair value — — 121,920 — 121,920 Weighted average yield(3) — % — % 1.13 % — % 1.13 % Residential mortgage-backed securities:(1) Amortized cost $ 24 $ 252 $ 17,339 $ 3,346,315 $ 3,363,930 Estimated fair value 26 280 16,652 3,287,764 3,304,722 Weighted average yield(3) 3.99 % 4.66 % 1.08 % 1.13 % 1.13 % Tax-exempt asset-backed securities:(1) Amortized Cost $ — $ — $ — $ 171,157 $ 171,157 Estimated fair value — — — 184,820 184,820 Weighted average yield(2)(3) — % — % — % 4.96 % 4.96 % CRT securities:(1) Amortized Cost $ — $ — $ 14.713 $ — $ 14,713 Estimated fair value — — 11.804 — 11,804 Weighted average yield(3) — % — % 0.08 % — % 0.08 % Total available-for-sale debt securities: Amortized cost $ 3,674,800 Estimated fair value $ 3,623,266 December 31, 2020 Available-for-sale: U.S. government agency securities:(1) Amortized cost $ — $ — $ 125,000 $ — $ 125,000 Estimated fair value — — 123,589 — 123,589 Weighted average yield(3) — % — % 1.13 % — % 1.13 % Residential mortgage-backed securities:(1) Amortized cost $ — $ 545 $ 17,500 $ 2,800,473 $ 2,818,518 Estimated fair value — 605 17,490 2,810,861 2,828,956 Weighted average yield(3) — % 4.58 % 1.08 % 1.25 % 1.25 % Tax-exempt asset-backed securities:(1) Amortized Cost $ — $ — $ — $ 184,940 $ 184,940 Estimated fair value — — — 199,176 199,176 Weighted average yield(2)(3) — % — % — % 4.92 % 4.92 % CRT securities:(1) Amortized Cost $ — $ — $ — $ 14,713 $ 14,713 Estimated fair value — — — 11,417 11,417 Weighted average yield(3) — % — % — % 0.15 % 0.15 % Total available-for-sale debt securities: Amortized cost $ 3,143,171 Estimated fair value $ 3,163,138 (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 have been adjusted to a tax equivalent basis assuming a 21% federal tax rate. (3) Yields are calculated based on amortized cost. The following table discloses our available-for-sale debt securities that have been in a continuous unrealized loss position for less than 12 months and those that have been in a continuous unrealized loss position for 12 or more months: Less Than 12 Months 12 Months or Longer Total (in thousands) Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss September 30, 2021 U.S. government agency securities $ 24,348 $ (652) $ 97,572 $ (2,428) $ 121,920 $ (3,080) Residential mortgage-backed securities 3,279,426 (59,539) 97 — 3,279,523 (59,539) CRT securities — — 11,804 (2,909) 11,804 (2,909) Total $ 3,303,774 $ (60,191) $ 109,473 $ (5,337) $ 3,413,247 $ (65,528) December 31, 2020 U.S. government agency securities $ 98,588 $ (1,412) $ — $ — $ 98,588 $ (1,412) Residential mortgage-backed securities 354,387 (1,128) — — 354,387 (1,128) CRT securities — — 11,417 (3,296) 11,417 (3,296) Total $ 452,975 $ (2,540) $ 11,417 $ (3,296) $ 464,392 $ (5,836) At September 30, 2021, we had 118 securities in an unrealized loss position, comprised of five U.S. government agency securities, two CRT securities and 111 residential mortgage-backed securities. Based upon our September 30, 2021 review of securities with unrealized losses we have determined that all losses resulted from factors not deemed credit-related. We have evaluated the near-term prospects of each securities portfolio in relation to the severity of the unrealized losses and adverse conditions related to the securities among other factors. Based on that evaluation management has determined that we have the ability and intent to hold the securities until recovery of fair value and have recorded the unrealized losses in accumulated other comprehensive income (“AOCI”). Available-for-sale debt securities with carrying values of approximately $24.0 million and $1.3 million were pledged to secure certain customer repurchase agreements and deposits, respectively, at September 30, 2021. The comparative amounts at December 31, 2020 were $31.7 million and $1.9 million, respectively. Equity Securities Equity securities consist of investments that qualify for consideration under the regulations implementing the Community Reinvestment Act and investments related to our non-qualified deferred compensation plan. At September 30, 2021 and December 31, 2020, we had $40.6 million and $33.8 million, respectively, in equity securities recorded at fair value. The following is a summary of unrealized and realized gains/(losses) recognized on equity securities included in other non-interest income in the consolidated statements of income and other comprehensive income: Three months ended September 30, Nine months ended September 30, (in thousands) 2021 2020 2021 2020 Net gains/(losses) recognized during the period $ 850 $ 1,350 $ 4,496 $ 1,285 Less: Realized net gains/(losses) recognized during the period on equity securities sold 347 177 1,096 (68) Unrealized net gains/(losses) recognized during the period on equity securities still held $ 503 $ 1,173 $ 3,400 $ 1,353

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Earnings Per Share	Earnings/(Loss) Per Share The following table presents the computation of basic and diluted earnings/(loss) per share: Three months ended September 30, Nine months ended September 30, (in thousands except share and per share data) 2021 2020 2021 2020 Numerator: Net income $ 43,390 $ 57,116 $ 188,809 $ 6,113 Preferred stock dividends 4,312 2,438 14,408 7,313 Net income/(loss) available to common stockholders $ 39,078 $ 54,678 $ 174,401 $ (1,200) Denominator: Denominator for basic earnings per share—weighted average shares 50,600,732 50,446,691 50,568,439 50,417,563 Effect of employee stock-based awards(1) 538,823 126,382 555,836 103,984 Denominator for dilutive earnings per share—adjusted weighted average shares and assumed conversions 51,139,555 50,573,073 51,124,275 50,521,547 Basic earnings/(loss) per common share $ 0.77 $ 1.08 $ 3.45 $ (0.02) Diluted earnings/(loss) per common share $ 0.76 $ 1.08 $ 3.41 $ (0.02) (1) SARs and RSUs outstanding of 208,813 at September 30, 2021 and 480,062 at September 30, 2020 have not been included in diluted earnings/(loss) per common share because to do so would have been antidilutive for the periods presented.

Loans Held for Investment and A

Loans Held for Investment and Allowance for Loan Losses	9 Months Ended
	Sep. 30, 2021
Receivables [Abstract]
Loans Held for Investment and Allowance for Loan Losses	Loans Held for Investment and Allowance for Credit Losses on Loans Loans held for investment are summarized by portfolio segment as follows: (in thousands) September 30, 2021 December 31, 2020 Commercial $ 9,377,274 $ 8,861,580 Energy 697,888 766,217 Mortgage finance(1) 8,528,313 9,079,409 Real estate 5,212,364 5,794,624 Gross loans held for investment(2) 23,815,839 24,501,830 Unearned income (net of direct origination costs) (66,122) (70,970) Allowance for credit losses on loans (221,957) (254,615) Total loans held for investment, net(2) $ 23,527,760 $ 24,176,245 (1) Balances at September 30, 2021 and December 31, 2020 are stated net of $677.6 million and $1.2 billion of participations sold, respectively. (2) Excludes accrued interest receivable of $50.3 million and $56.5 million at September 30, 2021 and December 31, 2020, respectively, that is recorded in accrued interest receivable and other assets on the consolidated balance sheets. The following tables summarize our gross loans held for investment by year of origination and internally assigned credit grades: (in thousands) 2021 2020 2019 2018 2017 2016 and prior Revolving lines of credit Revolving lines of credit converted to term loans Total September 30, 2021 Commercial (1-7) Pass $ 919,405 $ 3,228,097 $ 572,505 $ 321,356 $ 194,921 $ 284,804 $ 3,535,016 $ 50,565 $ 9,106,669 (8) Special mention 691 8,061 46,942 9,233 — 13,561 9,579 6,495 94,562 (9) Substandard - accruing — 4,763 60,192 39,177 6,202 16,137 15,592 6,906 148,969 (9+) Non-accrual 1,218 1,624 2,305 727 2,105 10,444 8,185 466 27,074 Total commercial $ 921,314 $ 3,242,545 $ 681,944 $ 370,493 $ 203,228 $ 324,946 $ 3,568,372 $ 64,432 $ 9,377,274 Energy (1-7) Pass $ 22,309 $ — $ — $ 2,516 $ — $ 28,854 $ 566,387 $ — $ 620,066 (8) Special mention — — — — — — 37,782 — 37,782 (9) Substandard - accruing — — — — — — — — — (9+) Non-accrual — — — — — 20,715 19,325 — 40,040 Total energy $ 22,309 $ — $ — $ 2,516 $ — $ 49,569 $ 623,494 $ — $ 697,888 Mortgage finance (1-7) Pass $ 295,565 $ 834,008 $ 744,105 $ 696,945 $ 409,308 $ 5,548,382 $ — $ — $ 8,528,313 (8) Special mention — — — — — — — — — (9) Substandard - accruing — — — — — — — — — (9+) Non-accrual — — — — — — — — — Total mortgage finance $ 295,565 $ 834,008 $ 744,105 $ 696,945 $ 409,308 $ 5,548,382 $ — $ — $ 8,528,313 Real estate CRE (1-7) Pass $ 292,248 $ 545,204 $ 703,910 $ 566,771 $ 187,565 $ 482,033 $ 45,008 $ 25,361 $ 2,848,100 (8) Special mention — — 30,497 8,881 48,049 17,022 — — 104,449 (9) Substandard - accruing 17,850 — — 41,209 61,051 62,978 — 2,354 185,442 (9+) Non-accrual — — — — — 202 — — 202 RBF (1-7) Pass 166,828 70,338 15,180 9,392 66 14,483 566,799 — 843,086 (8) Special mention — — — — — — — — — (9) Substandard - accruing — — — — — — — — — (9+) Non-accrual — — — — — — — — — Other (1-7) Pass 88,370 161,048 136,836 107,251 83,282 167,252 45,174 30,210 819,423 (8) Special mention — 13,903 1,990 — — 5,055 — — 20,948 (9) Substandard - accruing — — — 1,637 23,952 21,125 — — 46,714 (9+) Non-accrual — — — — 3,536 2,566 — 13,929 20,031 Secured by 1-4 family (1-7) Pass 71,682 62,514 53,285 24,610 34,666 69,988 4,491 — 321,236 (8) Special mention — — — — — 294 — — 294 (9) Substandard - accruing — — — — — 2,254 — — 2,254 (9+) Non-accrual — — — — — 185 — — 185 Total real estate $ 636,978 $ 853,007 $ 941,698 $ 759,751 $ 442,167 $ 845,437 $ 661,472 $ 71,854 $ 5,212,364 Total loans held for investment $ 1,876,166 $ 4,929,560 $ 2,367,747 $ 1,829,705 $ 1,054,703 $ 6,768,334 $ 4,853,338 $ 136,286 $ 23,815,839 (in thousands) 2020 2019 2018 2017 2016 2015 and prior Revolving lines of credit Revolving lines of credit converted to term loans Total December 31, 2020 Commercial (1-7) Pass $ 1,259,949 $ 2,816,425 $ 543,438 $ 374,455 $ 192,060 $ 213,212 $ 3,020,353 $ 40,253 $ 8,460,145 (8) Special mention 2,664 115,015 38,751 26,423 1,983 290 19,971 22,797 227,894 (9) Substandard - accruing 15,773 15,854 18,068 32,241 15,297 19,639 22,932 1,641 141,445 (9+) Non-accrual 1,820 8,360 377 1,292 802 15,157 3,836 452 32,096 Total commercial $ 1,280,206 $ 2,955,654 $ 600,634 $ 434,411 $ 210,142 $ 248,298 $ 3,067,092 $ 65,143 $ 8,861,580 Energy (1-7) Pass $ — $ 12,020 $ 7,598 $ 26,931 $ — $ 23,750 $ 553,970 $ — $ 624,269 (8) Special mention — — — — — 13,358 76,866 — 90,224 (9) Substandard - accruing — — — — — — — — — (9+) Non-accrual — — — 5,705 1,972 8,009 36,038 — 51,724 Total energy $ — $ 12,020 $ 7,598 $ 32,636 $ 1,972 $ 45,117 $ 666,874 $ — $ 766,217 Mortgage finance (1-7) Pass $ 755,309 $ 1,063,641 $ 821,122 $ 483,436 $ 106,013 $ 5,849,888 $ — $ — $ 9,079,409 (8) Special mention — — — — — — — — — (9) Substandard - accruing — — — — — — — — — (9+) Non-accrual — — — — — — — — — Total mortgage finance $ 755,309 $ 1,063,641 $ 821,122 $ 483,436 $ 106,013 $ 5,849,888 $ — $ — $ 9,079,409 Real estate CRE (1-7) Pass $ 352,688 $ 892,831 $ 923,762 $ 444,587 $ 208,426 $ 451,283 $ 62,336 $ 61,133 $ 3,397,046 (8) Special mention 3,475 11,170 6,485 88,633 11,153 17,623 — 1,247 139,786 (9) Substandard - accruing — 327 47,708 11,601 32,645 30,766 — 15,940 138,987 (9+) Non-accrual — — — — 5,749 4,852 — — 10,601 RBF (1-7) Pass 162,397 60,077 65,271 3,727 5,888 8,483 551,703 — 857,546 (8) Special mention — 353 — — — — — — 353 (9) Substandard - accruing — — — — — — — — — (9+) Non-accrual — — — — — — — — — Other (1-7) Pass 190,995 150,787 119,696 120,817 82,465 113,105 16,630 39,129 833,624 (8) Special mention — 6,700 2,240 — 1,843 7,195 — 1,018 18,996 (9) Substandard - accruing — — 2,567 14,452 3,301 14,453 — — 34,773 (9+) Non-accrual — — — 927 5,524 6,403 — 14,496 27,350 Secured by 1-4 family (1-7) Pass 58,515 63,031 46,623 54,096 72,527 31,880 4,697 — 331,369 (8) Special mention 646 — — 635 — 1,768 — — 3,049 (9) Substandard - accruing — — — 817 — 109 — — 926 (9+) Non-accrual — — — — — 218 — — 218 Total real estate $ 768,716 $ 1,185,276 $ 1,214,352 $ 740,292 $ 429,521 $ 688,138 $ 635,366 $ 132,963 $ 5,794,624 Total loans held for investment $ 2,804,231 $ 5,216,591 $ 2,643,706 $ 1,690,775 $ 747,648 $ 6,831,441 $ 4,369,332 $ 198,106 $ 24,501,830 The following table details activity in the allowance for credit losses on loans. Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. (in thousands) Commercial Energy Mortgage Real Total Nine months ended September 30, 2021 Allowance for credit losses on loans: Beginning balance $ 73,061 $ 84,064 $ 4,699 $ 92,791 $ 254,615 Provision for credit losses on loans 26,549 (24,730) 1,729 (24,325) (20,777) Charge-offs 8,211 6,418 — 1,192 15,821 Recoveries 2,462 1,366 — 112 3,940 Net charge-offs (recoveries) 5,749 5,052 — 1,080 11,881 Ending balance $ 93,861 $ 54,282 $ 6,428 $ 67,386 $ 221,957 Nine months ended September 30, 2020 Allowance for credit losses on loans: Beginning balance $ 102,254 $ 60,253 $ 2,265 $ 30,275 $ 195,047 Impact of Current Expected Credit Loss (“CECL”) adoption (15,740) 24,154 2,031 (1,860) 8,585 Provision for credit losses on loans 47,263 127,470 430 44,799 219,962 Charge-offs 35,376 100,239 — — 135,615 Recoveries 883 1,303 — — 2,186 Net charge-offs (recoveries) 34,493 98,936 — — 133,429 Ending balance $ 99,284 $ 112,941 $ 4,726 $ 73,214 $ 290,165 We recorded a $20.0 million negative provision for credit losses for the nine months ended September 30, 2021, compared to a provision of $226.0 million for the same period in 2020. The decreased provision resulted primarily from decreases in charge-offs and non-accrual loans during the nine month ended and as of September 30, 2021, as well as improvement in the economic outlook as the economy continues to recover from the impacts of the COVID-19 pandemic. We recorded $11.9 million in net charge-offs during the nine months ended September 30, 2021, compared to $133.4 million during the same period in 2020. Criticized loans totaled $728.9 million at September 30, 2021, compared to $1.1 billion at September 30, 2020. The table below provides an age analysis of our loans held for investment: (in thousands) 30-59 Days 60-89 Days 90 Days or More Past Due(1) Total Past Non-Accrual Loans(2) Current Total Non-Accrual With No Allowance September 30, 2021 Commercial $ 19,395 $ 18,313 $ 2,256 $ 39,964 $ 27,074 $ 9,310,236 $ 9,377,274 $ 10,899 Energy — — — — 40,040 657,848 697,888 9,281 Mortgage finance loans — — — — — 8,528,313 8,528,313 — Real estate CRE 250 — — 250 202 3,137,741 3,138,193 — RBF — — — — — 843,086 843,086 — Other 1,225 — — 1,225 20,031 885,860 907,116 2,697 Secured by 1-4 family 553 — 1,149 1,702 185 322,082 323,969 — Total loans held for investment $ 21,423 $ 18,313 $ 3,405 $ 43,141 $ 87,532 $ 23,685,166 $ 23,815,839 $ 22,877 (1) Loans past due 90 days and still accruing includes premium finance loans of $2.3 million. These loans are generally secured by obligations of insurance carriers to refund premiums on canceled insurance policies. The receipt of the refund of premiums from the insurance carriers can take 180 days or longer from the cancellation date. (2) As of September 30, 2021 and December 31, 2020, none of our non-accrual loans were earning interest income on a cash basis. Additionally, no interest income was recognized on non-accrual loans for the nine months ended September 30, 2021. Accrued interest of $674,000 was reversed during the nine months ended September 30, 2021.

