BOK Financial (BOKF) 10-Q 3 Nov 20 2020 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information	9 Months Ended
	Sep. 30, 2020shares
Document and Entity Information [Abstract]
Entity Incorporation, State or Country Code	OK
Entity Tax Identification Number	73-1373454
Entity Address, Address Line One	Boston Avenue at Second Street
Entity Address, City or Town	Tulsa,
Entity Address, State or Province	OK
Document Transition Report	false
Document Quarterly Report	true
Entity Registrant Name	BOK FINANCIAL CORP
Entity Central Index Key	0000875357
Current Fiscal Year End Date	--12-31
Entity Emerging Growth Company	false
Entity Bankruptcy Proceedings, Reporting Current	false
Entity Small Business	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	70,305,833
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Document Type	10-Q
Entity File Number	0-19341
Amendment Flag	false
Document Period End Date	Sep. 30, 2020
City Area Code	918
Local Phone Number	588-6000
Entity Address, Postal Zip Code	74192

Consolidated Statements of Earn

Consolidated Statements of Earnings (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest revenue [Abstract]
Loans	$ 215,977	$ 286,694	$ 674,633	$ 859,898
Residential mortgage loans held for sale	1,585	1,891	4,848	5,308
Trading securities	8,723	14,452	31,890	48,645
Investment securities	2,939	3,221	9,060	10,160
Available for sale securities	62,369	67,633	200,386	184,344
Fair value option securities	1,986	10,708	17,804	23,448
Restricted equity securities	913	7,558	8,687	20,419
Interest-bearing cash and cash equivalents	167	3,050	2,672	9,879
Total interest revenue	294,659	395,207	949,980	1,162,101
Interest expense [Abstract]
Deposits	14,658	46,917	78,562	127,517
Borrowed funds	4,856	65,381	49,637	180,595
Subordinated debentures	3,395	3,813	10,567	11,359
Total interest expense	22,909	116,111	138,766	319,471
Net interest revenue	271,750	279,096	811,214	842,630
Provision for credit losses	0	12,000	229,092	25,000
Net interest revenue after provision for credit losses	271,750	267,096	582,122	817,630
Total fees and commissions	222,865	186,119	629,269	522,779
Other gains, net	6,265	4,544	2,292	11,000
Gain on derivatives, net	2,354	3,778	42,659	19,595
Gain (loss) on fair value option securities, net	(754)	4,597	53,180	24,115
Change in fair value of mortgage servicing rights	3,441	(12,593)	(85,800)	(62,814)
Gain (loss) on available for sale securities, net	(12)	5	5,571	1,110
Total other operating revenue	234,159	186,450	647,171	515,785
Other operating expense [Abstract]
Personnel	179,860	162,573	512,276	492,143
Business promotion	2,633	8,859	10,783	26,875
Charitable contributions to BOKF Foundation	0	0	3,000	1,000
Professional fees and services	14,074	12,312	39,183	41,453
Net occupancy and equipment	28,111	27,558	84,847	83,959
Insurance	5,848	4,220	15,984	15,513
Data processing and communications	34,751	31,915	100,436	93,099
Printing, postage and supplies	3,482	3,825	11,256	12,817
Net losses and operating expenses of repossessed assets	6,244	1,728	9,541	4,304
Amortization of intangible assets	5,071	5,064	15,355	15,393
Mortgage banking costs	15,803	14,975	41,946	36,426
Other expense	5,388	6,263	20,669	20,604
Total other operating expense	301,265	279,292	865,276	843,586
Net income before taxes	204,644	174,254	364,017	489,829
Federal and state income taxes	50,552	32,396	83,655	99,926
Net income	154,092	141,858	280,362	389,903
Net income (loss) attributable to non-controlling interests	58	(373)	(444)	(503)
Net income attributable to BOK Financial Corporation shareholders	$ 154,034	$ 142,231	$ 280,806	$ 390,406
Dividends declared per share	$ 0.51	$ 0.50	$ 1.53	$ 1.50
Earnings Per Share [Abstract]
Basic	2.19	2	3.99	5.47
Diluted	$ 2.19	$ 2	$ 3.99	$ 5.47
Average shares used in computation: [Abstract]
Basic	69,877,866	70,596,307	69,958,944	70,953,544
Diluted	69,879,290	70,609,924	69,962,053	70,968,845
Brokerage and trading revenue [Member]
Total fees and commissions	$ 69,526	$ 43,840	$ 182,327	$ 115,983
Transaction card revenue [Member]
Total fees and commissions	23,465	22,015	68,286	64,668
Fiduciary and asset management revenue [Member]
Total fees and commissions	39,931	43,621	125,646	132,004
Deposit service charges and fees [Member]
Total fees and commissions	24,286	28,837	72,462	85,154
Mortgage banking revenue [Member]
Total fees and commissions	51,959	30,180	143,062	82,145
Other revenue [Member]
Total fees and commissions	$ 13,698	$ 17,626	$ 37,486	$ 42,825

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 154,092	$ 141,858	$ 280,362		$ 389,903
Other Comprehensive Income (Loss), before Tax [Abstract]
Net change in unrealized gain (loss)	(6,783)	46,285	347,985		274,441
Reclassification Adjustments Included in Earnings [Abstract]
Loss (gain) on available for sale securities, net	12	(5)	(5,571)		(1,110)
Other comprehensive income (loss) before income taxes	(6,771)	46,280	342,414		273,331
Federal and state income taxes	(1,625)	11,096	82,167	[1]	66,993	[1]
Other comprehensive income (loss), net of income taxes	(5,146)	35,184	260,247		206,338
Comprehensive income	148,946	177,042	540,609		596,241
Comprehensive income (loss) attributable to non-controlling interests	58	(373)	(444)		(503)
Comprehensive income attributable to BOK Financial Corp. shareholders	$ 148,888	$ 177,415	$ 541,053		$ 596,744
[1]	Calculated using a 25 percent blended federal and state statutory tax rate.

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Assets [Abstract]
Cash and due from banks	$ 658,612	$ 735,836
Interest-bearing cash and cash equivalents	347,759	522,985
Trading securities	2,245,480	1,623,921
Investment securities, net of allowance	256,001	293,418
Investment Securities, fair value	284,929	314,402
Available for sale securities	12,817,269	11,269,643
Fair value option securities	134,756	1,098,577
Restricted equity securities	111,656	460,552
Residential mortgage loans held for sale	295,290	182,271
Loans	23,803,300	21,750,987
Allowance for loan losses	(419,777)	(210,759)
Loans, net of allowance	23,383,523	21,540,228
Premises and equipment, net	542,625	535,519
Receivables	245,514	231,811
Goodwill	1,048,091	1,048,091
Intangible assets, net	118,524	125,271
Mortgage servicing rights	97,644	201,886
Real estate and other repossessed assets, net of allowance	52,847	20,359
Allowance for real estate and other repossessed assets	(14,910)	(11,013)
Derivative contracts, net	593,568	323,375
Cash surrender value of bank-owned life insurance	396,497	389,879
Receivable on unsettled securities sales	1,934,495	1,020,404
Other assets	787,073	547,995
Total assets	46,067,224	42,172,021
Deposits [Abstract]
Noninterest-bearing demand deposits	12,047,338	9,461,291
Interest-bearing deposits: [Abstract]
Transaction	20,196,740	15,391,752
Savings	720,949	550,276
Time	2,007,973	2,217,849
Total deposits	34,973,000	27,621,168
Funds purchased and repurchase agreements	973,652	3,818,350
Other borrowings	2,771,429	4,527,055
Subordinated debentures	275,986	275,923
Accrued interest, taxes and expense	335,914	259,701
Derivative contracts, net	446,328	251,128
Due on unsettled securities purchases	641,817	182,547
Other liabilities	422,989	372,230
Total liabilities	40,841,115	37,308,102
Shareholders' equity: [Abstract]
Common stock	$ 5	$ 5
Common stock, par value (in dollars per share)	$ 0.00006	$ 0.00006
Common stock, shares authorized (in shares)	2,500,000,000	2,500,000,000
Common stock, shares issued (in shares)	(75,998,338)	(75,758,597)
Common stock, shares outstanding (in shares)	(75,998,338)	(75,758,597)
Capital surplus	$ 1,366,460	$ 1,350,995
Retained earnings	3,856,046	3,729,778
Treasury stock	$ (368,894)	$ (329,906)
Treasury stock, shares at cost (in shares)	5,692,505	5,178,999
Accumulated other comprehensive gain	$ 365,170	$ 104,923
Total shareholders’ equity	5,218,787	4,855,795
Non-controlling interests	7,322	8,124
Total equity	5,226,109	4,863,919
Total liabilities and equity	$ 46,067,224	$ 42,172,021

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2020		Dec. 31, 2019
Investment securities [Abstract]
Investment securities, Allowance for Credit Loss	$ 739	[1]	$ 0
[1]	Effective with the adoption of FASB ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) on January 1, 2020.

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjusted Balance	Cumulative Effect, Period of Adoption, Adjustment	Common Stock [Member]	Common Stock [Member]Cumulative Effect, Period of Adoption, Adjusted Balance	Capital Surplus [Member]	Capital Surplus [Member]Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings [Member]	Retained Earnings [Member]Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings [Member]Cumulative Effect, Period of Adoption, Adjustment	Treasury Stock [Member]	Treasury Stock [Member]Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]Cumulative Effect, Period of Adoption, Adjusted Balance	Total Shareholders' Equity [Member]	Total Shareholders' Equity [Member]Cumulative Effect, Period of Adoption, Adjusted Balance	Total Shareholders' Equity [Member]Cumulative Effect, Period of Adoption, Adjustment	Non-Controlling Interests [Member]	Non-Controlling Interests [Member]Cumulative Effect, Period of Adoption, Adjusted Balance
Balance, beginning of period (in shares) at Dec. 31, 2018				75,711	75,711						3,589	3,589
Balance, beginning of period at Dec. 31, 2018	$ 4,443,045	$ 4,445,907	$ 2,862	$ 5	$ 5	$ 1,334,030	$ 1,334,030	$ 3,369,654	$ 3,372,516	$ 2,862	$ (198,995)	$ (198,995)	$ (72,585)	$ (72,585)	$ 4,432,109	$ 4,434,971	$ 2,862	$ 10,936	$ 10,936
Net income	389,903							390,406							390,406			(503)
Other comprehensive income (loss)	206,338												206,338		206,338
Repurchase of common stock (in shares)											1,292
Repurchase of common stock	(106,639)										$ (106,639)				(106,639)
Stock options exercised (in shares)				21
Stock options exercised	1,080					1,080									1,080
Non-vested shares awarded, net (in shares)				25
Non-vested shares awarded, net						0
Vesting of non-vested shares (in shares)											18
Vesting of non-vested shares	(1,428)										$ (1,428)				(1,428)
Share-based compensation	11,620					11,620									11,620
Cash dividends on common stock	(107,332)							(107,332)							(107,332)
Capital calls and distributions, net	(1,784)																	(1,784)
Balance, end of period (in shares) at Sep. 30, 2019				75,757							4,899
Balance, end of period at Sep. 30, 2019	4,837,665			$ 5		1,346,730		3,655,590			$ (307,062)		133,753		4,829,016			8,649
Balance, beginning of period (in shares) at Jun. 30, 2019				75,756							4,562
Balance, beginning of period at Jun. 30, 2019	4,718,475			$ 5		1,343,082		3,548,907			$ (281,125)		98,569		4,709,438			9,037
Net income	141,858							142,231							142,231			(373)
Other comprehensive income (loss)	35,184												35,184		35,184
Repurchase of common stock (in shares)											337
Repurchase of common stock	(25,937)										$ (25,937)				(25,937)
Stock options exercised (in shares)				3
Stock options exercised	177					177									177
Non-vested shares awarded, net (in shares)				(2)
Non-vested shares awarded, net						0
Vesting of non-vested shares (in shares)											0
Vesting of non-vested shares	0										$ 0				0
Share-based compensation	3,471					3,471									3,471
Cash dividends on common stock	(35,548)							(35,548)							(35,548)
Capital calls and distributions, net	(15)																	(15)
Balance, end of period (in shares) at Sep. 30, 2019				75,757							4,899
Balance, end of period at Sep. 30, 2019	4,837,665			$ 5		1,346,730		3,655,590			$ (307,062)		133,753		4,829,016			8,649
Balance, beginning of period (in shares) at Dec. 31, 2019				75,759	75,759						5,179	5,179
Balance, beginning of period at Dec. 31, 2019	4,863,919	$ 4,817,223	$ (46,696)	$ 5	$ 5	1,350,995	$ 1,350,995	3,729,778	$ 3,683,082	$ (46,696)	$ (329,906)	$ (329,906)	104,923	$ 104,923	4,855,795	$ 4,809,099	$ (46,696)	8,124	$ 8,124
Net income	280,362							280,806							280,806			(444)
Other comprehensive income (loss)	260,247												260,247		260,247
Repurchase of common stock (in shares)											442
Repurchase of common stock	(33,380)										$ (33,380)				(33,380)
Stock options exercised (in shares)				10
Stock options exercised	586					586									586
Non-vested shares awarded, net (in shares)				229
Non-vested shares awarded, net						0
Vesting of non-vested shares (in shares)											72
Vesting of non-vested shares	(5,608)										$ (5,608)				(5,608)
Share-based compensation	14,879					14,879									14,879
Cash dividends on common stock	(107,842)							(107,842)							(107,842)
Capital calls and distributions, net	(358)																	(358)
Balance, end of period (in shares) at Sep. 30, 2020				75,998							5,693
Balance, end of period at Sep. 30, 2020	5,226,109			$ 5		1,366,460		3,856,046			$ (368,894)		365,170		5,218,787			7,322
Balance, beginning of period (in shares) at Jun. 30, 2020				75,999							5,693
Balance, beginning of period at Jun. 30, 2020	5,104,423			$ 5		1,357,706		3,737,862			$ (368,894)		370,316		5,096,995			7,428
Net income	154,092							154,034							154,034			58
Other comprehensive income (loss)	(5,146)												(5,146)		(5,146)
Repurchase of common stock (in shares)											0
Repurchase of common stock	0										$ 0				0
Stock options exercised (in shares)				0
Stock options exercised	0					0									0
Non-vested shares awarded, net (in shares)				(1)
Non-vested shares awarded, net						0
Vesting of non-vested shares (in shares)											0
Vesting of non-vested shares	0										$ 0				0
Share-based compensation	8,754					8,754									8,754
Cash dividends on common stock	(35,850)							(35,850)							(35,850)
Capital calls and distributions, net	(164)																	(164)
Balance, end of period (in shares) at Sep. 30, 2020				75,998							5,693
Balance, end of period at Sep. 30, 2020	$ 5,226,109			$ 5		$ 1,366,460		$ 3,856,046			$ (368,894)		$ 365,170		$ 5,218,787			$ 7,322

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash Flows From Operating Activities: [Abstract]
Net income	$ 280,362	$ 389,903
Adjustments to reconcile net income to net cash used in operating activities: [Abstract]
Provision for credit losses	229,092	25,000
Change in fair value of mortgage servicing rights due to market assumption changes	85,800	62,814
Change in the fair value of mortgage servicing rights due to principal payments	28,971	27,600
Net unrealized (gains) losses from derivative contracts	(51,323)	(25,306)
Share-based compensation	14,879	11,620
Depreciation and amortization	74,330	69,762
Net amortization of discounts and premiums	1,921	(16,648)
Net losses (gains) on financial instruments and other losses (gains), net	(4,216)	(2,656)
Net gain on mortgage loans held for sale	(77,039)	(25,803)
Mortgage loans originated for sale	(2,773,686)	(2,170,287)
Proceeds from sale of mortgage loans held for sale	2,757,412	2,070,572
Capitalized mortgage servicing rights	(21,330)	(24,821)
Change in trading and fair value option securities	338,992	(1,251,759)
Change in receivables	(936,428)	(613,872)
Change in other assets	(8,574)	12,981
Change in accrued interest, taxes and expense	8,678	(15,600)
Change in other liabilities	412,686	419,982
Net cash provided by (used in) operating activities	360,527	(1,056,518)
Cash Flows From Investing Activities: [Abstract]
Proceeds from maturities or redemptions of investment securities	35,967	49,621
Proceeds from maturities or redemptions of available for sale securities	1,813,057	1,267,190
Purchases of available for sale securities	(3,238,556)	(3,802,635)
Proceeds from sales of available for sale securities	206,979	628,385
Change in amount receivable on unsettled available for sale securities transactions	3,988	29,010
Loans originated, net of principal collected	(1,894,663)	(590,196)
Net payments on derivative asset contracts	(96,109)	40,922
Proceeds from disposition of assets	1,302,013	127,476
Purchases of assets	(1,007,240)	(308,630)
Net cash used in investing activities	(2,874,564)	(2,558,857)
Cash Flows From Financing Activities: [Abstract]
Net change in demand deposits, transaction deposits and savings accounts	7,561,708	773,152
Net change in time deposits	(209,876)	129,980
Net change in other borrowed funds	(4,839,524)	3,027,298
Net proceeds on derivative liability contracts	102,064	(43,932)
Net change in derivative margin accounts	(260,949)	(85,468)
Change in amount due on unsettled available for sale securities transactions	54,408	111,828
Issuance of common and treasury stock, net	(5,022)	(348)
Repurchase of common stock	(33,380)	(106,639)
Dividends paid	(107,842)	(107,332)
Net cash provided by financing activities	2,261,587	3,698,539
Net increase (decrease) in cash and cash equivalents	(252,450)	83,164
Cash and cash equivalents at beginning of period	1,258,821	1,143,424
Cash and cash equivalents at end of period	1,006,371	1,226,588
Supplemental Cash Flow Information: [Abstract]
Cash paid for interest	138,877	316,481
Cash paid for taxes	91,977	77,912
Net loans and bank premises transferred to repossessed real estate and other assets	42,099	8,489
Residential mortgage loans guaranteed by U.S. government agencies that became eligible for repurchase during the period	239,200	65,286
Conveyance of other real estate owned guaranteed by U.S. government agencies	9,165	22,449
Right-of-use assets obtained in exchange for operating lease liabilities	$ 9,481	$ 58,766

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	Basis of Presentation The accompanying unaudited consolidated financial statements of BOK Financial Corporation (“BOK Financial” or “the Company”) have been prepared in accordance with accounting principles for interim financial information generally accepted in the United States and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. The unaudited consolidated financial statements include accounts of BOK Financial and its subsidiaries, principally BOKF, NA (“the Bank”), BOK Financial Securities, Inc., and BOK Financial Private Wealth, Inc. Operating divisions of the Bank include Bank of Albuquerque, Bank of Oklahoma, Bank of Texas, BOK Financial in Arizona, Arkansas, Colorado and Kansas/Missouri, BOK Financial Mortgage and the TransFund electronic funds network. Certain reclassifications have been made to conform to the current period presentation. The financial information should be read in conjunction with BOK Financial’s 2019 Form 10-K filed with the Securities and Exchange Commission, which contains audited financial statements. Amounts presented as of December 31, 2019 have been derived from the audited financial statements included in BOK Financial’s 2019 Form 10-K but do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. Operating results for the nine-month period ended September 30, 2020 are not necessarily indicative of the results that may be expected for the year ending December 31, 2020. Newly Adopted and Pending Accounting Policies Financial Accounting Standards Board (“FASB”) FASB Accounting Standards Update No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Assets Measured at Amortized Cost ("ASU 2016-13" or "CECL") On June 16, 2016, the FASB issued ASU 2016-13 to provide more timely recording of credit losses on loans and other financial assets measured at amortized cost. The Company adopted the new standard January 1, 2020, through a cumulative effect adjustment to retained earnings. Prior periods were not restated. Under ASU 2016-13, acquired loans must be reserved in a manner consistent with originated loans while the incurred loss model excluded purchased loans because the loans had been marked to fair value at acquisition. Under ASU 2016-13, the fair value discount will remain in place and be accreted into interest income over the life of any acquired loans in the portfolio. Another transition adjustment component is related to expected credit losses for residential mortgage loans sold that exceed amounts guaranteed by the U.S. Department of Veterans Affairs as we retain the credit risk for any amounts exceeding the guarantee as well as for recourse loans. Prior to ASU 2016-13, held-to-maturity non-agency securities carried no reserve for credit losses. Note 4 disaggregates the transition adjustment for loans and unfunded loan commitments among portfolio segments as well as on-and off-balance sheet reserves. FASB Accounting Standards Update No. 2019-01, Leases (Topic 842): Codification Improvements ("ASU 2019-01") On March 5, 2019, the FASB issued ASU 2019-01 which amends certain aspects of leasing standard ASU 2016-02. ASU 2019-01 provides guidance for determining the fair value of the underlying asset by lessors that are not manufacturers or dealers. The ASU also requires depository and lending lessors within the scope of ASC 942 to classify principal payments received from sales-type and direct financing leases within "investing activities" on the statement of cash flows. For the two issues above, the ASU is effective for the Company for fiscal years beginning after December 15, 2019, and interim periods therein; however early adoption is permitted. Additionally, ASU 2019-01 also clarifies interim disclosure requirements during transition and is effective with the original transition requirements in Topic 842. The Company adopted ASU 2019-01 in the first quarter of 2020. Adoption of ASU 2019-01 did not have a material impact on the Company's financial statements. FASB Accounting Standards Update No. 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments ("ASU 2019-04") On April 25, 2019, the FASB issued ASU 2019-04 which clarifies certain aspects of the accounting for credit losses, hedging activities, and financial instruments addressed by ASUs 2016-13, 2017-12, and 2016-01, respectively. Significant amendments made to the provisions of ASU 2016-13 by ASU 2019-04 include providing certain alternatives for the measurement of the allowance for credit losses on accrued interest receivable and clarifying steps entities should take when recording the transfer of loans or debt securities between measurement classification or categories. ASU 2019-04 further clarifies the expectation that entities include recoveries of financial assets in the calculation of the current expected credit losses allowance for both pools of financial assets and individual financial assets. Significant amendments made to the provisions of ASU 2017-12 by ASU 2019-04 include clarification on partial-term fair value hedges of interest rate risk, amortization of fair value hedge basis adjustments and disclosure of fair value hedge basis adjustments. Significant amendments made to provisions of ASU 2016-01 include clarification of the measurement alternative practice for equity securities and remeasurement of equity securities at historical exchange rates. ASU 2019-04 includes other amendments which clarify various provisions within the codification. The Company adopted ASU 2019-04 in the first quarter of 2020. Adoption of ASU 2019-04 did not have a material impact on the Company's financial statements. FASB Accounting Standards Update No. 2019-05, Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief ("ASU 2019-05") On May 15, 2019, the FASB issued ASU 2019-05 which provides transition relief for entities adopting the Board's credit losses standard, ASU 2016-13. ASU 2019-05 amends ASU 2016-13 to allow companies to irrevocably elect, upon adoption of ASU 2016-13, the fair value option for financial instruments that meet specific requirements and is effective for the Company for annual reporting periods beginning after December 15, 2019. The Company did not elect the fair value option for additional financial instruments. FASB Accounting Standards Update No. 2019-11, Codification Improvements to Topic 326: Financial Instruments-Credit Losses ("ASU 2019-11") On November 27, 2019, the FASB issued ASU 2019-11 which revises certain aspects of new guidance on credit losses. Topics addressed include purchased credit-deteriorated assets, transition relief for troubled debt restructurings, disclosure relief for accrued interest receivable, and financial assets secured by collateral maintenance provisions. ASU 2019-11 is effective for the Company for annual reporting periods beginning after December 15, 2019. The Company adopted ASU 2019-11 in the first quarter of 2020. Adoption of ASU 2019-11 did not have a material impact on the Company's financial statements. FASB Accounting Standards Update No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes ("ASU 2019-12")

Securities

Securities	9 Months Ended
	Sep. 30, 2020
Marketable Securities [Abstract]
Securities [Text Block]	Securities Trading Securities The fair value and net unrealized gain (loss) included in trading securities are as follows (in thousands): September 30, 2020 December 31, 2019 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. government agency debentures $ 5,181 $ (1) $ 44,264 $ 6 Residential agency mortgage-backed securities 2,150,759 (693) 1,504,651 2,293 Municipal and other tax-exempt securities 30,533 (44) 26,196 60 Asset-backed securities — — 14,084 (21) Other debt securities 59,007 61 34,726 21 Total trading securities $ 2,245,480 $ (677) $ 1,623,921 $ 2,359 Investment Securities The amortized cost and fair values of investment securities are as follows (in thousands): September 30, 2020 Amortized Fair Gross Unrealized Cost Value Gain Loss Municipal and other tax-exempt $ 76,109 $ 80,368 $ 4,259 $ — Residential agency mortgage-backed securities 9,317 10,219 902 — Other debt securities 171,314 194,342 23,227 (199) Total investment securities 256,740 284,929 28,388 (199) Allowance for credit losses 1 (739) Investment securities, net of allowance 256,001 284,929 28,388 (199) 1 Effective with the adoption of FASB ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) on January 1, 2020. December 31, 2019 Amortized Fair Gross Unrealized Cost Value Gain Loss Municipal and other tax-exempt $ 93,653 $ 96,897 $ 3,250 $ (6) Residential agency mortgage-backed securities 10,676 11,164 488 — Other debt securities 189,089 206,341 17,547 (295) Total investment securities $ 293,418 $ 314,402 $ 21,285 $ (301) The amortized cost and fair values of investment securities at September 30, 2020, by contractual maturity, are as shown in the following table (dollars in thousands): Less than One to Six to Over Total Weighted Average Maturity 1 Fixed maturity debt securities: Amortized cost $ 30,455 $ 87,606 $ 120,073 $ 9,289 $ 247,423 4.94 Fair value 30,761 95,912 138,580 9,457 274,710 Residential mortgage-backed securities: Amortized cost $ 9,317 2 Fair value 10,219 Total investment securities: Amortized cost $ 256,740 Fair value 284,929 1 Expected maturities may differ from contractual maturities, because borrowers may have the right to call or prepay obligations with or without penalty. 2 The average expected lives of residential mortgage-backed securities were 4.58 years based upon current prepayment assumptions. Temporarily Impaired Investment Securities (in thousands): September 30, 2020 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized Investment: Other debt securities 8 3,026 68 2,043 131 5,069 199 Total investment securities 8 $ 3,026 $ 68 $ 2,043 $ 131 $ 5,069 $ 199 December 31, 2019 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized Investment: Municipal and other tax-exempt 4 $ 1,001 $ 1 $ 1,706 $ 5 $ 2,707 $ 6 Other debt securities 13 275 1 8,041 294 8,316 295 Total investment securities 17 $ 1,276 $ 2 $ 9,747 $ 299 $ 11,023 $ 301 Available for Sale Securities The amortized cost and fair value of available for sale securities are as follows (in thousands): September 30, 2020 Amortized Fair Gross Unrealized Cost Value Gain Loss U.S. Treasury $ 500 $ 509 $ 9 $ — Municipal and other tax-exempt 50,050 51,601 1,648 (97) Mortgage-backed securities: Residential agency 9,033,728 9,384,998 354,669 (3,399) Residential non-agency 19,954 34,873 14,919 — Commercial agency 3,221,538 3,334,409 114,244 (1,373) Other debt securities 10,936 10,879 — (57) Total available for sale securities $ 12,336,706 $ 12,817,269 $ 485,489 $ (4,926) December 31, 2019 Amortized Fair Gross Unrealized Cost Value Gain Loss U.S. Treasury $ 1,598 $ 1,600 $ 2 $ — Municipal and other tax-exempt 1,789 1,861 72 — Mortgage-backed securities: Residential agency 7,956,297 8,046,096 104,912 (15,113) Residential non-agency 25,968 41,609 15,641 — Commercial agency 3,145,342 3,178,005 37,808 (5,145) Other debt securities 500 472 — (28) Total available for sale securities $ 11,131,494 $ 11,269,643 $ 158,435 $ (20,286) The amortized cost and fair values of available for sale securities at September 30, 2020, by contractual maturity, are as shown in the following table (dollars in thousands): Less than One to Six to Over Total Weighted Average Maturity 1 Fixed maturity debt securities: Amortized cost $ 70,791 $ 1,326,715 $ 1,282,122 $ 603,396 $ 3,283,024 8.02 Fair value 71,123 1,383,695 1,313,942 628,638 3,397,398 Residential mortgage-backed securities: Amortized cost $ 9,053,682 2 Fair value 9,419,871 Total available-for-sale securities: Amortized cost $ 12,336,706 Fair value 12,817,269 1 Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without penalty. 2 The average expected lives of residential mortgage-backed securities were 3.02 years based upon current prepayment assumptions. Sales of available for sale securities resulted in gains and losses as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Proceeds $ 1,034 $ 261,028 $ 206,979 $ 628,385 Gross realized gains 54 989 5,637 7,316 Gross realized losses (66) (984) (66) (6,206) Related federal and state income tax expense (benefit) (3) 1 1,419 282 The fair value of debt securities pledged as collateral for repurchase agreements, public trust funds on deposit and for other purposes, as required by law was $12.5 billion at September 30, 2020 and $10.1 billion at December 31, 2019. The secured parties do not have the right to sell or repledge these securities. Temporarily Impaired Available for Sale Securities (in thousands) September 30, 2020 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized Available for sale: Municipal and other tax-exempt 11 $ 19,768 $ 97 $ — $ — $ 19,768 $ 97 Mortgage-backed securities: Residential agency 32 630,460 3,178 165,726 221 796,186 3,399 Commercial agency 29 264,836 923 253,378 450 518,214 1,373 Other debt securities 5 10,407 29 472 28 10,879 57 Total available for sale securities 77 $ 925,471 $ 4,227 $ 419,576 $ 699 $ 1,345,047 $ 4,926 December 31, 2019 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized Available for sale: Mortgage-backed securities: Residential agency 133 $ 1,352,597 $ 6,690 $ 686,002 $ 8,423 $ 2,038,599 $ 15,113 Commercial agency 69 830,047 4,238 210,877 907 1,040,924 5,145 Other debt securities 1 — — 472 28 472 28 Total available for sale securities 203 $ 2,182,644 $ 10,928 $ 897,351 $ 9,358 $ 3,079,995 $ 20,286 Based on evaluations of impaired securities as of September 30, 2020, the Company does not intend to sell any impaired available for sale debt securities before fair value recovers to the current amortized cost and it is more-likely-than-not that the Company will not be required to sell impaired securities before fair value recovers, which may be maturity. Fair Value Option Securities Fair value option securities represent securities which the Company has elected to carry at fair value and are separately identified on the Consolidated Balance Sheets. Changes in the fair value are recognized in earnings as they occur. Certain securities are held as an economic hedge of the mortgage servicing rights. The fair value and net unrealized gain (loss) included in fair value option securities is as follows (in thousands): September 30, 2020 December 31, 2019 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. Treasury $ — $ — $ 9,917 $ (48) Residential agency mortgage-backed securities 134,756 4,926 1,088,660 14,109 Total $ 134,756 $ 4,926 $ 1,098,577 $ 14,061

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2020
Derivative Instrument Detail [Abstract]
Derivatives [Text Block]	Derivatives Derivative instruments may be used by the Company as part of its internal risk management programs or may be offered to customers. All derivative instruments are carried at fair value and changes in fair value are reported in earnings as they occur. Credit risk is also considered in determining fair value. Deterioration in the credit rating of customer or other counterparties reduced the fair value of asset contracts. Deterioration of our credit rating could decrease the fair value of our derivative liabilities. When bilateral netting agreements or similar arrangements exist between the Company and its counterparties that create a single legal claim or obligation to pay or receive the net amount in settlement of the individual derivative contracts, the Company reports derivative assets and liabilities on a net by derivative contract type by counterparty basis. Derivative contracts may require the Company to provide or receive cash margin as collateral for derivative assets and liabilities. Derivative assets and liabilities are reported net of cash margin when certain conditions are met. In addition, derivative contracts executed with customers under Customer Risk Management Programs may be secured by non-cash collateral in conjunction with a credit agreement with that customer. Access to collateral in the event of default is reasonably assured. None of these derivative contracts have been designated as hedging instruments for accounting purposes. Customer Risk Management Programs BOK Financial offers programs to permit its customers to manage various risks, including fluctuations in energy, cattle and other agricultural products, interest rates and foreign exchange rates with derivative contracts. Customers may also manage interest rate risk through interest rate swaps used by borrowers to modify interest rate terms of their loans. Derivative contracts are executed between the customers and BOK Financial. Offsetting contracts are executed between BOK Financial and other selected counterparties to minimize the risk of changes in commodity prices, interest rates or foreign exchange rates. The counterparty contracts are identical to customer contracts, except for a fixed pricing spread or fee paid to BOK Financial as profit and compensation for administrative costs and credit risk which is recognized over the life of the contracts and included in Other operating revenue – Brokerage and trading revenue in the Consolidated Statements of Earnings. Trading BOK Financial may offer derivative instruments such as to-be-announced securities to mortgage banking customers to enable them to manage their market risk or to mitigate the Company's market risk of holding trading securities. Changes in the fair value of derivative instruments for trading purposes or used to mitigate the market risk of holding trading securities are included in Other operating revenue – Brokerage and trading revenue. Internal Risk Management Programs BOK Financial may use derivative contracts in managing its interest rate sensitivity, as part of its economic hedge of the change in the fair value of mortgage servicing rights. Changes in the fair value of derivative instruments used in managing interest rate sensitivity and as part of the economic hedge of changes in the fair value of mortgage servicing rights are included in Other operating revenue – Gain (loss) on derivatives, net in the Consolidated Statements of Earnings. As discussed in Note 5, certain derivative contracts not designated as hedging instruments related to mortgage loan commitments and forward sales contracts are included in Residential mortgage loans held for sale on the Consolidated Balance Sheets. See Note 5 for additional discussion of notional, fair value and impact on earnings of these contracts. The following table summarizes the fair values of derivative contracts recorded as “derivative contracts” assets and liabilities in the balance sheet at September 30, 2020 (in thousands): Assets Notional 1 Gross Fair Value Netting Adjustments Net Fair Value Before Cash Collateral Cash Collateral Fair Value Net of Cash Collateral Customer risk management programs: Interest rate contracts 3,179,414 132,320 (107) 132,213 — 132,213 Energy contracts 3,482,226 400,646 (229,433) 171,213 (92,170) 79,043 Agricultural contracts 13,611 1,870 — 1,870 — 1,870 Foreign exchange contracts 311,626 309,130 — 309,130 (400) 308,730 Equity option contracts 73,447 937 — 937 (219) 718 Total customer risk management programs 7,060,324 844,903 (229,540) 615,363 (92,789) 522,574 Trading 65,290,962 235,176 (173,680) 61,496 (3,824) 57,672 Internal risk management programs 734,142 19,357 (6,035) 13,322 — 13,322 Total derivative contracts $ 73,085,428 $ 1,099,436 $ (409,255) $ 690,181 $ (96,613) $ 593,568 Liabilities Notional 1 Gross Fair Value Netting Adjustments Net Fair Value Before Cash Collateral Cash Collateral Fair Value Net of Cash Collateral Customer risk management programs: Interest rate contracts 3,179,414 132,689 (107) 132,582 (121,212) 11,370 Energy contracts 3,277,670 374,542 (229,433) 145,109 (37,276) 107,833 Agricultural contracts 13,627 1,856 — 1,856 (1,856) — Foreign exchange contracts 311,098 308,493 — 308,493 — 308,493 Equity option contracts 73,447 937 — 937 — 937 Total customer risk management programs 6,855,256 818,517 (229,540) 588,977 (160,344) 428,633 Trading 64,972,263 229,013 (173,680) 55,333 (38,999) 16,334 Internal risk management programs 559,452 7,655 (6,035) 1,620 (259) 1,361 Total derivative contracts $ 72,386,971 $ 1,055,185 $ (409,255) $ 645,930 $ (199,602) $ 446,328 1 Notional amounts for commodity contracts are converted into dollar-equivalent amounts based on dollar prices at the inception of the contract. The following table summarizes the fair values of derivative contracts recorded as “derivative contracts” assets and liabilities in the balance sheet at December 31, 2019 (in thousands): Assets Notional 1 Gross Fair Value Netting Adjustments Net Fair Value Before Cash Collateral Cash Collateral Fair Value Net of Cash Collateral Customer risk management programs: Interest rate contracts 2,464,478 49,100 (1,839) 47,261 — 47,261 Energy contracts 2,151,096 144,906 (107,591) 37,315 (38) 37,277 Agricultural contracts 16,118 1,522 (22) 1,500 — 1,500 Foreign exchange contracts 214,119 213,007 — 213,007 — 213,007 Equity option contracts 81,455 3,233 — 3,233 (660) 2,573 Total customer risk management programs 4,927,266 411,768 (109,452) 302,316 (698) 301,618 Trading 69,721,932 131,561 (115,949) 15,612 — 15,612 Internal risk management programs 1,268,180 6,226 (81) 6,145 — 6,145 Total derivative contracts $ 75,917,378 $ 549,555 $ (225,482) $ 324,073 $ (698) $ 323,375 Liabilities Notional 1 Gross Fair Value Netting Adjustments Net Fair Value Before Cash Collateral Cash Collateral Fair Value Net of Cash Collateral Customer risk management programs: Interest rate contracts 2,464,478 49,194 (1,839) 47,355 (43,932) 3,423 Energy contracts 2,105,391 139,311 (107,591) 31,720 (6,031) 25,689 Agricultural contracts 16,139 1,507 (22) 1,485 (1,485) — Foreign exchange contracts 207,919 207,020 — 207,020 — 207,020 Equity option contracts 81,455 3,233 — 3,233 — 3,233 Total customer risk management programs 4,875,382 400,265 (109,452) 290,813 (51,448) 239,365 Trading 65,144,388 125,535 (115,949) 9,586 — 9,586 Internal risk management programs 380,401 3,121 (81) 3,040 (863) 2,177 Total derivative contracts $ 70,400,171 $ 528,921 $ (225,482) $ 303,439 $ (52,311) $ 251,128 1 Notional amounts for commodity contracts are converted into dollar-equivalent amounts based on dollar prices at the inception of the contract. The following summarizes the pre-tax net gains (losses) on derivative instruments and where they are recorded in the income statement (in thousands): Three Months Ended September 30, 2020 September 30, 2019 Brokerage Gain (Loss) on Derivatives, Net Brokerage Gain (Loss)on Derivatives, Net Customer risk management programs: Interest rate contracts To-be-announced residential mortgage-backed securities $ — $ — $ 1,667 $ — Interest rate swaps 1,014 — 1,252 — Energy contracts 7,460 — 1,611 — Agricultural contracts 6 — 16 — Foreign exchange contracts 162 — 138 — Equity option contracts — — — — Total customer risk management programs 8,642 — 4,684 — Trading 1 (468) — 3,630 — Internal risk management programs — 2,354 — 3,778 Total derivative contracts $ 8,174 $ 2,354 $ 8,314 $ 3,778 1 Represents changes in fair value of to-be-announced securities and other derivative instruments held to mitigate market risk of trading securities portfolio, which is offset by changes in fair value of trading securities also include in Brokerage and Trading Revenue in the Consolidated Statements of Earnings. Nine Months Ended September 30, 2020 September 30, 2019 Brokerage Gain (Loss) on Derivatives, Net Brokerage Gain (Loss) on Derivatives, Net Customer risk management programs: Interest rate contracts To-be-announced residential mortgage-backed securities $ — $ — $ 9,579 $ — Interest rate swaps 2,702 — 2,787 — Energy contracts 14,850 — 3,923 — Agricultural contracts 27 — 24 — Foreign exchange contracts 527 — 392 — Equity option contracts — — — — Total customer risk management programs 18,106 — 16,705 — Trading 1 (8,546) — 4,365 — Internal risk management programs — 42,659 — 19,595 Total derivative contracts $ 9,560 $ 42,659 $ 21,070 $ 19,595

