Table of Contents

United States
Securities and Exchange Commission
Washington, D.C. 20549
Form 10-Q
ý Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
For the quarterly period ended:September 30, 20172020
Or
¨ Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
For the transition period from ________________ to ________________
Commission file number: 001-13221
Cullen/Frost Bankers, Inc.
(Exact name of registrant as specified in its charter)
Texas74-1751768
(State or other jurisdiction of
incorporation or organization)
(I.R.S. Employer
Identification No.)
100111 W. Houston Street,San Antonio, TexasTexas78205
(Address of principal executive offices)(Zip code)
(210)
(210)220-4011
(Registrant's telephone number, including area code)
(Registrant’s telephone number, including area code)
N/A
(Former name, former address and former fiscal year, if changed since last report
N/ASecurities registered pursuant to Section 12(b) of the Act:
(Former name, former address and former fiscal year, if changed since last report)
Title of each classTrading Symbol(s)Name of each exchange on
which registered
Common Stock, $.01 Par ValueCFRNew York Stock Exchange
Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.     Yes  ý    No  ¨
Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  ý    No  ¨
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.
Large accelerated filerýAccelerated filer¨
Non-accelerated filer
¨ (Do not check if a smaller reporting company)
Smaller reporting company¨
Emerging growth company¨
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.    ¨
Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  ý
As of October 19, 201722, 2020 there were 63,164,49162,854,581 shares of the registrant’s Common Stock, $.01 par value, outstanding.



Table of Contents
Cullen/Frost Bankers, Inc.
Quarterly Report on Form 10-Q
September 30, 20172020
Table of Contents
Page
Item 1.
Item 2.Management's Discussion and Analysis of Financial Condition and Results of Operations
Item 3.
Item 4.
Item 1.
Item 1A.
Item 2.
Item 3.
Item 4.
Item 5.
Item 6.

2

Table of Contents
Part I. Financial Information
Item 1. Financial Statements (Unaudited)
Cullen/Frost Bankers, Inc.
Consolidated Balance Sheets
(Dollars in thousands, except per share amounts)
September 30,
2017
 December 31,
2016
September 30,
2020
December 31,
2019
Assets:   Assets:
Cash and due from banks$503,961
 $561,838
Cash and due from banks$499,396 $581,857 
Interest-bearing deposits4,538,300
 3,560,865
Interest-bearing deposits6,655,784 2,849,950 
Federal funds sold and resell agreements49,642
 18,742
Federal funds sold and resell agreements20,500 356,374 
Total cash and cash equivalents5,091,903
 4,141,445
Total cash and cash equivalents7,175,680 3,788,181 
Securities held to maturity, at amortized cost1,442,222
 2,250,460
Securities held to maturity, net of allowance for credit losses of $160 at September 30, 2020Securities held to maturity, net of allowance for credit losses of $160 at September 30, 20201,951,384 2,030,005 
Securities available for sale, at estimated fair value10,185,100
 10,203,277
Securities available for sale, at estimated fair value10,604,480 11,269,591 
Trading account securities19,721
 16,703
Trading account securities25,808 24,298 
Loans, net of unearned discounts12,706,304
 11,975,392
Loans, net of unearned discounts18,223,877 14,750,332 
Less: Allowance for loan losses(154,303) (153,045)
Less: Allowance for credit losses on loansLess: Allowance for credit losses on loans(263,475)(132,167)
Net loans12,552,001
 11,822,347
Net loans17,960,402 14,618,165 
Premises and equipment, net520,639
 525,821
Premises and equipment, net1,055,064 1,011,947 
Goodwill654,952
 654,952
Goodwill654,952 654,952 
Other intangible assets, net5,475
 6,776
Other intangible assets, net1,771 2,481 
Cash surrender value of life insurance policies179,789
 177,884
Cash surrender value of life insurance policies189,148 187,156 
Accrued interest receivable and other assets338,170
 396,654
Accrued interest receivable and other assets482,551 440,652 
Total assets$30,989,972
 $30,196,319
Total assets$40,101,240 $34,027,428 
   
Liabilities:   Liabilities:
Deposits:   Deposits:
Non-interest-bearing demand deposits$11,174,251
 $10,513,369
Non-interest-bearing demand deposits$14,845,770 $10,873,629 
Interest-bearing deposits15,229,018
 15,298,206
Interest-bearing deposits18,653,733 16,765,935 
Total deposits26,403,269
 25,811,575
Total deposits33,499,503 27,639,564 
Federal funds purchased and repurchase agreements997,919
 976,992
Federal funds purchased and repurchase agreements1,608,667 1,695,342 
Junior subordinated deferrable interest debentures, net of unamortized issuance costs136,170
 136,127
Junior subordinated deferrable interest debentures, net of unamortized issuance costs136,342 136,299 
Subordinated notes, net of unamortized issuance costs98,512
 99,990
Subordinated notes, net of unamortized issuance costs98,982 98,865 
Accrued interest payable and other liabilities165,059
 169,107
Accrued interest payable and other liabilities672,720 545,690 
Total liabilities27,800,929
 27,193,791
Total liabilities36,016,214 30,115,760 
   
Shareholders’ Equity:   Shareholders’ Equity:
Preferred stock, par value $0.01 per share; 10,000,000 shares authorized; 6,000,000 Series A shares ($25 liquidation preference) issued at September 30, 2017 and December 31, 2016144,486
 144,486
Common stock, par value $0.01 per share; 210,000,000 shares authorized; 64,236,306 shares issued at September 30, 2017 and 63,632,464 shares issued at December 31, 2016642
 637
Preferred stock, par value $0.01 per share; 10,000,000 shares authorized; 6,000,000 Series A shares ($25 liquidation preference) issued at December 31, 2019Preferred stock, par value $0.01 per share; 10,000,000 shares authorized; 6,000,000 Series A shares ($25 liquidation preference) issued at December 31, 2019144,486 
Common stock, par value $0.01 per share; 210,000,000 shares authorized; 64,236,306 shares issued at September 30, 2020 and December 31, 2019Common stock, par value $0.01 per share; 210,000,000 shares authorized; 64,236,306 shares issued at September 30, 2020 and December 31, 2019642 642 
Additional paid-in capital951,893
 906,732
Additional paid-in capital991,477 983,250 
Retained earnings2,133,259
 1,985,569
Retained earnings2,724,681 2,667,534 
Accumulated other comprehensive income, net of tax57,675
 (24,623)
Treasury stock, at cost; 1,122,721 shares at September 30, 2017 and 158,243 shares at December 31, 2016(98,912) (10,273)
Accumulated other comprehensive income (loss), net of taxAccumulated other comprehensive income (loss), net of tax505,145 267,370 
Treasury stock, at cost; 1,454,736 shares at September 30, 2020 and 1,567,302 shares at December 31, 2019Treasury stock, at cost; 1,454,736 shares at September 30, 2020 and 1,567,302 shares at December 31, 2019(136,919)(151,614)
Total shareholders’ equity3,189,043
 3,002,528
Total shareholders’ equity4,085,026 3,911,668 
Total liabilities and shareholders’ equity$30,989,972
 $30,196,319
Total liabilities and shareholders’ equity$40,101,240 $34,027,428 
See Notes to Consolidated Financial Statements.



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Table of Contents
Cullen/Frost Bankers, Inc.
Consolidated Statements of Income
(Dollars in thousands, except per share amounts)
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended
September 30,
Nine Months Ended
September 30,
2017 2016 2017 20162020201920202019
Interest income:       Interest income:
Loans, including fees$138,400
 $114,368
 $392,073
 $340,303
Loans, including fees$169,002 $186,870 $512,444 $561,990 
Securities:       Securities:
Taxable23,203
 25,897
 72,032
 77,402
Taxable22,560 32,122 71,950 87,125 
Tax-exempt54,939
 53,065
 167,321
 154,308
Tax-exempt58,073 57,328 175,968 175,067 
Interest-bearing deposits10,800
 4,111
 26,712
 11,366
Interest-bearing deposits1,512 8,759 10,894 27,226 
Federal funds sold and resell agreements244
 48
 514
 165
Federal funds sold and resell agreements19 1,194 884 4,323 
Total interest income227,586
 197,489
 658,652
 583,544
Total interest income251,166 286,273 772,140 855,731 
Interest expense:       Interest expense:
Deposits5,668
 1,749
 9,709
 5,309
Deposits5,397 25,637 27,677 79,655 
Federal funds purchased and repurchase agreements523
 44
 849
 152
Federal funds purchased and repurchase agreements482 5,040 4,005 15,276 
Junior subordinated deferrable interest debentures1,020
 839
 2,890
 2,392
Junior subordinated deferrable interest debentures700 1,425 2,893 4,401 
Other long-term borrowings1,164
 350
 2,696
 958
Subordinated notesSubordinated notes1,164 1,164 3,492 3,492 
Federal Home Loan Bank advancesFederal Home Loan Bank advances318 
Total interest expense8,375
 2,982
 16,144
 8,811
Total interest expense7,743 33,266 38,385 102,824 
Net interest income219,211
 194,507
 642,508
 574,733
Net interest income243,423 253,007 733,755 752,907 
Provision for loan losses10,980
 5,045
 27,358
 42,734
Net interest income after provision for loan losses208,231
 189,462
 615,150
 531,999
Credit loss expenseCredit loss expense20,302 8,001 227,474 25,404 
Net interest income after credit loss expenseNet interest income after credit loss expense223,121 245,006 506,281 727,503 
Non-interest income:       Non-interest income:
Trust and investment management fees27,493
 26,451
 81,690
 77,806
Trust and investment management fees31,469 31,649 97,002 93,794 
Service charges on deposit accounts20,967
 20,540
 62,934
 60,769
Service charges on deposit accounts19,812 22,941 60,043 65,529 
Insurance commissions and fees10,892
 11,029
 34,441
 35,812
Insurance commissions and fees11,456 11,683 38,609 40,207 
Interchange and debit card transaction fees5,884
 5,435
 17,150
 15,838
Interchange and debit card transaction fees3,503 4,117 9,724 11,265 
Other charges, commissions and fees10,493
 10,703
 29,983
 29,825
Other charges, commissions and fees8,370 10,108 25,398 28,103 
Net gain (loss) on securities transactions(4,867) (37) (4,917) 14,866
Net gain (loss) on securities transactions96 108,989 265 
Other10,753
 7,993
 25,114
 21,358
Other8,991 8,630 34,352 29,484 
Total non-interest income81,615
 82,114
 246,395
 256,274
Total non-interest income83,601 89,224 374,117 268,647 
Non-interest expense:       Non-interest expense:
Salaries and wages84,388
 79,411
 247,895
 236,814
Salaries and wages93,323 93,812 282,485 277,078 
Employee benefits17,730
 17,844
 57,553
 55,861
Employee benefits16,074 21,002 59,824 64,579 
Net occupancy19,391
 18,202
 57,781
 53,631
Net occupancy25,466 24,202 76,116 64,602 
Furniture and equipment18,743
 17,979
 54,983
 53,474
Technology, furniture and equipmentTechnology, furniture and equipment26,482 22,415 77,768 66,236 
Deposit insurance4,862
 4,558
 15,347
 12,412
Deposit insurance2,372 2,491 7,796 7,752 
Intangible amortization405
 586
 1,301
 1,869
Intangible amortization212 274 710 904 
Other41,304
 41,925
 127,929
 125,048
Other38,221 44,668 121,293 132,722 
Total non-interest expense186,823
 180,505
 562,789
 539,109
Total non-interest expense202,150 208,864 625,992 613,873 
Income before income taxes103,023
 91,071
 298,756
 249,164
Income before income taxes104,572 125,366 254,406 382,277 
Income taxes9,892
 10,852
 35,131
 28,622
Income taxes9,516 13,530 11,525 42,359 
Net income93,131
 80,219
 263,625
 220,542
Net income95,056 111,836 242,881 339,918 
Preferred stock dividends2,016
 2,016
 6,047
 6,047
Preferred stock dividends2,016 2,016 6,047 
Redemption of preferred stockRedemption of preferred stock5,514 
Net income available to common shareholders$91,115
 $78,203
 $257,578
 $214,495
Net income available to common shareholders$95,056 $109,820 $235,351 $333,871 
       
Earnings per common share:       Earnings per common share:
Basic$1.43
 $1.24
 $4.02
 $3.44
Basic$1.50 $1.74 $3.72 $5.28 
Diluted1.41
 1.24
 3.98
 3.42
Diluted1.50 1.73 3.71 5.24 
See Notes to Consolidated Financial Statements.

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Table of Contents
Cullen/Frost Bankers, Inc.
Consolidated Statements of Comprehensive Income (Loss)
(Dollars in thousands)
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended
September 30,
Nine Months Ended
September 30,
2017 2016 2017 20162020201920202019
Net income$93,131
 $80,219
 $263,625
 $220,542
Net income$95,056 $111,836 $242,881 $339,918 
Other comprehensive income (loss), before tax:       Other comprehensive income (loss), before tax:
Securities available for sale and transferred securities:       Securities available for sale and transferred securities:
Change in net unrealized gain/loss during the period7,082
 (95,641) 131,283
 191,865
Change in net unrealized gain/loss during the period20,332 107,786 406,959 464,072 
Change in net unrealized gain on securities transferred to held to maturity(3,514) (7,278) (13,660) (24,629)Change in net unrealized gain on securities transferred to held to maturity(294)(305)(979)(957)
Reclassification adjustment for net (gains) losses included in net income4,867
 37
 4,917
 (14,866)Reclassification adjustment for net (gains) losses included in net income(97)(108,989)(266)
Total securities available for sale and transferred securities8,435
 (102,882) 122,540
 152,370
Total securities available for sale and transferred securities20,038 107,384 296,991 462,849 
Defined-benefit post-retirement benefit plans:       Defined-benefit post-retirement benefit plans:
Change in the net actuarial gain/loss
 
 
 (862)
Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit)1,357
 1,585
 4,072
 4,878
Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit)1,330 1,406 3,989 4,218 
Total defined-benefit post-retirement benefit plans1,357
 1,585
 4,072
 4,016
Total defined-benefit post-retirement benefit plans1,330 1,406 3,989 4,218 
Other comprehensive income (loss), before tax9,792
 (101,297) 126,612
 156,386
Other comprehensive income (loss), before tax21,368 108,790 300,980 467,067 
Deferred tax expense (benefit) related to other comprehensive income3,427
 (35,453) 44,314
 54,736
Deferred tax expense (benefit)Deferred tax expense (benefit)4,487 22,845 63,205 98,084 
Other comprehensive income (loss), net of tax6,365
 (65,844) 82,298
 101,650
Other comprehensive income (loss), net of tax16,881 85,945 237,775 368,983 
Comprehensive income (loss)$99,496
 $14,375
 $345,923
 $322,192
Comprehensive income (loss)$111,937 $197,781 $480,656 $708,901 
See Notes to Consolidated Financial Statements.

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Table of Contents
Cullen/Frost Bankers, Inc.
Consolidated Statements of Changes in Shareholders’ Equity
(Dollars in thousands, except per share amounts)
 Nine Months Ended 
 September 30,
 2017 2016
Total shareholders’ equity at beginning of period$3,002,528
 $2,890,343
Net income263,625
 220,542
Other comprehensive income (loss)82,298
 101,650
Stock option exercises/stock unit conversions (774,799 shares in 2017 and 908,921 shares in 2016)45,422
 47,873
Stock compensation expense recognized in earnings9,013
 7,998
Purchase of treasury stock (1,135,435 shares in 2017)(100,042) 
Cash dividends – preferred stock (approximately $1.01 per share in both 2017 and in 2016)(6,047) (6,047)
Cash dividends – common stock ($1.68 per share in 2017 and $1.61 per share in 2016)(107,754) (100,563)
Total shareholders’ equity at end of period$3,189,043
 $3,161,796
Preferred
Stock
Common
Stock
Additional
Paid-In
Capital
Retained
Earnings
Accumulated
Other
Comprehensive
Income (Loss),
Net of Tax
Treasury
Stock
Total
Three months ended:
September 30, 2020
Balance at beginning of period$$642 $989,034 $2,678,686 $488,264 $(147,825)$4,008,801 
Net income— — — 95,056 — — 95,056 
Other comprehensive income, net of tax— — — — 16,881 — 16,881 
Stock option exercises/stock unit conversions (53,425 shares)— — — (2,502)— 5,200 2,698 
Stock-based compensation expense recognized in earnings— — 2,443 — — — 2,443 
Purchase of treasury stock (400 shares)— — — — — (27)(27)
Treasury stock issued to the 401(k) stock purchase plan ( 58,900 shares)— — — (1,602)— 5,733 4,131 
Cash dividends – common stock ($0.71 per share)— — — (44,957)— — (44,957)
Balance at end of period$$642 $991,477 $2,724,681 $505,145 $(136,919)$4,085,026 
September 30, 2019
Balance at beginning of period$144,486 $642 $975,322 $2,556,235 $219,438 $(156,877)$3,739,246 
Net income— — — 111,836 — — 111,836 
Other comprehensive loss, net of tax— — — — 85,945 — 85,945 
Stock option exercises/stock unit conversions (101,284 shares)— — — (3,851)— 9,516 5,665 
Stock-based compensation expense recognized in earnings— — 2,675 — — — 2,675 
Purchase of treasury stock (202,724 shares)— — — — — (17,190)(17,190)
Cash dividends – preferred stock (approximately $0.34 per share)— — — (2,016)— — (2,016)
Cash dividends – common stock ($0.71 per share)— — — (44,704)— — (44,704)
Balance at end of period$144,486 $642 $977,997 $2,617,500 $305,383 $(164,551)$3,881,457 
See accompanying Notes to Consolidated Financial Statements.Statements




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Table of Contents
Cullen/Frost Bankers, Inc.
Consolidated Statements of Changes in Shareholders’ Equity (continued)
(Dollars in thousands, except per share amounts)
Preferred
Stock
Common
Stock
Additional
Paid-In
Capital
Retained
Earnings
Accumulated
Other
Comprehensive
Income (Loss),
Net of Tax
Treasury
Stock
Total
Nine months ended:
September 30, 2020
Balance at beginning of period$144,486 $642 $983,250 $2,667,534 $267,370 $(151,614)$3,911,668 
Cumulative effect of accounting change— — — (29,252)— — (29,252)
Total shareholders' equity at beginning of period, as adjusted144,486 642 983,250 2,638,282 267,370 (151,614)3,882,416 
Net income— — — 242,881 — — 242,881 
Other comprehensive income, net of tax— — — — 237,775 — 237,775 
Stock option exercises/stock unit conversions (196,948 shares)— — — (11,627)— 19,171 7,544 
Stock-based compensation expense recognized in earnings— — 8,227 — — — 8,227 
Redemption of preferred stock (6,000,000 shares)(144,486)— — (5,514)— — (150,000)
Purchase of treasury stock (182,225 shares)— — — — — (14,000)(14,000)
Treasury stock issued to the 401(k) stock purchase plan (97,843 shares)— — — (2,563)— 9,524 6,961 
Cash dividends – preferred stock (approximately $0.34 per share)— — — (2,016)— — (2,016)
Cash dividends – common stock ($2.13 per share)— — — (134,762)— — (134,762)
Balance at end of period$$642 $991,477 $2,724,681 $505,145 $(136,919)$4,085,026 
September 30, 2019
Balance at beginning of period$144,486 $642 $967,304 $2,440,002 $(63,600)$(119,917)$3,368,917 
Cumulative effect of accounting change— — — (14,672)— — (14,672)
Total shareholders' equity at beginning of period, as adjusted144,486 642 967,304 2,425,330 (63,600)(119,917)3,354,245 
Net income— — — 339,918 — — 339,918 
Other comprehensive loss, net of tax— — — — 368,983 — 368,983 
Stock option exercises/stock unit conversions (255,184 shares)— — — (9,569)— 23,075 13,506 
Stock-based compensation expense recognized in earnings— — 10,693 — — — 10,693 
Purchase of treasury stock (704,382 shares)— — — — — (67,709)(67,709)
Cash dividends – preferred stock (approximately $1.01 per share)— — — (6,047)— — (6,047)
Cash dividends – common stock ($2.09 per share)— — — (132,132)— — (132,132)
Balance at end of period$144,486 $642 $977,997 $2,617,500 $305,383 $(164,551)$3,881,457 
See accompanying Notes to Consolidated Financial Statements

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Table of Contents
Cullen/Frost Bankers, Inc.
Consolidated Statements of Cash Flows
(Dollars in thousands)
Nine Months Ended
September 30,
20202019
Operating Activities:
Net income$242,881 $339,918 
Adjustments to reconcile net income to net cash from operating activities:
Credit loss expense227,474 25,404 
Deferred tax expense (benefit)(8,803)(1,625)
Accretion of loan discounts(11,905)(11,364)
Securities premium amortization (discount accretion), net93,080 84,963 
Net (gain) loss on securities transactions(108,989)(265)
Depreciation and amortization47,752 39,182 
Net (gain) loss on sale/write-down of assets/foreclosed assets(6)(6,016)
Stock-based compensation8,227 10,693 
Net tax benefit from stock-based compensation694 1,602 
Earnings on life insurance policies(2,895)(2,744)
Net change in:
Trading account securities(197)(3,132)
Lease right-of-use assets17,419 14,618 
Accrued interest receivable and other assets(52,842)37,608 
Accrued interest payable and other liabilities23,208 56,354 
Net cash from operating activities475,098 585,196 
Investing Activities:
Securities held to maturity:
Purchases(1,500)
Maturities, calls and principal repayments63,333 69,273 
Securities available for sale:
Purchases(8,324,364)(9,815,936)
Sales1,162,352 8,236,066 
Maturities, calls and principal repayments8,162,036 1,007,783 
Proceeds from sale of loans24,036 
Net change in loans(3,551,650)(569,223)
Benefits received on life insurance policies903 
Proceeds from sales of premises and equipment3,054 8,019 
Purchases of premises and equipment(81,866)(168,326)
Proceeds from sales of repossessed properties73 131 
Net cash from investing activities(2,567,629)(1,208,177)
Financing Activities:
Net change in deposits5,859,939 (65,622)
Net change in short-term borrowings(86,675)(166,893)
Proceeds from Federal Home Loan Bank advances1,250,000 
Principal payments on Federal Home Loan Bank advances(1,250,000)
Redemption of preferred stock(150,000)
Proceeds from stock option exercises7,544 13,506 
Purchase of treasury stock(14,000)(67,709)
Cash dividends paid on preferred stock(2,016)(6,047)
Cash dividends paid on common stock(134,762)(132,132)
Net cash from financing activities5,480,030 (424,897)
Net change in cash and cash equivalents3,387,499 (1,047,878)
Cash and cash equivalents at beginning of period3,788,181 3,955,779 
Cash and cash equivalents at end of period$7,175,680 $2,907,901 
 Nine Months Ended 
 September 30,
 2017 2016
Operating Activities:   
Net income$263,625
 $220,542
Adjustments to reconcile net income to net cash from operating activities:   
Provision for loan losses27,358
 42,734
Deferred tax expense (benefit)(9,505) (11,629)
Accretion of loan discounts(11,567) (11,893)
Securities premium amortization (discount accretion), net66,455
 59,071
Net (gain) loss on securities transactions4,917
 (14,866)
Depreciation and amortization35,819
 35,712
Net (gain) loss on sale/write-down of assets/foreclosed assets(2,045) (373)
Stock-based compensation9,013
 7,998
Net tax benefit from stock-based compensation5,844
 1,610
Earnings on life insurance policies(2,367) (2,678)
Net change in:   
Trading account securities(3,018) 418
Accrued interest receivable and other assets10,495
 11,134
Accrued interest payable and other liabilities(39,580) (2,806)
Net cash from operating activities355,444
 334,974
    
Investing Activities:   
Securities held to maturity:   
Purchases
 
Sales
 135,610
Maturities, calls and principal repayments780,562
 227,760
Securities available for sale:   
Purchases(9,138,457) (10,079,302)
Sales8,993,963
 9,040,245
Maturities, calls and principal repayments283,278
 270,737
Proceeds from sale of loans
 30,470
Net change in loans(745,702) (142,698)
Benefits received on life insurance policies462
 906
Proceeds from sales of premises and equipment1,553
 1,517
Purchases of premises and equipment(23,796) (32,647)
Proceeds from sales of repossessed properties517
 297
Net cash from investing activities152,380
 (547,105)
    
Financing Activities:   
Net change in deposits591,694
 763,953
Net change in short-term borrowings20,927
 (89,220)
Proceeds from issuance of subordinated notes98,434
 
Principal payments on subordinated notes(100,000) 
Proceeds from stock option exercises45,422
 47,873
Purchase of treasury stock(100,042) 
Cash dividends paid on preferred stock(6,047) (6,047)
Cash dividends paid on common stock(107,754) (100,563)
Net cash from financing activities442,634
 615,996
    
Net change in cash and cash equivalents950,458
 403,865
Cash and equivalents at beginning of period4,141,445
 3,591,523
Cash and equivalents at end of period$5,091,903
 $3,995,388


See Notes to Consolidated Financial Statements.

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Notes to Consolidated Financial Statements
(Table amounts in thousands, except for share and per share amounts)
Note 1 - Significant Accounting Policies
Nature of Operations. Cullen/Frost Bankers, Inc. (“Cullen/Frost”) is a financial holding company and a bank holding company headquartered in San Antonio, Texas that provides, through its subsidiaries, a broad array of products and services throughout numerous Texas markets. The terms “Cullen/Frost,” “the Corporation,” “we,” “us” and “our” mean Cullen/Frost Bankers, Inc. and its subsidiaries, when appropriate. In addition to general commercial and consumer banking, other products and services offered include trust and investment management, insurance, brokerage, mutual funds, leasing, treasury management, capital markets advisory and item processing.
Basis of Presentation. The consolidated financial statements in this Quarterly Report on Form 10-Q include the accounts of Cullen/Frost and all other entities in which Cullen/Frost has a controlling financial interest. All significant intercompany balances and transactions have been eliminated in consolidation. The accounting and financial reporting policies we follow conform, in all material respects, to accounting principles generally accepted in the United States and to general practices within the financial services industry.
The consolidated financial statements in this Quarterly Report on Form 10-Q have not been audited by an independent registered public accounting firm, but in the opinion of management, reflect all adjustments necessary for a fair presentation of our financial position and results of operations. All such adjustments were of a normal and recurring nature. The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q adopted by the Securities and Exchange Commission (“SEC”). Accordingly, the financial statements do not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements and should be read in conjunction with our consolidated financial statements, and notes thereto, for the year ended December 31, 2016,2019, included in our Annual Report on Form 10-K filed with the SEC on February 3, 20174, 2020 (the “2016“2019 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 accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates. The allowance for loan losses and the fair values of financial instruments and the status of contingencies are particularly subject to change.
Cash Flow Reporting. Additional cash flow information was as follows:
Nine Months Ended
September 30,
20202019
Cash paid for interest$41,634 $100,041 
Cash paid for income taxes44,140 42,352 
Significant non-cash transactions:
Unsettled securities transactions6,698 82,064 
Loans foreclosed and transferred to other real estate owned and foreclosed assets140 1,302 
Loans to facilitate the sale of other real estate owned847 
Right-of-use lease assets obtained in exchange for lessee operating lease liabilities18,284 315,542 
Treasury stock issued to 401(k) stock purchase plan6,961 
Accounting Changes, Reclassifications and Restatements. Certain items in prior financial statements have been reclassified to conform to the current presentation. In addition, on January 1, 2020, we adopted Accounting Standards Update (“ASU”) 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” as subsequently updated for certain clarifications, targeted relief and codification improvements. Accounting Standards Codification (“ASC”) Topic 326 (“ASC 326”) replaces the previous “incurred loss” model for measuring credit losses, which encompassed allowances for current known and inherent losses within the portfolio, with an “expected loss” model, which encompasses allowances for losses expected to be incurred over the life of the portfolio. The new current expected credit loss (“CECL”) model requires the measurement of all expected credit losses for financial assets measured at amortized cost and certain off-balance-sheet credit exposures based on historical experience, current conditions, and reasonable and supportable forecasts. ASC 326 also requires enhanced disclosures related to the significant estimates and judgments used in estimating credit losses, as well as the credit quality and underwriting standards of an organization’s portfolio. In addition, ASC 326 includes certain changes to the accounting for available-for-sale securities including the requirement to present credit losses as
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 Nine Months Ended 
 September 30,
 2017 2016
Cash paid for interest$15,611
 $8,731
Cash paid for income taxes41,969
 39,160
Significant non-cash transactions:   
Unsettled purchases of securities41,763
 54,342
Loans foreclosed and transferred to other real estate owned and foreclosed assets257
 422
an allowance rather than as a direct write-down for available-for-sale securities management does not intend to sell or believes that it is more likely than not they will be required to sell.

We adopted ASC 326 using the modified retrospective method for all financial assets measured at amortized cost and off-balance-sheet credit exposures. Upon adoption, we recognized an after-tax cumulative effect reduction to retained earnings totaling $29.3 million, as detailed in the table below. Operating results for periods after January 1, 2020 are presented in accordance with ASC 326 while prior period amounts continue to be reported in accordance with previously applicable standards and the accounting policies described in our 2019 Form 10-K.
The following table details the impact of the adoption of ASC 326 on the allowance for credit losses as of January 1, 2020.
January 1, 2020
Pre-Adoption AllowanceImpact of AdoptionPost-Adoption AllowanceCumulative Effect on Retained Earnings
Securities held to maturity:
U.S. Treasury$$$$
Residential mortgage-backed securities
States and political subdivisions215 215 (170)
Other
Total$$215 $215 $(170)
Loans:
Commercial and industrial$51,593 $21,263 $72,856 $(16,798)
Energy37,382 (10,453)26,929 8,258 
Commercial real estate31,037 (13,519)17,518 10,680 
Consumer real estate4,113 2,392 6,505 (1,890)
Consumer and other8,042 (2,248)5,794 1,776 
Total$132,167 $(2,565)$129,602 $2,026 
Off-balance-sheet credit exposures$500 $39,377 $39,877 $(31,108)
In connection with the adoption of ASC 326, we revised certain accounting policies and implemented certain accounting policy elections. The revised accounting policies are described below.
Securities: Securities are classified as held to maturity and carried at amortized cost when management has the positive intent and ability to hold them until maturity. Securities to be held for indefinite periods of time are classified as available for sale and carried at fair value, with the unrealized holding gains and losses (those for which no allowance for credit losses are recorded) reported as a component of other comprehensive income, net of tax. Securities held for resale in anticipation of short-term market movements are classified as trading and are carried at fair value, with changes in unrealized holding gains and losses included in income. Management determines the appropriate classification of securities at the time of purchase. Securities with limited marketability, such as stock in the Federal Reserve Bank and the Federal Home Loan Bank, are carried at cost.
Interest income on securities includes amortization of purchase premiums and discounts. Premiums and discounts on securities are generally amortized using the interest method with a constant effective yield without anticipating prepayments, except for mortgage-backed securities where prepayments are anticipated. Premiums on callable securities are amortized to their earliest call date. A security is placed on non-accrual status if (i) principal or interest has been in default for a period of 90 days or more or (ii) full payment of principal and interest is not expected. Interest accrued but not received for a security placed on non-accrual status is reversed against interest income. Gains and losses on sales are recorded on the trade date and are derived from the amortized cost of the security sold.
Allowance For Credit Losses - Held-to-Maturity Securities: The allowance for credit losses on held-to-maturity securities is a contra-asset valuation account, calculated in accordance with ASC 326, that is deducted from the amortized cost basis of held-to-maturity securities to present management's best estimate of the net amount expected to be collected. Held-to-maturity securities are charged-off against the allowance when deemed uncollectible by management. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Management measures expected credit losses on held-to-maturity securities on a collective basis by major security type with each type sharing similar risk characteristics, and considers historical credit loss information that is adjusted for current conditions and reasonable and supportable forecasts. Management has made the accounting policy election to exclude accrued interest receivable on held-to-maturity securities from the estimate of credit losses. Further information regarding our policies and methodology used to estimate the allowance for credit losses on held-to-maturity securities is presented in Note 2 - Securities.
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Allowance For Credit Losses - Available-for-Sale Securities: For available-for-sale securities in an unrealized loss position, we first assess whether (i) we intend to sell, or (ii) it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis. If either case is affirmative, any previously recognized allowances are charged-off and the security's amortized cost is written down to fair value through income. If neither case is affirmative, the security is evaluated to determine whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency and any adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded for the credit loss, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive income. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Management has made the accounting policy election to exclude accrued interest receivable on available-for-sale securities from the estimate of credit losses. Available-for-sale securities are charged-off against the allowance or, in the absence of any allowance, written down through income when deemed uncollectible by management or when either of the aforementioned criteria regarding intent or requirement to sell is met.
Loans: Loans are reported at the principal balance outstanding net of unearned discounts. Interest income on loans is reported on the level-yield method and includes amortization of deferred loan fees and costs over the terms of the individual loans to which they relate, or, in certain cases, over the average expected term for loans where deferred fees and costs are accounted for on a pooled basis. Net loan commitment fees or costs for commitment periods greater than one year are deferred and amortized into fee income or other expense on a straight-line basis over the commitment period. Income on direct financing leases is recognized on a basis that achieves a constant periodic rate of return on the outstanding investment. Further information regarding our accounting policies related to past due loans, non-accrual loans, collateral dependent loans and troubled-debt restructurings is presented in Note 3 - Loans.
Allowance For Credit Losses - Loans: The allowance for credit losses on loans is a contra-asset valuation account, calculated in accordance with ASC 326, that is deducted from the amortized cost basis of loans to present management's best estimate of the net amount expected to be collected. Loans are charged-off against the allowance when deemed uncollectible by management. Expected recoveries do not exceed the aggregate of amounts previously charged-off and expected to be charged-off. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Management has made the accounting policy election to exclude accrued interest receivable on loans from the estimate of credit losses. Further information regarding our policies and methodology used to estimate the allowance for credit losses on loans is presented in Note 3 - Loans.
Allowance For Credit Losses - Off-Balance-Sheet Credit Exposures: The allowance for credit losses on off-balance-sheet credit exposures is a liability account, calculated in accordance with ASC 326, representing expected credit losses over the contractual period for which we are exposed to credit risk resulting from a contractual obligation to extend credit. No allowance is recognized if we have the unconditional right to cancel the obligation. The allowance is reported as a component of accrued interest payable and other liabilities in our consolidated balance sheets. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Further information regarding our policies and methodology used to estimate the allowance for credit losses on off-balance-sheet credit exposures is presented in Note 6 - Off-Balance-Sheet Arrangements, Commitments, Guarantees and Contingencies.
As more fully discussed in our 2019 Form 10-K, we adopted certain accounting standard updates related to accounting for leases as of January 1, 2019 using a modified-retrospective transition approach and recognized right-of-use lease assets and related lease liabilities totaling $170.5 million and $174.4 million, respectively, as of that date. We also adopted an accounting standard update which shortened the amortization period for certain callable debt securities held at a premium as of January 1, 2019 using a modified retrospective transition adoption approach and recognized a cumulative effect reduction to retained earnings totaling $14.7 million.
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Note 2 - Securities
Securities. Securities - Held to Maturity. A summary of the amortized cost, fair value and estimatedallowance for credit losses related to securities held to maturity as of September 30, 2020 and December 31, 2019 is presented below.
Amortized
Cost
Gross
Unrealized
Gains
Gross
Unrealized
Losses
Estimated
Fair Value
Allowance
for Credit
Losses
Net
Carrying
Amount
September 30, 2020
Residential mortgage-backed securities$529,290 $45,504 $$574,794 $$529,290 
States and political subdivisions1,420,754 61,808 1,482,562 (160)1,420,594 
Other1,500 1,499 1,500 
Total$1,951,544 $107,312 $$2,058,855 $(160)$1,951,384 
December 31, 2019
Residential mortgage-backed securities$530,861 $22 $9,365 $521,518 $$530,861 
States and political subdivisions1,497,644 28,909 896 1,525,657 1,497,644 
Other1,500 1,500 1,500 
Total$2,030,005 $28,931 $10,261 $2,048,675 $$2,030,005 
All mortgage-backed securities included in the above table were issued by U.S. government agencies and corporations. The carrying value of held-to-maturity securities pledged to secure public funds, trust deposits, repurchase agreements and for other purposes, as required or permitted by law was $663.2 million and $561.4 million at September 30, 2020 and December 31, 2019, respectively. Accrued interest receivable on held-to-maturity securities totaled $11.9 million and $21.1 million at September 30, 2020 and December 31, 2019, respectively and is included in accrued interest receivable and other assets in the accompanying consolidated balance sheets.
From time to time, we have reclassified certain securities from available for sale to held to maturity. During the fourth quarter of 2019, we reclassified securities with an aggregate fair value of $377.8 million and an aggregate net unrealized gain of $3.3 million ($2.6 million, net of tax) on the date of the transfer. The net unamortized, unrealized gain remaining on transferred securities, excluding tradingincluding those transferred in 2019 and in years prior, included in accumulated other comprehensive income in the accompanying balance sheet totaled $3.8 million ($3.0 million, net of tax) at September 30, 2020 and $4.8 million ($3.8 million, net of tax) at December 31, 2019. This amount will be amortized out of accumulated other comprehensive income over the remaining life of the underlying securities as an adjustment of the yield on those securities.
The allowance for credit losses on held-to-maturity securities is a contra-asset valuation account that is deducted from the amortized cost basis of held-to-maturity securities to present the net amount expected to be collected. Management measures expected credit losses on held-to-maturity securities on a collective basis by major security type with each type sharing similar risk characteristics, and considers historical credit loss information that is adjusted for current conditions and reasonable and supportable forecasts. With regard to U.S. Treasury and residential mortgage-backed securities issued by the U.S. government, or agencies thereof, it is expected that the securities will not be settled at prices less than the amortized cost bases of the securities as such securities are backed by the full faith and credit of and/or guaranteed by the U.S. government. Accordingly, no allowance for credit losses has been recorded for these securities. With regard to securities issued by States and political subdivisions and other held-to-maturity securities, management considers (i) issuer bond ratings, (ii) historical loss rates for given bond ratings, (iii) whether issuers continue to make timely principal and interest payments under the contractual terms of the securities, (iv) internal forecasts and (v) whether or not such securities are guaranteed by the Texas Permanent School Fund (“PSF”) or pre-refunded by the issuers.
The following table summarizes Moody's and/or Standard & Poor's bond ratings for our portfolio of held-to-maturity securities issued by States and political subdivisions and other securities as of September 30, 2020:
States and Political Subdivisions
Not Guaranteed or Pre-RefundedGuaranteed by the Texas PSFPre-RefundedTotalOther
Securities
Aaa/AAA$115,385 $797,659 $332,240 $1,245,284 $
Aa/AA112,614 112,614 
A62,856 62,856 
Not rated1,500 
Total$290,855 $797,659 $332,240 $1,420,754 $1,500 
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Historical loss rates associated with securities having similar grades as those in our portfolio have generally not been significant. Furthermore, as of September 30, 2020, there were no past due principal or interest payments associated with these securities. The PSF is a sovereign wealth fund which serves to provide revenues for funding of public primary and secondary education in the State of Texas. Based upon (i) the PSF's AAA insurer financial strength rating, (ii) the PSF's substantial capitalization and excess guarantee capacity and (iii) a zero historical loss rate, no allowance for credit losses has been recorded for securities guaranteed by the PSF as there is no current expectation of credit losses related to these securities. Pre-refunded securities have been defeased by the issuer and are fully secured by cash and/or U.S. Treasury securities held in escrow for payment to holders when the underlying call dates of the securities are reached. Accordingly, no allowance for credit losses has been recorded for securities that have been defeased as there is no current expectation of credit losses related to these securities.
The following table details activity in the allowance for credit losses on held-to-maturity securities during the three and nine months ended September 30, 2020.
Three Months Ended
September 30, 2020
Nine Months Ended September 30, 2020
Beginning balance$172 $
Impact of adopting ASC 326215 
Credit loss expense (benefit)(12)(55)
Ending balance$160 $160 
Securities - Available for Sale. A summary of the amortized cost, fair value and allowance for credit losses related to securities available for sale as of September 30, 2020 and December 31, 2019 is presented below.
Amortized
Cost
Gross
Unrealized
Gains
Gross
Unrealized
Losses
Allowance
for Credit
Losses
Estimated
Fair Value
September 30, 2020September 30, 2020
U.S. TreasuryU.S. Treasury$1,084,210 $40,755 $$$1,124,965 
September 30, 2017 December 31, 2016
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Estimated
Fair Value
 
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Estimated
Fair Value
Held to Maturity               
U.S. Treasury$
 $
 $
 $
 $249,889
 $1,762
 $
 $251,651
Residential mortgage-backed securities3,708
 21
 24
 3,705
 4,511
 39
 
 4,550
Residential mortgage-backed securities2,092,184 72,021 43 2,164,162 
States and political subdivisions1,437,164
 36,991
 2,556
 1,471,599
 1,994,710
 16,821
 6,335
 2,005,196
States and political subdivisions6,695,946 577,059 7,273,005 
Other1,350
 
 1
 1,349
 1,350
 
 
 1,350
Other42,348 42,348 
Total$1,442,222
 $37,012
 $2,581
 $1,476,653
 $2,250,460
 $18,622
 $6,335
 $2,262,747
Total$9,914,688 $689,835 $43 $$10,604,480 
Available for Sale               
December 31, 2019December 31, 2019
U.S. Treasury$3,452,882
 $23,796
 $3,050
 $3,473,628
 $4,003,692
 $24,984
 $8,945
 $4,019,731
U.S. Treasury$1,941,283 $18,934 $12,084 $$1,948,133 
Residential mortgage-backed securities658,281
 24,218
 1,304
 681,195
 756,072
 30,388
 1,293
 785,167
Residential mortgage-backed securities2,176,275 32,608 1,289 2,207,594 
States and political subdivisions5,898,098
 130,142
 40,501
 5,987,739
 5,403,918
 50,101
 98,134
 5,355,885
States and political subdivisions6,717,344 353,857 204 7,070,997 
Other42,538
 
 
 42,538
 42,494
 
 
 42,494
Other42,867 42,867 
Total$10,051,799
 $178,156
 $44,855
 $10,185,100
 $10,206,176
 $105,473
 $108,372
 $10,203,277
Total$10,877,769 $405,399 $13,577 $$11,269,591 
All mortgage-backed securities included in the above table were issued by U.S. government agencies and corporations. At September 30, 2017, approximately 98.1%2020, all of the securities in our available for sale municipal bond portfolio were issued by the State of Texas or political subdivisions or agencies within the State of Texas, of which approximately 67.7%75.8% are either guaranteed by the Texas Permanent School Fund, which has a “triple A” insurer financial strength rating,PSF or are secured by U.S. Treasury securities via defeasance of the debt by the issuers.have been pre-refunded. Securities with limited marketability, such as stock in the Federal Reserve Bank and the Federal Home Loan Bank, are carried at cost and are reported as other available for sale securities in the table above. The carrying value of available-for-sale securities pledged to secure public funds, trust deposits, repurchase agreements and for other purposes, as required or permitted by law was $3.5$3.8 billion and $3.4 billion at September 30, 20172020 and $3.9 billion at December 31, 2016.
During the fourth quarter of 2012, we reclassified certain2019, respectively. Accrued interest receivable on available-for-sale securities from available for sale to held to maturity. The securities had an aggregate fair value of $2.3 billion with an aggregate net unrealized gain of $165.7totaled $66.6 million ($107.7 and $115.9 million, net of tax) on the date of the transfer. The net unamortized, unrealized gain on the remaining transferred securities at September 30, 2020 and December 31, 2019, respectively, and is included in accumulatedaccrued interest receivable and other comprehensive incomeassets in the accompanying consolidated balance sheetsheets.
The table below summarizes, as of September 30, 2017 totaled $14.1 million ($9.2 million, net2020, securities available for sale in an unrealized loss position for which an allowance for credit losses has not been recorded, aggregated by type of tax).security and length of time in a continuous unrealized loss position.
Less than 12 MonthsMore than 12 MonthsTotal
Estimated
Fair Value
Unrealized
Losses
Estimated
Fair Value
Unrealized
Losses
Estimated
Fair Value
Unrealized
Losses
Residential mortgage-backed securities$7,527 $42 $124 $$7,651 $43 
Total$7,527 $42 $124 $$7,651 $43 
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As of September 30, 2020, no allowance for credit losses has been recognized on available for sale securities in an unrealized loss position as management does not believe any of the securities are impaired due to reasons of credit quality. This amount will be amortized out of accumulated other comprehensive income over the remaining lifeis based upon our analysis of the underlying risk characteristics, including credit ratings, and other qualitative factors (such as a PSF guarantee) related to our available for sale securities as an adjustmentand in consideration of our historical credit loss experience and internal forecasts. The issuers of these securities continue to make timely principal and interest payments under the contractual terms of the yield on those securities.
Unrealized Losses. As of September 30, 2017, securities with unrealized losses, segregated by length of impairment, were as follows:
 Less than 12 Months More than 12 Months Total
 
Estimated
Fair Value
 
Unrealized
Losses
 
Estimated
Fair Value
 
Unrealized
Losses
 
Estimated
Fair Value
 
Unrealized
Losses
Held to Maturity           
Residential mortgage-backed securities$2,212
 $24
 $
 $
 $2,212
 $24
States and political subdivisions5,301
 28
 74,965
 2,528
 80,266
 2,556
Other1,349
 1
 
 
 1,349
 1
Total$8,862
 $53
 $74,965
 $2,528
 $83,827
 $2,581
Available for Sale           
U.S. Treasury$840,074
 $3,050
 $
 $
 $840,074
 $3,050
Residential mortgage-backed securities75,441
 618
 19,458
 686
 94,899
 1,304
States and political subdivisions986,705
 9,713
 842,751
 30,788
 1,829,456
 40,501
Total$1,902,220
 $13,381
 $862,209
 $31,474
 $2,764,429
 $44,855