Certain Transfers of Financial

Certain Transfers of Financial Assets	9 Months Ended
	Sep. 30, 2021
Transfers and Servicing [Abstract]
Certain Transfers of Financial Assets	Certain Transfers of Financial Assets On April 20, 2021, we entered into an agreement to sell our portfolio of mortgage servicing rights (“MSRs”) and to transition the Mortgage Correspondent Aggregation (“MCA”) program to a third-party. The sale was completed on June 1, 2021 and the transfer of servicing on the underlying mortgage loans was completed on August 1, 2021. Transition activities began immediately following the execution of the agreement and are significantly complete as of September 30, 2021. At September 30, 2021, we have a remaining MSR balance of $1.2 million, which represents MSRs from loans sold after the cut-off date for the initial sale mentioned above. The sale of this MSR portfolio and the transfer of servicing on the underlying mortgage loans was completed on October 1, 2021 and all related hedges were closed as of September 30, 2021. The table below presents a reconciliation of the changes in loans held for sale: Nine Months Ended September 30, (in thousands) 2021 2020 Outstanding balance(1): Beginning balance $ 281,137 $ 2,568,362 Loans purchased and originated 1,413,899 8,963,499 Payments and loans sold (1,685,212) (10,889,549) Ending balance 9,824 642,312 Fair value adjustment: Beginning balance 2,028 8,772 Increase/(decrease) to fair value (2,192) (3,075) Ending balance (164) 5,697 Loans held for sale at fair value $ 9,660 $ 648,009 (1) Includes $1.3 million and $44.1 million of loans held for sale that are carried at lower of cost or market as of September 30, 2021 and December 31, 2020, respectively, as well as $9.0 million and $5.8 million as of September 30, 2020 and December 31, 2019, respectively. No loans held for sale were on non-accrual as of September 30, 2021. At December 31, 2020 we had $7.0 million in non-accrual loans held for sale, comprised of one loan previously reported in loans held for investment that was transferred to loans held for sale as of December 31, 2020 and subsequently sold at carrying value. At September 30, 2021 and December 31, 2020, we had $3.8 million and $16.7 million, respectively, of loans held for sale that were 90 days or more past due. The $3.8 million in loans held for sale that were 90 days or more past due at September 30, 2021 was comprised of loans guaranteed by U.S. government agencies that were purchased 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. At December 31, 2020, $3.3 million of the $16.7 million in loans held for sale that were 90 days or more past due were loans guaranteed by U.S. government agencies that were purchased out of Ginnie Mae securities and recorded as loans held for sale, at fair value, on the balance sheet and $13.4 million were 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 held for sale on our balance sheet regardless of whether the repurchase option has been exercised. Through the MCA program we retain the right to service the loans after they are sold, creating MSRs which are recorded as assets on our consolidated balance sheets. A summary of MSR activity is as follows: Nine months ended September 30, (in thousands) 2021 2020 MSRs: Balance, beginning of year $ 131,391 $ 70,707 Capitalized servicing rights 15,990 76,905 Amortization (18,663) (25,553) Direct write-down (279) — Sales (127,281) — Balance, end of period $ 1,158 $ 122,059 Valuation allowance: Balance, beginning of year $ 25,967 $ 5,803 Change in valuation allowance (25,967) 20,933 Balance, end of period $ — $ 26,736 MSRs, net $ 1,158 $ 95,323 MSRs, fair value $ 1,158 $ 95,323 At September 30, 2021 and December 31, 2020, our portfolio of MSRs was comprised of residential mortgage loans with outstanding principal balances of $143.4 million and $13.8 billion, respectively. In connection with the servicing of these loans, we hold deposits in the name of investors representing escrow funds for taxes and insurance, as well as collections in transit to such investors. These escrow funds are segregated and held in separate non-interest-bearing deposit accounts at the Bank. These deposits, included in total non-interest-bearing deposits on the consolidated balance sheets, were $2.4 million at September 30, 2021 and $152.6 million at December 31, 2020. The following tables summarize the assumptions used by management to determine the fair value of MSRs and a sensitivity analysis of changes in the fair value of our MSR portfolio resulting from certain key assumptions. The MSR balance at September 30, 2021 was valued utilizing the October 1, 2021 sale price, therefore only December 31, 2020 data is provided in the tables below. December 31, 2020 Average discount rates 9.09 % Expected prepayment speeds 16.37 % Weighted-average life, in years 4.9 (in thousands) December 31, 2020 50 bp adverse change in prepayment speed $ (12,203) 100 bp adverse change in prepayment speed (16,062) 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 repurchase, indemnification and make-whole agreements. Our estimated exposure related to those agreements totaled $619,000 and $621,000 at September 30, 2021 and December 31, 2020, respectively, and is recorded in other liabilities on the consolidated balance sheets. $76,000 in make-whole obligation payments were made during the nine months ended September 30, 2021 compared to $7.8 million during the nine months ended September 30, 2020.

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2021
Subordinated Borrowings [Abstract]
Long-Term Debt	Long-term Debt From November 2002 to September 2006 various Texas Capital Statutory Trusts were created and subsequently issued floating rate trust preferred securities in various private offerings totaling $113.4 million. For the three and nine months ended September 30, 2021, the combined weighted-average interest rate on the trust preferred subordinated debentures was 2.09% and 2.14%, respectively, compared to 2.28% and 3.03%, respectively, for the same periods in 2020. The details of the trust preferred subordinated debentures as of September 30, 2021 are summarized below: (dollar amounts in thousands) Texas Capital Texas Capital Texas Capital Texas Capital Texas Capital Date issued November 19, 2002 April 10, 2003 October 6, 2005 April 28, 2006 September 29, 2006 Trust preferred securities issued $10,310 $10,310 $25,774 $25,774 $41,238 Floating or fixed rate securities Floating Floating Floating Floating Floating Interest rate on subordinated debentures 3 month LIBOR + 3.35% 3 month LIBOR + 3.25% 3 month LIBOR + 1.51% 3 month LIBOR + 1.60% 3 month LIBOR + 1.71% Maturity date November 2032 April 2033 December 2035 June 2036 December 2036 On September 21, 2012, the Company issued $111.0 million of subordinated notes. The notes mature in September 2042 and bear interest at a rate of 6.50% per annum, payable quarterly. The indenture governing the notes contains customary covenants and restrictions. These notes were redeemed on June 21, 2021. On January 31, 2014, the Bank issued $175.0 million of subordinated notes in an offering to institutional investors exempt from registration under Section 3(a)(2) of the Securities Act of 1933 and 12 C.F.R. Part 16. The notes mature in January 2026 and bear interest at a rate of 5.25% per annum, payable semi-annually. The notes are unsecured and are subordinate to the Bank’s obligations to its depositors, its obligations under banker’s acceptances and letters of credit, certain obligations to Federal Reserve Banks and the FDIC and the Bank’s obligations to its other creditors, except any obligations which expressly rank on a parity with or junior to the notes. The notes qualify as Tier 2 capital for regulatory capital purposes, subject to applicable limitations. At the beginning of each of the last five years of the life of the notes, the amount that is eligible to be included in Tier 2 capital is reduced by 20% of the original amount of the notes (net of redemptions). In 2021, the amount of the notes that qualify as Tier 2 capital has been reduced by 20%. On March 9, 2021, the Bank issued and sold $275 million of senior unsecured credit-linked notes. The notes mature on September 30, 2024, and accrue interest at a rate equal to the higher of LIBOR plus 4.50% or 4.25%, payable quarterly on each of March 31, June 30, September 30 and December 31. For the three and nine months ended September 30, 2021, the weighted-average interest rate on the notes was 5.54% and 5.58%, respectively. The notes effectively transfer the risk of first losses on a $2.2 billion reference pool of the Bank’s mortgage warehouse loans to the purchasers of the notes in an amount up to $275.0 million. In the event of a failure to pay by the relevant mortgage originator, insolvency of the relevant mortgage originator, or restructuring of such loans that results in a loss on a loan included in the reference pool, the principal balance of the notes will be reduced to the extent of such loss and recognized as a debt extinguishment gain within non-interest income on our consolidated statements of income and other comprehensive income. The purchasers of the notes have the option to acquire the underlying mortgage loan collateralizing the reference warehouse line of credit in lieu of a principal reduction on the notes. Losses on our warehouse lines of credit have not generally been significant. The notes are recorded in long-term debt on our consolidated balance sheets and accounted for at amortized cost. The fair value of the credit-linked note is based on observable inputs, when available, and as such are categorized as Level 2 liabilities. Because the notes are variable rate debt, the fair value approximates carrying value. On May 6, 2021, the Company issued and sold $375.0 million of subordinated notes. The notes mature in May 2031 and bear interest at a fixed rate of 4.00% per annum, payable semi-annually. Net proceeds from the transaction were $370.7 million providing additional capital to be used for general corporate purposes. A portion of the proceeds were also used to redeem the Company’s 6.50% fixed rate subordinated notes, as is described above. The indenture governing the notes contains customary covenants and restrictions.

Financial Instruments with Off-

Financial Instruments with Off-Balance Sheet Risk	9 Months Ended
	Sep. 30, 2021
Risks and Uncertainties [Abstract]
Financial Instruments with Off-Balance Sheet Risk	Financial Instruments with Off-Balance Sheet Risk The table below presents our financial instruments with off-balance sheet risk, as well as the activity in the allowance for off-balance sheet credit losses related to those financial instruments. This allowance is recorded in other liabilities on the consolidated balance sheets. Three months ended September 30, Nine months ended September 30, (in thousands) 2021 2020 2021 2020 Beginning balance of allowance for off-balance sheet credit losses $ 16,747 $ 12,268 $ 17,434 $ 8,640 Impact of CECL adoption — — — 563 Provision for off-balance sheet credit losses 1,464 2,973 777 6,038 Ending balance of allowance for off-balance sheet credit losses $ 18,211 $ 15,241 $ 18,211 $ 15,241 (in thousands) September 30, 2021 December 31, 2020 Commitments to extend credit - period end balance $ 8,261,483 $ 8,530,453 Standby letters of credit - period end balance $ 340,896 $ 268,894

Regulatory Restrictions

Regulatory Restrictions	9 Months Ended
	Sep. 30, 2021
Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]
Regulatory Restrictions	Regulatory Restrictions 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. Additionally, the Basel III Capital Rules require that we maintain a 2.5% 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. 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. In February 2019, the federal bank regulatory agencies issued a final rule (the “2019 CECL Rule”) that revised certain capital regulations to account for changes to credit loss accounting under GAAP. The 2019 CECL Rule included a transition option that allows banking organizations to phase in, over a three-year period, the day-one adverse effects of adopting the new accounting standard related to the measurement of current expected credit losses on their regulatory capital ratios (three-year CECL transition option). In March 2020, the federal bank regulatory agencies issued an interim final rule that maintains the three-year CECL transition option of the 2019 CECL Rule and also provides banking organizations that were required under GAAP to implement CECL before the end of 2020 the option to delay for two years an estimate of the effect of CECL on regulatory capital, relative to the incurred loss methodology's effect on regulatory capital, followed by a three-year transition period (five-year CECL transition option). We adopted CECL on January 1, 2020 and have elected to utilize the five-year CECL transition option. Quantitative measures established by regulation 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 September 30, 2021, that the Company and the Bank meet all capital adequacy requirements to which they are subject. Financial institutions are categorized as well capitalized based on total risk-based, Tier 1 risk-based, CET1 and Tier 1 leverage ratios. As shown in the table below, the Company’s and the Bank’s capital ratios exceeded the regulatory definition of well capitalized as of September 30, 2021 and December 31, 2020. The regulatory authorities can apply changes in classification of assets and such changes may retroactively subject the Company and the Bank to changes in capital ratios. Any such change could reduce 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 effect on our 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. The ratios presented below include the effects of our election to utilize the five-year CECL transition described above. Actual Minimum Capital Required(2) Capital Required to be Well Capitalized (dollars in thousands) Capital Amount Ratio Capital Amount Ratio Capital Amount Ratio September 30, 2021 CET1 Company $ 2,883,517 10.70 % $ 1,886,355 7.00 % N/A N/A Bank 2,950,866 10.97 % 1,882,136 7.00 % 1,747,697 6.50 % Total capital (to risk-weighted assets) Company 4,027,375 14.95 % 2,829,533 10.50 % 2,694,793 10.00 % Bank 3,523,923 13.11 % 2,823,203 10.50 % 2,688,765 10.00 % Tier 1 capital (to risk-weighted assets) Company 3,293,517 12.22 % 2,290,574 8.50 % 1,616,876 6.00 % Bank 3,110,866 11.57 % 2,285,450 8.50 % 2,151,012 8.00 % Tier 1 capital (to average assets)(1) Company 3,293,517 8.96 % 1,469,597 4.00 % N/A N/A Bank 3,110,866 8.47 % 1,468,949 4.00 % 1,836,186 5.00 % December 31, 2020 CET1 Company $ 2,708,150 9.35 % $ 2,026,806 7.00 % N/A N/A Bank 2,744,211 9.48 % 2,025,417 7.00 % 1,880,745 6.50 % Total capital (to risk-weighted assets) Company 3,498,737 12.08 % 3,040,209 10.50 % 2,895,437 10.00 % Bank 3,375,983 11.67 % 3,038,126 10.50 % 2,893,453 10.00 % Tier 1 capital (to risk-weighted assets) Company 2,968,150 10.25 % 2,461,121 8.50 % 1,737,262 6.00 % Bank 2,904,211 10.04 % 2,459,435 8.50 % 2,314,763 8.00 % Tier 1 capital (to average assets)(1) Company 2,968,150 7.52 % 1,578,651 4.00 % N/A N/A Bank 2,904,211 7.36 % 1,578,207 4.00 % 1,972,758 5.00 % (1) The Tier 1 capital ratio (to average assets) is not impacted by the Basel III Capital Rules; however, 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. (2) Percentages represent the minimum capital ratios plus, as applicable, the fully phased-in 2.5% CET1 capital buffer under the Basel III Capital Rules. Our mortgage finance loan volumes can increase significantly at month-end, causing a meaningful difference between ending and average balances for any period. 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 loans held for sale, which receive lower risk weights), the period-end fluctuation in these balances can significantly impact our reported ratios. Due to the actual risk profile and liquidity of this asset class, we do not believe that the period-end balance is representative of risk characteristics that would justify higher allocations, and while we manage capital allocated to mortgage finance loans based on changing trends in average balances, we do monitor our capital allocation to confirm that all capital levels remain above well-capitalized levels. To better align the actual risk profile of this asset class to its required capital allocation, the Bank issued and sold senior unsecured credit-linked notes in the first quarter of 2021 that effectively transfer the risk of first losses on a $2.2 billion reference pool of the Bank's mortgage warehouse loans to the purchasers of the notes in an amount up to $275.0 million. The issuance of these notes decreases the required risk-weight on the $2.2 billion reference pool, which significantly improves our reported ratios. Dividends that may be paid by banks are routinely restricted by various regulatory authorities, including federal banking law requirements concerning the payment of dividends. The Basel III Capital Rules further limit the amount of dividends that may be paid by us or our Bank. No dividends were declared or paid on our common stock during the nine months ended September 30, 2021, or during the year ended December 31, 2020.