Loans and Allowances for Credit

Loans and Allowances for Credit Losses	9 Months Ended
	Sep. 30, 2020
Loans and Leases Receivable, Net Amount [Abstract]
Loans [Text Block]	Loans Loans are either secured or unsecured based on the type of loan and the financial condition of the borrower. Repayment is generally expected from cash flow or proceeds from the sale of selected assets of the borrower. BOK Financial is exposed to risk of loss on loans due to the borrower’s difficulties, which may arise from any number of factors, including problems within the respective industry or local economic conditions. Access to collateral, in the event of borrower default, is reasonably assured through adherence to applicable lending laws and through sound lending standards and credit review procedures. Accounting policies for all loans, excluding residential mortgage loans guaranteed by U.S. government agencies, are as follows. Interest is accrued at the applicable interest rate on the principal amount outstanding. Loans are placed on nonaccruing status when, in the opinion of management, full collection of principal or interest is uncertain. Internally risk graded loans are individually evaluated for nonaccruing status quarterly. Non-risk graded loans are generally placed on nonaccruing status when more than 90 days past due or within 60 days of being notified of the borrower's bankruptcy filing. Interest previously accrued but not collected is charged against interest income when the loan is placed on nonaccruing status. Accrued but not paid interest receivable is included in Receivables in the Consolidated Balance Sheets. Payments on nonaccruing loans are applied to principal or recognized as interest income, according to management’s judgment as to the collectability of principal. Loans may be returned to accruing status when, in the opinion of management, full collection of principal and interest, including principal previously charged off, is probable based on improvements in the borrower’s financial condition or a sustained period of performance. For loans acquired with no evidence of credit deterioration, discounts are accreted on either an individual basis for loans with unique characteristics or on a pool basis for groups of homogeneous loans. Accretion is discontinued when a loan with an individually attributed discount is placed on nonaccruing status. Loans to borrowers experiencing financial difficulties may be modified in troubled debt restructurings ("TDRs"). Primarily all TDRs are classified as nonaccruing, excluding loans guaranteed by U.S. government agencies. Modifications generally consist of extension of payment terms or interest rate concessions and may result either voluntarily through negotiations with the borrower or involuntarily through court order. Generally, principal and accrued but unpaid interest is not voluntarily forgiven. In accordance with the guidance provided by the banking agencies on April 7, 2020 concerning loan modifications for customers impacted by the COVID-19 pandemic, short-term (six months or less) payment deferrals made in good faith to borrowers current prior to the relief are not considered TDRs. Performing loans may be renewed under the current collateral value, debt service ratio and other underwriting standards. Nonaccruing loans may be renewed and will remain classified as nonaccruing. Occasionally, loans, other than residential mortgage loans, may be held for sale in order to manage credit concentration. These loans are carried at the lower of cost or fair value with gains or losses recognized in Other gains (losses), net in the Consolidated Statements of Earnings. All loans are charged off when the loan balance or a portion of the loan balance is no longer supported by the paying capacity of the borrower or when the required cash flow is reduced in a TDR. The charge-off amount is determined through a quarterly evaluation of available cash resources and collateral value and charge-offs are taken in the quarter in which the loss is identified. Non-risk graded loans that are past due between 60 days and 180 days, based on the loan product type, are charged off. Loans to borrowers whose personal obligation has been discharged through Chapter 7 bankruptcy proceedings are charged off within 60 days of notice of the bankruptcy filing, regardless of payment status. Loan origination and commitment fees and direct loan acquisition and origination costs are deferred and amortized as an adjustment to yield over the life of the loan or over the commitment period, as applicable. Amortization does not anticipate loan prepayments. Net unamortized fees are recognized in full at time of payoff. Qualifying residential mortgage loans guaranteed by U.S. government agencies have been sold into GNMA pools. Under certain performance conditions specified in government programs, the Company may have the right, but not the obligation to repurchase loans from GNMA pools. These loans no longer qualify for sale accounting and are recognized in the Consolidated Balance Sheets. The carrying value of these loans is reduced based on an estimate of the expected cash flows discounted at the original note rate plus a liquidity spread. Guaranteed loans may be modified in TDRs in accordance with U.S. government agency guidelines. Interest continues to accrue based on the modified rate. Guaranteed loans may either be resold into GNMA pools after a performance period specified by the programs or foreclosed and conveyed to the guarantors. Loans are disaggregated into portfolio segments and further disaggregated into classes. The portfolio segment is the level at which the Company develops and documents a systematic method for determining its allowance for credit losses. Classes are a further disaggregation of portfolio segments based on the risk characteristics of the loans and the Company’s method for monitoring and assessing credit risk. Portfolio segments of the loan portfolio are as follows (in thousands): September 30, 2020 Fixed Variable Non-accrual Total Commercial 1,424,416 11,971,337 169,953 $ 13,565,706 Commercial real estate 1,012,882 3,667,866 12,952 4,693,700 Paycheck protection program 2,097,325 — — 2,097,325 Loans to individuals 2,132,653 1,275,668 38,248 3,446,569 Total $ 6,667,276 $ 16,914,871 $ 221,153 $ 23,803,300 Credit Commitments Commitments to extend credit are agreements to lend to a customer as long as there is no violation of conditions established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. At September 30, 2020, outstanding commitments totaled $10.4 billion. Because some commitments are expected to expire before being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. BOK Financial uses the same credit policies in making commitments as it does loans. The amount of collateral obtained, if deemed necessary, is based upon management’s credit evaluation of the borrower. Standby letters of credit are conditional commitments issued to guarantee the performance of a customer to a third party. Because the credit risk involved in issuing standby letters of credit is essentially the same as that involved in extending loan commitments, BOK Financial uses the same credit policies in evaluating the creditworthiness of the customer. Additionally, BOK Financial uses the same evaluation process in obtaining collateral on standby letters of credit as it does for loan commitments. The term of these standby letters of credit is defined in each commitment and typically corresponds with the underlying loan commitment. At September 30, 2020, outstanding standby letters of credit totaled $678 million. Allowances for Credit Losses and Accrual for Off-balance Sheet Credit Risk from Unfunded Loans Commitments BOK Financial’s accounting policies have changed significantly with the adoption of CECL as of January 1, 2020. Prior periods are not restated. Prior to January 1, 2020, general allowances and nonspecific allowances were based on incurred credit losses in accordance with accounting policies disclosed in Note 1 of the Consolidated Financial Statements included in the 2019 Form 10-K. The allowance for loan losses and accrual for off-balance sheet credit risk from unfunded loan commitments represent the portion of the amortized cost basis of loans that we do not expect to collect over the asset’s contractual life, considering past events, current conditions, and reasonable and supportable forecasts of future economic conditions. The appropriateness of the allowance for credit losses, including industry and product adjustments, is assessed quarterly by a senior management Allowance Committee. This review is based on an on-going evaluation of the estimated expected credit losses in the portfolio and on unused commitments to provide financing. A well-documented methodology has been developed and is applied by an independent Credit Administration department to assure consistency across the Company. The allowance for loan losses consists of specific allowances attributed to certain individual loans, generally nonaccruing loans, with dissimilar risk characteristics that have not yet been charged down to amounts we expect to recover and general allowances for estimated credit losses on pools of loans that share similar risk characteristics. When full collection of principal or interest is uncertain, the loan’s risk characteristics have changed, and we exclude the loan from the general allowance pool, typically designating it as nonaccruing. For these loans, a specific allowance reflects the expected credit loss. We measure specific allowances for loans excluded from the general allowance pool by an evaluation of estimated future cash flows discounted at the loans initial effective interest rate or the fair value of collateral for certain collateral dependent loans. For a non-collateral dependent loan, the specific allowance is the amount by which the loan’s amortized cost basis exceeds its net realizable value. We measure the specific allowance for collateral dependent loans as the amount by which the loan’s amortized costs basis exceeds its fair value. When repayment is expected to be provided substantially through the sale of collateral, we deduct estimated selling costs from the collateral’s fair value. Generally, third party appraisals that conform to Uniform Standards of Professional Appraisal Practice serve as the basis for the fair value of real property held as collateral. These appraised values are on an “as-is” basis and generally are not adjusted by the Company. We obtain updated appraisals at least annually or more frequently if market conditions indicate collateral values may have declined. For energy loans, our internal staff of engineers generally determines collateral value of mineral rights based on projected cash flows from proven oil and gas reserves under existing economic and operating conditions. For real property held as collateral for other loans, third party appraisals that conform to Uniform Standards of Professional Appraisal Practice generally serve as the basis for the fair value. These appraised values are on an “as-is” basis and generally are not adjusted by the Company. We obtain updated appraisals at least annually or more frequently if market conditions indicate collateral values may have declined. Our special assets staff generally determines the value of other collateral based on projected liquidation cash flows under current market conditions. We evaluate collateral values and available cash resources quarterly. Historical statistics may be used to estimate specific allowances in limited situations, such as when a collateral dependent loan is removed from the general allowance pool near the end of a reporting period until an appraisal of collateral value is received or a full assessment of future cash flows is completed. General allowances estimate expected credit losses on pools of loans sharing similar risk characteristics that are expected to occur over the loan’s estimated remaining life. The loan’s estimated remaining life represents the contractual term adjusted for amortization, estimates of prepayments, and borrower-owned extension options. Approximately 90 percent of the committed dollars in the loan portfolio is risk graded loans with general allowance model inputs that include probability of default, loss given default, and exposure at default. Probability of default is based on the migration of loans from performing to nonperforming using historical life of loan analysis periods. Loss given default is based on the aggregate losses incurred, net of estimated recoveries. Exposure at default represents an estimate of the outstanding amount of credit exposure at the time a default may occur. Charge-off migration is used to calculate the general allowance for the majority of non-risk graded loans to individuals. The expected credit loss on less than 10 percent of the committed dollars in the portfolio is calculated using charge-off migration. The expected credit loss on approximately 1 percent of the committed dollars in the portfolio is calculated using a non-modeled approach. Specifically, the calculation applies a long-term net charge-off rate to the loan balances, adjusted for the weighted average remaining maturity of each portfolio. In estimating the expected credit losses for general allowances on performing risk-graded loans, each portfolio class is assigned relevant economic loss drivers which best explain variations in portfolio net loss rates. The probability of default estimates for each portfolio class are adjusted for current and forecasted economic conditions. The result is applied to the exposure at default and loss given default to calculate the lifetime expected credit loss estimate. Selection of relevant economic loss drivers is re-evaluated periodically and involves statistical analysis as well as management judgment. The unemployment rate factors significantly in the allowance for loan losses calculation, affecting commercial and loans to individuals segments. Other primary factors impacting the commercial portfolio include BBB corporate spreads, real gross domestic product growth rate, and energy commodity prices. The primary commercial real estate variables are vacancy rate and BBB corporate spreads. In addition to the unemployment rate, the forecast for loans to individuals is tied to home price index. The forecasts may include regional economic factors when localized conditions diverge from national conditions. An Economic Forecast Committee, consisting of senior management with members largely independent of the allowance process develops a twelve-month forward-looking forecast for the relevant economic loss drivers. Management develops these forecasts based on external data as well as a view of future economic conditions, which may include adjustments for regional conditions. The forecast includes three economic scenarios and probability weights for each scenario. The base forecast represents management's view of the most likely outcome, while the downside forecast reflects reasonably possible worsening economic conditions, and the upside forecast projects reasonably possible improving conditions. At the end of the one-year reasonable and supportable forecast period, we transition from shorter-term expected losses to long-term loss averages for the loan’s estimated remaining life. The difference between short-term loss forecasts and long-term loss averages is run-off over the reversion horizon, up to three years, depending on the forecasted economic scenarios. General allowances also consider the estimated impact of factors that are not captured in the modeled results or historical experience. These qualitative adjustments, determined by the Allowance Committee, may increase or decrease the allowance estimated by modeled results. Factors not captured in modeled results or historical experience may include for example, new lines of business, market conditions that have not been previously encountered, observed changes in credit risk that are not yet reflected in macro-economic factors, or economic conditions that impact loss given default assumptions. The accrual for off-balance sheet credit risk is maintained at a level that is appropriate to cover estimated losses associated with credit instruments that are not currently recognized as assets such as loan commitments, standby letters of credit or guarantees that are not unconditionally cancelable by the bank. This accrual is included in other liabilities in the Consolidated Balance Sheets. The appropriateness of the accrual is determined in the same manner as the allowance for loan losses, with the added consideration of commitment usage over the remaining life for those loans that the bank can not unconditionally cancel. A provision for credit losses is charged against or credited to earnings in amounts necessary to maintain an appropriate Allowance for Credit Losses. Recoveries of loans previously charged off are added to the allowance when received. The activity in the allowance for loan losses and the allowance for off-balance sheet credit losses related to loan commitments and standby letters of credit is summarized as follows (in thousands): Three Months Ended September 30, 2020 Commercial Commercial Real Estate Paycheck Protection Program Loans to Individuals Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 310,422 $ 68,756 $ — $ 56,419 $ — $ 435,597 Provision for loan losses 2,108 3,118 — 1,383 — 6,609 Loans charged off (25,319) (413) — (929) — (26,661) Recoveries of loans previously charged off 3,066 114 — 1,052 — 4,232 Ending Balance $ 290,277 $ 71,575 $ — $ 57,925 — $ 419,777 Allowance for off-balance sheet credit risk from unfunded loan commitments: Beginning balance $ 14,582 $ 16,419 $ — $ 1,918 $ — $ 32,919 Provision for off-balance sheet credit risk (2,618) (2,426) — 94 — (4,950) Ending Balance $ 11,964 $ 13,993 $ — $ 2,012 $ — $ 27,969 Nine Months Ended September 30, 2020 Commercial Commercial Real Estate Paycheck Protection Program Loans to Individuals Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 118,187 $ 51,805 $ — $ 23,572 $ 17,195 $ 210,759 Transition adjustment 33,681 (4,620) — 13,943 (17,195) 25,809 Beginning balance, adjusted 151,868 47,185 — 37,515 — 236,568 Provision for loan losses 190,984 25,454 — 20,500 — 236,938 Loans charged off (56,421) (1,300) — (3,427) — (61,148) Recoveries 3,846 236 — 3,337 — 7,419 Ending balance $ 290,277 $ 71,575 $ — $ 57,925 $ — $ 419,777 Allowance for off-balance sheet credit risk from unfunded loan commitments: Beginning balance $ 1,434 $ 107 $ — $ 44 $ — $ 1,585 Transition adjustment 10,144 11,660 — 1,748 — 23,552 Beginning balance, adjusted 11,578 11,767 — 1,792 — 25,137 Provision for off-balance sheet credit losses 386 2,226 — 220 — 2,832 Ending balance $ 11,964 $ 13,993 $ — $ 2,012 $ — $ 27,969 Changes in our reasonable and supportable forecasts of macroeconomic variables, primarily due to the anticipated impact of the on-going COVID-19 pandemic, and other assumptions, resulted in a $12.8 million reduction in the allowance for lending activities during the third quarter of 2020. Changes in the loan portfolio characteristics, including specific impairment and losses, loan balances and risk grading resulted in a $14.5 million increase in the allowance for lending activities. The allowance for loan losses and recorded investment of the related loans by portfolio segment for each measurement method at September 30, 2020 is as follows (in thousands): Collectively Measured Individually Measured Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Commercial $ 13,395,753 $ 271,122 $ 169,953 $ 19,155 $ 13,565,706 $ 290,277 Commercial real estate 4,680,748 71,035 12,952 540 4,693,700 71,575 Paycheck protection program 2,097,325 — — — 2,097,325 — Loans to individuals 3,408,321 57,925 38,248 — 3,446,569 57,925 Total 23,582,147 400,082 221,153 19,695 23,803,300 419,777 Credit Quality Indicators The Company utilizes risk grading as primary credit quality indicators as it influences the probability of default which is a key attribute in the expected credit losses calculation. Substantially all commercial as well as commercial real estate loans and certain loans to individuals are risk graded based on a quarterly evaluation of the borrowers’ ability to repay the loans. Certain commercial loans and most loans to individuals are small, homogeneous pools that are not risk-graded. The credit quality of these loans is based on past due days in accordance with regulatory guidelines. We have included in the credit quality indicator “pass” loans that are in compliance with the original terms of the agreement and currently exhibit no factors that cause management to have doubts about the borrowers’ ability to remain in compliance with the original terms of the agreement, which is consistent with the regulatory guideline of “pass.” This also includes past due residential mortgages that are guaranteed by agencies of the U.S. government that continue to accrue interest based on criteria of the guarantors’ programs. Other loans especially mentioned ("Special Mention") are currently performing in compliance with the original terms of the agreement but may have a potential weakness that deserves management’s close attention, consistent with regulatory guidelines. Non-graded loans 30 to 59 days past due are categorized as Special Mention. The risk grading process identified certain loans that have a well-defined weakness (for example, inadequate debt service coverage or liquidity or marginal capitalization; repayment may depend on collateral or other risk mitigation) that may jeopardize liquidation of the debt and represent a greater risk due to deterioration in the financial condition of the borrower. This is consistent with the regulatory guideline for “substandard.” Because the borrowers are still performing in accordance with the original terms of the loan agreements, these loans remain on accruing status. Non-graded loans 60 to 89 days past due are categorized as Accruing Substandard. Nonaccruing loans represent loans for which full collection of principal and interest is uncertain. This includes certain loans considered “substandard” and all loans considered “doubtful” by regulatory guidelines. Non-graded loans 90 or more days past due are categorized as Nonaccrual. Probability of default is lowest for pass graded loans and increases for each credit quality indicator, Special Mention, and Accruing Substandard. Vintage represents the year of origination, except for revolving loans which are considered in aggregate. Loans that were once revolving but have converted to term loans without additional underwriting appear in a separate vintage column. The following table summarizes the Company’s loan portfolio at September 30, 2020 by the risk grade categories and vintage (in thousands): Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total Commercial: Energy Pass $ 57,239 $ 58,923 $ 93,066 $ 7,959 $ 1,131 $ 6,716 $ 2,474,328 $ — $ 2,699,362 Special Mention — — — — — — 465,643 — 465,643 Accruing Substandard 295 — 951 — 14,406 — 409,628 — 425,280 Nonaccrual 1,652 6,541 15,496 — — 28,349 74,778 — 126,816 Total energy 59,186 65,464 109,513 7,959 15,537 35,065 3,424,377 — 3,717,101 Healthcare Pass 356,834 619,693 625,047 429,314 241,452 749,439 236,118 — 3,257,897 Special Mention — 27,500 — 3,019 — 13,393 3,255 — 47,167 Accruing Substandard — 2,843 1,705 947 143 11,443 — — 17,081 Nonaccrual — 18 183 — — 2,935 509 — 3,645 Total healthcare 356,834 650,054 626,935 433,280 241,595 777,210 239,882 — 3,325,790 Services Pass 356,443 445,488 406,761 345,936 380,205 758,036 689,917 651 3,383,437 Special Mention 344 11,778 1,734 597 8,415 5,410 10,043 — 38,321 Accruing Substandard 94 8,067 27,957 9,662 2,568 15,185 34,717 — 98,250 Nonaccrual — 3,420 — 13,898 1,147 6,726 626 — 25,817 Total services 356,881 468,753 436,452 370,093 392,335 785,357 735,303 651 3,545,825 General business Pass 327,729 446,214 342,469 242,267 126,259 229,142 1,145,429 2,766 2,862,275 Special Mention — 4,335 13,235 7,126 3,876 3,457 4,782 21 36,832 Accruing Substandard 1,005 15,955 11,316 11,007 7,501 8,526 8,894 4 64,208 Nonaccrual 1,675 3,853 4,865 1,647 787 118 659 71 13,675 Total general business 330,409 470,357 371,885 262,047 138,423 241,243 1,159,764 2,862 2,976,990 Total commercial 1,103,310 1,654,628 1,544,785 1,073,379 787,890 1,838,875 5,559,326 3,513 13,565,706 Commercial real estate: Pass 578,864 1,184,368 1,021,832 517,976 347,920 780,900 207,440 — 4,639,300 Special Mention — — 261 12,326 2,571 8,903 — — 24,061 Accruing Substandard — 8,349 — 4,187 — 4,824 27 — 17,387 Nonaccrual — — — 232 6,575 6,145 — — 12,952 Total commercial real estate 578,864 1,192,717 1,022,093 534,721 357,066 800,772 207,467 — 4,693,700 Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total Paycheck protection program: Pass 2,097,325 — — — — — — — 2,097,325 Total paycheck protection program 2,097,325 — — — — — — — 2,097,325 Loans to individuals: Residential mortgage Pass 414,273 166,795 138,524 157,514 178,830 390,803 341,673 26,129 1,814,541 Special Mention — 47 1,879 20 — 309 527 12 2,794 Accruing Substandard — — — — — 39 159 12 210 Nonaccrual — 43 1,509 735 2,057 24,431 2,066 758 31,599 Total residential mortgage 414,273 166,885 141,912 158,269 180,887 415,582 344,425 26,911 1,849,144 Residential mortgage guaranteed by U.S. government agencies Pass 2,385 29,819 29,745 43,690 57,322 214,889 — — 377,850 Nonaccrual — — 404 — — 5,993 — — 6,397 Total residential mortgage guaranteed by U.S. government agencies 2,385 29,819 30,149 43,690 57,322 220,882 — — 384,247 Personal: Pass 182,066 204,478 79,041 104,217 70,812 98,598 471,503 1,498 1,212,213 Special Mention 42 24 11 53 46 45 1 — 222 Accruing Substandard — 211 — 265 — — 15 — 491 Nonaccrual — 17 49 53 59 44 30 — 252 Total personal 182,108 204,730 79,101 104,588 70,917 98,687 471,549 1,498 1,213,178 Total loans to individuals 598,766 401,434 251,162 306,547 309,126 735,151 815,974 28,409 3,446,569 Total loans $ 4,378,265 $ 3,248,779 $ 2,818,040 $ 1,914,647 $ 1,454,082 $ 3,374,798 $ 6,582,767 $ 31,922 $ 23,803,300 Nonaccruing Loans A summary of nonaccruing loans at September 30, 2020 follows (in thousands): As of September 30, 2020 Total With No With Allowance Related Allowance Commercial: Energy $ 126,816 $ 86,793 $ 40,023 $ 16,504 Healthcare 3,645 3,645 — — Services 25,817 20,456 5,361 2,574 General business 13,675 13,177 498 77 Total commercial 169,953 124,071 45,882 19,155 Commercial real estate 12,952 7,584 5,368 540 Loans to individuals: Residential mortgage 31,599 31,599 — — Residential mortgage guaranteed by U.S. government agencies 6,397 6,397 — — Personal 252 252 — — Total loans to individuals 38,248 38,248 — — Total $ 221,153 $ 169,903 $ 51,250 $ 19,695 Troubled Debt Restructurings At September 30, 2020 the Company had $184 million in troubled debt restructurings ("TDRs"), of which $143 million were accruing residential mortgage loans guaranteed by U.S. government agencies, $11 million were nonaccruing energy loans with a related specific allowance of $2.0 million and $19 million were nonaccruing residential mortgage loans with no specific allowance necessary. Approximately $65 million of TDRs were performing in accordance with the modified terms. At December 31, 2019, the Company had $132 million in TDRs, of which $92 million were accruing residential mortgage loans guaranteed by U.S. government agencies. Approximately $57 million of TDRs were performing in accordance with the modified terms. TDRs generally consist of interest rate concessions, payment stream concessions or a combination of concessions to distressed borrowers. During the three and nine months ended September 30, 2020, $36 million and $76 million of loans were restructured and $6.4 million and $16.1 million of loans designated as TDRs were charged off. During the three and nine months ended September 30, 2019, $6.2 million and $40 million of loans were restructured and $2.5 million and $15.1 million of loans designated as TDRs were charged off. Past Due Loans Past due status for all loan classes is based on the actual number of days since the last payment was due according to the contractual terms of the loans, as modified for short-term payment deferral forbearance. A summary of loans currently performing and past due as of September 30, 2020 is as follows (in thousands): Past Due Past Due 90 Days or More and Accruing Current 30 to 59 60 to 89 Days 90 Days Total Commercial: Energy $ 3,603,548 $ 27,064 $ — $ 86,489 $ 3,717,101 $ — Healthcare 3,316,556 5,419 — 3,815 3,325,790 171 Services 3,521,644 6,503 5,168 12,510 3,545,825 58 General business 2,955,752 14,002 342 6,894 2,976,990 443 Total commercial 13,397,500 52,988 5,510 109,708 13,565,706 672 Commercial real estate 4,673,416 2,029 532 17,723 4,693,700 4,771 Paycheck protection program 2,097,325 — — — 2,097,325 — Loans to individuals: Residential mortgage 1,830,005 8,299 1,128 9,712 1,849,144 2,241 Residential mortgage guaranteed by U.S. government agencies 172,678 56,264 34,355 120,950 384,247 117,188 Personal 1,212,488 99 520 71 1,213,178 — Total loans to individuals 3,215,171 64,662 36,003 130,733 3,446,569 119,429 Total $ 23,383,412 $ 119,679 $ 42,045 $ 258,164 $ 23,803,300 $ 124,872 Following is disclosure of loans and the combined allowance for loan losses and accrual for off-balance sheet credit losses under the previous incurred loss model. Portfolio segments of the loan portfolio are as follows (in thousands): December 31, 2019 Fixed Variable Non-accrual Total Commercial $ 3,231,485 $ 10,684,749 $ 115,416 $ 14,031,650 Commercial real estate 1,056,321 3,349,836 27,626 4,433,783 Residential mortgage 1,652,653 393,897 37,622 2,084,172 Personal 193,903 1,007,192 287 1,201,382 Total $ 6,134,362 $ 15,435,674 $ 180,951 $ 21,750,987 Accruing loans past due (90 days) 1 $ 7,680 1 Excludes residential mortgage loans guaranteed by agencies of the U.S. government The activity in the allowance for loan losses and the allowance for off-balance sheet credit losses related to loan commitments and standby letters of credit is summarized as follows (in thousands): Three Months Ended September 30, 2019 Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 106,397 $ 54,188 $ 15,724 $ 9,388 $ 16,837 $ 202,534 Provision for loan losses 9,861 102 (253) 1,911 918 12,539 Loans charged off (9,875) — (56) (1,776) — (11,707) Recoveries 260 60 119 627 — 1,066 Ending balance $ 106,643 $ 54,350 $ 15,534 $ 10,150 $ 17,755 $ 204,432 Allowance for off-balance sheet credit losses: Beginning balance 1,742 116 44 1 — $ 1,903 Provision for off-balance sheet credit losses (536) (3) — — — (539) Ending balance $ 1,206 $ 113 $ 44 $ 1 $ — $ 1,364 Total provision for credit losses $ 9,325 $ 99 $ (253) $ 1,911 $ 918 $ 12,000 Nine Months Ended September 30, 2019 Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 102,226 $ 60,026 $ 17,964 $ 9,473 $ 17,768 $ 207,457 Provision for loan losses 34,740 (10,075) (2,660) 3,434 (13) 25,426 Loans charged off (31,728) (118) (192) (4,671) — (36,709) Recoveries 1,405 4,517 422 1,914 — 8,258 Ending balance $ 106,643 $ 54,350 $ 15,534 $ 10,150 $ 17,755 $ 204,432 Allowance for off-balance sheet credit losses: Beginning balance $ 1,655 $ 52 $ 52 $ 31 $ — $ 1,790 Provision for off-balance sheet credit losses (449) 61 (8) (30) — (426) Ending balance $ 1,206 $ 113 $ 44 $ 1 $ — $ 1,364 Total provision for credit losses $ 34,291 $ (10,014) $ (2,668) $ 3,404 $ (13) $ 25,000 The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at December 31, 2019 is as follows (in thousands): Collectively Measured Individually Measured Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Commercial $ 13,916,234 $ 100,773 $ 115,416 $ 17,414 $ 14,031,650 $ 118,187 Commercial real estate 4,406,157 51,805 27,626 — 4,433,783 51,805 Residential mortgage 2,046,550 14,400 37,622 — 2,084,172 14,400 Personal 1,201,095 9,172 287 — 1,201,382 9,172 Total 21,570,036 176,150 180,951 17,414 21,750,987 193,564 Nonspecific allowance — — — — — 17,195 Total $ 21,570,036 $ 176,150 $ 180,951 $ 17,414 $ 21,750,987 $ 210,759

Mortgage Banking Activities

Mortgage Banking Activities	9 Months Ended
	Sep. 30, 2020
Mortgage Banking [Abstract]
Mortgage Banking Activities [Text Block]	Mortgage Banking Activities Residential Mortgage Loan Production The Company originates, markets and services conventional and government-sponsored residential mortgage loans. Generally, conforming fixed rate residential mortgage loans are held for sale in the secondary market and non-conforming and adjustable-rate residential mortgage loans are retained for investment. Residential mortgage loans originated for sale by the Company are carried at fair value based on sales commitments and market quotes. Changes in the fair value of mortgage loans held for sale are included in Other operating revenue – Mortgage banking revenue. Residential mortgage loans held for sale also includes the fair value of residential mortgage loan commitments and forward sales commitments, which are considered derivative contracts that have not been designated as hedging instruments for accounting purposes. The volume of mortgage loans originated for sale and secondary market prices are the primary drivers of originating and marketing revenue. Residential mortgage loan commitments are generally outstanding for 60 to 90 days, which represents the typical period from commitment to originate a residential mortgage loan to when the closed loan is sold to an investor. Residential mortgage loan commitments are subject to both credit and interest rate risk. Credit risk is managed through underwriting policies and procedures, including collateral requirements, which are generally accepted by the secondary loan markets. Exposure to interest rate fluctuations is partially managed through forward sales of residential mortgage-backed securities and forward sales contracts. These latter contracts set the price for loans that will be delivered in the next 60 to 90 days. The unpaid principal balance of residential mortgage loans held for sale, notional amounts of derivative contracts related to residential mortgage loan commitments and forward contract sales and their related fair values included in Mortgage loans held for sale on the Consolidated Balance Sheets were (in thousands): September 30, 2020 December 31, 2019 Unpaid Principal Balance/ Fair Value Unpaid Principal Balance/ Fair Value Residential mortgage loans held for sale $ 259,076 $ 268,575 $ 175,117 $ 177,703 Residential mortgage loan commitments 560,493 29,224 158,460 5,233 Forward sales contracts 765,994 (2,509) 315,203 (665) $ 295,290 $ 182,271 No residential mortgage loans held for sale were 90 days or more past due or considered impaired as of September 30, 2020 or December 31, 2019. No credit losses were recognized on residential mortgage loans held for sale for the nine month period ended September 30, 2020 and 2019. Mortgage banking revenue was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Production revenue: Net realized gains on sale of mortgage loans $ 36,300 $ 8,971 $ 70,126 $ 24,838 Net change in unrealized gain (loss) on mortgage loans held for sale (1,672) 97 6,913 965 Net change in the fair value of mortgage loan commitments 1,593 514 23,991 4,733 Net change in the fair value of forward sales contracts 2,210 4,232 (1,844) 3,015 Total production revenue 38,431 13,814 99,186 33,551 Servicing revenue 13,528 16,366 43,876 48,594 Total mortgage banking revenue $ 51,959 $ 30,180 $ 143,062 $ 82,145 Production revenue includes gain (loss) on residential mortgage loans held for sale and changes in the fair value of derivative contracts not designated as hedging instruments for accounting purposes related to residential mortgage loan commitments and forward sales contracts. Servicing revenue includes servicing fee income and late charges on loans serviced for others. Residential Mortgage Servicing Mortgage servicing rights may be originated or purchased. Both originated and purchased mortgage servicing rights are initially recognized at fair value. The Company has elected to carry all mortgage servicing rights at fair value. Changes in the fair value are recognized in earnings as they occur. The unpaid principal balance of loans serviced for others is the primary driver of servicing revenue. The following represents a summary of mortgage servicing rights (dollars in thousands): September 30, 2020 December 31, 2019 Number of residential mortgage loans serviced for others 111,008 126,828 Outstanding principal balance of residential mortgage loans serviced for others $ 17,116,204 $ 20,727,106 Weighted average interest rate 3.91 % 3.98 % Remaining term (in months) 281 289 The following represents activity in capitalized mortgage servicing rights (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Beginning Balance $ 97,971 $ 208,308 $ 201,886 $ 259,254 Additions 7,424 9,882 21,330 24,821 Disposals — — (10,801) — Change in fair value due to principal payments (11,192) (11,936) (28,971) (27,600) Change in fair value due to market assumption changes 3,441 (12,593) (85,800) (62,814) Ending Balance $ 97,644 $ 193,661 $ 97,644 $ 193,661 Changes in the fair value of mortgage servicing rights due to market assumption changes are included in Other operating revenue in the Consolidated Statements of Earnings. Changes in fair value due to principal payments are included in Mortgage banking costs. Mortgage servicing rights are not traded in active markets. Fair value is determined by discounting the projected net cash flows. Significant market assumptions used to determine fair value based on significant unobservable inputs were as follows: September 30, 2020 December 31, 2019 Discount rate – risk-free rate plus a market premium 9.15% 9.81% Prepayment rate - based upon loan interest rate, original term and loan type 9.90% - 24.02% 8.28% - 16.05% Loan servicing costs – annually per loan based upon loan type: Performing loans $69 - $94 $68 - $94 Delinquent loans $150 - $500 $150 - $500 Loans in foreclosure $1,000 - $4,000 $1,000 - $4,000 Escrow earnings rate – indexed to rates paid on deposit accounts with comparable average life 0.34% 1.73% Primary/secondary mortgage rate spread 105 bps 104 bps Delinquency rate 3.72% 2.73% Changes in primary residential mortgage interest rates directly affect the prepayment speeds used in valuing our mortgage servicing rights. A separate third party model is used to estimate prepayment speeds based on interest rates, housing turnover rates, estimated loan curtailment, anticipated defaults and other relevant factors. The prepayment model is updated periodically for changes in market conditions and adjusted to better correlate with actual performance of BOK Financial’s servicing portfolio.

Commitments and Contingent Liab

Commitments and Contingent Liabilities	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities [Text Block]	Commitments and Contingent Liabilities Litigation Contingencies On June 24, 2015, BOKF, NA received a complaint alleging that an employee had colluded with a bond issuer and an individual in misusing revenues pledged to municipal bonds for which BOKF, NA served as trustee under the bond indenture. The Company conducted an investigation and concluded that employees in one of its Corporate Trust offices had, with respect to a single group of affiliated bond issuances, violated Company policies and procedures by waiving financial covenants, granting forbearances and accepting without disclosure to the bondholders, debt service payments from sources other than pledged revenues. The relationship manager was terminated. The Company reported the circumstances to, and cooperated with an investigation by, the Securities and Exchange Commission ("SEC"). On December 28, 2015, in an action brought by the SEC, the United States District Court for the District of New Jersey entered a judgment against the principals involved in issuing the bonds, precluding the principals from denying the alleged violations of the federal securities laws and requiring the principals to pay all outstanding principal, accrued interest, and other amounts required under the bond documents, less the value of the facilities securing repayment of the bonds, subject to oversight by a court appointed monitor (“Payment Plan”). On September 7, 2016, BOKF, NA agreed, and the SEC entered, a Consent Order finding that BOKF, NA had violated Section 17(a) of the Securities Act of 1933 and Section 10(b) of the Securities Exchange Act and requiring BOKF, NA to disgorge $1,067,721 of fees and pay a civil penalty of $600,000. BOKF, NA disgorged the fees and paid the penalty. On August 26, 2016, BOKF, NA was sued in the United States District Court for New Jersey by two bondholders in a putative class action on behalf of all holders of the bonds alleging BOKF, NA participated in the fraudulent sale of securities by the principals. The New Jersey Federal District Action remains stayed with no current deadlines pending. On September 14, 2016, BOKF, NA was sued in the District Court of Tulsa County, Oklahoma by 19 bondholders alleging BOKF, NA participated in the fraudulent sale of securities by the principals. The Tulsa County District Court Action is pending on BOKF, NA’s motion to dismiss the plaintiff's Third Amended Petition. On January 8, 2020, the New Jersey District Court entered judgment against the principal individual and his wife for $36,805,051 in principal amount and $10,937,831 in pre-judgment interest. On January 19, 2020, the New Jersey Federal District Court formally terminated the Payment Plan. Management is no longer able to conclude that the individual principal and his wife will be successful in paying the obligations they have to pay the bonds in full but such obligations remain and are not dischargeable in bankruptcy. On September 24, 2020, the SEC filed multiple garnishments on entities either related to or holding assets for the debtor. If the individual principal and his wife do not have the financial ability to pay the bonds in full, a bondholder loss could become probable. Management has been advised by counsel that BOKF, NA has valid defenses to claims of bondholders and that no loss to the company is probable. No provision for losses has been made at this time. BOKF, NA estimates that, upon sale of all remaining collateral securing payment of the bonds, approximately $20 million will remain outstanding. A reasonable estimate cannot be made of the amount of any bondholder loss, though the amount of bondholder loss could be material to the company in the event a loss to the company becomes probable. On March 5, 2018, BOKF, NA was sued in the Fulton, Georgia County District Court by a Wrongful Death Judgment Creditor of one of the operators of a nursing home financed by one of the bonds which are the subject of the litigation discussed above. The judgment is alleged to total approximately $8 million in principal and interest at this time. Plaintiff alleges that BOKF, as Trustee, colluded with the borrower and others to defraud creditors of the nursing home by misleading the public about the solvency of the nursing home. Plaintiff alleges that this conduct has prevented her from collecting on her judgment. On April 19, 2019, the Court granted BOKF, NA's Motion to Dismiss. On May 3, 2019, the plaintiff filed a Motion for Reconsideration which remains pending. BOKF, NA is advised by counsel that BOKF, NA has valid defenses to the plaintiffs’ claims and no loss is probable. On March 14, 2017, BOKF, NA was sued in the United States District Court for the Northern District of Oklahoma by bondholders in a second putative class action representing a different set of municipal securities. The bondholders in this second action allege two individuals purchased facilities from the principals who are the subject of the SEC New Jersey proceedings by means of the fraudulent sale of $60 million of municipal securities for which BOKF, NA also served as indenture trustee. The bondholders allege BOKF, NA failed to disclose that the seller of the purchased facilities had engaged in the conduct complained of in the New Jersey action. BOKF, NA properly performed all duties as indenture trustee of this second set of municipal securities, timely commenced proceedings against the issuer of the securities when default occurred, is cooperating with the SEC in actions against the two principals, is not a target of the SEC proceedings, and has been advised by counsel that BOKF, NA has valid defenses to the claims of these bondholders. On July 8, 2020, the Court ruled on the motion and dismissed six of Plaintiffs’ seven causes of action. On September 9, 2020 the Court entered a Scheduling Order for proceeding on the remaining claim with a January 18, 2022 trial date. Management is advised by counsel that a loss is not probable and that the loss, if any, cannot be reasonably estimated. On March 7, 2017, a plaintiff filed a putative class action in the United States District Court for the Northern District of Texas alleging an extended overdraft fee charged by BOKF, NA is interest and exceeds permitted rates. On September 18, 2018, the District Court dismissed the Texas action and the plaintiff appealed the dismissal to the United States Court of Appeals for the Fifth Circuit which heard argument on October 8, 2019. On August 22, 2018, a plaintiff filed a second putative class action in the United States District Court for New Mexico making the same allegations as the Texas action. The District Court dismissed the plaintiff's action. The plaintiff has appealed to the United States Court of Appeals for the Tenth Circuit. Management is advised by counsel that a loss is not probable in either the now dismissed Texas action or the New Mexico action and that the loss, if any, cannot be reasonably estimated. On March 7, 2020, three former employees sued BOKF, NA, the Plan Committee of the BOKF, NA 401k Plan, and Cavanal Hill Investment Management, Inc., a subsidiary of BOKF, NA, alleging that the Defendants included proprietary investment products as investment options in the BOKF, NA 401k Plan, whose fees were too high and performance too low, for the purpose of earning fees. The action is brought as a putative class action on behalf of all Plan Participants. The action is pending on the defendants' motion to dismiss. Management is advised by counsel that a loss is not probable and that the loss, if any, cannot be reasonably estimated. On May 12, 2020, an accounting firm filed a putative class action in the District Court of Colorado alleging that BOKF, NA failed to pay the agents of borrowers making application through the Bank to the Small Business Administration for Paycheck Protection Program (CARES Act) loans. BOKF, NA implemented a policy to pay, and paid, all agents of PPP borrowers where the principals agreed the principals had agents. Management is advised by counsel that a loss is not probable and that the loss, if any, cannot be reasonably estimated. In the ordinary course of business, BOK Financial and its subsidiaries are subject to legal actions and complaints. Management believes, based upon the opinion of counsel, that the actions and liability or loss, if any, resulting from the final outcomes of the proceedings, will not have a material effect on the Company’s financial condition, results of operations or cash flows. Alternative Investment Commitments The Company sponsors a private equity fund and invests in several tax credit entities and other funds as permitted by banking regulations. Consolidation of these investments is based on the variable interest model.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2020
Stockholders' Equity Note [Abstract]
Shareholders' Equity [Text Block]	Shareholders' Equity On November 3, 2020, the Company declared a quarterly cash dividend of $0.52 per common share payable on or about November 24, 2020 to shareholders of record as of November 16, 2020. Dividends declared were $0.51 and $1.53 per share during the three and nine months ended September 30, 2020 and $0.50 and $1.50 per share during the three and nine months ended September 30, 2019. Accumulated Other Comprehensive Income (Loss) AOCI includes unrealized gains and losses on available for sale ("AFS") securities and non-credit related unrealized losses on AFS securities for which an other-than-temporary impairment has been recorded in earnings. Unrealized losses on employee benefit plans will be reclassified into income as pension plan costs are recognized over the remaining service period of plan participants. Gains and losses in AOCI are net of deferred income taxes. A rollforward of the components of accumulated other comprehensive income (loss) is included as follows (in thousands): Unrealized Gain (Loss) on Available for Sale Securities Employee Benefit Plans Total Balance, Dec. 31, 2018 $ (70,999) $ (1,586) $ (72,585) Net change in unrealized gain (loss) 274,441 — 274,441 Reclassification adjustments included in earnings: Gain on available for sale securities, net (1,110) — (1,110) Other comprehensive income, before income taxes 273,331 — 273,331 Federal and state income taxes 1 66,993 — 66,993 Other comprehensive income, net of income taxes 206,338 — 206,338 Balance, September 30, 2019 $ 135,339 $ (1,586) $ 133,753 Balance, Dec. 31, 2019 $ 104,996 $ (73) $ 104,923 Net change in unrealized gain (loss) 347,985 — 347,985 Reclassification adjustments included in earnings: Gain on available for sale securities, net (5,571) — (5,571) Other comprehensive income, before income taxes 342,414 — 342,414 Federal and state income taxes 1 82,167 — 82,167 Other comprehensive income, net of income taxes 260,247 — 260,247 Balance, September 30, 2020 $ 365,243 $ (73) $ 365,170 1 Calculated using a 25 percent blended federal and state statutory tax rate.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	Earnings Per Share (In thousands, except share and per share amounts) Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Numerator: Net income attributable to BOK Financial Corp. shareholders $ 154,034 $ 142,231 $ 280,806 $ 390,406 Less: Earnings allocated to participating securities 938 875 1,678 2,553 Numerator for basic earnings per share – income available to common shareholders 153,096 141,356 279,128 387,853 Effect of reallocating undistributed earnings of participating securities — 1 — 1 Numerator for diluted earnings per share – income available to common shareholders $ 153,096 $ 141,357 $ 279,128 $ 387,854 Denominator: Weighted average shares outstanding 70,306,233 71,033,405 70,375,628 71,425,855 Less: Participating securities included in weighted average shares outstanding 428,367 437,098 416,684 472,311 Denominator for basic earnings per common share 69,877,866 70,596,307 69,958,944 70,953,544 Dilutive effect of employee stock compensation plans 1 1,424 13,617 3,109 15,301 Denominator for diluted earnings per common share 69,879,290 70,609,924 69,962,053 70,968,845 Basic earnings per share $ 2.19 $ 2.00 $ 3.99 $ 5.47 Diluted earnings per share $ 2.19 $ 2.00 $ 3.99 $ 5.47 1 Excludes employee stock options with exercise prices greater than current market price. 19,227 — — —