Declines in the fair value of held-to-maturity and available-for-sale securities below their cost that are deemed to be other than temporary are reflected in earnings as realized losses to the extent the impairment is related to credit losses. The amount of the impairment related to other factors is recognized in other comprehensive income. In estimating other-than-temporary impairment losses, management considers, among other things, (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer, and (iii) the intent and our ability to retain our investment in the issuer for a period of time sufficient to allow for any anticipated recovery in cost.
Management has the ability and intent to hold the securities classified as held to maturity in the table above until they mature, at which time we expect to receive full value for the securities. Furthermore, as of September 30, 2017, management does not have the intent to sell any of the securities classified as available for sale in the table above and believes that it is more likely than not that we will not have to sell any such securities before a recovery of cost. AnyThe unrealized losses are due to increases in market interest rates over the yields available at the time the underlying securities were purchased. The fair value is expected to recover as the securities approach their maturity date or repricing date or if market yields for such investments decline. Management does not believe any
Contractual Maturities. The following table summarizes the maturity distribution schedule of thesecurities held to maturity and securities available for sale as of September 30, 2020. Mortgage-backed securities are impaired due to reasons of credit quality. Accordingly, as of September 30, 2017, management believes the impairments detailedincluded in the table above are temporary and no impairment loss has been realized in our consolidated income statement.
Contractual Maturities. The amortized cost and estimated fair value of securities, excluding trading securities, at September 30, 2017 are presented below by contractual maturity.maturity categories based on their stated maturity date. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations. Residential mortgage-backedOther securities classified as available for sale include stock in the Federal Reserve Bank and equity securities are shown separately since they are not due at a singlethe Federal Home Loan Bank, which have no maturity date. These securities have been included in the total column only.
Within 1 Year1 - 5 Years5 - 10 YearsAfter 10 YearsTotal
Held To Maturity
Amortized Cost
Residential mortgage-backed securities$$231 $516,368 $12,691 $529,290 
States and political subdivisions55,180 355,409 399,377 610,788 1,420,754 
Other1,500 1,500 
Total$55,180 $357,140 $915,745 $623,479 $1,951,544 
Estimated Fair Value
Residential mortgage-backed securities$$233 $560,456 $14,105 $574,794 
States and political subdivisions56,043 369,536 411,517 645,466 1,482,562 
Other1,499 1,499 
Total$56,043 $371,268 $971,973 $659,571 $2,058,855 
Available For Sale
Amortized Cost
U. S. Treasury$299,355 $784,855 $$$1,084,210 
Residential mortgage-backed securities175 45,832 22,949 2,023,228 2,092,184 
States and political subdivisions201,529 1,029,750 696,654 4,768,013 6,695,946 
Other42,348 
Total$501,059 $1,860,437 $719,603 $6,791,241 $9,914,688 
Estimated Fair Value
U. S. Treasury$305,121 $819,844 $$$1,124,965 
Residential mortgage-backed securities182 47,995 23,439 2,092,546 2,164,162 
States and political subdivisions204,107 1,127,267 757,126 5,184,505 7,273,005 
Other42,348 
Total$509,410 $1,995,106 $780,565 $7,277,051 $10,604,480 
 Held to Maturity Available for Sale
 
Amortized
Cost
 
Estimated
Fair Value
 
Amortized
Cost
 
Estimated
Fair Value
Due in one year or less$251,739
 $256,716
 $37,321
 $38,127
Due after one year through five years116,604
 121,451
 4,056,709
 4,085,795
Due after five years through ten years411,074
 420,160
 385,649
 399,538
Due after ten years659,097
 674,621
 4,871,301
 4,937,907
Residential mortgage-backed securities3,708
 3,705
 658,281
 681,195
Equity securities
 
 42,538
 42,538
Total$1,442,222
 $1,476,653
 $10,051,799
 $10,185,100
Sales of Securities. As more fully discussed in our 2016 Form 10-K, during 2016, we sold certain securities issued by municipalities that, based upon our internal credit analysis, had experienced significant deterioration in creditworthiness. Some of the securities we sold were classified as held to maturity prior to their sale. Despite their classification as held to maturity, we believe the sale of these securities was merited and permissible under the applicable accounting guidelines because of the significant deterioration in the creditworthiness of the issuers.
Sales of securities held to maturity were as follows:
 Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
 2017 2016 2017 2016
Proceeds from sales$
 $
 $
 $135,610
Amortized cost
 
 
 131,840
Gross realized gains
 
 
 3,770
Gross realized losses
 
 
 
Tax (expense) benefit of securities gains/losses
 
 
 (1,319)
Sales of securities available for sale were as follows:
Three Months Ended
September 30,
Nine Months Ended
September 30,
2020201920202019
Proceeds from sales$$4,944,537 $1,162,352 $8,236,066 
Gross realized gains96 108,989 899 
Gross realized losses(634)
Tax (expense) benefit of securities gains/losses(21)(22,888)(56)
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Table of Contents
 Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
 2017 2016 2017 2016
Proceeds from sales$746,524
 $7,980,049
 $8,993,963
 $9,040,245
Gross realized gains
 1
 
 11,134
Gross realized losses(4,867) (38) (4,917) (38)
Tax (expense) benefit of securities gains/losses1,703
 13
 1,721
 (3,884)

Premiums and Discounts. Premium amortization and discount accretion included in interest income on securities was as follows:
Three Months Ended
September 30,
Nine Months Ended
September 30,
2020201920202019
Premium amortization$(31,540)$(29,511)$(94,873)$(88,798)
Discount accretion637 1,274 1,793 3,835 
Net (premium amortization) discount accretion$(30,903)$(28,237)$(93,080)$(84,963)
 Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
 2017 2016 2017 2016
Premium amortization$(24,586) $(22,762) $(72,733) $(67,321)
Discount accretion1,783
 2,497
 6,278
 8,250
Net (premium amortization) discount accretion$(22,803) $(20,265) $(66,455) $(59,071)
Trading Account Securities. Trading account securities, at estimated fair value, were as follows:
September 30,
2017
 December 31,
2016
September 30,
2020
December 31,
2019
U.S. Treasury$18,814
 $16,594
U.S. Treasury$24,495 $24,298 
States and political subdivisions907
 109
States and political subdivisions1,313 
Total$19,721
 $16,703
Total$25,808 $24,298 
Net gains and losses on trading account securities were as follows:
Three Months Ended
September 30,
Nine Months Ended
September 30,
2020201920202019
Net gain on sales transactions$159 $731 $933 $1,789 
Net mark-to-market gains (losses)(201)94 (170)
Net gain (loss) on trading account securities$160 $530 $1,027 $1,619 
 Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
 2017 2016 2017 2016
Net gain on sales transactions$414
 $379
 $1,018
 $1,032
Net mark-to-market gains (losses)(8) 
 (51) (1)
Net gain (loss) on trading account securities$406
 $379
 $967
 $1,031
Note 3 - Loans
Loans were as follows:
September 30,
2020
Percentage
of Total
December 31,
2019
Percentage
of Total
Commercial and industrial$4,820,018 26.4 %$5,187,466 35.2 %
Energy:
Production1,108,753 6.1 1,348,900 9.2 
Service163,197 0.9 192,996 1.3 
Other91,418 0.4 110,986 0.8 
Total energy1,363,368 7.4 1,652,882 11.2 
Paycheck Protection Program3,226,980 17.7 
Commercial real estate:
Commercial mortgages5,412,731 29.7 4,594,113 31.1 
Construction1,274,080 7.0 1,312,659 8.9 
Land320,407 1.8 289,467 2.0 
Total commercial real estate7,007,218 38.5 6,196,239 42.0 
Consumer real estate:
Home equity loans340,226 1.9 375,596 2.6 
Home equity lines of credit434,171 2.4 354,671 2.4 
Other533,356 2.9 464,146 3.1 
Total consumer real estate1,307,753 7.2 1,194,413 8.1 
Total real estate8,314,971 45.7 7,390,652 50.1 
Consumer and other498,540 2.8 519,332 3.5 
Total loans$18,223,877 100.0 %$14,750,332 100.0 %
 September 30,
2017
 
Percentage
of Total
 December 31,
2016
 
Percentage
of Total
Commercial and industrial$4,677,923
 36.8% $4,344,000
 36.3%
Energy:       
Production1,094,927
 8.6
 971,767
 8.1
Service159,893
 1.3
 221,213
 1.8
Other132,240
 1.0
 193,081
 1.7
Total energy1,387,060
 10.9
 1,386,061
 11.6
Commercial real estate:       
Commercial mortgages3,714,172
 29.2
 3,481,157
 29.1
Construction1,082,229
 8.5
 1,043,261
 8.7
Land307,701
 2.4
 311,030
 2.6
Total commercial real estate5,104,102
 40.1
 4,835,448
 40.4
Consumer real estate:       
Home equity loans357,542
 2.8
 345,130
 2.9
Home equity lines of credit288,981
 2.3
 264,862
 2.2
Other367,948
 2.9
 326,793
 2.7
Total consumer real estate1,014,471
 8.0
 936,785
 7.8
Total real estate6,118,573
 48.1
 5,772,233
 48.2
Consumer and other522,748
 4.2
 473,098
 3.9
Total loans$12,706,304
 100.0% $11,975,392
 100.0%
Concentrations of Credit. Most of our lending activity occurs within the State of Texas, including the four largest metropolitan areas of Austin, Dallas/Ft. Worth, Houston and San Antonio, as well as other markets. The majority of our loan portfolio consists of commercial and industrial and commercial real estate loans. As of September 30, 2017,2020, there were no0 concentrations of loans related to any single industry in excess of 10% of total loans other thanloans. The largest industry concentration was related to the energy loans,industry, which totaled 10.9%7.4% of total loans, or 9.1% excluding PPP loans. Unfunded commitments to extend credit and standby letters of credit issued to customers in the energy industry totaled $1.1 billion$910.3 million and $40.9$62.6 million, respectively, as of September 30, 2017.2020.

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Table of Contents
Foreign Loans. We have U.S. dollar denominated loans and commitments to borrowers in Mexico. The outstanding balance of these loans and the unfunded amounts available under these commitments were not significant at September 30, 20172020 or December 31, 2016.2019.
Related Party Loans. In the ordinary course of business, we have granted loans to certain directors, executive officers and their affiliates (collectively referred to as “related parties”). Such loans totaled $316.0 million at September 30, 2020 and $298.5 million at December 31, 2019.
Accrued Interest Receivable. Accrued interest receivable on loans totaled $43.9 million and $45.5 million at September 30, 2020 and December 31, 2019, respectively and is included in accrued interest receivable and other assets in the accompany consolidated balance sheets.
COVID-19 Loan Deferments. Certain borrowers are currently unable to meet their contractual payment obligations because of the adverse effects of COVID-19. To help mitigate these effects, loan customers may apply for a deferral of payments, or portions thereof, for up to 90 days. After 90 days, customers may apply for an additional deferral, and a small proportion of our customers have requested such an additional deferral. In the absence of other intervening factors, such short-term modifications made on a good faith basis are not categorized as troubled debt restructurings, nor are loans granted payment deferrals related to COVID-19 reported as past due or placed on non-accrual status (provided the loans were not past due or on non-accrual status prior to the deferral). At September 30, 2020, there were approximately 300 loans in COVID-19 related deferment with an aggregate outstanding balance of approximately $157.2 million.
Non-Accrual and Past Due Loans. Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. Loans are placed on non-accrual status when, in management’s opinion, the borrower may be unable to meet payment obligations as they become due, as well as when required by regulatory provisions. In determining whether or not a borrower may be unable to meet payment obligations for each class of loans, we consider the borrower’s debt service capacity through the analysis of current financial information, if available, and/or current information with regards to our collateral position. Regulatory provisions would typically require the placement of a loan on non-accrual status if (i) principal or interest has been in default for a period of 90 days or more unless the loan is both well secured and in the process of collection or (ii) full payment of principal and interest is not expected. Loans may be placed on non-accrual status regardless of whether or not such loans are considered past due. When interest accrual is discontinued, all unpaid accrued interest is reversed against income. Interest income on non-accrual loans is recognized only to the extent that cash payments are received in excess of principal due. A loan may be returned to accrual status when all the principal and interest amounts contractually due are brought current and future principal and interest amounts contractually due are reasonably assured, which is typically evidenced by a sustained period (at least six months) of repayment performance by the borrower.
Non-accrual loans, segregated by class of loans, were as follows:
September 30, 2020December 31, 2019
Total Non-AccrualNon-Accrual with No Credit Loss AllowanceTotal Non-AccrualNon-Accrual with No Credit Loss Allowance
Commercial and industrial$21,566 $6,583 $26,038 $13,266 
Energy54,041 33,324 65,761 3,281 
Paycheck Protection Program
Commercial real estate:
Buildings, land and other13,525 6,754 8,912 6,558 
Construction680 680 665 665 
Consumer real estate1,748 1,748 922 922 
Consumer and other18 
Total$91,578 $49,089 $102,303 $24,692 
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Table of Contents
 September 30,
2017
 December 31,
2016
Commercial and industrial$37,239
 $31,475
Energy96,717
 57,571
Commercial real estate:   
Buildings, land and other6,773
 8,550
Construction
 
Consumer real estate2,167
 2,130
Consumer and other208
 425
Total$143,104
 $100,151
AsThe following table presents non-accrual loans as of September 30, 2017, non-accrual loans reported in2020 by class and year of origination.
20202019201820172016PriorRevolving LoansRevolving Loans Converted to TermTotal
Commercial and industrial$9,317 $3,743 $1,886 $1,263 $110 $51 $1,879 $3,317 $21,566 
Energy24,149 7,021 2,204 15,054 5,613 54,041 
Paycheck Protection Program
Commercial real estate:
Buildings, land and other1,426 6,014 169 1,372 840 3,590 114 13,525 
Construction680 680 
Consumer real estate421 211 350 382 261 123 1,748 
Consumer and other18 18 
Total$35,572 $16,778 $4,680 $2,846 $1,300 $4,023 $17,326 $9,053 $91,578 
In the table above, included $54.1 million relatedloans reported as 2020 originations were, for the most part, first originated in various years prior to loans that2020 but were restructured as “troubled debt restructurings” during 2017. Seerenewed in the section captioned “Troubled Debt Restructurings” elsewhere in this note.current year. Had non-accrual loans performed in accordance with their original contract terms, we would have recognized additional interest income, net of tax, of approximately $783$670 thousand and $2.4$2.3 million for the three and nine months ended September 30, 2017, compared to $6472020, and approximately $937 thousand and $2.4$3.0 million for the three and nine months ended September 30, 2016.2019.
An age analysis of past due loans (including both accruing and non-accruing loans), segregated by class of loans, as of September 30, 2017 was as follows:
 
Loans
30-89 Days
Past Due
 
Loans
90 or More
Days
Past Due
 
Total
Past Due
Loans
 
Current
Loans
 
Total
Loans
 
Accruing
Loans 90 or
More Days
Past Due
Commercial and industrial$26,415
 $30,740
 $57,155
 $4,620,768
 $4,677,923
 $20,614
Energy12,585
 46,097
 58,682
 1,328,378
 1,387,060
 634
Commercial real estate:           
Buildings, land and other9,065
 4,065
 13,130
 4,008,743
 4,021,873
 2,229
Construction
 2,331
 2,331
 1,079,898
 1,082,229
 2,331
Consumer real estate7,671
 2,107
 9,778
 1,004,693
 1,014,471
 835
Consumer and other9,754
 486
 10,240
 512,508
 522,748
 478
Total$65,490
 $85,826
 $151,316
 $12,554,988
 $12,706,304
 $27,121
Impaired Loans. Impaired loans are set forth in the following table. No interest income was recognized on impaired loans subsequent to their classification as impaired.
 
Unpaid Contractual
Principal
Balance
 
Recorded Investment
With No
Allowance
 
Recorded Investment
With
Allowance
 
Total
Recorded
Investment
 
Related
Allowance
September 30, 2017         
Commercial and industrial$48,751
 $31,065
 $3,937
 $35,002
 $1,665
Energy107,883
 34,834
 61,805
 96,639
 13,267
Commercial real estate:      
  
Buildings, land and other9,976
 5,627
 
 5,627
 
Construction
 
 
 
 
Consumer real estate1,214
 1,214
 
 1,214
 
Consumer and other
 
 
 
 
Total$167,824
 $72,740
 $65,742
 $138,482
 $14,932

 Unpaid Contractual
Principal
Balance
 Recorded Investment
With No
Allowance
 Recorded Investment
With
Allowance
 Total
Recorded
Investment
 Related
Allowance
December 31, 2016         
Commercial and industrial$40,288
 $19,862
 $9,047
 $28,909
 $5,436
Energy60,522
 27,759
 29,804
 57,563
 3,750
Commercial real estate:         
Buildings, land and other11,369
 6,866
 
 6,866
 
Construction
 
 
 
 
Consumer real estate977
 655
 
 655
 
Consumer and other32
 30
 
 30
 
Total$113,188
 $55,172
 $38,851
 $94,023
 $9,186
The average recorded investment in impaired loans2020 was as follows:
Loans
30-89 Days
Past Due
Loans
90 or More
Days
Past Due
Total
Past Due
Loans
Current
Loans
Total
Loans
Accruing
Loans 90 or
More Days
Past Due
Commercial and industrial$36,067 $25,115 $61,182 $4,758,836 $4,820,018 $19,392 
Energy31,071 9,588 40,659 1,322,709 1,363,368 559 
Paycheck Protection Program3,226,980 3,226,980 
Commercial real estate:
Buildings, land and other25,113 19,571 44,684 5,688,454 5,733,138 11,676 
Construction1,274,080 1,274,080 
Consumer real estate11,054 4,761 15,815 1,291,938 1,307,753 3,406 
Consumer and other6,629 673 7,302 491,238 498,540 673 
Total$109,934 $59,708 $169,642 $18,054,235 $18,223,877 $35,706 
 Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
 2017 2016 2017
2016
Commercial and industrial$26,910
 $26,921
 $26,651
 $25,365
Energy76,008
 47,003
 72,055
 57,309
Commercial real estate:       
Buildings, land and other5,553
 8,904
 6,106
 20,444
Construction
 326
 
 548
Consumer real estate1,209
 545
 1,155
 508
Consumer and other
 48
 13
 24
Total$109,680
 $83,747
 $105,980
 $104,198
Troubled Debt Restructurings. Troubled debt restructurings during the nine months ended September 30, 20172020 and September 30, 20162019 are set forth in the following table.
Nine Months Ended 
 September 30, 2017
 Nine Months Ended 
 September 30, 2016
Nine Months Ended
September 30, 2020
Nine Months Ended
September 30, 2019
Balance at
Restructure
 
Balance at
Period-End
 
Balance at
Restructure
 
Balance at
Period-End
Balance at
Restructure
Balance at
Period-End
Balance at
Restructure
Balance at
Period-End
Commercial and industrial$4,026
 $3,875
 $510
 $505
Commercial and industrial$3,660 $1,415 $3,845 $2,188 
Energy56,097
 55,023
 73,977
 31,918
Commercial real estate:       Commercial real estate:
Buildings, land and other
 
 1,455
 1,455
Buildings, land and other6,606 6,585 9,456 9,494 
Construction
 
 243
 221
Construction1,192 1,181 
Consumer real estateConsumer real estate124 123 
Consumer and otherConsumer and other1,104 104 
$60,123
 $58,898
 $76,185
 $34,099
$12,562 $9,285 $13,425 $11,805 
Loan modifications are typically related to extending amortization periods, converting loans to interest only for a limited period of time, deferral of interest payments, waiver of certain covenants, consolidating notes and/or reducing collateral or interest rates. The modifications during the reported periods did not significantly impact our determination of the allowance for loan losses. Ascredit losses on loans.
17

Table of September 30, 2017, there was one loan totaling $43.1 million that wasContents
Additional information related to restructured during the third quarterloans as of 2017 that was in excess of 90 days past due, however, the underlying terms of the modification allowor for the deferral of payments. During the ninethree months ended September 30, 2017, we recognized charge-offs totaling $10.0 million related to loans restructured during the third2020 and fourth quarters of 2016. During the nine months ended September 30, 2016, we recognized a charge-off of $9.5 million related to a loan restructured during2019 is set forth in the first quarter of 2016. The loan was subsequently sold with proceeds from the sale totaling $30.5 million.following table.
September 30, 2020September 30, 2019
Restructured loans past due in excess of 90 days at period-end:
Number of loans
Dollar amount of loans$3,682 $3,244 
Restructured loans on non-accrual status at period end5,353 5,645 
Charge-offs of restructured loans:
Recognized in connection with restructuring1,500 
Recognized on previously restructured loans2,188 
Credit Quality Indicators. As part of the on-going monitoring of the credit quality of our loan portfolio, management tracks certain credit quality indicators including trends related to (i) the weighted-average risk grade of commercial loans, (ii) the level of classified commercial loans, (iii) the delinquency status of consumer loans (see details above), (iv) net charge-offs, (v) non-performing loans (see details above) and (vi) the general economic conditions in the State of Texas.
We utilize a risk grading matrix to assign a risk grade to each of our commercial loans. Loans are graded on a scale of 1 to 14. A description of the general characteristics of the 14 risk grades is set forth in our 20162019 Form 10-K. In monitoring credit quality

trends in the context of assessing the appropriate level of the allowance for loan losses, weWe monitor portfolio credit quality by the weighted-average risk grade of each class of commercial loan. Individual relationship managers, under the oversight of credit administration, review updated financial information for all pass grade loans to reassess the risk grade on at least an annual basis. When a loan has a risk grade of 9, it is still considered a pass grade loan; however, it is considered to be on management’s “watch list,” where a significant risk-modifying action is anticipated in the near term. When a loan has a risk grade of 10 or higher, a special assets officer monitors the loan on an on-going basis.
The following tables present weighted-average risk grades for all commercial loans, by class.class and year of origination/renewal as of September 30, 2020. Paycheck Protection Program (“PPP”) loans are excluded as such loans are fully guaranteed by the Small Business Administration (“SBA”).
20202019201820172016PriorRevolving LoansRevolving Loans Converted to TermTotalW/A Risk Grade
Commercial and industrial
Risk grades 1-8$1,101,917 $625,692 $340,799 $251,180 $120,777 $129,757 $1,788,761 $43,468 $4,402,351 6.12 
Risk grade 969,846 27,843 36,271 21,352 9,910 1,087 77,802 4,462 248,573 9.00 
Risk grade 104,394 7,722 13,867 6,875 812 824 60,028 4,347 98,869 10.00 
Risk grade 113,675 4,507 6,720 4,422 1,896 167 17,909 9,363 48,659 11.00 
Risk grade 126,917 2,791 1,544 708 110 51 1,350 3,022 16,493 12.00 
Risk grade 132,400 952 342 555 529 295 5,073 13.00 
$1,189,149 $669,507 $399,543 $285,092 $133,505 $131,886 $1,946,379 $64,957 $4,820,018 6.42 
W/A risk grade6.12 6.81 7.20 6.32 6.37 5.87 6.32 7.92 6.42 
Energy
Risk grades 1-8$454,901 $25,589 $10,956 $6,732 $1,481 $4,709 $407,478 $24,936 $936,782 6.18 
Risk grade 9108,859 5,542 3,190 90,292 14,974 222,857 9.00 
Risk grade 10486 4,113 1,461 907 7,837 2,105 16,909 10.00 
Risk grade 1178,832 15,724 3,280 1,210 1,066 32,398 269 132,779 11.00 
Risk grade 1224,149 4,829 714 10,629 5,613 45,934 12.00 
Risk grade 132,192 1,490 4,425 8,107 13.00 
$667,227 $57,989 $21,091 $7,942 $2,388 $5,775 $553,059 $47,897 $1,363,368 7.39 
W/A risk grade7.43 9.19 8.78 7.83 7.93 8.06 6.98 8.76 7.39 
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20202019201820172016PriorRevolving LoansRevolving Loans Converted to TermTotalW/A Risk Grade
September 30, 2017 December 31, 2016
Weighted
Average
Risk Grade
 Loans Weighted
Average
Risk Grade
 Loans
Commercial and industrial:       
Commercial real estate:Commercial real estate:
Buildings, land, otherBuildings, land, other
Risk grades 1-86.01
 $4,236,670
 6.01
 $3,989,722
Risk grades 1-8$1,167,872 $1,010,418 $829,640 $660,047 $430,971 $752,461 $62,672 $53,480 $4,967,561 6.98 
Risk grade 99.00
 201,635
 9.00
 106,988
Risk grade 926,056 93,113 67,546 66,365 45,477 92,060 4,413 1,042 396,072 9.00 
Risk grade 1010.00
 89,126
 10.00
 115,420
Risk grade 101,362 26,080 29,357 39,853 65,702 42,528 4,147 2,876 211,905 10.00 
Risk grade 1111.00
 113,253
 11.00
 100,245
Risk grade 117,416 7,108 13,425 42,660 10,487 59,730 3,038 211 144,075 11.00 
Risk grade 1212.00
 35,574
 12.00
 25,939
Risk grade 121,226 5,214 169 1,372 840 3,340 51 12,212 12.00 
Risk grade 1313.00
 1,665
 13.00
 5,686
Risk grade 13200 800 250 63 1,313 13.00 
Total6.38
 $4,677,923
 6.35
 $4,344,000
Energy       
Risk grades 1-86.19
 $1,082,349
 6.34
 $854,688
Risk grade 99.00
 46,285
 9.00
 78,524
Risk grade 1010.00
 67,694
 10.00
 150,872
Risk grade 1111.00
 94,015
 11.00
 244,406
Risk grade 1212.00
 83,450
 12.00
 53,821
Risk grade 1313.00
 13,267
 13.00
 3,750
Total7.21
 $1,387,060
 7.95
 $1,386,061
Commercial real estate:  
    
Buildings, land and other       
Risk grades 1-86.69
 $3,720,068
 6.67
 $3,463,064
Risk grade 99.00
 115,196
 9.00
 109,110
Risk grade 1010.00
 110,647
 10.00
 145,067
Risk grade 1111.00
 69,189
 11.00
 66,396
Risk grade 1212.00
 6,773
 12.00
 8,550
Risk grade 1313.00
 
 13.00
 
Total6.93
 $4,021,873
 6.95
 $3,792,187
$1,204,132 $1,142,733 $940,137 $810,297 $553,477 $950,369 $74,384 $57,609 $5,733,138 7.34 
W/A risk gradeW/A risk grade7.09 7.34 7.46 7.48 7.73 7.26 7.41 6.84 7.34 
Construction       Construction
Risk grades 1-87.14
 $1,058,847
 6.97
 $1,023,194
Risk grades 1-8$272,025 $480,166 $224,389 $753 $1,164 $1,786 $160,654 $$1,140,937 7.01 
Risk grade 99.00
 18,106
 9.00
 15,829
Risk grade 931,402 8,370 39,688 14,608 94,068 9.00 
Risk grade 1010.00
 3,768
 10.00
 2,889
Risk grade 106,133 27,479 3,838 37,450 10.00 
Risk grade 1111.00
 1,508
 11.00
 1,349
Risk grade 11945 945 11.00 
Risk grade 1212.00
 
 12.00
 
Risk grade 12680 680 12.00 
Risk grade 1313.00
 
 13.00
 
Risk grade 1313.00 
Total7.19
 $1,082,229
 7.01
 $1,043,261
$310,240 $488,536 $251,868 $40,441 $1,164 $2,731 $179,100 $$1,274,080 7.25 
W/A risk gradeW/A risk grade6.87 7.18 7.74 8.98 7.29 8.02 7.00 7.25 
Total commercial real estateTotal commercial real estate$1,514,372 $1,631,269 $1,192,005 $850,738 $554,641 $953,100 $253,484 $57,609 $7,007,218 7.33 
W/A risk gradeW/A risk grade7.04 7.29 7.52 7.55 7.73 7.26 7.12 6.84 7.33 

In the tables above, certain loans are reported as 2020 originations and have risk grades of 11 or higher. These loans were, for the most part, first originated in various years prior to 2020 but were renewed in the current year.
Net (charge-offs)/recoveries,The following tables present weighted average risk grades for all commercial loans by class as of December 31, 2019.
Commercial and IndustrialEnergyCommercial Real Estate - Buildings, Land and OtherCommercial Real Estate - ConstructionTotal Commercial Real Estate
W/A Risk GradeLoansW/A Risk GradeLoansW/A Risk GradeLoansW/A Risk GradeLoansW/A Risk GradeLoans
Risk grades 1-86.17 $4,788,857 5.90 $1,488,301 6.78 $4,523,271 7.25 $1,274,098 6.88 $5,797,369 
Risk grade 99.00 247,212 9.00 32,163 9.00 163,714 9.00 21,509 9.00 185,223 
Risk grade 1010.00 71,472 10.00 51,898 10.00 103,626 10.00 15,243 10.00 118,869 
Risk grade 1111.00 53,887 11.00 14,760 11.00 84,057 11.00 1,144 11.00 85,201 
Risk grade 1212.00 18,189 12.00 45,514 12.00 8,529 12.00 665 12.00 9,194 
Risk grade 1313.00 7,849 13.00 20,246 13.00 383 13.00 13.00 383 
Total6.44 $5,187,466 6.39 $1,652,882 7.01 $4,883,580 7.31 $1,312,659 7.07 $6,196,239 
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Information about the payment status of consumer loans, segregated by classportfolio segment and year of origination, as of September 30, 2020 was as follows:
20202019201820172016PriorRevolving LoansRevolving Loans Converted to TermTotal
Consumer real estate:
Past due 30-89 days$787 $850 $1,434 $858 $540 $4,558 $1,535 $492 $11,054 
Past due 90 or more days139 894 542 351 2,028 600 207 4,761 
Total past due787 989 2,328 1,400 891 6,586 2,135 699 15,815 
Current loans253,392 188,770 106,947 93,143 75,216 142,983 414,331 17,156 1,291,938 
Total$254,179 $189,759 $109,275 $94,543 $76,107 $149,569 $416,466 $17,855 $1,307,753 
Consumer and other:
Past due 30-89 days$1,328 $326 $288 $75 $$$4,313 $296 $6,629 
Past due 90 or more days69 189 372 39 673 
Total past due1,397 515 291 75 4,685 335 7,302 
Current loans38,114 32,214 7,985 3,131 2,070 950 376,762 30,012 491,238 
Total$39,511 $32,729 $8,276 $3,206 $2,072 $952 $381,447 $30,347 $498,540 
Revolving loans that converted to term during the three and nine months ended September 30, 2020 were as follows:
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
2017 2016 2017 2016Three Months Ended
September 30, 2020
Nine Months Ended
September 30, 2020
Commercial and industrial$(4,565) $(3,079) $(12,155) $(8,177)Commercial and industrial$10,224 $25,340 
Energy451
 (865) (10,010) (18,623)Energy7,144 38,642 
Commercial real estate:       Commercial real estate:
Buildings, land and other266
 259
 768
 801
Buildings, land and other637 8,094 
Construction2
 9
 8
 18
Construction
Consumer real estate(629) (195) (422) (22)Consumer real estate421 2,132 
Consumer and other(1,760) (1,115) (4,289) (2,817)Consumer and other5,494 15,338 
Total$(6,235) $(4,986) $(26,100) $(28,820)Total$23,920 $89,546 
In assessing the general economic conditions in the State of Texas, management monitors and tracks the Texas Leading Index (“TLI”), which is produced by the Federal Reserve Bank of Dallas. The TLI, the components of which are more fully described in our 20162019 Form 10-K, totaled 124.6113.1 at August 31, 2017 (most recent date available)September 30, 2020 and 123.1127.9 at December 31, 2016.2019. A higherlower TLI value implies moreless favorable economic conditions.
Allowance for LoanFor Credit Losses. - Loans. The allowance for loancredit losses on loans is a reserve established through a provision for loan losses chargedcontra-asset valuation account, calculated in accordance with ASC 326, that is deducted from the amortized cost basis of loans to expense, whichpresent the net amount expected to be collected. The amount of the allowance represents management’smanagement's best estimate of inherentcurrent expected credit losses on loans considering available information, from internal and external sources, relevant to assessing collectibility over the loans' contractual terms, adjusted for expected prepayments when appropriate. The contractual term excludes expected extensions, renewals and modifications unless (i) management has a reasonable expectation that have been incurred withina trouble debt restructuring will be executed with an individual borrower or (ii) such extension or renewal options are not unconditionally cancellable by us and, in such cases, the existing portfolioborrower is likely to meet applicable conditions and likely to request extension or renewal. Relevant available information includes historical credit loss experience, current conditions and reasonable and supportable forecasts. While historical credit loss experience provides the basis for the estimation of loans.expected credit losses, adjustments to historical loss information may be made for differences in current portfolio-specific risk characteristics, environmental conditions or other relevant factors. The allowance for credit losses is measured on a collective basis for portfolios of loans when similar risk characteristics exist. Loans that do not share risk characteristics are evaluated for expected credit losses on an individual basis and excluded from the collective evaluation. Expected credit losses for collateral dependent loans, including loans where the borrower is experiencing financial difficulty but foreclosure is not probable, are based on the fair value of the collateral at the reporting date, adjusted for selling costs as appropriate.

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Credit loss expense related to loans reflects the totality of actions taken on all loans for a particular period including any necessary increases or decreases in the judgmentallowance related to changes in credit loss expectations associated with specific loans or pools of management, is necessary to reserve for estimated loan losses and risks inherent in the loan portfolio. Our allowance for loan loss methodology, which is more fully described in our 2016 Form 10-K, follows the accounting guidance set forth in U.S. generally accepted accounting principles and the Interagency Policy Statement on the Allowance for Loan and Lease Losses, which was jointly issued by U.S. bank regulatory agencies. The level of the allowance reflects management’s continuing evaluation of industry concentrations, specific credit risks, loan loss and recovery experience, current loan portfolio quality, present economic, political and regulatory conditions and unidentified losses inherent in the current loan portfolio.loans. Portions of the allowance may be allocated for specific credits; however, the entire allowance is available for any credit that, in management’s judgment, should be charged off. While management utilizes its best judgment and information available, the ultimate appropriateness of the allowance is dependent upon a variety of factors beyond our control, including the performance of our loan portfolio, the economy, changes in interest rates and the view of the regulatory authorities toward loan classifications.
In calculating the allowance for credit losses, most loans are segmented into pools based upon similar characteristics and risk profiles. Common characteristics and risk profiles include the type/purpose of loan, underlying collateral, geographical similarity and historical/expected credit loss patterns. In developing these loan pools for the purposes of modeling expected credit losses, we also analyzed the degree of correlation in how loans within each portfolio respond when subjected to varying economic conditions and scenarios as well as other portfolio stress factors. For modeling purposes, our loan pools include (i) commercial and industrial and energy - non-revolving, (ii) commercial and industrial and energy - revolving, (iii) commercial real estate - owner occupied, (iv) commercial real estate - non-owner occupied, (v) commercial real estate - construction/land development, (vi) consumer real estate and (vii) consumer and other. We periodically reassess each pool to ensure the loans within the pool continue to share similar characteristics and risk profiles and to determine whether further segmentation is necessary.
For each loan pool, we measure expected credit losses over the life of each loan utilizing a combination of models which measure (i) probability of default (“PD”), which is the likelihood that loan will stop performing/default, (ii) probability of attrition (“PA”), which is the likelihood that a loan will pay-off prior to maturity, (iii) loss given default (“LGD”), which is the expected loss rate for loans in default and (iv) exposure at default (“EAD”), which is the estimated outstanding principal balance of the loans upon default, including the expected funding of unfunded commitments outstanding as of the measurement date. For certain commercial loan portfolios, the PD is calculated using a transition matrix to determine the likelihood of a customer’s risk grade migrating from one specified range of risk grades to a different specified range. Expected credit losses are calculated as the product of PD (adjusted for attrition), LGD and EAD. This methodology builds on default probabilities already incorporated into our risk grading process by utilizing pool-specific historical loss rates to calculate expected credit losses. These pool-specific historical loss rates may be adjusted for current macroeconomic assumptions, as further discussed below, and other factors such as differences in underwriting standards, portfolio mix, or when historical asset terms do not reflect the contractual terms of the financial assets being evaluated as of the measurement date. Each time we measure expected credit losses, we assess the relevancy of historical loss information and consider any necessary adjustments to address any differences in asset-specific characteristics. Due to their short-term nature, expected credit losses for overdrafts included in consumer and other loans are based solely upon a weighting of recent historical charge-offs over a period of three years.
The measurement of expected credit losses is impacted by loan/borrower attributes and certain macroeconomic variables. Significant loan/borrower attributes utilized in our modeling processes include, among other things, (i) origination date, (ii) maturity date, (iii) payment type, (iv) collateral type and amount, (v) current risk grade, (vi) current unpaid balance and commitment utilization rate, (vii) payment status/delinquency history and (viii) expected recoveries of previously charged-off amounts. Significant macroeconomic variables utilized in our modeling processes include, among other things, (i) Gross State Product for Texas and U.S. Gross Domestic Product, (ii) selected market interest rates including U.S. Treasury rates, bank prime rate, 30-year fixed mortgage rate, BBB corporate bond rate, among others, (iii) unemployment rates, (iv) commercial and residential property prices in Texas and the U.S. as a whole, (v) West Texas Intermediate crude oil price and (vi) total stock market index.
PD and PA were estimated by analyzing internally-sourced data related to historical performance of each loan pool over a complete economic cycle. PD and PA are adjusted to reflect the current impact of certain macroeconomic variables as well as their expected changes over a reasonable and supportable forecast period. We have determined that we are reasonably able to forecast the macroeconomic variables used in our modeling processes with an acceptable degree of confidence for a total of two years with the last twelve months of the forecast period encompassing a reversion process whereby the forecasted macroeconomic variables are reverted to their historical mean utilizing a rational, systematic basis. The macroeconomic variables utilized as inputs in our modeling processes were subjected to a variety of analysis procedures and were selected primarily based on statistical relevancy and correlation to our historical credit losses. By reverting these modeling inputs to their historical mean and considering loan/borrower specific attributes, our models will yield a measurement of expected credit losses that reflects our average historical loss rates for periods subsequent to the twelve-month reversion period. The LGD is based on historical recovery averages for each loan pool, adjusted to reflect the current impact of certain macroeconomic variables as well as their expected changes over a two-year forecast period, with the final twelve months of the forecast period encompassing a reversion process, which management considers to be both reasonable and supportable. This same forecast/reversion period is used for all macroeconomic variables used in all of our models. EAD is estimated using a linear regression model that estimates the average percentage of the loan balance that remains at the time of a default event.
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Management qualitatively adjusts model results for risk factors that are not considered within our modeling processes but are nonetheless relevant in assessing the expected credit losses within our loan pools. These qualitative factor (“Q-Factor”) adjustments may increase or decrease management's estimate of expected credit losses by a calculated percentage or amount based upon the estimated level of risk. The various risks that may be considered in making Q-Factor adjustments include, among other things, the impact of (i) changes in lending policies and procedures, including changes in underwriting standards and practices for collections, write-offs, and recoveries, (ii) actual and expected changes in international, national, regional, and local economic and business conditions and developments that affect the collectibility of the loan pools, (iii) changes in the nature and volume of the loan pools and in the terms of the underlying loans, (iv) changes in the experience, ability, and depth of our lending management and staff, (v) changes in volume and severity of past due financial assets, the volume of non-accrual assets, and the volume and severity of adversely classified or graded assets, (vi) changes in the quality of our credit review function, (vii) changes in the value of the underlying collateral for loans that are non-collateral dependent, (viii) the existence, growth, and effect of any concentrations of credit and (ix) other factors such as the regulatory, legal and technological environments; competition; and events such as natural disasters or health pandemics.
In some cases, management may determine that an individual loan exhibits unique risk characteristics which differentiate the loan from other loans within our loan pools. In such cases, the loans are evaluated for expected credit losses on an individual basis and excluded from the collective evaluation. Specific allocations of the allowance for credit losses are determined by analyzing the borrower’s ability to repay amounts owed, collateral deficiencies, the relative risk grade of the loan and economic conditions affecting the borrower’s industry, among other things. A loan is considered to be collateral dependent when, based upon management's assessment, the borrower is experiencing financial difficulty and repayment is expected to be provided substantially through the operation or sale of the collateral. In such cases, expected credit losses are based on the fair value of the collateral at the measurement date, adjusted for estimated selling costs if satisfaction of the loan depends on the sale of the collateral. We reevaluate the fair value of collateral supporting collateral dependent loans on a quarterly basis. The fair value of real estate collateral supporting collateral dependent loans is evaluated by our internal appraisal services using a methodology that is consistent with the Uniform Standards of Professional Appraisal Practice. The fair value of collateral supporting collateral dependent construction loans is based on an “as is” valuation.
The following table presents details of the allowance for loancredit losses allocated to eachon loans segregated by loan portfolio segment as of September 30, 2017 and December 31, 2016 and detailed on2020, calculated in accordance with the basis of the impairment evaluationCECL methodology we used:
 
Commercial
and
Industrial
 Energy 
Commercial
Real Estate
 
Consumer
Real Estate
 
Consumer
and Other
 Total
September 30, 2017           
Historical valuation allowances$27,190
 $21,900
 $18,304
 $2,443
 $5,491
 $75,328
Specific valuation allowances1,665
 13,267
 
 
 
 14,932
General valuation allowances7,397
 4,677
 4,841
 2,040
 163
 19,118
Macroeconomic valuation allowances12,185
 12,069
 14,930
 2,392
 3,349
 44,925
Total$48,437
 $51,913
 $38,075
 $6,875
 $9,003
 $154,303
Allocated to loans:           
Individually evaluated$1,665
 $13,267
 $
 $
 $
 $14,932
Collectively evaluated46,772
 38,646
 38,075
 6,875
 9,003
 139,371
Total$48,437
 $51,913
 $38,075
 $6,875
 $9,003
 $154,303
December 31, 2016           
Historical valuation allowances$33,251
 $34,626
 $16,976
 $2,225
 $4,585
 $91,663
Specific valuation allowances5,436
 3,750
 
 
 
 9,186
General valuation allowances6,708
 3,769
 5,004
 1,506
 (144) 16,843
Macroeconomic valuation allowances7,520
 18,508
 8,233
 507
 585
 35,353
Total$52,915
 $60,653
 $30,213
 $4,238
 $5,026
 $153,045
Allocated to loans:           
Individually evaluated$5,436
 $3,750
 $
 $
 $
 $9,186
Collectively evaluated47,479
 56,903
 30,213
 4,238
 5,026
 143,859
Total$52,915
 $60,653
 $30,213
 $4,238
 $5,026
 $153,045

Our recorded investment indescribed above. No allowance for credit losses has been recognized for PPP loans as such loans are fully guaranteed by the SBA.
Commercial
and
Industrial
EnergyCommercial
Real Estate
Consumer
Real Estate
Consumer
and Other
Total
Modeled expected credit losses$68,896 $21,644 $125,965 $10,226 $7,420 $234,151 
Q-Factor and other qualitative adjustments(1,647)24,630 (8,685)51 31 14,380 
Specific allocations5,256 8,357 1,313 18 14,944 
Total$72,505 $54,631 $118,593 $10,277 $7,469 $263,475 
The following table presents details of September 30, 2017 and December 31, 2016 related to each balance in the allowance for loancredit losses on loans segregated by loan portfolio segment and detailed on the basisas of the impairmentDecember 31, 2019, calculated in accordance with our prior incurred loss methodology we used was as follows:described in our 2019 Form 10-K.
Commercial
and
Industrial
EnergyCommercial
Real Estate
Consumer
Real Estate
Consumer
and Other
Total
Historical valuation allowances$29,015 $7,873 $21,947 $2,690 $7,562 $69,087 
Specific valuation allowances7,849 20,246 383 28,483 
General valuation allowances9,840 5,196 4,201 904 (409)19,732 
Macroeconomic valuation allowances4,889 4,067 4,506 519 884 14,865 
Total$51,593 $37,382 $31,037 $4,113 $8,042 $132,167 
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Table of Contents
 
Commercial
and
Industrial
 Energy Commercial
Real Estate
 Consumer
Real Estate
 Consumer
and Other
 Total
September 30, 2017           
Individually evaluated$35,002
 $96,639
 $5,627
 $1,214
 $
 $138,482
Collectively evaluated4,642,921
 1,290,421
 5,098,475
 1,013,257
 522,748
 12,567,822
Total$4,677,923
 $1,387,060
 $5,104,102
 $1,014,471
 $522,748
 $12,706,304
December 31, 2016           
Individually evaluated$28,909
 $57,563
 $6,866
 $655
 $30
 $94,023
Collectively evaluated4,315,091
 1,328,498
 4,828,582
 936,130
 473,068
 11,881,369
Total$4,344,000
 $1,386,061
 $4,835,448
 $936,785
 $473,098
 $11,975,392
The following table details activity in the allowance for loancredit losses on loans by portfolio segment for the three and nine months ended September 30, 20172020 and 2016.2019. Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. No allowance for credit losses has been recognized for PPP loans as such loans are fully guaranteed by the SBA.
Commercial
and
Industrial
EnergyCommercial
Real Estate
Consumer
Real Estate
Consumer
and Other
Total
Three months ended:
September 30, 2020
Beginning balance$98,536 $40,817 $93,425 $8,998 $8,285 $250,061 
Credit loss expense(18,547)13,814 25,368 1,794 1,161 23,590 
Charge-offs(8,605)(242)(1,088)(4,219)(14,154)
Recoveries1,121 42 573 2,242 3,978 
Net charge-offs(7,484)(200)(515)(1,977)(10,176)
Ending balance$72,505 $54,631 $118,593 $10,277 $7,469 $263,475 
September 30, 2019
Beginning balance$57,714 $25,818 $35,914 $5,637 $9,846 $134,929 
Credit loss expense(3,527)8,788 (607)(650)3,997 8,001 
Charge-offs(2,705)(2,000)(557)(6,357)(11,619)
Recoveries1,185 740 46 454 2,823 5,248 
Net charge-offs(1,520)(1,260)46 (103)(3,534)(6,371)
Ending balance$52,667 $33,346 $35,353 $4,884 $10,309 $136,559 
Nine months ended:
September 30, 2020
Beginning balance$51,593 $37,382 $31,037 $4,113 $8,042 $132,167 
Impact of adopting ASC 32621,263 (10,453)(13,519)2,392 (2,248)(2,565)
Credit loss expense10,737 96,478 104,716 3,716 8,096 223,743 
Charge-offs(14,815)(68,842)(3,826)(1,508)(13,402)(102,393)
Recoveries3,727 66 185 1,564 6,981 12,523 
Net charge-offs(11,088)(68,776)(3,641)56 (6,421)(89,870)
Ending balance$72,505 $54,631 $118,593 $10,277 $7,469 $263,475 
September 30, 2019
Beginning balance$48,580 $29,052 $38,777 $6,103 $9,620 $132,132 
Credit loss expense9,999 7,478 (2,972)859 10,040 25,404 
Charge-offs(8,782)(4,000)(617)(2,936)(17,157)(33,492)
Recoveries2,870 816 165 858 7,806 12,515 
Net charge-offs(5,912)(3,184)(452)(2,078)(9,351)(20,977)
Ending balance$52,667 $33,346 $35,353 $4,884 $10,309 $136,559 
The following table presents loans that were evaluated for expected credit losses on an individual basis and the related specific allocations, by loan portfolio segment as of September 30, 2020 and December 31, 2019.
September 30, 2020December 31, 2019
Loan
Balance
Specific AllocationsLoan
Balance
Specific Allocations
Commercial and industrial$22,930 $5,256 $24,360 $7,849 
Energy56,420 8,357 65,244 20,246 
Paycheck Protection Program
Commercial real estate:
Buildings, land and other25,611 1,313 8,609 383 
Construction680 665 
Consumer real estate1,335 570 
Consumer and other18 18 
Total$106,994 $14,944 $99,453 $28,483 
23
 
