BOK Financial (BOKF) 10-Q 31 Oct 16 2016 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	BOK FINANCIAL CORP ET AL
Entity Central Index Key	875,357
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	Yes
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float		$ 1,588,744,146
Entity Common Stock, Shares Outstanding	65,910,454
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016

Consolidated Statements of Earn

Consolidated Statements of Earnings (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Interest revenue [Abstract]
Loans	$ 146,840	$ 132,985	$ 427,512	$ 392,878
Residential mortgage loans held for sale	3,615	3,793	9,823	10,634
Trading securities	2,996	669	4,136	1,618
Taxable securities	3,000	3,211	9,244	9,788
Tax-exempt securities	1,132	1,274	3,492	3,933
Total investment securities	4,132	4,485	12,736	13,721
Taxable securities	42,513	43,473	130,790	128,933
Tax-exempt securities	529	535	1,591	1,718
Total available for sale securities	43,042	44,008	132,381	130,651
Fair value option securities	1,531	2,480	6,182	6,803
Restricted equity securities	4,510	3,802	12,684	9,627
Interest-bearing cash and cash equivalents	2,651	1,442	7,926	4,114
Total interest revenue	209,317	193,664	613,380	570,046
Interest expense [Abstract]
Deposits	9,812	10,731	30,351	34,102
Borrowed funds	9,191	3,701	25,943	9,395
Subordinated debentures	2,468	596	4,056	4,456
Total interest expense	21,471	15,028	60,350	47,953
Net interest revenue	187,846	178,636	553,030	522,093
Provision for credit losses	10,000	7,500	65,000	11,500
Net interest revenue after provision for credit losses	177,846	171,136	488,030	510,593
Other operating revenue [Abstract]
Brokerage and trading revenue	38,006	31,582	109,877	99,301
Transaction card revenue	33,933	32,514	101,237	96,302
Fiduciary and asset management revenue	34,073	30,807	100,942	94,988
Deposit service charges and fees	23,668	23,606	68,828	67,618
Mortgage banking revenue	42,548	33,170	115,202	109,336
Other revenue	13,080	12,978	38,336	35,650
Total fees and commissions	185,308	164,657	534,422	503,195
Other gains, net	2,442	1,161	5,309	3,373
Gain on derivatives, net	2,226	1,283	20,130	1,162
Gain (loss) on fair value option securities, net	(3,355)	5,926	10,367	443
Change in fair value of mortgage servicing rights	2,327	(11,757)	(41,944)	(12,269)
Gain on available for sale securities, net	2,394	2,166	11,684	9,926
Total other-than-temporary impairment losses	0	0	0	(781)
Portion of loss recognized in other comprehensive income	0	0	0	689
Net impairment losses recognized in earnings	0	0	0	(92)
Total other operating revenue	191,342	163,436	539,968	505,738
Other operating expense [Abstract]
Personnel	143,185	129,062	421,518	390,305
Business promotion	6,839	5,922	19,238	19,435
Charitable contributions to BOKF Foundation	0	796	0	796
Professional fees and services	14,038	10,147	39,955	29,766
Net occupancy and equipment	20,111	18,689	58,554	56,660
Insurance	9,390	4,864	23,784	14,960
Data processing and communications	33,331	30,708	98,150	91,135
Printing, postage and supplies	3,790	3,376	11,586	10,390
Net losses (gains) and operating expenses of repossessed assets	(926)	267	1,732	1,103
Amortization of intangible assets	1,521	1,089	5,304	3,269
Mortgage banking costs	16,022	9,107	44,210	27,501
Other expense	14,819	10,601	37,714	26,686
Total other operating expense	262,120	224,628	761,745	672,006
Net income before taxes	107,068	109,944	266,253	344,325
Federal and state income taxes	31,956	34,128	83,881	113,142
Net income	75,112	75,816	182,372	231,183
Net income (loss) attributable to non-controlling interests	835	925	(270)	2,219
Net income attributable to BOK Financial Corporation shareholders	$ 74,277	$ 74,891	$ 182,642	$ 228,964
Earnings per share: [Abstract]
Basic	$ 1.13	$ 1.09	$ 2.77	$ 3.33
Diluted	$ 1.13	$ 1.09	$ 2.76	$ 3.32
Average shares used in computation: [Abstract]
Basic	65,085,392	67,668,076	65,208,774	68,004,508
Diluted	65,157,841	67,762,483	65,263,566	68,104,017
Dividends declared per share	$ 0.43	$ 0.42	$ 1.29	$ 1.26

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016		Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 75,112	$ 75,816	$ 182,372		$ 231,183
Other comprehensive income (loss) before income taxes:
Net change in unrealized gain (loss)	(33,458)	57,892	133,108		57,763
Reclassification adjustments included in earnings:
Interest revenue, Investment securities, Taxable securities	0	(105)	(112)		(418)
Interest expense, Subordinated debentures	0	0	0		121
Net impairment losses recognized in earnings	0	0	0		92
Gain on available for sale securities, net	(2,394)	(2,166)	(11,684)		(9,926)
Other comprehensive income (loss) before income taxes	(35,852)	55,621	121,312		47,632
Federal and state income taxes	(13,947)	21,637	47,172	[1]	18,529	[1]
Other comprehensive income (loss), net of income taxes	(21,905)	33,984	74,140		29,103
Comprehensive income	53,207	109,800	256,512		260,286
Comprehensive income (loss) attributable to non-controlling interests	835	925	(270)		2,219
Comprehensive income attributable to BOK Financial Corp. shareholders	$ 52,372	$ 108,875	$ 256,782		$ 258,067
[1]	Calculated using a 39 percent effective tax rate.

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Assets [Abstract]
Cash and due from banks	$ 535,916	$ 573,699	$ 489,268
Interest-bearing cash and cash equivalents	2,080,978	2,069,900	1,830,105
Trading securities	546,615	122,404	181,131
Investment securities	546,457	597,836	612,384
Available for sale securities	8,862,283	9,042,733	8,801,089
Fair value option securities	222,409	444,217	427,760
Restricted equity securities	333,391	273,684	263,587
Residential mortgage loans held for sale	447,592	308,439	357,414
Loans	16,464,786	15,941,154	15,367,441
Allowance for loan losses	(245,103)	(225,524)	(204,116)
Loans, net of allowance	16,219,683	15,715,630	15,163,325
Premises and equipment, net	318,196	306,490	294,669
Receivables	650,368	163,480	151,451
Goodwill	382,739	385,461	385,461
Intangible assets, net	41,977	43,909	44,999
Mortgage servicing rights	203,621	218,605	200,049
Real estate and other repossessed assets, net of allowance	31,941	30,731	33,116
Derivative contracts, net	655,078	586,270	726,159
Cash surrender value of bank-owned life insurance	310,211	303,335	300,981
Receivable on unsettled securities sales	19,642	40,193	30,009
Other assets	370,134	249,112	273,948
Total assets	32,779,231	31,476,128	30,566,905
Deposits [Abstract]
Noninterest-bearing demand deposits	8,681,364	8,296,888	8,041,767
Interest-bearing deposits: [Abstract]
Transaction	9,824,160	9,998,954	9,698,849
Savings	420,349	386,252	380,296
Time	2,169,631	2,406,064	2,498,531
Total deposits	21,095,504	21,088,158	20,619,443
Funds purchased	109,031	491,192	62,297
Repurchase agreements	504,573	722,444	555,677
Other borrowings	6,533,443	4,837,879	4,635,150
Subordinated debentures	144,631	226,350	226,314
Accrued interest, taxes and expense	191,276	119,584	158,048
Derivative contracts, net	573,987	581,701	636,115
Due on unsettled securities purchases	677	16,897	98,351
Other liabilities	193,698	124,284	159,348
Total liabilities	29,346,820	28,208,489	27,150,743
Shareholders' equity: [Abstract]
Common stock	4	4	4
Capital surplus	995,680	982,009	973,824
Retained earnings	2,801,931	2,704,121	2,673,292
Treasury stock	(495,031)	(477,165)	(355,670)
Accumulated other comprehensive income	95,727	21,587	85,776
Total shareholders’ equity	3,398,311	3,230,556	3,377,226
Non-controlling interests	34,100	37,083	38,936
Total equity	3,432,411	3,267,639	3,416,162
Total liabilities and equity	$ 32,779,231	$ 31,476,128	$ 30,566,905

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Investment securities [Abstract]
Investment Securities, fair value	$ 580,310	$ 629,159	$ 643,091
Allowance for real estate and other repossessed assets	$ 9,524	$ 12,622	$ 12,874
Shareholders' equity: [Abstract]
Common stock, par value (in dollars per share)	$ 0.00006	$ 0.00006	$ 0.00006
Common stock, shares authorized (in shares)	2,500,000,000	2,500,000,000	2,500,000,000
Common stock, shares issued (in shares)	74,866,429	74,530,364	74,461,234
Common stock, shares outstanding (in shares)	74,866,429	74,530,364	74,461,234
Treasury stock, shares at cost (in shares)	8,955,975	8,636,332	6,748,203

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 [Member]	Total Shareholders' Equity [Member]	Non-Controlling Interests [Member]
Balance, beginning of period (in shares) at Dec. 31, 2014		74,004			4,890
Balance, beginning of period at Dec. 31, 2014	$ 3,336,206	$ 4	$ 954,644	$ 2,530,837	$ (239,979)	$ 56,673	$ 3,302,179	$ 34,027
Net income (loss)	231,183			228,964			228,964	2,219
Other comprehensive income	29,103					29,103	29,103
Repurchase of common stock (in shares)					1,760
Repurchase of common stock	(109,760)				$ (109,760)		(109,760)
Issuance of shares for equity compensation (in shares)		457			98
Issuance of shares for equity compensation	4,797		10,728		$ (5,931)		4,797
Tax effect from equity compensation, net	645		645				645
Share-based compensation	7,807		7,807				7,807
Cash dividends on common stock	(86,509)			(86,509)			(86,509)
Sale of non-controlling interest	5,500							5,500
Capital calls and distributions, net	(2,810)							(2,810)
Balance, end of period (in shares) at Sep. 30, 2015		74,461			6,748
Balance, end of period at Sep. 30, 2015	3,416,162	$ 4	973,824	2,673,292	$ (355,670)	85,776	3,377,226	38,936
Balance, beginning of period (in shares) at Dec. 31, 2015		74,530			8,636
Balance, beginning of period at Dec. 31, 2015	3,267,639	$ 4	982,009	2,704,121	$ (477,165)	21,587	3,230,556	37,083
Net income (loss)	182,372			182,642			182,642	(270)
Other comprehensive income	74,140					74,140	74,140
Repurchase of common stock (in shares)					305
Repurchase of common stock	(17,771)				$ (17,771)		(17,771)
Issuance of shares for equity compensation (in shares)		336			15
Issuance of shares for equity compensation	5,418		5,513		$ (95)		5,418
Tax effect from equity compensation, net	589		589				589
Share-based compensation	7,569		7,569				7,569
Cash dividends on common stock	(84,832)			(84,832)			(84,832)
Capital calls and distributions, net	(2,713)							(2,713)
Balance, end of period (in shares) at Sep. 30, 2016		74,866			8,956
Balance, end of period at Sep. 30, 2016	$ 3,432,411	$ 4	$ 995,680	$ 2,801,931	$ (495,031)	$ 95,727	$ 3,398,311	$ 34,100