Stock-based Compensation

Stock-based Compensation	9 Months Ended
	Sep. 30, 2021
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: Three months ended September 30, Nine months ended September 30, (in thousands) 2021 2020 2021 2020 Stock-settled awards: RSUs $ 8,324 $ 4,794 $ 22,099 $ 11,326 Restricted stock — 5 1 22 Cash-settled units 64 236 1,092 716 Total $ 8,388 $ 5,035 $ 23,192 $ 12,064 (in thousands except period data) September 30, 2021 Unrecognized compensation expense related to unvested stock-settled awards $ 39,463 Weighted average period over which expense is expected to be recognized, in years 2.5

Fair Value Disclosures

Fair Value Disclosures	9 Months Ended
	Sep. 30, 2021
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. See Note 1 - Operations and Summary of Significant Accounting Policies in our 2020 Form 10-K for information regarding the fair value hierarchy and a description of the methods and significant assumptions used by the Company in estimating its fair value disclosures for financial instruments. Assets and liabilities measured at fair value are as follows: Fair Value Measurements Using (in thousands) Level 1 Level 2 Level 3 September 30, 2021 Available-for-sale debt securities:(1) U.S. government agency securities $ — $ 121,920 $ — Residential mortgage-backed securities — 3,304,722 — Tax-exempt asset-backed securities — — 184,820 CRT securities — — 11,804 Equity securities(1)(2) 33,511 7,097 — Loans held for sale(3) — 658 7,701 Derivative assets(5) — 56,940 — Derivative liabilities(5) — 56,940 — Non-qualified deferred compensation plan liabilities(6) 28,186 — — December 31, 2020 Available-for-sale debt securities:(1) U.S. government agency securities $ — $ 123,589 $ — Residential mortgage-backed securities — 2,828,956 — Tax-exempt asset-backed securities — — 199,176 CRT securities — — 11,417 Equity securities(1)(2) 26,593 7,239 — Loans held for sale(3) — 232,147 6,933 Loans held for investment(4) — — 21,209 Derivative assets(5) — 102,720 — Derivative liabilities(5) — 99,255 — Non-qualified deferred compensation plan liabilities(6) 26,593 — — (1) Securities are measured at fair value on a recurring basis, generally monthly, except for tax-exempt asset-backed securities and CRT securities which are measured quarterly. (2) Equity securities consist of investments that qualify for consideration under the regulations implementing the Community Reinvestment Act and investments related to our non-qualified deferred compensation plan. (3) Loans held for sale purchased through the MCA program are measured at fair value on a recurring basis, generally monthly. (4) Includes certain collateral-dependent loans held for investment for which a specific allocation of the allowance for credit losses is based upon the fair value of the loan’s underlying collateral. These loans held for investment are measured on a nonrecurring basis, generally annually or more often as warranted by market and economic conditions. (5) Derivative assets and liabilities are measured at fair value on a recurring basis, generally quarterly. (6) Non-qualified deferred compensation plan liabilities represent the fair value of the obligation to the employee, which generally corresponds to the fair value of the invested assets, and are measured at fair value on a recurring basis, generally monthly. Level 3 Valuations The following table presents a reconciliation of the Level 3 fair value category measured at fair value on a recurring basis: Net Realized/Unrealized Gains (Losses) (in thousands) Balance at Beginning of Period Purchases / Additions Sales / Reductions Realized Unrealized Balance at End of Period Three months ended September 30, 2021 Available-for-sale debt securities:(1) Tax-exempt asset-backed securities $ 185,954 $ — $ (2,270) $ — $ 1,136 $ 184,820 CRT securities 11,713 — — — 91 11,804 Loans held for sale(2) 8,227 440 (870) — (96) 7,701 Three months ended September 30, 2020 Available-for-sale debt securities:(1) Tax-exempt asset-backed securities $ 191,417 $ — $ (2,248) $ — $ 11,652 $ 200,821 CRT securities 10,953 — — — 105 11,058 Loans held for sale(2) 6,159 785 (170) 132 68 6,974 Nine months ended September 30, 2021 Available-for-sale debt securities:(1) Tax-exempt asset-backed securities $ 199,176 $ — $ (13,783) $ — $ (573) $ 184,820 CRT securities 11,417 — — — 387 11,804 Loans held for sale(2) 6,933 2,125 (1,395) 5 33 7,701 Nine months ended September 30, 2020 Available-for-sale debt securities:(1) Tax-exempt asset-backed securities $ 197,027 $ 8,470 $ (6,733) $ — $ 2,057 $ 200,821 CRT securities 11,964 — — — (906) 11,058 Loans held for sale(2) 7,043 1,105 (1,634) 248 212 6,974 (1) Unrealized gains/(losses) on available-for-sale debt securities are recorded in AOCI and relate to assets that remain outstanding at period end. Realized gains/(losses) are recorded in other non-interest income. (2) Realized and unrealized gains/(losses) on loans held for sale are recorded in gain/(loss) on sale of loans held for sale. Tax-exempt asset-backed securities The fair value of tax-exempt asset-backed securities is based on a discounted cash flow model, which utilizes Level 3, or unobservable, inputs, the most significant of which were a discount rate and a weighted-average life. At September 30, 2021, the discount rates utilized ranged from 2.25% to 2.37% and the weighted-average life ranged from 4.8 to 4.9 years. On a combined amortized cost weighted-average basis a discount rate of 2.30% and weighted-average life of 4.8 years were utilized to determine the fair value of these securities at September 30, 2021. At December 31, 2020, the combined weighted-average discount rate and weighted-average life utilized were 2.49% and 5.5 years, respectively. CRT securities The fair value of CRT securities is based on a discounted cash flow model, which utilizes Level 3, or unobservable, inputs, the most significant of which were a discount rate and a weighted-average life. At September 30, 2021, the discount rates utilized ranged from 3.12% to 7.99% and the weighted-average life ranged from 5.0 years to 9.8 years. On a combined amortized cost weighted-average basis a discount rate of 4.74% and a weighted-average life of 6.6 years were utilized to determine the fair value of these securities at September 30, 2021. At December 31, 2020, the combined weighted-average discount rate and combined weighted-average life utilized were 4.36% and 7.5 years, respectively. Loans held for sale The fair value of loans held for sale using Level 3 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 September 30, 2021, the fair value of these loans was calculated using a weighted-average discounted price of 97.9%, compared to 97.2% at December 31, 2020. Loans held for investment Certain collateral-dependent loans held for investment are reported at fair value when, based upon an individual evaluation, the specific allocation of the allowance for credit losses that is deducted from the loan's amortized cost is based upon the fair value of the loan's underlying collateral. There were no collateral-dependent loans held for investment reported at fair value at September 30, 2021. The $21.2 million fair value of loans held for investment at December 31, 2020 reported above includes loans with a carrying value of $25.3 million that were reduced by specific allowance allocations totaling $4.1 million based on collateral valuations utilizing Level 3 inputs. Fair Value of Financial Instruments A summary of the carrying amounts and estimated fair values of financial instruments is as follows: September 30, 2021 December 31, 2020 (in thousands) Carrying Estimated Carrying Estimated Financial assets: Level 1 inputs: Cash and cash equivalents $ 8,535,051 $ 8,535,051 $ 9,206,380 $ 9,206,380 Investment securities 33,511 33,511 26,593 26,593 Level 2 inputs: Investment securities 3,433,739 3,433,739 2,959,784 2,959,784 Loans held for sale 658 658 232,147 232,147 Derivative assets 56,940 56,940 102,720 102,720 Level 3 inputs: Investment securities 196,624 196,624 210,593 210,593 Loans held for sale 7,701 7,701 6,933 6,933 Loans held for investment, net 23,527,760 23,575,556 24,176,245 24,233,185 Financial liabilities: Level 2 inputs: Federal funds purchased and repurchase agreements 3,470 3,470 111,751 111,751 Other borrowings 2,200,000 2,200,000 3,000,000 3,000,000 Long-term debt 928,062 953,859 395,896 405,110 Derivative liabilities 56,940 56,940 99,255 99,255 Level 3 inputs: Deposits 29,813,668 29,814,204 30,996,589 30,997,980

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments The notional amounts and estimated fair values of derivative positions outstanding are presented in the following table. All derivative positions related to residential MSRs and loans held for sale were closed as of September 30, 2021 as a result of the sale of our MSR portfolio and transition of the MCA program to a third-party. September 30, 2021 December 31, 2020 Estimated Fair Value Estimated Fair Value (in thousands) Notional Asset Derivative Liability Derivative Notional Asset Derivative Liability Derivative Non-hedging derivatives: Financial institution counterparties: Commercial loan/lease interest rate swaps $ 1,857,977 $ 1,320 $ 56,884 $ 1,922,956 $ 71 $ 96,246 Commercial loan/lease interest rate caps 204,655 56 — 565,634 34 — Foreign currency forward contracts — — — 6,667 214 78 Customer counterparties: Commercial loan/lease interest rate swaps 1,857,977 56,884 1,320 1,922,956 96,246 71 Commercial loan/lease interest rate caps 204,655 — 56 565,634 — 34 Foreign currency forward contracts — — — 6,667 78 214 Economic hedging derivatives to hedge: Residential MSRs: Interest rate swap futures — — — 320,000 474 — Forward sale commitments — — — 155,000 551 — Loans held for sale: Loan purchase commitments — — — 332,145 5,123 8 Forward sale commitments — — — 485,326 — 2,675 Gross derivatives 58,260 58,260 102,791 99,326 Offsetting derivative assets/liabilities (1,320) (1,320) (71) (71) Net derivatives included in the consolidated balance sheets $ 56,940 $ 56,940 $ 102,720 $ 99,255 The weighted-average received and paid interest rates for interest rate swaps outstanding were as follows: September 30, 2021 December 31, 2020 Weighted-Average Interest Rate Received Paid Received Paid Non-hedging interest rate swaps 2.74 % 1.15 % 3.14 % 1.38 % The weighted-average strike rate for outstanding interest rate caps was 2.67% at September 30, 2021 and 3.41% at December 31, 2020. 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 $56.9 million at September 30, 2021, and approximately $102.7 million at December 31, 2020. 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 sale commitments. At September 30, 2021, we had $62.1 million in cash collateral pledged for these derivatives that is included in interest-bearing deposits in other banks. At December 31, 2020, we had $108.3 million in cash collateral pledged for these derivatives, of which $104.4 million was included in interest-bearing deposits in other banks and $3.9 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 eight risk participation agreements where we are a participant bank with a notional amount of $109.2 million at September 30, 2021, compared to nine risk participation agreements having a notional amount of $119.5 million at December 31, 2020. The maximum estimated exposure to these agreements, assuming 100% default by all obligors, was approximately $3.2 million at September 30, 2021 and $6.0 million at December 31, 2020. The fair value of these exposures was insignificant to the consolidated financial statements at both September 30, 2021 and December 31, 2020. 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 16 risk participation agreements where

Material Transactions Affecting

Material Transactions Affecting Stockholders' Equity	9 Months Ended
	Sep. 30, 2021
Stockholders' Equity Note [Abstract]
Material Transactions Affecting Stockholders' Equity	Material Transactions Affecting Stockholders' Equity On March 3, 2021, we completed an issuance of 5.75% fixed rate non-cumulative perpetual preferred stock, Series B, with a liquidation preference of $1,000 per share (equivalent to $25 per depositary share) (the “Series B Preferred Stock”) and an issuance and sale of 12,000,000 depositary shares, each representing a 1/40th interest in a share of the Series B Preferred Stock. Dividends on the Series B Preferred Stock are not cumulative and will be paid when declared by our board of directors to the extent that we have legally available funds to pay dividends. If declared, dividends will accrue and be payable quarterly, in arrears, on the liquidation preference amount, on a non-cumulative basis, at a rate of 5.75% per annum. Holders of preferred stock will not have voting rights, except with respect to certain changes in the terms of the preferred stock, certain dividend non-payments and as otherwise required by applicable law. Net proceeds from the sale totaled $289.7 million, providing additional capital to be used for general corporate purposes. A portion of the proceeds were also used to redeem, in whole, our 6.50% non-cumulative perpetual preferred stock Series A, par value $0.01 per share, in accordance with its terms. On June 15, 2021 we redeemed all 6,000,000 outstanding shares of our 6.50% non-cumulative perpetual preferred stock, Series A.

Operations and Summary of Sig_2

Operations and Summary of Significant Accounting Policies Operations and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
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 the Company and its wholly owned subsidiary, Texas Capital Bank (the “Bank”). We serve the needs of commercial businesses and professionals and entrepreneurs located in Texas as well as operate several lines of business serving a regional or national clientele of commercial borrowers. We are primarily a secured lender, with the majority of our loans held for investment, excluding mortgage finance loans and other national lines of business, being made to businesses headquartered or with operations in Texas. Our national lines of business provide specialized lending products to businesses throughout the United States. In May 2021 the Bank applied to the Texas Department of Banking to convert from a national association to a Texas state-chartered bank. The application was approved during the third quarter and the conversion was effective at open of business on September 15, 2021. Effective as of the date of conversion, the Texas Department of Banking is the Bank’s primary regulator, the FDIC is the Bank’s primary federal regulator, and the Federal Reserve will continue to be the Company’s primary federal regulator.
Basis of Accounting	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 disclosures in the notes to consolidated financial statements that are 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 U.S. Securities and Exchange Commission (“SEC”). Accordingly, the financial statements do not include all of the information and notes to the consolidated financial statements required by GAAP for complete annual financial statements and should be read in conjunction with our consolidated financial statements, and notes thereto, for the year ended December 31, 2020, included in our Annual Report on Form 10-K for the year ended December 31, 2020 (the “2020 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 credit losses, the fair value of financial instruments and the status of contingencies are particularly susceptible to significant change.

