0000039263 cfr:A2017Member us-gaap:ConstructionLoansMember 2020-03-31

United States
Securities and Exchange Commission
Washington, D.C. 20549
Form 10-Q
Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
For the quarterly period ended: September 30, 2019March 31, 2020
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)
Texas 74-1751768
(State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.)
   
111 W. Houston Street,San Antonio,Texas 78205
(Address of principal executive offices) (Zip code)
 (210)220-4011 
(Registrant's telephone number, including area code)
N/A
(Former name, former address and former fiscal year, if changed since last report
Securities registered pursuant to Section 12(b) of the Act:
Title of each class Trading Symbol(s) 
Name of each exchange on
which registered
     
Common Stock, $.01 Par Value CFRNew York Stock Exchange
5.375% Non-Cumulative Perpetual Preferred Stock, Series ACFR.PRA New 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      No  
Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted 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 such files).    Yes      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 filerAccelerated filer
 Non-accelerated filerSmaller 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  
As of October 24, 2019April 27, 2020 there were 62,565,46962,553,394 shares of the registrant’s Common Stock, $.01 par value, outstanding.

Cullen/Frost Bankers, Inc.
Quarterly Report on Form 10-Q
September 30, 2019March 31, 2020
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.
   

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,
2019
 December 31,
2018
March 31,
2020
 December 31,
2019
Assets:      
Cash and due from banks$653,969
 $678,791
$572,129
 $581,857
Interest-bearing deposits1,865,883
 2,641,971
3,246,731
 2,849,950
Federal funds sold and resell agreements388,049
 635,017
376,725
 356,374
Total cash and cash equivalents2,907,901
 3,955,779
4,195,585
 3,788,181
Securities held to maturity, at amortized cost1,020,838
 1,106,057
Securities held to maturity, net of allowance for credit losses of $200 at March 31, 20201,984,149
 2,030,005
Securities available for sale, at estimated fair value12,420,446
 11,387,321
10,467,977
 11,269,591
Trading account securities27,669
 24,086
25,921
 24,298
Loans, net of unearned discounts14,634,928
 14,099,733
15,338,260
 14,750,332
Less: Allowance for loan losses(136,559) (132,132)
Less: Allowance for credit losses on loans(263,881) (132,167)
Net loans14,498,369
 13,967,601
15,074,379
 14,618,165
Premises and equipment, net987,503
 552,330
1,035,881
 1,011,947
Goodwill654,952
 654,952
654,952
 654,952
Other intangible assets, net2,745
 3,649
2,224
 2,481
Cash surrender value of life insurance policies186,217
 183,473
188,078
 187,156
Accrued interest receivable and other assets391,536
 457,718
518,159
 440,652
Total assets$33,098,176
 $32,292,966
$34,147,305
 $34,027,428
      
Liabilities:      
Deposits:      
Non-interest-bearing demand deposits$10,750,244
 $10,997,494
$11,202,208
 $10,873,629
Interest-bearing deposits16,333,338
 16,151,710
16,938,659
 16,765,935
Total deposits27,083,582
 27,149,204
28,140,867
 27,639,564
Federal funds purchased and repurchase agreements1,200,655
 1,367,548
1,170,978
 1,695,342
Junior subordinated deferrable interest debentures, net of unamortized issuance costs136,285
 136,242
136,314
 136,299
Subordinated notes, net of unamortized issuance costs98,826
 98,708
98,904
 98,865
Accrued interest payable and other liabilities697,371
 172,347
773,576
 545,690
Total liabilities29,216,719
 28,924,049
30,320,639
 30,115,760
      
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, 2019 and December 31, 2018144,486
 144,486
Common stock, par value $0.01 per share; 210,000,000 shares authorized; 64,236,306 shares issued at September 30, 2019 and December 31, 2018642
 642
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, 2019
 144,486
Common stock, par value $0.01 per share; 210,000,000 shares authorized; 64,236,306 shares issued at March 31, 2020 and December 31, 2019642
 642
Additional paid-in capital977,997
 967,304
985,762
 983,250
Retained earnings2,617,500
 2,440,002
2,635,588
 2,667,534
Accumulated other comprehensive income (loss), net of tax305,383
 (63,600)363,815
 267,370
Treasury stock, at cost; 1,699,662 shares at September 30, 2019 and 1,250,464 shares at December 31, 2018(164,551) (119,917)
Treasury stock, at cost; 1,682,912 shares at March 31, 2020 and 1,567,302 shares at December 31, 2019(159,141) (151,614)
Total shareholders’ equity3,881,457
 3,368,917
3,826,666
 3,911,668
Total liabilities and shareholders’ equity$33,098,176
 $32,292,966
$34,147,305
 $34,027,428
See Notes to Consolidated Financial Statements.


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 
 March 31,
2019 2018 2019 20182020 2019
Interest income:          
Loans, including fees$186,870
 $172,333
 $561,990
 $487,668
$172,137
 $185,272
Securities:          
Taxable32,122
 21,339
 87,125
 63,085
26,030
 24,679
Tax-exempt57,328
 59,200
 175,067
 173,209
58,886
 59,143
Interest-bearing deposits8,759
 14,445
 27,226
 42,456
8,125
 10,639
Federal funds sold and resell agreements1,194
 1,399
 4,323
 3,575
802
 1,588
Total interest income286,273
 268,716
 855,731
 769,993
265,980
 281,321
Interest expense:          
Deposits25,637
 22,201
 79,655
 50,414
16,053
 27,174
Federal funds purchased and repurchase agreements5,040
 2,292
 15,276
 3,557
3,037
 5,016
Junior subordinated deferrable interest debentures1,425
 1,394
 4,401
 3,847
1,205
 1,498
Other long-term borrowings1,164
 1,164
 3,492
 3,492
1,164
 1,164
Total interest expense33,266
 27,051
 102,824
 61,310
21,459
 34,852
Net interest income253,007
 241,665
 752,907
 708,683
244,521
 246,469
Provision for loan losses8,001
 2,650
 25,404
 17,846
Net interest income after provision for loan losses245,006
 239,015
 727,503
 690,837
Credit loss expense175,197
 11,003
Net interest income after credit loss expense69,324
 235,466
Non-interest income:          
Trust and investment management fees31,649
 30,801
 93,794
 89,509
34,473
 31,697
Service charges on deposit accounts22,941
 21,569
 65,529
 63,554
22,651
 20,790
Insurance commissions and fees11,683
 11,037
 40,207
 37,573
16,485
 18,406
Interchange and debit card transaction fees4,117
 3,499
 11,265
 10,103
3,255
 3,280
Other charges, commissions and fees10,108
 9,580
 28,103
 27,860
9,365
 9,062
Net gain (loss) on securities transactions96
 (34) 265
 (113)108,989
 
Other8,630
 11,205
 29,484
 35,682
17,697
 13,550
Total non-interest income89,224
 87,657
 268,647
 264,168
212,915
 96,785
Non-interest expense:          
Salaries and wages93,812
 87,547
 277,078
 259,434
98,812
 92,476
Employee benefits21,002
 18,355
 64,579
 58,257
24,889
 23,526
Net occupancy24,202
 19,894
 64,602
 59,089
25,384
 19,267
Technology, furniture and equipment22,415
 21,004
 66,236
 61,142
25,240
 21,664
Deposit insurance2,491
 4,694
 7,752
 14,178
2,624
 2,808
Intangible amortization274
 336
 904
 1,093
257
 325
Other44,668
 41,838
 132,722
 125,994
46,957
 41,734
Total non-interest expense208,864
 193,668
 613,873
 579,187
224,163
 201,800
Income before income taxes125,366
 133,004
 382,277
 375,818
58,076
 130,451
Income taxes13,530
 15,160
 42,359
 40,153
3,323
 13,955
Net income111,836
 117,844
 339,918
 335,665
54,753
 116,496
Preferred stock dividends2,016
 2,016
 6,047
 6,047
2,016
 2,016
Redemption of preferred stock5,514
 
Net income available to common shareholders$109,820
 $115,828
 $333,871
 $329,618
$47,223
 $114,480
          
Earnings per common share:          
Basic$1.74
 $1.80
 $5.28
 $5.13
$0.75
 $1.80
Diluted1.73
 1.78
 5.24
 5.08
0.75
 1.79
See Notes to Consolidated Financial Statements.

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 
 March 31,
2019 2018 2019 20182020 2019
Net income$111,836
 $117,844
 $339,918
 $335,665
$54,753
 $116,496
Other comprehensive income (loss), before tax:          
Securities available for sale and transferred securities:          
Change in net unrealized gain/loss during the period107,786
 (96,147) 464,072
 (286,935)230,118
 198,146
Change in net unrealized gain on securities transferred to held to maturity(305) (3,764) (957) (8,424)(377) (344)
Reclassification adjustment for net (gains) losses included in net income(97) 34
 (266) 113
(108,989) 
Total securities available for sale and transferred securities107,384
 (99,877) 462,849
 (295,246)120,752
 197,802
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)1,406
 1,250
 4,218
 3,751
1,330
 1,406
Total defined-benefit post-retirement benefit plans1,406
 1,250
 4,218
 3,751
1,330
 1,406
Other comprehensive income (loss), before tax108,790
 (98,627) 467,067
 (291,495)122,082
 199,208
Deferred tax expense (benefit)22,845
 (20,711) 98,084
 (61,213)25,637
 41,834
Other comprehensive income (loss), net of tax85,945
 (77,916) 368,983
 (230,282)96,445
 157,374
Comprehensive income (loss)$197,781
 $39,928
 $708,901
 $105,383
$151,198
 $273,870
See Notes to Consolidated Financial Statements.

Cullen/Frost Bankers, Inc.
Consolidated Statements of Changes in Shareholders’ Equity
(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
Three months ended:             
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
              
September 30, 2018             
Balance at beginning of period$144,486
 $642
 $960,121
 $2,297,099
 $(63,319) $(29,517) $3,309,512
Net income
 
 
 117,844
 
 
 117,844
Other comprehensive income, net of tax
 
 
 
 (77,916) 
 (77,916)
Stock option exercises/stock unit conversions (19,232 shares)
 
 
 (575) 
 1,694
 1,119
Stock-based compensation expense recognized in earnings
 
 2,796
 
 
 
 2,796
Cash dividends – preferred stock (approximately $0.34 per share)
 
 
 (2,016) 
 
 (2,016)
Cash dividends – common stock ($0.67 per share)
 
 
 (43,093) 
 
 (43,093)
Balance at end of period$144,486
 $642
 $962,917
 $2,369,259
 $(141,235) $(27,823) $3,308,246

See accompanying Notes to Consolidated Financial Statements

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
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, 2019             
Three months ended:             
March 31, 2020             
Balance at beginning of period$144,486
 $642
 $967,304
 $2,440,002
 $(63,600) $(119,917) $3,368,917
$144,486
 $642
 $983,250
 $2,667,534
 $267,370
 $(151,614) $3,911,668
Cumulative effect of accounting change
 
 
 (14,672) 
 
 (14,672)
 
 
 (29,252) 
 
 (29,252)
Total shareholders' equity at beginning of period, as adjusted144,486
 642
 967,304
 2,425,330
 (63,600) (119,917) 3,354,245
144,486
 642
 983,250
 2,638,282
 267,370
 (151,614) 3,882,416
Net income
 
 
 339,918
 
 
 339,918

 
 
 54,753
 
 
 54,753
Other comprehensive income, net of tax
 
 
 
 368,983
 
 368,983

 
 
 
 96,445
 
 96,445
Stock option exercises/stock unit conversions (255,184 shares)
 
 
 (9,569) 
 23,075
 13,506
Stock option exercises/stock unit conversions (66,215 shares)
 
 
 (4,983) 
 6,446
 1,463
Stock-based compensation expense recognized in earnings
 
 10,693
 
 
 
 10,693

 
 2,512
 
 
 
 2,512
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)
Redemption of preferred stock (6,000,000 shares)(144,486) 
 
 (5,514) 
 
 (150,000)
Purchase of treasury stock (181,825 shares)
 
 
 
 
 (13,973) (13,973)
Cash dividends – preferred stock (approximately $0.34 per share)
 
 
 (2,016) 
 
 (2,016)
Cash dividends – common stock ($0.71 per share)
 
 
 (44,934) 
 
 (44,934)
Balance at end of period$144,486
 $642
 $977,997
 $2,617,500
 $305,383
 $(164,551) $3,881,457
$
 $642
 $985,762
 $2,635,588
 $363,815
 $(159,141) $3,826,666
                          
September 30, 2018             
March 31, 2019             
Balance at beginning of period$144,486
 $642
 $953,361
 $2,187,069
 $79,512
 $(67,207) $3,297,863
$144,486
 $642
 $967,304
 $2,440,002
 $(63,600) $(119,917) $3,368,917
Cumulative effect of accounting change
 
 
 (2,285) 
 
 (2,285)
 
 
 (14,672) 
 
 (14,672)
Total shareholders' equity at beginning of period, as adjusted144,486
 642
 953,361
 2,184,784
 79,512
 (67,207) 3,295,578
144,486
 642
 967,304
 2,425,330
 (63,600) (119,917) 3,354,245
Net income
 
 
 335,665
 
 
 335,665

 
 
 116,496
 
 
 116,496
Other comprehensive loss, net of tax
 
 
 
 (230,282) 
 (230,282)
 
 
 
 157,374
 
 157,374
Reclassification of certain income tax effects related to the change in the U.S. statutory federal income tax rate under the Tax Cuts and Jobs Act
 
 
 (9,535) 9,535
 
 
Stock option exercises/stock unit conversions (447,831 shares)
 
 
 (12,887) 
 39,454
 26,567
Stock option exercises/stock unit conversions (100,865 shares)
 
 
 (4,001) 
 8,886
 4,885
Stock-based compensation expense recognized in earnings
 
 9,556
 
 
 
 9,556

 
 3,654
 
 
 
 3,654
Purchase of treasury stock (601 shares)
 
 
 
 
 (70) (70)
Cash dividends – preferred stock (approximately $1.01 per share)
 
 
 (6,047) 
 
 (6,047)
Cash dividends – common stock ($1.91 per share)
 
 
 (122,721) 
 
 (122,721)
Purchase of treasury stock (5,351 shares)
 
 
 
 
 (519) (519)
Cash dividends – preferred stock (approximately $0.34 per share)
 
 
 (2,016) 
 
 (2,016)
Cash dividends – common stock ($0.67 per share)
 
 
 (42,602) 
 
 (42,602)
Balance at end of period$144,486
 $642
 $962,917
 $2,369,259
 $(141,235) $(27,823) $3,308,246
$144,486
 $642
 $970,958
 $2,493,207
 $93,774
 $(111,550) $3,591,517

See accompanying Notes to Consolidated Financial Statements


Cullen/Frost Bankers, Inc.
Consolidated Statements of Cash Flows
(Dollars in thousands)
Nine Months Ended 
 September 30,
Three Months Ended 
 March 31,
2019 20182020 2019
Operating Activities:      
Net income$339,918
 $335,665
$54,753
 $116,496
Adjustments to reconcile net income to net cash from operating activities:      
Provision for loan losses25,404
 17,846
Credit loss expense175,197
 11,003
Deferred tax expense (benefit)(1,625) 39,198
(26,089) (1,044)
Accretion of loan discounts(11,364) (10,470)(4,060) (3,757)
Securities premium amortization (discount accretion), net84,963
 73,748
31,760
 28,696
Net (gain) loss on securities transactions(265) 113
(108,989) 
Depreciation and amortization39,182
 37,452
15,518
 12,752
Net (gain) loss on sale/write-down of assets/foreclosed assets(6,016) (6,122)397
 (4,437)
Stock-based compensation10,693
 9,556
2,512
 3,654
Net tax benefit from stock-based compensation1,602
 3,378
336
 716
Earnings on life insurance policies(2,744) (2,510)(922) (898)
Net change in:      
Trading account securities(3,132) (1,094)(12,819) 1,582
Lease right-of-use assets14,618
 
5,620
 4,833
Accrued interest receivable and other assets37,608
 (19,047)(81,100) 32,634
Accrued interest payable and other liabilities56,354
 (17,545)196,814
 (56,098)
Net cash from operating activities585,196
 460,168
248,928
 146,132
      
Investing Activities:      
Securities held to maturity:      
Purchases
 (1,500)(1,500) 
Maturities, calls and principal repayments69,273
 300,340
41,526
 23,421
Securities available for sale:      
Purchases(9,815,936) (14,983,642)(687,759) (1,526,279)
Sales8,236,066
 13,838,566
1,111,102
 944,903
Maturities, calls and principal repayments1,007,783
 182,028
581,882
 121,471
Proceeds from sale of loans24,036
 21,318

 12,699
Net change in loans(569,223) (718,551)(622,514) (322,308)
Benefits received on life insurance policies
 384

 
Proceeds from sales of premises and equipment8,019
 12,859
1
 4,667
Purchases of premises and equipment(168,326) (56,781)(31,749) (44,039)
Proceeds from sales of repossessed properties131
 1,106
8
 
Net cash from investing activities(1,208,177) (1,403,873)390,997
 (785,465)
      
Financing Activities:      
Net change in deposits(65,622) (523,535)501,303
 (854,341)
Net change in short-term borrowings(166,893) (64,047)(524,364) (140,399)
Redemption of preferred stock(150,000) 
Proceeds from stock option exercises13,506
 26,567
1,463
 4,885
Purchase of treasury stock(67,709) (70)(13,973) (519)
Cash dividends paid on preferred stock(6,047) (6,047)(2,016) (2,016)
Cash dividends paid on common stock(132,132) (122,721)(44,934) (42,602)
Net cash from financing activities(424,897) (689,853)(232,521) (1,034,992)
      
Net change in cash and cash equivalents(1,047,878) (1,633,558)407,404
 (1,674,325)
Cash and cash equivalents at beginning of period3,955,779
 5,053,047
3,788,181
 3,955,779
Cash and cash equivalents at end of period$2,907,901
 $3,419,489
$4,195,585
 $2,281,454

See Notes to Consolidated Financial Statements.

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, 20182019, included in our Annual Report on Form 10-K filed with the SEC on February 6, 20194, 2020 (the “2018“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,
Three Months Ended 
 March 31,
2019 20182020 2019
Cash paid for interest$100,041
 $59,764
$23,168
 $34,402
Cash paid for income taxes42,352
 5,112

 
Significant non-cash transactions:      
Unsettled purchases/sales of securities82,064
 74,191
Loans foreclosed and transferred to other real estate owned and foreclosed assets1,302
 2,898
Loans to facilitate the sale of other real estate owned847
 
Unsettled securities transactions11,196
 7,612
Right-of-use lease assets obtained in exchange for lessee operating lease liabilities315,542
 
9,892
 170,479

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 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 $29.3 million, as detailed in the table below. Operating results for periods after January 1, 2020 are presented in accordance with ASC 326 while prior period amounts continue to be reported in accordance with previously applicable standards and the accounting policies described in our 2019 Form 10-K.
The following table details the impact of the adoption of ASC 326 on the allowance for credit losses as of January 1, 2020.
 January 1, 2020
 Pre-Adoption Allowance Impact of Adoption Post-Adoption Allowance Cumulative Effect on Retained Earnings
Securities held to maturity:       
U.S. Treasury$
 $
 $
 $
Residential mortgage-backed securities
 
 
 
States and political subdivisions
 215
 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.

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 loan term. 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 (Topic 842 - Leases), primarily Accounting Standards Update (“ASU”) 2016-02 and subsequent updates. Among other things, these updates require lessees to recognize a lease liability, measured on a discounted basis, related to the lessee's obligation to make lease payments arising under a lease contract; and a right-of-use asset related to the lessee’s right to use, or control the useas of a specified asset for the lease term. The updates did not significantly change lease accounting requirements applicable to lessors and did not significantly impact our financial statements in relation to contracts whereby we act as a lessor. We adopted the updatesJanuary 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 January 1, 2019. We elected to apply certain practical adoption expedients provided under the updates whereby we did not reassess (i) whether any expired or existing contracts are or contain leases, (ii) the lease classification for any expired or existing leases and (iii) initial direct costs for any existing leases. We did not elect to apply the recognition requirements of the updates to any short-term leases (as discussed below). As of September 30, 2019, right-of-use lease assets and related lease liabilities totaled $299.5 million and $325.3 million, respectively. During the

second quarter of 2019, we recognized a right-of-use asset totaling $121.7 million and a related lease liability totaling $121.7 million in connection with the commencement of the lease of our new corporate headquarters facility in downtown San Antonio. See Note 6 - Commitments and Contingencies.
We lease certain office facilities and office equipment under operating leases. We also own certain office facilities which we lease to outside parties under operating lessor leases; however, such leases are not significant. We do not apply the recognition requirements of Topic 842 - Leases to short-term operating leases. A short-term operating lease has an original term of 12 months or less and does not have a purchase option that is likely to be exercised. For non-short-term operating leases, we recognized lease right-of-use assets and related lease liabilities on our balance sheet upon commencement of the lease in accordance with Topic 842 - Leases. In recognizing lease right-of-use assets and related lease liabilities, we account for lease and non-lease components (such as taxes, insurance, and common area maintenance costs) separately as such amounts are generally readily determinable under our lease contracts. Lease payments over the expected term are discounted using our incremental borrowing rate referenced to the Federal Home Loan Bank Secure Connect advance rates for borrowings of similar term. We also consider renewal and termination options in the determination of the term of the lease. If it is reasonably certain that a renewal or termination option will be exercised, the effects of such options are included in the determination of the expected lease term. Generally, we cannot be reasonably certain about whether or not we will renew a lease until such time the lease is within the last two years of the existing lease term. However, renewal options related to our regional headquarter facilities or operations centers are evaluated on a case-by-case basis, typically in advance of such time frame. When we are reasonably certain that a renewal option will be exercised, we measure/remeasure the right-of-use asset and related lease liability using the lease payments specified for the renewal period or, if such amounts are unspecified, we generally assume an increase (evaluated on a case-by-case basis in light of prevailing market conditions) in the lease payment over the final period of the existing lease term.
date. We also adopted ASU 2017-08 “Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20) - Premium Amortization on Purchased Callable Debt Securities” as of January 1, 2019. ASU 2017-08 shortensan accounting standard update which shortened 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 poolsas 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. Upon adoption,January 1, 2019 using a modified retrospective transition adoption approach weand recognized a cumulative effect reduction to retained earnings totaling$14.7 million. We previously reported a cumulative effect reduction of $12.6 million. During the third quarter of 2019, we retroactively corrected this amount and reduced retained earnings by an additional $2.1 million. All financial information related to prior periods has been revised to reflect this adjustment. We expect premium amortization expense for 2019 will be approximately $5.2 million higher than what would have been the case had we continued to amortize the affected securities to their respective maturity dates.

Note 2 - Securities
Securities.Securities - Held to Maturity. A summary of the amortized cost, and estimated fair value and allowance for credit losses related to securities held to maturity as of securities, excluding trading securities,March 31, 2020 and December 31, 2019 is presented below.
 September 30, 2019 December 31, 2018
 
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               
Residential mortgage-backed securities$2,472
 $25
 $2
 $2,495
 $2,737
 $8
 $85
 $2,660
States and political subdivisions1,016,866
 26,563
 
 1,043,429
 1,101,820
 11,525
 552
 1,112,793
Other1,500
 
 1
 1,499
 1,500
 
 
 1,500
Total$1,020,838
 $26,588
 $3
 $1,047,423
 $1,106,057
 $11,533
 $637
 $1,116,953
Available for Sale               
U.S. Treasury$2,806,802
 $20,725
 $1,731
 $2,825,796
 $3,455,417
 $1,772
 $29,500
 $3,427,689
Residential mortgage-backed securities2,198,466
 42,766
 780
 2,240,452
 823,208
 13,079
 6,547
 829,740
States and political subdivisions6,931,673
 380,113
 413
 7,311,373
 7,089,132
 70,760
 72,690
 7,087,202
Other42,825
 
 
 42,825
 42,690
 
 
 42,690
Total$11,979,766
 $443,604
 $2,924
 $12,420,446
 $11,410,447
 $85,611
 $108,737
 $11,387,321


 
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Estimated
Fair Value
 
Allowance
for Credit
Losses
 
Net
Carrying
Amount
March 31, 2020           
Residential mortgage-backed securities$530,396
 $37,234
 $
 $567,630
 $
 $530,396
States and political subdivisions1,452,453
 36,296
 
 1,488,749
 (200) 1,452,253
Other1,500
 
 
 1,500
 
 1,500
Total$1,984,349
 $73,530
 $
 $2,057,879
 $(200) $1,984,149
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. At September 30, 2019, approximately 99.7% of the securities in our municipal bond portfolio were issued by political subdivisions or agencies within the State of Texas, of which approximately 69.3% are either guaranteed by the Texas Permanent School Fund, which has a “triple A” insurer financial strength rating, or are secured by U.S. Treasury securities via defeasance of the debt by the issuers. Securities with limited marketability and that do not have readily determinable fair values are carried at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for identical or similar securities of the same issuer. These securities include stock in the Federal Reserve Bank and the Federal Home Loan Bank and are reported as other available for sale securities in the table above. 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 $3.6 billion$647.1 million and $561.4 million at September 30, 2019March 31, 2020 and $3.8 billion at December 31, 2018.2019, respectively. Accrued interest receivable on held-to-maturity securities totaled $12.1 million and $21.1 million at March 31, 2020 and December 31, 2019, respectively and is included in accrued interest receivable and other assets in the accompanying consolidated balance sheets.
During the fourth quarter of 2012,From time to time, we have reclassified certain securities from available for sale to held to maturity. TheDuring the fourth quarter of 2019, we reclassified securities hadwith an aggregate fair value of $2.3 billion with$377.8 million and an aggregate net unrealized gain of $165.7$3.3 million ($107.7 ($2.6 million,, net of tax) on the date of the transfer. The net unamortized, unrealized gain remaining on the remaining transferred securities, including those transferred in 2019 and in years prior, included in accumulated other comprehensive income in the accompanying balance sheet as of September 30, 2019 totaled $1.8$4.4 million ($1.43.5 million, net of tax). at March 31, 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.
Unrealized Losses. AsThe allowance for credit losses on held-to-maturity securities is a contra-asset valuation account that is deducted from the amortized cost basis of September 30, 2019,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 unrealizedeach 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 segregatedhas been recorded for these securities. With regard to securities issued by lengthStates 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 impairment, werethe 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 follows:of March 31, 2020:
 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$
 $
 $413
 $2
 $413
 $2
Other1,499
 1
 
 
 1,499
 1
Total$1,499
 $1
 $413
 $2
 $1,912
 $3
Available for Sale           
U.S. Treasury$
 $
 $1,722,158
 $1,731
 $1,722,158
 $1,731
Residential mortgage-backed securities49,657
 290
 44,458
 490
 94,115
 780
States and political subdivisions41,619
 413
 
 
 41,619
 413
Total$91,276
 $703
 $1,766,616
 $2,221
 $1,857,892
 $2,924
 States and Political Subdivisions  
 Not Guaranteed or Pre-Refunded Guaranteed by the Texas PSF Pre-Refunded Total 
Other
Securities
Aaa/AAA$131,760
 $849,396
 $284,678
 $1,265,834
 $
Aa/AA118,271
 
 
 118,271
 
A68,348
 
 
 68,348
 
Not rated
 
 
 
 1,500
Total$318,379
 $849,396
 $284,678
 $1,452,453
 $1,500

Declines
Historical loss rates associated with securities having similar grades as those in our portfolio have generally not been significant. Furthermore, as of March 31, 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 months ended March 31, 2020.
Beginning balance, prior to adoption of ASC 326$
Impact of adopting ASC 326215
Credit loss expense (benefit)(15)
Ending balance$200

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 held-to-maturityMarch 31, 2020 and December 31, 2019 is presented below.
 