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash Flows From Operating Activities: [Abstract]
Net income	$ 182,372	$ 231,183
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provision for credit losses	65,000	11,500
Change in fair value of mortgage servicing rights	41,944	12,269
Net unrealized gains from derivative contracts	(9,755)	(974)
Tax effect from equity compensation, net	(589)	(645)
Share-based compensation	7,569	7,807
Depreciation and amortization	64,543	50,088
Net amortization of securities discounts and premiums	31,373	42,757
Net realized gains on financial instruments and other net gains	(13,663)	(12,601)
Net gain on mortgage loans held for sale	(61,775)	(60,075)
Mortgage loans originated for sale	(4,927,442)	(5,007,471)
Proceeds from sale of mortgage loans held for sale	4,855,682	5,022,109
Capitalized mortgage servicing rights	(56,345)	(62,375)
Charitable contributions to BOKF Foundation	0	796
Change in trading and fair value option securities	(204,030)	(110,857)
Change in receivables	(483,836)	8,455
Change in other assets	(17,931)	(15,368)
Change in accrued interest, taxes and expense	27,780	14,447
Change in other liabilities	7,262	40,670
Net cash provided by (used in) operating activities	(491,841)	171,715
Cash Flows From Investing Activities: [Abstract]
Proceeds from maturities or redemptions of investment securities	65,104	53,795
Proceeds from maturities or redemptions of available for sale securities	1,120,917	1,307,177
Purchases of investment securities	(18,599)	(19,037)
Purchases of available for sale securities	(1,860,287)	(2,271,374)
Proceeds from sales of available for sale securities	1,027,379	1,164,425
Change in amount receivable on unsettled securities transactions	20,551	44,250
Loans originated, net of principal collected	(551,351)	(1,121,100)
Net payments on derivative asset contracts	(79,512)	(291,949)
Acquisitions, net of cash acquired	(7,700)	(18,098)
Proceeds from disposition of assets	131,761	131,824
Purchases of assets	(159,263)	(203,546)
Net cash used in investing activities	(311,000)	(1,223,633)
Cash Flows From Financing Activities: [Abstract]
Net change in demand deposits, transaction deposits and savings accounts	243,779	(411,231)
Net change in time deposits	(236,433)	(110,185)
Net change in other borrowed funds	1,015,822	1,786,438
Repayments of Subordinated Debt	226,550	121,810
Issuance of subordinated debentures	145,331	0
Net proceeds on derivative liability contracts	76,144	277,872
Net change in derivative margin accounts	(129,141)	(148,119)
Change in amount due on unsettled security transactions	(16,220)	(192,189)
Issuance of common and treasury stock, net	5,418	4,797
Tax effect from equity compensation, net	589	645
Sale of non-controlling interests	0	5,500
Repurchase of common stock	(17,771)	(109,760)
Dividends paid	(84,832)	(86,509)
Net cash provided by financing activities	776,136	895,449
Net decrease in cash and cash equivalents	(26,705)	(156,469)
Cash and cash equivalents at beginning of period	2,643,599	2,475,842
Cash and cash equivalents at end of period	2,616,894	2,319,373
Supplemental Cash Flow Information: [Abstract]
Cash paid for interest	61,522	50,066
Cash paid for taxes	43,096	78,115
Net loans and bank premises transferred to repossessed real estate and other assets	20,580	9,558
Residential mortgage loans guaranteed by U.S. government agencies that became eligible for repurchase during the period	79,710	86,242
Conveyance of other real estate owned guaranteed by U.S. government agencies	$ 50,855	$ 93,157

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	Significant Accounting Policies 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., The Milestone Group, Inc. and Cavanal Hill Investment Management Inc. Operating divisions of the Bank include Bank of Albuquerque, Bank of Arizona, Bank of Arkansas, Bank of Oklahoma, Bank of Texas, Colorado State Bank and Trust, Bank of Kansas City, 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 2015 Form 10-K filed with the Securities and Exchange Commission, which contains audited financial statements. Amounts presented as of December 31, 2015 have been derived from the audited financial statements included in BOK Financial’s 2015 Form 10-K but does 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, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016 . Newly Adopted and Pending Accounting Policies Financial Accounting Standards Board (“FASB”) FASB Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers ("ASU 2014-09") On May 28, 2014, the FASB issued ASU 2014-09 to clarify the principles for recognizing revenue by providing a more robust framework that will give greater consistency and comparability in revenue recognition practices. In the new framework, an entity recognizes revenue in an amount that reflects the consideration to which the entity expects to be entitled in exchange for goods or services. The new model requires the identification of performance obligations included in contracts with customers, a determination of the transaction price and an allocation of the price to those performance obligations. The entity recognizes revenue when performance obligations are satisfied. ASU 2014-09 is effective for the Company for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company is evaluating the impact the adoption of ASU 2014-09 will have on the Company's financial statements. FASB Accounting Standards Update No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ("ASU 2016-08") On March 17, 2016, the FASB Issued ASU 2016-08 to amend the principal versus agent implementation guidance in ASU 2014-09. The ASU clarifies that an entity should evaluate whether it is the principal or the agent for each specified good or service promised in a contract with a customer. ASU 2016-08 is effective for the Company for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company is evaluating the impact the adoption of ASU 2016-08 will have on the Company's financial statements along with ASU 2014-09. FASB Accounting Standards Update No. 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing ("ASU 2016-10") On April 14, 2016, the FASB issued ASU 2016-10 which amends certain sections of ASU 2014-09 related to identifying performance obligations and licensing implementation. ASU 2016-10 is effective for the Company for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company is evaluating the impact the adoption of ASU 2016-10 will have on the Company's financial statements along with ASU 2014-09. FASB Accounting Standards Update No. 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients ("ASU 2016-12") On May 9, 2016, the FASB issued ASU 2016-12, which amends certain aspects of the Board's new revenue standard, ASU 2014-09. The amendments clarify information regarding collectibility, presentation of sales tax and other similar taxes collected from customers, noncash consideration, contract modifications and completed contracts at transition, and transition disclosures. ASU 2016-12 is effective for the Company for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company is evaluating the impact the adoption of ASU 2016-12 will have on the Company's financial statements along with ASU 2014-09. FASB Accounting Standards Update No. 2014-16, Derivatives and Hedging (Topic 815): Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share is More Akin to Debt or to Equity ("ASU 2014-16") On November 3, 2014, the FASB issued ASU 2014-16 to eliminate the use of different methods and reduce diversity under GAAP in the accounting for hybrid financial instruments issued in the form of a share. For hybrid financial instruments issued in the form of a share, an entity should determine the nature of the host contract by considering all stated and implied substantive terms and features of the hybrid financial instrument. The entity should determine the nature of the host contract by considering the economic characteristics and risks of the entire hybrid financial instrument, including the embedded derivative feature that is being evaluated for separate accounting from the host contract. For public business entities, the ASU was effective for annual periods beginning after December 15, 2015, and interim periods within those annual periods. Adoption of ASU 2014-16 did not have a material impact on the Company's consolidated financial statements. FASB Accounting Standards Update No. 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis ("ASU 2015-02") On February 18, 2015, the FASB issued ASU 2015-02 to address concerns that current U.S. GAAP may require a reporting entity to consolidate another legal entity where the reporting entity's contractual rights do not give it the ability to act primarily on its own behalf, the reporting entity does not hold a majority of the legal entity's voting rights, or the reporting entity is not exposed to a majority of the legal entity's economic benefits or obligations. The amendments affect limited partnerships and similar legal entities, the evaluation of fees paid to a decision maker or a service provider as a variable interest, the effect of fee arrangements and related parties on the primary beneficiary determination, and certain investment funds. The ASU was effective for periods beginning after December 15, 2015 for public companies. Adoption of ASU 2015-02 did not have a material impact on the Company's consolidated financial statements. FASB Accounting Standards Update No. 2015-07, Fair Value Measurements (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent) ("ASU 2015-07") On May 1, 2015, the FASB issued ASU 2015-07 to gain consistency within the categorization of the fair value hierarchy. The update removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient. It also removes the requirement to make certain disclosures for all investments that are eligible to be measured at fair value using the net asset value per share practical expedient. The ASU was effective for the Company for interim and annual periods beginning after December 15, 2015 and should be applied retrospectively to all periods presented. Adoption of ASU 2015-07 did not have a material impact on the Company's consolidated financial statements. FASB Accounting Standards Update No. 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01") On January 5, 2016, the FASB issued ASU 2016-01 over the recognition and measurement of financial assets and liabilities. The update requires equity investments, in general, to be measured at fair value with changes in fair value recognized in earnings. It also eliminates the requirement to disclose the methods and significant assumptions used to estimate the fair value for financial instruments measured at amortized cost, requires entities to use the exit price notion when measuring fair value, requires an entity to present separately in other comprehensive income the portion of the total change in fair value of a liability resulting from a change in the instrument-specific credit risk when the fair value option has been elected, requires separate presentation of financial assets and liabilities by measurement category and form on the balance sheet or accompanying notes, clarifies that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity's other deferred tax assets, and simplifies the impairment assessment of equity investments without readily determinable fair values. The ASU is effective for the Company for interim and annual periods beginning after December 15, 2017. Upon adoption, unrealized gains and losses from equity securities will be reclassified from other comprehensive income to retained earnings. At September 30, 2016 , the Company had $3.3 million of unrealized gains included in accumulated other comprehensive income. 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 and disclosing key information about leasing arrangements. The final guidance requires lessees to put most leases on their balance sheets and may affect the presentation and timing of expense recognition, eliminates the current real estate-specific provisions, modifies the classification criteria and the accounting for sales-type and direct financing leases for lessors. The ASU is effective for the Company for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early application of the amendments is permitted. The Company is evaluating the impact the adoption of ASU 2016-02 will have on the Company's financial statements. FASB Accounting Standards Update No. 2016-05, Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships ("ASU 2016-05") On March 10, 2016, the FASB issued ASU 2016-05 which clarifies that "a change in the counterparty to a derivative instrument that has been designated as the hedging instrument in an existing hedging relationship would not, in and of itself, be considered a termination of the derivative instrument" or "a change in a critical term of the hedging relationship." If all other hedge accounting criteria in ASC 815 are met, a hedging relationship where the hedging derivative instrument is novated would not be discontinued or need to be redesignated. The ASU is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. An entity would apply the guidance prospectively unless modified retrospective transition is elected. Early adoption is permitted. Adoption of ASU 2016-05 is not expected to have a material impact on the Company's financial statements. FASB Accounting Standards Update No. 2016-07, Investments - Equity Method and Joint Ventures ("ASU 2016-07") On March 15, 2016, the FASB issued ASU 2016-07 to simplify the equity method of accounting by eliminating the requirement to retrospectively apply the equity method to an investment that subsequently qualifies for such accounting as result of an increase in the level of ownership interest or degree of influence. The ASU also requires that unrealized holding gains or losses in accumulated other comprehensive income related to an available for sale security that becomes eligible for the equity method be recognized in earnings as of the date the investment qualifies for the equity method. The ASU is effective for all entities for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted. Adoption of ASU 2016-07 is not expected to have a material impact on the Company's financial statements. FASB Accounting Standards Update No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09") On March 30, 2016, the FASB issued ASU 2016-09 to simplify multiple aspects of accounting for employee share-based payment transactions including accounting income taxes, forfeitures, and statutory tax withholding requirements. The ASU is effective for annual reporting periods beginning after December 15, 2016, including interim periods within those annual reporting periods. Implementation of ASU 2016-09 will add volatility to tax expense as stock prices change; however, we expect the impact to be insignificant. FASB Accounting Standards Update No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Assets Measured at Amortized Cost ("ASU 2016-13") On June 16, 2016, the FASB issued ASU 2016-13 in order to provide more timely recording of credit losses on loans and other financial instruments. The ASU adds an impairment model (known as the current expected credit loss ("CECL") model) that is based on expected credit losses rather than incurred credit losses. It requires an organization to measure all expected credit losses for financial assets carried at amortized cost at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. ASU 2016-13 is effective for the Company for annual reporting periods beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for annual reporting periods beginning after December 15, 2018. ASU 2016-13 will be applied through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The Company is evaluating the impact the adoption of ASU 2016-13 will have on the Company's financial statements. FASB Accounting Standards Update No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments ("ASU 2016-15") On August 26, 2016, the FASB issued ASU 2016-15, which amends guidance in ASC 230 on the classification of certain cash receipts and payments in the statement of cash flows, in order to reduce inconsistent application. The amendments address eight cash flow issues including debt repayment and extinguishment costs, settlement of zero-coupon debt instruments, contingent consideration payments following a business combination, proceeds from the settlement of insurance claims and corporate-owned life insurance policies, distributions received from equity method investees, beneficial interests in securitization transactions and separately identifiable cash flows. ASU 2016-15 is effective for the Company for annual reporting periods beginning after December 15, 2017, including interim periods within those fiscal years. Entities must apply the guidance retrospectively to all periods presented but may apply it prospectively from the earliest date practicable if retrospective application would be impracticable. Adoption of ASU 2016-15 is not expected to have a material impact on the Company's financial statements.