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Securities, Available-for-sale [Abstract]
Summary of securities	The following is a summary of available-for-sale debt securities: (in thousands) Amortized Gross Gross Estimated September 30, 2021 Available-for-sale debt securities: U.S. government agency securities $ 125,000 $ — $ (3,080) $ 121,920 Residential mortgage-backed securities 3,363,930 331 (59,539) 3,304,722 Tax-exempt asset-backed securities 171,157 13,663 — 184,820 Credit risk transfer (“CRT”) securities 14,713 — (2,909) 11,804 Total $ 3,674,800 $ 13,994 $ (65,528) $ 3,623,266 December 31, 2020 Available-for-sale debt securities: U.S. government agency securities $ 125,000 $ 1 $ (1,412) $ 123,589 Residential mortgage-backed securities 2,818,518 11,566 (1,128) 2,828,956 Tax-exempt asset-backed securities 184,940 14,236 — 199,176 CRT securities 14,713 — (3,296) 11,417 Total $ 3,143,171 $ 25,803 $ (5,836) $ 3,163,138 (1) Excludes accrued interest receivable of $6.7 million and $6.0 million at September 30, 2021 and December 31, 2020, respectively, that is recorded in accrued interest receivable and other assets on the consolidated balance sheets.
Schedule of amortized cost and estimated fair value of securities	The amortized cost and estimated fair value, excluding accrued interest receivable, and weighted average yield of available-for-sale debt securities are presented below by contractual maturity: (in thousands, except percentage data) Less Than After One After Five After Ten Total September 30, 2021 Available-for-sale: U.S. government agency securities:(1) Amortized cost $ — $ — $ 125,000 $ — $ 125,000 Estimated fair value — — 121,920 — 121,920 Weighted average yield(3) — % — % 1.13 % — % 1.13 % Residential mortgage-backed securities:(1) Amortized cost $ 24 $ 252 $ 17,339 $ 3,346,315 $ 3,363,930 Estimated fair value 26 280 16,652 3,287,764 3,304,722 Weighted average yield(3) 3.99 % 4.66 % 1.08 % 1.13 % 1.13 % Tax-exempt asset-backed securities:(1) Amortized Cost $ — $ — $ — $ 171,157 $ 171,157 Estimated fair value — — — 184,820 184,820 Weighted average yield(2)(3) — % — % — % 4.96 % 4.96 % CRT securities:(1) Amortized Cost $ — $ — $ 14.713 $ — $ 14,713 Estimated fair value — — 11.804 — 11,804 Weighted average yield(3) — % — % 0.08 % — % 0.08 % Total available-for-sale debt securities: Amortized cost $ 3,674,800 Estimated fair value $ 3,623,266 December 31, 2020 Available-for-sale: U.S. government agency securities:(1) Amortized cost $ — $ — $ 125,000 $ — $ 125,000 Estimated fair value — — 123,589 — 123,589 Weighted average yield(3) — % — % 1.13 % — % 1.13 % Residential mortgage-backed securities:(1) Amortized cost $ — $ 545 $ 17,500 $ 2,800,473 $ 2,818,518 Estimated fair value — 605 17,490 2,810,861 2,828,956 Weighted average yield(3) — % 4.58 % 1.08 % 1.25 % 1.25 % Tax-exempt asset-backed securities:(1) Amortized Cost $ — $ — $ — $ 184,940 $ 184,940 Estimated fair value — — — 199,176 199,176 Weighted average yield(2)(3) — % — % — % 4.92 % 4.92 % CRT securities:(1) Amortized Cost $ — $ — $ — $ 14,713 $ 14,713 Estimated fair value — — — 11,417 11,417 Weighted average yield(3) — % — % — % 0.15 % 0.15 % Total available-for-sale debt securities: Amortized cost $ 3,143,171 Estimated fair value $ 3,163,138 (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 have been adjusted to a tax equivalent basis assuming a 21% federal tax rate. (3) Yields are calculated based on amortized cost.
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value	The following table discloses our available-for-sale debt securities that have been in a continuous unrealized loss position for less than 12 months and those that have been in a continuous unrealized loss position for 12 or more months: Less Than 12 Months 12 Months or Longer Total (in thousands) Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss September 30, 2021 U.S. government agency securities $ 24,348 $ (652) $ 97,572 $ (2,428) $ 121,920 $ (3,080) Residential mortgage-backed securities 3,279,426 (59,539) 97 — 3,279,523 (59,539) CRT securities — — 11,804 (2,909) 11,804 (2,909) Total $ 3,303,774 $ (60,191) $ 109,473 $ (5,337) $ 3,413,247 $ (65,528) December 31, 2020 U.S. government agency securities $ 98,588 $ (1,412) $ — $ — $ 98,588 $ (1,412) Residential mortgage-backed securities 354,387 (1,128) — — 354,387 (1,128) CRT securities — — 11,417 (3,296) 11,417 (3,296) Total $ 452,975 $ (2,540) $ 11,417 $ (3,296) $ 464,392 $ (5,836)
Summary of unrealized and realized gains/(losses) recognized in net income on equity securities	The following is a summary of unrealized and realized gains/(losses) recognized on equity securities included in other non-interest income in the consolidated statements of income and other comprehensive income: Three months ended September 30, Nine months ended September 30, (in thousands) 2021 2020 2021 2020 Net gains/(losses) recognized during the period $ 850 $ 1,350 $ 4,496 $ 1,285 Less: Realized net gains/(losses) recognized during the period on equity securities sold 347 177 1,096 (68) Unrealized net gains/(losses) recognized during the period on equity securities still held $ 503 $ 1,173 $ 3,400 $ 1,353

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
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/(loss) per share: Three months ended September 30, Nine months ended September 30, (in thousands except share and per share data) 2021 2020 2021 2020 Numerator: Net income $ 43,390 $ 57,116 $ 188,809 $ 6,113 Preferred stock dividends 4,312 2,438 14,408 7,313 Net income/(loss) available to common stockholders $ 39,078 $ 54,678 $ 174,401 $ (1,200) Denominator: Denominator for basic earnings per share—weighted average shares 50,600,732 50,446,691 50,568,439 50,417,563 Effect of employee stock-based awards(1) 538,823 126,382 555,836 103,984 Denominator for dilutive earnings per share—adjusted weighted average shares and assumed conversions 51,139,555 50,573,073 51,124,275 50,521,547 Basic earnings/(loss) per common share $ 0.77 $ 1.08 $ 3.45 $ (0.02) Diluted earnings/(loss) per common share $ 0.76 $ 1.08 $ 3.41 $ (0.02) (1) SARs and RSUs outstanding of 208,813 at September 30, 2021 and 480,062 at September 30, 2020 have not been included in diluted earnings/(loss) per common share because to do so would have been antidilutive for the periods presented.

Loans Held for Investment and_2

Loans Held for Investment and Allowance for Loan Losses (Tables)	9 Months Ended
	Sep. 30, 2021
Receivables [Abstract]
Schedule of loans held for investments	Loans held for investment are summarized by portfolio segment as follows: (in thousands) September 30, 2021 December 31, 2020 Commercial $ 9,377,274 $ 8,861,580 Energy 697,888 766,217 Mortgage finance(1) 8,528,313 9,079,409 Real estate 5,212,364 5,794,624 Gross loans held for investment(2) 23,815,839 24,501,830 Unearned income (net of direct origination costs) (66,122) (70,970) Allowance for credit losses on loans (221,957) (254,615) Total loans held for investment, net(2) $ 23,527,760 $ 24,176,245 (1) Balances at September 30, 2021 and December 31, 2020 are stated net of $677.6 million and $1.2 billion of participations sold, respectively. (2) Excludes accrued interest receivable of $50.3 million and $56.5 million at September 30, 2021 and December 31, 2020, respectively, that is recorded in accrued interest receivable and other assets on the consolidated balance sheets.
Schedule of the credit risk profile of loan portfolio by internally assigned grades and nonaccrual status	The following tables summarize our gross loans held for investment by year of origination and internally assigned credit grades: (in thousands) 2021 2020 2019 2018 2017 2016 and prior Revolving lines of credit Revolving lines of credit converted to term loans Total September 30, 2021 Commercial (1-7) Pass $ 919,405 $ 3,228,097 $ 572,505 $ 321,356 $ 194,921 $ 284,804 $ 3,535,016 $ 50,565 $ 9,106,669 (8) Special mention 691 8,061 46,942 9,233 — 13,561 9,579 6,495 94,562 (9) Substandard - accruing — 4,763 60,192 39,177 6,202 16,137 15,592 6,906 148,969 (9+) Non-accrual 1,218 1,624 2,305 727 2,105 10,444 8,185 466 27,074 Total commercial $ 921,314 $ 3,242,545 $ 681,944 $ 370,493 $ 203,228 $ 324,946 $ 3,568,372 $ 64,432 $ 9,377,274 Energy (1-7) Pass $ 22,309 $ — $ — $ 2,516 $ — $ 28,854 $ 566,387 $ — $ 620,066 (8) Special mention — — — — — — 37,782 — 37,782 (9) Substandard - accruing — — — — — — — — — (9+) Non-accrual — — — — — 20,715 19,325 — 40,040 Total energy $ 22,309 $ — $ — $ 2,516 $ — $ 49,569 $ 623,494 $ — $ 697,888 Mortgage finance (1-7) Pass $ 295,565 $ 834,008 $ 744,105 $ 696,945 $ 409,308 $ 5,548,382 $ — $ — $ 8,528,313 (8) Special mention — — — — — — — — — (9) Substandard - accruing — — — — — — — — — (9+) Non-accrual — — — — — — — — — Total mortgage finance $ 295,565 $ 834,008 $ 744,105 $ 696,945 $ 409,308 $ 5,548,382 $ — $ — $ 8,528,313 Real estate CRE (1-7) Pass $ 292,248 $ 545,204 $ 703,910 $ 566,771 $ 187,565 $ 482,033 $ 45,008 $ 25,361 $ 2,848,100 (8) Special mention — — 30,497 8,881 48,049 17,022 — — 104,449 (9) Substandard - accruing 17,850 — — 41,209 61,051 62,978 — 2,354 185,442 (9+) Non-accrual — — — — — 202 — — 202 RBF (1-7) Pass 166,828 70,338 15,180 9,392 66 14,483 566,799 — 843,086 (8) Special mention — — — — — — — — — (9) Substandard - accruing — — — — — — — — — (9+) Non-accrual — — — — — — — — — Other (1-7) Pass 88,370 161,048 136,836 107,251 83,282 167,252 45,174 30,210 819,423 (8) Special mention — 13,903 1,990 — — 5,055 — — 20,948 (9) Substandard - accruing — — — 1,637 23,952 21,125 — — 46,714 (9+) Non-accrual — — — — 3,536 2,566 — 13,929 20,031 Secured by 1-4 family (1-7) Pass 71,682 62,514 53,285 24,610 34,666 69,988 4,491 — 321,236 (8) Special mention — — — — — 294 — — 294 (9) Substandard - accruing — — — — — 2,254 — — 2,254 (9+) Non-accrual — — — — — 185 — — 185 Total real estate $ 636,978 $ 853,007 $ 941,698 $ 759,751 $ 442,167 $ 845,437 $ 661,472 $ 71,854 $ 5,212,364 Total loans held for investment $ 1,876,166 $ 4,929,560 $ 2,367,747 $ 1,829,705 $ 1,054,703 $ 6,768,334 $ 4,853,338 $ 136,286 $ 23,815,839
Schedule of activity in the reserve for loan losses by portfolio segment	The following table details activity in the allowance for credit losses on loans. Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. (in thousands) Commercial Energy Mortgage Real Total Nine months ended September 30, 2021 Allowance for credit losses on loans: Beginning balance $ 73,061 $ 84,064 $ 4,699 $ 92,791 $ 254,615 Provision for credit losses on loans 26,549 (24,730) 1,729 (24,325) (20,777) Charge-offs 8,211 6,418 — 1,192 15,821 Recoveries 2,462 1,366 — 112 3,940 Net charge-offs (recoveries) 5,749 5,052 — 1,080 11,881 Ending balance $ 93,861 $ 54,282 $ 6,428 $ 67,386 $ 221,957 Nine months ended September 30, 2020 Allowance for credit losses on loans: Beginning balance $ 102,254 $ 60,253 $ 2,265 $ 30,275 $ 195,047 Impact of Current Expected Credit Loss (“CECL”) adoption (15,740) 24,154 2,031 (1,860) 8,585 Provision for credit losses on loans 47,263 127,470 430 44,799 219,962 Charge-offs 35,376 100,239 — — 135,615 Recoveries 883 1,303 — — 2,186 Net charge-offs (recoveries) 34,493 98,936 — — 133,429 Ending balance $ 99,284 $ 112,941 $ 4,726 $ 73,214 $ 290,165
Schedule of impaired loans, by portfolio class	The table below provides an age analysis of our loans held for investment: (in thousands) 30-59 Days 60-89 Days 90 Days or More Past Due(1) Total Past Non-Accrual Loans(2) Current Total Non-Accrual With No Allowance September 30, 2021 Commercial $ 19,395 $ 18,313 $ 2,256 $ 39,964 $ 27,074 $ 9,310,236 $ 9,377,274 $ 10,899 Energy — — — — 40,040 657,848 697,888 9,281 Mortgage finance loans — — — — — 8,528,313 8,528,313 — Real estate CRE 250 — — 250 202 3,137,741 3,138,193 — RBF — — — — — 843,086 843,086 — Other 1,225 — — 1,225 20,031 885,860 907,116 2,697 Secured by 1-4 family 553 — 1,149 1,702 185 322,082 323,969 — Total loans held for investment $ 21,423 $ 18,313 $ 3,405 $ 43,141 $ 87,532 $ 23,685,166 $ 23,815,839 $ 22,877 (1) Loans past due 90 days and still accruing includes premium finance loans of $2.3 million. These loans are generally secured by obligations of insurance carriers to refund premiums on canceled insurance policies. The receipt of the refund of premiums from the insurance carriers can take 180 days or longer from the cancellation date. (2) As of September 30, 2021 and December 31, 2020, none of our non-accrual loans were earning interest income on a cash basis. Additionally, no interest income was recognized on non-accrual loans for the nine months ended September 30, 2021. Accrued interest of $674,000 was reversed during the nine months ended September 30, 2021.
Schedule of loans that have been restructured	The following table details the recorded investment at September 30, 2020 of loans restructured during the nine months ended September 30, 2020: Extended Maturity Adjusted Payment Schedule Total (in thousands, except number of contracts) Number of Contracts Balance at Period End Number of Contracts Balance at Period End Number of Contracts Balance at Period End Nine months ended September 30, 2020 Commercial loans 2 $ 7,636 2 $ 14,663 4 $ 22,299 Energy loans 1 5,969 3 13,469 4 19,438 Total 3 $ 13,605 5 $ 28,132 8 $ 41,737

Certain Transfers of Financia_2

Certain Transfers of Financial Assets (Tables)	9 Months Ended
	Sep. 30, 2021
Transfers and Servicing [Abstract]
Schedule of Loans Held-for-sale [Table Text Block]	The table below presents a reconciliation of the changes in loans held for sale: Nine Months Ended September 30, (in thousands) 2021 2020 Outstanding balance(1): Beginning balance $ 281,137 $ 2,568,362 Loans purchased and originated 1,413,899 8,963,499 Payments and loans sold (1,685,212) (10,889,549) Ending balance 9,824 642,312 Fair value adjustment: Beginning balance 2,028 8,772 Increase/(decrease) to fair value (2,192) (3,075) Ending balance (164) 5,697 Loans held for sale at fair value $ 9,660 $ 648,009 (1) Includes $1.3 million and $44.1 million of loans held for sale that are carried at lower of cost or market as of September 30, 2021 and December 31, 2020, respectively, as well as $9.0 million and $5.8 million as of September 30, 2020 and December 31, 2019, respectively.
Schedule of Mortgage Servicing Rights Activity [Table Text Block]	A summary of MSR activity is as follows: Nine months ended September 30, (in thousands) 2021 2020 MSRs: Balance, beginning of year $ 131,391 $ 70,707 Capitalized servicing rights 15,990 76,905 Amortization (18,663) (25,553) Direct write-down (279) — Sales (127,281) — Balance, end of period $ 1,158 $ 122,059 Valuation allowance: Balance, beginning of year $ 25,967 $ 5,803 Change in valuation allowance (25,967) 20,933 Balance, end of period $ — $ 26,736 MSRs, net $ 1,158 $ 95,323 MSRs, fair value $ 1,158 $ 95,323
Schedule of Fair Value Assumption Used to Value Mortgage Servicing Rights Retained [Table Text Block]	The following tables summarize the assumptions used by management to determine the fair value of MSRs and a sensitivity analysis of changes in the fair value of our MSR portfolio resulting from certain key assumptions. The MSR balance at September 30, 2021 was valued utilizing the October 1, 2021 sale price, therefore only December 31, 2020 data is provided in the tables below. December 31, 2020 Average discount rates 9.09 % Expected prepayment speeds 16.37 % Weighted-average life, in years 4.9
Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table Text Block]	(in thousands) December 31, 2020 50 bp adverse change in prepayment speed $ (12,203) 100 bp adverse change in prepayment speed (16,062)