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Allowance
for Credit
Losses
 
Estimated
Fair Value
March 31, 2020         
U.S. Treasury$1,117,523
 $49,741
 $
 $
 $1,167,264
Residential mortgage-backed securities2,009,523
 80,423
 
 
 2,089,946
States and political subdivisions6,785,079
 382,976
 189
 
 7,167,866
Other42,901
 
 
 
 42,901
Total$9,955,026
 $513,140
 $189
 $
 $10,467,977
          
December 31, 2019         
U.S. Treasury$1,941,283
 $18,934
 $12,084
 $
 $1,948,133
Residential mortgage-backed securities2,176,275
 32,608
 1,289
 
 2,207,594
States and political subdivisions6,717,344
 353,857
 204
 
 7,070,997
Other42,867
 
 
 
 42,867
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 March 31, 2020, nearly 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 70.8% are either guaranteed by the PSF or 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 $2.6 billion and $3.4 billion at March 31, 2020 and December 31, 2019, respectively. Accrued interest receivable on available-for-sale securities totaled $69.5 million and $115.9 million at March 31, 2020 and December 31, 2019, respectively and is included in accrued interest receivable and other assets in the accompanying consolidated balance sheets.
The table below their cost that are deemed to be other than temporary are reflectedsummarizes, as of March 31, 2020, securities available for sale in earnings as realizedan unrealized loss position for which an allowance for credit losses to the extent the impairment is related to credit losses. The amounthas not been recorded, aggregated by type 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) thesecurity and length of time and the extent to which the fair valuein a continuous unrealized loss position.
 Less than 12 Months More than 12 Months Total
 
Estimated
Fair Value
 
Unrealized
Losses
 
Estimated
Fair Value
 
Unrealized
Losses
 
Estimated
Fair Value
 
Unrealized
Losses
States and political subdivisions$67,949
 $189
 $
 $
 $67,949
 $189
Total$67,949
 $189
 $
 $
 $67,949
 $189


As of March 31, 2020, no allowance for credit losses has been less than cost, (ii) the financial condition and near-term prospectsrecognized on available for sale securities in an unrealized loss position as management does not believe any of the issuer,securities are impaired due to reasons of credit quality. This is based upon our analysis of the underlying risk characteristics, including credit ratings, and (iii)other qualitative factors (such as a PSF guarantee) related to our available for sale securities and 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 intent and our ability to retain our investment in the issuer for a periodcontractual terms 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, 2019, 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 of the securities are impaired due to reasons of credit quality. Accordingly, as of September 30, 2019, management believes the impairments detailed 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 valuefollowing table summarizes the maturity distribution schedule of securities excluding tradingheld to maturity and securities at September 30, 2019available for sale as of March 31, 2020. Mortgage-backed securities are presented below by contractual maturity.included in 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.
 Held to Maturity Available for Sale
 
Amortized
Cost
 
Estimated
Fair Value
 
Amortized
Cost
 
Estimated
Fair Value
Due in one year or less$25,254
 $25,418
 $1,882,023
 $1,881,435
Due after one year through five years166,412
 170,675
 1,328,841
 1,356,833
Due after five years through ten years530,808
 543,464
 453,192
 480,892
Due after ten years295,892
 305,371
 6,074,419
 6,418,009
Residential mortgage-backed securities2,472
 2,495
 2,198,466
 2,240,452
Equity securities
 
 42,825
 42,825
Total$1,020,838
 $1,047,423
 $11,979,766
 $12,420,446

 Within 1 Year 1 - 5 Years 5 - 10 Years After 10 Years Total
Held To Maturity         
Amortized Cost         
Residential mortgage-backed securities$
 $332
 $516,866
 $13,198
 $530,396
States and political subdivisions25,324
 170,386
 496,235
 760,508
 1,452,453
Other
 1,500
 
 
 1,500
Total$25,324
 $172,218
 $1,013,101
 $773,706
 $1,984,349
Estimated Fair Value         
Residential mortgage-backed securities$
 $335
 $553,409
 $13,886
 $567,630
States and political subdivisions25,579
 174,896
 507,221
 781,053
 1,488,749
Other
 1,500
 
 
 1,500
Total$25,579
 $176,731
 $1,060,630
 $794,939
 $2,057,879
Available For Sale         
Amortized Cost         
U. S. Treasury$33,964
 $1,083,559
 $
 $
 $1,117,523
Residential mortgage-backed securities236
 68,185
 5,859
 1,935,243
 2,009,523
States and political subdivisions250,489
 220,504
 648,416
 5,665,670
 6,785,079
Other
 
 
 
 42,901
Total$284,689
 $1,372,248
 $654,275
 $7,600,913
 $9,955,026
Estimated Fair Value         
U. S. Treasury$34,181
 $1,133,083
 $
 $
 $1,167,264
Residential mortgage-backed securities249
 70,834
 6,379
 2,012,484
 2,089,946
States and political subdivisions252,108
 231,285
 686,745
 5,997,728
 7,167,866
Other
 
 
 
 42,901
Total$286,538
 $1,435,202
 $693,124
 $8,010,212
 $10,467,977
Sales of Securities. Sales of securities available for sale were as follows:
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended 
 March 31,
2019 2018 2019 20182020 2019
Proceeds from sales$4,944,537
 $2,948,178
 $8,236,066
 $13,838,566
$1,111,102
 $944,903
Gross realized gains96
 
 899
 3
108,989
 
Gross realized losses
 (34) (634) (116)
 
Tax (expense) benefit of securities gains/losses(21) 7
 (56) 24
22,888
 


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,
Three Months Ended 
 March 31,
2019 2018 2019 20182020 2019
Premium amortization$(29,511) $(27,381) $(88,798) $(80,104)$(32,345) $(29,879)
Discount accretion1,274
 2,569
 3,835
 6,356
585
 1,183
Net (premium amortization) discount accretion$(28,237) $(24,812) $(84,963) $(73,748)$(31,760) $(28,696)

Trading Account Securities. Trading account securities, at estimated fair value, were as follows:
September 30,
2019
 December 31,
2018
March 31,
2020
 December 31,
2019
U.S. Treasury$23,747
 $21,928
$24,491
 $24,298
States and political subdivisions3,922
 2,158
1,430
 
Total$27,669
 $24,086
$25,921
 $24,298

Net gains and losses on trading account securities were as follows:
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended 
 March 31,
2019 2018 2019 20182020 2019
Net gain on sales transactions$731
 $465
 $1,789
 $1,404
$470
 $506
Net mark-to-market gains (losses)(201) (8) (170) (21)115
 4
Net gain (loss) on trading account securities$530
 $457
 $1,619
 $1,383
$585
 $510


Note 3 - Loans
Loans were as follows:
September 30,
2019
 
Percentage
of Total
 December 31,
2018
 
Percentage
of Total
March 31,
2020
 
Percentage
of Total
 December 31,
2019
 
Percentage
of Total
Commercial and industrial$5,179,780
 35.4% $5,111,957
 36.3%$5,536,760
 36.1% $5,187,466
 35.2%
Energy:              
Production1,282,180
 8.7
 1,309,314
 9.3
1,268,832
 8.3
 1,348,900
 9.2
Service189,350
 1.3
 168,775
 1.2
185,210
 1.2
 192,996
 1.3
Other75,388
 0.5
 124,509
 0.9
114,812
 0.7
 110,986
 0.8
Total energy1,546,918
 10.5
 1,602,598
 11.4
1,568,854
 10.2
 1,652,882
 11.2
Commercial real estate:              
Commercial mortgages4,555,171
 31.1
 4,121,966
 29.2
4,920,882
 32.1
 4,594,113
 31.1
Construction1,370,206
 9.4
 1,267,717
 9.0
1,265,441
 8.3
 1,312,659
 8.9
Land290,706
 2.0
 306,755
 2.2
286,876
 1.9
 289,467
 2.0
Total commercial real estate6,216,083
 42.5
 5,696,438
 40.4
6,473,199
 42.3
 6,196,239
 42.0
Consumer real estate:              
Home equity loans363,224
 2.5
 353,924
 2.5
389,844
 2.5
 375,596
 2.6
Home equity lines of credit350,461
 2.4
 337,168
 2.4
350,330
 2.3
 354,671
 2.4
Other458,618
 3.1
 427,898
 3.0
480,933
 3.1
 464,146
 3.1
Total consumer real estate1,172,303
 8.0
 1,118,990
 7.9
1,221,107
 7.9
 1,194,413
 8.1
Total real estate7,388,386
 50.5
 6,815,428
 48.3
7,694,306
 50.2
 7,390,652
 50.1
Consumer and other519,844
 3.6
 569,750
 4.0
538,340
 3.5
 519,332
 3.5
Total loans$14,634,928
 100.0% $14,099,733
 100.0%$15,338,260
 100.0% $14,750,332
 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, 2019,March 31, 2020, there were 0 concentrations of loans related to any single industry in excess of 10% of total loans other than energy loans, which totaled 10.5%10.2% of total loans. Unfunded commitments to extend credit and standby letters of credit issued to customers in the energy industry totaled $1.3$1.2 billion and $66.1$84.4 million, respectively, as of September 30, 2019.March 31, 2020.

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, 2019March 31, 2020 or December 31, 2018.2019.
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 $326.1 million at September 30, 2019March 31, 2020 and $256.1$298.5 million at December 31, 2018.2019.
Accrued Interest Receivable. Accrued interest receivable on loans totaled $42.3 million and $45.5 million at March 31, 2020 and December 31, 2019, respectively and is included in accrued interest receivable and other assets in the accompany consolidated balance sheets.
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:
 March 31, 2020 December 31, 2019
 Total Non-Accrual Non-Accrual with No Credit Loss Allowance Total Non-Accrual Non-Accrual with No Credit Loss Allowance
Commercial and industrial$23,913
 $11,085
 $26,038
 $13,266
Energy28,702
 28,702
 65,761
 3,281
Commercial real estate:       
Buildings, land and other8,224
 5,922
 8,912
 6,558
Construction3,774
 683
 665
 665
Consumer real estate2,094
 2,094
 922
 922
Consumer and other20
 1
 5
 
Total$66,727
 $48,487
 $102,303
 $24,692

The following table presents non-accrual loans as of March 31, 2020 by class and year of origination.
September 30,
2019
 December 31,
2018
2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Total
Commercial and industrial$13,929
 $9,239
$
 $3,187
 $9,012
 $2,448
 $384
 $146
 $4,601
 $4,135
 $23,913
Energy70,883
 46,932

 
 
 
 
 
 3,035
 25,667
 28,702
Commercial real estate:                    
Buildings, land and other9,240
 15,268

 2,207
 34
 1,470
 306
 3,639
 568
 
 8,224
Construction697
 

 3,774
 
 
 
 
 
 
 3,774
Consumer real estate527
 892

 
 
 211
 350
 628
 844
 61
 2,094
Consumer and other2,170
 1,408

 1
 
 
 
 
 19
 
 20
Total$97,446
 $73,739
$
 $9,169
 $9,046
 $4,129
 $1,040
 $4,413
 $9,067
 $29,863
 $66,727

Had non-accrual loans performed in accordance with their original contract terms, we would have recognized additional interest income, net of tax, of approximately $0.9 million and $3.0$1.0 million for the three and nine months ended September 30, 2019, compared to $1.3 millionMarch 31, 2020, and $4.2approximately $1.0 million for the three and nine months ended September 30, 2018.March 31, 2019.

An age analysis of past due loans (including both accruing and non-accruing loans), segregated by class of loans, as of September 30, 2019March 31, 2020 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
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$39,540
 $13,622
 $53,162
 $5,126,618
 $5,179,780
 $3,574
$38,518
 $24,217
 $62,735
 $5,474,025
 $5,536,760
 $8,343
Energy3,350
 21,836
 25,186
 1,521,732
 1,546,918
 530
23,913
 25,667
 49,580
 1,519,274
 1,568,854
 
Commercial real estate:                      
Buildings, land and other29,147
 8,279
 37,426
 4,808,451
 4,845,877
 6,513
39,359
 3,472
 42,831
 5,164,927
 5,207,758
 817
Construction1,412
 1,471
 2,883
 1,367,323
 1,370,206
 774
4,701
 127
 4,828
 1,260,613
 1,265,441
 127
Consumer real estate8,305
 2,443
 10,748
 1,161,555
 1,172,303
 2,150
9,542
 3,230
 12,772
 1,208,335
 1,221,107
 1,572
Consumer and other7,815
 2,419
 10,234
 509,610
 519,844
 855
6,134
 1,013
 7,147
 531,193
 538,340
 1,013
Total$89,569
 $50,070
 $139,639
 $14,495,289
 $14,634,928
 $14,396
$122,167
 $57,726
 $179,893
 $15,158,367
 $15,338,260
 $11,872

Impaired Loans. Impaired loans are set forth in the following table. NaN 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, 2019         
Commercial and industrial$15,020
 $4,874
 $7,280
 $12,154
 $5,785
Energy88,531
 4,777
 65,800
 70,577
 19,722
Commercial real estate:      
  
Buildings, land and other9,553
 3,864
 5,015
 8,879
 1,483
Construction697
 697
 
 697
 
Consumer real estate293
 293
 
 293
 
Consumer and other2,171
 
 2,170
 2,170
 2,170
Total$116,265
 $14,505
 $80,265
 $94,770
 $29,160
December 31, 2018         
Commercial and industrial$9,094
 $2,842
 $4,287
 $7,129
 $2,558
Energy67,900
 6,817
 39,890
 46,707
 9,671
Commercial real estate:         
Buildings, land and other15,774
 2,168
 12,517
 14,685
 2,599
Construction
 
 
 
 
Consumer real estate293
 293
 
 293
 
Consumer and other1,475
 
 1,407
 1,407
 1,407
Total$94,536
 $12,120
 $58,101
 $70,221
 $16,235

The average recorded investment in impaired loans was as follows:
 Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
 2019 2018 2019
2018
Commercial and industrial$14,438
 $13,447
 $12,552
 $21,025
Energy55,195
 78,772
 50,642
 82,640
Commercial real estate:       
Buildings, land and other9,418
 14,306
 14,961
 12,328
Construction349
 
 277
 
Consumer real estate293
 671
 541
 807
Consumer and other1,795
 1,073
 1,605
 805
Total$81,488
 $108,269
 $80,578
 $117,605


Troubled Debt Restructurings. Troubled debt restructurings during the ninethree months ended September 30,March 31, 2020 and March 31, 2019 and September 30, 2018 are set forth in the following table.
Nine Months Ended 
 September 30, 2019
 Nine Months Ended 
 September 30, 2018
Three Months Ended 
 March 31, 2020
 Three Months Ended 
 March 31, 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$3,845
 $2,188
 $2,203
 $
$2,191
 $2,198
 $307
 $293
Energy
 
 13,708
 
Commercial real estate:              
Buildings, land and other9,456
 9,494
 
 

 
 5,901
 5,898
Consumer real estate124
 123
 
 
$13,425
 $11,805
 $15,911
 $
$2,191
 $2,198
 $6,208
 $6,191

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.credit losses on loans.
Additional information related to restructured loans as of or for the three months ended September 30,March 31, 2020 and March 31, 2019 and September 30, 2018 is set forth in the following table.
September 30, 2019 September 30, 2018March 31, 2020 March 31, 2019
Restructured loans past due in excess of 90 days at period-end:      
Number of loans4
 
3
 4
Dollar amount of loans$3,244
 $
$1,733
 $2,367
Restructured loans on non-accrual status at period end5,645
 
2,198
 2,162
Charge-offs of restructured loans:      
Recognized in connection with restructuring1,500
 

 
Recognized on previously restructured loans
 4,650
1,533
 
Proceeds from sale of restructured loans
 15,750
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. 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).
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 20182019 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 March 31, 2020.
September 30, 2019 December 31, 20182020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Total W/A Risk Grade
Weighted
Average
Risk Grade
 Loans Weighted
Average
Risk Grade
 Loans
Commercial and industrial:       
Commercial and industrial                   
Risk grades 1-86.19
 $4,856,712
 6.12
 $4,862,275
$765,088
 $813,141
 $433,145
 $333,114
 $168,744
 $143,770
 $2,362,308
 $47,080
 $5,066,390
 6.14
Risk grade 99.00
 165,195
 9.00
 112,431
15,539
 34,847
 51,906
 14,167
 7,700
 10,993
 127,148
 6,267
 268,567
 9.00
Risk grade 1010.00
 75,276
 10.00
 58,328
21,815
 10,918
 13,042
 7,237
 6,670
 3,377
 74,625
 679
 138,363
 10.00
Risk grade 1111.00
 68,668
 11.00
 69,684
45
 5,853
 2,276
 3,149
 922
 661
 17,664
 8,957
 39,527
 11.00
Risk grade 1212.00
 8,144
 12.00
 6,681

 536
 7,179
 1,432
 384
 146
 2,520
 2,512
 14,709
 12.00
Risk grade 1313.00
 5,785
 13.00
 2,558

 2,651
 1,833
 1,016
 
 
 2,081
 1,623
 9,204
 13.00
Total6.42
 $5,179,780
 6.30
 $5,111,957
$802,487
 $867,946
 $509,381
 $360,115
 $184,420
 $158,947
 $2,586,346
 $67,118
 $5,536,760
 6.44
W/A Risk grade5.75
 6.69
 7.12
 6.18
 6.24
 6.10
 6.46
 7.89
 6.44
  
Energy                          
Risk grades 1-85.85
 $1,379,566
 5.76
 $1,451,673
$585,655
 $95,004
 $22,101
 $11,048
 $3,187
 $5,514
 $665,347
 $9,642
 $1,397,498
 6.33
Risk grade 99.00
 80,170
 9.00
 35,565
215
 2,105
 999
 587
 
 
 25,658
 46
 29,610
 9.00
Risk grade 1010.00
 1,105
 10.00
 43,001

 669
 
 
 
 47
 10,250
 
 10,966
 10.00
Risk grade 1111.00
 15,194
 11.00
 25,427
62,509
 325
 941
 300
 8
 770
 36,105
 1,120
 102,078
 11.00
Risk grade 1212.00
 51,161
 12.00
 37,261

 
 
 
 
 
 3,035
 25,667
 28,702
 12.00
Risk grade 1313.00
 19,722
 13.00
 9,671

 
 
 
 
 
 
 
 
 13.00
Total6.36
 $1,546,918
 6.22
 $1,602,598
$648,379
 $98,103
 $24,041
 $11,935
 $3,195
 $6,331
 $740,395
 $36,475
 $1,568,854
 6.81
W/A Risk grade6.89
 7.21
 7.25
 7.34
 6.60
 7.48
 6.48
 10.69
 6.81
  
Commercial real estate:  
                       
Buildings, land and other       
Buildings, land, other                   
Risk grades 1-86.78
 $4,528,963
 6.76
 $4,143,264
$503,028
 $1,080,494
 $780,270
 $745,352
 $518,981
 $909,275
 $83,274
 $59,064
 $4,679,738
 6.89
Risk grade 99.00
 117,739
 9.00
 109,660
1,872
 89,718
 41,520
 79,696
 55,037
 59,672
 400
 264
 328,179
 9.00
Risk grade 1010.00
 97,083
 10.00
 62,353

 14,619
 500
 20,394
 26,200
 58,297
 632
 
 120,642
 10.00
Risk grade 1111.00
 92,852
 11.00
 98,176
249
 11,275
 1,789
 31,201
 8,235
 16,135
 100
 1,991
 70,975
 11.00
Risk grade 1212.00
 7,757
 12.00
 12,669

 2,207
 34
 1,470
 306
 3,389
 505
 
 7,911
 12.00
Risk grade 1313.00
 1,483
 13.00
 2,599

 
 
 
 
 250
 63
 
 313
 13.00
Total6.99
 $4,845,877
 6.98
 $4,428,721
$505,149
 $1,198,313
 $824,113
 $878,113
 $608,759
 $1,047,018
 $84,974
 $61,319
 $5,207,758
 7.16
W/A Risk grade6.97
 7.19
 7.08
 7.32
 7.37
 7.04
 7.03
 6.84
 7.16
  
Construction                          
Risk grades 1-87.19
 $1,314,076
 7.13
 $1,177,260
$115,476
 $374,393
 $456,568
 $105,160
 $1,196
 $17,193
 $144,922
 $
 $1,214,908
 7.15
Risk grade 99.00
 31,506
 9.00
 60,754
406
 14,003
 3,500
 2,919
 6,984
 
 127
 
 27,939
 9.00
Risk grade 1010.00
 21,686
 10.00
 24,877
12,991
 2,744
 
 917
 
 
 
 
 16,652
 10.00
Risk grade 1111.00
 2,241
 11.00
 4,826
1,192
 
 
 
 
 976
 
 
 2,168
 11.00
Risk grade 1212.00
 697
 12.00
 

 683
 
 
 
 
 
 
 683
 12.00
Risk grade 1313.00
 
 13.00
 

 3,091
 
 
 
 
 
 
 3,091
 13.00
Total7.28
 $1,370,206
 7.29
 $1,267,717
$130,065
 $394,914
 $460,068
 $108,996
 $8,180
 $18,169
 $145,049
 $
 $1,265,441
 7.25
W/A Risk grade7.59
 7.24
 7.24
 7.54
 8.71
 6.31
 6.84
 
 7.25
  
Total commercial real estate$635,214
 $1,593,227
 $1,284,181
 $987,109
 $616,939
 $1,065,187
 $230,023
 $61,319
 $6,473,199
 7.18
W/A Risk grade7.10
 7.21
 7.14
 7.35
 7.38
 7.02
 6.91
 6.84
 7.18
  

Net (charge-offs)/recoveries,In the table above, energy loans include $62.5 million related to 2020 originations/renewals that have a risk grade of 11. Of this amount, $50.9 million related to the renewal of a loan that was first originated in 2017 and $11.5 million related to the renewal of a loan that was first originated in 2016.

The following tables present weighted average risk grades for all commercial loans by class as of December 31, 2019.
 Commercial and Industrial Energy Commercial Real Estate - Buildings, Land and Other Commercial Real Estate - Construction Total Commercial Real Estate
 W/A Risk Grade Loans W/A Risk Grade Loans W/A Risk Grade Loans W/A Risk Grade Loans W/A Risk Grade Loans
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

Information about the payment status of consumer loans, segregated by classportfolio segment and year of origination, as of March 31, 2020 was as follows:
 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Total
Consumer real estate:                 
Past due 30-89 days$
 $623
 $771
 $1,490
 $763
 $3,575
 $1,206
 $1,114
 $9,542
Past due 90 or more days
 
 512
 108
 386
 1,000
 1,224
 
 3,230
Total past due
 623
 1,283
 1,598
 1,149
 4,575
 2,430
 1,114
 12,772
Current loans65,082
 217,726
 142,566
 122,282
 93,385
 180,883
 367,149
 19,262
 1,208,335
Total$65,082
 $218,349
 $143,849
 $123,880
 $94,534
 $185,458
 $369,579
 $20,376
 $1,221,107
Consumer and other:                 
Past due 30-89 days$1,414
 $801
 $263
 $151
 $102
 $23
 $3,380
 $
 $6,134
Past due 90 or more days
 902
 
 
 
 
 111
 
 1,013
Total past due1,414
 1,703
 263
 151
 102
 23
 3,491
 
 7,147
Current loans19,780
 44,825
 14,699
 4,329
 2,762
 1,490
 420,517
 22,791
 531,193
Total$21,194
 $46,528
 $14,962
 $4,480
 $2,864
 $1,513
 $424,008
 $22,791
 $538,340

Revolving loans that converted to term during the three months ended March 31, 2020 were as follows:
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
2019 2018 2019 2018
Commercial and industrial$(1,520) $(7,807) $(5,912) $(19,030)$11,346
Energy(1,260) (5,347) (3,184) (10,272)15,353
Commercial real estate:        
Buildings, land and other38
 33
 (466) (288)7,639
Construction8
 3
 14
 11

Consumer real estate(103) (388) (2,078) (1,078)1,071
Consumer and other(3,534) (1,792) (9,351) (4,975)
Total$(6,371) $(15,298) $(20,977) $(35,632)$35,409


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 20182019 Form 10-K, totaled 128.1111.8 at September 30, 2019March 31, 2020 (most recent date available) and 126.4127.9 at December 31, 2018.2019. A higher TLI value implies more 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.
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 2018 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.
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 external 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 credit losses on loans segregated by loan portfolio segment as of March 31, 2020, calculated in accordance with the CECL methodology described above.
 