Commercial
and
Industrial
 Energy 
Commercial
Real Estate
 
Consumer
Real Estate
 
Consumer
and Other
 Total
Three months ended:           
September 30, 2017           
Beginning balance$48,906
 $54,277
 $33,002
 $5,535
 $7,838
 $149,558
Provision for loan losses4,096
 (2,815) 4,805
 1,969
 2,925
 10,980
Charge-offs(5,468) 
 
 (766) (4,120) (10,354)
Recoveries903
 451
 268
 137
 2,360
 4,119
Net charge-offs(4,565) 451
 268
 (629) (1,760) (6,235)
Ending balance$48,437
 $51,913
 $38,075
 $6,875
 $9,003
 $154,303
September 30, 2016           
Beginning balance$47,578
 $66,339
 $27,063
 $3,935
 $4,799
 $149,714
Provision for loan losses4,632
 (3,231) 1,886
 427
 1,331
 5,045
Charge-offs(4,036) (884) (9) (287) (3,300) (8,516)
Recoveries957
 19
 277
 92
 2,185
 3,530
Net charge-offs(3,079) (865) 268
 (195) (1,115) (4,986)
Ending balance$49,131
 $62,243
 $29,217
 $4,167
 $5,015
 $149,773
            
Nine months ended:           
September 30, 2017           
Beginning balance$52,915
 $60,653
 $30,213
 $4,238
 $5,026
 $153,045
Provision for loan losses7,677
 1,270
 7,086
 3,059
 8,266
 27,358
Charge-offs(14,574) (10,595) (14) (779) (11,291) (37,253)
Recoveries2,419
 585
 790
 357
 7,002
 11,153
Net charge-offs(12,155) (10,010) 776
 (422) (4,289) (26,100)
Ending balance$48,437
 $51,913
 $38,075
 $6,875
 $9,003
 $154,303
September 30, 2016           
Beginning balance$42,993
 $54,696
 $24,313
 $4,659
 $9,198
 $135,859
Provision for loan losses14,315
 26,170
 4,085
 (470) (1,366) 42,734
Charge-offs(10,754) (18,644) (56) (464) (9,276) (39,194)
Recoveries2,577
 21
 875
 442
 6,459
 10,374
Net charge-offs(8,177) (18,623) 819
 (22) (2,817) (28,820)
Ending balance$49,131
 $62,243
 $29,217
 $4,167
 $5,015
 $149,773


Table of Contents
Note 4 - Goodwill and Other Intangible Assets
Goodwill and other intangible assets are presented in the table below. As of September 30, 2020, we evaluated recent potential triggering events that might be indicators that our goodwill was impaired. The events include the economic disruption and uncertainty surrounding the COVID-19 pandemic and the circumstances surrounding recent volatility in the market price of crude oil. Based on our evaluation, we concluded that our goodwill was not more than likely impaired as of that date.
September 30,
2020
December 31,
2019
Goodwill$654,952 $654,952 
Other intangible assets:
Core deposits$1,465 $2,043 
Customer relationships306 438 
$1,771 $2,481 
 September 30,
2017
 December 31,
2016
Goodwill$654,952
 $654,952
Other intangible assets:   
Core deposits$4,340
 $5,298
Customer relationships1,086
 1,410
Non-compete agreements49
 68
 $5,475
 $6,776
The estimated aggregate future amortization expense for intangible assets remaining as of September 30, 20172020 is as follows:
Remainder of 2020$208 
2021697 
2022481 
2023282 
202487 
Thereafter16 
$1,771 
Remainder of 2017$402
20181,424
20191,167
2020918
2021697
Thereafter867
 $5,475
Note 5 - Deposits
Deposits were as follows:
September 30,
2017
 
Percentage
of Total
 December 31,
2016
 
Percentage
of Total
September 30,
2020
Percentage
of Total
December 31,
2019
Percentage
of Total
Non-interest-bearing demand deposits:     Non-interest-bearing demand deposits:
Commercial and individual$10,466,844
 39.6% $9,670,989
 37.5%Commercial and individual$13,852,404 41.4 %$10,212,265 36.9 %
Correspondent banks226,313
 0.9
 280,751
 1.1
Correspondent banks208,836 0.6 246,181 0.9 
Public funds481,094
 1.8
 561,629
 2.2
Public funds784,530 2.3 415,183 1.5 
Total non-interest-bearing demand deposits11,174,251
 42.3
 10,513,369
 40.8
Total non-interest-bearing demand deposits14,845,770 44.3 10,873,629 39.3 
Interest-bearing deposits:       Interest-bearing deposits:
Private accounts:       Private accounts:
Savings and interest checking6,449,079
 24.4
 6,436,065
 24.9
Savings and interest checking8,176,608 24.4 7,147,327 25.9 
Money market accounts7,607,675
 28.8
 7,486,431
 29.0
Money market accounts8,684,470 25.9 7,888,433 28.5 
Time accounts of $100,000 or more454,096
 1.7
 460,028
 1.8
Time accounts of $100,000 or more791,004 2.4 736,481 2.7 
Time accounts under $100,000323,748
 1.3
 338,714
 1.3
Time accounts under $100,000339,174 1.0 347,418 1.2 
Total private accounts14,834,598
 56.2
 14,721,238
 57.0
Total private accounts17,991,256 53.7 16,119,659 58.3 
Public funds:       Public funds:
Savings and interest checking312,430
 1.2
 446,872
 1.7
Savings and interest checking583,214 1.8 548,399 2.0 
Money market accounts68,018
 0.3
 113,669
 0.4
Money market accounts76,088 0.2 73,180 0.3 
Time accounts of $100,000 or more13,462
 
 15,748
 0.1
Time accounts of $100,000 or more3,092 24,672 0.1 
Time accounts under $100,000510
 
 679
 
Time accounts under $100,00083 25 
Total public funds394,420
 1.5
 576,968
 2.2
Total public funds662,477 2.0 646,276 2.4 
Total interest-bearing deposits15,229,018
 57.7
 15,298,206
 59.2
Total interest-bearing deposits18,653,733 55.7 16,765,935 60.7 
Total deposits$26,403,269
 100.0% $25,811,575
 100.0%Total deposits$33,499,503 100.0 %$27,639,564 100.0 %
The following table presents additional information about our deposits:
September 30,
2020
December 31,
2019
Deposits from the Certificate of Deposit Account Registry Service (CDARS) deposits$369 $361 
Deposits from foreign sources (primarily Mexico)845,950 805,828 
Deposits not covered by deposit insurance17,265,358 13,115,796 
24
 September 30,
2017
 December 31,
2016
Deposits from foreign sources (primarily Mexico)$756,326
 $776,003
Deposits not covered by deposit insurance13,255,165
 12,889,047


Table of Contents
Note 6 - Borrowed Funds
Subordinated Notes Payable. In March 2017, we issued $100 million of 4.50% subordinated notes that mature on March 17, 2027. The notes, which qualify as Tier 2 capital for Cullen/Frost, bear interest at the rate of 4.50% per annum, payable semi-annually on each March 17 and September 17. The notes are unsecured and subordinated in right of payment to the payment of our existing and future senior indebtedness and structurally subordinated to all existing and future indebtedness of our subsidiaries. Unamortized debt issuance costs related to these notes, totaled approximately $1.5 million at September 30, 2017. Proceeds from sale of the notes were used for general corporate purposes.
Our $100 million of 5.75% fixed-to-floating rate subordinated notes matured and were redeemed on February 15, 2017. See Note 8 - Borrowed Funds in our 2016 Form 10-K for additional information about these notes.
Note 7 -Off-Balance-Sheet Arrangements, Commitments, Guarantees and Contingencies
Financial Instruments with Off-Balance-Sheet Risk. In the normal course of business, we enter into various transactions, which, in accordance with generally accepted accounting principles are not included in our consolidated balance sheets. We enter into these transactions to meet the financing needs of our customers. As more fully discussed in our 20162019 Form 10-K, these transactions include commitments to extend credit and standby letters of credit, which involve, to varying degrees, elements of credit risk and interest rate risk in excess of the amounts recognized in the consolidated balance sheets. We minimize our exposure to loss under these commitments by subjecting them to credit approval and monitoring procedures.
Financial instruments with off-balance-sheet risk were as follows:
September 30,
2020
December 31,
2019
Commitments to extend credit$9,586,212 $9,306,043 
Standby letters of credit260,683 260,587 
Deferred standby letter of credit fees1,716 1,276 
 September 30,
2017
 December 31,
2016
Commitments to extend credit$7,939,438
 $7,476,420
Standby letters of credit236,996
 239,482
Deferred standby letter of credit fees1,860
 2,054
Allowance For Credit Losses - Off-Balance-Sheet Credit Exposures. The allowance for credit losses on off-balance-sheet credit exposures is a liability account, calculated in accordance with ASC 326, representing expected credit losses over the contractual period for which we are exposed to credit risk resulting from a contractual obligation to extend credit. No allowance is recognized if we have the unconditional right to cancel the obligation. Off-balance-sheet credit exposures primarily consist of amounts available under outstanding lines of credit and letters of credit detailed in the table above. For the period of exposure, the estimate of expected credit losses considers both the likelihood that funding will occur and the amount expected to be funded over the estimated remaining life of the commitment or other off-balance-sheet exposure. The likelihood and expected amount of funding are based on historical utilization rates. The amount of the allowance represents management's best estimate of expected credit losses on commitments expected to be funded over the contractual life of the commitment. Estimating credit losses on amounts expected to be funded uses the same methodology as described for loans in Note 3 - Loans as if such commitments were funded.
The following table details activity in the allowance for credit losses on off-balance-sheet credit exposures.
Three Months Ended
September 30,
Nine Months Ended
September 30,
2020201920202019
Beginning balance$46,939 $500 $500 $500 
Impact of adopting ASC 32639,377 
Credit loss expense (benefit)(3,276)3,786 
Ending balance$43,663 $500 $43,663 $500 
Lease Commitments. We lease certain office facilities and office equipment under operating leases. RentThe components of total lease expense for allwere as follows:
Three Months Ended
September 30,
Nine Months Ended
September 30,
2020201920202019
Amortization of lease right-of-use assets$8,521 $7,415 $24,545 $19,698 
Short-term lease expense172 1,199 1,343 3,316 
Non-lease components (including taxes, insurance, common maintenance, etc.)2,586 3,114 8,410 7,022 
Total$11,279 $11,728 $34,298 $30,036 
Right-of-use lease assets totaled $298.6 million at September 30, 2020 and $297.7 million at December 31, 2019 and are reported as a component of premises and equipment on our accompanying consolidated balance sheets. The related lease liabilities totaled $328.9 million at September 30, 2020 and $323.7 million at December 31, 2019 and are reported as a component of accrued interest payable and other liabilities in the accompanying consolidated balance sheets. Lease payments under operating leases that were applied to our operating lease liability totaled $7.7$8.0 million and $23.0 million during the three and nine months ended September 30, 2017 and $7.5 million and $22.0$23.8 million during the three and nine months ended September 30, 2016.2020 and $7.6 million and $19.7 million during the three and nine months ended September 30, 2019. There has been no0 significant change in our expected future minimum lease payments since December 31, 2016.2019. See the 20162019 Form 10-K for information regarding these commitments.
Litigation.
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Table of Contents
Litigation. We are subject to various claims and legal actions that have arisen in the course of conducting business. Management does not expect the ultimate disposition of these matters to have a material adverse impact on our financial statements.
In May of 2020, a purported class action lawsuit was filed against Frost Bank in a Texas Federal court alleging that Frost Bank had refused to pay agent fees to purported agents of borrowers under the PPP in violation of SBA regulations. The Plaintiff's motion to dismiss the Federal lawsuit was effected and as a result the Federal lawsuit is resolved. In July of 2020, another purported class action lawsuit was filed against Frost Bank in a California Federal court alleging that Frost Bank had refused to pay agent fees to purported agents of borrowers under the PPP in violation of SBA regulations. Frost Bank believes the claims to be without merit. In October of 2020, a lawsuit was filed against Frost Bank in Texas State court alleging, among other claims, that Frost Bank refused to provide a PPP loan to the purported applicant. Frost Bank believes the claims to be without merit.
Note 87 - Capital and Regulatory Matters
Banks and bank holding companies are subject to various regulatory capital requirements administered by state and federal banking agencies. Capital adequacy guidelines and, additionally for banks, prompt corrective action regulations, involve quantitative measures of assets, liabilities, and certain off-balance-sheet items calculated under regulatory accounting practices. Capital amounts and classifications are also subject to qualitative judgments by regulators about components, risk weighting and other factors.
Cullen/Frost’s and Frost Bank’s Common Equity Tier 1 capital includes common stock and related paid-in capital, net of treasury stock, and retained earnings. In connection with the adoption of the Basel III Capital Rules, we elected to opt-out of the requirement to include most components of accumulated other comprehensive income in Common Equity Tier 1. We also elected to exclude, for a five-year transitional period, the effects of credit loss accounting under CECL from Common Equity Tier 1, as further discussed below. Common Equity Tier 1 for both Cullen/Frost and Frost Bank is reduced by goodwill and other intangible assets, net of associated deferred tax liabilities, and subject to transition provisions.liabilities. Frost Bank's Common Equity Tier 1 is also reduced by its equity investment in its financial subsidiary, Frost Insurance Agency (“FIA”).
Tier 1 capital includes Common Equity Tier 1 capital and additional Tier 1 capital. For Cullen/Frost additional Tier 1 capital at September 30, 2017 and December 31, 2016 includes $144.5 million of 5.375% non-cumulative perpetual preferred stock. Frost Bank did not0t have any additional Tier 1 capital beyond Common Equity Tier 1 at September 30, 2017 or2020. For Cullen/Frost, additional Tier 1 capital included $144.5 million of preferred stock at December 31, 2016.2019, the details of which are further discussed below. Frost Bank did 0t have any additional Tier 1 capital beyond Common Equity Tier 1 at December 31, 2019.
Total capital includes Tier 1 capital and Tier 2 capital. Tier 2 capital for both Cullen/Frost and Frost Bank includes a permissible portion of the allowanceallowances for loan losses.credit losses on securities, loans and off-balance-sheet credit exposures. Tier 2 capital for Cullen/Frost also includes $100.0 million of qualified subordinated debt at September 30, 2017 and $133.0 million of trust preferred securities at both September 30, 20172020 and December 31, 2016.2019.

As discussed in Note 1 - Significant Accounting Policies, in connection with the adoption of ASC 326, we recognized an after-tax cumulative effect reduction to retained earnings totaling $29.3 million. 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 U.S. 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 CECL on their regulatory capital ratios (three-year transition option). In March 2020, the federal bank regulatory agencies issued an interim final rule that maintains the three-year transition option of the 2019 CECL Rule and also provides banking organizations that were required under U.S. GAAP (as of January 2020) 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 transition option). We elected to adopt the five-year transition option. Accordingly, a CECL transitional amount totaling $63.7 million has been added back to CET1 as of September 30, 2020. The CECL transitional amount includes $29.3 million related to cumulative effect of adopting CECL and $34.4 million related to the estimated incremental effect of CECL since adoption.
In April 2020, we began originating loans to qualified small businesses under the PPP administered by the SBA. Federal bank regulatory agencies have issued an interim final rule that permits banks to neutralize the regulatory capital effects of participating in the Paycheck Protection Program Lending Facility (the “PPP Facility”) and clarify that PPP loans have a zero percent risk weight under applicable risk-based capital rules. Specifically, a bank may exclude all PPP loans pledged as collateral to the PPP Facility from its average total consolidated assets for the purposes of calculating its leverage ratio, while PPP loans that are not pledged as collateral to the PPP Facility will be included. Our PPP loans are included in the calculation of our leverage ratio as of September 30, 2020 as we did not utilize the PPP Facility for funding purposes.
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Table of Contents
The following table presents actual and required capital ratios as of September 30, 2020 and December 31, 2019 for Cullen/Frost and Frost Bank under the Basel III Capital Rules. The minimum required capital amounts presented include the minimum required capital levels as of September 30, 2017 and December 31, 2016 based on the phase-in provisions of the Basel III Capital Rules and the minimum required capital levels as of January 1, 2019 when the Basel III Capital Rules have been fully phased-in. Capital levels required to be considered well capitalized are based upon prompt corrective action regulations, as amended to reflect the changes under the Basel III Capital Rules. See the 20162019 Form 10-K for a more detailed discussion of the Basel III Capital Rules. After a review of risk-weight classifications during the first quarter of 2019, risk-weightings for certain loans were reclassified. Amounts reported as of December 31, 2019 have been revised to reflect these reclassifications.
ActualMinimum Capital Required - Basel IIIRequired to be
Considered Well
Capitalized
Capital
Amount
RatioCapital
Amount
RatioCapital
Amount
Ratio
September 30, 2020
Common Equity Tier 1 to Risk-Weighted Assets
Cullen/Frost$3,003,029 12.71 %$1,654,073 7.00 %$1,535,925 6.50 %
Frost Bank3,010,290 12.76 1,651,191 7.00 1,533,249 6.50 
Tier 1 Capital to Risk-Weighted Assets
Cullen/Frost3,003,029 12.71 2,008,517 8.50 1,890,369 8.00 
Frost Bank3,010,290 12.76 2,005,018 8.50 1,887,076 8.00 
Total Capital to Risk-Weighted Assets
Cullen/Frost3,471,898 14.69 2,481,109 10.50 2,362,961 10.00 
Frost Bank3,246,159 13.76 2,476,787 10.50 2,358,845 10.00 
Leverage Ratio
Cullen/Frost3,003,029 7.85 1,530,584 4.00 1,913,230 5.00 
Frost Bank3,010,290 7.87 1,530,076 4.00 1,912,596 5.00 
Actual Minimum Capital Required - Basel III Phase-In Schedule Minimum Capital Required - Basel III Fully Phased-In 
Required to be
Considered Well
Capitalized
Capital
Amount
 Ratio 
Capital
Amount
 Ratio 
Capital
Amount
 Ratio 
Capital
Amount
 Ratio
September 30, 2017               
December 31, 2019December 31, 2019
Common Equity Tier 1 to Risk-Weighted Assets               Common Equity Tier 1 to Risk-Weighted Assets
Cullen/Frost$2,345,433
 12.38% $1,089,289
 5.75% $1,326,014
 7.00% $1,231,370
 6.50%Cullen/Frost$2,857,250 12.36 %$1,617,886 7.00 %$1,502,323 6.50 %
Frost Bank2,461,004
 13.02
 1,086,527
 5.75
 1,322,652
 7.00
 1,228,248
 6.50
Frost Bank2,958,326 12.82 1,615,206 7.00 1,499,834 6.50 
Tier 1 Capital to Risk-Weighted Assets               Tier 1 Capital to Risk-Weighted Assets
Cullen/Frost2,489,919
 13.14
 1,373,451
 7.25
 1,610,160
 8.50
 1,515,532
 8.00
Cullen/Frost3,001,736 12.99 1,964,576 8.50 1,849,013 8.00 
Frost Bank2,461,004
 13.02
 1,369,969
 7.25
 1,606,077
 8.50
 1,511,690
 8.00
Frost Bank2,958,326 12.82 1,961,322 8.50 1,845,950 8.00 
Total Capital to Risk-Weighted Assets               Total Capital to Risk-Weighted Assets
Cullen/Frost2,877,222
 15.19
 1,752,334
 9.25
 1,989,021
 10.50
 1,894,415
 10.00
Cullen/Frost3,367,403 14.57 2,426,829 10.50 2,311,266 10.00 
Frost Bank2,615,307
 13.84
 1,747,891
 9.25
 1,983,978
 10.50
 1,889,612
 10.00
Frost Bank3,090,993 13.40 2,422,809 10.50 2,307,438 10.00 
Leverage Ratio               Leverage Ratio
Cullen/Frost2,489,919
 8.39
 1,187,616
 4.00
 1,187,573
 4.00
 1,484,521
 5.00
Cullen/Frost3,001,736 9.28 1,293,188 4.00 1,616,485 5.00 
Frost Bank2,461,004
 8.29
 1,186,763
 4.00
 1,186,719
 4.00
 1,483,453
 5.00
Frost Bank2,958,326 9.15 1,292,743 4.00 1,615,929 5.00 
December 31, 2016               
Common Equity Tier 1 to Risk-Weighted Assets               
Cullen/Frost$2,239,186
 12.52% $916,360
 5.125% $1,251,425
 7.00% $1,162,213
 6.50%
Frost Bank2,296,480
 12.88
 913,460
 5.125
 1,247,463
 7.00
 1,158,535
 6.50
Tier 1 Capital to Risk-Weighted Assets               
Cullen/Frost2,383,672
 13.33
 1,184,563
 6.625
 1,519,587
 8.50
 1,430,416
 8.00
Frost Bank2,296,480
 12.88
 1,180,814
 6.625
 1,514,776
 8.50
 1,425,889
 8.00
Total Capital to Risk-Weighted Assets               
Cullen/Frost2,669,717
 14.93
 1,542,168
 8.625
 1,877,137
 10.50
 1,788,020
 10.00
Frost Bank2,449,525
 13.74
 1,537,286
 8.625
 1,871,194
 10.50
 1,782,361
 10.00
Leverage Ratio               
Cullen/Frost2,383,672
 8.14
 1,171,682
 4.00
 1,171,573
 4.00
 1,464,602
 5.00
Frost Bank2,296,480
 7.85
 1,170,249
 4.00
 1,170,141
 4.00
 1,462,812
 5.00
As of September 30, 2017,2020, capital levels at Cullen/Frost and Frost Bank exceed all capital adequacy requirements under the Basel III Capital Rules on a fully phased-in basis.Rules. Based on the ratios presented above, capital levels as of September 30, 20172020 at Cullen/Frost and Frost Bank exceed the minimum levels necessary to be considered “well capitalized.”
Cullen/Frost and Frost Bank are subject to the regulatory capital requirements administered by the Federal Reserve Board and, for Frost Bank, the Federal Deposit Insurance Corporation (“FDIC”). Regulatory authorities can initiate certain mandatory actions if Cullen/Frost or Frost Bank fail to meet the minimum capital requirements, which could have a direct material effect on our financial statements. Management believes, as of September 30, 2017,2020, that Cullen/Frost and Frost Bank meet all capital adequacy requirements to which they are subject.
Preferred Stock. On March 16, 2020, we redeemed all 6,000,000 shares of our 5.375% Non-Cumulative Perpetual Preferred Stock, Series A, (“Series A Preferred Stock”) at a redemption price of $25 per share, or an aggregate redemption of $150.0 million. When issued, the net proceeds of the Series A Preferred Stock totaled $144.5 million after deducting $5.5 million of issuance costs including the underwriting discount and professional service fees, among other things. Upon redemption, these issuance costs were reclassified to retained earnings and reported as a reduction of net income available to common shareholders.
Stock Repurchase Plans. From time to time, our board of directors has authorized stock repurchase plans. In general, stock repurchase plans allow us to proactively manage our capital position and return excess capital to shareholders. Shares purchased under such plans also provide us with shares of common stock necessary to satisfy obligations related to stock compensation
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Table of Contents
awards. On October 27, 2016,July 24, 2019, our board of directors authorized a $100.0 million stock repurchase program, allowing us to

repurchase shares of our common stock over a two-yearone-year period from time to time at various prices in the open market or through private transactions. During the three months ended September 30, 2017,Under this plan, we repurchased 1,134,966177,834 shares under the plan at at a total cost of $100.0 million.$13.7 million during the first quarter of 2020 and 202,724 shares at a total cost of $17.2 million during the third quarter of 2019. Under the Basel III Capital Rules, Cullen/Frost may not repurchase or redeem any of its subordinated notes and, in some cases, its common stock without the prior approval of the Federal Reserve Board.
Dividend Restrictions. In the ordinary course of business, Cullen/Frost is dependent upon dividends from Frost Bank to provide funds for the payment of dividends to shareholders and to provide for other cash requirements.requirements, including to repurchase its common stock. Banking regulations may limit the amount of dividends that may be paid. Approval by regulatory authorities is required if the effect of dividends declared would cause the regulatory capital of Frost Bank to fall below specified minimum levels. Approval is also required if dividends declared exceed the net profits for that year combined with the retained net profits for the preceding two years. Under the foregoing dividend restrictions and while maintaining its “well capitalized” status, at September 30, 2017,2020, Frost Bank could pay aggregate dividends of up to $480.2$482.1 million to Cullen/Frost without prior regulatory approval.
Under the terms of the junior subordinated deferrable interest debentures that Cullen/Frost has issued to Cullen/Frost Capital Trust II and WNB Capital Trust I, Cullen/Frost has the right at any time during the term of the debentures to defer the payment of interest at any time or from time to time for an extension period not exceeding 20 consecutive quarterly periods with respect to each extension period. In the event that we have elected to defer interest on the debentures, we may not, with certain exceptions, declare or pay any dividends or distributions on our capital stock or purchase or acquire any of our capital stock.
Under the terms of our Series A Preferred Stock, in the event that we do not declare and pay dividends on our Series A Preferred Stock for the most recent dividend period, we may not, with certain exceptions, declare or pay dividends on, or purchase, redeem or otherwise acquire, shares of our common stock or any of our securities that rank junior to our Series A Preferred Stock.
Note 98 - Derivative Financial Instruments
The fair value of derivative positions outstanding is included in accrued interest receivable and other assets and accrued interest payable and other liabilities in the accompanying consolidated balance sheets and in the net change in each of these financial statement line items in the accompanying consolidated statements of cash flows.
Interest Rate Derivatives. We utilize interest rate swaps, caps and floors to mitigate exposure to interest rate risk and to facilitate the needs of our customers. Our objectives for utilizing these derivative instruments are described in our 20162019 Form 10-K.
The notional amounts and estimated fair values of interest rate derivative contracts are presented in the following table. The fair values of interest rate derivative contracts are estimated utilizing internal valuation models with observable market data inputs, or as determined by the Chicago Mercantile Exchange (“CME”) for centrally cleared derivative contracts. Beginning in 2017, CME rules legally characterize variation margin payments for centrally cleared derivatives as settlements of the derivatives' exposure rather than collateral. As a result, the variation margin payment and the related derivative instruments are considered a single unit of account for accounting and financial reporting purposes. Variation margin, as determined by the CME, is settled daily. As a result, derivative contracts that clear through the CME have an estimated fair value of zero0 as of September 30, 2017.2020 and December 31, 2019.
September 30, 2020December 31, 2019
Notional
Amount
Estimated
Fair Value
Notional
Amount
Estimated
Fair Value
Derivatives designated as hedges of fair value:
Financial institution counterparties:
Loan/lease interest rate swaps – assets$$$2,545 $
Loan/lease interest rate swaps – liabilities4,036 (167)6,000 (138)
Non-hedging interest rate derivatives:
Financial institution counterparties:
Loan/lease interest rate swaps – assets122,788 67 
Loan/lease interest rate swaps – liabilities1,192,762 (36,975)1,002,860 (19,483)
Loan/lease interest rate caps – assets306,171 1,197 107,835 266 
Customer counterparties:
Loan/lease interest rate swaps – assets1,192,762 95,462 1,002,860 43,857 
Loan/lease interest rate swaps – liabilities122,788 (310)
Loan/lease interest rate caps – liabilities306,171 (1,197)107,835 (266)
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 September 30, 2017 December 31, 2016
 
Notional
Amount
 
Estimated
Fair Value
 
Notional
Amount
 
Estimated
Fair Value
Derivatives designated as hedges of fair value:       
Financial institution counterparties:       
Loan/lease interest rate swaps – assets$39,372
 $296
 $41,818
 $368
Loan/lease interest rate swaps – liabilities14,077
 (764) 18,812
 (1,278)
Non-hedging interest rate derivatives:       
Financial institution counterparties:       
Loan/lease interest rate swaps – assets206,930
 747
 206,745
 2,649
Loan/lease interest rate swaps – liabilities735,583
 (14,623) 694,965
 (25,466)
Loan/lease interest rate caps – assets114,744
 547
 85,966
 575
Customer counterparties:       
Loan/lease interest rate swaps – assets735,583
 22,384
 694,965
 25,467
Loan/lease interest rate swaps – liabilities206,930
 (2,442) 206,745
 (2,649)
Loan/lease interest rate caps – liabilities114,744
 (547) 85,966
 (575)

The weighted-average rates paid and received for interest rate swaps outstanding at September 30, 20172020 were as follows:
Weighted-AverageWeighted-Average
Interest
Rate
Paid
 
Interest
Rate
Received
Interest
Rate
Paid
Interest
Rate
Received
Interest rate swaps:   Interest rate swaps:
Fair value hedge loan/lease interest rate swaps2.32% 1.23%Fair value hedge loan/lease interest rate swaps3.39 %0.15 %
Non-hedging interest rate swaps – financial institution counterparties3.96% 2.84%Non-hedging interest rate swaps – financial institution counterparties4.00 1.93 
Non-hedging interest rate swaps – customer counterparties2.84% 3.96%Non-hedging interest rate swaps – customer counterparties1.93 4.00 
The weighted-average strike rate for outstanding interest rate caps was 3.07%3.67% at September 30, 2017.2020.
Commodity Derivatives. We enter into commodity swaps and option contracts that are not designated as hedging instruments primarily to accommodate the business needs of our customers. Upon the origination of a commodity swap or option contract with a customer, we simultaneously enter into an offsetting contract with a third party financial institution to mitigate the exposure to fluctuations in commodity prices.
The notional amounts and estimated fair values of non-hedging commodity swap and option derivative positions outstanding are presented in the following table. We obtain dealer quotations and use internal valuation models with observable market data inputs to value our commodity derivative positions.
September 30, 2020December 31, 2019
Notional
Units
Notional
Amount
Estimated
Fair Value
Notional
Amount
Estimated
Fair Value
Financial institution counterparties:
Oil – assetsBarrels2,296 $18,718 1,214 $2,796 
Oil – liabilitiesBarrels3,089 (9,132)2,148 (6,916)
Natural gas – assetsMMBTUs5,623 932 8,295 2,131 
Natural gas – liabilitiesMMBTUs18,181 (5,879)2,689 (70)
Customer counterparties:
Oil – assetsBarrels3,106 9,461 2,172 7,208 
Oil – liabilitiesBarrels2,279 (18,506)1,190 (2,652)
Natural gas – assetsMMBTUs19,940 6,161 2,689 83 
Natural gas – liabilitiesMMBTUs3,864 (915)8,295 (2,039)
   September 30, 2017 December 31, 2016
 
Notional
Units
 
Notional
Amount
 
Estimated
Fair Value
 
Notional
Amount
 
Estimated
Fair Value
Financial institution counterparties:         
Oil – assetsBarrels 977
 $1,530
 227
 $206
Oil – liabilitiesBarrels 1,082
 (1,311) 944
 (4,400)
Natural gas – assetsMMBTUs 3,351
 319
 
 
Natural gas – liabilitiesMMBTUs 1,546
 (81) 1,299
 (1,357)
Customer counterparties:         
Oil – assetsBarrels 1,096
 1,459
 944
 4,580
Oil – liabilitiesBarrels 963
 (1,327) 227
 (206)
Natural gas – assetsMMBTUs 1,546
 96
 1,299
 1,393
Natural gas – liabilitiesMMBTUs 3,351
 (285) 
 
Foreign Currency Derivatives. We enter into foreign currency forward contracts that are not designated as hedging instruments primarily to accommodate the business needs of our customers. Upon the origination of a foreign currency denominated transaction with a customer, we simultaneously enter into an offsetting contract with a third party financial institution to negate the exposure to fluctuations in foreign currency exchange rates. We also utilize foreign currency forward contracts that are not designated as hedging instruments to mitigate the economic effect of fluctuations in foreign currency exchange rates on foreign currency holdings and certain short-term, non-U.S. dollar denominated loans. The notional amounts and fair values of open foreign currency forward contracts were as follows:
 September 30, 2020December 31, 2019
Notional
Currency
Notional
Amount
Estimated
Fair Value
Notional
Amount
Estimated
Fair Value
Financial institution counterparties:
Forward contracts – liabilitiesCAD4,593 $(33)
Customer counterparties:
Forward contracts – assetsCAD4,583 45 
   September 30, 2017 December 31, 2016
 
Notional
Currency
 
Notional
Amount
 
Estimated
Fair Value
 
Notional
Amount
 
Estimated
Fair Value
Financial institution counterparties:         
Forward contracts – assetsEUR 135
 $1
 
 $
Forward contracts – assetsCAD 7,234
 15
 
 
Forward contracts – assetsGBP 547
 1
 
 
Forward contracts – assetsAUD 60
 1
 
 
Forward contracts – liabilitiesEUR 4,693
 (80) 870
 (9)
Forward contracts – liabilitiesCAD 
 
 2,214
 (21)
Forward contracts – liabilitiesGBP 1,075
 (24) 419
 (3)
Customer counterparties:         
Forward contracts – assetsEUR 3,867
 104
 
 
Forward contracts – assetsCAD 7,205
 15
 2,205
 29
Forward contracts – assetsGBP 192
 2
 
 

Gains, Losses and Derivative Cash Flows. For fair value hedges, the changes in the fair value of both the derivative hedging instrument and the hedged item are included in other non-interest income or other non-interest expense. The extent that such changes in fair value do not offset represents hedge ineffectiveness. Net cash flows from interest rate swaps on commercial loans/leases designated as hedging instruments in effective hedges of fair value are included in interest income on loans. For non-hedging derivative instruments, gains and losses due to changes in fair value and all cash flows are included in other non-interest income and other non-interest expense.
29

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Amounts included in the consolidated statements of income related to interest rate derivatives designated as hedges of fair value were as follows:
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended
September 30,
Nine Months Ended
September 30,
2017 2016 2017 20162020201920202019
Commercial loan/lease interest rate swaps:       Commercial loan/lease interest rate swaps:
Amount of gain (loss) included in interest income on loans$(149) $(331) $(592) $(1,057)Amount of gain (loss) included in interest income on loans$(36)$24 $(79)$78 
Amount of (gain) loss included in other non-interest expense(2) 4
 (5) (3)Amount of (gain) loss included in other non-interest expense(1)
As stated above, we enter into non-hedge related derivative positions primarily to accommodate the business needs of our customers. Upon the origination of a derivative contract with a customer, we simultaneously enter into an offsetting derivative contract with a third party financial institution. We recognize immediate income based upon the difference in the bid/ask spread of the underlying transactions with our customers and the third party. Because we act only as an intermediary for our customer, subsequent changes in the fair value of the underlying derivative contracts for the most part offset each other and do not significantly impact our results of operations.
During the first quarter of 2020, we sold certain non-hedge related, short-term put options on U.S. Treasury securities with an aggregate notional amount of $500 million and realized gains totaling approximately $6.0 million in connection with the sales. The put options were not exercised and expired in March 2020.
Amounts included in the consolidated statements of income related to non-hedging interest rate, commodity and foreign currencynon-hedge related derivative instruments are presented in the table below.
Three Months Ended
September 30,
Nine Months Ended
September 30,
2020201920202019
Non-hedging interest rate derivatives:
Other non-interest income$280 $215 $2,615 $1,188 
Other non-interest expense
Non-hedging commodity derivatives:
Other non-interest income379 109 1,057 322 
Non-hedging foreign currency derivatives:
Other non-interest income10 12 28 41 
Non-hedging put options:
Other non-interest income5,980 
 Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
 2017 2016 2017 2016
Non-hedging interest rate derivatives:       
Other non-interest income$1,085
 $374
 $2,062
 $1,788
Other non-interest expense
 
 1
 
Non-hedging commodity derivatives:       
Other non-interest income231
 110
 387
 255
Non-hedging foreign currency derivatives:       
Other non-interest income83
 8
 101
 22
Counterparty Credit Risk. Our credit exposure relating to interest rate swaps, commodity swaps/options and foreign currency forward contracts with bank customers was approximately $23.6$103.0 million at September 30, 2017.2020. This credit exposure is partly mitigated as transactions with customers are generally secured by the collateral, if any, securing the underlying transaction being hedged. Our credit exposure, net of collateral pledged, relating to interest rate swaps, commodity swaps/options and foreign currency forward contracts with upstream financial institution counterparties was approximately $10.3$19.2 million at September 30, 2017.2020. This amount was primarily related to initial margin payments to the CME and excess collateral we posted to counterparties. Collateral levels for upstream financial institution counterparties are monitored and adjusted as necessary. See Note 109 – Balance Sheet Offsetting and Repurchase Agreements for additional information regarding our credit exposure with upstream financial institution counterparties.
The aggregate fair value of securities At September 30, 2020, we posted ashad $48.6 million in cash collateral related to derivative contracts totaled $13.2 million at September 30, 2017. At such date, we also had $10.6 million in cash collateral on deposit with other financial institution counterparties.

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Note 109 - Balance Sheet Offsetting and Repurchase Agreements
Balance Sheet Offsetting. Certain financial instruments, including resell and repurchase agreements and derivatives, may be eligible for offset in the consolidated balance sheet and/or subject to master netting arrangements or similar agreements. Our derivative transactions with upstream financial institution counterparties are generally executed under International Swaps and Derivative Association (“ISDA”) master agreements which include “right of set-off” provisions. In such cases there is generally a legally enforceable right to offset recognized amounts and there may be an intention to settle such amounts on a net basis. Nonetheless, we do not generally offset such financial instruments for financial reporting purposes.
Information about financial instruments that are eligible for offset in the consolidated balance sheet as of September 30, 20172020 is presented in the following tables.
Gross Amount
Recognized
Gross Amount
Offset
Net Amount
Recognized
September 30, 2020
Financial assets:
Derivatives:
Loan/lease interest rate swaps and caps$1,197 $$1,197 
Commodity swaps and options19,650 19,650 
Foreign currency forward contracts
Total derivatives20,847 20,847 
Resell agreements20,000 20,000 
Total$40,847 $$40,847 
Financial liabilities:
Derivatives:
Loan/lease interest rate swaps$37,142 $$37,142 
Commodity swaps and options15,011 15,011 
Foreign currency forward contracts
Total derivatives52,153 52,153 
Repurchase agreements1,574,367 1,574,367 
Total$1,626,520 $$1,626,520 
Gross Amounts Not Offset
Net Amount
Recognized
Financial
Instruments
CollateralNet
Amount
September 30, 2020
Financial assets:
Derivatives:
Counterparty A$$(8)$$
Counterparty B5,996 (5,996)
Other counterparties14,843 (14,510)(327)
Total derivatives20,847 (20,514)(327)
Resell agreements20,000 (20,000)
Total$40,847 $(20,514)$(20,327)$
Financial liabilities:
Derivatives:
Counterparty A$7,178 $(8)$(7,170)$
Counterparty B14,386 (5,996)(8,210)180 
Counterparty C94 (94)
Other counterparties30,495 (14,510)(13,971)2,014 
Total derivatives52,153 (20,514)(29,445)2,194 
Repurchase agreements1,574,367 (1,574,367)
Total$1,626,520 $(20,514)$(1,603,812)$2,194 
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Gross Amount
Recognized
 
Gross Amount
Offset
 
Net Amount
Recognized
September 30, 2017     
Financial assets:     
Derivatives:     
Loan/lease interest rate swaps and caps$1,590
 $
 $1,590
Commodity swaps and options1,849
 
 1,849
Foreign currency forward contracts18
 
 18
Total derivatives3,457
 
 3,457
Resell agreements17,642
 
 17,642
Total$21,099
 $
 $21,099
Financial liabilities:     
Derivatives:     
Loan/lease interest rate swaps$15,387
 $
 $15,387
Commodity swaps and options1,392
 
 1,392
Foreign currency forward contracts104
 
 104
Total derivatives16,883
 
 16,883
Repurchase agreements987,869
 
 987,869
Total$1,004,752
 $
 $1,004,752
   Gross Amounts Not Offset  
 
Net Amount
Recognized
 
Financial
Instruments
 Collateral 
Net
Amount
September 30, 2017       
Financial assets:       
Derivatives:       
Counterparty A$397
 $(397) $
 $
Counterparty B866
 (866) 
 
Counterparty C204
 (204) 
 
Counterparty D
 
 
 
Other counterparties1,990
 (1,631) (130) 229
Total derivatives3,457
 (3,098) (130) 229
Resell agreements17,642
 
 (17,642) 
Total$21,099
 $(3,098) $(17,772) $229
Financial liabilities:       
Derivatives:       
Counterparty A$8,984
 $(397) $(8,587) $
Counterparty B3,535
 (866) (2,669) 
Counterparty C1,128
 (204) (830) 94
Counterparty D
 
 
 
Other counterparties3,236
 (1,631) (1,605) 
Total derivatives16,883
 (3,098) (13,691) 94
Repurchase agreements987,869
 
 (987,869) 
Total$1,004,752
 $(3,098) $(1,001,560) $94

Information about financial instruments that are eligible for offset in the consolidated balance sheet as of December 31, 20162019 is presented in the following tables.
Gross Amount
Recognized
Gross Amount
Offset
Net Amount
Recognized
December 31, 2019
Financial assets:
Derivatives:
Loan/lease interest rate swaps and caps$339 $$339 
Commodity swaps and options4,927 4,927 
Total derivatives5,266 5,266 
Resell agreements31,299 31,299 
Total$36,565 $$36,565 
Financial liabilities:
Derivatives:
Loan/lease interest rate swaps$19,621 $$19,621 
Commodity swaps and options6,986 6,986 
Foreign currency forward contracts33 33 
Total derivatives26,640 26,640 
Repurchase agreements1,668,142 1,668,142 
Total$1,694,782 $$1,694,782 
Gross Amounts Not Offset
Net Amount
Recognized
Financial
Instruments
CollateralNet
Amount
December 31, 2019
Financial assets:
Derivatives:
Counterparty A$39 $(39)$$
Counterparty B1,650 (1,650)
Counterparty C(1)
Other counterparties3,576 (3,546)30 
Total derivatives5,266 (5,236)30 
Resell agreements31,299 (31,299)
Total$36,565 $(5,236)$(31,299)$30 
Financial liabilities:
Derivatives:
Counterparty A$5,192 $(39)$(5,153)$
Counterparty B7,424 (1,650)(5,774)
Counterparty C135 (1)(134)
Other counterparties13,889 (3,546)(10,343)
Total derivatives26,640 (5,236)(21,404)
Repurchase agreements1,668,142 (1,668,142)
Total$1,694,782 $(5,236)$(1,689,546)$
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Table of Contents
 
Gross Amount
Recognized
 
Gross Amount
Offset
 
Net Amount
Recognized
December 31, 2016     
Financial assets:     
Derivatives:     
Loan/lease interest rate swaps and caps$3,592
 $
 $3,592
Commodity swaps and options206
 
 206
Foreign currency forward contracts
 
 
Total derivatives3,798
 
 3,798
Resell agreements9,642
 
 9,642
Total$13,440
 $
 $13,440
Financial liabilities:     
Derivatives:     
Loan/lease interest rate swaps$26,744
 $
 $26,744
Commodity swaps and options5,757
 
 5,757
Foreign currency forward contracts33
 
 33
Total derivatives32,534
 
 32,534
Repurchase agreements963,317
 
 963,317
Total$995,851
 $
 $995,851
   Gross Amounts Not Offset  
 
Net Amount
Recognized
 
Financial
Instruments
 Collateral 
Net
Amount
December 31, 2016       
Financial assets:       
Derivatives:       
Counterparty A$687
 $(687) $
 $
Counterparty B223
 (223) 
 
Counterparty C158
 (158) 
 
Counterparty D1,820
 (1,820) 
 
Other counterparties910
 (677) (64) 169
Total derivatives3,798
 (3,565) (64) 169
Resell agreements9,642
 
 (9,642) 
Total$13,440
 $(3,565) $(9,706) $169
Financial liabilities:       
Derivatives:       
Counterparty A$11,233
 $(687) $(10,026) $520
Counterparty B6,867
 (223) (6,344) 300
Counterparty C4,578
 (158) (4,415) 5
Counterparty D7,706
 (1,820) (5,886) 
Other counterparties2,150
 (677) (676) 797
Total derivatives32,534
 (3,565) (27,347) 1,622
Repurchase agreements963,317
 