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2021
Subordinated Borrowings [Abstract]
Schedule of details of the trust preferred subordinated debentures	The details of the trust preferred subordinated debentures as of September 30, 2021 are summarized below: (dollar amounts in thousands) Texas Capital Texas Capital Texas Capital Texas Capital Texas Capital Date issued November 19, 2002 April 10, 2003 October 6, 2005 April 28, 2006 September 29, 2006 Trust preferred securities issued $10,310 $10,310 $25,774 $25,774 $41,238 Floating or fixed rate securities Floating Floating Floating Floating Floating Interest rate on subordinated debentures 3 month LIBOR + 3.35% 3 month LIBOR + 3.25% 3 month LIBOR + 1.51% 3 month LIBOR + 1.60% 3 month LIBOR + 1.71% Maturity date November 2032 April 2033 December 2035 June 2036 December 2036

Financial Instruments with Of_2

Financial Instruments with Off-Balance Sheet Risk (Tables)	9 Months Ended
	Sep. 30, 2021
Risks and Uncertainties [Abstract]
Schedule of financial instruments with off-balance sheet risk	The table below presents our financial instruments with off-balance sheet risk, as well as the activity in the allowance for off-balance sheet credit losses related to those financial instruments. This allowance is recorded in other liabilities on the consolidated balance sheets. Three months ended September 30, Nine months ended September 30, (in thousands) 2021 2020 2021 2020 Beginning balance of allowance for off-balance sheet credit losses $ 16,747 $ 12,268 $ 17,434 $ 8,640 Impact of CECL adoption — — — 563 Provision for off-balance sheet credit losses 1,464 2,973 777 6,038 Ending balance of allowance for off-balance sheet credit losses $ 18,211 $ 15,241 $ 18,211 $ 15,241 (in thousands) September 30, 2021 December 31, 2020 Commitments to extend credit - period end balance $ 8,261,483 $ 8,530,453 Standby letters of credit - period end balance $ 340,896 $ 268,894

Regulatory Restrictions (Tables

Regulatory Restrictions (Tables)	9 Months Ended
	Sep. 30, 2021
Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]
Schedule of compliance with Regulatory Capital Requirements	The table below summarizes our actual and required capital ratios under the Basel III Capital Rules. The ratios presented below include the effects of our election to utilize the five-year CECL transition described above. Actual Minimum Capital Required(2) Capital Required to be Well Capitalized (dollars in thousands) Capital Amount Ratio Capital Amount Ratio Capital Amount Ratio September 30, 2021 CET1 Company $ 2,883,517 10.70 % $ 1,886,355 7.00 % N/A N/A Bank 2,950,866 10.97 % 1,882,136 7.00 % 1,747,697 6.50 % Total capital (to risk-weighted assets) Company 4,027,375 14.95 % 2,829,533 10.50 % 2,694,793 10.00 % Bank 3,523,923 13.11 % 2,823,203 10.50 % 2,688,765 10.00 % Tier 1 capital (to risk-weighted assets) Company 3,293,517 12.22 % 2,290,574 8.50 % 1,616,876 6.00 % Bank 3,110,866 11.57 % 2,285,450 8.50 % 2,151,012 8.00 % Tier 1 capital (to average assets)(1) Company 3,293,517 8.96 % 1,469,597 4.00 % N/A N/A Bank 3,110,866 8.47 % 1,468,949 4.00 % 1,836,186 5.00 % December 31, 2020 CET1 Company $ 2,708,150 9.35 % $ 2,026,806 7.00 % N/A N/A Bank 2,744,211 9.48 % 2,025,417 7.00 % 1,880,745 6.50 % Total capital (to risk-weighted assets) Company 3,498,737 12.08 % 3,040,209 10.50 % 2,895,437 10.00 % Bank 3,375,983 11.67 % 3,038,126 10.50 % 2,893,453 10.00 % Tier 1 capital (to risk-weighted assets) Company 2,968,150 10.25 % 2,461,121 8.50 % 1,737,262 6.00 % Bank 2,904,211 10.04 % 2,459,435 8.50 % 2,314,763 8.00 % Tier 1 capital (to average assets)(1) Company 2,968,150 7.52 % 1,578,651 4.00 % N/A N/A Bank 2,904,211 7.36 % 1,578,207 4.00 % 1,972,758 5.00 % (1) The Tier 1 capital ratio (to average assets) is not impacted by the Basel III Capital Rules; however, 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. (2) Percentages represent the minimum capital ratios plus, as applicable, the fully phased-in 2.5% CET1 capital buffer under the Basel III Capital Rules.

Stock-based Compensation (Table

Stock-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Compensation Related Costs [Abstract]
Schedule of stock-based compensation costs	The table below summarizes our stock-based compensation expense: Three months ended September 30, Nine months ended September 30, (in thousands) 2021 2020 2021 2020 Stock-settled awards: RSUs $ 8,324 $ 4,794 $ 22,099 $ 11,326 Restricted stock — 5 1 22 Cash-settled units 64 236 1,092 716 Total $ 8,388 $ 5,035 $ 23,192 $ 12,064
Schedule of unrecognized compensation costs	(in thousands except period data) September 30, 2021 Unrecognized compensation expense related to unvested stock-settled awards $ 39,463 Weighted average period over which expense is expected to be recognized, in years 2.5

Fair Value Disclosures (Tables)

Fair Value Disclosures (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of assets and liabilities measured at fair value	Assets and liabilities measured at fair value are as follows: Fair Value Measurements Using (in thousands) Level 1 Level 2 Level 3 September 30, 2021 Available-for-sale debt securities:(1) U.S. government agency securities $ — $ 121,920 $ — Residential mortgage-backed securities — 3,304,722 — Tax-exempt asset-backed securities — — 184,820 CRT securities — — 11,804 Equity securities(1)(2) 33,511 7,097 — Loans held for sale(3) — 658 7,701 Derivative assets(5) — 56,940 — Derivative liabilities(5) — 56,940 — Non-qualified deferred compensation plan liabilities(6) 28,186 — — December 31, 2020 Available-for-sale debt securities:(1) U.S. government agency securities $ — $ 123,589 $ — Residential mortgage-backed securities — 2,828,956 — Tax-exempt asset-backed securities — — 199,176 CRT securities — — 11,417 Equity securities(1)(2) 26,593 7,239 — Loans held for sale(3) — 232,147 6,933 Loans held for investment(4) — — 21,209 Derivative assets(5) — 102,720 — Derivative liabilities(5) — 99,255 — Non-qualified deferred compensation plan liabilities(6) 26,593 — — (1) Securities are measured at fair value on a recurring basis, generally monthly, except for tax-exempt asset-backed securities and CRT securities which are measured quarterly. (2) Equity securities consist of investments that qualify for consideration under the regulations implementing the Community Reinvestment Act and investments related to our non-qualified deferred compensation plan. (3) Loans held for sale purchased through the MCA program are measured at fair value on a recurring basis, generally monthly. (4) Includes certain collateral-dependent loans held for investment for which a specific allocation of the allowance for credit losses is based upon the fair value of the loan’s underlying collateral. These loans held for investment are measured on a nonrecurring basis, generally annually or more often as warranted by market and economic conditions. (5) Derivative assets and liabilities are measured at fair value on a recurring basis, generally quarterly. (6) Non-qualified deferred compensation plan liabilities represent the fair value of the obligation to the employee, which generally corresponds to the fair value of the invested assets, and are measured at fair value on a recurring basis, generally monthly.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	The following table presents a reconciliation of the Level 3 fair value category measured at fair value on a recurring basis: Net Realized/Unrealized Gains (Losses) (in thousands) Balance at Beginning of Period Purchases / Additions Sales / Reductions Realized Unrealized Balance at End of Period Three months ended September 30, 2021 Available-for-sale debt securities:(1) Tax-exempt asset-backed securities $ 185,954 $ — $ (2,270) $ — $ 1,136 $ 184,820 CRT securities 11,713 — — — 91 11,804 Loans held for sale(2) 8,227 440 (870) — (96) 7,701 Three months ended September 30, 2020 Available-for-sale debt securities:(1) Tax-exempt asset-backed securities $ 191,417 $ — $ (2,248) $ — $ 11,652 $ 200,821 CRT securities 10,953 — — — 105 11,058 Loans held for sale(2) 6,159 785 (170) 132 68 6,974 Nine months ended September 30, 2021 Available-for-sale debt securities:(1) Tax-exempt asset-backed securities $ 199,176 $ — $ (13,783) $ — $ (573) $ 184,820 CRT securities 11,417 — — — 387 11,804 Loans held for sale(2) 6,933 2,125 (1,395) 5 33 7,701 Nine months ended September 30, 2020 Available-for-sale debt securities:(1) Tax-exempt asset-backed securities $ 197,027 $ 8,470 $ (6,733) $ — $ 2,057 $ 200,821 CRT securities 11,964 — — — (906) 11,058 Loans held for sale(2) 7,043 1,105 (1,634) 248 212 6,974 (1) Unrealized gains/(losses) on available-for-sale debt securities are recorded in AOCI and relate to assets that remain outstanding at period end. Realized gains/(losses) are recorded in other non-interest income. (2) Realized and unrealized gains/(losses) on loans held for sale are recorded in gain/(loss) on sale of loans held for sale.
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: September 30, 2021 December 31, 2020 (in thousands) Carrying Estimated Carrying Estimated Financial assets: Level 1 inputs: Cash and cash equivalents $ 8,535,051 $ 8,535,051 $ 9,206,380 $ 9,206,380 Investment securities 33,511 33,511 26,593 26,593 Level 2 inputs: Investment securities 3,433,739 3,433,739 2,959,784 2,959,784 Loans held for sale 658 658 232,147 232,147 Derivative assets 56,940 56,940 102,720 102,720 Level 3 inputs: Investment securities 196,624 196,624 210,593 210,593 Loans held for sale 7,701 7,701 6,933 6,933 Loans held for investment, net 23,527,760 23,575,556 24,176,245 24,233,185 Financial liabilities: Level 2 inputs: Federal funds purchased and repurchase agreements 3,470 3,470 111,751 111,751 Other borrowings 2,200,000 2,200,000 3,000,000 3,000,000 Long-term debt 928,062 953,859 395,896 405,110 Derivative liabilities 56,940 56,940 99,255 99,255 Level 3 inputs: Deposits 29,813,668 29,814,204 30,996,589 30,997,980

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	The notional amounts and estimated fair values of derivative positions outstanding are presented in the following table. All derivative positions related to residential MSRs and loans held for sale were closed as of September 30, 2021 as a result of the sale of our MSR portfolio and transition of the MCA program to a third-party. September 30, 2021 December 31, 2020 Estimated Fair Value Estimated Fair Value (in thousands) Notional Asset Derivative Liability Derivative Notional Asset Derivative Liability Derivative Non-hedging derivatives: Financial institution counterparties: Commercial loan/lease interest rate swaps $ 1,857,977 $ 1,320 $ 56,884 $ 1,922,956 $ 71 $ 96,246 Commercial loan/lease interest rate caps 204,655 56 — 565,634 34 — Foreign currency forward contracts — — — 6,667 214 78 Customer counterparties: Commercial loan/lease interest rate swaps 1,857,977 56,884 1,320 1,922,956 96,246 71 Commercial loan/lease interest rate caps 204,655 — 56 565,634 — 34 Foreign currency forward contracts — — — 6,667 78 214 Economic hedging derivatives to hedge: Residential MSRs: Interest rate swap futures — — — 320,000 474 — Forward sale commitments — — — 155,000 551 — Loans held for sale: Loan purchase commitments — — — 332,145 5,123 8 Forward sale commitments — — — 485,326 — 2,675 Gross derivatives 58,260 58,260 102,791 99,326 Offsetting derivative assets/liabilities (1,320) (1,320) (71) (71) Net derivatives included in the consolidated balance sheets $ 56,940 $ 56,940 $ 102,720 $ 99,255
Schedule Of Weighted Average Interest Rate Received And Paid	The weighted-average received and paid interest rates for interest rate swaps outstanding were as follows: September 30, 2021 December 31, 2020 Weighted-Average Interest Rate Received Paid Received Paid Non-hedging interest rate swaps 2.74 % 1.15 % 3.14 % 1.38 %

Investment Securities (Details)

Investment Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	$ 3,674,800	$ 3,143,171
Gross Unrealized Gains	13,994	25,803
Gross Unrealized Losses	(65,528)	(5,836)
Estimated fair value	3,623,266	3,163,138
Interest receivable	50,300	56,500
Available-for-sale Securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Interest receivable	6,700	6,000
U.S. government agency securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	125,000	125,000
Gross Unrealized Gains	0	1
Gross Unrealized Losses	(3,080)	(1,412)
Estimated fair value	121,920	123,589
Residential mortgage-backed securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	3,363,930	2,818,518
Gross Unrealized Gains	331	11,566
Gross Unrealized Losses	(59,539)	(1,128)
Estimated fair value	3,304,722	2,828,956
Tax-exempt asset-backed securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	171,157	184,940
Gross Unrealized Gains	13,663	14,236
Gross Unrealized Losses	0	0
Estimated fair value	184,820	199,176
Credit risk transfer (“CRT”) securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	14,713	14,713
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(2,909)	(3,296)
Estimated fair value	$ 11,804	$ 11,417