Commercial
and
Industrial
 Energy 
Commercial
Real Estate
 
Consumer
Real Estate
 
Consumer
and Other
 Total
Modeled expected credit losses$69,446
 $15,425
 $34,941
 $6,974
 $6,950
 $133,736
Q-Factor adjustments13,501
 87,776
 13,974
 1,196
 1,070
 117,517
Specific allocations9,205
 
 3,404
 
 19
 12,628
Total$92,152
 $103,201
 $52,319
 $8,170
 $8,039
 $263,881

The following table presents details of the allowance for loancredit losses allocated to eachon loans segregated by loan portfolio segment as of September 30, 2019 and December 31, 2018 and detailed on the basis of the impairment evaluation2019, calculated in accordance with our prior incurred loss methodology we used:described in our 2019 Form 10-K.
Commercial
and
Industrial
 Energy 
Commercial
Real Estate
 
Consumer
Real Estate
 
Consumer
and Other
 Total
Commercial
and
Industrial
 Energy 
Commercial
Real Estate
 
Consumer
Real Estate
 
Consumer
and Other
 Total
September 30, 2019           
December 31, 2019           
Historical valuation allowances$28,872
 $7,422
 $22,051
 $2,641
 $7,545
 $68,531
$29,015
 $7,873
 $21,947
 $2,690
 $7,562
 $69,087
Specific valuation allowances5,785
 19,722
 1,483
 
 2,170
 29,160
7,849
 20,246
 383
 
 5
 28,483
General valuation allowances10,866
 4,120
 4,349
 1,172
 (325) 20,182
9,840
 5,196
 4,201
 904
 (409) 19,732
Macroeconomic valuation allowances7,144
 2,082
 7,470
 1,071
 919
 18,686
4,889
 4,067
 4,506
 519
 884
 14,865
Total$52,667
 $33,346
 $35,353
 $4,884
 $10,309
 $136,559
$51,593
 $37,382
 $31,037
 $4,113
 $8,042
 $132,167
Allocated to loans:           
Individually evaluated$5,785
 $19,722
 $1,483
 $
 $2,170
 $29,160
Collectively evaluated46,882
 13,624
 33,870
 4,884
 8,139
 107,399
Total$52,667
 $33,346
 $35,353
 $4,884
 $10,309
 $136,559
December 31, 2018           
Historical valuation allowances$25,351
 $9,697
 $20,817
 $2,688
 $6,845
 $65,398
Specific valuation allowances2,558
 9,671
 2,599
 
 1,407
 16,235
General valuation allowances10,062
 6,014
 4,366
 1,671
 (13) 22,100
Macroeconomic valuation allowances10,609
 3,670
 10,995
 1,744
 1,381
 28,399
Total$48,580
 $29,052
 $38,777
 $6,103
 $9,620
 $132,132
Allocated to loans:           
Individually evaluated$2,558
 $9,671
 $2,599
 $
 $1,407
 $16,235
Collectively evaluated46,022
 19,381
 36,178
 6,103
 8,213
 115,897
Total$48,580
 $29,052
 $38,777
 $6,103
 $9,620
 $132,132


Our recorded investment in loans as of September 30, 2019 and December 31, 2018 related to each balance in the allowance for loan losses by portfolio segment and detailed on the basis of the impairment methodology we used was as follows:
 
Commercial
and
Industrial
 Energy Commercial
Real Estate
 Consumer
Real Estate
 Consumer
and Other
 Total
September 30, 2019           
Individually evaluated$12,154
 $70,577
 $9,576
 $293
 $2,170
 $94,770
Collectively evaluated5,167,626
 1,476,341
 6,206,507
 1,172,010
 517,674
 14,540,158
Total$5,179,780
 $1,546,918
 $6,216,083
 $1,172,303
 $519,844
 $14,634,928
December 31, 2018           
Individually evaluated$7,129
 $46,707
 $14,685
 $293
 $1,407
 $70,221
Collectively evaluated5,104,828
 1,555,891
 5,681,753
 1,118,697
 568,343
 14,029,512
Total$5,111,957
 $1,602,598
 $5,696,438
 $1,118,990
 $569,750
 $14,099,733

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, 2019March 31, 2020 and 2018.2019. Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories.
 
Commercial
and
Industrial
 Energy 
Commercial
Real Estate
 
Consumer
Real Estate
 
Consumer
and Other
 Total
March 31, 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 expense21,950
 110,006
 34,761
 1,570
 4,638
 172,925
Charge-offs(4,369) (33,800) (73) (285) (5,005) (43,532)
Recoveries1,715
 66
 113
 380
 2,612
 4,886
Net charge-offs(2,654) (33,734) 40
 95
 (2,393) (38,646)
Ending balance$92,152
 $103,201
 $52,319
 $8,170
 $8,039
 $263,881
March 31, 2019           
Beginning balance$48,580
 $29,052
 $38,777
 $6,103
 $9,620
 $132,132
Credit loss expense11,929
 (3,756) (2,352) 1,247
 3,935
 11,003
Charge-offs(2,688) 
 (60) (1,778) (5,697) (10,223)
Recoveries750
 47
 90
 89
 2,462
 3,438
Net charge-offs(1,938) 47
 30
 (1,689) (3,235) (6,785)
Ending balance$58,571
 $25,343
 $36,455
 $5,661
 $10,320
 $136,350

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 March 31, 2020 and December 31, 2019.
 
Commercial
and
Industrial
 Energy 
Commercial
Real Estate
 
Consumer
Real Estate
 
Consumer
and Other
 Total
Three months ended:           
September 30, 2019           
Beginning balance$57,714
 $25,818
 $35,914
 $5,637
 $9,846
 $134,929
Provision for loan losses(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
September 30, 2018           
Beginning balance$57,713
 $37,313
 $38,918
 $6,336
 $9,946
 $150,226
Provision for loan losses1,085
 (521) 250
 246
 1,590
 2,650
Charge-offs(8,491) (5,400) 
 (431) (4,274) (18,596)
Recoveries684
 53
 36
 43
 2,482
 3,298
Net charge-offs(7,807) (5,347) 36
 (388) (1,792) (15,298)
Ending balance$50,991
 $31,445
 $39,204
 $6,194
 $9,744
 $137,578
            
Nine months ended:           
September 30, 2019           
Beginning balance$48,580
 $29,052
 $38,777
 $6,103
 $9,620
 $132,132
Provision for loan losses9,999
 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
September 30, 2018           
Beginning balance$59,614
 $51,528
 $30,948
 $5,657
 $7,617
 $155,364
Provision for loan losses10,407
 (9,811) 8,533
 1,615
 7,102
 17,846
Charge-offs(21,896) (10,939) (619) (1,632) (12,240) (47,326)
Recoveries2,866
 667
 342
 554
 7,265
 11,694
Net charge-offs(19,030) (10,272) (277) (1,078) (4,975) (35,632)
Ending balance$50,991
 $31,445
 $39,204
 $6,194
 $9,744
 $137,578
 March 31, 2020 December 31, 2019
Loan
Balance
 Specific Allocations 
Loan
Balance
 Specific Allocations
Commercial and industrial$21,925
 $9,205
 $24,360
 $7,849
Energy28,330
 
 65,244
 20,246
Commercial real estate11,669
 3,404
 9,274
 383
Consumer real estate1,423
 
 570
 
Consumer and other20
 19
 5
 5
Total$63,367
 $12,628
 $99,453
 $28,483


Note 4 - Goodwill and Other Intangible Assets
Goodwill and other intangible assets are presented in the table below. As of March 31, 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,
2019
 December 31,
2018
March 31,
2020
 December 31,
2019
Goodwill$654,952
 $654,952
$654,952
 $654,952
Other intangible assets:      
Core deposits$2,254
 $2,959
$1,832
 $2,043
Customer relationships491
 672
392
 438
Non-compete agreements
 18
$2,745
 $3,649
$2,224
 $2,481
The estimated aggregate future amortization expense for intangible assets remaining as of September 30, 2019March 31, 2020 is as follows:
Remainder of 2019$263
2020919
Remainder of 2020$661
2021697
697
2022481
481
2023283
282
202487
Thereafter102
16
$2,745
$2,224

Note 5 - Deposits
Deposits were as follows:
September 30,
2019
 
Percentage
of Total
 December 31,
2018
 
Percentage
of Total
March 31,
2020
 
Percentage
of Total
 December 31,
2019
 
Percentage
of Total
Non-interest-bearing demand deposits:          
Commercial and individual$10,070,621
 37.2% $10,305,850
 37.9%$10,524,338
 37.4% $10,212,265
 36.9%
Correspondent banks258,981
 1.0
 235,748
 0.9
221,761
 0.8
 246,181
 0.9
Public funds420,642
 1.5
 455,896
 1.7
456,109
 1.6
 415,183
 1.5
Total non-interest-bearing demand deposits10,750,244
 39.7
 10,997,494
 40.5
11,202,208
 39.8
 10,873,629
 39.3
Interest-bearing deposits:              
Private accounts:              
Savings and interest checking6,741,340
 24.9
 6,977,813
 25.7
7,240,821
 25.7
 7,147,327
 25.9
Money market accounts7,960,223
 29.4
 7,777,470
 28.6
7,995,061
 28.4
 7,888,433
 28.5
Time accounts of $100,000 or more707,657
 2.6
 526,789
 2.0
773,373
 2.8
 736,481
 2.7
Time accounts under $100,000346,440
 1.3
 331,511
 1.2
347,349
 1.2
 347,418
 1.2
Total private accounts15,755,660
 58.2
 15,613,583
 57.5
16,356,604
 58.1
 16,119,659
 58.3
Public funds:              
Savings and interest checking483,303
 1.8
 473,754
 1.8
479,629
 1.7
 548,399
 2.0
Money market accounts68,321
 0.2
 59,953
 0.2
78,899
 0.3
 73,180
 0.3
Time accounts of $100,000 or more25,922
 0.1
 4,332
 
23,502
 0.1
 24,672
 0.1
Time accounts under $100,000132
 
 88
 
25
 
 25
 
Total public funds577,678
 2.1
 538,127
 2.0
582,055
 2.1
 646,276
 2.4
Total interest-bearing deposits16,333,338
 60.3
 16,151,710
 59.5
16,938,659
 60.2
 16,765,935
 60.7
Total deposits$27,083,582
 100.0% $27,149,204
 100.0%$28,140,867
 100.0% $27,639,564
 100.0%


The following table presents additional information about our deposits:
September 30,
2019
 December 31,
2018
March 31,
2020
 December 31,
2019
Deposits from the Certificate of Deposit Account Registry Service (CDARS) deposits$358
 $
$364
 $361
Deposits from foreign sources (primarily Mexico)776,490
 752,658
787,331
 805,828
Deposits not covered by deposit insurance12,681,664
 13,111,210
13,592,104
 13,115,796


Note 6 - 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 20182019 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,
2019
 December 31,
2018
March 31,
2020
 December 31,
2019
Commitments to extend credit$9,036,441
 $8,369,721
$9,204,873
 $9,306,043
Standby letters of credit283,821
 271,575
268,202
 260,587
Deferred standby letter of credit fees1,547
 2,069
1,773
 1,276

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 commitments.
 Three Months Ended 
 March 31,
 2020 2019
Beginning balance, prior to adoption of ASC 326$500
 $500
Impact of adopting ASC 32639,377
 
Credit loss expense2,287
 
Ending balance$42,164
 $500

Lease Commitments. We lease certain office facilities and office equipment under operating leases. RentThe components of total lease expense for all operating leaseswere as follows:
 Three Months Ended 
 March 31,
 2020 2019
Amortization of lease right-of-use assets$7,874
 $5,796
Short-term lease expense561
 1,079
Non-lease components (including taxes, insurance, common maintenance, etc.)2,927
 1,733
Total$11,362
 $8,608

Right-of-use lease assets totaled $11.7$302.0 million at March 31, 2020 and $30.0$297.7 million during the three and nine months ended September 30,at December 31, 2019 and $8.1 millionare reported as a component of premises and $24.4 million during the three and nine months ended September 30, 2018. On January 1, 2019, we adopted a new accounting standard which required the recognition of our operating leasesequipment on our accompanying consolidated balance sheet. See Note 1 - Significant Accounting Policies. As of September 30, 2019, right-of-use lease assets andsheets. The related lease liabilities totaled $299.5$331.5 million at March 31, 2020 and $325.3$323.7 million respectively,at December 31, 2019 and are included with premises and equipment andreported as a component of accrued interest payable and other liabilities respectively, on ourin the accompanying consolidated balance sheet. During the second quarter of 2019, we recognized a right-of-use asset totaling $121.7sheets. Lease payments under operating leases that were applied to our operating lease liability totaled $7.7 million and a related lease liability totaling $121.7$6.0 million in connection withduring the commencement of the lease of our new corporate headquarters facility in downtown San Antonio.three months March 31, 2020 and 2019, respectively. There has been no0 significant change in our expected future minimum lease payments since December 31, 2018.2019. See the 20182019 Form 10-K for information regarding these commitments.
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.

Note 7 - 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, 2019 and December 31, 2018 includes $144.5 million of 5.375% non-cumulative perpetual preferred stock. Frost Bank did not have any additional Tier 1 capital beyond Common Equity Tier 1 at September 30, 2019 orMarch 31, 2020. For Cullen/Frost, additional Tier 1 capital at December 31, 2018.2019 included $144.5 million of 5.375% non-cumulative perpetual preferred stock. This preferred stock was redeemed during the first quarter of 2020, as further discussed below. Frost Bank did not 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 and $133.0 million of trust preferred securities at both September 30, 2019March 31, 2020 and December 31, 2018.2019.
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 $63.4 million has been added back to CET1 as of March 31, 2020. The CECL transitional amount includes $29.3 million related to cumulative effect of adopting CECL and $34.1 million related to the estimated incremental effect of CECL during the three months ended March 31, 2020.

The following tables present actual and required capital ratios as of September 30, 2019March 31, 2020 and December 31, 20182019 for Cullen/Frost and Frost Bank under the Basel III Capital Rules. The Basel III Capital Rules became fully phased-in on January 1, 2019. The minimum required capital amounts presented as of December 31, 2018 include the minimum required capital levels applicable as of that date as well as the minimum required capital levels as of January 1, 2019 when the Basel III Capital Rules became 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 20182019 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, 20182019 have been revised to reflect these reclassifications.
 Actual Minimum Capital Required - Basel III Required to be
Considered Well
Capitalized
 Capital
Amount
 Ratio Capital
Amount
 Ratio Capital
Amount
 Ratio
September 30, 2019           
Common Equity Tier 1 to Risk-Weighted Assets           
Cullen/Frost$2,788,313
 12.35% $1,580,199
 7.00% $1,467,328
 6.50%
Frost Bank2,910,446
 12.92
 1,576,393
 7.00
 1,463,794
 6.50
Tier 1 Capital to Risk-Weighted Assets           
Cullen/Frost2,932,799
 12.99
 1,918,813
 8.50
 1,805,942
 8.00
Frost Bank2,910,446
 12.92
 1,914,192
 8.50
 1,801,593
 8.00
Total Capital to Risk-Weighted Assets           
Cullen/Frost3,302,858
 14.63
 2,370,298
 10.50
 2,257,427
 10.00
Frost Bank3,047,505
 13.53
 2,364,590
 10.50
 2,251,991
 10.00
Leverage Ratio           
Cullen/Frost2,932,798
 9.36
 1,252,781
 4.00
 1,565,976
 5.00
Frost Bank2,910,446
 9.30
 1,251,713
 4.00
 1,564,642
 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
Actual Minimum Capital Required - Basel III Required to be
Considered Well
Capitalized
Capital
Amount
 Ratio Capital
Amount
 Ratio Capital
Amount
 Ratio Capital
Amount
 RatioCapital
Amount
 Ratio Capital
Amount
 Ratio Capital
Amount
 Ratio
December 31, 2018               
March 31, 2020           
Common Equity Tier 1 to Risk-Weighted Assets                          
Cullen/Frost$2,642,475
 12.27% $1,372,573
 6.375% $1,507,139
 7.00% $1,358,171
 6.50%$2,884,385
 12.02% $1,679,810
 7.00% $1,559,824
 6.50%
Frost Bank2,743,973
 12.78
 1,368,701
 6.375
 1,502,887
 7.00
 1,354,222
 6.50
2,924,082
 12.21
 1,676,269
 7.00
 1,556,535
 6.50
Tier 1 Capital to Risk-Weighted Assets                          
Cullen/Frost2,786,961
 12.94
 1,695,532
 7.875
 1,830,098
 8.50
 1,671,595
 8.00
2,884,385
 12.02
 2,039,770
 8.50
 1,919,783
 8.00
Frost Bank2,743,973
 12.78
 1,690,748
 7.875
 1,824,934
 8.50
 1,666,735
 8.00
2,924,082
 12.21
 2,035,469
 8.50
 1,915,736
 8.00
Total Capital to Risk-Weighted Assets                          
Cullen/Frost3,152,593
 14.64
 2,126,143
 9.875
 2,260,709
 10.50
 2,089,494
 10.00
3,352,464
 13.97
 2,519,715
 10.50
 2,399,729
 10.00
Frost Bank2,876,605
 13.40
 2,120,144
 9.875
 2,254,331
 10.50
 2,083,419
 10.00
3,159,161
 13.19
 2,514,403
 10.50
 2,394,670
 10.00
Leverage Ratio                          
Cullen/Frost2,786,961
 9.06
 1,231,028
 4.00
 1,231,028
 4.00
 1,538,785
 5.00
2,884,385
 8.84
 1,305,429
 4.00
 1,631,786
 5.00
Frost Bank2,743,973
 8.93
 1,229,650
 4.00
 1,229,650
 4.00
 1,537,062
 5.00
2,924,082
 8.97
 1,304,257
 4.00
 1,630,322
 5.00

December 31, 2019           
Common Equity Tier 1 to Risk-Weighted Assets           
Cullen/Frost$2,857,250
 12.36% $1,617,886
 7.00% $1,502,323
 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           
Cullen/Frost3,001,736
 12.99
 1,964,576
 8.50
 1,849,013
 8.00
Frost Bank2,958,326
 12.82
 1,961,322
 8.50
 1,845,950
 8.00
Total Capital to Risk-Weighted Assets           
Cullen/Frost3,367,403
 14.57
 2,426,829
 10.50
 2,311,266
 10.00
Frost Bank3,090,993
 13.40
 2,422,809
 10.50
 2,307,438
 10.00
Leverage Ratio           
Cullen/Frost3,001,736
 9.28
 1,293,188
 4.00
 1,616,485
 5.00
Frost Bank2,958,326
 9.15
 1,292,743
 4.00
 1,615,929
 5.00
As of September 30, 2019,March 31, 2020, capital levels at Cullen/Frost and Frost Bank exceed all capital adequacy requirements under the fully phased-in Basel III Capital Rules. Based on the ratios presented above, capital levels as of September 30, 2019March 31, 2020 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, 2019March 31, 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

awards. On October 24, 2017, our board of directors authorized a $150.0 million stock repurchase program, allowing us to repurchase shares of our common stock over a two-year period from time to time at various prices in the open market or through private transactions. We repurchased 496,307 shares at a total cost of $50.0 million under this plan during the second quarter of 2019 and 1,027,292 shares at a total cost of $100.0 million during the fourth quarter of 2018. On 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 one-year period from time to time at various prices in the open market or through private transactions. WeUnder this plan, we repurchased 177,834 shares at a total cost of $13.7 million during the first quarter of 2020 and 202,724 shares at a total cost of $17.2 million under this plan during the third quarter of 2019. Under the Basel III Capital Rules, Cullen/Frost may not repurchase or redeem any of its preferred stock or 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, 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, 2019,March 31, 2020, Frost Bank could pay aggregate dividends of up to $633.8$395.9 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 8 - 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 20182019 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. 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 0 as of September 30, 2019March 31, 2020 and December 31, 2018.2019.
September 30, 2019 December 31, 2018March 31, 2020 December 31, 2019
Notional
Amount
 
Estimated
Fair Value
 
Notional
Amount
 
Estimated
Fair Value
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$5,583
 $15
 $10,941
 $207
$
 $
 $2,545
 $6
Loan/lease interest rate swaps – liabilities6,356
 (179) 3,885
 (199)4,732
 (219) 6,000
 (138)
Non-hedging interest rate derivatives:              
Financial institution counterparties:              
Loan/lease interest rate swaps – assets94,855
 65
 496,887
 2,384

 
 122,788
 67
Loan/lease interest rate swaps – liabilities1,008,173
 (24,268) 691,143
 (8,921)1,191,926
 (37,403) 1,002,860
 (19,483)
Loan/lease interest rate caps – assets102,634
 233
 122,791
 509
155,597
 682
 107,835
 266
Customer counterparties:              
Loan/lease interest rate swaps – assets1,008,173
 55,529
 691,143
 16,706
1,191,926
 97,232
 1,002,860
 43,857
Loan/lease interest rate swaps – liabilities94,855
 (175) 496,887
 (8,891)
 
 122,788
 (310)
Loan/lease interest rate caps – liabilities102,634
 (233) 122,791
 (509)155,597
 (682) 107,835
 (266)


The weighted-average rates paid and received for interest rate swaps outstanding at September 30, 2019March 31, 2020 were as follows:
Weighted-AverageWeighted-Average
Interest
Rate
Paid
 
Interest
Rate
Received
Interest
Rate
Paid
 
Interest
Rate
Received
Interest rate swaps:      
Fair value hedge loan/lease interest rate swaps2.33% 2.05%3.54% 1.26%
Non-hedging interest rate swaps – financial institution counterparties4.17
 3.71
4.05
 2.93
Non-hedging interest rate swaps – customer counterparties3.71
 4.17
2.93
 4.05

The weighted-average strike rate for outstanding interest rate caps was 3.16%2.86% at September 30, 2019.March 31, 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, 2019 December 31, 2018 March 31, 2020 December 31, 2019
Notional
Units
 
Notional
Amount
 
Estimated
Fair Value
 
Notional
Amount
 
Estimated
Fair Value
Notional
Units
 
Notional
Amount
 
Estimated
Fair Value
 
Notional
Amount
 
Estimated
Fair Value
Financial institution counterparties:                
Oil – assetsBarrels 2,280
 $12,884
 2,416
 $24,332
Barrels 2,639
 $61,479
 1,214
 $2,796
Oil – liabilitiesBarrels 727
 (1,363) 415
 (646)Barrels 576
 (634) 2,148
 (6,916)
Natural gas – assetsMMBTUs 8,716
 2,053
 5,745
 417
MMBTUs 5,807
 2,455
 8,295
 2,131
Natural gas – liabilitiesMMBTUs 3,439
 (191) 9,314
 (1,272)MMBTUs 4,313
 (346) 2,689
 (70)
Customer counterparties:                
Oil – assetsBarrels 730
 1,392
 415
 646
Barrels 576
 645
 2,172
 7,208
Oil – liabilitiesBarrels 2,277
 (12,572) 2,416
 (24,009)Barrels 2,639
 (61,087) 1,190
 (2,652)
Natural gas – assetsMMBTUs 3,543
 205
 10,236
 1,373
MMBTUs 4,313
 397
 2,689
 83
Natural gas – liabilitiesMMBTUs 8,613
 (1,960) 4,823
 (393)MMBTUs 5,807
 (2,392) 8,295
 (2,039)

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, 2019 December 31, 2018  March 31, 2020 December 31, 2019
Notional
Currency
 
Notional
Amount
 
Estimated
Fair Value
 
Notional
Amount
 
Estimated
Fair Value
Notional
Currency
 
Notional
Amount
 
Estimated
Fair Value
 
Notional
Amount
 
Estimated
Fair Value
Financial institution counterparties:                
Forward contracts – liabilitiesCAD 5,283
 $(11) 11,003
 $(13)CAD 2,821
 $(16) 4,593
 $(33)
Forward contracts – liabilitiesGBP 
 
 142
 (2)
Forward contracts – liabilitiesMXN 
 
 3,015
 (132)
Customer counterparties:                
Forward contracts – assetsCAD 5,271
 24
 10,979
 40
CAD 2,814
 24
 4,583
 45
Forward contracts – assetsGBP 
 
 145
 4
Forward contracts – assetsMXN 
 
 3,000
 149

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.

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 
 March 31,
2019 2018 2019 20182020 2019
Commercial loan/lease interest rate swaps:          
Amount of gain (loss) included in interest income on loans$24
 $12
 $78
 $1
$(8) $26
Amount of (gain) loss included in other non-interest expense(1) 
 
 (1)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 three months ended March 31, 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,
Three Months Ended 
 March 31,
2019 2018 2019 20182020 2019
Non-hedging interest rate derivatives:          
Other non-interest income$215
 $699
 $1,188
 $2,889
$2,039
 $586
Other non-interest expense
 2
 
 (2)
 
Non-hedging commodity derivatives:          
Other non-interest income109
 456
 322
 492
139
 103
Non-hedging foreign currency derivatives:          
Other non-interest income12
 53
 41
 203
7
 17
Non-hedging put options:   
Other non-interest income5,980
 

Counterparty Credit Risk. Our credit exposure relating to interest rate swaps, commodity swaps/options and foreign currency forward contracts with bank customers was approximately $55.4$96.8 million at September 30, 2019.March 31, 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 $18.6$22.6 million at September 30, 2019.March 31, 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 9 – Balance Sheet Offsetting and Repurchase Agreements for additional information regarding our credit exposure with upstream financial institution counterparties. At September 30, 2019,March 31, 2020, we had $32.1$41.6 million in cash collateral related to derivative contracts on deposit with other financial institution counterparties.