Securities

Securities	9 Months Ended
	Sep. 30, 2016
Marketable Securities [Abstract]
Securities [Text Block]	Securities Trading Securities The fair value and net unrealized gain (loss) included in trading securities is as follows (in thousands): September 30, 2016 December 31, 2015 September 30, 2015 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. government agency debentures $ 15,705 $ (7 ) $ 61,295 $ (71 ) $ 42,431 $ (38 ) U.S. government agency residential mortgage-backed securities 464,749 876 10,989 17 30,973 195 Municipal and other tax-exempt securities 54,856 (100 ) 31,901 210 84,261 421 Other trading securities 11,305 14 18,219 (16 ) 23,466 28 Total trading securities $ 546,615 $ 783 $ 122,404 $ 140 $ 181,131 $ 606 Investment Securities The amortized cost and fair values of investment securities are as follows (in thousands): September 30, 2016 Amortized Carrying Fair Gross Unrealized 1 Cost Value Value Gain Loss Municipal and other tax-exempt $ 323,225 $ 323,225 $ 327,788 $ 4,745 $ (182 ) U.S. government agency residential mortgage-backed securities – Other 22,166 22,166 23,452 1,286 — Other debt securities 201,066 201,066 229,070 28,014 (10 ) Total investment securities $ 546,457 $ 546,457 $ 580,310 $ 34,045 $ (192 ) 1 Gross unrealized gains and losses are not recognized in Accumulated Other Comprehensive Income "AOCI" in the Consolidated Balance Sheets. December 31, 2015 Amortized Carrying Fair Gross Unrealized 1 Cost Value Value Gain Loss Municipal and other tax-exempt $ 365,258 $ 365,258 $ 368,910 $ 3,935 $ (283 ) U.S. government agency residential mortgage-backed securities – Other 26,721 26,833 27,874 1,063 (22 ) Other debt securities 205,745 205,745 232,375 26,689 (59 ) Total investment securities $ 597,724 $ 597,836 $ 629,159 $ 31,687 $ (364 ) 1 Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets. September 30, 2015 Amortized Carrying Fair Gross Unrealized 1 Cost Value Value Gain Loss Municipal and other tax-exempt $ 379,980 $ 379,980 $ 384,310 $ 4,461 $ (131 ) U.S. government agency residential mortgage-backed securities – Other 28,456 28,653 30,080 1,427 — Other debt securities 203,751 203,751 228,701 25,063 (113 ) Total investment securities $ 612,187 $ 612,384 $ 643,091 $ 30,951 $ (244 ) 1 Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets. The amortized cost and fair values of investment securities at September 30, 2016 , 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 Maturity² Municipal and other tax-exempt: Carrying value $ 87,330 $ 195,763 $ 8,778 $ 31,354 $ 323,225 2.76 Fair value 87,331 196,864 9,023 34,570 327,788 Nominal yield¹ 1.42 % 2.01 % 3.20 % 6.08 % 2.28 % Other debt securities: Carrying value 15,047 42,314 125,955 17,750 201,066 6.84 Fair value 15,191 45,802 148,422 19,655 229,070 Nominal yield 3.49 % 5.03 % 5.88 % 4.86 % 5.43 % Total fixed maturity securities: Carrying value $ 102,377 $ 238,077 $ 134,733 $ 49,104 $ 524,291 4.32 Fair value 102,522 242,666 157,445 54,225 556,858 Nominal yield 1.72 % 2.54 % 5.70 % 5.64 % 3.48 % Residential mortgage-backed securities: Carrying value $ 22,166 ³ Fair value 23,452 Nominal yield 4 2.75 % Total investment securities: Carrying value $ 546,457 Fair value 580,310 Nominal yield 3.46 % 1 Calculated on a taxable equivalent basis using a 39 percent effective tax rate. 2 Expected maturities may differ from contractual maturities, because borrowers may have the right to call or prepay obligations with or without penalty. 3 The average expected lives of residential mortgage-backed securities were 4.3 years based upon current prepayment assumptions. 4 The nominal yield on residential mortgage-backed securities is based upon prepayment assumptions at the purchase date. Actual yields earned may differ significantly based upon actual prepayments. See Quarterly Financial Summary - Unaudited for current yields on the investment securities portfolio. Available for Sale Securities The amortized cost and fair value of available for sale securities are as follows (in thousands): September 30, 2016 Amortized Fair Gross Unrealized 1 Cost Value Gain Loss OTTI ² U.S. Treasury $ 1,000 $ 1,002 $ 2 $ — $ — Municipal and other tax-exempt 41,943 42,092 602 (453 ) — Residential mortgage-backed securities: U. S. government agencies: FNMA 3,035,041 3,101,136 67,859 (1,764 ) — FHLMC 1,611,887 1,641,178 29,640 (349 ) — GNMA 924,176 926,358 3,530 (1,348 ) — Other — — — — — Total U.S. government agencies 5,571,104 5,668,672 101,029 (3,461 ) — Private issue: Alt-A loans 47,039 54,065 7,230 — (204 ) Jumbo-A loans 61,377 67,538 6,187 (26 ) — Total private issue 108,416 121,603 13,417 (26 ) (204 ) Total residential mortgage-backed securities 5,679,520 5,790,275 114,446 (3,487 ) (204 ) Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,942,988 2,986,495 45,329 (1,822 ) — Other debt securities 4,400 4,151 — (249 ) — Perpetual preferred stock 15,562 19,578 4,016 — — Equity securities and mutual funds 17,337 18,690 1,370 (17 ) — Total available for sale securities $ 8,702,750 $ 8,862,283 $ 165,765 $ (6,028 ) $ (204 ) 1 Gross unrealized gain/loss recognized in AOCI in the consolidated balance sheet. 2 Amounts represent unrealized loss that remains in AOCI after an other-than-temporary credit loss has been recognized in income. December 31, 2015 Amortized Fair Gross Unrealized¹ Cost Value Gain Loss OTTI ² U.S. Treasury $ 1,000 $ 995 $ — $ (5 ) $ — Municipal and other tax-exempt 56,681 56,817 873 (737 ) — Residential mortgage-backed securities: U. S. government agencies: FNMA 3,156,214 3,187,215 41,502 (10,501 ) — FHLMC 1,940,915 1,949,335 14,727 (6,307 ) — GNMA 763,967 761,801 2,385 (4,551 ) — Other — — — — — Total U.S. government agencies 5,861,096 5,898,351 58,614 (21,359 ) — Private issue: Alt-A loans 56,387 62,574 6,574 — (387 ) Jumbo-A loans 71,724 76,544 5,260 — (440 ) Total private issue 128,111 139,118 11,834 — (827 ) Total residential mortgage-backed securities 5,989,207 6,037,469 70,448 (21,359 ) (827 ) Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,919,044 2,905,796 5,396 (18,644 ) — Other debt securities 4,400 4,151 — (249 ) — Perpetual preferred stock 17,171 19,672 2,501 — — Equity securities and mutual funds 17,121 17,833 752 (40 ) — Total available for sale securities $ 9,004,624 $ 9,042,733 $ 79,970 $ (41,034 ) $ (827 ) 1 Gross unrealized gain/loss recognized in AOCI in the consolidated balance sheet. 2 Amounts represent unrealized loss that remains in AOCI after an other-than-temporary credit loss has been recognized in income. September 30, 2015 Amortized Fair Gross Unrealized 1 Cost Value Gain Loss OTTI ² U.S. Treasury $ 1,000 $ 1,003 $ 3 $ — $ — Municipal and other tax-exempt 57,610 57,960 1,065 (715 ) — Residential mortgage-backed securities: U. S. government agencies: FNMA 3,115,810 3,185,097 69,757 (470 ) — FHLMC 1,853,379 1,885,201 32,646 (824 ) — GNMA 741,212 744,647 4,557 (1,122 ) — Other 3,922 4,182 260 — — Total U.S. government agencies 5,714,323 5,819,127 107,220 (2,416 ) — Private issue: Alt-A loans 58,801 64,700 6,519 — (620 ) Jumbo-A loans 75,258 80,982 6,121 — (397 ) Total private issue 134,059 145,682 12,640 — (1,017 ) Total residential mortgage-backed securities 5,848,382 5,964,809 119,860 (2,416 ) (1,017 ) Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,708,931 2,735,787 28,889 (2,033 ) — Other debt securities 4,400 4,150 — (250 ) — Perpetual preferred stock 17,171 19,163 2,030 (38 ) — Equity securities and mutual funds 18,711 18,217 950 (1,444 ) — Total available for sale securities $ 8,656,205 $ 8,801,089 $ 152,797 $ (6,896 ) $ (1,017 ) 1 Gross unrealized gain/loss recognized in AOCI in the consolidated balance sheet. 2 Amounts represent unrealized loss that remains in AOCI after an other-than-temporary credit loss has been recognized in income. The amortized cost and fair values of available for sale securities at September 30, 2016 , 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 5 U.S. Treasuries: Amortized cost $ — $ 1,000 $ — $ — $ 1,000 1.29 Fair value — 1,002 — — 1,002 Nominal yield — % 0.87 % — % — % 0.87 % Municipal and other tax-exempt: Amortized cost $ 9,089 $ 13,593 $ 2,092 $ 17,169 $ 41,943 8.14 Fair value 9,190 13,858 2,109 16,935 42,092 Nominal yield¹ 4.97 % 3.85 % 3.46 % 2.36 % 6 3.46 % Commercial mortgage-backed securities: Amortized cost $ — $ 931,761 $ 1,817,166 $ 194,061 $ 2,942,988 6.82 Fair value — 942,994 1,848,462 195,039 2,986,495 Nominal yield — % 1.74 % 1.84 % 1.54 % 1.79 % Other debt securities: Amortized cost $ — $ — $ — $ 4,400 $ 4,400 30.91 Fair value — — — 4,151 4,151 Nominal yield — % — % — % 1.71 % 6 1.71 % Total fixed maturity securities: Amortized cost $ 9,089 $ 946,354 $ 1,819,258 $ 215,630 $ 2,990,331 6.87 Fair value 9,190 957,854 1,850,571 216,125 3,033,740 Nominal yield 4.97 % 1.77 % 1.85 % 1.61 % 1.81 % Residential mortgage-backed securities: Amortized cost $ 5,679,520 2 Fair value 5,790,275 Nominal yield 4 1.87 % Equity securities and mutual funds: Amortized cost $ 32,899 ³ Fair value 38,268 Nominal yield — % Total available-for-sale securities: Amortized cost $ 8,702,750 Fair value 8,862,283 Nominal yield 1.84 % 1 Calculated on a taxable equivalent basis using a 39 percent effective tax rate. 2 The average expected lives of mortgage-backed securities were 3.4 years years based upon current prepayment assumptions. 3 Primarily common stock and preferred stock of corporate issuers with no stated maturity. 4 The nominal yield on mortgage-backed securities is based upon prepayment assumptions at the purchase date. Actual yields earned may differ significantly based upon actual prepayments. See Quarterly Financial Summary –– Unaudited following for current yields on available for sale securities portfolio. 5 Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without penalty. 6 Nominal yield on municipal and other tax-exempt securities and other debt securities with contractual maturity dates over ten years are based on variable rates which generally are reset within 35 days . Sales of available for sale securities resulted in gains and losses as follows (in thousands): Three Months Ended Nine Months Ended 2016 2015 2016 2015 Proceeds $ 232,239 $ 450,765 $ 1,027,379 $ 1,164,425 Gross realized gains 2,415 3,803 11,705 13,543 Gross realized losses (21 ) (1,637 ) (21 ) (3,617 ) Related federal and state income tax expense 931 843 4,545 3,861 A summary of investment and available for sale securities that have been pledged as collateral for repurchase agreements, public trust funds on deposit and for other purposes, as required by law was as follows (in thousands): Sept. 30,2016 Dec. 31, 2016 Sept. 30,2015 Investment: Carrying value $ 301,754 $ 231,033 $ 50,380 Fair value 307,264 234,382 52,249 Available for sale: Amortized cost 7,098,721 6,831,743 6,225,689 Fair value 7,213,520 6,849,524 6,318,330 The secured parties do not have the right to sell or re-pledge these securities. Temporarily Impaired Securities as of September 30, 2016 (in thousands): 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 75 $ 100,624 $ 106 $ 4,359 $ 76 $ 104,983 $ 182 U.S. government agency residential mortgage-backed securities – Other — — — — — — — Other debt securities 3 444 6 856 4 1,300 10 Total investment securities 78 $ 101,068 $ 112 $ 5,215 $ 80 $ 106,283 $ 192 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: Municipal and other tax-exempt 20 $ 2,210 $ 3 $ 6,396 $ 450 $ 8,606 $ 453 Residential mortgage-backed securities: U. S. government agencies: FNMA 14 365,201 1,712 14,229 52 379,430 1,764 FHLMC 6 122,713 91 20,306 258 143,019 349 GNMA 16 230,043 1,157 212,705 191 442,748 1,348 Total U.S. government agencies 36 717,957 2,960 247,240 501 965,197 3,461 Private issue 1 : Alt-A loans 5 8,231 141 7,773 63 16,004 204 Jumbo-A loans 1 6,583 26 — — 6,583 26 Total private issue 6 14,814 167 7,773 63 22,587 230 Total residential mortgage-backed securities 42 732,771 3,127 255,013 564 987,784 3,691 Commercial mortgage-backed securities guaranteed by U.S. government agencies 33 372,805 1,656 60,851 166 433,656 1,822 Other debt securities 2 — — 4,151 249 4,151 249 Perpetual preferred stocks — — — — — — — Equity securities and mutual funds 33 86 — 886 17 972 17 Total available for sale securities 130 $ 1,107,872 $ 4,786 $ 327,297 $ 1,446 $ 1,435,169 $ 6,232 1 Includes securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income. Temporarily Impaired Securities as of December 31, 2015 (In thousands) 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 73 $ 127,319 $ 207 $ 13,380 $ 77 $ 140,699 $ 284 U.S. government agency residential mortgage-backed securities – Other 1 5,533 22 — — 5,533 22 Other debt securities 11 1,082 41 1,715 18 2,797 59 Total investment securities 85 $ 133,934 $ 270 $ 15,095 $ 95 $ 149,029 $ 365 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 $ 995 $ 5 $ — $ — $ 995 $ 5 Municipal and other tax-exempt 20 $ 9,909 $ 27 $ 11,664 $ 710 $ 21,573 $ 737 Residential mortgage-backed securities: U. S. government agencies: FNMA 55 1,188,022 10,262 18,236 239 1,206,258 10,501 FHLMC 40 726,713 4,827 77,545 1,480 804,258 6,307 GNMA 15 364,919 1,951 102,109 2,600 467,028 4,551 Total U.S. government agencies 110 2,279,654 17,040 197,890 4,319 2,477,544 21,359 Private issue 1 : Alt-A loans 4 — — 9,264 387 9,264 387 Jumbo-A loans 8 — — 8,482 440 8,482 440 Total private issue 12 — — 17,746 827 17,746 827 Total residential mortgage-backed securities 122 2,279,654 17,040 215,636 5,146 2,495,290 22,186 Commercial mortgage-backed securities guaranteed by U.S. government agencies 213 1,582,469 11,419 484,258 7,225 2,066,727 18,644 Other debt securities 2 — — 4,151 249 4,151 249 Perpetual preferred stocks — — — — — — — Equity securities and mutual funds 61 782 5 991 35 1,773 40 Total available for sale securities 419 $ 3,873,809 $ 28,496 $ 716,700 $ 13,365 $ 4,590,509 $ 41,861 1 Includes securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income. Temporarily Impaired Securities as of September 30, 2015 (In thousands) 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 15 $ 6,250 $ 81 $ 13,438 $ 50 $ 19,688 $ 131 U.S. government agency residential mortgage-backed securities – Other — — — — — — — Other debt securities 17 1,283 64 4,577 49 5,860 113 Total investment securities 32 $ 7,533 $ 145 $ 18,015 $ 99 $ 25,548 $ 244 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: Municipal and other tax-exempt 1 18 $ 7,868 $ 485 $ 3,800 $ 230 $ 11,668 $ 715 Residential mortgage-backed securities: U. S. government agencies: FNMA 6 155,747 470 — — 155,747 470 FHLMC 4 71,930 503 26,848 321 98,778 824 GNMA 4 54,701 562 54,701 560 109,402 1,122 Total U.S. government agencies 14 282,378 1,535 81,549 881 363,927 2,416 Private issue 1 : Alt-A loans 4 2,857 186 6,667 434 9,524 620 Jumbo-A loans 8 5,380 236 3,681 161 9,061 397 Total private issue 12 8,237 422 10,348 595 18,585 1,017 Total residential mortgage-backed securities 26 290,615 1,957 91,897 1,476 382,512 3,433 Commercial mortgage-backed securities guaranteed by U.S. government agencies 31 327,790 1,488 223,007 545 550,797 2,033 Other debt securities 2 — — 4,149 250 4,149 250 Perpetual preferred stocks 1 1,912 38 — — 1,912 38 Equity securities and mutual funds 37 4,031 1,432 526 12 4,557 1,444 Total available for sale securities 115 $ 632,216 $ 5,400 $ 323,379 $ 2,513 $ 955,595 $ 7,913 1 Includes securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income. On a quarterly basis, the Company performs separate evaluations of impaired debt and equity investments and available for sale securities to determine if the unrealized losses are temporary. For debt securities, management determines whether it intends to sell or if it is more-likely-than-not that it will be required to sell impaired securities. This determination considers current and forecasted liquidity requirements, regulatory and capital requirements and securities portfolio management. Based on this evaluation as of September 30, 2016 , the Company does not intend to sell any impaired available for sale 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. Impairment of debt securities rated investment grade by all nationally-recognized rating agencies is considered temporary unless specific contrary information is identified. None of the debt securities rated investment grade were considered to be other-than-temporarily impaired at September 30, 2016 . At September 30, 2016 , the composition of the Company’s investment and available for sale securities portfolios by the lowest current credit rating assigned by any of the three nationally-recognized rating agencies is as follows (in thousands): AAA - AA A - BBB Below Investment Grade Not Rated Total Carrying Value Fair Value Carrying Value Fair Value Carrying Value Fair Value Carrying Value Fair Value Carrying Value Fair Value Investment: Municipal and other tax-exempt $ 207,881 $ 209,210 $ 5,094 $ 5,160 $ — $ — $ 110,250 $ 113,418 $ 323,225 $ 327,788 U.S. government agency residential mortgage-backed securities 1 — — — — — — 22,166 23,452 22,166 23,452 Other debt securities 140,184 164,118 — — — — 60,882 64,952 201,066 229,070 Total investment securities $ 348,065 $ 373,328 $ 5,094 $ 5,160 $ — $ — $ 193,298 $ 201,822 $ 546,457 $ 580,310 AAA - AA A - BBB Below Investment Grade Not Rated Total Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Available for Sale: U.S. Treasury $ — $ — $ — $ — $ — $ — $ 1,000 $ 1,002 $ 1,000 $ 1,002 Municipal and other tax-exempt 23,837 24,290 5,675 5,316 — — 12,431 12,486 41,943 42,092 U.S. government agency residential mortgage-backed securities 1 — — — — — — 5,571,104 5,668,672 5,571,104 5,668,672 Privately issued residential mortgage-backed securities — — — — 108,416 121,603 — — 108,416 121,603 Commercial mortgage-backed securities guaranteed by U.S. government agencies — — — — — — 2,942,988 2,986,495 2,942,988 2,986,495 Other debt securities 4,400 4,151 — — — — — — 4,400 4,151 Perpetual preferred stock — — 4,796 5,505 10,766 14,073 — — 15,562 19,578 Equity securities and mutual funds 4 591 — — — — 17,333 18,099 17,337 18,690 Total available for sale securities $ 28,241 $ 29,032 $ 10,471 $ 10,821 $ 119,182 $ 135,676 $ 8,544,856 $ 8,686,754 $ 8,702,750 $ 8,862,283 1 U.S. government and government sponsored enterprises are not rated by the nationally-recognized rating agencies as these securities are guaranteed by agencies of the U.S. government or government-sponsored enterprises. At September 30, 2016 , the entire portfolio of privately issued residential mortgage-backed securities was rated below investment grade by the nationally-recognized rating agencies. The gross unrealized loss on these securities totaled $230 thousand . Impairment of securities rated below investment grade was evaluated based on projections of estimated cash flows from individual loans underlying each security using current and anticipated unemployment and default rates, changes in housing prices and estimated liquidation costs at foreclosure. Each factor is considered in the evaluation. The primary assumptions used in this evaluation were: September 30, 2016 Dec. 31, 2015 September 30, 2015 Unemployment rate Moving down to 4.7 percent over the next 12 months and remain at 4.7 percent thereafter. Decreasing to 4.8 percent over the next 12 months and remain at 4.8 percent thereafter. Moving down to 5.1 percent over the next 12 months and remain at 5.1 percent thereafter. Housing price appreciation/depreciation Starting with current depreciated housing prices based on information derived from the FHFA 1 , appreciating 3.5 percent over the next 12 months, then flat for the following 12 months and then appreciating at 2 percent per year thereafter. Starting with current depreciated housing prices based on information derived from the FHFA 1 , appreciating 3.5 percent over the next 12 months, then flat for the following 12 months and then appreciating at 2 percent per year thereafter. Starting with current depreciated housing prices based on information derived from the FHFA 1 , appreciating 3.2 percent over the next 12 months, then flat for the following 12 months and then appreciating at 2 percent per year thereafter. Estimated liquidation costs Reflect actual historical liquidations costs observed on Jumbo and Alt-A residential mortgage loans in securities owned by the Company. Reflect actual historical liquidations costs observed on Jumbo and Alt-A residential mortgage loans in securities owned by the Company. Reflect actual historical liquidations costs observed on Jumbo and Alt-A residential mortgage loans in securities owned by the Company. Discount rates Estimated cash flows were discounted at rates that range from 2.00 percent to 6.25 percent based on our current expected yields. Estimated cash flows were discounted at rates that range from 2.00 percent to 6.25 percent based on our current expected yields. Estimated cash flows were discounted at rates that range from 2.00 percent to 6.25 percent based on our current expected yields. 1 Federal Housing Finance Agency Credit loss impairment is recorded as a charge to earnings. Additional impairment based on the difference between the total unrealized loss and the estimated credit loss on these securities is charged against other comprehensive income, net of deferred taxes. No credit loss impairments were recognized in earnings on privately issued residential mortgage-backed securities during the three months ended September 30, 2016 . A distribution of the amortized cost (after recognition of the other-than-temporary impairment), fair value and credit loss impairments recognized on our privately issued residential mortgage-backed securities is as follows (in thousands, except for number of securities): Credit Losses Recognized Three months ended September 30, 2016 Life-to-date Number of Securities Amortized Cost Fair Value Number of Securities Amount Number of Securities Amount Alt-A 14 $ 47,039 $ 54,065 — $ — 14 $ 36,284 Jumbo-A 30 61,377 67,538 — — 29 18,220 Total 44 $ 108,416 $ 121,603 — $ — 43 $ 54,504 Impaired equity securities, including perpetual preferred stocks, are evaluated based on management's ability and intent to hold the securities until fair value recovers over periods not to exceed three years. The assessment of the ability and intent to hold these securities focuses on the liquidity needs, asset/liability management objectives and securities portfolio objectives. Factors considered when assessing recovery include forecasts of general economic conditions and specific performance of the issuer, analyst ratings and credit spreads for preferred stocks which have debt-like characteristics. The Company has evaluated the near-term prospects of the investments in relation to the severity and duration of the impairment and based on that evaluation has the ability and intent to hold these investments until a recovery in fair value. Accordingly, all impairment of equity securities was considered temporary at September 30, 2016 . The following is a tabular roll forward of the amount of credit-related OTTI recognized on available for sale debt securities in earnings (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 Balance of credit-related OTTI recognized on available for sale debt securities, beginning of period $ 54,504 $ 54,439 $ 54,504 $ 54,347 Additions for credit-related OTTI not previously recognized — — — — Additions for increases in credit-related OTTI previously recognized when there is no intent to sell and no requirement to sell before recovery of amortized cost — — — 92 Reductions for change in intent to hold before recovery — — — — Sales — — — — Balance of credit-related OTTI recognized on available for sale debt securities, end of period $ 54,504 $ 54,439 $ 54,504 $ 54,439 Additions above exclude other-than-temporary impairment recorded due to change in intent to hold before recovery. 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 U.S. Treasury securities, residential mortgage-backed securities issued by U.S. government agencies and derivative contracts 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): Sept. 30,2016 Dec. 31, 2015 Sept. 30, 2015 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. Treasury $ 222,409 $ (2,397 ) $ — $ — $ — $ — U.S. government agency residential mortgage-backed securities $ — $ — $ 444,217 $ (2,060 ) $ 427,760 $ 2,067 Total $ 222,409 $ (2,397 ) $ 444,217 $ (2,060 ) $ 427,760 $ 2,067 Restricted Equity Securities Restricted equity securities primarily include stock we are required to hold as members of the Federal Reserve system and the Federal Home Loan Banks. Restricted equity securities are carried at cost as these securities do not have a readily determined fair value because ownership of these shares are restricted and lacks a market. A summary of restricted equity securities follows (in thousands): Sept. 30,2016 Dec. 31, 2015 Sept. 30,2015 Federal Reserve stock $ 36,283 $ 36,148 $ 35,148 Federal Home Loan Bank stock 296,907 237,365 228,268 Other 201 171 171 Total $ 333,391 $ 273,684 $ 263,587

