BOK Financial (BOKF) 10-Q 4 Aug 20 2020 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information	6 Months Ended
	Jun. 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 ET AL
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	70,306,690
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Document Type	10-Q
Entity File Number	0-19341
Amendment Flag	false
Document Period End Date	Jun. 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		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Interest revenue [Abstract]
Loans	$ 215,438	$ 293,332	$ 458,656	$ 573,204
Residential mortgage loans held for sale	2,140	1,754	3,263	3,417
Trading Securities	11,407	15,498	23,167	34,193
Investment securities	3,000	2,905	6,121	6,939
Available for sale securities	68,297	59,880	138,017	116,711
Fair value option securities	4,110	7,503	15,818	12,740
Restricted equity securities	1,880	6,516	7,774	12,861
Interest-bearing cash and cash equivalents	112	3,432	2,505	6,829
Total interest revenue	306,384	390,820	655,321	766,894
Interest expense [Abstract]
Deposits	17,745	43,183	63,904	80,600
Borrowed funds	6,996	58,404	44,781	115,214
Subordinated debentures	3,539	3,801	7,172	7,546
Total interest expense	28,280	105,388	115,857	203,360
Net interest revenue	278,104	285,432	539,464	563,534
Provision for credit losses	135,321	5,000	229,092	13,000
Net interest revenue after provision for credit losses	142,783	280,432	310,372	550,534
Total fees and commissions	213,680	176,108	406,404	336,660
Other gains (losses), net	6,768	3,480	(3,973)	6,456
Gain on derivatives, net	21,885	11,150	40,305	15,817
Gain (loss) on fair value option securities, net	(14,459)	9,853	53,934	19,518
Change in fair value of mortgage servicing rights	(761)	(29,555)	(89,241)	(50,221)
Gain on available for sale securities, net	5,580	1,029	5,583	1,105
Total other operating revenue	232,693	172,065	413,012	329,335
Other operating expense [Abstract]
Personnel	176,235	160,342	332,416	329,570
Business promotion	1,935	10,142	8,150	18,016
Contributions to BOKF Foundation	3,000	1,000	3,000	1,000
Professional fees and services	12,161	13,002	25,109	29,141
Net occupancy and equipment	30,675	26,880	56,736	56,401
Insurance	5,156	6,454	10,136	11,293
Data processing and communications	32,942	29,735	65,685	61,184
Printing, postage and supplies	3,502	4,107	7,774	8,992
Net losses and operating expenses of repossessed assets	1,766	580	3,297	2,576
Amortization of intangible assets	5,190	5,138	10,284	10,329
Mortgage banking costs	15,598	11,545	26,143	21,451
Other expense	7,227	8,212	15,281	14,341
Total other operating expense	295,387	277,137	564,011	564,294
Net income before taxes	80,089	175,360	159,373	315,575
Federal and state income taxes	15,803	37,580	33,103	67,530
Net income	64,286	137,780	126,270	248,045
Net income (loss) attributable to non-controlling interests	(407)	217	(502)	(130)
Net income attributable to BOK Financial Corporation shareholders	$ 64,693	$ 137,563	$ 126,772	$ 248,175
Dividends declared per share	$ 0.51	$ 0.50	$ 1.02	$ 1
Earnings Per Share [Abstract]
Basic	0.92	1.93	1.80	3.47
Diluted	$ 0.92	$ 1.93	$ 1.80	$ 3.46
Average shares used in computation: [Abstract]
Basic	69,876,043	70,887,063	69,999,865	71,135,414
Diluted	69,877,467	70,902,033	70,003,817	71,151,558
Brokerage and trading revenue [Member]
Total fees and commissions	$ 62,022	$ 40,526	$ 112,801	$ 72,143
Transaction card revenue [Member]
Total fees and commissions	22,940	21,915	44,821	42,653
Fiduciary and asset management revenue [Member]
Total fees and commissions	41,257	45,025	85,715	88,383
Deposit service charges and fees [Member]
Total fees and commissions	22,046	28,074	48,176	56,317
Mortgage banking revenue [Member]
Total fees and commissions	53,936	28,131	91,103	51,965
Other revenue [Member]
Total fees and commissions	$ 11,479	$ 12,437	$ 23,788	$ 25,199

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020		Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 64,286	$ 137,780	$ 126,270		$ 248,045
Other Comprehensive Income (Loss), before Tax [Abstract]
Net change in unrealized gain (loss)	56,922	135,417	354,765		228,156
Reclassification Adjustments Included in Earnings [Abstract]
Gain on available for sale securities, net	(5,577)	(1,029)	(5,580)		(1,105)
Other comprehensive income before income taxes	51,345	134,388	349,185		227,051
Federal and state income taxes	12,321	32,288	83,792	[1]	55,897	[1]
Other comprehensive income, net of income taxes	39,024	102,100	265,393		171,154
Comprehensive income	103,310	239,880	391,663		419,199
Comprehensive income (loss) attributable to non-controlling interests	(407)	217	(502)		(130)
Comprehensive income attributable to BOK Financial Corp. shareholders	$ 103,717	$ 239,663	$ 392,165		$ 419,329
[1]	Calculated using a 25 percent blended federal and state statutory tax rate.

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Assets [Abstract]
Cash and due from banks	$ 762,453	$ 735,836
Interest-bearing cash and cash equivalents	485,319	522,985
Trading securities	1,196,105	1,623,921
Investment securities, net of allowance	267,988	293,418
Available for sale securities	12,475,919	11,269,643
Fair value option securities	722,657	1,098,577
Restricted equity securities	125,683	460,552
Residential mortgage loans held for sale	319,357	182,271
Loans	24,155,890	21,750,987
Allowance for loan losses	(435,597)	(210,759)
Loans, net of allowance	23,720,293	21,540,228
Premises and equipment, net	550,230	535,519
Receivables	226,934	231,811
Goodwill	1,048,091	1,048,091
Intangible assets, net	123,595	125,271
Mortgage servicing rights	97,971	201,886
Real estate and other repossessed assets, net of allowance	35,330	20,359
Derivative contracts, net	651,553	323,375
Cash surrender value of bank-owned life insurance	393,741	389,879
Receivable on unsettled securities sales	1,863,719	1,020,404
Other assets	752,936	547,995
Total assets	45,819,874	42,172,021
Deposits [Abstract]
Noninterest-bearing demand deposits	11,992,165	9,461,291
Interest-bearing deposits: [Abstract]
Transaction	18,850,418	15,391,752
Savings	696,971	550,276
Time	2,352,760	2,217,849
Total deposits	33,892,314	27,621,168
Funds purchased and repurchase agreements	1,357,602	3,818,350
Other borrowings	3,173,563	4,527,055
Subordinated debentures	275,973	275,923
Accrued interest, taxes and expense	365,634	259,701
Derivative contracts, net	610,020	251,128
Due on unsettled securities purchases	599,510	182,547
Other liabilities	440,835	372,230
Total liabilities	40,715,451	37,308,102
Shareholders' equity: [Abstract]
Common stock	5	5
Capital surplus	1,357,706	1,350,995
Retained earnings	3,737,862	3,729,778
Treasury stock	(368,894)	(329,906)
Accumulated other comprehensive gain	370,316	104,923
Total shareholders’ equity	5,096,995	4,855,795
Non-controlling interests	7,428	8,124
Total equity	5,104,423	4,863,919
Total liabilities and equity	$ 45,819,874	$ 42,172,021

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020		Dec. 31, 2019
Investment securities [Abstract]
Investment Securities, fair value	$ 299,126		$ 314,402
Investment securities, Allowance for Credit Loss	1,628	[1]	0
Allowance for real estate and other repossessed assets	$ 10,861		$ 11,013
Shareholders' equity: [Abstract]
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)	75,999,195		75,758,597
Common stock, shares outstanding (in shares)	75,999,195		75,758,597
Treasury stock, shares at cost (in shares)	5,692,505		5,178,999
[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	248,045							248,175							248,175			(130)
Other comprehensive income (loss)	171,154												171,154		171,154
Repurchase of common stock (in shares)											955
Repurchase of common stock	(80,702)										$ (80,702)				(80,702)
Stock options exercised (in shares)				18
Stock options exercised	903					903									903
Non-vested shares awarded, net (in shares)				27
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	8,149					8,149									8,149
Cash dividends on common stock	(71,784)							(71,784)							(71,784)
Capital calls and distributions, net	(1,769)																	(1,769)
Balance, end of period (in shares) at Jun. 30, 2019				75,756							4,562
Balance, end 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
Balance, beginning of period (in shares) at Mar. 31, 2019				75,762							4,312
Balance, beginning of period at Mar. 31, 2019	4,531,709			$ 5		1,340,323		3,447,076			$ (261,000)		(3,531)		4,522,873			8,836
Net income	137,780							137,563							137,563			217
Other comprehensive income (loss)	102,100												102,100		102,100
Repurchase of common stock (in shares)											250
Repurchase of common stock	(20,125)										$ (20,125)				(20,125)
Stock options exercised (in shares)				0
Stock options exercised	24					24									24
Non-vested shares awarded, net (in shares)				(6)
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	2,735					2,735									2,735
Cash dividends on common stock	(35,732)							(35,732)							(35,732)
Capital calls and distributions, net	(16)																	(16)
Balance, end of period (in shares) at Jun. 30, 2019				75,756							4,562
Balance, end 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
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	126,270							126,772							126,772			(502)
Other comprehensive income (loss)	265,393												265,393		265,393
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)				230
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	6,125					6,125									6,125
Cash dividends on common stock	(71,992)							(71,992)							(71,992)
Capital calls and distributions, net	(194)																	(194)
Balance, end of period (in shares) at Jun. 30, 2020				75,999							5,693
Balance, end 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
Balance, beginning of period (in shares) at Mar. 31, 2020				76,001							5,692
Balance, beginning of period at Mar. 31, 2020	5,034,160			$ 5		1,354,826		3,709,019			$ (368,894)		331,292		5,026,248			7,912
Net income	64,286							64,693							64,693			(407)
Other comprehensive income (loss)	39,024												39,024		39,024
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)				(2)
Non-vested shares awarded, net						0
Vesting of non-vested shares (in shares)											1
Vesting of non-vested shares	0										$ 0				0
Share-based compensation	2,880					2,880									2,880
Cash dividends on common stock	(35,850)							(35,850)							(35,850)
Capital calls and distributions, net	(77)																	(77)
Balance, end of period (in shares) at Jun. 30, 2020				75,999							5,693
Balance, end 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

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash Flows From Operating Activities: [Abstract]
Net income	$ 126,270	$ 248,045
Adjustments to reconcile net income to net cash used in operating activities: [Abstract]
Provision for credit losses	229,092	13,000
Change in fair value of mortgage servicing rights due to market assumption changes	89,241	50,221
Change in the fair value of mortgage servicing rights due to principal payments	17,779	15,664
Net unrealized (gains) losses from derivative contracts	(56,678)	(17,095)
Share-based compensation	6,125	8,149
Depreciation and amortization	47,016	45,926
Net amortization of discounts and premiums	7,199	(10,913)
Net losses (gains) on financial instruments and other losses (gains), net	(2,186)	564
Net gain on mortgage loans held for sale	(42,411)	(16,735)
Mortgage loans originated for sale	(1,733,205)	(1,240,368)
Proceeds from sale of mortgage loans held for sale	1,654,433	1,215,756
Capitalized mortgage servicing rights	(13,906)	(14,939)
Change in trading and fair value option securities	801,215	(799,241)
Change in receivables	(724,486)	(228,973)
Change in other assets	(29,352)	(4,965)
Change in accrued interest, taxes and expense	36,773	(41,866)
Change in other liabilities	373,541	100,731
Net cash provided by (used in) operating activities	786,460	(677,039)
Cash Flows From Investing Activities: [Abstract]
Proceeds from maturities or redemptions of investment securities	23,296	26,513
Proceeds from maturities or redemptions of available for sale securities	1,070,585	704,542
Purchases of available for sale securities	(2,139,775)	(2,510,271)
Proceeds from sales of available for sale securities	205,945	367,357
Change in amount receivable on unsettled available for sale securities transactions	(118,744)	(28,580)
Loans originated, net of principal collected	(2,294,658)	(569,075)
Net payments on derivative asset contracts	(67,105)	(10,838)
Proceeds from disposition of assets	710,269	116,163
Purchases of assets	(416,815)	(250,911)
Net cash used in investing activities	(3,027,002)	(2,155,100)
Cash Flows From Financing Activities: [Abstract]
Net change in demand deposits, transaction deposits and savings accounts	6,136,235	(73,200)
Net change in time deposits	134,911	114,377
Net change in other borrowed funds	(3,971,540)	2,968,697
Net proceeds on derivative liability contracts	60,851	6,140
Net change in derivative margin accounts	(96,114)	(152,533)
Change in amount due on unsettled available for sale securities transactions	75,544	313,736
Issuance of common and treasury stock, net	(5,022)	(525)
Repurchase of common stock	(33,380)	(80,702)
Dividends paid	(71,992)	(71,784)
Net cash provided by financing activities	2,229,493	3,024,206
Net increase (decrease) in cash and cash equivalents	(11,049)	192,067
Cash and cash equivalents at beginning of period	1,258,821	1,143,424
Cash and cash equivalents at end of period	1,247,772	1,335,491
Supplemental Cash Flow Information: [Abstract]
Cash paid for interest	117,471	203,513
Cash paid for taxes	5,470	54,722
Net loans and bank premises transferred to repossessed real estate and other assets	19,556	2,606
Residential mortgage loans guaranteed by U.S. government agencies that became eligible for repurchase during the period	157,300	44,258
Conveyance of other real estate owned guaranteed by U.S. government agencies	6,255	15,484
Right-of-use assets obtained in exchange for operating lease liabilities	$ 9,151	$ 12,754

Significant Accounting Policies

Significant Accounting Policies	6 Months Ended
	Jun. 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 six-month period ended June 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	6 Months Ended
	Jun. 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): June 30, 2020 December 31, 2019 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. government agency debentures $ 4,237 $ 19 $ 44,264 $ 6 Residential agency mortgage-backed securities 1,146,454 3,589 1,504,651 2,293 Municipal and other tax-exempt securities 22,710 116 26,196 60 Asset-backed securities 5 — 14,084 (21) Other debt securities 22,699 127 34,726 21 Total trading securities $ 1,196,105 $ 3,851 $ 1,623,921 $ 2,359 Investment Securities The amortized cost and fair values of investment securities are as follows (in thousands): June 30, 2020 Amortized Fair Gross Unrealized Cost Value Gain Loss Municipal and other tax-exempt $ 84,239 $ 88,623 $ 4,384 $ — Residential agency mortgage-backed securities 9,812 10,734 922 — Other debt securities 175,565 199,769 24,235 (31) Total investment securities 269,616 299,126 29,541 (31) Allowance for credit losses 1 (1,628) Investment securities, net of allowance 267,988 299,126 29,541 (31) 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 June 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 $ 39,734 $ 87,863 $ 122,309 $ 9,898 $ 259,804 4.95 Fair value 40,151 96,615 141,378 10,248 288,392 Residential mortgage-backed securities: Amortized cost $ 9,812 2 Fair value 10,734 Total investment securities: Amortized cost $ 269,616 Fair value 299,126 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 4.6 years based upon current prepayment assumptions. Temporarily Impaired Investment Securities (in thousands): June 30, 2020 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized Investment: Other debt securities 4 — — 2,142 31 2,142 31 Total investment securities 4 $ — $ — $ 2,142 $ 31 $ 2,142 $ 31 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): June 30, 2020 Amortized Fair Gross Unrealized Cost Value Gain Loss U.S. Treasury $ 900 $ 912 $ 12 $ — Municipal and other tax-exempt 29,670 31,240 1,570 — Mortgage-backed securities: Residential agency 8,789,466 9,147,238 360,056 (2,284) Residential non-agency 21,941 35,250 13,318 (9) Commercial agency 3,146,108 3,260,807 116,042 (1,343) Other debt securities 500 472 — (28) Total available for sale securities $ 11,988,585 $ 12,475,919 $ 490,998 $ (3,664) 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 June 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 $ 34,044 $ 1,321,471 $ 1,241,310 $ 580,353 $ 3,177,178 8.03 Fair value 34,144 1,375,128 1,280,251 603,908 3,293,431 Residential mortgage-backed securities: Amortized cost $ 8,811,407 2 Fair value 9,182,488 Total available-for-sale securities: Amortized cost $ 11,988,585 Fair value 12,475,919 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 3.1 years based upon current prepayment assumptions. Sales of available for sale securities resulted in gains and losses as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Proceeds $ 179,051 $ 122,098 $ 205,945 $ 367,357 Gross realized gains 5,580 1,029 5,583 6,327 Gross realized losses — — — (5,222) Related federal and state income tax expense (benefit) 1,421 262 1,422 281 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 $12.3 billion at June 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) June 30, 2020 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 36 492,864 1,375 173,997 909 666,861 2,284 Residential non-agency 1 1,695 9 — — 1,695 9 Commercial agency 22 271,735 902 160,806 441 432,541 1,343 Other debt securities 1 — — 472 28 472 28 Total available for sale securities 60 $ 766,294 $ 2,286 $ 335,275 $ 1,378 $ 1,101,569 $ 3,664 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 June 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): June 30, 2020 December 31, 2019 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. Treasury $ 92,742 $ 307 $ 9,917 $ (48) Residential agency mortgage-backed securities 629,915 16,549 1,088,660 14,109 Total $ 722,657 $ 16,856 $ 1,098,577 $ 14,061

Derivatives

Derivatives	6 Months Ended
	Jun. 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 June 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 2,772,027 140,157 (42) 140,115 — 140,115 Energy contracts 2,912,225 434,455 (199,805) 234,650 (155,160) 79,490 Agricultural contracts 13,183 59 (35) 24 — 24 Foreign exchange contracts 283,424 281,801 — 281,801 (507) 281,294 Equity option contracts 75,987 1,097 — 1,097 (286) 811 Total customer risk management programs 6,056,846 857,569 (199,882) 657,687 (155,953) 501,734 Trading 50,132,348 219,647 (91,830) 127,817 — 127,817 Internal risk management programs 865,964 23,823 (1,821) 22,002 — 22,002 Total derivative contracts $ 57,055,158 $ 1,101,039 $ (293,533) $ 807,506 $ (155,953) $ 651,553 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 2,772,027 140,509 (42) 140,467 (129,094) 11,373 Energy contracts 2,718,690 408,813 (199,805) 209,008 (3,298) 205,710 Agricultural contracts 13,191 50 (35) 15 (15) — Foreign exchange contracts 270,594 269,013 — 269,013 — 269,013 Equity option contracts 75,987 1,097 — 1,097 — 1,097 Total customer risk management programs 5,850,489 819,482 (199,882) 619,600 (132,407) 487,193 Trading 52,408,519 213,170 (91,830) 121,340 — 121,340 Internal risk management programs 168,491 3,308 (1,821) 1,487 — 1,487 Total derivative contracts $ 58,427,499 $ 1,035,960 $ (293,533) $ 742,427 $ (132,407) $ 610,020 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 June 30, 2020 June 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 $ — $ — $ 2,212 $ — Interest rate swaps 746 — 942 — Energy contracts 5,383 — 2,086 — Agricultural contracts 6 — 4 — Foreign exchange contracts 107 — 100 — Equity option contracts — — — — Total customer risk management programs 6,242 — 5,344 — Trading 1 32,577 — 8,030 — Internal risk management programs — 21,885 — 11,150 Total derivative contracts $ 38,819 $ 21,885 $ 13,374 $ 11,150 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. Six Months Ended June 30, 2020 June 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 $ — $ — $ 7,912 $ — Interest rate swaps 1,688 — 1,535 — Energy contracts 7,390 — 2,312 — Agricultural contracts 21 — 8 — Foreign exchange contracts 365 — 254 — Equity option contracts — — — — Total customer risk management programs 9,464 — 12,021 — Trading 1 (8,078) — 735 — Internal risk management programs — 40,305 — 15,817 Total derivative contracts $ 1,386 $ 40,305 $ 12,756 $ 15,817