Note 9 - 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, 2019March 31, 2020 is presented in the following tables.
Gross Amount
Recognized
 
Gross Amount
Offset
 
Net Amount
Recognized
Gross Amount
Recognized
 
Gross Amount
Offset
 
Net Amount
Recognized
September 30, 2019     
March 31, 2020     
Financial assets:          
Derivatives:          
Loan/lease interest rate swaps and caps$313
 $
 $313
$682
 $
 $682
Commodity swaps and options14,937
 
 14,937
63,934
 
 63,934
Foreign currency forward contracts
 
 

 
 
Total derivatives15,250
 
 15,250
64,616
 
 64,616
Resell agreements11,299
 
 11,299
20,000
 
 20,000
Total$26,549
 $
 $26,549
$84,616
 $
 $84,616
Financial liabilities:          
Derivatives:          
Loan/lease interest rate swaps$24,447
 $
 $24,447
$37,622
 $
 $37,622
Commodity swaps and options1,554
 
 1,554
980
 
 980
Foreign currency forward contracts11
 
 11
16
 
 16
Total derivatives26,012
 
 26,012
38,618
 
 38,618
Repurchase agreements1,187,355
 
 1,187,355
1,146,478
 
 1,146,478
Total$1,213,367
 $
 $1,213,367
$1,185,096
 $
 $1,185,096

   Gross Amounts Not Offset  
 
Net Amount
Recognized
 
Financial
Instruments
 Collateral 
Net
Amount
March 31, 2020       
Financial assets:       
Derivatives:       
Counterparty A$10
 $(10) $
 $
Counterparty B10,483
 (10,483) 
 
Other counterparties54,123
 (8,728) (45,090) 305
Total derivatives64,616
 (19,221) (45,090) 305
Resell agreements20,000
 
 (20,000) 
Total$84,616
 $(19,221) $(65,090) $305
Financial liabilities:       
Derivatives:       
Counterparty A$7,606
 $(10) $(7,580) $16
Counterparty B11,111
 (10,483) (580) 48
Counterparty C146
 
 (146) 
Other counterparties19,755
 (8,728) (11,027) 
Total derivatives38,618
 (19,221) (19,333) 64
Repurchase agreements1,146,478
 
 (1,146,478) 
Total$1,185,096
 $(19,221) $(1,165,811) $64


   Gross Amounts Not Offset  
 
Net Amount
Recognized
 
Financial
Instruments
 Collateral 
Net
Amount
September 30, 2019       
Financial assets:       
Derivatives:       
Counterparty A$38
 $(38) $
 $
Counterparty B4,344
 (4,344) 
 
Counterparty C8
 (8) 
 
Other counterparties10,860
 (5,503) (2,880) 2,477
Total derivatives15,250
 (9,893) (2,880) 2,477
Resell agreements11,299
 
 (11,299) 
Total$26,549
 $(9,893) $(14,179) $2,477
Financial liabilities:       
Derivatives:       
Counterparty A$6,192
 $(38) $(6,154) $
Counterparty B7,810
 (4,344) (3,466) 
Counterparty C164
 (8) (156) 
Other counterparties11,846
 (5,503) (6,259) 84
Total derivatives26,012
 (9,893) (16,035) 84
Repurchase agreements1,187,355
 
 (1,187,355) 
Total$1,213,367
 $(9,893) $(1,203,390) $84

Information about financial instruments that are eligible for offset in the consolidated balance sheet as of December 31, 20182019 is presented in the following tables.
Gross Amount
Recognized
 
Gross Amount
Offset
 
Net Amount
Recognized
Gross Amount
Recognized
 
Gross Amount
Offset
 
Net Amount
Recognized
December 31, 2018     
December 31, 2019     
Financial assets:          
Derivatives:          
Loan/lease interest rate swaps and caps$3,100
 $
 $3,100
$339
 $
 $339
Commodity swaps and options24,749
 
 24,749
4,927
 
 4,927
Foreign currency forward contracts
 
 
Total derivatives27,849
 
 27,849
5,266
 
 5,266
Resell agreements11,642
 
 11,642
31,299
 
 31,299
Total$39,491
 $
 $39,491
$36,565
 $
 $36,565
Financial liabilities:          
Derivatives:          
Loan/lease interest rate swaps$9,120
 $
 $9,120
$19,621
 $
 $19,621
Commodity swaps and options1,918
 
 1,918
6,986
 
 6,986
Foreign currency forward contracts147
 
 147
33
 
 33
Total derivatives11,185
 
 11,185
26,640
 
 26,640
Repurchase agreements1,360,298
 
 1,360,298
1,668,142
 
 1,668,142
Total$1,371,483
 $
 $1,371,483
$1,694,782
 $
 $1,694,782

   Gross Amounts Not Offset  
 
Net Amount
Recognized
 
Financial
Instruments
 Collateral 
Net
Amount
December 31, 2019       
Financial assets:       
Derivatives:       
Counterparty A$39
 $(39) $
 $
Counterparty B1,650
 (1,650) 
 
Counterparty C1
 (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) $


   Gross Amounts Not Offset  
 
Net Amount
Recognized
 
Financial
Instruments
 Collateral 
Net
Amount
December 31, 2018       
Financial assets:       
Derivatives:       
Counterparty A$598
 $(598) $
 $
Counterparty B7,255
 (3,380) (3,875) 
Counterparty C81
 (81) 
 
Other counterparties19,915
 (2,084) (17,776) 55
Total derivatives27,849
 (6,143) (21,651) 55
Resell agreements11,642
 
 (11,642) 
Total$39,491
 $(6,143) $(33,293) $55
Financial liabilities:       
Derivatives:       
Counterparty A$4,293
 $(598) $(3,651) $44
Counterparty B3,380
 (3,380) 
 
Counterparty C326
 (81) (245) 
Other counterparties3,186
 (2,084) (725) 377
Total derivatives11,185
 (6,143) (4,621) 421
Repurchase agreements1,360,298
 
 (1,360,298) 
Total$1,371,483
 $(6,143) $(1,364,919) $421

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, 2019March 31, 2020 and December 31, 20182019 is presented in the following tables.
Remaining Contractual Maturity of the AgreementsRemaining Contractual Maturity of the Agreements
Overnight and Continuous Up to 30 Days 30-90 Days Greater than 90 Days TotalOvernight and Continuous Up to 30 Days 30-90 Days Greater than 90 Days Total
September 30, 2019         
March 31, 2020         
Repurchase agreements:         
Residential mortgage-backed securities$1,146,478
 $
 $
 $
 $1,146,478
Total borrowings$1,146,478
 $
 $
 $
 $1,146,478
Gross amount of recognized liabilities for repurchase agreementsGross amount of recognized liabilities for repurchase agreements $1,146,478
Amounts related to agreements not included in offsetting disclosures aboveAmounts related to agreements not included in offsetting disclosures above $
         
December 31, 2019         
Repurchase agreements:                  
U.S. Treasury$162,566
 $2,550
 $
 $
 $165,116
$435,904
 $
 $
 $
 $435,904
Residential mortgage-backed securities1,022,239
 
 
 
 1,022,239
1,232,238
 
 
 
 1,232,238
Total borrowings$1,184,805
 $2,550
 $
 $
 $1,187,355
$1,668,142
 $
 $
 $
 $1,668,142
Gross amount of recognized liabilities for repurchase agreementsGross amount of recognized liabilities for repurchase agreements $1,187,355
Gross amount of recognized liabilities for repurchase agreements $1,668,142
Amounts related to agreements not included in offsetting disclosures aboveAmounts related to agreements not included in offsetting disclosures above $
Amounts related to agreements not included in offsetting disclosures above $
         
December 31, 2018         
Repurchase agreements:         
U.S. Treasury$1,334,063
 $
 $
 $
 $1,334,063
Residential mortgage-backed securities26,235
 
 
 
 26,235
Total borrowings$1,360,298
 $
 $
 $
 $1,360,298
Gross amount of recognized liabilities for repurchase agreements $1,360,298
Amounts related to agreements not included in offsetting disclosures above $


Note 10 - 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. As of September 30, 2019,March 31, 2020, there were 1,277,5781,115,490 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 Outstanding 
Stock Options
Outstanding
 
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
 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, 2019 48,910
 $71.14
 383,797
 $85.59
 125,809
 $82.55
 2,352,008
 $63.55
Balance, January 1, 2020 55,370
 $74.76
 440,647
 $90.22
 177,288
 $83.48
 1,980,866
 $64.60
Authorized 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Granted 7,592
 102.70
 1,957
 91.96
 
 
 
 
 
 
 458
 65.43
 
 
 
 
Exercised/vested (1,132) 106.03
 (17,800) 65.11
 
 
 (236,252) 57.17
 
 
 
 
 (41,755) 69.70
 (24,460) 59.81
Forfeited/expired 
 
 (11,850) 89.29
 
 
 (11,000) 65.11
 
 
 (1,438) 88.69
 (6,894) 81.33
 (2,000) 72.02
Balance, September 30, 2019 55,370
 $74.76
 356,104
 $86.53
 125,809
 $82.55
 2,104,756
 $64.26
Balance, March 31, 2020 55,370
 $74.76
 439,667
 $90.20
 128,639
 $88.07
 1,954,406
 $64.65


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 
 March 31,
2019 2018 2019 20182020 2019
New shares issued from available authorized shares
 
 
 

 
Issued from available treasury stock71,284
 19,232
 225,184
 447,831
66,215
 100,865
Total71,284
 19,232
 225,184
 447,831
66,215
 100,865
          
Proceeds from stock option exercises$5,665
 $1,119
 $13,506
 $26,567
$1,463
 $4,885

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 
 March 31,
2019 2018 2019 20182020 2019
Stock options$330
 $960
 $1,091
 $3,064
$
 $382
Non-vested stock awards/stock units1,536
 1,357
 5,727
 4,196
2,264
 2,135
Director deferred stock units
 
 780
 720
Performance stock units809
 479
 3,095
 1,576
248
 1,137
Total$2,675
 $2,796
 $10,693
 $9,556
$2,512
 $3,654
Income tax benefit$452
 $587
 $1,768
 $2,007
$465
 $584

Unrecognized stock-based compensation expense at September 30, 2019March 31, 2020 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.
Stock options$96
Non-vested stock awards/stock units11,196
$16,524
Performance stock units3,432
5,536
Total$14,724
$22,060


Note 11 - Earnings Per Common Share
Earnings per common share is computed using the two-class method as more fully described in our 20182019 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,
Three Months Ended 
 March 31,
2019 2018 2019 20182020 2019
Net income$111,836
 $117,844
 $339,918
 $335,665
$54,753
 $116,496
Less: Preferred stock dividends2,016
 2,016
 6,047
 6,047
2,016
 2,016
Redemption of preferred stock5,514
 
Net income available to common shareholders109,820
 115,828
 333,871
 329,618
47,223
 114,480
Less: Earnings allocated to participating securities876
 750
 2,761
 2,178
445
 980
Net earnings allocated to common stock$108,944
 $115,078
 $331,110
 $327,440
$46,778
 $113,500
          
Distributed earnings allocated to common stock$44,370
 $42,811
 $131,069
 $121,907
$44,512
 $42,238
Undistributed earnings allocated to common stock64,574
 72,267
 200,041
 205,533
2,266
 71,262
Net earnings allocated to common stock$108,944
 $115,078
 $331,110
 $327,440
$46,778
 $113,500
          
Weighted-average shares outstanding for basic earnings per common share62,566,128
 63,892,023
 62,786,501
 63,793,514
62,642,682
 63,009,060
Dilutive effect of stock compensation592,866
 1,022,168
 725,911
 1,037,043
407,154
 818,896
Weighted-average shares outstanding for diluted earnings per common share63,158,994
 64,914,191
 63,512,412
 64,830,557
63,049,836
 63,827,956

Note 12 - 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 
 March 31,
2019 2018 2019 20182020 2019
Expected return on plan assets, net of expenses$(2,693) $(2,979) $(8,079) $(8,937)$(3,072) $(2,693)
Interest cost on projected benefit obligation1,618
 1,475
 4,854
 4,424
1,252
 1,618
Net amortization and deferral1,406
 1,250
 4,218
 3,751
1,330
 1,406
Net periodic expense (benefit)$331
 $(254) $993
 $(762)$(490) $331

Our non-qualified defined benefit pension plan is not funded. NaN contributions to the qualified defined benefit pension plan were made during the ninethree months ended September 30, 2019.March 31, 2020. We do not expect to make any contributions to the qualified defined benefit plan during the remainder of 2019.2020.

Note 13 - Income Taxes
Income tax expense was as follows:
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended 
 March 31,
2019 2018 2019 20182020 2019
Current income tax expense (benefit)$14,480
 $(1,152) $43,984
 $955
$29,412
 $14,999
Deferred income tax expense (benefit)(950) 16,312
 (1,625) 39,198
(26,089) (1,044)
Income tax expense, as reported$13,530
 $15,160
 $42,359
 $40,153
$3,323
 $13,955
          
Effective tax rate10.8% 11.4% 11.1% 10.7%5.7% 10.7%

We had a net deferred tax liability totaling $76.7$67.6 million at September 30, 2019March 31, 2020 and a net deferred tax asset totaling $19.8$75.8 million at December 31, 2018. The change in net deferred taxes was primarily related to unrealized gains on available-for-sale securities during the nine months ended September 30, 2019. NaN valuation allowance for deferred tax assets was recorded at September 30, 2019March 31, 2020 as management believes it is more likely than not that all of the deferred tax assets will be realized against deferred tax liabilities and projected future taxable income.

The effective income tax rates differed from the U.S. statutory federal income tax rates of 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. There were 0 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 2016.
Note 14 - 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 12 – Defined Benefit Plans).
 Three Months Ended 
 September 30, 2019
 Three Months Ended 
 September 30, 2018
 
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$107,786
 $22,635
 $85,151
 $(96,147) $(20,190) $(75,957)
Change in net unrealized gain on securities transferred to held to maturity(305) (64) (241) (3,764) (790) (2,974)
Reclassification adjustment for net (gains) losses included in net income(97) (21) (76) 34
 7
 27
Total securities available for sale and transferred securities107,384
 22,550
 84,834
 (99,877) (20,973) (78,904)
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)1,406
 295
 1,111
 1,250
 262
 988
Total defined-benefit post-retirement benefit plans1,406
 295
 1,111
 1,250
 262
 988
Total other comprehensive income (loss)$108,790
 $22,845
 $85,945
 $(98,627) $(20,711) $(77,916)
Nine Months Ended 
 September 30, 2019
 Nine Months Ended 
 September 30, 2018
Three Months Ended 
 March 31, 2020
 Three Months Ended 
 March 31, 2019
Before Tax
Amount
 
Tax  Expense,
(Benefit)
 
Net of  Tax
Amount
 
Before Tax
Amount
 
Tax  Expense,
(Benefit)
 
Net of  Tax
Amount
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$464,072
 $97,455
 $366,617
 $(286,935) $(60,256) $(226,679)$230,118
 $48,325
 $181,793
 $198,146
 $41,611
 $156,535
Change in net unrealized gain on securities transferred to held to maturity(957) (201) (756) (8,424) (1,769) (6,655)(377) (79) (298) (344) (72) (272)
Reclassification adjustment for net (gains) losses included in net income(266) (56) (210) 113
 24
 89
(108,989) (22,888) (86,101) 
 
 
Total securities available for sale and transferred securities462,849
 97,198
 365,651
 (295,246) (62,001) (233,245)120,752
 25,358
 95,394
 197,802
 41,539
 156,263
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)4,218
 886
 3,332
 3,751
 788
 2,963
1,330
 279
 1,051
 1,406
 295
 1,111
Total defined-benefit post-retirement benefit plans4,218
 886
 3,332
 3,751
 788
 2,963
1,330
 279
 1,051
 1,406
 295
 1,111
Total other comprehensive income (loss)$467,067
 $98,084
 $368,983
 $(291,495) $(61,213) $(230,282)$122,082
 $25,637
 $96,445
 $199,208
 $41,834
 $157,374


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 reclassifications181,495
 
 181,495
Reclassification of amounts included in net income(86,101) 1,051
 (85,050)
Net other comprehensive income (loss) during period95,394
 1,051
 96,445
Balance at March 31, 2020$408,698
 $(44,883) $363,815
Securities
Available
For Sale
 
Defined
Benefit
Plans
 
Accumulated
Other
Comprehensive
Income
     
Balance January 1, 2019$(16,103) $(47,497) $(63,600)$(16,103) $(47,497) $(63,600)
Other comprehensive income (loss) before reclassifications365,861
 
 365,861
156,263
 
 156,263
Reclassification of amounts included in net income(210) 3,332
 3,122

 1,111
 1,111
Net other comprehensive income (loss) during period365,651
 3,332
 368,983
156,263
 1,111
 157,374
Balance at September 30, 2019$349,548
 $(44,165) $305,383
     
Balance January 1, 2018$117,230
 $(37,718) $79,512
Other comprehensive income (loss) before reclassifications(233,334) 
 (233,334)
Reclassification of amounts included in net income89
 2,963
 3,052
Net other comprehensive income (loss) during period(233,245) 2,963
 (230,282)
Reclassification of certain income tax effects related to the change in the U.S. statutory federal income tax rate under the Tax Cuts and Jobs Act to retained earnings17,557
 (8,022) 9,535
Balance at September 30, 2018$(98,458) $(42,777) $(141,235)
Balance at March 31, 2019$140,160
 $(46,386) $93,774

Note 15 – Operating Segments
We are managed under a matrix organizational structure whereby our 2 primary operating segments, Banking and Frost Wealth Advisors, overlap a regional reporting structure. See our 20182019 Form 10-K for additional information regarding our operating segments. Summarized operating results by segment were as follows:
 Banking 
Frost  Wealth
Advisors
 Non-Banks Consolidated
Revenues from (expenses to) external customers:       
Three months ended:       
September 30, 2019$307,312
 $37,549
 $(2,630) $342,231
September 30, 2018295,062
 36,868
 (2,608) 329,322
Nine months ended:       
September 30, 2019$918,672
 $111,064
 $(8,182) $1,021,554
September 30, 2018874,056
 106,475
 (7,680) 972,851
Net income (loss):       
Three months ended:       
September 30, 2019$110,583
 $4,106
 $(2,853) $111,836
September 30, 2018114,214
 6,442
 (2,812) 117,844
Nine months ended:       
September 30, 2019$334,393
 $15,403
 $(9,878) $339,918
September 30, 2018327,131
 17,977
 (9,443) 335,665
 Banking 
Frost  Wealth
Advisors
 Non-Banks Consolidated
Revenues from (expenses to) external customers:       
Three months ended:       
March 31, 2020$419,429
 $40,607
 $(2,600) $457,436
March 31, 2019308,613
 37,351
 (2,710) 343,254
Net income (loss):       
Three months ended:       
March 31, 2020$52,024
 $5,587
 $(2,858) $54,753
March 31, 2019112,917
 6,400
 (2,821) 116,496


Note 16 – 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 20182019 Form 10-K for additional information regarding the fair value hierarchy and a description of our valuation techniques.
Financial Assets and Financial Liabilities. The table below summarizes financial assets and financial liabilities measured at fair value on a recurring basis as of September 30, 2019March 31, 2020 and December 31, 2018,2019, segregated by the level of the valuation inputs within the fair value hierarchy of ASC Topic 820 utilized to measure fair value.
Level 1
Inputs
 Level 2
Inputs
 Level 3
Inputs
 Total Fair
Value
Level 1
Inputs
 Level 2
Inputs
 Level 3
Inputs
 Total Fair
Value
September 30, 2019       
March 31, 2020       
Securities available for sale:              
U.S. Treasury$2,825,796
 $
 $
 $2,825,796
$1,167,264
 $
 $
 $1,167,264
Residential mortgage-backed securities
 2,240,452
 
 2,240,452

 2,089,946
 
 2,089,946
States and political subdivisions
 7,311,373
 
 7,311,373

 7,167,866
 
 7,167,866
Other
 42,825
 
 42,825

 42,901
 
 42,901
Trading account securities:              
U.S. Treasury23,747
 
 
 23,747
24,491
 
 
 24,491
States and political subdivisions
 3,922
 
 3,922

 1,430
 
 1,430
Derivative assets:              
Interest rate swaps, caps and floors
 55,842
 
 55,842

 97,914
 
 97,914
Commodity swaps and options
 16,534
 
 16,534

 64,976
 
 64,976
Foreign currency forward contracts24
 
 
 24
24
 
 
 24
Derivative liabilities:              
Interest rate swaps, caps and floors
 24,855
 
 24,855

 38,304
 
 38,304
Commodity swaps and options
 16,086
 
 16,086

 64,459
 
 64,459
Foreign currency forward contracts11
 
 
 11
16
 
 
 16
December 31, 2018       
December 31, 2019       
Securities available for sale:              
U.S. Treasury$3,427,689
 $
 $
 $3,427,689
$1,948,133
 $
 $
 $1,948,133
Residential mortgage-backed securities
 829,740
 
 829,740

 2,207,594
 
 2,207,594
States and political subdivisions
 7,087,202
 
 7,087,202

 7,070,997
 
 7,070,997
Other
 42,690
 
 42,690

 42,867
 
 42,867
Trading account securities:              
U.S. Treasury21,928
 
 
 21,928
24,298
 
 
 24,298
States and political subdivisions
 2,158
 
 2,158
Derivative assets:              
Interest rate swaps, caps and floors
 19,806
 
 19,806

 44,196
 
 44,196
Commodity swaps and options
 26,768
 
 26,768

 12,218
 
 12,218
Foreign currency forward contracts193
 
 
 193
45
 
 
 45
Derivative liabilities:              
Interest rate swaps, caps and floors
 18,520
 
 18,520

 20,197
 
 20,197
Commodity swaps and options
 26,320
 
 26,320

 11,677
 
 11,677
Foreign currency forward contracts147
 
 
 147
33
 
 
 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, 2019
 Nine Months Ended 
 September 30, 2018
 Level 2 Level 3 Level 2 Level 3
Carrying value of impaired loans before allocations$2,416
 $60,010
 $12,876
 $28,638
Specific valuation allowance (allocations) reversals of prior allocations1,116
 (12,437) (2,599) 4,256
Fair value$3,532
 $47,573
 $10,277
 $32,894
 Three Months Ended 
 March 31, 2020
 Three Months Ended 
 March 31, 2019
 Level 2 Level 3 Level 2 Level 3
Carrying value before allocations$1,919
 $3,867
 $11,487
 $37,525
Specific allocations70
 (244) (256) (3,441)
Fair value$1,989
 $3,623
 $11,231
 $34,084

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,
Three Months Ended 
 March 31,
2019 20182020 2019
Foreclosed assets remeasured at initial recognition:   
Carrying value of foreclosed assets prior to remeasurement$1,302
 $2,898
Charge-offs recognized in the allowance for loan losses(76) 
Fair value$1,226
 $2,898
Foreclosed assets remeasured subsequent to initial recognition:      
Carrying value of foreclosed assets prior to remeasurement$
 $1,823
$328
 $
Write-downs included in other non-interest expense
 (473)(231) 
Fair value$
 $1,350
$97
 $

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, 2019 December 31, 2018March 31, 2020 December 31, 2019
Carrying
Amount
 
Estimated
Fair Value
 
Carrying
Amount
 
Estimated
Fair Value
Carrying
Amount
 
Estimated
Fair Value
 
Carrying
Amount
 
Estimated
Fair Value
Financial assets:              
Level 2 inputs:              
Cash and cash equivalents$2,907,901
 $2,907,901
 $3,955,779
 $3,955,779
$4,195,585
 $4,195,585
 $3,788,181
 $3,788,181
Securities held to maturity1,020,838
 1,047,423
 1,106,057
 1,116,953
1,984,149
 2,057,879
 2,030,005
 2,048,675
Cash surrender value of life insurance policies186,217
 186,217
 183,473
 183,473
188,078
 188,078
 187,156
 187,156
Accrued interest receivable133,950
 133,950
 188,989
 188,989
123,995
 123,995
 183,850
 183,850
Level 3 inputs:              
Loans, net14,498,369
 14,542,918
 13,967,601
 13,933,239
15,074,379
 15,246,193
 14,618,165
 14,654,615
Financial liabilities:              
Level 2 inputs:              
Deposits27,083,582
 27,084,765
 27,149,204
 27,143,572
28,140,867
 28,150,786
 27,639,564
 27,641,255
Federal funds purchased and repurchase agreements1,200,655
 1,200,655
 1,367,548
 1,367,548
1,170,978
 1,170,978
 1,695,342
 1,695,342
Junior subordinated deferrable interest debentures136,285
 137,115
 136,242
 137,115
136,314
 137,115
 136,299
 137,115
Subordinated notes payable and other borrowings98,826
 106,447
 98,708
 98,458
98,904
 102,250
 98,865
 89,077
Accrued interest payable10,177
 10,177
 7,394
 7,394
10,684
 10,684
 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.

Note 17 - Accounting Standards Updates
Information about certain recently issued accounting standards updates is presented below. Also refer to Note 20 - Accounting Standards Updates in our 20182019 Form 10-K for additional information related to previously issued accounting standards updates.
ASU 2016-02, “Leases (Topic 842).” ASU 2016-02, among other things, requires 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. We adopted ASU 2016-02, along with several other subsequent codification updates related to lease accounting, as of January 1, 2019. See Note 1 - Significant Accounting Policies for additional information.
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, ASU 2016-13 amends the accounting for credit losses on available-for-sale debt securities and purchased financial assets with credit deterioration. In April 2019, ASU 2019-04, “Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments,” was issued to address certain codification improvements and to provide certain accounting policy electives related to accrued interest as well as disclosure related to credit losses, among other things. In May 2019, ASU 2019-05, “Financial Instruments—Credit Losses (Topic 326): Targeted Transition Relief,” was issued to provide transition relief in connection with the adoption of ASU 2016-03 whereby entities would have the option to irrevocably elect the fair value option for certain financial assets previously measured at amortized cost basis.We adopted ASU 2016-13, as subsequently updated will be effective onfor certain clarifications, targeted relief and codification improvements, as of January 1, 2020.
We are currently working through our implementation plan with our cross-functional working group, under the direction of our Chief Financial Officer and our Chief Credit Officer. The working group is comprised of individuals from various functional areas including credit, risk management, finance and information technology, among others. Our implementation plan includes assessment and documentation of processes, internal controls and data sources; model development, documentation and validation; and system configuration, among other things. We are also in the process of implementing a third-party vendor solution to assist us in the application of ASU 2016-13. Based upon our preliminary parallel run as of September 30, 2019, we currently expect the adoption of ASU 2016-13 will result in a combined 15.0% to 25.0% increase in our allowance for loan losses and our reserves for unfunded commitments. This increase is 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 for certain debt securities and other financial assets; however, we do not expect these allowances to be significant. Additionally, the adoption of ASU 2016-13 is not expected to have a significant impact on our regulatory capital ratios. The ultimate impact of adoption on January 1, 2020 could be significantly different than our current expectation as our modeling processes 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 that date, notwithstanding any further refinements to our expected credit loss models.
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 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 did not change the accounting for callable debt securities held at a discount. We adopted ASU 2017-08 effective January 1, 2019 and recognized a cumulative effect adjustment reducing retained earnings by $14.7 million. See Note 1 - Significant Accounting Policies.Policies for additional information.