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2016
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. 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. As of September 30, 2016 , a decrease in BOK Financial's credit rating to below investment grade would increase our obligation to post cash margin on existing contracts by approximately $18 million . 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, and foreign exchange rates, or to take positions in derivative contracts. Customers may also manage interest rate risk through interest rate swaps used by borrowers to modify interest rate terms of their loans or to-be-announced securities used by mortgage banking customers to hedge their loan production. 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. 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 as an economic hedge of trading securities. As of September 30, 2016 , derivative contracts under the internal risk management programs were primarily used as part of the economic hedges of the change in the fair value of the mortgage servicing rights and trading securities. 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, 2016 (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 $ 20,078,974 $ 90,999 $ (38,678 ) $ 52,321 $ — $ 52,321 Interest rate swaps 1,323,045 49,279 — 49,279 (794 ) 48,485 Energy contracts 729,202 41,775 (28,464 ) 13,311 (288 ) 13,023 Agricultural contracts 53,002 3,950 (1,571 ) 2,379 (1,076 ) 1,303 Foreign exchange contracts 550,828 536,264 — 536,264 (7,577 ) 528,687 Equity option contracts 103,464 4,654 — 4,654 (730 ) 3,924 Total customer risk management programs 22,838,515 726,921 (68,713 ) 658,208 (10,465 ) 647,743 Internal risk management programs 2,298,038 7,335 — 7,335 — 7,335 Total derivative contracts $ 25,136,553 $ 734,256 $ (68,713 ) $ 665,543 $ (10,465 ) $ 655,078 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 $ 19,776,883 $ 86,812 $ (38,678 ) $ 48,134 $ (39,042 ) $ 9,092 Interest rate swaps 1,323,045 49,518 — 49,518 (34,457 ) 15,061 Energy contracts 695,835 40,888 (28,464 ) 12,424 (3,857 ) 8,567 Agricultural contracts 52,997 3,943 (1,571 ) 2,372 — 2,372 Foreign exchange contracts 550,943 536,660 — 536,660 (5,396 ) 531,264 Equity option contracts 103,464 4,654 — 4,654 — 4,654 Total customer risk management programs 22,503,167 722,475 (68,713 ) 653,762 (82,752 ) 571,010 Interest risk management programs 1,485,691 2,977 — 2,977 — 2,977 Total derivative contracts $ 23,988,858 $ 725,452 $ (68,713 ) $ 656,739 $ (82,752 ) $ 573,987 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, 2015 (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 $ 14,583,052 $ 43,270 $ (28,305 ) $ 14,965 $ — $ 14,965 Interest rate swaps 1,332,044 31,744 — 31,744 (1,424 ) 30,320 Energy contracts 470,613 83,045 (22,970 ) 60,075 (18,606 ) 41,469 Agricultural contracts 61,662 2,591 (1,158 ) 1,433 — 1,433 Foreign exchange contracts 546,572 498,830 — 498,830 (4,140 ) 494,690 Equity option contracts 137,278 3,780 — 3,780 (470 ) 3,310 Total customer risk management programs 17,131,221 663,260 (52,433 ) 610,827 (24,640 ) 586,187 Interest risk management programs 22,000 83 — 83 — 83 Total derivative contracts $ 17,153,221 $ 663,343 $ (52,433 ) $ 610,910 $ (24,640 ) $ 586,270 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 $ 14,168,927 $ 40,141 $ (28,305 ) $ 11,836 $ (1,308 ) $ 10,528 Interest rate swaps 1,332,044 31,928 — 31,928 (20,530 ) 11,398 Energy contracts 463,703 81,869 (22,970 ) 58,899 — 58,899 Agricultural contracts 61,657 2,579 (1,158 ) 1,421 (1,248 ) 173 Foreign exchange contracts 546,405 498,574 — 498,574 (1,951 ) 496,623 Equity option contracts 137,278 3,780 — 3,780 — 3,780 Total customer risk management programs 16,710,014 658,871 (52,433 ) 606,438 (25,037 ) 581,401 Interest risk management programs 75,000 300 — 300 — 300 Total derivative contracts $ 16,785,014 $ 659,171 $ (52,433 ) $ 606,738 $ (25,037 ) $ 581,701 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 September 30, 2015 (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 $ 16,093,704 $ 136,435 $ (50,845 ) $ 85,590 $ — $ 85,590 Interest rate swaps 1,345,779 42,636 — 42,636 — 42,636 Energy contracts 560,997 89,948 (28,535 ) 61,413 (23,089 ) 38,324 Agricultural contracts 101,321 8,064 (4,053 ) 4,011 (1,558 ) 2,453 Foreign exchange contracts 618,991 557,313 — 557,313 (3,985 ) 553,328 Equity option contracts 143,452 3,784 — 3,784 (470 ) 3,314 Total customer risk management programs 18,864,244 838,180 (83,433 ) 754,747 (29,102 ) 725,645 Interest risk management programs 47,000 514 — 514 — 514 Total derivative contracts $ 18,911,244 $ 838,694 $ (83,433 ) $ 755,261 $ (29,102 ) $ 726,159 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 $ 16,050,271 $ 133,543 $ (50,845 ) $ 82,698 $ (82,225 ) $ 473 Interest rate swaps 1,345,779 42,901 — 42,901 (26,723 ) 16,178 Energy contracts 551,989 85,856 (28,535 ) 57,321 — 57,321 Agricultural contracts 101,325 8,045 (4,053 ) 3,992 — 3,992 Foreign exchange contracts 618,770 556,890 — 556,890 (2,619 ) 554,271 Equity option contracts 143,452 3,784 — 3,784 — 3,784 Total customer risk management programs 18,811,586 831,019 (83,433 ) 747,586 (111,567 ) 636,019 Interest risk management programs 7,500 96 — 96 — 96 Total derivative contracts $ 18,819,086 $ 831,115 $ (83,433 ) $ 747,682 $ (111,567 ) $ 636,115 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, 2016 September 30, 2015 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 $ 11,584 $ — $ 7,914 $ — Interest rate swaps 710 — 411 — Energy contracts 1,222 — 771 — Agricultural contracts 25 — 44 — Foreign exchange contracts 218 — 152 — Equity option contracts — — — — Total customer risk management programs 13,759 — 9,292 — Interest risk management programs (1,608 ) 2,226 (199 ) 1,283 Total derivative contracts $ 12,151 $ 2,226 $ 9,093 $ 1,283 Nine Months Ended September 30, 2016 September 30, 2015 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 $ 28,886 $ — $ 25,942 $ — Interest rate swaps 1,758 — 1,495 — Energy contracts 4,667 — 3,138 — Agricultural contracts 86 — 86 — Foreign exchange contracts 730 — 618 — Equity option contracts — — — — Total customer risk management programs 36,127 — 31,279 — Interest risk management programs (1,617 ) 20,130 (199 ) 1,162 Total derivative contracts $ 34,510 $ 20,130 $ 31,080 $ 1,162 Net interest revenue was not significantly impacted by the settlement of amounts receivable or payable on interest rate swaps for the nine months ended September 30, 2016 and 2015 , respectively.