Loans and Allowances for Credit

Loans and Allowances for Credit Losses	6 Months Ended
	Jun. 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): June 30, 2020 Fixed Variable Non-accrual Total Commercial 3,215,865 10,740,646 201,999 $ 14,158,510 Commercial real estate 1,029,544 3,510,644 13,956 4,554,144 Paycheck protection program 2,081,428 — — 2,081,428 Loans to individuals 2,038,990 1,283,377 39,441 3,361,808 Total $ 8,365,827 $ 15,534,667 $ 255,396 $ 24,155,890 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 June 30, 2020, outstanding commitments totaled $10.3 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 June 30, 2020, outstanding standby letters of credit totaled $693 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 June 30, 2020 Commercial Commercial Real Estate Paycheck Protection Program Loans to Individuals Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 213,438 $ 51,461 $ — $ 50,412 $ — $ 315,311 Provision for loan losses 111,153 17,221 — 5,991 — 134,365 Loans charged off (14,487) (1) — (1,082) — (15,570) Recoveries of loans previously charged off 318 75 — 1,098 — 1,491 Ending Balance $ 310,422 $ 68,756 $ — $ 56,419 — $ 435,597 Allowance for off-balance sheet credit risk from unfunded loan commitments: Beginning balance $ 14,040 $ 12,575 $ — $ 1,899 $ — $ 28,514 Provision for off-balance sheet credit risk 542 3,844 — 19 — 4,405 Ending Balance $ 14,582 $ 16,419 $ — $ 1,918 $ — $ 32,919 Six Months Ended June 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 188,876 22,336 — 19,117 — 230,329 Loans charged off (31,102) (887) — (2,498) — (34,487) Recoveries 780 122 — 2,285 — 3,187 Ending balance $ 310,422 $ 68,756 $ — $ 56,419 $ — $ 435,597 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 3,004 4,652 — 126 — 7,782 Ending balance $ 14,582 $ 16,419 $ — $ 1,918 $ — $ 32,919 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, required a provision of $54.6 million during the second quarter of 2020. All other changes totaled $84.2 million, $14.4 million related to changes in impairment, $55.7 million related to risk grading and other portfolio changes and net charge-offs of $14.1 million. The allowance for loan losses and recorded investment of the related loans by portfolio segment for each measurement method at June 30, 2020 is as follows (in thousands): Collectively Measured Individually Measured Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Commercial $ 13,956,511 $ 286,639 $ 201,999 $ 23,783 $ 14,158,510 $ 310,422 Commercial real estate 4,540,188 68,216 13,956 540 4,554,144 68,756 Paycheck protection program 2,081,428 — — — 2,081,428 — Loans to individuals 3,322,367 56,419 39,441 — 3,361,808 56,419 Total 23,900,494 411,274 255,396 24,323 24,155,890 435,597 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 June 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 $ 23,119 $ 62,250 $ 94,216 $ 8,344 $ 1,427 $ 2,908 $ 2,664,680 $ — $ 2,856,944 Special Mention — — 9,720 — — — 493,719 — 503,439 Accruing Substandard — — 194 — 49 — 450,559 — 450,802 Nonaccrual — 6,586 15,496 — — 38,325 102,582 — 162,989 Total energy 23,119 68,836 119,626 8,344 1,476 41,233 3,711,540 — 3,974,174 Healthcare Pass 212,781 609,757 641,607 489,096 248,094 767,193 245,123 — 3,213,651 Special Mention — 27,500 — 3,714 — 13,771 3,515 — 48,500 Accruing Substandard — 3,176 7,746 973 161 11,491 — — 23,547 Nonaccrual — 18 183 — — 2,935 509 — 3,645 Total healthcare 212,781 640,451 649,536 493,783 248,255 795,390 249,147 — 3,289,343 Services Pass 335,961 475,608 437,812 366,772 400,480 857,564 743,258 673 3,618,128 Special Mention — 3,919 1,474 170 4,513 3,626 35,203 — 48,905 Accruing Substandard 98 12,077 26,814 12,393 8,123 4,753 27,558 — 91,816 Nonaccrual — 2,978 — 8,647 1,153 7,529 725 — 21,032 Total services 336,059 494,582 466,100 387,982 414,269 873,472 806,744 673 3,779,881 General business Pass 256,821 485,956 359,249 256,403 147,056 251,326 1,258,843 2,671 3,018,325 Special Mention — 10,196 763 11,244 941 4,046 3,404 — 30,594 Accruing Substandard 21 13,906 13,989 2,353 6,216 5,206 10,165 4 51,860 Nonaccrual 1,675 3,713 5,168 1,938 1,315 140 369 15 14,333 Total general business 258,517 513,771 379,169 271,938 155,528 260,718 1,272,781 2,690 3,115,112 Total commercial 830,476 1,717,640 1,614,431 1,162,047 819,528 1,970,813 6,040,212 3,363 14,158,510 Commercial real estate: Pass 345,439 1,131,573 1,037,584 536,047 378,852 852,020 234,148 — 4,515,663 Special Mention — — — 12,200 1,622 3,283 100 — 17,205 Accruing Substandard — — — 7,228 — 65 27 — 7,320 Nonaccrual — — — 232 7,477 803 5,444 — 13,956 Total commercial real estate 345,439 1,131,573 1,037,584 555,707 387,951 856,171 239,719 — 4,554,144 Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total Paycheck protection program: Pass 2,081,428 — — — — — — — 2,081,428 Total paycheck protection program 2,081,428 — — — — — — — 2,081,428 Loans to individuals: Residential mortgage Pass 226,396 191,344 161,193 187,649 196,218 438,056 349,610 26,679 1,777,145 Special Mention — — 2,011 192 12 437 329 — 2,981 Accruing Substandard — — 123 — 40 4 — 51 218 Nonaccrual — 588 1,614 554 1,142 26,339 2,170 691 33,098 Total residential mortgage 226,396 191,932 164,941 188,395 197,412 464,836 352,109 27,421 1,813,442 Residential mortgage guaranteed by U.S. government agencies Pass 751 6,794 19,678 24,184 46,676 218,076 — — 316,159 Nonaccrual — — 244 — — 5,866 — — 6,110 Total residential mortgage guaranteed by U.S. government agencies 751 6,794 19,922 24,184 46,676 223,942 — — 322,269 Personal: Pass 123,394 246,327 83,000 115,562 71,036 99,322 479,958 1,738 1,220,337 Special Mention — 50 16 28 55 5,087 10 — 5,246 Accruing Substandard 19 229 11 6 — — 16 — 281 Nonaccrual — 22 60 29 47 44 31 — 233 Total personal 123,413 246,628 83,087 115,625 71,138 104,453 480,015 1,738 1,226,097 Total loans to individuals 350,560 445,354 267,950 328,204 315,226 793,231 832,124 29,159 3,361,808 Total loans $ 3,607,903 $ 3,294,567 $ 2,919,965 $ 2,045,958 $ 1,522,705 $ 3,620,215 $ 7,112,055 $ 32,522 $ 24,155,890 Nonaccruing Loans A summary of nonaccruing loans at June 30, 2020 follows (in thousands): As of June 30, 2020 Total With No With Allowance Related Allowance Commercial: Energy $ 162,989 $ 85,171 $ 77,818 $ 20,863 Healthcare 3,645 3,645 — — Services 21,032 15,503 5,529 2,574 General business 14,333 13,014 1,319 346 Total commercial 201,999 117,333 84,666 23,783 Commercial real estate 13,956 8,511 5,445 540 Loans to individuals: Residential mortgage 33,098 33,098 — — Residential mortgage guaranteed by U.S. government agencies 6,110 6,110 — — Personal 233 233 — — Total loans to individuals 39,441 39,441 — — Total $ 255,396 $ 165,285 $ 90,111 $ 24,323 Troubled Debt Restructurings At June 30, 2020 the Company had $166 million in troubled debt restructurings ("TDRs"), of which $118 million were accruing residential mortgage loans guaranteed by U.S. government agencies, $21 million were nonaccruing energy loans with a related specific allowance of $3.7 million and $20 million were nonaccruing residential mortgage loans with no specific allowance necessary. Approximately $55 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 six months ended June 30, 2020, $35 million and $59 million of loans were restructured and $7.7 million and $9.7 million of loans designated as TDRs were charged off. During the three and six months ended June 30, 2019, $21 million and $38 million of loans were restructured and $10 thousand and $12.6 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 June 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 $ 3,893,481 $ 32,439 $ 3,889 $ 44,365 $ 3,974,174 $ — Healthcare 3,284,305 1,216 177 3,645 3,289,343 — Services 3,754,841 7,357 4,440 13,243 3,779,881 632 General business 3,087,741 9,235 1,169 16,967 3,115,112 9,833 Total commercial 14,020,368 50,247 9,675 78,220 14,158,510 10,465 Commercial real estate 4,536,541 2,749 5,874 8,980 4,554,144 469 Paycheck protection program 2,081,428 — — — 2,081,428 — Loans to individuals: Residential mortgage 1,797,197 7,254 1,360 7,631 1,813,442 42 Residential mortgage guaranteed by U.S. government agencies 60,121 20,494 15,908 225,746 322,269 221,201 Personal 1,225,469 477 58 93 1,226,097 16 Total loans to individuals 3,082,787 28,225 17,326 233,470 3,361,808 221,259 Total $ 23,721,124 $ 81,221 $ 32,875 $ 320,670 $ 24,155,890 $ 232,193 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 June 30, 2019 Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 103,577 $ 58,134 $ 15,668 $ 8,783 $ 19,178 $ 205,340 Provision for loan losses 13,771 (8,173) 1 1,660 (2,341) 4,918 Loans charged off (11,385) (118) (94) (1,630) — (13,227) Recoveries 434 4,345 149 575 — 5,503 Ending balance $ 106,397 $ 54,188 $ 15,724 $ 9,388 $ 16,837 $ 202,534 Allowance for off-balance sheet credit losses: Beginning balance 1,725 48 47 1 — $ 1,821 Provision for off-balance sheet credit losses 17 68 (3) — — 82 Ending balance $ 1,742 $ 116 $ 44 $ 1 $ — $ 1,903 Total provision for credit losses $ 13,788 $ (8,105) $ (2) $ 1,660 $ (2,341) $ 5,000 Six Months Ended June 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 24,879 (10,177) (2,407) 1,523 (931) 12,887 Loans charged off (21,853) (118) (136) (2,895) — (25,002) Recoveries 1,145 4,457 303 1,287 — 7,192 Ending balance $ 106,397 $ 54,188 $ 15,724 $ 9,388 $ 16,837 $ 202,534 Allowance for off-balance sheet credit losses: Beginning balance $ 1,655 $ 52 $ 52 $ 31 $ — $ 1,790 Provision for off-balance sheet credit losses 87 64 (8) (30) — 113 Ending balance $ 1,742 $ 116 $ 44 $ 1 $ — $ 1,903 Total provision for credit losses $ 24,966 $ (10,113) $ (2,415) $ 1,493 $ (931) $ 13,000 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 The allowance for loan losses and recorded investment of the related loans by portfolio segment for risk graded and non-risk graded loans

Mortgage Banking Activities

Mortgage Banking Activities	12 Months Ended
	Dec. 31, 2019
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): June 30, 2020 December 31, 2019 Unpaid Principal Balance/ Fair Value Unpaid Principal Balance/ Fair Value Residential mortgage loans held for sale $ 285,274 $ 296,445 $ 175,117 $ 177,703 Residential mortgage loan commitments 546,304 27,631 158,460 5,233 Forward sales contracts 825,775 (4,719) 315,203 (665) $ 319,357 $ 182,271 No residential mortgage loans held for sale were 90 days or more past due or considered impaired as of June 30, 2020 or December 31, 2019. No credit losses were recognized on residential mortgage loans held for sale for the six month period ended June 30, 2020 and 2019. Mortgage banking revenue was as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Production revenue: Net realized gains on sale of mortgage loans $ 24,109 $ 10,174 $ 33,826 $ 15,867 Net change in unrealized gain on mortgage loans held for sale 5,024 921 8,585 868 Net change in the fair value of mortgage loan commitments 3,381 1,506 22,398 4,219 Net change in the fair value of forward sales contracts 6,671 (732) (4,054) (1,217) Total production revenue 39,185 11,869 60,755 19,737 Servicing revenue 14,751 16,262 30,348 32,228 Total mortgage banking revenue $ 53,936 $ 28,131 $ 91,103 $ 51,965 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): June 30, 2020 December 31, 2019 Number of residential mortgage loans serviced for others 116,232 126,828 Outstanding principal balance of residential mortgage loans serviced for others $ 18,038,428 $ 20,727,106 Weighted average interest rate 3.96 % 3.98 % Remaining term (in months) 283 289 The following represents activity in capitalized mortgage servicing rights (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Beginning Balance $ 110,828 $ 238,193 $ 201,886 $ 259,254 Additions 8,465 8,751 13,906 14,939 Disposals (10,801) — (10,801) — Change in fair value due to principal payments (9,760) (9,081) (17,779) (15,664) Change in fair value due to market assumption changes (761) (29,555) (89,241) (50,221) Ending Balance $ 97,971 $ 208,308 $ 97,971 $ 208,308 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: June 30, 2020 December 31, 2019 Discount rate – risk-free rate plus a market premium 9.67% 9.81% Prepayment rate - based upon loan interest rate, original term and loan type 9.04% - 30.87% 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 0.33% 1.73% Primary/secondary mortgage rate spread 105 bps 104 bps Delinquency rate 4.51% 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	6 Months Ended
	Jun. 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 has been stayed until September 25, 2020. 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 Second 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. 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 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 is 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. 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	6 Months Ended
	Jun. 30, 2020
Stockholders' Equity Note [Abstract]
Shareholders' Equity [Text Block]	Shareholders' Equity On August 4, 2020, the Company declared a quarterly cash dividend of $0.51 per common share payable on or about August 26, 2020 to shareholders of record as of August 17, 2020. Dividends declared were $0.51 and $1.02 per share during the three and six months ended June 30, 2020 and $0.50 and $1.00 per share during the three and six months ended June 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) 228,156 — 228,156 Reclassification adjustments included in earnings: Gain on available for sale securities, net (1,105) — (1,105) Other comprehensive income, before income taxes 227,051 — 227,051 Federal and state income taxes 1 55,897 — 55,897 Other comprehensive income, net of income taxes 171,154 — 171,154 Balance, June 30, 2019 $ 100,155 $ (1,586) $ 98,569 Balance, Dec. 31, 2019 $ 104,996 $ (73) $ 104,923 Net change in unrealized gain (loss) 354,765 — 354,765 Reclassification adjustments included in earnings: Gain on available for sale securities, net (5,580) — (5,580) Other comprehensive income, before income taxes 349,185 — 349,185 Federal and state income taxes 1 83,792 — 83,792 Other comprehensive income, net of income taxes 265,393 — 265,393 Balance, June 30, 2020 $ 370,389 $ (73) $ 370,316 1 Calculated using a 25 percent blended federal and state statutory tax rate.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 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 June 30, Six Months Ended June 30, 2020 2019 2020 2019 Numerator: Net income attributable to BOK Financial Corp. shareholders $ 64,693 $ 137,563 $ 126,772 $ 248,175 Less: Earnings allocated to participating securities 397 850 740 1,678 Numerator for basic earnings per share – income available to common shareholders 64,296 136,713 126,032 246,497 Effect of reallocating undistributed earnings of participating securities — — — — Numerator for diluted earnings per share – income available to common shareholders $ 64,296 $ 136,713 $ 126,032 $ 246,497 Denominator: Weighted average shares outstanding 70,307,606 71,327,928 70,410,707 71,625,332 Less: Participating securities included in weighted average shares outstanding 431,563 440,865 410,842 489,918 Denominator for basic earnings per common share 69,876,043 70,887,063 69,999,865 71,135,414 Dilutive effect of employee stock compensation plans 1 1,424 14,970 3,952 16,144 Denominator for diluted earnings per common share 69,877,467 70,902,033 70,003,817 71,151,558 Basic earnings per share $ 0.92 $ 1.93 $ 1.80 $ 3.47 Diluted earnings per share $ 0.92 $ 1.93 $ 1.80 $ 3.46 1 Excludes employee stock options with exercise prices greater than current market price. 22,238 — — —

Reportable Segments

Reportable Segments	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Reportable Segments [Text Block]	Reportable Segments Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended June 30, 2020 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other BOK Net interest revenue from external sources $ 174,314 $ 18,795 $ 34,359 $ 50,636 $ 278,104 Net interest revenue (expense) from internal sources (29,205) 20,475 (7,479) 16,209 — Net interest revenue 145,109 39,270 26,880 66,845 278,104 Provision for credit losses 13,762 535 (89) 121,113 135,321 Net interest revenue after provision for credit losses 131,347 38,735 26,969 (54,268) 142,783 Other operating revenue 47,898 67,192 106,674 10,929 232,693 Other operating expense 62,933 58,936 80,567 92,951 295,387 Net direct contribution 116,312 46,991 53,076 (136,290) 80,089 Gain on financial instruments, net 48 7,356 — (7,404) — Change in fair value of mortgage servicing rights — (761) — 761 — Gain on repossessed assets, net 191 27 — (218) — Corporate expense allocations 5,437 10,812 8,204 (24,453) — Net income before taxes 111,114 42,801 44,872 (118,698) 80,089 Federal and state income taxes 30,122 10,901 11,478 (36,698) 15,803 Net income 80,992 31,900 33,394 (82,000) 64,286 Net income (loss) attributable to non-controlling interests — — — (407) (407) Net income attributable to BOK Financial Corp. shareholders $ 80,992 $ 31,900 $ 33,394 $ (81,593) $ 64,693 Average assets $ 27,575,652 $ 9,920,005 $ 15,721,452 $ (3,460,078) $ 49,757,031 Reportable segments reconciliation to the Consolidated Financial Statements for the six months ended June 30, 2020 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other BOK Net interest revenue from external sources $ 376,216 $ 44,671 $ 48,725 $ 69,852 $ 539,464 Net interest revenue (expense) from internal sources (79,700) 38,531 (2,941) 44,110 — Net interest revenue 296,516 83,202 45,784 113,962 539,464 Provision for credit losses 30,642 1,791 (137) 196,796 229,092 Net interest revenue after provision for credit losses 265,874 81,411 45,921 (82,834) 310,372 Other operating revenue 86,118 122,254 204,555 85 413,012 Other operating expense 123,685 113,729 158,759 167,838 564,011 Net direct contribution 228,307 89,936 91,717 (250,587) 159,373 Gain on financial instruments, net 97 94,120 7 (94,224) — Change in fair value of mortgage servicing rights — (89,241) — 89,241 — Gain on repossessed assets, net 200 40 — (240) — Corporate expense allocations 14,342 21,299 16,469 (52,110) — Net income before taxes 214,262 73,556 75,255 (203,700) 159,373 Federal and state income taxes 58,295 18,735 19,288 (63,215) 33,103 Net income 155,967 54,821 55,967 (140,485) 126,270 Net income (loss) attributable to non-controlling interests — — — (502) (502) Net income attributable to BOK Financial Corp. shareholders $ 155,967 $ 54,821 $ 55,967 $ (139,983) $ 126,772 Average assets $ 26,131,814 $ 9,885,429 $ 14,222,432 $ (2,500,850) $ 47,738,825 Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended June 30, 2019 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other 1 BOK Net interest revenue from external sources $ 251,084 $ 25,300 $ 17,222 $ (8,174) $ 285,432 Net interest revenue (expense) from internal sources (66,613) 27,415 9,719 29,479 — Net interest revenue 184,471 52,715 26,941 21,305 285,432 Provision for credit losses 6,823 1,728 (48) (3,503) 5,000 Net interest revenue after provision for credit losses 177,648 50,987 26,989 24,808 280,432 Other operating revenue 41,611 48,811 86,017 (4,374) 172,065 Other operating expense 63,415 57,694 69,452 86,576 277,137 Net direct contribution 155,844 42,104 43,554 (66,142) 175,360 Gain (loss) on financial instruments, net 20 20,981 — (21,001) — Change in fair value of mortgage servicing rights — (29,555) — 29,555 — Gain (loss) on repossessed assets, net — 92 — (92) — Corporate expense allocations 10,652 11,695 9,168 (31,515) — Net income before taxes 145,212 21,927 34,386 (26,165) 175,360 Federal and state income taxes 38,932 5,585 8,842 (15,779) 37,580 Net income 106,280 16,342 25,544 (10,386) 137,780 Net income attributable to non-controlling interests — — — 217 217 Net income (loss) attributable to BOK Financial Corp. shareholders $ 106,280 $ 16,342 $ 25,544 $ (10,603) $ 137,563 Average assets $ 22,910,724 $ 9,212,667 $ 9,849,396 $ (1,128,010) $ 40,844,777 Reportable segments reconciliation to the Consolidated Financial Statements for the six months ended June 30, 2019 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other 1 BOK Net interest revenue from external sources $ 455,293 $ 47,775 $ 38,708 $ 21,758 $ 563,534 Net interest revenue (expense) from internal sources (120,251) 56,042 16,489 47,720 — Net interest revenue 335,042 103,817 55,197 69,478 563,534 Provision for credit losses 18,069 2,813 (167) (7,715) 13,000 Net interest revenue after provision for credit losses 316,973 101,004 55,364 77,193 550,534 Other operating revenue 79,223 91,559 159,431 (878) 329,335 Other operating expense 114,042 111,515 130,959 207,778 564,294 Net direct contribution 282,154 81,048 83,836 (131,463) 315,575 Gain (loss) on financial instruments, net 38 35,078 — (35,116) — Change in fair value of mortgage servicing rights — (50,221) — 50,221 — Gain (loss) on repossessed assets, net (346) 195 — 151 — Corporate expense allocations 20,107 23,595 17,528 (61,230) — Net income before taxes 261,739 42,505 66,308 (54,977) 315,575 Federal and state income taxes 69,938 10,826 17,045 (30,279) 67,530 Net income 191,801 31,679 49,263 (24,698) 248,045 Net income attributable to non-controlling interests — — — (130) (130) Net income attributable to BOK Financial Corp. shareholders $ 191,801 $ 31,679 $ 49,263 $ (24,568) $ 248,175 Average assets $ 21,432,513 $ 8,794,498 $ 9,590,629 $ 444,327 $ 40,261,967