Reportable Segments

Reportable Segments	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Reportable Segments [Text Block]	Reportable Segments Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended September 30, 2020 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other BOK Net interest revenue from external sources $ 173,248 $ 15,821 $ 34,098 $ 48,583 $ 271,750 Net interest revenue (expense) from internal sources (23,302) 17,309 (11,113) 17,106 — Net interest revenue 149,946 33,130 22,985 65,689 271,750 Provision for credit losses 22,599 79 (51) (22,627) — Net interest revenue after provision for credit losses 127,347 33,051 23,036 88,316 271,750 Other operating revenue 52,021 67,808 111,152 3,178 234,159 Other operating expense 66,846 59,839 82,868 91,712 301,265 Net direct contribution 112,522 41,020 51,320 (218) 204,644 Gain (loss) on financial instruments, net 38 1,540 — (1,578) — Change in fair value of mortgage servicing rights — 3,441 — (3,441) — Gain (loss) on repossessed assets, net (4,332) 41 — 4,291 — Corporate expense allocations 5,172 10,812 9,397 (25,381) — Net income before taxes 103,056 35,230 41,923 24,435 204,644 Federal and state income taxes 27,959 8,974 10,711 2,908 50,552 Net income 75,097 26,256 31,212 21,527 154,092 Net income attributable to non-controlling interests — — — 58 58 Net income attributable to BOK Financial Corp. shareholders $ 75,097 $ 26,256 $ 31,212 $ 21,469 $ 154,034 Average assets $ 28,000,183 $ 9,898,119 $ 16,206,522 $ (5,171,057) $ 48,933,767 Reportable segments reconciliation to the Consolidated Financial Statements for the nine months ended September 30, 2020 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other BOK Net interest revenue from external sources $ 549,464 $ 60,492 $ 82,823 $ 118,435 $ 811,214 Net interest revenue (expense) from internal sources (103,002) 55,840 (14,054) 61,216 — Net interest revenue 446,462 116,332 68,769 179,651 811,214 Provision for credit losses 53,241 1,870 (188) 174,169 229,092 Net interest revenue after provision for credit losses 393,221 114,462 68,957 5,482 582,122 Other operating revenue 138,139 190,062 315,707 3,263 647,171 Other operating expense 190,531 173,568 241,627 259,550 865,276 Net direct contribution 340,829 130,956 143,037 (250,805) 364,017 Gain (loss) on financial instruments, net 135 95,660 7 (95,802) — Change in fair value of mortgage servicing rights — (85,800) — 85,800 — Gain (loss) on repossessed assets, net (4,132) 81 — 4,051 — Corporate expense allocations 19,514 32,111 25,866 (77,491) — Net income before taxes 317,318 108,786 117,178 (179,265) 364,017 Federal and state income taxes 86,254 27,709 29,999 (60,307) 83,655 Net income 231,064 81,077 87,179 (118,958) 280,362 Net income (loss) attributable to non-controlling interests — — — (444) (444) Net income attributable to BOK Financial Corp. shareholders $ 231,064 $ 81,077 $ 87,179 $ (118,514) $ 280,806 Average assets $ 26,759,150 $ 9,889,690 $ 14,888,623 $ (3,397,417) $ 48,140,046 Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended September 30, 2019 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other BOK Net interest revenue from external sources $ 243,944 $ 27,580 $ 12,343 $ (4,771) $ 279,096 Net interest revenue (expense) from internal sources (64,984) 20,882 10,723 33,379 — Net interest revenue 178,960 48,462 23,066 28,608 279,096 Provision for credit losses 9,505 1,841 (42) 696 12,000 Net interest revenue after provision for credit losses 169,455 46,621 23,108 27,912 267,096 Other operating revenue 48,832 51,221 89,160 (2,763) 186,450 Other operating expense 69,127 59,699 71,619 78,847 279,292 Net direct contribution 149,160 38,143 40,649 (53,698) 174,254 Gain (loss) on financial instruments, net 28 8,339 — (8,367) — Change in fair value of mortgage servicing rights — (12,593) — 12,593 — Gain (loss) on repossessed assets, net 802 214 — (1,016) — Corporate expense allocations 11,772 11,776 9,416 (32,964) — Net income before taxes 138,218 22,327 31,233 (17,524) 174,254 Federal and state income taxes 37,232 5,687 8,027 (18,550) 32,396 Net income 100,986 16,640 23,206 1,026 141,858 Net income (loss) attributable to non-controlling interests — — — (373) (373) Net income attributable to BOK Financial Corp. shareholders $ 100,986 $ 16,640 $ 23,206 $ 1,399 $ 142,231 Average assets $ 23,973,925 $ 9,827,130 $ 10,391,225 $ (611,932) $ 43,580,348 Reportable segments reconciliation to the Consolidated Financial Statements for the nine months ended September 30, 2019 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other 1 BOK Net interest revenue from external sources $ 699,239 $ 75,353 $ 51,054 $ 16,984 $ 842,630 Net interest revenue (expense) from internal sources (185,235) 76,925 27,213 81,097 — Net interest revenue 514,004 152,278 78,267 98,081 842,630 Provision for credit losses 27,574 4,654 (209) (7,019) 25,000 Net interest revenue after provision for credit losses 486,430 147,624 78,476 105,100 817,630 Other operating revenue 128,055 142,780 248,591 (3,641) 515,785 Other operating expense 183,169 171,214 202,579 286,624 843,586 Net direct contribution 431,316 119,190 124,488 (185,165) 489,829 Gain (loss) on financial instruments, net 67 43,416 — (43,483) — Change in fair value of mortgage servicing rights — (62,814) — 62,814 — Gain (loss) on repossessed assets, net 455 409 — (864) — Corporate expense allocations 31,880 35,369 26,943 (94,192) — Net income before taxes 399,958 64,832 97,545 (72,506) 489,829 Federal and state income taxes 107,171 16,513 25,076 (48,834) 99,926 Net income 292,787 48,319 72,469 (23,672) 389,903 Net income (loss) attributable to non-controlling interests — — — (503) (503) Net income attributable to BOK Financial Corp. shareholders $ 292,787 $ 48,319 $ 72,469 $ (23,169) $ 390,406 Average assets $ 22,288,960 $ 9,142,491 $ 9,860,427 $ 88,371 $ 41,380,249

Fees and Commissions Revenue Fe

Fees and Commissions Revenue Fees and Commissions Revenue	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Fees and Commissions Revenue [Text Block]	Fees and Commissions Revenue Fees and commissions revenue is generated through the sales of products, consisting primarily of financial instruments, and the performance of services for customers under contractual obligations. Revenue from providing services for customers is recognized at the time services are provided in an amount that reflects the consideration we expect to be entitled to for those services. Revenue is recognized based on the application of five steps: • Identify the contract with a customer • Identify the performance obligations in the contract • Determine the transaction price • Allocate the transaction price to the performance obligations in the contract • Recognize revenue when (or as) the Company satisfies a performance obligation For contracts with multiple performance obligations, individual performance obligations are accounted for separately if the customer can benefit from the good or service on its own or with other resources readily available to the customer and the promise to transfer goods and services to the customer is separately identifiable in the contract. The transaction price is allocated to the performance obligations based on relative standalone selling prices. Revenue is recognized on a gross basis whenever we have primary responsibility and risk in providing the services or products to our customers and have discretion in establishing the price for the services or products. Revenue is recognized on a net basis whenever we act as an agent for products or services of others. Brokerage and trading revenue includes revenues from trading, customer hedging, retail brokerage and investment banking. Trading revenue includes net realized and unrealized gains primarily related to sales of securities to institutional customers and related derivative contracts. Customer hedging revenue includes realized and unrealized changes in the fair value of derivative contracts held for customer risk management programs including credit valuation adjustments, as necessary. We offer commodity, interest rate, foreign exchange and equity derivatives to our customers. These customer contracts are offset with contracts with selected counterparties and exchanges to minimize changes in market risk from changes in commodity prices, interest rates or foreign exchange rates. Retail brokerage revenue represents fees and commissions earned on sales of fixed income securities, annuities, mutual funds and other financial instruments to retail customers. Investment banking revenue includes fees earned upon completion of underwriting and financial advisory services. Investment banking revenue also includes fees earned in conjunction with loan syndications. Insurance brokerage revenues represents fees and commissions earned on placement of insurance products with carriers for property and casualty and health coverage. Transaction card revenue includes merchant discount fees and electronic funds transfer network fees, net of interchange fees paid to card issuers and assessments paid to card networks. Merchant discount fees represent fees paid by customers for account management and electronic processing of card transactions. Merchant discount fees are recognized at the time the customer’s transactions are processed or other services are performed. The Company also maintains the TransFund electronic funds transfer network for the benefit of its members, which includes the Bank. Electronic funds transfer fees are recognized as electronic transactions processed on behalf of its members. Fiduciary and asset management revenue includes fees from asset management, custody, recordkeeping, investment advisory and administration services. Revenue is recognized on an accrual basis at the time the services are performed and may be based on either the fair value of the account or the service provided. Deposit service charges and fees include commercial account service charges, overdraft fees, check card fee revenue and automated service charge and other deposit service fees. Fees are recognized at least quarterly in accordance with published deposit account agreements and disclosure statements for retail accounts or contractual agreements for commercial accounts. Item charges for overdraft or non-sufficient funds items are recognized as items are presented for payment. Account balance charges and activity fees are accrued monthly and collected in arrears. Commercial account activity fees may be offset by an earnings credit based on account balances. Check card fees represent interchange fees paid by a merchant bank for transactions processed from cards issued by the Company. Check card fees are recognized when transactions are processed. Mortgage banking revenue includes revenues recognized in conjunction with the origination, marketing and servicing of conventional and government-sponsored residential mortgage loans. Mortgage production revenue includes net realized gains (losses) on sales of residential mortgage loans in the secondary market and the net change in unrealized gains (losses) on residential mortgage loans held for sale. Mortgage production revenue also includes changes in the fair value of derivative contracts not designated as hedging instruments related to residential mortgage loan commitments and forward sales contracts. Mortgage servicing revenue includes servicing fee income and late charges on loans serviced for others. Fees and commissions revenue by reportable segment and primary service line is as follows for the three months ended September 30, 2020. Commercial Consumer Wealth Management Funds Management & Other Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 46,890 $ (1) $ 46,889 $ 46,889 $ — Customer hedging revenue 7,999 — 123 520 8,642 8,642 — Retail brokerage revenue — — 3,787 — 3,787 — 3,787 Insurance brokerage revenue — — 3,124 — 3,124 — 3,124 Investment banking revenue 2,314 — 4,770 — 7,084 2,280 4,804 Brokerage and trading revenue 10,313 — 58,694 519 69,526 57,811 11,715 TransFund EFT network revenue 18,840 913 (14) 2 19,741 — 19,741 Merchant services revenue 3,019 19 — — 3,038 — 3,038 Corporate card revenue 583 — 21 82 686 — 686 Transaction card revenue 22,442 932 7 84 23,465 — 23,465 Personal trust revenue — — 20,130 — 20,130 — 20,130 Corporate trust revenue — — 4,613 — 4,613 — 4,613 Institutional trust & retirement plan services revenue — — 11,030 — 11,030 — 11,030 Investment management services and other revenue — — 4,198 (40) 4,158 — 4,158 Fiduciary and asset management revenue — — 39,971 (40) 39,931 — 39,931 Commercial account service charge revenue 11,209 419 572 — 12,200 — 12,200 Overdraft fee revenue 32 5,411 16 4 5,463 — 5,463 Check card revenue — 5,565 — — 5,565 — 5,565 Automated service charge and other deposit fee revenue 27 1,007 24 — 1,058 — 1,058 Deposit service charges and fees 11,268 12,402 612 4 24,286 — 24,286 Mortgage production revenue — 38,431 — — 38,431 38,431 — Mortgage servicing revenue — 13,952 — (424) 13,528 13,528 — Mortgage banking revenue — 52,383 — (424) 51,959 51,959 — Other revenue 6,062 2,257 12,371 (6,992) 13,698 10,427 3,271 Total fees and commissions revenue $ 50,085 $ 67,974 $ 111,655 $ (6,849) $ 222,865 $ 120,197 $ 102,668 1 Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance. 2 In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers. Fees and commissions revenue by reportable segment and primary service line is as follows for the nine months ended September 30, 2020. Commercial Consumer Wealth Management Funds Management & Other Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 125,189 $ — $ 125,189 $ 125,189 $ — Customer hedging revenue 17,417 — 321 368 18,106 18,106 — Retail brokerage revenue — — 11,524 — 11,524 — 11,524 Insurance brokerage revenue — — 10,066 — 10,066 — 10,066 Investment banking revenue 5,325 — 12,117 — 17,442 4,959 12,483 Brokerage and trading revenue 22,742 — 159,217 368 182,327 148,254 34,073 TransFund EFT network revenue 56,699 2,300 (42) 4 58,961 — 58,961 Merchant services revenue 7,554 46 — — 7,600 — 7,600 Corporate card revenue 1,588 — 55 82 1,725 — 1,725 Transaction card revenue 65,841 2,346 13 86 68,286 — 68,286 Personal trust revenue — — 62,460 — 62,460 — 62,460 Corporate trust revenue — — 15,579 — 15,579 — 15,579 Institutional trust & retirement plan services revenue — — 33,510 — 33,510 — 33,510 Investment management services and other revenue — — 14,220 (123) 14,097 — 14,097 Fiduciary and asset management revenue — — 125,769 (123) 125,646 — 125,646 Commercial account service charge revenue 33,317 1,218 1,715 — 36,250 — 36,250 Overdraft fee revenue 101 16,223 54 7 16,385 — 16,385 Check card revenue — 15,916 — — 15,916 — 15,916 Automated service charge and other deposit fee revenue 285 3,572 54 — 3,911 — 3,911 Deposit service charges and fees 33,703 36,929 1,823 7 72,462 — 72,462 Mortgage production revenue — 99,186 — — 99,186 99,186 — Mortgage servicing revenue — 45,158 — (1,282) 43,876 43,876 — Mortgage banking revenue — 144,344 — (1,282) 143,062 143,062 — Other revenue 15,773 6,609 29,471 (14,367) 37,486 27,805 9,681 Total fees and commissions revenue $ 138,059 $ 190,228 $ 316,293 $ (15,311) $ 629,269 $ 319,121 $ 310,148 1 Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance. 2 In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers. Fees and commissions revenue by reportable segment and primary service line is as follows for the three months ended September 30, 2019. Commercial Consumer Wealth Management Funds Management & Other 3 Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 24,091 $ — $ 24,091 $ 24,091 $ — Customer hedging revenue 2,283 — 1,810 591 4,684 4,684 — Retail brokerage revenue — — 4,204 — 4,204 — 4,204 Insurance brokerage revenue — — 3,375 (513) 2,862 — 2,862 Investment banking revenue 4,408 — 3,590 1 7,999 3,762 4,237 Brokerage and trading revenue 6,691 — 37,070 79 43,840 32,537 11,303 TransFund EFT network revenue 18,465 1,020 (23) 2 19,464 — 19,464 Merchant services revenue 2,203 14 — — 2,217 — 2,217 Corporate card revenue 328 — 6 — 334 — 334 Transaction card revenue 20,996 1,034 (17) 2 22,015 — 22,015 Personal trust revenue — — 20,239 (1) 20,238 — 20,238 Corporate trust revenue — — 6,204 1 6,205 — 6,205 Institutional trust & retirement plan services revenue — — 10,740 — 10,740 — 10,740 Investment management services and other revenue — — 6,480 (42) 6,438 — 6,438 Fiduciary and asset management revenue — — 43,663 (42) 43,621 — 43,621 Commercial account service charge revenue 10,609 467 540 (3) 11,613 — 11,613 Overdraft fee revenue 81 9,603 45 3 9,732 — 9,732 Check card revenue — 5,721 — — 5,721 — 5,721 Automated service charge and other deposit fee revenue 197 1,519 53 2 1,771 — 1,771 Deposit service charges and fees 10,887 17,310 638 2 28,837 — 28,837 Mortgage production revenue — 13,815 — (1) 13,814 13,814 — Mortgage servicing revenue — 16,828 — (462) 16,366 16,366 — Mortgage banking revenue — 30,643 — (463) 30,180 30,180 — Other revenue 7,585 2,474 8,068 (501) 17,626 11,812 5,814 Total fees and commissions revenue $ 46,159 $ 51,461 $ 89,422 $ (923) $ 186,119 $ 74,529 $ 111,590 1 Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance. 2 In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers. 3 CoBiz operations are included in Funds Management and Other for the first quarter of 2019. Fees and commissions revenue by reportable segment and primary service line is as follows for the nine months ended September 30, 2019. Commercial Consumer Wealth Management Funds Management & Other 3 Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 58,890 $ — $ 58,890 $ 58,890 $ — Customer hedging revenue 6,243 — 9,444 1,019 16,706 16,706 — Retail brokerage revenue — — 12,192 (65) 12,127 — 12,127 Insurance brokerage revenue — — 7,063 3,729 10,792 — 10,792 Investment banking revenue 8,345 — 9,123 — 17,468 7,189 10,279 Brokerage and trading revenue 14,588 — 96,712 4,683 115,983 82,785 33,198 TransFund EFT network revenue 54,623 2,975 (60) 3 57,541 — 57,541 Merchant services revenue 6,351 43 — 122 6,516 — 6,516 Corporate card revenue 598 — 11 2 611 — 611 Transaction card revenue 61,572 3,018 (49) 127 64,668 — 64,668 Personal trust revenue — — 61,028 — 61,028 — 61,028 Corporate trust revenue — — 18,736 — 18,736 — 18,736 Institutional trust & retirement plan services revenue — — 32,919 — 32,919 — 32,919 Investment management services and other revenue — — 17,730 1,591 19,321 — 19,321 Fiduciary and asset management revenue — — 130,413 1,591 132,004 — 132,004 Commercial account service charge revenue 31,296 1,283 1,605 1,804 35,988 — 35,988 Overdraft fee revenue 248 26,971 108 (231) 27,096 — 27,096 Check card revenue — 16,299 — 165 16,464 — 16,464 Automated service charge and other deposit fee revenue 569 4,762 228 47 5,606 — 5,606 Deposit service charges and fees 32,113 49,315 1,941 1,785 85,154 — 85,154 Mortgage production revenue — 33,554 — (3) 33,551 33,551 — Mortgage servicing revenue — 50,014 — (1,420) 48,594 48,594 — Mortgage banking revenue — 83,568 — (1,423) 82,145 82,145 — Other revenue 17,037 7,211 19,586 (1,009) 42,825 28,655 14,170 Total fees and commissions revenue $ 125,310 $ 143,112 $ 248,603 $ 5,754 $ 522,779 $ 193,585 $ 329,194

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements [Text Block]	Fair Value Measurements Fair value is defined by applicable accounting guidance as the price to sell an asset or transfer a liability in an orderly transaction between market participants in the principal market for the given asset or liability at the measurement date based on market conditions at that date. An orderly transaction assumes exposure to the market for a customary period for marketing activities prior to the measurement date and not a forced liquidation or distressed sale. Certain assets and liabilities are recorded in the Company’s financial statements at fair value. Some are recorded on a recurring basis and some on a non-recurring basis. For some assets and liabilities, observable market transactions and market information might be available. For other assets and liabilities, observable market transactions and market information might not be available. A hierarchy for fair value has been established which categorizes into three levels the inputs to valuation techniques used to measure fair value. The three levels are as follows: Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) - Fair value is based on unadjusted quoted prices in active markets for identical assets or liabilities. Significant Other Observable Inputs (Level 2) - Fair value is based on significant other observable inputs which are generally determined based on a single price for each financial instrument provided to us by an applicable third-party pricing service and is based on one or more of the following: • Quoted prices for similar, but not identical, assets or liabilities in active markets; • Quoted prices for identical or similar assets or liabilities in inactive markets; • Inputs other than quoted prices that are observable, such as interest rate and yield curves, volatilities, prepayment speeds, loss severities, credit risks and default rates; • Other inputs derived from or corroborated by observable market inputs. Significant Unobservable Inputs (Level 3) - Fair value is based upon model-based valuation techniques for which at least one significant assumption is not observable in the market. Transfers between levels are recognized as of the end of the reporting period. There were no transfers in or out of quoted prices in active markets for identical instruments to significant other observable inputs or significant unobservable inputs during the nine months ended September 30, 2020 and 2019, respectively. Transfers between significant other observable inputs and significant unobservable inputs during the nine months ended September 30, 2020 and 2019 are included in the summary of changes in recurring fair values measured using unobservable inputs. The underlying methods used by the third-party pricing services are considered in determining the primary inputs used to determine fair values. Management has evaluated the methodologies employed by the third-party pricing services by comparing the price provided by the pricing service with other sources, including brokers' quotes, sales or purchases of similar instruments and discounted cash flows to establish a basis for reliance on the pricing service values. Significant differences between the pricing service provided value and other sources are discussed with the pricing service to understand the basis for their values. Based on all observable inputs, management may adjust prices obtained from third-party pricing services to more appropriately reflect the prices that would be received to sell assets or paid to transfer liabilities in orderly transactions in the current market. No significant adjustments were made to prices provided by third-party pricing services at September 30, 2020 or December 31, 2019. Assets and Liabilities Measured at Fair Value on a Recurring Basis The fair value of financial assets and liabilities measured on a recurring basis was as follows as of September 30, 2020 (in thousands): Total Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Assets: Trading securities: U.S. government agency debentures $ 5,181 $ — $ 5,181 $ — Residential agency mortgage-backed securities 2,150,759 — 2,150,759 — Municipal and other tax-exempt securities 30,533 — 30,533 — Other trading securities 59,007 — 59,007 — Total trading securities 2,245,480 — 2,245,480 — Available for sale securities: U.S. Treasury 509 509 — — Municipal and other tax-exempt securities 51,601 — 51,601 — Residential agency mortgage-backed securities 9,384,998 — 9,384,998 — Residential non-agency mortgage-backed securities 34,873 — 34,873 — Commercial agency mortgage-backed securities 3,334,409 — 3,334,409 — Other debt securities 10,879 — 10,407 472 Total available for sale securities 12,817,269 509 12,816,288 472 Fair value option securities – Residential agency mortgage-backed securities 134,756 — 134,756 — Residential mortgage loans held for sale 295,290 — 286,785 8,505 Mortgage servicing rights 1 97,644 — — 97,644 Derivative contracts, net of cash collateral 2 593,568 11,713 581,855 — Liabilities: Derivative contracts, net of cash collateral 2 446,328 — 446,328 — 1 A reconciliation of the beginning and ending fair value of mortgage servicing rights and disclosures of significant assumptions used to determine fair value are presented in Note 5, Mortgage Banking Activities. 2 See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts in asset positions that were valued based on quoted prices in active markets for identical instruments (Level 1) are primarily exchange-traded interest rate derivative contracts. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments are exchange-traded interest rate, energy and agricultural derivative contracts, fully offset by cash margin. The fair value of financial assets and liabilities measured on a recurring basis was as follows as of December 31, 2019 (in thousands): Total Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Assets: Trading securities: U.S. government agency debentures $ 44,264 $ — $ 44,264 $ — Residential agency mortgage-backed securities 1,504,651 — 1,504,651 — Municipal and other tax-exempt securities 26,196 — 26,196 — Asset-backed securities 14,084 — 14,084 — Other trading securities 34,726 — 34,726 — Total trading securities 1,623,921 — 1,623,921 — Available for sale securities: U.S. Treasury 1,600 1,600 — — Municipal and other tax-exempt securities 1,861 — 1,861 — Residential agency mortgage-backed securities 8,046,096 — 8,046,096 — Residential non-agency mortgage-backed securities 41,609 — 41,609 — Commercial agency mortgage-backed securities 3,178,005 — 3,178,005 — Other debt securities 472 — — 472 Total available for sale securities 11,269,643 1,600 11,267,571 472 Fair value option securities: U.S. Treasury 9,917 9,917 — — Residential agency mortgage-backed securities 1,088,660 — 1,088,660 — Total fair value option securities 1,098,577 9,917 1,088,660 — Residential mortgage loans held for sale 182,271 — 173,958 8,313 Mortgage servicing rights 1 201,886 — — 201,886 Derivative contracts, net of cash collateral 2 323,375 8,944 314,431 — Liabilities: Derivative contracts, net of cash collateral 2 251,128 — 251,128 — 1 A reconciliation of the beginning and ending fair value of mortgage servicing rights and disclosures of significant assumptions used to determine fair value are presented in Note 5, Mortgage Banking Activities. 2 See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts based on quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate and energy derivative contracts, net of cash margin. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate and agricultural contracts, fully offset by cash margin. Following is a description of the Company's valuation methodologies used for assets and liabilities measured on a recurring basis: Securities The fair values of trading, available for sale and fair value option securities are based on quoted prices for identical instruments in active markets, when available. If quoted prices for identical instruments are not available, fair values are based on significant other observable inputs such as quoted prices of comparable instruments or interest rates and credit spreads, yield curves, volatilities, prepayment speeds and loss severities. The Company has elected to carry all residential mortgage-backed securities guaranteed by U.S. government agencies held as economic hedges against changes in the fair value of mortgage servicing rights at fair value with changes in the fair value recognized in earnings. The fair value of certain available for sale municipal and other debt securities may be based on significant unobservable inputs. These significant unobservable inputs include limited observed trades, projected cash flows, current credit rating of the issuers and, when applicable, the insurers of the debt and observed trades of similar debt. Discount rates are primarily based on references to interest rate spreads on comparable securities of similar duration and credit rating as determined by the nationally-recognized rating agencies adjusted for a lack of trading volume. Significant unobservable inputs are developed by investment securities professionals involved in the active trading of similar securities. A summary of significant inputs used to value these securities follows. A management committee composed of senior members from the Company's Capital Markets, Risk Management and Finance departments assesses the appropriateness of these inputs quarterly. Derivatives All derivative instruments are carried on the balance sheet at fair value. Fair values for exchange-traded contracts are based on quoted prices. Fair values for over-the-counter interest rate, commodity and foreign exchange contracts are based on valuations provided either by third-party dealers in the contracts, quotes provided by independent pricing services, or a third-party provided pricing model that uses significant other observable market inputs. Credit risk is considered in determining the fair value of derivative instruments. Management determines fair value adjustments based on various risk factors including but not limited to current fair value, probability of default and loss given default. We also consider our own credit risk in determining the fair value of derivative contracts. Changes in our credit rating would affect the fair value of our derivative liabilities. In the event of a credit downgrade, the fair value of our derivative liabilities would increase. Residential Mortgage Loans Held for Sale Residential mortgage loans held for sale are carried on the balance sheet at fair value. The Company has elected to carry all residential mortgage loans originated for sale at fair value. Changes in the fair value of these financial instruments are recognized in earnings. The fair values of residential mortgage loans held for sale are based upon quoted market prices of such loans sold in securitization transactions, including related unfunded loan commitments and forward sales contracts. The fair value of mortgage loans that were unable to be sold to U.S. government agencies were determined using quoted prices of loans that are sold in securitization transactions with a liquidity discount applied. The following represents the changes for the three and nine months ended September 30, 2020 related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands): Available for sale - Other debt securities Residential mortgage loans held for sale Balance, June 30, 2020 $ 472 $ 9,685 Transfer to Level 3 from Level 2 1 — 304 Purchases — — Proceeds from sales — (1,612) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — 128 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, September 30, 2020 $ 472 $ 8,505 1 Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards. Available for sale - Other debt securities Residential mortgage loans held for sale Balance, December 31, 2019 $ 472 $ 8,313 Transfer to Level 3 from Level 2 1 — 3,896 Purchases — — Proceeds from sales — (3,200) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — (504) Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, September 30, 2020 $ 472 $ 8,505 1 Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards. The following represents the changes for the three and nine months ended September 30, 2019 related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands): Available for sale - Other debt securities Residential mortgage loans held for sale Balance, June 30, 2019 $ 472 $ 16,073 Transfer to Level 3 from Level 2 1 — 261 Purchases — — Proceeds from sales — (3,152) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — 386 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, September 30, 2019 $ 472 $ 13,568 1 Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards. Available for sale - Other debt securities Residential mortgage loans held for sale Balance, Dec. 31, 2018 $ 472 $ 15,207 Transfer to Level 3 from Level 2 1 — 2,150 Purchases — — Proceeds from sales — (4,531) Redemptions and distributions — — Gain (loss) recognized in earnings Mortgage banking revenue — 742 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, September 30, 2019 $ 472 $ 13,568 1 Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards. A summary of quantitative information about assets measured at fair value on a recurring basis using Significant Unobservable Inputs (Level 3) as of September 30, 2020 follows (in thousands): Fair Valuation Technique(s) Unobservable Input Range Available for sale securities – Other debt securities $ 472 Discounted cash flows 1 Interest rate spread 5.61%-5.61% (5.61%) 3 94.32%-94.32% (94.32%) 2 Residential mortgage loans held for sale 8,505 Quoted prices of loans sold in securitization transactions, with a liquidity discount applied Liquidity discount applied to the market value of mortgage loans qualifying for sale to U.S. government agencies. 90.24% 1 Discounted cash flows developed using discount rates primarily based on reference to interest rate spreads for comparable securities of similar duration and credit rating as determined by the nationally-recognized rating agencies, adjusted for lack of trading volume. 2 Represents fair value as a percentage of par value. 3 Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 2 percent. A summary of quantitative information about assets measured at fair value on a recurring basis using Significant Unobservable Inputs (Level 3) as of December 31, 2019 follows (in thousands): Fair Valuation Technique(s) Unobservable Input Range Available for sale securities – Other debt securities $ 472 Discounted cash flows 1 Interest rate spread 7.08%-7.08% (7.08%) 3 94.40%-94.40% (94.40%) 2 Residential mortgage loans held for sale 8,313 Quoted prices of loans sold in securitization transactions, with a liquidity discount applied Liquidity discount applied to the market value of mortgage loans qualifying for sale to U.S. government agencies. 95.23% 1 Discounted cash flows developed using discount rates primarily based on reference to interest rate spreads for comparable securities of similar duration and credit rating as determined by the nationally-recognized rating agencies, adjusted for lack of trading volume 2 Represents fair value as a percentage of par value. 3 Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 3 percent. Fair Value of Assets and Liabilities Measured on a Non-Recurring Basis Assets measured at fair value on a non-recurring basis include collateral for certain nonaccruing loans and real property and other assets acquired to satisfy loans, which are based primarily on comparisons to completed sales of similar assets. The following represents the carrying value of assets measured at fair value on a non-recurring basis (and related losses) during the period. The carrying value represents only those assets with a balance at September 30, 2020 for which the fair value was adjusted during the nine months ended September 30, 2020: Fair Value Adjustments for the Carrying Value at September 30, 2020 Three Months Ended Nine Months Ended Quoted Prices Significant Significant Gross charge-offs against allowance for loan losses Net losses (gains) and operating expenses of repossessed assets Gross charge-offs against allowance for loan losses Net losses (gains) and operating expenses of repossessed assets Nonaccruing loans $ — $ 396 $ 13,001 $ 6,371 $ — $ 28,624 $ — Real estate and other repossessed assets — 16,828 2,993 — (4,370) — (4,452) The following represents the carrying value of assets measured at fair value on a non-recurring basis (and related losses) during the period. The carrying value represents only those assets with a balance at September 30, 2019 for which the fair value was adjusted during the nine months ended September 30, 2019: Fair Value Adjustments for the Carrying Value at September 30, 2019 Three Months Ended Nine Months Ended Quoted Prices Significant Significant Gross charge-offs against allowance for loan losses Net losses (gains) and operating expenses of repossessed assets Gross charge-offs against allowance for loan losses Net losses (gains) and operating expenses of repossessed assets Nonaccruing loans $ — $ 79 $ 9,810 $ 2,644 $ — $ 13,868 $ — Real estate and other repossessed assets — 5,044 936 — (979) — (532) The fair value of collateral-dependent nonaccruing loans secured by real estate and real estate and other repossessed assets and the related fair value adjustments are generally based on unadjusted third-party appraisals. Our appraisal review policies require appraised values to be supported by observed inputs derived principally from or corroborated by observable market data. Appraisals that are not based on observable inputs or that require significant adjustments or fair value measurements that are not based on third-party appraisals are considered to be based on significant unobservable inputs. Non-recurring fair value measurements of collateral-dependent nonaccruing loans and real estate and other repossessed assets based on significant unobservable inputs are generally due to estimates of current fair values between appraisal dates. Significant unobservable inputs include listing prices for the same or comparable assets, uncorroborated expert opinions or management's knowledge of the collateral or industry. Non-recurring fair value measurements of collateral dependent loans secured by mineral rights are generally determined by our internal staff of engineers on projected cash flows under current market conditions and are based on significant unobservable inputs. Projected cash flows are discounted according to risk characteristics of the underlying oil and gas properties. Assets are evaluated to demonstrate with reasonable certainty that crude oil, natural gas and natural gas liquids can be recovered from known oil and gas reservoirs under existing economic and operating conditions at current prices with existing conventional equipment, operating methods and costs. Significant unobservable inputs are developed by asset management and workout professionals and approved by senior Credit Administration executives. A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of September 30, 2020 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range Nonaccruing loans $ 13,001 Discounted cash flows Management knowledge of industry and non-real estate collateral including but not limited to recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs 0% - 73% (18%) 1 Real estate and other repossessed assets 2,993 Discounted cash flows Management knowledge of industry and non-real estate collateral including but not limited to recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs N/A 1 Represents fair value as a percentage of the unpaid principal balance. A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of September 30, 2019 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range Nonaccruing loans $ 9,810 Discounted cash flows Management knowledge of industry and non-real estate collateral including but not limited to recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs 8% - 76% (28%) 1 Real estate and other repossessed assets 936 Appraised value, as adjusted Marketability adjustments off appraised value 2 75% - 89% (85%) 1 Represents fair value as a percentage of the unpaid principal balance. 2 Marketability adjustments include consideration of estimated costs to sell which is approximately 10% of the fair value. Fair Value of Financial Instruments The following table presents the carrying values and estimated fair values of all financial instruments, including those financial assets and liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis as of September 30, 2020 (dollars in thousands): Carrying Estimated Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs Cash and due from banks $ 658,612 $ 658,612 $ 658,612 $ — $ — Interest-bearing cash and cash equivalents 347,759 347,759 347,759 — — Trading securities: U.S. government agency debentures 5,181 5,181 — 5,181 — Residential agency mortgage-backed securities 2,150,759 2,150,759 — 2,150,759 — Municipal and other tax-exempt securities 30,533 30,533 — 30,533 — Other trading securities 59,007 59,007 — 59,007 — Total trading securities 2,245,480 2,245,480 — 2,245,480 — Investment securities: Municipal and other tax-exempt securities 76,109 80,368 — 80,368 — Residential agency mortgage-backed securities 9,317 10,219 — 10,219 — Other debt securities 171,314 194,342 — 7,376 186,966 Total investment securities 256,740 284,929 — 97,963 186,966 Allowance for credit losses (739) — — — — Investment securities, net of allowance 256,001 284,929 — 97,963 186,966 Available for sale securities: U.S. Treasury 509 509 509 — — Municipal and other tax-exempt securities 51,601 51,601 — 51,601 — Residential agency mortgage-backed securities 9,384,998 9,384,998 — 9,384,998 — Residential non-agency mortgage-backed securities 34,873 34,873 — 34,873 — Commercial agency mortgage-backed securities 3,334,409 3,334,409 — 3,334,409 — Other debt securities 10,879 10,879 — 10,407 472 Total available for sale securities 12,817,269 12,817,269 509 12,816,288 472 Fair value option securities – Residential agency mortgage-backed securities 134,756 134,756 — 134,756 — Residential mortgage loans held for sale 295,290 295,290 — 286,785 8,505 Loans: Commercial 13,565,706 13,500,846 — — 13,500,846 Commercial real estate 4,693,700 4,673,857 — — 4,673,857 Paycheck protection program 2,097,325 2,070,466 — — 2,070,466 Loans to individuals 3,446,569 3,452,042 — — 3,452,042 Total loans 23,803,300 23,697,211 — — 23,697,211 Allowance for loan losses (419,777) — — — — Loans, net of allowance 23,383,523 23,697,211 — — 23,697,211 Mortgage servicing rights 97,644 97,644 — — 97,644 Derivative instruments with positive fair value, net of cash collateral 593,568 593,568 11,713 581,855 — Deposits with no stated maturity 32,965,027 32,965,027 — — 32,965,027 Time deposits 2,007,973 2,019,474 — — 2,019,474 Other borrowed funds 3,745,081 3,741,686 — — 3,741,686 Subordinated debentures 275,986 269,083 — 269,083 — Derivative instruments with negative fair value, net of cash collateral 446,328 446,328 — 446,328 — The following table presents the carrying values and estimated fair values of all financial instruments, including those financial assets and liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis as of December 31, 2019 (dollars in thousands): Carrying Estimated Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs Cash and due from banks $ 735,836 $ 735,836 $ 735,836 $ — $ — Interest-bearing cash and cash equivalents 522,985 522,985 522,985 — — Trading securities: U.S. government agency debentures 44,264 44,264 — 44,264 — Residential agency mortgage-backed securities 1,504,651 1,504,651 — 1,504,651 — Municipal and other tax-exempt securities 26,196 26,196 — 26,196 — Asset-backed securities 14,084 14,084 — 14,084 — Other trading securities 34,726 34,726 — 34,726 — Total trading securities 1,623,921 1,623,921 — 1,623,921 — Investment securities: Municipal and other tax-exempt securities 93,653 96,897 — 96,897 — Residential agency mortgage-backed securities 10,676 11,164 — 11,164 — Other debt securities 189,089 206,341 — 8,206 198,135 Total investment securities 293,418 314,402 — 116,267 198,135 Available for sale securities: U.S. Treasury 1,600 1,600 1,600 — — Municipal and other tax-exempt securities 1,861 1,861 — 1,861 — Residential agency mortgage-backed securities 8,046,096 8,046,096 — 8,046,096 — Residential non-agency mortgage-backed securities 41,609 41,609 — 41,609 — Commercial agency mortgage-backed securities 3,178,005 3,178,005 — 3,178,005 — Other debt securities 472 472 — — 472 Total available for sale securities 11,269,643 11,269,643 1,600 11,267,571 472 Fair value option securities: U.S. Treasury 9,917 9,917 9,917 — — Residential agency mortgage-backed securities 1,088,660 1,088,660 — 1,088,660 — Total fair value option securities 1,098,577 1,098,577 9,917 1,088,660 — Residential mortgage loans held for sale 182,271 182,271 — 173,958 8,313 Loans: Commercial 14,031,650 13,966,221 — — 13,966,221 Commercial real estate 4,433,783 4,422,717 — — 4,422,717 Residential mortgage 2,084,172 2,098,093 — — 2,098,093 Personal 1,201,382 1,202,298 — — 1,202,298 Total loans 21,750,987 21,689,329 — — 21,689,329 Allowance for loan losses (210,759) — — — — Loans, net of allowance 21,540,228 21,689,329 — — 21,689,329 Mortgage servicing rights 201,886 201,886 — — 201,886 Derivative instruments with positive fair value, net of cash collateral 323,375 323,375 8,944 314,431 — Deposits with no stated maturity 25,403,319 25,403,319 — — 25,403,319 Time deposits 2,217,849 2,212,467 — — 2,212,467 Other borrowed funds 8,345,405 8,315,860 — — 8,315,860 Subordinated debentures 275,923 284,627 — 284,627 — Derivative instruments with negative fair value, net of cash collateral 251,128 251,128 — 251,128 — Because no market exists for certain of these financial instruments and management does not intend to sell these financial instruments, the fair values shown in the tables above may not represent values at which the respective financial instruments could be sold individually or in the aggregate at the given reporting date.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events The Company evaluated events from the date of the consolidated financial statements on September 30, 2020 through the issuance of those consolidated financial statements included in this Quarterly Report on Form 10-Q. No events were identified requiring recognition in and/or disclosure in the consolidated financial statements.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	The accompanying unaudited consolidated financial statements of BOK Financial Corporation (“BOK Financial” or “the Company”) have been prepared in accordance with accounting principles for interim financial information generally accepted in the United States and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included.
Principles of Consolidation [Policy Text Block]	The unaudited consolidated financial statements include accounts of BOK Financial and its subsidiaries, principally BOKF, NA (“the Bank”), BOK Financial Securities, Inc., and BOK Financial Private Wealth, Inc. Operating divisions of the Bank include Bank of Albuquerque, Bank of Oklahoma, Bank of Texas, BOK Financial in Arizona, Arkansas, Colorado and Kansas/Missouri, BOK Financial Mortgage and the TransFund electronic funds network.
Reclassification, Policy [Policy Text Block]	Certain reclassifications have been made to conform to the current period presentation.
Newly Adopted and Pending Accounting Policies [Policy Text Block]	Newly Adopted and Pending Accounting Policies Financial Accounting Standards Board (“FASB”) FASB Accounting Standards Update No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Assets Measured at Amortized Cost ("ASU 2016-13" or "CECL") On June 16, 2016, the FASB issued ASU 2016-13 to provide more timely recording of credit losses on loans and other financial assets measured at amortized cost. The Company adopted the new standard January 1, 2020, through a cumulative effect adjustment to retained earnings. Prior periods were not restated. Under ASU 2016-13, acquired loans must be reserved in a manner consistent with originated loans while the incurred loss model excluded purchased loans because the loans had been marked to fair value at acquisition. Under ASU 2016-13, the fair value discount will remain in place and be accreted into interest income over the life of any acquired loans in the portfolio. Another transition adjustment component is related to expected credit losses for residential mortgage loans sold that exceed amounts guaranteed by the U.S. Department of Veterans Affairs as we retain the credit risk for any amounts exceeding the guarantee as well as for recourse loans. Prior to ASU 2016-13, held-to-maturity non-agency securities carried no reserve for credit losses. Note 4 disaggregates the transition adjustment for loans and unfunded loan commitments among portfolio segments as well as on-and off-balance sheet reserves. FASB Accounting Standards Update No. 2019-01, Leases (Topic 842): Codification Improvements ("ASU 2019-01") On March 5, 2019, the FASB issued ASU 2019-01 which amends certain aspects of leasing standard ASU 2016-02. ASU 2019-01 provides guidance for determining the fair value of the underlying asset by lessors that are not manufacturers or dealers. The ASU also requires depository and lending lessors within the scope of ASC 942 to classify principal payments received from sales-type and direct financing leases within "investing activities" on the statement of cash flows. For the two issues above, the ASU is effective for the Company for fiscal years beginning after December 15, 2019, and interim periods therein; however early adoption is permitted. Additionally, ASU 2019-01 also clarifies interim disclosure requirements during transition and is effective with the original transition requirements in Topic 842. The Company adopted ASU 2019-01 in the first quarter of 2020. Adoption of ASU 2019-01 did not have a material impact on the Company's financial statements. FASB Accounting Standards Update No. 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments ("ASU 2019-04") On April 25, 2019, the FASB issued ASU 2019-04 which clarifies certain aspects of the accounting for credit losses, hedging activities, and financial instruments addressed by ASUs 2016-13, 2017-12, and 2016-01, respectively. Significant amendments made to the provisions of ASU 2016-13 by ASU 2019-04 include providing certain alternatives for the measurement of the allowance for credit losses on accrued interest receivable and clarifying steps entities should take when recording the transfer of loans or debt securities between measurement classification or categories. ASU 2019-04 further clarifies the expectation that entities include recoveries of financial assets in the calculation of the current expected credit losses allowance for both pools of financial assets and individual financial assets. Significant amendments made to the provisions of ASU 2017-12 by ASU 2019-04 include clarification on partial-term fair value hedges of interest rate risk, amortization of fair value hedge basis adjustments and disclosure of fair value hedge basis adjustments. Significant amendments made to provisions of ASU 2016-01 include clarification of the measurement alternative practice for equity securities and remeasurement of equity securities at historical exchange rates. ASU 2019-04 includes other amendments which clarify various provisions within the codification. The Company adopted ASU 2019-04 in the first quarter of 2020. Adoption of ASU 2019-04 did not have a material impact on the Company's financial statements. FASB Accounting Standards Update No. 2019-05, Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief ("ASU 2019-05") On May 15, 2019, the FASB issued ASU 2019-05 which provides transition relief for entities adopting the Board's credit losses standard, ASU 2016-13. ASU 2019-05 amends ASU 2016-13 to allow companies to irrevocably elect, upon adoption of ASU 2016-13, the fair value option for financial instruments that meet specific requirements and is effective for the Company for annual reporting periods beginning after December 15, 2019. The Company did not elect the fair value option for additional financial instruments. FASB Accounting Standards Update No. 2019-11, Codification Improvements to Topic 326: Financial Instruments-Credit Losses ("ASU 2019-11") On November 27, 2019, the FASB issued ASU 2019-11 which revises certain aspects of new guidance on credit losses. Topics addressed include purchased credit-deteriorated assets, transition relief for troubled debt restructurings, disclosure relief for accrued interest receivable, and financial assets secured by collateral maintenance provisions. ASU 2019-11 is effective for the Company for annual reporting periods beginning after December 15, 2019. The Company adopted ASU 2019-11 in the first quarter of 2020. Adoption of ASU 2019-11 did not have a material impact on the Company's financial statements. FASB Accounting Standards Update No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes ("ASU 2019-12")
Derivatives, Policy [Policy Text Block]	Derivative instruments may be used by the Company as part of its internal risk management programs or may be offered to customers. All derivative instruments are carried at fair value and changes in fair value are reported in earnings as they occur. Credit risk is also considered in determining fair value. Deterioration in the credit rating of customer or other counterparties reduced the fair value of asset contracts. Deterioration of our credit rating could decrease the fair value of our derivative liabilities. When bilateral netting agreements or similar arrangements exist between the Company and its counterparties that create a single legal claim or obligation to pay or receive the net amount in settlement of the individual derivative contracts, the Company reports derivative assets and liabilities on a net by derivative contract type by counterparty basis. Derivative contracts may require the Company to provide or receive cash margin as collateral for derivative assets and liabilities. Derivative assets and liabilities are reported net of cash margin when certain conditions are met. In addition, derivative contracts executed with customers under Customer Risk Management Programs may be secured by non-cash collateral in conjunction with a credit agreement with that customer. Access to collateral in the event of default is reasonably assured. None of these derivative contracts have been designated as hedging instruments for accounting purposes. Customer Risk Management Programs BOK Financial offers programs to permit its customers to manage various risks, including fluctuations in energy, cattle and other agricultural products, interest rates and foreign exchange rates with derivative contracts. Customers may also manage interest rate risk through interest rate swaps used by borrowers to modify interest rate terms of their loans. Derivative contracts are executed between the customers and BOK Financial. Offsetting contracts are executed between BOK Financial and other selected counterparties to minimize the risk of changes in commodity prices, interest rates or foreign exchange rates. The counterparty contracts are identical to customer contracts, except for a fixed pricing spread or fee paid to BOK Financial as profit and compensation for administrative costs and credit risk which is recognized over the life of the contracts and included in Other operating revenue – Brokerage and trading revenue in the Consolidated Statements of Earnings. Trading BOK Financial may offer derivative instruments such as to-be-announced securities to mortgage banking customers to enable them to manage their market risk or to mitigate the Company's market risk of holding trading securities. Changes in the fair value of derivative instruments for trading purposes or used to mitigate the market risk of holding trading securities are included in Other operating revenue – Brokerage and trading revenue. Internal Risk Management Programs BOK Financial may use derivative contracts in managing its interest rate sensitivity, as part of its economic hedge of the change in the fair value of mortgage servicing rights. Changes in the fair value of derivative instruments used in managing interest rate sensitivity and as part of the economic hedge of changes in the fair value of mortgage servicing rights are included in Other operating revenue – Gain (loss) on derivatives, net in the Consolidated Statements of Earnings.
Loans and Allowances for Credit Losses, Loans [Policy Text Block]	Loans Loans are either secured or unsecured based on the type of loan and the financial condition of the borrower. Repayment is generally expected from cash flow or proceeds from the sale of selected assets of the borrower. BOK Financial is exposed to risk of loss on loans due to the borrower’s difficulties, which may arise from any number of factors, including problems within the respective industry or local economic conditions. Access to collateral, in the event of borrower default, is reasonably assured through adherence to applicable lending laws and through sound lending standards and credit review procedures. Accounting policies for all loans, excluding residential mortgage loans guaranteed by U.S. government agencies, are as follows. Interest is accrued at the applicable interest rate on the principal amount outstanding. Loans are placed on nonaccruing status when, in the opinion of management, full collection of principal or interest is uncertain. Internally risk graded loans are individually evaluated for nonaccruing status quarterly. Non-risk graded loans are generally placed on nonaccruing status when more than 90 days past due or within 60 days of being notified of the borrower's bankruptcy filing. Interest previously accrued but not collected is charged against interest income when the loan is placed on nonaccruing status. Accrued but not paid interest receivable is included in Receivables in the Consolidated Balance Sheets. Payments on nonaccruing loans are applied to principal or recognized as interest income, according to management’s judgment as to the collectability of principal. Loans may be returned to accruing status when, in the opinion of management, full collection of principal and interest, including principal previously charged off, is probable based on improvements in the borrower’s financial condition or a sustained period of performance. For loans acquired with no evidence of credit deterioration, discounts are accreted on either an individual basis for loans with unique characteristics or on a pool basis for groups of homogeneous loans. Accretion is discontinued when a loan with an individually attributed discount is placed on nonaccruing status. Loans to borrowers experiencing financial difficulties may be modified in troubled debt restructurings ("TDRs"). Primarily all TDRs are classified as nonaccruing, excluding loans guaranteed by U.S. government agencies. Modifications generally consist of extension of payment terms or interest rate concessions and may result either voluntarily through negotiations with the borrower or involuntarily through court order. Generally, principal and accrued but unpaid interest is not voluntarily forgiven. In accordance with the guidance provided by the banking agencies on April 7, 2020 concerning loan modifications for customers impacted by the COVID-19 pandemic, short-term (six months or less) payment deferrals made in good faith to borrowers current prior to the relief are not considered TDRs. Performing loans may be renewed under the current collateral value, debt service ratio and other underwriting standards. Nonaccruing loans may be renewed and will remain classified as nonaccruing. Occasionally, loans, other than residential mortgage loans, may be held for sale in order to manage credit concentration. These loans are carried at the lower of cost or fair value with gains or losses recognized in Other gains (losses), net in the Consolidated Statements of Earnings. All loans are charged off when the loan balance or a portion of the loan balance is no longer supported by the paying capacity of the borrower or when the required cash flow is reduced in a TDR. The charge-off amount is determined through a quarterly evaluation of available cash resources and collateral value and charge-offs are taken in the quarter in which the loss is identified. Non-risk graded loans that are past due between 60 days and 180 days, based on the loan product type, are charged off. Loans to borrowers whose personal obligation has been discharged through Chapter 7 bankruptcy proceedings are charged off within 60 days of notice of the bankruptcy filing, regardless of payment status. Loan origination and commitment fees and direct loan acquisition and origination costs are deferred and amortized as an adjustment to yield over the life of the loan or over the commitment period, as applicable. Amortization does not anticipate loan prepayments. Net unamortized fees are recognized in full at time of payoff.
Loans and Allowances for Credit Losses, Allowances for Credit Losses [Policy Text Block]	Allowances for Credit Losses and Accrual for Off-balance Sheet Credit Risk from Unfunded Loans Commitments BOK Financial’s accounting policies have changed significantly with the adoption of CECL as of January 1, 2020. Prior periods are not restated. Prior to January 1, 2020, general allowances and nonspecific allowances were based on incurred credit losses in accordance with accounting policies disclosed in Note 1 of the Consolidated Financial Statements included in the 2019 Form 10-K. The allowance for loan losses and accrual for off-balance sheet credit risk from unfunded loan commitments represent the portion of the amortized cost basis of loans that we do not expect to collect over the asset’s contractual life, considering past events, current conditions, and reasonable and supportable forecasts of future economic conditions. The appropriateness of the allowance for credit losses, including industry and product adjustments, is assessed quarterly by a senior management Allowance Committee. This review is based on an on-going evaluation of the estimated expected credit losses in the portfolio and on unused commitments to provide financing. A well-documented methodology has been developed and is applied by an independent Credit Administration department to assure consistency across the Company. The allowance for loan losses consists of specific allowances attributed to certain individual loans, generally nonaccruing loans, with dissimilar risk characteristics that have not yet been charged down to amounts we expect to recover and general allowances for estimated credit losses on pools of loans that share similar risk characteristics. When full collection of principal or interest is uncertain, the loan’s risk characteristics have changed, and we exclude the loan from the general allowance pool, typically designating it as nonaccruing. For these loans, a specific allowance reflects the expected credit loss. We measure specific allowances for loans excluded from the general allowance pool by an evaluation of estimated future cash flows discounted at the loans initial effective interest rate or the fair value of collateral for certain collateral dependent loans. For a non-collateral dependent loan, the specific allowance is the amount by which the loan’s amortized cost basis exceeds its net realizable value. We measure the specific allowance for collateral dependent loans as the amount by which the loan’s amortized costs basis exceeds its fair value. When repayment is expected to be provided substantially through the sale of collateral, we deduct estimated selling costs from the collateral’s fair value. Generally, third party appraisals that conform to Uniform Standards of Professional Appraisal Practice serve as the basis for the fair value of real property held as collateral. These appraised values are on an “as-is” basis and generally are not adjusted by the Company. We obtain updated appraisals at least annually or more frequently if market conditions indicate collateral values may have declined. For energy loans, our internal staff of engineers generally determines collateral value of mineral rights based on projected cash flows from proven oil and gas reserves under existing economic and operating conditions. For real property held as collateral for other loans, third party appraisals that conform to Uniform Standards of Professional Appraisal Practice generally serve as the basis for the fair value. These appraised values are on an “as-is” basis and generally are not adjusted by the Company. We obtain updated appraisals at least annually or more frequently if market conditions indicate collateral values may have declined. Our special assets staff generally determines the value of other collateral based on projected liquidation cash flows under current market conditions. We evaluate collateral values and available cash resources quarterly. Historical statistics may be used to estimate specific allowances in limited situations, such as when a collateral dependent loan is removed from the general allowance pool near the end of a reporting period until an appraisal of collateral value is received or a full assessment of future cash flows is completed. General allowances estimate expected credit losses on pools of loans sharing similar risk characteristics that are expected to occur over the loan’s estimated remaining life. The loan’s estimated remaining life represents the contractual term adjusted for amortization, estimates of prepayments, and borrower-owned extension options. Approximately 90 percent of the committed dollars in the loan portfolio is risk graded loans with general allowance model inputs that include probability of default, loss given default, and exposure at default. Probability of default is based on the migration of loans from performing to nonperforming using historical life of loan analysis periods. Loss given default is based on the aggregate losses incurred, net of estimated recoveries. Exposure at default represents an estimate of the outstanding amount of credit exposure at the time a default may occur. Charge-off migration is used to calculate the general allowance for the majority of non-risk graded loans to individuals. The expected credit loss on less than 10 percent of the committed dollars in the portfolio is calculated using charge-off migration. The expected credit loss on approximately 1 percent of the committed dollars in the portfolio is calculated using a non-modeled approach. Specifically, the calculation applies a long-term net charge-off rate to the loan balances, adjusted for the weighted average remaining maturity of each portfolio. In estimating the expected credit losses for general allowances on performing risk-graded loans, each portfolio class is assigned relevant economic loss drivers which best explain variations in portfolio net loss rates. The probability of default estimates for each portfolio class are adjusted for current and forecasted economic conditions. The result is applied to the exposure at default and loss given default to calculate the lifetime expected credit loss estimate. Selection of relevant economic loss drivers is re-evaluated periodically and involves statistical analysis as well as management judgment. The unemployment rate factors significantly in the allowance for loan losses calculation, affecting commercial and loans to individuals segments. Other primary factors impacting the commercial portfolio include BBB corporate spreads, real gross domestic product growth rate, and energy commodity prices. The primary commercial real estate variables are vacancy rate and BBB corporate spreads. In addition to the unemployment rate, the forecast for loans to individuals is tied to home price index. The forecasts may include regional economic factors when localized conditions diverge from national conditions. An Economic Forecast Committee, consisting of senior management with members largely independent of the allowance process develops a twelve-month forward-looking forecast for the relevant economic loss drivers. Management develops these forecasts based on external data as well as a view of future economic conditions, which may include adjustments for regional conditions. The forecast includes three economic scenarios and probability weights for each scenario. The base forecast represents management's view of the most likely outcome, while the downside forecast reflects reasonably possible worsening economic conditions, and the upside forecast projects reasonably possible improving conditions. At the end of the one-year reasonable and supportable forecast period, we transition from shorter-term expected losses to long-term loss averages for the loan’s estimated remaining life. The difference between short-term loss forecasts and long-term loss averages is run-off over the reversion horizon, up to three years, depending on the forecasted economic scenarios. General allowances also consider the estimated impact of factors that are not captured in the modeled results or historical experience. These qualitative adjustments, determined by the Allowance Committee, may increase or decrease the allowance estimated by modeled results. Factors not captured in modeled results or historical experience may include for example, new lines of business, market conditions that have not been previously encountered, observed changes in credit risk that are not yet reflected in macro-economic factors, or economic conditions that impact loss given default assumptions. The accrual for off-balance sheet credit risk is maintained at a level that is appropriate to cover estimated losses associated with credit instruments that are not currently recognized as assets such as loan commitments, standby letters of credit or guarantees that are not unconditionally cancelable by the bank. This accrual is included in other liabilities in the Consolidated Balance Sheets. The appropriateness of the accrual is determined in the same manner as the allowance for loan losses, with the added consideration of commitment usage over the remaining life for those loans that the bank can not unconditionally cancel.
Revenue [Policy Text Block]	Fees and commissions revenue is generated through the sales of products, consisting primarily of financial instruments, and the performance of services for customers under contractual obligations. Revenue from providing services for customers is recognized at the time services are provided in an amount that reflects the consideration we expect to be entitled to for those services. Revenue is recognized based on the application of five steps: • Identify the contract with a customer • Identify the performance obligations in the contract • Determine the transaction price • Allocate the transaction price to the performance obligations in the contract • Recognize revenue when (or as) the Company satisfies a performance obligation For contracts with multiple performance obligations, individual performance obligations are accounted for separately if the customer can benefit from the good or service on its own or with other resources readily available to the customer and the promise to transfer goods and services to the customer is separately identifiable in the contract. The transaction price is allocated to the performance obligations based on relative standalone selling prices. Revenue is recognized on a gross basis whenever we have primary responsibility and risk in providing the services or products to our customers and have discretion in establishing the price for the services or products. Revenue is recognized on a net basis whenever we act as an agent for products or services of others. Brokerage and trading revenue includes revenues from trading, customer hedging, retail brokerage and investment banking. Trading revenue includes net realized and unrealized gains primarily related to sales of securities to institutional customers and related derivative contracts. Customer hedging revenue includes realized and unrealized changes in the fair value of derivative contracts held for customer risk management programs including credit valuation adjustments, as necessary. We offer commodity, interest rate, foreign exchange and equity derivatives to our customers. These customer contracts are offset with contracts with selected counterparties and exchanges to minimize changes in market risk from changes in commodity prices, interest rates or foreign exchange rates. Retail brokerage revenue represents fees and commissions earned on sales of fixed income securities, annuities, mutual funds and other financial instruments to retail customers. Investment banking revenue includes fees earned upon completion of underwriting and financial advisory services. Investment banking revenue also includes fees earned in conjunction with loan syndications. Insurance brokerage revenues represents fees and commissions earned on placement of insurance products with carriers for property and casualty and health coverage. Transaction card revenue includes merchant discount fees and electronic funds transfer network fees, net of interchange fees paid to card issuers and assessments paid to card networks. Merchant discount fees represent fees paid by customers for account management and electronic processing of card transactions. Merchant discount fees are recognized at the time the customer’s transactions are processed or other services are performed. The Company also maintains the TransFund electronic funds transfer network for the benefit of its members, which includes the Bank. Electronic funds transfer fees are recognized as electronic transactions processed on behalf of its members. Fiduciary and asset management revenue includes fees from asset management, custody, recordkeeping, investment advisory and administration services. Revenue is recognized on an accrual basis at the time the services are performed and may be based on either the fair value of the account or the service provided. Deposit service charges and fees include commercial account service charges, overdraft fees, check card fee revenue and automated service charge and other deposit service fees. Fees are recognized at least quarterly in accordance with published deposit account agreements and disclosure statements for retail accounts or contractual agreements for commercial accounts. Item charges for overdraft or non-sufficient funds items are recognized as items are presented for payment. Account balance charges and activity fees are accrued monthly and collected in arrears. Commercial account activity fees may be offset by an earnings credit based on account balances. Check card fees represent interchange fees paid by a merchant bank for transactions processed from cards issued by the Company. Check card fees are recognized when transactions are processed.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities (Policies)	9 Months Ended
	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives, Policy [Policy Text Block]	Derivative instruments may be used by the Company as part of its internal risk management programs or may be offered to customers. All derivative instruments are carried at fair value and changes in fair value are reported in earnings as they occur. Credit risk is also considered in determining fair value. Deterioration in the credit rating of customer or other counterparties reduced the fair value of asset contracts. Deterioration of our credit rating could decrease the fair value of our derivative liabilities. When bilateral netting agreements or similar arrangements exist between the Company and its counterparties that create a single legal claim or obligation to pay or receive the net amount in settlement of the individual derivative contracts, the Company reports derivative assets and liabilities on a net by derivative contract type by counterparty basis. Derivative contracts may require the Company to provide or receive cash margin as collateral for derivative assets and liabilities. Derivative assets and liabilities are reported net of cash margin when certain conditions are met. In addition, derivative contracts executed with customers under Customer Risk Management Programs may be secured by non-cash collateral in conjunction with a credit agreement with that customer. Access to collateral in the event of default is reasonably assured. None of these derivative contracts have been designated as hedging instruments for accounting purposes. Customer Risk Management Programs BOK Financial offers programs to permit its customers to manage various risks, including fluctuations in energy, cattle and other agricultural products, interest rates and foreign exchange rates with derivative contracts. Customers may also manage interest rate risk through interest rate swaps used by borrowers to modify interest rate terms of their loans. Derivative contracts are executed between the customers and BOK Financial. Offsetting contracts are executed between BOK Financial and other selected counterparties to minimize the risk of changes in commodity prices, interest rates or foreign exchange rates. The counterparty contracts are identical to customer contracts, except for a fixed pricing spread or fee paid to BOK Financial as profit and compensation for administrative costs and credit risk which is recognized over the life of the contracts and included in Other operating revenue – Brokerage and trading revenue in the Consolidated Statements of Earnings. Trading BOK Financial may offer derivative instruments such as to-be-announced securities to mortgage banking customers to enable them to manage their market risk or to mitigate the Company's market risk of holding trading securities. Changes in the fair value of derivative instruments for trading purposes or used to mitigate the market risk of holding trading securities are included in Other operating revenue – Brokerage and trading revenue. Internal Risk Management Programs BOK Financial may use derivative contracts in managing its interest rate sensitivity, as part of its economic hedge of the change in the fair value of mortgage servicing rights. Changes in the fair value of derivative instruments used in managing interest rate sensitivity and as part of the economic hedge of changes in the fair value of mortgage servicing rights are included in Other operating revenue – Gain (loss) on derivatives, net in the Consolidated Statements of Earnings.