ASU 2017-12, “Derivatives and Hedging2020-4, “Reference Rate Reform (Topic 815) - Targeted Improvements to Accounting for Hedging Activities.848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.ASU 2017-12 amends the hedge2020-4 provides optional expedients and exceptions for accounting recognitionrelated to contracts, hedging relationships and presentation requirements in ASC 815other transactions affected by reference rate reform if certain criteria are met. ASU 2020-04 applies only to improve the transparencycontracts, hedging relationships, and understandabilityother transactions that reference LIBOR or another reference rate expected to be discontinued because of information conveyedreference rate reform and do not apply to financial statement users about an entity’s risk management activities to better align the entity’s financial reportingcontract modifications made and hedging relationships entered into or evaluated after December 31, 2022, except for hedging relationships with those risk management activitiesexisting as of December 31, 2022, that an entity has elected certain optional expedients for and to reducethat are retained through the complexityend of the hedging relationship. ASU 2020-4 was effective upon issuance and simplify the applicationgenerally can be applied through December 31, 2022. The adoption of hedge accounting. ASU 2017-12 became effective for us on January 1, 2019 and2020-4 did not have a significantsignificantly impact on our financial statements. In April 2019, ASU 2019-04 was issued to clarify certain aspects of accounting for hedging activities addressed by ASU 2017-12, among other things.
ASU 2018-16, “Derivatives and Hedging (Topic 815) - Inclusion of the Secured Overnight Financing Rate (“SOFR”) Overnight Index Swap (“OIS”) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes.” The amendments in this update permit use of the OIS rate based on SOFR as a U.S. benchmark interest rate for hedge accounting purposes under Topic 815 in addition to the interest rates on direct U.S. Treasury obligations, the LIBOR swap rate, the OIS rate based on the Fed Funds Effective Rate and the Securities Industry and Financial Markets Association (“SIFMA”) Municipal Swap Rate. ASU 2018-16 became effective for us on January 1, 2019 and did not 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, 20182019, and the other information included in the 20182019 Form 10-K. Operating results for the three and nine months ended September 30, 2019March 31, 2020 are not necessarily indicative of the results for the year ending December 31, 20192020 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 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 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 failure, interruption, or breach of security of our systems.
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.
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 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 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 led to 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 the effect of actions taken, or that may yet be taken, 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 of non-essential businesses and related economic disruption has 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.
Temporarily closed all of our financial center lobbies and other corporate facilities to non-employees, except for certain limited cases by appointment only. 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 90% 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.
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 may 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 may 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, restaurants, hotels/lodging, aviation, entertainment, retail 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. Additionally, the temporary closures of bank 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% on March 15, 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% on March 3, 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. If 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. Alternatively, if the COVID-19 outbreak abates and general economic conditions improve, the Federal Reserve may determine to increase the targeted federal funds rates and overall interest rates will likely rise, which may positively impact our net interest income, but may negatively impact commercial lending activity and the U.S. economy.

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 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) authorizes 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) creates 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) provides certain credits against the 2020 personal income tax for eligible individuals and their dependents, (iv) expands 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) expands 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. We are continuing to monitor the potential development of so-called “Phase 4” 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 up to $2.6 trillion in financing in response to the financial disruptions caused by COVID-19. The programs include, among other things, (i) the Paycheck Protection Program Lending Facility (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, 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.
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 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 2018 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, 2018.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 21% federal tax rate, thus making tax-exempt yields comparable to taxable asset yields.

Results of Operations
Net income available to common shareholders totaled $109.8$47.2 million, or $1.73 per diluted common share, and $333.9 million, or $5.24$0.75 per diluted common share, for the three and nine months ended September 30, 2019March 31, 2020 compared to $115.8$114.5 million, or $1.78 per diluted common share, and $329.6 million, or $5.08$1.79 per diluted common share, for the three and nine months ended September 30, 2018.March 31, 2019.
Selected data for the comparable periods was as follows:
Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
Three Months Ended 
 March 31,
2019 2018 2019 20182020 2019
Taxable-equivalent net interest income$276,618
 $265,687
 $825,547
 $778,754
$268,453
 $271,179
Taxable-equivalent adjustment23,611
 24,022
 72,640
 70,071
23,932
 24,710
Net interest income253,007
 241,665
 752,907
 708,683
244,521
 246,469
Provision for loan losses8,001
 2,650
 25,404
 17,846
Net interest income after provision for loan losses245,006
 239,015
 727,503
 690,837
Credit loss expense175,197
 11,003
Net interest income after credit loss expense69,324
 235,466
Non-interest income89,224
 87,657
 268,647
 264,168
212,915
 96,785
Non-interest expense208,864
 193,668
 613,873
 579,187
224,163
 201,800
Income before income taxes125,366
 133,004
 382,277
 375,818
58,076
 130,451
Income taxes13,530
 15,160
 42,359
 40,153
3,323
 13,955
Net income111,836
 117,844
 339,918
 335,665
54,753
 116,496
Preferred stock dividends2,016
 2,016
 6,047
 6,047
2,016
 2,016
Redemption of preferred stock5,514
 
Net income available to common shareholders$109,820
 $115,828
 $333,871
 $329,618
$47,223
 $114,480
Earnings per common share – basic$1.74
 $1.80
 $5.28
 $5.13
$0.75
 $1.80
Earnings per common share – diluted1.73
 1.78
 5.24
 5.08
0.75
 1.79
Dividends per common share0.71
 0.67
 2.09
 1.91
0.71
 0.67
Return on average assets1.35% 1.49% 1.41% 1.42%0.57% 1.48%
Return on average common equity11.83
 14.40
 12.79
 14.02
4.88
 14.08
Average shareholders’ equity to average assets11.87
 10.79
 11.48
 10.63
11.95
 10.97
Net income available to common shareholders decreased $6.0$67.3 million, or 5.2%58.8%, for the three months ended September 30, 2019 and increased $4.3 million, or 1.3%, for the nine months ended September 30, 2019March 31, 2020 compared to the same periodsperiod in 2018.2019. The decrease during the three months ended September 30, 2019 was primarily the result of a $15.2$164.2 million increase in credit loss expense, a $22.4 million increase in non-interest expense and a $5.4$1.9 million increase in the provision for loan losses partly offset by an $11.3 million increasedecrease in net interest income partly offset by a $1.6$116.1 million increase in non-interest income and a $1.6$10.6 million decrease in income tax expense. The increase during the nine months ended September 30, 2019 was primarily the resultin credit loss expense resulted from both our adoption of a $44.2 million increasenew 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 net interest income and a $4.5 millionoil prices. The increase in non-interest income partly offsetwas primarily related to a $109.0 million net gain on securities transactions. Net income available to common shareholders for the three months ended March 31, 2020 was also impacted by a $34.7the reclassification of $5.5 million increase in non-interest expense, a $7.6 million increaseof issuance costs associated with our preferred stock to retained earnings upon redemption of the preferred stock in the provision for loan losses and a $2.2 million increase in income tax expense.first quarter.
Details of the changes in the various components of net income are further discussed below.
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 73.7%53.5% of total revenue during the first ninethree months of 2019.2020. Excluding the revenue associated with the $109.0 million net gain on securities transactions realized during the quarter, net interest income would have represented 70.2% of total revenue. 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 rate began 20182019 at 4.50%5.50% and subsequently increased 100 basis points (25 basis points in each of March, June, September and December) to end 2018 at 5.50%. The prime rate decreased 50 basis points during the third quarter of 2019 (25 basis points in each of August and September) and 25 basis points in October 2019 to end the year at 4.75%. During 2020, the prime rate decreased 150 basis points in March to end the first quarter at 5.00%3.25%. Our loan portfolio is also impacted by changes in the London Interbank Offered Rate (LIBOR). At September 30,March 31, 2020, the one-month and three-month U.S. dollar LIBOR interest rates were 0.99% and 1.45%, respectively, while at

March 31, 2019, the one-month and three-month U.S. dollar LIBOR interest rates were 2.02%2.50% and 2.09%, respectively, while at September 30, 2018, the one-month and three-month U.S. dollar LIBOR interest rates were 2.26% and 2.40%2.60%, respectively. The effectivetarget range for the federal funds rate, which is the cost of immediately available overnight funds, began 20182019 at 1.50%2.25% to 2.50% and subsequently increased 100 basis points (25 basis points in each of, March, June, September and December) to end

2018 at 2.50%. The effective federal funds rate decreased 50 basis points during the third quarter of 2019 (25 basis points in each of August and September) and 25 basis points in October 2019 to end the year at 1.50 to 1.75%. During 2020, the target range for the federal funds rate decreased 150 basis points in March to end the first quarter at 2.00%zero to 0.25%. As noted in the section captioned “Recent Developments Related to COVID-19” elsewhere in this discussion, the decrease in the target range for the federal funds rate in March 2020 was largely an emergency measure by the 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, as market interest rates have increased, we have 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 table 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 quarters 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.
Three Months Ended Nine Months Ended
September 30, 2019 vs. September 30, 2018 September 30, 2019 vs. September 30, 2018Three Months Ended
Increase (Decrease) Due to Change in   Increase (Decrease) Due to Change in  March 31, 2020 vs. March 31, 2019
    Increase (Decrease) Due to Change in  
Rate Volume Total Rate Volume TotalRate Volume Number of days Total
Interest-bearing deposits$934
 $(6,620) $(5,686) $11,214
 $(26,444) $(15,230)$(6,722) $4,119
 $89
 $(2,514)
Federal funds sold and resell agreements46
 (251) (205) 920
 (172) 748
(860) 65
 9
 (786)
Securities:                  
Taxable5,045
 5,738
 10,783
 11,954
 12,086
 24,040
1,975
 (720) 96
 1,351
Tax-exempt(1,398) (869) (2,267) (3,602) 7,734
 4,132
806
 (1,704) 
 (898)
Loans, net of unearned discounts4,247
 10,274
 14,521
 42,837
 31,780
 74,617
(25,224) 10,047
 1,905
 (13,272)
Total earning assets8,874
 8,272
 17,146
 63,323
 24,984
 88,307
(30,025) 11,807
 2,099
 (16,119)
Savings and interest checking(446) 5
 (441) 
 (46) (46)(1,140) 60
 4
 (1,076)
Money market deposit accounts
 369
 369
 18,360
 457
 18,817
(11,532) 481
 107
 (10,944)
Time accounts2,123
 596
 2,719
 6,568
 1,054
 7,622
580
 825
 51
 1,456
Public funds246
 543
 789
 1,740
 1,108
 2,848
(836) 264
 15
 (557)
Federal funds purchased and repurchase agreements1,970
 778
 2,748
 10,843
 876
 11,719
(2,342) 330
 33
 (1,979)
Junior subordinated deferrable interest debentures30
 1
 31
 552
 2
 554
(294) 1
 
 (293)
Subordinated notes payable and other notes(2) 2
 
 (6) 6
 
(2) 2
 
 
Total interest-bearing liabilities3,921
 2,294
 6,215
 38,057
 3,457
 41,514
(15,566) 1,963
 210
 (13,393)
Net change$4,953
 $5,978
 $10,931
 $25,266
 $21,527
 $46,793
$(14,459) $9,844
 $1,889
 $(2,726)
Taxable-equivalent net interest income for the three months ended September 30, 2019 increased $10.9March 31, 2020 decreased $2.7 million, or 4.1%1.0%, while taxable-equivalentcompared to the same period in 2019. Taxable-equivalent net interest income for the ninefirst quarter of 2020 included 91 days compared to 90 days for the first quarter of 2019 as a result of the leap year. The additional day added approximately $1.9 million to taxable-equivalent net interest income during the first quarter of 2020. Excluding the impact of the additional day during the first quarter of 2020 results in an effective decrease in taxable-equivalent net interest income of approximately $4.6 million during the first quarter of 2020. The taxable-equivalent net interest margin decreased 23 basis points from 3.79% during the three months ended September 30,March 31, 2019 increased $46.8 million, or 6.0%, compared to 3.56% during the same periodsthree months ended March 31, 2020. The decreases in 2018. The increasestaxable-equivalent net interest income and taxable-equivalent net interest margin were primarily related to increasesdecreases in the average yields on loans, taxable securities and interest-bearing deposits and federal funds sold and resell agreements combined with increasesdecreases in the average volumes of loanstax-exempt and taxable securities (based on amortized cost) and for the nine months ended September 30, 2019, an increase in the average balance in tax-exempt securities.volume of interest bearing liabilities. The impact of these items was partly offset by increasesdecreases in the average rates paid oncost of interest-bearing deposits and other borrowed funds, and a decreaseincreases in the average volumevolumes of interest bearingloans and interest-bearing deposits (primarily excess reservesamounts held in an interest-bearing account at the Federal Reserve). and increases in the average yields on taxable and tax-exempt securities.

The average volume of interest-earning assets for the three months ended September 30, 2019March 31, 2020 increased $897.6 million, while the average volume of interest-earning assets for the nine months ended September 30, 2019 increased $442.4 million$1.9 billion compared to the same periodsperiod in 2018.2019. The increase in the average volume of interest-earning assets for the three months ended September 30, 2019March 31, 2020 included a $1.1 billionan $866.9 million increase in average taxable securities,interest-bearing deposits, federal funds sold and resell agreements, a $788.1$790.0 million increase in average loans and a $276.0$238.6 million increase in average tax-exempt securities partly offset by a $1.3 billion$45.4 million decrease in average interest-bearing deposits, federal funds sold and resell agreements. The increase in the average volume of interest-earning assets for the nine months ended September 30, 2019 included an $845.3 million increase in average loans, a $793.9 million increase in average taxable securities and a $446.7

million increase in average tax-exempt securities partly offset by a $1.6 billion decrease in average interest-bearing deposits, federal funds sold and resell agreements
The taxable-equivalent net interest margin increased 10 basis points from 3.66% during the three months ended September 30, 2018 to 3.76% during the three months ended September 30, 2019 and increased 19 basis points from 3.61% during the nine months ended September 30, 2018 to 3.80% during the nine months ended September 30, 2019. The increases in the taxable-equivalent net interest margin during the three and nine months ended September 30, 2019 were primarily related to increases in the average yields on loans; taxable securities; interest-bearing deposits; and federal funds sold and resell agreements partly offset by increases in the average cost of interest-bearing deposits and other borrowed funds and a decrease in the average yield on tax-exempt securities. The taxable-equivalent net interest margin was also positively impacted by a decrease in the relative proportion of interest-earning assets invested in lower-yielding interest-bearing deposits (primarily excess reserves held in an interest-bearing account at the Federal Reserve).
The average taxable-equivalent yield on interest-earning assets increased 17decreased 43 basis points from 4.04%4.27% during the three months ended September 30, 2018March 31, 2019 to 4.21%3.84% during the three months ended September 30, 2019 and increased 38 basis points from 3.89% during the nine months ended September 30, 2018 to 4.27% during the nine months ended September 30, 2019.March 31, 2020. The average taxable-equivalent yield on interest-earning assets was primarily impacted by the aforementioned changes in market interest rates and changes in the volume and relative mix of interest-earning assets.
The average taxable-equivalent yield on loans increased 41decreased 68 basis points from 4.86%5.33% during the ninethree months ended September 30, 2018March 31, 2019 to 5.27%4.65% during the ninethree months ended September 30, 2019.March 31, 2020. The average taxable-equivalent yield on loans was positivelynegatively impacted by higherlower average market interest rates in 2019during the three months ended March 31, 2020 compared to 2018.the same period in 2019. The average volume of loans for the ninethree months ended September 30, 2019March 31, 2020 increased $845.3$790.0 million, or 6.3%5.6%, compared to the same period in 2018.2019. Loans made up approximately 49.0%48.7% of average interest-earning assets during the ninethree months ended September 30, 2019March 31, 2020 compared to 46.9%49.1% during the same period in 2018.2019.
The average taxable-equivalent yield on securities was 3.41%3.46% during the ninethree months ended September 30, 2019,March 31, 2020, increasing 39 basis points compared to the 3.38%3.37% during the same period in 2018.2019. The average taxable-equivalent yield on securities during the ninethree months ended September 30, 2019March 31, 2020 compared to the same period in 20182019 was positively impacted by increases in the average volumeyields on both taxable and tax-exempt securities as a result of investments in higher-yielding, longer-duration securities while the relative proportions of taxable and tax-exempt and taxable securities and an increase in the average yield on taxableto total securities but was negatively impacted by a decrease in the average yield on tax-exempt securities.did not significantly change. The average yield on taxable securities increased 3517 basis points from 2.00%2.19% during the ninethree months ended September 30, 2018March 31, 2019 to 2.35%2.36% during the ninethree months ended September 30, 2019.March 31, 2020. This increase resulted as the proceeds from the maturity of a significant volume of U.S. Treasury securities during the second half of 2019 were reinvested in higher-yielding residential mortgage-backed securities. The average taxable-equivalent yield on tax-exempt securities decreased 6increased 4 basis points from 4.12%4.03% during the ninethree months ended September 30, 2018March 31, 2019 to 4.06%4.07% during the ninethree months ended September 30, 2019.March 31, 2020. Tax exempt securities made up approximately 62.3%65.3% of total average securities during the ninethree months ended September 30, 2019,March 31, 2020, compared to 65.0%64.4% during the same period in 2018.2019. The average volume of total securities (based on carrying amount) during the ninethree months ended September 30, 2019March 31, 2020 increased $1.2 billion,$193.1 million, or 10.4%1.5%, compared to the same period in 2018.2019. Securities made up approximately 45.1%42.1% of average interest-earning assets during the ninethree months ended September 30, 2019March 31, 2020 compared to 41.4%44.1% during the same period in 2018.2019.
Average interest-bearing deposits, federal funds sold and resell agreements for the ninethree months ended September 30, 2019 decreased $1.6 billion,March 31, 2020 increased $866.9 million, or 48.8%43.8%, compared to the same period in 2018.2019. Interest-bearing deposits, federal funds sold and resell agreements made up approximately 5.9%9.2% of average interest-earning assets during the ninethree months ended September 30, 2019March 31, 2020 compared to 11.7%6.8% during the ninethree months ended September 30, 2018.March 31, 2019. The decreaseincrease in the average volume of interest-bearing deposits, federal funds sold and resell agreements was primarily due to a decreasean increase in the average volume of our excess reservesamounts held in an interest-bearing account at the Federal Reserve during the first ninethree months of 20192020 compared to the same period in 2018 as such funds were invested2019 primarily due to an increase in higher yielding loansthe average volume of deposits and the proceeds from the sale of securities. The combined average yield on interest-bearing deposits, federal funds sold and resell agreements was 2.41%1.24% during the ninethree months ended September 30, 2019March 31, 2020 compared to 1.83%2.51% during the same period in 2018.2019. The average yield on interest-bearing deposits, federal funds sold and resell agreements was positivelynegatively impacted by higherlower average market interest rates in 2019for the three months ended March 31, 2020 compared to 2018.the same period in 2019.
The average rate paid on interest-bearing liabilities was 0.79%0.47% during the ninethree months ended September 30, 2019 increasing 30March 31, 2020 decreasing 34 basis points from 0.49%0.81% during the same period in 2018.2019. Average deposits decreased $62.6 million,increased $1.3 billion, or 0.24%4.9%, during the ninethree months ended September 30, 2019March 31, 2020 compared to the same period in 20182019 and included a $543.2 million decrease in average non-interest bearing deposits mostly offset by a $480.7$734.8 million increase in average interest-bearing deposits and a $544.9 million increase in average non-interest bearing deposits. The ratio of average interest-bearing deposits to total average deposits was 60.9%60.8% during the ninethree months ended September 30, 2019March 31, 2020 compared to 58.9%61.0% during the same period in 2018.2019. 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 0.67%0.39% and 0.41%0.24%, respectively, during the ninethree months ended September 30, 2019March 31, 2020 compared to 0.44%0.69% and 0.26%0.42%, respectively, during the ninethree months ended September 30, 2018.March 31, 2019. The average cost of deposits during 2019the first quarter of 2020 was impacted by

increases decreases in the interest rates we pay on most of our interest-bearing deposit products as a result of the aforementioned increasesdecreases in market interest rates and market competition.rates.
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 3.48%3.37% during the ninethree months ended September 30, 2019March 31, 2020 compared to 3.40%3.46% during same period in 2018.2019. 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 8 - Derivative Financial Instruments in the accompanying notes to consolidated financial statements included elsewhere in 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.
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 U.S. Small Business Administration (“SBA”) under the provisions of the CARES Act. Through April 27, 2020, we have funded approximately $3.0 billion of SBA-approved PPP loans to over 10,500 customers. We expect to recognize approximately $87.0 million in PPP loan related processing fees as a yield adjustment over the terms of these loans. In April 2020, we borrowed $250 million from the FHLB under the COVID-19 Relief Program to provide supplemental funding for PPP loan originations. The short-term, full-recourse advance has a term of six months and bears interest at an annualized rate of 0.25%. We are currently considering participation in the Federal Reserve's PPP Facility, as further discussed in the sections captioned “Loans” and “Capital and Liquidity” elsewhere in this discussion.
We currently expect our net interest income and net interest margin to decline in the latter part of 2020 as a result of the aforementioned decreases in market interest rates and the expectation that interest rates will remain at such levels for some period of time. The near term impact of the decrease in market interest rates is partly mitigated as certain variable-rate loans adjust on a delayed basis. Additionally, our participation in the PPP, as further discussed below, is expected to positively impact net interest income and net interest margin.
Provision for Loan LossesCredit Loss Expense
The provision for loan lossesCredit 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. The provision for loan losseslives of the respective financial instruments. Credit loss expense totaled $8.0 million and $25.4$175.2 million for the three and nine months ended September 30, 2019 comparedMarch 31, 2020, of which $172.9 million related to $2.7loans and $2.3 million and $17.8related to off-balance-sheet credit exposures. Credit loss expense totaled $11.0 million for the three and nine months ended September 30, 2018.March 31, 2019, all of which related to loans and which was calculated under the 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 commitments.
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 
 March 31,
2019 2018 2019 20182020 2019
Trust and investment management fees$31,649
 $30,801
 $93,794
 $89,509
$34,473
 $31,697
Service charges on deposit accounts22,941
 21,569
 65,529
 63,554
22,651
 20,790
Insurance commissions and fees11,683
 11,037
 40,207
 37,573
16,485
 18,406
Interchange and debit card transaction fees4,117
 3,499
 11,265
 10,103
3,255
 3,280
Other charges, commissions and fees10,108
 9,580
 28,103
 27,860
9,365
 9,062
Net gain (loss) on securities transactions96
 (34) 265
 (113)108,989
 
Other8,630
 11,205
 29,484
 35,682
17,697
 13,550
Total$89,224
 $87,657
 $268,647
 $264,168
$212,915
 $96,785
Total non-interest income for the three months ended September 30, 2019March 31, 2020 increased $1.6$116.1 million, or 1.8%, while total non-interest income for the nine months ended September 30, 2019 increased $4.5 million, or 1.7%120.0%, compared to the same periodsperiod in 2018, respectively.2019. Excluding $109.0 million net gain on securities transaction during the three months ended March 31, 2020, total non-interest income increased $7.1 million, or 7.4%. 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, 2019March 31, 2020 increased $848 thousand, or 2.8%, and $4.3$2.8 million, or 4.8%8.8%, compared to the same periodsperiod in 2018, respectively.2019. Investment fees are the most significant component of trust and investment management fees, making up approximately 82.5%78.7% and 83.2% of total trust and investment management fees for both the first ninethree months of 2020 and 2019, respectively. The increase in trust and 2018.investment management fees was primarily the

result of increases in estate fees (up $1.1 million), trust investment fees (up $749 thousand), real estate fees (up $641 thousand) and oil and gas fees (up $475 thousand). Investment and other custodial account fees are generally based on the market value of assets within a trust account. The increase in estate fees and real estate fees were primarily related to an increase in transaction volume. The increase in trust investment fees was primarily related to an increase in the number of accounts partly offset by the impact of a decrease in average equity valuations. Volatility in the equity and bond markets impacts the market value of trust assets and the related investment fees. The increaseInvestor concerns related to the uncertain economic outlook arising from the COVID-19 pandemic have caused significant market volatility resulting in significant declines in market valuations, particularly among equity securities, during the latter part of the first quarter of 2020. We currently expect this volatility and the decline in market valuations will adversely affect trust and investment management fees during the three and nine months ended September 30, 2019 comparedfee income in future periods. Furthermore on-going uncertainty related to the same periods in 2018 was primarilyeconomic effects of COVID-19 is currently expected to impact the result of increases indemand and overall transaction volume for our other trust investment fees (up $793 thousandservices and $3.5 million, respectively) due to higher average equity valuations and an increase in the number of accounts.further adversely affect our revenues.
At September 30, 2019,March 31, 2020, trust assets, including both managed assets and custody assets, were primarily composed of equity securities (49.7%(46.1% of assets), fixed income securities (36.3%(37.6% of assets) and cash equivalents (8.7%(9.4% of assets). The estimated fair value of these assets was $36.4$33.9 billion (including managed assets of $15.7$14.6 billion and custody assets of $20.7$19.3 billion) at September 30, 2019,March 31, 2020, compared to $33.3$37.8 billion (including managed assets of $14.7$16.4 billion and custody assets of $18.7$21.4 billion) at December 31, 20182019 and $34.7$35.0 billion (including managed assets of $15.6$15.0 billion and custody assets of $19.1$20.0 billion) at September 30, 2018.

