BOK Financial (BOKF) 10-Q 30 Oct 19 2019 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information	9 Months Ended
	Sep. 30, 2019shares
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	70,858,010
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Document Type	10-Q
Entity File Number	0-19341
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
City Area Code	918
Local Phone Number	588-6000
Entity Address, Postal Zip Code	74192

Consolidated Statements of Earn

Consolidated Statements of Earnings (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest revenue [Abstract]
Loans	$ 286,694	$ 218,732	$ 859,898	$ 617,517
Residential mortgage loans held for sale	1,891	2,151	5,308	6,328
Trading securities	14,452	17,295	48,645	38,021
Investment securities	3,221	3,598	10,160	11,118
Available for sale securities	67,633	48,917	184,344	142,303
Fair value option securities	10,708	3,881	23,448	12,627
Restricted equity securities	7,558	5,232	20,419	15,757
Interest-bearing cash and cash equivalents	3,050	3,441	9,879	19,163
Total interest revenue	395,207	303,247	1,162,101	862,834
Interest expense [Abstract]
Deposits	46,917	24,535	127,517	63,717
Borrowed funds	65,381	35,804	180,595	93,860
Subordinated debentures	3,813	2,025	11,359	6,076
Total interest expense	116,111	62,364	319,471	163,653
Net interest revenue	279,096	240,883	842,630	699,181
Provision for credit losses	12,000	4,000	25,000	(1,000)
Net interest revenue after provision for credit losses	267,096	236,883	817,630	700,181
Total fees and commissions	186,119	166,197	522,779	483,069
Other gains, net	4,544	2,754	11,000	6,040
Gain (loss) on derivatives, net	3,778	(2,847)	19,595	(11,589)
Gain (loss) on fair value option securities, net	4,597	(4,385)	24,115	(25,290)
Change in fair value of mortgage servicing rights	(12,593)	5,972	(62,814)	28,901
Gain (loss) on available for sale securities, net	5	250	1,110	(802)
Total other operating revenue	186,450	167,941	515,785	480,329
Other operating expense [Abstract]
Personnel	162,573	143,531	492,143	422,425
Business promotion	8,859	7,620	26,875	21,316
Charitable contributions to BOKF Foundation	0	0	1,000	0
Professional fees and services	12,312	13,209	41,453	38,387
Net occupancy and equipment	27,558	23,394	83,959	70,201
Insurance	4,220	6,232	15,513	19,070
Data processing and communications	31,915	31,665	93,099	87,221
Printing, postage and supplies	3,825	3,837	12,817	11,937
Net losses and operating expenses of repossessed assets	1,728	4,044	4,304	14,471
Amortization of intangible assets	5,064	1,603	15,393	4,289
Mortgage banking costs	14,975	11,741	36,426	34,780
Other expense	6,263	5,741	20,604	19,426
Total other operating expense	279,292	252,617	843,586	743,523
Net income before taxes	174,254	152,207	489,829	436,987
Federal and state income taxes	32,396	34,662	99,926	98,940
Net income	141,858	117,545	389,903	338,047
Net income (loss) attributable to non-controlling interests	(373)	289	(503)	857
Net income attributable to BOK Financial Corporation shareholders	$ 142,231	$ 117,256	$ 390,406	$ 337,190
Earnings per share: [Abstract]
Basic	$ 2	$ 1.79	$ 5.47	$ 5.15
Diluted	$ 2	$ 1.79	$ 5.47	$ 5.15
Average shares used in computation: [Abstract]
Basic	70,596,307	64,901,095	70,953,544	64,883,319
Diluted	70,609,924	64,934,351	70,968,845	64,919,728
Dividends declared per share	$ 0.50	$ 0.50	$ 1.50	$ 1.40
Brokerage and trading revenue [Member]
Total fees and commissions	$ 43,840	$ 23,086	$ 115,983	$ 80,222
Transaction card revenue [Member]
Total fees and commissions	22,015	21,396	64,668	63,361
Fiduciary and asset management revenue [Member]
Total fees and commissions	43,621	57,514	132,004	141,038
Deposit service charges and fees [Member]
Total fees and commissions	28,837	27,765	85,154	82,760
Mortgage banking revenue [Member]
Total fees and commissions	30,180	23,536	82,145	75,907
Other revenue [Member]
Total fees and commissions	$ 17,626	$ 12,900	$ 42,825	$ 39,781

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019		Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 141,858	$ 117,545	$ 389,903		$ 338,047
Other comprehensive income (loss) before income taxes:
Net change in unrealized gain (loss)	46,285	(35,941)	274,441		(166,464)
Reclassification adjustments included in earnings:
Loss (gain) on available for sale securities, net	(5)	(250)	(1,110)		802
Other comprehensive income (loss) before income taxes	46,280	(36,191)	273,331		(165,662)
Federal and state income taxes	11,096	(9,134)	66,993	[1]	(42,183)	[1]
Other comprehensive income (loss), net of income taxes	35,184	(27,057)	206,338		(123,479)
Comprehensive income	177,042	90,488	596,241		214,568
Comprehensive income (loss) attributable to non-controlling interests	(373)	289	(503)		857
Comprehensive income attributable to BOK Financial Corp. shareholders	$ 177,415	$ 90,199	$ 596,744		$ 213,711
[1]	Calculated using a 25 percent blended federal and state statutory tax rate.

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Assets [Abstract]
Cash and due from banks	$ 761,130	$ 741,749
Interest-bearing cash and cash equivalents	465,458	401,675
Trading securities	1,675,212	1,956,923
Investment securities	304,224	355,187
Available for sale securities	11,024,551	8,857,120
Fair value option securities	1,816,398	283,235
Restricted equity securities	479,018	344,447
Residential mortgage loans held for sale	282,487	149,221
Loans	22,285,367	21,656,730
Allowance for loan losses	(204,432)	(207,457)
Loans, net of allowance	22,080,935	21,449,273
Premises and equipment, net	516,597	330,033
Receivables	219,420	204,960
Goodwill	1,048,091	1,049,263
Intangible assets, net	124,320	134,849
Mortgage servicing rights	193,661	259,254
Real estate and other repossessed assets, net of allowance	21,026	17,487
Derivative contracts, net	352,019	320,929
Cash surrender value of bank-owned life insurance	387,035	381,608
Receivable on unsettled securities sales	904,630	336,400
Other assets	470,993	446,891
Total assets	43,127,205	38,020,504
Deposits [Abstract]
Noninterest-bearing demand deposits	9,844,397	10,414,592
Interest-bearing deposits: [Abstract]
Transaction	13,521,545	12,206,576
Savings	557,593	529,215
Time	2,243,541	2,113,380
Total deposits	26,167,076	25,263,763
Funds purchased and repurchase agreements	3,413,051	1,018,411
Other borrowings	6,822,334	6,124,390
Subordinated debentures	275,909	275,913
Accrued interest, taxes and expense	218,775	192,826
Derivative contracts, net	336,791	362,306
Due on unsettled securities purchases	703,448	156,370
Other liabilities	352,156	183,480
Total liabilities	38,289,540	33,577,459
Shareholders' equity: [Abstract]
Common stock	5	5
Capital surplus	1,346,730	1,334,030
Retained earnings	3,655,590	3,369,654
Treasury stock	(307,062)	(198,995)
Accumulated other comprehensive gain (loss)	133,753	(72,585)
Total shareholders’ equity	4,829,016	4,432,109
Non-controlling interests	8,649	10,936
Total equity	4,837,665	4,443,045
Total liabilities and equity	$ 43,127,205	$ 38,020,504

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Investment securities [Abstract]
Investment Securities, fair value	$ 324,021	$ 367,298
Allowance for real estate and other repossessed assets	$ 11,278	$ 13,665
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)	75,757,009	75,711,492
Common stock, shares outstanding (in shares)	75,757,009	75,711,492
Treasury stock, shares at cost (in shares)	4,898,999	3,588,560

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total Shareholders' Equity [Member]	Non-Controlling Interests [Member]
Transition adjustment for new accounting principle in period of adoption	$ (2,709)			$ 2,709		$ (2,709)
Balance, beginning of period, adjusted	3,518,334	$ 4	$ 1,035,895	3,051,196	$ (552,845)	(38,883)	$ 3,495,367	$ 22,967
Balance, beginning of period (in shares) at Dec. 31, 2017		75,148			9,753
Balance, beginning of period at Dec. 31, 2017	3,518,334	$ 4	1,035,895	3,048,487	$ (552,845)	(36,174)	3,495,367	22,967
Net income	338,047			337,190			337,190	857
Other comprehensive income (loss)	(123,479)					(123,479)	(123,479)
Repurchase of common stock (in shares)					90
Repurchase of common stock	(8,408)				$ (8,408)		(8,408)
Stock options exercised (in shares)		49
Stock options exercised	2,560		2,560				2,560
Non-vested shares awarded, net (in shares)		112
Non-vested shares awarded, net			0
Vesting of non-vested shares (in shares)					31
Vesting of non-vested shares	(2,870)				$ (2,870)		(2,870)
Share-based compensation	5,975		5,975				5,975
Cash dividends on common stock	(91,303)			(91,303)			(91,303)
Capital calls and distributions, net	(13,096)							(13,096)
Balance, end of period (in shares) at Sep. 30, 2018		75,309			9,874
Balance, end of period at Sep. 30, 2018	3,625,760	$ 4	1,044,430	3,297,083	$ (564,123)	(162,362)	3,615,032	10,728
Balance, beginning of period (in shares) at Jun. 30, 2018		75,314			9,874
Balance, beginning of period at Jun. 30, 2018	3,576,045	$ 4	1,040,202	3,212,653	$ (564,123)	(135,305)	3,553,431	22,614
Net income	117,545			117,256			117,256	289
Other comprehensive income (loss)	(27,057)					(27,057)	(27,057)
Repurchase of common stock (in shares)					0
Repurchase of common stock	0				$ 0		0
Stock options exercised (in shares)		3
Stock options exercised	134		134				134
Non-vested shares awarded, net (in shares)		(8)
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	4,094		4,094				4,094
Cash dividends on common stock	(32,826)			(32,826)			(32,826)
Capital calls and distributions, net	(12,175)							(12,175)
Balance, end of period (in shares) at Sep. 30, 2018		75,309			9,874
Balance, end of period at Sep. 30, 2018	3,625,760	$ 4	1,044,430	3,297,083	$ (564,123)	(162,362)	3,615,032	10,728
Transition adjustment for new accounting principle in period of adoption	2,862			2,862			2,862
Balance, beginning of period, adjusted	4,445,907	$ 5	1,334,030	3,372,516	$ (198,995)	(72,585)	4,434,971	10,936
Balance, beginning of period (in shares) at Dec. 31, 2018		75,711			3,589
Balance, beginning of period at Dec. 31, 2018	4,443,045	$ 5	1,334,030	3,369,654	$ (198,995)	(72,585)	4,432,109	10,936
Net income	389,903			390,406			390,406	(503)
Other comprehensive income (loss)	206,338					206,338	206,338
Repurchase of common stock (in shares)					1,292
Repurchase of common stock	(106,639)				$ (106,639)		(106,639)
Stock options exercised (in shares)		21
Stock options exercised	1,080		1,080				1,080
Non-vested shares awarded, net (in shares)		25
Non-vested shares awarded, net			0
Vesting of non-vested shares (in shares)					18
Vesting of non-vested shares	(1,428)				$ (1,428)		(1,428)
Share-based compensation	11,620		11,620				11,620
Cash dividends on common stock	(107,332)			(107,332)			(107,332)
Capital calls and distributions, net	(1,784)							(1,784)
Balance, end of period (in shares) at Sep. 30, 2019		75,757			4,899
Balance, end of period at Sep. 30, 2019	4,837,665	$ 5	1,346,730	3,655,590	$ (307,062)	133,753	4,829,016	8,649
Balance, beginning of period (in shares) at Jun. 30, 2019		75,756			4,562
Balance, beginning of period at Jun. 30, 2019	4,718,475	$ 5	1,343,082	3,548,907	$ (281,125)	98,569	4,709,438	9,037
Net income	141,858			142,231			142,231	(373)
Other comprehensive income (loss)	35,184					35,184	35,184
Repurchase of common stock (in shares)					337
Repurchase of common stock	(25,937)				$ (25,937)		(25,937)
Stock options exercised (in shares)		3
Stock options exercised	177		177				177
Non-vested shares awarded, net (in shares)		(2)
Non-vested shares awarded, net			0
Vesting of non-vested shares (in shares)					0
Vesting of non-vested shares					$ 0		0
Share-based compensation	3,471		3,471				3,471
Cash dividends on common stock	(35,548)			(35,548)			(35,548)
Capital calls and distributions, net	(15)							(15)
Balance, end of period (in shares) at Sep. 30, 2019		75,757			4,899
Balance, end of period at Sep. 30, 2019	$ 4,837,665	$ 5	$ 1,346,730	$ 3,655,590	$ (307,062)	$ 133,753	$ 4,829,016	$ 8,649

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash Flows From Operating Activities: [Abstract]
Net income	$ 389,903	$ 338,047
Adjustments to reconcile net income to net cash used in operating activities:
Provision for credit losses	25,000	(1,000)
Change in fair value of mortgage servicing rights due to market changes	62,814	(28,901)
Change in the fair value of mortgage servicing rights due to principal payments	27,600	25,783
Net unrealized losses (gains) from derivative contracts	(25,306)	3,309
Share-based compensation	11,620	5,975
Depreciation and amortization	69,762	41,999
Net amortization of discounts and premiums	(16,648)	19,001
Net losses (gains) on financial instruments and other losses (gains), net	(2,656)	5,581
Net gain on mortgage loans held for sale	(25,803)	(26,242)
Mortgage loans originated for sale	(2,170,287)	(2,093,860)
Proceeds from sale of mortgage loans held for sale	2,070,572	2,165,989
Capitalized mortgage servicing rights	(24,821)	(28,688)
Change in trading and fair value option securities	(1,251,759)	(848,409)
Change in receivables	(613,872)	(249,347)
Change in other assets	12,981	(15,157)
Change in accrued interest, taxes and expense	(15,600)	66,697
Change in other liabilities	419,982	229,815
Net cash used in operating activities	(1,056,518)	(389,408)
Cash Flows From Investing Activities: [Abstract]
Proceeds from maturities or redemptions of investment securities	49,621	89,099
Proceeds from maturities or redemptions of available for sale securities	1,267,190	1,208,373
Purchases of investment securities	0	(4,218)
Purchases of available for sale securities	(3,802,635)	(1,404,291)
Proceeds from sales of available for sale securities	628,385	232,826
Change in amount receivable on unsettled available for sale securities transactions	29,010	67,775
Loans originated, net of principal collected	(590,196)	(1,187,762)
Net payments on derivative asset contracts	40,922	(39,485)
Acquisitions, net of cash acquired	0	(13,870)
Proceeds from disposition of assets	127,476	265,786
Purchases of assets	(308,630)	(250,447)
Net cash used in investing activities	(2,558,857)	(1,036,214)
Cash Flows From Financing Activities: [Abstract]
Net change in demand deposits, transaction deposits and savings accounts	773,152	(406,446)
Net change in time deposits	129,980	(22,570)
Net change in other borrowed funds	3,027,298	1,035,549
Net proceeds on derivative liability contracts	(43,932)	42,883
Net change in derivative margin accounts	(85,468)	(46,390)
Change in amount due on unsettled available for sale securities transactions	111,828	(148,190)
Issuance of common and treasury stock, net	(348)	(310)
Repurchase of common stock	(106,639)	(8,408)
Dividends paid	(107,332)	(91,303)
Net cash provided by financing activities	3,698,539	354,815
Net increase (decrease) in cash and cash equivalents	83,164	(1,070,807)
Cash and cash equivalents at beginning of period	1,143,424	2,317,054
Cash and cash equivalents at end of period	1,226,588	1,246,247
Supplemental Cash Flow Information: [Abstract]
Cash paid for interest	316,481	163,381
Cash paid for taxes	77,912	77,373
Net loans and bank premises transferred to repossessed real estate and other assets	8,489	9,513
Residential mortgage loans guaranteed by U.S. government agencies that became eligible for repurchase during the period	65,286	70,814
Conveyance of other real estate owned guaranteed by U.S. government agencies	22,449	32,206
Right-of-use assets obtained in exchange for operating lease liabilities	$ 58,766	$ 0

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
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 2018 Form 10-K filed with the Securities and Exchange Commission, which contains audited financial statements. Amounts presented as of December 31, 2018 have been derived from the audited financial statements included in BOK Financial’s 2018 Form 10-K but do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. Operating results for the nine -month period ended September 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019 . Newly Adopted and Pending Accounting Policies Financial Accounting Standards Board (“FASB”) FASB Accounting Standards Update No. 2016-02, Leases (Topic 842) ("ASU 2016-02") On February 25, 2016, the FASB issued ASU 2016-02 to increase transparency and comparability by recognizing lease assets and liabilities on the balance sheet and disclosing key information about leasing arrangements. Lessees are required to recognize an obligation for future lease payments measured on a discounted basis and a right-of-use asset. The Company adopted the new standard January 1, 2019 through a cumulative effect adjustment to retained earnings. Prior periods were not restated. BOKF elected to apply all practical expedients other than the lessee’s practical expedient to combine lease and non-lease components which would further gross up lease liability and the related right-of-use asset. The implementation of ASU 2016-02 increased the reported right-of-use asset and lease liability by $137 million . The effect on retained earnings was immaterial. 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, effective for the Company's annual reporting periods beginning after December 15, 2019, including interim periods within those fiscal years. The company has established a CECL implementation team to evaluate the impact to the Company’s financial statements. The CECL implementation team, overseen by the Chief Credit Officer, Chief Financial Officer and Chief Risk Officer, has developed a project plan that incorporates input from various departments within the bank including Credit, Financial Reporting, Risk and Information Technology among others. The Audit Committee and Credit Committee of the Board of Directors is periodically updated on project progress. In the second half of 2019, the implementation team is focused on design and operation of internal controls over the expected credit losses estimate and formalizing governance and approval processes. This includes finalizing model validation, refinement of model assumptions and qualitative framework, as well as drafting policies, reporting, and disclosures. These activities support our parallel runs and related results. The Company will adopt the standard on January 1, 2020 through a cumulative-effect adjustment to retained earnings. 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 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. Adoption of ASU 2019-01 is not expected to 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 2016-01include 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. ASU 2019-04 is effective for the Company for fiscal years beginning after December 15, 2019 and interim periods therein. Adoption of ASU 2019-04 is not expected to 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")

Securities

Securities	9 Months Ended
	Sep. 30, 2019
Marketable Securities [Abstract]
Securities [Text Block]	Securities Trading Securities The fair value and net unrealized gain (loss) included in trading securities are as follows (in thousands): September 30, 2019 December 31, 2018 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. government agency debentures $ 63,334 $ 23 $ 63,765 $ 254 Residential agency mortgage-backed securities 1,480,458 3,851 1,791,584 9,966 Municipal and other tax-exempt securities 44,105 (99 ) 34,507 (1 ) Asset-backed securities 36,928 50 42,656 685 Other debt securities 50,387 116 24,411 65 Total trading securities $ 1,675,212 $ 3,941 $ 1,956,923 $ 10,969 Investment Securities The amortized cost and fair values of investment securities are as follows (in thousands): September 30, 2019 Amortized Fair Gross Unrealized Cost Value Gain Loss Municipal and other tax-exempt $ 104,418 $ 107,647 $ 3,247 $ (18 ) Residential agency mortgage-backed securities 11,125 11,650 528 (3 ) Other debt securities 188,681 204,724 16,457 (414 ) Total investment securities $ 304,224 $ 324,021 $ 20,232 $ (435 ) December 31, 2018 Amortized Fair Gross Unrealized Cost Value Gain Loss Municipal and other tax-exempt $ 137,296 $ 138,562 $ 1,858 $ (592 ) Residential agency mortgage-backed securities 12,612 12,770 293 (135 ) Other debt securities 205,279 215,966 12,257 (1,570 ) Total investment securities $ 355,187 $ 367,298 $ 14,408 $ (2,297 ) The amortized cost and fair values of investment securities at September 30, 2019 , by contractual maturity, are as shown in the following table (dollars in thousands): Less than One Year One to Five Years Six to Ten Years Over Ten Years Total Weighted Average Maturity 1 Fixed maturity debt securities: Amortized cost $ 42,266 $ 93,139 $ 145,046 $ 12,648 $ 293,099 5.16 Fair value 42,426 96,704 160,698 12,543 312,371 Residential mortgage-backed securities: Amortized cost $ 11,125 2 Fair value 11,650 Total investment securities: Amortized cost $ 304,224 Fair value 324,021 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 4.5 years based upon current prepayment assumptions. Temporarily Impaired Investment Securities (in thousands): September 30, 2019 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Investment: Municipal and other tax-exempt 18 $ 10,302 $ 3 $ 2,213 $ 15 $ 12,515 $ 18 Residential agency mortgage-backed securities 1 2,318 3 — — 2,318 3 Other debt securities 18 275 1 10,897 413 11,172 414 Total investment securities 37 $ 12,895 $ 7 $ 13,110 $ 428 $ 26,005 $ 435 December 31, 2018 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Investment: Municipal and other tax-exempt 72 $ 18,255 $ 69 $ 66,141 $ 523 $ 84,396 $ 592 Residential agency mortgage-backed securities 2 — — 5,633 135 5,633 135 Other debt securities 72 13,372 64 23,028 1,506 36,400 1,570 Total investment securities 146 $ 31,627 $ 133 $ 94,802 $ 2,164 $ 126,429 $ 2,297 Available for Sale Securities The amortized cost and fair value of available for sale securities are as follows (in thousands): September 30, 2019 Amortized Fair Gross Unrealized Cost Value Gain Loss U.S. Treasury $ 2,294 $ 2,296 $ 2 $ — Municipal and other tax-exempt 1,772 1,848 76 — Mortgage-backed securities: Residential agency 7,636,923 7,740,461 114,646 (11,108 ) Residential non-agency 28,814 44,803 15,989 — Commercial agency 3,176,188 3,234,671 61,003 (2,520 ) Other debt securities 500 472 — (28 ) Total available for sale securities $ 10,846,491 $ 11,024,551 $ 191,716 $ (13,656 ) December 31, 2018 Amortized Fair Gross Unrealized Cost Value Gain Loss U.S. Treasury $ 496 $ 493 $ — $ (3 ) Municipal and other tax-exempt 2,782 2,864 82 — Mortgage-backed securities: Residential agency 5,886,323 5,804,708 16,149 (97,764 ) Residential non-agency 40,948 59,736 18,788 — Commercial agency 2,986,297 2,953,889 7,955 (40,363 ) Other debt securities 35,545 35,430 12 (127 ) Total available for sale securities $ 8,952,391 $ 8,857,120 $ 42,986 $ (138,257 ) The amortized cost and fair values of available for sale securities at September 30, 2019 , by contractual maturity, are as shown in the following table (dollars in thousands): Less than One Year One to Five Years Six to Ten Years Over Ten Years Total Weighted Average Maturity 1 Fixed maturity debt securities: Amortized cost $ 35,845 $ 1,069,415 $ 1,476,121 $ 599,373 $ 3,180,754 8.29 Fair value 35,806 1,081,571 1,512,308 609,602 3,239,287 Residential mortgage-backed securities: Amortized cost $ 7,665,737 2 Fair value 7,785,264 Total available-for-sale securities: Amortized cost $ 10,846,491 Fair value 11,024,551 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 4.0 years based upon current prepayment assumptions. Sales of available for sale securities resulted in gains and losses as follows (in thousands): Three Months Ended Nine Months Ended September 30, 2019 2018 2019 2018 Proceeds $ 261,028 $ 45,293 $ 628,385 $ 232,826 Gross realized gains 989 250 7,316 700 Gross realized losses (984 ) — (6,206 ) (1,502 ) Related federal and state income tax expense (benefit) 1 64 282 (204 ) 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 $10.8 billion at September 30, 2019 and $9.1 billion at December 31, 2018 . The secured parties do not have the right to sell or repledge these securities. Temporarily Impaired Available for Sale Securities (in thousands) September 30, 2019 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Available for sale: U.S. Treasury — $ — $ — $ — $ — $ — $ — Mortgage-backed securities: Residential agency 108 931,248 3,260 753,448 7,848 1,684,696 11,108 Commercial agency 57 449,798 1,612 224,409 908 674,207 2,520 Other debt securities 1 — — 472 28 472 28 Total available for sale securities 166 $ 1,381,046 $ 4,872 $ 978,329 $ 8,784 $ 2,359,375 $ 13,656 December 31, 2018 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Available for sale: U.S. Treasury 1 $ — $ — $ 493 $ 3 $ 493 $ 3 Mortgage-backed securities: Residential agency 289 510,824 1,158 3,641,370 96,606 4,152,194 97,764 Commercial agency 197 179,258 394 1,969,504 39,969 2,148,762 40,363 Other debt securities 3 9,982 63 20,436 64 30,418 127 Total available for sale securities 490 $ 700,064 $ 1,615 $ 5,631,803 $ 136,642 $ 6,331,867 $ 138,257 Based on evaluations of impaired securities as of September 30, 2019 , the Company does not intend to sell any impaired available for sale debt securities before fair value recovers to the current amortized cost and it is more-likely-than-not that the Company will not be required to sell impaired securities before fair value recovers, which may be maturity. Fair Value Option Securities Fair value option securities represent securities which the Company has elected to carry at fair value and are separately identified on the Consolidated Balance Sheets. Changes in the fair value are recognized in earnings as they occur. Certain securities are held as an economic hedge of the mortgage servicing rights. The fair value and net unrealized gain (loss) included in fair value option securities is as follows (in thousands): September 30, 2019 December 31, 2018 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. Treasury $ 552,536 $ 927 $ — $ — Residential agency mortgage-backed securities 1,263,862 18,588 283,235 2,766 Total $ 1,816,398 $ 19,515 $ 283,235 $ 2,766

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2019
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 hedge their loan production 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 and to mitigate the market risk of holding trading securities. 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 6 , 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 6 for additional discussion of notional, fair value and impact on earnings of these contracts. The following table summarizes the fair values of derivative contracts recorded as “derivative contracts” assets and liabilities in the balance sheet at September 30, 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 To-be-announced residential mortgage-backed securities $ — $ — $ — $ — $ — $ — Interest rate swaps 2,399,788 67,157 (240 ) 66,917 (277 ) 66,640 Energy contracts 1,980,406 183,204 (59,139 ) 124,065 (66,149 ) 57,916 Agricultural contracts 15,538 470 (302 ) 168 — 168 Foreign exchange contracts 209,515 206,914 — 206,914 — 206,914 Equity option contracts 82,860 3,114 — 3,114 (660 ) 2,454 Total customer risk management programs 4,688,107 460,859 (59,681 ) 401,178 (67,086 ) 334,092 Trading 73,658,685 205,188 (193,306 ) 11,882 — 11,882 Internal risk management programs 433,804 9,037 (2,992 ) 6,045 — 6,045 Total derivative contracts $ 78,780,596 $ 675,084 $ (255,979 ) $ 419,105 $ (67,086 ) $ 352,019 Liabilities Notional¹ 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 To-be-announced residential mortgage-backed securities $ — $ — $ — $ — $ — $ — Interest rate swaps 2,399,788 67,296 (240 ) 67,056 (61,563 ) 5,493 Energy contracts 1,936,369 175,613 (59,139 ) 116,474 (784 ) 115,690 Agricultural contracts 15,547 451 (302 ) 149 — 149 Foreign exchange contracts 200,347 197,807 — 197,807 (433 ) 197,374 Equity option contracts 82,860 3,114 — 3,114 — 3,114 Total customer risk management programs 4,634,911 444,281 (59,681 ) 384,600 (62,780 ) 321,820 Trading 75,247,769 207,542 (193,306 ) 14,236 — 14,236 Internal risk management programs 483,370 5,435 (2,992 ) 2,443 (1,708 ) 735 Total derivative contracts $ 80,366,050 $ 657,258 $ (255,979 ) $ 401,279 $ (64,488 ) $ 336,791 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, 2018 (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 To-be-announced residential mortgage-backed securities $ 10,671,151 $ 92,231 $ (26,787 ) $ 65,444 $ — $ 65,444 Interest rate swaps 1,924,131 36,112 (6,688 ) 29,424 (7,934 ) 21,490 Energy contracts 1,472,209 206,418 (60,983 ) 145,435 (106,752 ) 38,683 Agricultural contracts 21,210 842 (201 ) 641 — 641 Foreign exchange contracts 184,990 183,759 — 183,759 — 183,759 Equity option contracts 89,085 2,021 — 2,021 (648 ) 1,373 Total customer risk management programs 14,362,776 521,383 (94,659 ) 426,724 (115,334 ) 311,390 Trading 15,356,909 45,346 (39,521 ) 5,825 — 5,825 Internal risk management programs 553,079 5,064 (1,350 ) 3,714 — 3,714 Total derivative contracts $ 30,272,764 $ 571,793 $ (135,530 ) $ 436,263 $ (115,334 ) $ 320,929 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 To-be-announced residential mortgage-backed securities $ 10,558,151 $ 90,388 $ (26,787 ) $ 63,601 $ (63,596 ) $ 5 Interest rate swaps 1,924,131 36,288 (6,688 ) 29,600 (4,110 ) 25,490 Energy contracts 1,434,247 202,494 (60,983 ) 141,511 (1,490 ) 140,021 Agricultural contracts 21,214 812 (201 ) 611 — 611 Foreign exchange contracts 177,423 175,922 — 175,922 — 175,922 Equity option contracts 89,085 2,021 — 2,021 — 2,021 Total customer risk management programs 14,204,251 507,925 (94,659 ) 413,266 (69,196 ) 344,070 Trading 19,374,294 56,983 (39,521 ) 17,462 — 17,462 Internal risk management programs 260,348 9,439 (1,350 ) 8,089 (7,315 ) 774 Total derivative contracts $ 33,838,893 $ 574,347 $ (135,530 ) $ 438,817 $ (76,511 ) $ 362,306 1 Notional amounts for commodity contracts are converted into dollar-equivalent amounts based on dollar prices at the inception of the contract. The following summarizes the pre-tax net gains (losses) on derivative instruments and where they are recorded in the income statement (in thousands): Three Months Ended September 30, 2019 September 30, 2018 Brokerage and Trading Revenue Gain (Loss) on Derivatives, Net Brokerage and Trading Revenue Gain (Loss)on Derivatives, Net Customer risk management programs: Interest rate contracts To-be-announced residential mortgage-backed securities $ 1,667 $ — $ 7,272 $ — Interest rate swaps 1,252 — 618 — Energy contracts 1,611 — 541 — Agricultural contracts 16 — 6 — Foreign exchange contracts 138 — 78 — Equity option contracts — — — — Total customer risk management programs 4,684 — 8,515 — Trading 3,630 — 6,124 — Internal risk management programs — 3,778 — (2,847 ) Total derivative contracts $ 8,314 $ 3,778 $ 14,639 $ (2,847 ) Nine Months Ended September 30, 2019 September 30, 2018 Brokerage and Trading Revenue Gain (Loss) on Derivatives, Net Brokerage and Trading Revenue Gain (Loss) on Derivatives, Net Customer risk management programs: Interest rate contracts To-be-announced residential mortgage-backed securities $ 9,579 $ — $ 21,677 $ — Interest rate swaps 2,787 — 2,057 — Energy contracts 3,923 — 5,097 — Agricultural contracts 24 — 36 — Foreign exchange contracts 392 — 350 — Equity option contracts — — — — Total customer risk management programs 16,705 — 29,217 — Trading 4,365 — 3,260 — Internal risk management programs — 19,595 — (11,589 ) Total derivative contracts $ 21,070 $ 19,595 $ 32,477 $ (11,589 )