Revenue from Contract with Cust

Revenue from Contract with Customer (Policies)	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenue [Policy Text Block]	Fees and commissions revenue is generated through the sales of products, consisting primarily of financial instruments, and the performance of services for customers under contractual obligations. Revenue from providing services for customers is recognized at the time services are provided in an amount that reflects the consideration we expect to be entitled to for those services. Revenue is recognized based on the application of five steps: • Identify the contract with a customer • Identify the performance obligations in the contract • Determine the transaction price • Allocate the transaction price to the performance obligations in the contract • Recognize revenue when (or as) the Company satisfies a performance obligation For contracts with multiple performance obligations, individual performance obligations are accounted for separately if the customer can benefit from the good or service on its own or with other resources readily available to the customer and the promise to transfer goods and services to the customer is separately identifiable in the contract. The transaction price is allocated to the performance obligations based on relative standalone selling prices. Revenue is recognized on a gross basis whenever we have primary responsibility and risk in providing the services or products to our customers and have discretion in establishing the price for the services or products. Revenue is recognized on a net basis whenever we act as an agent for products or services of others. Brokerage and trading revenue includes revenues from trading, customer hedging, retail brokerage and investment banking. Trading revenue includes net realized and unrealized gains primarily related to sales of securities to institutional customers and related derivative contracts. Customer hedging revenue includes realized and unrealized changes in the fair value of derivative contracts held for customer risk management programs including credit valuation adjustments, as necessary. We offer commodity, interest rate, foreign exchange and equity derivatives to our customers. These customer contracts are offset with contracts with selected counterparties and exchanges to minimize changes in market risk from changes in commodity prices, interest rates or foreign exchange rates. Retail brokerage revenue represents fees and commissions earned on sales of fixed income securities, annuities, mutual funds and other financial instruments to retail customers. Investment banking revenue includes fees earned upon completion of underwriting and financial advisory services. Investment banking revenue also includes fees earned in conjunction with loan syndications. Insurance brokerage revenues represents fees and commissions earned on placement of insurance products with carriers for property and casualty and health coverage. Transaction card revenue includes merchant discount fees and electronic funds transfer network fees, net of interchange fees paid to card issuers and assessments paid to card networks. Merchant discount fees represent fees paid by customers for account management and electronic processing of card transactions. Merchant discount fees are recognized at the time the customer’s transactions are processed or other services are performed. The Company also maintains the TransFund electronic funds transfer network for the benefit of its members, which includes the Bank. Electronic funds transfer fees are recognized as electronic transactions processed on behalf of its members. Fiduciary and asset management revenue includes fees from asset management, custody, recordkeeping, investment advisory and administration services. Revenue is recognized on an accrual basis at the time the services are performed and may be based on either the fair value of the account or the service provided. Deposit service charges and fees include commercial account service charges, overdraft fees, check card fee revenue and automated service charge and other deposit service fees. Fees are recognized at least quarterly in accordance with published deposit account agreements and disclosure statements for retail accounts or contractual agreements for commercial accounts. Item charges for overdraft or non-sufficient funds items are recognized as items are presented for payment. Account balance charges and activity fees are accrued monthly and collected in arrears. Commercial account activity fees may be offset by an earnings credit based on account balances. Check card fees represent interchange fees paid by a merchant bank for transactions processed from cards issued by the Company. Check card fees are recognized when transactions are processed.

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2020
Marketable Securities [Abstract]
Trading Securities, [Table Text Block]	The fair value and net unrealized gain (loss) included in trading securities are as follows (in thousands): September 30, 2020 December 31, 2019 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. government agency debentures $ 5,181 $ (1) $ 44,264 $ 6 Residential agency mortgage-backed securities 2,150,759 (693) 1,504,651 2,293 Municipal and other tax-exempt securities 30,533 (44) 26,196 60 Asset-backed securities — — 14,084 (21) Other debt securities 59,007 61 34,726 21 Total trading securities $ 2,245,480 $ (677) $ 1,623,921 $ 2,359
Investment Securities (Held-to-Maturity) [Table Text Block]	The amortized cost and fair values of investment securities are as follows (in thousands): September 30, 2020 Amortized Fair Gross Unrealized Cost Value Gain Loss Municipal and other tax-exempt $ 76,109 $ 80,368 $ 4,259 $ — Residential agency mortgage-backed securities 9,317 10,219 902 — Other debt securities 171,314 194,342 23,227 (199) Total investment securities 256,740 284,929 28,388 (199) Allowance for credit losses 1 (739) Investment securities, net of allowance 256,001 284,929 28,388 (199) 1 Effective with the adoption of FASB ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) on January 1, 2020. December 31, 2019 Amortized Fair Gross Unrealized Cost Value Gain Loss Municipal and other tax-exempt $ 93,653 $ 96,897 $ 3,250 $ (6) Residential agency mortgage-backed securities 10,676 11,164 488 — Other debt securities 189,089 206,341 17,547 (295) Total investment securities $ 293,418 $ 314,402 $ 21,285 $ (301) The amortized cost and fair values of investment securities at September 30, 2020, by contractual maturity, are as shown in the following table (dollars in thousands): Less than One to Six to Over Total Weighted Average Maturity 1 Fixed maturity debt securities: Amortized cost $ 30,455 $ 87,606 $ 120,073 $ 9,289 $ 247,423 4.94 Fair value 30,761 95,912 138,580 9,457 274,710 Residential mortgage-backed securities: Amortized cost $ 9,317 2 Fair value 10,219 Total investment securities: Amortized cost $ 256,740 Fair value 284,929 1 Expected maturities may differ from contractual maturities, because borrowers may have the right to call or prepay obligations with or without penalty. 2 The average expected lives of residential mortgage-backed securities were 4.58 years based upon current prepayment assumptions. Temporarily Impaired Investment Securities (in thousands): September 30, 2020 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized Investment: Other debt securities 8 3,026 68 2,043 131 5,069 199 Total investment securities 8 $ 3,026 $ 68 $ 2,043 $ 131 $ 5,069 $ 199 December 31, 2019 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized Investment: Municipal and other tax-exempt 4 $ 1,001 $ 1 $ 1,706 $ 5 $ 2,707 $ 6 Other debt securities 13 275 1 8,041 294 8,316 295 Total investment securities 17 $ 1,276 $ 2 $ 9,747 $ 299 $ 11,023 $ 301
Available For Sale Securities [Table Text Block]	The amortized cost and fair value of available for sale securities are as follows (in thousands): September 30, 2020 Amortized Fair Gross Unrealized Cost Value Gain Loss U.S. Treasury $ 500 $ 509 $ 9 $ — Municipal and other tax-exempt 50,050 51,601 1,648 (97) Mortgage-backed securities: Residential agency 9,033,728 9,384,998 354,669 (3,399) Residential non-agency 19,954 34,873 14,919 — Commercial agency 3,221,538 3,334,409 114,244 (1,373) Other debt securities 10,936 10,879 — (57) Total available for sale securities $ 12,336,706 $ 12,817,269 $ 485,489 $ (4,926) December 31, 2019 Amortized Fair Gross Unrealized Cost Value Gain Loss U.S. Treasury $ 1,598 $ 1,600 $ 2 $ — Municipal and other tax-exempt 1,789 1,861 72 — Mortgage-backed securities: Residential agency 7,956,297 8,046,096 104,912 (15,113) Residential non-agency 25,968 41,609 15,641 — Commercial agency 3,145,342 3,178,005 37,808 (5,145) Other debt securities 500 472 — (28) Total available for sale securities $ 11,131,494 $ 11,269,643 $ 158,435 $ (20,286) The amortized cost and fair values of available for sale securities at September 30, 2020, by contractual maturity, are as shown in the following table (dollars in thousands): Less than One to Six to Over Total Weighted Average Maturity 1 Fixed maturity debt securities: Amortized cost $ 70,791 $ 1,326,715 $ 1,282,122 $ 603,396 $ 3,283,024 8.02 Fair value 71,123 1,383,695 1,313,942 628,638 3,397,398 Residential mortgage-backed securities: Amortized cost $ 9,053,682 2 Fair value 9,419,871 Total available-for-sale securities: Amortized cost $ 12,336,706 Fair value 12,817,269 1 Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without penalty. 2 The average expected lives of residential mortgage-backed securities were 3.02 years based upon current prepayment assumptions. Sales of available for sale securities resulted in gains and losses as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Proceeds $ 1,034 $ 261,028 $ 206,979 $ 628,385 Gross realized gains 54 989 5,637 7,316 Gross realized losses (66) (984) (66) (6,206) Related federal and state income tax expense (benefit) (3) 1 1,419 282
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table Text Block]	September 30, 2020 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized Available for sale: Municipal and other tax-exempt 11 $ 19,768 $ 97 $ — $ — $ 19,768 $ 97 Mortgage-backed securities: Residential agency 32 630,460 3,178 165,726 221 796,186 3,399 Commercial agency 29 264,836 923 253,378 450 518,214 1,373 Other debt securities 5 10,407 29 472 28 10,879 57 Total available for sale securities 77 $ 925,471 $ 4,227 $ 419,576 $ 699 $ 1,345,047 $ 4,926 December 31, 2019 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized Available for sale: Mortgage-backed securities: Residential agency 133 $ 1,352,597 $ 6,690 $ 686,002 $ 8,423 $ 2,038,599 $ 15,113 Commercial agency 69 830,047 4,238 210,877 907 1,040,924 5,145 Other debt securities 1 — — 472 28 472 28 Total available for sale securities 203 $ 2,182,644 $ 10,928 $ 897,351 $ 9,358 $ 3,079,995 $ 20,286
Fair Value Option Securities [Table Text Block]	The fair value and net unrealized gain (loss) included in fair value option securities is as follows (in thousands): September 30, 2020 December 31, 2019 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. Treasury $ — $ — $ 9,917 $ (48) Residential agency mortgage-backed securities 134,756 4,926 1,088,660 14,109 Total $ 134,756 $ 4,926 $ 1,098,577 $ 14,061

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Sep. 30, 2020
Derivative Instrument Detail [Abstract]
Derivative Contracts [Table Text Block]	The following table summarizes the fair values of derivative contracts recorded as “derivative contracts” assets and liabilities in the balance sheet at September 30, 2020 (in thousands): Assets Notional 1 Gross Fair Value Netting Adjustments Net Fair Value Before Cash Collateral Cash Collateral Fair Value Net of Cash Collateral Customer risk management programs: Interest rate contracts 3,179,414 132,320 (107) 132,213 — 132,213 Energy contracts 3,482,226 400,646 (229,433) 171,213 (92,170) 79,043 Agricultural contracts 13,611 1,870 — 1,870 — 1,870 Foreign exchange contracts 311,626 309,130 — 309,130 (400) 308,730 Equity option contracts 73,447 937 — 937 (219) 718 Total customer risk management programs 7,060,324 844,903 (229,540) 615,363 (92,789) 522,574 Trading 65,290,962 235,176 (173,680) 61,496 (3,824) 57,672 Internal risk management programs 734,142 19,357 (6,035) 13,322 — 13,322 Total derivative contracts $ 73,085,428 $ 1,099,436 $ (409,255) $ 690,181 $ (96,613) $ 593,568 Liabilities Notional 1 Gross Fair Value Netting Adjustments Net Fair Value Before Cash Collateral Cash Collateral Fair Value Net of Cash Collateral Customer risk management programs: Interest rate contracts 3,179,414 132,689 (107) 132,582 (121,212) 11,370 Energy contracts 3,277,670 374,542 (229,433) 145,109 (37,276) 107,833 Agricultural contracts 13,627 1,856 — 1,856 (1,856) — Foreign exchange contracts 311,098 308,493 — 308,493 — 308,493 Equity option contracts 73,447 937 — 937 — 937 Total customer risk management programs 6,855,256 818,517 (229,540) 588,977 (160,344) 428,633 Trading 64,972,263 229,013 (173,680) 55,333 (38,999) 16,334 Internal risk management programs 559,452 7,655 (6,035) 1,620 (259) 1,361 Total derivative contracts $ 72,386,971 $ 1,055,185 $ (409,255) $ 645,930 $ (199,602) $ 446,328 1 Notional amounts for commodity contracts are converted into dollar-equivalent amounts based on dollar prices at the inception of the contract. The following table summarizes the fair values of derivative contracts recorded as “derivative contracts” assets and liabilities in the balance sheet at December 31, 2019 (in thousands): Assets Notional 1 Gross Fair Value Netting Adjustments Net Fair Value Before Cash Collateral Cash Collateral Fair Value Net of Cash Collateral Customer risk management programs: Interest rate contracts 2,464,478 49,100 (1,839) 47,261 — 47,261 Energy contracts 2,151,096 144,906 (107,591) 37,315 (38) 37,277 Agricultural contracts 16,118 1,522 (22) 1,500 — 1,500 Foreign exchange contracts 214,119 213,007 — 213,007 — 213,007 Equity option contracts 81,455 3,233 — 3,233 (660) 2,573 Total customer risk management programs 4,927,266 411,768 (109,452) 302,316 (698) 301,618 Trading 69,721,932 131,561 (115,949) 15,612 — 15,612 Internal risk management programs 1,268,180 6,226 (81) 6,145 — 6,145 Total derivative contracts $ 75,917,378 $ 549,555 $ (225,482) $ 324,073 $ (698) $ 323,375 Liabilities Notional 1 Gross Fair Value Netting Adjustments Net Fair Value Before Cash Collateral Cash Collateral Fair Value Net of Cash Collateral Customer risk management programs: Interest rate contracts 2,464,478 49,194 (1,839) 47,355 (43,932) 3,423 Energy contracts 2,105,391 139,311 (107,591) 31,720 (6,031) 25,689 Agricultural contracts 16,139 1,507 (22) 1,485 (1,485) — Foreign exchange contracts 207,919 207,020 — 207,020 — 207,020 Equity option contracts 81,455 3,233 — 3,233 — 3,233 Total customer risk management programs 4,875,382 400,265 (109,452) 290,813 (51,448) 239,365 Trading 65,144,388 125,535 (115,949) 9,586 — 9,586 Internal risk management programs 380,401 3,121 (81) 3,040 (863) 2,177 Total derivative contracts $ 70,400,171 $ 528,921 $ (225,482) $ 303,439 $ (52,311) $ 251,128 1 Notional amounts for commodity contracts are converted into dollar-equivalent amounts based on dollar prices at the inception of the contract.
Derivative Instruments, Gain (Loss) in Statement of Earnings [Table Text Block]	The following summarizes the pre-tax net gains (losses) on derivative instruments and where they are recorded in the income statement (in thousands): Three Months Ended September 30, 2020 September 30, 2019 Brokerage Gain (Loss) on Derivatives, Net Brokerage Gain (Loss)on Derivatives, Net Customer risk management programs: Interest rate contracts To-be-announced residential mortgage-backed securities $ — $ — $ 1,667 $ — Interest rate swaps 1,014 — 1,252 — Energy contracts 7,460 — 1,611 — Agricultural contracts 6 — 16 — Foreign exchange contracts 162 — 138 — Equity option contracts — — — — Total customer risk management programs 8,642 — 4,684 — Trading 1 (468) — 3,630 — Internal risk management programs — 2,354 — 3,778 Total derivative contracts $ 8,174 $ 2,354 $ 8,314 $ 3,778 1 Represents changes in fair value of to-be-announced securities and other derivative instruments held to mitigate market risk of trading securities portfolio, which is offset by changes in fair value of trading securities also include in Brokerage and Trading Revenue in the Consolidated Statements of Earnings. Nine Months Ended September 30, 2020 September 30, 2019 Brokerage Gain (Loss) on Derivatives, Net Brokerage Gain (Loss) on Derivatives, Net Customer risk management programs: Interest rate contracts To-be-announced residential mortgage-backed securities $ — $ — $ 9,579 $ — Interest rate swaps 2,702 — 2,787 — Energy contracts 14,850 — 3,923 — Agricultural contracts 27 — 24 — Foreign exchange contracts 527 — 392 — Equity option contracts — — — — Total customer risk management programs 18,106 — 16,705 — Trading 1 (8,546) — 4,365 — Internal risk management programs — 42,659 — 19,595 Total derivative contracts $ 9,560 $ 42,659 $ 21,070 $ 19,595