March 31, 2019.
Service Charges on Deposit Accounts. Service charges on deposit accounts for the three and nine months ended September 30, 2019March 31, 2020 increased $1.4$1.9 million, or 6.4%, and $2.0 million, or 3.1%, respectively,9.0% compared to the same periodsperiod in 2018.2019. The increases wereincrease was primarily related to an increase in commercial service charges (up $1.3 million) and increases in overdraft/insufficient funds charges on consumer and commercial accounts (up $1.2 million$668 thousand and $3.2 million,$209 thousand, respectively) partly offset, during the nine months ended September 30, 2019, by a decrease. The increase in commercial service charges (down $942 thousand). Overdraft/insufficient funds charges totaled $11.2 million ($8.8 million consumer and $2.4 million commercial) during the three months ended September 30, 2019 compared to $10.0 million ($7.8 million consumer and $2.2 million) during the same period in 2018. Overdraft/insufficient funds charges totaled $31.1 million ($24.3 million consumer and $6.8 million commercial) during the nine months ended September 30, 2019 compared to $28.0 million ($21.6 million consumer and $6.4 million commercial) during the same period in 2018. The increases in overdraft/insufficient funds charges were partly due to increased transaction volumes during the three and nine months ended September 30, 2019 compared to the same periods in 2018. Overdraft/insufficient funds charges were alsowas impacted by a change in the fee schedule during the second quarter of 2019. The decrease in commercial service charges were partly related to a higherlower earnings credit rate. The earnings credit rate is the value given to deposits maintained by treasury management customers. Because average market interest rates in 2019 were higher compared to 2018, deposit balances have become more valuable and are yielding a higher earnings credit rate. Earnings credits applied to customer deposit balances offset service fees that would otherwise be charged. Because average market interest rates in 2020 were lower compared to 2019, deposit balances have become less valuable and are yielding a lower earnings credit rate. Overdraft/insufficient funds charges totaled $10.5 million ($8.1 million consumer and $2.4 million commercial) during the three months ended March 31, 2020 compared to $9.6 million ($7.4 million consumer and $2.2 million commercial) during the same period in 2019. The increases in overdraft/insufficient funds charges were partly due to increased transaction volumes during the three months ended March 31, 2020 compared to the same period in 2019. In response to the economic pressures and uncertainties faced by our customers as a result of the COVID-19 pandemic, we have begun to waive certain deposit account related fees on a case-by-case basis as needed and requested by our customers. In some cases, overdraft/insufficient funds charges are automatically waived or reimbursed. We currently expect these actions to result in reduced service charges on deposit accounts.
Insurance Commissions and Fees. Insurance commissions and fees for the three months ended September 30, 2019 increased $646 thousand,March 31, 2020 decreased $1.9 million, or 5.9%10.4%, compared to the same period in 2018.2019. The increasedecrease was related to an increasedecreases in commission income (up $666(down $1.3 million) and contingent income (down $591 thousand). Insurance commissions and fees for the nine months ended September 30, 2019 increased $2.6 million, or 7.0%, compared to the same period in 2018. The increase was related to an increasedecrease in commission income (up $3.0 million) partly offset by a decrease in contingent income (down $341 thousand). The increase in commission income during the three months ended September 30, 2019 was primarily related to an increasedecreases in benefit plan commissions, life insurance commissions and commissions on commercial lines property and casualty policies. The increasedecrease in commission income during the nine months ended September 30, 2019 was primarily related to increases in commissions on commercial lines property and casualty policies, benefit plan commissions was related to decreased business volumes, premium reductions and life insurance commissions.flat to lower market rates. The increasesdecreases in property and casualty commissions and benefit planlife insurance commissions were related to increased business volumes and market rates. The increase in life insurance commissions was related to increaseddecreased business volumes.
Contingent income totaled $254 thousand and $3.8$2.6 million during the three and nine months ended September 30, 2019, respectively,March 31, 2020 compared to $273 thousand and $4.2$3.2 million during the same periodsperiod in 2018.2019. 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 $2.8$2.0 million and $3.1$2.6 million during the ninethree months ended September 30,March 31, 2020 and 2019, and 2018, respectively. The decrease in performance related contingent income during 20192020 was related to lower growth within the portfolio partly offset by the impact of improvementcombined 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 $193$608 thousand and $1.1 million during the three and nine months ended September 30, 2019, respectively,March 31, 2020 and $200$603 thousand and $1.1 million during the same periodsperiod in 2018.2019.
We currently expect commission income to be adversely impacted by reduced business volumes resulting from the COVID-19 pandemic. We currently expect benefit plan commissions will be particularly impacted by the effects of temporary furloughs and permanent layoffs. Further, clients may drop or adjust coverage choices as part of expense control measures as their businesses reopen from the temporary shutdown. Reduced business volumes are also expected to adversely impact the level of contingent commissions we receive in 2021. The COVID-19 pandemic has also given rise to a hard insurance market characterized by decreased capacity for most types of insurance coupled with more stringent underwriting standards among insurers, which could potentially result in reduced commissions to agencies.

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 debit 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 reported periods is presented in the table below:
 Three Months Ended 
 September 30,
 Nine Months Ended 
 September 30,
 2019 2018 2019 2018
Income from debit card transactions$6,191
 $5,484
 $17,569
 $16,075
ATM service fees1,069
 991
 3,136
 2,954
Gross interchange and debit card transaction fees7,260
 6,475
 20,705
 19,029
Network costs3,143
 2,976
 9,440
 8,926
Net interchange and debit card transaction fees$4,117
 $3,499
 $11,265
 $10,103
The increase inbelow. We currently expect that revenue from interchange and debit card transactions will be impacted by reduced transaction fees during 2019, on a net basis, was primarily related to increased transaction volumes.volumes and fee waivers resulting from the COVID-19 pandemic.
 Three Months Ended 
 March 31,
 2020 2019
Income from debit card transactions$5,805
 $5,405
ATM service fees927
 981
Gross interchange and debit card transaction fees6,732
 6,386
Network costs3,477
 3,106
Net interchange and debit card transaction fees$3,255
 $3,280
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, 2019March 31, 2020 increased $528$303 thousand, or 5.5%3.3%, compared to the same period in 2018.2019. The increase was primarily related toincluded increases in income from the sale of mutual funds (up $412 thousand), money market accounts (up $426$253 thousand) and annuities (up $218 thousand); and an increase in brokerage commissions (up $139 thousand), among other things. These items were partly offset by decreases in income from the sale of life insurance (down $377 thousand), letter of credit fees (up $256(down $366 thousand) and income from capital markets advisory services (up $131(down $135 thousand), among other things, partly offsetthings. We currently expect that most of the aforementioned revenue streams will be adversely impacted by decreases in income from sale of life insurance (down $322 thousand) and processing fees (down $181 thousand). Other charges, commissions and fees for the nine months ended September 30, 2019 increased $243 thousand, or 0.9%, compared to the same period in 2018. The increase was primarily related to increases in incomereduced transaction volumes resulting from the sale of money market accounts (up $1.1 million) and letter of credit fees (up $534 thousand), among other things, mostly offset by decreases in processing fees (down $592 thousand), brokerage commissions (down $392 thousand), income from the sale of mutual funds and annuities (down $268 thousand and $247 thousand, respectively) and income from capital markets advisory services (down $225 thousand).COVID-19 pandemic.
Net Gain/Loss on Securities Transactions. During the ninethree months ended September 30,March 31, 2020 and 2019, and 2018, we sold certain available-for-sale U.S Treasury securities with amortized costs totaling $7.4$1.0 billion and $13.8 billion,$944.9 million, respectively. We realized a net gain of $99 thousand$109.0 million on the 2020 sales while no significant net gain or loss was realized on the 2019 salessales. During the first quarter of 2020, we sold $483.1 million of residential mortgage-backed securities and realized a net lossgain of $113 thousand$1.9 million on the 2018those sales. The proceeds from these sales were reinvested into other residential mortgage-backed securities that had lower pre-payment rates. We also sold $519.1 million of 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 the 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. The sales of securities during the first quarter of 2019 were primarily related to securities purchased and subsequently sold in the same period of their purchase 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.
Additionally, during the second quarter of 2019, we sold certain available-for-sale U.S. Treasury securities with an amortized cost totaling $548.9 million and certain available-for-sale municipal securities with an amortized cost totaling $310.7 million. We realized a net gain of $166 thousand on those sales. The proceeds from the sales provided short-term liquidity and were subsequently reinvested in other higher yielding securities.
Other Non-Interest Income. Other non-interest income for the three months ended September 30, 2019 decreased $2.6March 31, 2020 increased $4.1 million, or 23.0%30.6%, compared to the same period in 2018.2019. Other non-interest income during the three months ended March 31, 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 decreaseput options were not exercised and expired in March 2020. The increase in other non-interest income during the three months ended March 31, 2020 was primarilyalso partly related to decreasesan increase in sundry and other miscellaneous income (down $2.9 million) and income from customer derivative and trading activities (down $798 thousand)(up $1.6 million), primarily due to an increase in business volume, and an increase in sundry and other miscellaneous income (up $1.2 million). During the comparable periods, sundry and other miscellaneous income included $2.5 million and $931 thousand related to the recovery of prior write-offs in 2020 and 2019, respectively, and $250 thousand related to a settlement in 2019. The aforementioned items were partly offset by increasesa decrease in gains on the sale of foreclosed and other assets (up $638 thousand) and public finance underwriting fees (up $430 thousand)(down $4.6 million). Other non-interest income for the ninethree months ended September 30,March 31, 2019 decreased $6.2 million, or 17.4%, compared to the same period in 2018. The decrease was primarily related to decreases in sundry and other miscellaneous income (down $4.9 million) and income from customer derivative and trading activities (down $1.8 million) partly offset by an increase in public finance underwriting fees (up $299 thousand). Sundry income during the nine months ended September 30, 2019 included $1.1 million related to the recovery of prior write-offs, $277 thousand related to distributions from a private equity investment and $250 thousand related to a settlement, among other things, while sundry income for the same period in 2018 included $4.5 million related to the recovery of prior write-offs, $1.2 million related to a distribution from a private equity investment and $775 thousand related to the settlement of an insurance claim, among other things. The fluctuations in public finance underwriting fees and income from customer derivative and trading activities during the three and nine months ended September 30, 2019 were primarily related to changes in business volumes. Other non-interest income also included gains on the sale of various branch and operational facilities totaling $6.7 million during the nine months ended September 30, 2019 and $6.8 million during the same period in 2018.$4.7 million.

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 
 March 31,
2019 2018 2019 20182020 2019
Salaries and wages$93,812
 $87,547
 $277,078
 $259,434
$98,812
 $92,476
Employee benefits21,002
 18,355
 64,579
 58,257
24,889
 23,526
Net occupancy24,202
 19,894
 64,602
 59,089
25,384
 19,267
Technology, furniture and equipment22,415
 21,004
 66,236
 61,142
25,240
 21,664
Deposit insurance2,491
 4,694
 7,752
 14,178
2,624
 2,808
Intangible amortization274
 336
 904
 1,093
257
 325
Other44,668
 41,838
 132,722
 125,994
46,957
 41,734
Total$208,864
 $193,668
 $613,873
 $579,187
$224,163
 $201,800
Total non-interest expense for the three and nine months ended September 30, 2019March 31, 2020 increased $15.2$22.4 million, or 7.8%, and $34.7 million, or 6.0%11.1%, compared to the same periodsperiod in 2018, respectively.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, 2019March 31, 2020 increased $6.3 million, or 7.2%, and $17.6 million, or 6.8%6.9%, compared to the same periodsperiod in 2018.2019. The increases wereincrease was primarily related to increasesan increase in salaries, due to an increase in the number of employees and normal annual merit and market increases and, to a lesser extent, increases in incentive compensation. The increase for the nine months ended September 30, 2019 was also impacted by an increase in stock compensation.increases.
Employee Benefits. Employee benefits expense for the three and nine months ended September 30, 2019March 31, 2020 increased $2.6$1.4 million, or 14.4%, and $6.3 million, or 10.9%5.8%, compared to the same periodsperiod in 2018, respectively.2019. The increases wereincrease was primarily due to increases in medical benefits expense (up $838 thousand$1.5 million) and $2.1 million, respectively), expensespayroll taxes (up $639 thousand) partly offset by a decrease in expense related to our defined benefit retirement plans (up $585 thousand and $1.8 million, respectively), expenses related to our 401(k) plan (up $373 thousand and $1.3 million, respectively) and payroll taxes (up $562 thousand and $859 thousand, respectively)(down $821 thousand).
During the three and nine months ended September 30, 2019,March 31, 2020, we recognized a combined net periodic pension expensebenefit of $331$490 thousand and $993 thousand, respectively, related to our defined benefit retirement plans compared to a combined net periodic pension benefitexpense of $254 thousand and $762$331 thousand during the same periodsperiod in 2018.2019. Our defined benefit retirement and restoration plans were frozen effective as of December 31, 2001 and were replaced by a profit sharing 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, 2019March 31, 2020 increased $4.3$6.1 million, or 21.7%31.7%, and $5.5 million, or 9.3%, respectively, compared to the same periodsperiod in 2018.2019. The increases during the three and nine months ended September 30, 2019 wereincrease was primarily related to increases in lease expense (up $3.8 million and $6.0 million, respectively) and$2.8 million), depreciation on leasehold improvements (up $708 thousand and $1.2 million, respectively) partly offset by decreases in$1.1 million), property taxes (down $370 thousand(up $813 thousand), building depreciation (up $498 thousand) and $1.9 million, respectively)repairs and utilitiesmaintenance/service contracts expense (down $438 thousand and $838 thousand, respectively)(up $475 thousand). Fluctuations in the foregoing categories of netNet occupancy expense were primarily related towas impacted by the commencement of the lease of our new corporate headquarters building in San Antonio andin June 2019, as well as renewals of other leases related to existing facilities and new locations, in part related to our expansion within the Houston market area.
Technology, Furniture and Equipment. Technology, furniture and equipment expense for the three and nine months ended September 30, 2019March 31, 2020 increased $1.4$3.6 million, or 6.7%16.5%, and $5.1 million, or 8.3%, respectively, compared to the same periodsperiod in 2018.2019. The increases wereincrease was primarily related to increases in cloud services expense (up $1.5 million), software maintenance (up $1.7 million$1.2 million) and $4.8 million for the threedepreciation of furniture and nine months ended September 30, 2019, respectively). The increase for the nine months ended September 30, 2019 was also impacted by an increase in software amortizationequipment (up $483$995 thousand).
Deposit Insurance. Deposit insurance expense totaled $2.5 million and $7.8$2.6 million for the three and nine months ended September 30, 2019March 31, 2020 compared to $4.7 million and $14.2$2.8 million for the three and nine months ended September 30, 2018. The decrease inMarch 31, 2019. Provisions of the CARES Act allow, but do not require, the FDIC to expand deposit insurance expense during 2019 was primarily related to the terminationcoverage for non-interest-bearing transaction accounts through December 31, 2020. Such action could result in additional deposit insurance expense. Other provisions of the quarterly Deposit Insurance Fund surcharge in the fourth quarter of 2018,CARES Act as further discussed below.
In August 2016, the Federal Deposit Insurance Corporation (“FDIC”) announced that the Deposit Insurance Fund reserve ratio had surpassed 1.15%well as of June 30, 2016. Asactions taken by bank regulators, such as potential relief for working with borrowers who are distressed as a result beginning inof the third quartereffects 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 was terminated in the fourth quarter of 2018 as the Deposit Insurance Fund reserve ratio as of September 30, 2018 exceeded the statutory minimum of 1.35% required by the Dodd-Frank Act.COVID-19, could similarly impact aggregate deposit insurance expense.

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, 2019March 31, 2020 decreased $62$68 thousand, or 18.5%20.9%, and $189 thousand, or 17.3%, respectively, compared to the same periodsperiod in 2018.2019. The decrease in amortization during 20192020 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 and nine months ended September 30, 2019March 31, 2020 increased $2.8$5.2 million, or 6.8%12.5%, and $6.7 million, or 5.3%, respectively, compared to the same periodsperiod in 2018.2019. The increase during the three months ended September 30, 2019 included among other things, increases in professional services expense (up $2.3$1.5 million); donations expense (up $912 thousand); platform fees related to investment services (up $558$697 thousand); losses on the sale of foreclosed and other assets (up $424 thousand) and computer services expense (up $325 thousand). The increase from these items was partly offset by a decrease in advertising/promotions expense (down $1.3 million), among other things. The increase during the nine months ended September 30, 2019 included, among other things, increases in advertising/promotions expense, partly related to new sponsorship arrangements (up $5.5 million); professional services expense (up $2.2 million); platform fees related to investment services (up $2.1 million); and travel, meals and entertainment expense (up $1.4 million). The increase from these items was partly offset by decreases in donations expense, which was impacted by a significant contribution to our charitable foundation in 2018 (down $4.1 million)$548 thousand); and sundry and other miscellaneous expense (down $1.4 million).(up $435 thousand), among other things.
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 15 - 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 
 March 31,
2019 2018 2019 20182020 2019
Banking$110,583
 $114,214
 $334,393
 $327,131
$52,024
 $112,917
Frost Wealth Advisors4,106
 6,442
 15,403
 17,977
5,587
 6,400
Non-Banks(2,853) (2,812) (9,878) (9,443)(2,858) (2,821)
Consolidated net income$111,836
 $117,844
 $339,918
 $335,665
$54,753
 $116,496
Banking
Net income for the three and nine months ended September 30, 2019March 31, 2020 decreased $3.6$60.9 million, or 3.2%, and increased $7.3 million, or 2.2%53.9%, compared to the same periodsperiod in 2018.2019. The decrease during the three months ended September 30, 2019March 31, 2020 was primarily the result of an $11.5a $164.2 million increase in credit loss expense, a $17.6 million increase in non-interest expense and a $5.4$2.2 million increase in the provision for loan losses partly offset by an $11.4 million increase in net interest income, an $839 thousand increase in non-interest income and a $980 thousand decrease in income tax expense. The increase during the nine months ended September 30, 2019 was primarily the result of a $44.8 million increase in net interest income partly offset by a $27.1$113.0 million increase in non-interest expense, a $7.6 million increase in the provision for loan lossesincome and a $2.7$10.1 million increasedecrease in income tax expense.
Net interest income for the three and nine months ended September 30, 2019 increased $11.4March 31, 2020 decreased $2.2 million, or 4.7%, and $44.8 million, or 6.3%0.9%, compared to the same periodsperiod in 2018.2019. The increases weredecrease was primarily related to increasesdecreases in the average yields on loans, taxable securities and interest-bearing deposits and federal funds sold and resell agreements combined with increasesdecreases in the average volumes of loanstax-exempt and taxable securities (based on amortized cost) and for the nine months ended September 30, 2019, an increase in the average balance in tax-exempt securities.volume of interest bearing liabilities. The impact of these items was partly offset by increasesdecreases in the average rates paid oncost of interest-bearing deposits and other borrowed funds, and a decreaseincreases in the average volumevolumes of interest bearingloans and interest-bearing deposits (primarily excess reservesamounts held in an interest-bearing account at the Federal Reserve). and increases in the average yields on taxable and tax-exempt securities. Net interest income for the first quarter of 2020 was also positively impacted by the additional day as a result of leap year. 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, 2019March 31, 2020 totaled $8.0 million and $25.4$175.2 million compared to $2.6 million and $17.8$11.0 million for the same periods in 2018.2019. The increase 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.discussion for further analysis of credit loss expense related to loans and off-balance-sheet commitments.
Non-interest income for the three and nine months ended September 30, 2019March 31, 2020 increased $839 thousand,$113.0 million, or 1.6%, and decreased$161 thousand, or 0.1%,186.9% compared to the same periodsperiod in 2018, respectively.2019. The increase was primarily due to a $109.0 million net gain on securities transactions during the three months ended September 30, 2019March 31, 2020. Excluding the net gain on securities transactions during the three months ended March 31, 2020, total non-interest income for the Banking segment increased $4.0 million, or 6.6%. This increase was primarily due to increases in other non-interest income and service charges on deposit accounts;accounts partly offset by decreases in insurance commissions and fees; interchange and debit card transaction fees;fees and other charges, commissions and feesfees. The increase in other non-interest income was partly related to $6.0 million in gains realized on the sale of certain non-hedge related, short-term put options on U.S. Treasury securities during the three months ended March 31, 2020. The increase in other non-interest income was also partly related to an increase in income from customer derivative and trading activities, primarily due to an increase in business volume, and an increase in sundry and other miscellaneous income. The aforementioned items were partly offset by a decrease in gains on the sale of foreclosed and other non-interest income. The decrease duringassets as we realized gains on the nine months ended September 30, 2019 was primarily due to a decrease in other non-interest income mostly offset by increases in insurance commissionssale of various branch and fees; service charges on deposit accounts and interchange and debit card transaction fees. The increase in insurance commissions and feesoperational facilities totaling $4.7 million during the three and nine months ended September 30, 2019 was primarily related to increased business volumes and market rates partly offset by a decrease in contingent income.March 31, 2019. The

increase in service charges on deposit accounts during 2019 was primarily related to an increase in commercial service charges, which was partly due to a lower earnings credit rate given to our treasury management customers due to lower average market interest rates, and increases in overdraft/insufficient funds charges on consumer and commercial accounts, which was partly offset by a decrease in commercial service charges. The increase in interchange and debit card transaction fees during 2019 was primarily relateddue to increased transaction volumes. The increasedecrease in

insurance commissions and fees was partly related to decreases in business volumes and, for benefit plan commissions, premium reductions and flat to lower market rates. The decrease was also partly related to a decrease in contingent income due to lower growth and a deterioration in the loss performance of insurance policies previously placed. The decrease in other charges, commissions and fees during the three months ended September 30, 2019 was primarily related to increasesdecreases in letter of credit fees and income from capital markets advisory services, and unused balance fees on loan commitments. The decreases inamong other non-interest income during the three and nine months ended September 30, 2019 were primarily related to decreases in sundry and other miscellaneous income and income from customer derivative and trading activities partly offset by an increase in public finance underwriting fees and, for the three months ended September 30, 2019, gains on the sale of foreclosed and other assets.things. 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 for the three and nine months ended September 30, 2019March 31, 2020 increased $11.5$17.6 million, or 7.0%, and $27.1 million, or 5.5%10.3%, compared to the same periodsperiod in 2018.2019. The increases wereincrease was primarily related to increases in salaries and wages; employee benefits;net occupancy expense; technology, furniture and equipment expense; net occupancy expense; and other non-interest expense partly offset by decreases in deposit insurance expense.and employee benefits. The increasesincrease in salaries and wages during 2019 werewas primarily related to an increase in salaries, due to an increase in the number of employees and normal annual merit and market increases and, to a lesser extent increases in incentive compensation.increases. The increase in salaries expense during the nine months ended September 30, 2019 was also impacted by an increase in stock compensation. The increases in employee benefits were primarily related to increases in medical benefits expense, expenses related to our defined benefit retirement plans, expenses related to our 401(k) plan and payroll taxes. The increases in technology, furniture and equipment expense during 2019 were primarily related to increases in software maintenance, software amortization and depreciation. The increases in net occupancy expense during 2019 werewas primarily related to increases in lease expense, depreciation on leasehold improvements, and insurance expense partly offset by decreases in property taxes, building depreciation and utilities expenses.repairs and maintenance/service contracts expense. Net occupancy expense was impacted by the commencement of the lease of our new corporate headquarters building in San Antonio in June 2019, as well as renewals of other leases related to existing facilities and new locations, in part related to our expansion within the Houston market area. The increase in technology, furniture and equipment expense was primarily related to increases in cloud services expense, software maintenance and depreciation of furniture and equipment. The increase in other non-interest expense during the three months ended September 30, 2019 compared to the same period in 2018 included increases in professional services expense; losses on the sale of foreclosed and other assets; and stationary/suppliesdonations expense, partly offset by a decrease in advertising/promotions expense, among other things. The increase in other non-interest expense during the nine months ended September 30, 2019 compared to the same period in 2018 included increases in advertising/promotions expense; professional services expense; travel, meals and entertainment; losses on the sale of foreclosed and other assets; and stationary/supplies expense partly offset by decreases in donations expense and sundry and other miscellaneous expense, among other things. The decreasesincrease in deposit insuranceemployee benefits was primarily due to increases in medical benefits expense during 2019 were primarilyand payroll taxes partly offset by a decrease in expense related to the termination of the quarterly Deposit Insurance Fund surcharge in the fourth quarter of 2018.our defined benefit retirement plans. 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 $11.7$16.6 million and $40.3 million during the three and nine months ended September 30, 2019 compared to $11.0 million and $37.7 million during the three and nine months ended September 30, 2018. The increase during the three months ended September 30, 2019March 31, 2020 compared to $18.5 million during the three months ended March 31, 2019. The decrease during the three months ended March 31, 2020 was primarilypartly related to an increasedecreases in commissions on commercial lines propertybusiness volumes and, casualty policies. The increase during the nine months ended September 30, 2019 was primarily related to increases in commissions on commercial lines property and casualty policies; benefit plan commissions; and life insurance commissions. The increases in property and casualty commissions andfor benefit plan commissions, were relatedpremium reductions and flat to increased business volumes andlower market rates. The increase in life insurance commissionsdecrease was also partly related to increased business volumes.a decrease in contingent income 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, 2019March 31, 2020 decreased $2.3 million,$813 thousand, or 36.3%, and $2.6 million, or 14.3%12.7%, compared to the same periodsperiod in 2018.2019. The decreases were primarily related to increases in non-interest expense (up $3.6 million and $7.8 million, respectively) partly offset by increases in non-interest income (up $720 thousand and $4.6 million, respectively) and decreases in income tax expense (down $621 thousand and $686 thousand, respectively).
Non-interest income for the three and nine months ended September 30, 2019 increased $720 thousand, or 2.0%, and $4.6 million, or 4.4%, compared to the same periods in 2018. The increases were primarily related to an increase in non-interest expense (up $4.3 million) partly offset by an increase in non-interest income (up $3.3 million) and a decrease in income tax expense (down $216 thousand.
Non-interest income for the three months ended March 31, 2020 increased $3.3 million, or 9.2%, compared to the same period in 2019. The increase was primarily related to an increases in trust and investment management fees and 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 82.5%78.7% of total trust and investment management fees for the first ninethree months of 2019.2020. The increase in trust and investment management fees was primarily the result of increases in estate fees, trust investment fees, real estate fees and oil and gas fees. Investment and other custodial account fees are generally based on the market value of assets within a trust account. VolatilityThe increase in the equityestate fees and bond markets impacts the market value of trust assets and the related investment fees. The increases in trust and investment managementreal estate fees during the three and nine months ended September 30, 2019 compared to the same periods in 2018 were primarily the result of increasesrelated to an increase in transaction volume. The increase in trust investment fees duewas primarily related to higher average equity valuations and an increase in the number of accounts.accounts partly offset by the impact of a decrease in average equity valuations. The increase in other charges, commissions and fees was primarily due to increases in income from the sale of mutual funds, money market accounts and annuities; and an increase in brokerage commissions, among other things, partly offset by a decrease in income from the sale of life insurance, among other things. 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, 2019March 31, 2020 increased $3.6$4.3 million, or 12.7%, and $7.8 million, or 9.4%,14.7% compared to the same periodsperiod in 2018.2019. The increases wereincrease was primarily related to increases in net occupancy expense, other non-interest expense, net occupancy expense and salaries and wages. The increasesincrease in net occupancy expense was primarily related to an increase in lease expense. The increase in other non-interest expense during 2019 were primarily

was due to increases in platform fees related to investment services; outside computer services; professional serviceservices expense; and travel, mealssundry and entertainmentother miscellaneous expense, among other things. The increasesincrease in salaries and wages during 2019 were primarilywas partly due to an increase in the number of employees and normal annual merit and market increases, as well as increases in incentive compensation. The increases in net occupancy expense during 2019 were partly related to increases in lease overhead allocations.increases.