Investment Securities (Details

Investment Securities (Details 1) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)security	Dec. 31, 2020USD ($)
Amortized cost
Total amortized cost	$ 3,674,800	$ 3,143,171
Estimated fair value
Total estimated fair value	$ 3,623,266	3,163,138
Weighted average yield
Federal tax rate (percent)	21.00%
Less Than 12 Months, Fair Value	$ 3,303,774	452,975
Less Than 12 Months, Unrealized Loss	(60,191)	(2,540)
12 Months or Longer, Fair Value	109,473	11,417
12 Months or Longer, Unrealized Loss	(5,337)	(3,296)
Total, Fair Value	3,413,247	464,392
Total, Unrealized Loss	$ (65,528)	(5,836)
Available-for-sale Securities, Other Disclosure Items
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	118
Debt Securities, Available-for-sale, Amortized Cost	$ 3,674,800	3,143,171
U.S. government agency securities
Amortized cost
Less Than One Year	0	0
After One Through Five Years	0	0
After Five Through Ten Years	125,000	125,000
After Ten Years	0	0
Total amortized cost	125,000	125,000
Estimated fair value
Less Than One Year	0	0
After One Through Five Years	0	0
After Five Through Ten Years	121,920	123,589
After Ten Years	0	0
Total estimated fair value	$ 121,920	$ 123,589
Weighted average yield
Less Than One Year	0.00%	0.00%
After One Through Five Years	0.00%	0.00%
After Five Through Ten Years	1.13%	1.13%
After Ten Years	0.00%	0.00%
Weighted average yield	1.13%	1.13%
Less Than 12 Months, Fair Value	$ 24,348	$ 98,588
Less Than 12 Months, Unrealized Loss	(652)	(1,412)
12 Months or Longer, Fair Value	97,572	0
12 Months or Longer, Unrealized Loss	(2,428)	0
Total, Fair Value	121,920	98,588
Total, Unrealized Loss	$ (3,080)	(1,412)
Available-for-sale Securities, Other Disclosure Items
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	5
Debt Securities, Available-for-sale, Amortized Cost	$ 125,000	125,000
Residential mortgage-backed securities
Amortized cost
Less Than One Year	24	0
After One Through Five Years	252	545
After Five Through Ten Years	17,339	17,500
After Ten Years	3,346,315	2,800,473
Total amortized cost	3,363,930	2,818,518
Estimated fair value
Less Than One Year	26	0
After One Through Five Years	280	605
After Five Through Ten Years	16,652	17,490
After Ten Years	3,287,764	2,810,861
Total estimated fair value	$ 3,304,722	$ 2,828,956
Weighted average yield
Less Than One Year	3.99%	0.00%
After One Through Five Years	4.66%	4.58%
After Five Through Ten Years	1.08%	1.08%
After Ten Years	1.13%	1.25%
Weighted average yield	1.13%	1.25%
Less Than 12 Months, Fair Value	$ 3,279,426	$ 354,387
Less Than 12 Months, Unrealized Loss	(59,539)	(1,128)
12 Months or Longer, Fair Value	97	0
12 Months or Longer, Unrealized Loss	0	0
Total, Fair Value	3,279,523	354,387
Total, Unrealized Loss	$ (59,539)	(1,128)
Available-for-sale Securities, Other Disclosure Items
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	111
Debt Securities, Available-for-sale, Amortized Cost	$ 3,363,930	2,818,518
Tax-exempt asset-backed securities
Amortized cost
Less Than One Year	0	0
After One Through Five Years	0	0
After Five Through Ten Years	0	0
After Ten Years	171,157	184,940
Total amortized cost	171,157	184,940
Estimated fair value
Less Than One Year	0	0
After One Through Five Years	0	0
After Five Through Ten Years	0	0
After Ten Years	184,820	199,176
Total estimated fair value	$ 184,820	$ 199,176
Weighted average yield
Less Than One Year	0.00%	0.00%
After One Through Five Years	0.00%	0.00%
After Five Through Ten Years	0.00%	0.00%
After Ten Years	4.96%	4.92%
Weighted average yield	4.96%	4.92%
Available-for-sale Securities, Other Disclosure Items
Debt Securities, Available-for-sale, Amortized Cost	$ 171,157	$ 184,940
Credit risk transfer (“CRT”) securities
Amortized cost
Less Than One Year	0	0
After One Through Five Years	0	0
After Five Through Ten Years	14,713	0
After Ten Years	0	14,713
Total amortized cost	14,713	14,713
Estimated fair value
Less Than One Year	0	0
After One Through Five Years	0	0
After Five Through Ten Years	11,804	0
After Ten Years	0	11,417
Total estimated fair value	$ 11,804	$ 11,417
Weighted average yield
Less Than One Year	0.00%	0.00%
After One Through Five Years	0.00%	0.00%
After Five Through Ten Years	0.08%	0.00%
After Ten Years	0.00%	0.15%
Weighted average yield	0.08%	0.15%
Less Than 12 Months, Fair Value	$ 0	$ 0
Less Than 12 Months, Unrealized Loss	0	0
12 Months or Longer, Fair Value	11,804	11,417
12 Months or Longer, Unrealized Loss	(2,909)	(3,296)
Total, Fair Value	11,804	11,417
Total, Unrealized Loss	$ (2,909)	(3,296)
Available-for-sale Securities, Other Disclosure Items
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | security	2
Debt Securities, Available-for-sale, Amortized Cost	$ 14,713	14,713
Customer repurchase agreements
Available-for-sale Securities, Other Disclosure Items
Available-for-sale debt securities pledged to secure certain customer repurchase agreements and deposits	24,000	31,700
Deposits
Available-for-sale Securities, Other Disclosure Items
Available-for-sale debt securities pledged to secure certain customer repurchase agreements and deposits	$ 1,300	$ 1,900

Investment Securities (Detail_2

Investment Securities (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Debt Securities, Available-for-sale [Abstract]
Equity securities, fair value	$ 40,600		$ 40,600		$ 33,800
Net gains/(losses) recognized during the period	850	$ 1,350	4,496	$ 1,285
Less: Realized net gains/(losses) recognized during the period on equity securities sold	(347)	(177)	(1,096)	68
Unrealized net gains/(losses) recognized during the period on equity securities still held	$ 503	$ 1,173	$ 3,400	$ 1,353

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net income	$ 43,390	$ 57,116	$ 188,809	$ 6,113
Preferred stock dividends	4,312	2,438	14,408	7,313
Net income/(loss) available to common stockholders	$ 39,078	$ 54,678	$ 174,401	$ (1,200)
Denominator:
Basic earnings per share - weighted average shares	50,600,732	50,446,691	50,568,439	50,417,563
Effect of employee stock-based awards	538,823	126,382	555,836	103,984
Denominator for dilutive earnings per share—adjusted weighted average shares and assumed conversions	51,139,555	50,573,073	51,124,275	50,521,547
Basic earnings/(loss) per common share	$ 0.77	$ 1.08	$ 3.45	$ (0.02)
Diluted earnings/(loss) per common share	$ 0.76	$ 1.08	$ 3.41	$ (0.02)
Stock options excluded from computation of EPS			208,813	480,062

Loans Held for Investment and_3

Loans Held for Investment and Allowance for Loan Losses - Loans By Portfolio Segment (Details) - USD ($)	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans held for investment	$ 23,815,839,000	$ 24,501,830,000
Unearned income (net of direct origination costs)	(66,122,000)	(70,970,000)
Allowance for credit losses on loans	(221,957,000)	(254,615,000)	$ (290,165,000)	$ (195,047,000)
Loans held for investment, net	23,527,760,000	24,176,245,000
Participations sold	677,600,000	1,200,000,000
Interest receivable	50,300,000	56,500,000
Commercial
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans held for investment	9,377,274,000	8,861,580,000
Allowance for credit losses on loans	(93,861,000)	(73,061,000)	(99,284,000)	(102,254,000)
Energy
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans held for investment	697,888,000	766,217,000
Allowance for credit losses on loans	(54,282,000)	(84,064,000)	(112,941,000)	(60,253,000)
Mortgage finance
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans held for investment	8,528,313,000	9,079,409,000
Allowance for credit losses on loans	(6,428,000)	(4,699,000)	(4,726,000)	(2,265,000)
Real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans held for investment	5,212,364,000	5,794,624,000
Allowance for credit losses on loans	$ (67,386,000)	$ (92,791,000)	$ (73,214,000)	$ (30,275,000)

Loans Held for Investment and_4

Loans Held for Investment and Allowance for Loan Losses - Loans by Credit Quality Grade (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 1,876,166	$ 2,804,231
2019	4,929,560	5,216,591
2018	2,367,747	2,643,706
2017	1,829,705	1,690,775
2016	1,054,703	747,648
2016 and prior	6,768,334	6,831,441
Revolving lines of credit	4,853,338	4,369,332
Revolving lines of credit converted to term loans	136,286	198,106
Total	23,815,839	24,501,830
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	921,314	1,280,206
2019	3,242,545	2,955,654
2018	681,944	600,634
2017	370,493	434,411
2016	203,228	210,142
2016 and prior	324,946	248,298
Revolving lines of credit	3,568,372	3,067,092
Revolving lines of credit converted to term loans	64,432	65,143
Total	9,377,274	8,861,580
Commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	919,405	1,259,949
2019	3,228,097	2,816,425
2018	572,505	543,438
2017	321,356	374,455
2016	194,921	192,060
2016 and prior	284,804	213,212
Revolving lines of credit	3,535,016	3,020,353
Revolving lines of credit converted to term loans	50,565	40,253
Total	9,106,669	8,460,145
Commercial | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	691	2,664
2019	8,061	115,015
2018	46,942	38,751
2017	9,233	26,423
2016	0	1,983
2016 and prior	13,561	290
Revolving lines of credit	9,579	19,971
Revolving lines of credit converted to term loans	6,495	22,797
Total	94,562	227,894
Commercial | Substandard-accruing
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	15,773
2019	4,763	15,854
2018	60,192	18,068
2017	39,177	32,241
2016	6,202	15,297
2016 and prior	16,137	19,639
Revolving lines of credit	15,592	22,932
Revolving lines of credit converted to term loans	6,906	1,641
Total	148,969	141,445
Commercial | Non-accrual
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,218	1,820
2019	1,624	8,360
2018	2,305	377
2017	727	1,292
2016	2,105	802
2016 and prior	10,444	15,157
Revolving lines of credit	8,185	3,836
Revolving lines of credit converted to term loans	466	452
Total	27,074	32,096
Energy
Financing Receivable, Credit Quality Indicator [Line Items]
2020	22,309	0
2019	0	12,020
2018	0	7,598
2017	2,516	32,636
2016	0	1,972
2016 and prior	49,569	45,117
Revolving lines of credit	623,494	666,874
Revolving lines of credit converted to term loans	0	0
Total	697,888	766,217
Energy | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	22,309	0
2019	0	12,020
2018	0	7,598
2017	2,516	26,931
2016	0	0
2016 and prior	28,854	23,750
Revolving lines of credit	566,387	553,970
Revolving lines of credit converted to term loans	0	0
Total	620,066	624,269
Energy | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
2016 and prior	0	13,358
Revolving lines of credit	37,782	76,866
Revolving lines of credit converted to term loans	0	0
Total	37,782	90,224
Energy | Substandard-accruing
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
2016 and prior	0	0
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	0	0
Energy | Non-accrual
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	5,705
2016	0	1,972
2016 and prior	20,715	8,009
Revolving lines of credit	19,325	36,038
Revolving lines of credit converted to term loans	0	0
Total	40,040	51,724
Mortgage finance
Financing Receivable, Credit Quality Indicator [Line Items]
2020	295,565	755,309
2019	834,008	1,063,641
2018	744,105	821,122
2017	696,945	483,436
2016	409,308	106,013
2016 and prior	5,548,382	5,849,888
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	8,528,313	9,079,409
Mortgage finance | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	295,565	755,309
2019	834,008	1,063,641
2018	744,105	821,122
2017	696,945	483,436
2016	409,308	106,013
2016 and prior	5,548,382	5,849,888
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	8,528,313	9,079,409
Mortgage finance | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
2016 and prior	0	0
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	0	0
Mortgage finance | Substandard-accruing
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
2016 and prior	0	0
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	0	0
Mortgage finance | Non-accrual
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
2016 and prior	0	0
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	0	0
Real estate
Financing Receivable, Credit Quality Indicator [Line Items]
2020	636,978	768,716
2019	853,007	1,185,276
2018	941,698	1,214,352
2017	759,751	740,292
2016	442,167	429,521
2016 and prior	845,437	688,138
Revolving lines of credit	661,472	635,366
Revolving lines of credit converted to term loans	71,854	132,963
Total	5,212,364	5,794,624
Real estate | Commercial Real Estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	292,248	352,688
2019	545,204	892,831
2018	703,910	923,762
2017	566,771	444,587
2016	187,565	208,426
2016 and prior	482,033	451,283
Revolving lines of credit	45,008	62,336
Revolving lines of credit converted to term loans	25,361	61,133
Total	2,848,100	3,397,046
Real estate | Commercial Real Estate | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	3,475
2019	0	11,170
2018	30,497	6,485
2017	8,881	88,633
2016	48,049	11,153
2016 and prior	17,022	17,623
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	1,247
Total	104,449	139,786
Real estate | Commercial Real Estate | Substandard-accruing
Financing Receivable, Credit Quality Indicator [Line Items]
2020	17,850	0
2019	0	327
2018	0	47,708
2017	41,209	11,601
2016	61,051	32,645
2016 and prior	62,978	30,766
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	2,354	15,940
Total	185,442	138,987
Real estate | Commercial Real Estate | Non-accrual
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	5,749
2016 and prior	202	4,852
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	202	10,601
Real estate | Residential Homebuilder Finance | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	166,828	162,397
2019	70,338	60,077
2018	15,180	65,271
2017	9,392	3,727
2016	66	5,888
2016 and prior	14,483	8,483
Revolving lines of credit	566,799	551,703
Revolving lines of credit converted to term loans	0	0
Total	843,086	857,546
Real estate | Residential Homebuilder Finance | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	353
2018	0	0
2017	0	0
2016	0	0
2016 and prior	0	0
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	0	353
Real estate | Residential Homebuilder Finance | Substandard-accruing
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
2016 and prior	0	0
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	0	0
Real estate | Residential Homebuilder Finance | Non-accrual
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
2016 and prior	0	0
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	0	0
Real estate | Other Financing Receivable | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	88,370	190,995
2019	161,048	150,787
2018	136,836	119,696
2017	107,251	120,817
2016	83,282	82,465
2016 and prior	167,252	113,105
Revolving lines of credit	45,174	16,630
Revolving lines of credit converted to term loans	30,210	39,129
Total	819,423	833,624
Real estate | Other Financing Receivable | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	13,903	6,700
2018	1,990	2,240
2017	0	0
2016	0	1,843
2016 and prior	5,055	7,195
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	1,018
Total	20,948	18,996
Real estate | Other Financing Receivable | Substandard-accruing
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	0
2018	0	2,567
2017	1,637	14,452
2016	23,952	3,301
2016 and prior	21,125	14,453
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	46,714	34,773
Real estate | Other Financing Receivable | Non-accrual
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	927
2016	3,536	5,524
2016 and prior	2,566	6,403
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	13,929	14,496
Total	20,031	27,350
Real estate | Secured by 1-4 family | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	71,682	58,515
2019	62,514	63,031
2018	53,285	46,623
2017	24,610	54,096
2016	34,666	72,527
2016 and prior	69,988	31,880
Revolving lines of credit	4,491	4,697
Revolving lines of credit converted to term loans	0	0
Total	321,236	331,369
Real estate | Secured by 1-4 family | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	646
2019	0	0
2018	0	0
2017	0	635
2016	0	0
2016 and prior	294	1,768
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	294	3,049
Real estate | Secured by 1-4 family | Substandard-accruing
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	817
2016	0	0
2016 and prior	2,254	109
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	2,254	926
Real estate | Secured by 1-4 family | Non-accrual
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
2016 and prior	185	218
Revolving lines of credit	0	0
Revolving lines of credit converted to term loans	0	0
Total	$ 185	$ 218

Loans Held for Investment and_5

Loans Held for Investment and Allowance for Loan Losses - Allowance for Credit Losses (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 254,615	$ 195,047
Provision for credit losses on loans	(20,777)	219,962
Charge-offs	15,821	135,615
Recoveries	3,940	2,186
Net charge-offs (recoveries)	11,881	133,429
Ending balance	221,957	290,165
Cumulative Effect, Period Of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance		8,585
Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	73,061	102,254
Provision for credit losses on loans	26,549	47,263
Charge-offs	8,211	35,376
Recoveries	2,462	883
Net charge-offs (recoveries)	5,749	34,493
Ending balance	93,861	99,284
Commercial | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance		(15,740)
Energy
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	84,064	60,253
Provision for credit losses on loans	(24,730)	127,470
Charge-offs	6,418	100,239
Recoveries	1,366	1,303
Net charge-offs (recoveries)	5,052	98,936
Ending balance	54,282	112,941
Energy | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance		24,154
Mortgage finance
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	4,699	2,265
Provision for credit losses on loans	1,729	430
Charge-offs	0	0
Recoveries	0	0
Net charge-offs (recoveries)	0	0
Ending balance	6,428	4,726
Mortgage finance | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance		2,031
Real estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	92,791	30,275
Provision for credit losses on loans	(24,325)	44,799
Charge-offs	1,192	0
Recoveries	112	0
Net charge-offs (recoveries)	1,080	0
Ending balance	$ 67,386	73,214
Real estate | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance		$ (1,860)