Loans and Allowances for Credit

Loans and Allowances for Credit Losses	9 Months Ended
	Sep. 30, 2019
Loans and Leases Receivable, Net Amount [Abstract]
Loans [Text Block]	Loans and Allowances for Credit Losses 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. 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. 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. 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 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. Guaranteed loans are considered impaired because we do not expect to receive all principal and interest based on the loan's contractual terms. The original principal guarantee remains; however, interest accrues at a curtailed rate as specified in the programs. The carrying value of these loans is reduced based on an estimate of the expected cash flows discounted at the original note rate plus a liquidity spread. Guaranteed loans may be modified in TDRs in accordance with U.S. government agency guidelines. Interest continues to accrue based on the modified rate. Guaranteed loans may either be resold into GNMA pools after a performance period specified by the programs or foreclosed and conveyed to the guarantors. Loans are disaggregated into portfolio segments and further disaggregated into classes. The portfolio segment is the level at which the Company develops and documents a systematic method for determining its allowance for credit losses. Classes are a further disaggregation of portfolio segments based on the risk characteristics of the loans and the Company’s method for monitoring and assessing credit risk. Portfolio segments of the loan portfolio are as follows (in thousands): September 30, 2019 December 31, 2018 Fixed Rate Variable Rate Non-accrual Total Fixed Rate Variable Rate Non-accrual Total Commercial $ 3,184,237 $ 11,128,682 $ 111,706 $ 14,424,625 $ 2,251,188 $ 11,285,049 $ 99,841 $ 13,636,078 Commercial real estate 1,070,050 3,532,822 23,185 4,626,057 1,477,274 3,265,918 21,621 4,764,813 Residential mortgage 1,690,286 389,713 37,304 2,117,303 1,830,224 358,254 41,555 2,230,033 Personal 191,827 925,284 271 1,117,382 190,687 834,889 230 1,025,806 Total $ 6,136,400 $ 15,976,501 $ 172,466 $ 22,285,367 $ 5,749,373 $ 15,744,110 $ 163,247 $ 21,656,730 Accruing loans past due (90 days) 1 $ 1,541 $ 1,338 1 Excludes residential mortgage loans guaranteed by agencies of the U.S. government Credit Commitments Commitments to extend credit are agreements to lend to a customer as long as there is no violation of conditions established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. At September 30, 2019 , outstanding commitments totaled $11 billion . Because some commitments are expected to expire before being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. BOK Financial uses the same credit policies in making commitments as it does loans. The amount of collateral obtained, if deemed necessary, is based upon management’s credit evaluation of the borrower. Standby letters of credit are conditional commitments issued to guarantee the performance of a customer to a third party. Because the credit risk involved in issuing standby letters of credit is essentially the same as that involved in extending loan commitments, BOK Financial uses the same credit policies in evaluating the creditworthiness of the customer. Additionally, BOK Financial uses the same evaluation process in obtaining collateral on standby letters of credit as it does for loan commitments. The term of these standby letters of credit is defined in each commitment and typically corresponds with the underlying loan commitment. At September 30, 2019 , outstanding standby letters of credit totaled $713 million . Allowances for Credit Losses BOK Financial maintains an allowance for loan losses and an accrual for off-balance sheet credit risk. 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. As discussed in greater detail in Note 6 , the Company also has separate accruals for off-balance sheet credit risk related to residential mortgage loans previously sold with full or partial recourse and for residential mortgage loans sold to government sponsored agencies under standard representations and warranties. The appropriateness of the allowance for loan losses and accrual for off-balance sheet credit losses (collectively "allowance for credit losses") is assessed by management based on an ongoing quarterly evaluation of the probable estimated losses inherent in the portfolio, including probable losses on both outstanding loans and unused commitments. The allowance for loan losses consists of specific allowances attributed to impaired loans that have not yet been charged down to amounts we expect to recover, general allowances for unimpaired loans based on estimated loss rates by loan class and nonspecific allowances based on general economic conditions, risk concentration and related factors. There have been no material changes in the approach or techniques utilized in developing the allowance for loan losses and the accrual for off-balance sheet credit losses for the three and nine months ended September 30, 2019 . Loans are considered to be impaired when it becomes probable that BOK Financial will be unable to collect all amounts due according to the contractual terms of the loan agreements. Internally risk graded loans are evaluated individually for impairment. Substantially all commercial and commercial real estate loans and certain residential mortgage and consumer loans are risk graded based on evaluation of the borrowers' ability to repay. Certain commercial loans and most residential mortgage and consumer loans are small balance, homogeneous pools of loans that are not risk graded. Non-risk graded loans are identified as impaired based on performance status. Generally, non-risk graded loans 90 days or more past due or modified in a TDR or in bankruptcy are considered to be impaired. Specific allowances for impaired loans are measured 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. Collateral value of real property is generally based on third party appraisals that conform to Uniform Standards of Professional Appraisal Practice, less estimated selling costs. Appraised values are on an "as-is" basis and are generally not adjusted by the Company. Updated appraisals are obtained at least annually or more frequently if market conditions indicate collateral values have declined. Collateral value of mineral rights is generally determined by our internal staff of engineers based on projected cash flows under current market conditions. Collateral values and available cash resources that support impaired loans are evaluated quarterly. Historical statistics may be used as a practical way to estimate impairment in limited situations, such as when a collateral dependent loan is identified as impaired at the end of a reporting period, until an updated appraisal of collateral value is received or a full assessment of future cash flows is completed. Estimates of future cash flows and collateral values require significant judgments and may be volatile. General allowances for unimpaired loans are based on estimated loss rates by loan class. The gross loss rate for each loan class is determined by the greater of the current gross loss rate based on the most recent twelve months or a long-term gross loss rate. Recoveries are not directly considered in the estimation of loss rates. Recoveries generally do not follow predictable patterns and are not received until well after the charge-off date as a result of protracted legal actions. For risk graded loans, gross loss rates are adjusted for changes in risk grading. For each loan class, the current weighted average risk grade is compared to the long-term average risk grade. This comparison determines whether credit risk in each loan class is increasing or decreasing. Loss rates are adjusted upward or downward in proportion to changes in average risk grading. General allowances for unimpaired loans also consider inherent risks identified for each loan class. Inherent risks consider loss rates that most appropriately represent the current credit cycle and other factors attributable to specific loan classes which have not yet been represented in the gross loss rates or risk grading. These factors include changes in commodity prices or engineering imprecision, which may affect the value of reserves that secure our energy loan portfolio, construction risk that may affect commercial real estate loans, changes in regulations and public policy that may disproportionately impact health care loans and changes in loan products. Nonspecific allowances are maintained for risks beyond factors specific to a particular loan or loan class. These factors include trends in the economy of our primary lending areas, concentrations in large balance loans and other relevant factors. An accrual for off-balance sheet credit losses is included in Other liabilities in the Consolidated Balance Sheets. The appropriateness of this accrual is determined in the same manner as the allowance for loan losses. 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 for the three months ended September 30, 2019 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 106,397 $ 54,188 $ 15,724 $ 9,388 $ 16,837 $ 202,534 Provision for loan losses 9,861 102 (253 ) 1,911 918 12,539 Loans charged off (9,875 ) — (56 ) (1,776 ) — (11,707 ) Recoveries 260 60 119 627 — 1,066 Ending balance $ 106,643 $ 54,350 $ 15,534 $ 10,150 $ 17,755 $ 204,432 Allowance for off-balance sheet credit losses: Beginning balance $ 1,742 $ 116 $ 44 $ 1 $ — $ 1,903 Provision for off-balance sheet credit losses (536 ) (3 ) — — — (539 ) Ending balance $ 1,206 $ 113 $ 44 $ 1 $ — $ 1,364 Total provision for credit losses $ 9,325 $ 99 $ (253 ) $ 1,911 $ 918 $ 12,000 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 for the nine months ended September 30, 2019 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 102,226 $ 60,026 $ 17,964 $ 9,473 $ 17,768 $ 207,457 Provision for loan losses 34,740 (10,075 ) (2,660 ) 3,434 (13 ) 25,426 Loans charged off (31,728 ) (118 ) (192 ) (4,671 ) — (36,709 ) Recoveries 1,405 4,517 422 1,914 — 8,258 Ending balance $ 106,643 $ 54,350 $ 15,534 $ 10,150 $ 17,755 $ 204,432 Allowance for off-balance sheet credit losses: Beginning balance $ 1,655 $ 52 $ 52 $ 31 $ — $ 1,790 Provision for off-balance sheet credit losses (449 ) 61 (8 ) (30 ) — (426 ) Ending balance $ 1,206 $ 113 $ 44 $ 1 $ — $ 1,364 Total provision for credit losses $ 34,291 $ (10,014 ) $ (2,668 ) $ 3,404 $ (13 ) $ 25,000 The 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 for the three months ended September 30, 2018 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 113,722 $ 58,758 $ 18,544 $ 8,646 $ 15,472 $ 215,142 Provision for loan losses (1,285 ) 1,391 1 883 3,418 4,408 Loans charged off (9,602 ) — (91 ) (1,380 ) — (11,073 ) Recoveries 1,263 40 229 560 — 2,092 Ending balance $ 104,098 $ 60,189 $ 18,683 $ 8,709 $ 18,890 $ 210,569 Allowance for off-balance sheet credit losses: Beginning balance 2,361 17 53 2 — $ 2,433 Provision for off-balance sheet credit losses (424 ) 19 (3 ) — — (408 ) Ending balance $ 1,937 $ 36 $ 50 $ 2 $ — $ 2,025 Total provision for credit losses $ (1,709 ) $ 1,410 $ (2 ) $ 883 $ 3,418 $ 4,000 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 for the nine months ended September 30, 2018 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 124,269 $ 56,621 $ 18,451 $ 9,124 $ 22,217 $ 230,682 Provision for loan losses 2,720 248 (418 ) 1,486 (3,327 ) 709 Loans charged off (24,940 ) — (326 ) (3,802 ) — (29,068 ) Recoveries 2,049 3,320 976 1,901 — 8,246 Ending balance $ 104,098 $ 60,189 $ 18,683 $ 8,709 $ 18,890 $ 210,569 Allowance for off-balance sheet credit losses: Beginning balance $ 3,644 $ 45 $ 43 $ 2 $ — $ 3,734 Provision for off-balance sheet credit losses (1,707 ) (9 ) 7 — — (1,709 ) Ending balance $ 1,937 $ 36 $ 50 $ 2 $ — $ 2,025 Total provision for credit losses $ 1,013 $ 239 $ (411 ) $ 1,486 $ (3,327 ) $ (1,000 ) The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at September 30, 2019 is as follows (in thousands): Collectively Measured for Impairment Individually Measured for Impairment Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 14,312,919 $ 99,110 $ 111,706 $ 7,533 $ 14,424,625 $ 106,643 Commercial real estate 4,602,872 54,350 23,185 — 4,626,057 54,350 Residential mortgage 2,079,999 15,534 37,304 — 2,117,303 15,534 Personal 1,117,111 10,150 271 — 1,117,382 10,150 Total 22,112,901 179,144 172,466 7,533 22,285,367 186,677 Nonspecific allowance — — — — — 17,755 Total $ 22,112,901 $ 179,144 $ 172,466 $ 7,533 $ 22,285,367 $ 204,432 The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at December 31, 2018 is as follows (in thousands): Collectively Measured for Impairment Individually Measured for Impairment Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 13,536,237 $ 93,494 $ 99,841 $ 8,732 $ 13,636,078 $ 102,226 Commercial real estate 4,743,192 60,026 21,621 — 4,764,813 60,026 Residential mortgage 2,188,478 17,964 41,555 — 2,230,033 17,964 Personal 1,025,576 9,473 230 — 1,025,806 9,473 Total 21,493,483 180,957 163,247 8,732 21,656,730 189,689 Nonspecific allowance — — — — — 17,768 Total $ 21,493,483 $ 180,957 $ 163,247 $ 8,732 $ 21,656,730 $ 207,457 Credit Quality Indicators The Company utilizes loan class and risk grading as primary credit quality indicators. Substantially all commercial and commercial real estate loans and certain residential mortgage and consumer loans are risk graded based on a quarterly evaluation of the borrowers’ ability to repay the loans. Certain commercial loans and most residential mortgage and consumer loans are small, homogeneous pools that are not risk graded. The allowance for loan losses and recorded investment of the related loans by portfolio segment for risk graded and non-risk graded loans at September 30, 2019 is as follows (in thousands): Internally Risk Graded Non-Graded Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 14,396,278 $ 105,714 $ 28,347 $ 929 $ 14,424,625 $ 106,643 Commercial real estate 4,626,057 54,350 — — 4,626,057 54,350 Residential mortgage 283,297 3,375 1,834,006 12,159 2,117,303 15,534 Personal 1,032,522 7,836 84,860 2,314 1,117,382 10,150 Total 20,338,154 171,275 1,947,213 15,402 22,285,367 186,677 Nonspecific allowance — — — — — 17,755 Total $ 20,338,154 $ 171,275 $ 1,947,213 $ 15,402 $ 22,285,367 $ 204,432 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, 2018 is as follows (in thousands): Internally Risk Graded Non-Graded Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 13,586,654 $ 101,303 $ 49,424 $ 923 $ 13,636,078 $ 102,226 Commercial real estate 4,764,813 60,026 — — 4,764,813 60,026 Residential mortgage 505,046 3,310 1,724,987 14,654 2,230,033 17,964 Personal 948,890 6,633 76,916 2,840 1,025,806 9,473 Total 19,805,403 171,272 1,851,327 18,417 21,656,730 189,689 Nonspecific allowance — — — — — 17,768 Total $ 19,805,403 $ 171,272 $ 1,851,327 $ 18,417 $ 21,656,730 $ 207,457 Loans are considered to be performing if they 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.” Performing loans also include 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 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. The risk grading process identified certain loans that have a well-defined weakness (e.g. 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 were not placed in nonaccruing status. Nonaccruing loans represent loans for which full collection of principal and interest is uncertain. This is substantially the same criteria used to determine whether a loan is impaired and includes certain loans considered “substandard” and all loans considered “doubtful” by regulatory guidelines. The following table summarizes the Company’s loan portfolio at September 30, 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 $ 3,927,285 $ 60,405 $ 37,685 $ 88,894 $ — $ — $ 4,114,269 Services 3,185,367 38,118 36,645 6,119 — — 3,266,249 Wholesale/retail 1,829,614 9,757 7,742 1,504 — — 1,848,617 Manufacturing 652,804 24,229 12,634 8,741 — — 698,408 Healthcare 2,984,306 25,205 17,479 5,978 — — 3,032,968 Public finance 744,840 — — — — — 744,840 Other commercial and industrial 671,819 2,053 16,632 423 28,300 47 719,274 Total commercial 13,996,035 159,767 128,817 111,659 28,300 47 14,424,625 Commercial real estate: Residential construction and land development 135,011 — — 350 — — 135,361 Retail 765,708 12,067 1,262 20,132 — — 799,169 Office 1,007,136 5,203 1,081 855 — — 1,014,275 Multifamily 1,316,856 1,196 6,501 286 — — 1,324,839 Industrial 872,627 — — 909 — — 873,536 Other commercial real estate 474,465 784 2,975 653 — — 478,877 Total commercial real estate 4,571,803 19,250 11,819 23,185 — — 4,626,057 Residential mortgage: Permanent mortgage 280,243 326 2,191 537 763,535 19,628 1,066,460 Permanent mortgages guaranteed by U.S. government agencies — — — — 185,432 6,332 191,764 Home equity — — — — 848,272 10,807 859,079 Total residential mortgage 280,243 326 2,191 537 1,797,239 36,767 2,117,303 Personal 1,032,381 46 33 63 84,651 208 1,117,382 Total $ 19,880,462 $ 179,389 $ 142,860 $ 135,444 $ 1,910,190 $ 37,022 $ 22,285,367 The following table summarizes the Company’s loan portfolio at December 31, 2018 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 $ 3,414,039 $ 42,176 $ 86,624 $ 47,494 $ — $ — $ 3,590,333 Services 3,167,203 49,761 32,661 8,567 — — 3,258,192 Wholesale/retail 1,593,902 18,809 7,131 1,316 — — 1,621,158 Manufacturing 668,438 30,934 22,230 8,919 — — 730,521 Healthcare 2,730,121 14,920 37,698 16,538 — — 2,799,277 Public finance 804,550 — — — — — 804,550 Other commercial and industrial 756,815 1,266 7,588 16,954 49,371 53 832,047 Total commercial 13,135,068 157,866 193,932 99,788 49,371 53 13,636,078 Commercial real estate: Residential construction and land development 148,234 — — 350 — — 148,584 Retail 885,588 11,926 1,289 20,279 — — 919,082 Office 1,059,334 10,532 3,054 — — — 1,072,920 Multifamily 1,287,471 281 12 301 — — 1,288,065 Industrial 776,898 — 1,208 — — — 778,106 Other commercial real estate 555,301 1,188 876 691 — — 558,056 Total commercial real estate 4,712,826 23,927 6,439 21,621 — — 4,764,813 Residential mortgage: Permanent mortgage 269,678 52 9,730 1,991 819,199 21,960 1,122,610 Permanent mortgages guaranteed by U.S. government agencies — — — — 183,734 7,132 190,866 Home equity 223,298 — 296 — 682,491 10,472 916,557 Total residential mortgage 492,976 52 10,026 1,991 1,685,424 39,564 2,230,033 Personal 944,256 115 4,443 76 76,762 154 1,025,806 Total $ 19,285,126 $ 181,960 $ 214,840 $ 123,476 $ 1,811,557 $ 39,771 $ 21,656,730 Impaired Loans Loans are considered to be impaired when it is probable that the Company will not be able to collect all amounts due according to the contractual terms of the loan agreement. This generally includes all nonaccruing loans, all loans modified in a TDR and all loans repurchased from GNMA pools. A summary of impaired loans at September 30, 2019 follows (in thousands): As of For the For the September 30, 2019 Three Months Ended Nine Months Ended Recorded Investment September 30, 2019 September 30, 2019 Unpaid Principal Balance Total With No With Allowance Related Allowance Average Recorded Interest Income Recognized Average Recorded Interest Income Recognized Commercial: Energy $ 139,897 $ 88,894 $ 62,981 $ 25,913 $ 7,176 $ 80,263 $ — $ 67,705 $ — Services 9,390 6,119 6,093 26 26 8,103 — 5,172 — Wholesale/retail 1,718 1,504 1,243 261 101 1,447 — 1,087 — Manufacturing 1 9,153 8,741 8,511 230 230 8,677 — 8,448 — Healthcare 17,786 5,978 5,978 — — 11,063 — 8,547 — Public finance — — — — — — — — — Other commercial and industrial 8,261 470 470 — — 7,998 — 8,585 — Total commercial 186,205 111,706 85,276 26,430 7,533 117,551 — 99,544 — Commercial real estate: Residential construction and land development 1,306 350 350 — — 350 — 350 — Retail 20,516 20,132 20,132 — — 20,094 — 20,206 — Office 855 855 855 — — 855 — 427 — Multifamily 286 286 286 — — 281 — 294 — Industrial 909 909 909 — — 454 — 454 — Other commercial real estate 813 653 653 — — 393 — 672 — Total commercial real estate 24,685 23,185 23,185 — — 22,427 — 22,403 — Residential mortgage: Permanent mortgage 24,639 20,165 20,165 — — 20,984 280 22,058 894 Permanent mortgage guaranteed by U.S. government agencies 2 197,847 191,764 191,764 — — 196,310 2,020 194,751 5,863 Home equity 12,621 10,807 10,807 — — 10,369 — 10,639 — Total residential mortgage 235,107 222,736 222,736 — — 227,663 2,300 227,448 6,757 Personal 338 271 271 — — 254 — 251 — Total $ 446,335 $ 357,898 $ 331,468 $ 26,430 $ 7,533 $ 367,895 $ 2,300 $ 349,646 $ 6,757 1 Impaired manufacturing sector loans included $4.7 million of loans from an affiliated entity, with no allowance as the fair value of the collateral exceeded the outstanding principal balance at September 30, 2019 . 2 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 September 30, 2019 , the majority were accruing based on the guarantee by U.S. government agencies. Generally, no interest income is recognized on impaired loans until all principal balances, including amounts charged-off, are recovered. A summary of impaired loans at December 31, 2018 follows (in thousands): Recorded Investment Unpaid Principal Balance Total With No Allowance With Allowance Related Allowance Commercial: Energy $ 79,675 $ 47,494 $ 18,639 $ 28,855 $ 5,362 Services 13,437 8,567 8,489 78 74 Wholesale/retail 1,722 1,316 1,015 301 101 Manufacturing 10,055 8,919 8,673 246 246 Healthcare 24,319 16,538 10,563 5,975 2,949 Public finance — — — — — Other commercial and industrial 26,955 17,007 17,007 — — Total commercial 156,163 99,841 64,386 35,455 8,732 Commercial real estate: Residential construction and land development 1,306 350 350 — — Retail 27,680 20,279 20,279 — — Office — — — — — Multifamily 301 301 301 — — Industrial — — — — — Other commercial real estate 851 691 691 — — Total commercial real estate 30,138 21,621 21,621 — — Residential mortgage: Permanent mortgage 28,716 23,951 23,951 — — Permanent mortgage guaranteed by U.S. government agencies 1 196,296 190,866 190,866 — — Home equity 12,196 10,472 10,472 — — Total residential mortgage 237,208 225,289 225,289 — — Personal 278 230 230 — — Total $ 423,787 $ 346,981 $ 311,526 $ 35,455 $ 8,732 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, 2018 , the majority were accruing based on the guarantee by U.S. government agencies. Troubled Debt Restructurings At September 30, 2019 the Company had $145 million in troubled debt restructurings (TDRs), of which $93 million were accruing residential mortgage loans guaranteed by U.S. government agencies. Approximately $70 million of TDRs were performing in accordance with the modified terms. At December 31, 2018 , the Company had $166 million in TDRs, of which $86 million were accruing residential mortgage loans guaranteed by U.S. government agencies. Approximately $71 million of TDRs were performing in accordance with the modified terms. TDRs generally consist of interest rate concessions, payment stream concessions or a combination of concessions to distressed borrowers. During the three and nine months ended September 30, 2019 , $6.2 million and $40 million of loans were restructured. During the three and nine months ended September 30, 2018 , $31 million and $76 million of loans were restructured. Nonaccrual & 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. A summary of loans currently performing, loans past due and accruing and nonaccrual loans as of September 30, 2019 is as follows (in thousands): Past Due Current 30 to 59 Days 60 to 89 Days 90 Days or More Nonaccrual Total Commercial: Energy $ 4,025,375 $ — $ — $ — $ 88,894 $ 4,114,269 Services 3,249,994 7,305 2,096 735 6,119 3,266,249 Wholesale/retail 1,844,203 2,910 — — 1,504 1,848,617 Manufacturing 687,358 2,309 — — 8,741 698,408 Healthcare 3,026,838 94 2 56 5,978 3,032,968 Public finance 744,840 — — — — 744,840 Other commercial and industrial 718,419 337 48 — 470 719,274 Total commercial 14,297,027 12,955 2,146 791 111,706 14,424,625 Commercial real estate: Residential construction and land development 134,947 — — 64 350 135,361 Retail 779,037 — — — 20,132 799,169 Office 1,013,420 — — — 855 1,014,275 Multifamily 1,318,148 6,405 — — 286 1,324,839 Industrial 872,627 — — — 909 873,536 Other commercial real estate 477,126 335 106 657 653 478,877 Total commercial real estate 4,595,305 6,740 106 721 23,185 4,626,057 Residential mortgage: Permanent mortgage 1,036,793 6,097 3,405 — 20,165 1,066,460 Permanent mortgages guaranteed by U.S. government agencies 47,207 23,412 21,676 93,137 6,332 191,764 Home equity 845,616 2,282 374 — 10,807 859,079 Total residential mortgage 1,929,616 31,791 25,455 93,137 37,304 2,117,303 Personal 1,116,888 100 94 29 271 1,117,382 Total $ 21,938,836 $ 51,586 $ 27,801 $ 94,678 $ 172,466 $ 22,285,367 A summary of loans currently performing, loans past due and accruing and nonaccrual loans as of December 31, 2018 is as follows (in thousands): Past Due Current 30 to 59 Days 60 to 89 Days 90 Days or More Nonaccrual Total Commercial: Energy $ 3,542,839

Leasing Leasing

Leasing Leasing	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases of Lessee Disclosure [Text Block]	Leasing Effective January 1, 2019, premises and equipment included right-of-use assets for leased office space and facilities. Leases are at market rates at inception and may contain escalations based on consumer price index or similar benchmarks and options to renew at then market rates. Renewal options, variable lease payments and residual value guarantees are included in the measurement of right-of-use assets when certain conditions are met. Lease component cash flows are discounted at the applicable FHLB advance rate. At September 30, 2019 , right-of-use assets were $180 million , the weighted-average remaining lease term was 11.0 years and the weighted average discount rate on operating leases was 3.2 percent . Operating lease costs recognized as occupancy and equipment expense were $7.1 million and $19.3 million for the three and nine months ended September 30, 2019 . Operating cash flows from operating leases were $5.9 million and $17.3 million for the three and nine months ended September 30, 2019 . At September 30, 2019 , un-discounted operating lease liabilities are scheduled to mature as follows: $7.0 million in 2019, $29.6 million in 2020, $27.4 million in 2021, $20.3 million in 2022, $18.6 million in 2023 and $136.3 million thereafter. Operating expense and short term lease costs total $3.3 million and $10.9 million for the three and nine months ended September 30, 2019.

Mortgage Banking Activities

Mortgage Banking Activities	9 Months Ended
	Sep. 30, 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): September 30, 2019 December 31, 2018 Unpaid Principal Balance/ Notional Fair Value Unpaid Principal Balance/ Notional Fair Value Residential mortgage loans held for sale $ 269,610 $ 272,489 $ 145,057 $ 146,971 Residential mortgage loan commitments 379,377 10,111 160,848 5,378 Forward sales contracts 649,161 (113 ) 274,000 (3,128 ) $ 282,487 $ 149,221 No residential mortgage loans held for sale were 90 days or more past due or considered impaired as of September 30, 2019 or December 31, 2018 . No credit losses were recognized on residential mortgage loans held for sale for the nine month period ended September 30, 2019 and 2018 . Mortgage banking revenue was as follows (in thousands): Three Months Ended Nine Months Ended September 30, 2019 2018 2019 2018 Production revenue: Net realized gains on sale of mortgage loans $ 8,971 $ 9,063 $ 24,838 $ 28,699 Net change in unrealized gain on mortgage loans held for sale 97 (2,135 ) 965 (2,457 ) Net change in the fair value of mortgage loan commitments 514 (2,446 ) 4,733 (1,496 ) Net change in the fair value of forward sales contracts 4,232 2,768 3,015 1,871 Total production revenue 13,814 7,250 33,551 26,617 Servicing revenue 16,366 16,286 48,594 49,290 Total mortgage banking revenue $ 30,180 $ 23,536 $ 82,145 $ 75,907 Production revenue includes gain (loss) on residential mortgage loans held for sale and changes in the fair value of derivative contracts not designated as hedging instruments for accounting purposes related to residential mortgage loan commitments and forward sales contracts. Servicing revenue includes servicing fee income and late charges on loans serviced for others. Residential Mortgage Servicing Mortgage servicing rights may be originated or purchased. Both originated and purchased mortgage servicing rights are initially recognized at fair value. The Company has elected to carry all mortgage servicing rights at fair value. Changes in the fair value are recognized in earnings as they occur. The unpaid principal balance of loans serviced for others is the primary driver of servicing revenue. The following represents a summary of mortgage servicing rights (dollars in thousands): September 30, 2019 December 31, 2018 Number of residential mortgage loans serviced for others 128,463 132,463 Outstanding principal balance of residential mortgage loans serviced for others $ 21,046,136 $ 21,658,335 Weighted average interest rate 3.99 % 3.99 % Remaining term (in months) 290 293 The following represents activity in capitalized mortgage servicing rights (in thousands): Three Months Ended Nine Months Ended September 30, 2019 2018 2019 2018 Beginning Balance $ 208,308 $ 278,719 $ 259,254 $ 252,867 Additions, net 9,882 8,968 24,821 28,688 Change in fair value due to principal payments (11,936 ) (8,986 ) (27,600 ) (25,783 ) Change in fair value due to market assumption changes (12,593 ) 5,972 (62,814 ) 28,901 Ending Balance $ 193,661 $ 284,673 $ 193,661 $ 284,673 Changes in the fair value of mortgage servicing rights due to market assumption changes are included in Other operating revenue in the Consolidated Statements of Earnings. Changes in fair value due to principal payments are included in Mortgage banking costs. Mortgage servicing rights are not traded in active markets. Fair value is determined by discounting the projected net cash flows. Significant market assumptions used to determine fair value based on significant unobservable inputs were as follows: September 30, 2019 December 31, 2018 Discount rate – risk-free rate plus a market premium 9.82% 9.90% Prepayment rate - based upon loan interest rate, original term and loan type 8.31% - 17.22% 8.05% - 15.74% Loan servicing costs – annually per loan based upon loan type: Performing loans $68 - $94 $67 - $93 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 1.51% 2.57% Primary/secondary mortgage rate spread 102 bps 105 bps Changes in primary residential mortgage interest rates directly affect the prepayment speeds used in valuing our mortgage servicing rights. A separate third party model is used to estimate prepayment speeds based on interest rates, housing turnover rates, estimated loan curtailment, anticipated defaults and other relevant factors. The prepayment model is updated periodically for changes in market conditions and adjusted to better correlate with actual performance of BOK Financial’s servicing portfolio.

Commitments and Contingent Liab

Commitments and Contingent Liabilities	9 Months Ended
	Sep. 30, 2019
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 December 17, 2019. 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. Four separate small groups of bondholders filed arbitration complaints with the Financial Institutions Regulatory Association respecting the bonds and other bonds for which BOKF, NA served as indenture trustee. BOKF, NA challenged the FINRA proceedings in the United States District Court of Nevada. On appeal, the United States Court of Appeals for the Ninth Circuit held BOKF, NA was not subject to FINRA jurisdiction. The four FINRA complaints were then dismissed. On July 9, 2019, the New Jersey Federal District Court, upon motion of the SEC, terminated the Payment Plan except with respect to facilities then under contract to be sold. The SEC has announced its intention to seek judgment against the principal individual and his wife for the amount remaining on the bonds. As a result, management is no longer able to conclude that the individual principal and his wife will be successful in paying the obligations he has to pay the bonds in full. 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 facilities securing payment of the bonds, including those currently under contract and those not currently under contract, approximately $20 million will remain outstanding. BOKF, NA is unable at this time to assess whether the individual principal and his wife will have the financial capacity to pay in full the balance due on the bonds. 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. Under all circumstances, the obligation of the principals to repay the bonds continues as an obligation not dischargeable in bankruptcy. 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 the administratrix of a deceased resident who had sued for and obtained a judgment for wrongful death against 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, in its capacity as indenture trustee for the bonds, 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. 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. 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 July 6, 2018, a plaintiff served a petition in a putative class action in the Oklahoma District Court for Tulsa County Oklahoma alleging BOKF NA breached its Demand Deposit Agreements by charging overdraft and not sufficient funds fees to deposit accounts on the day of the transaction triggering the fee and by the bank's debit hold process causing overdraft fees. 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 two private equity funds 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. At September 30, 2019 , the Company has $245 million in interests in various alternative investments generally consisting of unconsolidated limited partnership interests in entities for which investment return is in the form of low income housing tax credits or other investments in merchant banking activities. This investment balance also includes $70 million

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2019
Stockholders' Equity Note [Abstract]
Shareholders' Equity [Text Block]	Shareholders' Equity On October 29, 2019 , the Company declared a quarterly cash dividend of $0.51 per common share payable on or about November 27, 2019 to shareholders of record as of November 12, 2019 . Dividends declared were $0.50 and $1.50 per share during the three and nine months ended September 30, 2019 and $0.50 and $1.40 per share during the three and nine months ended September 30, 2018 . 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, December 31, 2017 $ (35,385 ) $ (789 ) $ (36,174 ) Transition adjustment for net unrealized gains on equity securities (2,709 ) — (2,709 ) Net change in unrealized gain (loss) (166,464 ) — (166,464 ) Reclassification adjustments included in earnings: Loss on available for sale securities, net 802 — 802 Other comprehensive loss, before income taxes (165,662 ) — (165,662 ) Federal and state income taxes 1 (42,183 ) — (42,183 ) Other comprehensive loss, net of income taxes (123,479 ) — (123,479 ) Balance, September 30, 2018 $ (161,573 ) $ (789 ) $ (162,362 ) Balance, December 31, 2018 $ (70,999 ) $ (1,586 ) $ (72,585 ) Net change in unrealized gain (loss) 274,441 — 274,441 Reclassification adjustments included in earnings: Gain on available for sale securities, net (1,110 ) — (1,110 ) Other comprehensive income, before income taxes 273,331 — 273,331 Federal and state income taxes 1 66,993 — 66,993 Other comprehensive income, net of income taxes 206,338 — 206,338 Balance, September 30, 2019 $ 135,339 $ (1,586 ) $ 133,753 1 Calculated using a 25 percent blended federal and state statutory tax rate.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	Earnings Per Share (In thousands, except share and per share amounts) Three Months Ended Nine Months Ended September 30, 2019 2018 2019 2018 Numerator: Net income attributable to BOK Financial Corp. shareholders $ 142,231 $ 117,256 $ 390,406 $ 337,190 Less: Earnings allocated to participating securities 875 963 2,553 2,940 Numerator for basic earnings per share – income available to common shareholders 141,356 116,293 387,853 334,250 Effect of reallocating undistributed earnings of participating securities 1 1 1 1 Numerator for diluted earnings per share – income available to common shareholders $ 141,357 $ 116,294 $ 387,854 $ 334,251 Denominator: Weighted average shares outstanding 71,033,405 65,438,849 71,425,855 65,455,306 Less: Participating securities included in weighted average shares outstanding 437,098 537,754 472,311 571,987 Denominator for basic earnings per common share 70,596,307 64,901,095 70,953,544 64,883,319 Dilutive effect of employee stock compensation plans 1 13,617 33,256 15,301 36,409 Denominator for diluted earnings per common share 70,609,924 64,934,351 70,968,845 64,919,728 Basic earnings per share $ 2.00 $ 1.79 $ 5.47 $ 5.15 Diluted earnings per share $ 2.00 $ 1.79 $ 5.47 $ 5.15 1 Excludes employee stock options with exercise prices greater than current market price. — — — —