Non-Banks
The Non-Banks operating segment had a net lossesloss of $2.9 million and $9.9 million during the three and nine months ended September 30, 2019, respectively,March 31, 2020, compared to a net losses of $2.8 million and $9.4 million during the same periods in 2018. The increased net losses2019. Net loss for the three and nine months ended September 30,March 31, 2020 compared to the same period in 2019 werewas negatively impacted by an increase in other non-interest expense, which was primarily due to increasesan increase in professional services expense, among other things, and a decrease in other non-interest income, which was primarily due to a decrease in mineral interest income. The impact from these items was mostly offset by a decrease in net interest expense, duewhich was primarily related to increasesa decrease in the interestaverage rate paid on our long-term borrowings, and increasesan increase in other non-interest expense partly offset by decreases in salaries and wages compared to the same periods in 2018.income tax benefit.
Income Taxes
We recognized income tax expense of $13.5 million and $42.4$3.3 million, for an effective tax rate of 10.8% and 11.1%5.7% for the three and nine months ended September 30, 2019March 31, 2020 compared to $15.2 million and $40.2$14.0 million, for an effective tax rate of 11.4% and 10.7% for the three and nine months ended September 30, 2018.March 31, 2019. The effective income tax rates differed from the U.S. statutory federal income tax ratesrate of 21% during 20192020 and 20182019 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 decrease in the effective tax rate during the three months ended March 31, 2020 was primarily related to a decrease in pre-tax net income.
Average Balance Sheet
Average assets totaled $31.7$33.5 billion for the ninethree months ended September 30, 2019March 31, 2020 representing an increase of $744.8 million,$2.2 billion, or 2.4%6.9%, compared to average assets for the same period in 2018.2019. Earning assets increased $442.4 million,$1.9 billion, or 1.5%6.4%, during the first ninethree months of 20192020 compared to the same period in 2018.2019. The increase in earning assets was primarily related to an $845.3a $790.0 million increase in average loans, a $793.9loans; an $866.9 million increase in average taxable securities and a $446.7 million increase in average tax-exempt securities mostly offset by a $1.6 billion decrease in average interest-bearing deposits, federal funds sold and resell agreements.agreements; and a $238.6 million increase in average tax-exempt securities partly offset by a $45.4 million decrease in average taxable securities. Average premises and equipment increased $301.5$287.3 million, or 56.6%39.1%, primarily resulting fromin part due to the adoptioncommencement of a new accounting standard which required the recognition of our operating leaseslease on our balance sheet (See Note 1 - Significant Accounting Policiesnew downtown San Antonio headquarters in the accompanying Notes to Financial Statements).second quarter of 2019. Average deposits decreased $62.6 million,increased $1.3 billion, or 0.2%4.9%, during the first ninethree months of 20192020 compared to the same period in 2018.2019. The decreaseincrease included a $543.2 million decrease in non-interest bearing deposits mostly offset by a $480.7$734.8 million increase in interest-bearing deposit accounts.accounts and a $544.9 million increase in non-interest bearing deposits. Average non-interest bearing deposits made up 39.1%39.2% and 41.1%39.0% of average total deposits during the first ninethree months of 20192020 and 2018,2019, respectively.
Loans
Loans were as follows as of the dates indicated:
September 30,
2019
 
Percentage
of Total
 December 31,
2018
 
Percentage
of Total
March 31,
2020
 
Percentage
of Total
 December 31,
2019
 
Percentage
of Total
Commercial and industrial$5,179,780
 35.4% $5,111,957
 36.3%$5,536,760
 36.1% $5,187,466
 35.2%
Energy:              
Production1,282,180
 8.7
 1,309,314
 9.3
1,268,832
 8.3
 1,348,900
 9.2
Service189,350
 1.3
 168,775
 1.2
185,210
 1.2
 192,996
 1.3
Other75,388
 0.5
 124,509
 0.9
114,812
 0.7
 110,986
 0.8
Total energy1,546,918
 10.5
 1,602,598
 11.4
1,568,854
 10.2
 1,652,882
 11.2
Commercial real estate:              
Commercial mortgages4,555,171
 31.1
 4,121,966
 29.2
4,920,882
 32.1
 4,594,113
 31.1
Construction1,370,206
 9.4
 1,267,717
 9.0
1,265,441
 8.3
 1,312,659
 8.9
Land290,706
 2.0
 306,755
 2.2
286,876
 1.9
 289,467
 2.0
Total commercial real estate6,216,083
 42.5
 5,696,438
 40.4
6,473,199
 42.3
 6,196,239
 42.0
Consumer real estate:              
Home equity loans363,224
 2.5
 353,924
 2.5
389,844
 2.5
 375,596
 2.6
Home equity lines of credit350,461
 2.4
 337,168
 2.4
350,330
 2.3
 354,671
 2.4
Other458,618
 3.1
 427,898
 3.0
480,933
 3.1
 464,146
 3.1
Total consumer real estate1,172,303
 8.0
 1,118,990
 7.9
1,221,107
 7.9
 1,194,413
 8.1
Total real estate7,388,386
 50.5
 6,815,428
 48.3
7,694,306
 50.2
 7,390,652
 50.1
Consumer and other519,844
 3.6
 569,750
 4.0
538,340
 3.5
 519,332
 3.5
Total loans$14,634,928
 100.0% $14,099,733
 100.0%$15,338,260
 100.0% $14,750,332
 100.0%
Loans increased $535.2$587.9 million, or 3.8%4.0%, compared to December 31, 2018.2019. 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 35.4%36.1% and 36.3%35.2% of total loans at September 30, 2019March 31, 2020 and December 31, 2018,2019, respectively, while energy loans made up 10.5%10.2% and 11.4%11.2% of total loans, respectively, and real estate loans made up 50.5%50.2% and 48.3%50.1% 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 20182019 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, we have not experienced any unusual or significant declines or increases in our loan portfolio since March 31, 2020. Nonetheless, it is possible that the effects of COVID-19 could result in less demand for our loan products.
Commercial and industrial. Commercial and industrial loans increased $67.8$349.3 million, or 1.3%6.7%, during the first ninethree months of 2019.2020. 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).
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 decreased $55.7$84.0 million, or 3.5%5.1%, during the first ninethree months of 20192020 compared to December 31, 2018.2019. 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 $876.9 million$1.0 billion at September 30, 2019,March 31, 2020, increasing $119.3$72.7 million, or 15.8%7.7%, from $757.5$948.8 million at December 31, 2018.2019. At September 30, 2019, 46.4%March 31, 2020, 40.9% of outstanding purchased SNCs were related to the energy industry and 17.2%while 17.5% were related to the construction industry and 10.3% were related to the financial services 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 $6.2$6.5 billion at September 30, 2019,March 31, 2020, increasing $519.6$277.0 million, or 9.1%4.5%, compared to $5.7$6.2 billion at December 31, 2018.2019. At such dates, commercial real estate loans represented 84.1% and 83.6%83.8% of total real estate loans, respectively. The majority of this 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, 2019,March 31, 2020, approximately 47%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 $1.8 billion at March 31, 2020 and $1.7 billion at both September 30, 2019 and December 31, 2018.2019. Consumer real estate loans increased $53.3$26.7 million, or 4.8%2.2%, from December 31, 2018.2019. Combined, home equity loans and lines of credit made up 60.9%60.6% and 61.8%61.1% of the consumer real estate loan total at September 30, 2019March 31, 2020 and December 31, 2018,2019, 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 decreased $49.9increased $19.0 million, or 8.8%3.7%, from December 31, 2018.2019. 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 two years, (iii) interest rate of 1.00%, (iv) no collateral or personal guarantees are required, (v) no payments are required for six months following the loan disbursement date 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 25% of the loan forgiveness

amount may be attributable to non-payroll costs. In return for processing and booking the loan, the SBA will pay the lender a processing fee tiered by the size of the loan (5% for loans of not more than $350 thousand; 3% for loans more than $350 thousand and less than $2 million; and 1% for loans of at least $2 million). Through April 27, 2020, we have funded approximately $3.0 billion of SBA-approved PPP loans to over 10,500 customers. We expect to recognize approximately $87.0 million in PPP loan related processing fees as a yield adjustment over the terms of these loans.
We are currently considering participation in the Federal Reserve's PPP Facility which, through September 30, 2020, will extend loans to banks who are loaning money to small businesses under the PPP. Should we ultimately participate in the PPP Facility, amounts borrowed would be non-recourse and secured by and limited to the amount of the PPP loans we originate. The maturity date of a borrowing under the PPP Facility is equal the maturity date of the PPP loan pledged to secure the borrowing and would be accelerated (i) if the underlying PPP loan goes into default and is sold to the SBA to realize on the SBA guarantee or (ii) to the extent that any loan forgiveness reimbursement is received from the SBA. Borrowings under the PPP Facility will bear interest at a rate of 0.35% and there would be no fees to us.
Federal bank regulatory agencies have issued an interim final rule that permits banks to neutralize the regulatory capital effects of participating in the PPP and, if applicable, the PPP Facility. Specifically, all PPP loans have a zero percent risk weight under applicable risk-based capital rules. Additionally, 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.
Purported class action lawsuits have been filed against Frost Bank in Federal and Texas State courts alleging, among other claims, unspecified violations of the CARES Act and the SBA's 7(a) loan program in connection with Frost Bank's participation in the PPP. The lawsuits seek monetary damages and injunctive relief. Frost Bank believes the claims to be without merit.
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,
2019
 December 31,
2018
March 31,
2020
 December 31,
2019
Non-accrual loans:      
Commercial and industrial$13,929
 $9,239
$23,913
 $26,038
Energy70,883
 46,932
28,702
 65,761
Commercial real estate:      
Buildings, land and other9,240
 15,268
8,224
 8,912
Construction697
 
3,774
 665
Consumer real estate527
 892
2,094
 922
Consumer and other2,170
 1,408
20
 5
Total non-accrual loans97,446
 73,739
66,727
 102,303
Restructured loans6,160
 

 6,098
Foreclosed assets:      
Real estate1,427
 1,175
806
 1,084
Other
 

 
Total foreclosed assets1,427
 1,175
806
 1,084
Total non-performing assets$105,033
 $74,914
$67,533
 $109,485
   
Ratio of non-performing assets to:      
Total loans and foreclosed assets0.72% 0.53%0.44% 0.74%
Total assets0.32
 0.23
0.20
 0.32
Accruing past due loans:      
30 to 89 days past due$85,678
 $59,595
$110,274
 $50,784
90 or more days past due14,396
 20,468
11,872
 7,421
Total accruing past due loans$100,074
 $80,063
$122,146
 $58,205
Ratio of accruing past due loans to total loans:      
30 to 89 days past due0.59% 0.42%0.72% 0.34%
90 or more days past due0.10
 0.15
0.08
 0.05
Total accruing past due loans0.69% 0.57%0.80% 0.39%

Non-performing assets include non-accrual loans, troubled debt restructurings and foreclosed assets. Non-performing assets at September 30, 2019 increased $30.1March 31, 2020 decreased $42.0 million from December 31, 20182019 reflecting increasesdecreases primarily in non-accrual energy loans, restructured loans and commercial and industrial loans, energy loans and restructured loans partly offset by decreasesincreases in non-accrual commercialconstruction loans and consumer real estate loans. There were no non-accrual commercial and industrial loans in excess of $5.0 million at September 30, 2019 or December 31, 2018. Non-accrual energy loans included two credit relationships in excess of $5 million totaling $65.8 million at September 30, 2019. This included a single credit relationship totaling $34.0 million that was classified as non-accrual during the third quarter of 2019. The other credit relationship, which totaled $31.8 million at September 30, 2019, was previously reported as non-accrual with an aggregate balance of $37.6 million at December 31, 2018. We charged off $4.0 million related to this credit relationship during the nine months ended September 30, 2019. Non-accrual energy loans included one other credit relationship in excess of $5 million totaling $6.4 million at December 31, 2018. 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, 2019. Non-accrual commercial real estate loans included one relationship in excess of $5.0 million totaling $12.2 million at December 31, 2018. This credit relationship was sold during the second quarter of 2019.
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 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 $8.5 million at March 31, 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 two credit relationships in excess of $5 million totaling $28.3 million at March 31, 2020. Both credit relationships were previously reported as non-accrual with an aggregate balance of $61.7 million at December 31, 2019. We charged off $33.8 million related to these credit relationships during the three months ended March 31, 2020. 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 March 31, 2020 or December 31, 2019.
There were no restructured loans at March 31, 2020. Restructured loans at December 31, 2019 totaled $6.2$6.1 million at September 30, 2019 and consisted of three credit relationships primarily related to commercial real estate. There were no restructured loans at December 31, 2018.

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. ThereWrite-downs of foreclosed assets totaled $231 thousand during the three months ended March 31, 2020, while there were no write-downs of foreclosed assets during the ninethree months ended September 30, 2019 while write-downs of foreclosed assets totaled $473 thousand during the nine months ended September 30, 2018.March 31, 2019.
Accruing past due loans at March 31, 2020 increased $63.9 million compared to December 31, 2019. The increase was primarily related to increases in past due commercial real estate loans (up 26.0 million), commercial and industrial loans (up $19.2 million) and energy loans ($15.2 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, 2019March 31, 2020 and December 31, 2018,2019, we had $62.0$105.9 million and $63.4 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, 2019,March 31, 2020, potential problem loans consisted of thirteeneleven credit relationships. Of the total outstanding balance at September 30, 2019, 18.3%March 31, 2020, 72.7% was related to the energy industry 18.2%and 13.4% was related to the restaurant industry, 13.6% was related to the medical industry, 12.8% was related to the leasing industry and 10.6% was related to the entertainment industry. Weakness in these organizations’ operating performance and financial condition, 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 effects of COVID-19. In an effort to mitigate the adverse effects of COVID-19 on our loan customers, we are providing them the opportunity to defer payments, or portions thereof, for up to 90 days, should they so request. 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. We currently expect that a significant number and amount of our loans will experience ratings downgrades, credit deterioration and defaults in many industries, particularly energy, aviation, restaurants, hotels/lodging, entertainment, retail 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.

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 2018 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,
2019
 December 31,
2018
March 31,
2020
 
Post ASC 326 Adoption on January 1,
2020
 December 31,
2019
Commercial and industrial$52,667
 $48,580
$92,152
 $72,856
 $51,593
Energy33,346
 29,052
103,201
 26,929
 37,382
Commercial real estate35,353
 38,777
52,319
 17,518
 31,037
Consumer real estate4,884
 6,103
8,170
 6,505
 4,113
Consumer and other10,309
 9,620
8,039
 5,794
 8,042
Total$136,559
 $132,132
$263,881
 $129,602
 $132,167
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 March 31, 2020 compared to the post ASC 326 estimate of expected credit losses as of January 1, 2020.
The reserveallowance allocated to commercial and industrial loans totaled $92.2 million, or 1.66% of total commercial and industrial loans, at September 30, 2019 increased $4.1March 31, 2020 increasing $19.3 million, or 26.5%, compared to December$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 $12.3 million while Q-Factor adjustments related to commercial and industrial loans increased $5.8 million. Specific allocations for commercial and industrial loans that were evaluated for expected credit losses on an individual basis increased from $7.9 million post ASC 326 adoption on January 1, 2020 to $9.2 million at March 31, 2018.2020. The allowance allocated to energy loans totaled $103.2 million, or 6.58% of total energy loans, at March 31, 2020 increasing $76.3 million, or 283.2%, 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 energy loans increased $9.5 million while Q-Factor adjustments related to energy loans increased $87.0 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 no specific allocations at March 31, 2020. The allowance allocated to commercial real estate loans totaled $52.3 million, or 0.81% of total commercial real estate loans, at March 31, 2020 increasing $34.8 million, or 198.7%, 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 $19.6 million while Q-Factor adjustments related to commercial real estate loans increased $12.2 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 $3.4 million at March 31, 2020. The allowance allocated to consumer real estate loans totaled $8.2 million, or 0.67% of total consumer real estate loans, at March 31, 2020 increasing $1.7 million, or 25.6%, 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 $1.1 million while Q-Factor adjustments related to consumer real estate loans increased $605 thousand. The allowance allocated to consumer loans totaled $8.0 million, or 1.49% of total consumer loans, at March 31, 2020 increasing $2.2 million, or 38.7%, 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 $1.3 million while Q-Factor adjustments related to consumer loans increased $916 thousand.
As more fully described in Note 3 - Loans in the accompanying 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 given 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 March 31, 2020, we utilized the Moody’s Analytics March 2020 S8 Low Oil Price Scenario (the “S8 Scenario”) to forecast the macroeconomic variables used in our models. The S8 scenario used the Moody’s Baseline forecast, updated during the week of March 16, 2020, adjusted to assume that the price per barrel of West Texas Intermediate (“WTI”) crude oil will remain at $35 flat for two years. The S8 Scenario also assumed the persistence of the oil price war between Saudi Arabia and Russia and increasing oil supplies in the face of decreasing global demand. At that time, the S8 Scenario forecasted declines in the U.S. Gross Domestic Product and the Texas Gross State Product in the second quarter of 2020, a flat U.S. unemployment rate for the remainder of 2020 and the 10-yr Treasury rate dropping to 0.49% in second quarter of 2020 and remaining below 1.0% until the second quarter of 2021. The low oil prices incorporated in the S8 Scenario also resulted in a forecasted gradual increase was primarily duein the Texas unemployment rate, from 3.6% in the first quarter of 2020 to 6.2% by the first quarter of 2022, exceeding the forecasted U.S. unemployment rate of 4.1% for the first quarter of 2022 and reflecting the impact of oil prices on the overall Texas economy. 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 historical valuation allowancesmodeled expected credit losses across all of our loan portfolios as of March 31, 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 portfolio volumes and specific valuation allowancesrisk attributes, as discussed below, and also partly related to the changes in our economic forecast.
The overall loan portfolio increased $587.9 million, or 4.0%, which included a $349.3 million, or 6.7%, increase in commercial and industrial loans and a $277.0 million, or 4.5%, increase in commercial real estate loan partly offset by aan $84.0 million, or 5.08%, decrease in macroeconomic valuation allowances. Historical valuation allowances increased $3.5 million from $25.4 millionenergy loans. The weighted average risk grade for commercial and industrial loans remained unchanged totaling 6.44 at both March 31, 2020 and December 31, 2018 to $28.9 million at September 30, 2019. The increase was primarily related to an increase in the historical loss allocation factor applied to classifiedCommercial and industrial loans graded as "substandard - accrual"“watch” and “special mention” (risk grade 11)grades 9 and an increase in10) increased $88.2 million during the volumefirst quarter of non-classified2020 while classified commercial and industrial loans graded "watch" (risk grade 9).decreased $16.5 million. Classified loans consist of loans having a risk grade of 11, 12 or 13. Classified commercial and industrial loans totaled $82.6 million at September 30, 2019 compared to $78.9 million at December 31, 2018. The weighted-average risk grade of commercial and industrialfor energy loans was 6.42increased to 6.81 at September 30, 2019 compared to 6.30March 31, 2020 from 6.39 at December 31, 2018. Commercial loan net charge-offs totaled $5.9 million during the first nine months of 2019 compared to $19.0 million during the first nine months of 2018. Charge-offs in 2018 included $15.3 million related to four credit relationships. Specific valuation allowances for commercial and industrial loans increased $3.2 million from $2.6 million at December 31, 2018 to $5.8 million at September 30, 2019. The increase included a new specific valuation allowance totaling $2.5 million on a single credit relationships which had an aggregate outstanding balance totaling $3.1 million at September 30, 2019. Macroeconomic valuation allowances for commercial and industrial loans decreased $3.5 million from $10.6 million at December 31, 2018 to $7.1 million at September 30, 2019. The decreasein weighted average risk grade was primarily related to a decrease in the general macroeconomic risk allocation (down $2.5 million), as further discussed below, and a decrease in the environmental risk adjustment (down $936 thousand) as a result of a decrease in the environmental adjustment factor. General valuation allowances

for commercial and industrial loans increased $804 thousand from $10.1$50.3 million at December 31, 2018 to $10.9 million at September 30, 2019 primarily due to an increase in allocations for excessive industry concentrations.
classified loans while non classified loans decreased $134.3 million. The reserve allocated to energy loans at September 30, 2019 increased $4.3 million compared to December 31, 2018. As a result, reserves allocated to energy loans as a percentage of total energy loans totaled 2.16% at September 30, 2019 compared to 1.81% at December 31, 2018. This increase was primarily related to an increase in specific valuation allowances partly offset by decreases in historical valuation allowances, general valuation allowances and macroeconomic valuation allowances. Specific valuation allowances for energy loans totaled $19.7 million at September 30, 2019 and related to two credit relationships totaling $65.8 million while specific valuation allowances for energy loans totaled $9.7 million at December 31, 2018 and related to four credit relationships totaling $39.9 million. Historical valuation allowances decreased $2.3 million from $9.7 million at December 31, 2018 to $7.4 million at September 30, 2019. The decrease was partly related to decreases in the historical loss allocation factors for both non-classified energy loans and classified energy loans. The decrease was also partly related to decreases in the volume of non-classified energy loans graded as "pass"(risk grades below 9) (down $72.1 million) and "special mention" (risk grade 10) (down $41.9 million) and classified energy loans graded as "substandard - accrual" (risk grade 11) (down $10.2 million) partly offset by an increase in the volume of non-classified energy loans graded as "watch" (risk grade 9) (up $44.6 million). Total classified energy loans increased $13.7 million from $72.4 million at December 31, 2018 to $86.1 million at September 30, 2019. The weighted-averageweighted average risk grade of energy loans increased to 6.36 at September 30, 2019 from 6.22 at December 31, 2018. Energy loan net charge-offs totaled $3.2 million during the nine months ended September 30, 2019 compared to net charge-offs of $10.3 million during the same period in 2018. Charge-offs in 2019 included $4.0 million related to a single credit relationship. We also charged-off $3.0 million related to this credit relationship in 2018 as well as $7.3 million related to two other credit relationships. General valuation allowances for energy loans decreased $1.9 million from $6.0 million at December 31, 2018 to $4.1 million at September 30, 2019. The decrease was primarily related to a decrease in the allocation for highly-leveraged transactions. Macroeconomic valuation allowances related to energy loans decreased $1.6 million from $3.7 million at December 31, 2018 to $2.1 million at September 30, 2019, due to a decrease in the general macroeconomic risk allocation (down $805 thousand), as further discussed below, and a decrease in the environmental risk adjustment (down $783 thousand), as a result of decreases in the environmental adjustment factor and the historical loss valuation allowances to which the environmental risk adjustment factor is applied.
The reserve allocated to commercial real estate loans at September 30, 2019 decreased $3.4 million compared to December 31, 2018. The decrease was primarily related to decreases in macroeconomic valuation allowances and specific valuation allowances partly offset by an increase in historical valuation allowances. Macroeconomic valuation allowances decreased $3.5 million from $11.0 million at December 31, 2018 to $7.5 million at September 30, 2019. The decrease was primarily related to a decrease in the general macroeconomic risk allocation (down $2.5 million), as further discussed below, and a decrease in the environmental risk adjustment (down $1.0 million), primarily resulting from a decrease in the environmental risk adjustment factor. Specific valuation allowances for commercial real estate loans totaled $1.5 millionincrease to 7.18 at September 30, 2019 decreasing $1.1 millionMarch 31, 2020 from $2.6 million7.07 at December 31, 2018. Specific valuation allowances at December 31, 2018 primarily related to a single credit relationship totaling $12.2 million. This relationship was sold during the second quarter of 2019. We recognized net charge-offs totaling $266 thousand in connection with the sale. Specific valuation allowances for commercialCommercial real estate loans at September 30, 2019 related to three credit relationships totaling $5.0 million. Historical valuation allowances related to commercial real estate loansgraded as “watch” increased $1.2$170.9 million from $20.8 million at December 31, 2018 to $22.1 million at September 30, 2019. Non-classified commercial real estate loans increased $532.9 million from $5.6 billion at December 31, 2018 to $6.1 billion at September 30, 2019 while classified commercial real estate loans decreased $13.2 million$9.6 million.
As noted above our credit loss models utilized the economic forecasts in the Moody’s S8 Scenario from $118.3 million atthe week of March 16, 2020. In late March and early April 2020, Moody's updated various macroeconomic variables in Moody's Baseline forecast subsequent to our modeling processes in order to incorporate the expected economic impact of recent developments related to the COVID-19 pandemic. Given the level of economic disruption and uncertainty within the State of Texas and the nation as a whole, arising from the COVID-19 pandemic and volatility and declines in oil and gas prices driven by decreased demand and increased supply, we qualitatively adjusted the model results for these and other 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. Also see 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.