Loans Held for Investment and_6

Loans Held for Investment and Allowance for Loan Losses - Impact of Adoption Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable Allowance For Credit Losses Off Balance Sheet Liability	$ 18,211	$ 15,241	$ 18,211	$ 15,241	$ 16,747	$ 17,434	$ 12,268		$ 8,640
Provision for credit losses	5,000	30,000	(20,000)	226,000
Net charge-offs			11,881	133,429
Financing Receivable, before Allowance for Credit Loss	23,815,839		23,815,839			24,501,830
Criticized
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, before Allowance for Credit Loss	728,900	$ 1,100,000	728,900	1,100,000
Leveraged Lending
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net charge-offs				133,400
Energy
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net charge-offs			5,052	98,936
Financing Receivable, before Allowance for Credit Loss	$ 697,888		697,888			$ 766,217
Cumulative Effect, Period Of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable Allowance For Credit Losses Off Balance Sheet Liability								$ 0	$ 563
Provision for credit losses			$ (20,000)	$ 226,000

Loans Held for Investment and_7

Loans Held for Investment and Allowance for Loan Losses - Age Analysis (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	$ 23,815,839,000
Non-accrual	87,532,000
Non-Accrual With No Allowance	22,877,000
Premium finance loans past due and still accruing	2,300,000
Nonaccrual, interest income	0	$ 0
Interest income reversed	674,000
30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	21,423,000
60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	18,313,000
Greater Than 90 Days
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	3,405,000
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	43,141,000
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	23,685,166,000
Commercial
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	9,377,274,000
Non-accrual	27,074,000
Non-Accrual With No Allowance	10,899,000
Commercial | 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	19,395,000
Commercial | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	18,313,000
Commercial | Greater Than 90 Days
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	2,256,000
Commercial | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	39,964,000
Commercial | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	9,310,236,000
Energy
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	697,888,000
Non-accrual	40,040,000
Non-Accrual With No Allowance	9,281,000
Energy | 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Energy | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Energy | Greater Than 90 Days
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Energy | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Energy | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	657,848,000
Mortgage finance
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	8,528,313,000
Non-accrual	0
Non-Accrual With No Allowance	0
Mortgage finance | 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Mortgage finance | 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Mortgage finance | Greater Than 90 Days
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Mortgage finance | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Mortgage finance | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	8,528,313,000
Real estate | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	3,138,193,000
Non-accrual	202,000
Non-Accrual With No Allowance	0
Real estate | Residential Homebuilder Finance
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	843,086,000
Non-accrual	0
Non-Accrual With No Allowance	0
Real estate | Other Financing Receivable
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	907,116,000
Non-accrual	20,031,000
Non-Accrual With No Allowance	2,697,000
Real estate | Secured by 1-4 family
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	323,969,000
Non-accrual	185,000
Non-Accrual With No Allowance	0
Real estate | 30 to 59 Days Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	250,000
Real estate | 30 to 59 Days Past Due | Residential Homebuilder Finance
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Real estate | 30 to 59 Days Past Due | Other Financing Receivable
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	1,225,000
Real estate | 30 to 59 Days Past Due | Secured by 1-4 family
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	553,000
Real estate | 60 to 89 Days Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Real estate | 60 to 89 Days Past Due | Residential Homebuilder Finance
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Real estate | 60 to 89 Days Past Due | Other Financing Receivable
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Real estate | 60 to 89 Days Past Due | Secured by 1-4 family
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Real estate | Greater Than 90 Days | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Real estate | Greater Than 90 Days | Residential Homebuilder Finance
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Real estate | Greater Than 90 Days | Other Financing Receivable
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Real estate | Greater Than 90 Days | Secured by 1-4 family
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	1,149,000
Real estate | Financial Asset, Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	250,000
Real estate | Financial Asset, Past Due | Residential Homebuilder Finance
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0
Real estate | Financial Asset, Past Due | Other Financing Receivable
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	1,225,000
Real estate | Financial Asset, Past Due | Secured by 1-4 family
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	1,702,000
Real estate | Financial Asset, Not Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	3,137,741,000
Real estate | Financial Asset, Not Past Due | Residential Homebuilder Finance
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	843,086,000
Real estate | Financial Asset, Not Past Due | Other Financing Receivable
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	885,860,000
Real estate | Financial Asset, Not Past Due | Secured by 1-4 family
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	$ 322,082,000

Loans Held for Investment and_8

Loans Held for Investment and Allowance for Loan Losses - Restructured Loans (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)loan	Dec. 31, 2020USD ($)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccrual loans that met the criteria for restructured	$ 23,700	$ 45,400
Number of contracts | loan	8
Loans modified as restructured loans	$ 41,737
Extended maturity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | loan	3
Loans modified as restructured loans	$ 13,605
Adjusted interest rates
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | loan	5
Loans modified as restructured loans	$ 28,132
Commercial Loan | Business Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | loan	4
Loans modified as restructured loans	$ 22,299
Commercial Loan | Energy
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | loan	4
Loans modified as restructured loans	$ 19,438
Commercial Loan | Extended maturity | Business Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | loan	2
Loans modified as restructured loans	$ 7,636
Commercial Loan | Extended maturity | Energy
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | loan	1
Loans modified as restructured loans	$ 5,969
Commercial Loan | Adjusted interest rates | Business Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | loan	2
Loans modified as restructured loans	$ 14,663
Commercial Loan | Adjusted interest rates | Energy
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | loan	3
Loans modified as restructured loans	$ 13,469

Certain Transfers of Financia_3

Certain Transfers of Financial Assets Certain Transfers of Financial Assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Outstanding balance:
Beginning balance	$ 281,137	$ 2,568,362
Loans purchased and originated	1,413,899	8,963,499
Payments and loans sold	(1,685,212)	(10,889,549)
Ending balance	9,824	642,312
Fair value adjustment:
Fair value over (under) outstanding balance	2,028	8,772
Increase/(decrease) to fair value	(2,192)	(3,075)
Fair value over (under) outstanding balance	(164)	5,697
Loans held for sale	9,660	648,009	$ 283,165
Small Business Administration Loans [Member]
Fair value adjustment:
Fair value over (under) outstanding balance	44,100	5,800
Fair value over (under) outstanding balance	$ 1,300	$ 9,000

Certain Transfers of Financia_4

Certain Transfers of Financial Assets (Details 1) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Loans and Leases Receivable Disclosure [Line Items]
Loans held for sale	$ 9,824,000	$ 642,312,000	$ 281,137,000	$ 2,568,362,000
Principal amount outstanding of loans in servicing portfolio	143,400,000		13,800,000,000
Escrow deposits related to servicing portfolio			152,600,000
Loss Contingency Accrual	619,000		621,000
Losses due to repurchase indemnification and make-whole obligations	76,000	$ 7,800,000
Greater Than 90 Days
Loans and Leases Receivable Disclosure [Line Items]
Loans held for sale	3,800,000		16,700,000
Government guarantees | Greater Than 90 Days
Loans and Leases Receivable Disclosure [Line Items]
Loans held for sale			3,300,000
Government guarantees | Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Greater Than 90 Days
Loans and Leases Receivable Disclosure [Line Items]
Total Past Due			13,400,000
Non-accrual
Loans and Leases Receivable Disclosure [Line Items]
Loans held for sale	$ 0		$ 7,000,000

Certain Transfers of Financia_5

Certain Transfers of Financial Assets (Details 2) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Sales	$ (127,281)	$ 0
Mortgage Servicing Rights
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Balance, beginning of year	131,391	70,707
Capitalized servicing rights	15,990	76,905
Amortization	(18,663)	(25,553)
Direct write-down	(279)	0
Balance, end of period	1,158	122,059
Valuation Allowance for Impairment of Recognized Servicing Assets, Sales and Disposals [Abstract]
Valuation allowance, beginning balance	25,967	5,803
Change in valuation allowance	(25,967)	20,933
Valuation allowance, ending balance	0	26,736
MSRs, net	1,158	95,323
Fair value	$ 1,158	$ 95,323

Certain Transfers of Financia_6

Certain Transfers of Financial Assets (Details 3) - Mortgage Servicing Rights	12 Months Ended
	Dec. 31, 2020
Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Line Items]
Average discount rates (percent)	9.09%
Expected prepayment speeds (percent)	16.37%
Weighted-average life, in years	4 years 10 months 24 days

Certain Transfers of Financia_7

Certain Transfers of Financial Assets Certain Transfers of Financial Assets (Details 4) $ in Thousands	Dec. 31, 2020USD ($)
Transfers and Servicing [Abstract]
50 bp adverse change in prepayment speed	$ (12,203)
100 bp adverse change in prepayment speed	$ (16,062)

Long-Term Debt (Details)

Long-Term Debt (Details) - USD ($)	May 06, 2021	Mar. 09, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Jan. 31, 2014	Sep. 21, 2012
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Subordinated Debt	$ 375,000,000						$ 175,000,000	$ 111,000,000
Stated interest rate	4.00%						5.25%	6.50%
Reference pool of mortgage warehouse loans			$ 2,200,000,000		$ 2,200,000,000
Limit for loss risk transferred			$ 275,000,000		$ 275,000,000
Proceeds from issuance of subordinated long-term debt	$ 370,700,000
Senior Unsecured Credit-Linked Notes
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Combined weighted-average interest rate (in percent)			5.54%		5.58%
Face amount		$ 275,000,000
LIBOR | Minimum | Senior Unsecured Credit-Linked Notes
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Interest rate on subordinated debentures, spread on variable rate		4.50%
LIBOR | Maximum | Senior Unsecured Credit-Linked Notes
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Interest rate on subordinated debentures, spread on variable rate		4.25%
Texas Capital Bancshares Statutory Trust I
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Subordinated Debt			$ 10,310,000		$ 10,310,000
Texas Capital Statutory Trust II
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Subordinated Debt			10,310,000		10,310,000
Texas Capital Statutory Trust III
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Subordinated Debt			25,774,000		25,774,000
Texas Capital Statutory Trust IV
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Subordinated Debt			25,774,000		25,774,000
Texas Capital Statutory Trust V
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Subordinated Debt			$ 41,238,000		$ 41,238,000
Trust preferred subordinated debentures
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Combined weighted-average interest rate (in percent)			2.09%	2.28%	2.14%	3.03%
Trust preferred subordinated debentures | Texas Capital Bancshares Statutory Trust I | LIBOR
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Interest rate on subordinated debentures, spread on variable rate					3.35%
Trust preferred subordinated debentures | Texas Capital Statutory Trust II | LIBOR
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Interest rate on subordinated debentures, spread on variable rate					3.25%
Trust preferred subordinated debentures | Texas Capital Statutory Trust III | LIBOR
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Interest rate on subordinated debentures, spread on variable rate					1.51%
Trust preferred subordinated debentures | Texas Capital Statutory Trust IV | LIBOR
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Interest rate on subordinated debentures, spread on variable rate					1.71%
Trust preferred subordinated debentures | Texas Capital Statutory Trust V | LIBOR
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Interest rate on subordinated debentures, spread on variable rate					1.60%

Long-Term Debt (Details 1)

Long-Term Debt (Details 1) - USD ($)	Sep. 30, 2021	May 06, 2021	Jan. 31, 2014	Sep. 21, 2012
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Subordinated Debt		$ 375,000,000	$ 175,000,000	$ 111,000,000
Texas Capital Bancshares Statutory Trust I
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Subordinated Debt	$ 10,310,000
Texas Capital Statutory Trust II
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Subordinated Debt	10,310,000
Texas Capital Statutory Trust III
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Subordinated Debt	25,774,000
Texas Capital Statutory Trust IV
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Subordinated Debt	25,774,000
Texas Capital Statutory Trust V
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Subordinated Debt	$ 41,238,000

Financial Instruments with Of_3

Financial Instruments with Off-Balance Sheet Risk (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Beginning balance of allowance for off-balance sheet credit losses	$ 16,747	$ 12,268	$ 17,434	$ 8,640
Provision for off-balance sheet credit losses	1,464	2,973	777	6,038
Ending balance of allowance for off-balance sheet credit losses	18,211	$ 15,241	18,211	15,241
Commitments to extend credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet liability	8,261,483		8,261,483		$ 8,530,453
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet liability	$ 340,896		$ 340,896		$ 268,894
Cumulative Effect, Period Of Adoption, Adjustment
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Beginning balance of allowance for off-balance sheet credit losses				$ 563

Regulatory Restrictions (Detail

Regulatory Restrictions (Details) $ in Thousands	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)	Jan. 01, 2019	Dec. 31, 2009USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Assets	$ 36,404,320	$ 37,726,096		$ 15,000,000
Mortgage finance(1)	8,528,313	9,079,409
Common Equity Tier 1 [Abstract]
CET1, actual amount	2,883,517	2,708,150
Total capital (to risk-weighted assets):
Total capital (to risk weighted assets), actual amount	4,027,375	3,498,737
Total capital (to risk weighted assets) to be well capitalized under prompt corrective action provisions, amount	2,694,793	2,895,437
Tier 1 capital (to risk-weighted assets):
Tier 1 capital (to risk-weighted assets), actual amount	3,293,517	2,968,150
Tier 1 capital (to risk weighted assets) to be well capitalized under prompt corrective action provisions, amount	1,616,876	1,737,262
Tier 1 capital (to average assets):
Tier 1 capital (to average assets), actual amount	$ 3,293,517	$ 2,968,150
Banking Regulation, Risk-Based Information [Abstract]
CET1, actual ratio	10.70%	9.35%
Total capital (to risk weighted assets), actual ratio	0.1495	0.1208
Total capital (to risk weighted assets) to be well capitalized under prompt corrective action provisions, ratio	0.1000	0.1000
Tier 1 capital (to risk-weighted assets), actual ratio	0.1222	0.1025
Tier 1 capital (to risk weighted assets) to be well capitalized under prompt corrective action provisions, ratio	0.0600	0.0600
Tier 1 capital (to average assets), actual ratio	0.0896	0.0752
Bank
Common Equity Tier 1 [Abstract]
CET1, actual amount	$ 2,950,866	$ 2,744,211
CET1 to be well capitalized under prompt corrective action provisions, amount	1,747,697	1,880,745
Total capital (to risk-weighted assets):
Total capital (to risk weighted assets), actual amount	3,523,923	3,375,983
Total capital (to risk weighted assets) to be well capitalized under prompt corrective action provisions, amount	2,688,765	2,893,453
Tier 1 capital (to risk-weighted assets):
Tier 1 capital (to risk-weighted assets), actual amount	3,110,866	2,904,211
Tier 1 capital (to risk weighted assets) to be well capitalized under prompt corrective action provisions, amount	2,151,012	2,314,763
Tier 1 capital (to average assets):
Tier 1 capital (to average assets), actual amount	3,110,866	2,904,211
Tier 1 capital (to average assets) to be well capitalized under prompt corrective action provisions, amount	$ 1,836,186	$ 1,972,758
Banking Regulation, Risk-Based Information [Abstract]
CET1, actual ratio	10.97%	9.48%
CET1 to be well capitalized under prompt corrective action provisions, ratio	6.50%	6.50%
Total capital (to risk weighted assets), actual ratio	0.1311	0.1167
Total capital (to risk weighted assets) to be well capitalized under prompt corrective action provisions, ratio	0.1000	0.1000
Tier 1 capital (to risk-weighted assets), actual ratio	0.1157	0.1004
Tier 1 capital (to risk weighted assets) to be well capitalized under prompt corrective action provisions, ratio	0.0800	0.0800
Tier 1 capital (to average assets), actual ratio	0.0847	0.0736
Tier 1 capital (to average assets) to be well capitalized under prompt corrective action provisions, ratio	0.0500	0.0500
Basel III, Phased-In
Common Equity Tier 1 [Abstract]
CET1 for capital adequacy purposes, amount	$ 1,886,355	$ 2,026,806
Total capital (to risk-weighted assets):
Total capital (to risk weighted assets) for capital adequacy purposes, amount	2,829,533	3,040,209
Tier 1 capital (to risk-weighted assets):
Tier 1 capital (to risk-weighted assets) for capital adequacy purposes, amount	2,290,574	2,461,121
Tier 1 capital (to average assets):
Tier 1 capital (to average assets) for capital adequacy purposes, amount	$ 1,469,597	$ 1,578,651
Banking Regulation, Risk-Based Information [Abstract]
CET1 for capital adequacy purposes, ratio	7.00%	7.00%
Total capital (to risk weighted assets) for capital adequacy purposes, ratio	0.1050	0.1050
Tier 1 capital (to risk-weighted assets) for capital adequacy purposes, ratio	0.0850	0.0850
Tier 1 capital (to average assets) for capital adequacy purposes, ratio	0.0400	0.0400
Tier 1 capital (to average assets) to be well capitalized under prompt corrective action provisions, ratio			0.025
Basel III, Phased-In | Bank
Common Equity Tier 1 [Abstract]
CET1 for capital adequacy purposes, amount	$ 1,882,136	$ 2,025,417
Total capital (to risk-weighted assets):
Total capital (to risk weighted assets) for capital adequacy purposes, amount	2,823,203	3,038,126
Tier 1 capital (to risk-weighted assets):
Tier 1 capital (to risk-weighted assets) for capital adequacy purposes, amount	2,285,450	2,459,435
Tier 1 capital (to average assets):
Tier 1 capital (to average assets) for capital adequacy purposes, amount	$ 1,468,949	$ 1,578,207
Banking Regulation, Risk-Based Information [Abstract]
CET1 for capital adequacy purposes, ratio	7.00%	7.00%
Total capital (to risk weighted assets) for capital adequacy purposes, ratio	0.1050	0.1050
Tier 1 capital (to risk-weighted assets) for capital adequacy purposes, ratio	0.0850	0.0850
Tier 1 capital (to average assets) for capital adequacy purposes, ratio	0.0400	0.0400