Fees and Commissions Revenue Fe

Fees and Commissions Revenue Fees and Commissions Revenue	6 Months Ended
	Jun. 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 June 30, 2020. Commercial Consumer Wealth Management Funds Management & Other Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 43,915 $ — $ 43,915 $ 43,915 $ — Customer hedging revenue 6,893 — 63 (714) 6,242 6,242 — Retail brokerage revenue — — 3,394 — 3,394 — 3,394 Insurance brokerage revenue — — 3,153 — 3,153 — 3,153 Investment banking revenue 1,131 — 4,187 — 5,318 851 4,467 Brokerage and trading revenue 8,024 — 54,712 (714) 62,022 51,008 11,014 TransFund EFT network revenue 19,647 556 (9) — 20,194 — 20,194 Merchant services revenue 2,230 13 — — 2,243 — 2,243 Corporate card revenue 485 — 18 — 503 — 503 Transaction card revenue 22,362 569 9 — 22,940 — 22,940 Personal trust revenue — — 21,681 — 21,681 — 21,681 Corporate trust revenue — — 4,604 — 4,604 — 4,604 Institutional trust & retirement plan services revenue — — 10,723 — 10,723 — 10,723 Investment management services and other revenue — — 4,291 (42) 4,249 — 4,249 Fiduciary and asset management revenue — — 41,299 (42) 41,257 — 41,257 Commercial account service charge revenue 11,069 389 598 — 12,056 — 12,056 Overdraft fee revenue 20 3,607 16 — 3,643 — 3,643 Check card revenue — 5,122 — — 5,122 — 5,122 Automated service charge and other deposit fee revenue 29 1,179 17 — 1,225 — 1,225 Deposit service charges and fees 11,118 10,297 631 — 22,046 — 22,046 Mortgage production revenue — 39,186 — — 39,186 39,186 — Mortgage servicing revenue — 15,164 — (414) 14,750 14,750 — Mortgage banking revenue — 54,350 — (414) 53,936 53,936 — Other revenue 5,011 1,976 10,106 (5,614) 11,479 8,970 2,509 Total fees and commissions revenue $ 46,515 $ 67,192 $ 106,757 $ (6,784) $ 213,680 $ 113,914 $ 99,766 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 six months ended June 30, 2020. Commercial Consumer Wealth Management Funds Management & Other Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 78,299 $ — $ 78,299 $ 78,299 $ — Customer hedging revenue 9,418 — 198 (151) 9,465 9,465 — Retail brokerage revenue — — 7,737 — 7,737 — 7,737 Insurance brokerage revenue — — 6,942 — 6,942 — 6,942 Investment banking revenue 3,011 — 7,347 — 10,358 2,679 7,679 Brokerage and trading revenue 12,429 — 100,523 (151) 112,801 90,443 22,358 TransFund EFT network revenue 37,859 1,387 (28) 2 39,220 — 39,220 Merchant services revenue 4,535 27 — — 4,562 — 4,562 Corporate card revenue 1,005 — 34 — 1,039 — 1,039 Transaction card revenue 43,399 1,414 6 2 44,821 — 44,821 Personal trust revenue — — 42,330 — 42,330 — 42,330 Corporate trust revenue — — 10,966 — 10,966 — 10,966 Institutional trust & retirement plan services revenue — — 22,480 — 22,480 — 22,480 Investment management services and other revenue — — 10,022 (83) 9,939 — 9,939 Fiduciary and asset management revenue — — 85,798 (83) 85,715 — 85,715 Commercial account service charge revenue 22,108 799 1,143 (1) 24,049 — 24,049 Overdraft fee revenue 69 10,812 38 2 10,921 — 10,921 Check card revenue — 10,351 — — 10,351 — 10,351 Automated service charge and other deposit fee revenue 258 2,565 30 2 2,855 — 2,855 Deposit service charges and fees 22,435 24,527 1,211 3 48,176 — 48,176 Mortgage production revenue — 60,755 — — 60,755 60,755 — Mortgage servicing revenue — 31,206 — (858) 30,348 30,348 — Mortgage banking revenue — 91,961 — (858) 91,103 91,103 — Other revenue 9,711 4,352 17,100 (7,375) 23,788 17,378 6,410 Total fees and commissions revenue $ 87,974 $ 122,254 $ 204,638 $ (8,462) $ 406,404 $ 198,924 $ 207,480 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 June 30, 2019. Commercial Consumer Wealth Management Funds Management & Other 3 Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 21,879 $ — $ 21,879 $ 21,879 $ — Customer hedging revenue 2,385 — 1,906 1,054 5,345 5,345 — Retail brokerage revenue — — 3,914 (13) 3,901 — 3,901 Insurance brokerage revenue — — 3,309 513 3,822 — 3,822 Investment banking revenue 2,548 — 3,032 (1) 5,579 2,198 3,381 Brokerage and trading revenue 4,933 — 34,040 1,553 40,526 29,422 11,104 TransFund EFT network revenue 18,504 997 (20) — 19,481 — 19,481 Merchant services revenue 2,223 15 — (1) 2,237 — 2,237 Corporate card revenue 190 — 5 2 197 — 197 Transaction card revenue 20,917 1,012 (15) 1 21,915 — 21,915 Personal trust revenue — — 21,215 1 21,216 — 21,216 Corporate trust revenue — — 6,331 (1) 6,330 — 6,330 Institutional trust & retirement plan services revenue — — 11,072 — 11,072 — 11,072 Investment management services and other revenue — — 6,449 (42) 6,407 — 6,407 Fiduciary and asset management revenue — — 45,067 (42) 45,025 — 45,025 Commercial account service charge revenue 10,625 429 538 — 11,592 — 11,592 Overdraft fee revenue 93 8,973 36 2 9,104 — 9,104 Check card revenue — 5,586 — 1 5,587 — 5,587 Automated service charge and other deposit fee revenue 214 1,578 (2) 1 1,791 — 1,791 Deposit service charges and fees 10,932 16,566 572 4 28,074 — 28,074 Mortgage production revenue — 11,871 — (2) 11,869 11,869 — Mortgage servicing revenue — 16,741 — (479) 16,262 16,262 — Mortgage banking revenue — 28,612 — (481) 28,131 28,131 — Other revenue 4,323 2,640 6,261 (787) 12,437 8,123 4,314 Total fees and commissions revenue $ 41,105 $ 48,830 $ 85,925 $ 248 $ 176,108 $ 65,676 $ 110,432 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 six months ended June 30, 2019. Commercial Consumer Wealth Management Funds Management & Other 3 Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 34,799 $ — $ 34,799 $ 34,799 $ — Customer hedging revenue 3,960 — 7,634 428 12,022 12,022 — Retail brokerage revenue — — 7,988 (65) 7,923 — 7,923 Insurance brokerage revenue — — 3,688 4,242 7,930 — 7,930 Investment banking revenue 3,937 — 5,533 (1) 9,469 3,427 6,042 Brokerage and trading revenue 7,897 — 59,642 4,604 72,143 50,248 21,895 TransFund EFT network revenue 36,158 1,955 (37) 1 38,077 — 38,077 Merchant services revenue 4,148 29 — 122 4,299 — 4,299 Corporate card revenue 270 — 5 2 277 — 277 Transaction card revenue 40,576 1,984 (32) 125 42,653 — 42,653 Personal trust revenue — — 40,789 1 40,790 — 40,790 Corporate trust revenue — — 12,532 (1) 12,531 — 12,531 Institutional trust & retirement plan services revenue — — 22,179 — 22,179 — 22,179 Investment management services and other revenue — — 11,250 1,633 12,883 — 12,883 Fiduciary and asset management revenue — — 86,750 1,633 88,383 — 88,383 Commercial account service charge revenue 20,687 816 1,065 1,807 24,375 — 24,375 Overdraft fee revenue 167 17,368 63 (234) 17,364 — 17,364 Check card revenue — 10,578 — 165 10,743 — 10,743 Automated service charge and other deposit fee revenue 372 3,243 175 45 3,835 — 3,835 Deposit service charges and fees 21,226 32,005 1,303 1,783 56,317 — 56,317 Mortgage production revenue — 19,739 — (2) 19,737 19,737 — Mortgage servicing revenue — 33,186 — (958) 32,228 32,228 — Mortgage banking revenue — 52,925 — (960) 51,965 51,965 — Other revenue 9,452 4,737 11,518 (508) 25,199 16,843 8,356 Total fees and commissions revenue $ 79,151 $ 91,651 $ 159,181 $ 6,677 $ 336,660 $ 119,056 $ 217,604

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 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 six months ended June 30, 2020 and 2019, respectively. Transfers between significant other observable inputs and significant unobservable inputs during the six months ended June 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 June 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 June 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 $ 4,237 $ — $ 4,237 $ — Residential agency mortgage-backed securities 1,146,454 — 1,146,454 — Municipal and other tax-exempt securities 22,710 — 22,710 — Asset-backed securities 5 — 5 — Other trading securities 22,699 — 22,699 — Total trading securities 1,196,105 — 1,196,105 — Available for sale securities: U.S. Treasury 912 912 — — Municipal and other tax-exempt securities 31,240 — 31,240 — Residential agency mortgage-backed securities 9,147,238 — 9,147,238 — Residential non-agency mortgage-backed securities 35,250 — 35,250 — Commercial agency mortgage-backed securities 3,260,807 — 3,260,807 — Other debt securities 472 — — 472 Total available for sale securities 12,475,919 912 12,474,535 472 Fair value option securities: U.S. Treasury 92,742 92,742 — — Residential agency mortgage-backed securities 629,915 — 629,915 — Total fair value option securities 722,657 92,742 629,915 — Residential mortgage loans held for sale 319,357 — 309,672 9,685 Mortgage servicing rights 1 97,971 — — 97,971 Derivative contracts, net of cash collateral 2 651,553 66,207 585,346 — Liabilities: Derivative contracts, net of cash collateral 2 610,020 — 610,020 — 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 energy and interest rate derivative contacts, net of cash margin. Derivative contacts in liability positions that were valued using quoted prices in active markets for identical instruments are exchange-traded interest rate 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 contacts, 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 six months ended June 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, Mar. 31, 2020 $ 472 $ 9,574 Transfer to Level 3 from Level 2 1 — 1,328 Purchases — — Proceeds from sales — (648) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — (569) Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, June 30, 2020 $ 472 $ 9,685 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 — 3,592 Purchases — — Proceeds from sales — (1,588) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — (632) Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, June 30, 2020 $ 472 $ 9,685 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 six months ended June 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, Mar. 31, 2019 $ 472 $ 15,776 Transfer to Level 3 from Level 2 1 — 907 Purchases — — Proceeds from sales — (998) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — 388 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, June 30, 2019 $ 472 $ 16,073 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 — 1,889 Purchases — — Proceeds from sales — (1,379) Redemptions and distributions — — Gain (loss) recognized in earnings Mortgage banking revenue — 356 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, June 30, 2019 $ 472 $ 16,073 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 June 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 5.23%-5.23% (5.23%) 3 94.30%-94.30% (94.30%) 2 Residential mortgage loans held for sale 9,685 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 approximately 1 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 June 30, 2020 for which the fair value was adjusted during the six months ended June 30, 2020: Fair Value Adjustments for the Carrying Value at June 30, 2020 Three Months Ended Six Months Ended Quoted Prices Significant Significant Gross charge-offs against allowance for loan losses Net losses 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 $ — $ 400 $ 32,448 $ 13,871 $ — $ 29,659 $ — Real estate and other repossessed assets — 918 400 — 5 — 131 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 June 30, 2019 for which the fair value was adjusted during the six months ended June 30, 2019: Fair Value Adjustments for the Carrying Value at June 30, 2019 Three Months Ended Six Months Ended Quoted Prices Significant Significant Gross charge-offs against allowance for loan losses Net losses and operating expenses of repossessed assets Gross charge-offs against allowance for loan losses Net losses and operating expenses of repossessed assets Nonaccruing loans $ — $ — $ 29,187 $ 11,335 $ — $ 20,917 $ — Real estate and other repossessed assets — 2,642 427 — 86 — 512 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 June 30, 2020 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range Nonaccruing loans $ 32,448 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% - 83% (35%) 1 Real estate and other repossessed assets 400 Appraised value, as adjusted Marketability adjustments off appraised value 2 87% - 87% (87%) 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. A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of June 30, 2019 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range Nonaccruing loans $ 29,187 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 12% - 76% (47%) 1 Real estate and other repossessed assets 427 Appraised value, as adjusted Marketability adjustments off appraised value 2 75% - 89% (88%) 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 June 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 $ 762,453 $ 762,453 $ 762,453 $ — $ — Interest-bearing cash and cash equivalents 485,319 485,319 485,319 — — Trading securities: U.S. government agency debentures 4,237 4,237 — 4,237 — Residential agency mortgage-backed securities 1,146,454 1,146,454 — 1,146,454 — Municipal and other tax-exempt securities 22,710 22,710 — 22,710 — Asset-backed securities 5 5 — 5 — Other trading securities 22,699 22,699 — 22,699 — Total trading securities 1,196,105 1,196,105 — 1,196,105 — Investment securities: Municipal and other tax-exempt securities 84,239 88,623 — 88,623 — Residential agency mortgage-backed securities 9,812 10,734 — 10,734 — Other debt securities 175,565 199,769 — 8,048 191,721 Total investment securities 269,616 299,126 — 107,405 191,721 Allowance for credit losses (1,628) — — — — Investment securities, net of allowance 267,988 299,126 — 107,405 191,721 Available for sale securities: U.S. Treasury 912 912 912 — — Municipal and other tax-exempt securities 31,240 31,240 — 31,240 — Residential agency mortgage-backed securities 9,147,238 9,147,238 — 9,147,238 — Residential non-agency mortgage-backed securities 35,250 35,250 — 35,250 — Commercial agency mortgage-backed securities 3,260,807 3,260,807 — 3,260,807 — Other debt securities 472 472 — — 472 Total available for sale securities 12,475,919 12,475,919 912 12,474,535 472 Fair value option securities: U.S. Treasury 92,742 92,742 92,742 — — Residential agency mortgage-backed securities 629,915 629,915 — 629,915 — Total fair value option securities 722,657 722,657 92,742 629,915 — Residential mortgage loans held for sale 319,357 319,357 — 309,672 9,685 Loans: Commercial 14,158,510 14,038,257 — — 14,038,257 Commercial real estate 4,554,144 4,558,274 — — 4,558,274 Paycheck protection program 2,081,428 2,062,278 — — 2,062,278 Loans to individuals 3,361,808 3,393,293 — — 3,393,293 Total loans 24,155,890 24,052,102 — — 24,052,102 Allowance for loan losses (435,597) — — — — Loans, net of allowance 23,720,293 24,052,102 — — 24,052,102 Mortgage servicing rights 97,971 97,971 — — 97,971 Derivative instruments with positive fair value, net of cash collateral 651,553 651,553 66,207 585,346 — Deposits with no stated maturity 31,539,554 31,539,554 — — 31,539,554 Time deposits 2,352,760 2,367,446 — — 2,367,446 Other borrowed funds 4,531,165 4,527,814 — — 4,527,814 Subordinated debentures 275,973 273,293 — 273,293 — Derivative instruments with negative fair value, net of cash collateral 610,020 610,020 — 610,020 — 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	6 Months Ended
	Jun. 30, 2020
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events The Company evaluated events from the date of the consolidated financial statements on June 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)	6 Months Ended
	Jun. 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)	6 Months Ended
	Jun. 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)	6 Months Ended
	Jun. 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)	6 Months Ended
	Jun. 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): June 30, 2020 December 31, 2019 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. government agency debentures $ 4,237 $ 19 $ 44,264 $ 6 Residential agency mortgage-backed securities 1,146,454 3,589 1,504,651 2,293 Municipal and other tax-exempt securities 22,710 116 26,196 60 Asset-backed securities 5 — 14,084 (21) Other debt securities 22,699 127 34,726 21 Total trading securities $ 1,196,105 $ 3,851 $ 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): June 30, 2020 Amortized Fair Gross Unrealized Cost Value Gain Loss Municipal and other tax-exempt $ 84,239 $ 88,623 $ 4,384 $ — Residential agency mortgage-backed securities 9,812 10,734 922 — Other debt securities 175,565 199,769 24,235 (31) Total investment securities 269,616 299,126 29,541 (31) Allowance for credit losses 1 (1,628) Investment securities, net of allowance 267,988 299,126 29,541 (31) 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 June 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 $ 39,734 $ 87,863 $ 122,309 $ 9,898 $ 259,804 4.95 Fair value 40,151 96,615 141,378 10,248 288,392 Residential mortgage-backed securities: Amortized cost $ 9,812 2 Fair value 10,734 Total investment securities: Amortized cost $ 269,616 Fair value 299,126 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 4.6 years based upon current prepayment assumptions. Temporarily Impaired Investment Securities (in thousands): June 30, 2020 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized Investment: Other debt securities 4 — — 2,142 31 2,142 31 Total investment securities 4 $ — $ — $ 2,142 $ 31 $ 2,142 $ 31 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): June 30, 2020 Amortized Fair Gross Unrealized Cost Value Gain Loss U.S. Treasury $ 900 $ 912 $ 12 $ — Municipal and other tax-exempt 29,670 31,240 1,570 — Mortgage-backed securities: Residential agency 8,789,466 9,147,238 360,056 (2,284) Residential non-agency 21,941 35,250 13,318 (9) Commercial agency 3,146,108 3,260,807 116,042 (1,343) Other debt securities 500 472 — (28) Total available for sale securities $ 11,988,585 $ 12,475,919 $ 490,998 $ (3,664) 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 June 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 $ 34,044 $ 1,321,471 $ 1,241,310 $ 580,353 $ 3,177,178 8.03 Fair value 34,144 1,375,128 1,280,251 603,908 3,293,431 Residential mortgage-backed securities: Amortized cost $ 8,811,407 2 Fair value 9,182,488 Total available-for-sale securities: Amortized cost $ 11,988,585 Fair value 12,475,919 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 3.1 years based upon current prepayment assumptions. Sales of available for sale securities resulted in gains and losses as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Proceeds $ 179,051 $ 122,098 $ 205,945 $ 367,357 Gross realized gains 5,580 1,029 5,583 6,327 Gross realized losses — — — (5,222) Related federal and state income tax expense (benefit) 1,421 262 1,422 281
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table Text Block]	June 30, 2020 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 36 492,864 1,375 173,997 909 666,861 2,284 Residential non-agency 1 1,695 9 — — 1,695 9 Commercial agency 22 271,735 902 160,806 441 432,541 1,343 Other debt securities 1 — — 472 28 472 28 Total available for sale securities 60 $ 766,294 $ 2,286 $ 335,275 $ 1,378 $ 1,101,569 $ 3,664 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): June 30, 2020 December 31, 2019 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. Treasury $ 92,742 $ 307 $ 9,917 $ (48) Residential agency mortgage-backed securities 629,915 16,549 1,088,660 14,109 Total $ 722,657 $ 16,856 $ 1,098,577 $ 14,061

Derivatives (Tables)

Derivatives (Tables)	6 Months Ended
	Jun. 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 June 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 2,772,027 140,157 (42) 140,115 — 140,115 Energy contracts 2,912,225 434,455 (199,805) 234,650 (155,160) 79,490 Agricultural contracts 13,183 59 (35) 24 — 24 Foreign exchange contracts 283,424 281,801 — 281,801 (507) 281,294 Equity option contracts 75,987 1,097 — 1,097 (286) 811 Total customer risk management programs 6,056,846 857,569 (199,882) 657,687 (155,953) 501,734 Trading 50,132,348 219,647 (91,830) 127,817 — 127,817 Internal risk management programs 865,964 23,823 (1,821) 22,002 — 22,002 Total derivative contracts $ 57,055,158 $ 1,101,039 $ (293,533) $ 807,506 $ (155,953) $ 651,553 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 2,772,027 140,509 (42) 140,467 (129,094) 11,373 Energy contracts 2,718,690 408,813 (199,805) 209,008 (3,298) 205,710 Agricultural contracts 13,191 50 (35) 15 (15) — Foreign exchange contracts 270,594 269,013 — 269,013 — 269,013 Equity option contracts 75,987 1,097 — 1,097 — 1,097 Total customer risk management programs 5,850,489 819,482 (199,882) 619,600 (132,407) 487,193 Trading 52,408,519 213,170 (91,830) 121,340 — 121,340 Internal risk management programs 168,491 3,308 (1,821) 1,487 — 1,487 Total derivative contracts $ 58,427,499 $ 1,035,960 $ (293,533) $ 742,427 $ (132,407) $ 610,020 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 June 30, 2020 June 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 $ — $ — $ 2,212 $ — Interest rate swaps 746 — 942 — Energy contracts 5,383 — 2,086 — Agricultural contracts 6 — 4 — Foreign exchange contracts 107 — 100 — Equity option contracts — — — — Total customer risk management programs 6,242 — 5,344 — Trading 1 32,577 — 8,030 — Internal risk management programs — 21,885 — 11,150 Total derivative contracts $ 38,819 $ 21,885 $ 13,374 $ 11,150 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. Six Months Ended June 30, 2020 June 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 $ — $ — $ 7,912 $ — Interest rate swaps 1,688 — 1,535 — Energy contracts 7,390 — 2,312 — Agricultural contracts 21 — 8 — Foreign exchange contracts 365 — 254 — Equity option contracts — — — — Total customer risk management programs 9,464 — 12,021 — Trading 1 (8,078) — 735 — Internal risk management programs — 40,305 — 15,817 Total derivative contracts $ 1,386 $ 40,305 $ 12,756 $ 15,817