Q-Factor adjustments are based upon management judgment and current assessment as to 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. 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 this assessment as of March 31, 2020, modeled expected credit losses were adjusted upwards by a weighted-average Q-Factor adjustment of approximately 17.9%. This weighted-average Q-Factor adjustment is based upon a severely negative expected impact from changes in economic and business conditions resulting from the COVID-19 pandemic and a negative to limited negative expected impact associated with changes in loan portfolio attributes and concentrations, risk grades and other practices and procedures; the depth and experience of lending staff in dealing with potential issues related to credit deterioration; and potential deterioration of collateral values. The weighted-average Q-Factor adjustment also includes 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. 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 also included the aforementioned 10% upward adjustment related to model uncertainty and under-prediction. We expect to continue to adjust modeled expected credit loss results for model uncertainty and under-prediction until such time as the models are enhanced and the degree of uncertainty and under-prediction is reduced. Management also made certain other qualitative adjustments for loans within certain industries that are expected to be more significantly impacted by the COVID-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 demand resulting from the COVID-19 pandemic resulted in further decreases in energy prices. The WTI price per barrel of crude oil was approximately $20 per barrel on March 31, 2020 down from approximately $61 per barrel as of December 31, 20182019. In late March 2020, we established a special Energy Oversight Council to $105.0oversee and assess the credit quality of our energy loan portfolio.
As of March 31, 2020, we provided an additional $85.0 million at September 30, 2019.of qualitative adjustments for our energy loan portfolio. In assessing the energy portfolio for the additional qualitative adjustment, we performed a series of different stress testing exercises to assess borrowing base deficiencies for energy production loans. The weighted-averagefinal stress testing exercise approved by management was based on an oil price deck of $9 in 2020 and increasing to $36 in 2021, $40 in 2022 and $45 thereafter. From this exercise, we determined which borrowers had a borrowing base deficiency. We further identified which of these borrowers we believed to have strong secondary sources of capital and those that did not. We determined that the borrowers with insufficient secondary sources of capital had an aggregate net borrowing based deficiency of approximately $106.0 million. We concluded that this amount should serve as the minimum level of expected credit losses for energy production loans. Accordingly, we provided an additional qualitative adjustment of $84.0 million for this category of energy loans. We performed a separate assessment of other energy loans which includes borrowers associated with transportation and logistics; equipment manufacturing and energy services, among other things. Over half of this portfolio of energy loans was made up of a small number of borrowers with loans in excess of $5.0 million. Based upon further analysis of these loans, we provided an additional qualitative adjustment of $1.0 million.
As of April 27, 2020, the WTI price per barrel of crude oil was approximately $13. Oil prices continue to be impacted by concerns that the demand for oil will remain depressed as the COVID-19 pandemic has led to a sharp decrease in global travel and business activity in other energy-heavy industries. Excess oil supply has compounded concerns related to oil storage capacity, as the cost for producers to store unused oil has begun to exceed the value of the underlying oil.
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. Efforts to limit the spread of COVID-19 have led to 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. 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 of the COVID-19 pandemic. These industries include, with outstanding balances as of March 31, 2020, restaurants (approximately $274.9 million, or 1.79% of total loans), hotels/lodging (approximately $238.9 million, or 1.56% of total loans), aviation (approximately $196.4 million, or 1.28% of total loans), entertainment (approximately $113.8 million, or 0.74% of total loans) and retail (approximately $85.6 million, or 0.56% of total loans). We are continuing to monitor these customers closely. In assessing these portfolios for an additional qualitative adjustment as of March 31, 2020, 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 these portfolios had an elevated level of risk gradedue to nationwide and global restrictions impacting each of these industries. As a result, we provided an additional qualitative adjustment of $8.8 million, of which $7.8 million was allocated to commercial real estate loans was 7.05 at both September 30, 2019 and December 31, 2018. General valuation allowances for commercial real estate loans decreased $17 thousand from $4.4$1.0 million at December 31, 2018 to $4.3 million at September 30, 2019.
The reservewas allocated to consumer real estate loans at September 30, 2019 decreased $1.2 million comparedcommercial and industrial loans.

According to December 31, 2018. This decrease was primarily due to a $531 thousand decreaseDepartment of Labor statistical data, in the general macroeconomic risk allocation, as further discussed below,final week of March 2020, there was a record number of initial unemployment insurance claims totaling 6.6 million. For the entire month, initial claims totaled in excess of 10 million. Through April 16, 2020, the four-week moving average of initial unemployment claims was approximately 5.5 million per week. The rapid rate and a $499 thousand decreasemagnitude of job losses is unprecedented. During this time, the U.S. government has also enacted certain monetary and fiscal stimulus measures in general valuation allowances, which was primarily relatedseveral phases to an increase incounteract the adjustment for recoveries combined with a decrease ineconomic disruption caused by the allocation for loans not reviewed by concurrence.
The reserve allocated to consumer and other loans at September 30, 2019 increased $689 thousand compared to December 31, 2018. The increase was primarily related to an increase in specific valuation allowances (up $763 thousand) as well as an increase in historical valuation allowances (up $700 thousand) primarily due to an increase in the historical loss allocation factor. These items were partly offset by decreases in macroeconomic valuation allowances (down $462 thousand) and general valuation allowances (down $312 thousand). The decrease in macroeconomic valuation allowances was primarily related to a decrease in the general macroeconomic risk allocation, as further discussed below, and a decrease in the environmental risk adjustment due to a decrease in the environmental risk adjustment factor. The decrease in general valuation allowances was primarily related to a decrease in the allocation for loans not reviewed by concurrence combined with an increase in the adjustment for recoveries.

AsCOVID-19. Such measures are more fully discussed in our 2018 Form 10-K, under our allowance methodology, we allocate additional reserves for general macroeconomic riskthe section captioned “Recent Developments Related to COVID-19” elsewhere in excessthis discussion. The success of our minimum calculated need using our allowance model. These additional reserves are based upon management's assessmentthese measures is unknown and they may not be sufficient to fully mitigate the negative impact of current and expected economic conditions,the COVID-19 pandemic. In light of this uncertainty as well as other uncertainties related to unemployment trends and how long business closures and restrictions on travel and public gatherings will continue, we determined that our consumer and other quantitative andportfolio had an elevated level of risk, particularly related to the performance unsecured loans within this portfolio. As a result, we provided an additional qualitative portfolio risk factors that are external to us or that are not otherwise captured in our allowance modeling process but impact the credit risk or inherent losses within our loan portfolio segments. These additional reserves are allocated to our various portfolio segments based upon management judgment.adjustment of $800 thousand for these loans.
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,
Three Months Ended 
 March 31,
2019 2018 2019 20182020 2019
Balance at beginning of period$134,929
 $150,226
 $132,132
 $155,364
$132,167
 $132,132
Provision for loan losses8,001
 2,650
 25,404
 17,846
Impact of adopting ASC 326(2,565) 
Credit loss expense172,925
 11,003
Charge-offs:          
Commercial and industrial(2,705) (8,491) (8,782) (21,896)(4,369) (2,688)
Energy(2,000) (5,400) (4,000) (10,939)(33,800) 
Commercial real estate
 
 (617) (619)(73) (60)
Consumer real estate(557) (431) (2,936) (1,632)(285) (1,778)
Consumer and other(6,357) (4,274) (17,157) (12,240)(5,005) (5,697)
Total charge-offs(11,619) (18,596) (33,492) (47,326)(43,532) (10,223)
Recoveries:          
Commercial and industrial1,185
 684
 2,870
 2,866
1,715
 750
Energy740
 53
 816
 667
66
 47
Commercial real estate46
 36
 165
 342
113
 90
Consumer real estate454
 43
 858
 554
380
 89
Consumer and other2,823
 2,482
 7,806
 7,265
2,612
 2,462
Total recoveries5,248
 3,298
 12,515
 11,694
4,886
 3,438
Net charge-offs(6,371) (15,298) (20,977) (35,632)(38,646) (6,785)
Balance at end of period$136,559
 $137,578
 $136,559
 $137,578
$263,881
 $136,350
          
Ratio of allowance for loan losses to:       
Ratio of allowance for credit losses on loans to:   
Total loans0.93% 1.00% 0.93% 1.00%1.72% 0.95%
Non-accrual loans140.14
 166.56
 140.14
 166.56
395.46
 147.95
Ratio of annualized net charge-offs to average total loans0.17
 0.44
 0.20
 0.35
1.04
 0.19
The provision for loan lossesCredit loss expense related to loans increased $7.6$161.9 million or 42.4%, during the ninethree months ended September 30, 2019March 31, 2020 compared to the same period in 2018. The provision for loan losses2019. Credit loss expense related to loans during the ninethree months ended September 30, 2019March 31, 2020 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 the sharp decline in oil prices. Credit loss expense also reflects the level of net charge-offs, and specific valuation allowances as well as the impactdeterioration of an increase in classified/non-accrual loanscredit quality and the overall growth in the loan portfolio since December 31, 2018. Net charge-offs totaled $21.0 million forduring the nine months ended September 30, 2019 compared to $35.6 million for the same period in 2018. Specific valuation allowances totaled $29.2 million at September 30, 2019 compared to $16.2 million at December 31, 2018 and $21.5 million at September 30, 2018. Classified energy, commercial and industrial and commercial real estate loans totaled $273.7 million at September 30, 2019 compared to $269.6 million at December 31, 2018 and $288.3 million at September 30, 2018. The overall weighted-average risk gradefirst quarter of our energy, commercial and industrial and commercial real estate loan portfolios was 6.72 at September 30, 2019 compared to 6.63 at December 31, 2018 and 6.65 at September 30, 2018.
2020. The ratio of the allowance for loancredit losses on loans to total loans was 0.93%1.72% at September 30, 2019March 31, 2020 compared to 0.94%0.90% at December 31, 2018.2019. 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 $2.3 million during the first quarter of 2020 to increase the amount of the related allowance for credit losses on off-balance-sheet credit exposures to $42.2 million as of March 31, 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 $3.9$3.8 billion at September 30, 2019both March 31, 2020 and $3.4 billion December 31, 2018.2019. In addition to net income of $339.9$54.8 million, other sources of capital during the ninethree months ended September 30, 2019March 31, 2020 included other comprehensive income, net of tax, of $369.0$96.4 million; $13.5$2.5 million related to stock-based compensation and $1.5 million in proceeds from stock option exercises and $10.7 million

related to stock-based compensation.exercises. Uses of capital during the ninethree months ended September 30, 2019March 31, 2020 included $138.2a $150.0 million redemption of preferred stock, $47.0 million of dividends paid on preferred and common stock, $67.7 million of treasury stock purchases and $14.7$29.3 million related to the cumulative effect of adopting a new accounting principle adopted during the first quarterand $14.0 million of 2019.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 $305.4$363.8 million at September 30, 2019March 31, 2020 compared to a net, after-tax, unrealized loss of $63.6$267.4 million at December 31, 2018.2019. The change was primarily due to a $366.4$95.7 million net, after-tax, changeincrease in the net unrealized gain/lossgain 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 7 - Capital and Regulatory Matters in the accompanying notes to consolidated financial statements included elsewhere in this report.
We paid a quarterly dividend of $0.67, $0.71 and $0.71 per common share during the first, second and third quarters of 2019, respectively, and a quarterly dividend of $0.57, $0.67 and $0.67 per common share during the first second and third quarters of 2018,2020 and 2019, respectively. This equates to a common stock dividend payout ratio of 39.6%95.2% and 37.2% during the first ninethree months of 20192020 and 2018,2019, 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 described in Note 7 - 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 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 awards. On October 24, 2017, our board of directors authorized a $150.0 million stock repurchase program, allowing us to repurchase shares of our common stock over a two-year period from time to time at various prices in the open market or through private transactions. We repurchased 496,307 shares under this plan at a total cost of $50.0 million during the second quarter of 2019 while we repurchased 1,027,292 shares at a total cost of $100.0 million during the fourth quarter of 2018. On 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 one-year period from time to time at various prices in the open market or through private transactions. We repurchased 177,834 shares at a total cost of $13.7 million during the first quarter of 2020 and 202,724 shares at a total cost of $17.2 million under this plan during the third quarter of 2019. In light of the uncertainties arising from the COVID-19 pandemic, we currently do not anticipate any further repurchases of common stock under this stock repurchase program. See Note 7 - Capital

and Regulatory Matters in the accompanying 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 20182019 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, 2019, managementApril 27, 2020, we had approximately $4.3 billion held in an interest-bearing account at the Federal Reserve. We also have the ability to borrow funds as a member of the Federal Home Loan Bank (“FHLB”). As of March 31, 2020, based upon available, pledgeable collateral, our total borrowing capacity with the FHLB was approximately $2.6 billion. Furthermore, at March 31, 2020, we had approximately $9.1 billion in securities that were unencumbered by a pledge and could be used to support additional borrowings through repurchase agreements or the Federal Reserve discount window, as needed.
As further 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. Through April 27, 2020, we have funded approximately $3.0 billion of SBA-approved PPP loans to over 10,500 customers. We expect to recognize approximately $87.0 million in PPP loan related processing fees as a yield adjustment over the terms of these loans. In April 2020, we borrowed $250 million from the FHLB under the COVID-19 Relief Program to provide supplemental funding for PPP loan originations. The short-term, full-recourse advance has a term of six months and bears interest at an annualized rate of 0.25%. We are also considering participation in the Federal Reserve's PPP Facility, which is not awarefurther discussed in the section captioned “Loans” elsewhere in this discussion. Federal bank regulatory agencies have issued an interim final rule that permits banks to neutralize the regulatory capital effects of any eventsparticipating in the PPP and, if applicable, the PPP Facility. Specifically, all PPP loans have a zero percent risk weight under applicable risk-based capital rules. Additionally, 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 reasonably likelynot pledged as collateral to have a material adverse effect on our liquidity, capital resources or operations.the PPP Facility will be included.
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 7 - Capital and Regulatory Matters in the accompanying notes to consolidated financial statements included elsewhere in this report regarding such dividends. At September 30, 2019,March 31, 2020, Cullen/Frost had liquid assets, including cash and resell agreements, totaling $230.3$178.2 million.
Accounting Standards Updates
See Note 17 - 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.

Consolidated Average Balance Sheets and Interest Income Analysis - Quarter To Date
(Dollars in thousands - taxable-equivalent basis)
 September 30, 2019 September 30, 2018
 Average
Balance
 Interest
Income/
Expense
 Yield/
Cost
 Average
Balance
 Interest
Income/
Expense
 Yield/
Cost
Assets:           
Interest-bearing deposits$1,565,515
 $8,759
 2.19% $2,799,277
 $14,445
 2.05%
Federal funds sold and resell agreements211,756
 1,194
 2.21
 259,563
 1,399
 2.14
Securities:           
Taxable5,278,040
 32,122
 2.45
 4,162,978
 21,339
 2.02
Tax-exempt8,166,344
 79,617
 4.08
 7,890,373
 81,884
 4.15
Total securities13,444,384
 111,739
 3.43
 12,053,351
 103,223
 3.41
Loans, net of unearned discounts14,471,414
 188,192
 5.16
 13,683,311
 173,671
 5.04
Total Earning Assets and Average Rate Earned29,693,069
 309,884
 4.21
 28,795,502
 292,738
 4.04
Cash and due from banks479,357
     475,701
    
Allowance for loan losses(136,783)     (151,654)    
Premises and equipment, net954,989
     542,011
    
Accrued interest and other assets1,257,836
     1,255,983
    
Total Assets$32,248,468
     $30,917,543
    
            
Liabilities:           
Non-interest-bearing demand deposits:           
Commercial and individual$9,819,992
     $10,139,627
    
Correspondent banks207,394
     195,387
    
Public funds289,079
     355,005
    
Total non-interest-bearing demand deposits10,316,465
     10,690,019
    
Interest-bearing deposits:           
Private accounts           
Savings and interest checking6,711,866
 1,140
 0.07
 6,674,665
 1,581
 0.09
Money market deposit accounts7,763,380
 18,201
 0.93
 7,619,901
 17,832
 0.93
Time accounts1,022,716
 4,476
 1.74
 798,500
 1,757
 0.87
Public funds537,599
 1,820
 1.34
 369,180
 1,031
 1.11
Total interest-bearing deposits16,035,561
 25,637
 0.63
 15,462,246
 22,201
 0.57
Total deposits26,352,026
     26,152,265
    
Federal funds purchased and repurchase agreements1,290,963
 5,040
 1.53
 1,011,290
 2,292
 0.90
Junior subordinated deferrable interest debentures136,279
 1,425
 4.18
 136,222
 1,394
 4.09
Subordinated notes payable and other notes98,811
 1,164
 4.71
 98,654
 1,164
 4.72
Total Interest-Bearing Funds and Average Rate Paid17,561,614
 33,266
 0.75
 16,708,412
 27,051
 0.64
Accrued interest and other liabilities542,091
     184,222
    
Total Liabilities28,420,170
     27,582,653
    
Shareholders’ Equity3,828,298
     3,334,890
    
Total Liabilities and Shareholders’ Equity$32,248,468
     $30,917,543
    
Net interest income  $276,618
     $265,687
  
Net interest spread    3.46%     3.40%
Net interest income to total average earning assets    3.76%     3.66%
For these computations: (i) average balances are presented on a daily average basis, (ii) information is shown on a taxable-equivalent basis assuming a 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.

Consolidated Average Balance Sheets and Interest Income Analysis - Year To Date
(Dollars in thousands - taxable-equivalent basis)
September 30, 2019 September 30, 2018March 31, 2020 March 31, 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:                      
Interest-bearing deposits$1,487,947
 $27,226
 2.41% $3,119,311
 $42,456
 1.82%$2,585,692
 $8,125
 1.24% $1,728,982
 $10,639
 2.50%
Federal funds sold and resell agreements235,612
 4,323
 2.42
 247,660
 3,575
 1.93
260,134
 802
 1.22
 249,946
 1,588
 2.58
Securities:                      
Taxable4,969,843
 87,125
 2.35
 4,175,985
 63,085
 2.00
4,495,407
 26,030
 2.36
 4,540,814
 24,679
 2.19
Tax-exempt8,211,558
 243,628
 4.06
 7,764,855
 239,496
 4.12
8,467,982
 81,577
 4.07
 8,229,430
 82,475
 4.03
Total securities13,181,401
 330,753
 3.41
 11,940,840
 302,581
 3.38
12,963,389
 107,607
 3.46
 12,770,244
 107,154
 3.37
Loans, net of unearned discounts14,351,562
 566,069
 5.27
 13,506,270
 491,452
 4.86
14,995,175
 173,378
 4.65
 14,205,191
 186,650
 5.33
Total Earning Assets and Average Rate Earned29,256,522
 928,371
 4.27
 28,814,081
 840,064
 3.89
30,804,390
 289,912
 3.84
 28,954,363
 306,031
 4.27
Cash and due from banks495,222
     487,821
    542,890
     522,701
    
Allowance for loan losses(136,271)     (152,890)    
Allowance for credit losses on loans and securities(131,317)     (133,647)    
Premises and equipment, net833,861
     532,400
    1,022,413
     735,090
    
Accrued interest and other assets1,228,440
     1,251,554
    1,295,784
     1,277,795
    
Total Assets$31,677,774
     $30,932,966
    $33,534,160
     $31,356,302
    
                      
Liabilities:                      
Non-interest-bearing demand deposits:                      
Commercial and individual$9,699,019
     $10,161,035
    $10,119,185
     $9,634,087
    
Correspondent banks204,975
     203,625
    238,888
     205,735
    
Public funds315,249
     397,822
    379,151
     352,467
    
Total non-interest-bearing demand deposits10,219,243
     10,762,482
    10,737,224
     10,192,289
    
Interest-bearing deposits:                      
Private accounts                      
Savings and interest checking6,753,063
 3,976
 0.08
 6,666,044
 4,022
 0.08
7,030,285
 396
 0.02
 6,773,862
 1,472
 0.09
Money market deposit accounts7,682,565
 58,370
 1.02
 7,596,128
 39,553
 0.70
7,874,446
 9,696
 0.50
 7,695,514
 20,640
 1.09
Time accounts963,082
 11,653
 1.62
 788,160
 4,031
 0.68
1,109,076
 4,612
 1.67
 895,464
 3,156
 1.43
Public funds535,034
 5,656
 1.41
 402,723
 2,808
 0.93
640,208
 1,349
 0.85
 554,415
 1,906
 1.39
Total interest-bearing deposits15,933,744
 79,655
 0.67
 15,453,055
 50,414
 0.44
16,654,015
 16,053
 0.39
 15,919,255
 27,174
 0.69
Total deposits26,152,987
     26,215,537
    27,391,239
     26,111,544
    
Federal funds purchased and repurchase agreements1,238,197
 15,276
 1.63
 1,027,077
 3,557
 0.46
1,259,306
 3,037
 0.95
 1,180,163
 5,016
 1.72
Junior subordinated deferrable interest debentures136,265
 4,401
 4.31
 136,208
 3,847
 3.77
136,308
 1,205
 3.54
 136,251
 1,498
 4.40
Subordinated notes payable and other notes98,772
 3,492
 4.71
 98,616
 3,492
 4.72
98,889
 1,164
 4.71
 98,733
 1,164
 4.72
Total Interest-Bearing Funds and Average Rate Paid17,406,978
 102,824
 0.79
 16,714,956
 61,310
 0.49
18,148,518
 21,459
 0.47
 17,334,402
 34,852
 0.81
Accrued interest and other liabilities416,288
     168,514
    639,874
     388,743
    
Total Liabilities28,042,509
     27,645,952
    29,525,616
     27,915,434
    
Shareholders’ Equity3,635,265
     3,287,014
    4,008,544
     3,440,868
    
Total Liabilities and Shareholders’ Equity$31,677,774
     $30,932,966
    $33,534,160
     $31,356,302
    
Net interest income  $825,547
     $778,754
    $268,453
     $271,179
  
Net interest spread    3.48%     3.40%    3.37%     3.46%
Net interest income to total average earning assets    3.80%     3.61%    3.56%     3.79%
For these computations: (i) average balances are presented on a daily average basis, (ii) information is shown on a taxable-equivalent basis assuming a 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.



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 20182019 Form 10-K. There has been no significant change in the types of market risks we face since December 31, 2018.2019.
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, 2019,March 31, 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 0.2%1.6% and 1.3%3.9%, respectively, relative to the flat-rate case over the next 12 months, while 100 and 200a 25 basis point ratable decreasesdecrease in interest rates would result in a negative variancesvariance in net interest income of 1.7% and 5.7%, respectively,4.5% relative to the flat-rate case over the next 12 months. The September 30, 2019March 31, 2020 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 fourthsecond quarter of 2019,2020, as further discussed below. For modeling purposes, as of September 30, 2018,March 31, 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 0.3%0.2% and 1.5%1.2%, respectively, relative to the flat-rate case over the next 12 months, while 100 and 200 basis point ratable decreases in interest rates would result in negative variances in net interest income of 2.9%2.5% and 8.0%7.3%, respectively, relative to the flat-rate case over the next 12 months. The September 30, 2018March 31, 2019 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 fourthsecond quarter of 2018,2019, as further discussed below. The likelihood of a decrease in interest rates beyond 25 basis points as of March 31, 2020 was considered remote given prevailing interest rate levels.
The model simulations as of September 30, 2019March 31, 2020 indicate that our projected balance sheet is lessmore asset sensitive in comparison to our projected balance sheet as of September 30, 2018.March 31, 2019. The shift to a lessmore asset sensitive position was primarily due to a decrease in the assumed interest rate paid on projected commercial demand deposits (those not already receiving an earnings credit rate), as further discussed below, and an increase in the relative proportion of interest-bearing deposits and federal funds sold to projected average interest-earning assets. Interest-bearing deposits and federal funds sold are more immediately impacted by changes in interest rates in comparison to our other categories of earning assets.
We do not currently pay interest on a significant portion of our commercial demand deposits. If we began to pay interest on commercial demand deposits (those not already receiving an earnings credit rate), our balance sheet would likely become less asset sensitive. Any interest rate that would ultimately be paid on these commercial demand deposits would likely depend upon a variety of factors, some of which are beyond our control. ForOur modeling purposes, we havesimulation as of March 31, 2020 assumed a moderate pricing structure with regards to interest payments on commercial demand deposits (those not already receiving an earnings credit) with interest payments assumed to begin in the second quarter of 2020. This moderate pricing structure on commercial demand deposits assumes 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 March 31, 2019 assumed a much more aggressive pricing structure with regards to interest payments for commercial demand deposits (those not already receiving anand earnings credit) beginningwith interest payments assumed to begin in the fourth quarterssecond quarter of 2018 and2019. We modified our assumed pricing structure during 2020 compared to 2019 respectively, for each simulation. Shouldbased upon our market observations during the actualmost recent interest rate paid on commercial demand deposits be less than the rate assumed in the model simulations, or should the interest rate paid for commercial demand deposits become an administered 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, 2019,March 31, 2020, the effects of a 200 basis point increase and a 20025 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.

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.

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 20182019 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, 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 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 confidence 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 and natural resources, restaurants, hospitality, entertainment, transportation 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.
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 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 any 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 March 31, 2020, we had $1.6 billion of energy loans which comprised approximately 10.2% 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. Further, increased 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 $13 as of April 27, 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, 2019.March 31, 2020. Dollar amounts in thousands.
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, 2019 to July 31, 2019
 $
 
 $100,000
August 1, 2019 to August 31, 2019202,724
 84.80
 202,724
 82,809
September 1, 2019 to September 30, 2019
 
 
 82,809
Total202,724
   202,724
  
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
January 1, 2020 to January 31, 2020
 $
 
 $82,809
February 1, 2020 to February 29, 2020
 
 
 82,809
March 1, 2020 to March 31, 2020181,825
(1) 
76.85
 177,834
 69,153
Total181,825
   177,834
  

(1)Includes 3,991 shares repurchased in connection with the vesting of certain share awards.

Item 3. Defaults Upon Senior Securities
None.
Item 4. Mine Safety Disclosures
None.
Item 5. Other Information
None.

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)
Interactive Data File - The instance document does not appear in the interactive data file because itsInline XBRL tags are embedded within the inline XBRL document.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 - The cover page XBRL tags are embedded within the inline XBRL document (included in Exhibit 101)

+(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.


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 31, 2019April 30, 2020 By:  /s/ Jerry Salinas 
    Jerry Salinas 
    Group Executive Vice President 
    and Chief Financial Officer 
    (Duly Authorized Officer, Principal Financial 
    Officer and Principal Accounting Officer) 

5869