Loans and Allowances for Cred_2

Loans and Allowances for Credit Losses (Tables)	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Loans and Leases Receivable, Net Amount [Abstract]
Schedule of Loans by Portfolio Segment [Table Text Block]	Portfolio segments of the loan portfolio are as follows (in thousands): September 30, 2020 Fixed Variable Non-accrual Total Commercial 1,424,416 11,971,337 169,953 $ 13,565,706 Commercial real estate 1,012,882 3,667,866 12,952 4,693,700 Paycheck protection program 2,097,325 — — 2,097,325 Loans to individuals 2,132,653 1,275,668 38,248 3,446,569 Total $ 6,667,276 $ 16,914,871 $ 221,153 $ 23,803,300	Portfolio segments of the loan portfolio are as follows (in thousands): December 31, 2019 Fixed Variable Non-accrual Total Commercial $ 3,231,485 $ 10,684,749 $ 115,416 $ 14,031,650 Commercial real estate 1,056,321 3,349,836 27,626 4,433,783 Residential mortgage 1,652,653 393,897 37,622 2,084,172 Personal 193,903 1,007,192 287 1,201,382 Total $ 6,134,362 $ 15,435,674 $ 180,951 $ 21,750,987 Accruing loans past due (90 days) 1 $ 7,680 1 Excludes residential mortgage loans guaranteed by agencies of the U.S. government
Rollforward of Allowance For Loan Losses And Accrual for Off-Balance Sheet Credit Losses [Table Text Block]	The activity in the allowance for loan losses and the allowance for off-balance sheet credit losses related to loan commitments and standby letters of credit is summarized as follows (in thousands): Three Months Ended September 30, 2020 Commercial Commercial Real Estate Paycheck Protection Program Loans to Individuals Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 310,422 $ 68,756 $ — $ 56,419 $ — $ 435,597 Provision for loan losses 2,108 3,118 — 1,383 — 6,609 Loans charged off (25,319) (413) — (929) — (26,661) Recoveries of loans previously charged off 3,066 114 — 1,052 — 4,232 Ending Balance $ 290,277 $ 71,575 $ — $ 57,925 — $ 419,777 Allowance for off-balance sheet credit risk from unfunded loan commitments: Beginning balance $ 14,582 $ 16,419 $ — $ 1,918 $ — $ 32,919 Provision for off-balance sheet credit risk (2,618) (2,426) — 94 — (4,950) Ending Balance $ 11,964 $ 13,993 $ — $ 2,012 $ — $ 27,969 Nine Months Ended September 30, 2020 Commercial Commercial Real Estate Paycheck Protection Program Loans to Individuals Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 118,187 $ 51,805 $ — $ 23,572 $ 17,195 $ 210,759 Transition adjustment 33,681 (4,620) — 13,943 (17,195) 25,809 Beginning balance, adjusted 151,868 47,185 — 37,515 — 236,568 Provision for loan losses 190,984 25,454 — 20,500 — 236,938 Loans charged off (56,421) (1,300) — (3,427) — (61,148) Recoveries 3,846 236 — 3,337 — 7,419 Ending balance $ 290,277 $ 71,575 $ — $ 57,925 $ — $ 419,777 Allowance for off-balance sheet credit risk from unfunded loan commitments: Beginning balance $ 1,434 $ 107 $ — $ 44 $ — $ 1,585 Transition adjustment 10,144 11,660 — 1,748 — 23,552 Beginning balance, adjusted 11,578 11,767 — 1,792 — 25,137 Provision for off-balance sheet credit losses 386 2,226 — 220 — 2,832 Ending balance $ 11,964 $ 13,993 $ — $ 2,012 $ — $ 27,969 Changes in our reasonable and supportable forecasts of macroeconomic variables, primarily due to the anticipated impact of the on-going COVID-19 pandemic, and other assumptions, resulted in a $12.8 million reduction in the allowance for lending activities during the third quarter of 2020. Changes in the loan portfolio characteristics, including specific impairment and losses, loan balances and risk grading resulted in a $14.5 million increase in the allowance for lending activities. The allowance for loan losses and recorded investment of the related loans by portfolio segment for each measurement method at September 30, 2020 is as follows (in thousands): Collectively Measured Individually Measured Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Commercial $ 13,395,753 $ 271,122 $ 169,953 $ 19,155 $ 13,565,706 $ 290,277 Commercial real estate 4,680,748 71,035 12,952 540 4,693,700 71,575 Paycheck protection program 2,097,325 — — — 2,097,325 — Loans to individuals 3,408,321 57,925 38,248 — 3,446,569 57,925 Total 23,582,147 400,082 221,153 19,695 23,803,300 419,777	The activity in the allowance for loan losses and the allowance for off-balance sheet credit losses related to loan commitments and standby letters of credit is summarized as follows (in thousands): Three Months Ended September 30, 2019 Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 106,397 $ 54,188 $ 15,724 $ 9,388 $ 16,837 $ 202,534 Provision for loan losses 9,861 102 (253) 1,911 918 12,539 Loans charged off (9,875) — (56) (1,776) — (11,707) Recoveries 260 60 119 627 — 1,066 Ending balance $ 106,643 $ 54,350 $ 15,534 $ 10,150 $ 17,755 $ 204,432 Allowance for off-balance sheet credit losses: Beginning balance 1,742 116 44 1 — $ 1,903 Provision for off-balance sheet credit losses (536) (3) — — — (539) Ending balance $ 1,206 $ 113 $ 44 $ 1 $ — $ 1,364 Total provision for credit losses $ 9,325 $ 99 $ (253) $ 1,911 $ 918 $ 12,000 Nine Months Ended September 30, 2019 Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 102,226 $ 60,026 $ 17,964 $ 9,473 $ 17,768 $ 207,457 Provision for loan losses 34,740 (10,075) (2,660) 3,434 (13) 25,426 Loans charged off (31,728) (118) (192) (4,671) — (36,709) Recoveries 1,405 4,517 422 1,914 — 8,258 Ending balance $ 106,643 $ 54,350 $ 15,534 $ 10,150 $ 17,755 $ 204,432 Allowance for off-balance sheet credit losses: Beginning balance $ 1,655 $ 52 $ 52 $ 31 $ — $ 1,790 Provision for off-balance sheet credit losses (449) 61 (8) (30) — (426) Ending balance $ 1,206 $ 113 $ 44 $ 1 $ — $ 1,364 Total provision for credit losses $ 34,291 $ (10,014) $ (2,668) $ 3,404 $ (13) $ 25,000 The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at December 31, 2019 is as follows (in thousands): Collectively Measured Individually Measured Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Commercial $ 13,916,234 $ 100,773 $ 115,416 $ 17,414 $ 14,031,650 $ 118,187 Commercial real estate 4,406,157 51,805 27,626 — 4,433,783 51,805 Residential mortgage 2,046,550 14,400 37,622 — 2,084,172 14,400 Personal 1,201,095 9,172 287 — 1,201,382 9,172 Total 21,570,036 176,150 180,951 17,414 21,750,987 193,564 Nonspecific allowance — — — — — 17,195 Total $ 21,570,036 $ 176,150 $ 180,951 $ 17,414 $ 21,750,987 $ 210,759
Schedule of Credit Quality Indicators [Table Text Block]	The following table summarizes the Company’s loan portfolio at September 30, 2020 by the risk grade categories and vintage (in thousands): Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total Commercial: Energy Pass $ 57,239 $ 58,923 $ 93,066 $ 7,959 $ 1,131 $ 6,716 $ 2,474,328 $ — $ 2,699,362 Special Mention — — — — — — 465,643 — 465,643 Accruing Substandard 295 — 951 — 14,406 — 409,628 — 425,280 Nonaccrual 1,652 6,541 15,496 — — 28,349 74,778 — 126,816 Total energy 59,186 65,464 109,513 7,959 15,537 35,065 3,424,377 — 3,717,101 Healthcare Pass 356,834 619,693 625,047 429,314 241,452 749,439 236,118 — 3,257,897 Special Mention — 27,500 — 3,019 — 13,393 3,255 — 47,167 Accruing Substandard — 2,843 1,705 947 143 11,443 — — 17,081 Nonaccrual — 18 183 — — 2,935 509 — 3,645 Total healthcare 356,834 650,054 626,935 433,280 241,595 777,210 239,882 — 3,325,790 Services Pass 356,443 445,488 406,761 345,936 380,205 758,036 689,917 651 3,383,437 Special Mention 344 11,778 1,734 597 8,415 5,410 10,043 — 38,321 Accruing Substandard 94 8,067 27,957 9,662 2,568 15,185 34,717 — 98,250 Nonaccrual — 3,420 — 13,898 1,147 6,726 626 — 25,817 Total services 356,881 468,753 436,452 370,093 392,335 785,357 735,303 651 3,545,825 General business Pass 327,729 446,214 342,469 242,267 126,259 229,142 1,145,429 2,766 2,862,275 Special Mention — 4,335 13,235 7,126 3,876 3,457 4,782 21 36,832 Accruing Substandard 1,005 15,955 11,316 11,007 7,501 8,526 8,894 4 64,208 Nonaccrual 1,675 3,853 4,865 1,647 787 118 659 71 13,675 Total general business 330,409 470,357 371,885 262,047 138,423 241,243 1,159,764 2,862 2,976,990 Total commercial 1,103,310 1,654,628 1,544,785 1,073,379 787,890 1,838,875 5,559,326 3,513 13,565,706 Commercial real estate: Pass 578,864 1,184,368 1,021,832 517,976 347,920 780,900 207,440 — 4,639,300 Special Mention — — 261 12,326 2,571 8,903 — — 24,061 Accruing Substandard — 8,349 — 4,187 — 4,824 27 — 17,387 Nonaccrual — — — 232 6,575 6,145 — — 12,952 Total commercial real estate 578,864 1,192,717 1,022,093 534,721 357,066 800,772 207,467 — 4,693,700 Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total Paycheck protection program: Pass 2,097,325 — — — — — — — 2,097,325 Total paycheck protection program 2,097,325 — — — — — — — 2,097,325 Loans to individuals: Residential mortgage Pass 414,273 166,795 138,524 157,514 178,830 390,803 341,673 26,129 1,814,541 Special Mention — 47 1,879 20 — 309 527 12 2,794 Accruing Substandard — — — — — 39 159 12 210 Nonaccrual — 43 1,509 735 2,057 24,431 2,066 758 31,599 Total residential mortgage 414,273 166,885 141,912 158,269 180,887 415,582 344,425 26,911 1,849,144 Residential mortgage guaranteed by U.S. government agencies Pass 2,385 29,819 29,745 43,690 57,322 214,889 — — 377,850 Nonaccrual — — 404 — — 5,993 — — 6,397 Total residential mortgage guaranteed by U.S. government agencies 2,385 29,819 30,149 43,690 57,322 220,882 — — 384,247 Personal: Pass 182,066 204,478 79,041 104,217 70,812 98,598 471,503 1,498 1,212,213 Special Mention 42 24 11 53 46 45 1 — 222 Accruing Substandard — 211 — 265 — — 15 — 491 Nonaccrual — 17 49 53 59 44 30 — 252 Total personal 182,108 204,730 79,101 104,588 70,917 98,687 471,549 1,498 1,213,178 Total loans to individuals 598,766 401,434 251,162 306,547 309,126 735,151 815,974 28,409 3,446,569 Total loans $ 4,378,265 $ 3,248,779 $ 2,818,040 $ 1,914,647 $ 1,454,082 $ 3,374,798 $ 6,582,767 $ 31,922 $ 23,803,300	The allowance for loan losses and recorded investment of the related loans by portfolio segment for risk graded and non-risk graded loans at December 31, 2019 is as follows (in thousands): Internally Risk Graded Non-Graded Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Commercial $ 13,997,538 $ 117,236 $ 34,112 $ 951 $ 14,031,650 $ 118,187 Commercial real estate 4,433,783 51,805 — — 4,433,783 51,805 Residential mortgage 279,113 3,085 1,805,059 11,315 2,084,172 14,400 Personal 1,116,297 7,003 85,085 2,169 1,201,382 9,172 Total 19,826,731 179,129 1,924,256 14,435 21,750,987 193,564 Nonspecific allowance — — — — — 17,195 Total $ 19,826,731 $ 179,129 $ 1,924,256 $ 14,435 $ 21,750,987 $ 210,759 The following table summarizes the Company’s loan portfolio at December 31, 2019 by the risk grade categories (in thousands): Internally Risk Graded Non-Graded Performing Pass Other Loans Especially Mentioned Accruing Substandard Nonaccrual Performing Nonaccrual Total Commercial: Energy $ 3,700,406 $ 117,298 $ 63,951 $ 91,722 $ — $ — $ 3,973,377 Services 3,050,946 29,943 33,791 7,483 — — 3,122,163 Wholesale/retail 1,749,023 5,281 5,399 1,163 — — 1,760,866 Manufacturing 623,219 18,214 13,883 10,133 — — 665,449 Healthcare 2,995,514 13,117 20,805 4,480 — — 3,033,916 Public finance 709,868 — — — — — 709,868 Other commercial and industrial 709,729 4,028 17,744 398 34,075 37 766,011 Total commercial 13,538,705 187,881 155,573 115,379 34,075 37 14,031,650 Commercial real estate: Residential construction and land development 150,529 — — 350 — — 150,879 Retail 743,343 12,067 1,243 18,868 — — 775,521 Office 923,202 5,177 — — — — 928,379 Multifamily 1,257,005 1,604 95 6,858 — — 1,265,562 Industrial 852,539 1,658 1,011 909 — — 856,117 Other commercial real estate 455,045 1,639 — 641 — — 457,325 Total commercial real estate 4,381,663 22,145 2,349 27,626 — — 4,433,783 Residential mortgage: Permanent mortgage 276,138 78 2,404 493 758,260 19,948 1,057,321 Permanent mortgage guaranteed by U.S. government agencies — — — — 191,694 6,100 197,794 Home equity — — — — 817,976 11,081 829,057 Total residential mortgage 276,138 78 2,404 493 1,767,930 37,129 2,084,172 Personal 1,116,196 45 — 56 84,853 232 1,201,382 Total $ 19,312,702 $ 210,149 $ 160,326 $ 143,554 $ 1,886,858 $ 37,398 $ 21,750,987
Summary of Impaired Loans [Table Text Block]		A summary of impaired loans at December 31, 2019 follows (in thousands): Recorded Investment Unpaid Total With No With Allowance Related Allowance Commercial: Energy $ 149,441 $ 91,722 $ 44,244 $ 47,478 $ 16,854 Services 10,923 7,483 6,301 1,182 240 Wholesale/retail 1,980 1,163 902 261 101 Manufacturing 10,848 10,133 9,914 219 219 Healthcare 13,774 4,480 4,480 — — Public finance — — — — — Other commercial and industrial 8,227 435 435 — — Total commercial 195,193 115,416 66,276 49,140 17,414 Commercial real estate: Residential construction and land development 1,306 350 350 — — Retail 20,265 18,868 18,868 — — Office — — — — — Multifamily 6,858 6,858 6,858 — — Industrial 909 909 909 — — Other commercial real estate 801 641 641 — — Total commercial real estate 30,139 27,626 27,626 — — Residential mortgage: Permanent mortgage 24,868 20,441 20,441 — — Permanent mortgage guaranteed by U.S. government agencies 1 204,187 197,794 197,794 — — Home equity 12,967 11,081 11,081 — — Total residential mortgage 242,022 229,316 229,316 — — Personal 360 287 287 — — Total $ 467,714 $ 372,645 $ 323,505 $ 49,140 $ 17,414 1 All permanent mortgage loans guaranteed by U.S. government agencies are considered impaired as we do not expect full collection of contractual principal and interest. At December 31, 2019, the majority were accruing based on the guarantee by U.S. government agencies.
Summary of Loans by Aging Status [Table Text Block]	A summary of loans currently performing and past due as of September 30, 2020 is as follows (in thousands): Past Due Past Due 90 Days or More and Accruing Current 30 to 59 60 to 89 Days 90 Days Total Commercial: Energy $ 3,603,548 $ 27,064 $ — $ 86,489 $ 3,717,101 $ — Healthcare 3,316,556 5,419 — 3,815 3,325,790 171 Services 3,521,644 6,503 5,168 12,510 3,545,825 58 General business 2,955,752 14,002 342 6,894 2,976,990 443 Total commercial 13,397,500 52,988 5,510 109,708 13,565,706 672 Commercial real estate 4,673,416 2,029 532 17,723 4,693,700 4,771 Paycheck protection program 2,097,325 — — — 2,097,325 — Loans to individuals: Residential mortgage 1,830,005 8,299 1,128 9,712 1,849,144 2,241 Residential mortgage guaranteed by U.S. government agencies 172,678 56,264 34,355 120,950 384,247 117,188 Personal 1,212,488 99 520 71 1,213,178 — Total loans to individuals 3,215,171 64,662 36,003 130,733 3,446,569 119,429 Total $ 23,383,412 $ 119,679 $ 42,045 $ 258,164 $ 23,803,300 $ 124,872	A summary of loans currently performing, loans past due and accruing and nonaccrual loans as of December 31, 2019 is as follows (in thousands): Past Due Current 30 to 59 60 to 89 Days 90 Days Nonaccrual Total Commercial: Energy $ 3,881,244 $ 401 $ 10 $ — 91,722 $ 3,973,377 Services 3,105,621 1,737 523 6,799 7,483 3,122,163 Wholesale 1,758,878 712 113 — 1,163 1,760,866 Manufacturing 654,329 410 190 387 10,133 665,449 Healthcare 3,027,329 2,039 — 68 4,480 3,033,916 Public finance 707,638 2,230 — — — 709,868 Other commercial and industrial 764,390 414 772 — 435 766,011 Total commercial 13,899,429 7,943 1,608 7,254 115,416 14,031,650 Commercial real estate: Residential construction and land development 147,379 3,093 — 57 350 150,879 Retail 756,653 — — — 18,868 775,521 Office 928,379 — — — — 928,379 Multifamily 1,258,704 — — — 6,858 1,265,562 Industrial 855,208 — — — 909 856,117 Other commercial real estate 454,253 1,827 250 354 641 457,325 Total commercial real estate 4,400,576 4,920 250 411 27,626 4,433,783 Residential Mortgage: Permanent mortgage 1,034,716 2,011 153 — 20,441 1,057,321 Permanent mortgage guaranteed by U.S. government agencies 46,898 24,203 18,187 102,406 6,100 197,794 Home equity 814,325 3,343 308 — 11,081 829,057 Total residential mortgage 1,895,939 29,557 18,648 102,406 37,622 2,084,172 Personal 1,196,362 4,664 54 15 287 1,201,382 Total $ 21,392,306 $ 47,084 $ 20,560 $ 110,086 $ 180,951 $ 21,750,987
Financing Receivable, Nonaccrual [Table Text Block]	A summary of nonaccruing loans at September 30, 2020 follows (in thousands): As of September 30, 2020 Total With No With Allowance Related Allowance Commercial: Energy $ 126,816 $ 86,793 $ 40,023 $ 16,504 Healthcare 3,645 3,645 — — Services 25,817 20,456 5,361 2,574 General business 13,675 13,177 498 77 Total commercial 169,953 124,071 45,882 19,155 Commercial real estate 12,952 7,584 5,368 540 Loans to individuals: Residential mortgage 31,599 31,599 — — Residential mortgage guaranteed by U.S. government agencies 6,397 6,397 — — Personal 252 252 — — Total loans to individuals 38,248 38,248 — — Total $ 221,153 $ 169,903 $ 51,250 $ 19,695

Mortgage Banking Activities (Ta

Mortgage Banking Activities (Tables)	9 Months Ended
	Sep. 30, 2020
Mortgage Banking [Abstract]
Components of Residential Mortgage Loans Held For Sale [Table Text Block]	September 30, 2020 December 31, 2019 Unpaid Principal Balance/ Fair Value Unpaid Principal Balance/ Fair Value Residential mortgage loans held for sale $ 259,076 $ 268,575 $ 175,117 $ 177,703 Residential mortgage loan commitments 560,493 29,224 158,460 5,233 Forward sales contracts 765,994 (2,509) 315,203 (665) $ 295,290 $ 182,271
Mortgage Banking Revenue [Table Text Block]	Mortgage banking revenue was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Production revenue: Net realized gains on sale of mortgage loans $ 36,300 $ 8,971 $ 70,126 $ 24,838 Net change in unrealized gain (loss) on mortgage loans held for sale (1,672) 97 6,913 965 Net change in the fair value of mortgage loan commitments 1,593 514 23,991 4,733 Net change in the fair value of forward sales contracts 2,210 4,232 (1,844) 3,015 Total production revenue 38,431 13,814 99,186 33,551 Servicing revenue 13,528 16,366 43,876 48,594 Total mortgage banking revenue $ 51,959 $ 30,180 $ 143,062 $ 82,145
Summary of Mortgage Servicing Rights [Table Text Block]	The following represents a summary of mortgage servicing rights (dollars in thousands): September 30, 2020 December 31, 2019 Number of residential mortgage loans serviced for others 111,008 126,828 Outstanding principal balance of residential mortgage loans serviced for others $ 17,116,204 $ 20,727,106 Weighted average interest rate 3.91 % 3.98 % Remaining term (in months) 281 289
Activity in Capitalized Mortgage Servicing Rights [Table Text Block]	The following represents activity in capitalized mortgage servicing rights (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Beginning Balance $ 97,971 $ 208,308 $ 201,886 $ 259,254 Additions 7,424 9,882 21,330 24,821 Disposals — — (10,801) — Change in fair value due to principal payments (11,192) (11,936) (28,971) (27,600) Change in fair value due to market assumption changes 3,441 (12,593) (85,800) (62,814) Ending Balance $ 97,644 $ 193,661 $ 97,644 $ 193,661
Assumptions to Value Mortgage Servicing Rights [Table Text Block]	Mortgage servicing rights are not traded in active markets. Fair value is determined by discounting the projected net cash flows. Significant market assumptions used to determine fair value based on significant unobservable inputs were as follows: September 30, 2020 December 31, 2019 Discount rate – risk-free rate plus a market premium 9.15% 9.81% Prepayment rate - based upon loan interest rate, original term and loan type 9.90% - 24.02% 8.28% - 16.05% Loan servicing costs – annually per loan based upon loan type: Performing loans $69 - $94 $68 - $94 Delinquent loans $150 - $500 $150 - $500 Loans in foreclosure $1,000 - $4,000 $1,000 - $4,000 Escrow earnings rate – indexed to rates paid on deposit accounts with comparable average life 0.34% 1.73% Primary/secondary mortgage rate spread 105 bps 104 bps Delinquency rate 3.72% 2.73%

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2020
Stockholders' Equity Note [Abstract]
Accumulated Other Comprehensive Income (Loss) [Table Text Block]	A rollforward of the components of accumulated other comprehensive income (loss) is included as follows (in thousands): Unrealized Gain (Loss) on Available for Sale Securities Employee Benefit Plans Total Balance, Dec. 31, 2018 $ (70,999) $ (1,586) $ (72,585) Net change in unrealized gain (loss) 274,441 — 274,441 Reclassification adjustments included in earnings: Gain on available for sale securities, net (1,110) — (1,110) Other comprehensive income, before income taxes 273,331 — 273,331 Federal and state income taxes 1 66,993 — 66,993 Other comprehensive income, net of income taxes 206,338 — 206,338 Balance, September 30, 2019 $ 135,339 $ (1,586) $ 133,753 Balance, Dec. 31, 2019 $ 104,996 $ (73) $ 104,923 Net change in unrealized gain (loss) 347,985 — 347,985 Reclassification adjustments included in earnings: Gain on available for sale securities, net (5,571) — (5,571) Other comprehensive income, before income taxes 342,414 — 342,414 Federal and state income taxes 1 82,167 — 82,167 Other comprehensive income, net of income taxes 260,247 — 260,247 Balance, September 30, 2020 $ 365,243 $ (73) $ 365,170 1 Calculated using a 25 percent blended federal and state statutory tax rate.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Share [Table Text Block]	(In thousands, except share and per share amounts) Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Numerator: Net income attributable to BOK Financial Corp. shareholders $ 154,034 $ 142,231 $ 280,806 $ 390,406 Less: Earnings allocated to participating securities 938 875 1,678 2,553 Numerator for basic earnings per share – income available to common shareholders 153,096 141,356 279,128 387,853 Effect of reallocating undistributed earnings of participating securities — 1 — 1 Numerator for diluted earnings per share – income available to common shareholders $ 153,096 $ 141,357 $ 279,128 $ 387,854 Denominator: Weighted average shares outstanding 70,306,233 71,033,405 70,375,628 71,425,855 Less: Participating securities included in weighted average shares outstanding 428,367 437,098 416,684 472,311 Denominator for basic earnings per common share 69,877,866 70,596,307 69,958,944 70,953,544 Dilutive effect of employee stock compensation plans 1 1,424 13,617 3,109 15,301 Denominator for diluted earnings per common share 69,879,290 70,609,924 69,962,053 70,968,845 Basic earnings per share $ 2.19 $ 2.00 $ 3.99 $ 5.47 Diluted earnings per share $ 2.19 $ 2.00 $ 3.99 $ 5.47 1 Excludes employee stock options with exercise prices greater than current market price. 19,227 — — —

Reportable Segments (Tables)

Reportable Segments (Tables)	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Reportable Segments [Table Text Block]	Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended September 30, 2020 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other BOK Net interest revenue from external sources $ 173,248 $ 15,821 $ 34,098 $ 48,583 $ 271,750 Net interest revenue (expense) from internal sources (23,302) 17,309 (11,113) 17,106 — Net interest revenue 149,946 33,130 22,985 65,689 271,750 Provision for credit losses 22,599 79 (51) (22,627) — Net interest revenue after provision for credit losses 127,347 33,051 23,036 88,316 271,750 Other operating revenue 52,021 67,808 111,152 3,178 234,159 Other operating expense 66,846 59,839 82,868 91,712 301,265 Net direct contribution 112,522 41,020 51,320 (218) 204,644 Gain (loss) on financial instruments, net 38 1,540 — (1,578) — Change in fair value of mortgage servicing rights — 3,441 — (3,441) — Gain (loss) on repossessed assets, net (4,332) 41 — 4,291 — Corporate expense allocations 5,172 10,812 9,397 (25,381) — Net income before taxes 103,056 35,230 41,923 24,435 204,644 Federal and state income taxes 27,959 8,974 10,711 2,908 50,552 Net income 75,097 26,256 31,212 21,527 154,092 Net income attributable to non-controlling interests — — — 58 58 Net income attributable to BOK Financial Corp. shareholders $ 75,097 $ 26,256 $ 31,212 $ 21,469 $ 154,034 Average assets $ 28,000,183 $ 9,898,119 $ 16,206,522 $ (5,171,057) $ 48,933,767 Reportable segments reconciliation to the Consolidated Financial Statements for the nine months ended September 30, 2020 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other BOK Net interest revenue from external sources $ 549,464 $ 60,492 $ 82,823 $ 118,435 $ 811,214 Net interest revenue (expense) from internal sources (103,002) 55,840 (14,054) 61,216 — Net interest revenue 446,462 116,332 68,769 179,651 811,214 Provision for credit losses 53,241 1,870 (188) 174,169 229,092 Net interest revenue after provision for credit losses 393,221 114,462 68,957 5,482 582,122 Other operating revenue 138,139 190,062 315,707 3,263 647,171 Other operating expense 190,531 173,568 241,627 259,550 865,276 Net direct contribution 340,829 130,956 143,037 (250,805) 364,017 Gain (loss) on financial instruments, net 135 95,660 7 (95,802) — Change in fair value of mortgage servicing rights — (85,800) — 85,800 — Gain (loss) on repossessed assets, net (4,132) 81 — 4,051 — Corporate expense allocations 19,514 32,111 25,866 (77,491) — Net income before taxes 317,318 108,786 117,178 (179,265) 364,017 Federal and state income taxes 86,254 27,709 29,999 (60,307) 83,655 Net income 231,064 81,077 87,179 (118,958) 280,362 Net income (loss) attributable to non-controlling interests — — — (444) (444) Net income attributable to BOK Financial Corp. shareholders $ 231,064 $ 81,077 $ 87,179 $ (118,514) $ 280,806 Average assets $ 26,759,150 $ 9,889,690 $ 14,888,623 $ (3,397,417) $ 48,140,046 Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended September 30, 2019 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other BOK Net interest revenue from external sources $ 243,944 $ 27,580 $ 12,343 $ (4,771) $ 279,096 Net interest revenue (expense) from internal sources (64,984) 20,882 10,723 33,379 — Net interest revenue 178,960 48,462 23,066 28,608 279,096 Provision for credit losses 9,505 1,841 (42) 696 12,000 Net interest revenue after provision for credit losses 169,455 46,621 23,108 27,912 267,096 Other operating revenue 48,832 51,221 89,160 (2,763) 186,450 Other operating expense 69,127 59,699 71,619 78,847 279,292 Net direct contribution 149,160 38,143 40,649 (53,698) 174,254 Gain (loss) on financial instruments, net 28 8,339 — (8,367) — Change in fair value of mortgage servicing rights — (12,593) — 12,593 — Gain (loss) on repossessed assets, net 802 214 — (1,016) — Corporate expense allocations 11,772 11,776 9,416 (32,964) — Net income before taxes 138,218 22,327 31,233 (17,524) 174,254 Federal and state income taxes 37,232 5,687 8,027 (18,550) 32,396 Net income 100,986 16,640 23,206 1,026 141,858 Net income (loss) attributable to non-controlling interests — — — (373) (373) Net income attributable to BOK Financial Corp. shareholders $ 100,986 $ 16,640 $ 23,206 $ 1,399 $ 142,231 Average assets $ 23,973,925 $ 9,827,130 $ 10,391,225 $ (611,932) $ 43,580,348 Reportable segments reconciliation to the Consolidated Financial Statements for the nine months ended September 30, 2019 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other 1 BOK Net interest revenue from external sources $ 699,239 $ 75,353 $ 51,054 $ 16,984 $ 842,630 Net interest revenue (expense) from internal sources (185,235) 76,925 27,213 81,097 — Net interest revenue 514,004 152,278 78,267 98,081 842,630 Provision for credit losses 27,574 4,654 (209) (7,019) 25,000 Net interest revenue after provision for credit losses 486,430 147,624 78,476 105,100 817,630 Other operating revenue 128,055 142,780 248,591 (3,641) 515,785 Other operating expense 183,169 171,214 202,579 286,624 843,586 Net direct contribution 431,316 119,190 124,488 (185,165) 489,829 Gain (loss) on financial instruments, net 67 43,416 — (43,483) — Change in fair value of mortgage servicing rights — (62,814) — 62,814 — Gain (loss) on repossessed assets, net 455 409 — (864) — Corporate expense allocations 31,880 35,369 26,943 (94,192) — Net income before taxes 399,958 64,832 97,545 (72,506) 489,829 Federal and state income taxes 107,171 16,513 25,076 (48,834) 99,926 Net income 292,787 48,319 72,469 (23,672) 389,903 Net income (loss) attributable to non-controlling interests — — — (503) (503) Net income attributable to BOK Financial Corp. shareholders $ 292,787 $ 48,319 $ 72,469 $ (23,169) $ 390,406 Average assets $ 22,288,960 $ 9,142,491 $ 9,860,427 $ 88,371 $ 41,380,249

Fees and Commissions Revenue _2

Fees and Commissions Revenue Fees and Commissions Rvenue (Tables)	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Fees and Commissions Revenue [Table Text Block]	Fees and commissions revenue by reportable segment and primary service line is as follows for the three months ended September 30, 2020. Commercial Consumer Wealth Management Funds Management & Other Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 46,890 $ (1) $ 46,889 $ 46,889 $ — Customer hedging revenue 7,999 — 123 520 8,642 8,642 — Retail brokerage revenue — — 3,787 — 3,787 — 3,787 Insurance brokerage revenue — — 3,124 — 3,124 — 3,124 Investment banking revenue 2,314 — 4,770 — 7,084 2,280 4,804 Brokerage and trading revenue 10,313 — 58,694 519 69,526 57,811 11,715 TransFund EFT network revenue 18,840 913 (14) 2 19,741 — 19,741 Merchant services revenue 3,019 19 — — 3,038 — 3,038 Corporate card revenue 583 — 21 82 686 — 686 Transaction card revenue 22,442 932 7 84 23,465 — 23,465 Personal trust revenue — — 20,130 — 20,130 — 20,130 Corporate trust revenue — — 4,613 — 4,613 — 4,613 Institutional trust & retirement plan services revenue — — 11,030 — 11,030 — 11,030 Investment management services and other revenue — — 4,198 (40) 4,158 — 4,158 Fiduciary and asset management revenue — — 39,971 (40) 39,931 — 39,931 Commercial account service charge revenue 11,209 419 572 — 12,200 — 12,200 Overdraft fee revenue 32 5,411 16 4 5,463 — 5,463 Check card revenue — 5,565 — — 5,565 — 5,565 Automated service charge and other deposit fee revenue 27 1,007 24 — 1,058 — 1,058 Deposit service charges and fees 11,268 12,402 612 4 24,286 — 24,286 Mortgage production revenue — 38,431 — — 38,431 38,431 — Mortgage servicing revenue — 13,952 — (424) 13,528 13,528 — Mortgage banking revenue — 52,383 — (424) 51,959 51,959 — Other revenue 6,062 2,257 12,371 (6,992) 13,698 10,427 3,271 Total fees and commissions revenue $ 50,085 $ 67,974 $ 111,655 $ (6,849) $ 222,865 $ 120,197 $ 102,668 1 Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance. 2 In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers. Fees and commissions revenue by reportable segment and primary service line is as follows for the nine months ended September 30, 2020. Commercial Consumer Wealth Management Funds Management & Other Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 125,189 $ — $ 125,189 $ 125,189 $ — Customer hedging revenue 17,417 — 321 368 18,106 18,106 — Retail brokerage revenue — — 11,524 — 11,524 — 11,524 Insurance brokerage revenue — — 10,066 — 10,066 — 10,066 Investment banking revenue 5,325 — 12,117 — 17,442 4,959 12,483 Brokerage and trading revenue 22,742 — 159,217 368 182,327 148,254 34,073 TransFund EFT network revenue 56,699 2,300 (42) 4 58,961 — 58,961 Merchant services revenue 7,554 46 — — 7,600 — 7,600 Corporate card revenue 1,588 — 55 82 1,725 — 1,725 Transaction card revenue 65,841 2,346 13 86 68,286 — 68,286 Personal trust revenue — — 62,460 — 62,460 — 62,460 Corporate trust revenue — — 15,579 — 15,579 — 15,579 Institutional trust & retirement plan services revenue — — 33,510 — 33,510 — 33,510 Investment management services and other revenue — — 14,220 (123) 14,097 — 14,097 Fiduciary and asset management revenue — — 125,769 (123) 125,646 — 125,646 Commercial account service charge revenue 33,317 1,218 1,715 — 36,250 — 36,250 Overdraft fee revenue 101 16,223 54 7 16,385 — 16,385 Check card revenue — 15,916 — — 15,916 — 15,916 Automated service charge and other deposit fee revenue 285 3,572 54 — 3,911 — 3,911 Deposit service charges and fees 33,703 36,929 1,823 7 72,462 — 72,462 Mortgage production revenue — 99,186 — — 99,186 99,186 — Mortgage servicing revenue — 45,158 — (1,282) 43,876 43,876 — Mortgage banking revenue — 144,344 — (1,282) 143,062 143,062 — Other revenue 15,773 6,609 29,471 (14,367) 37,486 27,805 9,681 Total fees and commissions revenue $ 138,059 $ 190,228 $ 316,293 $ (15,311) $ 629,269 $ 319,121 $ 310,148 1 Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance. 2 In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers. Fees and commissions revenue by reportable segment and primary service line is as follows for the three months ended September 30, 2019. Commercial Consumer Wealth Management Funds Management & Other 3 Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 24,091 $ — $ 24,091 $ 24,091 $ — Customer hedging revenue 2,283 — 1,810 591 4,684 4,684 — Retail brokerage revenue — — 4,204 — 4,204 — 4,204 Insurance brokerage revenue — — 3,375 (513) 2,862 — 2,862 Investment banking revenue 4,408 — 3,590 1 7,999 3,762 4,237 Brokerage and trading revenue 6,691 — 37,070 79 43,840 32,537 11,303 TransFund EFT network revenue 18,465 1,020 (23) 2 19,464 — 19,464 Merchant services revenue 2,203 14 — — 2,217 — 2,217 Corporate card revenue 328 — 6 — 334 — 334 Transaction card revenue 20,996 1,034 (17) 2 22,015 — 22,015 Personal trust revenue — — 20,239 (1) 20,238 — 20,238 Corporate trust revenue — — 6,204 1 6,205 — 6,205 Institutional trust & retirement plan services revenue — — 10,740 — 10,740 — 10,740 Investment management services and other revenue — — 6,480 (42) 6,438 — 6,438 Fiduciary and asset management revenue — — 43,663 (42) 43,621 — 43,621 Commercial account service charge revenue 10,609 467 540 (3) 11,613 — 11,613 Overdraft fee revenue 81 9,603 45 3 9,732 — 9,732 Check card revenue — 5,721 — — 5,721 — 5,721 Automated service charge and other deposit fee revenue 197 1,519 53 2 1,771 — 1,771 Deposit service charges and fees 10,887 17,310 638 2 28,837 — 28,837 Mortgage production revenue — 13,815 — (1) 13,814 13,814 — Mortgage servicing revenue — 16,828 — (462) 16,366 16,366 — Mortgage banking revenue — 30,643 — (463) 30,180 30,180 — Other revenue 7,585 2,474 8,068 (501) 17,626 11,812 5,814 Total fees and commissions revenue $ 46,159 $ 51,461 $ 89,422 $ (923) $ 186,119 $ 74,529 $ 111,590 1 Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance. 2 In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers. 3 CoBiz operations are included in Funds Management and Other for the first quarter of 2019. Fees and commissions revenue by reportable segment and primary service line is as follows for the nine months ended September 30, 2019. Commercial Consumer Wealth Management Funds Management & Other 3 Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 58,890 $ — $ 58,890 $ 58,890 $ — Customer hedging revenue 6,243 — 9,444 1,019 16,706 16,706 — Retail brokerage revenue — — 12,192 (65) 12,127 — 12,127 Insurance brokerage revenue — — 7,063 3,729 10,792 — 10,792 Investment banking revenue 8,345 — 9,123 — 17,468 7,189 10,279 Brokerage and trading revenue 14,588 — 96,712 4,683 115,983 82,785 33,198 TransFund EFT network revenue 54,623 2,975 (60) 3 57,541 — 57,541 Merchant services revenue 6,351 43 — 122 6,516 — 6,516 Corporate card revenue 598 — 11 2 611 — 611 Transaction card revenue 61,572 3,018 (49) 127 64,668 — 64,668 Personal trust revenue — — 61,028 — 61,028 — 61,028 Corporate trust revenue — — 18,736 — 18,736 — 18,736 Institutional trust & retirement plan services revenue — — 32,919 — 32,919 — 32,919 Investment management services and other revenue — — 17,730 1,591 19,321 — 19,321 Fiduciary and asset management revenue — — 130,413 1,591 132,004 — 132,004 Commercial account service charge revenue 31,296 1,283 1,605 1,804 35,988 — 35,988 Overdraft fee revenue 248 26,971 108 (231) 27,096 — 27,096 Check card revenue — 16,299 — 165 16,464 — 16,464 Automated service charge and other deposit fee revenue 569 4,762 228 47 5,606 — 5,606 Deposit service charges and fees 32,113 49,315 1,941 1,785 85,154 — 85,154 Mortgage production revenue — 33,554 — (3) 33,551 33,551 — Mortgage servicing revenue — 50,014 — (1,420) 48,594 48,594 — Mortgage banking revenue — 83,568 — (1,423) 82,145 82,145 — Other revenue 17,037 7,211 19,586 (1,009) 42,825 28,655 14,170 Total fees and commissions revenue $ 125,310 $ 143,112 $ 248,603 $ 5,754 $ 522,779 $ 193,585 $ 329,194

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Assets And Liabilities Measured On A Recurring Basis [Table Text Block]	The fair value of financial assets and liabilities measured on a recurring basis was as follows as of September 30, 2020 (in thousands): Total Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Assets: Trading securities: U.S. government agency debentures $ 5,181 $ — $ 5,181 $ — Residential agency mortgage-backed securities 2,150,759 — 2,150,759 — Municipal and other tax-exempt securities 30,533 — 30,533 — Other trading securities 59,007 — 59,007 — Total trading securities 2,245,480 — 2,245,480 — Available for sale securities: U.S. Treasury 509 509 — — Municipal and other tax-exempt securities 51,601 — 51,601 — Residential agency mortgage-backed securities 9,384,998 — 9,384,998 — Residential non-agency mortgage-backed securities 34,873 — 34,873 — Commercial agency mortgage-backed securities 3,334,409 — 3,334,409 — Other debt securities 10,879 — 10,407 472 Total available for sale securities 12,817,269 509 12,816,288 472 Fair value option securities – Residential agency mortgage-backed securities 134,756 — 134,756 — Residential mortgage loans held for sale 295,290 — 286,785 8,505 Mortgage servicing rights 1 97,644 — — 97,644 Derivative contracts, net of cash collateral 2 593,568 11,713 581,855 — Liabilities: Derivative contracts, net of cash collateral 2 446,328 — 446,328 — 1 A reconciliation of the beginning and ending fair value of mortgage servicing rights and disclosures of significant assumptions used to determine fair value are presented in Note 5, Mortgage Banking Activities. 2 See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts in asset positions that were valued based on quoted prices in active markets for identical instruments (Level 1) are primarily exchange-traded interest rate derivative contracts. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments are exchange-traded interest rate, energy and agricultural derivative contracts, fully offset by cash margin. The fair value of financial assets and liabilities measured on a recurring basis was as follows as of December 31, 2019 (in thousands): Total Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Assets: Trading securities: U.S. government agency debentures $ 44,264 $ — $ 44,264 $ — Residential agency mortgage-backed securities 1,504,651 — 1,504,651 — Municipal and other tax-exempt securities 26,196 — 26,196 — Asset-backed securities 14,084 — 14,084 — Other trading securities 34,726 — 34,726 — Total trading securities 1,623,921 — 1,623,921 — Available for sale securities: U.S. Treasury 1,600 1,600 — — Municipal and other tax-exempt securities 1,861 — 1,861 — Residential agency mortgage-backed securities 8,046,096 — 8,046,096 — Residential non-agency mortgage-backed securities 41,609 — 41,609 — Commercial agency mortgage-backed securities 3,178,005 — 3,178,005 — Other debt securities 472 — — 472 Total available for sale securities 11,269,643 1,600 11,267,571 472 Fair value option securities: U.S. Treasury 9,917 9,917 — — Residential agency mortgage-backed securities 1,088,660 — 1,088,660 — Total fair value option securities 1,098,577 9,917 1,088,660 — Residential mortgage loans held for sale 182,271 — 173,958 8,313 Mortgage servicing rights 1 201,886 — — 201,886 Derivative contracts, net of cash collateral 2 323,375 8,944 314,431 — Liabilities: Derivative contracts, net of cash collateral 2 251,128 — 251,128 — 1 A reconciliation of the beginning and ending fair value of mortgage servicing rights and disclosures of significant assumptions used to determine fair value are presented in Note 5, Mortgage Banking Activities. 2 See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts based on quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate and energy derivative contracts, net of cash margin. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate and agricultural contracts, fully offset by cash margin.
Fair Value Assets Measured On Recurring Basis, Significant Unobservable Inputs [Table Text Block]	The following represents the changes for the three and nine months ended September 30, 2020 related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands): Available for sale - Other debt securities Residential mortgage loans held for sale Balance, June 30, 2020 $ 472 $ 9,685 Transfer to Level 3 from Level 2 1 — 304 Purchases — — Proceeds from sales — (1,612) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — 128 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, September 30, 2020 $ 472 $ 8,505 1 Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards. Available for sale - Other debt securities Residential mortgage loans held for sale Balance, December 31, 2019 $ 472 $ 8,313 Transfer to Level 3 from Level 2 1 — 3,896 Purchases — — Proceeds from sales — (3,200) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — (504) Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, September 30, 2020 $ 472 $ 8,505 1 Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards. The following represents the changes for the three and nine months ended September 30, 2019 related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands): Available for sale - Other debt securities Residential mortgage loans held for sale Balance, June 30, 2019 $ 472 $ 16,073 Transfer to Level 3 from Level 2 1 — 261 Purchases — — Proceeds from sales — (3,152) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — 386 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, September 30, 2019 $ 472 $ 13,568 1 Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards. Available for sale - Other debt securities Residential mortgage loans held for sale Balance, Dec. 31, 2018 $ 472 $ 15,207 Transfer to Level 3 from Level 2 1 — 2,150 Purchases — — Proceeds from sales — (4,531) Redemptions and distributions — — Gain (loss) recognized in earnings Mortgage banking revenue — 742 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, September 30, 2019 $ 472 $ 13,568
Fair Value Inputs, Fair Value Measured On a Recurring Basis, Quantitative Information [Table Text Block]	A summary of quantitative information about assets measured at fair value on a recurring basis using Significant Unobservable Inputs (Level 3) as of September 30, 2020 follows (in thousands): Fair Valuation Technique(s) Unobservable Input Range Available for sale securities – Other debt securities $ 472 Discounted cash flows 1 Interest rate spread 5.61%-5.61% (5.61%) 3 94.32%-94.32% (94.32%) 2 Residential mortgage loans held for sale 8,505 Quoted prices of loans sold in securitization transactions, with a liquidity discount applied Liquidity discount applied to the market value of mortgage loans qualifying for sale to U.S. government agencies. 90.24% 1 Discounted cash flows developed using discount rates primarily based on reference to interest rate spreads for comparable securities of similar duration and credit rating as determined by the nationally-recognized rating agencies, adjusted for lack of trading volume. 2 Represents fair value as a percentage of par value. 3 Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 2 percent. A summary of quantitative information about assets measured at fair value on a recurring basis using Significant Unobservable Inputs (Level 3) as of December 31, 2019 follows (in thousands): Fair Valuation Technique(s) Unobservable Input Range Available for sale securities – Other debt securities $ 472 Discounted cash flows 1 Interest rate spread 7.08%-7.08% (7.08%) 3 94.40%-94.40% (94.40%) 2 Residential mortgage loans held for sale 8,313 Quoted prices of loans sold in securitization transactions, with a liquidity discount applied Liquidity discount applied to the market value of mortgage loans qualifying for sale to U.S. government agencies. 95.23% 1 Discounted cash flows developed using discount rates primarily based on reference to interest rate spreads for comparable securities of similar duration and credit rating as determined by the nationally-recognized rating agencies, adjusted for lack of trading volume 2 Represents fair value as a percentage of par value.
Fair Value Assets Measured on Nonrecurring Basis [Table Text Block]	The following represents the carrying value of assets measured at fair value on a non-recurring basis (and related losses) during the period. The carrying value represents only those assets with a balance at September 30, 2020 for which the fair value was adjusted during the nine months ended September 30, 2020: Fair Value Adjustments for the Carrying Value at September 30, 2020 Three Months Ended Nine Months Ended Quoted Prices Significant Significant Gross charge-offs against allowance for loan losses Net losses (gains) and operating expenses of repossessed assets Gross charge-offs against allowance for loan losses Net losses (gains) and operating expenses of repossessed assets Nonaccruing loans $ — $ 396 $ 13,001 $ 6,371 $ — $ 28,624 $ — Real estate and other repossessed assets — 16,828 2,993 — (4,370) — (4,452) The following represents the carrying value of assets measured at fair value on a non-recurring basis (and related losses) during the period. The carrying value represents only those assets with a balance at September 30, 2019 for which the fair value was adjusted during the nine months ended September 30, 2019: Fair Value Adjustments for the Carrying Value at September 30, 2019 Three Months Ended Nine Months Ended Quoted Prices Significant Significant Gross charge-offs against allowance for loan losses Net losses (gains) and operating expenses of repossessed assets Gross charge-offs against allowance for loan losses Net losses (gains) and operating expenses of repossessed assets Nonaccruing loans $ — $ 79 $ 9,810 $ 2,644 $ — $ 13,868 $ — Real estate and other repossessed assets — 5,044 936 — (979) — (532)
Fair Value Inputs, Fair Value Measured On a Nonrecurring Basis, Quantitative Information [Table Text Block]	A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of September 30, 2020 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range Nonaccruing loans $ 13,001 Discounted cash flows Management knowledge of industry and non-real estate collateral including but not limited to recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs 0% - 73% (18%) 1 Real estate and other repossessed assets 2,993 Discounted cash flows Management knowledge of industry and non-real estate collateral including but not limited to recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs N/A 1 Represents fair value as a percentage of the unpaid principal balance. A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of September 30, 2019 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range Nonaccruing loans $ 9,810 Discounted cash flows Management knowledge of industry and non-real estate collateral including but not limited to recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs 8% - 76% (28%) 1 Real estate and other repossessed assets 936 Appraised value, as adjusted Marketability adjustments off appraised value 2 75% - 89% (85%) 1 Represents fair value as a percentage of the unpaid principal balance. 2 Marketability adjustments include consideration of estimated costs to sell which is approximately 10% of the fair value.
Fair Value of Financial Instruments [Table Text Block]	The following table presents the carrying values and estimated fair values of all financial instruments, including those financial assets and liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis as of September 30, 2020 (dollars in thousands): Carrying Estimated Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs Cash and due from banks $ 658,612 $ 658,612 $ 658,612 $ — $ — Interest-bearing cash and cash equivalents 347,759 347,759 347,759 — — Trading securities: U.S. government agency debentures 5,181 5,181 — 5,181 — Residential agency mortgage-backed securities 2,150,759 2,150,759 — 2,150,759 — Municipal and other tax-exempt securities 30,533 30,533 — 30,533 — Other trading securities 59,007 59,007 — 59,007 — Total trading securities 2,245,480 2,245,480 — 2,245,480 — Investment securities: Municipal and other tax-exempt securities 76,109 80,368 — 80,368 — Residential agency mortgage-backed securities 9,317 10,219 — 10,219 — Other debt securities 171,314 194,342 — 7,376 186,966 Total investment securities 256,740 284,929 — 97,963 186,966 Allowance for credit losses (739) — — — — Investment securities, net of allowance 256,001 284,929 — 97,963 186,966 Available for sale securities: U.S. Treasury 509 509 509 — — Municipal and other tax-exempt securities 51,601 51,601 — 51,601 — Residential agency mortgage-backed securities 9,384,998 9,384,998 — 9,384,998 — Residential non-agency mortgage-backed securities 34,873 34,873 — 34,873 — Commercial agency mortgage-backed securities 3,334,409 3,334,409 — 3,334,409 — Other debt securities 10,879 10,879 — 10,407 472 Total available for sale securities 12,817,269 12,817,269 509 12,816,288 472 Fair value option securities – Residential agency mortgage-backed securities 134,756 134,756 — 134,756 — Residential mortgage loans held for sale 295,290 295,290 — 286,785 8,505 Loans: Commercial 13,565,706 13,500,846 — — 13,500,846 Commercial real estate 4,693,700 4,673,857 — — 4,673,857 Paycheck protection program 2,097,325 2,070,466 — — 2,070,466 Loans to individuals 3,446,569 3,452,042 — — 3,452,042 Total loans 23,803,300 23,697,211 — — 23,697,211 Allowance for loan losses (419,777) — — — — Loans, net of allowance 23,383,523 23,697,211 — — 23,697,211 Mortgage servicing rights 97,644 97,644 — — 97,644 Derivative instruments with positive fair value, net of cash collateral 593,568 593,568 11,713 581,855 — Deposits with no stated maturity 32,965,027 32,965,027 — — 32,965,027 Time deposits 2,007,973 2,019,474 — — 2,019,474 Other borrowed funds 3,745,081 3,741,686 — — 3,741,686 Subordinated debentures 275,986 269,083 — 269,083 — Derivative instruments with negative fair value, net of cash collateral 446,328 446,328 — 446,328 — The following table presents the carrying values and estimated fair values of all financial instruments, including those financial assets and liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis as of December 31, 2019 (dollars in thousands): Carrying Estimated Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs Significant Unobservable Inputs Cash and due from banks $ 735,836 $ 735,836 $ 735,836 $ — $ — Interest-bearing cash and cash equivalents 522,985 522,985 522,985 — — Trading securities: U.S. government agency debentures 44,264 44,264 — 44,264 — Residential agency mortgage-backed securities 1,504,651 1,504,651 — 1,504,651 — Municipal and other tax-exempt securities 26,196 26,196 — 26,196 — Asset-backed securities 14,084 14,084 — 14,084 — Other trading securities 34,726 34,726 — 34,726 — Total trading securities 1,623,921 1,623,921 — 1,623,921 — Investment securities: Municipal and other tax-exempt securities 93,653 96,897 — 96,897 — Residential agency mortgage-backed securities 10,676 11,164 — 11,164 — Other debt securities 189,089 206,341 — 8,206 198,135 Total investment securities 293,418 314,402 — 116,267 198,135 Available for sale securities: U.S. Treasury 1,600 1,600 1,600 — — Municipal and other tax-exempt securities 1,861 1,861 — 1,861 — Residential agency mortgage-backed securities 8,046,096 8,046,096 — 8,046,096 — Residential non-agency mortgage-backed securities 41,609 41,609 — 41,609 — Commercial agency mortgage-backed securities 3,178,005 3,178,005 — 3,178,005 — Other debt securities 472 472 — — 472 Total available for sale securities 11,269,643 11,269,643 1,600 11,267,571 472 Fair value option securities: U.S. Treasury 9,917 9,917 9,917 — — Residential agency mortgage-backed securities 1,088,660 1,088,660 — 1,088,660 — Total fair value option securities 1,098,577 1,098,577 9,917 1,088,660 — Residential mortgage loans held for sale 182,271 182,271 — 173,958 8,313 Loans: Commercial 14,031,650 13,966,221 — — 13,966,221 Commercial real estate 4,433,783 4,422,717 — — 4,422,717 Residential mortgage 2,084,172 2,098,093 — — 2,098,093 Personal 1,201,382 1,202,298 — — 1,202,298 Total loans 21,750,987 21,689,329 — — 21,689,329 Allowance for loan losses (210,759) — — — — Loans, net of allowance 21,540,228 21,689,329 — — 21,689,329 Mortgage servicing rights 201,886 201,886 — — 201,886 Derivative instruments with positive fair value, net of cash collateral 323,375 323,375 8,944 314,431 — Deposits with no stated maturity 25,403,319 25,403,319 — — 25,403,319 Time deposits 2,217,849 2,212,467 — — 2,212,467 Other borrowed funds 8,345,405 8,315,860 — — 8,315,860 Subordinated debentures 275,923 284,627 — 284,627 — Derivative instruments with negative fair value, net of cash collateral 251,128 251,128 — 251,128 —