 (963,317) 
Total$995,851
 $(3,565) $(990,664) $1,622

Repurchase Agreements. We utilize securities sold under agreements to repurchase to facilitate the needs of our customers and to facilitate secured short-term funding needs. Securities sold under agreements to repurchase are stated at the amount of cash received in connection with the transaction. We monitor collateral levels on a continuous basis. We may be required to provide additional collateral based on the fair value of the underlying securities. Securities pledged as collateral under repurchase agreements are maintained with our safekeeping agents.
The remaining contractual maturity of repurchase agreements in the consolidated balance sheets as of September 30, 20172020 and December 31, 20162019 is presented in the following tables.
Remaining Contractual Maturity of the Agreements
Overnight and ContinuousUp to 30 Days30-90 DaysGreater than 90 DaysTotal
September 30, 2020
Repurchase agreements:
U.S. Treasury$99,365 $$$$99,365 
Residential mortgage-backed securities1,475,002 1,475,002 
Total borrowings$1,574,367 $$$$1,574,367 
Gross amount of recognized liabilities for repurchase agreements$1,574,367 
Amounts related to agreements not included in offsetting disclosures above$
December 31, 2019
Repurchase agreements:
U.S. Treasury$435,904 $$$$435,904 
Residential mortgage-backed securities1,232,238 1,232,238 
Total borrowings$1,668,142 $$$$1,668,142 
Gross amount of recognized liabilities for repurchase agreements$1,668,142 
Amounts related to agreements not included in offsetting disclosures above$
 Remaining Contractual Maturity of the Agreements
 Overnight and Continuous Up to 30 Days 30-90 Days Greater than 90 Days Total
September 30, 2017         
Repurchase agreements:         
U.S. Treasury$907,509
 $
 $
 $
 $907,509
Residential mortgage-backed securities80,360
 
 
 
 80,360
Total borrowings$987,869
 $
 $
 $
 $987,869
Gross amount of recognized liabilities for repurchase agreements $987,869
Amounts related to agreements not included in offsetting disclosures above $
          
December 31, 2016         
Repurchase agreements:         
U.S. Treasury$841,475
 $
 $
 $
 $841,475
Residential mortgage-backed securities121,842
 
 
 
 121,842
Total borrowings$963,317
 $
 $
 $
 $963,317
Gross amount of recognized liabilities for repurchase agreements $963,317
Amounts related to agreements not included in offsetting disclosures above $
Note 1110 - Stock-Based Compensation
A combined summary of activity in our active stock plans is presented in the table. Performance stock units outstanding are presented assuming attainment of the maximum payout rate as set forth by the performance criteria. The target award level for performance stock units granted in 2016 was 29,240.As of September 30, 2017,2020, there were 1,499,3991,109,864 shares remaining available for grant for future stock-based compensation awards.
Director Deferred
Stock Units
Outstanding
Non-Vested Stock
Awards/Stock Units
Outstanding
Performance Stock Units OutstandingStock Options
Outstanding
Number of UnitsWeighted-
Average
Fair Value
at Grant
Number
of Shares/Units
Weighted-
Average
Fair Value
at Grant
Number of UnitsWeighted-
Average
Fair Value
at Grant
Number
of Shares
Weighted-
Average
Exercise
Price
Balance, January 1, 202055,370 $74.76 440,647 $90.22 177,288 $83.48 1,980,866 $64.60 
Authorized— — — — — — — — 
Granted10,428 73.84 458 65.43 — — — — 
Exercised/vested(12,938)71.09 (1,640)76.07 (41,755)69.70 (140,615)53.65 
Forfeited/expired— — (2,813)90.20 (6,894)81.33 (5,427)75.74 
Balance, September 30, 202052,860 $75.47 436,652 $90.24 128,639 $88.07 1,834,824 $65.41 
33

  
Director Deferred
Stock Units
Outstanding
 
Non-Vested Stock
Awards/Stock Units
Outstanding
 Performance Stock Units Outstanding 
Stock Options
Outstanding
  Number of Units 
Weighted-
Average
Fair Value
at Grant
 
Number
of Shares/Units
 
Weighted-
Average
Fair Value
at Grant
 Number of Units 
Weighted-
Average
Fair Value
at Grant
 
Number
of Shares
 
Weighted-
Average
Exercise
Price
Balance, January 1, 2017 53,659
 $61.48
 256,850
 $73.43
 43,860
 $69.70
 4,089,028
 $62.67
Authorized 
 
 
 
 
 
 
 
Granted 5,447
 95.37
 
 
 
 
 
 
Exercised/vested (6,098) 62.29
 (1,730) 76.07
 
 
 (766,971) 59.22
Forfeited/expired 
 
 (2,860) 76.07
 
 
 (50,764) 69.65
Balance, September 30, 2017 53,008
 $64.87
 252,260
 $73.38
 43,860
 $69.70
 3,271,293
 $63.37
Table of Contents

Shares issued in connection with stock compensation awards are issued from available treasury shares. If no treasury shares are available, new shares are issued from available authorized shares. Shares issued in connection with stock compensation awards along with other related information were as follows:
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended
September 30,
Nine Months Ended
September 30,
2017 2016 2017 20162020201920202019
New shares issued from available authorized shares9,299
 
 602,662
 
New shares issued from available authorized shares
Issued from available treasury stock13,425
 841,846
 172,137
 908,921
Issued from available treasury stock53,425 71,284 196,948 225,184 
Total22,724
 841,846
 774,799
 908,921
Total53,425 71,284 196,948 225,184 
       
Proceeds from stock option exercises$1,274
 $44,287
 $45,422
 $47,873
Proceeds from stock option exercises$2,698 $5,665 $7,544 $13,506 
Stock-based compensation expense is recognized ratably over the requisite service period for all awards. For most stock option awards, the service period generally matches the vesting period. For stock options granted to certain executive officers and for non-vested stock units granted to all participants, the service period does not extend past the date the participant reaches 65 years of age. Deferred stock units granted to non-employee directors generally have immediate vesting and the related expense is fully recognized on the date of grant. For performance stock units, the service period generally matches the three-year performance period specified by the award, however, the service period does not extend past the date the participant reaches 65 years of age. Expense recognized each period is dependent upon our estimate of the number of shares that will ultimately be issued.
Stock-based compensation expense and the related income tax benefit is presented in the following table.
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended
September 30,
Nine Months Ended
September 30,
2017 2016 2017 20162020201920202019
Stock options$1,532
 $2,163
 $4,892
 $6,405
Stock options$$330 $$1,091 
Non-vested stock awards/stock units813
 358
 2,747
 1,073
Non-vested stock awards/stock units1,999 1,536 6,325 5,727 
Director deferred stock units
 
 519
 520
Director deferred stock units770 780 
Performance stock units377
 
 855
 
Performance stock units444 809 1,132 3,095 
Total$2,722
 $2,521
 $9,013
 $7,998
Total$2,443 $2,675 $8,227 $10,693 
Income tax benefit$953
 $882
 $3,155
 $2,799
Income tax benefit$450 $452 $1,539 $1,768 
Unrecognized stock-based compensation expense at September 30, 20172020 is presented in the table below. Unrecognized stock-based compensation expense related to performance stock units is presented assuming attainment of the maximum payout rate as set forth by the performance criteria.
Non-vested stock awards/stock units$12,337 
Performance stock units4,651 
Total$16,988 
34
Stock options$6,952
Non-vested stock awards/stock units7,448
Performance stock units2,202
Total$16,602


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Note 1211 - Earnings Per Common Share
Earnings per common share is computed using the two-class method as more fully described in our 20162019 Form 10-K. The following table presents a reconciliation of net income available to common shareholders, net earnings allocated to common stock and the number of shares used in the calculation of basic and diluted earnings per common share.
Three Months Ended
September 30,
Nine Months Ended
September 30,
2020201920202019
Net income$95,056 $111,836 $242,881 $339,918 
Less: Preferred stock dividends2,016 2,016 6,047 
Redemption of preferred stock5,514 
Net income available to common shareholders95,056 109,820 235,351 333,871 
Less: Earnings allocated to participating securities877 876 2,236 2,761 
Net earnings allocated to common stock$94,179 $108,944 $233,115 $331,110 
Distributed earnings allocated to common stock$44,546 $44,370 $133,511 $131,069 
Undistributed earnings allocated to common stock49,633 64,574 99,604 200,041 
Net earnings allocated to common stock$94,179 $108,944 $233,115 $331,110 
Weighted-average shares outstanding for basic earnings per common share62,726,542 62,566,128 62,655,393 62,786,501 
Dilutive effect of stock compensation193,116 592,866 263,028 725,911 
Weighted-average shares outstanding for diluted earnings per common share62,919,658 63,158,994 62,918,421 63,512,412 
 Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
 2017 2016 2017 2016
Net income$93,131
 $80,219
 $263,625
 $220,542
Less: Preferred stock dividends2,016
 2,016
 6,047
 6,047
Net income available to common shareholders91,115
 78,203
 257,578
 214,495
Less: Earnings allocated to participating securities475
 282
 1,346
 769
Net earnings allocated to common stock$90,640
 $77,921
 $256,232
 $213,726
        
Distributed earnings allocated to common stock$36,174
 $33,918
 $107,194
 $100,203
Undistributed earnings allocated to common stock54,466
 44,003
 149,038
 113,523
Net earnings allocated to common stock$90,640
 $77,921
 $256,232
 $213,726
        
Weighted-average shares outstanding for basic earnings per common share63,667,356
 62,449,660
 63,822,011
 62,114,075
Dilutive effect of stock compensation897,945
 691,543
 957,337
 448,290
Weighted-average shares outstanding for diluted earnings per common share64,565,301
 63,141,203
 64,779,348
 62,562,365
Note 1312 - Defined Benefit Plans
The components of the combined net periodic expense (benefit) for our defined benefit pension plans are presented in the table below.
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended
September 30,
Nine Months Ended
September 30,
2017 2016 2017 20162020201920202019
Expected return on plan assets, net of expenses$(2,779) $(2,890) $(8,338) $(8,669)Expected return on plan assets, net of expenses$(3,073)$(2,693)$(9,217)$(8,079)
Interest cost on projected benefit obligation1,547
 1,732
 4,642
 5,230
Interest cost on projected benefit obligation1,252 1,618 3,757 4,854 
Net amortization and deferral1,357
 1,585
 4,072
 4,691
Net amortization and deferral1,330 1,406 3,989 4,218 
SERP settlement costs
 
 
 187
Net periodic expense (benefit)$125
 $427
 $376
 $1,439
Net periodic expense (benefit)$(491)$331 $(1,471)$993 
Our non-qualified defined benefit pension plan is not funded. NoNaN contributions to the qualified defined benefit pension plan were made during the nine months ended September 30, 2017.2020. We do not expect to make any contributions to the qualified defined benefit plan during the remainder of 2017.2020.

Note 1413 - Income Taxes
Income tax expense was as follows:
Three Months Ended
September 30,
Nine Months Ended
September 30,
2020201920202019
Current income tax expense (benefit)$(33,614)$14,480 $20,328 $43,984 
Deferred income tax expense (benefit)43,130 (950)(8,803)(1,625)
Income tax expense, as reported$9,516 $13,530 $11,525 $42,359 
Effective tax rate9.1 %10.8 %4.5 %11.1 %
 Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
 2017 2016 2017 2016
Current income tax expense$15,224
 $12,848
 $44,636
 $40,251
Deferred income tax expense (benefit)(5,332) (1,996) (9,505) (11,629)
Income tax expense, as reported$9,892
 $10,852
 $35,131
 $28,622
        
Effective tax rate9.6% 11.9% 11.8% 11.5%
NetWe had a net deferred tax assets totaled $28.9liability totaling $122.4 million at September 30, 20172020 and $63.7$75.8 million at December 31, 2016. No2019. NaN valuation allowance for deferred tax assets was recorded at September 30, 20172020 as management believes it is more likely than not that all of the deferred tax assets will be realized because they were supported by recoverable taxes paid in prior years.against deferred tax liabilities and projected future taxable income.
The effective income tax rates differed from the U.S. statutory ratefederal income tax rates of 35%21% during the comparable periods primarily due to the effect of tax-exempt income from loans, securities and life insurance policies and the income tax effects associated with stock-based compensation. The effective income tax rates for the three and nine months ended September 30, 2017during 2020 were also impacted by a one-time, discrete tax benefit associated with an asset contribution to a charitable trust during the correction of an over-accrual of taxes that resulted from incorrectly classifying certain tax-exempt loans as taxable for federal income tax purposes since 2013. As a result, we recognized tax benefits totaling $3.7 million, which included $2.9 million related to the 2013 through 2016 tax years and $756 thousand related to the first and second quarters of 2017.quarter. There were no 0
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unrecognized tax benefits during any of the reported periods. Interest and/or penalties related to income taxes are reported as a component of income tax expense. Such amounts were not significant during the reported periods.
We file income tax returns in the U.S. federal jurisdiction. We are no longer subject to U.S. federal income tax examinations by tax authorities for years before 2013.2016.

Note 1514 - Other Comprehensive Income (Loss)
The before and after tax amounts allocated to each component of other comprehensive income (loss) are presented in the following table. Reclassification adjustments related to securities available for sale are included in net gain (loss) on securities transactions in the accompanying consolidated statements of income. Reclassification adjustments related to defined-benefit post-retirement benefit plans are included in the computation of net periodic pension expense (see Note 1312 – Defined Benefit Plans).
Three Months Ended
September 30, 2020
Three Months Ended
September 30, 2019
Before Tax
Amount
Tax  Expense,
(Benefit)
Net of  Tax
Amount
Before Tax
Amount
Tax  Expense,
(Benefit)
Net of  Tax
Amount
Securities available for sale and transferred securities:
Change in net unrealized gain/loss during the period$20,332 $4,269 $16,063 $107,786 $22,635 $85,151 
Change in net unrealized gain on securities transferred to held to maturity(294)(62)(232)(305)(64)(241)
Reclassification adjustment for net (gains) losses included in net income(97)(21)(76)
Total securities available for sale and transferred securities20,038 4,207 15,831 107,384 22,550 84,834 
Defined-benefit post-retirement benefit plans:
Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit)1,330 280 1,050 1,406 295 1,111 
Total defined-benefit post-retirement benefit plans1,330 280 1,050 1,406 295 1,111 
Total other comprehensive income (loss)$21,368 $4,487 $16,881 $108,790 $22,845 $85,945 
Nine Months Ended
September 30, 2020
Nine Months Ended
September 30, 2019
Before Tax
Amount
Tax  Expense,
(Benefit)
Net of  Tax
Amount
Before Tax
Amount
Tax  Expense,
(Benefit)
Net of  Tax
Amount
Securities available for sale and transferred securities:
Change in net unrealized gain/loss during the period$406,959 $85,462 $321,497 $464,072 $97,455 $366,617 
Change in net unrealized gain on securities transferred to held to maturity(979)(206)(773)(957)(201)(756)
Reclassification adjustment for net (gains) losses included in net income(108,989)(22,888)(86,101)(266)(56)(210)
Total securities available for sale and transferred securities296,991 62,368 234,623 462,849 97,198 365,651 
Defined-benefit post-retirement benefit plans:
Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit)3,989 837 3,152 4,218 886 3,332 
Total defined-benefit post-retirement benefit plans3,989 837 3,152 4,218 886 3,332 
Total other comprehensive income (loss)$300,980 $63,205 $237,775 $467,067 $98,084 $368,983 
36

 Three Months Ended 
 September 30, 2017
 Three Months Ended 
 September 30, 2016
 
Before Tax
Amount
 
Tax  Expense,
(Benefit)
 
Net of  Tax
Amount
 
Before Tax
Amount
 
Tax  Expense,
(Benefit)
 
Net of  Tax
Amount
Securities available for sale and transferred securities:           
Change in net unrealized gain/loss during the period$7,082
 $2,479
 $4,603
 $(95,641) $(33,473) $(62,168)
Change in net unrealized gain on securities transferred to held to maturity(3,514) (1,230) (2,284) (7,278) (2,547) (4,731)
Reclassification adjustment for net (gains) losses included in net income4,867
 1,703
 3,164
 37
 12
 25
Total securities available for sale and transferred securities8,435
 2,952
 5,483
 (102,882) (36,008) (66,874)
Defined-benefit post-retirement benefit plans:           
Change in the net actuarial gain/loss
 
 
 
 
 
Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit)1,357
 475
 882
 1,585
 555
 1,030
Total defined-benefit post-retirement benefit plans1,357
 475
 882
 1,585
 555
 1,030
Total other comprehensive income (loss)$9,792
 $3,427
 $6,365
 $(101,297) $(35,453) $(65,844)
 
 Nine Months Ended 
 September 30, 2017
 Nine Months Ended 
 September 30, 2016
 
Before Tax
Amount
 
Tax  Expense,
(Benefit)
 
Net of  Tax
Amount
 
Before Tax
Amount
 
Tax  Expense,
(Benefit)
 
Net of  Tax
Amount
Securities available for sale and transferred securities:           
Change in net unrealized gain/loss during the period$131,283
 $45,949
 $85,334
 $191,865
 $67,154
 $124,711
Change in net unrealized gain on securities transferred to held to maturity(13,660) (4,781) (8,879) (24,629) (8,620) (16,009)
Reclassification adjustment for net (gains) losses included in net income4,917
 1,721
 3,196
 (14,866) (5,204) (9,662)
Total securities available for sale and transferred securities122,540
 42,889
 79,651
 152,370
 53,330
 99,040
Defined-benefit post-retirement benefit plans:           
Change in the net actuarial gain/loss
 
 
 (862) (302) (560)
Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit)4,072
 1,425
 2,647
 4,878
 1,708
 3,170
Total defined-benefit post-retirement benefit plans4,072
 1,425
 2,647
 4,016
 1,406
 2,610
Total other comprehensive income (loss)$126,612
 $44,314
 $82,298
 $156,386
 $54,736
 $101,650
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Activity in accumulated other comprehensive income (loss), net of tax, was as follows:
Securities
Available
For Sale
Defined
Benefit
Plans
Accumulated
Other
Comprehensive
Income
Balance January 1, 2020$313,304 $(45,934)$267,370 
Other comprehensive income (loss) before reclassifications320,724 320,724 
Reclassification of amounts included in net income(86,101)3,152 (82,949)
Net other comprehensive income (loss) during period234,623 3,152 237,775 
Balance at September 30, 2020$547,927 $(42,782)$505,145 
Balance January 1, 2019$(16,103)$(47,497)$(63,600)
Other comprehensive income (loss) before reclassifications365,861 365,861 
Reclassification of amounts included in net income(210)3,332 3,122 
Net other comprehensive income (loss) during period365,651 3,332 368,983 
Balance at September 30, 2019$349,548 $(44,165)$305,383 
 
Securities
Available
For Sale
 
Defined
Benefit
Plans
 
Accumulated
Other
Comprehensive
Income
Balance January 1, 2017$16,153
 $(40,776) $(24,623)
Other comprehensive income (loss) before reclassifications76,455
 
 76,455
Amounts reclassified from accumulated other comprehensive income (loss)3,196
 2,647
 5,843
Net other comprehensive income (loss) during period79,651
 2,647
 82,298
Balance at September 30, 2017$95,804
 $(38,129) $57,675
      
Balance January 1, 2016$160,611
 $(46,748) $113,863
Other comprehensive income (loss) before reclassifications108,702
 2,489
 111,191
Amounts reclassified from accumulated other comprehensive income (loss)(9,662) 121
 (9,541)
Net other comprehensive income (loss) during period99,040
 2,610
 101,650
Balance at September 30, 2016$259,651
 $(44,138) $215,513
Note 1615 – Operating Segments
We are managed under a matrix organizational structure whereby our two2 primary operating segments, Banking and Frost Wealth Advisors, overlap a regional reporting structure. See our 20162019 Form 10-K for additional information regarding our operating segments. Summarized operating results by segment were as follows:
BankingFrost  Wealth
Advisors
Non-BanksConsolidated
Revenues from (expenses to) external customers:
Three months ended:
September 30, 2020$293,855 $35,282 $(2,113)$327,024 
September 30, 2019307,312 37,549 (2,630)342,231 
Nine months ended:
September 30, 2020$1,003,469 $111,493 $(7,090)$1,107,872 
September 30, 2019918,672 111,064 (8,182)1,021,554 
Net income (loss):
Three months ended:
September 30, 2020$93,507 $4,130 $(2,581)$95,056 
September 30, 2019110,583 4,106 (2,853)111,836 
Nine months ended:
September 30, 2020$238,023 $13,642 $(8,784)$242,881 
September 30, 2019334,393 15,403 (9,878)339,918 
 Banking 
Frost  Wealth
Advisors
 Non-Banks Consolidated
Revenues from (expenses to) external customers:       
Three months ended:       
September 30, 2017$266,582
 $36,529
 $(2,285) $300,826
September 30, 2016244,343
 33,536
 (1,258) 276,621
Nine months ended:       
September 30, 2017$786,743
 $107,829
 $(5,669) $888,903
September 30, 2016737,060
 97,484
 (3,537) 831,007
Net income (loss):       
Three months ended:       
September 30, 2017$88,368
 $6,417
 $(1,654) $93,131
September 30, 201676,347
 4,797
 (925) 80,219
Nine months ended:       
September 30, 2017$250,766
 $17,990
 $(5,131) $263,625
September 30, 2016210,454
 13,809
 (3,721) 220,542

Note 1716 – Fair Value Measurements
The fair value of an asset or liability is the price that would be received to sell that asset or paid to transfer that liability in an orderly transaction occurring in the principal market (or most advantageous market in the absence of a principal market) for such asset or liability. In estimating fair value, we utilize valuation techniques that are consistent with the market approach, the income approach and/or the cost approach. Such valuation techniques are consistently applied. Inputs to valuation techniques include the assumptions that market participants would use in pricing an asset or liability. ASC Topic 820 establishes a three-level fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. See our 20162019 Form 10-K for additional information regarding the fair value hierarchy and a description of our valuation techniques.
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Financial Assets and Financial Liabilities. The tabletables below summarizessummarize financial assets and financial liabilities measured at fair value on a recurring basis as of September 30, 20172020 and December 31, 2016,2019, segregated by the level of the valuation inputs within the fair value hierarchy of ASC Topic 820 utilized to measure fair value.
Level 1 InputsLevel 2 InputsLevel 3 InputsTotal Fair Value
September 30, 2020
Securities available for sale:
U.S. Treasury$1,124,965 $— $— $1,124,965 
Residential mortgage-backed securities— 2,164,162 — 2,164,162 
States and political subdivisions— 7,273,005 — 7,273,005 
Other— 42,348 — 42,348 
Trading account securities:
U.S. Treasury24,495 — — 24,495 
States and political subdivisions— 1,313 — 1,313 
Derivative assets:
Interest rate swaps, caps and floors— 96,659 — 96,659 
Commodity swaps and options— 35,272 — 35,272 
Foreign currency forward contracts— — — — 
Derivative liabilities:
Interest rate swaps, caps and floors— 38,339 — 38,339 
Commodity swaps and options— 34,432 — 34,432 
Foreign currency forward contracts— — — — 
Level 1
Inputs
 Level 2
Inputs
 Level 3
Inputs
 Total Fair
Value
September 30, 2017       
December 31, 2019December 31, 2019
Securities available for sale:       Securities available for sale:
U.S. Treasury$3,473,628
 $
 $
 $3,473,628
U.S. Treasury$1,948,133 $— $— $1,948,133 
Residential mortgage-backed securities
 681,195
 
 681,195
Residential mortgage-backed securities— 2,207,594 — 2,207,594 
States and political subdivisions
 5,987,739
 
 5,987,739
States and political subdivisions— 7,070,997 — 7,070,997 
Other
 42,538
 
 42,538
Other— 42,867 — 42,867 
Trading account securities:       Trading account securities:
U.S. Treasury18,814
 
 
 18,814
U.S. Treasury24,298 — — 24,298 
States and political subdivisions
 907
 
 907
Derivative assets:       Derivative assets:
Interest rate swaps, caps and floors
 23,974
 
 23,974
Interest rate swaps, caps and floors— 44,196 — 44,196 
Commodity swaps and options
 3,404
 
 3,404
Commodity swaps and options— 12,218 — 12,218 
Foreign currency forward contracts139
 
 
 139
Foreign currency forward contracts45 — — 45 
Derivative liabilities:       Derivative liabilities:
Interest rate swaps, caps and floors
 18,376
 
 18,376
Interest rate swaps, caps and floors— 20,197 — 20,197 
Commodity swaps and options
 3,004
 
 3,004
Commodity swaps and options— 11,677 — 11,677 
Foreign currency forward contracts104
 
 
 104
Foreign currency forward contracts33 — — 33 
December 31, 2016       
Securities available for sale:       
U.S. Treasury$4,019,731
 $
 $
 $4,019,731
Residential mortgage-backed securities
 785,167
 
 785,167
States and political subdivisions
 5,355,885
 
 5,355,885
Other
 42,494
 
 42,494
Trading account securities:       
U.S. Treasury16,594
 
 
 16,594
States and political subdivisions
 109
 
 109
Derivative assets:       
Interest rate swaps, caps and floors
 29,059
 
 29,059
Commodity swaps and options
 6,179
 
 6,179
Foreign currency forward contracts29
 
 
 29
Derivative liabilities:       
Interest rate swaps, caps and floors
 29,968
 
 29,968
Commodity swaps and options
 5,963
 
 5,963
Foreign currency forward contracts33
 
 
 33
Certain financial assets and financial liabilities are measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment).circumstances. Financial assets measured at fair value on a non-recurring basis during the reported periods include certain impairedcollateral dependent loans reported at the fair value of the underlying collateral if repayment is expected solely from the collateral.
The following table presents impairedcollateral dependent loans that were remeasured and reported at fair value through a specific valuation allowance allocation of the allowance for loancredit losses on loans based upon the fair value of the underlying collateral during the reported periods.
Nine Months Ended
September 30, 2020
Nine Months Ended
September 30, 2019
Level 2Level 3Level 2Level 3
Carrying value before allocations$6,388 $8,660 $2,416 $60,010 
Specific (allocations) reversals of prior allocations(930)14,928 1,116 (12,437)
Fair value$5,458 $23,588 $3,532 $47,573 
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 Nine Months Ended 
 September 30, 2017
 Nine Months Ended 
 September 30, 2016
 Level 2 Level 3 Level 2 Level 3
Carrying value of impaired loans before allocations$
 $64,287
 $
 $11,023
Specific valuation allowance (allocations) reversals of prior allocations
 (13,477) 
 (3,750)
Fair value$
 $50,810
 $
 $7,273
Non-Financial Assets and Non-Financial Liabilities. We do not have any non-financial assets or non-financial liabilities measured at fair value on a recurring basis. Non-financial assets measured at fair value on a non-recurring basis during the reported periods may include certain foreclosed assets which, upon initial recognition, were remeasured and reported at fair value through a charge-off to the allowance for loan losses and certain foreclosed assets which, subsequent to their initial recognition, were remeasured at fair value through a write-down included in other non-interest expense. The following table presents foreclosed assets that were remeasured and reported at fair value during the reported periods:
Nine Months Ended
September 30,
20202019
Foreclosed assets remeasured at initial recognition:
Carrying value of foreclosed assets prior to remeasurement$$1,302 
Charge-offs recognized in the allowance for credit losses on loan(76)
Fair value$$1,226 
Foreclosed assets remeasured subsequent to initial recognition:
Carrying value of foreclosed assets prior to remeasurement$328 $
Write-downs included in other non-interest expense(231)
Fair value$97 $
 Nine Months Ended 
 September 30, 2017
 2017 2016
Foreclosed assets remeasured at initial recognition:   
Carrying value of foreclosed assets prior to remeasurement$
 $425
Charge-offs recognized in the allowance for loan losses
 (3)
Fair value$
 $422
Foreclosed assets remeasured subsequent to initial recognition:   
Carrying value of foreclosed assets prior to remeasurement$89
 $492
Write-downs included in other non-interest expense(16) (217)
Fair value$73
 $275
Financial Instruments Reported at Amortized Cost. The estimated fair values of financial instruments that are reported at amortized cost in our consolidated balance sheets, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value, were as follows:
September 30, 2020December 31, 2019
Carrying
Amount
Estimated
Fair Value
Carrying
Amount
Estimated
Fair Value
Financial assets:
Level 2 inputs:
Cash and cash equivalents$7,175,680 $7,175,680 $3,788,181 $3,788,181 
Securities held to maturity1,951,384 2,058,855 2,030,005 2,048,675 
Cash surrender value of life insurance policies189,148 189,148 187,156 187,156 
Accrued interest receivable122,618 122,618 183,850 183,850 
Level 3 inputs:
Loans, net17,960,402 18,160,904 14,618,165 14,654,615 
Financial liabilities:
Level 2 inputs:
Deposits33,499,503 33,503,668 27,639,564 27,641,255 
Federal funds purchased and repurchase agreements1,608,667 1,608,667 1,695,342 1,695,342 
Junior subordinated deferrable interest debentures136,342 137,115 136,299 137,115 
Subordinated notes98,982 112,912 98,865 89,077 
Accrued interest payable9,144 9,144 12,393 12,393 
Under ASC Topic 825, entities may choose to measure eligible financial instruments at fair value at specified election dates. The fair value measurement option (i) may be applied instrument by instrument, with certain exceptions, (ii) is generally irrevocable and (iii) is applied only to entire instruments and not to portions of instruments. Unrealized gains and losses on items for which the fair value measurement option has been elected must be reported in earnings at each subsequent reporting date. During the reported periods, we had 0 financial instruments measured at fair value under the fair value measurement option.

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 September 30, 2017 December 31, 2016
 
Carrying
Amount
 
Estimated
Fair Value
 
Carrying
Amount
 
Estimated
Fair Value
Financial assets:       
Level 2 inputs:       
Cash and cash equivalents$5,091,903
 $5,091,903
 $4,141,445
 $4,141,445
Securities held to maturity1,442,222
 1,476,653
 2,250,460
 2,262,747
Cash surrender value of life insurance policies179,789
 179,789
 177,884
 177,884
Accrued interest receivable118,035
 118,035
 156,714
 156,714
Level 3 inputs:       
Loans, net12,552,001
 12,574,862
 11,822,347
 11,903,956
Financial liabilities:       
Level 2 inputs:       
Deposits26,403,269
 26,398,885
 25,811,575
 25,812,039
Federal funds purchased and repurchase agreements997,919
 997,919
 976,992
 976,992
Junior subordinated deferrable interest debentures136,170
 137,115
 136,127
 137,115
Subordinated notes payable and other borrowings98,512
 102,072
 99,990
 100,000
Accrued interest payable1,737
 1,737
 1,204
 1,204
Table of Contents

Note 1817 - Accounting Standards Updates
Information about certain recently issued accounting standards updates is presented below. Also refer to Note 2120 - Accounting Standards Updates in our 20162019 Form 10-K for additional information related to previously issued accounting standards updates.
Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 implements a common revenue standard that clarifies the principles for recognizing revenue. The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve that core principle, an entity should apply the following steps: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract and (v) recognize revenue when (or as) the entity satisfies a performance obligation. ASU 2014-09 was originally going to be effective for us on January 1, 2017; however, the FASB issued ASU 2015-14, “Revenue from Contracts with Customers (Topic 606) – Deferral of the Effective Date" which deferred the effective date of ASU 2014-09 by one year to January 1, 2018. Our revenue is comprised of net interest income on financial assets and financial liabilities, which is explicitly excluded from the scope of ASU 2014-09, and non-interest income. We expect that ASU 2014-09 will require us to change how we recognize certain recurring revenue streams within trust and investment management fees, insurance commissions and fees and other categories of non-interest income; however, we do not expect these changes to have a significant impact on our financial statements. We expect to adopt the standard in the first quarter of 2018 with a cumulative effect adjustment to opening retained earnings, if such adjustment is deemed to be significant.
ASU 2016-02,“Leases (Topic 842).” ASU 2016-02 will, among other things, require lessees to recognize a lease liability, which is a lessee's obligation to make lease payments arising from a lease, measured on a discounted basis; and a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. ASU 2016-02 does not significantly change lease accounting requirements applicable to lessors; however, certain changes were made to align, where necessary, lessor accounting with the lessee accounting model and ASC Topic 606, “Revenue from Contracts with Customers.” ASU 2016-02 will be effective for us on January 1, 2019 and will require transition using a modified retrospective approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. We are currently evaluating the potential impact of ASU 2016-02 on our financial statements. In that regard, we have selected, and will soon implement, a third-party vendor solution to assist us in the application of ASU 2016-02.
ASU 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts and requires enhanced disclosures related to the significant estimates and judgments used in estimating credit losses, as well as the credit quality and underwriting standards of an organization’s portfolio. In addition,We adopted ASU 2016-13, amendsas subsequently updated for certain clarifications, targeted relief and codification improvements, as of January 1, 2020. See Note 1 - Significant Accounting Policies for additional information.
ASU 2020-4, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” ASU 2020-4 provides optional expedients and exceptions for accounting related to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. ASU 2020-04 applies only to contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform and do not apply to contract modifications made and hedging relationships entered into or evaluated after December 31, 2022, except for hedging relationships existing as of December 31, 2022, that an entity has elected certain optional expedients for and that are retained through the end of the hedging relationship. ASU 2020-4 was effective upon issuance and generally can be applied through December 31, 2022. The adoption of ASU 2020-4 did not significantly impact our financial statements.
ASU 2020-8, “Codification Improvements to Subtopic 310-20, Receivables - Nonrefundable Fees and Other Costs.” ASU 2020-8 clarifies the accounting for credit losses on available-for-salethe amortization of purchase premiums for callable debt securities and purchased financial assets with credit deterioration.multiple call dates. ASU 2016-13 will be effective on January 1, 2020. We are currently evaluating the potential impact of ASU 2016-13 on our financial statements. In that regard, we have formed a cross-functional working group, under the direction of our Chief Financial Officer and our Chief Risk Officer. The working group is comprised of individuals from various functional areas including credit, risk management, finance and information technology, among others. We are currently developing an implementation plan to include assessment of processes, portfolio segmentation, model development, system requirements and the identification of data and resource needs, among other things. We are also currently evaluating selected third-party vendor solutions to assist us in the application of the ASU 2016-13. The adoption of the ASU 2016-13 is likely to result in an increase in the allowance for loan losses as a result of changing from an “incurred loss” model, which encompasses allowances for current known and inherent losses within the portfolio, to an “expected loss” model, which encompasses allowances for losses expected to be incurred over the life of the portfolio. Furthermore, ASU 2016-13 will necessitate that we establish an allowance for expected credit losses on debt securities. While we are currently unable to reasonably estimate the impact of adopting ASU 2016-13, we expect that the impact of adoption will be significantly influenced by the composition, characteristics and quality of our loan and securities portfolios as well as the prevailing economic conditions and forecasts as of the adoption date.
ASU 2017-04, “Intangibles - Goodwill and Other (Topic 350) - Simplifying the Test for Goodwill Impairment.” ASU 2017-04 eliminates Step 2 from the goodwill impairment test which required entities to compute the implied fair value of goodwill. Under ASU 2017-04, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. ASU 2017-042020-8 will be effective for us on January 1, 2020, with early adoption permitted for interim or annual impairment tests beginning in 2017. ASU 2017-04 is not expected to have a significant impact on our financial statements.

ASU 2017-05, “Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20) - Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets.” ASU 2017-05 clarifies the scope of Subtopic 610-20 and adds guidance for partial sales of nonfinancial assets, including partial sales of real estate. Historically, U.S. GAAP contained several different accounting models to evaluate whether the transfer of certain assets qualified for sale treatment. ASU 2017-05 reduces the number of potential accounting models that might apply and clarifies which model does apply in various circumstances. ASU 2017-05 will be effective for us on January 1, 20182021 and is not expected to have a significant impact on our financial statements.
ASU 2017-08,“Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20) - Premium Amortization on Purchased Callable Debt Securities.” ASU 2017-08 shortens the amortization period for certain callable debt securities held at a premium to require such premiums to be amortized to the earliest call date unless applicable guidance related to certain pools
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Table of securities is applied to consider estimated prepayments. Under prior guidance, entities were generally required to amortize premiums on individual, non-pooled callable debt securities as a yield adjustment over the contractual life of the security. ASU 2017-08 does not change the accounting for callable debt securities held at a discount. ASU 2017-08 will be effective for us on January 1, 2019, with early adoption permitted. We are currently evaluating the potential impact of ASU 2017-08 on our financial statements.Contents
ASU 2017-09, “Compensation - Stock Compensation (Topic 718) - Scope of Modification Accounting.” ASU 2017-09 clarifies when changes to the terms or conditions of a share-based payment award must be accounted for as modifications. Under ASU 2017-09, an entity will not apply modification accounting to a share-based payment award if all of the following are the same immediately before and after the change: (i) the award's fair value, (ii) the award's vesting conditions and (iii) the award's classification as an equity or liability instrument. ASU 2017-09 will be effective for us on January 1, 2018 and is not expected to have a significant impact on our financial statements.
ASU 2017-12, “Derivatives and Hedging (Topic 815) - Targeted Improvements to Accounting for Hedging Activities.” ASU 2017-12 amends the hedge accounting recognition and presentation requirements in ASC 815 to improve the transparency and understandability of information conveyed to financial statement users about an entity’s risk management activities to better align the entity’s financial reporting for hedging relationships with those risk management activities and to reduce the complexity of and simplify the application of hedge accounting. ASU 2017-12 will be effective for us on January 1, 2019 and is not expected to have a significant impact on our financial statements.


Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations
Financial Review
Cullen/Frost Bankers, Inc.
The following discussion should be read in conjunction with our consolidated financial statements, and notes thereto, for the year ended December 31, 2016,2019, and the other information included in the 20162019 Form 10-K. Operating results for the three and nine months ended September 30, 20172020 are not necessarily indicative of the results for the year ending December 31, 20172020 or any future period.
Dollar amounts in tables are stated in thousands, except for per share amounts.
Forward-Looking Statements and Factors that Could Affect Future Results
Certain statements contained in this Quarterly Report on Form 10-Q that are not statements of historical fact constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 (the “Act”), including statements regarding the potential effects of the ongoing COVID-19 pandemic on our business, financial condition, liquidity and results of operations, notwithstanding that such statements are not specifically identified as such. In addition, certain statements may be contained in our future filings with the SEC, in press releases, and in oral and written statements made by us or with our approval that are not statements of historical fact and constitute forward-looking statements within the meaning of the Act. Examples of forward-looking statements include, but are not limited to: (i) projections of revenues, expenses, income or loss, earnings or loss per share, the payment or nonpayment of dividends, capital structure and other financial items; (ii) statements of plans, objectives and expectations of Cullen/Frost or its management or Board of Directors, including those relating to products, services or services;operations; (iii) statements of future economic performance; and (iv) statements of assumptions underlying such statements. Words such as “believes”, “anticipates”, “expects”, “intends”, “targeted”, “continue”, “remain”, “will”, “should”, “may” and other similar expressions are intended to identify forward-looking statements but are not the exclusive means of identifying such statements.
Forward-looking statements involve risks and uncertainties that may cause actual results to differ materially from those in such statements. Factors that could cause actual results to differ from those discussed in the forward-looking statements include, but are not limited to:
Local, regional, national and international economic conditions and the impact they may have on us and our customers and our assessment of that impact.
Volatility and disruption in national and international financial and commodity markets.
Government intervention in the U.S. financial system.
Changes in the mix of loan geographies, sectors and types or the level of non-performing assets and charge-offs.
Changes in estimates of future reserve requirements based upon the periodic review thereof under relevant regulatory and accounting requirements.
The effects of and changes in trade and monetary and fiscal policies and laws, including the interest rate policies of the Federal Reserve Board.
Inflation, interest rate, securities market and monetary fluctuations.
The effect of changes in laws and regulations (including laws and regulations concerning taxes, banking, securities and insurance) with which we and our subsidiaries must comply.
The soundness of other financial institutions.
Political instability.
Impairment of our goodwill or other intangible assets.
Acts of God or of war or terrorism.
The timely development and acceptance of new products and services and perceived overall value of these products and services by users.
Changes in consumer spending, borrowings and savings habits.
Changes in the financial performance and/or condition of our borrowers.
Technological changes.
The cost and effects of cyber incidents or other failures, interruptions or security breaches of our systems or those of third-party providers.
Acquisitions and integration of acquired businesses.
Our ability to increase market share and control expenses.
Our ability to attract and retain qualified employees.
Changes in the competitive environment in our markets and among banking organizations and other financial service providers.
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The effect of changes in accounting policies and practices, as may be adopted by the regulatory agencies, as well as the Public Company Accounting Oversight Board, the Financial Accounting Standards Board and other accounting standard setters.
Changes in the reliability of our vendors, internal control systems or information systems.
Changes in our liquidity position.