Reportable Segments

Reportable Segments	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Reportable Segments [Text Block]	Reportable Segments Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended September 30, 2019 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 243,944 $ 27,580 $ 12,343 $ (4,771 ) $ 279,096 Net interest revenue (expense) from internal sources (63,797 ) 20,882 10,723 32,192 — Net interest revenue 180,147 48,462 23,066 27,421 279,096 Provision for credit losses 9,505 1,841 (42 ) 696 12,000 Net interest revenue after provision for credit losses 170,642 46,621 23,108 26,725 267,096 Other operating revenue 48,832 51,221 89,160 (2,763 ) 186,450 Other operating expense 68,685 59,699 71,619 79,289 279,292 Net direct contribution 150,789 38,143 40,649 (55,327 ) 174,254 Gain on financial instruments, net 28 8,339 — (8,367 ) — Change in fair value of mortgage servicing rights — (12,593 ) — 12,593 — Gain on repossessed assets, net 802 214 — (1,016 ) — Corporate expense allocations 12,613 11,776 9,416 (33,805 ) — Net income before taxes 139,006 22,327 31,233 (18,312 ) 174,254 Federal and state income taxes 37,433 5,687 8,027 (18,751 ) 32,396 Net income 101,573 16,640 23,206 439 141,858 Net income (loss) attributable to non-controlling interests — — — (373 ) (373 ) Net income attributable to BOK Financial Corp. shareholders $ 101,573 $ 16,640 $ 23,206 $ 812 $ 142,231 Average assets $ 23,973,067 $ 9,827,130 $ 10,392,988 $ (611,075 ) $ 43,582,110 Reportable segments reconciliation to the Consolidated Financial Statements for the nine months ended September 30, 2019 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other 1 BOK Financial Consolidated Net interest revenue from external sources $ 699,239 $ 75,353 $ 51,054 $ 16,984 $ 842,630 Net interest revenue (expense) from internal sources (181,829 ) 76,925 27,213 77,691 — Net interest revenue 517,410 152,278 78,267 94,675 842,630 Provision for credit losses 27,574 4,654 (209 ) (7,019 ) 25,000 Net interest revenue after provision for credit losses 489,836 147,624 78,476 101,694 817,630 Other operating revenue 128,055 142,780 248,591 (3,641 ) 515,785 Other operating expense 181,809 171,214 202,579 287,984 843,586 Net direct contribution 436,082 119,190 124,488 (189,931 ) 489,829 Gain on financial instruments, net 67 43,416 — (43,483 ) — Change in fair value of mortgage servicing rights — (62,814 ) — 62,814 — Gain on repossessed assets, net 455 409 — (864 ) — Corporate expense allocations 34,146 35,369 26,943 (96,458 ) — Net income before taxes 402,458 64,832 97,545 (75,006 ) 489,829 Federal and state income taxes 107,807 16,513 25,076 (49,470 ) 99,926 Net income 294,651 48,319 72,469 (25,536 ) 389,903 Net income (loss) attributable to non-controlling interests — — — (503 ) (503 ) Net income attributable to BOK Financial Corp. shareholders $ 294,651 $ 48,319 $ 72,469 $ (25,033 ) $ 390,406 Average assets $ 22,288,129 $ 9,142,491 $ 9,861,021 $ 89,202 $ 41,380,843 1 CoBiz operations are included in Funds Management and Other for the first quarter of 2019 and subsequently allocated to the respective segments in the second quarter of 2019. Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended September 30, 2018 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 187,417 $ 20,005 $ 22,509 $ 10,952 $ 240,883 Net interest revenue (expense) from internal sources (42,270 ) 19,039 6,267 16,964 — Net interest revenue 145,147 39,044 28,776 27,916 240,883 Provision for credit losses 8,047 1,451 (84 ) (5,414 ) 4,000 Net interest revenue after provision for credit losses 137,100 37,593 28,860 33,330 236,883 Other operating revenue 40,522 44,024 83,357 38 167,941 Other operating expense 51,039 58,482 62,256 80,840 252,617 Net direct contribution 126,583 23,135 49,961 (47,472 ) 152,207 Gain (loss) on financial instruments, net (3 ) (7,229 ) 7 7,225 — Change in fair value of mortgage servicing rights — 5,972 — (5,972 ) — Gain (loss) on repossessed assets, net (1,869 ) (87 ) — 1,956 — Corporate expense allocations 9,124 11,037 11,127 (31,288 ) — Net income before taxes 115,587 10,754 38,841 (12,975 ) 152,207 Federal and state income taxes 30,623 2,739 9,975 (8,675 ) 34,662 Net income 84,964 8,015 28,866 (4,300 ) 117,545 Net income attributable to non-controlling interests — — — 289 289 Net income (loss) attributable to BOK Financial Corp. shareholders $ 84,964 $ 8,015 $ 28,866 $ (4,589 ) $ 117,256 Average assets $ 18,499,979 $ 8,323,543 $ 8,498,363 $ (1,626,068 ) $ 33,695,817 Reportable segments reconciliation to the Consolidated Financial Statements for the nine months ended September 30, 2018 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 529,958 $ 63,504 $ 56,990 $ 48,729 $ 699,181 Net interest revenue (expense) from internal sources (107,715 ) 51,811 26,431 29,473 — Net interest revenue 422,243 115,315 83,421 78,202 699,181 Provision for credit losses 18,781 3,890 (238 ) (23,433 ) (1,000 ) Net interest revenue after provision for credit losses 403,462 111,425 83,659 101,635 700,181 Other operating revenue 123,245 135,291 228,766 (6,973 ) 480,329 Other operating expense 148,796 174,728 188,691 231,308 743,523 Net direct contribution 377,911 71,988 123,734 (136,646 ) 436,987 Gain (loss) on financial instruments, net 13 (36,901 ) 7 36,881 — Change in fair value of mortgage servicing rights — 28,901 — (28,901 ) — Gain (loss) on repossessed assets, net (6,102 ) (21 ) — 6,123 — Corporate expense allocations 29,092 33,283 31,084 (93,459 ) — Net income before taxes 342,730 30,684 92,657 (29,084 ) 436,987 Federal and state income taxes 90,943 7,816 23,824 (23,643 ) 98,940 Net income 251,787 22,868 68,833 (5,441 ) 338,047 Net income attributable to non-controlling interests — — — 857 857 Net income attributable to BOK Financial Corp. shareholders $ 251,787 $ 22,868 $ 68,833 $ (6,298 ) $ 337,190 Average assets $ 18,124,571 $ 8,381,205 $ 8,364,712 $ (1,094,993 ) $ 33,775,495

Fees and Commissions Revenue Fe

Fees and Commissions Revenue Fees and Commissions Revenue	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Fees and Commissions Revenue [Text Block]	Fees and Commissions Revenue Fees and commissions revenue is generated through the sales of products, consisting primarily of financial instruments, and the performance of services for customers under contractual obligations. Revenue from providing services for customers is recognized at the time services are provided in an amount that reflects the consideration we expect to be entitled to for those services. Revenue is recognized based on the application of five steps: • Identify the contract with a customer • Identify the performance obligations in the contract • Determine the transaction price • Allocate the transaction price to the performance obligations in the contract • Recognize revenue when (or as) the Company satisfies a performance obligation For contracts with multiple performance obligations, individual performance obligations are accounted for separately if the customer can benefit from the good or service on its own or with other resources readily available to the customer and the promise to transfer goods and services to the customer is separately identifiable in the contract. The transaction price is allocated to the performance obligations based on relative standalone selling prices. Revenue is recognized on a gross basis whenever we have primary responsibility and risk in providing the services or products to our customers and have discretion in establishing the price for the services or products. Revenue is recognized on a net basis whenever we act as an agent for products or services of others. Brokerage and trading revenue includes revenues from trading, customer hedging, retail brokerage and investment banking. Trading revenue includes net realized and unrealized gains primarily related to sales of securities to institutional customers and related derivative contracts. Customer hedging revenue includes realized and unrealized changes in the fair value of derivative contracts held for customer risk management programs including credit valuation adjustments, as necessary. We offer commodity, interest rate, foreign exchange and equity derivatives to our customers. These customer contracts are offset with contracts with selected counterparties and exchanges to minimize changes in market risk from changes in commodity prices, interest rates or foreign exchange rates. Retail brokerage revenue represents fees and commissions earned on sales of fixed income securities, annuities, mutual funds and other financial instruments to retail customers. Investment banking revenue includes fees earned upon completion of underwriting and financial advisory services. Investment banking revenue also includes fees earned in conjunction with loan syndications. Insurance brokerage revenues represents fees and commissions earned on placement of insurance products with carriers for property and casualty and health coverage. Transaction card revenue includes merchant discount fees and electronic funds transfer network fees, net of interchange fees paid to card issuers and assessments paid to card networks. Merchant discount fees represent fees paid by customers for account management and electronic processing of card transactions. Merchant discount fees are recognized at the time the customer’s transactions are processed or other services are performed. The Company also maintains the TransFund electronic funds transfer network for the benefit of its members, which includes the Bank. Electronic funds transfer fees are recognized as electronic transactions processed on behalf of its members. Fiduciary and asset management revenue includes fees from asset management, custody, recordkeeping, investment advisory and administration services. Revenue is recognized on an accrual basis at the time the services are performed and may be based on either the fair value of the account or the service provided. Deposit service charges and fees include commercial account service charges, overdraft fees, check card fee revenue and automated service charge and other deposit service fees. Fees are recognized at least quarterly in accordance with published deposit account agreements and disclosure statements for retail accounts or contractual agreements for commercial accounts. Item charges for overdraft or non-sufficient funds items are recognized as items are presented for payment. Account balance charges and activity fees are accrued monthly and collected in arrears. Commercial account activity fees may be offset by an earnings credit based on account balances. Check card fees represent interchange fees paid by a merchant bank for transactions processed from cards issued by the Company. Check card fees are recognized when transactions are processed. Mortgage banking revenue includes revenues recognized in conjunction with the origination, marketing and servicing of conventional and government-sponsored residential mortgage loans. Mortgage production revenue includes net realized gains (losses) on sales of residential mortgage loans in the secondary market and the net change in unrealized gains (losses) on residential mortgage loans held for sale. Mortgage production revenue also includes changes in the fair value of derivative contracts not designated as hedging instruments related to residential mortgage loan commitments and forward sales contracts. Mortgage servicing revenue includes servicing fee income and late charges on loans serviced for others. Fees and commissions revenue by reportable segment and primary service line is as follows for the three months ended September 30, 2019 . Commercial Consumer Wealth Management Funds Management & Other 3 Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 24,091 $ — $ 24,091 $ 24,091 $ — Customer hedging revenue 2,283 — 1,810 591 4,684 4,684 — Retail brokerage revenue — — 4,204 — 4,204 — 4,204 Insurance brokerage revenue — — 3,375 (513 ) 2,862 — 2,862 Investment banking revenue 4,408 — 3,590 1 7,999 3,762 4,237 Brokerage and trading revenue 6,691 — 37,070 79 43,840 32,537 11,303 TransFund EFT network revenue 18,465 1,020 (23 ) 2 19,464 — 19,464 Merchant services revenue 2,203 14 — — 2,217 — 2,217 Corporate card revenue 328 — 6 — 334 — 334 Transaction card revenue 20,996 1,034 (17 ) 2 22,015 — 22,015 Personal trust revenue — — 20,239 (1 ) 20,238 — 20,238 Corporate trust revenue — — 6,204 1 6,205 — 6,205 Institutional trust & retirement plan services revenue — — 10,740 — 10,740 — 10,740 Investment management services and other revenue — — 6,480 (42 ) 6,438 — 6,438 Fiduciary and asset management revenue — — 43,663 (42 ) 43,621 — 43,621 Commercial account service charge revenue 10,609 467 540 (3 ) 11,613 — 11,613 Overdraft fee revenue 81 9,603 45 3 9,732 — 9,732 Check card revenue — 5,721 — — 5,721 — 5,721 Automated service charge and other deposit fee revenue 197 1,519 53 2 1,771 — 1,771 Deposit service charges and fees 10,887 17,310 638 2 28,837 — 28,837 Mortgage production revenue — 13,815 — (1 ) 13,814 13,814 — Mortgage servicing revenue — 16,828 — (462 ) 16,366 16,366 — Mortgage banking revenue — 30,643 — (463 ) 30,180 30,180 — Other revenue 7,585 2,474 8,068 (501 ) 17,626 11,812 5,814 Total fees and commissions revenue $ 46,159 $ 51,461 $ 89,422 $ (923 ) $ 186,119 $ 74,529 $ 111,590 1 Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance. 2 In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers. 3 CoBiz operations are included in Funds Management and Other for the first quarter of 2019. Fees and commissions revenue by reportable segment and primary service line is as follows for the nine months ended September 30, 2019 . Commercial Consumer Wealth Management Funds Management & Other 3 Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 58,890 $ — $ 58,890 $ 58,890 $ — Customer hedging revenue 6,243 — 9,444 1,019 16,706 16,706 — Retail brokerage revenue — — 12,192 (65 ) 12,127 — 12,127 Insurance brokerage revenue — — 7,063 3,729 10,792 — 10,792 Investment banking revenue 8,345 — 9,123 — 17,468 7,189 10,279 Brokerage and trading revenue 14,588 — 96,712 4,683 115,983 82,785 33,198 TransFund EFT network revenue 54,623 2,975 (60 ) 3 57,541 — 57,541 Merchant services revenue 6,351 43 — 122 6,516 — 6,516 Corporate card revenue 598 — 11 2 611 — 611 Transaction card revenue 61,572 3,018 (49 ) 127 64,668 — 64,668 Personal trust revenue — — 61,028 — 61,028 — 61,028 Corporate trust revenue — — 18,736 — 18,736 — 18,736 Institutional trust & retirement plan services revenue — — 32,919 — 32,919 — 32,919 Investment management services and other revenue — — 17,730 1,591 19,321 — 19,321 Fiduciary and asset management revenue — — 130,413 1,591 132,004 — 132,004 Commercial account service charge revenue 31,296 1,283 1,605 1,804 35,988 — 35,988 Overdraft fee revenue 248 26,971 108 (231 ) 27,096 — 27,096 Check card revenue — 16,299 — 165 16,464 — 16,464 Automated service charge and other deposit fee revenue 569 4,762 228 47 5,606 — 5,606 Deposit service charges and fees 32,113 49,315 1,941 1,785 85,154 — 85,154 Mortgage production revenue — 33,554 — (3 ) 33,551 33,551 — Mortgage servicing revenue — 50,014 — (1,420 ) 48,594 48,594 — Mortgage banking revenue — 83,568 — (1,423 ) 82,145 82,145 — Other revenue 17,037 7,211 19,586 (1,009 ) 42,825 28,655 14,170 Total fees and commissions revenue $ 125,310 $ 143,112 $ 248,603 $ 5,754 $ 522,779 $ 193,585 $ 329,194 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 three months ended September 30, 2018 . Commercial Consumer Wealth Management Funds Management & Other Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 4,830 $ — $ 4,830 $ 4,830 $ — Customer hedging revenue 1,350 — 6,935 229 8,514 8,514 — Retail brokerage revenue — — 4,398 (73 ) 4,325 — 4,325 Insurance brokerage revenue — — 170 — 170 — 170 Investment banking revenue 1,765 — 3,482 — 5,247 1,410 3,837 Brokerage and trading revenue 3,115 — 19,815 156 23,086 14,754 8,332 TransFund EFT network revenue 18,397 1,009 (21 ) 2 19,387 — 19,387 Merchant services revenue 1,995 14 — — 2,009 — 2,009 Corporate card revenue — — — — — — — Transaction card revenue 20,392 1,023 (21 ) 2 21,396 — 21,396 Personal trust revenue — — 35,822 1 35,823 — 35,823 Corporate trust revenue — — 5,741 — 5,741 — 5,741 Institutional trust & retirement plan services revenue — — 11,095 (1 ) 11,094 — 11,094 Investment management services and other revenue — — 4,903 (47 ) 4,856 — 4,856 Fiduciary and asset management revenue — — 57,561 (47 ) 57,514 — 57,514 Commercial account service charge revenue 10,294 366 587 (3 ) 11,244 — 11,244 Overdraft fee revenue 95 9,413 30 3 9,541 — 9,541 Check card revenue — 5,254 — — 5,254 — 5,254 Automated service charge and other deposit fee revenue 35 1,661 22 8 1,726 — 1,726 Deposit service charges and fees 10,424 16,694 639 8 27,765 — 27,765 Mortgage production revenue — 7,250 — — 7,250 7,250 — Mortgage servicing revenue — 16,748 — (462 ) 16,286 16,286 — Mortgage banking revenue — 23,998 — (462 ) 23,536 23,536 — Other revenue 5,460 2,323 5,568 (451 ) 12,900 8,799 4,101 Total fees and commissions revenue $ 39,391 $ 44,038 $ 83,562 $ (794 ) $ 166,197 $ 47,089 $ 119,108 1 Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance. 2 In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers. Fees and commissions revenue by reportable segment and primary service line is as follows for the nine months ended September 30, 2018 . Commercial Consumer Wealth Management Funds Management & Other Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 21,562 $ — $ 21,562 $ 21,562 $ — Customer hedging revenue 6,264 — 21,511 1,441 29,216 29,216 — Retail brokerage revenue — — 13,751 (246 ) 13,505 — 13,505 Insurance brokerage revenue — — 555 — 555 — 555 Investment banking revenue 5,729 — 9,655 — 15,384 4,772 10,612 Brokerage and trading revenue 11,993 — 67,034 1,195 80,222 55,550 24,672 TransFund EFT network revenue 54,647 3,005 (61 ) 5 57,596 — 57,596 Merchant services revenue 5,720 45 — — 5,765 — 5,765 Corporate card revenue — — — — — — — Transaction card revenue 60,367 3,050 (61 ) 5 63,361 — 63,361 Personal trust revenue — — 76,481 (2 ) 76,479 — 76,479 Corporate trust revenue — — 16,317 — 16,317 — 16,317 Institutional trust & retirement plan services revenue — — 33,584 3 33,587 — 33,587 Investment management services and other revenue — — 14,808 (153 ) 14,655 — 14,655 Fiduciary and asset management revenue — — 141,190 (152 ) 141,038 — 141,038 Commercial account service charge revenue 32,150 1,087 1,802 (3 ) 35,036 — 35,036 Overdraft fee revenue 283 26,665 96 13 27,057 — 27,057 Check card revenue — 15,515 — — 15,515 — 15,515 Automated service charge and other deposit fee revenue 110 4,953 72 17 5,152 — 5,152 Deposit service charges and fees 32,543 48,220 1,970 27 82,760 — 82,760 Mortgage production revenue — 26,617 — — 26,617 26,617 — Mortgage servicing revenue — 50,677 — (1,387 ) 49,290 49,290 — Mortgage banking revenue — 77,294 — (1,387 ) 75,907 75,907 — Other revenue 17,379 6,770 18,725 (3,093 ) 39,781 27,552 12,229 Total fees and commissions revenue $ 122,282 $ 135,334 $ 228,858 $ (3,405 ) $ 483,069 $ 159,009 $ 324,060 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.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2019
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 three and nine months ended September 30, 2019 and 2018 , respectively. Transfers between significant other observable inputs and significant unobservable inputs during the three and nine months ended September 30, 2019 and 2018 are included in the summary of changes in recurring fair values measured using unobservable inputs. The underlying methods used by the third-party pricing services are considered in determining the primary inputs used to determine fair values. Management has evaluated the methodologies employed by the third-party pricing services by comparing the price provided by the pricing service with other sources, including brokers' quotes, sales or purchases of similar instruments and discounted cash flows to establish a basis for reliance on the pricing service values. Significant differences between the pricing service provided value and other sources are discussed with the pricing service to understand the basis for their values. Based on all observable inputs, management may adjust prices obtained from third-party pricing services to more appropriately reflect the prices that would be received to sell assets or paid to transfer liabilities in orderly transactions in the current market. No significant adjustments were made to prices provided by third-party pricing services at September 30, 2019 or December 31, 2018 . Assets and Liabilities Measured at Fair Value on a Recurring Basis The fair value of financial assets and liabilities measured on a recurring basis was as follows as of September 30, 2019 (in thousands): Total Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Trading securities: U.S. government agency debentures $ 63,334 $ — $ 63,334 $ — Residential agency mortgage-backed securities 1,480,458 — 1,480,458 — Municipal and other tax-exempt securities 44,105 — 44,105 — Asset-backed securities 36,928 — 36,928 — Other trading securities 50,387 — 50,387 — Total trading securities 1,675,212 — 1,675,212 — Available for sale securities: U.S. Treasury 2,296 2,296 — — Municipal and other tax-exempt securities 1,848 — 1,848 — Residential agency mortgage-backed securities 7,740,461 — 7,740,461 — Residential non-agency mortgage-backed securities 44,803 — 44,803 — Commercial agency mortgage-backed securities 3,234,671 — 3,234,671 — Other debt securities 472 — — 472 Total available for sale securities 11,024,551 2,296 11,021,783 472 Fair value option securities: U.S. Treasury 552,536 552,536 — — Residential agency mortgage-backed securities 1,263,862 — 1,263,862 — Total fair value option securities 1,816,398 552,536 1,263,862 — Residential mortgage loans held for sale 282,487 — 268,919 13,568 Mortgage servicing rights 1 193,661 — — 193,661 Derivative contracts, net of cash collateral 2 352,019 40,491 311,528 — Liabilities: Derivative contracts, net of cash collateral 2 336,791 — 336,791 — 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 6 , 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, interest rate and agricultural 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 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, 2018 (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 $ 63,765 $ — $ 63,765 $ — Residential agency mortgage-backed securities 1,791,584 — 1,791,584 — Municipal and other tax-exempt securities 34,507 — 34,507 — Asset-backed securities 42,656 — 42,656 — Other trading securities 24,411 — 24,411 — Total trading securities 1,956,923 — 1,956,923 — Available for sale securities: U.S. Treasury 493 493 — — Municipal and other tax-exempt securities 2,864 — 2,864 — Residential agency mortgage-backed securities 5,804,708 — 5,804,708 — Residential non-agency mortgage-backed securities 59,736 — 59,736 — Commercial agency mortgage-backed securities 2,953,889 — 2,953,889 — Other debt securities 35,430 — 34,958 472 Total available for sale securities 8,857,120 493 8,856,155 472 Fair value option securities – Residential agency mortgage-backed securities 283,235 — 283,235 — Residential mortgage loans held for sale 149,221 — 134,014 15,207 Mortgage servicing rights 1 259,254 — — 259,254 Derivative contracts, net of cash collateral 2 320,929 44,074 276,855 — Liabilities: Derivative contracts, net of cash collateral 2 362,306 — 362,306 — 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 6 , 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, energy and agricultural 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 contracts, fully offset by cash margin. Following is a description of the Company's valuation methodologies used for assets and liabilities measured on a recurring basis: Securities The fair values of trading, available for sale and fair value option securities are based on quoted prices for identical instruments in active markets, when available. If quoted prices for identical instruments are not available, fair values are based on significant other observable inputs such as quoted prices of comparable instruments or interest rates and credit spreads, yield curves, volatilities, prepayment speeds and loss severities. The Company has elected to carry all residential mortgage-backed securities guaranteed by U.S. government agencies held as economic hedges against changes in the fair value of mortgage servicing rights at fair value with changes in the fair value recognized in earnings. The fair value of certain available for sale municipal and other debt securities may be based on significant unobservable inputs. These significant unobservable inputs include limited observed trades, projected cash flows, current credit rating of the issuers and, when applicable, the insurers of the debt and observed trades of similar debt. Discount rates are primarily based on references to interest rate spreads on comparable securities of similar duration and credit rating as determined by the nationally-recognized rating agencies adjusted for a lack of trading volume. Significant unobservable inputs are developed by investment securities professionals involved in the active trading of similar securities. A summary of significant inputs used to value these securities follows. A management committee composed of senior members from the Company's Capital Markets, Risk Management and Finance departments assesses the appropriateness of these inputs quarterly. Derivatives All derivative instruments are carried on the balance sheet at fair value. Fair values for exchange-traded contracts are based on quoted prices. Fair values for over-the-counter interest rate, commodity and foreign exchange contracts are based on valuations provided either by third-party dealers in the contracts, quotes provided by independent pricing services, or a third-party provided pricing model that uses significant other observable market inputs. Credit risk is considered in determining the fair value of derivative instruments. Management determines fair value adjustments based on various risk factors including but not limited to current fair value, probability of default and loss given default. We also consider our own credit risk in determining the fair value of derivative contracts. Changes in our credit rating would affect the fair value of our derivative liabilities. In the event of a credit downgrade, the fair value of our derivative liabilities would increase. Residential Mortgage Loans Held for Sale Residential mortgage loans held for sale are carried on the balance sheet at fair value. The Company has elected to carry all residential mortgage loans originated for sale at fair value. Changes in the fair value of these financial instruments are recognized in earnings. The fair values of residential mortgage loans held for sale are based upon quoted market prices of such loans sold in securitization transactions, including related unfunded loan commitments and forward sales contracts. The fair value of mortgage loans that were unable to be sold to U.S. government agencies were determined using quoted prices of loans that are sold in securitization transactions with a liquidity discount applied. The following represents the changes for the three and nine months ended September 30, 2019 related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands): Available for sale - Other debt securities Residential mortgage loans held for sale Balance, June 30, 2019 $ 472 $ 16,073 Transfer to Level 3 from Level 2 1 — 261 Purchases — — Proceeds from sales — (3,152 ) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — 386 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, September 30, 2019 $ 472 $ 13,568 1 Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards. Available for sale - Other debt securities Residential mortgage loans held for sale Balance, December 31, 2018 $ 472 $ 15,207 Transfer to Level 3 from Level 2 1 — 2,150 Purchases — — Proceeds from sales — (4,531 ) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — 742 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, September 30, 2019 $ 472 $ 13,568 1 Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards. The following represents the changes for the three and nine months ended September 30, 2018 related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands): Available for Sale Securities Municipal and other tax-exempt securities Other debt securities Residential mortgage loans held for sale Balance, June 30, 2018 $ 2,030 $ 471 $ 14,243 Transfer to Level 3 from Level 2 1 — — 2,862 Purchases — — — Proceeds from sales — — (143 ) Redemptions and distributions (2,050 ) — — Gain (loss) recognized in earnings: Mortgage banking revenue — — (124 ) Other comprehensive income (loss): Net change in unrealized gain (loss) 20 1 — Balance, September 30, 2018 $ — $ 472 $ 16,838 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 Securities Municipal and other tax-exempt Other debt securities Residential mortgage loans held for sale Balance, December 31, 2017 $ 4,802 $ 472 $ 12,299 Transfer to Level 3 from Level 2 1 — — 5,603 Purchases — — — Proceeds from sales — — (853 ) Redemptions and distributions (5,095 ) — — Gain (loss) recognized in earnings Mortgage banking revenue — — (211 ) Other comprehensive income (loss): Net change in unrealized gain (loss) 293 — — Balance, September 30, 2018 $ — $ 472 $ 16,838 1 Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards. A summary of quantitative information about assets measured at fair value on a recurring basis using Significant Unobservable Inputs (Level 3) as of September 30, 2019 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Available for sale securities – Other debt securities 472 Discounted cash flows 1 Interest rate spread 7.46%-7.46% (7.46%) 3 94.42%-94.42% (94.42%) 2 Residential mortgage loans held for sale 13,568 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. 96.36% 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 3 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, 2018 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Available for sale securities – Other debt securities 472 Discounted cash flows 1 Interest rate spread 7.88%-7.88% (7.88%) 3 94.44%-94.44% (94.44%) 2 Residential mortgage loans held for sale 15,207 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. 92.38% 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 impaired loans and real property and other assets acquired to satisfy loans, which are based primarily on comparisons to completed sales of similar assets. The following represents the carrying value of assets measured at fair value on a non-recurring basis (and related losses) during the period. The carrying value represents only those assets with a balance at September 30, 2019 for which the fair value was adjusted during the nine months ended September 30, 2019 : Fair Value Adjustments for the Carrying Value at September 30, 2019 Three Months Ended Nine Months Ended Quoted Prices in Active Markets for Identical Instruments Significant Other Observable Inputs Significant Unobservable Inputs Gross charge-offs against allowance for loan losses Net losses (gains) and operating expenses of repossessed assets Gross charge-offs against allowance for loan losses Net losses (gains) and operating expenses of repossessed assets Impaired loans $ — $ 79 $ 9,810 $ 2,644 $ — $ 13,868 $ — Real estate and other repossessed assets — 5,044 936 — (979 ) — (532 ) The following represents the carrying value of assets measured at fair value on a non-recurring basis (and related losses) during the period. The carrying value represents only those assets with a balance at September 30, 2018 for which the fair value was adjusted during the nine months ended September 30, 2018 : Fair Value Adjustments for the Carrying Value at September 30, 2018 Three Months Ended Nine Months Ended Quoted Prices in Active Markets for Identical Instruments Significant Other Observable Inputs Significant Unobservable Inputs 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 Impaired loans $ — $ 1,065 $ 24,428 $ 9,086 $ — $ 16,279 $ — Real estate and other repossessed assets — 4,608 6,545 — 2,161 — 7,388 The fair value of collateral-dependent impaired 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 impaired loans and real estate and other repossessed assets based on significant unobservable inputs are generally due to estimates of current fair values between appraisal dates. Significant unobservable inputs include listing prices for the same or comparable assets, uncorroborated expert opinions or management's knowledge of the collateral or industry. Non-recurring fair value measurements of collateral dependent loans secured by mineral rights are generally determined by our internal staff of engineers on projected cash flows under current market conditions and are based on significant unobservable inputs. Projected cash flows are discounted according to risk characteristics of the underlying oil and gas properties. Assets are evaluated to demonstrate with reasonable certainty that crude oil, natural gas and natural gas liquids can be recovered from known oil and gas reservoirs under existing economic and operating conditions at current prices with existing conventional equipment, operating methods and costs. Significant unobservable inputs are developed by asset management and workout professionals and approved by senior Credit Administration executives. A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of September 30, 2019 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Impaired loans $ 9,810 Discounted cash flows Management knowledge of industry and non-real estate collateral including but not limited to recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs 8% - 76% (28%) 1 Real estate and other repossessed assets 936 Appraised value, as adjusted Marketability adjustments off appraised value 2 75% - 89% (85%) 1 Represents fair value as a percentage of the unpaid principal balance. 2 Marketability adjustments include consideration of estimated costs to sell which is approximately 10% of the fair value. A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of September 30, 2018 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Impaired loans $ 24,428 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 41% - 84% (55%) 1 Real estate and other repossessed assets 6,545 Discounted cash flows Recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs N/A 1 Represents fair value as a percentage of the unpaid principal balance. Fair Value of Financial Instruments The following table presents the carrying values and estimated fair values of all financial instruments, including those financial assets and liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis as of September 30, 2019 (dollars in thousands): Carrying Value Estimated Fair Value Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Cash and due from banks $ 761,130 $ 761,130 $ 761,130 $ — $ — Interest-bearing cash and cash equivalents 465,458 465,458 465,458 — — Trading securities: U.S. government agency debentures 63,334 63,334 — 63,334 — Residential agency mortgage-backed securities 1,480,458 1,480,458 — 1,480,458 — Municipal and other tax-exempt securities 44,105 44,105 — 44,105 — Asset-backed securities 36,928 36,928 — 36,928 — Other trading securities 50,387 50,387 — 50,387 — Total trading securities 1,675,212 1,675,212 — 1,675,212 — Investment securities: Municipal and other tax-exempt securities 104,418 107,647 — 107,647 — Residential agency mortgage-backed securities 11,125 11,650 — 11,650 — Other debt securities 188,681 204,724 — 7,702 197,022 Total investment securities 304,224 324,021 — 126,999 197,022 Available for sale securities: U.S. Treasury 2,296 2,296 2,296 — — Municipal and other tax-exempt securities 1,848 1,848 — 1,848 — Residential agency mortgage-backed securities 7,740,461 7,740,461 — 7,740,461 — Residential non-agency mortgage-backed securities 44,803 44,803 — 44,803 — Commercial agency mortgage-backed securities 3,234,671 3,234,671 — 3,234,671 — Other debt securities 472 472 — — 472 Total available for sale securities 11,024,551 11,024,551 2,296 11,021,783 472 Fair value option securities: U.S. Treasury 552,536 552,536 552,536 — — Residential agency mortgage-backed securities 1,263,862 1,263,862 — 1,263,862 — Total fair value option securities 1,816,398 1,816,398 552,536 1,263,862 — Residential mortgage loans held for sale 282,487 282,487 — 268,919 13,568 Loans: — Commercial 14,424,625 14,397,846 — — 14,397,846 Commercial real estate 4,626,057 4,626,804 — — 4,626,804 Residential mortgage 2,117,303 2,132,158 — — 2,132,158 Personal 1,117,382 1,108,984 — — 1,108,984 Total loans 22,285,367 22,265,792 — — 22,265,792 Allowance for loan losses (204,432 ) — — — — Loans, net of allowance 22,080,935 22,265,792 — — 22,265,792 Mortgage servicing rights 193,661 193,661 — — 193,661 Derivative instruments with positive fair value, net of cash collateral 352,019 352,019 40,491 311,528 — Deposits with no stated maturity 23,923,535 23,923,535 — — 23,923,535 Time deposits 2,243,541 2,241,778 — — 2,241,778 Other borrowed funds 10,235,385 10,193,602 — — 10,193,602 Subordinated debentures 275,909 276,393 — 276,393 — Derivative instruments with negative fair value, net of cash collateral 336,791 336,791 — 336,791 — 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, 2018 (dollars in thousands): Carrying Value Estimated Fair Value Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Cash and due from banks $ 741,749 $ 741,749 $ 741,749 $ — $ — Interest-bearing cash and cash equivalents 401,675 401,675 401,675 — — Trading securities: U.S. government agency debentures 63,765 63,765 — 63,765 — Residential agency mortgage-backed securities 1,791,584 1,791,584 — 1,791,584 — Municipal and other tax-exempt securities 34,507 34,507 — 34,507 — Asset-backed securities 42,656 42,656 — 42,656 — Other trading securities 24,411 24,411 — 24,411 — Total trading securities 1,956,923 1,956,923 — 1,956,923 — Investment securities: Municipal and other tax-exempt securities 137,296 138,562 — 138,562 — Residential agency mortgage-backed securities 12,612 12,770 — 12,770 — Other debt securities 205,279 215,966 — 7,905 208,061 Total investment securities 355,187 367,298 — 159,237 208,061 Available for sale securities: U.S. Treasury 493 493 493 — — Municipal and other tax-exempt securities 2,864 2,864 — 2,864 — Residential agency mortgage-backed securities 5,804,708 5,804,708 — 5,804,708 — Residential non-agency mortgage-backed securities 59,736 59,736 — 59,736 — Commercial agency mortgage-backed securities 2,953,889 2,953,889 — 2,953,889 — Other debt securities 35,430 35,430 — 34,958 472 Total available for sale securities 8,857,120 8,857,120 493 8,856,155 472 Fair value option securities – Residential agency mortgage-backed securities 283,235 283,235 — 283,235 — Residential mortgage loans held for sale 149,221 149,221 — 134,014 15,207 Loans: Commercial 13,636,078 13,526,162 — — 13,526,162 Commercial real estate 4,764,813 4,713,747 — — 4,713,747 Residential mortgage 2,230,033 2,213,951 — — 2,213,951 Personal 1,025,806 1,024,368 — — 1,024,368 Total loans 21,656,730 21,478,228 — — 21,478,228 Allowance for loan losses (207,457 ) — — — — Loans, net of allowance 21,449,273 21,478,228 — — 21,478,228 Mortgage servicing rights 259,254 259,254 — — 259,254 Derivative instruments with positive fair value, net of cash collateral 320,929 320,929 44,074 276,855 — Deposits with no stated maturity 23,150,383 23,150,383 — — 23,150,383 Time deposits 2,113,380 2,073,538 — — 2,073,538 Other borrowed funds 7,142,801 7,071,953 — — 7,071,953 Subordinated debentures 275,913 261,977 — 261,977 — Derivative instruments with negative fair value, net of cash collateral 362,306 362,306 — 362,306 — Because no market exists for certain of these financial instruments and management does not intend to sell these financial instruments, the fair values shown in the tables above may not represent values at which the respective financial instruments could be sold individually or in the aggregate at the given reporting date.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2019
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events The Company evaluated events from the date of the consolidated financial statements on September 30, 2019 through the issuance of those consolidated financial statements included in this Quarterly Report on Form 10-Q. No events were identified requiring recognition in and/or disclosure in the consolidated financial statements.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
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. 2016-02, Leases (Topic 842) ("ASU 2016-02") On February 25, 2016, the FASB issued ASU 2016-02 to increase transparency and comparability by recognizing lease assets and liabilities on the balance sheet and disclosing key information about leasing arrangements. Lessees are required to recognize an obligation for future lease payments measured on a discounted basis and a right-of-use asset. The Company adopted the new standard January 1, 2019 through a cumulative effect adjustment to retained earnings. Prior periods were not restated. BOKF elected to apply all practical expedients other than the lessee’s practical expedient to combine lease and non-lease components which would further gross up lease liability and the related right-of-use asset. The implementation of ASU 2016-02 increased the reported right-of-use asset and lease liability by $137 million . The effect on retained earnings was immaterial. 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, effective for the Company's annual reporting periods beginning after December 15, 2019, including interim periods within those fiscal years. The company has established a CECL implementation team to evaluate the impact to the Company’s financial statements. The CECL implementation team, overseen by the Chief Credit Officer, Chief Financial Officer and Chief Risk Officer, has developed a project plan that incorporates input from various departments within the bank including Credit, Financial Reporting, Risk and Information Technology among others. The Audit Committee and Credit Committee of the Board of Directors is periodically updated on project progress. In the second half of 2019, the implementation team is focused on design and operation of internal controls over the expected credit losses estimate and formalizing governance and approval processes. This includes finalizing model validation, refinement of model assumptions and qualitative framework, as well as drafting policies, reporting, and disclosures. These activities support our parallel runs and related results. The Company will adopt the standard on January 1, 2020 through a cumulative-effect adjustment to retained earnings. 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 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. Adoption of ASU 2019-01 is not expected to 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 2016-01include 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. ASU 2019-04 is effective for the Company for fiscal years beginning after December 15, 2019 and interim periods therein. Adoption of ASU 2019-04 is not expected to 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")
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 hedge their loan production 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 and to mitigate the market risk of holding trading securities. 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 6 , 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 6 for additional discussion of notional, fair value and impact on earnings of these contracts.
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. 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. 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. 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 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. Guaranteed loans are considered impaired because we do not expect to receive all principal and interest based on the loan's contractual terms. The original principal guarantee remains; however, interest accrues at a curtailed rate as specified in the programs. 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 and Allowances for Credit Losses, Allowances for Credit Losses [Policy Text Block]	Allowances for Credit Losses BOK Financial maintains an allowance for loan losses and an accrual for off-balance sheet credit risk. 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. As discussed in greater detail in Note 6 , the Company also has separate accruals for off-balance sheet credit risk related to residential mortgage loans previously sold with full or partial recourse and for residential mortgage loans sold to government sponsored agencies under standard representations and warranties. The appropriateness of the allowance for loan losses and accrual for off-balance sheet credit losses (collectively "allowance for credit losses") is assessed by management based on an ongoing quarterly evaluation of the probable estimated losses inherent in the portfolio, including probable losses on both outstanding loans and unused commitments. The allowance for loan losses consists of specific allowances attributed to impaired loans that have not yet been charged down to amounts we expect to recover, general allowances for unimpaired loans based on estimated loss rates by loan class and nonspecific allowances based on general economic conditions, risk concentration and related factors. There have been no material changes in the approach or techniques utilized in developing the allowance for loan losses and the accrual for off-balance sheet credit losses for the three and nine months ended September 30, 2019 . Loans are considered to be impaired when it becomes probable that BOK Financial will be unable to collect all amounts due according to the contractual terms of the loan agreements. Internally risk graded loans are evaluated individually for impairment. Substantially all commercial and commercial real estate loans and certain residential mortgage and consumer loans are risk graded based on evaluation of the borrowers' ability to repay. Certain commercial loans and most residential mortgage and consumer loans are small balance, homogeneous pools of loans that are not risk graded. Non-risk graded loans are identified as impaired based on performance status. Generally, non-risk graded loans 90 days or more past due or modified in a TDR or in bankruptcy are considered to be impaired. Specific allowances for impaired loans are measured 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. Collateral value of real property is generally based on third party appraisals that conform to Uniform Standards of Professional Appraisal Practice, less estimated selling costs. Appraised values are on an "as-is" basis and are generally not adjusted by the Company. Updated appraisals are obtained at least annually or more frequently if market conditions indicate collateral values have declined. Collateral value of mineral rights is generally determined by our internal staff of engineers based on projected cash flows under current market conditions. Collateral values and available cash resources that support impaired loans are evaluated quarterly. Historical statistics may be used as a practical way to estimate impairment in limited situations, such as when a collateral dependent loan is identified as impaired at the end of a reporting period, until an updated appraisal of collateral value is received or a full assessment of future cash flows is completed. Estimates of future cash flows and collateral values require significant judgments and may be volatile. General allowances for unimpaired loans are based on estimated loss rates by loan class. The gross loss rate for each loan class is determined by the greater of the current gross loss rate based on the most recent twelve months or a long-term gross loss rate. Recoveries are not directly considered in the estimation of loss rates. Recoveries generally do not follow predictable patterns and are not received until well after the charge-off date as a result of protracted legal actions. For risk graded loans, gross loss rates are adjusted for changes in risk grading. For each loan class, the current weighted average risk grade is compared to the long-term average risk grade. This comparison determines whether credit risk in each loan class is increasing or decreasing. Loss rates are adjusted upward or downward in proportion to changes in average risk grading. General allowances for unimpaired loans also consider inherent risks identified for each loan class. Inherent risks consider loss rates that most appropriately represent the current credit cycle and other factors attributable to specific loan classes which have not yet been represented in the gross loss rates or risk grading. These factors include changes in commodity prices or engineering imprecision, which may affect the value of reserves that secure our energy loan portfolio, construction risk that may affect commercial real estate loans, changes in regulations and public policy that may disproportionately impact health care loans and changes in loan products. Nonspecific allowances are maintained for risks beyond factors specific to a particular loan or loan class. These factors include trends in the economy of our primary lending areas, concentrations in large balance loans and other relevant factors. An accrual for off-balance sheet credit losses is included in Other liabilities in the Consolidated Balance Sheets. The appropriateness of this accrual is determined in the same manner as the allowance for loan losses. 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.
Lessee, Leases [Policy Text Block]	Effective January 1, 2019, premises and equipment included right-of-use assets for leased office space and facilities. Leases are at market rates at inception and may contain escalations based on consumer price index or similar benchmarks and options to renew at then market rates. Renewal options, variable lease payments and residual value guarantees are included in the measurement of right-of-use assets when certain conditions are met. Lease component cash flows are discounted at the applicable FHLB advance rate.
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. 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.