Significant Accounting Polici_3

Significant Accounting Policies Loans and Allowance for Credit Losses (Details)	9 Months Ended
	Sep. 30, 2020
Loans and Allowance for Credit Losses [Abstract]
Loans, Number of Days Past Due for a Non-Risk Graded Loan to be Placed on Nonaccruing Status	90 days
Loans, Number of Days After Notification of Chapter 7 Bankruptcy Non-Risk Graded Loan is Placed on Nonaccruing Status	60 days
Loans and Allowances for Credit Losses, Minimum No of Days After Which Past Due Non-Risk Graded Loans Are Charged Off	60 days
Loans and Allowances for Credit Losses, Maximum No of Days After Which Past Due Non-Risk Graded Loans Are Charged Off	180 days
Loans, Number of Days After Notification of Chapter 7 Bankruptcy Non-Risk Graded Loan is Charged Off	60 days

Trading Securities (Details)

Trading Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule of Trading Securities [Line Items]
Trading securities	$ 2,245,480	$ 1,623,921
Trading Securities, Net Unrealized Gain (Loss)	(677)	2,359
U.S. government agency debentures [Member]
Schedule of Trading Securities [Line Items]
Trading securities	5,181	44,264
Trading Securities, Net Unrealized Gain (Loss)	(1)	6
Residential agency mortgage-backed securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	2,150,759	1,504,651
Trading Securities, Net Unrealized Gain (Loss)	(693)	2,293
Municipal and other tax-exempt securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	30,533	26,196
Trading Securities, Net Unrealized Gain (Loss)	(44)	60
Asset-backed securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	0	14,084
Trading Securities, Net Unrealized Gain (Loss)	0	(21)
Other debt securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	59,007	34,726
Trading Securities, Net Unrealized Gain (Loss)	$ 61	$ 21

Investment (Held-to-Maturity) S

Investment (Held-to-Maturity) Securities (Details) $ in Thousands		9 Months Ended
		Sep. 30, 2020USD ($)		Dec. 31, 2019USD ($)
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Gross Amortized Cost		$ 256,740		$ 293,418
Investment securities, Allowance for Credit Loss		(739)	[1]	0
Investments securities, Amortized Cost, Net of Allowance		256,001		293,418
Investment Securities, Fair Value		284,929		314,402
Investment Securities, Gross Unrealized Gain		28,388		21,285
Investment Securities, Gross Unrealized Loss		$ (199)		$ (301)
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		8		17
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 3,026		$ 1,276
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		2,043		9,747
Investment Securities, Continuous Unrealized Loss Position, Fair Value		5,069		11,023
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		68		2
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		131		299
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss		199		301
Fixed Maturity Securities [Member]
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Net Carrying Value		30,455
Investment Securities, Debt Maturities, One to Five Years, Net Carrying Value		87,606
Investment Securities, Debt Maturities, Six to Ten Years, Net Carrying Value		120,073
Investment Securities, Debt Maturities, Over Ten Years, Net Carrying Value		9,289
Investment Securities, Debt Maturities, Single Maturity Date, Net Carrying Value		247,423
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Fair Value		30,761
Investment Securities, Debt Maturities, One to Five Years, Fair Value		95,912
Investment Securities, Debt Maturities, Six to Ten Years, Fair Value		138,580
Investment Securities, Debt Maturities, Over Ten Years, Fair Value		9,457
Investment Securities, Debt Maturities, Single Maturity Date, Fair Value		$ 274,710
Investment Securities, Debt Maturities, Weighted Average Maturity	[2]	4.94
Municipal and other tax-exempt securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Gross Amortized Cost		$ 76,109		93,653
Investment Securities, Fair Value		80,368		96,897
Investment Securities, Gross Unrealized Gain		4,259		3,250
Investment Securities, Gross Unrealized Loss		0		$ (6)
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions				4
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value				$ 1,001
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value				1,706
Investment Securities, Continuous Unrealized Loss Position, Fair Value				2,707
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss				1
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss				5
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss				6
Other debt securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Gross Amortized Cost		171,314		189,089
Investment Securities, Fair Value		194,342		206,341
Investment Securities, Gross Unrealized Gain		23,227		17,547
Investment Securities, Gross Unrealized Loss		$ (199)		$ (295)
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		8		13
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 3,026		$ 275
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		2,043		8,041
Investment Securities, Continuous Unrealized Loss Position, Fair Value		5,069		8,316
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		68		1
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		131		294
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss		199		295
Residential agency mortgage-backed securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Gross Amortized Cost		9,317		10,676
Investment Securities, Fair Value		10,219		11,164
Investment Securities, Gross Unrealized Gain		902		488
Investment Securities, Gross Unrealized Loss		0		$ 0
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, without Single Maturity Date, Net Carrying Value	[3]	9,317
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, without Single Maturity Date, Fair Value		$ 10,219
Investment Securities, Debt Maturities, Average Expected Life of Mortgage-backed Securities		4.58
[1]	Effective with the adoption of FASB ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) on January 1, 2020.
[2]	Expected maturities may differ from contractual maturities, because borrowers may have the right to call or prepay obligations with or without penalty.
[3]	The average expected lives of residential mortgage-backed securities were 4.58 years based upon current prepayment assumptions.

Available for Sale Securities (

Available for Sale Securities (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		$ 12,336,706		$ 12,336,706		$ 11,131,494
Available-for-sale Securities, Fair Value		12,817,269		12,817,269		11,269,643
Available-for-sale Securities, Gross Unrealized Gain		485,489		485,489		158,435
Available-for-sale Securities, Gross Unrealized Loss		(4,926)		(4,926)		(20,286)
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Available-for-sale Securities, Proceeds		1,034	$ 261,028	206,979	$ 628,385
Available-for-sale Securities, Gross realized gains		54	989	5,637	7,316
Available-for-sale Securities, Gross realized losses		(66)	(984)	(66)	(6,206)
Available-for-sale Securities, Related federal and state income tax expense (benefit)		(3)	$ 1	1,419	$ 282
Pledged Assets Separately Reported, Securities Pledged as Collateral, at Fair Value		12,500,000		12,500,000		10,100,000
Fixed Maturity Securities [Member]
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost Basis		70,791		70,791
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost Basis		1,326,715		1,326,715
Available-for-sale Securities, Debt Maturities, Six To Ten Years, Amortized Cost Basis		1,282,122		1,282,122
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost Basis		603,396		603,396
Available-for-sale Securities, Debt Maturities, Allocated and Single Maturity Date, Amortized Cost		3,283,024		3,283,024
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Fair Value		71,123		71,123
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value		1,383,695		1,383,695
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value		1,313,942		1,313,942
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value		628,638		628,638
Available-for-sale Securities, Debt Maturities, Allocated and Single Maturity Date, Fair Value		$ 3,397,398		$ 3,397,398
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	[1]	8.02		8.02
U.S. Treasury [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		$ 500		$ 500		1,598
Available-for-sale Securities, Fair Value		509		509		1,600
Available-for-sale Securities, Gross Unrealized Gain		9		9		2
Available-for-sale Securities, Gross Unrealized Loss		0		0		0
Municipal and other tax-exempt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		50,050		50,050		1,789
Available-for-sale Securities, Fair Value		51,601		51,601		1,861
Available-for-sale Securities, Gross Unrealized Gain		1,648		1,648		72
Available-for-sale Securities, Gross Unrealized Loss		(97)		(97)		0
Commercial agency mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		3,221,538		3,221,538		3,145,342
Available-for-sale Securities, Fair Value		3,334,409		3,334,409		3,178,005
Available-for-sale Securities, Gross Unrealized Gain		114,244		114,244		37,808
Available-for-sale Securities, Gross Unrealized Loss		(1,373)		(1,373)		(5,145)
Other debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		10,936		10,936		500
Available-for-sale Securities, Fair Value		10,879		10,879		472
Available-for-sale Securities, Gross Unrealized Gain		0		0		0
Available-for-sale Securities, Gross Unrealized Loss		(57)		(57)		(28)
Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost	[2]	9,053,682		9,053,682
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value		9,419,871		$ 9,419,871
Available-for-sale Securities, Debt Maturities, Average Expected Life of Mortgage-backed Securities				3.02
Residential agency mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		9,033,728		$ 9,033,728		7,956,297
Available-for-sale Securities, Fair Value		9,384,998		9,384,998		8,046,096
Available-for-sale Securities, Gross Unrealized Gain		354,669		354,669		104,912
Available-for-sale Securities, Gross Unrealized Loss		(3,399)		(3,399)		(15,113)
Residential non-agency mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		19,954		19,954		25,968
Available-for-sale Securities, Fair Value		34,873		34,873		41,609
Available-for-sale Securities, Gross Unrealized Gain		14,919		14,919		15,641
Available-for-sale Securities, Gross Unrealized Loss		$ 0		$ 0		$ 0
[1]	Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without penalty.
[2]	The average expected lives of residential mortgage-backed securities were 3.02 years based upon current prepayment assumptions.

Securities Debt Securities, Ava

Securities Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value (Details) $ in Thousands	Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	77	203
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 925,471	$ 2,182,644
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	419,576	897,351
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,345,047	3,079,995
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	4,227	10,928
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	699	9,358
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 4,926	$ 20,286
Municipal and other tax-exempt securities [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	11
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 19,768
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	19,768
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	97
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 97
Residential agency mortgage-backed securities [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	32	133
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 630,460	$ 1,352,597
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	165,726	686,002
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	796,186	2,038,599
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	3,178	6,690
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	221	8,423
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 3,399	$ 15,113
Commercial agency mortgage-backed securities [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	29	69
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 264,836	$ 830,047
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	253,378	210,877
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	518,214	1,040,924
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	923	4,238
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	450	907
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 1,373	$ 5,145
Other debt securities [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	5	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 10,407	$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	472	472
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	10,879	472
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	29	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	28	28
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 57	$ 28

Securities Fair Value Option Se

Securities Fair Value Option Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value Option Securities [Line Items]
Fair value option securities, Fair Value	$ 134,756	$ 1,098,577
Fair value option securities, Net Unrealized Gain (Loss)	4,926	14,061
U.S. Treasury [Member]
Fair Value Option Securities [Line Items]
Fair value option securities, Fair Value	0	9,917
Fair value option securities, Net Unrealized Gain (Loss)	0	(48)
Residential agency mortgage-backed securities [Member]
Fair Value Option Securities [Line Items]
Fair value option securities, Fair Value	134,756	1,088,660
Fair value option securities, Net Unrealized Gain (Loss)	$ 4,926	$ 14,109

Derivatives, Fair Value of Deri

Derivatives, Fair Value of Derivatives Contracts (Details) - USD ($) $ in Thousands	Sep. 30, 2020		Dec. 31, 2019
Derivative Assets, Fair Value, Net [Abstract]
Derviative contracts, net of cash collateral, Assets, Fair value	$ 593,568		$ 323,375
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Fair Value, Net of Cash Collateral	446,328		251,128
Not Designated as Hedging Instrument [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	73,085,428	[1]	75,917,378	[2]
Derivative Liabilities, Notional	72,386,971	[1]	70,400,171	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	1,099,436		549,555
Derivative Assets, Netting Adjustments	(409,255)		(225,482)
Derivative Assets, Net Fair Value Before Cash Collateral	690,181		324,073
Derivative Assets, Cash Collateral	(96,613)		(698)
Derviative contracts, net of cash collateral, Assets, Fair value	593,568		323,375
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	1,055,185		528,921
Derivative Liabilities, Netting Adjustments	(409,255)		(225,482)
Derivative Liabilities, Net Fair Value Before Cash Collateral	645,930		303,439
Derivative Liabilities, Cash Collateral	(199,602)		(52,311)
Derivative Liabilities, Fair Value, Net of Cash Collateral	446,328		251,128
Not Designated as Hedging Instrument [Member] | Total customer risk management programs
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	7,060,324	[1]	4,927,266	[2]
Derivative Liabilities, Notional	6,855,256	[1]	4,875,382	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	844,903		411,768
Derivative Assets, Netting Adjustments	(229,540)		(109,452)
Derivative Assets, Net Fair Value Before Cash Collateral	615,363		302,316
Derivative Assets, Cash Collateral	(92,789)		(698)
Derviative contracts, net of cash collateral, Assets, Fair value	522,574		301,618
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	818,517		400,265
Derivative Liabilities, Netting Adjustments	(229,540)		(109,452)
Derivative Liabilities, Net Fair Value Before Cash Collateral	588,977		290,813
Derivative Liabilities, Cash Collateral	(160,344)		(51,448)
Derivative Liabilities, Fair Value, Net of Cash Collateral	428,633		239,365
Not Designated as Hedging Instrument [Member] | Interest rate contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	3,179,414	[1]	2,464,478	[2]
Derivative Liabilities, Notional	3,179,414	[1]	2,464,478	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	132,320		49,100
Derivative Assets, Netting Adjustments	(107)		(1,839)
Derivative Assets, Net Fair Value Before Cash Collateral	132,213		47,261
Derivative Assets, Cash Collateral	0		0
Derviative contracts, net of cash collateral, Assets, Fair value	132,213		47,261
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	132,689		49,194
Derivative Liabilities, Netting Adjustments	(107)		(1,839)
Derivative Liabilities, Net Fair Value Before Cash Collateral	132,582		47,355
Derivative Liabilities, Cash Collateral	(121,212)		(43,932)
Derivative Liabilities, Fair Value, Net of Cash Collateral	11,370		3,423
Not Designated as Hedging Instrument [Member] | Energy contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	3,482,226	[1]	2,151,096	[2]
Derivative Liabilities, Notional	3,277,670	[1]	2,105,391	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	400,646		144,906
Derivative Assets, Netting Adjustments	(229,433)		(107,591)
Derivative Assets, Net Fair Value Before Cash Collateral	171,213		37,315
Derivative Assets, Cash Collateral	(92,170)		(38)
Derviative contracts, net of cash collateral, Assets, Fair value	79,043		37,277
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	374,542		139,311
Derivative Liabilities, Netting Adjustments	(229,433)		(107,591)
Derivative Liabilities, Net Fair Value Before Cash Collateral	145,109		31,720
Derivative Liabilities, Cash Collateral	(37,276)		(6,031)
Derivative Liabilities, Fair Value, Net of Cash Collateral	107,833		25,689
Not Designated as Hedging Instrument [Member] | Agricultural contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	13,611	[1]	16,118	[2]
Derivative Liabilities, Notional	13,627	[1]	16,139	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	1,870		1,522
Derivative Assets, Netting Adjustments	0		(22)
Derivative Assets, Net Fair Value Before Cash Collateral	1,870		1,500
Derivative Assets, Cash Collateral	0		0
Derviative contracts, net of cash collateral, Assets, Fair value	1,870		1,500
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	1,856		1,507
Derivative Liabilities, Netting Adjustments	0		(22)
Derivative Liabilities, Net Fair Value Before Cash Collateral	1,856		1,485
Derivative Liabilities, Cash Collateral	(1,856)		(1,485)
Derivative Liabilities, Fair Value, Net of Cash Collateral	0		0
Not Designated as Hedging Instrument [Member] | Foreign exchange contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	311,626	[1]	214,119	[2]
Derivative Liabilities, Notional	311,098	[1]	207,919	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	309,130		213,007
Derivative Assets, Netting Adjustments	0		0
Derivative Assets, Net Fair Value Before Cash Collateral	309,130		213,007
Derivative Assets, Cash Collateral	(400)		0
Derviative contracts, net of cash collateral, Assets, Fair value	308,730		213,007
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	308,493		207,020
Derivative Liabilities, Netting Adjustments	0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral	308,493		207,020
Derivative Liabilities, Cash Collateral	0		0
Derivative Liabilities, Fair Value, Net of Cash Collateral	308,493		207,020
Not Designated as Hedging Instrument [Member] | Equity option contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	73,447	[1]	81,455	[2]
Derivative Liabilities, Notional	73,447	[1]	81,455	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	937		3,233
Derivative Assets, Netting Adjustments	0		0
Derivative Assets, Net Fair Value Before Cash Collateral	937		3,233
Derivative Assets, Cash Collateral	(219)		(660)
Derviative contracts, net of cash collateral, Assets, Fair value	718		2,573
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	937		3,233
Derivative Liabilities, Netting Adjustments	0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral	937		3,233
Derivative Liabilities, Cash Collateral	0		0
Derivative Liabilities, Fair Value, Net of Cash Collateral	937		3,233
Not Designated as Hedging Instrument [Member] | Trading [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	65,290,962	[1]	69,721,932	[2]
Derivative Liabilities, Notional	64,972,263	[1]	65,144,388	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	235,176		131,561
Derivative Assets, Netting Adjustments	(173,680)		(115,949)
Derivative Assets, Net Fair Value Before Cash Collateral	61,496		15,612
Derivative Assets, Cash Collateral	(3,824)		0
Derviative contracts, net of cash collateral, Assets, Fair value	57,672		15,612
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	229,013		125,535
Derivative Liabilities, Netting Adjustments	(173,680)		(115,949)
Derivative Liabilities, Net Fair Value Before Cash Collateral	55,333		9,586
Derivative Liabilities, Cash Collateral	(38,999)		0
Derivative Liabilities, Fair Value, Net of Cash Collateral	16,334		9,586
Not Designated as Hedging Instrument [Member] | Internal risk management programs [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	734,142	[1]	1,268,180	[2]
Derivative Liabilities, Notional	559,452	[1]	380,401	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	19,357		6,226
Derivative Assets, Netting Adjustments	(6,035)		(81)
Derivative Assets, Net Fair Value Before Cash Collateral	13,322		6,145
Derivative Assets, Cash Collateral	0		0
Derviative contracts, net of cash collateral, Assets, Fair value	13,322		6,145
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	7,655		3,121
Derivative Liabilities, Netting Adjustments	(6,035)		(81)
Derivative Liabilities, Net Fair Value Before Cash Collateral	1,620		3,040
Derivative Liabilities, Cash Collateral	(259)		(863)
Derivative Liabilities, Fair Value, Net of Cash Collateral	$ 1,361		$ 2,177
[1]	Notional amounts for commodity contracts are converted into dollar-equivalent amounts based on dollar prices at the inception of the contract.
[2]	Notional amounts for commodity contracts are converted into dollar-equivalent amounts based on dollar prices at the inception of the contract.

Derivatives, Derivatives Instru

Derivatives, Derivatives Instruments Gain (Loss) in Income Statement (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2020		Sep. 30, 2019		Sep. 30, 2020		Sep. 30, 2019
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	$ 8,174		$ 8,314		$ 9,560		$ 21,070
Gain (Loss) on Derivatives, Net	2,354		3,778		42,659		19,595
Total customer risk management programs
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	8,642		4,684		18,106		16,705
Gain (Loss) on Derivatives, Net	0		0		0		0
To-be-announced residential mortgage-backed securities [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	0		1,667		0		9,579
Gain (Loss) on Derivatives, Net	0		0		0		0
Interest rate contracts [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	1,014		1,252		2,702		2,787
Gain (Loss) on Derivatives, Net	0		0		0		0
Energy contracts [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	7,460		1,611		14,850		3,923
Gain (Loss) on Derivatives, Net	0		0		0		0
Agricultural contracts [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	6		16		27		24
Gain (Loss) on Derivatives, Net	0		0		0		0
Foreign exchange contracts [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	162		138		527		392
Gain (Loss) on Derivatives, Net	0		0		0		0
Equity option contracts [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	0		0		0		0
Gain (Loss) on Derivatives, Net	0		0		0		0
Trading [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	(468)	[1]	3,630	[1]	(8,546)	[2]	4,365	[2]
Gain (Loss) on Derivatives, Net	0	[1]	0	[1]	0	[2]	0	[2]
Internal risk management programs [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	0		0		0		0
Gain (Loss) on Derivatives, Net	$ 2,354		$ 3,778		$ 42,659		$ 19,595
[1]	Represents changes in fair value of to-be-announced securities and other derivative instruments held to mitigate market risk of trading securities portfolio, which is offset by changes in fair value of trading securities also include in Brokerage and Trading Revenue in the Consolidated Statements of Earnings.
[2]	Represents changes in fair value of to-be-announced securities and other derivative instruments held to mitigate market risk of trading securities portfolio, which is offset by changes in fair value of trading securities also include in Brokerage and Trading Revenue in the Consolidated Statements of Earnings.

Loans and Allowance for Credit

Loans and Allowance for Credit Losses, Loans by Portfolio Type (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest	$ 6,667,276	$ 6,134,362
Loans, variable rate of interest	16,914,871	15,435,674
Loans, non-accrual	221,153	180,951
Total	23,803,300	21,750,987
Past Due 90 Days or More and Accruing	124,872	7,680
Credit Commitments [Abstract]
Outstanding commitments to extend credit	10,400,000
Outstanding standby letters of credit	678,000
Commercial [Member]
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest	1,424,416	3,231,485
Loans, variable rate of interest	11,971,337	10,684,749
Loans, non-accrual	169,953	115,416
Total	13,565,706	14,031,650
Past Due 90 Days or More and Accruing	672
Commercial real estate [Member]
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest	1,012,882	1,056,321
Loans, variable rate of interest	3,667,866	3,349,836
Loans, non-accrual	12,952	27,626
Total	4,693,700	4,433,783
Past Due 90 Days or More and Accruing	4,771
Paycheck Protection Program
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest	2,097,325
Loans, variable rate of interest	0
Loans, non-accrual	0
Total	2,097,325
Past Due 90 Days or More and Accruing	0
Loans to individuals [Member]
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest	2,132,653
Loans, variable rate of interest	1,275,668
Loans, non-accrual	38,248
Total	3,446,569	2,084,172
Past Due 90 Days or More and Accruing	119,429
Loans to individuals [Member] | Residential mortgage [Member]
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest		1,652,653
Loans, variable rate of interest		393,897
Loans, non-accrual		37,622
Total	1,849,144	2,084,172
Past Due 90 Days or More and Accruing	2,241
Loans to individuals [Member] | Personal [Member]
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest		193,903
Loans, variable rate of interest		1,007,192
Loans, non-accrual		287
Total	1,213,178	$ 1,201,382
Past Due 90 Days or More and Accruing	$ 0

Loans and Allowances for Cred_3

Loans and Allowances for Credit Losses, Activity in Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL	$ 435,597		$ 236,568
Beginning balance - Incurred Loss Model		$ 202,534	210,759	$ 207,457
Provision for loan losses - CECL	6,609		236,938
Provision for loan losses - incurred		12,539		25,426
Loans charged off	(26,661)	(11,707)	(61,148)	(36,709)
Recoveries of loans previously charged off	4,232	1,066	7,419	8,258
Ending balance - CECL	419,777		419,777
Ending balance - Incurred Loss Model	419,777	204,432	419,777	204,432
Provision Details [Abstract]
Change in provision due to changes in reasonable and supportable forecasts, primarily due to COVID-19 pandemic	(12,800)
Other changes to provision	14,500
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL	32,919		25,137
Provision for off-balance sheet credit risk	(4,950)		2,832
Ending balance - CECL	27,969		27,969
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred Loss Model		1,903		1,790
Provision for off-balance sheet credit losses		(539)		(426)
Ending balance - Incurred Loss Model		1,364		1,364
Total provision for credit losses	0	12,000	229,092	25,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					$ 23,582,147	$ 21,570,036
Individually measured for impairment, recorded investment					221,153	180,951
Total					23,803,300	21,750,987
Related allowance [Abstract]
Collectively measured for impairment, related allowance					400,082	176,150
Individually measured for impairment, related allowance					19,695	17,414
Total	419,777	204,432	419,777	207,457	419,777	210,759
Commercial [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL	310,422		151,868
Beginning balance - Incurred Loss Model		106,397	118,187	102,226
Provision for loan losses - CECL	2,108		190,984
Provision for loan losses - incurred		9,861		34,740
Loans charged off	(25,319)	(9,875)	(56,421)	(31,728)
Recoveries of loans previously charged off	3,066	260	3,846	1,405
Ending balance - CECL	290,277		290,277
Ending balance - Incurred Loss Model	290,277	106,643	290,277	106,643
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL	14,582		11,578
Provision for off-balance sheet credit risk	(2,618)		386
Ending balance - CECL	11,964		11,964
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred Loss Model		1,742		1,655
Provision for off-balance sheet credit losses		(536)		(449)
Ending balance - Incurred Loss Model		1,206		1,206
Total provision for credit losses		9,325		34,291
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					13,395,753	13,916,234
Individually measured for impairment, recorded investment					169,953	115,416
Total					13,565,706	14,031,650
Related allowance [Abstract]
Collectively measured for impairment, related allowance					271,122	100,773
Individually measured for impairment, related allowance					19,155	17,414
Total	290,277	106,643	118,187	102,226	290,277	118,187
Commercial real estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL	68,756		47,185
Beginning balance - Incurred Loss Model		54,188	51,805	60,026
Provision for loan losses - CECL	3,118		25,454
Provision for loan losses - incurred		102		(10,075)
Loans charged off	(413)	0	(1,300)	(118)
Recoveries of loans previously charged off	114	60	236	4,517
Ending balance - CECL	71,575		71,575
Ending balance - Incurred Loss Model	71,575	54,350	71,575	54,350
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL	16,419		11,767
Provision for off-balance sheet credit risk	(2,426)		2,226
Ending balance - CECL	13,993		13,993
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred Loss Model		116		52
Provision for off-balance sheet credit losses		(3)		61
Ending balance - Incurred Loss Model		113		113
Total provision for credit losses		99		(10,014)
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					4,680,748	4,406,157
Individually measured for impairment, recorded investment					12,952	27,626
Total					4,693,700	4,433,783
Related allowance [Abstract]
Collectively measured for impairment, related allowance					71,035	51,805
Individually measured for impairment, related allowance					540	0
Total	71,575	54,350	51,805	60,026	71,575	51,805
Paycheck Protection Program
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL	0		0
Provision for loan losses - CECL	0		0
Loans charged off	0		0
Recoveries of loans previously charged off	0		0
Ending balance - CECL	0		0
Ending balance - Incurred Loss Model	0		0
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL	0		0
Provision for off-balance sheet credit risk	0		0
Ending balance - CECL	0		0
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					2,097,325
Individually measured for impairment, recorded investment					0
Total					2,097,325
Related allowance [Abstract]
Collectively measured for impairment, related allowance					0
Individually measured for impairment, related allowance					0
Total	0		0		0
Loans to individuals [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL	56,419		37,515
Provision for loan losses - CECL	1,383		20,500
Loans charged off	(929)		(3,427)
Recoveries of loans previously charged off	1,052		3,337
Ending balance - CECL	57,925		57,925
Ending balance - Incurred Loss Model	57,925		57,925
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL	1,918		1,792
Provision for off-balance sheet credit risk	94		220
Ending balance - CECL	2,012		2,012
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					3,408,321
Individually measured for impairment, recorded investment					38,248
Total					3,446,569	2,084,172
Related allowance [Abstract]
Collectively measured for impairment, related allowance					57,925
Individually measured for impairment, related allowance					0
Total	57,925		57,925		57,925
Loans to individuals [Member] | Residential mortgage [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - Incurred Loss Model		15,724	14,400	17,964
Provision for loan losses - incurred		(253)		(2,660)
Loans charged off		(56)		(192)
Recoveries of loans previously charged off		119		422
Ending balance - Incurred Loss Model		15,534		15,534
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred Loss Model		44		52
Provision for off-balance sheet credit losses		0		(8)
Ending balance - Incurred Loss Model		44		44
Total provision for credit losses		(253)		(2,668)
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment						2,046,550
Individually measured for impairment, recorded investment						37,622
Total					1,849,144	2,084,172
Related allowance [Abstract]
Collectively measured for impairment, related allowance						14,400
Individually measured for impairment, related allowance						0
Total		15,534	14,400	15,534		14,400
Loans to individuals [Member] | Personal [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - Incurred Loss Model		9,388	9,172	9,473
Provision for loan losses - incurred		1,911		3,434
Loans charged off		(1,776)		(4,671)
Recoveries of loans previously charged off		627		1,914
Ending balance - Incurred Loss Model		10,150		10,150
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred Loss Model		1		31
Provision for off-balance sheet credit losses		0		(30)
Ending balance - Incurred Loss Model		1		1
Total provision for credit losses		1,911		3,404
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment						1,201,095
Individually measured for impairment, recorded investment						287
Total					$ 1,213,178	1,201,382
Related allowance [Abstract]
Collectively measured for impairment, related allowance						9,172
Individually measured for impairment, related allowance						0
Total		10,150	9,172	10,150		9,172
Specific Allowance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - Incurred Loss Model			193,564
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment						21,570,036
Individually measured for impairment, recorded investment						180,951
Total						21,750,987
Related allowance [Abstract]
Collectively measured for impairment, related allowance						176,150
Individually measured for impairment, related allowance						17,414
Total			193,564			193,564
Nonspecific Allowance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL	0		0
Beginning balance - Incurred Loss Model		16,837	17,195	17,768
Provision for loan losses - CECL	0		0
Provision for loan losses - incurred		918		(13)
Loans charged off	0	0	0	0
Recoveries of loans previously charged off	0	0	0	0
Ending balance - CECL	0		0
Ending balance - Incurred Loss Model		17,755		17,755
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL	0		0
Provision for off-balance sheet credit risk	0		0
Ending balance - CECL	$ 0		0
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred Loss Model		0		0
Provision for off-balance sheet credit losses		0		0
Ending balance - Incurred Loss Model		0		0
Total provision for credit losses		918		(13)
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment						0
Individually measured for impairment, recorded investment						0
Total						0
Related allowance [Abstract]
Collectively measured for impairment, related allowance						0
Individually measured for impairment, related allowance						0
Total		$ 17,755	17,195	$ 17,768		$ 17,195
Previously Reported [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL			210,759
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL			1,585
Previously Reported [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL			118,187
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL			1,434
Previously Reported [Member] | Commercial real estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL			51,805
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL			107
Previously Reported [Member] | Paycheck Protection Program
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL			0
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL			0
Previously Reported [Member] | Loans to individuals [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL			23,572
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL			44
Previously Reported [Member] | Nonspecific Allowance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL			17,195
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL			0
Restatement Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL			25,809
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL			23,552
Restatement Adjustment [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL			33,681
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL			10,144
Restatement Adjustment [Member] | Commercial real estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL			(4,620)
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL			11,660
Restatement Adjustment [Member] | Paycheck Protection Program
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL			0
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL			0
Restatement Adjustment [Member] | Loans to individuals [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL			13,943
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL			1,748
Restatement Adjustment [Member] | Nonspecific Allowance [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL			(17,195)
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL			$ 0