Changes in our organization, compensation and benefit plans.
The impact of the ongoing COVID-19 pandemic and any other pandemic, epidemic or health-related crisis.
The costs and effects of legal and regulatory developments, the resolution of legal proceedings or regulatory or other governmental inquiries, the results of regulatory examinations or reviews and the ability to obtain required regulatory approvals.
Greater than expected costs or difficulties related to the integration of new products and lines of business.
Our success at managing the risks involved in the foregoing items.
Further, statements about the potential effects of the ongoing COVID-19 pandemic on our business, financial condition, liquidity and results of operations may constitute forward-looking statements and are subject to the risk that the actual effects may differ, possibly materially, from what is reflected in those forward-looking statements due to factors and future developments that are uncertain, unpredictable and in many cases beyond our control, including the scope and duration of the pandemic, actions taken by governmental authorities in response to the pandemic, and the direct and indirect impact of the pandemic on our customers, clients, third parties and us.
Forward-looking statements speak only as of the date on which such statements are made. We do not undertake any obligation to update any forward-looking statement to reflect events or circumstances after the date on which such statement is made, or to reflect the occurrence of unanticipated events.
Recent Developments Related to COVID-19
Overview. Our business has been, and continues to be, impacted by the recent and ongoing outbreak of COVID-19. In March 2020, COVID-19 was declared a pandemic by the World Health Organization and a national emergency by the President of the United States. Efforts to limit the spread of COVID-19 have included shelter-in-place orders, the closure of non-essential businesses, travel restrictions, supply chain disruptions and prohibitions on public gatherings, among other things, throughout many parts of the United States and, in particular, the markets in which we operate. As the current pandemic is ongoing and dynamic in nature, there are many uncertainties related to COVID-19 including, among other things, its ultimate geographic spread; its severity; the duration of the outbreak; the impact to our customers, employees and vendors; the impact to the financial services and banking industry; and the impact to the economy as a whole as well as the effect of actions taken, or that may yet be taken, or inaction by governmental authorities to contain the outbreak or to mitigate its impact (both economic and health-related). COVID-19 has negatively affected, and is expected to continue to negatively affect, our business, financial position and operating results. In light of the uncertainties and continuing developments discussed herein, the ultimate adverse impact of COVID-19 cannot be reliably estimated at this time, but it has been and is expected to continue to be material.
Impact on our Operations. In the State of Texas, many jurisdictions have declared health emergencies. The resulting closures and/or limited operations of non-essential businesses and related economic disruption have impacted our operations as well as the operations of our customers. Financial services have been identified as a Critical Infrastructure Sector by the Department of Homeland Security. Accordingly, our business remains open. To address the issues arising as a result of COVID-19, and in order to facilitate the continued delivery of essential services while maintaining a high level of safety for our customers as well as our employees, we have implemented our Business Continuity and Health Emergency Response plans. Among other things, significant actions taken under these plans include:
Implemented our communications plans to ensure our employees, customers and critical vendors are kept abreast of developments affecting our operations.
Restricted all non-essential travel and large external gatherings and have instituted a mandatory quarantine period for anyone that has traveled to an impacted area.
After temporarily closing all of our financial center lobbies and other corporate facilities to non-employees, except for certain limited cases by appointment only, we reopened our financial center lobbies with limited capacity. We continue to serve our consumer and business customers through our motor-banks, ATMs, internet banking, mobile app and telephone customer service capabilities.
Expanded remote-access availability so that nearly all of our work-force has the capability to work from home or other remote locations. All activities are performed in accordance with our compliance and information security policies designed to ensure customer data and other information is properly safeguarded.
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Instituted mandatory social distancing policies for those employees not working remotely. Members of certain operations teams have been split into separate buildings or locations to create redundancy for key functions across the organization.
Notwithstanding the foregoing actions, the COVID-19 outbreak could still greatly affect our routine and essential operations due to staff absenteeism, particularly among key personnel; further limited access to or closures of our branch facilities and other physical offices; operational, technical or security-related risks arising from a remote work-force; and government or regulatory agency orders, among other things. The business and operations of our third-party service providers, many of whom perform critical services for our business, could also be significantly impacted, which in turn could impact us. As a result, we are currently unable to fully assess or predict the extent of the effects of COVID-19 on our operations as the ultimate impact will depend on factors that are currently unknown and/or beyond our control.
Impact on our Financial Position and Results of Operations. Our financial position and results of operations are particularly susceptible to the ability of our loan customers to meet loan obligations, the availability of our workforce, the availability of our vendors and the decline in the value of assets held by us. While its effects continue to materialize, the COVID-19 pandemic has resulted in a significant decrease in commercial activity throughout the State of Texas as well as nationally. This decrease in commercial activity has caused and may continue to cause our customers (including affected businesses and individuals), vendors and counterparties to be unable to meet existing payment or other obligations to us. The national public health crisis arising from the COVID-19 pandemic (and public expectations about it), combined with certain pre-existing factors, including, but not limited to, international trade disputes, inflation risks and oil price volatility, could further destabilize the financial markets and geographies in which we operate. The resulting economic pressure on consumers and uncertainty regarding the sustainability of any economic improvements has impacted the creditworthiness of potential and current borrowers. Borrower loan defaults that adversely affect our earnings correlate with deteriorating economic conditions (such as the unemployment rate), which, in turn, are likely to impact our borrowers' creditworthiness and our ability to make loans. See further information related to the risk exposure of our loan portfolio under the sections captioned “Loans” and “Allowance for Credit Losses” elsewhere in this discussion.
In addition, the economic pressures and uncertainties arising from the COVID-19 pandemic has resulted in and may continue to result in specific changes in consumer and business spending and borrowing and saving habits, affecting the demand for loans and other products and services we offer. Consumers affected by COVID-19 may continue to demonstrate changed behavior even after the crisis is over. For example, consumers may decrease discretionary spending on a permanent or long-term basis, certain industries may take longer to recover (particularly those that rely on travel or large gatherings) as consumers may be hesitant to return to full social interaction. We lend to customers operating in such industries including energy, retail/strip centers, hotels/lodging, restaurants, entertainment and commercial real estate, among others, that have been significantly impacted by COVID-19 and we are continuing to monitor these customers closely. To help mitigate the adverse effects of COVID-19, loan customers may apply for a deferral of payments, or portions thereof, for up to 90 days. After 90 days, customers may apply for an additional deferral. Additionally, the temporary closures of bank branches and the safety precautions implemented at re-opened branches could result in consumers becoming more comfortable with technology and devaluing face-to-face interaction. Our business is relationship driven and such changes could necessitate changes to our business practices to accommodate changing consumer behaviors. The potential changes in behaviors driven by COVID-19 also present heightened liquidity risks, for example, arising from increased demand for our products and services (such as unusually high draws on credit facilities) or decreased demand for our products and services (such as idiosyncratic, or broad-based, market or other developments that lead to deposit outflows).
Legislative and Regulatory Developments. Recent actions taken by the federal government and the Federal Reserve and other bank regulatory agencies to mitigate the economic effects of COVID-19 will also have an impact on our financial position and results of operations. These actions are further discussed below.
In an emergency measure aimed at blunting the economic impact of COVID-19, the Federal Reserve lowered the target for the federal funds rate to a range of between zero to 0.25% effective on March 16, 2020. This action by the Federal Reserve followed a prior reduction of the targeted federal funds rates to a range of 1.0% to 1.25% effective on March 4, 2020. Our earnings and cash flows are largely dependent upon our net interest income. Net interest income is the difference between interest income earned on interest-earning assets such as loans and securities and interest expense paid on interest-bearing liabilities such as deposits and borrowed funds. As our balance sheet is more asset sensitive, our earnings are more adversely affected by decreases in market interest rates as the interest rates received on loans and other investments fall more quickly and to a larger degree than the interest rates paid on deposits and other borrowings. The decline in interest rates has already led to new all-time low yields across the US Treasury maturity curve. In September 2020, the Federal Reserve indicated that it expects to maintain the targeted federal funds rate at current levels until such time that labor market conditions have reached levels consistent with the Federal Open Market Committee's assessments of maximum employment and inflation has risen to 2% and is on track to moderately exceed 2% for some time. This timeframe is currently expected to last through 2023. Nonetheless, if
43

the Federal Reserve decreases the targeted federal funds rates even further in response to the economic effects of COVID-19, overall interest rates will decline further, which will negatively impact our net interest income and further compress our net interest margin.
Other actions taken by the Federal Reserve in an effort to provide monetary stimulus to counteract the economic disruption caused by COVID-19 include:
Expanded reverse repo operations, adding liquidity to the banking system.
Restarted quantitative easing.
Lowered the interest rate on the discount window by 1.5% to 0.25%.
Reduced reserve requirement ratios to zero percent.
Encouraged banks to use their capital and liquidity buffers to lend.
Introduced and expanded several new programs that will operate on a temporary basis to help preserve market liquidity.
The U.S. government has also enacted certain fiscal stimulus measures in several phases to counteract the economic disruption caused by the COVID-19. The Phase 1 legislation, the Coronavirus Preparedness and Response Supplemental Appropriations Act, was enacted on March 6, 2020 and, among other things, authorized funding for research and development of vaccines and allocated money to state and local governments to aid containment and response measures. The Phase 2 legislation, the Families First Coronavirus Response Act, was enacted on March 18, 2020 and provides for paid sick/medical leave, establishes no-cost coverage for coronavirus testing, expands unemployment benefits, expands food assistance, and provides additional funding to states for the ongoing economic consequences of the pandemic, among other provisions. The Phase 3 legislation, the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”), was enacted on March 27, 2020. Among other provisions, the CARES Act (i) authorized the Secretary of the Treasury to make loans, loan guarantees and other investments, up to $500 billion, for assistance to eligible businesses, States and municipalities with limited, targeted relief for passenger air carriers, cargo air carriers, and businesses critical to maintaining national security, (ii) created a $349 billion loan program called the Paycheck Protection Program (the “PPP”) for loans to small businesses for, among other things, payroll, group health care benefit costs and qualifying mortgage, rent and utility payments, (iii) provided certain credits against the 2020 personal income tax for eligible individuals and their dependents, (iv) expanded eligibility for unemployment insurance and provides eligible recipients with an additional $600 per week on top of the unemployment amount determined by each State and (v) expanded tele-health services in Medicare. The Phase 3.5 legislation, the Paycheck Protection Program and Healthcare Enhancement Act of 2020 (the “PPPHE Act”), was enacted on April 24, 2020. Among other things, the PPPHE Act provided an additional $310 billion of funding for the PPP of which, $30 billion is specifically allocated for use by banks and other insured depository institutions that have assets between $10 billion and $50 billion.
The Paycheck Protection Program Flexibility Act of 2020” (the “PPPF Act”) was enacted in June 2020 and modified the PPP as follows: (i) established a minimum maturity of five years for all loans made after the enactment of the PPPF Act and permits an extension of the maturity of existing loans to five years if the borrower and lender agree; (ii) extended the “covered period” of the CARES Act from June 30, 2020, to December 31, 2020; (iii) extended the eight-week “covered period” for expenditures that qualify for forgiveness to the earlier of 24 weeks following loan origination or December 31, 2020; (iv) extended the deferral period for payment of principal, interest and fees to the date on which the forgiveness amount is remitted to the lender by the SBA; (v) changed requirements such that the borrower must use at least 60% (down from 75%) of the proceeds of the loan for payroll costs, and up to 40% (up from 25%), for other permitted purposes, as a condition to obtaining forgiveness of the loan; (vi) delayed from June 30, 2020 to December 31, 2020 the date by which employees must be rehired to avoid a reduction in the amount of forgiveness of a loan, and creates a “rehiring safe harbor” that allows businesses to remain eligible for loan forgiveness if they make a good-faith attempt to rehire employees or hire similarly qualified employees, but are unable to do so, or are able to document an inability to return to pre-COVID-19 levels of business activity due to compliance with social distancing measures; and (vii) allows borrowers to receive both loan forgiveness under the PPP and the payroll tax deferral permitted under the CARES Act, rather than having to choose which of the two would be more advantageous.
In July 2020, the CARES Act was amended to extend, through August 8, 2020, the SBA’s authority to make commitments under the PPP. The SBA’s existing authority had previously expired on June 30, 2020. In August 2020, President Trump signed four executive actions to provide additional COVID-19 relief. The first action authorized the Lost Wages Assistance Program (“LWAP”), which provides for a $400-per-week payment to those currently receiving more than $100 a week in unemployment benefits due to disruptions caused by COVID-19. The LWAP per-week payment is retroactive to the week ending August 1, 2020. The second executive action extended the moratorium on payments and interest accrual on student loans held by the government until the end of 2020. The moratorium was previously set to expire September 30, 2020. The third action instructed the Department of the Treasury and the Department of Housing and Urban Development to help provide temporary assistance to renters and homeowners and promote their ability to avoid eviction or foreclosure. The fourth executive action allows
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employers to defer, for the period from September 1, 2020 through December 31, 2020, the employee portion of Social Security payroll taxes for certain individuals earning less than approximately $104 thousand per year. We are continuing to monitor the potential development of additional legislation and further actions taken by the U.S. government.
The Federal Reserve has created various additional lending facilities and expanded existing facilities to help provide financing in response to the financial disruptions caused by COVID-19. The programs include, among other things, (i) the PPP Facility, which is intended to extend loans to banks making PPP loans, (ii) the Municipal Liquidity Facility, which is intended to facilitate the purchase of eligible notes from states, and certain counties and cities around the country, and (iii) the Main Street Lending Program (“MSLP”), which is intended to facilitate credit flows to businesses affected by the COVID-19 pandemic with up to 10,000 employees or up to $2.5 billion in 2019 annual revenues. As more fully discussed in the section captioned “Loans” elsewhere in this discussion, we are currently participating in the PPP as a lender. We do not currently expect to participate in the MSLP.
Banks and bank holding companies have been particularly impacted by the COVID-19 pandemic as a result of disruption and volatility in the global capital markets. This disruption has impacted our cost of capital and may adversely affect our ability to access the capital markets if we need or desire to do so and, although the ultimate impact cannot be reliably estimated at this time in light of the uncertainties and ongoing developments noted herein, such impacts could be material. Furthermore, bank regulatory agencies have been (and are expected to continue to be) very proactive in responding to both market and supervisory concerns arising from the COVID-19 pandemic as well as the potential impact on customers, especially borrowers. As shown during and following the financial crisis of 2007-2008, periods of economic and financial disruption and stress have, in the past, resulted in increased scrutiny of banking organizations. We are closely monitoring the potential for new laws and regulations impacting lending and funding practices as well as capital and liquidity standards. Such changes could require us to maintain significantly more capital, with common equity as a more predominant component, or manage the composition of our assets and liabilities to comply with formulaic liquidity requirements. Furthermore, provisions of the CARES Act allow, but do not require, the FDIC to guarantee deposit obligations of banks in non-interest-bearing transaction accounts through December 31, 2020. Participation in any such guarantee program may result in fees and other assessments as the FDIC determines and may include special assessments. Other provisions of the CARES Act as well as actions taken by bank regulators, such as potential relief for working with borrowers who are distressed as a result of the effects of COVID-19, could similarly impact aggregate deposit insurance expense.
Application of Critical Accounting Policies and Accounting Estimates
We follow accounting and reporting policies that conform, in all material respects, to accounting principles generally accepted in the United States and to general practices within the financial services industry. The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. While we base estimates on historical experience, current information and other factors deemed to be relevant, actual results could differ from those estimates.
We consider accounting estimates to be critical to reported financial results if (i) the accounting estimate requires management to make assumptions about matters that are highly uncertain and (ii) different estimates that management reasonably could have used for the accounting estimate in the current period, or changes in the accounting estimate that are reasonably likely to occur from period to period, could have a material impact on our financial statements.
Accounting policies related to the allowance for loancredit losses on financial instruments including loans and off-balance-sheet credit exposures are considered to be critical as these policies involve considerable subjective judgment and estimation by management. As discussed in Note 1 - Summary of Significant Accounting Policies, our policies related to allowances for credit losses changed on January 1, 2020 in connection with the adoption of a new accounting standard update as codified in Accounting Standards Codification (“ASC”) Topic 326 (“ASC 326”) Financial Instruments - Credit Losses. In the case of loans, the allowance for credit losses is a contra-asset valuation account, calculated in accordance with ASC 326, that is deducted from the amortized cost basis of loans to present the net amount expected to be collected. In the case of off-balance-sheet credit exposures, the allowance for credit losses is a liability account, calculated in accordance with ASC 326, reported as a component of accrued interest payable and other liabilities in our consolidated balance sheets. The amount of each allowance account represents management's best estimate of current expected credit losses on these financial instruments considering available information, from internal and external sources, relevant to assessing exposure to credit loss over the contractual term of the instrument. Relevant available information includes historical credit loss experience, current conditions and reasonable and supportable forecasts. While historical credit loss experience provides the basis for the estimation of expected credit losses, adjustments to historical loss information may be made for differences in current portfolio-specific risk characteristics, environmental conditions or other relevant factors. While management utilizes its best judgment and information available, the ultimate adequacy of our allowance accounts is dependent upon a variety of factors beyond our control, including the
45

performance of our portfolios, the economy, changes in interest rates and the view of the regulatory authorities toward classification of assets. For additional information regarding critical accounting policies, refer to Note 1 - Summary of Significant Accounting Policies and Note 3 - Loans in the notes to consolidated financial statements and the sections captioned “Application of Critical Accounting Policies and Accounting Estimates” and “Allowance for Loan Losses” in Management’s Discussion and Analysis of Financial Condition and Results of Operations included in the 2016 Form 10-K. There have been no significant changes in our application of critical accounting policies related to the allowance for loan losses since December 31, 2016.statements.
Overview
A discussion of our results of operations is presented below. Certain reclassifications have been made to make prior periods comparable. Taxable-equivalent adjustments are the result of increasing income from tax-free loans and investments by an amount equal to the taxes that would be paid if the income were fully taxable based on a 35%21% federal tax rate, thus making tax-exempt yields comparable to taxable asset yields.

Results of Operations
Net income available to common shareholders totaled $91.1$95.1 million, or $1.41$1.50 per diluted common share, and $257.6$235.4 million, or $3.98$3.71 per diluted common share, for the three and nine months ended September 30, 20172020 compared to $78.2$109.8 million, or $1.24$1.73 per diluted common share, and $214.5$333.9 million, or $3.42$5.24 per diluted common share, for the three and nine months ended September 30, 2016.2019.
Selected data for the comparable periods was as follows:
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended
September 30,
Nine Months Ended
September 30,
2017 2016 2017 20162020201920202019
Taxable-equivalent net interest income$264,406
 $235,665
 $774,819
 $694,997
Taxable-equivalent net interest income$267,041 $276,618 $805,216 $825,547 
Taxable-equivalent adjustment45,195
 41,158
 132,311
 120,264
Taxable-equivalent adjustment23,618 23,611 71,461 72,640 
Net interest income219,211
 194,507
 642,508
 574,733
Net interest income243,423 253,007 733,755 752,907 
Provision for loan losses10,980
 5,045
 27,358
 42,734
Net interest income after provision for loan losses208,231
 189,462
 615,150
 531,999
Credit loss expenseCredit loss expense20,302 8,001 227,474 25,404 
Net interest income after credit loss expenseNet interest income after credit loss expense223,121 245,006 506,281 727,503 
Non-interest income81,615
 82,114
 246,395
 256,274
Non-interest income83,601 89,224 374,117 268,647 
Non-interest expense186,823
 180,505
 562,789
 539,109
Non-interest expense202,150 208,864 625,992 613,873 
Income before income taxes103,023
 91,071
 298,756
 249,164
Income before income taxes104,572 125,366 254,406 382,277 
Income taxes9,892
 10,852
 35,131
 28,622
Income tax expense\(benefit)Income tax expense\(benefit)9,516 13,530 11,525 42,359 
Net income93,131
 80,219
 263,625
 220,542
Net income95,056 111,836 242,881 339,918 
Preferred stock dividends2,016
 2,016
 6,047
 6,047
Preferred stock dividends— 2,016 2,016 6,047 
Redemption of preferred stockRedemption of preferred stock— — 5,514 — 
Net income available to common shareholders$91,115
 $78,203
 $257,578
 $214,495
Net income available to common shareholders$95,056 $109,820 $235,351 $333,871 
Earnings per common share – basic$1.43
 $1.24
 $4.02
 $3.44
Earnings per common share – basic$1.50 $1.74 $3.72 $5.28 
Earnings per common share – diluted1.41
 1.24
 3.98
 3.42
Earnings per common share – diluted1.50 1.73 3.71 5.24 
Dividends per common share0.57
 0.54
 1.68
 1.61
Dividends per common share0.71 0.71 2.13 2.09 
Return on average assets1.19% 1.07% 1.14% 1.01%Return on average assets0.96 %1.35 %0.85 %1.41 %
Return on average common equity11.71
 10.31
 11.44
 9.87
Return on average common equity9.30 11.83 7.95 12.79 
Average shareholders’ equity to average assets10.63
 10.85
 10.43
 10.70
Average shareholders’ equity to average assets10.31 11.87 10.80 11.48 
Net income available to common shareholders increased $12.9decreased $14.8 million, or 16.5%13.4%, for the three months ended September 30, 20172020 and increased $43.1decreased $98.5 million, or 20.1%29.5%, for the nine months ended September 30, 20172020 compared to the same periods in 2016.2019. The increasedecrease during the three months ended September 30, 20172020 was primarily the result of a $24.7$12.3 million increase in credit loss expense, a $9.6 million decrease in net interest income and a $960 thousand$5.6 million decrease in non-interest income partly offset by a $6.7 million decrease in non-interest expense and a $4.0 million decrease in income tax expense partly offset by a $6.3 million increase in non-interest expense, a $5.9 million increase in the provision for loan losses and a $499 thousandexpense. The decrease in non-interest income. The increase during the nine months ended September 30, 20172020 was primarily the result of a $67.8$202.1 million increase in credit loss expense, a $19.2 million decrease in net interest income and a $15.4 million decrease in the provision for loan losses partly offset by a $23.7$12.1 million increase in non-interest expense partly offset by a $9.9$105.5 million decreaseincrease in non-interest income and a $6.5$30.8 million increasedecrease in income tax expense. The increase in credit loss expense during the comparable periods resulted from both our adoption of a new credit loss accounting standard and the adverse events impacting our loan portfolio, including those arising from the COVID-19 pandemic and the significant volatility in oil prices. The increase in non-interest income during the nine months ended September 30, 2020 was primarily related to a $109.0 million net gain on securities transactions. Net income available to common shareholders for the nine months ended September 30, 2020 was also impacted by the reclassification of $5.5 million of issuance costs associated with our preferred stock to retained earnings upon redemption of the preferred stock in the first quarter.
Details of the changes in the various components of net income are further discussed below.
During the third quarter

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Table of 2017, our operations in our Houston and Corpus Christi market areas were disrupted by hurricane Harvey. As a result, we incurred certain additional expenses, as discussed below; lost potential revenue as a result of branch closures; and allocated a portion of our allowance for loan losses for probable losses related to the impact of the hurricane, as discussed below. While the ultimate impact of the hurricane on our operations is uncertain, we expect that it will be mitigated, at least in part, by insurance coverage and, based on the information available to us at this time, we do not expect any significant impact on our financial statements.Contents
Net Interest Income
Net interest income is the difference between interest income on earning assets, such as loans and securities, and interest expense on liabilities, such as deposits and borrowings, which are used to fund those assets. Net interest income is our largest source of revenue, representing 72.3%66.2% of total revenue during the first nine months of 2017.2020. Excluding the revenue associated with the $109.0 million net gain on securities transactions realized during the first quarter of 2020, net interest income would have represented 73.5% of total revenue during the first nine months of 2020. Net interest margin is the ratio of taxable-equivalent net interest income to average earning assets for the period. The level of interest rates and the volume and mix of earning assets and interest-bearing liabilities impact net interest income and net interest margin.
The Federal Reserve influences the general market rates of interest, including the deposit and loan rates offered by many financial institutions. Our loan portfolio is significantly affected by changes in the prime interest rate. The prime interest rate which isbegan 2019 at 5.50% and decreased 50 basis points during the rate offered on loansthird quarter of 2019 (25 basis points in each of August and September) and 25 basis points in October 2019 to borrowers with strong credit, remainedend the year at 3.50% during most of 2016. In December 2016,4.75%. During 2020, the prime rate increased 25decreased 150 basis points in March to 3.75% and3.25% where it remained at that level until March 2017, when the prime rated increased

another 25 basis points to 4.00%. In June 2017, the prime rate increased an additional 25 basis points to 4.25%.through September 30, 2020. Our loan portfolio is also impacted by changes in the London Interbank Offered Rate (LIBOR). At September 30, 2017,2020, the one-month and three-month U.S. dollar LIBOR interest rates were 1.23%0.15% and 1.33%0.23%, respectively, while at September 30, 2016,2019, the one-month and three-month U.S. dollar LIBOR interest rates were 0.53%2.02% and 0.85%2.09%, respectively. The effectivetarget range for the federal funds rate, which is the cost of immediately available overnight funds, remainedbegan 2019 at 0.50%2.25% to 2.50% and decreased 50 basis points during mostthe third quarter of 2016. In December 2016,2019 (25 basis points in each of August and September) and 25 basis points in October 2019 to end the effectiveyear at 1.50 to 1.75%. During 2020, the target range for the federal funds rate increased 25decreased 150 basis points in March to 0.75% andzero to 0.25% where it remained at that level until March 2017, whenthrough September 30, 2020. As noted in the effectivesection captioned “Recent Developments Related to COVID-19” elsewhere in this discussion, the decrease in the target range for the federal funds rate increased another 25 basis points to 1.00%. In June 2017,in March 2020 was largely an emergency measure by the effective federal funds rate was increased an additional 25 basis points to 1.25%.Federal Reserve aimed at blunting the economic impact of COVID-19.
We are primarily funded by core deposits, with non-interest-bearing demand deposits historically being a significant source of funds. This lower-cost funding base is expected to have a positive impact on our net interest income and net interest margin in a rising interest rate environment. The Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) repealed theThough federal prohibitions on the payment of interest on demand deposits thereby permitting depository institutions to pay interest on business transaction and other accounts beginning July 21, 2011. To date,were repealed in 2011, we have not experienced any significant additional interest costs as a result of the repeal. However, in light of the aforementioned increases in market interest rates, in late July 2017, we increased the interest rates we pay on most of our interest-bearing deposit products.result. See Item 3. Quantitative and Qualitative Disclosures About Market Risk elsewhere in this report for information about the expected impact of this legislation on our sensitivity to interest rates. Further analysis of the components of our net interest margin is presented below.
The following tables presenttable presents the changes in taxable-equivalent net interest income and identifies the changes due to differences in the average volume of earning assets and interest-bearing liabilities and the changes due to changes in the average interest rate on those assets and liabilities. The changes in net interest income due to changes in both average volume and average interest rate have been allocated to the average volume change or the average interest rate change in proportion to the absolute amounts of the change in each. The comparison between the periodsquarters includes an additional change factor that shows the effect of the difference in the number of days in each period for assets and liabilities that accrue interest based upon the actual number of days in the period, as further discussed below.
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Three Months EndedThree Months Ended
September 30, 2017 vs. September 30, 2016September 30, 2020 vs. September 30, 2019
Increase (Decrease) Due to Change in  Increase (Decrease) Due to Change in
Rate Volume Number of Days TotalRateVolumeNumber of daysTotal
Interest-bearing deposits$6,472
 $217
 $
 $6,689
Interest-bearing deposits$(14,019)$6,772 $— $(7,247)
Federal funds sold and resell agreements75
 121
 
 196
Federal funds sold and resell agreements(600)(575)— (1,175)
Securities:       Securities:
Taxable(1,176) (1,518) 
 (2,694)Taxable(2,937)(6,625)— (9,562)
Tax-exempt(3,239) 7,234
 
 3,995
Tax-exempt— 949 — 949 
Loans, net of unearned discounts13,650
 12,298
 
 25,948
Loans, net of unearned discounts(58,920)40,855 — (18,065)
Total earning assets15,782
 18,352
 
 34,134
Total earning assets(76,476)41,376 — (35,100)
Savings and interest checking
 83
 
 83
Savings and interest checking(1,016)189 — (827)
Money market deposit accounts3,339
 4
 
 3,343
Money market deposit accounts(17,919)1,658 — (16,261)
Time accounts147
 (13) 
 134
Time accounts(1,747)387 — (1,360)
Public funds362
 (3) 
 359
Public funds(1,790)(2)— (1,792)
Federal funds purchased and repurchase agreements467
 12
 
 479
Federal funds purchased and repurchase agreements(5,441)883 — (4,558)
Junior subordinated deferrable interest debentures181
 
 
 181
Junior subordinated deferrable interest debentures(726)— (725)
Subordinated notes payable and other notes819
 (5) 
 814
Subordinated notesSubordinated notes(2)— — 
Total interest-bearing liabilities5,315
 78
 
 5,393
Total interest-bearing liabilities(28,641)3,118 — (25,523)
Net change$10,467
 $18,274
 $
 $28,741
Net change$(47,835)$38,258 $— $(9,577)

Nine Months EndedNine Months Ended
September 30, 2017 vs. September 30, 2016September 30, 2020 vs. September 30, 2019
Increase (Decrease) Due to Change in  Increase (Decrease) Due to Change in
Rate Volume Number of Days TotalRateVolumeNumber of daysTotal
Interest-bearing deposits$13,757
 $1,630
 $(41) $15,346
Interest-bearing deposits$(37,564)$21,192 $40 $(16,332)
Federal funds sold and resell agreements202
 148
 (1) 349
Federal funds sold and resell agreements(1,983)(1,459)(3,439)
Securities:       Securities:
Taxable(4,440) (726) (204) (5,370)Taxable(1,087)(14,088)— (15,175)
Tax-exempt(9,516) 32,818
 
 23,302
Tax-exempt784 (451)— 333 
Loans, net of unearned discounts28,934
 25,851
 (1,257) 53,528
Loans, net of unearned discounts(142,044)90,004 1,883 (50,157)
Total earning assets28,937
 59,721
 (1,503) 87,155
Total earning assets(181,894)95,198 1,926 (84,770)
Savings and interest checking
 117
 (3) 114
Savings and interest checking(3,403)435 (2,964)
Money market deposit accounts3,391
 6
 (13) 3,384
Money market deposit accounts(48,768)3,881 49 (44,838)
Time accounts231
 (41) (3) 187
Time accounts(1,785)1,719 42 (24)
Public funds721
 (6) 
 715
Public funds(4,599)442 (4,152)
Federal funds purchased and repurchase agreements638
 60
 (1) 697
Federal funds purchased and repurchase agreements(12,820)1,534 15 (11,271)
Junior subordinated deferrable interest debentures497
 1
 
 498
Junior subordinated deferrable interest debentures(1,510)— (1,508)
Subordinated notes payable and other notes1,875
 (137) 
 1,738
Subordinated notesSubordinated notes— — — — 
Federal home loan bank advancesFederal home loan bank advances— 318 — 318 
Total interest-bearing liabilities7,353
 
 (20) 7,333
Total interest-bearing liabilities(72,885)8,331 115 (64,439)
Net change$21,584
 $59,721
 $(1,483) $79,822
Net change$(109,009)$86,867 $1,811 $(20,331)
Taxable-equivalent net interest income for the three months ended September 30, 2017 increased $28.72020 decreased $9.6 million, or 12.2%3.5%, while taxable-equivalent net interest income for the nine months ended September 30, 2017 increased $79.82020 decreased $20.3 million, or 11.5%2.5%, compared to the same periods in 2016.2019. Taxable-equivalent net interest income for the nine months ended September 30, 20172020 included 273274 days compared to 274273 days for the same period in 20162019 as a result of the leap year. The additional day added approximately $1.5$1.8 million to taxable-equivalent net interest income during the nine months ended September 30, 2016.2020. Excluding the impact of the additional day results in an effective increasedecrease in taxable-equivalent net interest income of approximately $81.3$22.1 million during the nine months ended September 30, 2017.2020. The increasestaxable-equivalent net interest margin decreased 81 basis points from 3.76% during the three months ended September 30, 2019 to 2.95% during the three months ended September 30, 2020 while the taxable-equivalent net interest margin decreased 60 basis points from 3.80% during the nine months ended September 30, 2019 to 3.20% during the nine months ended September 30, 2020.
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Table of Contents
The decreases in taxable-equivalent net interest income and taxable-equivalent net interest margin during the three and nine months ended September 30, 2017, excluding the impact of the aforementioned additional day during the nine months ended September 30, 2016,2020 were primarily related to the impact of increases in the average volume of tax-exempt securities, loans and interest-bearing deposits as well as increasesdecreases in the average yields on loans and interest-bearing deposits partly offset by(primarily amounts held in an interest-bearing account at the impact ofFederal Reserve) combined with, to a significantly lesser extent, decreases in the average yields on tax-exempt andvolume of taxable securities (based on amortized cost) and the impact of increases in the average rate paid onvolume of interest-bearing deposit liabilities. The impact of these items was partly offset by increases in the average volumes of loans and interest-bearing deposits (primarily amounts held in an interest-bearing account at the Federal Reserve) combined with decreases in the average cost of interest-bearing deposit liabilities and other borrowed funds.
The average volume of interest-earning assets for the three and nine months ended September 30, 2020 increased $7.1 billion and $5.0 billion compared to the same periods in 2019, respectively. The increase in the average volume of interest-earning assets for the three months ended September 30, 2017 increased $1.32020 included a $4.3 billion whileincrease in average interest-bearing deposits, a $3.7 billion increase in average loans (of which approximately $3.2 billion related to PPP loans, as further discussed below) and a $312.5 million increase in average tax-exempt securities partly offset by a $1.1 billion decrease in average taxable securities and a $180.6 million decrease in average federal funds sold and resale agreements. The increase in the average volume of interest-earning assets for the nine months ended September 30, 2020 included a $3.0 billion increase in average interest-bearing deposits, a $2.6 billion increase in average loans (of which $1.9 billion related to PPP loans, as further discussed below) and a $256.8 million increase in average tax-exempt securities partly offset by a $723.5 million decrease in average taxable securities and a $108.2 million decrease in average federal funds sold and resell agreements.
The average taxable-equivalent yield on interest-earning assets decreased 117 basis points from 4.21% during the three months ended September 30, 2019 to 3.04% during the three months ended September 30, 2020 while the average taxable-equivalent yield on interest-earning assets decreased 92 basis points from 4.27% during the nine months ended September 30, 2017 increased $1.7 billion compared2019 to the same periods in 2016. The increase in average earning assets during the three months ended September 30, 2017, included a $1.1 billion increase in average loans, a $377.0 million increase in average tax-exempt securities, and a $161.3 million increase in average interest-bearing deposits partly offset by a $421.2 million decrease in average taxable securities. The increase in average earning assets3.35% during the nine months ended September 30, 2017, included an $821.8 million increase in average loans, a $648.9 million increase in average tax-exempt securities and a $384.9 million increase in average interest-bearing deposits partly offset by a $133.6 million decrease in average taxable securities.
The net interest margin increased 20 basis points from 3.53% during the three months ended September 30, 2016 to 3.73% during the three months ended September 30, 2017 and increased 13 basis points from 3.56% during the nine months ended September 30, 2016 to 3.69% during the nine months ended September 30, 2017. The increases in the net interest margin during the three and nine months ended September 30, 2017 were primarily due to increases in the average yield on interest earning assets.2020. The average yieldtaxable-equivalent yields on interest-earning assets increased 28 basis points from 3.57% during the three months ended September 30, 2016 to 3.85% during the three months ended September 30, 2017 and increased 17 basis points from 3.60% during the nine months ended September 30, 2016 to 3.77% during the nine months ended September 30, 2017. The increases in the average yield on interest earning assets during the three and nine months ended September 30, 2017 were mostly due to increases in the average yields on interest-bearing deposits and loans. The average yield on interest-earning assets is primarily impacted by the aforementioned changes in market interest rates as well asand changes in the volume and relative mix of interest-earning assets.
The average taxable-equivalent yield on loans increased 32decreased 143 basis points from 4.00%5.16% during the firstthree months ended September 30, 2019 to 3.73% during the three months ended September 30, 2020 while the average taxable-equivalent yield on loans decreased 119 basis points from 5.27% during the nine months of 2016ended September 30, 2019 to 4.32%4.08% during the first nine months of 2017.ended September 30, 2020. The average taxable-equivalent yield on loans was negatively impacted by lower average market interest rates during the three and nine months ended September 30, 2020 compared to the same periods in 2019. The average volume of loans for the three and nine months ended September 30, 2020 increased $3.7 billion, or 25.4%, and $2.6 billion, or 17.8%, compared to the same periods in 2019. Loans made up approximately 49.4% of average interest-earning assets during both of the three and nine months ended September 30, 2020, compared to 48.7% and 49.0% during the same periods in 2019 respectively. As discussed in the section captioned “Loans” elsewhere in this discussion, in April 2020, we began originating loans to qualified small businesses under the PPP administered by the SBA under the provisions of the CARES Act. Through September 30, 2020, we have funded approximately $3.3 billion of SBA-approved PPP loans. During the three and nine months ended September 30, 2020, we recognized approximately $21.1 million and $40.4 million, respectively, in PPP loan related deferred processing fees (net of amortization of related deferred origination costs) as a yield adjustment and this amount is included in interest income on loans. As a result of the inclusion of these net fees in interest income, the average yield on PPP loans was approximately 3.65% and 3.86% during the three and nine months ended September 30, 2020, respectively, compared to the stated interest rate of 1.0% on these loans. As of September 30, 2020, we expect to recognize additional PPP loan related deferred processing fees (net of deferred origination costs) totaling approximately $58.5 million as a yield adjustment over the remaining terms of these loans.
The average taxable-equivalent yield on securities was 3.44% during the three months ended September 30, 2020, increasing 1 basis point from 3.43% during the same period in 2019 while the average taxable-equivalent yield on securities was 3.48% during the nine months ended September 30, 2020, increasing 7 basis points from 3.41% during the same period in 2019. The average taxable-equivalent yields on securities during the three and nine months ended September 30, 2020 were positively impacted by increases in market interest ratesthe relative proportion tax-exempt securities to total securities.
The average yield on taxable securities decreased 24 basis points from 2.45% during the three months ended September 30, 2019 to 2.21% during the three months ended September 30, 2020 while the average yield on taxable securities decreased 3 basis points from 2.35% during the nine months ended September 30, 2019 to 2.32% during the nine months ended September 30, 2020. The average taxable-equivalent yield on tax-exempt securities remained unchanged at 4.08% during the three months ended September 30, 2020 and 2019 while the average taxable-equivalent yield on tax-exempt securities increased 1 basis point from 4.06% during the nine months ended September 30, 2019 to 4.07% during the nine months ended September 30, 2020. Tax exempt securities made up approximately 66.9% and 66.6% of total average securities during the three and nine months ended September 30, 2020, respectively, compared to 60.7% and 62.3% during the same periodrespective periods in 2016, as discussed above.2019. The average volume of loanstotal securities (based on carrying amount) during the first ninethree months ended
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Table of 2017 increased $821.8Contents
September 30, 2020 decreased $764.0 million, or 7.1%5.7%, compared to the same period in 2016. Loans made up approximately 43.8% of average interest-earning assets during2019 while the first nine months of 2017 compared to 43.6% during the same period in 2016.

The average yield on securities was 3.96% during the first nine months of 2017, decreasing 5 basis points from 4.01% during the first nine months of 2016. Despite the fact that the average yield on taxable securities decreased 12 basis points from 2.02% during the first nine months of 2016 to 1.90% during the first nine months of 2017 and the average yield on tax-exempt securities decreased 19 basis point from 5.58% during the first nine months of 2016 to 5.39% during the first nine months of 2017, the overall average yield on securities only decreased 5 basis points because of a higher proportion of average securities invested in higher yielding tax-exempt securities during the first nine months of 2017 compared to the same period in 2016. Tax exempt securities made up approximately 58.8% of total average securities during the first nine months of 2017, compared to 55.9% during the same period in 2016. The average volume of total securities (based on carrying amount) during the first nine months of 2017 increased $515.3ended September 30, 2020 decreased $466.7 million, or 4.3%3.5%, compared to the same period in 2016.2019. Securities made up approximately 44.1%34.5% and 37.1% of average interest-earning assets during the firstthree and nine months of 2017ended September 30, 2020, respectively, compared to 45.3% and 45.1% during the same periodrespective periods in 2016.2019. The decreases were partly related to the impact of PPP loans and increased interest-bearing deposits on total average interest-earning assets.
Average federal funds sold, resell agreements and interest-bearing deposits during(primarily amounts held in an interest-bearing account at the firstFederal Reserve) for the three and nine months of 2017ended September 30, 2020 increased $407.3 million$4.3 billion, or 276.1%, and $3.0 billion, or 201.87%, respectively, compared to the same periodperiods in 2016.The increase in average federal funds sold, resell agreements and interest-bearing deposits was primarily related to growth in average deposits. Federal funds sold, resell agreements and interest-bearing2019. Interest-bearing deposits made up approximately 12.1%16.0% and 13.1% of average interest-earning assets during the firstthree and nine months of 2017ended September 30, 2020, respectively, compared to 11.3%5.3% and 5.1% during the same periodperiods in 2016.2019. The combinedincreases in the average volume of interest-bearing deposits (primarily amounts held in an interest-bearing account at the Federal Reserve) were primarily due to increases in the average volumes of deposits and other borrowed funds and the proceeds from the sale of securities. The average yield on interest-bearing deposits was 0.10% and 0.32% during the three and nine months ended September 30, 2020, respectively, compared to 2.19% and 2.41% during the same periods in 2019, respectively. The average yields on interest-bearing deposits were negatively impacted by lower interest rates paid on excess reserves held at the Federal Reserve for the three and nine months ended September 30, 2020 compared to the same periods in 2019.
Average federal funds sold and resell agreements for the three and nine months ended September 30, 2020 decreased $180.6 million, or 85.3%, and $108.2 million, or 45.9%, respectively, compared to the same periods in 2019. Federal funds sold and resell agreements were not a significant component of interest-earning assets during the comparable periods. The average yield on federal funds sold and resell agreements was 0.24% and interest-bearing deposits was 1.07%0.91% during the firstthree and nine months of 2017ended September 30, 2020, respectively, compared to 0.51%2.21% and 2.42% during the same periodrespective periods in 2016. As discussed above, the effective2019. The average yields on federal funds rate increased from 0.50%sold and resell agreements were negatively impacted by lower average market interest rates for the three and nine months ended September 30, 2020 compared to 0.75%the same periods in December 2016, increased from 0.75% to 1.00% in March 2017 and increased from 1.00% to 1.25% in June 2017.2019.
The average rate paid on interest-bearing liabilities was 0.13%0.15% during the first ninethree months of 2017, increasing 5ended September 30, 2020, decreasing 60 basis points from 0.08%0.75% during the same period in 2016.2019 while the average rate paid on interest-bearing liabilities was 0.27% during the nine months ended September 30, 2020, decreasing 52 basis points from 0.79% during the same period in 2019. Average deposits increased $1.5$6.5 billion, or 24.8%, during the first ninethree months of 2017ended September 30, 2020 compared to the same period in 2016.2019 and included a $2.3 billion increase in average interest-bearing deposits and a $4.3 billion increase in average non-interest bearing deposits. Average non-interest-bearing deposits forincreased $4.4 billion, or 16.8%, during the first nine months of 2017 increased $832.2 millionended September 30, 2020 compared to the same period in 2016, while2019 and included a $1.6 billion increase in average interest-bearing deposits for the first nine months of 2017 increased $699.7 million compared to the same periodand a $2.8 billion increase in 2016.average non-interest bearing deposits. The ratio of average interest-bearing deposits to total average deposits was 58.3%55.6% and 57.3% during the firstthree and nine months of 2017ended September 30, 2020, respectively, compared to 59.1%60.9% during each of the same periodperiods in 2016.2019. The average cost of deposits is primarily impacted by changes in market interest rates as well as changes in the volume and relative mix of interest-bearing deposits. The average cost of interest-bearing deposits and total deposits was 0.09%0.12% and 0.05%0.07%, respectively, during the first ninethree months of 2017ended September 30, 2020 compared to 0.05%0.63% and 0.03%0.39%, respectively, during the firstsame period in 2019. The average cost of interest-bearing deposits and total deposits was 0.21% and 0.12%, respectively, during the nine months of 2016.ended September 30, 2020 compared to 0.67% and 0.41%, respectively, during the same period in 2019. The average cost of deposits during 2017the three and nine months ended September 30, 2020 was impacted by decreases in the aforementioned increases in interest rates paidwe pay on most of our interest-bearing deposit products duringas a result of the third quarter.aforementioned decreases in market interest rates.
In April 2020, we borrowed an aggregate $1.3 billion from the Federal Home Loan Bank (“FHLB”) to provide additional liquidity in light of our significant PPP lending volume. These advances were subsequently paid-off in May 2020 as we determined additional liquidity resources were not necessary.
Our net interest spread, which represents the difference between the average rate earned on earning assets and the average rate paid on interest-bearing liabilities, was 3.64%2.89% and 3.08% during the firstthree and nine months of 2017ended September 30, 2020, respectively, compared to 3.52%3.46% and 3.48% during the same periodperiods in 2016.2019. The net interest spread, as well as the net interest margin, will be impacted by future changes in short-term and long-term interest rate levels, as well as the impact from the competitive environment. A discussion of the effects of changing interest rates on net interest income is set forth in Item 3. Quantitative and Qualitative Disclosures About Market Risk included elsewhere in this report.
Our hedging policies permit the use of various derivative financial instruments, including interest rate swaps, swaptions, caps and floors, to manage exposure to changes in interest rates. Details of our derivatives and hedging activities are set forth in Note 98 - Derivative Financial Instruments in the accompanying notes to consolidated financial statements included elsewhere in
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this report. Information regarding the impact of fluctuations in interest rates on our derivative financial instruments is set forth in Item 3. Quantitative and Qualitative Disclosures About Market Risk included elsewhere in this report.
Our net interest income and net interest margin have been, and we currently expect them to continue to be, impacted by the aforementioned decreases in market interest rates and the expectation that interest rates will remain at these low levels for some period of time in light of the on-going economic disruption arising from the COVID-19 pandemic. Notwithstanding the foregoing, our participation in the PPP, as discussed above, is expected to continue to positively impact net interest income and net interest margin in the near term.
Provision for Loan Losses
The provision for loan lossesCredit Loss Expense
Credit loss expense is determined by management as the amount to be added to the allowance for loan lossescredit loss accounts for various types of financial instruments including loans, securities and off-balance-sheet credit exposures after net charge-offs have been deducted to bring the allowanceallowances to a level which, in management’s best estimate, is necessary to absorb inherentexpected credit losses withinover the existing loan portfolio.lives of the respective financial instruments. The provision for loan losses totaled $11.0 million and $27.4 millioncomponents of credit loss expense were as follows:
Three Months Ended
September 30,
Nine Months Ended
September 30,
2020201920202019
Credit loss expense related to:
Loans$23,590 $8,001 $223,743 $25,404 
Off-balance-sheet credit exposures(3,276)— 3,786 — 
Securities held to maturity(12)— (55)— 
Total$20,302 $8,001 $227,474 $25,404 
Credit loss expense for the three and nine months ended September 30, 2017 compared to $5.0 million and $42.7 million for2019 was calculated under the three and nine months ended September 30, 2016.prior incurred loss accounting methodology. See the section captioned “Allowance for LoanCredit Losses” elsewhere in this discussion for further analysis of the provision for loan losses.credit loss expense related to loans and off-balance-sheet credit exposures.