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2019
Marketable Securities [Abstract]
Trading Securities, [Table Text Block]	The fair value and net unrealized gain (loss) included in trading securities are as follows (in thousands): September 30, 2019 December 31, 2018 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. government agency debentures $ 63,334 $ 23 $ 63,765 $ 254 Residential agency mortgage-backed securities 1,480,458 3,851 1,791,584 9,966 Municipal and other tax-exempt securities 44,105 (99 ) 34,507 (1 ) Asset-backed securities 36,928 50 42,656 685 Other debt securities 50,387 116 24,411 65 Total trading securities $ 1,675,212 $ 3,941 $ 1,956,923 $ 10,969
Investment Securities (Held-to-Maturity) [Table Text Block]	The amortized cost and fair values of investment securities are as follows (in thousands): September 30, 2019 Amortized Fair Gross Unrealized Cost Value Gain Loss Municipal and other tax-exempt $ 104,418 $ 107,647 $ 3,247 $ (18 ) Residential agency mortgage-backed securities 11,125 11,650 528 (3 ) Other debt securities 188,681 204,724 16,457 (414 ) Total investment securities $ 304,224 $ 324,021 $ 20,232 $ (435 ) December 31, 2018 Amortized Fair Gross Unrealized Cost Value Gain Loss Municipal and other tax-exempt $ 137,296 $ 138,562 $ 1,858 $ (592 ) Residential agency mortgage-backed securities 12,612 12,770 293 (135 ) Other debt securities 205,279 215,966 12,257 (1,570 ) Total investment securities $ 355,187 $ 367,298 $ 14,408 $ (2,297 ) The amortized cost and fair values of investment securities at September 30, 2019 , by contractual maturity, are as shown in the following table (dollars in thousands): Less than One Year One to Five Years Six to Ten Years Over Ten Years Total Weighted Average Maturity 1 Fixed maturity debt securities: Amortized cost $ 42,266 $ 93,139 $ 145,046 $ 12,648 $ 293,099 5.16 Fair value 42,426 96,704 160,698 12,543 312,371 Residential mortgage-backed securities: Amortized cost $ 11,125 2 Fair value 11,650 Total investment securities: Amortized cost $ 304,224 Fair value 324,021 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 4.5 years based upon current prepayment assumptions. Temporarily Impaired Investment Securities (in thousands): September 30, 2019 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Investment: Municipal and other tax-exempt 18 $ 10,302 $ 3 $ 2,213 $ 15 $ 12,515 $ 18 Residential agency mortgage-backed securities 1 2,318 3 — — 2,318 3 Other debt securities 18 275 1 10,897 413 11,172 414 Total investment securities 37 $ 12,895 $ 7 $ 13,110 $ 428 $ 26,005 $ 435 December 31, 2018 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Investment: Municipal and other tax-exempt 72 $ 18,255 $ 69 $ 66,141 $ 523 $ 84,396 $ 592 Residential agency mortgage-backed securities 2 — — 5,633 135 5,633 135 Other debt securities 72 13,372 64 23,028 1,506 36,400 1,570 Total investment securities 146 $ 31,627 $ 133 $ 94,802 $ 2,164 $ 126,429 $ 2,297
Available For Sale Securities [Table Text Block]	The amortized cost and fair value of available for sale securities are as follows (in thousands): September 30, 2019 Amortized Fair Gross Unrealized Cost Value Gain Loss U.S. Treasury $ 2,294 $ 2,296 $ 2 $ — Municipal and other tax-exempt 1,772 1,848 76 — Mortgage-backed securities: Residential agency 7,636,923 7,740,461 114,646 (11,108 ) Residential non-agency 28,814 44,803 15,989 — Commercial agency 3,176,188 3,234,671 61,003 (2,520 ) Other debt securities 500 472 — (28 ) Total available for sale securities $ 10,846,491 $ 11,024,551 $ 191,716 $ (13,656 ) December 31, 2018 Amortized Fair Gross Unrealized Cost Value Gain Loss U.S. Treasury $ 496 $ 493 $ — $ (3 ) Municipal and other tax-exempt 2,782 2,864 82 — Mortgage-backed securities: Residential agency 5,886,323 5,804,708 16,149 (97,764 ) Residential non-agency 40,948 59,736 18,788 — Commercial agency 2,986,297 2,953,889 7,955 (40,363 ) Other debt securities 35,545 35,430 12 (127 ) Total available for sale securities $ 8,952,391 $ 8,857,120 $ 42,986 $ (138,257 ) The amortized cost and fair values of available for sale securities at September 30, 2019 , by contractual maturity, are as shown in the following table (dollars in thousands): Less than One Year One to Five Years Six to Ten Years Over Ten Years Total Weighted Average Maturity 1 Fixed maturity debt securities: Amortized cost $ 35,845 $ 1,069,415 $ 1,476,121 $ 599,373 $ 3,180,754 8.29 Fair value 35,806 1,081,571 1,512,308 609,602 3,239,287 Residential mortgage-backed securities: Amortized cost $ 7,665,737 2 Fair value 7,785,264 Total available-for-sale securities: Amortized cost $ 10,846,491 Fair value 11,024,551 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 4.0 years based upon current prepayment assumptions. Sales of available for sale securities resulted in gains and losses as follows (in thousands): Three Months Ended Nine Months Ended September 30, 2019 2018 2019 2018 Proceeds $ 261,028 $ 45,293 $ 628,385 $ 232,826 Gross realized gains 989 250 7,316 700 Gross realized losses (984 ) — (6,206 ) (1,502 ) Related federal and state income tax expense (benefit) 1 64 282 (204 )
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table Text Block]	Temporarily Impaired Available for Sale Securities (in thousands) September 30, 2019 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Available for sale: U.S. Treasury — $ — $ — $ — $ — $ — $ — Mortgage-backed securities: Residential agency 108 931,248 3,260 753,448 7,848 1,684,696 11,108 Commercial agency 57 449,798 1,612 224,409 908 674,207 2,520 Other debt securities 1 — — 472 28 472 28 Total available for sale securities 166 $ 1,381,046 $ 4,872 $ 978,329 $ 8,784 $ 2,359,375 $ 13,656 December 31, 2018 Number of Securities Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Available for sale: U.S. Treasury 1 $ — $ — $ 493 $ 3 $ 493 $ 3 Mortgage-backed securities: Residential agency 289 510,824 1,158 3,641,370 96,606 4,152,194 97,764 Commercial agency 197 179,258 394 1,969,504 39,969 2,148,762 40,363 Other debt securities 3 9,982 63 20,436 64 30,418 127 Total available for sale securities 490 $ 700,064 $ 1,615 $ 5,631,803 $ 136,642 $ 6,331,867 $ 138,257
Fair Value Option Securities [Table Text Block]	The fair value and net unrealized gain (loss) included in fair value option securities is as follows (in thousands): September 30, 2019 December 31, 2018 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. Treasury $ 552,536 $ 927 $ — $ — Residential agency mortgage-backed securities 1,263,862 18,588 283,235 2,766 Total $ 1,816,398 $ 19,515 $ 283,235 $ 2,766

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Sep. 30, 2019
Derivative Instrument Detail [Abstract]
Derivative Contracts [Table Text Block]	The following table summarizes the fair values of derivative contracts recorded as “derivative contracts” assets and liabilities in the balance sheet at September 30, 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 To-be-announced residential mortgage-backed securities $ — $ — $ — $ — $ — $ — Interest rate swaps 2,399,788 67,157 (240 ) 66,917 (277 ) 66,640 Energy contracts 1,980,406 183,204 (59,139 ) 124,065 (66,149 ) 57,916 Agricultural contracts 15,538 470 (302 ) 168 — 168 Foreign exchange contracts 209,515 206,914 — 206,914 — 206,914 Equity option contracts 82,860 3,114 — 3,114 (660 ) 2,454 Total customer risk management programs 4,688,107 460,859 (59,681 ) 401,178 (67,086 ) 334,092 Trading 73,658,685 205,188 (193,306 ) 11,882 — 11,882 Internal risk management programs 433,804 9,037 (2,992 ) 6,045 — 6,045 Total derivative contracts $ 78,780,596 $ 675,084 $ (255,979 ) $ 419,105 $ (67,086 ) $ 352,019 Liabilities Notional¹ 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 To-be-announced residential mortgage-backed securities $ — $ — $ — $ — $ — $ — Interest rate swaps 2,399,788 67,296 (240 ) 67,056 (61,563 ) 5,493 Energy contracts 1,936,369 175,613 (59,139 ) 116,474 (784 ) 115,690 Agricultural contracts 15,547 451 (302 ) 149 — 149 Foreign exchange contracts 200,347 197,807 — 197,807 (433 ) 197,374 Equity option contracts 82,860 3,114 — 3,114 — 3,114 Total customer risk management programs 4,634,911 444,281 (59,681 ) 384,600 (62,780 ) 321,820 Trading 75,247,769 207,542 (193,306 ) 14,236 — 14,236 Internal risk management programs 483,370 5,435 (2,992 ) 2,443 (1,708 ) 735 Total derivative contracts $ 80,366,050 $ 657,258 $ (255,979 ) $ 401,279 $ (64,488 ) $ 336,791 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, 2018 (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 To-be-announced residential mortgage-backed securities $ 10,671,151 $ 92,231 $ (26,787 ) $ 65,444 $ — $ 65,444 Interest rate swaps 1,924,131 36,112 (6,688 ) 29,424 (7,934 ) 21,490 Energy contracts 1,472,209 206,418 (60,983 ) 145,435 (106,752 ) 38,683 Agricultural contracts 21,210 842 (201 ) 641 — 641 Foreign exchange contracts 184,990 183,759 — 183,759 — 183,759 Equity option contracts 89,085 2,021 — 2,021 (648 ) 1,373 Total customer risk management programs 14,362,776 521,383 (94,659 ) 426,724 (115,334 ) 311,390 Trading 15,356,909 45,346 (39,521 ) 5,825 — 5,825 Internal risk management programs 553,079 5,064 (1,350 ) 3,714 — 3,714 Total derivative contracts $ 30,272,764 $ 571,793 $ (135,530 ) $ 436,263 $ (115,334 ) $ 320,929 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 To-be-announced residential mortgage-backed securities $ 10,558,151 $ 90,388 $ (26,787 ) $ 63,601 $ (63,596 ) $ 5 Interest rate swaps 1,924,131 36,288 (6,688 ) 29,600 (4,110 ) 25,490 Energy contracts 1,434,247 202,494 (60,983 ) 141,511 (1,490 ) 140,021 Agricultural contracts 21,214 812 (201 ) 611 — 611 Foreign exchange contracts 177,423 175,922 — 175,922 — 175,922 Equity option contracts 89,085 2,021 — 2,021 — 2,021 Total customer risk management programs 14,204,251 507,925 (94,659 ) 413,266 (69,196 ) 344,070 Trading 19,374,294 56,983 (39,521 ) 17,462 — 17,462 Internal risk management programs 260,348 9,439 (1,350 ) 8,089 (7,315 ) 774 Total derivative contracts $ 33,838,893 $ 574,347 $ (135,530 ) $ 438,817 $ (76,511 ) $ 362,306 1 Notional amounts for commodity contracts are converted into dollar-equivalent amounts based on dollar prices at the inception of the contract.
Derivative Instruments, Gain (Loss) in Statement of Earnings [Table Text Block]	The following summarizes the pre-tax net gains (losses) on derivative instruments and where they are recorded in the income statement (in thousands): Three Months Ended September 30, 2019 September 30, 2018 Brokerage and Trading Revenue Gain (Loss) on Derivatives, Net Brokerage and Trading Revenue Gain (Loss)on Derivatives, Net Customer risk management programs: Interest rate contracts To-be-announced residential mortgage-backed securities $ 1,667 $ — $ 7,272 $ — Interest rate swaps 1,252 — 618 — Energy contracts 1,611 — 541 — Agricultural contracts 16 — 6 — Foreign exchange contracts 138 — 78 — Equity option contracts — — — — Total customer risk management programs 4,684 — 8,515 — Trading 3,630 — 6,124 — Internal risk management programs — 3,778 — (2,847 ) Total derivative contracts $ 8,314 $ 3,778 $ 14,639 $ (2,847 ) Nine Months Ended September 30, 2019 September 30, 2018 Brokerage and Trading Revenue Gain (Loss) on Derivatives, Net Brokerage and Trading Revenue Gain (Loss) on Derivatives, Net Customer risk management programs: Interest rate contracts To-be-announced residential mortgage-backed securities $ 9,579 $ — $ 21,677 $ — Interest rate swaps 2,787 — 2,057 — Energy contracts 3,923 — 5,097 — Agricultural contracts 24 — 36 — Foreign exchange contracts 392 — 350 — Equity option contracts — — — — Total customer risk management programs 16,705 — 29,217 — Trading 4,365 — 3,260 — Internal risk management programs — 19,595 — (11,589 ) Total derivative contracts $ 21,070 $ 19,595 $ 32,477 $ (11,589 )

Loans and Allowances for Cred_2

Loans and Allowances for Credit Losses (Tables)	9 Months Ended
	Sep. 30, 2019
Loans and Leases Receivable, Net Amount [Abstract]
Schedule of Loans by Portfolio Segment [Table Text Block]	Portfolio segments of the loan portfolio are as follows (in thousands): September 30, 2019 December 31, 2018 Fixed Rate Variable Rate Non-accrual Total Fixed Rate Variable Rate Non-accrual Total Commercial $ 3,184,237 $ 11,128,682 $ 111,706 $ 14,424,625 $ 2,251,188 $ 11,285,049 $ 99,841 $ 13,636,078 Commercial real estate 1,070,050 3,532,822 23,185 4,626,057 1,477,274 3,265,918 21,621 4,764,813 Residential mortgage 1,690,286 389,713 37,304 2,117,303 1,830,224 358,254 41,555 2,230,033 Personal 191,827 925,284 271 1,117,382 190,687 834,889 230 1,025,806 Total $ 6,136,400 $ 15,976,501 $ 172,466 $ 22,285,367 $ 5,749,373 $ 15,744,110 $ 163,247 $ 21,656,730 Accruing loans past due (90 days) 1 $ 1,541 $ 1,338 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 for the three months ended September 30, 2019 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 106,397 $ 54,188 $ 15,724 $ 9,388 $ 16,837 $ 202,534 Provision for loan losses 9,861 102 (253 ) 1,911 918 12,539 Loans charged off (9,875 ) — (56 ) (1,776 ) — (11,707 ) Recoveries 260 60 119 627 — 1,066 Ending balance $ 106,643 $ 54,350 $ 15,534 $ 10,150 $ 17,755 $ 204,432 Allowance for off-balance sheet credit losses: Beginning balance $ 1,742 $ 116 $ 44 $ 1 $ — $ 1,903 Provision for off-balance sheet credit losses (536 ) (3 ) — — — (539 ) Ending balance $ 1,206 $ 113 $ 44 $ 1 $ — $ 1,364 Total provision for credit losses $ 9,325 $ 99 $ (253 ) $ 1,911 $ 918 $ 12,000 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 for the nine months ended September 30, 2019 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 102,226 $ 60,026 $ 17,964 $ 9,473 $ 17,768 $ 207,457 Provision for loan losses 34,740 (10,075 ) (2,660 ) 3,434 (13 ) 25,426 Loans charged off (31,728 ) (118 ) (192 ) (4,671 ) — (36,709 ) Recoveries 1,405 4,517 422 1,914 — 8,258 Ending balance $ 106,643 $ 54,350 $ 15,534 $ 10,150 $ 17,755 $ 204,432 Allowance for off-balance sheet credit losses: Beginning balance $ 1,655 $ 52 $ 52 $ 31 $ — $ 1,790 Provision for off-balance sheet credit losses (449 ) 61 (8 ) (30 ) — (426 ) Ending balance $ 1,206 $ 113 $ 44 $ 1 $ — $ 1,364 Total provision for credit losses $ 34,291 $ (10,014 ) $ (2,668 ) $ 3,404 $ (13 ) $ 25,000 The 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 for the three months ended September 30, 2018 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 113,722 $ 58,758 $ 18,544 $ 8,646 $ 15,472 $ 215,142 Provision for loan losses (1,285 ) 1,391 1 883 3,418 4,408 Loans charged off (9,602 ) — (91 ) (1,380 ) — (11,073 ) Recoveries 1,263 40 229 560 — 2,092 Ending balance $ 104,098 $ 60,189 $ 18,683 $ 8,709 $ 18,890 $ 210,569 Allowance for off-balance sheet credit losses: Beginning balance 2,361 17 53 2 — $ 2,433 Provision for off-balance sheet credit losses (424 ) 19 (3 ) — — (408 ) Ending balance $ 1,937 $ 36 $ 50 $ 2 $ — $ 2,025 Total provision for credit losses $ (1,709 ) $ 1,410 $ (2 ) $ 883 $ 3,418 $ 4,000 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 for the nine months ended September 30, 2018 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 124,269 $ 56,621 $ 18,451 $ 9,124 $ 22,217 $ 230,682 Provision for loan losses 2,720 248 (418 ) 1,486 (3,327 ) 709 Loans charged off (24,940 ) — (326 ) (3,802 ) — (29,068 ) Recoveries 2,049 3,320 976 1,901 — 8,246 Ending balance $ 104,098 $ 60,189 $ 18,683 $ 8,709 $ 18,890 $ 210,569 Allowance for off-balance sheet credit losses: Beginning balance $ 3,644 $ 45 $ 43 $ 2 $ — $ 3,734 Provision for off-balance sheet credit losses (1,707 ) (9 ) 7 — — (1,709 ) Ending balance $ 1,937 $ 36 $ 50 $ 2 $ — $ 2,025 Total provision for credit losses $ 1,013 $ 239 $ (411 ) $ 1,486 $ (3,327 ) $ (1,000 ) The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at September 30, 2019 is as follows (in thousands): Collectively Measured for Impairment Individually Measured for Impairment Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 14,312,919 $ 99,110 $ 111,706 $ 7,533 $ 14,424,625 $ 106,643 Commercial real estate 4,602,872 54,350 23,185 — 4,626,057 54,350 Residential mortgage 2,079,999 15,534 37,304 — 2,117,303 15,534 Personal 1,117,111 10,150 271 — 1,117,382 10,150 Total 22,112,901 179,144 172,466 7,533 22,285,367 186,677 Nonspecific allowance — — — — — 17,755 Total $ 22,112,901 $ 179,144 $ 172,466 $ 7,533 $ 22,285,367 $ 204,432 The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at December 31, 2018 is as follows (in thousands): Collectively Measured for Impairment Individually Measured for Impairment Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 13,536,237 $ 93,494 $ 99,841 $ 8,732 $ 13,636,078 $ 102,226 Commercial real estate 4,743,192 60,026 21,621 — 4,764,813 60,026 Residential mortgage 2,188,478 17,964 41,555 — 2,230,033 17,964 Personal 1,025,576 9,473 230 — 1,025,806 9,473 Total 21,493,483 180,957 163,247 8,732 21,656,730 189,689 Nonspecific allowance — — — — — 17,768 Total $ 21,493,483 $ 180,957 $ 163,247 $ 8,732 $ 21,656,730 $ 207,457
Schedule of Credit Quality Indicators [Table Text Block]	The allowance for loan losses and recorded investment of the related loans by portfolio segment for risk graded and non-risk graded loans at September 30, 2019 is as follows (in thousands): Internally Risk Graded Non-Graded Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 14,396,278 $ 105,714 $ 28,347 $ 929 $ 14,424,625 $ 106,643 Commercial real estate 4,626,057 54,350 — — 4,626,057 54,350 Residential mortgage 283,297 3,375 1,834,006 12,159 2,117,303 15,534 Personal 1,032,522 7,836 84,860 2,314 1,117,382 10,150 Total 20,338,154 171,275 1,947,213 15,402 22,285,367 186,677 Nonspecific allowance — — — — — 17,755 Total $ 20,338,154 $ 171,275 $ 1,947,213 $ 15,402 $ 22,285,367 $ 204,432 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, 2018 is as follows (in thousands): Internally Risk Graded Non-Graded Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 13,586,654 $ 101,303 $ 49,424 $ 923 $ 13,636,078 $ 102,226 Commercial real estate 4,764,813 60,026 — — 4,764,813 60,026 Residential mortgage 505,046 3,310 1,724,987 14,654 2,230,033 17,964 Personal 948,890 6,633 76,916 2,840 1,025,806 9,473 Total 19,805,403 171,272 1,851,327 18,417 21,656,730 189,689 Nonspecific allowance — — — — — 17,768 Total $ 19,805,403 $ 171,272 $ 1,851,327 $ 18,417 $ 21,656,730 $ 207,457 Loans are considered to be performing if they 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.” Performing loans also include 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 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. The risk grading process identified certain loans that have a well-defined weakness (e.g. 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 were not placed in nonaccruing status. Nonaccruing loans represent loans for which full collection of principal and interest is uncertain. This is substantially the same criteria used to determine whether a loan is impaired and includes certain loans considered “substandard” and all loans considered “doubtful” by regulatory guidelines. The following table summarizes the Company’s loan portfolio at September 30, 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 $ 3,927,285 $ 60,405 $ 37,685 $ 88,894 $ — $ — $ 4,114,269 Services 3,185,367 38,118 36,645 6,119 — — 3,266,249 Wholesale/retail 1,829,614 9,757 7,742 1,504 — — 1,848,617 Manufacturing 652,804 24,229 12,634 8,741 — — 698,408 Healthcare 2,984,306 25,205 17,479 5,978 — — 3,032,968 Public finance 744,840 — — — — — 744,840 Other commercial and industrial 671,819 2,053 16,632 423 28,300 47 719,274 Total commercial 13,996,035 159,767 128,817 111,659 28,300 47 14,424,625 Commercial real estate: Residential construction and land development 135,011 — — 350 — — 135,361 Retail 765,708 12,067 1,262 20,132 — — 799,169 Office 1,007,136 5,203 1,081 855 — — 1,014,275 Multifamily 1,316,856 1,196 6,501 286 — — 1,324,839 Industrial 872,627 — — 909 — — 873,536 Other commercial real estate 474,465 784 2,975 653 — — 478,877 Total commercial real estate 4,571,803 19,250 11,819 23,185 — — 4,626,057 Residential mortgage: Permanent mortgage 280,243 326 2,191 537 763,535 19,628 1,066,460 Permanent mortgages guaranteed by U.S. government agencies — — — — 185,432 6,332 191,764 Home equity — — — — 848,272 10,807 859,079 Total residential mortgage 280,243 326 2,191 537 1,797,239 36,767 2,117,303 Personal 1,032,381 46 33 63 84,651 208 1,117,382 Total $ 19,880,462 $ 179,389 $ 142,860 $ 135,444 $ 1,910,190 $ 37,022 $ 22,285,367 The following table summarizes the Company’s loan portfolio at December 31, 2018 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 $ 3,414,039 $ 42,176 $ 86,624 $ 47,494 $ — $ — $ 3,590,333 Services 3,167,203 49,761 32,661 8,567 — — 3,258,192 Wholesale/retail 1,593,902 18,809 7,131 1,316 — — 1,621,158 Manufacturing 668,438 30,934 22,230 8,919 — — 730,521 Healthcare 2,730,121 14,920 37,698 16,538 — — 2,799,277 Public finance 804,550 — — — — — 804,550 Other commercial and industrial 756,815 1,266 7,588 16,954 49,371 53 832,047 Total commercial 13,135,068 157,866 193,932 99,788 49,371 53 13,636,078 Commercial real estate: Residential construction and land development 148,234 — — 350 — — 148,584 Retail 885,588 11,926 1,289 20,279 — — 919,082 Office 1,059,334 10,532 3,054 — — — 1,072,920 Multifamily 1,287,471 281 12 301 — — 1,288,065 Industrial 776,898 — 1,208 — — — 778,106 Other commercial real estate 555,301 1,188 876 691 — — 558,056 Total commercial real estate 4,712,826 23,927 6,439 21,621 — — 4,764,813 Residential mortgage: Permanent mortgage 269,678 52 9,730 1,991 819,199 21,960 1,122,610 Permanent mortgages guaranteed by U.S. government agencies — — — — 183,734 7,132 190,866 Home equity 223,298 — 296 — 682,491 10,472 916,557 Total residential mortgage 492,976 52 10,026 1,991 1,685,424 39,564 2,230,033 Personal 944,256 115 4,443 76 76,762 154 1,025,806 Total $ 19,285,126 $ 181,960 $ 214,840 $ 123,476 $ 1,811,557 $ 39,771 $ 21,656,730
Summary of Impaired Loans [Table Text Block]	Impaired Loans Loans are considered to be impaired when it is probable that the Company will not be able to collect all amounts due according to the contractual terms of the loan agreement. This generally includes all nonaccruing loans, all loans modified in a TDR and all loans repurchased from GNMA pools. A summary of impaired loans at September 30, 2019 follows (in thousands): As of For the For the September 30, 2019 Three Months Ended Nine Months Ended Recorded Investment September 30, 2019 September 30, 2019 Unpaid Principal Balance Total With No With Allowance Related Allowance Average Recorded Interest Income Recognized Average Recorded Interest Income Recognized Commercial: Energy $ 139,897 $ 88,894 $ 62,981 $ 25,913 $ 7,176 $ 80,263 $ — $ 67,705 $ — Services 9,390 6,119 6,093 26 26 8,103 — 5,172 — Wholesale/retail 1,718 1,504 1,243 261 101 1,447 — 1,087 — Manufacturing 1 9,153 8,741 8,511 230 230 8,677 — 8,448 — Healthcare 17,786 5,978 5,978 — — 11,063 — 8,547 — Public finance — — — — — — — — — Other commercial and industrial 8,261 470 470 — — 7,998 — 8,585 — Total commercial 186,205 111,706 85,276 26,430 7,533 117,551 — 99,544 — Commercial real estate: Residential construction and land development 1,306 350 350 — — 350 — 350 — Retail 20,516 20,132 20,132 — — 20,094 — 20,206 — Office 855 855 855 — — 855 — 427 — Multifamily 286 286 286 — — 281 — 294 — Industrial 909 909 909 — — 454 — 454 — Other commercial real estate 813 653 653 — — 393 — 672 — Total commercial real estate 24,685 23,185 23,185 — — 22,427 — 22,403 — Residential mortgage: Permanent mortgage 24,639 20,165 20,165 — — 20,984 280 22,058 894 Permanent mortgage guaranteed by U.S. government agencies 2 197,847 191,764 191,764 — — 196,310 2,020 194,751 5,863 Home equity 12,621 10,807 10,807 — — 10,369 — 10,639 — Total residential mortgage 235,107 222,736 222,736 — — 227,663 2,300 227,448 6,757 Personal 338 271 271 — — 254 — 251 — Total $ 446,335 $ 357,898 $ 331,468 $ 26,430 $ 7,533 $ 367,895 $ 2,300 $ 349,646 $ 6,757 1 Impaired manufacturing sector loans included $4.7 million of loans from an affiliated entity, with no allowance as the fair value of the collateral exceeded the outstanding principal balance at September 30, 2019 . 2 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 September 30, 2019 , the majority were accruing based on the guarantee by U.S. government agencies. Generally, no interest income is recognized on impaired loans until all principal balances, including amounts charged-off, are recovered. A summary of impaired loans at December 31, 2018 follows (in thousands): Recorded Investment Unpaid Principal Balance Total With No Allowance With Allowance Related Allowance Commercial: Energy $ 79,675 $ 47,494 $ 18,639 $ 28,855 $ 5,362 Services 13,437 8,567 8,489 78 74 Wholesale/retail 1,722 1,316 1,015 301 101 Manufacturing 10,055 8,919 8,673 246 246 Healthcare 24,319 16,538 10,563 5,975 2,949 Public finance — — — — — Other commercial and industrial 26,955 17,007 17,007 — — Total commercial 156,163 99,841 64,386 35,455 8,732 Commercial real estate: Residential construction and land development 1,306 350 350 — — Retail 27,680 20,279 20,279 — — Office — — — — — Multifamily 301 301 301 — — Industrial — — — — — Other commercial real estate 851 691 691 — — Total commercial real estate 30,138 21,621 21,621 — — Residential mortgage: Permanent mortgage 28,716 23,951 23,951 — — Permanent mortgage guaranteed by U.S. government agencies 1 196,296 190,866 190,866 — — Home equity 12,196 10,472 10,472 — — Total residential mortgage 237,208 225,289 225,289 — — Personal 278 230 230 — — Total $ 423,787 $ 346,981 $ 311,526 $ 35,455 $ 8,732 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, 2018 , 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, loans past due and accruing and nonaccrual loans as of September 30, 2019 is as follows (in thousands): Past Due Current 30 to 59 Days 60 to 89 Days 90 Days or More Nonaccrual Total Commercial: Energy $ 4,025,375 $ — $ — $ — $ 88,894 $ 4,114,269 Services 3,249,994 7,305 2,096 735 6,119 3,266,249 Wholesale/retail 1,844,203 2,910 — — 1,504 1,848,617 Manufacturing 687,358 2,309 — — 8,741 698,408 Healthcare 3,026,838 94 2 56 5,978 3,032,968 Public finance 744,840 — — — — 744,840 Other commercial and industrial 718,419 337 48 — 470 719,274 Total commercial 14,297,027 12,955 2,146 791 111,706 14,424,625 Commercial real estate: Residential construction and land development 134,947 — — 64 350 135,361 Retail 779,037 — — — 20,132 799,169 Office 1,013,420 — — — 855 1,014,275 Multifamily 1,318,148 6,405 — — 286 1,324,839 Industrial 872,627 — — — 909 873,536 Other commercial real estate 477,126 335 106 657 653 478,877 Total commercial real estate 4,595,305 6,740 106 721 23,185 4,626,057 Residential mortgage: Permanent mortgage 1,036,793 6,097 3,405 — 20,165 1,066,460 Permanent mortgages guaranteed by U.S. government agencies 47,207 23,412 21,676 93,137 6,332 191,764 Home equity 845,616 2,282 374 — 10,807 859,079 Total residential mortgage 1,929,616 31,791 25,455 93,137 37,304 2,117,303 Personal 1,116,888 100 94 29 271 1,117,382 Total $ 21,938,836 $ 51,586 $ 27,801 $ 94,678 $ 172,466 $ 22,285,367 A summary of loans currently performing, loans past due and accruing and nonaccrual loans as of December 31, 2018 is as follows (in thousands): Past Due Current 30 to 59 Days 60 to 89 Days 90 Days or More Nonaccrual Total Commercial: Energy $ 3,542,839 $ — $ — $ — $ 47,494 $ 3,590,333 Services 3,237,578 6,009 6,038 — 8,567 3,258,192 Wholesale/retail 1,619,290 515 37 — 1,316 1,621,158 Manufacturing 721,204 392 6 — 8,919 730,521 Healthcare 2,781,944 241 — 554 16,538 2,799,277 Public finance 804,550 — — — — 804,550 Other commercial and industrial 814,489 518 25 8 17,007 832,047 Total commercial 13,521,894 7,675 6,106 562 99,841 13,636,078 Commercial real estate: Residential construction and land development 147,705 249 280 — 350 148,584 Retail 884,424 14,379 — — 20,279 919,082 Office 1,072,920 — — — — 1,072,920 Multifamily 1,287,483 281 — — 301 1,288,065 Industrial 776,898 1,208 — — — 778,106 Other commercial real estate 556,239 412 — 714 691 558,056 Total commercial real estate 4,725,669 16,529 280 714 21,621 4,764,813 Residential mortgage: Permanent mortgage 1,095,097 3,196 366 — 23,951 1,122,610 Permanent mortgages guaranteed by U.S. government agencies 37,459 24,369 16,345 105,561 7,132 190,866 Home equity 904,572 1,102 352 59 10,472 916,557 Total residential mortgage 2,037,128 28,667 17,063 105,620 41,555 2,230,033 Personal 1,024,298 479 796 3 230 1,025,806 Total $ 21,308,989 $ 53,350 $ 24,245 $ 106,899 $ 163,247 $ 21,656,730