Loans and Allowances for Credit

Loans and Allowances for Credit Losses	9 Months Ended
	Sep. 30, 2016
Loans Receivable, Net [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"). 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. 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 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. 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 principal balance continues to be guaranteed; 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, 2016 December 31, 2015 Fixed Rate Variable Rate Non-accrual Total Fixed Rate Variable Rate Non-accrual Total Commercial $ 1,991,423 $ 7,952,276 $ 176,464 $ 10,120,163 $ 1,850,548 $ 8,325,559 $ 76,424 $ 10,252,531 Commercial real estate 565,429 3,220,819 7,350 3,793,598 627,678 2,622,354 9,001 3,259,033 Residential mortgage 1,572,288 248,053 52,452 1,872,793 1,598,992 216,661 61,240 1,876,893 Personal 104,408 573,138 686 678,232 91,816 460,418 463 552,697 Total $ 4,233,548 $ 11,994,286 $ 236,952 $ 16,464,786 $ 4,169,034 $ 11,624,992 $ 147,128 $ 15,941,154 Accruing loans past due (90 days) 1 $ 3,839 $ 1,207 September 30, 2015 Fixed Rate Variable Rate Non-accrual Total Commercial $ 1,854,163 $ 7,909,461 $ 33,798 $ 9,797,422 Commercial real estate 588,604 2,635,507 10,956 3,235,067 Residential mortgage 1,624,759 200,136 44,100 1,868,995 Personal 100,615 364,848 494 465,957 Total $ 4,168,141 $ 11,109,952 $ 89,348 $ 15,367,441 Accruing loans past due (90 days) 1 $ 101 1 Excludes residential mortgage loans guaranteed by agencies of the U.S. government At September 30, 2016 , $5.3 billion or 32 percent of our total loan portfolio is to businesses and individuals attributed to the Texas market and $3.7 billion or 22 percent of the total loan portfolio is to businesses and individuals attributed to the Oklahoma market. These geographic concentrations subject the loan portfolio to the general economic conditions within these areas. Commercial Commercial loans represent loans for working capital, facilities acquisition or expansion, purchases of equipment and other needs of commercial customers primarily located within our geographical footprint. Commercial loans are underwritten individually and represent on-going relationships based on a thorough knowledge of the customer, the customer’s industry and market. While commercial loans are generally secured by the customer’s assets including real property, inventory, accounts receivable, operating equipment, interest in mineral rights and other property and may also include personal guarantees of the owners and related parties, the primary source of repayment of the loans is the on-going cash flow from operations of the customer’s business. Inherent lending risk is centrally monitored on a continuous basis from underwriting throughout the life of the loan for compliance with commercial lending policies. At September 30, 2016 , commercial loans attributed to the Texas market totaled $3.3 billion or 33 percent of the commercial loan portfolio segment and commercial loans attributed to the Oklahoma market totaled $2.3 billion or 23 percent of the commercial loan portfolio segment. The commercial loan portfolio segment is further divided into loan classes. The energy loan class totaled $2.5 billion or 15 percent of total loans at September 30, 2016 , including $2.0 billion of outstanding loans to energy producers. Approximately 57 percent of committed production loans are secured by properties primarily producing oil and 43 percent are secured by properties producing natural gas. The services loan class totaled $2.9 billion or 18 percent of total loans at September 30, 2016 . Approximately $1.3 billion of loans in the services category consist of loans with individual balances of less than $10 million . Businesses included in the services class include governmental, finance and insurance, not-for-profit, educational services and loans to entities providing services for real estate and construction. The healthcare loan class totaled $2.1 billion or 13 percent of total loans at September 30, 2016 . The healthcare loan class consists primarily of loans for the development and operation of senior housing and care facilities, including independent living, assisted living and skill nursing. Healthcare also includes loans to hospitals and other medical service providers. Commercial Real Estate Commercial real estate loans are for the construction of buildings or other improvements to real estate and property held by borrowers for investment purposes primarily within our geographical footprint. We require collateral values in excess of the loan amounts, demonstrated cash flows in excess of expected debt service requirements, equity investment in the project and a portion of the project already sold, leased or permanent financing already secured. The expected cash flows from all significant new or renewed income producing property commitments are stress tested to reflect the risks in varying interest rates, vacancy rates and rental rates. As with commercial loans, inherent lending risks are centrally monitored on a continuous basis from underwriting throughout the life of the loan for compliance with applicable lending policies. At September 30, 2016 , 30 percent of commercial real estate loans are secured by properties primarily located in the Dallas and Houston areas of Texas. An additional 12 percent of commercial real estate loans are secured by properties located primarily in the Tulsa and Oklahoma City metropolitan areas of Oklahoma. Residential Mortgage and Personal Residential mortgage loans provide funds for our customers to purchase or refinance their primary residence or to borrow against the equity in their home. Residential mortgage loans are secured by a first or second mortgage on the customer’s primary residence. Personal loans consist primarily of loans secured by the cash surrender value of insurance policies and marketable securities. It also includes direct loans secured by and for the purchase of automobiles, recreational and marine equipment as well as unsecured loans. Residential mortgage and personal loans are made in accordance with underwriting policies we believe to be conservative and are fully documented. Loans may be individually underwritten or credit scored based on size and other criteria. Credit scoring is assessed based on significant credit characteristics including credit history, residential and employment stability. Residential mortgage loans retained in the Company’s portfolio are primarily composed of various mortgage programs to support customer relationships including jumbo mortgage loans, non-builder construction loans and special loan programs for high net worth individuals and certain professionals. Jumbo loans may be fixed or variable rate and are fully amortizing. Jumbo loans generally conform to government sponsored entity standards, except that the loan size exceeds maximums required under these standards. These loans generally require a minimum FICO score of 720 and a maximum debt-to-income ratio (“DTI”) of 38 percent . Loan-to-value (“LTV”) ratios are tiered from 60 percent to 100 percent , depending on the market. Special mortgage programs include fixed and variable fully amortizing loans tailored to the needs of certain healthcare professionals. Variable rate loans are fully indexed at origination and may have fixed rates for three to ten years , then adjust annually thereafter. At September 30, 2016 , residential mortgage loans included $190 million of loans guaranteed by U.S. government agencies previously sold into GNMA mortgage pools. These loans either have been repurchased or are eligible to be repurchased by the Company when certain defined delinquency criteria are met. Although payments on these loans generally are past due more than 90 days, interest continues to accrue based on the government guarantee. Home equity loans totaled $713 million at September 30, 2016 . Approximately, 66 percent of the home equity loan portfolio is comprised of first lien loans and 34 percent of the home equity portfolio is comprised of junior lien loans. Junior lien loans are distributed 58 percent to amortizing term loans and 42 percent to revolving lines of credit. Home equity loans generally require a minimum FICO score of 700 and a maximum DTI of 40 percent. The maximum loan amount available for our home equity loan products is generally $400 thousand . Revolving loans have a 5 year revolving period followed by a 15 year term of amortizing repayments. Interest-only home equity loans may not be extended for any additional revolving time. All other home equity loans may be extended at management's discretion for an additional 5 year revolving term, subject to an update of certain credit information. 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, 2016 , outstanding commitments totaled $8.7 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, 2016 , outstanding standby letters of credit totaled $500 million . Commercial letters of credit are used to facilitate customer trade transactions with the drafts being drawn when the underlying transaction is consummated. At September 30, 2016 , outstanding commercial letters of credit totaled $5.2 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 on-going 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, 2016 . 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 ten-year 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, 2016 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 145,139 $ 46,745 $ 18,690 $ 6,001 $ 26,684 $ 243,259 Provision for loan losses 2,420 2,551 (466 ) 1,900 1,502 7,907 Loans charged off (6,266 ) — (285 ) (1,550 ) — (8,101 ) Recoveries 177 521 650 690 — 2,038 Ending balance $ 141,470 $ 49,817 $ 18,589 $ 7,041 $ 28,186 $ 245,103 Allowance for off-balance sheet credit losses: Beginning balance $ 8,752 $ 203 $ 62 $ 28 $ — $ 9,045 Provision for off-balance sheet credit losses 2,170 (53 ) (7 ) (17 ) — 2,093 Ending balance $ 10,922 $ 150 $ 55 $ 11 $ — $ 11,138 Total provision for credit losses $ 4,590 $ 2,498 $ (473 ) $ 1,883 $ 1,502 $ 10,000 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, 2016 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 130,334 $ 41,391 $ 19,509 $ 4,164 $ 30,126 $ 225,524 Provision for loan losses 45,995 7,538 (829 ) 4,809 (1,940 ) 55,573 Loans charged off (35,747 ) — (1,104 ) (4,086 ) — (40,937 ) Recoveries 888 888 1,013 2,154 — 4,943 Ending balance $ 141,470 $ 49,817 $ 18,589 $ 7,041 $ 28,186 $ 245,103 Allowance for off-balance sheet credit losses: Beginning balance $ 1,506 $ 153 $ 30 $ 22 $ — $ 1,711 Provision for off-balance sheet credit losses 9,416 (3 ) 25 (11 ) — 9,427 Ending balance $ 10,922 $ 150 $ 55 $ 11 $ — $ 11,138 Total provision for credit losses $ 55,411 $ 7,535 $ (804 ) $ 4,798 $ (1,940 ) $ 65,000 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, 2015 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 107,037 $ 39,744 $ 21,449 $ 3,955 $ 28,902 $ 201,087 Provision for loan losses 4,694 180 (349 ) 1,413 (1,156 ) 4,782 Loans charged off (3,497 ) — (446 ) (1,331 ) — (5,274 ) Recoveries 759 1,865 205 692 — 3,521 Ending balance $ 108,993 $ 41,789 $ 20,859 $ 4,729 $ 27,746 $ 204,116 Allowance for off-balance sheet credit losses: Beginning balance $ 595 $ 242 $ 26 $ 19 $ — $ 882 Provision for off-balance sheet credit losses 1,873 847 (2 ) — — 2,718 Ending balance $ 2,468 $ 1,089 $ 24 $ 19 $ — $ 3,600 Total provision for credit losses $ 6,567 $ 1,027 $ (351 ) $ 1,413 $ (1,156 ) $ 7,500 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, 2015 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 90,875 $ 42,445 $ 23,458 $ 4,233 $ 28,045 $ 189,056 Provision for loan losses 20,869 (11,571 ) (1,938 ) 2,069 (299 ) 9,130 Loans charged off (4,552 ) (44 ) (1,784 ) (3,940 ) — (10,320 ) Recoveries 1,801 10,959 1,123 2,367 — 16,250 Ending balance $ 108,993 $ 41,789 $ 20,859 $ 4,729 $ 27,746 $ 204,116 Allowance for off-balance sheet credit losses: Beginning balance $ 475 $ 707 $ 28 $ 20 $ — $ 1,230 Provision for off-balance sheet credit losses 1,993 382 (4 ) (1 ) — 2,370 Ending balance $ 2,468 $ 1,089 $ 24 $ 19 $ — $ 3,600 Total provision for credit losses $ 22,862 $ (11,189 ) $ (1,942 ) $ 2,068 $ (299 ) $ 11,500 The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at September 30, 2016 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 $ 9,943,699 $ 134,968 $ 176,464 $ 6,502 $ 10,120,163 $ 141,470 Commercial real estate 3,786,248 49,817 7,350 — 3,793,598 49,817 Residential mortgage 1,820,341 18,527 52,452 62 1,872,793 18,589 Personal 677,546 7,041 686 — 678,232 7,041 Total 16,227,834 210,353 236,952 6,564 16,464,786 216,917 Nonspecific allowance — — — — — 28,186 Total $ 16,227,834 $ 210,353 $ 236,952 $ 6,564 $ 16,464,786 $ 245,103 The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at December 31, 2015 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 $ 10,176,107 $ 114,027 $ 76,424 $ 16,307 $ 10,252,531 $ 130,334 Commercial real estate 3,250,032 41,373 9,001 18 3,259,033 41,391 Residential mortgage 1,815,653 19,441 61,240 68 1,876,893 19,509 Personal 552,234 4,164 463 — 552,697 4,164 Total 15,794,026 179,005 147,128 16,393 15,941,154 195,398 Nonspecific allowance — — — — — 30,126 Total $ 15,794,026 $ 179,005 $ 147,128 $ 16,393 $ 15,941,154 $ 225,524 The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at September 30, 2015 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 $ 9,763,624 $ 104,157 $ 33,798 $ 4,836 $ 9,797,422 $ 108,993 Commercial real estate 3,224,111 41,771 10,956 18 3,235,067 41,789 Residential mortgage 1,824,896 20,762 44,099 97 1,868,995 20,859 Personal 465,463 4,729 494 — 465,957 4,729 Total 15,278,094 171,419 89,347 4,951 15,367,441 176,370 Nonspecific allowance — — — — — 27,746 Total $ 15,278,094 $ 171,419 $ 89,347 $ 4,951 $ 15,367,441 $ 204,116 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, 2016 is as follows (in thousands): Internally Risk Graded Non-Graded Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 10,093,884 $ 140,552 $ 26,279 $ 918 $ 10,120,163 $ 141,470 Commercial real estate 3,793,598 49,817 — — 3,793,598 49,817 Residential mortgage 206,430 3,028 1,666,363 15,561 1,872,793 18,589 Personal 586,869 4,182 91,363 2,859 678,232 7,041 Total 14,680,781 197,579 1,784,005 19,338 16,464,786 216,917 Nonspecific allowance — — — — — 28,186 Total $ 14,680,781 $ 197,579 $ 1,784,005 $ 19,338 $ 16,464,786 $ 245,103 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, 2015 is as follows (in thousands): Internally Risk Graded Non-Graded Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 10,227,303 $ 129,426 $ 25,228 $ 908 $ 10,252,531 $ 130,334 Commercial real estate 3,259,033 41,391 — — 3,259,033 41,391 Residential mortgage 196,701 2,883 1,680,192 16,626 1,876,893 19,509 Personal 467,955 1,390 84,742 2,774 552,697 4,164 Total 14,150,992 175,090 1,790,162 20,308 15,941,154 195,398 Nonspecific allowance — — — — — 30,126 Total $ 14,150,992 $ 175,090 $ 1,790,162 $ 20,308 $ 15,941,154 $ 225,524 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, 2015 is as follows (in thousands): Internally Risk Graded Non-Graded Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 9,771,003 $ 108,101 $ 26,419 $ 892 $ 9,797,422 $ 108,993 Commercial real estate 3,235,067 41,789 — — 3,235,067 41,789 Residential mortgage 190,361 2,938 1,678,634 17,921 1,868,995 20,859 Personal 380,376 1,790 85,581 2,939 465,957 4,729 Total 13,576,807 154,618 1,790,634 21,752 15,367,441 176,370 Nonspecific allowance — — — — — 27,746 Total $ 13,576,807 $ 154,618 $ 1,790,634 $ 21,752 $ 15,367,441 $ 204,116 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, 2016 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 $ 1,869,598 $ 147,153 $ 361,087 $ 142,966 $ — $ — $ 2,520,804 Services 2,882,065 14,861 31,196 8,477 — — 2,936,599 Wholesale/retail 1,557,067 15,337 27,173 2,453 — — 1,602,030 Manufacturing 470,702 8,774 19,736 274 — — 499,486 Healthcare 2,022,757 42,224 19,210 855 — — 2,085,046 Other commercial and industrial 415,769 2,478 10,302 21,370 26,210 69 476,198 Total commercial 9,217,958 230,827 468,704 176,395 26,210 69 10,120,163 Commercial real estate: Residential construction and land development 155,737 — 470 3,739 — — 159,946 Retail 794,920 4,802 406 1,249 — — 801,377 Office 750,924 899 — 882 — — 752,705 Multifamily 868,501 — 5,221 51 — — 873,773 Industrial 837,945 — — 76 — — 838,021 Other commercial real estate 366,416 — 7 1,353