Non-Interest Income
The components of non-interest income were as follows:
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended
September 30,
Nine Months Ended
September 30,
2017 2016 2017 20162020201920202019
Trust and investment management fees$27,493
 $26,451
 $81,690
 $77,806
Trust and investment management fees$31,469 $31,649 $97,002 $93,794 
Service charges on deposit accounts20,967
 20,540
 62,934
 60,769
Service charges on deposit accounts19,812 22,941 60,043 65,529 
Insurance commissions and fees10,892
 11,029
 34,441
 35,812
Insurance commissions and fees11,456 11,683 38,609 40,207 
Interchange and debit card transaction fees5,884
 5,435
 17,150
 15,838
Interchange and debit card transaction fees3,503 4,117 9,724 11,265 
Other charges, commissions and fees10,493
 10,703
 29,983
 29,825
Other charges, commissions and fees8,370 10,108 25,398 28,103 
Net gain (loss) on securities transactions(4,867) (37) (4,917) 14,866
Net gain (loss) on securities transactions— 96 108,989 265 
Other10,753
 7,993
 25,114
 21,358
Other8,991 8,630 34,352 29,484 
Total$81,615
 $82,114
 $246,395
 $256,274
Total$83,601 $89,224 $374,117 $268,647 
Total non-interest income for the three and nine months ended September 30, 20172020 decreased $499 thousand, or 0.6% and decreased $9.9$5.6 million, or 3.9%6.3%, and increased $105.5 million, or 39.3%, respectively compared to the same periods in 2016, respectively.2019. Excluding the impact of the$109.0 million and $265 thousand in net gain (loss)gains on securities transactions total non-interest income effectively increased $4.3 million, or 5.3%, and $9.9 million, or 4.1%, respectively, forduring the three and nine months ended September 30, 2017 compared to2020 and 2019, respectively, total non-interest income decreased $3.3 million, or 1.2%, during the same period in 2016.nine months ended September 30, 2020. Changes in the various components of non-interest income are discussed in more detail below.
Trust and Investment Management Fees. Trust and investment management fees for the three and nine months ended September 30, 2017 increased $1.0 million,2020 decreased $180 thousand, or 3.9%0.6%, and increased $3.9$3.2 million, or 5.0%3.4%, respectively compared to the same periods in 2016, respectively.2019. Investment fees are the most significant component of trust and investment management fees, making up approximately 83.5%82.7% and 81.6%82.5% of total trust and investment management fees for the first nine months of 20172020 and 2016,2019, respectively. The decrease in trust and investment management fees during the three months ended September 30, 2020 was primarily due to decreases in oil and gas fees (down $1.2 million), custody fees (down $267 thousand) and tax fees (down $229 thousand) mostly offset by an increase in trust investment fees (up $1.4 million). The increase in trust and investment management fees during the nine months ended September 30, 2020 was primarily due to increases in trust investment fees (up $2.8 million), estate fees (up $987 thousand), real estate fees (up $575 thousand) partly offset by decreases in oil and gas fees (down $784 thousand) and tax fees (down ($332 thousand). Investment and other custodial account fees are generally based on
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the market value of assets within a trust account. The increases in trust investment fees were primarily related to an increase in the number of accounts. The fluctuations in estate fees, real estate fees, custody fees and tax fees were primarily related to variation in transaction volume. Oil and gas fees during the second and third quarters of 2020 were impacted by the sharp decline in oil prices in March 2020. Though the $40 price per barrel of oil as of September 30, 2020 has rebounded from recent lows, it still remains significantly lower than the $61 price per barrel as of December 31, 2019. Volatility in the equity and bond markets impacts the market value of trust assets and the related investment fees.
The increase Investor concerns related to the uncertain economic outlook arising from the COVID-19 pandemic caused significant market volatility resulting in trust and investment management feessignificant declines in market valuations, particularly among equity securities, during the threelatter part of the first quarter of 2020 and nine months endedthe early part of the second quarter of 2020. Market valuations as of September 30, 2017 compared to2020 have rebounded from the same period in 2016 was primarily the result of increases in trust investment fees (up $1.6 million and $4.7 million, respectively). The increase in trust investment fees during 2017 was due to higher average equity valuations. The increases in trust investment fees were partly offset by decreases in estate fees (down $212 thousand and $537 thousand during the three and nine months ended September 30, 2017, respectively) and oil and gas fees (down $294 thousand and $159 thousand during the three and nine months ended September 30, 2017, respectively).recent declines.
At September 30, 2017,2020, trust assets, including both managed assets and custody assets, were primarily composed of equity securities (49.6%(50.8% of assets), fixed income securities (39.1%(34.5% of assets) and cash equivalents (6.9%(8.7% of assets). The estimated fair value of these assets was $31.0$36.6 billion (including managed assets of $13.9$16.2 billion and custody assets of $17.2$20.4 billion) at September 30, 2017,2020, compared to $29.3$37.8 billion (including managed assets of $13.4$16.4 billion and custody assets of $15.9$21.4 billion) at December 31, 20162019 and $29.7$36.4 billion (including managed assets of $13.3$15.7 billion and custody assets of $16.4$20.7 billion) at September 30, 2016.2019.
Service Charges on Deposit Accounts. Service charges on deposit accounts for the three and nine months ended September 30, 2017 increased $427 thousand,2020 decreased $3.1 million, or 2.1%13.6%, and $5.5 million, or 8.4%, compared to the same periodperiods in 2016.2019. The increase wasdecreases were primarily duerelated to increases in consumer service charges (up $429 thousand) and overdraft/insufficient funds charges on consumer and commercial accounts (up $315 thousand and $62 thousand, respectively) partly offset by a decrease in commercial service charges (down $368 thousand). Service charges on deposit accounts for the nine months ended September 30, 2017 increased $2.2 million, or 3.6%, compared to the same period in 2016. The increase was primarily due to increasesdecreases in overdraft/insufficient funds charges on consumer and commercial accounts (up $1.6 million and $361 thousand, respectively) and consumer service charges (up $451 thousand) partly offset by a decrease in commercial service charges (down $221 thousand).accounts. Overdraft/insufficient funds charges totaled $8.7$7.6 million ($6.86.2 million consumer and $2.0$1.3 million commercial) during the three months ended September 30, 20172020 compared to $8.4$11.2 million ($6.58.8 million consumer and $1.9$2.4 million commercial) during the same period in 2016.2019. Overdraft/insufficient funds charges totaled $25.9$23.7 million ($20.018.8 million consumer and $5.9$4.9 million commercial) during the nine months ended September 30, 20172020 compared to $23.9$31.1 million ($18.424.3 million consumer and $5.5$6.8 million commercial) during the same period in 2016.
Insurance Commissions2019. Consumer overdraft/insufficient funds charges decreased $2.6 million and Fees. Insurance commissions$5.5 million during the three months and fees for the threenine months ended September 30, 20172020, respectively, while commercial overdrafts/insufficient funds charges decreased $137 thousand, or 1.2%, compared to$1.1 million and $1.9 million during the same periodrespective periods. The decreases in 2016. The decrease wasoverdraft/insufficient funds charges during the three and nine months ended September 30, 2020 were primarily related to a decrease in contingent income (down $212 thousand) partly offset by an increase in commission income (up $75 thousand). Insurance commissions and fees for the nine months ended September 30, 2017 decreased $1.4 million, or 3.8%, comparedvolume of overdrafts relative to the same periodperiods in 2016. The decrease was2019.

related to a decrease in contingent income (down $2.7 million) partly offset by an increase in commission income (up $1.3 million). Insurance commissions and fees include contingent income totaling $358Commercial service charges increased $727 thousand and $3.4$2.7 million during the three and nine months ended September 30, 2017,2020, respectively. The increases in commercial service charges were impacted by a lower earnings credit rate partly offset by decreases in the volume of billable services. The earnings credit rate is the value given to deposits maintained by treasury management customers. Earnings credits applied to customer deposit balances offset service fees that would otherwise be charged. Because average market interest rates in 2020 have been lower compared to 2019, deposit balances have become less valuable and are yielding a lower earnings credit.
Insurance Commissions and Fees. Insurance commissions and fees for the three and nine months ended September 30, 2020 decreased $227 thousand, or 1.9%, and $1.6 million, or 4.0%, respectively, and $570compared to the same periods in 2019. The decreases were the result of decreases in commission income (down $90 thousand and $6.1$926 thousand during the three and nine months ended September 30, 2020, respectively) and contingent income (down $136 thousand and $672 thousand during the three and nine months ended September 30, 2020, respectively). The decreases in commission income were primarily related to decreases in benefit plan commissions and, during the nine months ended September 30, 2020, life insurance commissions partly offset by increases in both commercial lines and personal lines property and casualty commissions and, during the three months ended September 30, 2020, life insurance commissions. The decreases in benefit plan commissions were related to decreased business volumes, premium reductions and flat to lower market rates. The increases in commercial lines and personal lines property and casualty commissions were primarily related to increased rates. The fluctuations in life insurance commissions were related to changes in business volumes.
Contingent income totaled $117 thousand and $3.2 million during the three and nine months ended September 30, 2020, respectively, compared to $254 thousand and $3.8 million during the same periods in 2016.2019. Contingent income primarily consists of amounts received from various property and casualty insurance carriers related to the loss performance of insurance policies previously placed. These performance related contingent payments are seasonal in nature and are mostly received during the first quarter of each year. This performance related contingent income totaled $2.1 million and $4.6$2.8 million during the nine months ended September 30, 20172020 and 2016,2019, respectively. The decrease in performance related contingent income during 20172020 was related to a lack oflower growth within the portfolio andcombined with a deterioration in the loss performance of insurance policies previously placed. Contingent income also includes amounts received from various benefit plan insurance companies related to the volume of business generated and/or the subsequent retention of such business. This benefit plan related contingent income totaled $311$77 thousand and $1.3$1.1 million during the three and nine months ended September 30, 2017 and $4172020, respectively, compared to $193 thousand and $1.5$1.1 million during the three and nine months ended September 30, 2016. The increasessame periods in 2019.
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Notwithstanding normal seasonal variation, commission income during the threesecond and nine months ended September 30, 2016 were primarily relatedthird quarters of 2020 was partly impacted by reduced business volumes resulting from the COVID-19 pandemic, relative to increasesthe first quarter of 2020. Commission income in benefitfuture periods may be similarly impacted. Benefit plan commissions duemay be particularly impacted by the effects of temporary furloughs and permanent layoffs. The COVID-19 pandemic has also given rise to increaseda hard insurance market characterized by decreased capacity for most types of insurance coupled with more stringent underwriting standards among insurers. This may cause clients to drop or adjust coverage choices as part of expense control measures. Reduced business volumes partly offset by decreasesmay also adversely impact the level of contingent commissions we receive in commissions on property and casualty policies.2021.
Interchange and Debit Card Transaction Fees. Interchange fees, or “swipe” fees, are charges that merchants pay to us and other card-issuing banks for processing electronic payment transactions. Interchange and debit card transaction fees consist of income from checkdebit card usage, point of sale income from PIN-based debit card transactions and ATM service fees. Interchange and debit card transaction fees are reported net of related network costs.
A comparison of gross and net interchange and debit card transaction fees for the threereported periods is presented in the table below. Net revenues from interchange and nine months ended September 30, 2017 increased $449 thousand, or 8.3%, and $1.3 million, or 8.3%, compared to the three and nine months ended September 30, 2016. The increases were primarily due to increases in income from debit card transactions (up $381 thousand and $1.0 million forduring the three and nine months ended September 30, 2017, respectively) and ATM service fees (up $68 thousand and $267 thousand for the three and nine months ended September 30, 2017, respectively). The increasesreported periods were primarilyimpacted by reduced transaction volumes, in part related to the COVID-19 pandemic, and increased transaction volumes.network costs.
Three Months Ended
September 30,
Nine Months Ended
September 30,
2020201920202019
Income from debit card transactions$6,097 $6,191 $17,429 $17,569 
ATM service fees842 1,069 2,522 3,136 
Gross interchange and debit card transaction fees6,939 7,260 19,951 20,705 
Network costs3,436 3,143 10,227 9,440 
Net interchange and debit card transaction fees$3,503 $4,117 $9,724 $11,265 
Federal Reserve rules applicable to financial institutions that have assets of $10 billion or more provide that the maximum permissible interchange fee for an electronic debit transaction is the sum of 21 cents per transaction and 5 basis points multiplied by the value of the transaction. An upward adjustment of no more than 1 cent to an issuer's debit card interchange fee is allowed if the card issuer develops and implements policies and procedures reasonably designed to achieve certain fraud-prevention standards. The Federal Reserve also has rules governing routing and exclusivity that require issuers to offer two unaffiliated networks for routing transactions on each debit or prepaid product.
Other Charges, Commissions and Fees. Other charges, commissions and fees for the three months ended September 30, 20172020 decreased $210 thousand,$1.7 million, or 2.0%17.2%, compared to the same period in 2016.2019. The decrease includedwas primarily related to decreases in human resources consulting fee income from the placement of money market accounts (down $160 thousand)$1.3 million) and income from corporate finance and capital market advisory services (down $109 thousand), among other things. These items were partly offset by an increase in income related to the sale of mutual funds (up $128(down $113 thousand), among other things. Other charges, commissions and fees for the nine months ended September 30, 2017 increased $158 thousand,2020 decreased $2.7 million, or 0.5%9.6%, compared to the same period in 2016.2019. The increasedecrease included increasesdecreases in income related tofrom the placement of money market accounts (down $1.6 million); letter of credit fees (down $519 thousand); income from the sale of mutuallife insurance (down $398 thousand); and funds (up $911transfer service charges (down $200 thousand) and wire transfer fees (up $235 thousand),; among other things. TheseThe decreases in these items were partly offset by decreasesincreases in human resources consulting fee income (down $486from the sale of annuities (up $263 thousand) and incomemutual funds (up $165 thousand) and an increase in brokerage commissions (up $118 thousand). Income from corporate finance and capitalthe placement of money market advisory services (down $476 thousand), among other things. Human resources consulting fee income decreased as we no longer provide these services. Changesaccounts was impacted by a decrease in themarket rates. The other aforementioned categories of other charges, commissions and feesrevenue streams were due toimpacted by fluctuations in businesstransaction volumes.
Net Gain/Loss on Securities Transactions. During the nine months ended September 30, 2017,2020 and 2019, we sold certain available-for-sale U.S Treasury securities with an amortized costcosts totaling $1.0 billion and $8.2 billion, respectively. We realized a net gain of $109.0 million on the 2020 sales and a net gain of $265 thousand on the 2019 sales. During the first quarter of 2020, we sold $483.1 million of residential mortgage-backed securities and realized a net lossgain of $50 thousand$1.9 million on those sales. The proceeds from these sales were primarily related toreinvested into other residential mortgage-backed securities that had lower pre-payment rates. We also sold $519.1 million of 30-year U.S Treasury securities during the first quarter of 2020 and realized a net gain of $107.1 million on those sales. These U.S. Treasury securities were purchased during 2017the fourth quarter of 2019 to hedge, in effect, against falling interest rates. Prior to their sale, these securities had significant unrealized holding gains as a result of decreases in market interest rates during the first quarter of 2020. We elected to sell these securities to provide liquidity and realize the gains.
During the first nine months of 2019, we purchased and subsequently sold $7.4 billion of U.S. Treasury securities in connection with our tax planning strategies related to the Texas franchise tax. The gross proceeds from the sales of these securities outside of Texas are included in total revenues/receipts from all sources reported for Texas franchise tax purposes, which results in a reduction in the overall percentage of revenues/receipts apportioned to Texas and subjected to taxation under the Texas franchise tax. We realized a net gain of $99 thousand on those sales. We also sold during the third quarter of 2017, certain other available-for-sale U.S. Treasury securities with an amortized cost totaling $751.4$548.9 million and certain available-for-sale municipal securities with an
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amortized cost totaling $310.7 million. We realized a net lossgain of $4.9 million on those sales. These securities were sold with the intent to reinvest the sales proceeds in higher yielding debt securities and other investments.
During the nine months ended September 30, 2016, we sold certain available-for sale U.S. Treasury securities with an amortized cost totaling $8.0 billion and realized a net loss of $37$166 thousand on those sales. The sales were primarily related to securities purchased during 2016 and subsequently sold in connection with our aforementioned tax planning strategies related to the Texas franchise tax. We also sold certain other available-for-sale U.S. Treasury securities with an amortized cost totaling $749.5 million and realized a net gain of $2.8 million on those sales. The securities sold were due to mature during 2016. Most of the proceeds from the sale of these securitiessales provided short-term liquidity and were subsequently reinvested into U.S. Treasury securities having comparable yields, but longer-terms. During the nine months ended September 30, 2016, we also sold certain municipal securities that were classified as both available forin other higher yielding securities.

sale and held to maturity due to a significant deterioration in the creditworthiness of the issuers. These securities had a total amortized cost of $431.4 million and we realized a gain of $12.1 million on those sales. Refer to our 2016 Form 10-K for additional information related to these sales.
Other Non-Interest Income. Income. Other non-interest income for the three months ended September 30, 20172020 increased $2.8 million,$361 thousand, or 34.5%4.2%, compared to the same period in 2016.2019. The increase was primarily related to increasesan increase in sundry and other miscellaneous income (up $1.1$1.3 million), income from customer derivative and trading activitiespublic finance underwriting fees (up $935$833 thousand), partly offset by a decrease in gains on the sale of foreclosed and other assets (up $724 thousand) and income from customer foreign currency transactions (up $248 thousand).(down $1.3 million), among other things. Sundry and other miscellaneous income during the three months ended September 30, 2017third quarter of 2020 included $1.2$1.0 million related to the collection of amounts charged-off by Western National Bank prior to our acquisitiona Visa rebate and $426$512 thousand related to recoveries of prior write-offs, among other things, while sundry and other miscellaneous income during the same periodsettlements. The increase in 2016 included $453 thousand related to recoveries of prior write-offs, among other things. The fluctuations in income from customer derivative and trading activities and income from customer foreign currency transactions werepublic finance underwriting fees was primarily related to changes inincreased business volumes. During the third quarter of 2017, gainsGains on the sale of foreclosed and other assets included $700 thousand related to amortization of the deferreda $1.3 million gain on our headquarters building, which we sold in December 2016.the sale of a branch facility during the third quarter of 2019.
Other non-interest income for the nine months ended September 30, 20172020 increased $3.8$4.9 million, or 17.6%16.5%, compared to the same period in 2016.2019. Other non-interest income during the nine months ended September 30, 2020 included approximately $6.0 million in gains realized on the sale of certain non-hedge related, short-term put options on U.S. Treasury securities with an aggregate notional amount of $500 million. The put options were not exercised and expired in March 2020. The increase in other non-interest income during the nine months ended September 30, 2020 was primarilyalso partly related to increases in sundry and other miscellaneous income (up $2.4 million), income from customer derivative and trading activities (up $1.6 million) and public finance underwriting fees (up $1.5 million). The aforementioned items were partly offset by decreases in gains on the sale of foreclosed and other assets (up $1.5(down $5.9 million) and income from customer foreign exchange transactions (down $464 thousand), sundryamong other things. Sundry and other miscellaneous income (up $1.5 million),during 2020 included $1.0 million related to a Visa volume-related bonus, $512 thousand related to settlements and $2.8 million related to the recovery of prior write-offs. Sundry and other miscellaneous income from customer foreign currency transactions (up $497 thousand)during 2019 included $1.1 million related to the recovery of prior write-offs, $278 thousand related to a distribution on a private equity investment and $250 thousand related to a settlement. The fluctuations in income from customer derivative and trading activities, (up $422 thousand), among other things, partly offset by decreases in lease rental income (down $384 thousand) and earnings on the cash surrender value of life insurance policies (down $311 thousand), among other things. Sundry income during the nine months ended September 30, 2017 included the aforementioned $1.2 million related to the collection of amounts charged-off by Western National Bank prior to our acquisition, $864 thousand related to the settlement of a non-solicitation agreement and $541 thousand related to recoveries of prior write-offs among other things, while sundry and other miscellaneous income during the same period in 2016 included $1.1 million related to recoveries of prior write-offs, among other things. The fluctuations in income from customer foreign currency transactionspublic finance underwriting fees and income from customer derivative and trading activitiesforeign exchange transactions were primarily related to changes in business volumes. During the first nine months of 2017, gainsGains on the sale of foreclosed and other assets included $2.2gains on the sale of various branch and operational facilities totaling $758 thousand and $6.7 million, related to amortization ofduring the aforementioned deferred gain on our headquarters building.nine months ended September 30, 2020 and 2019, respectively.
Non-Interest Expense
The components of non-interest expense were as follows:
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended
September 30,
Nine Months Ended
September 30,
2017 2016 2017 20162020201920202019
Salaries and wages$84,388
 $79,411
 $247,895
 $236,814
Salaries and wages$93,323 $93,812 $282,485 $277,078 
Employee benefits17,730
 17,844
 57,553
 55,861
Employee benefits16,074 21,002 59,824 64,579 
Net occupancy19,391
 18,202
 57,781
 53,631
Net occupancy25,466 24,202 76,116 64,602 
Furniture and equipment18,743
 17,979
 54,983
 53,474
Technology, furniture and equipmentTechnology, furniture and equipment26,482 22,415 77,768 66,236 
Deposit insurance4,862
 4,558
 15,347
 12,412
Deposit insurance2,372 2,491 7,796 7,752 
Intangible amortization405
 586
 1,301
 1,869
Intangible amortization212 274 710 904 
Other41,304
 41,925
 127,929
 125,048
Other38,221 44,668 121,293 132,722 
Total$186,823
 $180,505
 $562,789
 $539,109
Total$202,150 $208,864 $625,992 $613,873 
Total non-interest expense for the three and nine months ended September 30, 2017 increased $6.32020 decreased $6.7 million, or 3.5%3.2%, and $23.7increased $12.1 million, or 4.4%2.0%, respectively, compared to the same periods in 2016.2019. Changes in the various components of non-interest expense are discussed below.
Salaries and Wages. Salaries and wages for the three and nine months ended September 30, 20172020 decreased $489 thousand, or 0.5%, and increased $5.0$5.4 million, or 6.3%, and $11.1 million, or 4.7%2.0%, compared to the same periods in 2016. The2019. Despite an increase wasin salaries, due to an increase in the number of employees and normal, annual merit and market increases, salaries and wages during the three months ended September 30, 2020, decreased primarily relatedas a result of decreases in incentive compensation, commissions and stock-based compensation. Salaries and wages during the nine months ended September 30, 2020 increased primarily due to an increase in salaries, due to an increase in the number of employees and normal, annual merit and market increases,increases. This increase was partly offset by an increase in salary costs deferred as well as increasesloan origination costs, up $5.9 million primarily in stockconnection with the high volume of PPP loan originations during the second quarter of 2020, and decreases in incentive compensation, stock-based compensation and incentive compensation. Salaries and wages duringcommissions. Salary costs deferred in connection with loan originations will be recognized as a yield adjustment component of interest income over the remaining terms of these loans.

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Employee Benefits. Employee benefits expense for the three and nine months ended September 30, 2017 also included approximately $1.22020 decreased $4.9 million, in severance expense primarily related to the closure of certain branch locations.
Employee Benefits. Employee benefits expense for the three months ended September 30, 2017or 23.5%, and decreased $114 thousand,$4.8 million, or 0.6%7.4%, compared to the same periodperiods in 2016.2019. The decrease wasdecreases in employee benefits expense were primarily duerelated to decreases in medical insurance expense (down $502 thousand),certain discretionary benefit plan expenses and expenses related to our defined benefit retirement plans (down $302 thousand) and other employee benefits (down $120 thousand)restoration plans partly offset by an increase in expenses related to our 401(k) and profit sharing plans (up $851 thousand). Employee

benefits expense for the nine months ended September 30, 2017 increased $1.7 million, or 3.0%, compared to the same period in 2016. The increase was primarily due to increases in expenses related to our 401(k) and profit sharing plans (up $1.6 million)medical benefits expense and payroll taxes, (up $1.1 million) partly offset by a decrease in expenses related to our defined benefit retirement plans (down $1.1 million).among other things.
During the three and nine months ended September 30, 2017, we recognized a combined net periodic pension expense of $125 thousand and $376 thousand, respectively, related to our defined benefit retirement plans compared to a combined net periodic pension expense of $427 thousand and $1.4 million during the same periods in 2016. Net periodic pension expense during the nine months ended September 30, 2016 included $187 thousand in supplemental executive retirement plan (“SERP”) settlement costs related to the retirement of a former executive officer. Our defined benefit retirement and restoration plans were frozen effective as of December 31, 2001 and were replaced by a profit sharing plan.plan (which was merged with and into our 401(k) plan during 2019). Management believes these actions helped to reduce the volatility in retirement plan expense. However, we still have funding obligations related to the defined benefit and restoration plans and could recognize retirement expense related to these plans in future years, which would be dependent on the return earned on plan assets, the level of interest rates and employee turnover. A prolonged negative impact on the value of stocks and other asset classes due to the COVID-19 pandemic could result in a significant reduction to pension plan asset values and expected returns, which could impact the level of future funding and expense. See Note 12 - Defined Benefit Plans for additional information related to our net periodic pension benefit/cost.
Net Occupancy. Net occupancy expense for the three and nine months ended September 30, 20172020 increased $1.2$1.3 million, or 6.5%5.2%, and $4.2increased $11.5 million, or 7.7%17.8%, respectively, compared to the same periods in 2016.2019. The increase during the three months ended September 30, 20172020 was primarily related to increases in lease expensedepreciation on leasehold improvements (up $782$842 thousand), property taxes (up $338$805 thousand) and building depreciation (up $300 thousand), utilities expense (up $140 thousand) and depreciation on leasehold improvements (up $125 thousand)among other things, partly offset by a decrease in building depreciationrepairs and maintenance/service contracts expense (down $372$602 thousand). The increase during the nine months ended September 30, 20172020 was primarily related to increases in lease expense (up $2.6 million), property taxes (up $1.0$4.5 million), depreciation on leasehold improvements (up $604 thousand)$3.2 million), property taxes (up $2.4 million) and building depreciation (up $1.3 million), among other things, partly offset by a decrease in repairs and maintenance/service contracts expense (up $535 thousand) and utilities(down $1.2 million). Net occupancy expense (up $336 thousand) partly offsetwas impacted by a decrease in building depreciation (down $1.1 million). The increases inthe commencement of the lease expense and the decreases in building depreciation during the reported periods were primarily related to the sale and lease back of our new corporate headquarters building in December 2016,San Antonio in June 2019, as more fully discussedwell as renewals of other leases related to existing facilities and new locations, in part related to our 2016 Form 10-K.expansion within the Houston market area.
Technology, Furniture and Equipment. Furniture Technology, furniture and equipment expense for the three and nine months ended September 30, 20172020 increased $764 thousand,$4.1 million, or 4.2%18.1%, and $1.5$11.5 million, or 2.8%17.4%, respectively, compared to the same periods in 2016.2019. The increases were primarily related to increases in cloud services expense (up $2.6 million and $6.5 million, respectively), depreciation of furniture and equipment (up $1.2 thousand and $3.2 million, respectively), software maintenance (up $974$299 thousand and $2.3$2.1 million respectively) and software amortization (up $481 thousand and $1.1 million, respectively).
Deposit Insurance. Deposit insurance expense totaled $2.4 million and $7.8 million for the three and nine months ended September 30, 2017, respectively)2020 compared to $2.5 million and depreciation on furniture and equipment (up $198 thousand and $1.4$7.8 million for the three and nine months ended September 30, 2017, respectively) partly offset2019. Provisions of the CARES Act allow, but do not require, the FDIC to expand deposit insurance coverage for non-interest-bearing transaction accounts through December 31, 2020. Such action could result in additional deposit insurance expense. Other provisions of the CARES Act as well as actions taken by bank regulators, such as potential relief for working with borrowers who are distressed as a decrease in equipment rentalresult of the effects of COVID-19, could similarly impact aggregate deposit insurance expense.
Other Non-Interest Expense. Other non-interest expense (down $576 thousand and $1.6 million for the three and nine months ended September 30, 2017, respectively)2020 decreased $6.4 million, or 14.4%, and for the nine months ended September 30, 2017, a decrease in service contracts (down $413 thousand), among other things.
Deposit Insurance. Deposit insurance expense totaled $4.9$11.4 million, and $15.3 million for the three and nine months ended September 30, 2017 compared to $4.6 million and $12.4 million for the three and nine months ended September 30, 2016. Deposit insurance expense was impacted by an increase in assets and, during the nine-months ended September 30, 2017, an increase in the overall assessment rate. The increase in the assessment rate was partly related to a new surcharge that became applicable during the third quarter of 2016. In August 2016, the Federal Deposit Insurance Corporation (“FDIC”) announced that the Deposit Insurance Fund (“DIF”) reserve ratio had surpassed 1.15% as of June 30, 2016. As a result, beginning in the third quarter of 2016, the range of initial assessment rates for all institutions was adjusted downward and institutions with $10 billion or more in assets were assessed a quarterly surcharge. The quarterly surcharge will continue to be assessed until such time as the reserve ratio reaches the statutory minimum of 1.35% required by the Dodd-Frank Wall Street Reform and Consumer Protection Act.
Intangible Amortization. Intangible amortization is primarily related to core deposit intangibles and, to a lesser extent, intangibles related to customer relationships and non-compete agreements. Intangible amortization for the three and nine months ended September 30, 2017 decreased $181 thousand, or 30.9%, and $568 thousand, or 30.4%8.6%, respectively, compared to the same periods in 2016.2019. The decrease in amortization was primarily related to the completion of amortization of certain previously recognized intangible assets as well as a reduction in the annual amortization rate of certain previously recognized intangible assets as we use an accelerated amortization approach which results in higher amortization rates during the earlier years of the useful lives of intangible assets.
Other Non-Interest Expense. Other non-interest expense for the three months ended September 30, 2017 decreased $621 thousand, or 1.5%, compared to the same period in 2016. The decrease2020 included decreases in check card expense (down $1.2 million), sundry and other miscellaneous expense (down $711 thousand), regulatory examination fees (down $198 thousand) and losses on the sale/write-down of foreclosed and other assets (down $170 thousand). These items were partly offset by increases in guard services expense (up $580 thousand), the provision for losses on unfunded loan commitments (up$250 thousand), business development expenses (up $207 thousand), point-of-sale related expenses (up $205 thousand), platform fees associated with our managed mutual funds (up $198 thousand) and travel/travel, meals and entertainment expense (up $194 thousand),(down $3.1 million); professional services expense (down $1.6 million); and advertising/promotions expense (down $1.2 million); among other things. Other non-interest expense forThe decrease during the nine months ended September 30, 2017 increased

$2.92020 included decreases in travel, meals and entertainment expense (down $6.1 million); advertising/promotions expense (down $3.7 million); professional services expense (down $1.1 million); and business development expense (down $702 thousand); among other things. The decrease in other non-interest expense during the nine months ended September 30, 2020 was also partly due to an increase in costs deferred as loan origination costs, up $1.9 million or 2.3%, compared toprimarily in connection with the same periodhigh volume of PPP loan originations during the second quarter of 2020. Costs deferred in 2016.connection with loan originations will be recognized as a yield adjustment component of interest income over the remaining terms of these loans. The increase includedimpact of the aforementioned items was partly offset by increases in guard servicesdonations expense (up $1.1 million), fraud losses (up $924 thousand), travel/meals and entertainmenttelephone/data communications expense (up $828$907 thousand), advertising/promotions expenseand platform fees related to investment services (up $688 thousand) and outside computer services expense (up $760$727 thousand), among other things. These items were partly offset by a decrease in check card expense (down $1.8 million), among other things. Guard services expense during the three and nine months ended September 30, 2017 was impacted by the effects

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Table of hurricane Harvey during the third quarter. The increase in fraud losses was primarily related to check cards, ATMs and checks.Contents
Results of Segment Operations
Our operations are managed along two primary operating segments: Banking and Frost Wealth Advisors. A description of each business and the methodologies used to measure financial performance is described in Note 1615 - Operating Segments in the accompanying notes to consolidated financial statements included elsewhere in this report. Net income (loss) by operating segment is presented below:
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended
September 30,
Nine Months Ended
September 30,
2017 2016 2017 20162020201920202019
Banking$88,368
 $76,347
 $250,766
 $210,454
Banking$93,507 $110,583 $238,023 $334,393 
Frost Wealth Advisors6,417
 4,797
 17,990
 13,809
Frost Wealth Advisors4,130 4,106 13,642 15,403 
Non-Banks(1,654) (925) (5,131) (3,721)Non-Banks(2,581)(2,853)(8,784)(9,878)
Consolidated net income$93,131
 $80,219
 $263,625
 $220,542
Consolidated net income$95,056 $111,836 $242,881 $339,918 
Banking
Net income for the three and nine months ended September 30, 2017 increased $12.02020 decreased $17.1 million, or 15.7%15.4%, and $40.3decreased $96.4 million, or 19.2%28.8%, respectively, compared to the same periods in 2016.2019. The increasedecrease during the three months ended September 30, 20172020 was primarily the result of a $24.0$12.3 million increase in credit loss expense, a $9.9 million decrease in net interest income and a $1.8$3.5 million decrease in non-interest income partly offset by a $4.8 million decrease in non-interest expense and a $3.9 million decrease in income tax expense partly offset by a $6.1 million increase in non-interest expense, a $5.9 million increase in the provision for loan losses and a $1.8 millionexpense. The decrease in non-interest income. The increase during the nine months ended September 30, 20172020 was primarily the result of a $65.0$202.1 million increase in credit loss expense, a $19.8 million decrease in net interest income and a $15.4 million decrease in the provision for loan losses partly offset by a $20.2$9.0 million increase in non-interest expense partly offset by a $15.4$104.6 million decreaseincrease in non-interest income and a $4.5$29.9 million increasedecrease in income tax expense.
Net interest income for the three and nine months ended September 30, 2017 increased $24.02020 decreased $9.9 million, or 12.5%3.9%, and $65.0decreased $19.8 million, or 11.4%2.6%, compared to the same periods in 2016. Taxable-equivalent net2019. The decreases were primarily related to decreases in the average yields on loans, interest-bearing deposits and federal funds sold and resell agreements combined with, to a significantly lesser extent, decreases in the average volumes of taxable securities (based on amortized cost) and increases in the average volume of interest bearing liabilities. The impact of these items was partly offset by increases in the average volumes of loans and interest-bearing deposits (primarily amounts held in an interest-bearing account at the Federal Reserve) combined with decreases in the average cost of interest-bearing deposit liabilities and other borrowed funds. Net interest income for the first nine months of 2017 included 273 days compared to 274 days for2020 was also positively impacted by the same period in 2016additional day as a result of the leap year. The additional day added approximately $1.5 million to taxable-equivalent net interest income during the first nine months of 2016. Despite the effect of this additional day during 2016, net interest income during the three and nine months ended September 30, 2017 increased due to the impact of increases in the average volume of tax-exempt securities, loans and interest-bearing deposits as well as increases in the average yields on loans and interest-bearing deposits partly offset by the impact of decreases in the average yields on tax-exempt and taxable securities combined with the impact of increases in the average rate paid on interest-bearing liabilities. See the analysis of net interest income included in the section captioned “Net Interest Income” included elsewhere in this discussion.
The provision for loan lossesCredit loss expense for the three and nine months ended September 30, 20172020 totaled $11.0$20.3 million and $27.4$227.5 million, respectively, compared to $5.0$8.0 million and $42.7$25.4 million for the same periods in 2016.2019. The increases resulted from both our adoption of a new credit loss accounting standard and the adverse events impacting our loan portfolio, including those arising from the COVID-19 pandemic and the significant decline in oil prices. See the analysis of the provision for loan losses included in the sectionsections captioned “Credit Loss Expense” and “Allowance for LoanCredit Losses” included elsewhere in this discussion.
Non-interest incomediscussion for the three months ended September 30, 2017 decreased $1.8 million, or 3.5%, while non-interest income for the nine months ended September 30, 2017 decreased $15.4 million, or 9.2%, compared to the same periods in 2016. Both the three and nine months ended September 30, 2017 included a net loss on securities transactions of $4.9 million compared to a net loss of $37 thousand during the three months ended September 30, 2016 and a net gain of $14.9 million during the nine months ended September 30, 2016. See thefurther analysis of these net gainscredit loss expense related to loans and losses included in the section captioned “Net Gain/Loss on Securities Transactions” included elsewhere in this discussion. Excluding the impact of the net gains or losses on securities transactions, total non-interest income during the three and nine months ended September 30, 2017 effectively increased $3.0 million, or 5.9%, and $4.4 million, or 2.9%, respectively compared to the same periods in 2016 primarily due to increases in other non-interest income, service charges on deposit accounts and interchange and debit card transactions fees partly offset by decreases in insurance commissions and fees and other charges, commissions and fees. The increases in other non-interestoff-balance-sheet commitments.
Non-interest income for the three and nine months ended September 30, 2017 were2020 decreased $3.5 million, or 6.7% and increased $104.6 million, or 65.0%, respectively, compared to the same periods in 2019. The decrease during the three months ended September 30, 2020 was primarily relateddue to increasesdecreases in gainsservices charges on the sale of forecloseddeposit accounts; interchange and debit card transaction fees; other assets, sundrycharges, commissions and other miscellaneous income, income from customer foreign currency transactionsfees; and income from customer derivativeinsurance commissions and trading activities, among other things,fees partly offset by decreasesan increase in lease rental income and earnings on the cash surrender value of life insurance policies, among other things. Sundry incomenon-interest income. The increase during the three and nine months ended September 30, 2017 included $1.22020 was primarily due to a $109.0 million relatednet gain on securities transactions. Excluding the net gain on securities transactions during the nine months ended September 30, 2020, total non-interest income for the Banking segment decreased $4.1 million, or 2.6%, compared to the collection of amounts charged-off by Western National Bank priorsame period in 2019. This decrease was primarily due to our acquisition,

among other things. Gainsdecreases in services charges on the sale of forecloseddeposit accounts; insurance commissions and fees; interchange and debit card transaction fees; and other assets during 2017 included the amortization of the deferred gain on our headquarters building, which we sold in December 2016. Thecharges, commissions and fees partly offset by an increase in serviceother non-interest income. The decreases in services charges on deposit accounts during the three and nine months ended September 30, 20172020 were primarily duerelated to increasesdecreases in overdraft/insufficient funds charges on consumer and commercial accounts and consumer service charges partly offset bydue to decreases in commercial service charges.transaction volumes. The increasedecreases in interchange and debit card transactions fees during the three and nine months ended September 30, 20172020 were primarily due to increasesimpacted by reduced transaction volumes, in income from debit card transactions and ATM service fees. The increases were primarilypart related to increased transaction volumes. The decrease in insurance commissions and fees during the three and nine months ended September 30, 2017 were related to decreases in contingent income, primarily related to a lack of growth within the portfolio and a deterioration in the loss performance of insurance policies previously placed, partly offset by increases in commission income, primarily related to increases in benefit plan commissions due to increased business volumes.COVID-19 pandemic. The decrease in other charges, commissions and fees during the three and nine months ended September 30, 20172020 included decreases in letter of credit fees and funds transfer service charges, among other things. The decreases in insurance commissions and fees for the three and nine months ended September 30, 2020 were the result of decreases in commission income and contingent income, which are further discussed below in relation to Frost Insurance Agency. The increase in other non-interest income during the three months ended September 30, 2020 was primarily duerelated to decreasesan increase in human resources consulting feesundry and other
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miscellaneous income and income from corporatepublic finance and capital market advisory services, among other things,underwriting fees partly offset by increasesa decrease in wire transfer fees,gains on the sale of foreclosed and forother assets, among other things. The increase in other non-interest income during the nine months ended September 30, 2017,2020 included approximately $6.0 million in gains realized on the sale of certain non-hedge related, short-term put options on U.S. Treasury securities with an aggregate notional amount of $500 million. The put options were not exercised and expired in March 2020. The increase in loan processing fees,other non-interest income during the nine months ended September 30, 2020 was also partly related to increases in sundry and other miscellaneous income, income from customer derivative and trading activities and public finance underwriting fees. The aforementioned items were partly offset by decreases in gains on the sale of foreclosed and other assets and income from customer foreign exchange transactions, among other things. The fluctuations in 2020 income from customer derivative and trading activities, public finance underwriting fees and income from foreign exchange transactions were primarily related to changes in business volumes. See the analysis of these categories of non-interest income included in the section captioned “Non-Interest Income” included elsewhere in this discussion.
Non-interest expense decreased $4.8 million, or 2.7%, for the three months ended September 30, 2020 and increased $9.0 million, or 1.7%, for the nine months ended September 30, 2020, compared to the same periods in 2019. The decrease during the three months ended was primarily due to decreases in other non-interest expense and employee benefits partly offset by increases in technology, furniture and equipment expense and net occupancy expense. The increase during the nine months ended was primarily related to increases in technology, furniture and equipment expense, net occupancy expense and salaries and wages partly offset by a decrease in other non-interest expense and employee benefits. The decreases in other non-interest expense during the three and nine months ended September 30, 2017 increased $6.1 million, or 4.0%,2020 included decreases in travel, meals and $20.2 million, or 4.4%, compared to the same periodsentertainment expense; professional services expense; advertising/promotions expense; and business development expense among other things. The decrease in 2016. The increase during the three months ended September 30, 2017 was primarily related to increases in salaries and wages, other non-interest expense and furniture and equipment expense. The increase during the nine months ended September 30, 20172020 was also partly due to an increase in costs deferred as loan origination costs in connection with the high volume of PPP loan originations during the second quarter of 2020. The impact of the aforementioned items was partly offset by increases in donations expense, and telephone/data communications expense, among other things. The decreases in employee benefits expense during the three and nine months ended September 30, 2020 were primarily related to decreases in certain discretionary benefit plan expenses and expenses related to ourdefined benefit retirement and restoration plans partly offset by increases in medical benefits expense and payroll taxes, among other things. The increases in technology, furniture and equipment expense during the three and nine months ended September 30, 2020 were primarily related to increases in cloud services expense, depreciation of furniture and equipment, software maintenance and software amortization. The increases in net occupancy expense during the three and nine months ended September 30, 2020 were primarily related to increases in depreciation on leasehold improvements, property taxes, and building depreciation, among other things, and, for the nine months ended September 30, 2020, an increase in lease expense. The increases from these items were partly offset by decreases in repairs and maintenance/service contracts expense. The increase in salaries and wages other non-interest expense, deposit insurance expense, employee benefits and furniture and equipment expense. The increasesduring the nine months ended September 30, 2020 was primarily related to an increase in salaries, were primarily due to increasesan increase in the number of employees and normal, annual merit and market increases, as well as increases in stock compensation and incentive compensation. The increases in other non-interest expense were primarily related to increases in guard services expense, sundry and other miscellaneous expense and travel/meals and entertainment, among other things. Guard services expense during the three and nine months ended September 30, 2017 was impacted by the effects of hurricane Harvey during the third quarter. The increases in furniture and equipment expense were primarily related to increases in software maintenance and depreciation on furniture and equipment partly offset by a decrease in equipment rental expense, among other things. The increase in deposit insurance expense during the nine months ended September 30, 2017 was related to an increase in salary costs deferred as loan origination costs, primarily in connection with the assessment rate due to a new quarterly surcharge which began inhigh volume of PPP loan originations during the thirdsecond quarter of 20162020, and an increasedecreases in assets. The increase in employee benefits during the nine months ended September 30, 2017 was primarily due to increases in payroll taxesincentive compensation, stock-based compensation and expenses related to our 401(k) and profit sharing plans partly offset by a decrease in expenses related to our defined benefit retirement plans.commissions. See the analysis of these categories of non-interest expense included in the section captioned “Non-Interest Expense” included elsewhere in this discussion.
Frost Insurance Agency, which is included in the Banking operating segment, had gross commission revenues of $10.9$11.5 million and $34.6$38.7 million during the three and nine months ended September 30, 2017 and $11.02020 compared to $11.7 million and $35.9$40.3 million during the three and nine months ended September 30, 2016.2019. The decreases for the three and nine months ended September 30, 2020 were the result of decreases in commission income and contingent incomes. The decreases in commission income were primarily related to decreases in contingentbenefit plan commissions and, during the nine months ended September 30, 2020, life insurance commissions partly offset by increases in both commercial lines and personal lines property and casualty commissions and, during the three months ended September 30, 2020, life insurance commissions. The decreases in benefit plan commissions.commissions were related to decreased business volumes, premium reductions and flat to lower market rates. The increases in commercial lines and personal lines property and casualty commissions were primarily related to increased rates. The fluctuations in life insurance commissions were related to changes in business volumes. The decrease in contingent income during 2020 was partly due to lower growth and a deterioration in the loss performance of insurance policies previously placed. See the analysis of insurance commissions and fees included in the section captioned “Non-Interest Income” included elsewhere in this discussion.
Frost Wealth Advisors
Net income for the three and nine months ended September 30, 20172020 increased $1.6$24 thousand, or 0.6%, and decreased $1.8 million, or 33.8% and $4.2 million, or 30.3%11.4%, respectively, compared to the same periods in 2016. The increase during2019. During the three months ended September 30, 20172020 a $2.3 million decrease in non-interest expense was primarily due tomostly offset by a $1.7$1.9 million increasedecrease in non-interest income, a $387 thousand decrease in net interest income and a $1.3 million increase in non-interest income partly offset by an $873$7 thousand increase in income tax expense and a $500 thousand increase in non-interest expense. The increasedecrease in net income during the nine months ended September 30, 20172020 was primarily duerelated to a $5.4$2.7 million increase in non-interest incomeexpense and a $5.0 million increase$875
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thousand decrease in net interest income partly offset by a $3.9$1.3 million increase in non-interest expenseincome and a $2.3 million increase$467 thousand decrease in income tax expense.
Net interest income for the three and nine months ended September 30, 2017 increased $1.7 million,2020 decreased $387 thousand, or 57.0%39.1%, and $5.0 million,$875 thousand, or 64.5%28.8%, respectively, compared to the same periods in 2016. The increases2019. These decreases were primarily due to an increase in the funds transfer price received for funds provided related to Frost Wealth Advisors' repurchase agreements and increasesdecreases in the average volumefunds transfer prices allocated to the funds provided by Frost Wealth Advisors. The decreases in the average funds transfer prices were primarily due to decreases in market interest rates. See the analysis of funds provided.net interest income included in the section captioned “Net Interest Income” included elsewhere in this discussion.
Non-interest income for the three and nine months ended September 30, 20172020 decreased $1.9 million, or 5.1%, and increased $1.3 million, or 4.3%1.2%, and $5.4 million, or 6.0%,respectively, compared to the same periods in 2016.2019. The increases in non-interest incomedecrease during the three and nine months ended September 30, 2017 were2020 was primarily related to increasesa decrease in other charges, commissions and fees. The increase during the nine months end September 30, 2020 was primarily related to an increase in trust and investment management fees andpartly offset by decreases in other charges, commissions and fees. Trust and investment management fee income is the most significant income component for Frost Wealth Advisors. Investment fees are the most significant component of trust and investment management fees, making up approximately 83.5%82.7% of total trust and investment management fees for the first nine months of 2017. Investment and other custodial account fees are

generally based on the market value of assets within a trust account. Volatility in the equity and bond markets impacts the market value of trust assets and the related investment fees. The increases in trust2020. Trust and investment management fees during the three and nine months ended September 30, 2017 compared to the same periods in 20162020 were primarily the result ofimpacted by increases in trust investment fees, estate fees and real estate fees and decreases in oil and gas fees and tax fees. The increase in trust investment fees during 2017 was due to higher average equity valuations and an increase in the number of accounts. The increasedecrease in other charges, commissions and fees during the three months ended September 30, 2020 was primarily related to decreases in income from the placement of money market accounts and mutual funds, among other things, partly offset by an increase in income from the placement of annuities. The decrease in other charges commissions and fees during the nine months ended September 30, 20172020 was primarily due to decreases in income from the placement of money market accounts and life insurance, among other things, partly offset by increases in income related tofrom the saleplacement of annuities and mutual funds.funds and an increase in brokerage commissions. Income from the placement of money market accounts was impacted by a decrease in market rates. The other aforementioned revenue streams were impacted by fluctuations in transaction volumes. See the analysis of trust and investment management fees, particularly as it relates to the effects of the COVID-19 pandemic, and other charges, commissions and fees included in the section captioned “Non-Interest Income” included elsewhere in this discussion.
Non-interest expense for the three and nine months ended September 30, 2017 increased $500 thousand,2020 decreased $2.3 million, or 1.9%7.1%, and $3.9increased $2.7 million, or 5.1%2.9%, respectively, compared to the same periods in 2016.2019. The decrease during the three months ended September 30, 2020 was primarily due to decreases in other non-interest expense and salaries and wages. The increase during the nine months ended September 30, 2020 was primarily due to increases in net occupancy expense partly offset by a decrease in other non-interest expense. The decreases in other non-interest expense during the three and nine months ended September 30, 20172020 were primarily related to increases in net occupancy expense, salaries and wages and employee benefits partly offset by decreases in other non-interest expense. The increase in net occupancytravel, meals and entertainment expense and decrease inprofessional service expense, among other non-interest expense were related to a change in the way we allocate occupancy expenses among our operating segments. Beginning in 2017, operating segments receive a direct charge for occupancy expense based upon cost centers within the segment. Such amounts are now reported as occupancy expense. Previously, these costs were included within the allocated overhead and reported as a component of other non-interest expense. The increases in salariesthings. Salaries and wages during the three and nine months ended September 30, 20172020 were primarily relatedimpacted by decreases in incentive compensation, commissions and stock-based compensation despite an increase in salaries, due to an increasesincrease in the number of employees and normal, annual merit and market increases. The increasesincrease in employee benefitsnet occupancy expense during the nine months end September 30, 2020 was primarily related to an increase in lease expense.
Non-Banks
The Non-Banks operating segment had net losses of $2.6 million and $8.8 million during the three and nine months ended September 30, 2017 were primarily related2020, respectively, compared to increases in payroll taxes, expenses related to our defined benefit retirement plans and medical insurance expense.
Non-Banks
The Non-Banks operating segment had a net losslosses of $1.7$2.9 million and $5.1$9.9 million during the same periods in 2019. The decreases in the net losses for the three and nine months ended September 30, 2017, respectively, compared2020 were primarily due to adecreases in net loss of $925 thousandinterest expense, primarily related to decreases in the average rates paid on our long term borrowings, and $3.7 million for the same periods in 2016. The increases in net loss duringincome tax benefit.
Income Taxes
During the three and nine months ended September 30, 2017 were primarily due to increases in net interest expense due to an increase in the interest rates paid on our long-term borrowings.
Income Taxes
We2020, we recognized income tax expense of $9.9 million and $35.1$9.5 million, for an effective tax rate of 9.6% and 11.8% for the three and nine months ended September 30, 20179.1%, compared to $10.9 million and $28.6income tax expense of $13.5 million, for an effective tax rate of 11.9% and 11.5% for10.8%, during the three andsame period in 2019. During the nine months ended September 30, 2016. 2020, we recognized income tax expense of $11.5 million, for an effective tax rate of 4.5%, compared to income tax expense of $42.4 million, for an effective tax rate of 11.1%, for the same period in 2019.
The effective income tax rates differed from the U.S. statutory federal income tax rate of 35%21% during the comparable periods2020 and 2019 primarily due to the effect of tax-exempt income from loans, securities and life insurance policies and the income tax effects associated with stock-based compensation.compensation, among other things, and their relative proportion to total pre-tax net income. The decreasedecreases in income tax expense and the effective tax raterates during the three months ended September 30, 2017 compared to the same period in 2016 was2020 were primarily related to the correction of an over-accrual of taxes that resulted from incorrectly classifying certain tax-exempt loans as taxable for federal income tax purposes since 2013. As a result, we recognized tax benefits totaling $3.7 million, which included $2.9 million related to the 2013 through 2016 tax years and $756 thousand related to the first and second quarters of 2017.decrease in pre-tax net income. The increase in income tax expense and the effective tax rate during the nine months ended September 30, 2017 was primarily related to an increase in total income with a higher proportion of taxable income relative to tax-exempt income, partly offset by the effect of the aforementioned tax benefits related to tax-exempt loans. Excluding the effect of the corrections related to tax-exempt loan interest, our effective tax rates would have been 13.2% and 12.7% forduring 2020 were also impacted by a one-time, discrete tax benefit associated with an asset contribution to a charitable trust during the three and nine months ended September 30, 2017, respectively.second quarter.
Excluding the deferred tax effects related to other comprehensive income, net deferred tax assets totaled $59.9 million at September 30, 2017. This amount is based upon the current statutory federal income tax rate
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Table of 35%. There have been recent legislative proposals to reduce the statutory federal income tax rate. While there can be no assurance that a reduction will ultimately occur, any such reduction in the statutory federal income tax rate would impact the carrying value of our net deferred tax assets with a corresponding charge to income tax expense.Contents