Loans and Allowances for Cred_4

Loans and Allowances for Credit Losses, Credit Quality Indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	$ 4,378,265
Financing Receivable, Originated, 2019	3,248,779
Financing Receivable, Originated, 2018	2,818,040
Financing Receivable, Originated, 2017	1,914,647
Financing Receivable, Originated, 2016	1,454,082
Financing Receivable, Originated, 2015 or Prior	3,374,798
Financing Receivable, Revolving	6,582,767
Financing Receivable, Revolving, Converted to Term Loan	31,922
Total	23,803,300
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		$ 19,826,731
Non-Graded, Recorded Investment		1,924,256
Total	23,803,300	21,750,987
Related Allowance [Abstract]
Internally Risk Graded, Allowance		179,129
Non-Graded, Allowance		14,435
Total	419,777	210,759	$ 204,432	$ 202,534	$ 207,457
Commercial [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	1,103,310
Financing Receivable, Originated, 2019	1,654,628
Financing Receivable, Originated, 2018	1,544,785
Financing Receivable, Originated, 2017	1,073,379
Financing Receivable, Originated, 2016	787,890
Financing Receivable, Originated, 2015 or Prior	1,838,875
Financing Receivable, Revolving	5,559,326
Financing Receivable, Revolving, Converted to Term Loan	3,513
Total	13,565,706
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		13,997,538
Non-Graded, Recorded Investment		34,112
Total	13,565,706	14,031,650
Related Allowance [Abstract]
Internally Risk Graded, Allowance		117,236
Non-Graded, Allowance		951
Total	290,277	118,187	106,643	106,397	102,226
Commercial [Member] | Energy [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	59,186
Financing Receivable, Originated, 2019	65,464
Financing Receivable, Originated, 2018	109,513
Financing Receivable, Originated, 2017	7,959
Financing Receivable, Originated, 2016	15,537
Financing Receivable, Originated, 2015 or Prior	35,065
Financing Receivable, Revolving	3,424,377
Financing Receivable, Revolving, Converted to Term Loan	0
Total	3,717,101
Recorded Investment [Abstract]
Total	3,717,101	3,973,377
Commercial [Member] | Healthcare [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	356,834
Financing Receivable, Originated, 2019	650,054
Financing Receivable, Originated, 2018	626,935
Financing Receivable, Originated, 2017	433,280
Financing Receivable, Originated, 2016	241,595
Financing Receivable, Originated, 2015 or Prior	777,210
Financing Receivable, Revolving	239,882
Financing Receivable, Revolving, Converted to Term Loan	0
Total	3,325,790
Recorded Investment [Abstract]
Total	3,325,790	3,033,916
Commercial [Member] | Services [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	356,881
Financing Receivable, Originated, 2019	468,753
Financing Receivable, Originated, 2018	436,452
Financing Receivable, Originated, 2017	370,093
Financing Receivable, Originated, 2016	392,335
Financing Receivable, Originated, 2015 or Prior	785,357
Financing Receivable, Revolving	735,303
Financing Receivable, Revolving, Converted to Term Loan	651
Total	3,545,825
Recorded Investment [Abstract]
Total	3,545,825	3,122,163
Commercial [Member] | General business [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	330,409
Financing Receivable, Originated, 2019	470,357
Financing Receivable, Originated, 2018	371,885
Financing Receivable, Originated, 2017	262,047
Financing Receivable, Originated, 2016	138,423
Financing Receivable, Originated, 2015 or Prior	241,243
Financing Receivable, Revolving	1,159,764
Financing Receivable, Revolving, Converted to Term Loan	2,862
Total	2,976,990
Recorded Investment [Abstract]
Total	2,976,990
Commercial [Member] | Wholesale/retail [Member]
Recorded Investment [Abstract]
Total		1,760,866
Commercial [Member] | Manufacturing [Member]
Recorded Investment [Abstract]
Total		665,449
Commercial [Member] | Public finance [Member]
Recorded Investment [Abstract]
Total		709,868
Commercial [Member] | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Total		766,011
Commercial real estate [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	578,864
Financing Receivable, Originated, 2019	1,192,717
Financing Receivable, Originated, 2018	1,022,093
Financing Receivable, Originated, 2017	534,721
Financing Receivable, Originated, 2016	357,066
Financing Receivable, Originated, 2015 or Prior	800,772
Financing Receivable, Revolving	207,467
Financing Receivable, Revolving, Converted to Term Loan	0
Total	4,693,700
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		4,433,783
Non-Graded, Recorded Investment		0
Total	4,693,700	4,433,783
Related Allowance [Abstract]
Internally Risk Graded, Allowance		51,805
Non-Graded, Allowance		0
Total	71,575	51,805	54,350	54,188	60,026
Commercial real estate [Member] | Residential construction and land development [Member]
Recorded Investment [Abstract]
Total		150,879
Commercial real estate [Member] | Retail [Member]
Recorded Investment [Abstract]
Total		775,521
Commercial real estate [Member] | Office [Member]
Recorded Investment [Abstract]
Total		928,379
Commercial real estate [Member] | Multifamily [Member]
Recorded Investment [Abstract]
Total		1,265,562
Commercial real estate [Member] | Industrial [Member]
Recorded Investment [Abstract]
Total		856,117
Commercial real estate [Member] | Other commercial real estate [Member]
Recorded Investment [Abstract]
Total		457,325
Paycheck Protection Program
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	2,097,325
Financing Receivable, Originated, 2019	0
Financing Receivable, Originated, 2018	0
Financing Receivable, Originated, 2017	0
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	0
Financing Receivable, Revolving	0
Financing Receivable, Revolving, Converted to Term Loan	0
Total	2,097,325
Recorded Investment [Abstract]
Total	2,097,325
Related Allowance [Abstract]
Total	0
Loans to individuals [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	598,766
Financing Receivable, Originated, 2019	401,434
Financing Receivable, Originated, 2018	251,162
Financing Receivable, Originated, 2017	306,547
Financing Receivable, Originated, 2016	309,126
Financing Receivable, Originated, 2015 or Prior	735,151
Financing Receivable, Revolving	815,974
Financing Receivable, Revolving, Converted to Term Loan	28,409
Total	3,446,569
Recorded Investment [Abstract]
Total	3,446,569	2,084,172
Related Allowance [Abstract]
Total	57,925
Loans to individuals [Member] | Permanent Residential Mortgage [Member]
Recorded Investment [Abstract]
Total		1,057,321
Loans to individuals [Member] | Permanent Residential Mortgage [Member] | US Government Agency Insured Loans [Member]
Recorded Investment [Abstract]
Total		197,794
Loans to individuals [Member] | Home Equity Loan [Member]
Recorded Investment [Abstract]
Total		829,057
Loans to individuals [Member] | Residential mortgage [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	414,273
Financing Receivable, Originated, 2019	166,885
Financing Receivable, Originated, 2018	141,912
Financing Receivable, Originated, 2017	158,269
Financing Receivable, Originated, 2016	180,887
Financing Receivable, Originated, 2015 or Prior	415,582
Financing Receivable, Revolving	344,425
Financing Receivable, Revolving, Converted to Term Loan	26,911
Total	1,849,144
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		279,113
Non-Graded, Recorded Investment		1,805,059
Total	1,849,144	2,084,172
Related Allowance [Abstract]
Internally Risk Graded, Allowance		3,085
Non-Graded, Allowance		11,315
Total		14,400	15,534	15,724	17,964
Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	2,385
Financing Receivable, Originated, 2019	29,819
Financing Receivable, Originated, 2018	30,149
Financing Receivable, Originated, 2017	43,690
Financing Receivable, Originated, 2016	57,322
Financing Receivable, Originated, 2015 or Prior	220,882
Financing Receivable, Revolving	0
Financing Receivable, Revolving, Converted to Term Loan	0
Total	384,247
Recorded Investment [Abstract]
Total	384,247
Loans to individuals [Member] | Personal [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	182,108
Financing Receivable, Originated, 2019	204,730
Financing Receivable, Originated, 2018	79,101
Financing Receivable, Originated, 2017	104,588
Financing Receivable, Originated, 2016	70,917
Financing Receivable, Originated, 2015 or Prior	98,687
Financing Receivable, Revolving	471,549
Financing Receivable, Revolving, Converted to Term Loan	1,498
Total	1,213,178
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		1,116,297
Non-Graded, Recorded Investment		85,085
Total	1,213,178	1,201,382
Related Allowance [Abstract]
Internally Risk Graded, Allowance		7,003
Non-Graded, Allowance		2,169
Total		9,172	10,150	9,388	9,473
Specific Allowance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		19,826,731
Non-Graded, Recorded Investment		1,924,256
Total		21,750,987
Related Allowance [Abstract]
Internally Risk Graded, Allowance		179,129
Non-Graded, Allowance		14,435
Total		193,564
Nonspecific Allowance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Non-Graded, Recorded Investment		0
Total		0
Related Allowance [Abstract]
Internally Risk Graded, Allowance		0
Non-Graded, Allowance		0
Total		17,195	$ 17,755	$ 16,837	$ 17,768
Performing [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		1,886,858
Performing [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		19,312,702
Performing [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		210,149
Performing [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		160,326
Performing [Member] | Commercial [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		34,075
Performing [Member] | Commercial [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		13,538,705
Performing [Member] | Commercial [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		187,881
Performing [Member] | Commercial [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		155,573
Performing [Member] | Commercial [Member] | Energy [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		0
Performing [Member] | Commercial [Member] | Energy [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	57,239
Financing Receivable, Originated, 2019	58,923
Financing Receivable, Originated, 2018	93,066
Financing Receivable, Originated, 2017	7,959
Financing Receivable, Originated, 2016	1,131
Financing Receivable, Originated, 2015 or Prior	6,716
Financing Receivable, Revolving	2,474,328
Financing Receivable, Revolving, Converted to Term Loan	0
Total	2,699,362
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		3,700,406
Performing [Member] | Commercial [Member] | Energy [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	0
Financing Receivable, Originated, 2018	0
Financing Receivable, Originated, 2017	0
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	0
Financing Receivable, Revolving	465,643
Financing Receivable, Revolving, Converted to Term Loan	0
Total	465,643
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		117,298
Performing [Member] | Commercial [Member] | Energy [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	295
Financing Receivable, Originated, 2019	0
Financing Receivable, Originated, 2018	951
Financing Receivable, Originated, 2017	0
Financing Receivable, Originated, 2016	14,406
Financing Receivable, Originated, 2015 or Prior	0
Financing Receivable, Revolving	409,628
Financing Receivable, Revolving, Converted to Term Loan	0
Total	425,280
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		63,951
Performing [Member] | Commercial [Member] | Healthcare [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		0
Performing [Member] | Commercial [Member] | Healthcare [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	356,834
Financing Receivable, Originated, 2019	619,693
Financing Receivable, Originated, 2018	625,047
Financing Receivable, Originated, 2017	429,314
Financing Receivable, Originated, 2016	241,452
Financing Receivable, Originated, 2015 or Prior	749,439
Financing Receivable, Revolving	236,118
Financing Receivable, Revolving, Converted to Term Loan	0
Total	3,257,897
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		2,995,514
Performing [Member] | Commercial [Member] | Healthcare [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	27,500
Financing Receivable, Originated, 2018	0
Financing Receivable, Originated, 2017	3,019
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	13,393
Financing Receivable, Revolving	3,255
Financing Receivable, Revolving, Converted to Term Loan	0
Total	47,167
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		13,117
Performing [Member] | Commercial [Member] | Healthcare [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	2,843
Financing Receivable, Originated, 2018	1,705
Financing Receivable, Originated, 2017	947
Financing Receivable, Originated, 2016	143
Financing Receivable, Originated, 2015 or Prior	11,443
Financing Receivable, Revolving	0
Financing Receivable, Revolving, Converted to Term Loan	0
Total	17,081
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		20,805
Performing [Member] | Commercial [Member] | Services [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		0
Performing [Member] | Commercial [Member] | Services [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	356,443
Financing Receivable, Originated, 2019	445,488
Financing Receivable, Originated, 2018	406,761
Financing Receivable, Originated, 2017	345,936
Financing Receivable, Originated, 2016	380,205
Financing Receivable, Originated, 2015 or Prior	758,036
Financing Receivable, Revolving	689,917
Financing Receivable, Revolving, Converted to Term Loan	651
Total	3,383,437
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		3,050,946
Performing [Member] | Commercial [Member] | Services [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	344
Financing Receivable, Originated, 2019	11,778
Financing Receivable, Originated, 2018	1,734
Financing Receivable, Originated, 2017	597
Financing Receivable, Originated, 2016	8,415
Financing Receivable, Originated, 2015 or Prior	5,410
Financing Receivable, Revolving	10,043
Financing Receivable, Revolving, Converted to Term Loan	0
Total	38,321
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		29,943
Performing [Member] | Commercial [Member] | Services [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	94
Financing Receivable, Originated, 2019	8,067
Financing Receivable, Originated, 2018	27,957
Financing Receivable, Originated, 2017	9,662
Financing Receivable, Originated, 2016	2,568
Financing Receivable, Originated, 2015 or Prior	15,185
Financing Receivable, Revolving	34,717
Financing Receivable, Revolving, Converted to Term Loan	0
Total	98,250
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		33,791
Performing [Member] | Commercial [Member] | General business [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	327,729
Financing Receivable, Originated, 2019	446,214
Financing Receivable, Originated, 2018	342,469
Financing Receivable, Originated, 2017	242,267
Financing Receivable, Originated, 2016	126,259
Financing Receivable, Originated, 2015 or Prior	229,142
Financing Receivable, Revolving	1,145,429
Financing Receivable, Revolving, Converted to Term Loan	2,766
Total	2,862,275
Performing [Member] | Commercial [Member] | General business [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	4,335
Financing Receivable, Originated, 2018	13,235
Financing Receivable, Originated, 2017	7,126
Financing Receivable, Originated, 2016	3,876
Financing Receivable, Originated, 2015 or Prior	3,457
Financing Receivable, Revolving	4,782
Financing Receivable, Revolving, Converted to Term Loan	21
Total	36,832
Performing [Member] | Commercial [Member] | General business [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	1,005
Financing Receivable, Originated, 2019	15,955
Financing Receivable, Originated, 2018	11,316
Financing Receivable, Originated, 2017	11,007
Financing Receivable, Originated, 2016	7,501
Financing Receivable, Originated, 2015 or Prior	8,526
Financing Receivable, Revolving	8,894
Financing Receivable, Revolving, Converted to Term Loan	4
Total	64,208
Performing [Member] | Commercial [Member] | Wholesale/retail [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		0
Performing [Member] | Commercial [Member] | Wholesale/retail [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		1,749,023
Performing [Member] | Commercial [Member] | Wholesale/retail [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		5,281
Performing [Member] | Commercial [Member] | Wholesale/retail [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		5,399
Performing [Member] | Commercial [Member] | Manufacturing [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		0
Performing [Member] | Commercial [Member] | Manufacturing [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		623,219
Performing [Member] | Commercial [Member] | Manufacturing [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		18,214
Performing [Member] | Commercial [Member] | Manufacturing [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		13,883
Performing [Member] | Commercial [Member] | Public finance [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		0
Performing [Member] | Commercial [Member] | Public finance [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		709,868
Performing [Member] | Commercial [Member] | Public finance [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Performing [Member] | Commercial [Member] | Public finance [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Performing [Member] | Commercial [Member] | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		34,075
Performing [Member] | Commercial [Member] | Other commercial and industrial [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		709,729
Performing [Member] | Commercial [Member] | Other commercial and industrial [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		4,028
Performing [Member] | Commercial [Member] | Other commercial and industrial [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		17,744
Performing [Member] | Commercial real estate [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		0
Performing [Member] | Commercial real estate [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	578,864
Financing Receivable, Originated, 2019	1,184,368
Financing Receivable, Originated, 2018	1,021,832
Financing Receivable, Originated, 2017	517,976
Financing Receivable, Originated, 2016	347,920
Financing Receivable, Originated, 2015 or Prior	780,900
Financing Receivable, Revolving	207,440
Financing Receivable, Revolving, Converted to Term Loan	0
Total	4,639,300
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		4,381,663
Performing [Member] | Commercial real estate [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	0
Financing Receivable, Originated, 2018	261
Financing Receivable, Originated, 2017	12,326
Financing Receivable, Originated, 2016	2,571
Financing Receivable, Originated, 2015 or Prior	8,903
Financing Receivable, Revolving	0
Financing Receivable, Revolving, Converted to Term Loan	0
Total	24,061
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		22,145
Performing [Member] | Commercial real estate [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	8,349
Financing Receivable, Originated, 2018	0
Financing Receivable, Originated, 2017	4,187
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	4,824
Financing Receivable, Revolving	27
Financing Receivable, Revolving, Converted to Term Loan	0
Total	17,387
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		2,349
Performing [Member] | Commercial real estate [Member] | Residential construction and land development [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		0
Performing [Member] | Commercial real estate [Member] | Residential construction and land development [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		150,529
Performing [Member] | Commercial real estate [Member] | Residential construction and land development [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Performing [Member] | Commercial real estate [Member] | Residential construction and land development [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Performing [Member] | Commercial real estate [Member] | Retail [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		0
Performing [Member] | Commercial real estate [Member] | Retail [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		743,343
Performing [Member] | Commercial real estate [Member] | Retail [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		12,067
Performing [Member] | Commercial real estate [Member] | Retail [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		1,243
Performing [Member] | Commercial real estate [Member] | Office [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		0
Performing [Member] | Commercial real estate [Member] | Office [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		923,202
Performing [Member] | Commercial real estate [Member] | Office [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		5,177
Performing [Member] | Commercial real estate [Member] | Office [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Performing [Member] | Commercial real estate [Member] | Multifamily [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		0
Performing [Member] | Commercial real estate [Member] | Multifamily [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		1,257,005
Performing [Member] | Commercial real estate [Member] | Multifamily [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		1,604
Performing [Member] | Commercial real estate [Member] | Multifamily [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		95
Performing [Member] | Commercial real estate [Member] | Industrial [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		0
Performing [Member] | Commercial real estate [Member] | Industrial [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		852,539
Performing [Member] | Commercial real estate [Member] | Industrial [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		1,658
Performing [Member] | Commercial real estate [Member] | Industrial [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		1,011
Performing [Member] | Commercial real estate [Member] | Other commercial real estate [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		0
Performing [Member] | Commercial real estate [Member] | Other commercial real estate [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		455,045
Performing [Member] | Commercial real estate [Member] | Other commercial real estate [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		1,639
Performing [Member] | Commercial real estate [Member] | Other commercial real estate [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Performing [Member] | Paycheck Protection Program | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	2,097,325
Financing Receivable, Originated, 2019	0
Financing Receivable, Originated, 2018	0
Financing Receivable, Originated, 2017	0
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	0
Financing Receivable, Revolving	0
Financing Receivable, Revolving, Converted to Term Loan	0
Total	2,097,325
Performing [Member] | Loans to individuals [Member] | Permanent Residential Mortgage [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		758,260
Performing [Member] | Loans to individuals [Member] | Permanent Residential Mortgage [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		276,138
Performing [Member] | Loans to individuals [Member] | Permanent Residential Mortgage [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		78
Performing [Member] | Loans to individuals [Member] | Permanent Residential Mortgage [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		2,404
Performing [Member] | Loans to individuals [Member] | Permanent Residential Mortgage [Member] | US Government Agency Insured Loans [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		191,694
Performing [Member] | Loans to individuals [Member] | Permanent Residential Mortgage [Member] | US Government Agency Insured Loans [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Performing [Member] | Loans to individuals [Member] | Permanent Residential Mortgage [Member] | US Government Agency Insured Loans [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Performing [Member] | Loans to individuals [Member] | Permanent Residential Mortgage [Member] | US Government Agency Insured Loans [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Performing [Member] | Loans to individuals [Member] | Home Equity Loan [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		817,976
Performing [Member] | Loans to individuals [Member] | Home Equity Loan [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Performing [Member] | Loans to individuals [Member] | Home Equity Loan [Member] | Special Mention [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Performing [Member] | Loans to individuals [Member] | Home Equity Loan [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Performing [Member] | Loans to individuals [Member] | Residential mortgage [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		1,767,930
Performing [Member] | Loans to individuals [Member] | Residential mortgage [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	414,273
Financing Receivable, Originated, 2019	166,795
Financing Receivable, Originated, 2018	138,524
Financing Receivable, Originated, 2017	157,514
Financing Receivable, Originated, 2016	178,830
Financing Receivable, Originated, 2015 or Prior	390,803
Financing Receivable, Revolving	341,673
Financing Receivable, Revolving, Converted to Term Loan	26,129
Total	1,814,541
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		276,138
Performing [Member] | Loans to individuals [Member] | Residential mortgage [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	47
Financing Receivable, Originated, 2018	1,879
Financing Receivable, Originated, 2017	20
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	309
Financing Receivable, Revolving	527
Financing Receivable, Revolving, Converted to Term Loan	12
Total	2,794
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		78
Performing [Member] | Loans to individuals [Member] | Residential mortgage [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	0
Financing Receivable, Originated, 2018	0
Financing Receivable, Originated, 2017	0
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	39
Financing Receivable, Revolving	159
Financing Receivable, Revolving, Converted to Term Loan	12
Total	210
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		2,404
Performing [Member] | Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	2,385
Financing Receivable, Originated, 2019	29,819
Financing Receivable, Originated, 2018	29,745
Financing Receivable, Originated, 2017	43,690
Financing Receivable, Originated, 2016	57,322
Financing Receivable, Originated, 2015 or Prior	214,889
Financing Receivable, Revolving	0
Financing Receivable, Revolving, Converted to Term Loan	0
Total	377,850
Performing [Member] | Loans to individuals [Member] | Personal [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment		84,853
Performing [Member] | Loans to individuals [Member] | Personal [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	182,066
Financing Receivable, Originated, 2019	204,478
Financing Receivable, Originated, 2018	79,041
Financing Receivable, Originated, 2017	104,217
Financing Receivable, Originated, 2016	70,812
Financing Receivable, Originated, 2015 or Prior	98,598
Financing Receivable, Revolving	471,503
Financing Receivable, Revolving, Converted to Term Loan	1,498
Total	1,212,213
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		1,116,196
Performing [Member] | Loans to individuals [Member] | Personal [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	42
Financing Receivable, Originated, 2019	24
Financing Receivable, Originated, 2018	11
Financing Receivable, Originated, 2017	53
Financing Receivable, Originated, 2016	46
Financing Receivable, Originated, 2015 or Prior	45
Financing Receivable, Revolving	1
Financing Receivable, Revolving, Converted to Term Loan	0
Total	222
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		45
Performing [Member] | Loans to individuals [Member] | Personal [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	211
Financing Receivable, Originated, 2018	0
Financing Receivable, Originated, 2017	265
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	0
Financing Receivable, Revolving	15
Financing Receivable, Revolving, Converted to Term Loan	0
Total	491
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		143,554
Non-Graded, Recorded Investment		37,398
Nonperforming Financial Instruments [Member] | Commercial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		115,379
Non-Graded, Recorded Investment		37
Nonperforming Financial Instruments [Member] | Commercial [Member] | Energy [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		91,722
Non-Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member] | Commercial [Member] | Energy [Member] | Nonaccruing substandard and doubtful [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	1,652
Financing Receivable, Originated, 2019	6,541
Financing Receivable, Originated, 2018	15,496
Financing Receivable, Originated, 2017	0
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	28,349
Financing Receivable, Revolving	74,778
Financing Receivable, Revolving, Converted to Term Loan	0
Total	126,816
Nonperforming Financial Instruments [Member] | Commercial [Member] | Healthcare [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		4,480
Non-Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member] | Commercial [Member] | Healthcare [Member] | Nonaccruing substandard and doubtful [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	18
Financing Receivable, Originated, 2018	183
Financing Receivable, Originated, 2017	0
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	2,935
Financing Receivable, Revolving	509
Financing Receivable, Revolving, Converted to Term Loan	0
Total	3,645
Nonperforming Financial Instruments [Member] | Commercial [Member] | Services [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		7,483
Non-Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member] | Commercial [Member] | Services [Member] | Nonaccruing substandard and doubtful [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	3,420
Financing Receivable, Originated, 2018	0
Financing Receivable, Originated, 2017	13,898
Financing Receivable, Originated, 2016	1,147
Financing Receivable, Originated, 2015 or Prior	6,726
Financing Receivable, Revolving	626
Financing Receivable, Revolving, Converted to Term Loan	0
Total	25,817
Nonperforming Financial Instruments [Member] | Commercial [Member] | General business [Member] | Nonaccruing substandard and doubtful [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	1,675
Financing Receivable, Originated, 2019	3,853
Financing Receivable, Originated, 2018	4,865
Financing Receivable, Originated, 2017	1,647
Financing Receivable, Originated, 2016	787
Financing Receivable, Originated, 2015 or Prior	118
Financing Receivable, Revolving	659
Financing Receivable, Revolving, Converted to Term Loan	71
Total	13,675
Nonperforming Financial Instruments [Member] | Commercial [Member] | Wholesale/retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		1,163
Non-Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member] | Commercial [Member] | Manufacturing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		10,133
Non-Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member] | Commercial [Member] | Public finance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Non-Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member] | Commercial [Member] | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		398
Non-Graded, Recorded Investment		37
Nonperforming Financial Instruments [Member] | Commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		27,626
Non-Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member] | Commercial real estate [Member] | Nonaccruing substandard and doubtful [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	0
Financing Receivable, Originated, 2018	0
Financing Receivable, Originated, 2017	232
Financing Receivable, Originated, 2016	6,575
Financing Receivable, Originated, 2015 or Prior	6,145
Financing Receivable, Revolving	0
Financing Receivable, Revolving, Converted to Term Loan	0
Total	12,952
Nonperforming Financial Instruments [Member] | Commercial real estate [Member] | Residential construction and land development [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		350
Non-Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member] | Commercial real estate [Member] | Retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		18,868
Non-Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member] | Commercial real estate [Member] | Office [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Non-Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member] | Commercial real estate [Member] | Multifamily [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		6,858
Non-Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member] | Commercial real estate [Member] | Industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		909
Non-Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member] | Commercial real estate [Member] | Other commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		641
Non-Graded, Recorded Investment		0
Nonperforming Financial Instruments [Member] | Loans to individuals [Member] | Permanent Residential Mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		493
Non-Graded, Recorded Investment		19,948
Nonperforming Financial Instruments [Member] | Loans to individuals [Member] | Permanent Residential Mortgage [Member] | US Government Agency Insured Loans [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Non-Graded, Recorded Investment		6,100
Nonperforming Financial Instruments [Member] | Loans to individuals [Member] | Home Equity Loan [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		0
Non-Graded, Recorded Investment		11,081
Nonperforming Financial Instruments [Member] | Loans to individuals [Member] | Residential mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		493
Non-Graded, Recorded Investment		37,129
Nonperforming Financial Instruments [Member] | Loans to individuals [Member] | Residential mortgage [Member] | Nonaccruing substandard and doubtful [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	43
Financing Receivable, Originated, 2018	1,509
Financing Receivable, Originated, 2017	735
Financing Receivable, Originated, 2016	2,057
Financing Receivable, Originated, 2015 or Prior	24,431
Financing Receivable, Revolving	2,066
Financing Receivable, Revolving, Converted to Term Loan	758
Total	31,599
Nonperforming Financial Instruments [Member] | Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans [Member] | Nonaccruing substandard and doubtful [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	0
Financing Receivable, Originated, 2018	404
Financing Receivable, Originated, 2017	0
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	5,993
Financing Receivable, Revolving	0
Financing Receivable, Revolving, Converted to Term Loan	0
Total	6,397
Nonperforming Financial Instruments [Member] | Loans to individuals [Member] | Personal [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		56
Non-Graded, Recorded Investment		$ 232
Nonperforming Financial Instruments [Member] | Loans to individuals [Member] | Personal [Member] | Nonaccruing substandard and doubtful [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	0
Financing Receivable, Originated, 2019	17
Financing Receivable, Originated, 2018	49
Financing Receivable, Originated, 2017	53
Financing Receivable, Originated, 2016	59
Financing Receivable, Originated, 2015 or Prior	44
Financing Receivable, Revolving	30
Financing Receivable, Revolving, Converted to Term Loan	0
Total	$ 252

Loans and Allowances for Cred_5

Loans and Allowances for Credit Losses Loans and Allowances for Credit Losses, Nonaccrual (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	$ 221,153	$ 180,951
Financing Receivable, Nonaccrual, No Allowance	169,903
Financing Receivable, Nonaccrual, With Allowance	51,250
Financing Receivable, Nonaccrual, Related Allowance	19,695
Commercial [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	169,953	115,416
Financing Receivable, Nonaccrual, No Allowance	124,071
Financing Receivable, Nonaccrual, With Allowance	45,882
Financing Receivable, Nonaccrual, Related Allowance	19,155
Commercial [Member] | Energy [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	126,816	91,722
Financing Receivable, Nonaccrual, No Allowance	86,793
Financing Receivable, Nonaccrual, With Allowance	40,023
Financing Receivable, Nonaccrual, Related Allowance	16,504
Commercial [Member] | Healthcare [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	3,645	4,480
Financing Receivable, Nonaccrual, No Allowance	3,645
Financing Receivable, Nonaccrual, With Allowance	0
Financing Receivable, Nonaccrual, Related Allowance	0
Commercial [Member] | Services [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	25,817	7,483
Financing Receivable, Nonaccrual, No Allowance	20,456
Financing Receivable, Nonaccrual, With Allowance	5,361
Financing Receivable, Nonaccrual, Related Allowance	2,574
Commercial [Member] | General business [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	13,675
Financing Receivable, Nonaccrual, No Allowance	13,177
Financing Receivable, Nonaccrual, With Allowance	498
Financing Receivable, Nonaccrual, Related Allowance	77
Commercial real estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	12,952	27,626
Financing Receivable, Nonaccrual, No Allowance	7,584
Financing Receivable, Nonaccrual, With Allowance	5,368
Financing Receivable, Nonaccrual, Related Allowance	540
Loans to individuals [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	38,248	37,622
Financing Receivable, Nonaccrual, No Allowance	38,248
Financing Receivable, Nonaccrual, With Allowance	0
Financing Receivable, Nonaccrual, Related Allowance	0
Loans to individuals [Member] | Residential mortgage [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	31,599
Financing Receivable, Nonaccrual, No Allowance	31,599
Financing Receivable, Nonaccrual, With Allowance	0
Financing Receivable, Nonaccrual, Related Allowance	0
Loans to individuals [Member] | Personal [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	252	$ 287
Financing Receivable, Nonaccrual, No Allowance	252
Financing Receivable, Nonaccrual, With Allowance	0
Financing Receivable, Nonaccrual, Related Allowance	0
US Government Agency Insured Loans [Member] | Loans to individuals [Member] | Residential mortgage [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	6,397
Financing Receivable, Nonaccrual, No Allowance	6,397
Financing Receivable, Nonaccrual, With Allowance	0
Financing Receivable, Nonaccrual, Related Allowance	$ 0

Loans and Allowances for Cred_6

Loans and Allowances for Credit Losses, Troubled Debt Restructurings (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Recorded Investment	$ 184,000,000		$ 184,000,000		$ 132,000,000
Financing Receivable, Troubled Debt Restructuring, Performing in Accordance With Modified Terms	65,000,000		65,000,000		57,000,000
Financing Receivable, Troubled Debt Restructuring, Postmodification	36,000,000	$ 6,200,000	76,000,000	$ 40,000,000
Financing Receivable, Impaired, Troubled Debt Restructuring, Write-down	6,400,000	$ 2,500,000	16,100,000	$ 15,100,000
Residential mortgage [Member] | Loans to individuals [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Specific Allowance	0		0
Residential mortgage [Member] | Nonperforming Financial Instruments [Member] | Loans to individuals [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Recorded Investment	19,000,000		19,000,000
Energy [Member] | Commercial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Specific Allowance	2,000,000		2,000,000
Energy [Member] | Nonperforming Financial Instruments [Member] | Commercial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Recorded Investment	11,000,000		11,000,000
US Government Agency Insured Loans [Member] | Residential mortgage [Member] | Performing [Member] | Loans to individuals [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Recorded Investment	$ 143,000,000		$ 143,000,000		$ 92,000,000

Loans and Allowances for Cred_7

Loans and Allowances for Credit Losses, By Aging Category (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing receivable, recorded investment, aging [Abstract]
Current	$ 23,383,412	$ 21,392,306
Nonaccrual	221,153	180,951
Total	23,803,300	21,750,987
Past Due 90 Days or More and Accruing	124,872	7,680
30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	119,679	47,084
60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	42,045	20,560
90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	258,164	110,086
Commercial [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	13,397,500	13,899,429
Nonaccrual	169,953	115,416
Total	13,565,706	14,031,650
Past Due 90 Days or More and Accruing	672
Commercial [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	52,988	7,943
Commercial [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	5,510	1,608
Commercial [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	109,708	7,254
Commercial [Member] | Energy [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	3,603,548	3,881,244
Nonaccrual	126,816	91,722
Total	3,717,101	3,973,377
Past Due 90 Days or More and Accruing	0
Commercial [Member] | Energy [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	27,064	401
Commercial [Member] | Energy [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	10
Commercial [Member] | Energy [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	86,489	0
Commercial [Member] | Healthcare [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	3,316,556	3,027,329
Nonaccrual	3,645	4,480
Total	3,325,790	3,033,916
Past Due 90 Days or More and Accruing	171
Commercial [Member] | Healthcare [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	5,419	2,039
Commercial [Member] | Healthcare [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
Commercial [Member] | Healthcare [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	3,815	68
Commercial [Member] | Services [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	3,521,644	3,105,621
Nonaccrual	25,817	7,483
Total	3,545,825	3,122,163
Past Due 90 Days or More and Accruing	58
Commercial [Member] | Services [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	6,503	1,737
Commercial [Member] | Services [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	5,168	523
Commercial [Member] | Services [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	12,510	6,799
Commercial [Member] | Wholesale/retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Current		1,758,878
Nonaccrual		1,163
Total		1,760,866
Commercial [Member] | Wholesale/retail [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		712
Commercial [Member] | Wholesale/retail [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		113
Commercial [Member] | Wholesale/retail [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial [Member] | General business [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	2,955,752
Nonaccrual	13,675
Total	2,976,990
Past Due 90 Days or More and Accruing	443
Commercial [Member] | General business [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	14,002
Commercial [Member] | General business [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	342
Commercial [Member] | General business [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	6,894
Commercial [Member] | Manufacturing [Member]
Financing receivable, recorded investment, aging [Abstract]
Current		654,329
Nonaccrual		10,133
Total		665,449
Commercial [Member] | Manufacturing [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		410
Commercial [Member] | Manufacturing [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		190
Commercial [Member] | Manufacturing [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		387
Commercial [Member] | Public finance [Member]
Financing receivable, recorded investment, aging [Abstract]
Current		707,638
Nonaccrual		0
Total		709,868
Commercial [Member] | Public finance [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		2,230
Commercial [Member] | Public finance [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial [Member] | Public finance [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial [Member] | Other commercial and industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Current		764,390
Nonaccrual		435
Total		766,011
Commercial [Member] | Other commercial and industrial [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		414
Commercial [Member] | Other commercial and industrial [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		772
Commercial [Member] | Other commercial and industrial [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	4,673,416	4,400,576
Nonaccrual	12,952	27,626
Total	4,693,700	4,433,783
Past Due 90 Days or More and Accruing	4,771
Commercial real estate [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	2,029	4,920
Commercial real estate [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	532	250
Commercial real estate [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	17,723	411
Commercial real estate [Member] | Residential construction and land development [Member]
Financing receivable, recorded investment, aging [Abstract]
Current		147,379
Nonaccrual		350
Total		150,879
Commercial real estate [Member] | Residential construction and land development [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		3,093
Commercial real estate [Member] | Residential construction and land development [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member] | Residential construction and land development [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		57
Commercial real estate [Member] | Retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Current		756,653
Nonaccrual		18,868
Total		775,521
Commercial real estate [Member] | Retail [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member] | Retail [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member] | Retail [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member] | Office [Member]
Financing receivable, recorded investment, aging [Abstract]
Current		928,379
Nonaccrual		0
Total		928,379
Commercial real estate [Member] | Office [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member] | Office [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member] | Office [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member] | Multifamily [Member]
Financing receivable, recorded investment, aging [Abstract]
Current		1,258,704
Nonaccrual		6,858
Total		1,265,562
Commercial real estate [Member] | Multifamily [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member] | Multifamily [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member] | Multifamily [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member] | Industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Current		855,208
Nonaccrual		909
Total		856,117
Commercial real estate [Member] | Industrial [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member] | Industrial [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member] | Industrial [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Commercial real estate [Member] | Other commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Current		454,253
Nonaccrual		641
Total		457,325
Commercial real estate [Member] | Other commercial real estate [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		1,827
Commercial real estate [Member] | Other commercial real estate [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		250
Commercial real estate [Member] | Other commercial real estate [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		354
Paycheck Protection Program
Financing receivable, recorded investment, aging [Abstract]
Current	2,097,325
Total	2,097,325
Past Due 90 Days or More and Accruing	0
Paycheck Protection Program | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0
Paycheck Protection Program | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0
Paycheck Protection Program | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0
Loans to individuals [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	3,215,171	1,895,939
Nonaccrual	38,248	37,622
Total	3,446,569	2,084,172
Past Due 90 Days or More and Accruing	119,429
Loans to individuals [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	64,662	29,557
Loans to individuals [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	36,003	18,648
Loans to individuals [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	130,733	102,406
Loans to individuals [Member] | Residential mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	1,830,005
Nonaccrual	31,599
Total	1,849,144	2,084,172
Past Due 90 Days or More and Accruing	2,241
Loans to individuals [Member] | Residential mortgage [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	8,299
Loans to individuals [Member] | Residential mortgage [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	1,128
Loans to individuals [Member] | Residential mortgage [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	9,712
Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	172,678
Nonaccrual	6,397
Total	384,247
Past Due 90 Days or More and Accruing	117,188
Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	56,264
Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	34,355
Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	120,950
Loans to individuals [Member] | Permanent Residential Mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Current		1,034,716
Nonaccrual		20,441
Total		1,057,321
Loans to individuals [Member] | Permanent Residential Mortgage [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		2,011
Loans to individuals [Member] | Permanent Residential Mortgage [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		153
Loans to individuals [Member] | Permanent Residential Mortgage [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Loans to individuals [Member] | Permanent Residential Mortgage [Member] | US Government Agency Insured Loans [Member]
Financing receivable, recorded investment, aging [Abstract]
Current		46,898
Nonaccrual		6,100
Total		197,794
Loans to individuals [Member] | Permanent Residential Mortgage [Member] | US Government Agency Insured Loans [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		24,203
Loans to individuals [Member] | Permanent Residential Mortgage [Member] | US Government Agency Insured Loans [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		18,187
Loans to individuals [Member] | Permanent Residential Mortgage [Member] | US Government Agency Insured Loans [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		102,406
Loans to individuals [Member] | Home equity [Member]
Financing receivable, recorded investment, aging [Abstract]
Current		814,325
Nonaccrual		11,081
Total		829,057
Loans to individuals [Member] | Home equity [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		3,343
Loans to individuals [Member] | Home equity [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		308
Loans to individuals [Member] | Home equity [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due		0
Loans to individuals [Member] | Personal [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	1,212,488	1,196,362
Nonaccrual	252	287
Total	1,213,178	1,201,382
Past Due 90 Days or More and Accruing	0
Loans to individuals [Member] | Personal [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	99	4,664
Loans to individuals [Member] | Personal [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	520	54
Loans to individuals [Member] | Personal [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	$ 71	$ 15

Loans and Allowance for Credi_2

Loans and Allowance for Credit Losses, Impaired Loans (Details) $ in Thousands	Dec. 31, 2019USD ($)
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	$ 467,714
Impaired loans, recorded investment, total	372,645
Impaired loans, recorded investment with no related allowance	323,505
Impaired loans, recorded investment with related allowance	49,140
Impaired loans, related allowance	17,414
Commercial [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	195,193
Impaired loans, recorded investment, total	115,416
Impaired loans, recorded investment with no related allowance	66,276
Impaired loans, recorded investment with related allowance	49,140
Impaired loans, related allowance	17,414
Commercial [Member] | Energy [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	149,441
Impaired loans, recorded investment, total	91,722
Impaired loans, recorded investment with no related allowance	44,244
Impaired loans, recorded investment with related allowance	47,478
Impaired loans, related allowance	16,854
Commercial [Member] | Services [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	10,923
Impaired loans, recorded investment, total	7,483
Impaired loans, recorded investment with no related allowance	6,301
Impaired loans, recorded investment with related allowance	1,182
Impaired loans, related allowance	240
Commercial [Member] | Wholesale/retail [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	1,980
Impaired loans, recorded investment, total	1,163
Impaired loans, recorded investment with no related allowance	902
Impaired loans, recorded investment with related allowance	261
Impaired loans, related allowance	101
Commercial [Member] | Manufacturing [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	10,848
Impaired loans, recorded investment, total	10,133
Impaired loans, recorded investment with no related allowance	9,914
Impaired loans, recorded investment with related allowance	219
Impaired loans, related allowance	219
Commercial [Member] | Healthcare [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	13,774
Impaired loans, recorded investment, total	4,480
Impaired loans, recorded investment with no related allowance	4,480
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
Commercial [Member] | Public finance [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	0
Impaired loans, recorded investment, total	0
Impaired loans, recorded investment with no related allowance	0
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
Commercial [Member] | Other commercial and industrial [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	8,227
Impaired loans, recorded investment, total	435
Impaired loans, recorded investment with no related allowance	435
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
Commercial real estate [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	30,139
Impaired loans, recorded investment, total	27,626
Impaired loans, recorded investment with no related allowance	27,626
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
Commercial real estate [Member] | Residential construction and land development [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	1,306
Impaired loans, recorded investment, total	350
Impaired loans, recorded investment with no related allowance	350
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
Commercial real estate [Member] | Retail [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	20,265
Impaired loans, recorded investment, total	18,868
Impaired loans, recorded investment with no related allowance	18,868
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
Commercial real estate [Member] | Office [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	0
Impaired loans, recorded investment, total	0
Impaired loans, recorded investment with no related allowance	0
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
Commercial real estate [Member] | Multifamily [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	6,858
Impaired loans, recorded investment, total	6,858
Impaired loans, recorded investment with no related allowance	6,858
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
Commercial real estate [Member] | Industrial [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	909
Impaired loans, recorded investment, total	909
Impaired loans, recorded investment with no related allowance	909
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
Commercial real estate [Member] | Other commercial real estate [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	801
Impaired loans, recorded investment, total	641
Impaired loans, recorded investment with no related allowance	641
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
Loans to individuals [Member] | Permanent Residential Mortgage [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	24,868
Impaired loans, recorded investment, total	20,441
Impaired loans, recorded investment with no related allowance	20,441
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
Loans to individuals [Member] | Permanent Residential Mortgage [Member] | US Government Agency Insured Loans [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	204,187	[1]
Impaired loans, recorded investment, total	197,794	[1]
Impaired loans, recorded investment with no related allowance	197,794	[1]
Impaired loans, recorded investment with related allowance	0	[1]
Impaired loans, related allowance	0	[1]
Loans to individuals [Member] | Home equity [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	12,967
Impaired loans, recorded investment, total	11,081
Impaired loans, recorded investment with no related allowance	11,081
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
Loans to individuals [Member] | Residential mortgage [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	242,022
Impaired loans, recorded investment, total	229,316
Impaired loans, recorded investment with no related allowance	229,316
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
Loans to individuals [Member] | Personal [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	360
Impaired loans, recorded investment, total	287
Impaired loans, recorded investment with no related allowance	287
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	$ 0
[1]	All permanent mortgage loans guaranteed by U.S. government agencies are considered impaired as we do not expect full collection of contractual principal and interest. At December 31, 2019, the majority were accruing based on the guarantee by U.S. government agencies.

Mortgage Banking Activities, Co

Mortgage Banking Activities, Components of Loans Held For Sale (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Schedule of Residential Mortgage Loans Held For Sale [Line Items]
Number of days for past due for loan to be considered nonperforming (in days)	90		90
Residential mortgage loans held for sale, nonperforming	$ 0		$ 0
Credit losses recognized on residential mortgage loans held for sale	0	$ 0
Components of Residential Mortgage Loans Held for Sale [Abstract]
Unpaid principal balance	259,076		175,117
Residential mortgage loans held for sale, Fair value	268,575		177,703
Residential mortgage loans held for sale	$ 295,290		$ 182,271
Residential Mortgage Loan Commitments [Member] | Not Designated as Hedging Instrument [Member]
Schedule of Residential Mortgage Loans Held For Sale [Line Items]
General number of days outstanding for residential mortgage commitments, minimum (in days)	60		60
General number of days outstanding for residential mortgage commitments, maximum (in days)	90		90
Components of Residential Mortgage Loans Held for Sale [Abstract]
Derivative, Notional Amount	$ 560,493		$ 158,460
Derivative, Net fair value	$ 29,224		$ 5,233
Forward sales contracts [Member] | Not Designated as Hedging Instrument [Member]
Schedule of Residential Mortgage Loans Held For Sale [Line Items]
General number of days for delivery of loans, for which the price is set by forward sales contracts, minimum (in days)	60		60
General number of days for delivery for loans, for which the price is set by forward sales contracts, maximum (in days)	90		90
Components of Residential Mortgage Loans Held for Sale [Abstract]
Derivative, Notional Amount	$ 765,994		$ 315,203
Derivative, Net fair value	$ (2,509)		$ (665)

Mortgage Banking Activities Mor

Mortgage Banking Activities Mortgage Banking Activities, Mortgage Banking Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Mortgage Banking Revenue [Abstract]
Net realized gains on sale of mortgage loans	$ 36,300	$ 8,971	$ 70,126	$ 24,838
Net change in unrealized gain (loss) on mortgage loans held for sale	(1,672)	97	6,913	965
Net change in the fair value of mortgage loan commitments	1,593	514	23,991	4,733
Net change in the fair value of forward sales contracts	2,210	4,232	(1,844)	3,015
Total production revenue	38,431	13,814	99,186	33,551
Servicing revenue	13,528	16,366	43,876	48,594
Total mortgage banking revenue	$ 51,959	$ 30,180	$ 143,062	$ 82,145

Mortgage Banking Activities, Mo

Mortgage Banking Activities, Mortgage Servicing Rights (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Summary of Mortgage Servicing Rights [Abstract]
Number of residential mortgage loans serviced for others	111,008		111,008		126,828
Outstanding principal balance of residential mortgage loans serviced for others	$ 17,116,204,000		$ 17,116,204,000		$ 20,727,106,000
Weighted average interest rate	3.91%		3.91%		3.98%
Remaining term (in months)			281		289
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 97,971,000	$ 208,308,000	$ 201,886,000	$ 259,254,000	$ 259,254,000
Additions	7,424,000	9,882,000	21,330,000	24,821,000
Disposals	0	0	(10,801,000)	0
Change in fair value due to principal payments	(11,192,000)	(11,936,000)	(28,971,000)	(27,600,000)
Change in fair value due to market assumption changes	3,441,000	(12,593,000)	(85,800,000)	(62,814,000)
Ending balance	$ 97,644,000	$ 193,661,000	$ 97,644,000	$ 193,661,000	$ 201,886,000
Servicing Assets at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Discount rate - risk-free rate plus a market premium (in hundredths)			9.15%		9.81%
Prepayment rate - based upon loan interest rate, original term and loan type, minimum			9.90%		8.28%
Prepayment rate - based upon loan interest rate, original term and loan type, maximum			24.02%		16.05%
Loan servicing costs - annually per loan based upon loan type, performing, minimum (in dollars per loan)			$ 69		$ 68
Loan servicing costs - annually per loan based upon loan type, performing, maximum (in dollars per loan)			94		94
Loan servicing costs - annually per loan based upon loan type, delinquent, minimum (in dollars per loan)			150		150
Loan servicing costs - annually per loan based upon loan type, delinquent, maximum (in dollars per loan)			500		500
Loan servicing costs - annually per loan based upon loan type, foreclosure, minimum (in dollars per loan)			1,000		1,000
Loan servicing costs - annually per loan based upon loan type, foreclosure, maximum (in dollars per loan)			$ 4,000		$ 4,000
Escrow earnings rate - indexed to rates paid on deposit accounts with comparable average life (in hundredths)			0.34%		1.73%
Primary secondary mortgage rate spread	105		105		104
Delinquency rate			3.72%		2.73%

Commitments and Contingent Li_2

Commitments and Contingent Liabilities (Details)	9 Months Ended
	Sep. 30, 2020USD ($)
Judicial Ruling [Member] | Misuse of Revenues Pledged to Municipal Bonds [Member]
Litigation Settlement [Abstract]
Disgorged fees	$ 1,067,721
Litigation Settlement, Amount Awarded to Other Party	$ 600,000
Pending Litigation [Member] | Misuse of Revenues Pledged to Municipal Bonds [Member]
Litigation Settlement [Abstract]
Loss Contingency, Number of Plaintiffs	2
Alleged total of judgment against nursing home operator	$ 8,000,000
Pending Litigation [Member] | Bank Participation in Fraudulent Sale of Securities by Principals [Member]
Litigation Settlement [Abstract]
Loss Contingency, Number of Plaintiffs	19
Outstanding principal accrued interest and other amounts upon sale of facilities securing payment of the bonds	$ 20,000,000
Principal amount of entered judgment against the principal individual and his wife	36,805,051
Pre-judgment interest amount of entered judgment against the principal individual and his wife	$ 10,937,831
Pending Litigation [Member] | Purchase of facilities from principals subject to SEC New Jersey proceedings [Member]
Litigation Settlement [Abstract]
Number of individuals who purchased facilities from the principals subject to SEC New Jersey proceedings	2
Outstanding principal, accrued interest and other amounts required by bond documents	$ 60,000,000
Number of principals in SEC New Jersey proceedings	2
Pending Litigation [Member] | Inclusion of Proprietary Investment Products as Investment Options in 401k Plan Whose Fees Were Too High and Performance Too Low [Member]
Litigation Settlement [Abstract]
Loss Contingency, Number of Plaintiffs	3

Commitments and Contingent Li_3

Commitments and Contingent Liabilities Variable Interest Entities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Unfunded commitments	$ 40,841,115	$ 37,308,102
Other Assets [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated Entities, Assets	270,000
Other Liabilities [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Unfunded commitments	$ 89,000

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands		Nov. 03, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019
Dividends declared (in dollars per share)			$ 0.51	$ 0.50	$ 1.53		$ 1.50
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period					$ 104,923		$ (72,585)
Net change in unrealized gain (loss)			$ (6,783)	$ 46,285	347,985		274,441
Reclassification Adjustments Included in Earnings [Abstract]
Loss (gain) on available for sale securities, net			12	(5)	(5,571)		(1,110)
Other comprehensive income, before income taxes			(6,771)	46,280	342,414		273,331
Federal and state income taxes			(1,625)	11,096	82,167	[1]	66,993	[1]
Other comprehensive income, net of income taxes			(5,146)	35,184	260,247		206,338
Balance, End of Period			365,170	133,753	365,170		133,753
Accumulated Net Unrealized Gain (Loss) on Available for Sale Securities [Member]
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period					104,996		(70,999)
Net change in unrealized gain (loss)					347,985		274,441
Reclassification Adjustments Included in Earnings [Abstract]
Loss (gain) on available for sale securities, net					(5,571)		(1,110)
Other comprehensive income, before income taxes					342,414		273,331
Federal and state income taxes	[1]				82,167		66,993
Other comprehensive income, net of income taxes					260,247		206,338
Balance, End of Period			365,243	135,339	365,243		135,339
Accumulated Unrealized Gain (Loss) on Employee Benefit Plans [Member]
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period					(73)		(1,586)
Net change in unrealized gain (loss)					0		0
Reclassification Adjustments Included in Earnings [Abstract]
Loss (gain) on available for sale securities, net					0		0
Other comprehensive income, before income taxes					0		0
Federal and state income taxes	[1]				0		0
Other comprehensive income, net of income taxes					0		0
Balance, End of Period			$ (73)	$ (1,586)	$ (73)		$ (1,586)
Subsequent Event [Member]
Dividends Payable, Date Declared		Nov. 3, 2020
Dividends declared (in dollars per share)		$ 0.52
Dividends Payable, Date to be Paid		Nov. 24, 2020
Dividends Payable, Date of Record		Nov. 16, 2020
[1]	Calculated using a 25 percent blended federal and state statutory tax rate.