Mortgage Banking Activities (Ta

Mortgage Banking Activities (Tables)	9 Months Ended
	Sep. 30, 2019
Mortgage Banking [Abstract]
Components of Residential Mortgage Loans Held For Sale [Table Text Block]	September 30, 2019 December 31, 2018 Unpaid Principal Balance/ Notional Fair Value Unpaid Principal Balance/ Notional Fair Value Residential mortgage loans held for sale $ 269,610 $ 272,489 $ 145,057 $ 146,971 Residential mortgage loan commitments 379,377 10,111 160,848 5,378 Forward sales contracts 649,161 (113 ) 274,000 (3,128 ) $ 282,487 $ 149,221
Mortgage Banking Revenue [Table Text Block]	Mortgage banking revenue was as follows (in thousands): Three Months Ended Nine Months Ended September 30, 2019 2018 2019 2018 Production revenue: Net realized gains on sale of mortgage loans $ 8,971 $ 9,063 $ 24,838 $ 28,699 Net change in unrealized gain on mortgage loans held for sale 97 (2,135 ) 965 (2,457 ) Net change in the fair value of mortgage loan commitments 514 (2,446 ) 4,733 (1,496 ) Net change in the fair value of forward sales contracts 4,232 2,768 3,015 1,871 Total production revenue 13,814 7,250 33,551 26,617 Servicing revenue 16,366 16,286 48,594 49,290 Total mortgage banking revenue $ 30,180 $ 23,536 $ 82,145 $ 75,907
Summary of Mortgage Servicing Rights [Table Text Block]	The following represents a summary of mortgage servicing rights (dollars in thousands): September 30, 2019 December 31, 2018 Number of residential mortgage loans serviced for others 128,463 132,463 Outstanding principal balance of residential mortgage loans serviced for others $ 21,046,136 $ 21,658,335 Weighted average interest rate 3.99 % 3.99 % Remaining term (in months) 290 293
Activity in Capitalized Mortgage Servicing Rights [Table Text Block]	The following represents activity in capitalized mortgage servicing rights (in thousands): Three Months Ended Nine Months Ended September 30, 2019 2018 2019 2018 Beginning Balance $ 208,308 $ 278,719 $ 259,254 $ 252,867 Additions, net 9,882 8,968 24,821 28,688 Change in fair value due to principal payments (11,936 ) (8,986 ) (27,600 ) (25,783 ) Change in fair value due to market assumption changes (12,593 ) 5,972 (62,814 ) 28,901 Ending Balance $ 193,661 $ 284,673 $ 193,661 $ 284,673
Assumptions to Value Mortgage Servicing Rights [Table Text Block]	Mortgage servicing rights are not traded in active markets. Fair value is determined by discounting the projected net cash flows. Significant market assumptions used to determine fair value based on significant unobservable inputs were as follows: September 30, 2019 December 31, 2018 Discount rate – risk-free rate plus a market premium 9.82% 9.90% Prepayment rate - based upon loan interest rate, original term and loan type 8.31% - 17.22% 8.05% - 15.74% Loan servicing costs – annually per loan based upon loan type: Performing loans $68 - $94 $67 - $93 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 1.51% 2.57% Primary/secondary mortgage rate spread 102 bps 105 bps

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2019
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, December 31, 2017 $ (35,385 ) $ (789 ) $ (36,174 ) Transition adjustment for net unrealized gains on equity securities (2,709 ) — (2,709 ) Net change in unrealized gain (loss) (166,464 ) — (166,464 ) Reclassification adjustments included in earnings: Loss on available for sale securities, net 802 — 802 Other comprehensive loss, before income taxes (165,662 ) — (165,662 ) Federal and state income taxes 1 (42,183 ) — (42,183 ) Other comprehensive loss, net of income taxes (123,479 ) — (123,479 ) Balance, September 30, 2018 $ (161,573 ) $ (789 ) $ (162,362 ) Balance, December 31, 2018 $ (70,999 ) $ (1,586 ) $ (72,585 ) Net change in unrealized gain (loss) 274,441 — 274,441 Reclassification adjustments included in earnings: Gain on available for sale securities, net (1,110 ) — (1,110 ) Other comprehensive income, before income taxes 273,331 — 273,331 Federal and state income taxes 1 66,993 — 66,993 Other comprehensive income, net of income taxes 206,338 — 206,338 Balance, September 30, 2019 $ 135,339 $ (1,586 ) $ 133,753 1 Calculated using a 25 percent blended federal and state statutory tax rate.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Share [Table Text Block]	(In thousands, except share and per share amounts) Three Months Ended Nine Months Ended September 30, 2019 2018 2019 2018 Numerator: Net income attributable to BOK Financial Corp. shareholders $ 142,231 $ 117,256 $ 390,406 $ 337,190 Less: Earnings allocated to participating securities 875 963 2,553 2,940 Numerator for basic earnings per share – income available to common shareholders 141,356 116,293 387,853 334,250 Effect of reallocating undistributed earnings of participating securities 1 1 1 1 Numerator for diluted earnings per share – income available to common shareholders $ 141,357 $ 116,294 $ 387,854 $ 334,251 Denominator: Weighted average shares outstanding 71,033,405 65,438,849 71,425,855 65,455,306 Less: Participating securities included in weighted average shares outstanding 437,098 537,754 472,311 571,987 Denominator for basic earnings per common share 70,596,307 64,901,095 70,953,544 64,883,319 Dilutive effect of employee stock compensation plans 1 13,617 33,256 15,301 36,409 Denominator for diluted earnings per common share 70,609,924 64,934,351 70,968,845 64,919,728 Basic earnings per share $ 2.00 $ 1.79 $ 5.47 $ 5.15 Diluted earnings per share $ 2.00 $ 1.79 $ 5.47 $ 5.15 1 Excludes employee stock options with exercise prices greater than current market price. — — — —

Reportable Segments (Tables)

Reportable Segments (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Reportable Segments [Table Text Block]	Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended September 30, 2019 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 243,944 $ 27,580 $ 12,343 $ (4,771 ) $ 279,096 Net interest revenue (expense) from internal sources (63,797 ) 20,882 10,723 32,192 — Net interest revenue 180,147 48,462 23,066 27,421 279,096 Provision for credit losses 9,505 1,841 (42 ) 696 12,000 Net interest revenue after provision for credit losses 170,642 46,621 23,108 26,725 267,096 Other operating revenue 48,832 51,221 89,160 (2,763 ) 186,450 Other operating expense 68,685 59,699 71,619 79,289 279,292 Net direct contribution 150,789 38,143 40,649 (55,327 ) 174,254 Gain on financial instruments, net 28 8,339 — (8,367 ) — Change in fair value of mortgage servicing rights — (12,593 ) — 12,593 — Gain on repossessed assets, net 802 214 — (1,016 ) — Corporate expense allocations 12,613 11,776 9,416 (33,805 ) — Net income before taxes 139,006 22,327 31,233 (18,312 ) 174,254 Federal and state income taxes 37,433 5,687 8,027 (18,751 ) 32,396 Net income 101,573 16,640 23,206 439 141,858 Net income (loss) attributable to non-controlling interests — — — (373 ) (373 ) Net income attributable to BOK Financial Corp. shareholders $ 101,573 $ 16,640 $ 23,206 $ 812 $ 142,231 Average assets $ 23,973,067 $ 9,827,130 $ 10,392,988 $ (611,075 ) $ 43,582,110 Reportable segments reconciliation to the Consolidated Financial Statements for the nine months ended September 30, 2019 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other 1 BOK Financial Consolidated Net interest revenue from external sources $ 699,239 $ 75,353 $ 51,054 $ 16,984 $ 842,630 Net interest revenue (expense) from internal sources (181,829 ) 76,925 27,213 77,691 — Net interest revenue 517,410 152,278 78,267 94,675 842,630 Provision for credit losses 27,574 4,654 (209 ) (7,019 ) 25,000 Net interest revenue after provision for credit losses 489,836 147,624 78,476 101,694 817,630 Other operating revenue 128,055 142,780 248,591 (3,641 ) 515,785 Other operating expense 181,809 171,214 202,579 287,984 843,586 Net direct contribution 436,082 119,190 124,488 (189,931 ) 489,829 Gain on financial instruments, net 67 43,416 — (43,483 ) — Change in fair value of mortgage servicing rights — (62,814 ) — 62,814 — Gain on repossessed assets, net 455 409 — (864 ) — Corporate expense allocations 34,146 35,369 26,943 (96,458 ) — Net income before taxes 402,458 64,832 97,545 (75,006 ) 489,829 Federal and state income taxes 107,807 16,513 25,076 (49,470 ) 99,926 Net income 294,651 48,319 72,469 (25,536 ) 389,903 Net income (loss) attributable to non-controlling interests — — — (503 ) (503 ) Net income attributable to BOK Financial Corp. shareholders $ 294,651 $ 48,319 $ 72,469 $ (25,033 ) $ 390,406 Average assets $ 22,288,129 $ 9,142,491 $ 9,861,021 $ 89,202 $ 41,380,843 1 CoBiz operations are included in Funds Management and Other for the first quarter of 2019 and subsequently allocated to the respective segments in the second quarter of 2019. Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended September 30, 2018 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 187,417 $ 20,005 $ 22,509 $ 10,952 $ 240,883 Net interest revenue (expense) from internal sources (42,270 ) 19,039 6,267 16,964 — Net interest revenue 145,147 39,044 28,776 27,916 240,883 Provision for credit losses 8,047 1,451 (84 ) (5,414 ) 4,000 Net interest revenue after provision for credit losses 137,100 37,593 28,860 33,330 236,883 Other operating revenue 40,522 44,024 83,357 38 167,941 Other operating expense 51,039 58,482 62,256 80,840 252,617 Net direct contribution 126,583 23,135 49,961 (47,472 ) 152,207 Gain (loss) on financial instruments, net (3 ) (7,229 ) 7 7,225 — Change in fair value of mortgage servicing rights — 5,972 — (5,972 ) — Gain (loss) on repossessed assets, net (1,869 ) (87 ) — 1,956 — Corporate expense allocations 9,124 11,037 11,127 (31,288 ) — Net income before taxes 115,587 10,754 38,841 (12,975 ) 152,207 Federal and state income taxes 30,623 2,739 9,975 (8,675 ) 34,662 Net income 84,964 8,015 28,866 (4,300 ) 117,545 Net income attributable to non-controlling interests — — — 289 289 Net income (loss) attributable to BOK Financial Corp. shareholders $ 84,964 $ 8,015 $ 28,866 $ (4,589 ) $ 117,256 Average assets $ 18,499,979 $ 8,323,543 $ 8,498,363 $ (1,626,068 ) $ 33,695,817 Reportable segments reconciliation to the Consolidated Financial Statements for the nine months ended September 30, 2018 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 529,958 $ 63,504 $ 56,990 $ 48,729 $ 699,181 Net interest revenue (expense) from internal sources (107,715 ) 51,811 26,431 29,473 — Net interest revenue 422,243 115,315 83,421 78,202 699,181 Provision for credit losses 18,781 3,890 (238 ) (23,433 ) (1,000 ) Net interest revenue after provision for credit losses 403,462 111,425 83,659 101,635 700,181 Other operating revenue 123,245 135,291 228,766 (6,973 ) 480,329 Other operating expense 148,796 174,728 188,691 231,308 743,523 Net direct contribution 377,911 71,988 123,734 (136,646 ) 436,987 Gain (loss) on financial instruments, net 13 (36,901 ) 7 36,881 — Change in fair value of mortgage servicing rights — 28,901 — (28,901 ) — Gain (loss) on repossessed assets, net (6,102 ) (21 ) — 6,123 — Corporate expense allocations 29,092 33,283 31,084 (93,459 ) — Net income before taxes 342,730 30,684 92,657 (29,084 ) 436,987 Federal and state income taxes 90,943 7,816 23,824 (23,643 ) 98,940 Net income 251,787 22,868 68,833 (5,441 ) 338,047 Net income attributable to non-controlling interests — — — 857 857 Net income attributable to BOK Financial Corp. shareholders $ 251,787 $ 22,868 $ 68,833 $ (6,298 ) $ 337,190 Average assets $ 18,124,571 $ 8,381,205 $ 8,364,712 $ (1,094,993 ) $ 33,775,495

Fees and Commissions Revenue _2

Fees and Commissions Revenue Fees and Commissions Rvenue (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Fees and Commissions Revenue [Table Text Block]	Fees and commissions revenue by reportable segment and primary service line is as follows for the three months ended September 30, 2019 . Commercial Consumer Wealth Management Funds Management & Other 3 Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 24,091 $ — $ 24,091 $ 24,091 $ — Customer hedging revenue 2,283 — 1,810 591 4,684 4,684 — Retail brokerage revenue — — 4,204 — 4,204 — 4,204 Insurance brokerage revenue — — 3,375 (513 ) 2,862 — 2,862 Investment banking revenue 4,408 — 3,590 1 7,999 3,762 4,237 Brokerage and trading revenue 6,691 — 37,070 79 43,840 32,537 11,303 TransFund EFT network revenue 18,465 1,020 (23 ) 2 19,464 — 19,464 Merchant services revenue 2,203 14 — — 2,217 — 2,217 Corporate card revenue 328 — 6 — 334 — 334 Transaction card revenue 20,996 1,034 (17 ) 2 22,015 — 22,015 Personal trust revenue — — 20,239 (1 ) 20,238 — 20,238 Corporate trust revenue — — 6,204 1 6,205 — 6,205 Institutional trust & retirement plan services revenue — — 10,740 — 10,740 — 10,740 Investment management services and other revenue — — 6,480 (42 ) 6,438 — 6,438 Fiduciary and asset management revenue — — 43,663 (42 ) 43,621 — 43,621 Commercial account service charge revenue 10,609 467 540 (3 ) 11,613 — 11,613 Overdraft fee revenue 81 9,603 45 3 9,732 — 9,732 Check card revenue — 5,721 — — 5,721 — 5,721 Automated service charge and other deposit fee revenue 197 1,519 53 2 1,771 — 1,771 Deposit service charges and fees 10,887 17,310 638 2 28,837 — 28,837 Mortgage production revenue — 13,815 — (1 ) 13,814 13,814 — Mortgage servicing revenue — 16,828 — (462 ) 16,366 16,366 — Mortgage banking revenue — 30,643 — (463 ) 30,180 30,180 — Other revenue 7,585 2,474 8,068 (501 ) 17,626 11,812 5,814 Total fees and commissions revenue $ 46,159 $ 51,461 $ 89,422 $ (923 ) $ 186,119 $ 74,529 $ 111,590 1 Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance. 2 In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers. 3 CoBiz operations are included in Funds Management and Other for the first quarter of 2019. Fees and commissions revenue by reportable segment and primary service line is as follows for the nine months ended September 30, 2019 . Commercial Consumer Wealth Management Funds Management & Other 3 Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 58,890 $ — $ 58,890 $ 58,890 $ — Customer hedging revenue 6,243 — 9,444 1,019 16,706 16,706 — Retail brokerage revenue — — 12,192 (65 ) 12,127 — 12,127 Insurance brokerage revenue — — 7,063 3,729 10,792 — 10,792 Investment banking revenue 8,345 — 9,123 — 17,468 7,189 10,279 Brokerage and trading revenue 14,588 — 96,712 4,683 115,983 82,785 33,198 TransFund EFT network revenue 54,623 2,975 (60 ) 3 57,541 — 57,541 Merchant services revenue 6,351 43 — 122 6,516 — 6,516 Corporate card revenue 598 — 11 2 611 — 611 Transaction card revenue 61,572 3,018 (49 ) 127 64,668 — 64,668 Personal trust revenue — — 61,028 — 61,028 — 61,028 Corporate trust revenue — — 18,736 — 18,736 — 18,736 Institutional trust & retirement plan services revenue — — 32,919 — 32,919 — 32,919 Investment management services and other revenue — — 17,730 1,591 19,321 — 19,321 Fiduciary and asset management revenue — — 130,413 1,591 132,004 — 132,004 Commercial account service charge revenue 31,296 1,283 1,605 1,804 35,988 — 35,988 Overdraft fee revenue 248 26,971 108 (231 ) 27,096 — 27,096 Check card revenue — 16,299 — 165 16,464 — 16,464 Automated service charge and other deposit fee revenue 569 4,762 228 47 5,606 — 5,606 Deposit service charges and fees 32,113 49,315 1,941 1,785 85,154 — 85,154 Mortgage production revenue — 33,554 — (3 ) 33,551 33,551 — Mortgage servicing revenue — 50,014 — (1,420 ) 48,594 48,594 — Mortgage banking revenue — 83,568 — (1,423 ) 82,145 82,145 — Other revenue 17,037 7,211 19,586 (1,009 ) 42,825 28,655 14,170 Total fees and commissions revenue $ 125,310 $ 143,112 $ 248,603 $ 5,754 $ 522,779 $ 193,585 $ 329,194 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 three months ended September 30, 2018 . Commercial Consumer Wealth Management Funds Management & Other Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 4,830 $ — $ 4,830 $ 4,830 $ — Customer hedging revenue 1,350 — 6,935 229 8,514 8,514 — Retail brokerage revenue — — 4,398 (73 ) 4,325 — 4,325 Insurance brokerage revenue — — 170 — 170 — 170 Investment banking revenue 1,765 — 3,482 — 5,247 1,410 3,837 Brokerage and trading revenue 3,115 — 19,815 156 23,086 14,754 8,332 TransFund EFT network revenue 18,397 1,009 (21 ) 2 19,387 — 19,387 Merchant services revenue 1,995 14 — — 2,009 — 2,009 Corporate card revenue — — — — — — — Transaction card revenue 20,392 1,023 (21 ) 2 21,396 — 21,396 Personal trust revenue — — 35,822 1 35,823 — 35,823 Corporate trust revenue — — 5,741 — 5,741 — 5,741 Institutional trust & retirement plan services revenue — — 11,095 (1 ) 11,094 — 11,094 Investment management services and other revenue — — 4,903 (47 ) 4,856 — 4,856 Fiduciary and asset management revenue — — 57,561 (47 ) 57,514 — 57,514 Commercial account service charge revenue 10,294 366 587 (3 ) 11,244 — 11,244 Overdraft fee revenue 95 9,413 30 3 9,541 — 9,541 Check card revenue — 5,254 — — 5,254 — 5,254 Automated service charge and other deposit fee revenue 35 1,661 22 8 1,726 — 1,726 Deposit service charges and fees 10,424 16,694 639 8 27,765 — 27,765 Mortgage production revenue — 7,250 — — 7,250 7,250 — Mortgage servicing revenue — 16,748 — (462 ) 16,286 16,286 — Mortgage banking revenue — 23,998 — (462 ) 23,536 23,536 — Other revenue 5,460 2,323 5,568 (451 ) 12,900 8,799 4,101 Total fees and commissions revenue $ 39,391 $ 44,038 $ 83,562 $ (794 ) $ 166,197 $ 47,089 $ 119,108 1 Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance. 2 In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers. Fees and commissions revenue by reportable segment and primary service line is as follows for the nine months ended September 30, 2018 . Commercial Consumer Wealth Management Funds Management & Other Consolidated Out of Scope 1 In Scope 2 Trading revenue $ — $ — $ 21,562 $ — $ 21,562 $ 21,562 $ — Customer hedging revenue 6,264 — 21,511 1,441 29,216 29,216 — Retail brokerage revenue — — 13,751 (246 ) 13,505 — 13,505 Insurance brokerage revenue — — 555 — 555 — 555 Investment banking revenue 5,729 — 9,655 — 15,384 4,772 10,612 Brokerage and trading revenue 11,993 — 67,034 1,195 80,222 55,550 24,672 TransFund EFT network revenue 54,647 3,005 (61 ) 5 57,596 — 57,596 Merchant services revenue 5,720 45 — — 5,765 — 5,765 Corporate card revenue — — — — — — — Transaction card revenue 60,367 3,050 (61 ) 5 63,361 — 63,361 Personal trust revenue — — 76,481 (2 ) 76,479 — 76,479 Corporate trust revenue — — 16,317 — 16,317 — 16,317 Institutional trust & retirement plan services revenue — — 33,584 3 33,587 — 33,587 Investment management services and other revenue — — 14,808 (153 ) 14,655 — 14,655 Fiduciary and asset management revenue — — 141,190 (152 ) 141,038 — 141,038 Commercial account service charge revenue 32,150 1,087 1,802 (3 ) 35,036 — 35,036 Overdraft fee revenue 283 26,665 96 13 27,057 — 27,057 Check card revenue — 15,515 — — 15,515 — 15,515 Automated service charge and other deposit fee revenue 110 4,953 72 17 5,152 — 5,152 Deposit service charges and fees 32,543 48,220 1,970 27 82,760 — 82,760 Mortgage production revenue — 26,617 — — 26,617 26,617 — Mortgage servicing revenue — 50,677 — (1,387 ) 49,290 49,290 — Mortgage banking revenue — 77,294 — (1,387 ) 75,907 75,907 — Other revenue 17,379 6,770 18,725 (3,093 ) 39,781 27,552 12,229 Total fees and commissions revenue $ 122,282 $ 135,334 $ 228,858 $ (3,405 ) $ 483,069 $ 159,009 $ 324,060 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.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Assets And Liabilities Measured On A Recurring Basis [Table Text Block]	The fair value of financial assets and liabilities measured on a recurring basis was as follows as of September 30, 2019 (in thousands): Total Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Trading securities: U.S. government agency debentures $ 63,334 $ — $ 63,334 $ — Residential agency mortgage-backed securities 1,480,458 — 1,480,458 — Municipal and other tax-exempt securities 44,105 — 44,105 — Asset-backed securities 36,928 — 36,928 — Other trading securities 50,387 — 50,387 — Total trading securities 1,675,212 — 1,675,212 — Available for sale securities: U.S. Treasury 2,296 2,296 — — Municipal and other tax-exempt securities 1,848 — 1,848 — Residential agency mortgage-backed securities 7,740,461 — 7,740,461 — Residential non-agency mortgage-backed securities 44,803 — 44,803 — Commercial agency mortgage-backed securities 3,234,671 — 3,234,671 — Other debt securities 472 — — 472 Total available for sale securities 11,024,551 2,296 11,021,783 472 Fair value option securities: U.S. Treasury 552,536 552,536 — — Residential agency mortgage-backed securities 1,263,862 — 1,263,862 — Total fair value option securities 1,816,398 552,536 1,263,862 — Residential mortgage loans held for sale 282,487 — 268,919 13,568 Mortgage servicing rights 1 193,661 — — 193,661 Derivative contracts, net of cash collateral 2 352,019 40,491 311,528 — Liabilities: Derivative contracts, net of cash collateral 2 336,791 — 336,791 — 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 6 , 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, interest rate and agricultural 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 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, 2018 (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 $ 63,765 $ — $ 63,765 $ — Residential agency mortgage-backed securities 1,791,584 — 1,791,584 — Municipal and other tax-exempt securities 34,507 — 34,507 — Asset-backed securities 42,656 — 42,656 — Other trading securities 24,411 — 24,411 — Total trading securities 1,956,923 — 1,956,923 — Available for sale securities: U.S. Treasury 493 493 — — Municipal and other tax-exempt securities 2,864 — 2,864 — Residential agency mortgage-backed securities 5,804,708 — 5,804,708 — Residential non-agency mortgage-backed securities 59,736 — 59,736 — Commercial agency mortgage-backed securities 2,953,889 — 2,953,889 — Other debt securities 35,430 — 34,958 472 Total available for sale securities 8,857,120 493 8,856,155 472 Fair value option securities – Residential agency mortgage-backed securities 283,235 — 283,235 — Residential mortgage loans held for sale 149,221 — 134,014 15,207 Mortgage servicing rights 1 259,254 — — 259,254 Derivative contracts, net of cash collateral 2 320,929 44,074 276,855 — Liabilities: Derivative contracts, net of cash collateral 2 362,306 — 362,306 — 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 6 , 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, energy and agricultural 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 contracts, fully offset by cash margin.
Fair Value Assets Measured On Recurring Basis, Significant Unobservable Inputs [Table Text Block]	The following represents the changes for the three and nine months ended September 30, 2019 related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands): Available for sale - Other debt securities Residential mortgage loans held for sale Balance, June 30, 2019 $ 472 $ 16,073 Transfer to Level 3 from Level 2 1 — 261 Purchases — — Proceeds from sales — (3,152 ) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — 386 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, September 30, 2019 $ 472 $ 13,568 1 Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards. Available for sale - Other debt securities Residential mortgage loans held for sale Balance, December 31, 2018 $ 472 $ 15,207 Transfer to Level 3 from Level 2 1 — 2,150 Purchases — — Proceeds from sales — (4,531 ) Redemptions and distributions — — Gain (loss) recognized in earnings: Mortgage banking revenue — 742 Other comprehensive income (loss): Net change in unrealized gain (loss) — — Balance, September 30, 2019 $ 472 $ 13,568 1 Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards. The following represents the changes for the three and nine months ended September 30, 2018 related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands): Available for Sale Securities Municipal and other tax-exempt securities Other debt securities Residential mortgage loans held for sale Balance, June 30, 2018 $ 2,030 $ 471 $ 14,243 Transfer to Level 3 from Level 2 1 — — 2,862 Purchases — — — Proceeds from sales — — (143 ) Redemptions and distributions (2,050 ) — — Gain (loss) recognized in earnings: Mortgage banking revenue — — (124 ) Other comprehensive income (loss): Net change in unrealized gain (loss) 20 1 — Balance, September 30, 2018 $ — $ 472 $ 16,838 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 Securities Municipal and other tax-exempt Other debt securities Residential mortgage loans held for sale Balance, December 31, 2017 $ 4,802 $ 472 $ 12,299 Transfer to Level 3 from Level 2 1 — — 5,603 Purchases — — — Proceeds from sales — — (853 ) Redemptions and distributions (5,095 ) — — Gain (loss) recognized in earnings Mortgage banking revenue — — (211 ) Other comprehensive income (loss): Net change in unrealized gain (loss) 293 — — Balance, September 30, 2018 $ — $ 472 $ 16,838 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.
Fair Value Inputs, Fair Value Measured On a Recurring Basis, Quantitative Information [Table Text Block]	A summary of quantitative information about assets measured at fair value on a recurring basis using Significant Unobservable Inputs (Level 3) as of September 30, 2019 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Available for sale securities – Other debt securities 472 Discounted cash flows 1 Interest rate spread 7.46%-7.46% (7.46%) 3 94.42%-94.42% (94.42%) 2 Residential mortgage loans held for sale 13,568 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. 96.36% 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 3 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, 2018 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Available for sale securities – Other debt securities 472 Discounted cash flows 1 Interest rate spread 7.88%-7.88% (7.88%) 3 94.44%-94.44% (94.44%) 2 Residential mortgage loans held for sale 15,207 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. 92.38% 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 Assets Measured on Nonrecurring Basis [Table Text Block]	The following represents the carrying value of assets measured at fair value on a non-recurring basis (and related losses) during the period. The carrying value represents only those assets with a balance at September 30, 2019 for which the fair value was adjusted during the nine months ended September 30, 2019 : Fair Value Adjustments for the Carrying Value at September 30, 2019 Three Months Ended Nine Months Ended Quoted Prices in Active Markets for Identical Instruments Significant Other Observable Inputs Significant Unobservable Inputs Gross charge-offs against allowance for loan losses Net losses (gains) and operating expenses of repossessed assets Gross charge-offs against allowance for loan losses Net losses (gains) and operating expenses of repossessed assets Impaired loans $ — $ 79 $ 9,810 $ 2,644 $ — $ 13,868 $ — Real estate and other repossessed assets — 5,044 936 — (979 ) — (532 ) The following represents the carrying value of assets measured at fair value on a non-recurring basis (and related losses) during the period. The carrying value represents only those assets with a balance at September 30, 2018 for which the fair value was adjusted during the nine months ended September 30, 2018 : Fair Value Adjustments for the Carrying Value at September 30, 2018 Three Months Ended Nine Months Ended Quoted Prices in Active Markets for Identical Instruments Significant Other Observable Inputs Significant Unobservable Inputs 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 Impaired loans $ — $ 1,065 $ 24,428 $ 9,086 $ — $ 16,279 $ — Real estate and other repossessed assets — 4,608 6,545 — 2,161 — 7,388
Fair Value Inputs, Fair Value Measured On a Nonrecurring Basis, Quantitative Information [Table Text Block]	A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of September 30, 2019 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Impaired loans $ 9,810 Discounted cash flows Management knowledge of industry and non-real estate collateral including but not limited to recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs 8% - 76% (28%) 1 Real estate and other repossessed assets 936 Appraised value, as adjusted Marketability adjustments off appraised value 2 75% - 89% (85%) 1 Represents fair value as a percentage of the unpaid principal balance. 2 Marketability adjustments include consideration of estimated costs to sell which is approximately 10% of the fair value. A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of September 30, 2018 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Impaired loans $ 24,428 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 41% - 84% (55%) 1 Real estate and other repossessed assets 6,545 Discounted cash flows Recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs N/A 1 Represents fair value as a percentage of the unpaid principal balance.
Fair Value of Financial Instruments [Table Text Block]	The following table presents the carrying values and estimated fair values of all financial instruments, including those financial assets and liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis as of September 30, 2019 (dollars in thousands): Carrying Value Estimated Fair Value Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Cash and due from banks $ 761,130 $ 761,130 $ 761,130 $ — $ — Interest-bearing cash and cash equivalents 465,458 465,458 465,458 — — Trading securities: U.S. government agency debentures 63,334 63,334 — 63,334 — Residential agency mortgage-backed securities 1,480,458 1,480,458 — 1,480,458 — Municipal and other tax-exempt securities 44,105 44,105 — 44,105 — Asset-backed securities 36,928 36,928 — 36,928 — Other trading securities 50,387 50,387 — 50,387 — Total trading securities 1,675,212 1,675,212 — 1,675,212 — Investment securities: Municipal and other tax-exempt securities 104,418 107,647 — 107,647 — Residential agency mortgage-backed securities 11,125 11,650 — 11,650 — Other debt securities 188,681 204,724 — 7,702 197,022 Total investment securities 304,224 324,021 — 126,999 197,022 Available for sale securities: U.S. Treasury 2,296 2,296 2,296 — — Municipal and other tax-exempt securities 1,848 1,848 — 1,848 — Residential agency mortgage-backed securities 7,740,461 7,740,461 — 7,740,461 — Residential non-agency mortgage-backed securities 44,803 44,803 — 44,803 — Commercial agency mortgage-backed securities 3,234,671 3,234,671 — 3,234,671 — Other debt securities 472 472 — — 472 Total available for sale securities 11,024,551 11,024,551 2,296 11,021,783 472 Fair value option securities: U.S. Treasury 552,536 552,536 552,536 — — Residential agency mortgage-backed securities 1,263,862 1,263,862 — 1,263,862 — Total fair value option securities 1,816,398 1,816,398 552,536 1,263,862 — Residential mortgage loans held for sale 282,487 282,487 — 268,919 13,568 Loans: — Commercial 14,424,625 14,397,846 — — 14,397,846 Commercial real estate 4,626,057 4,626,804 — — 4,626,804 Residential mortgage 2,117,303 2,132,158 — — 2,132,158 Personal 1,117,382 1,108,984 — — 1,108,984 Total loans 22,285,367 22,265,792 — — 22,265,792 Allowance for loan losses (204,432 ) — — — — Loans, net of allowance 22,080,935 22,265,792 — — 22,265,792 Mortgage servicing rights 193,661 193,661 — — 193,661 Derivative instruments with positive fair value, net of cash collateral 352,019 352,019 40,491 311,528 — Deposits with no stated maturity 23,923,535 23,923,535 — — 23,923,535 Time deposits 2,243,541 2,241,778 — — 2,241,778 Other borrowed funds 10,235,385 10,193,602 — — 10,193,602 Subordinated debentures 275,909 276,393 — 276,393 — Derivative instruments with negative fair value, net of cash collateral 336,791 336,791 — 336,791 — 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, 2018 (dollars in thousands): Carrying Value Estimated Fair Value Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Cash and due from banks $ 741,749 $ 741,749 $ 741,749 $ — $ — Interest-bearing cash and cash equivalents 401,675 401,675 401,675 — — Trading securities: U.S. government agency debentures 63,765 63,765 — 63,765 — Residential agency mortgage-backed securities 1,791,584 1,791,584 — 1,791,584 — Municipal and other tax-exempt securities 34,507 34,507 — 34,507 — Asset-backed securities 42,656 42,656 — 42,656 — Other trading securities 24,411 24,411 — 24,411 — Total trading securities 1,956,923 1,956,923 — 1,956,923 — Investment securities: Municipal and other tax-exempt securities 137,296 138,562 — 138,562 — Residential agency mortgage-backed securities 12,612 12,770 — 12,770 — Other debt securities 205,279 215,966 — 7,905 208,061 Total investment securities 355,187 367,298 — 159,237 208,061 Available for sale securities: U.S. Treasury 493 493 493 — — Municipal and other tax-exempt securities 2,864 2,864 — 2,864 — Residential agency mortgage-backed securities 5,804,708 5,804,708 — 5,804,708 — Residential non-agency mortgage-backed securities 59,736 59,736 — 59,736 — Commercial agency mortgage-backed securities 2,953,889 2,953,889 — 2,953,889 — Other debt securities 35,430 35,430 — 34,958 472 Total available for sale securities 8,857,120 8,857,120 493 8,856,155 472 Fair value option securities – Residential agency mortgage-backed securities 283,235 283,235 — 283,235 — Residential mortgage loans held for sale 149,221 149,221 — 134,014 15,207 Loans: Commercial 13,636,078 13,526,162 — — 13,526,162 Commercial real estate 4,764,813 4,713,747 — — 4,713,747 Residential mortgage 2,230,033 2,213,951 — — 2,213,951 Personal 1,025,806 1,024,368 — — 1,024,368 Total loans 21,656,730 21,478,228 — — 21,478,228 Allowance for loan losses (207,457 ) — — — — Loans, net of allowance 21,449,273 21,478,228 — — 21,478,228 Mortgage servicing rights 259,254 259,254 — — 259,254 Derivative instruments with positive fair value, net of cash collateral 320,929 320,929 44,074 276,855 — Deposits with no stated maturity 23,150,383 23,150,383 — — 23,150,383 Time deposits 2,113,380 2,073,538 — — 2,073,538 Other borrowed funds 7,142,801 7,071,953 — — 7,071,953 Subordinated debentures 275,913 261,977 — 261,977 — Derivative instruments with negative fair value, net of cash collateral 362,306 362,306 — 362,306 —