Loans and Allowances for Cred_2

Loans and Allowances for Credit Losses (Tables)	6 Months Ended	12 Months Ended
	Jun. 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): June 30, 2020 Fixed Variable Non-accrual Total Commercial 3,215,865 10,740,646 201,999 $ 14,158,510 Commercial real estate 1,029,544 3,510,644 13,956 4,554,144 Paycheck protection program 2,081,428 — — 2,081,428 Loans to individuals 2,038,990 1,283,377 39,441 3,361,808 Total $ 8,365,827 $ 15,534,667 $ 255,396 $ 24,155,890	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 June 30, 2020 Commercial Commercial Real Estate Paycheck Protection Program Loans to Individuals Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 213,438 $ 51,461 $ — $ 50,412 $ — $ 315,311 Provision for loan losses 111,153 17,221 — 5,991 — 134,365 Loans charged off (14,487) (1) — (1,082) — (15,570) Recoveries of loans previously charged off 318 75 — 1,098 — 1,491 Ending Balance $ 310,422 $ 68,756 $ — $ 56,419 — $ 435,597 Allowance for off-balance sheet credit risk from unfunded loan commitments: Beginning balance $ 14,040 $ 12,575 $ — $ 1,899 $ — $ 28,514 Provision for off-balance sheet credit risk 542 3,844 — 19 — 4,405 Ending Balance $ 14,582 $ 16,419 $ — $ 1,918 $ — $ 32,919 Six Months Ended June 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 188,876 22,336 — 19,117 — 230,329 Loans charged off (31,102) (887) — (2,498) — (34,487) Recoveries 780 122 — 2,285 — 3,187 Ending balance $ 310,422 $ 68,756 $ — $ 56,419 $ — $ 435,597 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 3,004 4,652 — 126 — 7,782 Ending balance $ 14,582 $ 16,419 $ — $ 1,918 $ — $ 32,919 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, required a provision of $54.6 million during the second quarter of 2020. All other changes totaled $84.2 million, $14.4 million related to changes in impairment, $55.7 million related to risk grading and other portfolio changes and net charge-offs of $14.1 million. The allowance for loan losses and recorded investment of the related loans by portfolio segment for each measurement method at June 30, 2020 is as follows (in thousands): Collectively Measured Individually Measured Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Commercial $ 13,956,511 $ 286,639 $ 201,999 $ 23,783 $ 14,158,510 $ 310,422 Commercial real estate 4,540,188 68,216 13,956 540 4,554,144 68,756 Paycheck protection program 2,081,428 — — — 2,081,428 — Loans to individuals 3,322,367 56,419 39,441 — 3,361,808 56,419 Total 23,900,494 411,274 255,396 24,323 24,155,890 435,597	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 June 30, 2019 Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 103,577 $ 58,134 $ 15,668 $ 8,783 $ 19,178 $ 205,340 Provision for loan losses 13,771 (8,173) 1 1,660 (2,341) 4,918 Loans charged off (11,385) (118) (94) (1,630) — (13,227) Recoveries 434 4,345 149 575 — 5,503 Ending balance $ 106,397 $ 54,188 $ 15,724 $ 9,388 $ 16,837 $ 202,534 Allowance for off-balance sheet credit losses: Beginning balance 1,725 48 47 1 — $ 1,821 Provision for off-balance sheet credit losses 17 68 (3) — — 82 Ending balance $ 1,742 $ 116 $ 44 $ 1 $ — $ 1,903 Total provision for credit losses $ 13,788 $ (8,105) $ (2) $ 1,660 $ (2,341) $ 5,000 Six Months Ended June 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 24,879 (10,177) (2,407) 1,523 (931) 12,887 Loans charged off (21,853) (118) (136) (2,895) — (25,002) Recoveries 1,145 4,457 303 1,287 — 7,192 Ending balance $ 106,397 $ 54,188 $ 15,724 $ 9,388 $ 16,837 $ 202,534 Allowance for off-balance sheet credit losses: Beginning balance $ 1,655 $ 52 $ 52 $ 31 $ — $ 1,790 Provision for off-balance sheet credit losses 87 64 (8) (30) — 113 Ending balance $ 1,742 $ 116 $ 44 $ 1 $ — $ 1,903 Total provision for credit losses $ 24,966 $ (10,113) $ (2,415) $ 1,493 $ (931) $ 13,000 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 June 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 $ 23,119 $ 62,250 $ 94,216 $ 8,344 $ 1,427 $ 2,908 $ 2,664,680 $ — $ 2,856,944 Special Mention — — 9,720 — — — 493,719 — 503,439 Accruing Substandard — — 194 — 49 — 450,559 — 450,802 Nonaccrual — 6,586 15,496 — — 38,325 102,582 — 162,989 Total energy 23,119 68,836 119,626 8,344 1,476 41,233 3,711,540 — 3,974,174 Healthcare Pass 212,781 609,757 641,607 489,096 248,094 767,193 245,123 — 3,213,651 Special Mention — 27,500 — 3,714 — 13,771 3,515 — 48,500 Accruing Substandard — 3,176 7,746 973 161 11,491 — — 23,547 Nonaccrual — 18 183 — — 2,935 509 — 3,645 Total healthcare 212,781 640,451 649,536 493,783 248,255 795,390 249,147 — 3,289,343 Services Pass 335,961 475,608 437,812 366,772 400,480 857,564 743,258 673 3,618,128 Special Mention — 3,919 1,474 170 4,513 3,626 35,203 — 48,905 Accruing Substandard 98 12,077 26,814 12,393 8,123 4,753 27,558 — 91,816 Nonaccrual — 2,978 — 8,647 1,153 7,529 725 — 21,032 Total services 336,059 494,582 466,100 387,982 414,269 873,472 806,744 673 3,779,881 General business Pass 256,821 485,956 359,249 256,403 147,056 251,326 1,258,843 2,671 3,018,325 Special Mention — 10,196 763 11,244 941 4,046 3,404 — 30,594 Accruing Substandard 21 13,906 13,989 2,353 6,216 5,206 10,165 4 51,860 Nonaccrual 1,675 3,713 5,168 1,938 1,315 140 369 15 14,333 Total general business 258,517 513,771 379,169 271,938 155,528 260,718 1,272,781 2,690 3,115,112 Total commercial 830,476 1,717,640 1,614,431 1,162,047 819,528 1,970,813 6,040,212 3,363 14,158,510 Commercial real estate: Pass 345,439 1,131,573 1,037,584 536,047 378,852 852,020 234,148 — 4,515,663 Special Mention — — — 12,200 1,622 3,283 100 — 17,205 Accruing Substandard — — — 7,228 — 65 27 — 7,320 Nonaccrual — — — 232 7,477 803 5,444 — 13,956 Total commercial real estate 345,439 1,131,573 1,037,584 555,707 387,951 856,171 239,719 — 4,554,144 Origination Year 2020 2019 2018 2017 2016 Prior Revolving Loans Revolving Loans Converted to Term Loans Total Paycheck protection program: Pass 2,081,428 — — — — — — — 2,081,428 Total paycheck protection program 2,081,428 — — — — — — — 2,081,428 Loans to individuals: Residential mortgage Pass 226,396 191,344 161,193 187,649 196,218 438,056 349,610 26,679 1,777,145 Special Mention — — 2,011 192 12 437 329 — 2,981 Accruing Substandard — — 123 — 40 4 — 51 218 Nonaccrual — 588 1,614 554 1,142 26,339 2,170 691 33,098 Total residential mortgage 226,396 191,932 164,941 188,395 197,412 464,836 352,109 27,421 1,813,442 Residential mortgage guaranteed by U.S. government agencies Pass 751 6,794 19,678 24,184 46,676 218,076 — — 316,159 Nonaccrual — — 244 — — 5,866 — — 6,110 Total residential mortgage guaranteed by U.S. government agencies 751 6,794 19,922 24,184 46,676 223,942 — — 322,269 Personal: Pass 123,394 246,327 83,000 115,562 71,036 99,322 479,958 1,738 1,220,337 Special Mention — 50 16 28 55 5,087 10 — 5,246 Accruing Substandard 19 229 11 6 — — 16 — 281 Nonaccrual — 22 60 29 47 44 31 — 233 Total personal 123,413 246,628 83,087 115,625 71,138 104,453 480,015 1,738 1,226,097 Total loans to individuals 350,560 445,354 267,950 328,204 315,226 793,231 832,124 29,159 3,361,808 Total loans $ 3,607,903 $ 3,294,567 $ 2,919,965 $ 2,045,958 $ 1,522,705 $ 3,620,215 $ 7,112,055 $ 32,522 $ 24,155,890	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 June 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 $ 3,893,481 $ 32,439 $ 3,889 $ 44,365 $ 3,974,174 $ — Healthcare 3,284,305 1,216 177 3,645 3,289,343 — Services 3,754,841 7,357 4,440 13,243 3,779,881 632 General business 3,087,741 9,235 1,169 16,967 3,115,112 9,833 Total commercial 14,020,368 50,247 9,675 78,220 14,158,510 10,465 Commercial real estate 4,536,541 2,749 5,874 8,980 4,554,144 469 Paycheck protection program 2,081,428 — — — 2,081,428 — Loans to individuals: Residential mortgage 1,797,197 7,254 1,360 7,631 1,813,442 42 Residential mortgage guaranteed by U.S. government agencies 60,121 20,494 15,908 225,746 322,269 221,201 Personal 1,225,469 477 58 93 1,226,097 16 Total loans to individuals 3,082,787 28,225 17,326 233,470 3,361,808 221,259 Total $ 23,721,124 $ 81,221 $ 32,875 $ 320,670 $ 24,155,890 $ 232,193	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 June 30, 2020 follows (in thousands): As of June 30, 2020 Total With No With Allowance Related Allowance Commercial: Energy $ 162,989 $ 85,171 $ 77,818 $ 20,863 Healthcare 3,645 3,645 — — Services 21,032 15,503 5,529 2,574 General business 14,333 13,014 1,319 346 Total commercial 201,999 117,333 84,666 23,783 Commercial real estate 13,956 8,511 5,445 540 Loans to individuals: Residential mortgage 33,098 33,098 — — Residential mortgage guaranteed by U.S. government agencies 6,110 6,110 — — Personal 233 233 — — Total loans to individuals 39,441 39,441 — — Total $ 255,396 $ 165,285 $ 90,111 $ 24,323

Mortgage Banking Activities (Ta

Mortgage Banking Activities (Tables)	6 Months Ended
	Jun. 30, 2020
Mortgage Banking [Abstract]
Components of Residential Mortgage Loans Held For Sale [Table Text Block]	June 30, 2020 December 31, 2019 Unpaid Principal Balance/ Fair Value Unpaid Principal Balance/ Fair Value Residential mortgage loans held for sale $ 285,274 $ 296,445 $ 175,117 $ 177,703 Residential mortgage loan commitments 546,304 27,631 158,460 5,233 Forward sales contracts 825,775 (4,719) 315,203 (665) $ 319,357 $ 182,271
Mortgage Banking Revenue [Table Text Block]	Mortgage banking revenue was as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Production revenue: Net realized gains on sale of mortgage loans $ 24,109 $ 10,174 $ 33,826 $ 15,867 Net change in unrealized gain on mortgage loans held for sale 5,024 921 8,585 868 Net change in the fair value of mortgage loan commitments 3,381 1,506 22,398 4,219 Net change in the fair value of forward sales contracts 6,671 (732) (4,054) (1,217) Total production revenue 39,185 11,869 60,755 19,737 Servicing revenue 14,751 16,262 30,348 32,228 Total mortgage banking revenue $ 53,936 $ 28,131 $ 91,103 $ 51,965
Summary of Mortgage Servicing Rights [Table Text Block]	The following represents a summary of mortgage servicing rights (dollars in thousands): June 30, 2020 December 31, 2019 Number of residential mortgage loans serviced for others 116,232 126,828 Outstanding principal balance of residential mortgage loans serviced for others $ 18,038,428 $ 20,727,106 Weighted average interest rate 3.96 % 3.98 % Remaining term (in months) 283 289
Activity in Capitalized Mortgage Servicing Rights [Table Text Block]	The following represents activity in capitalized mortgage servicing rights (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Beginning Balance $ 110,828 $ 238,193 $ 201,886 $ 259,254 Additions 8,465 8,751 13,906 14,939 Disposals (10,801) — (10,801) — Change in fair value due to principal payments (9,760) (9,081) (17,779) (15,664) Change in fair value due to market assumption changes (761) (29,555) (89,241) (50,221) Ending Balance $ 97,971 $ 208,308 $ 97,971 $ 208,308
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: June 30, 2020 December 31, 2019 Discount rate – risk-free rate plus a market premium 9.67% 9.81% Prepayment rate - based upon loan interest rate, original term and loan type 9.04% - 30.87% 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 0.33% 1.73% Primary/secondary mortgage rate spread 105 bps 104 bps Delinquency rate 4.51% 2.73%

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	6 Months Ended
	Jun. 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) 228,156 — 228,156 Reclassification adjustments included in earnings: Gain on available for sale securities, net (1,105) — (1,105) Other comprehensive income, before income taxes 227,051 — 227,051 Federal and state income taxes 1 55,897 — 55,897 Other comprehensive income, net of income taxes 171,154 — 171,154 Balance, June 30, 2019 $ 100,155 $ (1,586) $ 98,569 Balance, Dec. 31, 2019 $ 104,996 $ (73) $ 104,923 Net change in unrealized gain (loss) 354,765 — 354,765 Reclassification adjustments included in earnings: Gain on available for sale securities, net (5,580) — (5,580) Other comprehensive income, before income taxes 349,185 — 349,185 Federal and state income taxes 1 83,792 — 83,792 Other comprehensive income, net of income taxes 265,393 — 265,393 Balance, June 30, 2020 $ 370,389 $ (73) $ 370,316 1 Calculated using a 25 percent blended federal and state statutory tax rate.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Share [Table Text Block]	(In thousands, except share and per share amounts) Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Numerator: Net income attributable to BOK Financial Corp. shareholders $ 64,693 $ 137,563 $ 126,772 $ 248,175 Less: Earnings allocated to participating securities 397 850 740 1,678 Numerator for basic earnings per share – income available to common shareholders 64,296 136,713 126,032 246,497 Effect of reallocating undistributed earnings of participating securities — — — — Numerator for diluted earnings per share – income available to common shareholders $ 64,296 $ 136,713 $ 126,032 $ 246,497 Denominator: Weighted average shares outstanding 70,307,606 71,327,928 70,410,707 71,625,332 Less: Participating securities included in weighted average shares outstanding 431,563 440,865 410,842 489,918 Denominator for basic earnings per common share 69,876,043 70,887,063 69,999,865 71,135,414 Dilutive effect of employee stock compensation plans 1 1,424 14,970 3,952 16,144 Denominator for diluted earnings per common share 69,877,467 70,902,033 70,003,817 71,151,558 Basic earnings per share $ 0.92 $ 1.93 $ 1.80 $ 3.47 Diluted earnings per share $ 0.92 $ 1.93 $ 1.80 $ 3.46 1 Excludes employee stock options with exercise prices greater than current market price. 22,238 — — —

Reportable Segments (Tables)

Reportable Segments (Tables)	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Reportable Segments [Table Text Block]	Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended June 30, 2020 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other BOK Net interest revenue from external sources $ 174,314 $ 18,795 $ 34,359 $ 50,636 $ 278,104 Net interest revenue (expense) from internal sources (29,205) 20,475 (7,479) 16,209 — Net interest revenue 145,109 39,270 26,880 66,845 278,104 Provision for credit losses 13,762 535 (89) 121,113 135,321 Net interest revenue after provision for credit losses 131,347 38,735 26,969 (54,268) 142,783 Other operating revenue 47,898 67,192 106,674 10,929 232,693 Other operating expense 62,933 58,936 80,567 92,951 295,387 Net direct contribution 116,312 46,991 53,076 (136,290) 80,089 Gain on financial instruments, net 48 7,356 — (7,404) — Change in fair value of mortgage servicing rights — (761) — 761 — Gain on repossessed assets, net 191 27 — (218) — Corporate expense allocations 5,437 10,812 8,204 (24,453) — Net income before taxes 111,114 42,801 44,872 (118,698) 80,089 Federal and state income taxes 30,122 10,901 11,478 (36,698) 15,803 Net income 80,992 31,900 33,394 (82,000) 64,286 Net income (loss) attributable to non-controlling interests — — — (407) (407) Net income attributable to BOK Financial Corp. shareholders $ 80,992 $ 31,900 $ 33,394 $ (81,593) $ 64,693 Average assets $ 27,575,652 $ 9,920,005 $ 15,721,452 $ (3,460,078) $ 49,757,031 Reportable segments reconciliation to the Consolidated Financial Statements for the six months ended June 30, 2020 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other BOK Net interest revenue from external sources $ 376,216 $ 44,671 $ 48,725 $ 69,852 $ 539,464 Net interest revenue (expense) from internal sources (79,700) 38,531 (2,941) 44,110 — Net interest revenue 296,516 83,202 45,784 113,962 539,464 Provision for credit losses 30,642 1,791 (137) 196,796 229,092 Net interest revenue after provision for credit losses 265,874 81,411 45,921 (82,834) 310,372 Other operating revenue 86,118 122,254 204,555 85 413,012 Other operating expense 123,685 113,729 158,759 167,838 564,011 Net direct contribution 228,307 89,936 91,717 (250,587) 159,373 Gain on financial instruments, net 97 94,120 7 (94,224) — Change in fair value of mortgage servicing rights — (89,241) — 89,241 — Gain on repossessed assets, net 200 40 — (240) — Corporate expense allocations 14,342 21,299 16,469 (52,110) — Net income before taxes 214,262 73,556 75,255 (203,700) 159,373 Federal and state income taxes 58,295 18,735 19,288 (63,215) 33,103 Net income 155,967 54,821 55,967 (140,485) 126,270 Net income (loss) attributable to non-controlling interests — — — (502) (502) Net income attributable to BOK Financial Corp. shareholders $ 155,967 $ 54,821 $ 55,967 $ (139,983) $ 126,772 Average assets $ 26,131,814 $ 9,885,429 $ 14,222,432 $ (2,500,850) $ 47,738,825 Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended June 30, 2019 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other 1 BOK Net interest revenue from external sources $ 251,084 $ 25,300 $ 17,222 $ (8,174) $ 285,432 Net interest revenue (expense) from internal sources (66,613) 27,415 9,719 29,479 — Net interest revenue 184,471 52,715 26,941 21,305 285,432 Provision for credit losses 6,823 1,728 (48) (3,503) 5,000 Net interest revenue after provision for credit losses 177,648 50,987 26,989 24,808 280,432 Other operating revenue 41,611 48,811 86,017 (4,374) 172,065 Other operating expense 63,415 57,694 69,452 86,576 277,137 Net direct contribution 155,844 42,104 43,554 (66,142) 175,360 Gain (loss) on financial instruments, net 20 20,981 — (21,001) — Change in fair value of mortgage servicing rights — (29,555) — 29,555 — Gain (loss) on repossessed assets, net — 92 — (92) — Corporate expense allocations 10,652 11,695 9,168 (31,515) — Net income before taxes 145,212 21,927 34,386 (26,165) 175,360 Federal and state income taxes 38,932 5,585 8,842 (15,779) 37,580 Net income 106,280 16,342 25,544 (10,386) 137,780 Net income attributable to non-controlling interests — — — 217 217 Net income (loss) attributable to BOK Financial Corp. shareholders $ 106,280 $ 16,342 $ 25,544 $ (10,603) $ 137,563 Average assets $ 22,910,724 $ 9,212,667 $ 9,849,396 $ (1,128,010) $ 40,844,777 Reportable segments reconciliation to the Consolidated Financial Statements for the six months ended June 30, 2019 is as follows (in thousands): Commercial Consumer Wealth Funds Management and Other 1 BOK Net interest revenue from external sources $ 455,293 $ 47,775 $ 38,708 $ 21,758 $ 563,534 Net interest revenue (expense) from internal sources (120,251) 56,042 16,489 47,720 — Net interest revenue 335,042 103,817 55,197 69,478 563,534 Provision for credit losses 18,069 2,813 (167) (7,715) 13,000 Net interest revenue after provision for credit losses 316,973 101,004 55,364 77,193 550,534 Other operating revenue 79,223 91,559 159,431 (878) 329,335 Other operating expense 114,042 111,515 130,959 207,778 564,294 Net direct contribution 282,154 81,048 83,836 (131,463) 315,575 Gain (loss) on financial instruments, net 38 35,078 — (35,116) — Change in fair value of mortgage servicing rights — (50,221) — 50,221 — Gain (loss) on repossessed assets, net (346) 195 — 151 — Corporate expense allocations 20,107 23,595 17,528 (61,230) — Net income before taxes 261,739 42,505 66,308 (54,977) 315,575 Federal and state income taxes 69,938 10,826 17,045 (30,279) 67,530 Net income 191,801 31,679 49,263 (24,698) 248,045 Net income attributable to non-controlling interests — — — (130) (130) Net income attributable to BOK Financial Corp. shareholders $ 191,801 $ 31,679 $ 49,263 $ (24,568) $ 248,175 Average assets $ 21,432,513 $ 8,794,498 $ 9,590,629 $ 444,327 $ 40,261,967

Fees and Commissions Revenue _2

Fees and Commissions Revenue Fees and Commissions Rvenue (Tables)	6 Months Ended
	Jun. 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 June 30, 2020. Commercial Consumer Wealth Management Funds Management & Other Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 43,915 $ — $ 43,915 $ 43,915 $ — Customer hedging revenue 6,893 — 63 (714) 6,242 6,242 — Retail brokerage revenue — — 3,394 — 3,394 — 3,394 Insurance brokerage revenue — — 3,153 — 3,153 — 3,153 Investment banking revenue 1,131 — 4,187 — 5,318 851 4,467 Brokerage and trading revenue 8,024 — 54,712 (714) 62,022 51,008 11,014 TransFund EFT network revenue 19,647 556 (9) — 20,194 — 20,194 Merchant services revenue 2,230 13 — — 2,243 — 2,243 Corporate card revenue 485 — 18 — 503 — 503 Transaction card revenue 22,362 569 9 — 22,940 — 22,940 Personal trust revenue — — 21,681 — 21,681 — 21,681 Corporate trust revenue — — 4,604 — 4,604 — 4,604 Institutional trust & retirement plan services revenue — — 10,723 — 10,723 — 10,723 Investment management services and other revenue — — 4,291 (42) 4,249 — 4,249 Fiduciary and asset management revenue — — 41,299 (42) 41,257 — 41,257 Commercial account service charge revenue 11,069 389 598 — 12,056 — 12,056 Overdraft fee revenue 20 3,607 16 — 3,643 — 3,643 Check card revenue — 5,122 — — 5,122 — 5,122 Automated service charge and other deposit fee revenue 29 1,179 17 — 1,225 — 1,225 Deposit service charges and fees 11,118 10,297 631 — 22,046 — 22,046 Mortgage production revenue — 39,186 — — 39,186 39,186 — Mortgage servicing revenue — 15,164 — (414) 14,750 14,750 — Mortgage banking revenue — 54,350 — (414) 53,936 53,936 — Other revenue 5,011 1,976 10,106 (5,614) 11,479 8,970 2,509 Total fees and commissions revenue $ 46,515 $ 67,192 $ 106,757 $ (6,784) $ 213,680 $ 113,914 $ 99,766 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 six months ended June 30, 2020. Commercial Consumer Wealth Management Funds Management & Other Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 78,299 $ — $ 78,299 $ 78,299 $ — Customer hedging revenue 9,418 — 198 (151) 9,465 9,465 — Retail brokerage revenue — — 7,737 — 7,737 — 7,737 Insurance brokerage revenue — — 6,942 — 6,942 — 6,942 Investment banking revenue 3,011 — 7,347 — 10,358 2,679 7,679 Brokerage and trading revenue 12,429 — 100,523 (151) 112,801 90,443 22,358 TransFund EFT network revenue 37,859 1,387 (28) 2 39,220 — 39,220 Merchant services revenue 4,535 27 — — 4,562 — 4,562 Corporate card revenue 1,005 — 34 — 1,039 — 1,039 Transaction card revenue 43,399 1,414 6 2 44,821 — 44,821 Personal trust revenue — — 42,330 — 42,330 — 42,330 Corporate trust revenue — — 10,966 — 10,966 — 10,966 Institutional trust & retirement plan services revenue — — 22,480 — 22,480 — 22,480 Investment management services and other revenue — — 10,022 (83) 9,939 — 9,939 Fiduciary and asset management revenue — — 85,798 (83) 85,715 — 85,715 Commercial account service charge revenue 22,108 799 1,143 (1) 24,049 — 24,049 Overdraft fee revenue 69 10,812 38 2 10,921 — 10,921 Check card revenue — 10,351 — — 10,351 — 10,351 Automated service charge and other deposit fee revenue 258 2,565 30 2 2,855 — 2,855 Deposit service charges and fees 22,435 24,527 1,211 3 48,176 — 48,176 Mortgage production revenue — 60,755 — — 60,755 60,755 — Mortgage servicing revenue — 31,206 — (858) 30,348 30,348 — Mortgage banking revenue — 91,961 — (858) 91,103 91,103 — Other revenue 9,711 4,352 17,100 (7,375) 23,788 17,378 6,410 Total fees and commissions revenue $ 87,974 $ 122,254 $ 204,638 $ (8,462) $ 406,404 $ 198,924 $ 207,480 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 June 30, 2019. Commercial Consumer Wealth Management Funds Management & Other 3 Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 21,879 $ — $ 21,879 $ 21,879 $ — Customer hedging revenue 2,385 — 1,906 1,054 5,345 5,345 — Retail brokerage revenue — — 3,914 (13) 3,901 — 3,901 Insurance brokerage revenue — — 3,309 513 3,822 — 3,822 Investment banking revenue 2,548 — 3,032 (1) 5,579 2,198 3,381 Brokerage and trading revenue 4,933 — 34,040 1,553 40,526 29,422 11,104 TransFund EFT network revenue 18,504 997 (20) — 19,481 — 19,481 Merchant services revenue 2,223 15 — (1) 2,237 — 2,237 Corporate card revenue 190 — 5 2 197 — 197 Transaction card revenue 20,917 1,012 (15) 1 21,915 — 21,915 Personal trust revenue — — 21,215 1 21,216 — 21,216 Corporate trust revenue — — 6,331 (1) 6,330 — 6,330 Institutional trust & retirement plan services revenue — — 11,072 — 11,072 — 11,072 Investment management services and other revenue — — 6,449 (42) 6,407 — 6,407 Fiduciary and asset management revenue — — 45,067 (42) 45,025 — 45,025 Commercial account service charge revenue 10,625 429 538 — 11,592 — 11,592 Overdraft fee revenue 93 8,973 36 2 9,104 — 9,104 Check card revenue — 5,586 — 1 5,587 — 5,587 Automated service charge and other deposit fee revenue 214 1,578 (2) 1 1,791 — 1,791 Deposit service charges and fees 10,932 16,566 572 4 28,074 — 28,074 Mortgage production revenue — 11,871 — (2) 11,869 11,869 — Mortgage servicing revenue — 16,741 — (479) 16,262 16,262 — Mortgage banking revenue — 28,612 — (481) 28,131 28,131 — Other revenue 4,323 2,640 6,261 (787) 12,437 8,123 4,314 Total fees and commissions revenue $ 41,105 $ 48,830 $ 85,925 $ 248 $ 176,108 $ 65,676 $ 110,432 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 six months ended June 30, 2019. Commercial Consumer Wealth Management Funds Management & Other 3 Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 34,799 $ — $ 34,799 $ 34,799 $ — Customer hedging revenue 3,960 — 7,634 428 12,022 12,022 — Retail brokerage revenue — — 7,988 (65) 7,923 — 7,923 Insurance brokerage revenue — — 3,688 4,242 7,930 — 7,930 Investment banking revenue 3,937 — 5,533 (1) 9,469 3,427 6,042 Brokerage and trading revenue 7,897 — 59,642 4,604 72,143 50,248 21,895 TransFund EFT network revenue 36,158 1,955 (37) 1 38,077 — 38,077 Merchant services revenue 4,148 29 — 122 4,299 — 4,299 Corporate card revenue 270 — 5 2 277 — 277 Transaction card revenue 40,576 1,984 (32) 125 42,653 — 42,653 Personal trust revenue — — 40,789 1 40,790 — 40,790 Corporate trust revenue — — 12,532 (1) 12,531 — 12,531 Institutional trust & retirement plan services revenue — — 22,179 — 22,179 — 22,179 Investment management services and other revenue — — 11,250 1,633 12,883 — 12,883 Fiduciary and asset management revenue — — 86,750 1,633 88,383 — 88,383 Commercial account service charge revenue 20,687 816 1,065 1,807 24,375 — 24,375 Overdraft fee revenue 167 17,368 63 (234) 17,364 — 17,364 Check card revenue — 10,578 — 165 10,743 — 10,743 Automated service charge and other deposit fee revenue 372 3,243 175 45 3,835 — 3,835 Deposit service charges and fees 21,226 32,005 1,303 1,783 56,317 — 56,317 Mortgage production revenue — 19,739 — (2) 19,737 19,737 — Mortgage servicing revenue — 33,186 — (958) 32,228 32,228 — Mortgage banking revenue — 52,925 — (960) 51,965 51,965 — Other revenue 9,452 4,737 11,518 (508) 25,199 16,843 8,356 Total fees and commissions revenue $ 79,151 $ 91,651 $ 159,181 $ 6,677 $ 336,660 $ 119,056 $ 217,604