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2016
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	Acquisitions On December 8, 2015, the Company announced the signing of a definitive purchase agreement with MBT Bancshares (“MBT”). MBT is headquartered in Kansas City, Mo. and is the parent company of Missouri Bank and Trust of Kansas City (“mobank”). mobank operates four banking branches in the Kansas City, Mo. area. Under terms of the definitive agreement, BOK Financial will pay $102.5 million in an all-cash deal for all outstanding shares of MBT stock, subject to certain conditions and potential adjustments. The transaction has been approved by the boards of directors of both companies and is expected to close by the end of 2016, subject to customary closing conditions, including regulatory approval. In the first quarter of 2016, the Company acquired Weaver and Tidwell Financial Advisors LTD d/b/a Weaver Wealth Management, a registered investment advisor and E-Spectrum Advisors, an energy investment banking firm in Texas. The cash purchase price for these acquisitions was $7.7 million . The purchase price allocation included $5.3 million of identifiable intangible assets and $3.3 million of goodwill. On May 4, 2015, the Company acquired a majority voting interest in Heartland Food Products, LLC, a Kansas-based food product and restaurant equipment company. The cash purchase price for this acquisition was $18 million . The final purchase price allocation included $11 million of identifiable intangible assets and $2.7 million of goodwill. The pro-forma impact of these transactions was not material to the Company's consolidated financial statements.