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator: [Abstract]
Net income attributable to BOK Financial Corp. shareholders	$ 154,034	$ 142,231	$ 280,806	$ 390,406
Less: Earnings allocated to participating securities	938	875	1,678	2,553
Numerator for basic earnings per share – income available to common shareholders	153,096	141,356	279,128	387,853
Effect of reallocating undistributed earnings of participating securities	0	1	0	1
Numerator for diluted earnings per share – income available to common shareholders	$ 153,096	$ 141,357	$ 279,128	$ 387,854
Denominator: [Abstract]
Weighted average shares outstanding (in shares)	70,306,233	71,033,405	70,375,628	71,425,855
Less: Participating securities included in weighted average shares (in shares)	428,367	437,098	416,684	472,311
Denominator for basic earnings per common share (in shares)	69,877,866	70,596,307	69,958,944	70,953,544
Dilutive effect of employee stock compensation plans (in shares)	1,424	13,617	3,109	15,301
Denominator for diluted earnings per common share (in shares)	69,879,290	70,609,924	69,962,053	70,968,845
Basic earnings per share	$ 2.19	$ 2	$ 3.99	$ 5.47
Diluted earnings per share	$ 2.19	$ 2	$ 3.99	$ 5.47
Excludes employee stock options with exercise prices greater than current market price.	19,227	0	0	0

Reportable Segments (Details)

Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Net interest revenue from external sources	$ 271,750	$ 279,096	$ 811,214	$ 842,630
Net interest revenue (expense) from internal sources	0	0	0	0
Net interest revenue	271,750	279,096	811,214	842,630
Provision for credit losses	0	12,000	229,092	25,000
Net interest revenue after provision for credit losses	271,750	267,096	582,122	817,630
Other operating revenue	234,159	186,450	647,171	515,785
Other operating expense	301,265	279,292	865,276	843,586
Net direct contribution	204,644	174,254	364,017	489,829
Gain (loss) on financial instruments, net	0	0	0	0
Change in fair value of mortgage servicing rights	0	0	0	0
Gain (loss) on repossessed assets, net	0	0	0	0
Corporate expense allocations	0	0	0	0
Net income before taxes	204,644	174,254	364,017	489,829
Federal and state income taxes	50,552	32,396	83,655	99,926
Net income	154,092	141,858	280,362	389,903
Net income (loss) attributable to non-controlling interests	58	(373)	(444)	(503)
Net income attributable to BOK Financial Corp. shareholders	154,034	142,231	280,806	390,406
Average assets	48,933,767	43,580,348	48,140,046	41,380,249
Operating Segments [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	173,248	243,944	549,464	699,239
Net interest revenue (expense) from internal sources	(23,302)	(64,984)	(103,002)	(185,235)
Net interest revenue	149,946	178,960	446,462	514,004
Provision for credit losses	22,599	9,505	53,241	27,574
Net interest revenue after provision for credit losses	127,347	169,455	393,221	486,430
Other operating revenue	52,021	48,832	138,139	128,055
Other operating expense	66,846	69,127	190,531	183,169
Net direct contribution	112,522	149,160	340,829	431,316
Gain (loss) on financial instruments, net	38	28	135	67
Change in fair value of mortgage servicing rights	0	0	0	0
Gain (loss) on repossessed assets, net	(4,332)	802	(4,132)	455
Corporate expense allocations	5,172	11,772	19,514	31,880
Net income before taxes	103,056	138,218	317,318	399,958
Federal and state income taxes	27,959	37,232	86,254	107,171
Net income	75,097	100,986	231,064	292,787
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	75,097	100,986	231,064	292,787
Average assets	28,000,183	23,973,925	26,759,150	22,288,960
Operating Segments [Member] | Consumer [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	15,821	27,580	60,492	75,353
Net interest revenue (expense) from internal sources	17,309	20,882	55,840	76,925
Net interest revenue	33,130	48,462	116,332	152,278
Provision for credit losses	79	1,841	1,870	4,654
Net interest revenue after provision for credit losses	33,051	46,621	114,462	147,624
Other operating revenue	67,808	51,221	190,062	142,780
Other operating expense	59,839	59,699	173,568	171,214
Net direct contribution	41,020	38,143	130,956	119,190
Gain (loss) on financial instruments, net	1,540	8,339	95,660	43,416
Change in fair value of mortgage servicing rights	3,441	(12,593)	(85,800)	(62,814)
Gain (loss) on repossessed assets, net	41	214	81	409
Corporate expense allocations	10,812	11,776	32,111	35,369
Net income before taxes	35,230	22,327	108,786	64,832
Federal and state income taxes	8,974	5,687	27,709	16,513
Net income	26,256	16,640	81,077	48,319
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	26,256	16,640	81,077	48,319
Average assets	9,898,119	9,827,130	9,889,690	9,142,491
Operating Segments [Member] | Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	34,098	12,343	82,823	51,054
Net interest revenue (expense) from internal sources	(11,113)	10,723	(14,054)	27,213
Net interest revenue	22,985	23,066	68,769	78,267
Provision for credit losses	(51)	(42)	(188)	(209)
Net interest revenue after provision for credit losses	23,036	23,108	68,957	78,476
Other operating revenue	111,152	89,160	315,707	248,591
Other operating expense	82,868	71,619	241,627	202,579
Net direct contribution	51,320	40,649	143,037	124,488
Gain (loss) on financial instruments, net	0	0	7	0
Change in fair value of mortgage servicing rights	0	0	0	0
Gain (loss) on repossessed assets, net	0	0	0	0
Corporate expense allocations	9,397	9,416	25,866	26,943
Net income before taxes	41,923	31,233	117,178	97,545
Federal and state income taxes	10,711	8,027	29,999	25,076
Net income	31,212	23,206	87,179	72,469
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	31,212	23,206	87,179	72,469
Average assets	16,206,522	10,391,225	14,888,623	9,860,427
Funds Management and Other [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	48,583	(4,771)	118,435	16,984	[1]
Net interest revenue (expense) from internal sources	17,106	33,379	61,216	81,097	[1]
Net interest revenue	65,689	28,608	179,651	98,081	[1]
Provision for credit losses	(22,627)	696	174,169	(7,019)	[1]
Net interest revenue after provision for credit losses	88,316	27,912	5,482	105,100	[1]
Other operating revenue	3,178	(2,763)	3,263	(3,641)	[1]
Other operating expense	91,712	78,847	259,550	286,624	[1]
Net direct contribution	(218)	(53,698)	(250,805)	(185,165)	[1]
Gain (loss) on financial instruments, net	(1,578)	(8,367)	(95,802)	(43,483)	[1]
Change in fair value of mortgage servicing rights	(3,441)	12,593	85,800	62,814	[1]
Gain (loss) on repossessed assets, net	4,291	(1,016)	4,051	(864)	[1]
Corporate expense allocations	(25,381)	(32,964)	(77,491)	(94,192)	[1]
Net income before taxes	24,435	(17,524)	(179,265)	(72,506)	[1]
Federal and state income taxes	2,908	(18,550)	(60,307)	(48,834)	[1]
Net income	21,527	1,026	(118,958)	(23,672)	[1]
Net income (loss) attributable to non-controlling interests	58	(373)	(444)	(503)	[1]
Net income attributable to BOK Financial Corp. shareholders	21,469	1,399	(118,514)	(23,169)	[1]
Average assets	$ (5,171,057)	$ (611,932)	$ (3,397,417)	$ 88,371	[1]
[1]	CoBiz operations were included in Funds Management and Other for the first quarter of 2019.

Fees and Commissions Revenue _3

Fees and Commissions Revenue Fees and Commissions (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2020		Sep. 30, 2019		Sep. 30, 2020		Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Total fees and commissions	$ 222,865		$ 186,119		$ 629,269		$ 522,779
Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	222,865		186,119		629,269		522,779
Fees and commission revenue not from contracts with customers	120,197	[1]	74,529	[2]	319,121	[3]	193,585	[4]
Fees and commissions revenue from contracts with customers	102,668	[5]	111,590	[6]	310,148	[7]	329,194	[8]
Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	69,526		43,840		182,327		115,983
Fees and commission revenue not from contracts with customers	57,811	[1]	32,537	[2]	148,254	[3]	82,785	[4]
Fees and commissions revenue from contracts with customers	11,715	[5]	11,303	[6]	34,073	[7]	33,198	[8]
Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	46,889		24,091		125,189		58,890
Fees and commission revenue not from contracts with customers	46,889	[1]	24,091	[2]	125,189	[3]	58,890	[4]
Fees and commissions revenue from contracts with customers	0	[5]	0	[6]	0	[7]	0	[8]
Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	8,642		4,684		18,106		16,706
Fees and commission revenue not from contracts with customers	8,642	[1]	4,684	[2]	18,106	[3]	16,706	[4]
Fees and commissions revenue from contracts with customers	0	[5]	0	[6]	0	[7]	0	[8]
Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3,787		4,204		11,524		12,127
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	3,787	[5]	4,204	[6]	11,524	[7]	12,127	[8]
Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3,124		2,862		10,066		10,792
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	3,124	[5]	2,862	[6]	10,066	[7]	10,792	[8]
Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	7,084		7,999		17,442		17,468
Fees and commission revenue not from contracts with customers	2,280	[1]	3,762	[2]	4,959	[3]	7,189	[4]
Fees and commissions revenue from contracts with customers	4,804	[5]	4,237	[6]	12,483	[7]	10,279	[8]
Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	23,465		22,015		68,286		64,668
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	23,465	[5]	22,015	[6]	68,286	[7]	64,668	[8]
TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	19,741		19,464		58,961		57,541
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	19,741	[5]	19,464	[6]	58,961	[7]	57,541	[8]
Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3,038		2,217		7,600		6,516
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	3,038	[5]	2,217	[6]	7,600	[7]	6,516	[8]
Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	686		334		1,725		611
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	686	[5]	334	[6]	1,725	[7]	611	[8]
Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	39,931		43,621		125,646		132,004
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	39,931	[5]	43,621	[6]	125,646	[7]	132,004	[8]
Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	20,130		20,238		62,460		61,028
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	20,130	[5]	20,238	[6]	62,460	[7]	61,028	[8]
Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	4,613		6,205		15,579		18,736
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	4,613	[5]	6,205	[6]	15,579	[7]	18,736	[8]
Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	11,030		10,740		33,510		32,919
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	11,030	[5]	10,740	[6]	33,510	[7]	32,919	[8]
Investment management services and other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	4,158		6,438		14,097		19,321
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	4,158	[5]	6,438	[6]	14,097	[7]	19,321	[8]
Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	24,286		28,837		72,462		85,154
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	24,286	[5]	28,837	[6]	72,462	[7]	85,154	[8]
Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	12,200		11,613		36,250		35,988
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	12,200	[5]	11,613	[6]	36,250	[7]	35,988	[8]
Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	5,463		9,732		16,385		27,096
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	5,463	[5]	9,732	[6]	16,385	[7]	27,096	[8]
Check card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	5,565		5,721		15,916		16,464
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	5,565	[5]	5,721	[6]	15,916	[7]	16,464	[8]
Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	1,058		1,771		3,911		5,606
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	1,058	[5]	1,771	[6]	3,911	[7]	5,606	[8]
Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	51,959		30,180		143,062		82,145
Fees and commission revenue not from contracts with customers	51,959	[1]	30,180	[2]	143,062	[3]	82,145	[4]
Fees and commissions revenue from contracts with customers	0	[5]	0	[6]	0	[7]	0	[8]
Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	38,431		13,814		99,186		33,551
Fees and commission revenue not from contracts with customers	38,431	[1]	13,814	[2]	99,186	[3]	33,551	[4]
Fees and commissions revenue from contracts with customers	0	[5]	0	[6]	0	[7]	0	[8]
Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	13,528		16,366		43,876		48,594
Fees and commission revenue not from contracts with customers	13,528	[1]	16,366	[2]	43,876	[3]	48,594	[4]
Fees and commissions revenue from contracts with customers	0	[5]	0	[6]	0	[7]	0	[8]
Other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	13,698		17,626		37,486		42,825
Fees and commission revenue not from contracts with customers	10,427	[1]	11,812	[2]	27,805	[3]	28,655	[4]
Fees and commissions revenue from contracts with customers	3,271	[5]	5,814	[6]	9,681	[7]	14,170	[8]
Operating Segments [Member] | Commercial [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	50,085		46,159		138,059		125,310
Operating Segments [Member] | Commercial [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	10,313		6,691		22,742		14,588
Operating Segments [Member] | Commercial [Member] | Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Commercial [Member] | Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	7,999		2,283		17,417		6,243
Operating Segments [Member] | Commercial [Member] | Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Commercial [Member] | Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Commercial [Member] | Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	2,314		4,408		5,325		8,345
Operating Segments [Member] | Commercial [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	22,442		20,996		65,841		61,572
Operating Segments [Member] | Commercial [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	18,840		18,465		56,699		54,623
Operating Segments [Member] | Commercial [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3,019		2,203		7,554		6,351
Operating Segments [Member] | Commercial [Member] | Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	583		328		1,588		598
Operating Segments [Member] | Commercial [Member] | Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Commercial [Member] | Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Commercial [Member] | Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Commercial [Member] | Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Commercial [Member] | Investment management services and other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Commercial [Member] | Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	11,268		10,887		33,703		32,113
Operating Segments [Member] | Commercial [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	11,209		10,609		33,317		31,296
Operating Segments [Member] | Commercial [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	32		81		101		248
Operating Segments [Member] | Commercial [Member] | Check card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Commercial [Member] | Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	27		197		285		569
Operating Segments [Member] | Commercial [Member] | Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Commercial [Member] | Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Commercial [Member] | Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Commercial [Member] | Other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	6,062		7,585		15,773		17,037
Operating Segments [Member] | Consumer [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	67,974		51,461		190,228		143,112
Operating Segments [Member] | Consumer [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Consumer [Member] | Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Consumer [Member] | Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Consumer [Member] | Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Consumer [Member] | Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Consumer [Member] | Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Consumer [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	932		1,034		2,346		3,018
Operating Segments [Member] | Consumer [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	913		1,020		2,300		2,975
Operating Segments [Member] | Consumer [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	19		14		46		43
Operating Segments [Member] | Consumer [Member] | Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Consumer [Member] | Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Consumer [Member] | Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Consumer [Member] | Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Consumer [Member] | Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Consumer [Member] | Investment management services and other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Consumer [Member] | Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	12,402		17,310		36,929		49,315
Operating Segments [Member] | Consumer [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	419		467		1,218		1,283
Operating Segments [Member] | Consumer [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	5,411		9,603		16,223		26,971
Operating Segments [Member] | Consumer [Member] | Check card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	5,565		5,721		15,916		16,299
Operating Segments [Member] | Consumer [Member] | Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	1,007		1,519		3,572		4,762
Operating Segments [Member] | Consumer [Member] | Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	52,383		30,643		144,344		83,568
Operating Segments [Member] | Consumer [Member] | Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	38,431		13,815		99,186		33,554
Operating Segments [Member] | Consumer [Member] | Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	13,952		16,828		45,158		50,014
Operating Segments [Member] | Consumer [Member] | Other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	2,257		2,474		6,609		7,211
Operating Segments [Member] | Wealth Management [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	111,655		89,422		316,293		248,603
Operating Segments [Member] | Wealth Management [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	58,694		37,070		159,217		96,712
Operating Segments [Member] | Wealth Management [Member] | Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	46,890		24,091		125,189		58,890
Operating Segments [Member] | Wealth Management [Member] | Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	123		1,810		321		9,444
Operating Segments [Member] | Wealth Management [Member] | Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3,787		4,204		11,524		12,192
Operating Segments [Member] | Wealth Management [Member] | Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3,124		3,375		10,066		7,063
Operating Segments [Member] | Wealth Management [Member] | Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	4,770		3,590		12,117		9,123
Operating Segments [Member] | Wealth Management [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	7		(17)		13		(49)
Operating Segments [Member] | Wealth Management [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(14)		(23)		(42)		(60)
Operating Segments [Member] | Wealth Management [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Wealth Management [Member] | Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	21		6		55		11
Operating Segments [Member] | Wealth Management [Member] | Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	39,971		43,663		125,769		130,413
Operating Segments [Member] | Wealth Management [Member] | Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	20,130		20,239		62,460		61,028
Operating Segments [Member] | Wealth Management [Member] | Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	4,613		6,204		15,579		18,736
Operating Segments [Member] | Wealth Management [Member] | Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	11,030		10,740		33,510		32,919
Operating Segments [Member] | Wealth Management [Member] | Investment management services and other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	4,198		6,480		14,220		17,730
Operating Segments [Member] | Wealth Management [Member] | Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	612		638		1,823		1,941
Operating Segments [Member] | Wealth Management [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	572		540		1,715		1,605
Operating Segments [Member] | Wealth Management [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	16		45		54		108
Operating Segments [Member] | Wealth Management [Member] | Check card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Wealth Management [Member] | Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	24		53		54		228
Operating Segments [Member] | Wealth Management [Member] | Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Wealth Management [Member] | Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Wealth Management [Member] | Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0		0		0
Operating Segments [Member] | Wealth Management [Member] | Other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	12,371		8,068		29,471		19,586
Funds Management and Other [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(6,849)		(923)	[9]	(15,311)		5,754	[10]
Funds Management and Other [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	519		79	[9]	368		4,683	[10]
Funds Management and Other [Member] | Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(1)		0	[9]	0		0	[10]
Funds Management and Other [Member] | Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	520		591	[9]	368		1,019	[10]
Funds Management and Other [Member] | Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0	[9]	0		(65)	[10]
Funds Management and Other [Member] | Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		(513)	[9]	0		3,729	[10]
Funds Management and Other [Member] | Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		1	[9]	0		0	[10]
Funds Management and Other [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	84		2	[9]	86		127	[10]
Funds Management and Other [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	2		2	[9]	4		3	[10]
Funds Management and Other [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0	[9]	0		122	[10]
Funds Management and Other [Member] | Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	82		0	[9]	82		2	[10]
Funds Management and Other [Member] | Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(40)		(42)	[9]	(123)		1,591	[10]
Funds Management and Other [Member] | Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		(1)	[9]	0		0	[10]
Funds Management and Other [Member] | Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		1	[9]	0		0	[10]
Funds Management and Other [Member] | Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0	[9]	0		0	[10]
Funds Management and Other [Member] | Investment management services and other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(40)		(42)	[9]	(123)		1,591	[10]
Funds Management and Other [Member] | Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	4		2	[9]	7		1,785	[10]
Funds Management and Other [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		(3)	[9]	0		1,804	[10]
Funds Management and Other [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	4		3	[9]	7		(231)	[10]
Funds Management and Other [Member] | Check card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0	[9]	0		165	[10]
Funds Management and Other [Member] | Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		2	[9]	0		47	[10]
Funds Management and Other [Member] | Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(424)		(463)	[9]	(1,282)		(1,423)	[10]
Funds Management and Other [Member] | Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		(1)	[9]	0		(3)	[10]
Funds Management and Other [Member] | Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(424)		(462)	[9]	(1,282)		(1,420)	[10]
Funds Management and Other [Member] | Other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	$ (6,992)		$ (501)	[9]	$ (14,367)		$ (1,009)	[10]
[1]	Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance.
[2]	Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance.
[3]	Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance.
[4]	Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance.
[5]	In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers.
[6]	In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers.
[7]	In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers.
[8]	In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers.
[9]	CoBiz operations are included in Funds Management and Other for the first quarter of 2019.
[10]	CoBiz operations are included in Funds Management and Other for the first quarter of 2019.

Fair Value Measurements, Fair V

Fair Value Measurements, Fair Value Of Financial Instruments as Measured On a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2020		Jun. 30, 2020	Dec. 31, 2019		Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Assets: [Abstract]
Trading securities	$ 2,245,480			$ 1,623,921
Available for sale securities	12,817,269			11,269,643
Fair value option securities	134,756			1,098,577
Mortgage servicing rights	97,644		$ 97,971	201,886		$ 193,661	$ 208,308	$ 259,254
Derviative contracts, net of cash collateral, Assets, Fair value	593,568			323,375
Liabilities: [Abstract]
Derivative contracts, net of cash collateral, Liabilities, Fair Value	446,328			251,128
U.S. government agency debentures [Member]
Assets: [Abstract]
Trading securities	5,181			44,264
Residential agency mortgage-backed securities [Member]
Assets: [Abstract]
Trading securities	2,150,759			1,504,651
Available for sale securities	9,384,998			8,046,096
Fair value option securities	134,756			1,088,660
Municipal and other tax-exempt securities [Member]
Assets: [Abstract]
Trading securities	30,533			26,196
Available for sale securities	51,601			1,861
Asset-backed securities [Member]
Assets: [Abstract]
Trading securities	0			14,084
U.S. Treasury [Member]
Assets: [Abstract]
Available for sale securities	509			1,600
Fair value option securities	0			9,917
Residential non-agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	34,873			41,609
Commercial agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	3,334,409			3,178,005
Other debt securities [Member]
Assets: [Abstract]
Trading securities	59,007			34,726
Available for sale securities	10,879			472
Fair Value, Recurring [Member]
Assets: [Abstract]
Trading securities	2,245,480			1,623,921
Available for sale securities	12,817,269			11,269,643
Fair value option securities				1,098,577
Residential mortgage loans held for sale	295,290			182,271
Mortgage servicing rights	97,644	[1]		201,886	[2]
Derviative contracts, net of cash collateral, Assets, Fair value	593,568	[3]		323,375	[4]
Liabilities: [Abstract]
Derivative contracts, net of cash collateral, Liabilities, Fair Value	446,328	[3]		251,128	[4]
Fair Value, Recurring [Member] | U.S. government agency debentures [Member]
Assets: [Abstract]
Trading securities	5,181			44,264
Fair Value, Recurring [Member] | Residential agency mortgage-backed securities [Member]
Assets: [Abstract]
Trading securities	2,150,759			1,504,651
Available for sale securities	9,384,998			8,046,096
Fair value option securities	134,756			1,088,660
Fair Value, Recurring [Member] | Municipal and other tax-exempt securities [Member]
Assets: [Abstract]
Trading securities	30,533			26,196
Available for sale securities	51,601			1,861
Fair Value, Recurring [Member] | Asset-backed securities [Member]
Assets: [Abstract]
Trading securities				14,084
Fair Value, Recurring [Member] | U.S. Treasury [Member]
Assets: [Abstract]
Available for sale securities	509			1,600
Fair value option securities				9,917
Fair Value, Recurring [Member] | Residential non-agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	34,873			41,609
Fair Value, Recurring [Member] | Commercial agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	3,334,409			3,178,005
Fair Value, Recurring [Member] | Other debt securities [Member]
Assets: [Abstract]
Trading securities	59,007			34,726
Available for sale securities	10,879			472
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets: [Abstract]
Trading securities	0			0
Available for sale securities	509			1,600
Fair value option securities				9,917
Residential mortgage loans held for sale	0			0
Mortgage servicing rights	0	[1]		0	[2]
Derviative contracts, net of cash collateral, Assets, Fair value	11,713	[3]		8,944	[4]
Liabilities: [Abstract]
Derivative contracts, net of cash collateral, Liabilities, Fair Value	0	[3]		0	[4]
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. government agency debentures [Member]
Assets: [Abstract]
Trading securities	0			0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Residential agency mortgage-backed securities [Member]
Assets: [Abstract]
Trading securities	0			0
Available for sale securities	0			0
Fair value option securities	0			0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal and other tax-exempt securities [Member]
Assets: [Abstract]
Trading securities	0			0
Available for sale securities	0			0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-backed securities [Member]
Assets: [Abstract]
Trading securities				0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Treasury [Member]
Assets: [Abstract]
Available for sale securities	509			1,600
Fair value option securities				9,917
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Residential non-agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	0			0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	0			0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other debt securities [Member]
Assets: [Abstract]
Trading securities	0			0
Available for sale securities	0			0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets: [Abstract]
Trading securities	2,245,480			1,623,921
Available for sale securities	12,816,288			11,267,571
Fair value option securities				1,088,660
Residential mortgage loans held for sale	286,785			173,958
Mortgage servicing rights	0	[1]		0	[2]
Derviative contracts, net of cash collateral, Assets, Fair value	581,855	[3]		314,431	[4]
Liabilities: [Abstract]
Derivative contracts, net of cash collateral, Liabilities, Fair Value	446,328	[3]		251,128	[4]
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. government agency debentures [Member]
Assets: [Abstract]
Trading securities	5,181			44,264
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential agency mortgage-backed securities [Member]
Assets: [Abstract]
Trading securities	2,150,759			1,504,651
Available for sale securities	9,384,998			8,046,096
Fair value option securities	134,756			1,088,660
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal and other tax-exempt securities [Member]
Assets: [Abstract]
Trading securities	30,533			26,196
Available for sale securities	51,601			1,861
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed securities [Member]
Assets: [Abstract]
Trading securities				14,084
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Treasury [Member]
Assets: [Abstract]
Available for sale securities	0			0
Fair value option securities				0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential non-agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	34,873			41,609
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	3,334,409			3,178,005
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other debt securities [Member]
Assets: [Abstract]
Trading securities	59,007			34,726
Available for sale securities	10,407			0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets: [Abstract]
Trading securities	0			0
Available for sale securities	472			472
Fair value option securities				0
Residential mortgage loans held for sale	8,505			8,313
Mortgage servicing rights	97,644	[1]		201,886	[2]
Derviative contracts, net of cash collateral, Assets, Fair value	0	[3]		0	[4]
Liabilities: [Abstract]
Derivative contracts, net of cash collateral, Liabilities, Fair Value	0	[3]		0	[4]
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. government agency debentures [Member]
Assets: [Abstract]
Trading securities	0			0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Residential agency mortgage-backed securities [Member]
Assets: [Abstract]
Trading securities	0			0
Available for sale securities	0			0
Fair value option securities	0			0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal and other tax-exempt securities [Member]
Assets: [Abstract]
Trading securities	0			0
Available for sale securities				0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed securities [Member]
Assets: [Abstract]
Trading securities				0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Treasury [Member]
Assets: [Abstract]
Available for sale securities	0			0
Fair value option securities				0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Residential non-agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	0			0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	0			0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other debt securities [Member]
Assets: [Abstract]
Trading securities	0			0
Available for sale securities	$ 472			$ 472
[1]	A reconciliation of the beginning and ending fair value of mortgage servicing rights and disclosures of significant assumptions used to determine fair value are presented in Note 5, Mortgage Banking Activities.
[2]	A reconciliation of the beginning and ending fair value of mortgage servicing rights and disclosures of significant assumptions used to determine fair value are presented in Note 5, Mortgage Banking Activities.
[3]	See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts in asset positions that were valued based on quoted prices in active markets for identical instruments (Level 1) are primarily exchange-traded interest rate derivative contracts. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments are exchange-traded interest rate, energy and agricultural derivative contracts, fully offset by cash margin.
[4]	See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts based on quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate and energy derivative contracts, net of cash margin. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate and agricultural contracts, fully offset by cash margin.

Fair Value Measurements, Measur

Fair Value Measurements, Measured On Recurring Basis Significant Unobservable Inputs (Details) - Fair Value, Recurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2020		Sep. 30, 2019		Sep. 30, 2020		Sep. 30, 2019
Available-for-sale securities [Member] | Other debt securities [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period	$ 472		$ 472		$ 472		$ 472
Transfer to Level 3 from Level 2	0	[1]	0	[2]	0	[3]	0	[4]
Purchases	0		0		0		0
Proceeds from sales	0		0		0		0
Redemptions and distributions	0		0		0		0
Other comprehensive income (loss)	0		0		0		0
Balance, end of period	472		472		472		472
Available-for-sale securities [Member] | Other debt securities [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0		0		0		0
Residential mortgage loans held for sale [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period	9,685		16,073		8,313		15,207
Transfer to Level 3 from Level 2	304	[1]	261	[2]	3,896	[3]	2,150	[4]
Purchases	0		0		0		0
Proceeds from sales	(1,612)		(3,152)		(3,200)		(4,531)
Redemptions and distributions	0		0		0		0
Other comprehensive income (loss)	0		0		0		0
Balance, end of period	8,505		13,568		8,505		13,568
Residential mortgage loans held for sale [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	$ 128		$ 386		$ (504)		$ 742
[1]	Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards.
[2]	Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards.
[3]	Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards.
[4]	Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards.

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Measurements, Financial Instruments Measured On a Recurring Basis, Quantitative Information (Details) - USD ($) $ in Thousands	Sep. 30, 2020		Dec. 31, 2019
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	$ 12,817,269		$ 11,269,643
Other debt securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	10,879		472
Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	12,817,269		11,269,643
Residential mortgage loans held for sale	295,290		182,271
Fair Value, Recurring [Member] | Other debt securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	10,879		472
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	472		472
Residential mortgage loans held for sale	8,505		8,313
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other debt securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	$ 472		$ 472
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Available-for-sale securities [Member] | Other debt securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Average Yields On Comparable Short-term Taxable Securities Maximum	2.00%		3.00%
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Residential mortgage loans held for sale [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Liquidity Discount on Mortgage Loans Qualifying for Sale to US Govt Agencies	90.24%		95.23%
Interest Rate Spread [Member] | Discounted Cash Flow [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Available-for-sale securities [Member] | Other debt securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	$ 472		$ 472
Liquidity discount [Member] | Quoted prices of loans sold in securitization transactions, with a liquidity discount applied [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Residential mortgage loans held for sale [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Residential mortgage loans held for sale	$ 8,505		$ 8,313
Minimum [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Available-for-sale securities [Member] | Other debt securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Range of Interest Rates used to Value Securities	5.61%	[1]	7.08%	[2]
Range of fair value as a percentage of par value	94.32%	[3]	94.40%	[4]
Maximum [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Available-for-sale securities [Member] | Other debt securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Range of Interest Rates used to Value Securities	5.61%	[1]	7.08%	[2]
Range of fair value as a percentage of par value	94.32%	[3]	94.40%	[4]
Weighted Average [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Available-for-sale securities [Member] | Other debt securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Range of Interest Rates used to Value Securities	5.61%	[1]	7.08%	[2]
Range of fair value as a percentage of par value	94.32%	[3]	94.40%	[4]
[1]	Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 2 percent.
[2]	Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 3 percent.
[3]	Represents fair value as a percentage of par value.
[4]	Represents fair value as a percentage of par value.

Fair Value Measurements, Fair_2

Fair Value Measurements, Fair Value Measured On a Nonrecurring Basis (Details) - Fair Value, Nonrecurring [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Nonaccruing Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross charge-offs against allowance for loan losses	$ 6,371	$ 2,644	$ 28,624	$ 13,868
Net losses (gains) and expenses of repossessed assets, net	0	0	0	0
Real estate and other repossessed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross charge-offs against allowance for loan losses	0	0	0	0
Net losses (gains) and expenses of repossessed assets, net	(4,370)	(979)	(4,452)	(532)
Fair Value, Inputs, Level 1 [Member] | Nonaccruing Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0	0	0
Fair Value, Inputs, Level 1 [Member] | Real estate and other repossessed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0	0	0
Fair Value, Inputs, Level 2 [Member] | Nonaccruing Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	396	79	396	79
Fair Value, Inputs, Level 2 [Member] | Real estate and other repossessed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	16,828	5,044	16,828	5,044
Fair Value, Inputs, Level 3 [Member] | Nonaccruing Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	13,001	9,810	13,001	9,810
Fair Value, Inputs, Level 3 [Member] | Real estate and other repossessed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 2,993	$ 936	$ 2,993	$ 936

Fair Value Measurements Fair _2

Fair Value Measurements Fair Value Measurement, Measured On Non-Recurring Basis, Signfiicant Unobservable Inputs, Quantitative Information (Details) - Fair Value, Nonrecurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	Sep. 30, 2020		Sep. 30, 2019
Nonaccruing Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 13,001		$ 9,810
Real estate and other repossessed assets [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	2,993		936
Discounted Cash Flow [Member] | Nonaccruing Loans [Member] | Management knowledge of Industry [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	13,001		9,810
Discounted Cash Flow [Member] | Real estate and other repossessed assets [Member] | Management knowledge of Industry [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 2,993
Appraised Value, as Adjusted [Member] | Real estate and other repossessed assets [Member] | Marketability adjustments off appraised value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure			$ 936
Minimum [Member] | Nonaccruing Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value of Impaired Loans as Percentage of Unpaid Principal Balance	0.00%	[1]	8.00%	[2]
Minimum [Member] | Real estate and other repossessed assets [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value Measurement, Percentage of Appraised Value.			75.00%
Maximum [Member] | Nonaccruing Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value of Impaired Loans as Percentage of Unpaid Principal Balance	73.00%	[1]	76.00%	[2]
Maximum [Member] | Real estate and other repossessed assets [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value Measurement, Percentage of Appraised Value.			89.00%
Weighted Average [Member] | Nonaccruing Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value of Impaired Loans as Percentage of Unpaid Principal Balance	18.00%	[1]	28.00%	[2]
Weighted Average [Member] | Real estate and other repossessed assets [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value Measurement, Percentage of Appraised Value.			85.00%
[1]	Represents fair value as a percentage of the unpaid principal balance.
[2]	Represents fair value as a percentage of the unpaid principal balance.

Fair Value Measurements, Financ

Fair Value Measurements, Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2020		Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	$ 2,245,480			$ 1,623,921
Investment Securities, Gross Amortized Cost	256,740			293,418
Investment securities, Allowance for Credit Loss	739	[1]		0
Investment securities, net of allowance	256,001			293,418
Available for sale securities	12,817,269			11,269,643
Fair value option securities	134,756			1,098,577
Residential mortgage loans held for sale	295,290			182,271
Loans	23,803,300			21,750,987
Allowance for loan losses	(419,777)			(210,759)	$ (204,432)	$ (202,534)	$ (207,457)
Loans, net of allowance	23,383,523			21,540,228
Mortgage servicing rights	97,644		$ 97,971	201,886	193,661	208,308	259,254
Derviative contracts, net of cash collateral, Assets, Fair value	593,568			323,375
Time deposits	2,007,973			2,217,849
Subordinated debentures	275,986			275,923
Derivative contracts, net of cash collateral, Liabilities, Fair Value	446,328			251,128
Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	13,565,706			14,031,650
Allowance for loan losses	(290,277)			(118,187)	(106,643)	(106,397)	(102,226)
Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,693,700			4,433,783
Allowance for loan losses	(71,575)			(51,805)	$ (54,350)	$ (54,188)	$ (60,026)
Loans to individuals [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	3,446,569			2,084,172
Allowance for loan losses	(57,925)
Paycheck Protection Program
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,097,325
Allowance for loan losses	0
U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	5,181			44,264
Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	2,150,759			1,504,651
Investment Securities, Gross Amortized Cost	9,317			10,676
Available for sale securities	9,384,998			8,046,096
Fair value option securities	134,756			1,088,660
Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	30,533			26,196
Investment Securities, Gross Amortized Cost	76,109			93,653
Available for sale securities	51,601			1,861
U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	509			1,600
Fair value option securities	0			9,917
Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	34,873			41,609
Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	3,334,409			3,178,005
Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	59,007			34,726
Investment Securities, Gross Amortized Cost	171,314			189,089
Available for sale securities	10,879			472
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	658,612			735,836
Interest-bearing cash and cash equivalents	347,759			522,985
Trading securities	2,245,480			1,623,921
Investment Securities, Gross Amortized Cost	256,740
Investment securities, Allowance for Credit Loss	(739)
Investment securities, net of allowance	256,001			293,418
Available for sale securities	12,817,269			11,269,643
Fair value option securities				1,098,577
Residential mortgage loans held for sale	295,290			182,271
Loans	23,803,300			21,750,987
Allowance for loan losses	(419,777)			(210,759)
Loans, net of allowance	23,383,523			21,540,228
Mortgage servicing rights	97,644			201,886
Derviative contracts, net of cash collateral, Assets, Fair value	593,568			323,375
Deposits with no stated maturity	32,965,027			25,403,319
Time deposits	2,007,973			2,217,849
Other borrowed funds	3,745,081			8,345,405
Subordinated debentures	275,986			275,923
Derivative contracts, net of cash collateral, Liabilities, Fair Value	446,328			251,128
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	13,565,706			14,031,650
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,693,700			4,433,783
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Residential mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans				2,084,172
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Loans to individuals [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	3,446,569
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans				1,201,382
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Paycheck Protection Program
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,097,325
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	5,181			44,264
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	2,150,759			1,504,651
Investment Securities, Gross Amortized Cost	9,317
Investment securities, net of allowance				10,676
Available for sale securities	9,384,998			8,046,096
Fair value option securities	134,756			1,088,660
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	30,533			26,196
Investment Securities, Gross Amortized Cost	76,109
Investment securities, net of allowance				93,653
Available for sale securities	51,601			1,861
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Asset-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities				14,084
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	59,007			34,726
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	509			1,600
Fair value option securities				9,917
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	34,873			41,609
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	3,334,409			3,178,005
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment Securities, Gross Amortized Cost	171,314
Investment securities, net of allowance				189,089
Available for sale securities	10,879			472
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	658,612			735,836
Interest-bearing cash and cash equivalents	347,759			522,985
Trading securities	2,245,480			1,623,921
Investment Securities, Gross Amortized Cost	284,929
Investment securities, Allowance for Credit Loss	0
Investment securities, net of allowance	284,929			314,402
Available for sale securities	12,817,269			11,269,643
Fair value option securities				1,098,577
Residential mortgage loans held for sale	295,290			182,271
Loans	23,697,211			21,689,329
Allowance for loan losses	0			0
Loans, net of allowance	23,697,211			21,689,329
Mortgage servicing rights	97,644			201,886
Derviative contracts, net of cash collateral, Assets, Fair value	593,568			323,375
Deposits with no stated maturity	32,965,027			25,403,319
Time deposits	2,019,474			2,212,467
Other borrowed funds	3,741,686			8,315,860
Subordinated debentures	269,083			284,627
Derivative contracts, net of cash collateral, Liabilities, Fair Value	446,328			251,128
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	13,500,846			13,966,221
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,673,857			4,422,717
Estimate of Fair Value, Fair Value Disclosure [Member] | Residential mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans				2,098,093
Estimate of Fair Value, Fair Value Disclosure [Member] | Loans to individuals [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	3,452,042
Estimate of Fair Value, Fair Value Disclosure [Member] | Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans				1,202,298
Estimate of Fair Value, Fair Value Disclosure [Member] | Paycheck Protection Program
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,070,466
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	5,181			44,264
Estimate of Fair Value, Fair Value Disclosure [Member] | Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	2,150,759			1,504,651
Investment Securities, Gross Amortized Cost	10,219
Investment securities, net of allowance				11,164
Available for sale securities	9,384,998			8,046,096
Fair value option securities	134,756			1,088,660
Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	30,533			26,196
Investment Securities, Gross Amortized Cost	80,368
Investment securities, net of allowance				96,897
Available for sale securities	51,601			1,861
Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities				14,084
Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	59,007			34,726
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	509			1,600
Fair value option securities				9,917
Estimate of Fair Value, Fair Value Disclosure [Member] | Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	34,873			41,609
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	3,334,409			3,178,005
Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment Securities, Gross Amortized Cost	194,342
Investment securities, net of allowance				206,341
Available for sale securities	10,879			472
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	658,612			735,836
Interest-bearing cash and cash equivalents	347,759			522,985
Trading securities	0			0
Investment Securities, Gross Amortized Cost	0
Investment securities, Allowance for Credit Loss	0
Investment securities, net of allowance	0			0
Available for sale securities	509			1,600
Fair value option securities				9,917
Residential mortgage loans held for sale	0			0
Loans	0			0
Allowance for loan losses	0			0
Loans, net of allowance	0			0
Mortgage servicing rights	0			0
Derviative contracts, net of cash collateral, Assets, Fair value	11,713			8,944
Deposits with no stated maturity	0			0
Time deposits	0			0
Other borrowed funds	0			0
Subordinated debentures	0			0
Derivative contracts, net of cash collateral, Liabilities, Fair Value	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans				0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Loans to individuals [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans				0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Paycheck Protection Program
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Investment Securities, Gross Amortized Cost	0
Investment securities, net of allowance				0
Available for sale securities	0			0
Fair value option securities	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Investment Securities, Gross Amortized Cost	0
Investment securities, net of allowance				0
Available for sale securities	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities				0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	509			1,600
Fair value option securities				9,917
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment Securities, Gross Amortized Cost	0
Investment securities, net of allowance				0
Available for sale securities	0			0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	0			0
Interest-bearing cash and cash equivalents	0			0
Trading securities	2,245,480			1,623,921
Investment Securities, Gross Amortized Cost	97,963
Investment securities, Allowance for Credit Loss	0
Investment securities, net of allowance	97,963			116,267
Available for sale securities	12,816,288			11,267,571
Fair value option securities				1,088,660
Residential mortgage loans held for sale	286,785			173,958
Loans	0			0
Allowance for loan losses	0			0
Loans, net of allowance	0			0
Mortgage servicing rights	0			0
Derviative contracts, net of cash collateral, Assets, Fair value	581,855			314,431
Deposits with no stated maturity	0			0
Time deposits	0			0
Other borrowed funds	0			0
Subordinated debentures	269,083			284,627
Derivative contracts, net of cash collateral, Liabilities, Fair Value	446,328			251,128
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0			0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0			0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans				0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Loans to individuals [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans				0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Paycheck Protection Program
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	5,181			44,264
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	2,150,759			1,504,651
Investment Securities, Gross Amortized Cost	10,219
Investment securities, net of allowance				11,164
Available for sale securities	9,384,998			8,046,096
Fair value option securities	134,756			1,088,660
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	30,533			26,196
Investment Securities, Gross Amortized Cost	80,368
Investment securities, net of allowance				96,897
Available for sale securities	51,601			1,861
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities				14,084
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	59,007			34,726
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0
Fair value option securities				0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	34,873			41,609
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	3,334,409			3,178,005
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment Securities, Gross Amortized Cost	7,376
Investment securities, net of allowance				8,206
Available for sale securities	10,407			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	0			0
Interest-bearing cash and cash equivalents	0			0
Trading securities	0			0
Investment Securities, Gross Amortized Cost	186,966
Investment securities, Allowance for Credit Loss	0
Investment securities, net of allowance	186,966			198,135
Available for sale securities	472			472
Fair value option securities				0
Residential mortgage loans held for sale	8,505			8,313
Loans	23,697,211			21,689,329
Allowance for loan losses	0			0
Loans, net of allowance	23,697,211			21,689,329
Mortgage servicing rights	97,644			201,886
Derviative contracts, net of cash collateral, Assets, Fair value	0			0
Deposits with no stated maturity	32,965,027			25,403,319
Time deposits	2,019,474			2,212,467
Other borrowed funds	3,741,686			8,315,860
Subordinated debentures	0			0
Derivative contracts, net of cash collateral, Liabilities, Fair Value	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	13,500,846			13,966,221
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,673,857			4,422,717
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans				2,098,093
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Loans to individuals [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	3,452,042
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans				1,202,298
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Paycheck Protection Program
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,070,466
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Investment Securities, Gross Amortized Cost	0
Investment securities, net of allowance				0
Available for sale securities	0			0
Fair value option securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Investment Securities, Gross Amortized Cost	0
Investment securities, net of allowance				0
Available for sale securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities				0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0
Fair value option securities				0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment Securities, Gross Amortized Cost	186,966
Investment securities, net of allowance				198,135
Available for sale securities	$ 472			$ 472
[1]	Effective with the adoption of FASB ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) on January 1, 2020.