Stock-based Compensation (Detai

Stock-based Compensation (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 8,388	$ 5,035	$ 23,192	$ 12,064
Unrecognized compensation expense related to unvested stock-settled awards	39,463		$ 39,463
Weighted average period over which unrecognized compensation expense is expected to be recognized (in years)			2 years 6 months
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	8,324	4,794	$ 22,099	11,326
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	0	5	1	22
Cash-settled performance units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 64	$ 236	$ 1,092	$ 716
Long-Term Incentive Plan 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized under the plan	2,550		2,550

Fair Value Disclosures (Details

Fair Value Disclosures (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	$ 3,623,266	$ 3,163,138
Equity securities, fair value	40,600	33,800
Loans held for sale	8,400	239,100
U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	121,920	123,589
Tax-exempt asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	184,820	199,176
Credit risk transfer (“CRT”) securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	11,804	11,417
Fair value measurements, recurring basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	0	0
Derivative assets	0	0
Derivative liabilities	0	0
Non-qualified deferred compensation plan liabilities	28,186	26,593
Fair value measurements, recurring basis | Level 1 | U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	0	0
Fair value measurements, recurring basis | Level 1 | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	0	0
Fair value measurements, recurring basis | Level 1 | Tax-exempt asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	0	0
Fair value measurements, recurring basis | Level 1 | Credit risk transfer (“CRT”) securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	0	0
Fair value measurements, recurring basis | Level 1 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, fair value	33,511	26,593
Fair value measurements, recurring basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	658	232,147
Derivative liabilities		99,255
Non-qualified deferred compensation plan liabilities	0	0
Fair value measurements, recurring basis | Level 2 | U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	121,920	123,589
Fair value measurements, recurring basis | Level 2 | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	3,304,722	2,828,956
Fair value measurements, recurring basis | Level 2 | Tax-exempt asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	0	0
Fair value measurements, recurring basis | Level 2 | Credit risk transfer (“CRT”) securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	0	0
Fair value measurements, recurring basis | Level 2 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, fair value	7,097	7,239
Fair value measurements, recurring basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	7,701	6,933
Derivative assets	0	0
Derivative liabilities	0	0
Non-qualified deferred compensation plan liabilities	0	0
Fair value measurements, recurring basis | Level 3 | U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	0	0
Fair value measurements, recurring basis | Level 3 | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	0	0
Fair value measurements, recurring basis | Level 3 | Tax-exempt asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	184,820	199,176
Fair value measurements, recurring basis | Level 3 | Credit risk transfer (“CRT”) securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities	11,804	11,417
Fair value measurements, recurring basis | Level 3 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, fair value	0	0
Fair value measurements, nonrecurring basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans		0
Fair value measurements, nonrecurring basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans		0
Fair value measurements, nonrecurring basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans		21,209
Not Designated as Hedging Instrument [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		102,720
Derivative liabilities		99,255
Not Designated as Hedging Instrument [Member] | Fair value measurements, recurring basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	56,940	$ 102,720
Derivative liabilities	$ 56,940

Fair Value Disclosures (Detai_2

Fair Value Disclosures (Details 1) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Tax-exempt asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period	$ 185,954	$ 191,417	$ 199,176	$ 197,027
Purchases / Additions	0	0	0	8,470
Sales / Reductions	(2,270)	(2,248)	(13,783)	(6,733)
Realized	0	0	0	0
Unrealized	1,136	11,652	(573)	2,057
Balance at End of Period	184,820	200,821	184,820	200,821
Credit risk transfer (“CRT”) securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period	11,713	10,953	11,417	11,964
Purchases / Additions	0	0	0	0
Sales / Reductions	0	0	0	0
Realized	0	0	0	0
Unrealized	91	105	387	(906)
Balance at End of Period	11,804	11,058	11,804	11,058
Loans Held For Sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at Beginning of Period	8,227	6,159	6,933	7,043
Purchases / Additions	440	785	2,125	1,105
Sales / Reductions	(870)	(170)	(1,395)	(1,634)
Realized	0	132	5	248
Unrealized	(96)	68	33	212
Balance at End of Period	$ 7,701	$ 6,974	$ 7,701	$ 6,974

Fair Value Disclosures (Detai_3

Fair Value Disclosures (Details 2)	9 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Impaired loans
Fair Value Assets Measured On Non Recurring Basis Unobservable Input Reconciliation [Line Items]
Asset measured on nonrecurring basis, reported fair value		$ 0	$ 21,200,000
Asset measured on nonrecurring basis, carrying value			$ 25,300,000
Asset measured on nonrecurring basis, specific valuation allowance	$ 4,100,000
Measurement Input, Discount Rate
Fair Value Assets Measured On Non Recurring Basis Unobservable Input Reconciliation [Line Items]
Loans Held-for-sale, measurement input		0.979	0.972
Minimum | Tax-exempt asset-backed securities
Fair Value Assets Measured On Non Recurring Basis Unobservable Input Reconciliation [Line Items]
AFS, term		4 years 9 months 18 days
Minimum | Credit risk transfer (“CRT”) securities
Fair Value Assets Measured On Non Recurring Basis Unobservable Input Reconciliation [Line Items]
AFS, term		5 years
Minimum | Measurement Input, Discount Rate | Tax-exempt asset-backed securities
Fair Value Assets Measured On Non Recurring Basis Unobservable Input Reconciliation [Line Items]
AFS, measurement input		0.0225
Minimum | Measurement Input, Discount Rate | Credit risk transfer (“CRT”) securities
Fair Value Assets Measured On Non Recurring Basis Unobservable Input Reconciliation [Line Items]
AFS, measurement input		0.0312
Maximum | Tax-exempt asset-backed securities
Fair Value Assets Measured On Non Recurring Basis Unobservable Input Reconciliation [Line Items]
AFS, term		4 years 10 months 24 days
Maximum | Credit risk transfer (“CRT”) securities
Fair Value Assets Measured On Non Recurring Basis Unobservable Input Reconciliation [Line Items]
AFS, term		9 years 9 months 18 days
Maximum | Measurement Input, Discount Rate | Tax-exempt asset-backed securities
Fair Value Assets Measured On Non Recurring Basis Unobservable Input Reconciliation [Line Items]
AFS, measurement input		0.0237
Maximum | Measurement Input, Discount Rate | Credit risk transfer (“CRT”) securities
Fair Value Assets Measured On Non Recurring Basis Unobservable Input Reconciliation [Line Items]
AFS, measurement input		0.0799
Weighted Average | Measurement Input, Discount Rate | Tax-exempt asset-backed securities
Fair Value Assets Measured On Non Recurring Basis Unobservable Input Reconciliation [Line Items]
AFS, measurement input		0.0230	0.0249
AFS, term		4 years 9 months 18 days	5 years 6 months
Weighted Average | Measurement Input, Discount Rate | Credit risk transfer (“CRT”) securities
Fair Value Assets Measured On Non Recurring Basis Unobservable Input Reconciliation [Line Items]
AFS, measurement input		0.0474	0.0436
AFS, term		6 years 7 months 6 days	7 years 6 months

Fair Value Disclosures (Detai_4

Fair Value Disclosures (Details 3) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	$ 3,623,266	$ 3,163,138
Loans held for sale	8,400	239,100
Federal funds purchased and repurchase agreements	3,470	111,751
Long-term Debt	928,062	395,896
Level 1 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	33,511	26,593
Level 1 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	8,535,051	9,206,380
Investment securities	33,511	26,593
Level 2 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	3,433,739	2,959,784
Loans held for sale	658	232,147
Derivative assets		102,720
Federal funds purchased and repurchase agreements	3,470	111,751
Other borrowings	2,200,000	3,000,000
Long-term Debt	928,062	395,896
Derivative liabilities		99,255
Level 2 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	3,433,739	2,959,784
Loans held for sale	658	232,147
Derivative assets	56,940	102,720
Federal funds purchased and repurchase agreements	3,470	111,751
Other borrowings	2,200,000	3,000,000
Long-term Debt	953,859	405,110
Derivative liabilities	56,940	99,255
Level 3 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	196,624	210,593
Loans held for sale	7,701	6,933
Loans held for investment, net	23,527,760	24,176,245
Deposits	29,813,668	30,996,589
Level 3 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	196,624	210,593
Loans held for sale	7,701	6,933
Loans held for investment, net	23,575,556	24,233,185
Deposits	$ 29,814,204	$ 30,997,980

Derivative Financial Instrume_3

Derivative Financial Instruments (Details 1) - Non-hedging - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Estimated fair value, asset derivative	$ 58,260	$ 102,791
Estimated fair value, liability derivative	58,260	99,326
Offsetting derivative liabilities	(1,320)	(71)
Offsetting derivative assets	(1,320)	(71)
Net asset derivatives included in the consolidated balance sheets		102,720
Net liability derivatives included in the consolidated balance sheets		99,255
Interest rate swap futures
Derivative [Line Items]
Notional amount	0	320,000
Estimated fair value, asset derivative	0	474
Estimated fair value, liability derivative	0	0
Forward sale commitments
Derivative [Line Items]
Notional amount	0	155,000
Estimated fair value, asset derivative	0	551
Estimated fair value, liability derivative	0	0
Interest rate contract | Loan purchase commitments
Derivative [Line Items]
Notional amount	0	332,145
Estimated fair value, asset derivative	0	5,123
Estimated fair value, liability derivative	0	8
Interest rate contract | Loan purchase commitments
Derivative [Line Items]
Notional amount	0	485,326
Estimated fair value, asset derivative	0	0
Estimated fair value, liability derivative	0	2,675
Financial institution counterparties | Commercial loan/lease | Interest rate swap
Derivative [Line Items]
Notional amount	1,857,977	1,922,956
Estimated fair value, asset derivative	1,320	71
Estimated fair value, liability derivative	56,884	96,246
Financial institution counterparties | Commercial loan/lease | Interest rate cap
Derivative [Line Items]
Notional amount	204,655	565,634
Estimated fair value, asset derivative	56	34
Estimated fair value, liability derivative	0	0
Financial institution counterparties | Commercial loan/lease | Foreign currency forward contracts
Derivative [Line Items]
Notional amount	0	6,667
Estimated fair value, asset derivative	0	214
Estimated fair value, liability derivative	0	78
Customer counterparties | Commercial loan/lease | Interest rate swap
Derivative [Line Items]
Notional amount	1,857,977	1,922,956
Estimated fair value, asset derivative	56,884	96,246
Estimated fair value, liability derivative	1,320	71
Customer counterparties | Commercial loan/lease | Interest rate cap
Derivative [Line Items]
Notional amount	204,655	565,634
Estimated fair value, asset derivative	0	0
Estimated fair value, liability derivative	56	34
Customer counterparties | Commercial loan/lease | Foreign currency forward contracts
Derivative [Line Items]
Notional amount	0	6,667
Estimated fair value, asset derivative	0	78
Estimated fair value, liability derivative	$ 0	$ 214

Derivative Financial Instrume_4

Derivative Financial Instruments Derivative Financial Instruments (Details 2) - Non-hedging - Commercial loan/lease - Interest rate swap	Sep. 30, 2021	Dec. 31, 2020
Interest rate received
Derivative [Line Items]
Weighted average fixed interest rate	2.74%	3.14%
Interest rate paid
Derivative [Line Items]
Weighted average fixed interest rate	1.15%	1.38%

Derivative Financial Instrume_5

Derivative Financial Instruments Derivative Financial Instruments (Details 3) $ in Millions	Sep. 30, 2021USD ($)instrument	Dec. 31, 2020USD ($)instrument
Derivative [Line Items]
Cash collateral pledged for derivatives	$ 62.1	$ 108.3
Risk participation agreement - participant bank
Derivative [Line Items]
Instruments held | instrument	8	9
Maximum exposure	$ 3.2	$ 6
Notional amount	$ 109.2	$ 119.5
Risk participation agreement - lead bank
Derivative [Line Items]
Instruments held | instrument	16	16
Notional amount	$ 167.4	$ 165.9
Non-hedging | Commercial loan/lease
Derivative [Line Items]
Credit risk exposure, net of collateral pledged, relating to derivatives	$ 56.9	$ 102.7
Non-hedging | Interest rate cap | Commercial loan/lease
Derivative [Line Items]
Weighted average fixed interest rate	2.67%	3.41%
Interest-bearing deposits
Derivative [Line Items]
Cash collateral pledged for derivatives		$ 104.4
Other assets
Derivative [Line Items]
Cash collateral pledged for derivatives		$ 3.9

Material Transactions Affecti_2

Material Transactions Affecting Stockholders' Equity (Details) - USD ($)	Jun. 15, 2021	Mar. 09, 2021	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020
Equity Distribution Agreement [Line Items]
Preferred stock, Liquidation value			$ 1,000	$ 1,000	$ 1,000
Issuance of stock - shares			300,000
Net proceeds from issuance of stock			$ 289,723,000
Par value of preferred stock			$ 0.01	$ 0.01	$ 0.01
Series B Preferred Stock
Equity Distribution Agreement [Line Items]
Preferred Stock, Dividend Rate, Percentage		5.75%
Preferred stock, Liquidation value		$ 1,000
Net proceeds from issuance of stock				$ 289,700,000
Depository Shares
Equity Distribution Agreement [Line Items]
Preferred stock, Liquidation value		$ 25
Issuance of stock - shares		12,000,000
Series A Preferred Stock
Equity Distribution Agreement [Line Items]
Preferred Stock, Dividend Rate, Percentage	6.50%			6.50%
Par value of preferred stock			$ 0.01	$ 0.01
Redemption of preferred stock - shares	6,000,000