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 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 June 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 $ 4,237 $ — $ 4,237 $ — Residential agency mortgage-backed securities 1,146,454 — 1,146,454 — Municipal and other tax-exempt securities 22,710 — 22,710 — Asset-backed securities 5 — 5 — Other trading securities 22,699 — 22,699 — Total trading securities 1,196,105 — 1,196,105 — Available for sale securities: U.S. Treasury 912 912 — — Municipal and other tax-exempt securities 31,240 — 31,240 — Residential agency mortgage-backed securities 9,147,238 — 9,147,238 — Residential non-agency mortgage-backed securities 35,250 — 35,250 — Commercial agency mortgage-backed securities 3,260,807 — 3,260,807 — Other debt securities 472 — — 472 Total available for sale securities 12,475,919 912 12,474,535 472 Fair value option securities: U.S. Treasury 92,742 92,742 — — Residential agency mortgage-backed securities 629,915 — 629,915 — Total fair value option securities 722,657 92,742 629,915 — Residential mortgage loans held for sale 319,357 — 309,672 9,685 Mortgage servicing rights 1 97,971 — — 97,971 Derivative contracts, net of cash collateral 2 651,553 66,207 585,346 — Liabilities: Derivative contracts, net of cash collateral 2 610,020 — 610,020 — 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 energy and interest rate derivative contacts, net of cash margin. Derivative contacts in liability positions that were valued using quoted prices in active markets for identical instruments are exchange-traded interest rate 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 contacts, 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 six months ended June 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, Mar. 31, 2020 $ 472 $ 9,574 Transfer to Level 3 from Level 2 1 — 1,328 Purchases — — Proceeds from sales — (648) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — (569) Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, June 30, 2020 $ 472 $ 9,685 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 — 3,592 Purchases — — Proceeds from sales — (1,588) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — (632) Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, June 30, 2020 $ 472 $ 9,685 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 six months ended June 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, Mar. 31, 2019 $ 472 $ 15,776 Transfer to Level 3 from Level 2 1 — 907 Purchases — — Proceeds from sales — (998) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — 388 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, June 30, 2019 $ 472 $ 16,073 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 — 1,889 Purchases — — Proceeds from sales — (1,379) Redemptions and distributions — — Gain (loss) recognized in earnings Mortgage banking revenue — 356 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, June 30, 2019 $ 472 $ 16,073
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 June 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 5.23%-5.23% (5.23%) 3 94.30%-94.30% (94.30%) 2 Residential mortgage loans held for sale 9,685 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 approximately 1 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 June 30, 2020 for which the fair value was adjusted during the six months ended June 30, 2020: Fair Value Adjustments for the Carrying Value at June 30, 2020 Three Months Ended Six Months Ended Quoted Prices Significant Significant Gross charge-offs against allowance for loan losses Net losses 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 $ — $ 400 $ 32,448 $ 13,871 $ — $ 29,659 $ — Real estate and other repossessed assets — 918 400 — 5 — 131 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 June 30, 2019 for which the fair value was adjusted during the six months ended June 30, 2019: Fair Value Adjustments for the Carrying Value at June 30, 2019 Three Months Ended Six Months Ended Quoted Prices Significant Significant Gross charge-offs against allowance for loan losses Net losses and operating expenses of repossessed assets Gross charge-offs against allowance for loan losses Net losses and operating expenses of repossessed assets Nonaccruing loans $ — $ — $ 29,187 $ 11,335 $ — $ 20,917 $ — Real estate and other repossessed assets — 2,642 427 — 86 — 512
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 June 30, 2020 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range Nonaccruing loans $ 32,448 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% - 83% (35%) 1 Real estate and other repossessed assets 400 Appraised value, as adjusted Marketability adjustments off appraised value 2 87% - 87% (87%) 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. A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of June 30, 2019 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range Nonaccruing loans $ 29,187 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 12% - 76% (47%) 1 Real estate and other repossessed assets 427 Appraised value, as adjusted Marketability adjustments off appraised value 2 75% - 89% (88%) 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 June 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 $ 762,453 $ 762,453 $ 762,453 $ — $ — Interest-bearing cash and cash equivalents 485,319 485,319 485,319 — — Trading securities: U.S. government agency debentures 4,237 4,237 — 4,237 — Residential agency mortgage-backed securities 1,146,454 1,146,454 — 1,146,454 — Municipal and other tax-exempt securities 22,710 22,710 — 22,710 — Asset-backed securities 5 5 — 5 — Other trading securities 22,699 22,699 — 22,699 — Total trading securities 1,196,105 1,196,105 — 1,196,105 — Investment securities: Municipal and other tax-exempt securities 84,239 88,623 — 88,623 — Residential agency mortgage-backed securities 9,812 10,734 — 10,734 — Other debt securities 175,565 199,769 — 8,048 191,721 Total investment securities 269,616 299,126 — 107,405 191,721 Allowance for credit losses (1,628) — — — — Investment securities, net of allowance 267,988 299,126 — 107,405 191,721 Available for sale securities: U.S. Treasury 912 912 912 — — Municipal and other tax-exempt securities 31,240 31,240 — 31,240 — Residential agency mortgage-backed securities 9,147,238 9,147,238 — 9,147,238 — Residential non-agency mortgage-backed securities 35,250 35,250 — 35,250 — Commercial agency mortgage-backed securities 3,260,807 3,260,807 — 3,260,807 — Other debt securities 472 472 — — 472 Total available for sale securities 12,475,919 12,475,919 912 12,474,535 472 Fair value option securities: U.S. Treasury 92,742 92,742 92,742 — — Residential agency mortgage-backed securities 629,915 629,915 — 629,915 — Total fair value option securities 722,657 722,657 92,742 629,915 — Residential mortgage loans held for sale 319,357 319,357 — 309,672 9,685 Loans: Commercial 14,158,510 14,038,257 — — 14,038,257 Commercial real estate 4,554,144 4,558,274 — — 4,558,274 Paycheck protection program 2,081,428 2,062,278 — — 2,062,278 Loans to individuals 3,361,808 3,393,293 — — 3,393,293 Total loans 24,155,890 24,052,102 — — 24,052,102 Allowance for loan losses (435,597) — — — — Loans, net of allowance 23,720,293 24,052,102 — — 24,052,102 Mortgage servicing rights 97,971 97,971 — — 97,971 Derivative instruments with positive fair value, net of cash collateral 651,553 651,553 66,207 585,346 — Deposits with no stated maturity 31,539,554 31,539,554 — — 31,539,554 Time deposits 2,352,760 2,367,446 — — 2,367,446 Other borrowed funds 4,531,165 4,527,814 — — 4,527,814 Subordinated debentures 275,973 273,293 — 273,293 — Derivative instruments with negative fair value, net of cash collateral 610,020 610,020 — 610,020 — 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)	6 Months Ended
	Jun. 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	Jun. 30, 2020	Dec. 31, 2019
Schedule of Trading Securities [Line Items]
Trading securities	$ 1,196,105	$ 1,623,921
Trading Securities, Net Unrealized Gain (Loss)	3,851	2,359
U.S. government agency debentures [Member]
Schedule of Trading Securities [Line Items]
Trading securities	4,237	44,264
Trading Securities, Net Unrealized Gain (Loss)	19	6
Residential agency mortgage-backed securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	1,146,454	1,504,651
Trading Securities, Net Unrealized Gain (Loss)	3,589	2,293
Municipal and other tax-exempt securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	22,710	26,196
Trading Securities, Net Unrealized Gain (Loss)	116	60
Asset-backed securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	5	14,084
Trading Securities, Net Unrealized Gain (Loss)	0	(21)
Other debt securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	22,699	34,726
Trading Securities, Net Unrealized Gain (Loss)	$ 127	$ 21

Investment (Held-to-Maturity) S

Investment (Held-to-Maturity) Securities (Details) $ in Thousands		6 Months Ended
		Jun. 30, 2020USD ($)		Dec. 31, 2019USD ($)
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Gross Amortized Cost		$ 269,616		$ 293,418
Investment securities, Allowance for Credit Loss		(1,628)	[1]	0
Investments securities, Amortized Cost, Net of Allowance		267,988		293,418
Investment Securities, Fair Value		299,126		314,402
Investment Securities, Gross Unrealized Gain		29,541		21,285
Investment Securities, Gross Unrealized Loss		$ (31)		$ (301)
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		4		17
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 0		$ 1,276
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		2,142		9,747
Investment Securities, Continuous Unrealized Loss Position, Fair Value		2,142		11,023
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0		2
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		31		299
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss		31		301
Fixed Maturity Securities [Member]
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Net Carrying Value		39,734
Investment Securities, Debt Maturities, One to Five Years, Net Carrying Value		87,863
Investment Securities, Debt Maturities, Six to Ten Years, Net Carrying Value		122,309
Investment Securities, Debt Maturities, Over Ten Years, Net Carrying Value		9,898
Investment Securities, Debt Maturities, Single Maturity Date, Net Carrying Value		259,804
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Fair Value		40,151
Investment Securities, Debt Maturities, One to Five Years, Fair Value		96,615
Investment Securities, Debt Maturities, Six to Ten Years, Fair Value		141,378
Investment Securities, Debt Maturities, Over Ten Years, Fair Value		10,248
Investment Securities, Debt Maturities, Single Maturity Date, Fair Value		$ 288,392
Investment Securities, Debt Maturities, Weighted Average Maturity	[2]	4.95
Municipal and other tax-exempt securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Gross Amortized Cost		$ 84,239		93,653
Investment Securities, Fair Value		88,623		96,897
Investment Securities, Gross Unrealized Gain		4,384		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		175,565		189,089
Investment Securities, Fair Value		199,769		206,341
Investment Securities, Gross Unrealized Gain		24,235		17,547
Investment Securities, Gross Unrealized Loss		$ (31)		$ (295)
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		4		13
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 0		$ 275
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		2,142		8,041
Investment Securities, Continuous Unrealized Loss Position, Fair Value		2,142		8,316
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0		1
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		31		294
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss		31		295
Residential agency mortgage-backed securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Gross Amortized Cost		9,812		10,676
Investment Securities, Fair Value		10,734		11,164
Investment Securities, Gross Unrealized Gain		922		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]	9,812
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, without Single Maturity Date, Fair Value		$ 10,734
Investment Securities, Debt Maturities, Average Expected Life of Mortgage-backed Securities		4.6 years
[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 4.6 years based upon current prepayment assumptions.

Available for Sale Securities (

Available for Sale Securities (Details) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		$ 11,988,585		$ 11,988,585		$ 11,131,494
Available-for-sale Securities, Fair Value		12,475,919		12,475,919		11,269,643
Available-for-sale Securities, Gross Unrealized Gain		490,998		490,998		158,435
Available-for-sale Securities, Gross Unrealized Loss		(3,664)		(3,664)		(20,286)
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Available-for-sale Securities, Proceeds		179,051	$ 122,098	205,945	$ 367,357
Available-for-sale Securities, Gross realized gains		5,580	1,029	5,583	6,327
Available-for-sale Securities, Gross realized losses		0	0	0	(5,222)
Available-for-sale Securities, Related federal and state income tax expense (benefit)		1,421	$ 262	1,422	$ 281
Pledged Assets Separately Reported, Securities Pledged as Collateral, at Fair Value		12,300,000		12,300,000		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		34,044		34,044
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost Basis		1,321,471		1,321,471
Available-for-sale Securities, Debt Maturities, Six To Ten Years, Amortized Cost Basis		1,241,310		1,241,310
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost Basis		580,353		580,353
Available-for-sale Securities, Debt Maturities, Allocated and Single Maturity Date, Amortized Cost		3,177,178		3,177,178
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Fair Value		34,144		34,144
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value		1,375,128		1,375,128
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value		1,280,251		1,280,251
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value		603,908		603,908
Available-for-sale Securities, Debt Maturities, Allocated and Single Maturity Date, Fair Value		$ 3,293,431		$ 3,293,431
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	[1]	8.03		8.03
U.S. Treasury [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		$ 900		$ 900		1,598
Available-for-sale Securities, Fair Value		912		912		1,600
Available-for-sale Securities, Gross Unrealized Gain		12		12		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		29,670		29,670		1,789
Available-for-sale Securities, Fair Value		31,240		31,240		1,861
Available-for-sale Securities, Gross Unrealized Gain		1,570		1,570		72
Available-for-sale Securities, Gross Unrealized Loss		0		0		0
Commercial agency mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		3,146,108		3,146,108		3,145,342
Available-for-sale Securities, Fair Value		3,260,807		3,260,807		3,178,005
Available-for-sale Securities, Gross Unrealized Gain		116,042		116,042		37,808
Available-for-sale Securities, Gross Unrealized Loss		(1,343)		(1,343)		(5,145)
Other debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		500		500		500
Available-for-sale Securities, Fair Value		472		472		472
Available-for-sale Securities, Gross Unrealized Gain		0		0		0
Available-for-sale Securities, Gross Unrealized Loss		(28)		(28)		(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]	8,811,407		8,811,407
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value		9,182,488		$ 9,182,488
Available-for-sale Securities, Debt Maturities, Average Expected Life of Mortgage-backed Securities				3.1 years
Residential agency mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		8,789,466		$ 8,789,466		7,956,297
Available-for-sale Securities, Fair Value		9,147,238		9,147,238		8,046,096
Available-for-sale Securities, Gross Unrealized Gain		360,056		360,056		104,912
Available-for-sale Securities, Gross Unrealized Loss		(2,284)		(2,284)		(15,113)
Residential non-agency mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		21,941		21,941		25,968
Available-for-sale Securities, Fair Value		35,250		35,250		41,609
Available-for-sale Securities, Gross Unrealized Gain		13,318		13,318		15,641
Available-for-sale Securities, Gross Unrealized Loss		$ (9)		$ (9)		$ 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 3.1 years based upon current prepayment assumptions.

Securities Debt Securities, Ava

Securities Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value (Details) $ in Thousands	Jun. 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	60	203
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 766,294	$ 2,182,644
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	335,275	897,351
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,101,569	3,079,995
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2,286	10,928
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	1,378	9,358
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 3,664	$ 20,286
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	36	133
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 492,864	$ 1,352,597
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	173,997	686,002
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	666,861	2,038,599
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1,375	6,690
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	909	8,423
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 2,284	$ 15,113
Residential non-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	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 1,695
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	1,695
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	9
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	$ 9
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	22	69
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 271,735	$ 830,047
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	160,806	210,877
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	432,541	1,040,924
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	902	4,238
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	441	907
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 1,343	$ 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	1	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 0	$ 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	472	472
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	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	$ 28	$ 28

Securities Fair Value Option Se

Securities Fair Value Option Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair Value Option Securities [Line Items]
Fair value option securities, Fair Value	$ 722,657	$ 1,098,577
Fair value option securities, Net Unrealized Gain (Loss)	16,856	14,061
U.S. Treasury [Member]
Fair Value Option Securities [Line Items]
Fair value option securities, Fair Value	92,742	9,917
Fair value option securities, Net Unrealized Gain (Loss)	307	(48)
Residential agency mortgage-backed securities [Member]
Fair Value Option Securities [Line Items]
Fair value option securities, Fair Value	629,915	1,088,660
Fair value option securities, Net Unrealized Gain (Loss)	$ 16,549	$ 14,109

Derivatives, Fair Value of Deri

Derivatives, Fair Value of Derivatives Contracts (Details) - USD ($) $ in Thousands	Jun. 30, 2020		Dec. 31, 2019
Derivative Assets, Fair Value, Net [Abstract]
Derviative contracts, net of cash collateral, Assets, Fair value	$ 651,553		$ 323,375
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Fair Value, Net of Cash Collateral	610,020		251,128
Not Designated as Hedging Instrument [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	57,055,158	[1]	75,917,378	[2]
Derivative Liabilities, Notional	58,427,499	[1]	70,400,171	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	1,101,039		549,555
Derivative Assets, Netting Adjustments	(293,533)		(225,482)
Derivative Assets, Net Fair Value Before Cash Collateral	807,506		324,073
Derivative Assets, Cash Collateral	(155,953)		(698)
Derviative contracts, net of cash collateral, Assets, Fair value	651,553		323,375
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	1,035,960		528,921
Derivative Liabilities, Netting Adjustments	(293,533)		(225,482)
Derivative Liabilities, Net Fair Value Before Cash Collateral	742,427		303,439
Derivative Liabilities, Cash Collateral	(132,407)		(52,311)
Derivative Liabilities, Fair Value, Net of Cash Collateral	610,020		251,128
Not Designated as Hedging Instrument [Member] | Total customer risk management programs
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	6,056,846	[1]	4,927,266	[2]
Derivative Liabilities, Notional	5,850,489	[1]	4,875,382	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	857,569		411,768
Derivative Assets, Netting Adjustments	(199,882)		(109,452)
Derivative Assets, Net Fair Value Before Cash Collateral	657,687		302,316
Derivative Assets, Cash Collateral	(155,953)		(698)
Derviative contracts, net of cash collateral, Assets, Fair value	501,734		301,618
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	819,482		400,265
Derivative Liabilities, Netting Adjustments	(199,882)		(109,452)
Derivative Liabilities, Net Fair Value Before Cash Collateral	619,600		290,813
Derivative Liabilities, Cash Collateral	(132,407)		(51,448)
Derivative Liabilities, Fair Value, Net of Cash Collateral	487,193		239,365
Not Designated as Hedging Instrument [Member] | Interest rate contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	2,772,027	[1]	2,464,478	[2]
Derivative Liabilities, Notional	2,772,027	[1]	2,464,478	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	140,157		49,100
Derivative Assets, Netting Adjustments	(42)		(1,839)
Derivative Assets, Net Fair Value Before Cash Collateral	140,115		47,261
Derivative Assets, Cash Collateral	0		0
Derviative contracts, net of cash collateral, Assets, Fair value	140,115		47,261
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	140,509		49,194
Derivative Liabilities, Netting Adjustments	(42)		(1,839)
Derivative Liabilities, Net Fair Value Before Cash Collateral	140,467		47,355
Derivative Liabilities, Cash Collateral	(129,094)		(43,932)
Derivative Liabilities, Fair Value, Net of Cash Collateral	11,373		3,423
Not Designated as Hedging Instrument [Member] | Energy contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	2,912,225	[1]	2,151,096	[2]
Derivative Liabilities, Notional	2,718,690	[1]	2,105,391	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	434,455		144,906
Derivative Assets, Netting Adjustments	(199,805)		(107,591)
Derivative Assets, Net Fair Value Before Cash Collateral	234,650		37,315
Derivative Assets, Cash Collateral	(155,160)		(38)
Derviative contracts, net of cash collateral, Assets, Fair value	79,490		37,277
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	408,813		139,311
Derivative Liabilities, Netting Adjustments	(199,805)		(107,591)
Derivative Liabilities, Net Fair Value Before Cash Collateral	209,008		31,720
Derivative Liabilities, Cash Collateral	(3,298)		(6,031)
Derivative Liabilities, Fair Value, Net of Cash Collateral	205,710		25,689
Not Designated as Hedging Instrument [Member] | Agricultural contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	13,183	[1]	16,118	[2]
Derivative Liabilities, Notional	13,191	[1]	16,139	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	59		1,522
Derivative Assets, Netting Adjustments	(35)		(22)
Derivative Assets, Net Fair Value Before Cash Collateral	24		1,500
Derivative Assets, Cash Collateral	0		0
Derviative contracts, net of cash collateral, Assets, Fair value	24		1,500
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	50		1,507
Derivative Liabilities, Netting Adjustments	(35)		(22)
Derivative Liabilities, Net Fair Value Before Cash Collateral	15		1,485
Derivative Liabilities, Cash Collateral	(15)		(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	283,424	[1]	214,119	[2]
Derivative Liabilities, Notional	270,594	[1]	207,919	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	281,801		213,007
Derivative Assets, Netting Adjustments	0		0
Derivative Assets, Net Fair Value Before Cash Collateral	281,801		213,007
Derivative Assets, Cash Collateral	(507)		0
Derviative contracts, net of cash collateral, Assets, Fair value	281,294		213,007
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	269,013		207,020
Derivative Liabilities, Netting Adjustments	0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral	269,013		207,020
Derivative Liabilities, Cash Collateral	0		0
Derivative Liabilities, Fair Value, Net of Cash Collateral	269,013		207,020
Not Designated as Hedging Instrument [Member] | Equity option contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	75,987	[1]	81,455	[2]
Derivative Liabilities, Notional	75,987	[1]	81,455	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	1,097		3,233
Derivative Assets, Netting Adjustments	0		0
Derivative Assets, Net Fair Value Before Cash Collateral	1,097		3,233
Derivative Assets, Cash Collateral	(286)		(660)
Derviative contracts, net of cash collateral, Assets, Fair value	811		2,573
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	1,097		3,233
Derivative Liabilities, Netting Adjustments	0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral	1,097		3,233
Derivative Liabilities, Cash Collateral	0		0
Derivative Liabilities, Fair Value, Net of Cash Collateral	1,097		3,233
Not Designated as Hedging Instrument [Member] | Trading [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	50,132,348	[1]	69,721,932	[2]
Derivative Liabilities, Notional	52,408,519	[1]	65,144,388	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	219,647		131,561
Derivative Assets, Netting Adjustments	(91,830)		(115,949)
Derivative Assets, Net Fair Value Before Cash Collateral	127,817		15,612
Derivative Assets, Cash Collateral	0		0
Derviative contracts, net of cash collateral, Assets, Fair value	127,817		15,612
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	213,170		125,535
Derivative Liabilities, Netting Adjustments	(91,830)		(115,949)
Derivative Liabilities, Net Fair Value Before Cash Collateral	121,340		9,586
Derivative Liabilities, Cash Collateral	0		0
Derivative Liabilities, Fair Value, Net of Cash Collateral	121,340		9,586
Not Designated as Hedging Instrument [Member] | Internal risk management programs [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	865,964	[1]	1,268,180	[2]
Derivative Liabilities, Notional	168,491	[1]	380,401	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	23,823		6,226
Derivative Assets, Netting Adjustments	(1,821)		(81)
Derivative Assets, Net Fair Value Before Cash Collateral	22,002		6,145
Derivative Assets, Cash Collateral	0		0
Derviative contracts, net of cash collateral, Assets, Fair value	22,002		6,145
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	3,308		3,121
Derivative Liabilities, Netting Adjustments	(1,821)		(81)
Derivative Liabilities, Net Fair Value Before Cash Collateral	1,487		3,040
Derivative Liabilities, Cash Collateral	0		(863)
Derivative Liabilities, Fair Value, Net of Cash Collateral	$ 1,487		$ 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				6 Months Ended
	Jun. 30, 2020		Jun. 30, 2019		Jun. 30, 2020		Jun. 30, 2019
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	$ 38,819		$ 13,374		$ 1,386		$ 12,756
Gain (Loss) on Derivatives, Net	21,885		11,150		40,305		15,817
Total customer risk management programs
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	6,242		5,344		9,464		12,021
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		2,212		0		7,912
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	746		942		1,688		1,535
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	5,383		2,086		7,390		2,312
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		4		21		8
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	107		100		365		254
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	32,577	[1]	8,030	[1]	(8,078)	[2]	735	[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	$ 21,885		$ 11,150		$ 40,305		$ 15,817
[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	Jun. 30, 2020	Dec. 31, 2019
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest	$ 8,365,827	$ 6,134,362
Loans, variable rate of interest	15,534,667	15,435,674
Loans, non-accrual	255,396	180,951
Total	24,155,890	21,750,987
Past Due 90 Days or More and Accruing	232,193	7,680
Credit Commitments [Abstract]
Outstanding commitments to extend credit	10,300,000
Outstanding standby letters of credit	693,000
Commercial [Member]
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest	3,215,865	3,231,485
Loans, variable rate of interest	10,740,646	10,684,749
Loans, non-accrual	201,999	115,416
Total	14,158,510	14,031,650
Past Due 90 Days or More and Accruing	10,465
Commercial real estate [Member]
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest	1,029,544	1,056,321
Loans, variable rate of interest	3,510,644	3,349,836
Loans, non-accrual	13,956	27,626
Total	4,554,144	4,433,783
Past Due 90 Days or More and Accruing	469
Paycheck Protection Program
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest	2,081,428
Loans, variable rate of interest	0
Loans, non-accrual	0
Total	2,081,428
Past Due 90 Days or More and Accruing	0
Loans to individuals [Member]
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest	2,038,990
Loans, variable rate of interest	1,283,377
Loans, non-accrual	39,441
Total	3,361,808	2,084,172
Past Due 90 Days or More and Accruing	221,259
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	1,813,442	2,084,172
Past Due 90 Days or More and Accruing	42
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	1,226,097	$ 1,201,382
Past Due 90 Days or More and Accruing	$ 16