Significant Accounting Polici_3

Significant Accounting Policies Loans and Allowance for Credit Losses (Details)	9 Months Ended
	Sep. 30, 2019
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

Significant Accounting Polici_4

Significant Accounting Policies Newly Adopted and Pending Accounting Pronouncements (Details) - USD ($) $ in Millions	Sep. 30, 2019	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Operating Lease, Right-of-Use Asset	$ 180	$ 137

Trading Securities (Details)

Trading Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Trading Securities [Line Items]
Trading securities	$ 1,675,212	$ 1,956,923
Trading Securities, Net Unrealized Gain (Loss)	3,941	10,969
U.S. government agency debentures [Member]
Schedule of Trading Securities [Line Items]
Trading securities	63,334	63,765
Trading Securities, Net Unrealized Gain (Loss)	23	254
Residential agency mortgage-backed securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	1,480,458	1,791,584
Trading Securities, Net Unrealized Gain (Loss)	3,851	9,966
Municipal and other tax-exempt securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	44,105	34,507
Trading Securities, Net Unrealized Gain (Loss)	(99)	(1)
Asset-backed securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	36,928	42,656
Trading Securities, Net Unrealized Gain (Loss)	50	685
Other debt securities [Member]
Schedule of Trading Securities [Line Items]
Trading securities	50,387	24,411
Trading Securities, Net Unrealized Gain (Loss)	$ 116	$ 65

Investment (Held-to-Maturity) S

Investment (Held-to-Maturity) Securities (Details) $ in Thousands		9 Months Ended
		Sep. 30, 2019USD ($)	Dec. 31, 2018USD ($)
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investments Securities, Amortized Cost		$ 304,224	$ 355,187
Investment Securities, fair value		324,021	367,298
Investment Securities, Gross Unrealized Gain		20,232	14,408
Investment Securities, Gross Unrealized Loss		(435)	(2,297)
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investments Securities, Debt Maturities, Amortized Cost		304,224	355,187
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Fair Value		$ 324,021	$ 367,298
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		37	146
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 12,895	$ 31,627
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		13,110	94,802
Investment Securities, Continuous Unrealized Loss Position, Fair Value		26,005	126,429
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		7	133
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		428	2,164
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss		435	2,297
Fixed Maturity Securities [Member]
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Net Carrying Value		42,266
Investment Securities, Debt Maturities, One to Five Years, Net Carrying Value		93,139
Investment Securities, Debt Maturities, Six to Ten Years, Net Carrying Value		145,046
Investment Securities, Debt Maturities, Over Ten Years, Net Carrying Value		12,648
Investment Securities, Debt Maturities, Single Maturity Date, Net Carrying Value		293,099
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Fair Value		42,426
Investment Securities, Debt Maturities, One to Five Years, Fair Value		96,704
Investment Securities, Debt Maturities, Six to Ten Years, Fair Value		160,698
Investment Securities, Debt Maturities, Over Ten Years, Fair Value		12,543
Investment Securities, Debt Maturities, Single Maturity Date, Fair Value		$ 312,371
Investment Securities, Debt Maturities, Weighted Average Maturity	[1]	5.16
Municipal and other tax-exempt securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investments Securities, Amortized Cost		$ 104,418	137,296
Investment Securities, fair value		107,647	138,562
Investment Securities, Gross Unrealized Gain		3,247	1,858
Investment Securities, Gross Unrealized Loss		(18)	(592)
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investments Securities, Debt Maturities, Amortized Cost		104,418	137,296
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Fair Value		$ 107,647	$ 138,562
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		18	72
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 10,302	$ 18,255
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		2,213	66,141
Investment Securities, Continuous Unrealized Loss Position, Fair Value		12,515	84,396
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		3	69
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		15	523
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss		18	592
Other debt securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investments Securities, Amortized Cost		188,681	205,279
Investment Securities, fair value		204,724	215,966
Investment Securities, Gross Unrealized Gain		16,457	12,257
Investment Securities, Gross Unrealized Loss		(414)	(1,570)
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investments Securities, Debt Maturities, Amortized Cost		188,681	205,279
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Fair Value		$ 204,724	$ 215,966
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		18	72
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 275	$ 13,372
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		10,897	23,028
Investment Securities, Continuous Unrealized Loss Position, Fair Value		11,172	36,400
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		1	64
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		413	1,506
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss		414	1,570
Residential agency mortgage-backed securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investments Securities, Amortized Cost		11,125	12,612
Investment Securities, fair value		11,650	12,770
Investment Securities, Gross Unrealized Gain		528	293
Investment Securities, Gross Unrealized Loss		(3)	(135)
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, without Single Maturity Date, Net Carrying Value	[2]	11,125
Investments Securities, Debt Maturities, Amortized Cost		11,125	12,612
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, without Single Maturity Date, Fair Value		11,650
Investment Securities, Debt Maturities, Fair Value		$ 11,650	$ 12,770
Investment Securities, Debt Maturities, Average Expected Life of Mortgage-backed Securities		4 years 6 months
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		1	2
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 2,318	$ 0
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0	5,633
Investment Securities, Continuous Unrealized Loss Position, Fair Value		2,318	5,633
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		3	0
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0	135
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss		$ 3	$ 135
[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 4.5 years based upon current prepayment assumptions.

Available for Sale Securities (

Available for Sale Securities (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		$ 10,846,491		$ 10,846,491		$ 8,952,391
Available for sale securities		11,024,551		11,024,551		8,857,120
Available-for-sale Securities, Gross Unrealized Gain		191,716		191,716		42,986
Available-for-sale Securities, Gross Unrealized Loss		(13,656)		(13,656)		(138,257)
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Proceeds from sales of available for sale securities		261,028	$ 45,293	628,385	$ 232,826
Available-for-sale Securities, Gross realized gains		989	250	7,316	700
Available-for-sale Securities, Gross realized losses		(984)	0	(6,206)	(1,502)
Available-for-sale Securities, Related federal and state income tax expense (benefit)		1	$ 64	282	$ (204)
Pledged Assets Separately Reported, Securities Pledged as Collateral, at Fair Value		10,800,000		10,800,000		9,100,000
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		35,845		35,845
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost Basis		1,069,415		1,069,415
Available-for-sale Securities, Debt Maturities, Six To Ten Years, Amortized Cost Basis		1,476,121		1,476,121
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost Basis		599,373		599,373
Available-for-sale Securities, Debt Maturities, Allocated and Single Maturity Date, Amortized Cost		3,180,754		3,180,754
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Fair Value		35,806		35,806
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value		1,081,571		1,081,571
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value		1,512,308		1,512,308
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value		609,602		609,602
Available-for-sale Securities, Debt Maturities, Allocated and Single Maturity Date, Fair Value		$ 3,239,287		$ 3,239,287
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	[1]	8.29		8.29
U.S. Treasury [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		$ 2,294		$ 2,294		496
Available for sale securities		2,296		2,296		493
Available-for-sale Securities, Gross Unrealized Gain		2		2		0
Available-for-sale Securities, Gross Unrealized Loss		0		0		(3)
Municipal and other tax-exempt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		1,772		1,772		2,782
Available for sale securities		1,848		1,848		2,864
Available-for-sale Securities, Gross Unrealized Gain		76		76		82
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		3,176,188		3,176,188		2,986,297
Available for sale securities		3,234,671		3,234,671		2,953,889
Available-for-sale Securities, Gross Unrealized Gain		61,003		61,003		7,955
Available-for-sale Securities, Gross Unrealized Loss		(2,520)		(2,520)		(40,363)
Other debt securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		500		500		35,545
Available for sale securities		472		472		35,430
Available-for-sale Securities, Gross Unrealized Gain		0		0		12
Available-for-sale Securities, Gross Unrealized Loss		(28)		(28)		(127)
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]	7,665,737		7,665,737
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value		7,785,264		$ 7,785,264
Available-for-sale Securities, Debt Maturities, Average Expected Life of Mortgage-backed Securities				4 years
Residential agency mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		7,636,923		$ 7,636,923		5,886,323
Available for sale securities		7,740,461		7,740,461		5,804,708
Available-for-sale Securities, Gross Unrealized Gain		114,646		114,646		16,149
Available-for-sale Securities, Gross Unrealized Loss		(11,108)		(11,108)		(97,764)
Residential non-agency mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost		28,814		28,814		40,948
Available for sale securities		44,803		44,803		59,736
Available-for-sale Securities, Gross Unrealized Gain		15,989		15,989		18,788
Available-for-sale Securities, Gross Unrealized Loss		$ 0		$ 0		$ 0
[1]	Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without penalty.
[2]	The average expected lives of residential mortgage-backed securities were 4.0 years based upon current prepayment assumptions.

Securities Debt Securities, Ava

Securities Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value (Details) $ in Thousands	Sep. 30, 2019USD ($)	Dec. 31, 2018USD ($)
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	166	490
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 1,381,046	$ 700,064
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	978,329	5,631,803
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,359,375	6,331,867
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	4,872	1,615
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	8,784	136,642
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 13,656	$ 138,257
U.S. Treasury [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	0	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	0	493
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	0	493
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	0	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 0	$ 3
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	108	289
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 931,248	$ 510,824
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	753,448	3,641,370
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,684,696	4,152,194
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	3,260	1,158
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	7,848	96,606
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 11,108	$ 97,764
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	57	197
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 449,798	$ 179,258
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	224,409	1,969,504
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	674,207	2,148,762
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1,612	394
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	908	39,969
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 2,520	$ 40,363
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	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 0	$ 9,982
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	472	20,436
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	472	30,418
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	63
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	28	64
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 28	$ 127

Securities Fair Value Option Se

Securities Fair Value Option Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value Option Securities [Line Items]
Fair value option securities, Fair Value	$ 1,816,398	$ 283,235
Fair value option securities, Net Unrealized Gain (Loss)	19,515	2,766
U.S. Treasury [Member]
Fair Value Option Securities [Line Items]
Fair value option securities, Fair Value	552,536	0
Fair value option securities, Net Unrealized Gain (Loss)	927	0
Residential agency mortgage-backed securities [Member]
Fair Value Option Securities [Line Items]
Fair value option securities, Fair Value	1,263,862	283,235
Fair value option securities, Net Unrealized Gain (Loss)	$ 18,588	$ 2,766

Derivatives, Fair Value of Deri

Derivatives, Fair Value of Derivatives Contracts (Details) - USD ($) $ in Thousands	Sep. 30, 2019		Dec. 31, 2018
Derivative Assets, Fair Value, Net [Abstract]
Derviative contracts, net of cash collateral, Assets, Fair value	$ 352,019		$ 320,929
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Fair Value, Net of Cash Collateral	336,791		362,306
Not Designated as Hedging Instrument [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	78,780,596	[1]	30,272,764	[2]
Derivative Liabilities, Notional	80,366,050	[1]	33,838,893	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	675,084		571,793
Derivative Assets, Netting Adjustments	(255,979)		(135,530)
Derivative Assets, Net Fair Value Before Cash Collateral	419,105		436,263
Derivative Assets, Cash Collateral	(67,086)		(115,334)
Derviative contracts, net of cash collateral, Assets, Fair value	352,019		320,929
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	657,258		574,347
Derivative Liabilities, Netting Adjustments	(255,979)		(135,530)
Derivative Liabilities, Net Fair Value Before Cash Collateral	401,279		438,817
Derivative Liabilities, Cash Collateral	(64,488)		(76,511)
Derivative Liabilities, Fair Value, Net of Cash Collateral	336,791		362,306
Not Designated as Hedging Instrument [Member] | Total customer risk management programs
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	4,688,107	[1]	14,362,776	[2]
Derivative Liabilities, Notional	4,634,911	[1]	14,204,251	[2]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	460,859		521,383
Derivative Assets, Netting Adjustments	(59,681)		(94,659)
Derivative Assets, Net Fair Value Before Cash Collateral	401,178		426,724
Derivative Assets, Cash Collateral	(67,086)		(115,334)
Derviative contracts, net of cash collateral, Assets, Fair value	334,092		311,390
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	444,281		507,925
Derivative Liabilities, Netting Adjustments	(59,681)		(94,659)
Derivative Liabilities, Net Fair Value Before Cash Collateral	384,600		413,266
Derivative Liabilities, Cash Collateral	(62,780)		(69,196)
Derivative Liabilities, Fair Value, Net of Cash Collateral	321,820		344,070
Not Designated as Hedging Instrument [Member] | To-be-announced residential mortgage-backed securities [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	0		10,671,151
Derivative Liabilities, Notional	0		10,558,151
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	0		92,231
Derivative Assets, Netting Adjustments	0		(26,787)
Derivative Assets, Net Fair Value Before Cash Collateral	0		65,444
Derivative Assets, Cash Collateral	0		0
Derviative contracts, net of cash collateral, Assets, Fair value	0		65,444
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	0		90,388
Derivative Liabilities, Netting Adjustments	0		(26,787)
Derivative Liabilities, Net Fair Value Before Cash Collateral	0		63,601
Derivative Liabilities, Cash Collateral	0		(63,596)
Derivative Liabilities, Fair Value, Net of Cash Collateral	0		5
Not Designated as Hedging Instrument [Member] | Interest rate swaps [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	2,399,788		1,924,131
Derivative Liabilities, Notional	2,399,788		1,924,131
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	67,157		36,112
Derivative Assets, Netting Adjustments	(240)		(6,688)
Derivative Assets, Net Fair Value Before Cash Collateral	66,917		29,424
Derivative Assets, Cash Collateral	(277)		(7,934)
Derviative contracts, net of cash collateral, Assets, Fair value	66,640		21,490
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	67,296		36,288
Derivative Liabilities, Netting Adjustments	(240)		(6,688)
Derivative Liabilities, Net Fair Value Before Cash Collateral	67,056		29,600
Derivative Liabilities, Cash Collateral	(61,563)		(4,110)
Derivative Liabilities, Fair Value, Net of Cash Collateral	5,493		25,490
Not Designated as Hedging Instrument [Member] | Energy contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	1,980,406		1,472,209
Derivative Liabilities, Notional	1,936,369		1,434,247
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	183,204		206,418
Derivative Assets, Netting Adjustments	(59,139)		(60,983)
Derivative Assets, Net Fair Value Before Cash Collateral	124,065		145,435
Derivative Assets, Cash Collateral	(66,149)		(106,752)
Derviative contracts, net of cash collateral, Assets, Fair value	57,916		38,683
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	175,613		202,494
Derivative Liabilities, Netting Adjustments	(59,139)		(60,983)
Derivative Liabilities, Net Fair Value Before Cash Collateral	116,474		141,511
Derivative Liabilities, Cash Collateral	(784)		(1,490)
Derivative Liabilities, Fair Value, Net of Cash Collateral	115,690		140,021
Not Designated as Hedging Instrument [Member] | Agricultural contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	15,538		21,210
Derivative Liabilities, Notional	15,547		21,214
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	470		842
Derivative Assets, Netting Adjustments	(302)		(201)
Derivative Assets, Net Fair Value Before Cash Collateral	168		641
Derivative Assets, Cash Collateral	0		0
Derviative contracts, net of cash collateral, Assets, Fair value	168		641
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	451		812
Derivative Liabilities, Netting Adjustments	(302)		(201)
Derivative Liabilities, Net Fair Value Before Cash Collateral	149		611
Derivative Liabilities, Cash Collateral	0		0
Derivative Liabilities, Fair Value, Net of Cash Collateral	149		611
Not Designated as Hedging Instrument [Member] | Foreign exchange contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	209,515		184,990
Derivative Liabilities, Notional	200,347		177,423
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	206,914		183,759
Derivative Assets, Netting Adjustments	0		0
Derivative Assets, Net Fair Value Before Cash Collateral	206,914		183,759
Derivative Assets, Cash Collateral	0		0
Derviative contracts, net of cash collateral, Assets, Fair value	206,914		183,759
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	197,807		175,922
Derivative Liabilities, Netting Adjustments	0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral	197,807		175,922
Derivative Liabilities, Cash Collateral	(433)		0
Derivative Liabilities, Fair Value, Net of Cash Collateral	197,374		175,922
Not Designated as Hedging Instrument [Member] | Equity option contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	82,860		89,085
Derivative Liabilities, Notional	82,860		89,085
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	3,114		2,021
Derivative Assets, Netting Adjustments	0		0
Derivative Assets, Net Fair Value Before Cash Collateral	3,114		2,021
Derivative Assets, Cash Collateral	(660)		(648)
Derviative contracts, net of cash collateral, Assets, Fair value	2,454		1,373
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	3,114		2,021
Derivative Liabilities, Netting Adjustments	0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral	3,114		2,021
Derivative Liabilities, Cash Collateral	0		0
Derivative Liabilities, Fair Value, Net of Cash Collateral	3,114		2,021
Not Designated as Hedging Instrument [Member] | Trading [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	73,658,685		15,356,909
Derivative Liabilities, Notional	75,247,769		19,374,294
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	205,188		45,346
Derivative Assets, Netting Adjustments	(193,306)		(39,521)
Derivative Assets, Net Fair Value Before Cash Collateral	11,882		5,825
Derivative Assets, Cash Collateral	0		0
Derviative contracts, net of cash collateral, Assets, Fair value	11,882		5,825
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	207,542		56,983
Derivative Liabilities, Netting Adjustments	(193,306)		(39,521)
Derivative Liabilities, Net Fair Value Before Cash Collateral	14,236		17,462
Derivative Liabilities, Cash Collateral	0		0
Derivative Liabilities, Fair Value, Net of Cash Collateral	14,236		17,462
Not Designated as Hedging Instrument [Member] | Internal risk management programs [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	433,804		553,079
Derivative Liabilities, Notional	483,370		260,348
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	9,037		5,064
Derivative Assets, Netting Adjustments	(2,992)		(1,350)
Derivative Assets, Net Fair Value Before Cash Collateral	6,045		3,714
Derivative Assets, Cash Collateral	0		0
Derviative contracts, net of cash collateral, Assets, Fair value	6,045		3,714
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value	5,435		9,439
Derivative Liabilities, Netting Adjustments	(2,992)		(1,350)
Derivative Liabilities, Net Fair Value Before Cash Collateral	2,443		8,089
Derivative Liabilities, Cash Collateral	(1,708)		(7,315)
Derivative Liabilities, Fair Value, Net of Cash Collateral	$ 735		$ 774
[1]	Notional amounts for commodity contracts are converted into dollar-equivalent amounts based on dollar prices at the inception of the contract.
[2]	Notional amounts for commodity contracts are converted into dollar-equivalent amounts based on dollar prices at the inception of the contract.

Derivatives, Derivatives Instru

Derivatives, Derivatives Instruments Gain (Loss) in Income Statement (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	$ 8,314	$ 14,639	$ 21,070	$ 32,477
Gain (Loss) on Derivatives, Net	3,778	(2,847)	19,595	(11,589)
To-be-announced residential mortgage-backed securities [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	1,667	7,272	9,579	21,677
Gain (Loss) on Derivatives, Net	0	0	0	0
Interest rate swaps [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	1,252	618	2,787	2,057
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	1,611	541	3,923	5,097
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	16	6	24	36
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	138	78	392	350
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
Total customer risk management programs
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	4,684	8,515	16,705	29,217
Gain (Loss) on Derivatives, Net	0	0	0	0
Trading [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	3,630	6,124	4,365	3,260
Gain (Loss) on Derivatives, Net	0	0	0	0
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	$ 3,778	$ (2,847)	$ 19,595	$ (11,589)

Loans and Allowance for Credit

Loans and Allowance for Credit Losses, Loans by Portfolio Type (Details) - USD ($) $ in Thousands		Sep. 30, 2019	Dec. 31, 2018
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest		$ 6,136,400	$ 5,749,373
Loans, variable rate of interest		15,976,501	15,744,110
Loans, non-accrual		172,466	163,247
Total		22,285,367	21,656,730
Accruing loans past due (90 days)	[1]	1,541	1,338
Credit Commitments [Abstract]
Outstanding commitments to extend credit		11,000,000
Outstanding standby letters of credit		713,000
Commercial [Member]
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest		3,184,237	2,251,188
Loans, variable rate of interest		11,128,682	11,285,049
Loans, non-accrual		111,706	99,841
Total		14,424,625	13,636,078
Commercial real estate [Member]
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest		1,070,050	1,477,274
Loans, variable rate of interest		3,532,822	3,265,918
Loans, non-accrual		23,185	21,621
Total		4,626,057	4,764,813
Residential mortgage [Member]
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest		1,690,286	1,830,224
Loans, variable rate of interest		389,713	358,254
Loans, non-accrual		37,304	41,555
Total		2,117,303	2,230,033
Personal [Member]
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest		191,827	190,687
Loans, variable rate of interest		925,284	834,889
Loans, non-accrual		271	230
Total		$ 1,117,382	$ 1,025,806
[1]	Excludes residential mortgage loans guaranteed by agencies of the U.S. government

Loans and Allowances for Cred_3

Loans and Allowances for Credit Losses, Activity in Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Dec. 31, 2018
Allowance for loan losses [Roll Forward]
Beginning balance	$ 202,534	$ 215,142	$ 207,457	$ 230,682
Provision for loan losses	12,539	4,408	25,426	709
Loans charged off	(11,707)	(11,073)	(36,709)	(29,068)
Recoveries	1,066	2,092	8,258	8,246
Ending balance	204,432	210,569	204,432	210,569
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance	1,903	2,433	1,790	3,734
Provision for off-balance sheet credit losses	(539)	(408)	(426)	(1,709)
Ending balance	1,364	2,025	1,364	2,025
Total provision for credit losses	12,000	4,000	25,000	(1,000)
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					$ 22,112,901	$ 21,493,483
Individually measured for impairment, recorded investment					172,466	163,247
Total					22,285,367	21,656,730
Related allowance [Abstract]
Collectively measured for impairment, related allowance					179,144	180,957
Individually measured for impairment, related allowance					7,533	8,732
Total	204,432	215,142	204,432	210,569	204,432	207,457
Commercial [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	106,397	113,722	102,226	124,269
Provision for loan losses	9,861	(1,285)	34,740	2,720
Loans charged off	(9,875)	(9,602)	(31,728)	(24,940)
Recoveries	260	1,263	1,405	2,049
Ending balance	106,643	104,098	106,643	104,098
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance	1,742	2,361	1,655	3,644
Provision for off-balance sheet credit losses	(536)	(424)	(449)	(1,707)
Ending balance	1,206	1,937	1,206	1,937
Total provision for credit losses	9,325	(1,709)	34,291	1,013
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					14,312,919	13,536,237
Individually measured for impairment, recorded investment					111,706	99,841
Total					14,424,625	13,636,078
Related allowance [Abstract]
Collectively measured for impairment, related allowance					99,110	93,494
Individually measured for impairment, related allowance					7,533	8,732
Total	106,397	113,722	102,226	104,098	106,643	102,226
Commercial real estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	54,188	58,758	60,026	56,621
Provision for loan losses	102	1,391	(10,075)	248
Loans charged off	0	0	(118)	0
Recoveries	60	40	4,517	3,320
Ending balance	54,350	60,189	54,350	60,189
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance	116	17	52	45
Provision for off-balance sheet credit losses	(3)	19	61	(9)
Ending balance	113	36	113	36
Total provision for credit losses	99	1,410	(10,014)	239
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					4,602,872	4,743,192
Individually measured for impairment, recorded investment					23,185	21,621
Total					4,626,057	4,764,813
Related allowance [Abstract]
Collectively measured for impairment, related allowance					54,350	60,026
Individually measured for impairment, related allowance					0	0
Total	54,188	58,758	60,026	56,621	54,350	60,026
Residential mortgage [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	15,724	18,544	17,964	18,451
Provision for loan losses	(253)	1	(2,660)	(418)
Loans charged off	(56)	(91)	(192)	(326)
Recoveries	119	229	422	976
Ending balance	15,534	18,683	15,534	18,683
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance	44	53	52	43
Provision for off-balance sheet credit losses	0	(3)	(8)	7
Ending balance	44	50	44	50
Total provision for credit losses	(253)	(2)	(2,668)	(411)
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					2,079,999	2,188,478
Individually measured for impairment, recorded investment					37,304	41,555
Total					2,117,303	2,230,033
Related allowance [Abstract]
Collectively measured for impairment, related allowance					15,534	17,964
Individually measured for impairment, related allowance					0	0
Total	15,724	18,544	15,534	18,451	15,534	17,964
Personal [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	9,388	8,646	9,473	9,124
Provision for loan losses	1,911	883	3,434	1,486
Loans charged off	(1,776)	(1,380)	(4,671)	(3,802)
Recoveries	627	560	1,914	1,901
Ending balance	10,150	8,709	10,150	8,709
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance	1	2	31	2
Provision for off-balance sheet credit losses	0	0	(30)	0
Ending balance	1	2	1	2
Total provision for credit losses	1,911	883	3,404	1,486
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					1,117,111	1,025,576
Individually measured for impairment, recorded investment					271	230
Total					1,117,382	1,025,806
Related allowance [Abstract]
Collectively measured for impairment, related allowance					10,150	9,473
Individually measured for impairment, related allowance					0	0
Total	9,388	8,646	10,150	9,124	10,150	9,473
Specific Allowance [Member]
Allowance for loan losses [Roll Forward]
Beginning balance			189,689
Ending balance	186,677		186,677
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					22,112,901	21,493,483
Individually measured for impairment, recorded investment					172,466	163,247
Total					22,285,367	21,656,730
Related allowance [Abstract]
Collectively measured for impairment, related allowance					179,144	180,957
Individually measured for impairment, related allowance					7,533	8,732
Total	186,677		186,677		186,677	189,689
Nonspecific Allowance [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	16,837	15,472	17,768	22,217
Provision for loan losses	918	3,418	(13)	(3,327)
Loans charged off	0	0	0	0
Recoveries	0	0	0	0
Ending balance	17,755	18,890	17,755	18,890
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance	0	0	0	0
Provision for off-balance sheet credit losses	0	0	0	0
Ending balance	0	0	0	0
Total provision for credit losses	918	3,418	(13)	(3,327)
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					0	0
Individually measured for impairment, recorded investment					0	0
Total					0	0
Related allowance [Abstract]
Collectively measured for impairment, related allowance					0	0
Individually measured for impairment, related allowance					0	0
Total	$ 16,837	$ 15,472	$ 17,755	$ 22,217	$ 17,755	$ 17,768