Average Balance Sheet
Average assets totaled $30.2$37.0 billion for the nine months ended September 30, 20172020 representing an increase of $1.7$5.3 billion, or 6.1%16.7%, compared to average assets for the same period in 2016. The growth in average2019. Earning assets was primarily funded by deposit growth, an increase in average federal funds purchased and repurchase agreements and earnings retention. The increase was primarily reflected in earning assets, which increased $1.7$5.0 billion, or 6.6%17.0%, during the first nine months of 20172020 compared to the same period in 2016.2019. The increase in earning assets included an $821.8 millionwas primarily related to a $2.9 billion increase in average loans,interest-bearing deposits, federal funds sold and resell agreements; a $648.9$2.6 billion increase in average loans; and a $256.8 million increase in average tax-exempt securities and a $384.9 million increase in average interest-bearing deposits partly offset by a $133.6$723.5 million decrease in average taxable securities. Average deposit growthpremises and equipment increased $206.6 million, or 24.8%, in part due to the commencement of the lease on our new downtown San Antonio headquarters in the second quarter of 2019 as well as the commencement of other new leases associated with various new branch locations. Average deposits increased $4.4 billion, or 16.8%, during the first nine months of 2020 compared to the same period in 2019. The increase included an $832.2 milliona $2.8 billion increase in non-interest bearing deposits and a $699.7 million$1.6 billion increase in interest-bearing deposit accounts. Average non-interest bearing deposits made up 41.7%42.7% and 40.9%39.1% of average total deposits during the first nine months of 20172020 and 2016,2019, respectively.
Loans
Loans were as follows as of the dates indicated:
September 30,
2017
 
Percentage
of Total
 December 31,
2016
 
Percentage
of Total
September 30,
2020
Percentage
of Total
December 31,
2019
Percentage
of Total
Commercial and industrial$4,677,923
 36.8% $4,344,000
 36.3%Commercial and industrial$4,820,018 26.4 %$5,187,466 35.2 %
Energy:       Energy:
Production1,094,927
 8.6
 971,767
 8.1
Production1,108,753 6.1 1,348,900 9.2 
Service159,893
 1.3
 221,213
 1.8
Service163,197 0.9 192,996 1.3 
Other132,240
 1.0
 193,081
 1.7
Other91,418 0.4 110,986 0.8 
Total energy1,387,060
 10.9
 1,386,061
 11.6
Total energy1,363,368 7.4 1,652,882 11.2 
Paycheck Protection ProgramPaycheck Protection Program3,226,980 17.7 — — 
Commercial real estate:       Commercial real estate:
Commercial mortgages3,714,172
 29.2
 3,481,157
 29.1
Commercial mortgages5,412,731 29.7 4,594,113 31.1 
Construction1,082,229
 8.5
 1,043,261
 8.7
Construction1,274,080 7.0 1,312,659 8.9 
Land307,701
 2.4
 311,030
 2.6
Land320,407 1.8 289,467 2.0 
Total commercial real estate5,104,102
 40.1
 4,835,448
 40.4
Total commercial real estate7,007,218 38.5 6,196,239 42.0 
Consumer real estate:       Consumer real estate:
Home equity loans357,542
 2.8
 345,130
 2.9
Home equity loans340,226 1.9 375,596 2.6 
Home equity lines of credit288,981
 2.3
 264,862
 2.2
Home equity lines of credit434,171 2.4 354,671 2.4 
Other367,948
 2.9
 326,793
 2.7
Other533,356 2.9 464,146 3.1 
Total consumer real estate1,014,471
 8.0
 936,785
 7.8
Total consumer real estate1,307,753 7.2 1,194,413 8.1 
Total real estate6,118,573
 48.1
 5,772,233
 48.2
Total real estate8,314,971 45.7 7,390,652 50.1 
Consumer and other522,748
 4.2
 473,098
 3.9
Consumer and other498,540 2.8 519,332 3.5 
Total loans$12,706,304
 100.0% $11,975,392
 100.0%Total loans$18,223,877 100.0 %$14,750,332 100.0 %
Loans increased $730.9 million,$3.5 billion, or 6.1%23.5%, compared to December 31, 2016.2019. As further discussed below, during the second quarter of 2020, we began originating loans to qualified small businesses under the PPP administered by the SBA under the provisions of the CARES Act. Excluding PPP loans, total loans would have otherwise increased $246.6 million, or 1.7%, from December 31, 2019, and decreased $341.4 million, or 2.2%, from total loans of $15.3 billion at March 31, 2020, near the beginning of the COVID-19 pandemic. The majority of our loan portfolio is comprised of commercial and industrial loans, energy loans, and real estate loans. Commercial and industrial loans made up 36.8% and 36.3% of total loans at September 30, 2017 and December 31, 2016, respectively, while energy loans made up 10.9% and 11.6% of total loans, respectively, and real estate loans made up 48.1% and 48.2% of total loans, respectively, at those dates. Real estate loans include both commercial and consumer balances. Selected details related to our loan portfolio segments are presented below. Refer to our 20162019 Form 10-K for a more detailed discussion of our loan origination and risk management processes. Other than in connection with our making PPP loans as described below, it is possible that the effects of COVID-19 could continue to result in less demand for our loan products.
Commercial and industrial. Commercial and industrial loans increased $333.9decreased $367.4 million, or 7.7%7.1%, during the first nine months of 2017.2020. Our commercial and industrial loans are a diverse group of loans to small, medium and large businesses. The purpose of these loans varies from supporting seasonal working capital needs to term financing of equipment. While some short-term loans may be made on an unsecured basis, most are secured by the assets being financed with collateral margins that are consistent with our loan policy guidelines. The commercial and industrial loan portfolio also includes commercial leases and purchased shared national credits ("SNC"s).

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Energy. Energy loans include loans to entities and individuals that are engaged in various energy-related activities including (i) the development and production of oil or natural gas, (ii) providing oil and gas field servicing, (iii) providing energy-related transportation services, (iv) providing equipment to support oil and gas drilling, (v) refining petrochemicals, or (vi) trading oil, gas and related commodities. Energy loans increased $999 thousand,decreased $289.5 million, or 0.1%17.5%, during the first nine months of 2017 compared tofrom December 31, 2016. The increase was related to an increase in production loans mostly offset by decreases in service and other loans.2019. The average loan size, the significance of the portfolio and the specialized nature of the energy industry requires a highly

prescriptive underwriting policy. Exceptions to this policy are rarely granted. Due to the large borrowing requirements of this customer base, the energy loan portfolio includes participations and SNCs.
Purchased Shared National Credits. Purchased shared national credits are participations purchased from upstream financial organizations and tend to be larger in size than our originated portfolio. Our purchased SNC portfolio totaled $795.4$838.1 million at September 30, 2017, increasing $23.32020, decreasing $110.7 million, or 3.0%11.7%, from $772.2$948.8 million at December 31, 2016.2019. At September 30, 2017, 53.4%2020, 41.3% of outstanding purchased SNCs were related to the energy industry and 16.4% of outstanding purchased SNCswhile 19.4% were related to the construction industry and 11.3% were related to the real estate management industry. The remaining purchased SNCs were diversified throughout various other industries, with no other single industry exceeding 10% of the total purchased SNC portfolio. Additionally, almost all of the outstanding balance of purchased SNCs was included in the energy and commercial and industrial portfolio, with the remainder included in the real estate categories. SNC participations are originated in the normal course of business to meet the needs of our customers. As a matter of policy, we generally only participate in SNCs for companies headquartered in or which have significant operations within our market areas. In addition, we must have direct access to the company’s management, an existing banking relationship or the expectation of broadening the relationship with other banking products and services within the following 12 to 24 months. SNCs are reviewed at least quarterly for credit quality and business development successes.
Commercial Real Estate. Commercial real estate loans totaled $5.1$7.0 billion at September 30, 2017,2020, increasing $268.7$811.0 million, or 13.1%, compared to $4.8$6.2 billion at December 31, 2016. At such dates,2019. The increase in commercial real estate loans was related to new loan production and the funding of prior committed amounts. The growth was broad-based across various property types and related to both previously existing and new customers. Commercial real estate loans represented 83.4% and 83.8%84.3% of total real estate loans respectively.at September 30, 2020 compared to 83.8% at December 31, 2019. The majority of thisour commercial real estate loan portfolio consists of commercial real estate mortgages, which includes both permanent and intermediate term loans. These loans are viewed primarily as cash flow loans and secondarily as loans secured by real estate. Consequently, these loans must undergo the analysis and underwriting process of a commercial and industrial loan, as well as that of a real estate loan. At September 30, 2017,2020, approximately 51%46% of the outstanding principal balance of our commercial real estate loans were secured by owner-occupied properties.
Consumer Real Estate and Other Consumer Loans. The consumer loan portfolio, including all consumer real estate and consumer installment loans, totaled $1.5$1.8 billion at September 30, 20172020 and $1.4$1.7 billion at December 31, 2016.2019. Consumer real estate loans increased $77.7$113.3 million, or 8.3%9.5%, from December 31, 2016.2019. Combined, home equity loans and lines of credit made up 63.7%59.2% and 65.1%61.1% of the consumer real estate loan total at September 30, 20172020 and December 31, 2016,2019, respectively. We offer home equity loans up to 80% of the estimated value of the personal residence of the borrower, less the value of existing mortgages and home improvement loans. In general, we do not originate 1-4 family mortgage loans; however, from time to time, we may invest in such loans to meet the needs of our customers or for other regulatory compliance purposes. Consumer and other loans increased $49.7decreased $20.8 million, or 10.5%4.0%, from December 31, 2016.2019. The consumer and other loan portfolio primarily consists of automobile loans, overdrafts, unsecured revolving credit products, personal loans secured by cash and cash equivalents and other similar types of credit facilities.

Paycheck Protection Program. In April 2020, we began originating loans to qualified small businesses under the PPP administered by the SBA under the provisions of the CARES Act. Loans covered by the PPP may be eligible for loan forgiveness for certain costs incurred related to payroll, group health care benefit costs and qualifying mortgage, rent and utility payments. The remaining loan balance after forgiveness of any amounts is still fully guaranteed by the SBA. Terms of the PPP loans include the following (i) maximum amount limited to the lesser of $10 million or an amount calculated using a payroll-based formula, (ii) maximum loan term of five years, (iii) interest rate of 1.00%, (iv) no collateral or personal guarantees are required, (v) no payments are required until the date on which the forgiveness amount relating to the loan is remitted to the lender and (vi) loan forgiveness up to the full principal amount of the loan and any accrued interest, subject to certain requirements including that no more than 40% of the loan forgiveness amount may be attributable to non-payroll costs. In return for processing and booking a PPP loan, the SBA paid lenders a processing fee tiered by the size of the loan (5% for loans of not more than $350 thousand; 3% for loans of more than $350 thousand and less than $2 million; and 1% for loans of at least $2 million).
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Through September 30, 2020, we have funded approximately $3.3 billion of SBA-approved PPP loans. During the three and nine months ended September 30, 2020, we recognized approximately $21.1 million and $40.4 million, respectively, in PPP loan related deferred processing fees (net of amortization of related deferred origination costs) as yield adjustments and these amounts are included in interest income on loans during each respective period. As a result of the inclusion of these net fees in interest income, the average yield on PPP loans was approximately 3.65% and 3.86% during the three and nine months ended September 30, 2020, respectively, compared to the stated interest rate of 1.0% on these loans. As of September 30, 2020, we expect to recognize additional PPP loan related deferred processing fees (net of deferred origination costs) totaling approximately $58.5 million as a yield adjustment over the remaining terms of these loans.

Non-Performing Assets
Non-performing assets and accruing past due loans are presented in the table below. Troubled debt restructurings on non-accrual status are reported as non-accrual loans. Troubled debt restructurings on accrual status are reported separately.
September 30,
2017
 December 31,
2016
September 30,
2020
December 31,
2019
Non-accrual loans:   Non-accrual loans:
Commercial and industrial$37,239
 $31,475
Commercial and industrial$21,566 $26,038 
Energy96,717
 57,571
Energy54,041 65,761 
Paycheck Protection ProgramPaycheck Protection Program— — 
Commercial real estate:   Commercial real estate:
Buildings, land and other6,773
 8,550
Buildings, land and other13,525 8,912 
Construction
 
Construction680 665 
Consumer real estate2,167
 2,130
Consumer real estate1,748 922 
Consumer and other208
 425
Consumer and other18 
Total non-accrual loans143,104
 100,151
Total non-accrual loans91,578 102,303 
Restructured loans4,815
 
Restructured loans3,932 6,098 
Foreclosed assets:   Foreclosed assets:
Real estate2,094
 2,440
Real estate850 1,084 
Other
 
Other— — 
Total foreclosed assets2,094
 2,440
Total foreclosed assets850 1,084 
Total non-performing assets$150,013
 $102,591
Total non-performing assets$96,360 $109,485 
   
Ratio of non-performing assets to:   Ratio of non-performing assets to:
Total loans and foreclosed assets1.18% 0.86%Total loans and foreclosed assets0.53 %0.74 %
Total loans, excluding PPP loans, and foreclosed assetsTotal loans, excluding PPP loans, and foreclosed assets0.64 0.74 
Total assets0.48
 0.34
Total assets0.24 0.32 
Accruing past due loans:   Accruing past due loans:
30 to 89 days past due$52,044
 $55,456
30 to 89 days past due$96,935 $50,784 
90 or more days past due27,121
 24,864
90 or more days past due35,706 7,421 
Total accruing past due loans$79,165
 $80,320
Total accruing past due loans$132,641 $58,205 
Ratio of accruing past due loans to total loans:   Ratio of accruing past due loans to total loans:
30 to 89 days past due0.41% 0.46%30 to 89 days past due0.53 %0.34 %
90 or more days past due0.21
 0.21
90 or more days past due0.20 0.05 
Total accruing past due loans0.62% 0.67%Total accruing past due loans0.73 %0.39 %
Ratio of accruing past due loans to total loans, excluding PPP loans:Ratio of accruing past due loans to total loans, excluding PPP loans:
30 to 89 days past due30 to 89 days past due0.65 %0.34 %
90 or more days past due90 or more days past due0.24 0.05 
Total accruing past due loansTotal accruing past due loans0.89 %0.39 %
Non-performing assets include non-accrual loans, troubled debt restructurings and foreclosed assets. Non-performing assets at September 30, 2017 increased $47.42020 decreased $13.1 million from December 31, 20162019 primarily due to an increasedecreases in non-accrual energy loans and to a lesser extent, non-accrual commercial and industrial loans. Non-accrual energy loans included four credit relationships in excess of $5 million totaling $86.4 million at September 30, 2017. Of this amount, $29.0 million related to two credit relationships that were previously reported as non-accrual at December 31, 2016 and $57.5 million related to two credit relationships that were placed on non-accrual status during the third quarter of 2017, one of which was a $43.1 million credit relationship that was previously reported as a potential problem loan at June 30, 2017. Non-accrual energy loans included four credit relationships in excess of $5 million totaling $52.1 million at December 31, 2016. Of this amount, we charged-off a total of $10.0 million related to two credit relationships during the first and second quarters of 2017. The outstanding balance of these two credit relationships was $20.5 million at December 31, 2016. Subsequent to the charge-off, the remaining balance of one of these credit relationships was paid-off. The outstanding balance of the other credit relationship totaled $4.9 million at September 30, 2017 and is included in non-accrual energy loans in the table above. Non-accrual commercial and industrial loans, included one credit relationshipwhich, for the most part, were related to the recognition of charge-offs, and a decrease in excess of $5 million totaling $22.0 million at September 30, 2017. This credit relationship was placed on non-accrual status during the third quarter of 2017 and was previously classified as “substandard - accrual” (risk grade 11) at June 30, 2017, though not reported as a potential problem at that time. Non-accrual commercial and industrial loans included one credit relationship in excess of $5 million totaling $9.8 million at December 31, 2016. Of this amount, we charged-off $4.7 million during the third quarter of 2017. The outstanding balance of this credit relationship totaled $4.9 million at September 30, 2017 and is includedrestructured loans. These decreases were partly offset by an increase in non-accrual commercial and industrial loans in the table above. Non-accrual real estate loans primarily consist of land development, 1-4 family residential construction credit relationships and loans secured by office buildings and religious facilities.loans.
Generally, loans are placed on non-accrual status if principal or interest payments become 90 days past due and/or management deems the collectibility of the principal and/or interest to be in question, as well as when required by regulatory requirements. Once interest accruals are discontinued, accrued but uncollected interest is charged to current year operations. Subsequent receipts

on non-accrual loans are recorded as a reduction of principal, and interest income is recorded only after
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principal recovery is reasonably assured. Classification of a loan as non-accrual does not preclude the ultimate collection of loan principal or interest. Non-accrual commercial and industrial loans included one credit relationship in excess of $5.0 million totaling $9.4 million at September 30, 2020. This credit relationship was previously reported as non-accrual with an aggregate balance of $8.4 million at December 31, 2019. Non-accrual energy loans included three credit relationships in excess of $5 million totaling $53.7 million at September 30, 2020 and two credit relationships in excess of $5 million totaling $61.7 million at December 31, 2019. During the nine months ended September 30, 2020, we charged off $68.8 million related to energy loans. Of that amount, $48.8 million related to credit relationships previously reported as non-accrual as of December 31, 2019. Non-accrual real estate loans primarily consist of land development, 1-4 family residential construction credit relationships and loans secured by office buildings and religious facilities. There were no non-accrual commercial real estate loans in excess of $5.0 million at September 30, 2020 or December 31, 2019.
Restructured loans totaled $3.9 million at September 30, 2020 and consisted of a single credit relationship including commercial and industrial loans, a commercial real estate loan and a consumer loan. Restructured loans at December 31, 2019 totaled $6.1 million and consisted of three credit relationships primarily related to commercial real estate.
Foreclosed assets represent property acquired as the result of borrower defaults on loans. Foreclosed assets are recorded at estimated fair value, less estimated selling costs, at the time of foreclosure. Write-downs occurring at foreclosure are charged against the allowance for loan losses. Regulatory guidelines require us to reevaluate the fair value of foreclosed assets on at least an annual basis. Our policy is to comply with the regulatory guidelines. Write-downs are provided for subsequent declines in value and are included in other non-interest expense along with other expenses related to maintaining the properties. Write-downs of foreclosed assets were not significanttotaled $231 thousand during the nine months ended September 30, 2017 or 2016.2020, while there were no write-downs of foreclosed assets during the nine months ended September 30, 2019.
Accruing past due loans at September 30, 2020 increased $74.4 million compared to December 31, 2019. The increase was primarily related to increases in all loan portfolio segments with the largest increases in past due commercial and industrial loans (up $30.5 million), commercial real estate loans (up $21.2 million) and energy (up $15.5 million).
Potential problem loans consist of loans that are performing in accordance with contractual terms but for which management has concerns about the ability of an obligor to continue to comply with repayment terms because of the obligor’s potential operating or financial difficulties. Management monitors these loans closely and reviews their performance on a regular basis. At September 30, 20172020 and December 31, 2016,2019, we had $89.7$126.0 million and $62.7$46.8 million in loans of this type which are not included in any one of the non-performing non-accrual, restructured or 90 days past due loan categories. At September 30, 2017,2020, potential problem loans consisted of seven12 credit relationships. Of the total outstanding balance at September 30, 2017, 32.5%2020, 63.7% was related to the energy industry 24.8%and 20.6% was related to the manufacturing industry and 13.9% was related to the chemicalshotel/lodging industry. Weakness in these organizations’ operating performance and financial condition, loan agreement breaches and borrowing base deficits for certain energy credits, among other factors, have caused us to heighten the attention given to these credits.
Certain borrowers are currently unable to meet their contractual payment obligations because of the adverse effects of COVID-19. In an effort to mitigate these effects, loan customers may apply for a deferral of payments, or portions thereof, for up to 90 days. After 90 days, customers may apply for an additional deferral, and a small proportion of our customers have requested such an additional deferral. In the absence of other intervening factors, such short-term modifications made on a good faith basis are not categorized as troubled debt restructurings, nor are loans granted payment deferrals related to COVID-19 reported as past due or placed on non-accrual status (provided the loans were not past due or on non-accrual status prior to the deferral). The COVID-19 pandemic has contributed to an increased risk of delinquencies, defaults and foreclosures. As a result of the COVID-19 pandemic, a significant number and amount of our loans have experienced ratings downgrades, credit deterioration and defaults. We have a significant amount of loans in certain industries that have been particularly impacted. These include energy, retail/strip centers, hotels/lodging, restaurants, entertainment and commercial real estate, among others. See additional information about the effects of and risks associated with the COVID-19 pandemic in the section captioned “Recent Developments Related to COVID-19” elsewhere in this discussion and Part II. Other Information, Item 1A. Risk Factors elsewhere in this report.

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Allowance for LoanCredit Losses
TheAs discussed in Note 1 - Summary of Significant Accounting Policies in the accompanying notes to consolidated financial statements, our policies and procedures related to accounting for credit losses changed on January 1, 2020 in connection with the adoption of a new accounting standard update as codified in Accounting Standards Codification (“ASC”) Topic 326 (“ASC 326”) Financial Instruments - Credit Losses. In the case of loans and securities, allowances for credit losses are contra-asset valuation accounts, calculated in accordance with ASC 326, that are deducted from the amortized cost basis of these assets to present the net amount expected to be collected. In the case of off-balance-sheet credit exposures, the allowance for loancredit losses is a reserve established throughliability account, calculated in accordance with ASC 326, reported as a provision for loan losses charged to expense, whichcomponent of accrued interest payable and other liabilities in our consolidated balance sheets. The amount of each allowance account represents management’smanagement's best estimate of inherentcurrent expected credit losses that have been incurred within(“CECL”) on these financial instruments considering available information, from internal and external sources, relevant to assessing exposure to credit loss over the existing portfoliocontractual term of loans. Thethe instrument. Relevant available information includes historical credit loss experience, current conditions and reasonable and supportable forecasts. While historical credit loss experience provides the basis for the estimation of expected credit losses, adjustments to historical loss information may be made for differences in current portfolio-specific risk characteristics, environmental conditions or other relevant factors. While management utilizes its best judgment and information available, the ultimate adequacy of our allowance accounts is dependent upon a variety of factors beyond our control, including the performance of our portfolios, the economy, changes in interest rates and the view of the regulatory authorities toward classification of assets. For additional information regarding critical accounting policies, refer to Note 1 - Summary of Significant Accounting Policies and Note 3 - Loans in the judgment of management, is necessaryaccompanying notes to reserve for estimated loan losses and risks inherent in the loan portfolio. Our allowance for loan loss methodology, which is more fully described in our 2016 Form 10-K, follows the accounting guidance set forth in U.S. generally accepted accounting principles and the Interagency Policy Statement on the consolidated financial statements.
Allowance for Loan and LeaseCredit Losses which was jointly issued by U.S. bank regulatory agencies. The level of the allowance reflects management’s continuing evaluation of industry concentrations, specific credit risks, loan loss and recovery experience, current loan portfolio quality, present economic, political and regulatory conditions and unidentified losses inherent in the current loan portfolio. Portions of the allowance may be allocated for specific credits; however, the entire allowance is available for any credit that, in management’s judgment, should be charged off.
- Loans. The table below provides, as of the dates indicated, an allocation of the allowance for loan losses by loan type;portfolio segment; however, allocation of a portion of the allowance to one category of loanssegment does not preclude its availability to absorb losses in other categories:segments:
September 30,
2020
June 30,
2020
Post ASC 326 Adoption on January 1,
2020
December 31,
2019
Commercial and industrial$72,505 $98,536 $72,856 $51,593 
Energy54,631 40,817 26,929 37,382 
Commercial real estate118,593 93,425 17,518 31,037 
Consumer real estate10,277 8,998 6,505 4,113 
Consumer and other7,469 8,285 5,794 8,042 
Total$263,475 $250,061 $129,602 $132,167 
 September 30,
2017
 December 31,
2016
Commercial and industrial$48,437
 $52,915
Energy51,913
 60,653
Commercial real estate38,075
 30,213
Consumer real estate6,875
 4,238
Consumer and other9,003
 5,026
Total$154,303
 $153,045
Upon the adoption of ASC 326 on January 1, 2020, the total amount of the allowance for credit losses on loans estimated using the CECL methodology decreased $2.6 million compared to the total amount of the allowance for credit losses on loans estimated as of December 31, 2019 using the prior incurred loss model. Fluctuations in the estimated allowances by portfolio segment offset one another, for the most part, and, as a result, the overall estimated amount of allowance for credit losses did not significantly change as a result of the change in methodology. The manner in which credit loss allowances are allocated to the individual portfolio segments was partly impacted by a change in the way the underlying loans within each segment are pooled for modeling purposes. The impact of varying economic conditions and portfolio stress factors are now a component of the credit loss models applied to each modeling pool. In that regard, the amounts allocated to the underlying pools of loans within each portfolio segment more directly reflect the economic variables and portfolio stress factors that correlate with credit losses within each portfolio. Under the prior methodology, allocations in excess of those derived from historical loss rates were recognized as an overlay on each of the various portfolios based upon management judgment. Nonetheless, despite fluctuations in the allocation of portions of the overall allowance to the various portfolio segments, the entire allowance is available to absorb any credit losses within the entire loan portfolio. The remainder of this discussion focuses on expected credit losses estimated as of September 30, 2020 compared to the post ASC 326 estimate of expected credit losses as of January 1, 2020 and, in some cases, June 30, 2020.
The reserveallowance allocated to commercial and industrial loans totaled $72.5 million, or 1.50% of total commercial and industrial loans, at September 30, 2017 decreased $4.5 million2020 decreasing $351 thousand, or 0.5%, compared to December 31, 2016. The decrease was due$72.9 million, or 1.40% of total commercial and industrial loans, post ASC 326 adoption on January 1, 2020. Modeled expected credit losses increased $11.7 million while Q-Factor adjustments related to decreases in historicalcommercial and specific valuation allowances partly offset by increases in macroeconomic valuation allowancesindustrial loans decreased $9.4 million. Specific allocations for commercial and general valuation allowances. Historical valuation allowancesindustrial loans that were evaluated for expected credit losses on an individual basis decreased $6.1from $7.9 million from $33.3 million at December 31, 2016post ASC 326 adoption on January 1, 2020 to $27.2$5.3 million at September 30, 2017.2020. The decrease was primarilyallowance allocated to energy loans totaled $54.6 million, or 4.01% of total energy loans, at September 30, 2020 increasing $27.7 million, or 102.9%, compared to $26.9 million, or 1.63% of total energy loans, post ASC 326 adoption on January 1, 2020. Modeled expected credit losses related to decreasesenergy loans increased $15.8 million while Q-Factor adjustments related to energy loans increased $23.8
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million. Specific allocations for energy loans that were evaluated for expected credit losses on an individual basis totaled $20.2 million post ASC 326 adoption on January 1, 2020. The loans to which these specific allocations were related were subsequently charged off and there were $8.4 million of specific allocations related to energy loans at September 30, 2020. The allowance allocated to commercial real estate loans totaled $118.6 million, or 1.69% of total commercial real estate loans, at September 30, 2020 increasing $101.1 million, or 577.0%, compared to $17.5 million, or 0.28% of total commercial real estate loans, post ASC 326 adoption on January 1, 2020. Modeled expected credit losses related to commercial real estate loans increased $110.6 million while Q-Factor adjustments related to commercial real estate loans decreased $10.5 million. Specific allocations for commercial real estate loans that were evaluated for expected credit losses on an individual basis increased from $383 thousand post ASC 326 adoption on January 1, 2020 to $1.3 million at September 30, 2020. The allowance allocated to consumer real estate loans totaled $10.3 million, or 0.79% of total consumer real estate loans, at September 30, 2020 increasing $3.8 million, or 58.0%, compared to $6.5 million, or 0.54% of total consumer real estate loans, post ASC 326 adoption on January 1, 2020. Modeled expected credit losses related to consumer real estate loans increased $4.3 million while Q-Factor adjustments related to consumer real estate loans decreased $540 thousand. The allowance allocated to consumer loans totaled $7.5 million, or 1.50% of total consumer loans, at September 30, 2020 increasing $1.7 million, or 28.9%, compared to $5.8 million, or 1.12% of total consumer loans, post ASC 326 adoption on January 1, 2020. Modeled expected credit losses related to consumer loans increased $1.8 million while Q-Factor adjustments related to consumer loans decreased $123 thousand.
As more fully described in Note 3 - Loans in the historicalaccompanying consolidated financial statements, we measure expected credit losses over the life of each loan utilizing a combination of models which measure probability of default and loss allocation factorsgiven default, among other things. The measurement of expected credit losses is impacted by loan/borrower attributes and certain macroeconomic variables. Models are adjusted to reflect current impact of certain macroeconomic variables as well as their expected changes over a reasonable and supportable forecast period.
In estimating expected credit losses as of September 30, 2020, we utilized the Moody’s Analytics September 2020 CF Consensus Scenario (the “September CF Scenario”) to forecast the macroeconomic variables used in our models. The September CF Scenario was based on the review of a variety of surveys of baseline forecasts of the U.S. economy. The September CF Scenario projections included, among other things, (i) U.S. Gross Domestic Product (“GDP”) annualized quarterly growth rates of 27.4% and 8.7% in the third and fourth quarters of 2020, respectively, followed by annualized quarterly growth rates in the range of 5.0% to 7.0% during 2021 and 3.0% to 5.0% through the end of the forecast period in the third quarter of 2022; (ii) a U.S. unemployment rate of 8.9% in the third quarter of 2020 improving to 6.6% by the fourth quarter of 2021 and 6.3% by the end of the forecast period in the third quarter of 2022 with Texas unemployment rates slightly less at those dates; and (iii) an average 10 year Treasury rate of 0.64% in the third quarter of 2020, dropping to a low of 0.30% in the third quarter of 2021 and increasing to 0.92% by the end of the forecast period in the third quarter of 2022. The September CF Scenario also projected average oil prices of $42 per barrel in the third quarter of 2020, $38 per barrel in the fourth quarter of 2020, $47 per barrel on average for non-classifiedthe year in 2021 and $52 in the third quarter of 2022.
For our estimate of expected credit losses during the first and second quarters of 2020, our outlook for oil prices was significantly more negative as a result of the assumed persistence of the oil price war between Saudi Arabia and Russia and increasing oil supplies in the face of decreasing global demand resulting from the COVID-19 pandemic. As a result, we used significant qualitative adjustments in the determination of the allowance for credit losses on energy loans. For the third quarter of 2020, we continue to make qualitative adjustments related to the impact of oil price volatility in the determination of the allowance for credit losses on energy loans, as further discussed below.
In estimating expected credit losses as of June 30, 2020, we utilized the Moody’s Analytics June 2020 CF Consensus Scenario (the “June CF Scenario”) to forecast the macroeconomic variables used in our models. The June CF Scenario was based on the review of a variety of surveys of baseline forecasts of the U.S. economy. The June CF Scenario projections included, among other things, (i) a 36.9% decline in the U.S. GDP in the second quarter of 2020 followed by a 23.5% rebound in the third quarter of 2020; (ii) a U.S. unemployment rate of 15.8% for in the second quarter of 2020 improving to 9.6% by the fourth quarter of 2020 and 6.5% by the end of the forecast period in the second quarter of 2022 with Texas unemployment rates slightly less at those dates; and (iii) an average 10 year Treasury rate of 0.67% in the second quarter of 2020, dropping to a low of 0.34% in the second quarter of 2021 and increasing to 0.91% by the end of the forecast period in the second quarter of 2022. The June CF Scenario also projected average oil prices of $26 per barrel in the second quarter of 2020, $32 per barrel in the fourth quarter of 2020, $42 per barrel on average for the year in 2021 and $50 in the second quarter of 2022.
The economic forecast used in our initial estimate of expected credit losses under ASC 326 on January 1, 2020 projected that the Texas unemployment rate would remain below 4.0% through 2021. The increases in modeled expected credit losses across all of our loan portfolios as of September 30, 2020 compared to the modeled expected credit losses as of our initial adoption of ASC 326 on January 1, 2020 were primarily the result of changes in our economic forecast, particularly forecasts related to unemployment and the gross domestic product, as well as changes in portfolio volumes and risk attributes, as discussed below.
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The overall loan portfolio, excluding PPP loans which are fully guaranteed by the SBA, increased $246.6 million, or 1.7%, which included a $811.0 million, or 13.1%, increase in commercial real estate loans and a $113.3 million, or 9.5%, increase in consumer real estate loans partly offset by a $367.4 million, or 7.1%, decrease in commercial and industrial loans, a $289.5 million, or 17.5%, decrease in energy loans and a $20.8 million, or 4.0% decrease in consumer and other loans. The weighted average risk grade for commercial and industrial loans did not significantly change totaling 6.42 at September 30, 2020 compared to 6.44 at December 31, 2019. Commercial and industrial loans graded as “watch” (risk grade 9) and “special mention” (risk gradegrades 9 and 10) andincreased $28.8 million during the first nine months of 2020 while classified commercial and industrial loans partly offset by increases in the volume of certain categories of both non-classified and classified loans.decreased $9.7 million. Classified loans consist of loans having a risk grade of 11, 12 or 13. Classified commercial and industrial loans totaled $150.5 million at September 30, 2017 compared to $131.9 million at December 31, 2016. The weighted-average risk grade of commercial and industrialfor energy loans was 6.38increased to 7.39 at September 30, 2017 compared to 6.352020 from 6.39 at December 31, 2016. Commercial loan net charge-offs totaled $12.2 million during2019. The increase in the first nine months of 2017 compared to $8.2 million during the first nine months of 2016. Specific valuation allowances decreased $3.8 million from $5.4 million at December 31, 2016 to $1.7 million at September 30, 2017. Charge-offs in 2017 included $3.6 million related to two credit relationships that, as of December 31, 2016, had associated specific valuation allowances totaling $3.5 million. Charge-offs in 2017 also included $7.4 million related to two credit relationships for which we had no specific allocation as of December 31, 2016, or at the time of charge-off. Macroeconomic valuation allowances for commercial and industrial loans increased $4.7 million from $7.5 million at December 31,

2016 to $12.2 million at September 30, 2017. The increaseweighted average risk grade was primarily related to ana $106.3 million increase in the general macroeconomic allocation (up $5.5 million) partly offset by a decrease in the environmental risk adjustment (down $980 thousand). The general macroeconomic risk allocation at September 30, 2017 was partly impacted by the effect of hurricane Harvey on our Houston and Corpus Christi market areas. General valuation allowances for commercial and industrial loans increased $689 thousand from $6.7 million at December 31, 2016 to $7.4 million at September 30, 2017. The increase was primarily related to increases in the allocations for highly leveraged credit relationships, large credit relationships and loans not reviewed by concurrence combined with a decrease in the adjustment for recoveries. These items were partly offset by a decrease in the allocation for excessive industry concentrations.
The reserve allocated to energy loans at September 30, 2017 decreased $8.7 million compared to December 31, 2016. As a result, reserves allocated to energy loans as a percentage of total energy loans totaled 3.74% at September 30, 2017 compared to 4.38% at December 31, 2016. This decrease was primarily related to decreases in historical valuation allowances and macroeconomic valuation allowances and partly offset by increases in specific valuation allowances and general valuation allowances. Historical valuation allowances decreased $12.7 million from $34.6 million at December 31, 2016 to $21.9 million at September 30, 2017. The decrease was primarily related to decreases in the volume of classified energy loans and higher risk categories of non-classifieda $155.7 million increase in energy loans partly offset by increases in the historical loss allocation factors for both non-classifiedgraded “watch” and classified energy loans. Classified“special mention,” while pass grade energy loans totaled $190.7 milliondecreased $551.5 million. The weighted average risk grade for commercial real estate loans increased to 7.33 at September 30, 2017 compared to $302.0 million2020 from 7.07 at December 31, 2016, decreasing $111.2 million. Non-classified energy2019. Commercial real estate loans graded as “watch” and “special mention” totaled $114.0 million at September 30, 2017 compared to $229.4 million at December 31, 2016, decreasing $115.4increased $435.4 million while "pass" grade energyclassified commercial real estate loans increased $227.7 million from $854.7 million at December 31, 2016$64.4 million.
As noted above our credit loss models utilized the economic forecasts in the Moody’s CF Consensus Scenario for September 2020 in the third quarter of 2020 and the Moody's CF Consensus Scenario for June 2020 in the second quarter of 2020. We qualitatively adjust the model results based on this scenario for various risk factors that are not considered within our modeling processes but are nonetheless relevant in assessing the expected credit losses within our loan pools. These Q-Factor adjustments are discussed below.
Q-Factor adjustments are based upon management judgment and current assessment as to $1.1 billion at September 30, 2017.the impact of risks related to changes in lending policies and procedures; economic and business conditions; loan portfolio attributes and credit concentrations; and external factors, among other things, that are not already captured within the modeling inputs, assumptions and other processes. Management assesses the potential impact of such items within a range of severely negative impact to positive impact and adjusts the modeled expected credit loss by an aggregate adjustment percentage based upon the assessment. As a result of these changes,this assessment as of September 30, 2020, modeled expected credit losses were adjusted upwards by a weighted-average Q-Factor adjustment of approximately 1.1%, increasing slightly from 0.7% at June 30, 2020 and decreasing from 12.9% upon the adoption of ASC 326 on January 1, 2020 (as further discussed below). The weighted-average risk grade of energy loans decreased to 7.21Q-Factor adjustment at September 30, 2017 from 7.95 at December 31, 2016. Macroeconomic valuation allowances2020 was based on a positive expected impact related to energy loans decreased $6.4 millionchanges in lending policies, procedures and underwriting standards; a limited negative expected impact associated with changes in loan portfolio attributes and concentrations, changes in risk grades, changes in the volumes and severity of loan delinquencies and adverse classifications and potential deterioration of collateral values; and a severely negative impact from $18.5 million at December 31, 2016other risk factors associated with our commercial real estate construction and land loan portfolios, particularly the risks related to $12.1 million atexpected extensions.
In connection with our assessment of Q-Factor adjustments for our initial estimate of expected credit losses upon the adoption of ASC 326 on January 1, 2020, modeled expected credit losses were adjusted upwards by a weighted-average Q-Factor adjustment of approximately 12.9%, which included a 10% upward adjustment to modeled expected credit losses related to risks associated with model uncertainty and under-prediction. This adjustment was based upon the results of certain back testing procedures performed on our credit loss models. The Q-Factor adjustment as of September 30, 2017,2020 and June 30, 2020 did not include this additional 10% upward adjustment related to risks associated with model uncertainty and under-prediction. While management believes this adjustment is appropriate in part duea relatively benign or moderately stressful economic environment, management nonetheless believes this adjustment is not currently appropriate given the extreme levels and volatility in macroeconomic indicators under the current economic conditions and the fact that such conditions are expected to improving trendspersist for the foreseeable future. The increase in weighted-average Q-Factor adjustment during the third quarter of 2020 compared to the second quarter reflects increased risk primarily associated with our commercial real estate loan portfolio coupled with the increase in the weighted-average risk graderelative proportion of such loans within our total loan portfolio.
Management also made certain other qualitative adjustments for loans within certain industries that are expected to be more significantly impacted by the energy loan portfolioCOVID-19 pandemic and oil price volatility and declines as described below.
In early March 2020, Saudi Arabia announced significant price discounts on oil which resulted in a sharp decrease in global oil prices including the benchmark WTI. Saudi Arabia further announced that it would significantly increase its production leading Russia to respond in kind. These actions arose in the face of increasing global supplies and decreasing global demand. The subsequent worsening global economic outlook and decreased oil price volatility.demand resulting from the COVID-19 pandemic resulted in further decreases in energy prices. The WTI price per barrel of crude oil was approximately $54 at$40 as of September 30, 2020 up from $20 per barrel as of March 31, 2020 but still down from approximately $61 per barrel as of December 31, 20162019. In late March 2020, we established a special Energy Oversight Council to oversee and $52assess the credit quality of our energy loan portfolio.
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As of September 30, 2020, we provided an additional qualitative adjustment for our energy loan portfolio. This adjustment was estimated based on borrowing base determinations for our energy production loans using current engineering valuations and a projected oil price deck of $30 for 2020 and increasing to $36 for 2021 and $40 for 2022. We also perform an analysis of our customers' secondary sources of capital. Through this process at September 30, 2017. Despite2020, we estimated an aggregate borrowing base deficiency on energy production loans totaling approximately $44.4 million compared to an aggregate borrowing base deficiency of approximately $36.0 million at June 30, 2020. The June 30, 2020 borrowing base determinations were also based on a projected oil price deck of $30 for 2020 and increasing to $36 for 2021 and $40 for 2022. Management believes that the overall decrease, macroeconomic valuation allowances related toaggregate borrowing base deficiency amount should serve as the appropriate level of expected credit losses for energy production loans. Accordingly, this resulted in an additional qualitative adjustment of $24.4 million for energy production loans at September 30, 20172020, up from $20.5 million at June 30, 2020.
We performed a separate assessment of other energy loans which are primarily made up of borrowers associated with oilfield services such as transportation and logistics; equipment manufacturing and other services, among other things. Business activity among oilfield service firms has experienced contraction since March 2020; however, there are indications that the pace of contraction has significantly lessened during the third quarter of 2020 relative to the second quarter. There has been a significant decrease in the number of active oil rigs in Texas since March 2020, though the rate of decline in utilization has slowed considerably in the third quarter of 2020 relative to the second quarter. Based on the level of modeled expected credit losses for this portfolio and the expectation of more stabilized conditions with regard to business activity related to oilfield services, we determined that no additional qualitative adjustment for non-production energy loans was necessary as of September 30, 2020. As of June 30, 2020, we provided an additional qualitative adjustment of $5.0 million for non-production energy loans based upon the more negative prevailing outlook for business activity and rig utilization at that time.
In late June 2020, we established a special Commercial Real Estate Oversight Council to oversee and assess the credit quality of our non-owner occupied and construction commercial real estate loan portfolios. Due to the adverse economic effects of the COVID-19 pandemic, management believes these portfolios have an elevated level of risk that requires a higher level of oversight, particularly as it relates to monitoring risk grades, payment deferrals, covenant modifications and structuring issues, among other things.
In estimating current expected credit losses as of September 30, 2020, we determined that our credit loss models for our owner occupied commercial real estate loan portfolio were partlyoverly sensitive to the volatility of the forecasted Texas unemployment rate and the forecasted U.S. GDP. The modeled loss rate for this portfolio was significantly higher than the modeled loss rate for our commercial and industrial loan portfolio. Management believes that the loss rates for our owner occupied commercial real estate loan portfolio and our commercial and industrial loan portfolio should be similar due to the fact that that the loans within both portfolios are underwritten with the assumption that the primary repayment source is the cash flow from the operations of the borrower. This differs from non-owner occupied real estate where the primary repayment source is the cash flow generated by the underlying real estate being financed. Furthermore, our owner occupied commercial real estate loan portfolio and our commercial and industrial loan portfolio have a similar customer base. The loans within our owner occupied commercial real estate loan portfolio generally have a longer term than the loans within our commercial and industrial loan portfolio, which increases the modeled loss rate of the portfolio, despite the fact that this portfolio generally experiences lower losses in the case of default due to higher collateral valuations relative to the amount of the underlying loans. In light of the foregoing, management reduced the modeled loss allocation for owner occupied commercial real estate loans by $45.4 million as of September 30, 2020. Of this amount, $3.3 million was reallocated to the non-owner occupied commercial real estate loan portfolio and $2.3 million was reallocated to the commercial real estate construction loan portfolio. Additional qualitative adjustments were made for these portfolios as we believe our borrowers' ability to access the capital markets for the sale or refinancing of assets, including those under construction, may be impaired for a significant amount of time. This would require secondary sources of capital and liquidity to support completed projects, access to which may take considerably longer to stabilize than was expected at the time the loans to these borrowers were originally underwritten. Additionally, management reallocated an additional $27.1 million for specific industries within the commercial real estate loan portfolio that have been particularly impacted by the economic effects of the COVID-19 pandemic, as further discussed below. The net effect of hurricane Harveythese additional qualitative adjustments, when combined with the aforementioned 1.1% weighted-average Q-Factor adjustment, was an overall negative qualitative adjustment to the allowance for credit losses on our Houstoncommercial real estate loans totaling $8.7 million.
The COVID-19 pandemic has resulted in a significant decrease in commercial activity throughout the State of Texas as well as nationally. Efforts to limit the spread of COVID-19 have led to the closure of non-essential businesses, travel restrictions, supply chain disruptions and Corpus Christi market areas. Specific valuation allowancesprohibitions on public gatherings, among other things, throughout many parts of the United States and, in particular, the markets in which we operate. Aside from the energy industry, which is discussed above, we lend to customers operating in certain other industries that have been, and are expected to be, more significantly impacted by the effects
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of the COVID-19 pandemic. These industries are presented in the following table and include amounts reported as both commercial and industrial loans and commercial real estate loans while PPP loans are excluded.
Outstanding Balance at September 30, 2020Percentage of Total Loans, Excluding PPP LoansAllocated AllowanceAllocated Allowance as a Percentage of Outstanding Balance
Retail/strip centers$860,889 5.74 %$19,105 2.22 %
Hotels/lodging281,411 1.88 14,014 4.98 
Restaurants273,625 1.82 13,057 4.77 
Entertainment128,373 0.86 5,821 4.53 
Total$1,544,298 10.30 %$51,997 3.37 %
We are continuing to monitor customers in these industries closely. In assessing these portfolios for energy loans increased $9.5 million from $3.8 million at December 31, 2016 to $13.3 million atan additional qualitative adjustment as of September 30, 2017. Specific valuation allowances at September 30, 2017 were related2020, we performed a comprehensive review of the financial condition and overall outlook of the borrowers within these portfolios. Based on this analysis, we determined that there continues to two credit relationships totaling $61.8 million while specific valuation allowances at December 31, 2016 were related to three credit relationships totaling $29.8 million. Energy loan net charge-offs totaled $10.0 million during the first nine monthsbe an elevated level of 2017 compared to net charge-offs of $18.6 million during the first nine months of 2016. The charge-offs in 2017 included $10.0 million related to two credit relationships that, as of December 31, 2016, had associated specific valuation allowances totaling $3.4 million. General valuation allowances increased $908 thousand primarilyrisk due to state and nationwide restrictions impacting each of these industries. As a result, we provided an increase inadditional qualitative adjustment of $27.1 million, which, for the allocation for excessive industry concentrations partly offset by and increase in the adjustment for recoveries.
The reservemost part, was allocated to commercial real estate loans at September 30, 2017 increased $7.9 million compared to December 31, 2016. The increase was primarily related to increases in macroeconomic valuation allowances and historical valuation allowances. Macroeconomic valuation allowances increased $6.7 millionloans. This amount is up from $8.2$10.9 million at December 31, 2016 to $14.9 million at SeptemberJune 30, 2017. The increase was primarily related to an increase in the general macroeconomic allocation (up $6.3 million) and the environmental risk adjustment (up $503 thousand). The increase in macroeconomic valuation allowances reflects current economic trends impacting our Houston market area which has been impacted by decreased construction, higher rent concessions and higher vacancy rates. Macroeconomic valuation allowances were also partly impacted by the effect of hurricane Harvey on our Houston and Corpus Christi market areas. Historical valuation allowances increased $1.3 million primarily due to an increase in the volume of non-classified commercial real estate loans. Non-classified commercial real estate loans increased $267.5 million from December 31, 2016 to September 30, 2017 primarily due to an increase in commercial real estate loans graded as “pass.” Classified commercial real estate loans increased $1.2 million from $76.3 million at December 31, 2016 to $77.5 million at September 30, 2017 due to an increase in loans classified as “substandard - accrual” (risk grade 11). The weighted-average risk grade of commercial real estate loans was 6.98 at September 30, 2017 compared to 6.96 at December 31, 2016.
The reserve allocated to consumer real estate loans at September 30, 2017 increased $2.6 million compared to December 31, 2016. This increase was mostly due to a $1.9 million increase in macroeconomic valuation allowances, which was partly impacted by the effect of hurricane Harvey on our Houston and Corpus Christi market areas, and a $534 thousand increase in general valuation allowances, which was primarily related to an increase in allowances allocated for loans not reviewed by concurrence and a decrease in the reduction for recoveries.
The reserve allocated to consumer and other loans at September 30, 2017 increased $4.0 million compared to December 31, 2016. The increase was primarily related to increases in macroeconomic valuation allowances, historical valuation allowances and, to a lesser extent, an increase in general valuation allowances. The increase in macroeconomic valuation allowances was related to a $2.7 million increase in the general macroeconomic allocation, which was primarily related to growth in unsecured personal lines of credit, and also partly impacted by the effect of hurricane Harvey on our Houston and Corpus Christi market