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		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL	$ 315,311		$ 236,568
Beginning balance - Incurred Loss Model		$ 205,340	210,759	$ 207,457
Provision for loan losses - CECL	134,365		230,329
Provision for loan losses - incurred		4,918		12,887
Loans charged off	(15,570)	(13,227)	(34,487)	(25,002)
Recoveries of loans previously charged off	1,491	5,503	3,187	7,192
Ending balance - CECL	435,597		435,597
Ending balance - Incurred Loss Model	435,597	202,534	435,597	202,534
Provision Details [Abstract]
Change in provision due to changes in reasonable and supportable forecasts, primarily due to COVID-19 pandemic	54,600
Other changes to provision	84,200
Provision change due to changes in impairment, risk grading, and other portfolio changes	14,400
Provision change due to risk grading	55,700
Provision changes due to net charge-offs	14,100
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL	28,514		25,137
Provision for off-balance sheet credit risk	4,405		7,782
Ending balance - CECL	32,919		32,919
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred Loss Model		1,821		1,790
Provision for off-balance sheet credit losses		82		113
Ending balance - Incurred Loss Model		1,903		1,903
Total provision for credit losses	135,321	5,000	229,092	13,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					$ 23,900,494	$ 21,570,036
Individually measured for impairment, recorded investment					255,396	180,951
Total					24,155,890	21,750,987
Related allowance [Abstract]
Collectively measured for impairment, related allowance					411,274	176,150
Individually measured for impairment, related allowance					24,323	17,414
Total	435,597	202,534	210,759	202,534	435,597	210,759
Commercial [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL	213,438		151,868
Beginning balance - Incurred Loss Model		103,577	118,187	102,226
Provision for loan losses - CECL	111,153		188,876
Provision for loan losses - incurred		13,771		24,879
Loans charged off	(14,487)	(11,385)	(31,102)	(21,853)
Recoveries of loans previously charged off	318	434	780	1,145
Ending balance - CECL	310,422		310,422
Ending balance - Incurred Loss Model	310,422	106,397	310,422	106,397
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL	14,040		11,578
Provision for off-balance sheet credit risk	542		3,004
Ending balance - CECL	14,582		14,582
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred Loss Model		1,725		1,655
Provision for off-balance sheet credit losses		17		87
Ending balance - Incurred Loss Model		1,742		1,742
Total provision for credit losses		13,788		24,966
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					13,956,511	13,916,234
Individually measured for impairment, recorded investment					201,999	115,416
Total					14,158,510	14,031,650
Related allowance [Abstract]
Collectively measured for impairment, related allowance					286,639	100,773
Individually measured for impairment, related allowance					23,783	17,414
Total	310,422	106,397	118,187	106,397	310,422	118,187
Commercial real estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - CECL	51,461		47,185
Beginning balance - Incurred Loss Model		58,134	51,805	60,026
Provision for loan losses - CECL	17,221		22,336
Provision for loan losses - incurred		(8,173)		(10,177)
Loans charged off	(1)	(118)	(887)	(118)
Recoveries of loans previously charged off	75	4,345	122	4,457
Ending balance - CECL	68,756		68,756
Ending balance - Incurred Loss Model	68,756	54,188	68,756	54,188
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL	12,575		11,767
Provision for off-balance sheet credit risk	3,844		4,652
Ending balance - CECL	16,419		16,419
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred Loss Model		48		52
Provision for off-balance sheet credit losses		68		64
Ending balance - Incurred Loss Model		116		116
Total provision for credit losses		(8,105)		(10,113)
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					4,540,188	4,406,157
Individually measured for impairment, recorded investment					13,956	27,626
Total					4,554,144	4,433,783
Related allowance [Abstract]
Collectively measured for impairment, related allowance					68,216	51,805
Individually measured for impairment, related allowance					540	0
Total	68,756	54,188	51,805	54,188	68,756	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					2,081,428
Individually measured for impairment, recorded investment					0
Total					2,081,428
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	50,412		37,515
Provision for loan losses - CECL	5,991		19,117
Loans charged off	(1,082)		(2,498)
Recoveries of loans previously charged off	1,098		2,285
Ending balance - CECL	56,419		56,419
Ending balance - Incurred Loss Model	56,419		56,419
Off-Balance Sheet, Credit Loss, Liability [Roll Forward]
Beginning balance - CECL	1,899		1,792
Provision for off-balance sheet credit risk	19		126
Ending balance - CECL	1,918		1,918
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					3,322,367
Individually measured for impairment, recorded investment					39,441
Total					3,361,808	2,084,172
Related allowance [Abstract]
Collectively measured for impairment, related allowance					56,419
Individually measured for impairment, related allowance					0
Total	56,419		56,419		56,419
Loans to individuals [Member] | Residential mortgage [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - Incurred Loss Model		15,668	14,400	17,964
Provision for loan losses - incurred		1		(2,407)
Loans charged off		(94)		(136)
Recoveries of loans previously charged off		149		303
Ending balance - Incurred Loss Model		15,724		15,724
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance - Incurred Loss Model		47		52
Provision for off-balance sheet credit losses		(3)		(8)
Ending balance - Incurred Loss Model		44		44
Total provision for credit losses		(2)		(2,415)
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment						2,046,550
Individually measured for impairment, recorded investment						37,622
Total					1,813,442	2,084,172
Related allowance [Abstract]
Collectively measured for impairment, related allowance						14,400
Individually measured for impairment, related allowance						0
Total		15,724	14,400	17,964		14,400
Loans to individuals [Member] | Personal [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance - Incurred Loss Model		8,783	9,172	9,473
Provision for loan losses - incurred		1,660		1,523
Loans charged off		(1,630)		(2,895)
Recoveries of loans previously charged off		575		1,287
Ending balance - Incurred Loss Model		9,388		9,388
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		1,660		1,493
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment						1,201,095
Individually measured for impairment, recorded investment						287
Total					$ 1,226,097	1,201,382
Related allowance [Abstract]
Collectively measured for impairment, related allowance						9,172
Individually measured for impairment, related allowance						0
Total		9,388	9,172	9,473		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		19,178	17,195	17,768
Provision for loan losses - CECL	0		0
Provision for loan losses - incurred		(2,341)		(931)
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		16,837		16,837
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		(2,341)		(931)
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		$ 16,837	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	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	$ 3,607,903
Financing Receivable, Originated, 2019	3,294,567
Financing Receivable, Originated, 2018	2,919,965
Financing Receivable, Originated, 2017	2,045,958
Financing Receivable, Originated, 2016	1,522,705
Financing Receivable, Originated, 2015 or Prior	3,620,215
Financing Receivable, Revolving	7,112,055
Financing Receivable, Revolving, Converted to Term Loan	32,522
Total	24,155,890
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		$ 19,826,731
Non-Graded, Recorded Investment		1,924,256
Total	24,155,890	21,750,987
Related Allowance [Abstract]
Internally Risk Graded, Allowance		179,129
Non-Graded, Allowance		14,435
Total	435,597	210,759	$ 202,534	$ 205,340	$ 207,457
Commercial [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	830,476
Financing Receivable, Originated, 2019	1,717,640
Financing Receivable, Originated, 2018	1,614,431
Financing Receivable, Originated, 2017	1,162,047
Financing Receivable, Originated, 2016	819,528
Financing Receivable, Originated, 2015 or Prior	1,970,813
Financing Receivable, Revolving	6,040,212
Financing Receivable, Revolving, Converted to Term Loan	3,363
Total	14,158,510
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		13,997,538
Non-Graded, Recorded Investment		34,112
Total	14,158,510	14,031,650
Related Allowance [Abstract]
Internally Risk Graded, Allowance		117,236
Non-Graded, Allowance		951
Total	310,422	118,187	106,397	103,577	102,226
Commercial [Member] | Energy [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	23,119
Financing Receivable, Originated, 2019	68,836
Financing Receivable, Originated, 2018	119,626
Financing Receivable, Originated, 2017	8,344
Financing Receivable, Originated, 2016	1,476
Financing Receivable, Originated, 2015 or Prior	41,233
Financing Receivable, Revolving	3,711,540
Financing Receivable, Revolving, Converted to Term Loan	0
Total	3,974,174
Recorded Investment [Abstract]
Total	3,974,174	3,973,377
Commercial [Member] | Healthcare [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	212,781
Financing Receivable, Originated, 2019	640,451
Financing Receivable, Originated, 2018	649,536
Financing Receivable, Originated, 2017	493,783
Financing Receivable, Originated, 2016	248,255
Financing Receivable, Originated, 2015 or Prior	795,390
Financing Receivable, Revolving	249,147
Financing Receivable, Revolving, Converted to Term Loan	0
Total	3,289,343
Recorded Investment [Abstract]
Total	3,289,343	3,033,916
Commercial [Member] | Services [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	336,059
Financing Receivable, Originated, 2019	494,582
Financing Receivable, Originated, 2018	466,100
Financing Receivable, Originated, 2017	387,982
Financing Receivable, Originated, 2016	414,269
Financing Receivable, Originated, 2015 or Prior	873,472
Financing Receivable, Revolving	806,744
Financing Receivable, Revolving, Converted to Term Loan	673
Total	3,779,881
Recorded Investment [Abstract]
Total	3,779,881	3,122,163
Commercial [Member] | General business [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	258,517
Financing Receivable, Originated, 2019	513,771
Financing Receivable, Originated, 2018	379,169
Financing Receivable, Originated, 2017	271,938
Financing Receivable, Originated, 2016	155,528
Financing Receivable, Originated, 2015 or Prior	260,718
Financing Receivable, Revolving	1,272,781
Financing Receivable, Revolving, Converted to Term Loan	2,690
Total	3,115,112
Recorded Investment [Abstract]
Total	3,115,112
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	345,439
Financing Receivable, Originated, 2019	1,131,573
Financing Receivable, Originated, 2018	1,037,584
Financing Receivable, Originated, 2017	555,707
Financing Receivable, Originated, 2016	387,951
Financing Receivable, Originated, 2015 or Prior	856,171
Financing Receivable, Revolving	239,719
Financing Receivable, Revolving, Converted to Term Loan	0
Total	4,554,144
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		4,433,783
Non-Graded, Recorded Investment		0
Total	4,554,144	4,433,783
Related Allowance [Abstract]
Internally Risk Graded, Allowance		51,805
Non-Graded, Allowance		0
Total	68,756	51,805	54,188	58,134	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	2,081,428
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	2,081,428
Recorded Investment [Abstract]
Total	2,081,428
Related Allowance [Abstract]
Total	0
Loans to individuals [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	350,560
Financing Receivable, Originated, 2019	445,354
Financing Receivable, Originated, 2018	267,950
Financing Receivable, Originated, 2017	328,204
Financing Receivable, Originated, 2016	315,226
Financing Receivable, Originated, 2015 or Prior	793,231
Financing Receivable, Revolving	832,124
Financing Receivable, Revolving, Converted to Term Loan	29,159
Total	3,361,808
Recorded Investment [Abstract]
Total	3,361,808	2,084,172
Related Allowance [Abstract]
Total	56,419
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	226,396
Financing Receivable, Originated, 2019	191,932
Financing Receivable, Originated, 2018	164,941
Financing Receivable, Originated, 2017	188,395
Financing Receivable, Originated, 2016	197,412
Financing Receivable, Originated, 2015 or Prior	464,836
Financing Receivable, Revolving	352,109
Financing Receivable, Revolving, Converted to Term Loan	27,421
Total	1,813,442
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		279,113
Non-Graded, Recorded Investment		1,805,059
Total	1,813,442	2,084,172
Related Allowance [Abstract]
Internally Risk Graded, Allowance		3,085
Non-Graded, Allowance		11,315
Total		14,400	15,724	15,668	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	751
Financing Receivable, Originated, 2019	6,794
Financing Receivable, Originated, 2018	19,922
Financing Receivable, Originated, 2017	24,184
Financing Receivable, Originated, 2016	46,676
Financing Receivable, Originated, 2015 or Prior	223,942
Financing Receivable, Revolving	0
Financing Receivable, Revolving, Converted to Term Loan	0
Total	322,269
Recorded Investment [Abstract]
Total	322,269
Loans to individuals [Member] | Personal [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	123,413
Financing Receivable, Originated, 2019	246,628
Financing Receivable, Originated, 2018	83,087
Financing Receivable, Originated, 2017	115,625
Financing Receivable, Originated, 2016	71,138
Financing Receivable, Originated, 2015 or Prior	104,453
Financing Receivable, Revolving	480,015
Financing Receivable, Revolving, Converted to Term Loan	1,738
Total	1,226,097
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment		1,116,297
Non-Graded, Recorded Investment		85,085
Total	1,226,097	1,201,382
Related Allowance [Abstract]
Internally Risk Graded, Allowance		7,003
Non-Graded, Allowance		2,169
Total		9,172	9,388	8,783	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	$ 16,837	$ 19,178	$ 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	23,119
Financing Receivable, Originated, 2019	62,250
Financing Receivable, Originated, 2018	94,216
Financing Receivable, Originated, 2017	8,344
Financing Receivable, Originated, 2016	1,427
Financing Receivable, Originated, 2015 or Prior	2,908
Financing Receivable, Revolving	2,664,680
Financing Receivable, Revolving, Converted to Term Loan	0
Total	2,856,944
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	9,720
Financing Receivable, Originated, 2017	0
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	0
Financing Receivable, Revolving	493,719
Financing Receivable, Revolving, Converted to Term Loan	0
Total	503,439
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	0
Financing Receivable, Originated, 2019	0
Financing Receivable, Originated, 2018	194
Financing Receivable, Originated, 2017	0
Financing Receivable, Originated, 2016	49
Financing Receivable, Originated, 2015 or Prior	0
Financing Receivable, Revolving	450,559
Financing Receivable, Revolving, Converted to Term Loan	0
Total	450,802
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	212,781
Financing Receivable, Originated, 2019	609,757
Financing Receivable, Originated, 2018	641,607
Financing Receivable, Originated, 2017	489,096
Financing Receivable, Originated, 2016	248,094
Financing Receivable, Originated, 2015 or Prior	767,193
Financing Receivable, Revolving	245,123
Financing Receivable, Revolving, Converted to Term Loan	0
Total	3,213,651
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	3,714
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	13,771
Financing Receivable, Revolving	3,515
Financing Receivable, Revolving, Converted to Term Loan	0
Total	48,500
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	3,176
Financing Receivable, Originated, 2018	7,746
Financing Receivable, Originated, 2017	973
Financing Receivable, Originated, 2016	161
Financing Receivable, Originated, 2015 or Prior	11,491
Financing Receivable, Revolving	0
Financing Receivable, Revolving, Converted to Term Loan	0
Total	23,547
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	335,961
Financing Receivable, Originated, 2019	475,608
Financing Receivable, Originated, 2018	437,812
Financing Receivable, Originated, 2017	366,772
Financing Receivable, Originated, 2016	400,480
Financing Receivable, Originated, 2015 or Prior	857,564
Financing Receivable, Revolving	743,258
Financing Receivable, Revolving, Converted to Term Loan	673
Total	3,618,128
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	0
Financing Receivable, Originated, 2019	3,919
Financing Receivable, Originated, 2018	1,474
Financing Receivable, Originated, 2017	170
Financing Receivable, Originated, 2016	4,513
Financing Receivable, Originated, 2015 or Prior	3,626
Financing Receivable, Revolving	35,203
Financing Receivable, Revolving, Converted to Term Loan	0
Total	48,905
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	98
Financing Receivable, Originated, 2019	12,077
Financing Receivable, Originated, 2018	26,814
Financing Receivable, Originated, 2017	12,393
Financing Receivable, Originated, 2016	8,123
Financing Receivable, Originated, 2015 or Prior	4,753
Financing Receivable, Revolving	27,558
Financing Receivable, Revolving, Converted to Term Loan	0
Total	91,816
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	256,821
Financing Receivable, Originated, 2019	485,956
Financing Receivable, Originated, 2018	359,249
Financing Receivable, Originated, 2017	256,403
Financing Receivable, Originated, 2016	147,056
Financing Receivable, Originated, 2015 or Prior	251,326
Financing Receivable, Revolving	1,258,843
Financing Receivable, Revolving, Converted to Term Loan	2,671
Total	3,018,325
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	10,196
Financing Receivable, Originated, 2018	763
Financing Receivable, Originated, 2017	11,244
Financing Receivable, Originated, 2016	941
Financing Receivable, Originated, 2015 or Prior	4,046
Financing Receivable, Revolving	3,404
Financing Receivable, Revolving, Converted to Term Loan	0
Total	30,594
Performing [Member] | Commercial [Member] | General business [Member] | Accruing Substandard [Member]
Financing Receivable, Credit Quality Indicator Line Items [Abstract]
Financing Receivable, Originated, 2020	21
Financing Receivable, Originated, 2019	13,906
Financing Receivable, Originated, 2018	13,989
Financing Receivable, Originated, 2017	2,353
Financing Receivable, Originated, 2016	6,216
Financing Receivable, Originated, 2015 or Prior	5,206
Financing Receivable, Revolving	10,165
Financing Receivable, Revolving, Converted to Term Loan	4
Total	51,860
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	345,439
Financing Receivable, Originated, 2019	1,131,573
Financing Receivable, Originated, 2018	1,037,584
Financing Receivable, Originated, 2017	536,047
Financing Receivable, Originated, 2016	378,852
Financing Receivable, Originated, 2015 or Prior	852,020
Financing Receivable, Revolving	234,148
Financing Receivable, Revolving, Converted to Term Loan	0
Total	4,515,663
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	0
Financing Receivable, Originated, 2017	12,200
Financing Receivable, Originated, 2016	1,622
Financing Receivable, Originated, 2015 or Prior	3,283
Financing Receivable, Revolving	100
Financing Receivable, Revolving, Converted to Term Loan	0
Total	17,205
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	0
Financing Receivable, Originated, 2018	0
Financing Receivable, Originated, 2017	7,228
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	65
Financing Receivable, Revolving	27
Financing Receivable, Revolving, Converted to Term Loan	0
Total	7,320
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	2,081,428
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	2,081,428
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	226,396
Financing Receivable, Originated, 2019	191,344
Financing Receivable, Originated, 2018	161,193
Financing Receivable, Originated, 2017	187,649
Financing Receivable, Originated, 2016	196,218
Financing Receivable, Originated, 2015 or Prior	438,056
Financing Receivable, Revolving	349,610
Financing Receivable, Revolving, Converted to Term Loan	26,679
Total	1,777,145
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	0
Financing Receivable, Originated, 2018	2,011
Financing Receivable, Originated, 2017	192
Financing Receivable, Originated, 2016	12
Financing Receivable, Originated, 2015 or Prior	437
Financing Receivable, Revolving	329
Financing Receivable, Revolving, Converted to Term Loan	0
Total	2,981
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	123
Financing Receivable, Originated, 2017	0
Financing Receivable, Originated, 2016	40
Financing Receivable, Originated, 2015 or Prior	4
Financing Receivable, Revolving	0
Financing Receivable, Revolving, Converted to Term Loan	51
Total	218
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	751
Financing Receivable, Originated, 2019	6,794
Financing Receivable, Originated, 2018	19,678
Financing Receivable, Originated, 2017	24,184
Financing Receivable, Originated, 2016	46,676
Financing Receivable, Originated, 2015 or Prior	218,076
Financing Receivable, Revolving	0
Financing Receivable, Revolving, Converted to Term Loan	0
Total	316,159
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	123,394
Financing Receivable, Originated, 2019	246,327
Financing Receivable, Originated, 2018	83,000
Financing Receivable, Originated, 2017	115,562
Financing Receivable, Originated, 2016	71,036
Financing Receivable, Originated, 2015 or Prior	99,322
Financing Receivable, Revolving	479,958
Financing Receivable, Revolving, Converted to Term Loan	1,738
Total	1,220,337
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	0
Financing Receivable, Originated, 2019	50
Financing Receivable, Originated, 2018	16
Financing Receivable, Originated, 2017	28
Financing Receivable, Originated, 2016	55
Financing Receivable, Originated, 2015 or Prior	5,087
Financing Receivable, Revolving	10
Financing Receivable, Revolving, Converted to Term Loan	0
Total	5,246
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	19
Financing Receivable, Originated, 2019	229
Financing Receivable, Originated, 2018	11
Financing Receivable, Originated, 2017	6
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	0
Financing Receivable, Revolving	16
Financing Receivable, Revolving, Converted to Term Loan	0
Total	281
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	0
Financing Receivable, Originated, 2019	6,586
Financing Receivable, Originated, 2018	15,496
Financing Receivable, Originated, 2017	0
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	38,325
Financing Receivable, Revolving	102,582
Financing Receivable, Revolving, Converted to Term Loan	0
Total	162,989
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	2,978
Financing Receivable, Originated, 2018	0
Financing Receivable, Originated, 2017	8,647
Financing Receivable, Originated, 2016	1,153
Financing Receivable, Originated, 2015 or Prior	7,529
Financing Receivable, Revolving	725
Financing Receivable, Revolving, Converted to Term Loan	0
Total	21,032
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	3,713
Financing Receivable, Originated, 2018	5,168
Financing Receivable, Originated, 2017	1,938
Financing Receivable, Originated, 2016	1,315
Financing Receivable, Originated, 2015 or Prior	140
Financing Receivable, Revolving	369
Financing Receivable, Revolving, Converted to Term Loan	15
Total	14,333
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	7,477
Financing Receivable, Originated, 2015 or Prior	803
Financing Receivable, Revolving	5,444
Financing Receivable, Revolving, Converted to Term Loan	0
Total	13,956
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	588
Financing Receivable, Originated, 2018	1,614
Financing Receivable, Originated, 2017	554
Financing Receivable, Originated, 2016	1,142
Financing Receivable, Originated, 2015 or Prior	26,339
Financing Receivable, Revolving	2,170
Financing Receivable, Revolving, Converted to Term Loan	691
Total	33,098
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	244
Financing Receivable, Originated, 2017	0
Financing Receivable, Originated, 2016	0
Financing Receivable, Originated, 2015 or Prior	5,866
Financing Receivable, Revolving	0
Financing Receivable, Revolving, Converted to Term Loan	0
Total	6,110
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	22
Financing Receivable, Originated, 2018	60
Financing Receivable, Originated, 2017	29
Financing Receivable, Originated, 2016	47
Financing Receivable, Originated, 2015 or Prior	44
Financing Receivable, Revolving	31
Financing Receivable, Revolving, Converted to Term Loan	0
Total	$ 233