Loans and Allowances for Cred_4

Loans and Allowances for Credit Losses, Credit Quality Indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	$ 20,338,154		$ 19,805,403
Non-Graded, Recorded Investment	1,947,213		1,851,327
Total	22,285,367		21,656,730
Related Allowance [Abstract]
Internally Risk Graded, Allowance	171,275		171,272
Non-Graded, Allowance	15,402		18,417
Total	204,432	$ 202,534	207,457	$ 210,569	$ 215,142	$ 230,682
Commercial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	14,396,278		13,586,654
Non-Graded, Recorded Investment	28,347		49,424
Total	14,424,625		13,636,078
Related Allowance [Abstract]
Internally Risk Graded, Allowance	105,714		101,303
Non-Graded, Allowance	929		923
Total	106,643	106,397	102,226	104,098	113,722	124,269
Commercial [Member] | Energy [Member]
Recorded Investment [Abstract]
Total	4,114,269		3,590,333
Commercial [Member] | Services [Member]
Recorded Investment [Abstract]
Total	3,266,249		3,258,192
Commercial [Member] | Wholesale/retail [Member]
Recorded Investment [Abstract]
Total	1,848,617		1,621,158
Commercial [Member] | Manufacturing [Member]
Recorded Investment [Abstract]
Total	698,408		730,521
Commercial [Member] | Healthcare [Member]
Recorded Investment [Abstract]
Total	3,032,968		2,799,277
Commercial [Member] | Public finance [Member]
Recorded Investment [Abstract]
Total	744,840		804,550
Commercial [Member] | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Total	719,274		832,047
Commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	4,626,057		4,764,813
Non-Graded, Recorded Investment	0		0
Total	4,626,057		4,764,813
Related Allowance [Abstract]
Internally Risk Graded, Allowance	54,350		60,026
Non-Graded, Allowance	0		0
Total	54,350	54,188	60,026	60,189	58,758	56,621
Commercial real estate [Member] | Residential construction and land development [Member]
Recorded Investment [Abstract]
Total	135,361		148,584
Commercial real estate [Member] | Retail [Member]
Recorded Investment [Abstract]
Total	799,169		919,082
Commercial real estate [Member] | Office [Member]
Recorded Investment [Abstract]
Total	1,014,275		1,072,920
Commercial real estate [Member] | Multifamily [Member]
Recorded Investment [Abstract]
Total	1,324,839		1,288,065
Commercial real estate [Member] | Industrial [Member]
Recorded Investment [Abstract]
Total	873,536		778,106
Commercial real estate [Member] | Other commercial real estate [Member]
Recorded Investment [Abstract]
Total	478,877		558,056
Residential mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	283,297		505,046
Non-Graded, Recorded Investment	1,834,006		1,724,987
Total	2,117,303		2,230,033
Related Allowance [Abstract]
Internally Risk Graded, Allowance	3,375		3,310
Non-Graded, Allowance	12,159		14,654
Total	15,534	15,724	17,964	18,683	18,544	18,451
Residential mortgage [Member] | Permanent mortgage [Member]
Recorded Investment [Abstract]
Total	1,066,460		1,122,610
Residential mortgage [Member] | Permanent mortgages guaranteed by US government agencies [Member]
Recorded Investment [Abstract]
Total	191,764		190,866
Residential mortgage [Member] | Home equity [Member]
Recorded Investment [Abstract]
Total	859,079		916,557
Personal [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,032,522		948,890
Non-Graded, Recorded Investment	84,860		76,916
Total	1,117,382		1,025,806
Related Allowance [Abstract]
Internally Risk Graded, Allowance	7,836		6,633
Non-Graded, Allowance	2,314		2,840
Total	10,150	9,388	9,473	8,709	8,646	9,124
Specific Allowance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	20,338,154		19,805,403
Non-Graded, Recorded Investment	1,947,213		1,851,327
Total	22,285,367		21,656,730
Related Allowance [Abstract]
Internally Risk Graded, Allowance	171,275		171,272
Non-Graded, Allowance	15,402		18,417
Total	186,677		189,689
Nonspecific Allowance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0
Non-Graded, Recorded Investment	0		0
Total	0		0
Related Allowance [Abstract]
Internally Risk Graded, Allowance	0		0
Non-Graded, Allowance	0		0
Total	17,755	$ 16,837	17,768	$ 18,890	$ 15,472	$ 22,217
Performing [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	1,910,190		1,811,557
Performing [Member] | Commercial [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	28,300		49,371
Performing [Member] | Commercial [Member] | Energy [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0
Performing [Member] | Commercial [Member] | Services [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0
Performing [Member] | Commercial [Member] | Wholesale/retail [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0
Performing [Member] | Commercial [Member] | Manufacturing [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0
Performing [Member] | Commercial [Member] | Healthcare [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0
Performing [Member] | Commercial [Member] | Public finance [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0
Performing [Member] | Commercial [Member] | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	28,300		49,371
Performing [Member] | Commercial real estate [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0
Performing [Member] | Commercial real estate [Member] | Residential construction and land development [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0
Performing [Member] | Commercial real estate [Member] | Retail [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0
Performing [Member] | Commercial real estate [Member] | Office [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0
Performing [Member] | Commercial real estate [Member] | Multifamily [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0
Performing [Member] | Commercial real estate [Member] | Industrial [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0
Performing [Member] | Commercial real estate [Member] | Other commercial real estate [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0
Performing [Member] | Residential mortgage [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	1,797,239		1,685,424
Performing [Member] | Residential mortgage [Member] | Permanent mortgage [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	763,535		819,199
Performing [Member] | Residential mortgage [Member] | Permanent mortgages guaranteed by US government agencies [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	185,432		183,734
Performing [Member] | Residential mortgage [Member] | Home equity [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	848,272		682,491
Performing [Member] | Personal [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	84,651		76,762
Performing [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	19,880,462		19,285,126
Performing [Member] | Pass [Member] | Commercial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	13,996,035		13,135,068
Performing [Member] | Pass [Member] | Commercial [Member] | Energy [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	3,927,285		3,414,039
Performing [Member] | Pass [Member] | Commercial [Member] | Services [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	3,185,367		3,167,203
Performing [Member] | Pass [Member] | Commercial [Member] | Wholesale/retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,829,614		1,593,902
Performing [Member] | Pass [Member] | Commercial [Member] | Manufacturing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	652,804		668,438
Performing [Member] | Pass [Member] | Commercial [Member] | Healthcare [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,984,306		2,730,121
Performing [Member] | Pass [Member] | Commercial [Member] | Public finance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	744,840		804,550
Performing [Member] | Pass [Member] | Commercial [Member] | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	671,819		756,815
Performing [Member] | Pass [Member] | Commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	4,571,803		4,712,826
Performing [Member] | Pass [Member] | Commercial real estate [Member] | Residential construction and land development [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	135,011		148,234
Performing [Member] | Pass [Member] | Commercial real estate [Member] | Retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	765,708		885,588
Performing [Member] | Pass [Member] | Commercial real estate [Member] | Office [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,007,136		1,059,334
Performing [Member] | Pass [Member] | Commercial real estate [Member] | Multifamily [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,316,856		1,287,471
Performing [Member] | Pass [Member] | Commercial real estate [Member] | Industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	872,627		776,898
Performing [Member] | Pass [Member] | Commercial real estate [Member] | Other commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	474,465		555,301
Performing [Member] | Pass [Member] | Residential mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	280,243		492,976
Performing [Member] | Pass [Member] | Residential mortgage [Member] | Permanent mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	280,243		269,678
Performing [Member] | Pass [Member] | Residential mortgage [Member] | Permanent mortgages guaranteed by US government agencies [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0
Performing [Member] | Pass [Member] | Residential mortgage [Member] | Home equity [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		223,298
Performing [Member] | Pass [Member] | Personal [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,032,381		944,256
Performing [Member] | Other Loans Especially Mentioned [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	179,389		181,960
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	159,767		157,866
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial [Member] | Energy [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	60,405		42,176
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial [Member] | Services [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	38,118		49,761
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial [Member] | Wholesale/retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	9,757		18,809
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial [Member] | Manufacturing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	24,229		30,934
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial [Member] | Healthcare [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	25,205		14,920
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial [Member] | Public finance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial [Member] | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,053		1,266
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	19,250		23,927
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate [Member] | Residential construction and land development [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate [Member] | Retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	12,067		11,926
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate [Member] | Office [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	5,203		10,532
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate [Member] | Multifamily [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,196		281
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate [Member] | Industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate [Member] | Other commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	784		1,188
Performing [Member] | Other Loans Especially Mentioned [Member] | Residential mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	326		52
Performing [Member] | Other Loans Especially Mentioned [Member] | Residential mortgage [Member] | Permanent mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	326		52
Performing [Member] | Other Loans Especially Mentioned [Member] | Residential mortgage [Member] | Permanent mortgages guaranteed by US government agencies [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0
Performing [Member] | Other Loans Especially Mentioned [Member] | Residential mortgage [Member] | Home equity [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0
Performing [Member] | Other Loans Especially Mentioned [Member] | Personal [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	46		115
Performing [Member] | Accruing Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	142,860		214,840
Performing [Member] | Accruing Substandard [Member] | Commercial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	128,817		193,932
Performing [Member] | Accruing Substandard [Member] | Commercial [Member] | Energy [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	37,685		86,624
Performing [Member] | Accruing Substandard [Member] | Commercial [Member] | Services [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	36,645		32,661
Performing [Member] | Accruing Substandard [Member] | Commercial [Member] | Wholesale/retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	7,742		7,131
Performing [Member] | Accruing Substandard [Member] | Commercial [Member] | Manufacturing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	12,634		22,230
Performing [Member] | Accruing Substandard [Member] | Commercial [Member] | Healthcare [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	17,479		37,698
Performing [Member] | Accruing Substandard [Member] | Commercial [Member] | Public finance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0
Performing [Member] | Accruing Substandard [Member] | Commercial [Member] | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	16,632		7,588
Performing [Member] | Accruing Substandard [Member] | Commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	11,819		6,439
Performing [Member] | Accruing Substandard [Member] | Commercial real estate [Member] | Residential construction and land development [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0
Performing [Member] | Accruing Substandard [Member] | Commercial real estate [Member] | Retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,262		1,289
Performing [Member] | Accruing Substandard [Member] | Commercial real estate [Member] | Office [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,081		3,054
Performing [Member] | Accruing Substandard [Member] | Commercial real estate [Member] | Multifamily [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	6,501		12
Performing [Member] | Accruing Substandard [Member] | Commercial real estate [Member] | Industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		1,208
Performing [Member] | Accruing Substandard [Member] | Commercial real estate [Member] | Other commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,975		876
Performing [Member] | Accruing Substandard [Member] | Residential mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,191		10,026
Performing [Member] | Accruing Substandard [Member] | Residential mortgage [Member] | Permanent mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,191		9,730
Performing [Member] | Accruing Substandard [Member] | Residential mortgage [Member] | Permanent mortgages guaranteed by US government agencies [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0
Performing [Member] | Accruing Substandard [Member] | Residential mortgage [Member] | Home equity [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		296
Performing [Member] | Accruing Substandard [Member] | Personal [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	33		4,443
Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	135,444		123,476
Non-Graded, Recorded Investment	37,022		39,771
Nonaccrual [Member] | Commercial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	111,659		99,788
Non-Graded, Recorded Investment	47		53
Nonaccrual [Member] | Commercial [Member] | Energy [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	88,894		47,494
Non-Graded, Recorded Investment	0		0
Nonaccrual [Member] | Commercial [Member] | Services [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	6,119		8,567
Non-Graded, Recorded Investment	0		0
Nonaccrual [Member] | Commercial [Member] | Wholesale/retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,504		1,316
Non-Graded, Recorded Investment	0		0
Nonaccrual [Member] | Commercial [Member] | Manufacturing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	8,741		8,919
Non-Graded, Recorded Investment	0		0
Nonaccrual [Member] | Commercial [Member] | Healthcare [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	5,978		16,538
Non-Graded, Recorded Investment	0		0
Nonaccrual [Member] | Commercial [Member] | Public finance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0
Non-Graded, Recorded Investment	0		0
Nonaccrual [Member] | Commercial [Member] | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	423		16,954
Non-Graded, Recorded Investment	47		53
Nonaccrual [Member] | Commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	23,185		21,621
Non-Graded, Recorded Investment	0		0
Nonaccrual [Member] | Commercial real estate [Member] | Residential construction and land development [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	350		350
Non-Graded, Recorded Investment	0		0
Nonaccrual [Member] | Commercial real estate [Member] | Retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	20,132		20,279
Non-Graded, Recorded Investment	0		0
Nonaccrual [Member] | Commercial real estate [Member] | Office [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	855		0
Non-Graded, Recorded Investment	0		0
Nonaccrual [Member] | Commercial real estate [Member] | Multifamily [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	286		301
Non-Graded, Recorded Investment	0		0
Nonaccrual [Member] | Commercial real estate [Member] | Industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	909		0
Non-Graded, Recorded Investment	0		0
Nonaccrual [Member] | Commercial real estate [Member] | Other commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	653		691
Non-Graded, Recorded Investment	0		0
Nonaccrual [Member] | Residential mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	537		1,991
Non-Graded, Recorded Investment	36,767		39,564
Nonaccrual [Member] | Residential mortgage [Member] | Permanent mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	537		1,991
Non-Graded, Recorded Investment	19,628		21,960
Nonaccrual [Member] | Residential mortgage [Member] | Permanent mortgages guaranteed by US government agencies [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0
Non-Graded, Recorded Investment	6,332		7,132
Nonaccrual [Member] | Residential mortgage [Member] | Home equity [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0
Non-Graded, Recorded Investment	10,807		10,472
Nonaccrual [Member] | Personal [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	63		76
Non-Graded, Recorded Investment	$ 208		$ 154

Loans and Allowance for Credi_2

Loans and Allowance for Credit Losses, Impaired Loans (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019		Sep. 30, 2019		Dec. 31, 2018
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		$ 446,335		$ 446,335		$ 423,787
Impaired loans, recorded investment, total		357,898		357,898		346,981
Impaired loans, recorded investment with no related allowance		331,468		331,468		311,526
Impaired loans, recorded investment with related allowance		26,430		26,430		35,455
Impaired loans, related allowance		7,533		7,533		8,732
Impaired loans, average recorded investment		367,895		349,646
Impaired loans, interest income recognized		2,300		6,757
Commercial [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		186,205		186,205		156,163
Impaired loans, recorded investment, total		111,706		111,706		99,841
Impaired loans, recorded investment with no related allowance		85,276		85,276		64,386
Impaired loans, recorded investment with related allowance		26,430		26,430		35,455
Impaired loans, related allowance		7,533		7,533		8,732
Impaired loans, average recorded investment		117,551		99,544
Impaired loans, interest income recognized		0		0
Commercial [Member] | Energy [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		139,897		139,897		79,675
Impaired loans, recorded investment, total		88,894		88,894		47,494
Impaired loans, recorded investment with no related allowance		62,981		62,981		18,639
Impaired loans, recorded investment with related allowance		25,913		25,913		28,855
Impaired loans, related allowance		7,176		7,176		5,362
Impaired loans, average recorded investment		80,263		67,705
Impaired loans, interest income recognized		0		0
Commercial [Member] | Services [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		9,390		9,390		13,437
Impaired loans, recorded investment, total		6,119		6,119		8,567
Impaired loans, recorded investment with no related allowance		6,093		6,093		8,489
Impaired loans, recorded investment with related allowance		26		26		78
Impaired loans, related allowance		26		26		74
Impaired loans, average recorded investment		8,103		5,172
Impaired loans, interest income recognized		0		0
Commercial [Member] | Wholesale/retail [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		1,718		1,718		1,722
Impaired loans, recorded investment, total		1,504		1,504		1,316
Impaired loans, recorded investment with no related allowance		1,243		1,243		1,015
Impaired loans, recorded investment with related allowance		261		261		301
Impaired loans, related allowance		101		101		101
Impaired loans, average recorded investment		1,447		1,087
Impaired loans, interest income recognized		0		0
Commercial [Member] | Manufacturing [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		9,153	[1]	9,153	[1]	10,055
Impaired loans, recorded investment, total		8,741	[1]	8,741	[1]	8,919
Impaired loans, recorded investment with no related allowance		8,511	[1]	8,511	[1]	8,673
Impaired loans, recorded investment with related allowance		230	[1]	230	[1]	246
Impaired loans, related allowance		230	[1]	230	[1]	246
Impaired loans, average recorded investment	[1]	8,677		8,448
Impaired loans, interest income recognized	[1]	0		0
Impaired loans, unpaid principal balance to affiliates		4,700		4,700
Commercial [Member] | Healthcare [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		17,786		17,786		24,319
Impaired loans, recorded investment, total		5,978		5,978		16,538
Impaired loans, recorded investment with no related allowance		5,978		5,978		10,563
Impaired loans, recorded investment with related allowance		0		0		5,975
Impaired loans, related allowance		0		0		2,949
Impaired loans, average recorded investment		11,063		8,547
Impaired loans, interest income recognized		0		0
Commercial [Member] | Public finance [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		0		0		0
Impaired loans, recorded investment, total		0		0		0
Impaired loans, recorded investment with no related allowance		0		0		0
Impaired loans, recorded investment with related allowance		0		0		0
Impaired loans, related allowance		0		0		0
Impaired loans, average recorded investment				0
Impaired loans, interest income recognized		0		0
Commercial [Member] | Other commercial and industrial [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		8,261		8,261		26,955
Impaired loans, recorded investment, total		470		470		17,007
Impaired loans, recorded investment with no related allowance		470		470		17,007
Impaired loans, recorded investment with related allowance		0		0		0
Impaired loans, related allowance		0		0		0
Impaired loans, average recorded investment		7,998		8,585
Impaired loans, interest income recognized		0		0
Commercial real estate [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		24,685		24,685		30,138
Impaired loans, recorded investment, total		23,185		23,185		21,621
Impaired loans, recorded investment with no related allowance		23,185		23,185		21,621
Impaired loans, recorded investment with related allowance		0		0		0
Impaired loans, related allowance		0		0		0
Impaired loans, average recorded investment		22,427		22,403
Impaired loans, interest income recognized		0		0
Commercial real estate [Member] | Residential construction and land development [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		1,306		1,306		1,306
Impaired loans, recorded investment, total		350		350		350
Impaired loans, recorded investment with no related allowance		350		350		350
Impaired loans, recorded investment with related allowance		0		0		0
Impaired loans, related allowance		0		0		0
Impaired loans, average recorded investment		350		350
Impaired loans, interest income recognized		0		0
Commercial real estate [Member] | Retail [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		20,516		20,516		27,680
Impaired loans, recorded investment, total		20,132		20,132		20,279
Impaired loans, recorded investment with no related allowance		20,132		20,132		20,279
Impaired loans, recorded investment with related allowance		0		0		0
Impaired loans, related allowance		0		0		0
Impaired loans, average recorded investment		20,094		20,206
Impaired loans, interest income recognized		0		0
Commercial real estate [Member] | Office [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		855		855		0
Impaired loans, recorded investment, total		855		855		0
Impaired loans, recorded investment with no related allowance		855		855		0
Impaired loans, recorded investment with related allowance		0		0		0
Impaired loans, related allowance		0		0		0
Impaired loans, average recorded investment		855		427
Impaired loans, interest income recognized		0		0
Commercial real estate [Member] | Multifamily [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		286		286		301
Impaired loans, recorded investment, total		286		286		301
Impaired loans, recorded investment with no related allowance		286		286		301
Impaired loans, recorded investment with related allowance		0		0		0
Impaired loans, related allowance		0		0		0
Impaired loans, average recorded investment		281		294
Impaired loans, interest income recognized		0		0
Commercial real estate [Member] | Industrial [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		909		909		0
Impaired loans, recorded investment, total		909		909		0
Impaired loans, recorded investment with no related allowance		909		909		0
Impaired loans, recorded investment with related allowance		0		0		0
Impaired loans, related allowance		0		0		0
Impaired loans, average recorded investment		454		454
Impaired loans, interest income recognized		0		0
Commercial real estate [Member] | Other commercial real estate [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		813		813		851
Impaired loans, recorded investment, total		653		653		691
Impaired loans, recorded investment with no related allowance		653		653		691
Impaired loans, recorded investment with related allowance		0		0		0
Impaired loans, related allowance		0		0		0
Impaired loans, average recorded investment		393		672
Impaired loans, interest income recognized		0		0
Residential mortgage [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		235,107		235,107		237,208
Impaired loans, recorded investment, total		222,736		222,736		225,289
Impaired loans, recorded investment with no related allowance		222,736		222,736		225,289
Impaired loans, recorded investment with related allowance		0		0		0
Impaired loans, related allowance		0		0		0
Impaired loans, average recorded investment		227,663		227,448
Impaired loans, interest income recognized		2,300		6,757
Residential mortgage [Member] | Permanent mortgage [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		24,639		24,639		28,716
Impaired loans, recorded investment, total		20,165		20,165		23,951
Impaired loans, recorded investment with no related allowance		20,165		20,165		23,951
Impaired loans, recorded investment with related allowance		0		0		0
Impaired loans, related allowance		0		0		0
Impaired loans, average recorded investment		20,984		22,058
Impaired loans, interest income recognized		280		894
Residential mortgage [Member] | Permanent mortgages guaranteed by US government agencies [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		197,847	[2]	197,847	[2]	196,296	[3]
Impaired loans, recorded investment, total		191,764	[2]	191,764	[2]	190,866	[3]
Impaired loans, recorded investment with no related allowance		191,764	[2]	191,764	[2]	190,866	[3]
Impaired loans, recorded investment with related allowance		0	[2]	0	[2]	0	[3]
Impaired loans, related allowance		0	[2]	0	[2]	0	[3]
Impaired loans, average recorded investment	[2]	196,310		194,751
Impaired loans, interest income recognized	[2]	2,020		5,863
Residential mortgage [Member] | Home equity [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		12,621		12,621		12,196
Impaired loans, recorded investment, total		10,807		10,807		10,472
Impaired loans, recorded investment with no related allowance		10,807		10,807		10,472
Impaired loans, recorded investment with related allowance		0		0		0
Impaired loans, related allowance		0		0		0
Impaired loans, average recorded investment		10,369		10,639
Impaired loans, interest income recognized		0		0
Personal [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance		338		338		278
Impaired loans, recorded investment, total		271		271		230
Impaired loans, recorded investment with no related allowance		271		271		230
Impaired loans, recorded investment with related allowance		0		0		0
Impaired loans, related allowance		0		0		$ 0
Impaired loans, average recorded investment		254		251
Impaired loans, interest income recognized		$ 0		$ 0
[1]	Impaired manufacturing sector loans included $4.7 million of loans from an affiliated entity, with no allowance as the fair value of the collateral exceeded the outstanding principal balance at September 30, 2019 .
[2]	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 September 30, 2019 , the majority were accruing based on the guarantee by U.S. government agencies.
[3]	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, 2018 , the majority were accruing based on the guarantee by U.S. government agencies.

Loans and Allowances for Cred_5

Loans and Allowances for Credit Losses, Troubled Debt Restructurings (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled Debt Restructuring, Recorded Investment	$ 145		$ 145		$ 166
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	70		70		71
Financing Receivable, Troubled Debt Restructuring, Postmodification	6.2	$ 31	40	$ 76
Permanent mortgages guaranteed by US government agencies [Member] | Accruing [Member] | Residential mortgage [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled Debt Restructuring, Recorded Investment	$ 93		$ 93		$ 86

Loans and Allowances for Cred_6

Loans and Allowances for Credit Losses, By Aging Category (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Financing receivable, recorded investment, aging [Abstract]
Current	$ 21,938,836,000	$ 21,308,989,000
Nonaccrual	172,466,000	163,247,000
Total	22,285,367,000	21,656,730,000
Commercial [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	14,297,027,000	13,521,894,000
Nonaccrual	111,706,000	99,841,000
Total	14,424,625,000	13,636,078,000
Commercial [Member] | Energy [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	4,025,375,000	3,542,839,000
Nonaccrual	88,894,000	47,494,000
Total	4,114,269,000	3,590,333,000
Commercial [Member] | Services [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	3,249,994,000	3,237,578,000
Nonaccrual	6,119,000	8,567,000
Total	3,266,249,000	3,258,192,000
Commercial [Member] | Wholesale/retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	1,844,203,000	1,619,290,000
Nonaccrual	1,504,000	1,316,000
Total	1,848,617,000	1,621,158,000
Commercial [Member] | Manufacturing [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	687,358,000	721,204,000
Nonaccrual	8,741,000	8,919,000
Total	698,408,000	730,521,000
Commercial [Member] | Healthcare [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	3,026,838,000	2,781,944,000
Nonaccrual	5,978,000	16,538,000
Total	3,032,968,000	2,799,277,000
Commercial [Member] | Public finance [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	744,840,000	804,550,000
Nonaccrual	0	0
Total	744,840,000	804,550,000
Commercial [Member] | Other commercial and industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	718,419,000	814,489,000
Nonaccrual	470,000	17,007,000
Total	719,274,000	832,047,000
Commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	4,595,305,000	4,725,669,000
Nonaccrual	23,185,000	21,621,000
Total	4,626,057,000	4,764,813,000
Commercial real estate [Member] | Residential construction and land development [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	134,947,000	147,705,000
Nonaccrual	350,000	350,000
Total	135,361,000	148,584,000
Commercial real estate [Member] | Retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	779,037,000	884,424,000
Nonaccrual	20,132,000	20,279,000
Total	799,169,000	919,082,000
Commercial real estate [Member] | Office [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	1,013,420,000	1,072,920,000
Nonaccrual	855,000	0
Total	1,014,275,000	1,072,920,000
Commercial real estate [Member] | Multifamily [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	1,318,148,000	1,287,483,000
Nonaccrual	286,000	301,000
Total	1,324,839,000	1,288,065,000
Commercial real estate [Member] | Industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	872,627,000	776,898,000
Nonaccrual	909,000	0
Total	873,536,000	778,106,000
Commercial real estate [Member] | Other commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	477,126,000	556,239,000
Nonaccrual	653,000	691,000
Total	478,877,000	558,056,000
Residential mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	1,929,616,000	2,037,128,000
Nonaccrual	37,304,000	41,555,000
Total	2,117,303,000	2,230,033,000
Residential mortgage [Member] | Permanent mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	1,036,793,000	1,095,097,000
Nonaccrual	20,165,000	23,951,000
Total	1,066,460,000	1,122,610,000
Residential mortgage [Member] | Permanent mortgages guaranteed by US government agencies [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	47,207,000	37,459,000
Nonaccrual	6,332,000	7,132,000
Total	191,764,000	190,866,000
Residential mortgage [Member] | Home equity [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	845,616,000	904,572,000
Nonaccrual	10,807,000	10,472,000
Total	859,079,000	916,557,000
Personal [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	1,116,888,000	1,024,298,000
Nonaccrual	271,000	230,000
Total	1,117,382,000	1,025,806,000
30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	51,586,000	53,350,000
30 to 59 Days [Member] | Commercial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	12,955,000	7,675,000
30 to 59 Days [Member] | Commercial [Member] | Energy [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
30 to 59 Days [Member] | Commercial [Member] | Services [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	7,305,000	6,009,000
30 to 59 Days [Member] | Commercial [Member] | Wholesale/retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	2,910,000	515,000
30 to 59 Days [Member] | Commercial [Member] | Manufacturing [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	2,309,000	392,000
30 to 59 Days [Member] | Commercial [Member] | Healthcare [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	94,000	241,000
30 to 59 Days [Member] | Commercial [Member] | Public finance [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
30 to 59 Days [Member] | Commercial [Member] | Other commercial and industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	337,000	518,000
30 to 59 Days [Member] | Commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	6,740,000	16,529,000
30 to 59 Days [Member] | Commercial real estate [Member] | Residential construction and land development [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	249,000
30 to 59 Days [Member] | Commercial real estate [Member] | Retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	14,379,000
30 to 59 Days [Member] | Commercial real estate [Member] | Office [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
30 to 59 Days [Member] | Commercial real estate [Member] | Multifamily [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	6,405,000	281,000
30 to 59 Days [Member] | Commercial real estate [Member] | Industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	1,208,000
30 to 59 Days [Member] | Commercial real estate [Member] | Other commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	335,000	412,000
30 to 59 Days [Member] | Residential mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	31,791,000	28,667,000
30 to 59 Days [Member] | Residential mortgage [Member] | Permanent mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	6,097,000	3,196,000
30 to 59 Days [Member] | Residential mortgage [Member] | Permanent mortgages guaranteed by US government agencies [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	23,412,000	24,369,000
30 to 59 Days [Member] | Residential mortgage [Member] | Home equity [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	2,282,000	1,102,000
30 to 59 Days [Member] | Personal [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	100,000	479,000
60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	27,801,000	24,245,000
60 to 89 Days [Member] | Commercial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	2,146,000	6,106,000
60 to 89 Days [Member] | Commercial [Member] | Energy [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
60 to 89 Days [Member] | Commercial [Member] | Services [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	2,096,000	6,038,000
60 to 89 Days [Member] | Commercial [Member] | Wholesale/retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	37,000
60 to 89 Days [Member] | Commercial [Member] | Manufacturing [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	6,000
60 to 89 Days [Member] | Commercial [Member] | Healthcare [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	2,000	0
60 to 89 Days [Member] | Commercial [Member] | Public finance [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
60 to 89 Days [Member] | Commercial [Member] | Other commercial and industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	48,000	25,000
60 to 89 Days [Member] | Commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	106,000	280,000
60 to 89 Days [Member] | Commercial real estate [Member] | Residential construction and land development [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	280,000
60 to 89 Days [Member] | Commercial real estate [Member] | Retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
60 to 89 Days [Member] | Commercial real estate [Member] | Office [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
60 to 89 Days [Member] | Commercial real estate [Member] | Multifamily [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
60 to 89 Days [Member] | Commercial real estate [Member] | Industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
60 to 89 Days [Member] | Commercial real estate [Member] | Other commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	106,000	0
60 to 89 Days [Member] | Residential mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	25,455,000	17,063,000
60 to 89 Days [Member] | Residential mortgage [Member] | Permanent mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	3,405,000	366,000
60 to 89 Days [Member] | Residential mortgage [Member] | Permanent mortgages guaranteed by US government agencies [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	21,676,000	16,345,000
60 to 89 Days [Member] | Residential mortgage [Member] | Home equity [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	374,000	352,000
60 to 89 Days [Member] | Personal [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	94,000	796,000
90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	94,678,000	106,899,000
90 Days or More [Member] | Commercial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	791,000	562,000
90 Days or More [Member] | Commercial [Member] | Energy [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
90 Days or More [Member] | Commercial [Member] | Services [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	735,000	0
90 Days or More [Member] | Commercial [Member] | Wholesale/retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
90 Days or More [Member] | Commercial [Member] | Manufacturing [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
90 Days or More [Member] | Commercial [Member] | Healthcare [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	56,000	554,000
90 Days or More [Member] | Commercial [Member] | Public finance [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
90 Days or More [Member] | Commercial [Member] | Other commercial and industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	8,000
90 Days or More [Member] | Commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	721,000	714,000
90 Days or More [Member] | Commercial real estate [Member] | Residential construction and land development [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	64,000	0
90 Days or More [Member] | Commercial real estate [Member] | Retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
90 Days or More [Member] | Commercial real estate [Member] | Office [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
90 Days or More [Member] | Commercial real estate [Member] | Multifamily [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
90 Days or More [Member] | Commercial real estate [Member] | Industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
90 Days or More [Member] | Commercial real estate [Member] | Other commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	657,000	714,000
90 Days or More [Member] | Residential mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	93,137,000	105,620,000
90 Days or More [Member] | Residential mortgage [Member] | Permanent mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0
90 Days or More [Member] | Residential mortgage [Member] | Permanent mortgages guaranteed by US government agencies [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	93,137,000	105,561,000
90 Days or More [Member] | Residential mortgage [Member] | Home equity [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	59,000
90 Days or More [Member] | Personal [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	$ 29,000	$ 3,000

Leasing Leasing (Details)

Leasing Leasing (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Mar. 31, 2019
Leases [Abstract]
Operating Lease, Right-of-Use Asset	$ 180	$ 180	$ 137
Lease, Cost [Abstract]
Weighted-average remaining lease term	11 years	11 years
Weighted-average discount rate operating leases	3.20%	3.20%
Operating lease cost recognized as occupancy and equipment expense	$ 7.1	$ 19.3
Operating cash flows from operating leases	5.9	17.3
Short-term Lease, Cost	3.3	10.9
Finance Lease, Liability, Payment, Due, Rolling Maturity [Abstract]
Lessee, Operating Lease, Liability, Payments, Due Next Rolling Twelve Months	7	7
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Two	29.6	29.6
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Three	27.4	27.4
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Four	20.3	20.3
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Five	18.6	18.6
Lessee, Operating Lease, Liability, Payments, Due after Rolling Year Five	$ 136.3	$ 136.3

Mortgage Banking Activities, Co

Mortgage Banking Activities, Components of Loans Held For Sale (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
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	269,610	145,057
Residential mortgage loans held for sale, Fair value	272,489	146,971
Residential mortgage loans held for sale	$ 282,487	$ 149,221
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	$ 379,377	$ 160,848
Derivative, Net fair value	$ 10,111	$ 5,378
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	$ 649,161	$ 274,000
Derivative, Net fair value	$ (113)	$ (3,128)

Mortgage Banking Activities Mor

Mortgage Banking Activities Mortgage Banking Activities, Mortgage Banking Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Mortgage Banking Revenue [Abstract]
Net realized gains on sale of mortgage loans	$ 8,971	$ 9,063	$ 24,838	$ 28,699
Net change in unrealized gain on mortgage loans held for sale	97	(2,135)	965	(2,457)
Net change in the fair value of mortgage loan commitments	514	(2,446)	4,733	(1,496)
Net change in the fair value of forward sales contracts	4,232	2,768	3,015	1,871
Total production revenue	13,814	7,250	33,551	26,617
Servicing revenue	16,366	16,286	48,594	49,290
Total mortgage banking revenue	$ 30,180	$ 23,536	$ 82,145	$ 75,907

Mortgage Banking Activities, Mo

Mortgage Banking Activities, Mortgage Servicing Rights (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)
Summary of Mortgage Servicing Rights [Abstract]
Number of residential mortgage loans serviced for others	128,463		128,463		132,463
Outstanding principal balance of residential mortgage loans serviced for others	$ 21,046,136,000		$ 21,046,136,000		$ 21,658,335,000
Weighted average interest rate	3.99%		3.99%		3.99%
Remaining term (in months)			290 months		293 months
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 208,308,000	$ 278,719,000	$ 259,254,000	$ 252,867,000	$ 252,867,000
Additions, net	9,882,000	8,968,000	24,821,000	28,688,000
Change in fair value due to principal payments	(11,936,000)	(8,986,000)	(27,600,000)	(25,783,000)
Change in fair value due to market assumption changes	(12,593,000)	5,972,000	(62,814,000)	28,901,000
Ending balance	$ 193,661,000	$ 284,673,000	$ 193,661,000	$ 284,673,000	$ 259,254,000
Servicing Assets at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Discount rate - risk-free rate plus a market premium (in hundredths)			9.82%		9.90%
Prepayment rate - based upon loan interest rate, original term and loan type, minimum			8.31%		8.05%
Prepayment rate - based upon loan interest rate, original term and loan type, maximum			17.22%		15.74%
Loan servicing costs - annually per loan based upon loan type, performing, minimum (in dollars per loan)			$ 68		$ 67
Loan servicing costs - annually per loan based upon loan type, performing, maximum (in dollars per loan)			94		93
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)			1.51%		2.57%
Primary secondary mortgage rate spread	102		102		105

Commitments and Contingent Li_2

Commitments and Contingent Liabilities (Details)	9 Months Ended
	Sep. 30, 2019USD ($)
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
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

Commitments and Contingent Li_3

Commitments and Contingent Liabilities Variable Interest Entities (Details) $ in Millions	Sep. 30, 2019USD ($)
Other Assets [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	$ 245
Other Liabilities [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	$ 70

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands		Oct. 29, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019		Sep. 30, 2018		Dec. 31, 2018	Dec. 31, 2017
Dividends declared (in dollars per share)			$ 0.50	$ 0.50	$ 1.50		$ 1.40
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period					$ (72,585)		$ (36,174)
Transition adjustment for new accounting principle in period of adoption									$ 2,862	$ (2,709)
Net change in unrealized gain (loss)			$ 46,285	$ (35,941)	274,441		(166,464)
Reclassification adjustments included in earnings:
Loss (gain) on available for sale securities, net			(5)	(250)	(1,110)		802
Other comprehensive income (loss), before income taxes			46,280	(36,191)	273,331		(165,662)
Federal and state income taxes			11,096	(9,134)	66,993	[1]	(42,183)	[1]
Other comprehensive income (loss), net of income taxes			35,184	(27,057)	206,338		(123,479)
Balance, End of Period			133,753	(162,362)	133,753		(162,362)
Accumulated Net Unrealized Gain (Loss) on Available for Sale Securities [Member]
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period					(70,999)		(35,385)
Transition adjustment for new accounting principle in period of adoption										(2,709)
Net change in unrealized gain (loss)					274,441		(166,464)
Reclassification adjustments included in earnings:
Loss (gain) on available for sale securities, net					(1,110)		802
Other comprehensive income (loss), before income taxes					273,331		(165,662)
Federal and state income taxes	[1]				66,993		(42,183)
Other comprehensive income (loss), net of income taxes					206,338		(123,479)
Balance, End of Period			135,339	(161,573)	135,339		(161,573)
Accumulated Unrealized Gain (Loss) on Employee Benefit Plans [Member]
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period					(1,586)		(789)
Transition adjustment for new accounting principle in period of adoption										$ 0
Net change in unrealized gain (loss)					0		0
Reclassification adjustments included in earnings:
Loss (gain) on available for sale securities, net					0		0
Other comprehensive income (loss), before income taxes					0		0
Federal and state income taxes					0		0
Other comprehensive income (loss), net of income taxes					0		0
Balance, End of Period			$ (1,586)	$ (789)	$ (1,586)		$ (789)
Subsequent Event [Member]
Dividends Payable, Date Declared		Oct. 29, 2019
Dividends declared (in dollars per share)		$ 0.51
Dividends Payable, Date to be Paid		Nov. 27, 2019
Dividends Payable, Date of Record		Nov. 12, 2019
[1]	Calculated using a 25 percent blended federal and state statutory tax rate.