areas. The increase in historical valuation allowances was primarily due to an increase in the volume of non-classified consumer and other loans. The increase in general valuation allowances was primarily related to an increase in the allocation for loans not reviewed by concurrence and a decrease in the adjustment for recoveries.2020.
Activity in the allowance for loancredit losses on loans is presented in the following table.
Three Months Ended
September 30,
Nine Months Ended
September 30,
2020201920202019
Balance at beginning of period$250,061 $134,929 $132,167 $132,132 
Impact of adopting ASC 326— — (2,565)— 
Credit loss expense23,590 8,001 223,743 25,404 
Charge-offs:
Commercial and industrial(8,605)(2,705)(14,815)(8,782)
Energy— (2,000)(68,842)(4,000)
Commercial real estate(242)— (3,826)(617)
Consumer real estate(1,088)(557)(1,508)(2,936)
Consumer and other(4,219)(6,357)(13,402)(17,157)
Total charge-offs(14,154)(11,619)(102,393)(33,492)
Recoveries:
Commercial and industrial1,121 1,185 3,727 2,870 
Energy— 740 66 816 
Commercial real estate42 46 185 165 
Consumer real estate573 454 1,564 858 
Consumer and other2,242 2,823 6,981 7,806 
Total recoveries3,978 5,248 12,523 12,515 
Net charge-offs(10,176)(6,371)(89,870)(20,977)
Balance at end of period$263,475 $136,559 $263,475 $136,559 
Ratio of allowance for credit losses on loans to:
Total loans1.45 %0.93 %1.45 %0.93 %
Total loans - excluding PPP loans1.76 0.93 1.76 0.93 
Non-accrual loans287.71 140.14 287.71 140.14 
Ratio of annualized net charge-offs to:
Average total loans0.22 0.17 0.71 0.20 
Average total loans - excluding PPP loans0.27 0.17 0.80 0.20 
 Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
 2017 2016 2017 2016
Balance at beginning of period$149,558
 $149,714
 $153,045
 $135,859
Provision for loan losses10,980
 5,045
 27,358
 42,734
Charge-offs:       
Commercial and industrial(5,468) (4,036) (14,574) (10,754)
Energy
 (884) (10,595) (18,644)
Commercial real estate
 (9) (14) (56)
Consumer real estate(766) (287) (779) (464)
Consumer and other(4,120) (3,300) (11,291) (9,276)
Total charge-offs(10,354) (8,516) (37,253) (39,194)
Recoveries:       
Commercial and industrial903
 957
 2,419
 2,577
Energy451
 19
 585
 21
Commercial real estate268
 277
 790
 875
Consumer real estate137
 92
 357
 442
Consumer and other2,360
 2,185
 7,002
 6,459
Total recoveries4,119
 3,530
 11,153
 10,374
Net charge-offs(6,235) (4,986) (26,100) (28,820)
Balance at end of period$154,303
 $149,773
 $154,303
 $149,773
        
Ratio of allowance for loan losses to:       
Total loans1.21% 1.29% 1.21% 1.29%
Non-accrual loans107.83
 154.67
 107.83
 154.67
Ratio of annualized net charge-offs to average total loans0.20
 0.17
 0.28
 0.33
The provision for loan losses decreased $15.4Credit loss expense related to loans increased $198.3 million or 36.0%, during the nine months ended September 30, 20172020 compared to the same period in 2016. The level of the provision for loan losses in 2016 was reflective of a significant increase in the volume of classified energy loans, specific valuation allowances taken on certain classified energy loans and increases in the weighted-average risk grades of our energy, commercial and industrial and commercial real estate loan portfolios. Classified energy, commercial and industrial and commercial real estate loans totaled $418.7 million at September 30, 2017 compared to $510.1 million at December 31, 2016 and $498.7 million at September 30, 2016. Specific valuation allowances2019. Credit loss expense related to energy, commercial and industrial and commercial real estate loans totaled $14.9 million at September 30, 2017 compared to $9.2 million at December 31, 2016 and $7.8 million at September 30, 2016. The overall weighted-average risk grade of our energy, commercial and industrial and commercial real estate loan portfolios was 6.76 at September 30, 2017 compared to 6.84 at December 31, 2016 and 6.85 at September 30, 2016. The level of the provision for loan losses during 2017 was mostly reflective of the level of net charge-offs during during the nine months ended September 30, 2017, which totaled $26.1 million. These2020 primarily reflects the increase in expected credit losses resulting from a deterioration in forecasted economic conditions and the current and uncertain future impacts associated with the COVID-19 pandemic and recent volatility in oil prices. Credit loss expense also reflects the level of net charge-offs, were mostly related to sixthe deterioration of credit relationships, as discussed above.quality and other changes within the loan portfolio during the first nine months of 2020. The ratio of the allowance for loancredit losses on loans to total loans was 1.21%1.45% (1.76% excluding PPP
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loans) at September 30, 20172020 compared to 1.28%0.90% at December 31, 2016.2019. Management believes the recorded amount of the allowance for loancredit losses on loans is appropriate based upon management’s best estimate of probablecurrent expected credit losses that have been incurred within the existing portfolio of loans. Should any of the factors considered by management in evaluating the appropriate level of the allowance for loan lossesmaking this estimate change, our estimate of probable loancurrent expect credit losses could also change, which could affect the level of future provisionscredit loss expense related to loans.
Allowance for loan losses.Credit Losses - Off-Balance-Sheet Credit Exposures. Upon the adoption of ASC 326 on January 1, 2020, the total amount of the allowance for credit losses on off-balance-sheet credit exposures estimated using the CECL methodology increased $39.4 million compared to the total amount of the allowance for credit losses on off-balance-sheet credit exposures estimated as of December 31, 2019 using the prior incurred loss model. The increase reflects the impact of assuming portions of all of these commitments will fund in the future and applying our credit loss modeling processes to such amounts as if such amounts were funded loans. Previously, we only recognized a liability for estimated incurred credit losses on off-balance-sheet credit exposures when the borrowers to which such commitments were extended exceeded certain risk grades and had not violated any underlying covenants that would relieve us of any obligation to fund additional amounts under the commitment. Subsequent to the adoption of ASC 326 on January 1, 2020, we recognized credit loss expense related to off-balance-sheet credit exposures totaling $3.8 million during the first nine months of 2020 to increase the amount of the related allowance for credit losses on off-balance-sheet credit exposures to $43.7 million as of September 30, 2020. The increase primarily reflects changes in underlying risk grades and expected utilization of available funds, an increase in overall off-balance-sheet credit exposures and a deterioration in forecasted economic conditions and the current and uncertain future impacts associated with COVID-19. Further information regarding our policies and methodology used to estimate the allowance for credit losses on off-balance-sheet credit exposures is presented in Note 6 - Off-Balance-Sheet Arrangements, Commitments, Guarantees and Contingencies in the accompanying notes to consolidated financial statements.

Capital and Liquidity
Capital. Shareholders’ equity totaled $3.2$4.1 billion at September 30, 20172020 and $3.0$3.9 billion December 31, 2016.2019. In addition to net income of $263.6$242.9 million, other sources of capital during the nine months ended September 30, 20172020 included $82.3 million of other comprehensive income, net of tax, $45.4of $237.8 million; $8.2 million related to stock-based compensation and $7.5 million in proceeds from stock option exercises and $9.0exercises. Additionally, we issued $7.0 million relatedof common stock held in treasury to stock-based compensation.our 401(k) plan. During the second quarter of 2020, we began to issue shares of our common stock directly to our 401(k) plan in connection with matching contributions. Previously, we contributed the matching contributions in cash which were then utilized to purchase shares of our common stock on the open market. Uses of capital during the nine months ended September 30, 20172020 included $113.8a $150.0 million redemption of preferred stock, $136.8 million of dividends paid on preferred and common stock.stock, $29.3 million related to the cumulative effect of adopting a new accounting principle and $14.0 million of treasury stock purchases. See Note 1 - Significant Accounting Policies.
The accumulated other comprehensive income/loss component of shareholders’ equity totaled a net, after-tax, unrealized gain of $57.7$505.1 million at September 30, 20172020 compared to a net, after-tax, unrealized loss of $24.6$267.4 million at December 31, 2016.2019. The change was primarily due to an $85.3a $235.4 million net, after-tax, increase in the net unrealized gain on securities available for sale.
Under the Basel III Capital Rules, we have elected to opt-out of the requirement to include most components of accumulated other comprehensive income in regulatory capital. Accordingly, amounts reported as accumulated other comprehensive income/loss do not increase or reduce regulatory capital and are not included in the calculation of risk-basedour regulatory capital ratios. In connection with the adoption of ASC 326 on January 1, 2020, we also elected to exclude, for a transitional period, the effects of credit loss accounting under CECL in the calculation of our regulatory capital and leverageregulatory capital ratios. Regulatory agencies for banks and bank holding companies utilize capital guidelines designed to measure capital and take into consideration the risk inherent in both on-balance sheeton-balance-sheet and off-balance sheetoff-balance-sheet items. See Note 87 - Capital and Regulatory Matters in the accompanying notes to consolidated financial statements included elsewhere in this report.
We paid a quarterly dividend of $0.54, $0.57 and $0.57$0.71 per common share during the first, second and third quarters of 2017,2020, respectively, and a quarterly dividenddividends of $0.53, $0.54$0.67, $0.71 and $0.54$0.71 per common share during the first, second and third quarters of 2016,2019, respectively. This equates to a common stock dividend payout ratio of 41.8%57.3% and 46.9%39.6% during the first nine months of 20172020 and 2016,2019, respectively. Our ability to declare or pay dividends on, or purchase, redeem or otherwise acquire, shares of our capital stock may be impacted by certain restrictions under the terms of our junior subordinated deferrable interest debentures and our Series A Preferred Stock as described in Note 87 - Capital and Regulatory Matters in the accompanying notes to consolidated financial statements included elsewhere in this report.
Preferred Stock. On March 16, 2020, we redeemed all 6,000,000 shares of our 5.375% Non-Cumulative Perpetual Preferred Stock, Series A, (“Series A Preferred Stock”) at a redemption price of $25 per share, or an aggregate redemption of $150.0 million. When issued, the net proceeds of the Series A Preferred Stock totaled $144.5 million after deducting $5.5 million of issuance costs including the underwriting discount and professional service fees, among other things. Upon redemption, these
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issuance costs were reclassified to retained earnings and reported as a reduction of net income available to common shareholders. See Note 7 – Capital and Regulatory Matters in the accompanying notes to consolidated financial statements included elsewhere in this report.
Stock Repurchase Plans. From time to time, our board of directors has authorized stock repurchase plans. In general, stock repurchase plans allow us to proactively manage our capital position and return excess capital to shareholders. Shares purchased under such plans also provide us with shares of common stock necessary to satisfy obligations related to stock compensation awards. On October 27, 2016,July 24, 2019, our board of directors authorized a $100.0 million stock repurchase program, allowing us to repurchase shares of our common stock over a two-yearone-year period from time to time at various prices in the open market or through private transactions. During the third quarter of 2017, weWe repurchased 1,134,966177,834 shares under the plan at a total cost of $100.0 million. On October$13.7 million during the first quarter of 2020 and 202,724 shares at a total cost of $17.2 million during the third quarter of 2019. No further repurchases were made under this plan prior to its expiration on July 24, 2017, our board of directors authorized a new $150.0 million stock repurchase plan allowing us to repurchase shares of our common stock over a two-year period from time to time at various prices2020. See Note 7 - Capital and Regulatory Matters in the open market or through private transactions. Seeaccompanying notes to consolidated financial statements and Part II, Item 2 - Unregistered Sales of Equity Securities and Use of Proceeds, each included elsewhere in this report.
Liquidity. As more fully discussed in our 20162019 Form 10-K, our liquidity position is continuously monitored and adjustments are made to the balance between sources and uses of funds as deemed appropriate. Liquidity risk management is an important element in our asset/liability management process. We regularly model liquidity stress scenarios to assess potential liquidity outflows or funding problems resulting from economic disruptions, volatility in the financial markets, unexpected credit events or other significant occurrences deemed problematic by management. These scenarios are incorporated into our contingency funding plan, which provides the basis for the identification of our liquidity needs. Our principal source of funding has been our customer deposits, supplemented by our short-term and long-term borrowings as well as maturities of securities and loan amortization. As of September 30, 2017, management is not aware2020, we had approximately $6.6 billion held in an interest-bearing account at the Federal Reserve. We also have the ability to borrow funds as a member of any eventsthe Federal Home Loan Bank (“FHLB”). As of September 30, 2020, based upon available, pledgeable collateral, our total borrowing capacity with the FHLB was approximately $2.7 billion. Furthermore, at September 30, 2020, we had approximately $8.1 billion in securities that are reasonably likelywere unencumbered by a pledge and could be used to have a material adverse effect on our liquidity, capital resourcessupport additional borrowings through repurchase agreements or operations. In addition, management is not aware of any regulatory recommendations regarding liquidity, that would have a material adverse effect on us.the Federal Reserve discount window, as needed.
Since Cullen/Frost is a holding company and does not conduct operations, its primary sources of liquidity are dividends upstreamed from Frost Bank and borrowings from outside sources. Banking regulations may limit the amount of dividends that may be paid by Frost Bank. See Note 87 - Capital and Regulatory Matters in the accompanying notes to consolidated financial statements included elsewhere in this report regarding such dividends. At September 30, 2017,2020, Cullen/Frost had liquid assets, including cash and resell agreements, totaling $241.3$207.6 million.
Accounting Standards Updates
See Note 1817 - Accounting Standards Updates in the accompanying notes to consolidated financial statements included elsewhere in this report for details of recently issued accounting pronouncements and their expected impact on our financial statements.

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Consolidated Average Balance Sheets and Interest Income Analysis - Quarter To Date
(Dollars in thousands - taxable-equivalent basis)
September 30, 2017 September 30, 2016September 30, 2020September 30, 2019
Average
Balance
 Interest
Income/
Expense
 Yield/
Cost
 Average
Balance
 Interest
Income/
Expense
 Yield/
Cost
Average
Balance
Interest
Income/
Expense
Yield/
Cost
Average
Balance
Interest
Income/
Expense
Yield/
Cost
Assets:           Assets:
Interest-bearing deposits$3,351,576
 $10,800
 1.28% $3,190,306
 $4,111
 0.51%Interest-bearing deposits$5,887,903 $1,512 0.10 %$1,565,515 $8,759 2.19 %
Federal funds sold and resell agreements72,239
 244
 1.34
 28,152
 48
 0.68
Federal funds sold and resell agreements31,165 19 0.24 211,756 1,194 2.21 
Securities:           Securities:
Taxable4,970,647
 23,203
 1.88
 5,391,848
 25,897
 1.97
Taxable4,201,559 22,560 2.21 5,278,040 32,122 2.45 
Tax-exempt7,360,643
 96,912
 5.34
 6,983,626
 92,917
 5.53
Tax-exempt8,478,804 80,566 4.08 8,166,344 79,617 4.08 
Total securities12,331,290
 120,115
 3.94
 12,375,474
 118,814
 3.97
Total securities12,680,363 103,126 3.44 13,444,384 111,739 3.43 
Loans, net of unearned discounts12,587,290
 141,622
 4.46
 11,457,464
 115,674
 4.02
Loans, net of unearned discounts18,149,187 170,127 3.73 14,471,414 188,192 5.16 
Total Earning Assets and Average Rate Earned28,342,395
 272,781
 3.85
 27,051,396
 238,647
 3.57
Total Earning Assets and Average Rate Earned36,748,618 274,784 3.04 29,693,069 309,884 4.21 
Cash and due from banks483,497
     487,456
    Cash and due from banks512,557 479,357 
Allowance for loan losses(152,237)     (152,549)    
Allowance for credit losses on loans and securitiesAllowance for credit losses on loans and securities(259,973)(136,783)
Premises and equipment, net522,413
     564,764
    Premises and equipment, net1,053,725 954,989 
Accrued interest and other assets1,194,316
     1,180,987
    Accrued interest and other assets1,380,138 1,257,836 
Total Assets$30,390,384
     $29,132,054
    Total Assets$39,435,065 $32,248,468 
           
Liabilities:           Liabilities:
Non-interest-bearing demand deposits:           Non-interest-bearing demand deposits:
Commercial and individual$10,159,636
     $9,225,059
    Commercial and individual$13,782,790 $9,819,992 
Correspondent banks233,748
     292,971
    Correspondent banks243,946 207,394 
Public funds362,779
     484,543
    Public funds558,703 289,079 
Total non-interest-bearing demand deposits10,756,163
     10,002,573
    Total non-interest-bearing demand deposits14,585,439 10,316,465 
Interest-bearing deposits:           Interest-bearing deposits:
Private accounts           Private accounts
Savings and interest checking6,344,476
 347
 0.02
 5,948,616
 264
 0.02
Savings and interest checking8,076,797 313 0.02 6,711,866 1,140 0.07 
Money market deposit accounts7,501,285
 4,513
 0.24
 7,473,650
 1,170
 0.06
Money market deposit accounts8,555,381 1,940 0.09 7,763,380 18,201 0.93 
Time accounts766,339
 412
 0.21
 807,055
 278
 0.14
Time accounts1,120,021 3,116 1.11 1,022,716 4,476 1.74 
Public funds381,632
 396
 0.41
 420,281
 37
 0.03
Public funds536,917 28 0.02 537,599 1,820 1.34 
Total interest-bearing deposits14,993,732
 5,668
 0.15
 14,649,602
 1,749
 0.05
Total interest-bearing deposits18,289,116 5,397 0.12 16,035,561 25,637 0.63 
Total deposits25,749,895
     24,652,175
    Total deposits32,874,555  26,352,026  
Federal funds purchased and repurchase agreements1,005,486
 523
 0.21
 797,417
 44
 0.02
Federal funds purchased and repurchase agreements1,578,122 482 0.12 1,290,963 5,040 1.53 
Junior subordinated deferrable interest debentures136,164
 1,020
 3.00
 136,107
 839
 2.47
Junior subordinated deferrable interest debentures136,337 700 2.05 136,279 1,425 4.18 
Subordinated notes payable and other notes98,498
 1,164
 4.73
 99,948
 350
 1.40
Subordinated notesSubordinated notes98,968 1,164 4.70 98,811 1,164 4.71 
Total Interest-Bearing Funds and Average Rate Paid16,233,880
 8,375
 0.21
 15,683,074
 2,982
 0.08
Total Interest-Bearing Funds and Average Rate Paid20,102,543 7,743 0.15 17,561,614 33,266 0.75 
Accrued interest and other liabilities168,572
     285,585
    Accrued interest and other liabilities682,525 542,091 
Total Liabilities27,158,615
     25,971,232
    Total Liabilities35,370,507 28,420,170 
Shareholders’ Equity3,231,769
     3,160,822
    Shareholders’ Equity4,064,558 3,828,298 
Total Liabilities and Shareholders’ Equity$30,390,384
     $29,132,054
    Total Liabilities and Shareholders’ Equity$39,435,065 $32,248,468 
Net interest income  $264,406
     $235,665
  Net interest income$267,041 $276,618 
Net interest spread    3.64%     3.49%Net interest spread2.89 %3.46 %
Net interest income to total average earning assets    3.73%     3.53%Net interest income to total average earning assets2.95 %3.76 %
For these computations: (i) average balances are presented on a daily average basis, (ii) information is shown on a taxable-equivalent basis assuming a 35%21% tax rate, (iii) average loans include loans on non-accrual status, and (iv) average securities include unrealized gains and losses on securities available for sale while yields are based on average amortized cost.




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Consolidated Average Balance Sheets and Interest Income Analysis - Year To Date
(Dollars in thousands - taxable-equivalent basis)
September 30, 2017 September 30, 2016September 30, 2020September 30, 2019
Average
Balance
 Interest
Income/
Expense
 Yield/
Cost
 Average
Balance
 Interest
Income/
Expense
 Yield/
Cost
Average
Balance
Interest
Income/
Expense
Yield/
Cost
Average
Balance
Interest
Income/
Expense
Yield/
Cost
Assets:           Assets:
Interest-bearing deposits$3,341,710
 $26,712
 1.07% $2,956,822
 $11,366
 0.51%Interest-bearing deposits$4,491,737 $10,894 0.32 %$1,487,947 $27,226 2.41 %
Federal funds sold and resell agreements56,581
 514
 1.21
 34,179
 165
 0.64
Federal funds sold and resell agreements127,409 884 0.91 235,612 4,323 2.42 
Securities:           Securities:
Taxable5,112,072
 72,032
 1.90
 5,245,649
 77,402
 2.02
Taxable4,246,298 71,950 2.32 4,969,843 87,125 2.35 
Tax-exempt7,309,739
 293,888
 5.39
 6,660,843
 270,586
 5.58
Tax-exempt8,468,372 243,961 4.07 8,211,558 243,628 4.06 
Total securities12,421,811
 365,920
 3.96
 11,906,492
 347,988
 4.01
Total securities12,714,670 315,911 3.48 13,181,401 330,753 3.41��
Loans, net of unearned discounts12,319,125
 397,817
 4.32
 11,497,340
 344,289
 4.00
Loans, net of unearned discounts16,902,533 515,912 4.08 14,351,562 566,069 5.27 
Total Earning Assets and Average Rate Earned28,139,227
 790,963
 3.77
 26,394,833
 703,808
 3.60
Total Earning Assets and Average Rate Earned34,236,349 843,601 3.35 29,256,522 928,371 4.27 
Cash and due from banks503,818
     504,074
    Cash and due from banks525,627 495,222 
Allowance for loan losses(152,604)     (151,643)    
Allowance for credit losses on loans and securitiesAllowance for credit losses on loans and securities(219,312)(136,271)
Premises and equipment, net522,768
     561,215
    Premises and equipment, net1,040,451 833,861 
Accrued interest and other assets1,211,309
     1,180,513
    Accrued interest and other assets1,371,366 1,228,440 
Total Assets$30,224,518
     $28,488,992
    Total Assets$36,954,481 $31,677,774 
           
Liabilities:           Liabilities:
Non-interest-bearing demand deposits:           Non-interest-bearing demand deposits:
Commercial and individual$10,054,481
     $9,055,750
    Commercial and individual$12,330,235 $9,699,019 
Correspondent banks253,567
     322,495
    Correspondent banks239,911 204,975 
Public funds417,555
     515,195
    Public funds471,321 315,249 
Total non-interest-bearing demand deposits10,725,603
     9,893,440
    Total non-interest-bearing demand deposits13,041,467 10,219,243 
Interest-bearing deposits:           Interest-bearing deposits:
Private accounts           Private accounts
Savings and interest checking6,352,986
 892
 0.02
 5,610,695
 778
 0.02
Savings and interest checking7,575,992 1,012 0.02 6,753,063 3,976 0.08 
Money market deposit accounts7,454,421
 6,929
 0.12
 7,441,626
 3,545
 0.06
Money market deposit accounts8,221,183 13,532 0.22 7,682,565 58,370 1.02 
Time accounts777,202
 1,040
 0.18
 813,297
 853
 0.14
Time accounts1,115,666 11,629 1.39 963,082 11,653 1.62 
Public funds433,395
 848
 0.26
 452,655
 133
 0.04
Public funds580,437 1,504 0.35 535,034 5,656 1.41 
Total interest-bearing deposits15,018,004
 9,709
 0.09
 14,318,273
 5,309
 0.05
Total interest-bearing deposits17,493,278 27,677 0.21 15,933,744 79,655 0.67 
Total deposits25,743,607
     24,211,713
    Total deposits30,534,745 26,152,987 
Federal funds purchased and repurchase agreements942,400
 849
 0.12
 734,022
 152
 0.03
Federal funds purchased and repurchase agreements1,378,349 4,005 0.38 1,238,197 15,276 1.63 
Junior subordinated deferrable interest debentures136,150
 2,890
 2.83
 136,092
 2,392
 2.34
Junior subordinated deferrable interest debentures136,323 2,893 2.83 136,265 4,401 4.31 
Subordinated notes payable and other notes87,173
 2,696
 4.12
 99,918
 958
 1.28
Subordinated notesSubordinated notes98,929 3,492 4.71 98,772 3,492 4.71 
Federal Home Loan Bank advancesFederal Home Loan Bank advances145,985 318 0.29 — — — 
Total Interest-Bearing Funds and Average Rate Paid16,183,727
 16,144
 0.13
 15,288,305
 8,811
 0.08
Total Interest-Bearing Funds and Average Rate Paid19,252,864 38,385 0.27 17,406,978 102,824 0.79 
Accrued interest and other liabilities161,643
     259,131
    Accrued interest and other liabilities669,297 416,288 
Total Liabilities27,070,973
     25,440,876
    Total Liabilities32,963,628 28,042,509 
Shareholders’ Equity3,153,545
     3,048,116
    Shareholders’ Equity3,990,853 3,635,265 
Total Liabilities and Shareholders’ Equity$30,224,518
     $28,488,992
    Total Liabilities and Shareholders’ Equity$36,954,481 $31,677,774 
Net interest income  $774,819
     $694,997
  Net interest income$805,216 $825,547 
Net interest spread    3.64%     3.52%Net interest spread3.08 %3.48 %
Net interest income to total average earning assets    3.69%     3.56%Net interest income to total average earning assets3.20 %3.80 %
For these computations: (i) average balances are presented on a daily average basis, (ii) information is shown on a taxable-equivalent basis assuming a 35%21% tax rate, (iii) average loans include loans on non-accrual status, and (iv) average securities include unrealized gains and losses on securities available for sale while yields are based on average amortized cost.





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Item 3. Quantitative and Qualitative Disclosures About Market Risk
The disclosures set forth in this item are qualified by the section captioned “Forward-Looking Statements and Factors that Could Affect Future Results” included in Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations of this report and other cautionary statements set forth elsewhere in this report.
Refer to the discussion of market risks included in Item 7A. Quantitative and Qualitative Disclosures About Market Risk in the 20162019 Form 10-K. There has been no significant change in the types of market risks we face since December 31, 2016.2019.
We utilize an earnings simulation model as the primary quantitative tool in measuring the amount of interest rate risk associated with changing market rates. The model quantifies the effects of various interest rate scenarios on projected net interest income and net income over the next 12 months. The model measures the impact on net interest income relative to a flat-rate case scenario of hypothetical fluctuations in interest rates over the next 12 months. These simulations incorporate assumptions regarding balance sheet growth and mix, pricing and the repricing and maturity characteristics of the existing and projected balance sheet. The impact of interest rate derivatives, such as interest rate swaps, caps and floors, is also included in the model. Other interest rate-related risks such as prepayment, basis and option risk are also considered.
For modeling purposes, as of September 30, 2017,2020, the model simulations projected that 100 and 200 basis point ratable increases in interest rates would result in positive variances in net interest income of 1.2%1.9% and 3.3%5.3%, respectively, relative to the flat-rate case over the next 12 months, while 100 and 125a 25 basis point ratable decreasesdecrease in interest rates would result in a negative variancesvariance in net interest income of 5.1% and 9.9%, respectively,1.5% relative to the flat-rate case over the next 12 months. The September 30, 20172020 model simulations for increased interest rates were impacted by the assumption, for modeling purposes, that we will begin to pay interest on commercial demand deposits (those not already receiving an earnings credit rate) in the fourth quarter of 2017,2020, as further discussed below. For modeling purposes, as of September 30, 2016,2019, the model simulations projected that 100 and 200 basis point ratable increases in interest rates would result in positive variances in net interest income of 0.4%0.2% and 1.5%1.3%, respectively, relative to the flat-rate case over the next 12 months, while a decrease100 and 200 basis point ratable decreases in interest rates of 50 basis points would result in a negative variancevariances in net interest income of 6.5%1.7% and 5.7%, respectively, relative to the flat-rate case over the next 12 months. The September 30, 20162019 model simulations for increased interest rates were impacted by the assumption, for modeling purposes, that we would begin to pay interest on commercial demand deposits (those not already receiving an earnings credit rate) in the fourth quarter of 2016,2019, as further discussed below. The likelihood of a decrease in interest rates beyond 12525 basis points as of September 30, 2017 and 50 basis points as of September 30, 20162020 was considered to be remote given prevailing interest rate levels.
The model simulations as of September 30, 20172020 indicate that our projected balance sheet is more asset sensitive in comparison to our balance sheet as of September 30, 2016.2019. The shift to a more asset sensitive position was primarily due to increasesan increase in the relative proportion of interest-bearing deposits (primarily amounts held in an interest-bearing account at the Federal Reserve) and federal funds sold to projected average interest-earning assets. FederalInterest-bearing deposits and federal funds sold are more immediately impacted by changes in interest rates in comparison to our other categories of earning assets.
Financial regulatory reform legislation entitled The shift to a more asset sensitive position was also partly due to a decrease in the “Dodd-Frank Wall Street Reform and Consumer Protection Act” (the “Dodd-Frank Act”) repealed the federal prohibitionassumed interest rate paid on the payment of interest on demand deposits, thereby permitting depository institutions to pay interest on business transaction and other accounts beginning July 21, 2011. To date, we have not experienced any significant additional interest costs as a result of the repeal. However, in light of recent increases in market interest rates, in late July 2017, we increased the interest rates we pay on most of our interest-bearing deposit products. If we began to pay interest onprojected commercial demand deposits (those not already receiving an earnings credit rate), as further discussed below.
We do not currently pay interest on a significant portion of our balance sheet would likely become less asset sensitive. Because thecommercial demand deposits. Any interest rate that willwould ultimately be paid on these commercial demand deposits dependswould likely depend upon a variety of factors, some of which are beyond our control, wecontrol. Our modeling simulation as of September 30, 2020 assumed an aggressivea moderate pricing structure for the purposes of the model simulations discussed abovewith regards to interest payments on commercial demand deposits (those not already receiving an earnings credit) with interest payments beginningassumed to begin in the fourth quarter of 2017. Should the actual interest rate paid2020. This moderate pricing structure on commercial demand deposits be less than the rateassumes a deposit pricing beta of 25%. The pricing beta is a measure of how much deposit rates reprice, up or down, given a defined change in market rates. Our modeling simulation as of September 30, 2019 assumed in the model simulations, or should thea much more aggressive pricing structure with regards to interest rate paidpayments for commercial demand deposits become an administered(those not already receiving and earnings credit) with interest payments assumed to begin in the fourth quarter of 2019. We modified our assumed pricing structure during 2020 compared to 2019 based upon our market observations during the most recent interest rate with less direct correlation to movements in general market interest rates, our balance sheet could be more asset sensitive than the model simulations might otherwise indicate.cycle.
As of September 30, 2017,2020, the effects of a 200 basis point increase and a 12525 basis point decrease in interest rates on our derivative holdings would not result in a significant variance in our net interest income.
The effects of hypothetical fluctuations in interest rates on our securities classified as “trading” under ASC Topic 320, “Investments—Debt and Equity Securities,” are not significant, and, as such, separate quantitative disclosure is not presented.

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Item 4. Controls and Procedures
As of the end of the period covered by this Quarterly Report on Form 10-Q, an evaluation was carried out by management, with the participation of its Chief Executive Officer and Chief Financial Officer, of the effectiveness of our disclosure controls and procedures (as defined in Rule 13a-15(e) under the Securities Exchange Act of 1934). Based upon that evaluation, the Chief Executive Officer and Chief Financial Officer concluded that the disclosure controls and procedures were effective as of the end of the period covered by this report. No change in our internal control over financial reporting (as defined in Rule 13a-15(f) under the Securities Exchange Act of 1934) occurred during the last fiscal quarter that materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

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Part II. Other Information
Item 1. Legal Proceedings
We are subject to various claims and legal actions that have arisen in the course of conducting business. Management does not expect the ultimate disposition of these matters to have a material adverse impact on our financial statements.
Item 1A. Risk Factors
There has been no material change inRefer to the risk factors disclosed under Item 1A. of our 20162019 Form 10-K.10-K for a discussion of certain material risks and uncertainties that management believed affect our business. The following risk factors are provided to supplement that discussion.

Our business, financial condition, liquidity and results of operations have been, and will likely continue to be, adversely affected by the COVID-19 pandemic.
The COVID-19 pandemic has created economic and financial disruptions that have adversely affected, and are likely to continue to adversely affect, our business, financial condition, liquidity and results of operations. The extent to which the COVID-19 pandemic will continue to negatively affect our business, financial condition, liquidity and results of operations will depend on future developments, which are highly uncertain and cannot be predicted, including the scope and duration of the pandemic (including the possibility of resurgence of COVID-19 after initial abatement), the effectiveness of our Business Continuity and Health Emergency Response plans, the direct and indirect impact of the pandemic on our employees, customers, clients, counterparties and service providers, as well as other market participants, and actions taken, or that may yet be taken, or inaction by governmental authorities and other third parties in response to the pandemic.
The COVID-19 pandemic has contributed to:
Increased unemployment and business disruption and decreased consumer and business confidence and consumer and commercial activity generally, leading to an increased risk of delinquencies, defaults and foreclosures.
Higher and more volatile credit loss expense and potential for increased charge-offs, particularly as customers may need to draw on their committed credit lines to help finance their businesses and activities.
Ratings downgrades, credit deterioration and defaults in many industries, particularly energy, retail/strip centers, hotels/lodging, restaurants, entertainment and commercial real estate.
A sudden and significant reduction in the valuation of the equity, fixed-income and commodity markets and the significant increase in the volatility of those markets.
A decrease in the rates and yields on U.S. Treasury securities, which may lead to decreased net interest income.
Increased demands on capital and liquidity, leading us to cease repurchases of our common stock in order to preserve capital and provide added liquidity.
A reduction in the value of the assets that we manage or otherwise administer or service for others, affecting related fee income and demand for our services.
Heightened cybersecurity, information security and operational risks as a result of work-from-home arrangements and impacts on our service providers.
Any disruption to our ability to deliver financial products or services to, or interact with, our clients and customers could result in losses or increased operational costs, regulatory fines, penalties and other sanctions, or harm our reputation.
As noted in the section captioned “Recent Developments Related to COVID-19” in Part I. Financial Information, Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations elsewhere in this report, the Federal Reserve has taken various actions and the U.S. government has enacted several fiscal stimulus measures to counteract the economic disruption caused by the COVID-19 pandemic and provide economic assistance to individual households and businesses, stabilize the markets and support economic growth. The success of these measures is unknown and they may not be sufficient to fully mitigate the negative impact of the COVID-19 pandemic. We face an increased risk of litigation and governmental, regulatory and third-party scrutiny as a result of the effects of COVID-19 on market and economic conditions and actions governmental authorities take in response to those conditions. Furthermore, various governmental programs such as the PPP are complex and our participation may lead to additional litigation and governmental, regulatory and third-party scrutiny, negative publicity and damage to our reputation. For example, our participation in the PPP as a lender may adversely affect our revenue and results of operations depending on the timing and amount of forgiveness, if any, to which our borrowers will be entitled.
The length of the pandemic and the efficacy of the extraordinary measures being put in place to address it are unknown. Until the pandemic subsides, we expect continued draws on lines of credit, reduced fee income and revenues related to investment management, insurance and brokerage operations and increased customer and client defaults, including defaults of
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unsecured loans. Even after the pandemic subsides, the U.S. economy may continue to experience a recession, and we anticipate our businesses would be materially and adversely affected by a prolonged recession. To the extent the pandemic adversely affects our business, financial condition, liquidity or results of operations, it may also have the effect of heightening many of the other risks described in the section entitled “Risk Factors” in our 2019 Form 10-K and subsequent Quarterly Reports on Form 10-Q. See the section captioned “Recent Developments Related to COVID-19” in Part I. Financial Information, Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations elsewhere in this report for further discussion.
We Are Subject To Volatility Risk In Crude Oil Prices
As of September 30, 2020, we had $1.4 billion of energy loans which comprised approximately 7.4% of our loan portfolio at that date. Furthermore, energy production and related industries represent a large part of the economies in some of our primary markets. In recent years, actions by certain members of the Organization of Petroleum Exporting Countries (“OPEC”) impacting crude oil production levels have led to increased global oil supplies, which has resulted in significant declines in market oil prices. Decreased market oil prices compressed margins for many U.S. and Texas-based oil producers, particularly those that utilize higher-cost production technologies such as hydraulic fracking and horizontal drilling, as well as oilfield service providers, energy equipment manufacturers and transportation suppliers, among others. In March of 2020, disagreements between members of OPEC signaled that production levels would rise and led to a significant decline in market oil prices. While oil prices have recovered from recent lows, on-going oil price volatility and depressed market oil prices, are expected to continue due to the uncertainties and economic impacts of COVID-19. See the section captioned “Recent Developments Related to COVID-19” in Part I. Financial Information, Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations elsewhere in this report for further discussion. The price per barrel of crude oil was approximately $40 as of September 30, 2020 down from $61 as of December 31, 2019. We have experienced increased losses within our energy portfolio recently as a result of depressed oil prices and increased oil price volatility, relative to our historical experience. Continued and further depressed oil prices and increased oil price volatility could have further negative impacts on the U.S. economy, in particular, the economies of energy-dominant states such as Texas, and our borrowers and customers.
Item 2. Unregistered Sales of Equity Securities and Use of Proceeds
The following table provides information with respect to purchases we made or were made on our behalf or any “affiliated purchaser” (as defined in Rule 10b-18(a)(3) under the Securities Exchange Act of 1934), of our common stock during the three months ended September 30, 2017.2020. Dollar amounts in thousands.
PeriodTotal Number of
Shares Purchased
Average Price
Paid Per Share
Total Number of
Shares Purchased
as Part of Publicly
Announced Plan
Maximum
Number of Shares
(or Approximate
Dollar Value)
That May Yet Be
Purchased Under
the Plan at the
End of the Period
July 1, 2020 to July 31, 2020400 (1)$70.56 — $— 
August 1, 2020 to August 31, 2020— — — — 
September 1, 2020 to September 30, 2020— — — — 
Total400 — 

(1)Repurchases made in connection with the vesting of certain share awards.
Period
Total Number of
Shares Purchased
 
Average Price
Paid Per Share
 
Total Number of
Shares Purchased
as Part of Publicly
Announced Plan
 
Maximum
Number of Shares
(or Approximate
Dollar Value)
That May Yet Be
Purchased Under
the Plan at the
End of the Period
July 1, 2017 to July 31, 2017169,342
 $91.11
 169,342
 $84,572
August 1, 2017 to August 31, 2017614,493
 88.69
 614,493
 30,070
September 1, 2017 to September 30, 2017351,131
 85.64
 351,131
 
Total1,134,966
 $88.11
 1,134,966
  


Item 3. Defaults Upon Senior Securities
None.
Item 4. Mine Safety Disclosures
None.
Item 5. Other Information
None.
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Item 6. Exhibits
(a) Exhibits
Exhibit

Number
Description
31.1
31.2
32.1+
32.1(1)
32.2+
32.2(1)
101
101.INS(2)
Inline XBRL Instance Document
101.SCHInline XBRL Taxonomy Extension Schema Document
101.CALInline XBRL Taxonomy Extension Calculation Linkbase Document
101.DEFInline XBRL Taxonomy Extension Definition Linkbase Document
101.LABInlineXBRL Taxonomy Extension Label Linkbase Document
101.PREInline XBRL Taxonomy Extension Presentation Linkbase Document
104(3)
Cover Page Interactive Data File
+This exhibit shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, or otherwise subject to the liability of that section, and shall not be deemed to be incorporated by reference into any filing under the Securities Act of 1933 or the Securities Exchange Act of 1934.

(1)This exhibit shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, or otherwise subject to the liability of that section, and shall not be deemed to be incorporated by reference into any filing under the Securities Act of 1933 or the Securities Exchange Act of 1934.
(2)The instance document does not appear in the interactive data file because its XBRL tags are embedded within the Inline XBRL document.
(3)Formatted as Inline XBRL and contained within the Inline XBRL Instance Document in Exhibit 101.

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Signatures
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

Cullen/Frost Bankers, Inc.
(Registrant)
Date:October 26, 201729, 2020By:/s/ Jerry Salinas
Jerry Salinas
Group Executive Vice President
and Chief Financial Officer
(Duly Authorized Officer, Principal Financial
Officer and Principal Accounting Officer)

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