Loans and Allowances for Cred_5

Loans and Allowances for Credit Losses Loans and Allowances for Credit Losses, Nonaccrual (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	$ 255,396	$ 180,951
Financing Receivable, Nonaccrual, No Allowance	165,285
Financing Receivable, Nonaccrual, With Allowance	90,111
Financing Receivable, Nonaccrual, Related Allowance	24,323
Commercial [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	201,999	115,416
Financing Receivable, Nonaccrual, No Allowance	117,333
Financing Receivable, Nonaccrual, With Allowance	84,666
Financing Receivable, Nonaccrual, Related Allowance	23,783
Commercial [Member] | Energy [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	162,989	91,722
Financing Receivable, Nonaccrual, No Allowance	85,171
Financing Receivable, Nonaccrual, With Allowance	77,818
Financing Receivable, Nonaccrual, Related Allowance	20,863
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	21,032	7,483
Financing Receivable, Nonaccrual, No Allowance	15,503
Financing Receivable, Nonaccrual, With Allowance	5,529
Financing Receivable, Nonaccrual, Related Allowance	2,574
Commercial [Member] | General business [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	14,333
Financing Receivable, Nonaccrual, No Allowance	13,014
Financing Receivable, Nonaccrual, With Allowance	1,319
Financing Receivable, Nonaccrual, Related Allowance	346
Commercial real estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	13,956	27,626
Financing Receivable, Nonaccrual, No Allowance	8,511
Financing Receivable, Nonaccrual, With Allowance	5,445
Financing Receivable, Nonaccrual, Related Allowance	540
Loans to individuals [Member]
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	39,441	37,622
Financing Receivable, Nonaccrual, No Allowance	39,441
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	33,098
Financing Receivable, Nonaccrual, No Allowance	33,098
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	233	$ 287
Financing Receivable, Nonaccrual, No Allowance	233
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	6,110
Financing Receivable, Nonaccrual, No Allowance	6,110
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		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Recorded Investment	$ 166,000,000		$ 166,000,000		$ 132,000,000
Financing Receivable, Troubled Debt Restructuring, Performing in Accordance With Modified Terms	55,000,000		55,000,000		57,000,000
Financing Receivable, Troubled Debt Restructuring, Postmodification	35,000,000	$ 21,000,000	59,000,000	$ 38,000,000
Financing Receivable, Impaired, Troubled Debt Restructuring, Write-down	7,700,000	$ 10,000	9,700,000	$ 12,600,000
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	20,000,000		20,000,000
Energy [Member] | Commercial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Specific Allowance	3,700,000		3,700,000
Energy [Member] | Nonperforming Financial Instruments [Member] | Commercial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Recorded Investment	21,000,000		21,000,000
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	$ 118,000,000		$ 118,000,000		$ 92,000,000

Loans and Allowances for Cred_7

Loans and Allowances for Credit Losses, By Aging Category (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing receivable, recorded investment, aging [Abstract]
Current	$ 23,721,124	$ 21,392,306
Nonaccrual	255,396	180,951
Total	24,155,890	21,750,987
Past Due 90 Days or More and Accruing	232,193	7,680
30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	81,221	47,084
60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	32,875	20,560
90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	320,670	110,086
Commercial [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	14,020,368	13,899,429
Nonaccrual	201,999	115,416
Total	14,158,510	14,031,650
Past Due 90 Days or More and Accruing	10,465
Commercial [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	50,247	7,943
Commercial [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	9,675	1,608
Commercial [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	78,220	7,254
Commercial [Member] | Energy [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	3,893,481	3,881,244
Nonaccrual	162,989	91,722
Total	3,974,174	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	32,439	401
Commercial [Member] | Energy [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	3,889	10
Commercial [Member] | Energy [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	44,365	0
Commercial [Member] | Healthcare [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	3,284,305	3,027,329
Nonaccrual	3,645	4,480
Total	3,289,343	3,033,916
Past Due 90 Days or More and Accruing	0
Commercial [Member] | Healthcare [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	1,216	2,039
Commercial [Member] | Healthcare [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	177	0
Commercial [Member] | Healthcare [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	3,645	68
Commercial [Member] | Services [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	3,754,841	3,105,621
Nonaccrual	21,032	7,483
Total	3,779,881	3,122,163
Past Due 90 Days or More and Accruing	632
Commercial [Member] | Services [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	7,357	1,737
Commercial [Member] | Services [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	4,440	523
Commercial [Member] | Services [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	13,243	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	3,087,741
Nonaccrual	14,333
Total	3,115,112
Past Due 90 Days or More and Accruing	9,833
Commercial [Member] | General business [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	9,235
Commercial [Member] | General business [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	1,169
Commercial [Member] | General business [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	16,967
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	4,536,541	4,400,576
Nonaccrual	13,956	27,626
Total	4,554,144	4,433,783
Past Due 90 Days or More and Accruing	469
Commercial real estate [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	2,749	4,920
Commercial real estate [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	5,874	250
Commercial real estate [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	8,980	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	2,081,428
Total	2,081,428
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	3,082,787	1,895,939
Nonaccrual	39,441	37,622
Total	3,361,808	2,084,172
Past Due 90 Days or More and Accruing	221,259
Loans to individuals [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	28,225	29,557
Loans to individuals [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	17,326	18,648
Loans to individuals [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	233,470	102,406
Loans to individuals [Member] | Residential mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	1,797,197
Nonaccrual	33,098
Total	1,813,442	2,084,172
Past Due 90 Days or More and Accruing	42
Loans to individuals [Member] | Residential mortgage [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	7,254
Loans to individuals [Member] | Residential mortgage [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	1,360
Loans to individuals [Member] | Residential mortgage [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	7,631
Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	60,121
Nonaccrual	6,110
Total	322,269
Past Due 90 Days or More and Accruing	221,201
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	20,494
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	15,908
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	225,746
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	1,225,469	1,196,362
Nonaccrual	233	287
Total	1,226,097	1,201,382
Past Due 90 Days or More and Accruing	16
Loans to individuals [Member] | Personal [Member] | 30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	477	4,664
Loans to individuals [Member] | Personal [Member] | 60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	58	54
Loans to individuals [Member] | Personal [Member] | 90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	$ 93	$ 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
Impaired loans, recorded investment, total	197,794
Impaired loans, recorded investment with no related allowance	197,794
Impaired loans, recorded investment with related allowance	0
Impaired loans, related allowance	0
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

Mortgage Banking Activities, Co

Mortgage Banking Activities, Components of Loans Held For Sale (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 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 days		90 days
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	285,274		175,117
Residential mortgage loans held for sale, Fair value	296,445		177,703
Residential mortgage loans held for sale	$ 319,357		$ 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 days		60 days
General number of days outstanding for residential mortgage commitments, maximum (in days)	90 days		90 days
Components of Residential Mortgage Loans Held for Sale [Abstract]
Derivative, Notional Amount	$ 546,304		$ 158,460
Derivative, Net fair value	$ 27,631		$ 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 days		60 days
General number of days for delivery for loans, for which the price is set by forward sales contracts, maximum (in days)	90 days		90 days
Components of Residential Mortgage Loans Held for Sale [Abstract]
Derivative, Notional Amount	$ 825,775		$ 315,203
Derivative, Net fair value	$ (4,719)		$ (665)

Mortgage Banking Activities Mor

Mortgage Banking Activities Mortgage Banking Activities, Mortgage Banking Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Mortgage Banking Revenue [Abstract]
Net realized gains on sale of mortgage loans	$ 24,109	$ 10,174	$ 33,826	$ 15,867
Net change in unrealized gain on mortgage loans held for sale	5,024	921	8,585	868
Net change in the fair value of mortgage loan commitments	3,381	1,506	22,398	4,219
Net change in the fair value of forward sales contracts	6,671	(732)	(4,054)	(1,217)
Total production revenue	39,185	11,869	60,755	19,737
Servicing revenue	14,751	16,262	30,348	32,228
Total mortgage banking revenue	$ 53,936	$ 28,131	$ 91,103	$ 51,965

Mortgage Banking Activities, Mo

Mortgage Banking Activities, Mortgage Servicing Rights (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Summary of Mortgage Servicing Rights [Abstract]
Number of residential mortgage loans serviced for others	116,232		116,232		126,828
Outstanding principal balance of residential mortgage loans serviced for others	$ 18,038,428,000		$ 18,038,428,000		$ 20,727,106,000
Weighted average interest rate	3.96%		3.96%		3.98%
Remaining term (in months)			283		289
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 110,828,000	$ 238,193,000	$ 201,886,000	$ 259,254,000	$ 259,254,000
Additions	8,465,000	8,751,000	13,906,000	14,939,000
Disposals	(10,801,000)	0	(10,801,000)	0
Change in fair value due to principal payments	(9,760,000)	(9,081,000)	(17,779,000)	(15,664,000)
Change in fair value due to market assumption changes	(761,000)	(29,555,000)	(89,241,000)	(50,221,000)
Ending balance	$ 97,971,000	$ 208,308,000	$ 97,971,000	$ 208,308,000	$ 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)			9.67%		9.81%
Prepayment rate - based upon loan interest rate, original term and loan type, minimum			9.04%		8.28%
Prepayment rate - based upon loan interest rate, original term and loan type, maximum			30.87%		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)			0.33%		1.73%
Primary secondary mortgage rate spread	105		105		104
Delinquency rate			4.51%		2.73%

Commitments and Contingent Li_2

Commitments and Contingent Liabilities (Details)	6 Months Ended
	Jun. 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	Jun. 30, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Liabilities	$ 40,715,451	$ 37,308,102
Other Assets [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated Entities, Assets	260,000
Other Liabilities [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Liabilities	$ 78,000

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands		Aug. 04, 2020	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020		Jun. 30, 2019
Dividends declared (in dollars per share)			$ 0.51	$ 0.50	$ 1.02		$ 1
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period					$ 104,923		$ (72,585)
Net change in unrealized gain (loss)			$ 56,922	$ 135,417	354,765		228,156
Reclassification Adjustments Included in Earnings [Abstract]
Gain on available for sale securities, net			(5,577)	(1,029)	(5,580)		(1,105)
Other comprehensive income, before income taxes			51,345	134,388	349,185		227,051
Federal and state income taxes			12,321	32,288	83,792	[1]	55,897	[1]
Other comprehensive income, net of income taxes			39,024	102,100	265,393		171,154
Balance, End of Period			370,316	98,569	370,316		98,569
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)					354,765		228,156
Reclassification Adjustments Included in Earnings [Abstract]
Gain on available for sale securities, net					(5,580)		(1,105)
Other comprehensive income, before income taxes					349,185		227,051
Federal and state income taxes	[1]				83,792		55,897
Other comprehensive income, net of income taxes					265,393		171,154
Balance, End of Period			370,389	100,155	370,389		100,155
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]
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		Aug. 4, 2020
Dividends declared (in dollars per share)		$ 0.51
Dividends Payable, Date to be Paid		Aug. 26, 2020
Dividends Payable, Date of Record		Aug. 17, 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		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator: [Abstract]
Net income attributable to BOK Financial Corp. shareholders	$ 64,693	$ 137,563	$ 126,772	$ 248,175
Less: Earnings allocated to participating securities	397	850	740	1,678
Numerator for basic earnings per share – income available to common shareholders	64,296	136,713	126,032	246,497
Effect of reallocating undistributed earnings of participating securities	0	0	0	0
Numerator for diluted earnings per share – income available to common shareholders	$ 64,296	$ 136,713	$ 126,032	$ 246,497
Denominator: [Abstract]
Weighted average shares outstanding (in shares)	70,307,606	71,327,928	70,410,707	71,625,332
Less: Participating securities included in weighted average shares (in shares)	431,563	440,865	410,842	489,918
Denominator for basic earnings per common share (in shares)	69,876,043	70,887,063	69,999,865	71,135,414
Dilutive effect of employee stock compensation plans (in shares)	1,424	14,970	3,952	16,144
Denominator for diluted earnings per common share (in shares)	69,877,467	70,902,033	70,003,817	71,151,558
Basic	$ 0.92	$ 1.93	$ 1.80	$ 3.47
Diluted	$ 0.92	$ 1.93	$ 1.80	$ 3.46
Excludes employee stock options with exercise prices greater than current market price.	22,238	0	0	0
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Diluted	$ 0.92	$ 1.93	$ 1.80	$ 3.46

Reportable Segments (Details)

Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Net interest revenue from external sources	$ 278,104	$ 285,432	$ 539,464	$ 563,534
Net interest revenue (expense) from internal sources	0	0	0	0
Net interest revenue	278,104	285,432	539,464	563,534
Provision for credit losses	135,321	5,000	229,092	13,000
Net interest revenue after provision for credit losses	142,783	280,432	310,372	550,534
Other operating revenue	232,693	172,065	413,012	329,335
Other operating expense	295,387	277,137	564,011	564,294
Net direct contribution	80,089	175,360	159,373	315,575
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	80,089	175,360	159,373	315,575
Federal and state income taxes	15,803	37,580	33,103	67,530
Net income	64,286	137,780	126,270	248,045
Net income (loss) attributable to non-controlling interests	(407)	217	(502)	(130)
Net income attributable to BOK Financial Corp. shareholders	64,693	137,563	126,772	248,175
Average assets	49,757,031	40,844,777	47,738,825	40,261,967
Operating Segments [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	174,314	251,084	376,216	455,293
Net interest revenue (expense) from internal sources	(29,205)	(66,613)	(79,700)	(120,251)
Net interest revenue	145,109	184,471	296,516	335,042
Provision for credit losses	13,762	6,823	30,642	18,069
Net interest revenue after provision for credit losses	131,347	177,648	265,874	316,973
Other operating revenue	47,898	41,611	86,118	79,223
Other operating expense	62,933	63,415	123,685	114,042
Net direct contribution	116,312	155,844	228,307	282,154
Gain (loss) on financial instruments, net	48	20	97	38
Change in fair value of mortgage servicing rights	0	0	0	0
Gain (loss) on repossessed assets, net	191	0	200	(346)
Corporate expense allocations	5,437	10,652	14,342	20,107
Net income before taxes	111,114	145,212	214,262	261,739
Federal and state income taxes	30,122	38,932	58,295	69,938
Net income	80,992	106,280	155,967	191,801
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	80,992	106,280	155,967	191,801
Average assets	27,575,652	22,910,724	26,131,814	21,432,513
Operating Segments [Member] | Consumer [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	18,795	25,300	44,671	47,775
Net interest revenue (expense) from internal sources	20,475	27,415	38,531	56,042
Net interest revenue	39,270	52,715	83,202	103,817
Provision for credit losses	535	1,728	1,791	2,813
Net interest revenue after provision for credit losses	38,735	50,987	81,411	101,004
Other operating revenue	67,192	48,811	122,254	91,559
Other operating expense	58,936	57,694	113,729	111,515
Net direct contribution	46,991	42,104	89,936	81,048
Gain (loss) on financial instruments, net	7,356	20,981	94,120	35,078
Change in fair value of mortgage servicing rights	(761)	(29,555)	(89,241)	(50,221)
Gain (loss) on repossessed assets, net	27	92	40	195
Corporate expense allocations	10,812	11,695	21,299	23,595
Net income before taxes	42,801	21,927	73,556	42,505
Federal and state income taxes	10,901	5,585	18,735	10,826
Net income	31,900	16,342	54,821	31,679
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	31,900	16,342	54,821	31,679
Average assets	9,920,005	9,212,667	9,885,429	8,794,498
Operating Segments [Member] | Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	34,359	17,222	48,725	38,708
Net interest revenue (expense) from internal sources	(7,479)	9,719	(2,941)	16,489
Net interest revenue	26,880	26,941	45,784	55,197
Provision for credit losses	(89)	(48)	(137)	(167)
Net interest revenue after provision for credit losses	26,969	26,989	45,921	55,364
Other operating revenue	106,674	86,017	204,555	159,431
Other operating expense	80,567	69,452	158,759	130,959
Net direct contribution	53,076	43,554	91,717	83,836
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	8,204	9,168	16,469	17,528
Net income before taxes	44,872	34,386	75,255	66,308
Federal and state income taxes	11,478	8,842	19,288	17,045
Net income	33,394	25,544	55,967	49,263
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	33,394	25,544	55,967	49,263
Average assets	15,721,452	9,849,396	14,222,432	9,590,629
Funds Management and Other [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	50,636	(8,174)	69,852	21,758	[1]
Net interest revenue (expense) from internal sources	16,209	29,479	44,110	47,720	[1]
Net interest revenue	66,845	21,305	113,962	69,478	[1]
Provision for credit losses	121,113	(3,503)	196,796	(7,715)	[1]
Net interest revenue after provision for credit losses	(54,268)	24,808	(82,834)	77,193	[1]
Other operating revenue	10,929	(4,374)	85	(878)	[1]
Other operating expense	92,951	86,576	167,838	207,778	[1]
Net direct contribution	(136,290)	(66,142)	(250,587)	(131,463)	[1]
Gain (loss) on financial instruments, net	(7,404)	(21,001)	(94,224)	(35,116)	[1]
Change in fair value of mortgage servicing rights	761	29,555	89,241	50,221	[1]
Gain (loss) on repossessed assets, net	(218)	(92)	(240)	151	[1]
Corporate expense allocations	(24,453)	(31,515)	(52,110)	(61,230)	[1]
Net income before taxes	(118,698)	(26,165)	(203,700)	(54,977)	[1]
Federal and state income taxes	(36,698)	(15,779)	(63,215)	(30,279)	[1]
Net income	(82,000)	(10,386)	(140,485)	(24,698)	[1]
Net income (loss) attributable to non-controlling interests	(407)	217	(502)	(130)	[1]
Net income attributable to BOK Financial Corp. shareholders	(81,593)	(10,603)	(139,983)	(24,568)	[1]
Average assets	$ (3,460,078)	$ (1,128,010)	$ (2,500,850)	$ 444,327	[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				6 Months Ended
	Jun. 30, 2020		Jun. 30, 2019		Jun. 30, 2020		Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Total fees and commissions	$ 213,680		$ 176,108		$ 406,404		$ 336,660
Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	213,680		176,108		406,404		336,660
Fees and commission revenue not from contracts with customers	113,914	[1]	65,676	[2]	198,924	[3]	119,056	[4]
Fees and commissions revenue from contracts with customers	99,766	[5]	110,432	[6]	207,480	[7]	217,604	[8]
Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	62,022		40,526		112,801		72,143
Fees and commission revenue not from contracts with customers	51,008	[1]	29,422	[2]	90,443	[3]	50,248	[4]
Fees and commissions revenue from contracts with customers	11,014	[5]	11,104	[6]	22,358	[7]	21,895	[8]
Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	43,915		21,879		78,299		34,799
Fees and commission revenue not from contracts with customers	43,915	[1]	21,879	[2]	78,299	[3]	34,799	[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	6,242		5,345		9,465		12,022
Fees and commission revenue not from contracts with customers	6,242	[1]	5,345	[2]	9,465	[3]	12,022	[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	3,394		3,901		7,737		7,923
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	3,394	[5]	3,901	[6]	7,737	[7]	7,923	[8]
Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3,153		3,822		6,942		7,930
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	3,153	[5]	3,822	[6]	6,942	[7]	7,930	[8]
Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	5,318		5,579		10,358		9,469
Fees and commission revenue not from contracts with customers	851	[1]	2,198	[2]	2,679	[3]	3,427	[4]
Fees and commissions revenue from contracts with customers	4,467	[5]	3,381	[6]	7,679	[7]	6,042	[8]
Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	22,940		21,915		44,821		42,653
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	22,940	[5]	21,915	[6]	44,821	[7]	42,653	[8]
TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	20,194		19,481		39,220		38,077
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	20,194	[5]	19,481	[6]	39,220	[7]	38,077	[8]
Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	2,243		2,237		4,562		4,299
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	2,243	[5]	2,237	[6]	4,562	[7]	4,299	[8]
Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	503		197		1,039		277
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	503	[5]	197	[6]	1,039	[7]	277	[8]
Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	41,257		45,025		85,715		88,383
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	41,257	[5]	45,025	[6]	85,715	[7]	88,383	[8]
Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	21,681		21,216		42,330		40,790
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	21,681	[5]	21,216	[6]	42,330	[7]	40,790	[8]
Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	4,604		6,330		10,966		12,531
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	4,604	[5]	6,330	[6]	10,966	[7]	12,531	[8]
Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	10,723		11,072		22,480		22,179
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	10,723	[5]	11,072	[6]	22,480	[7]	22,179	[8]
Investment management services and other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	4,249		6,407		9,939		12,883
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	4,249	[5]	6,407	[6]	9,939	[7]	12,883	[8]
Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	22,046		28,074		48,176		56,317
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	22,046	[5]	28,074	[6]	48,176	[7]	56,317	[8]
Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	12,056		11,592		24,049		24,375
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	12,056	[5]	11,592	[6]	24,049	[7]	24,375	[8]
Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3,643		9,104		10,921		17,364
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	3,643	[5]	9,104	[6]	10,921	[7]	17,364	[8]
Check card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	5,122		5,587		10,351		10,743
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	5,122	[5]	5,587	[6]	10,351	[7]	10,743	[8]
Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	1,225		1,791		2,855		3,835
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	1,225	[5]	1,791	[6]	2,855	[7]	3,835	[8]
Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	53,936		28,131		91,103		51,965
Fees and commission revenue not from contracts with customers	53,936	[1]	28,131	[2]	91,103	[3]	51,965	[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	39,186		11,869		60,755		19,737
Fees and commission revenue not from contracts with customers	39,186	[1]	11,869	[2]	60,755	[3]	19,737	[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	14,750		16,262		30,348		32,228
Fees and commission revenue not from contracts with customers	14,750	[1]	16,262	[2]	30,348	[3]	32,228	[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	11,479		12,437		23,788		25,199
Fees and commission revenue not from contracts with customers	8,970	[1]	8,123	[2]	17,378	[3]	16,843	[4]
Fees and commissions revenue from contracts with customers	2,509	[5]	4,314	[6]	6,410	[7]	8,356	[8]
Operating Segments [Member] | Commercial [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	46,515		41,105		87,974		79,151
Operating Segments [Member] | Commercial [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	8,024		4,933		12,429		7,897
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	6,893		2,385		9,418		3,960
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	1,131		2,548		3,011		3,937
Operating Segments [Member] | Commercial [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	22,362		20,917		43,399		40,576
Operating Segments [Member] | Commercial [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	19,647		18,504		37,859		36,158
Operating Segments [Member] | Commercial [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	2,230		2,223		4,535		4,148
Operating Segments [Member] | Commercial [Member] | Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	485		190		1,005		270
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	11,118		10,932		22,435		21,226
Operating Segments [Member] | Commercial [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	11,069		10,625		22,108		20,687
Operating Segments [Member] | Commercial [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	20		93		69		167
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	29		214		258		372
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	5,011		4,323		9,711		9,452
Operating Segments [Member] | Consumer [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	67,192		48,830		122,254		91,651
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	569		1,012		1,414		1,984
Operating Segments [Member] | Consumer [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	556		997		1,387		1,955
Operating Segments [Member] | Consumer [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	13		15		27		29
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	10,297		16,566		24,527		32,005
Operating Segments [Member] | Consumer [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	389		429		799		816
Operating Segments [Member] | Consumer [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3,607		8,973		10,812		17,368
Operating Segments [Member] | Consumer [Member] | Check card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	5,122		5,586		10,351		10,578
Operating Segments [Member] | Consumer [Member] | Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	1,179		1,578		2,565		3,243
Operating Segments [Member] | Consumer [Member] | Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	54,350		28,612		91,961		52,925
Operating Segments [Member] | Consumer [Member] | Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	39,186		11,871		60,755		19,739
Operating Segments [Member] | Consumer [Member] | Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	15,164		16,741		31,206		33,186
Operating Segments [Member] | Consumer [Member] | Other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	1,976		2,640		4,352		4,737
Operating Segments [Member] | Wealth Management [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	106,757		85,925		204,638		159,181
Operating Segments [Member] | Wealth Management [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	54,712		34,040		100,523		59,642
Operating Segments [Member] | Wealth Management [Member] | Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	43,915		21,879		78,299		34,799
Operating Segments [Member] | Wealth Management [Member] | Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	63		1,906		198		7,634
Operating Segments [Member] | Wealth Management [Member] | Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3,394		3,914		7,737		7,988
Operating Segments [Member] | Wealth Management [Member] | Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3,153		3,309		6,942		3,688
Operating Segments [Member] | Wealth Management [Member] | Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	4,187		3,032		7,347		5,533
Operating Segments [Member] | Wealth Management [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	9		(15)		6		(32)
Operating Segments [Member] | Wealth Management [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(9)		(20)		(28)		(37)
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	18		5		34		5
Operating Segments [Member] | Wealth Management [Member] | Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	41,299		45,067		85,798		86,750
Operating Segments [Member] | Wealth Management [Member] | Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	21,681		21,215		42,330		40,789
Operating Segments [Member] | Wealth Management [Member] | Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	4,604		6,331		10,966		12,532
Operating Segments [Member] | Wealth Management [Member] | Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	10,723		11,072		22,480		22,179
Operating Segments [Member] | Wealth Management [Member] | Investment management services and other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	4,291		6,449		10,022		11,250
Operating Segments [Member] | Wealth Management [Member] | Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	631		572		1,211		1,303
Operating Segments [Member] | Wealth Management [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	598		538		1,143		1,065
Operating Segments [Member] | Wealth Management [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	16		36		38		63
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	17		(2)		30		175
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	10,106		6,261		17,100		11,518
Funds Management and Other [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(6,784)		248	[9]	(8,462)		6,677	[10]
Funds Management and Other [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(714)		1,553	[9]	(151)		4,604	[10]
Funds Management and Other [Member] | Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0	[9]	0		0	[10]
Funds Management and Other [Member] | Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(714)		1,054	[9]	(151)		428	[10]
Funds Management and Other [Member] | Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		(13)	[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		4,242	[10]
Funds Management and Other [Member] | Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		(1)	[9]	0		(1)	[10]
Funds Management and Other [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		1	[9]	2		125	[10]
Funds Management and Other [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0	[9]	2		1	[10]
Funds Management and Other [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		(1)	[9]	0		122	[10]
Funds Management and Other [Member] | Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		2	[9]	0		2	[10]
Funds Management and Other [Member] | Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(42)		(42)	[9]	(83)		1,633	[10]
Funds Management and Other [Member] | Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		1	[9]	0		1	[10]
Funds Management and Other [Member] | Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		(1)	[9]	0		(1)	[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	(42)		(42)	[9]	(83)		1,633	[10]
Funds Management and Other [Member] | Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		4	[9]	3		1,783	[10]
Funds Management and Other [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		0	[9]	(1)		1,807	[10]
Funds Management and Other [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		2	[9]	2		(234)	[10]
Funds Management and Other [Member] | Check card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		1	[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		1	[9]	2		45	[10]
Funds Management and Other [Member] | Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(414)		(481)	[9]	(858)		(960)	[10]
Funds Management and Other [Member] | Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0		(2)	[9]	0		(2)	[10]
Funds Management and Other [Member] | Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(414)		(479)	[9]	(858)		(958)	[10]
Funds Management and Other [Member] | Other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	$ (5,614)		$ (787)	[9]	$ (7,375)		$ (508)	[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	Jun. 30, 2020		Mar. 31, 2020	Dec. 31, 2019		Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Assets: [Abstract]
Trading securities	$ 1,196,105			$ 1,623,921
Available for sale securities	12,475,919			11,269,643
Fair value option securities	722,657			1,098,577
Mortgage servicing rights	97,971		$ 110,828	201,886		$ 208,308	$ 238,193	$ 259,254
Derviative contracts, net of cash collateral, Assets, Fair value	651,553			323,375
Liabilities: [Abstract]
Derivative contracts, net of cash collateral, Liabilities, Fair Value	610,020			251,128
U.S. government agency debentures [Member]
Assets: [Abstract]
Trading securities	4,237			44,264
Residential agency mortgage-backed securities [Member]
Assets: [Abstract]
Trading securities	1,146,454			1,504,651
Available for sale securities	9,147,238			8,046,096
Fair value option securities	629,915			1,088,660
Municipal and other tax-exempt securities [Member]
Assets: [Abstract]
Trading securities	22,710			26,196
Available for sale securities	31,240			1,861
Asset-backed securities [Member]
Assets: [Abstract]
Trading securities	5			14,084
U.S. Treasury [Member]
Assets: [Abstract]
Available for sale securities	912			1,600
Fair value option securities	92,742			9,917
Residential non-agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	35,250			41,609
Commercial agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	3,260,807			3,178,005
Other debt securities [Member]
Assets: [Abstract]
Trading securities	22,699			34,726
Available for sale securities	472			472
Fair Value, Recurring [Member]
Assets: [Abstract]
Trading securities	1,196,105			1,623,921
Available for sale securities	12,475,919			11,269,643
Fair value option securities	722,657			1,098,577
Residential mortgage loans held for sale	319,357			182,271
Mortgage servicing rights	97,971	[1]		201,886	[2]
Derviative contracts, net of cash collateral, Assets, Fair value	651,553	[3]		323,375	[4]
Liabilities: [Abstract]
Derivative contracts, net of cash collateral, Liabilities, Fair Value	610,020	[3]		251,128	[4]
Fair Value, Recurring [Member] | U.S. government agency debentures [Member]
Assets: [Abstract]
Trading securities	4,237			44,264
Fair Value, Recurring [Member] | Residential agency mortgage-backed securities [Member]
Assets: [Abstract]
Trading securities	1,146,454			1,504,651
Available for sale securities	9,147,238			8,046,096
Fair value option securities	629,915			1,088,660
Fair Value, Recurring [Member] | Municipal and other tax-exempt securities [Member]
Assets: [Abstract]
Trading securities	22,710			26,196
Available for sale securities	31,240			1,861
Fair Value, Recurring [Member] | Asset-backed securities [Member]
Assets: [Abstract]
Trading securities	5			14,084
Fair Value, Recurring [Member] | U.S. Treasury [Member]
Assets: [Abstract]
Available for sale securities	912			1,600
Fair value option securities	92,742			9,917
Fair Value, Recurring [Member] | Residential non-agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	35,250			41,609
Fair Value, Recurring [Member] | Commercial agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	3,260,807			3,178,005
Fair Value, Recurring [Member] | Other debt securities [Member]
Assets: [Abstract]
Trading securities	22,699			34,726
Available for sale securities	472			472
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets: [Abstract]
Trading securities	0			0
Available for sale securities	912			1,600
Fair value option securities	92,742			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	66,207	[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			0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Treasury [Member]
Assets: [Abstract]
Available for sale securities	912			1,600
Fair value option securities	92,742			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	1,196,105			1,623,921
Available for sale securities	12,474,535			11,267,571
Fair value option securities	629,915			1,088,660
Residential mortgage loans held for sale	309,672			173,958
Mortgage servicing rights	0	[1]		0	[2]
Derviative contracts, net of cash collateral, Assets, Fair value	585,346	[3]		314,431	[4]
Liabilities: [Abstract]
Derivative contracts, net of cash collateral, Liabilities, Fair Value	610,020	[3]		251,128	[4]
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. government agency debentures [Member]
Assets: [Abstract]
Trading securities	4,237			44,264
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential agency mortgage-backed securities [Member]
Assets: [Abstract]
Trading securities	1,146,454			1,504,651
Available for sale securities	9,147,238			8,046,096
Fair value option securities	629,915			1,088,660
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal and other tax-exempt securities [Member]
Assets: [Abstract]
Trading securities	22,710			26,196
Available for sale securities	31,240			1,861
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed securities [Member]
Assets: [Abstract]
Trading securities	5			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			0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential non-agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	35,250			41,609
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	3,260,807			3,178,005
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other debt securities [Member]
Assets: [Abstract]
Trading securities	22,699			34,726
Available for sale securities	0			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			0
Residential mortgage loans held for sale	9,685			8,313
Mortgage servicing rights	97,971	[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			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			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 energy and interest rate derivative contacts, net of cash margin. Derivative contacts in liability positions that were valued using quoted prices in active markets for identical instruments are exchange-traded interest rate 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 contacts, 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				6 Months Ended
	Jun. 30, 2020		Jun. 30, 2019		Jun. 30, 2020		Jun. 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	9,574		15,776		8,313		15,207
Transfer to Level 3 from Level 2	1,328	[1]	907	[2]	3,592	[3]	1,889	[4]
Purchases	0		0		0		0
Proceeds from sales	(648)		(998)		(1,588)		(1,379)
Redemptions and distributions	0		0		0		0
Other comprehensive income (loss)	0		0		0		0
Balance, end of period	9,685		16,073		9,685		16,073
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	$ (569)		$ 388		$ (632)		$ 356
[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	Jun. 30, 2020		Dec. 31, 2019
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	$ 12,475,919		$ 11,269,643
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 Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	12,475,919		11,269,643
Residential mortgage loans held for sale	319,357		182,271
Fair Value, Recurring [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]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	472		472
Residential mortgage loans held for sale	9,685		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	1.00%		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	$ 9,685		$ 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	5.23%	[1]	7.08%	[2]
Range of fair value as a percentage of par value	94.30%	[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	5.23%	[1]	7.08%	[2]
Range of fair value as a percentage of par value	94.30%	[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	5.23%	[1]	7.08%	[2]
Range of fair value as a percentage of par value	94.30%	[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 approximately 1 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		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 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	$ 13,871	$ 11,335	$ 29,659	$ 20,917
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	5	86	131	512
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	400	0	400	0
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	918	2,642	918	2,642
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	32,448	29,187	32,448	29,187
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	$ 400	$ 427	$ 400	$ 427

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	Jun. 30, 2020		Jun. 30, 2019
Nonaccruing Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 32,448		$ 29,187
Real estate and other repossessed assets [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	400		427
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	32,448		29,187
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	$ 400		$ 427
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]	12.00%	[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. Minimum	87.00%		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	83.00%	[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. Minimum	87.00%		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	35.00%	[1]	47.00%	[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. Minimum	87.00%		88.00%
[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	Jun. 30, 2020		Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	$ 1,196,105			$ 1,623,921
Investment Securities, Gross Amortized Cost	269,616			293,418
Investment securities, Allowance for Credit Loss	1,628	[1]		0
Investment securities, net of allowance	267,988			293,418
Available for sale securities	12,475,919			11,269,643
Fair value option securities	722,657			1,098,577
Residential mortgage loans held for sale	319,357			182,271
Loans	24,155,890			21,750,987
Allowance for loan losses	(435,597)			(210,759)	$ (202,534)	$ (205,340)	$ (207,457)
Loans, net of allowance	23,720,293			21,540,228
Mortgage servicing rights	97,971		$ 110,828	201,886	208,308	238,193	259,254
Derviative contracts, net of cash collateral, Assets, Fair value	651,553			323,375
Time deposits	2,352,760			2,217,849
Subordinated debentures	275,973			275,923
Derivative contracts, net of cash collateral, Liabilities, Fair Value	610,020			251,128
Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	14,158,510			14,031,650
Allowance for loan losses	(310,422)			(118,187)	(106,397)	(103,577)	(102,226)
Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,554,144			4,433,783
Allowance for loan losses	(68,756)			(51,805)	$ (54,188)	$ (58,134)	$ (60,026)
Loans to individuals [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	3,361,808			2,084,172
Allowance for loan losses	(56,419)
Paycheck Protection Program
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,081,428
Allowance for loan losses	0
U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	4,237			44,264
Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	1,146,454			1,504,651
Investment Securities, Gross Amortized Cost	9,812			10,676
Available for sale securities	9,147,238			8,046,096
Fair value option securities	629,915			1,088,660
Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	22,710			26,196
Investment Securities, Gross Amortized Cost	84,239			93,653
Available for sale securities	31,240			1,861
U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	912			1,600
Fair value option securities	92,742			9,917
Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	35,250			41,609
Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	3,260,807			3,178,005
Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	22,699			34,726
Investment Securities, Gross Amortized Cost	175,565			189,089
Available for sale securities	472			472
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	762,453			735,836
Interest-bearing cash and cash equivalents	485,319			522,985
Trading securities	1,196,105			1,623,921
Investment Securities, Gross Amortized Cost	269,616
Investment securities, Allowance for Credit Loss	(1,628)
Investment securities, net of allowance	267,988			293,418
Available for sale securities	12,475,919			11,269,643
Fair value option securities	722,657			1,098,577
Residential mortgage loans held for sale	319,357			182,271
Loans	24,155,890			21,750,987
Allowance for loan losses	(435,597)			(210,759)
Loans, net of allowance	23,720,293			21,540,228
Mortgage servicing rights	97,971			201,886
Derviative contracts, net of cash collateral, Assets, Fair value	651,553			323,375
Deposits with no stated maturity	31,539,554			25,403,319
Time deposits	2,352,760			2,217,849
Other borrowed funds	4,531,165			8,345,405
Subordinated debentures	275,973			275,923
Derivative contracts, net of cash collateral, Liabilities, Fair Value	610,020			251,128
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	14,158,510			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	4,554,144			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	3,361,808
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	2,081,428
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	4,237			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	1,146,454			1,504,651
Investment Securities, Gross Amortized Cost	9,812
Investment securities, net of allowance				10,676
Available for sale securities	9,147,238			8,046,096
Fair value option securities	629,915			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	22,710			26,196
Investment Securities, Gross Amortized Cost	84,239
Investment securities, net of allowance				93,653
Available for sale securities	31,240			1,861
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Asset-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	5			14,084
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	22,699			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	912			1,600
Fair value option securities	92,742			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	35,250			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	3,260,807			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	175,565
Investment securities, net of allowance				189,089
Available for sale securities	472			472
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	762,453			735,836
Interest-bearing cash and cash equivalents	485,319			522,985
Trading securities	1,196,105			1,623,921
Investment Securities, Gross Amortized Cost	299,126
Investment securities, Allowance for Credit Loss	0
Investment securities, net of allowance	299,126			314,402
Available for sale securities	12,475,919			11,269,643
Fair value option securities	722,657			1,098,577
Residential mortgage loans held for sale	319,357			182,271
Loans	24,052,102			21,689,329
Allowance for loan losses	0			0
Loans, net of allowance	24,052,102			21,689,329
Mortgage servicing rights	97,971			201,886
Derviative contracts, net of cash collateral, Assets, Fair value	651,553			323,375
Deposits with no stated maturity	31,539,554			25,403,319
Time deposits	2,367,446			2,212,467
Other borrowed funds	4,527,814			8,315,860
Subordinated debentures	273,293			284,627
Derivative contracts, net of cash collateral, Liabilities, Fair Value	610,020			251,128
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	14,038,257			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	4,558,274			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	3,393,293
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	2,062,278
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	4,237			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	1,146,454			1,504,651
Investment Securities, Gross Amortized Cost	10,734
Investment securities, net of allowance				11,164
Available for sale securities	9,147,238			8,046,096
Fair value option securities	629,915			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	22,710			26,196
Investment Securities, Gross Amortized Cost	88,623
Investment securities, net of allowance				96,897
Available for sale securities	31,240			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	5			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	22,699			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	912			1,600
Fair value option securities	92,742			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	35,250			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	3,260,807			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	199,769
Investment securities, net of allowance				206,341
Available for sale securities	472			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	762,453			735,836
Interest-bearing cash and cash equivalents	485,319			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	912			1,600
Fair value option securities	92,742			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	66,207			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			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	912			1,600
Fair value option securities	92,742			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	1,196,105			1,623,921
Investment Securities, Gross Amortized Cost	107,405
Investment securities, Allowance for Credit Loss	0
Investment securities, net of allowance	107,405			116,267
Available for sale securities	12,474,535			11,267,571
Fair value option securities	629,915			1,088,660
Residential mortgage loans held for sale	309,672			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	585,346			314,431
Deposits with no stated maturity	0			0
Time deposits	0			0
Other borrowed funds	0			0
Subordinated debentures	273,293			284,627
Derivative contracts, net of cash collateral, Liabilities, Fair Value	610,020			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	4,237			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	1,146,454			1,504,651
Investment Securities, Gross Amortized Cost	10,734
Investment securities, net of allowance				11,164
Available for sale securities	9,147,238			8,046,096
Fair value option securities	629,915			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	22,710			26,196
Investment Securities, Gross Amortized Cost	88,623
Investment securities, net of allowance				96,897
Available for sale securities	31,240			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	5			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	22,699			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			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	35,250			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	3,260,807			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	8,048
Investment securities, net of allowance				8,206
Available for sale securities	0			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	191,721
Investment securities, Allowance for Credit Loss	0
Investment securities, net of allowance	191,721			198,135
Available for sale securities	472			472
Fair value option securities	0			0
Residential mortgage loans held for sale	9,685			8,313
Loans	24,052,102			21,689,329
Allowance for loan losses	0			0
Loans, net of allowance	24,052,102			21,689,329
Mortgage servicing rights	97,971			201,886
Derviative contracts, net of cash collateral, Assets, Fair value	0			0
Deposits with no stated maturity	31,539,554			25,403,319
Time deposits	2,367,446			2,212,467
Other borrowed funds	4,527,814			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	14,038,257			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	4,558,274			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	3,393,293
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	2,062,278
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			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			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	191,721
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.