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator: [Abstract]
Net income attributable to BOK Financial Corp. shareholders	$ 142,231	$ 117,256	$ 390,406	$ 337,190
Less: Earnings allocated to participating securities	875	963	2,553	2,940
Numerator for basic earnings per share – income available to common shareholders	141,356	116,293	387,853	334,250
Effect of reallocating undistributed earnings of participating securities	1	1	1	1
Numerator for diluted earnings per share – income available to common shareholders	$ 141,357	$ 116,294	$ 387,854	$ 334,251
Denominator: [Abstract]
Weighted average shares outstanding (in shares)	71,033,405	65,438,849	71,425,855	65,455,306
Less: Participating securities included in weighted average shares (in shares)	437,098	537,754	472,311	571,987
Denominator for basic earnings per common share (in shares)	70,596,307	64,901,095	70,953,544	64,883,319
Dilutive effect of employee stock compensation plans (in shares)	13,617	33,256	15,301	36,409
Denominator for diluted earnings per common share (in shares)	70,609,924	64,934,351	70,968,845	64,919,728
Basic earnings per share (per share)	$ 2	$ 1.79	$ 5.47	$ 5.15
Diluted earnings per share (per share)	$ 2	$ 1.79	$ 5.47	$ 5.15
Excludes employee stock options with exercise prices greater than current market price.	0	0	0	0

Reportable Segments (Details)

Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019		Sep. 30, 2018
Segment Reporting Information [Line Items]
Net interest revenue from external sources	$ 279,096	$ 240,883	$ 842,630		$ 699,181
Net interest revenue (expense) from internal sources	0	0	0		0
Net interest revenue	279,096	240,883	842,630		699,181
Provision for credit losses	12,000	4,000	25,000		(1,000)
Net interest revenue after provision for credit losses	267,096	236,883	817,630		700,181
Other operating revenue	186,450	167,941	515,785		480,329
Other operating expense	279,292	252,617	843,586		743,523
Net direct contribution	174,254	152,207	489,829		436,987
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	174,254	152,207	489,829		436,987
Federal and state income taxes	32,396	34,662	99,926		98,940
Net income	141,858	117,545	389,903		338,047
Net income attributable to non-controlling interests	(373)	289	(503)		857
Net income attributable to BOK Financial Corp. shareholders	142,231	117,256	390,406		337,190
Average assets	43,582,110	33,695,817	41,380,843		33,775,495
Operating Segments [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	243,944	187,417	699,239		529,958
Net interest revenue (expense) from internal sources	(63,797)	(42,270)	(181,829)		(107,715)
Net interest revenue	180,147	145,147	517,410		422,243
Provision for credit losses	9,505	8,047	27,574		18,781
Net interest revenue after provision for credit losses	170,642	137,100	489,836		403,462
Other operating revenue	48,832	40,522	128,055		123,245
Other operating expense	68,685	51,039	181,809		148,796
Net direct contribution	150,789	126,583	436,082		377,911
Gain (loss) on financial instruments, net	28	(3)	67		13
Change in fair value of mortgage servicing rights	0	0	0		0
Gain (loss) on repossessed assets, net	802	(1,869)	455		(6,102)
Corporate expense allocations	12,613	9,124	34,146		29,092
Net income before taxes	139,006	115,587	402,458		342,730
Federal and state income taxes	37,433	30,623	107,807		90,943
Net income	101,573	84,964	294,651		251,787
Net income attributable to non-controlling interests	0	0	0		0
Net income attributable to BOK Financial Corp. shareholders	101,573	84,964	294,651		251,787
Average assets	23,973,067	18,499,979	22,288,129		18,124,571
Operating Segments [Member] | Consumer [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	27,580	20,005	75,353		63,504
Net interest revenue (expense) from internal sources	20,882	19,039	76,925		51,811
Net interest revenue	48,462	39,044	152,278		115,315
Provision for credit losses	1,841	1,451	4,654		3,890
Net interest revenue after provision for credit losses	46,621	37,593	147,624		111,425
Other operating revenue	51,221	44,024	142,780		135,291
Other operating expense	59,699	58,482	171,214		174,728
Net direct contribution	38,143	23,135	119,190		71,988
Gain (loss) on financial instruments, net	8,339	(7,229)	43,416		(36,901)
Change in fair value of mortgage servicing rights	(12,593)	5,972	(62,814)		28,901
Gain (loss) on repossessed assets, net	214	(87)	409		(21)
Corporate expense allocations	11,776	11,037	35,369		33,283
Net income before taxes	22,327	10,754	64,832		30,684
Federal and state income taxes	5,687	2,739	16,513		7,816
Net income	16,640	8,015	48,319		22,868
Net income attributable to non-controlling interests	0	0	0		0
Net income attributable to BOK Financial Corp. shareholders	16,640	8,015	48,319		22,868
Average assets	9,827,130	8,323,543	9,142,491		8,381,205
Operating Segments [Member] | Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	12,343	22,509	51,054		56,990
Net interest revenue (expense) from internal sources	10,723	6,267	27,213		26,431
Net interest revenue	23,066	28,776	78,267		83,421
Provision for credit losses	(42)	(84)	(209)		(238)
Net interest revenue after provision for credit losses	23,108	28,860	78,476		83,659
Other operating revenue	89,160	83,357	248,591		228,766
Other operating expense	71,619	62,256	202,579		188,691
Net direct contribution	40,649	49,961	124,488		123,734
Gain (loss) on financial instruments, net	0	7	0		7
Change in fair value of mortgage servicing rights	0	0	0		0
Gain (loss) on repossessed assets, net	0	0	0		0
Corporate expense allocations	9,416	11,127	26,943		31,084
Net income before taxes	31,233	38,841	97,545		92,657
Federal and state income taxes	8,027	9,975	25,076		23,824
Net income	23,206	28,866	72,469		68,833
Net income attributable to non-controlling interests	0	0	0		0
Net income attributable to BOK Financial Corp. shareholders	23,206	28,866	72,469		68,833
Average assets	10,392,988	8,498,363	9,861,021		8,364,712
Funds Management and Other [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	(4,771)	10,952	16,984	[1]	48,729
Net interest revenue (expense) from internal sources	32,192	16,964	77,691	[1]	29,473
Net interest revenue	27,421	27,916	94,675	[1]	78,202
Provision for credit losses	696	(5,414)	(7,019)	[1]	(23,433)
Net interest revenue after provision for credit losses	26,725	33,330	101,694	[1]	101,635
Other operating revenue	(2,763)	38	(3,641)	[1]	(6,973)
Other operating expense	79,289	80,840	287,984	[1]	231,308
Net direct contribution	(55,327)	(47,472)	(189,931)	[1]	(136,646)
Gain (loss) on financial instruments, net	(8,367)	7,225	(43,483)	[1]	36,881
Change in fair value of mortgage servicing rights	12,593	(5,972)	62,814	[1]	(28,901)
Gain (loss) on repossessed assets, net	(1,016)	1,956	(864)	[1]	6,123
Corporate expense allocations	(33,805)	(31,288)	(96,458)	[1]	(93,459)
Net income before taxes	(18,312)	(12,975)	(75,006)	[1]	(29,084)
Federal and state income taxes	(18,751)	(8,675)	(49,470)	[1]	(23,643)
Net income	439	(4,300)	(25,536)	[1]	(5,441)
Net income attributable to non-controlling interests	(373)	289	(503)	[1]	857
Net income attributable to BOK Financial Corp. shareholders	812	(4,589)	(25,033)	[1]	(6,298)
Average assets	$ (611,075)	$ (1,626,068)	$ 89,202	[1]	$ (1,094,993)
[1]	CoBiz operations are included in Funds Management and Other for the first quarter of 2019 and subsequently allocated to the respective segments in the second quarter of 2019.

Fees and Commissions Revenue _3

Fees and Commissions Revenue Fees and Commissions (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2019		Sep. 30, 2018		Sep. 30, 2019		Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Total fees and commissions	$ 186,119		$ 166,197		$ 522,779		$ 483,069
Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	186,119		166,197		522,779		483,069
Fees and commission revenue not from contracts with customers	74,529	[1]	47,089	[2]	193,585	[3]	159,009	[4]
Fees and commissions revenue from contracts with customers	111,590	[5]	119,108	[6]	329,194	[7]	324,060	[8]
Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	43,840		23,086		115,983		80,222
Fees and commission revenue not from contracts with customers	32,537	[1]	14,754	[2]	82,785	[3]	55,550	[4]
Fees and commissions revenue from contracts with customers	11,303	[5]	8,332	[6]	33,198	[7]	24,672	[8]
Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	24,091		4,830		58,890		21,562
Fees and commission revenue not from contracts with customers	24,091	[1]	4,830	[2]	58,890	[3]	21,562	[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	4,684		8,514		16,706		29,216
Fees and commission revenue not from contracts with customers	4,684	[1]	8,514	[2]	16,706	[3]	29,216	[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	4,204		4,325		12,127		13,505
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	4,204	[5]	4,325	[6]	12,127	[7]	13,505	[8]
Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	2,862		170		10,792		555
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	2,862		170		10,792	[7]	555	[8]
Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	7,999		5,247		17,468		15,384
Fees and commission revenue not from contracts with customers	3,762	[1]	1,410	[2]	7,189	[3]	4,772	[4]
Fees and commissions revenue from contracts with customers	4,237	[5]	3,837	[6]	10,279	[7]	10,612	[8]
Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	22,015		21,396		64,668		63,361
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	22,015	[5]	21,396	[6]	64,668	[7]	63,361	[8]
TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	19,464		19,387		57,541		57,596
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	19,464	[5]	19,387	[6]	57,541	[7]	57,596	[8]
Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	2,217		2,009		6,516		5,765
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	2,217	[5]	2,009	[6]	6,516	[7]	5,765	[8]
Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	334		0		611		0
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	334	[5]	0	[6]	611	[7]	0	[8]
Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	43,621		57,514		132,004		141,038
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	43,621	[5]	57,514	[6]	132,004	[7]	141,038	[8]
Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	20,238		35,823		61,028		76,479
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	20,238	[5]	35,823	[6]	61,028	[7]	76,479	[8]
Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	6,205		5,741		18,736		16,317
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	6,205	[5]	5,741	[6]	18,736	[7]	16,317	[8]
Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	10,740		11,094		32,919		33,587
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	10,740	[5]	11,094	[6]	32,919	[7]	33,587	[8]
Investment management services and other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	6,438		4,856		19,321		14,655
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	6,438	[5]	4,856	[6]	19,321	[7]	14,655	[8]
Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	28,837		27,765		85,154		82,760
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	28,837	[5]	27,765	[6]	85,154	[7]	82,760	[8]
Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	11,613		11,244		35,988		35,036
Fees and commission revenue not from contracts with customers	0	[1]	0	[2]	0	[3]	0	[4]
Fees and commissions revenue from contracts with customers	11,613	[5]	11,244	[6]	35,988	[7]	35,036	[8]
Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	9,732		9,541		27,096		27,057
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	9,732	[5]	9,541	[6]	27,096	[7]	27,057	[8]
Check card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	5,721		5,254		16,464		15,515
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	5,721	[5]	5,254	[6]	16,464	[7]	15,515	[8]
Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	1,771		1,726		5,606		5,152
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	1,771	[5]	1,726	[6]	5,606	[7]	5,152	[8]
Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	30,180		23,536		82,145		75,907
Fees and commission revenue not from contracts with customers	30,180	[1]	23,536	[2]	82,145	[3]	75,907	[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	13,814		7,250		33,551		26,617
Fees and commission revenue not from contracts with customers	13,814	[1]	7,250	[2]	33,551	[3]	26,617	[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	16,366		16,286		48,594		49,290
Fees and commission revenue not from contracts with customers	16,366	[1]	16,286	[2]	48,594	[3]	49,290	[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	17,626		12,900		42,825		39,781
Fees and commission revenue not from contracts with customers	11,812	[1]	8,799	[2]	28,655	[3]	27,552	[4]
Fees and commissions revenue from contracts with customers	5,814	[5]	4,101	[6]	14,170	[7]	12,229	[8]
Operating Segments [Member] | Commercial [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	46,159		39,391		125,310		122,282
Operating Segments [Member] | Commercial [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	6,691		3,115		14,588		11,993
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	2,283		1,350		6,243		6,264
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	4,408		1,765		8,345		5,729
Operating Segments [Member] | Commercial [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	20,996		20,392		61,572		60,367
Operating Segments [Member] | Commercial [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	18,465		18,397		54,623		54,647
Operating Segments [Member] | Commercial [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	2,203		1,995		6,351		5,720
Operating Segments [Member] | Commercial [Member] | Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	328		0		598		0
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	10,887		10,424		32,113		32,543
Operating Segments [Member] | Commercial [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	10,609		10,294		31,296		32,150
Operating Segments [Member] | Commercial [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	81		95		248		283
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	197		35		569		110
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	7,585		5,460		17,037		17,379
Operating Segments [Member] | Consumer [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	51,461		44,038		143,112		135,334
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	1,034		1,023		3,018		3,050
Operating Segments [Member] | Consumer [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	1,020		1,009		2,975		3,005
Operating Segments [Member] | Consumer [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	14		14		43		45
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	17,310		16,694		49,315		48,220
Operating Segments [Member] | Consumer [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	467		366		1,283		1,087
Operating Segments [Member] | Consumer [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	9,603		9,413		26,971		26,665
Operating Segments [Member] | Consumer [Member] | Check card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	5,721		5,254		16,299		15,515
Operating Segments [Member] | Consumer [Member] | Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	1,519		1,661		4,762		4,953
Operating Segments [Member] | Consumer [Member] | Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	30,643		23,998		83,568		77,294
Operating Segments [Member] | Consumer [Member] | Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	13,815		7,250		33,554		26,617
Operating Segments [Member] | Consumer [Member] | Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	16,828		16,748		50,014		50,677
Operating Segments [Member] | Consumer [Member] | Other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	2,474		2,323		7,211		6,770
Operating Segments [Member] | Wealth Management [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	89,422		83,562		248,603		228,858
Operating Segments [Member] | Wealth Management [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	37,070		19,815		96,712		67,034
Operating Segments [Member] | Wealth Management [Member] | Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	24,091		4,830		58,890		21,562
Operating Segments [Member] | Wealth Management [Member] | Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	1,810		6,935		9,444		21,511
Operating Segments [Member] | Wealth Management [Member] | Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	4,204		4,398		12,192		13,751
Operating Segments [Member] | Wealth Management [Member] | Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3,375		170		7,063		555
Operating Segments [Member] | Wealth Management [Member] | Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3,590		3,482		9,123		9,655
Operating Segments [Member] | Wealth Management [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(17)		(21)		(49)		(61)
Operating Segments [Member] | Wealth Management [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(23)		(21)		(60)		(61)
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	6		0		11		0
Operating Segments [Member] | Wealth Management [Member] | Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	43,663		57,561		130,413		141,190
Operating Segments [Member] | Wealth Management [Member] | Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	20,239		35,822		61,028		76,481
Operating Segments [Member] | Wealth Management [Member] | Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	6,204		5,741		18,736		16,317
Operating Segments [Member] | Wealth Management [Member] | Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	10,740		11,095		32,919		33,584
Operating Segments [Member] | Wealth Management [Member] | Investment management services and other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	6,480		4,903		17,730		14,808
Operating Segments [Member] | Wealth Management [Member] | Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	638		639		1,941		1,970
Operating Segments [Member] | Wealth Management [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	540		587		1,605		1,802
Operating Segments [Member] | Wealth Management [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	45		30		108		96
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	53		22		228		72
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	8,068		5,568		19,586		18,725
Funds Management and Other [Member] | Fees and commissions revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(923)	[9]	(794)		5,754	[10]	(3,405)
Funds Management and Other [Member] | Brokerage and trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	79	[9]	156		4,683	[10]	1,195
Funds Management and Other [Member] | Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0	[9]	0		0	[10]	0
Funds Management and Other [Member] | Customer hedging revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	591	[9]	229		1,019	[10]	1,441
Funds Management and Other [Member] | Retail brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0	[9]	(73)		(65)	[10]	(246)
Funds Management and Other [Member] | Insurance brokerage revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(513)	[9]	0		3,729	[10]	0
Funds Management and Other [Member] | Investment banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	1	[9]	0		0	[10]	0
Funds Management and Other [Member] | Transaction card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	2	[9]	2		127	[10]	5
Funds Management and Other [Member] | TransFund EFT network revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	2	[9]	2		3	[10]	5
Funds Management and Other [Member] | Merchant services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0	[9]	0		122	[10]	0
Funds Management and Other [Member] | Corporate card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0	[9]	0		2	[10]	0
Funds Management and Other [Member] | Fiduciary and asset management revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(42)	[9]	(47)		1,591	[10]	(152)
Funds Management and Other [Member] | Personal trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(1)	[9]	1		0	[10]	(2)
Funds Management and Other [Member] | Corporate trust revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	1	[9]	0		0	[10]	0
Funds Management and Other [Member] | Institutional trust & retirement plan services revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0	[9]	(1)		0	[10]	3
Funds Management and Other [Member] | Investment management services and other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(42)	[9]	(47)		1,591	[10]	(153)
Funds Management and Other [Member] | Deposit service charges and fees [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	2	[9]	8		1,785	[10]	27
Funds Management and Other [Member] | Commercial account service charge revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(3)	[9]	(3)		1,804	[10]	(3)
Funds Management and Other [Member] | Overdraft fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	3	[9]	3		(231)	[10]	13
Funds Management and Other [Member] | Check card revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	0	[9]	0		165	[10]	0
Funds Management and Other [Member] | Automated service charge and other deposit fee revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	2	[9]	8		47	[10]	17
Funds Management and Other [Member] | Mortgage banking revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(463)	[9]	(462)		(1,423)	[10]	(1,387)
Funds Management and Other [Member] | Mortgage production revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(1)	[9]	0		(3)	[10]	0
Funds Management and Other [Member] | Mortgage servicing revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	(462)	[9]	(462)		(1,420)	[10]	(1,387)
Funds Management and Other [Member] | Other revenue [Member]
Disaggregation of Revenue [Line Items]
Total fees and commissions	$ (501)	[9]	$ (451)		$ (1,009)	[10]	$ (3,093)
[1]	Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance.
[2]	Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance.
[3]	Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance.
[4]	Out of scope revenue generally relates to financial instruments or contractual rights and obligations within the scope of other applicable accounting guidance.
[5]	In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers.
[6]	In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers.
[7]	In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers.
[8]	In scope revenue represents revenue subject to FASB ASC Topic 606, Revenue from Contracts with Customers.
[9]	CoBiz operations are included in Funds Management and Other for the first quarter of 2019.
[10]	CoBiz operations are included in Funds Management and Other for the first quarter of 2019.

Fair Value Measurements, Fair V

Fair Value Measurements, Fair Value Of Financial Instruments as Measured On a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2019		Jun. 30, 2019	Dec. 31, 2018		Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Assets: [Abstract]
Trading securities	$ 1,675,212			$ 1,956,923
Available for sale securities	11,024,551			8,857,120
Fair value option securities	1,816,398			283,235
Mortgage servicing rights	193,661		$ 208,308	259,254		$ 284,673	$ 278,719	$ 252,867
Derviative contracts, net of cash collateral, Assets, Fair value	352,019			320,929
Liabilities: [Abstract]
Derivative contracts, net of cash collateral, Liabilities, Fair Value	336,791			362,306
U.S. government agency debentures [Member]
Assets: [Abstract]
Trading securities	63,334			63,765
Residential agency mortgage-backed securities [Member]
Assets: [Abstract]
Trading securities	1,480,458			1,791,584
Available for sale securities	7,740,461			5,804,708
Fair value option securities	1,263,862			283,235
Municipal and other tax-exempt securities [Member]
Assets: [Abstract]
Trading securities	44,105			34,507
Available for sale securities	1,848			2,864
Asset-backed securities [Member]
Assets: [Abstract]
Trading securities	36,928			42,656
U.S. Treasury [Member]
Assets: [Abstract]
Available for sale securities	2,296			493
Fair value option securities	552,536			0
Residential non-agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	44,803			59,736
Commercial agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	3,234,671			2,953,889
Other debt securities [Member]
Assets: [Abstract]
Trading securities	50,387			24,411
Available for sale securities	472			35,430
Fair Value, Recurring [Member]
Assets: [Abstract]
Trading securities	1,675,212			1,956,923
Available for sale securities	11,024,551			8,857,120
Fair value option securities	1,816,398
Residential mortgage loans held for sale	282,487			149,221
Mortgage servicing rights	193,661	[1]		259,254	[2]
Derviative contracts, net of cash collateral, Assets, Fair value	352,019	[3]		320,929	[4]
Liabilities: [Abstract]
Derivative contracts, net of cash collateral, Liabilities, Fair Value	336,791	[3]		362,306	[4]
Fair Value, Recurring [Member] | U.S. government agency debentures [Member]
Assets: [Abstract]
Trading securities	63,334			63,765
Fair Value, Recurring [Member] | Residential agency mortgage-backed securities [Member]
Assets: [Abstract]
Trading securities	1,480,458			1,791,584
Available for sale securities	7,740,461			5,804,708
Fair value option securities	1,263,862			283,235
Fair Value, Recurring [Member] | Municipal and other tax-exempt securities [Member]
Assets: [Abstract]
Trading securities	44,105			34,507
Available for sale securities	1,848			2,864
Fair Value, Recurring [Member] | Asset-backed securities [Member]
Assets: [Abstract]
Trading securities	36,928			42,656
Fair Value, Recurring [Member] | U.S. Treasury [Member]
Assets: [Abstract]
Available for sale securities	2,296			493
Fair value option securities	552,536
Fair Value, Recurring [Member] | Residential non-agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	44,803			59,736
Fair Value, Recurring [Member] | Commercial agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	3,234,671			2,953,889
Fair Value, Recurring [Member] | Other debt securities [Member]
Assets: [Abstract]
Trading securities	50,387			24,411
Available for sale securities	472			35,430
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets: [Abstract]
Trading securities	0			0
Available for sale securities	2,296			493
Fair value option securities	552,536
Residential mortgage loans held for sale	0			0
Mortgage servicing rights	0	[1]		0	[2]
Derviative contracts, net of cash collateral, Assets, Fair value	40,491	[3]		44,074	[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	2,296			493
Fair value option securities	552,536
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	1,675,212			1,956,923
Available for sale securities	11,021,783			8,856,155
Fair value option securities	1,263,862
Residential mortgage loans held for sale	268,919			134,014
Mortgage servicing rights	0	[1]		0	[2]
Derviative contracts, net of cash collateral, Assets, Fair value	311,528	[3]		276,855	[4]
Liabilities: [Abstract]
Derivative contracts, net of cash collateral, Liabilities, Fair Value	336,791	[3]		362,306	[4]
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. government agency debentures [Member]
Assets: [Abstract]
Trading securities	63,334			63,765
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential agency mortgage-backed securities [Member]
Assets: [Abstract]
Trading securities	1,480,458			1,791,584
Available for sale securities	7,740,461			5,804,708
Fair value option securities	1,263,862			283,235
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal and other tax-exempt securities [Member]
Assets: [Abstract]
Trading securities	44,105			34,507
Available for sale securities	1,848			2,864
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed securities [Member]
Assets: [Abstract]
Trading securities	36,928			42,656
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Treasury [Member]
Assets: [Abstract]
Available for sale securities	0			0
Fair value option securities	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential non-agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	44,803			59,736
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial agency mortgage-backed securities [Member]
Assets: [Abstract]
Available for sale securities	3,234,671			2,953,889
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other debt securities [Member]
Assets: [Abstract]
Trading securities	50,387			24,411
Available for sale securities	0			34,958
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets: [Abstract]
Trading securities	0			0
Available for sale securities	472			472
Fair value option securities	0
Residential mortgage loans held for sale	13,568			15,207
Mortgage servicing rights	193,661	[1]		259,254	[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
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 6 , 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 6 , 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, interest rate and agricultural 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 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, energy and agricultural 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 contracts, fully offset by cash margin.

Fair Value Measurements, Measur

Fair Value Measurements, Measured On Recurring Basis Significant Unobservable Inputs (Details) - Fair Value, Recurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2019		Sep. 30, 2018		Sep. 30, 2019		Sep. 30, 2018
Available-for-sale securities [Member] | Municipal and other tax-exempt securities [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period			$ 2,030				$ 4,802
Transfer to Level 3 from Level 2			0	[1]			0	[2]
Purchases			0				0
Proceeds from sales			0				0
Redemptions and distributions			(2,050)				(5,095)
Other comprehensive income (loss)			20				293
Balance, end of period			0				0
Available-for-sale securities [Member] | Municipal and other tax-exempt securities [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings			0				0
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		471		$ 472		472
Transfer to Level 3 from Level 2	0	[3]	0	[1]	0	[3]	0	[2]
Purchases	0		0		0		0
Proceeds from sales	0		0		0		0
Redemptions and distributions	0		0		0		0
Other comprehensive income (loss)	0		1		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	16,073		14,243		15,207		12,299
Transfer to Level 3 from Level 2	261	[3]	2,862	[1]	2,150	[3]	5,603	[2]
Purchases	0		0		0		0
Proceeds from sales	(3,152)		(143)		(4,531)		(853)
Redemptions and distributions	0		0		0		0
Other comprehensive income (loss)	0		0		0		0
Balance, end of period	13,568		16,838		13,568		16,838
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	$ 386		$ (124)		$ 742		$ (211)
[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.

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Measurements, Financial Instruments Measured On a Recurring Basis, Quantitative Information (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	$ 11,024,551	$ 8,857,120
Other debt securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	472	35,430
Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	11,024,551	8,857,120
Residential mortgage loans held for sale	282,487	149,221
Fair Value, Recurring [Member] | Other debt securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale securities	472	35,430
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	13,568	15,207
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	3.00%	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	96.36%	92.38%
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	$ 13,568	$ 15,207
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	7.46%	7.88%
Range of fair value as a percentage of par value	94.42%	94.44%
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	7.46%	7.88%
Range of fair value as a percentage of par value	94.42%	94.44%
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	7.46%	7.88%
Range of fair value as a percentage of par value	94.42%	94.44%

Fair Value Measurements, Fair_2

Fair Value Measurements, Fair Value Measured On a Nonrecurring Basis (Details) - Fair Value, Nonrecurring [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross charge-offs against allowance for loan losses	$ 2,644	$ 9,086	$ 13,868	$ 16,279
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	(979)	2,161	(532)	7,388
Fair Value, Inputs, Level 1 [Member] | Impaired 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] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	79	1,065	79	1,065
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	5,044	4,608	5,044	4,608
Fair Value, Inputs, Level 3 [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	9,810	24,428	9,810	24,428
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	$ 936	$ 6,545	$ 936	$ 6,545

Fair Value Measurements Fair _2

Fair Value Measurements Fair Value Measurement, Measured On Non-Recurring Basis, Signfiicant Unobservable Inputs, Quantitative Information (Details) - Fair Value, Nonrecurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Impaired Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 9,810	$ 24,428
Real estate and other repossessed assets [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	936	6,545
Discounted Cash Flow [Member] | Impaired Loans [Member] | Management knowledge of Industry [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	9,810	24,428
Discounted Cash Flow [Member] | Real estate and other repossessed assets [Member] | Marketability adjustments off appraised value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 936
Discounted Cash Flow [Member] | Real estate and other repossessed assets [Member] | Recoverable oil and gas reserves, forward-looking commodity prices, and estimated operating costs [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure		$ 6,545
Minimum [Member] | Impaired Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value of Impaired Loans as Percentage of Unpaid Principal Balance	8.00%	41.00%
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	75.00%
Maximum [Member] | Impaired Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value of Impaired Loans as Percentage of Unpaid Principal Balance	76.00%	84.00%
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	89.00%
Weighted Average [Member] | Impaired Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value of Impaired Loans as Percentage of Unpaid Principal Balance	28.00%	55.00%
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	85.00%

Fair Value Measurements, Financ

Fair Value Measurements, Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	$ 1,675,212		$ 1,956,923
Investment securities	304,224		355,187
Available for sale securities	11,024,551		8,857,120
Fair value option securities	1,816,398		283,235
Residential mortgage loans held for sale	282,487		149,221
Loans	22,285,367		21,656,730
Allowance for loan losses	(204,432)	$ (202,534)	(207,457)	$ (210,569)	$ (215,142)	$ (230,682)
Loans, net of allowance	22,080,935		21,449,273
Mortgage servicing rights	193,661	208,308	259,254	284,673	278,719	252,867
Derviative contracts, net of cash collateral, Assets, Fair value	352,019		320,929
Time deposits	2,243,541		2,113,380
Subordinated debentures	275,909		275,913
Derivative contracts, net of cash collateral, Liabilities, Fair Value	336,791		362,306
Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	14,424,625		13,636,078
Allowance for loan losses	(106,643)	(106,397)	(102,226)	(104,098)	(113,722)	(124,269)
Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,626,057		4,764,813
Allowance for loan losses	(54,350)	(54,188)	(60,026)	(60,189)	(58,758)	(56,621)
Residential mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,117,303		2,230,033
Allowance for loan losses	(15,534)	(15,724)	(17,964)	(18,683)	(18,544)	(18,451)
Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,117,382		1,025,806
Allowance for loan losses	(10,150)	$ (9,388)	(9,473)	$ (8,709)	$ (8,646)	$ (9,124)
U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	63,334		63,765
Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	1,480,458		1,791,584
Investment securities	11,125		12,612
Available for sale securities	7,740,461		5,804,708
Fair value option securities	1,263,862		283,235
Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	44,105		34,507
Investment securities	104,418		137,296
Available for sale securities	1,848		2,864
U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,296		493
Fair value option securities	552,536		0
Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	44,803		59,736
Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	3,234,671		2,953,889
Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	50,387		24,411
Investment securities	188,681		205,279
Available for sale securities	472		35,430
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	761,130		741,749
Interest-bearing cash and cash equivalents	465,458		401,675
Trading securities	1,675,212		1,956,923
Investment securities	304,224		355,187
Available for sale securities	11,024,551		8,857,120
Fair value option securities	1,816,398
Residential mortgage loans held for sale	282,487		149,221
Loans	22,285,367		21,656,730
Allowance for loan losses	(204,432)		(207,457)
Loans, net of allowance	22,080,935		21,449,273
Mortgage servicing rights	193,661		259,254
Derviative contracts, net of cash collateral, Assets, Fair value	352,019		320,929
Deposits with no stated maturity	23,923,535		23,150,383
Time deposits	2,243,541		2,113,380
Other borrowed funds	10,235,385		7,142,801
Subordinated debentures	275,909		275,913
Derivative contracts, net of cash collateral, Liabilities, Fair Value	336,791		362,306
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	14,424,625		13,636,078
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,626,057		4,764,813
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Residential mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,117,303		2,230,033
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,117,382		1,025,806
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	63,334		63,765
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	1,480,458		1,791,584
Investment securities	11,125		12,612
Available for sale securities	7,740,461		5,804,708
Fair value option securities	1,263,862		283,235
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	44,105		34,507
Investment securities	104,418		137,296
Available for sale securities	1,848		2,864
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Asset-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	36,928		42,656
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	50,387		24,411
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	2,296		493
Fair value option securities	552,536
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	44,803		59,736
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	3,234,671		2,953,889
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	188,681		205,279
Available for sale securities	472		35,430
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	761,130		741,749
Interest-bearing cash and cash equivalents	465,458		401,675
Trading securities	1,675,212		1,956,923
Investment securities	324,021		367,298
Available for sale securities	11,024,551		8,857,120
Fair value option securities	1,816,398
Residential mortgage loans held for sale	282,487		149,221
Loans	22,265,792		21,478,228
Allowance for loan losses	0		0
Loans, net of allowance	22,265,792		21,478,228
Mortgage servicing rights	193,661		259,254
Derviative contracts, net of cash collateral, Assets, Fair value	352,019		320,929
Deposits with no stated maturity	23,923,535		23,150,383
Time deposits	2,241,778		2,073,538
Other borrowed funds	10,193,602		7,071,953
Subordinated debentures	276,393		261,977
Derivative contracts, net of cash collateral, Liabilities, Fair Value	336,791		362,306
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	14,397,846		13,526,162
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	4,626,804		4,713,747
Estimate of Fair Value, Fair Value Disclosure [Member] | Residential mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,132,158		2,213,951
Estimate of Fair Value, Fair Value Disclosure [Member] | Personal [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,108,984		1,024,368
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	63,334		63,765
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	1,480,458		1,791,584
Investment securities	11,650		12,770
Available for sale securities	7,740,461		5,804,708
Fair value option securities	1,263,862		283,235
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	44,105		34,507
Investment securities	107,647		138,562
Available for sale securities	1,848		2,864
Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	36,928		42,656
Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	50,387		24,411
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	2,296		493
Fair value option securities	552,536
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	44,803		59,736
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	3,234,671		2,953,889
Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	204,724		215,966
Available for sale securities	472		35,430
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	761,130		741,749
Interest-bearing cash and cash equivalents	465,458		401,675
Trading securities	0		0
Investment securities	0		0
Available for sale securities	2,296		493
Fair value option securities	552,536
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	40,491		44,074
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		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		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	0		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	0		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	2,296		493
Fair value option securities	552,536
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	0		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	1,675,212		1,956,923
Investment securities	126,999		159,237
Available for sale securities	11,021,783		8,856,155
Fair value option securities	1,263,862
Residential mortgage loans held for sale	268,919		134,014
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	311,528		276,855
Deposits with no stated maturity	0		0
Time deposits	0		0
Other borrowed funds	0		0
Subordinated debentures	276,393		261,977
Derivative contracts, net of cash collateral, Liabilities, Fair Value	336,791		362,306
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		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		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	63,334		63,765
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	1,480,458		1,791,584
Investment securities	11,650		12,770
Available for sale securities	7,740,461		5,804,708
Fair value option securities	1,263,862		283,235
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	44,105		34,507
Investment securities	107,647		138,562
Available for sale securities	1,848		2,864
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	36,928		42,656
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	50,387		24,411
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0		0
Fair value option securities	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	44,803		59,736
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	3,234,671		2,953,889
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	7,702		7,905
Available for sale securities	0		34,958
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	197,022		208,061
Available for sale securities	472		472
Fair value option securities	0
Residential mortgage loans held for sale	13,568		15,207
Loans	22,265,792		21,478,228
Allowance for loan losses	0		0
Loans, net of allowance	22,265,792		21,478,228
Mortgage servicing rights	193,661		259,254
Derviative contracts, net of cash collateral, Assets, Fair value	0		0
Deposits with no stated maturity	23,923,535		23,150,383
Time deposits	2,241,778		2,073,538
Other borrowed funds	10,193,602		7,071,953
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	14,397,846		13,526,162
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	4,626,804		4,713,747
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	2,132,158		2,213,951
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	1,108,984		1,024,368
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	0		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	0		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
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	197,022		208,061
Available for sale securities	$ 472		$ 472