Mortgage Banking Activities

Mortgage Banking Activities	9 Months Ended
	Sep. 30, 2016
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 sale commitments which are considered derivative contracts that have not been designated as hedging instruments. 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, 2016 Dec. 31, 2015 September 30, 2015 Unpaid Principal Balance/ Notional Fair Value Unpaid Principal Balance/ Notional Fair Value Unpaid Principal Balance/ Notional Fair Value Residential mortgage loans held for sale $ 422,523 $ 433,040 $ 293,637 $ 299,505 $ 336,974 $ 348,400 Residential mortgage loan commitments 630,804 18,598 601,147 8,134 742,742 18,161 Forward sales contracts 929,907 (4,046 ) 884,710 800 1,073,343 (9,147 ) $ 447,592 $ 308,439 $ 357,414 No residential mortgage loans held for sale were 90 days or more past due or considered impaired as of September 30, 2016 , December 31, 2015 or September 30, 2015 . No credit losses were recognized on residential mortgage loans held for sale for the nine month periods ended September 30, 2016 and 2015 . Mortgage banking revenue was as follows (in thousands): Three Months Ended Nine Months Ended 2016 2015 2016 2015 Production revenue: Net realized gains on sale of mortgage loans $ 27,142 $ 18,968 $ 57,126 $ 60,075 Net change in unrealized gain on mortgage loans held for sale (2,518 ) 6,666 4,649 4,751 Net change in the fair value of mortgage loan commitments (6,901 ) 9,838 10,464 8,190 Net change in the fair value of forward sales contracts 8,267 (16,755 ) (4,846 ) (5,146 ) Total production revenue 25,990 18,717 67,393 67,870 Servicing revenue 16,558 14,453 47,809 41,466 Total mortgage banking revenue $ 42,548 $ 33,170 $ 115,202 $ 109,336 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 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, Dec. 31, September 30, Number of residential mortgage loans serviced for others 139,587 131,859 128,828 Outstanding principal balance of residential mortgage loans serviced for others $ 21,851,536 $ 19,678,226 $ 18,928,726 Weighted average interest rate 4.01 % 4.12 % 4.15 % Remaining term (in months) 302 300 300 Activity in capitalized mortgage servicing rights during the three months ended September 30, 2016 was as follows (in thousands): Purchased Originated Total Balance, June 30, 2016 $ 4,067 $ 186,680 $ 190,747 Additions, net — 21,990 21,990 Change in fair value due to scheduled payments and full-balance payoffs (753 ) (10,690 ) (11,443 ) Change in fair value due to market assumption changes 251 2,076 2,327 Balance, Sept. 30, 2016 $ 3,565 $ 200,056 $ 203,621 Activity in capitalized mortgage servicing rights during the nine months ended September 30, 2016 was as follows (in thousands): Purchased Originated Total Balance, Dec. 31, 2015 $ 9,911 $ 208,694 $ 218,605 Additions, net — 56,345 56,345 Change in fair value due to scheduled payments and full-balance payoffs (2,109 ) (27,276 ) (29,385 ) Change in fair value due to market assumption changes (4,237 ) (37,707 ) (41,944 ) Balance, Sept. 30, 2016 $ 3,565 $ 200,056 $ 203,621 Activity in capitalized mortgage servicing rights during the three months ended September 30, 2015 was as follows (in thousands): Purchased Originated Total Balance, June 30, 2015 $ 10,730 $ 187,964 $ 198,694 Additions, net — 19,993 19,993 Change in fair value due to scheduled payments and full-balance payoffs (661 ) (6,220 ) (6,881 ) Change in fair value due to market assumption changes (656 ) (11,101 ) (11,757 ) Balance, Sept. 30, 2015 $ 9,413 $ 190,636 $ 200,049 Activity in capitalized mortgage servicing rights during the nine months ended September 30, 2015 was as follows (in thousands): Purchased Originated Total Balance, Dec. 31, 2014 $ 11,114 $ 160,862 $ 171,976 Additions, net — 62,375 62,375 Change in fair value due to scheduled payments and full-balance payoffs (2,171 ) (19,862 ) (22,033 ) Change in fair value due to market assumption changes 470 (12,739 ) (12,269 ) Balance, Sept. 30, 2015 $ 9,413 $ 190,636 $ 200,049 Changes in the fair value of mortgage servicing rights are included in Other operating revenue in the Consolidated Statements of Earnings. Changes in fair value due to actual loan payments are included in Mortgage banking costs. Changes in fair value due to market assumption changes are reported separately. Changes in fair value due to market assumption changes during the period relate to assets held at the reporting date. There is no active market for trading in mortgage servicing rights after origination. Fair value is determined by discounting the projected net cash flows. Significant assumptions used to determine fair value based on significant unobservable inputs were as follows: September 30, Dec. 31, September 30, Discount rate – risk-free rate plus a market premium 10.08% 10.11% 10.12% Loan servicing costs – annually per loan based upon loan type: Performing loans $63-$120 $63 - $105 $63 - $105 Delinquent loans $150 - $500 $150 - $500 $150 - $500 Loans in foreclosure $650 - $4,250 $650 - $4,250 $650 - $4,250 Escrow earnings rate – indexed to rates paid on deposit accounts with comparable average life 1.18% 1.73% 1.40% Primary/secondary mortgage rate spread 115 bps 130 bps 135 bps The Company is exposed to interest rate risk as benchmark residential mortgage interest rates directly affect the prepayment speeds used in valuing our mortgage servicing rights, which is partially managed through forward sales of residential mortgage-backed securities and forward sales contracts. 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 daily for changes in market conditions and adjusted to better correlate with actual performance of BOK Financial’s servicing portfolio. Stratification of the residential mortgage loan servicing portfolio and outstanding principal of loans serviced for others by interest rate at September 30, 2016 follows (in thousands): < 4.00% 4.00% - 4.99% 5.00% - 5.99% > 5.99% Total Fair value $ 121,802 $ 74,830 $ 4,968 $ 2,021 $ 203,621 Outstanding principal of loans serviced for others $ 12,145,996 $ 7,720,311 $ 1,215,692 $ 769,537 $ 21,851,536 Weighted average prepayment rate 1 9.16 % 12.48 % 36.75 % 47.15 % 13.20 % 1 Annual prepayment estimates based upon loan interest rate, original term and loan type. Weighted average prepayment rate is determined by weighting the prepayment speed for each loan by its unpaid principal balance. The interest rate sensitivity of our mortgage servicing rights is modeled over a range of +/- 50 basis points. At September 30, 2016 , a 50 basis point decrease in mortgage interest rates is expected to decrease the fair value of our mortgage servicing rights by $52.6 million . A 50 basis point increase in mortgage interest rates is expected to increase the fair value of our mortgage servicing rights by $30.6 million . In the model, changes in the value of servicing rights due to changes in interest rates assume stable relationships between residential mortgage rates and prepayment speeds. Changes in market conditions can cause variations from these assumptions. These factors and others may cause changes in the value of our mortgage servicing rights to differ from our expectations. The aging status of our mortgage loans serviced for others by investor at September 30, 2016 follows (in thousands): Past Due Current 30 to 59 Days 60 to 89 Days 90 Days or More Total FHLMC $ 7,760,547 $ 34,145 $ 10,399 $ 23,938 $ 7,829,029 FNMA 6,944,158 43,046 8,704 17,097 7,013,005 GNMA 6,338,155 150,386 48,790 16,624 6,553,955 Other 452,083 1,219 596 1,649 455,547 Total $ 21,494,943 $ 228,796 $ 68,489 $ 59,308 $ 21,851,536 The Company has off-balance sheet credit risk related to residential mortgage loans sold to U.S. government agencies with recourse prior to 2008 under various community development programs. These loans consist of first lien, fixed-rate residential mortgage loans underwritten to standards approved by the agencies including full documentation and originated under programs available only for owner-occupied properties. However, these loans have a higher risk of delinquency and loss given default than traditional residential mortgage loans. The Company no longer sells residential mortgage loans with recourse other than obligations under standard representations and warranties. The recourse obligation relates to loan performance for the life of the loan and the Company is obligated to repurchase the loan at the time of foreclosure for the unpaid principal balance plus unpaid interest. The principal balance of residential mortgage loans sold subject to recourse obligations totaled $139 million at September 30, 2016 , $155 million at December 31, 2015 and $162 million at September 30, 2015 . A separate accrual for these off-balance sheet commitments is included in Other liabilities in the Consolidated Balance Sheets. At September 30, 2016 , approximately 2 percent of the loans sold with recourse with an outstanding principal balance of $3.3 million were either delinquent more than 90 days, in bankruptcy or in foreclosure and 5 percent with an outstanding balance of $7.1 million were past due 30 to 89 days. The provision for credit losses on loans sold with recourse is included in Mortgage banking costs in the Consolidated Statements of Earnings. The activity in the accrual for losses on loans sold with recourse included in Other liabilities in the Consolidated Balance Sheets is summarized as follows (in thousands): Three Months Ended Nine Months Ended 2016 2015 2016 2015 Beginning balance $ 4,339 $ 6,691 $ 4,649 $ 7,299 Provision for recourse losses 113 81 504 211 Loans charged off, net (235 ) (506 ) (936 ) (1,244 ) Ending balance $ 4,217 $ 6,266 $ 4,217 $ 6,266 The Company also has obligations to repurchase or provide indemnification for residential mortgage loans sold to government sponsored entities due to standard representations and warranties made under contractual agreements and to service loans in accordance with investor guidelines. The Company has established accruals for losses related to these obligations that are included in Other liabilities in the Consolidated Balance Sheets and in Mortgage banking costs in the Consolidated Statements of Earnings. The Company repurchased 2 loans from the agencies for $ 309 thousand during the third quarter of 2016 . There were no indemnifications on loans paid during the third quarter of 2016 . Losses recognized on repurchases were insignificant. A summary of unresolved deficiency requests from the agencies follows (in thousands, except for number of unresolved deficiency requests): September 30, 2016 2015 Number of unresolved deficiency requests 221 194 Aggregate outstanding principal balance subject to unresolved deficiency requests $ 15,750 $ 14,237 Unpaid principal balance subject to indemnification by the Company 5,399 4,604 The activity in the accruals for mortgage losses is summarized as follows (in thousands). Three Months Ended Nine Months Ended 2016 2015 2016 2015 Beginning balance $ 8,043 $ 8,908 $ 7,732 $ 11,868 Provision for losses 1,357 (52 ) 5,260 (3,056 ) Charge-offs, net (1,758 ) (1,262 ) (5,350 ) (1,218 ) Ending balance $ 7,642 $ 7,594 $ 7,642 $ 7,594

Commitments and Contingent Liab

Commitments and Contingent Liabilities	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities [Text Block]	( 7 ) Commitments and Contingent Liabilities Litigation Contingencies As a member of Visa, BOK Financial is obligated for a proportionate share of certain covered litigation losses incurred by Visa under a retrospective responsibility plan. A contingent liability was recognized for the Company’s share of Visa’s covered litigation liabilities. Visa funded an escrow account to cover litigation claims, including covered litigation losses under the retrospective responsibility plan, with proceeds from its initial public offering in 2008 and from available cash. BOK Financial currently owns 252,233 Visa Class B shares which are convertible into 415,755 shares of Visa Class A shares after the final settlement of all covered litigation. Class B shares may be diluted in the future if the escrow fund is not adequate to cover future covered litigation costs. Therefore, no value has been currently assigned to the Class B shares and no value may be assigned until the Class B shares are converted into a known number of Class A shares. On March 3, 2015, the Bank and the Company were named as defendants in a class action alleging (1) that the manner in which the Bank posted charges to its consumer deposit accounts was improper from September 1, 2011 through July 8, 2014, the period after which the Bank and BOK Financial had settled a class action respecting a similar claim, and before it made changes to its posting order and (2) that the manner in which the Bank posted charges to its small business deposit accounts was improper from July 9, 2009 through July 8, 2014. Following mediation of the case in August 2016, the Class Representatives and the Bank reached a settlement of the action for $7.8 million . The settlement is subject to the approval of the Court which the Parties to the Action expect. Management has established an accrual for the settlement. On June 24, 2015, the Bank 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 the Bank 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 the 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 (estimated to be approximately $73 million , less the value of the facilities securing repayment of the bonds), subject to oversight by a court appointed monitor. On September 7, 2016, the Bank agreed, and the SEC entered, a consent order finding that the Bank had violated Section 17(a) of the Securities Act of 1933 and Section 10(b) of the Securities Exchange Act and requiring the Bank to disgorge $1,067,721 of fees and pay a civil penalty of $600,000 . The Bank has disgorged the fees and paid the penalty. On January 7, 2016, the terminated employee filed an action against the Bank alleging the Bank defamed the employee and made a demand for indemnification respecting the SEC investigation which demand the respective boards of directors of the Company and the Bank denied. On September 9, 2016, the SEC filed a complaint against the terminated employee alleging the employee violated Section 17(a) of the Securities Act of 1933 and Section 10(b) of the Securities Exchange Act and requiring the employee to disgorge ill-gotten gains. On September 26, 2016, the employee dismissed the action without prejudice. On August 26, 2016, the Bank 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 the Bank participated in the fraudulent sale of securities by the principals. On September 14, 2016, the Bank was sued in the District Court of Tulsa County, Oklahoma by 19 bondholders alleging the Bank participated in the fraudulent sale of securities by the principals. Management has been advised by counsel that the Bank has valid defenses to the claims. The Bank expects the Court ordered payment plan will result in the payment of the bonds by the principals. Accordingly, no loss is probable at this time and no provision for loss has been made. If the payment plan does not result in payment of the bonds, a loss could become probable. A reasonable estimate cannot be made at this time though the amount could be material to the Company. The Director of the New Mexico Securities Division of the State of New Mexico Regulation and Licensing Department ("the Director") issued a Notice of Contemplated Action in connection with the purchase of various municipal bonds by the elected County Treasurer of Bernalillo County, New Mexico, from BOK Financial Securities, Inc., the Company’s broker-dealer affiliate. The Notice was settled by a $125,000 payment to the Division’s Educational fund, without any fine, penalty or sanction. The County of Bernalillo, New Mexico, has commenced arbitration pursuant to the Arbitration Rules of FINRA seeking recovery of $5.6 million arising out of the purchase. The Company has been advised that any recovery by the County is remote. 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 determined by the nature of the entity. Variable interest entities are generally defined as entities that either do not have sufficient equity to finance their activities without support from other parties or whose equity investors lack a controlling financial interest. Variable interest entities are consolidated based on the determination that the Company is the primary beneficiary including the power to direct the activities that most significantly impact the variable interest's economic performance and the obligation to absorb losses of the variable interest or the right to receive benefits of the variable interest that could be significant to the variable interest. BOKF Equity, LLC, an indirect wholly-owned subsidiary, is the general partner of two consolidated private equity funds (“the Funds”). The Funds provide alternative investment opportunities to certain customers, some of which are related parties, through unaffiliated limited partnerships. These unaffiliated limited partnerships generally invest in distressed assets, asset buy-outs or venture capital companies. As general partner, BOKF Equity, LLC has the power to direct activities that most significantly affect the Funds' performance and contingent obligations to make additional investments totaling $4.6 million at September 30, 2016 . Substantially all of the obligations are offset by limited partner commitments. The Company does not accrue its contingent liability to fund investments. The Volcker Rule in Title VI of the Dodd-Frank Act will limit both the amount and structure of these types of investments. Consolidated tax credit investment entities represent the Company's interest in entities earning federal new market tax credits related to qualifying loans. The Company has the power to direct the activities that most significantly impact the variable interest's economic performance of the entity including being the primary beneficiary of or the obligation to absorb losses of the variable interest that could be significant to the variable interest. Other consolidated alternative investments include entities held under merchant banking authority. While the Company owns a majority of the voting interest in these entities, its ability to manage daily operations is limited by applicable banking regulations. Consolidated other assets includes total tangible assets, identifiable intangible assets and goodwill held by these entities. The Company also has interests in various unrelated alternative investments generally consisting of unconsolidated limited partnership interests in or loans to entities for which investment return is primarily in the form of tax credits or that invest in distressed real estate loans and properties, energy development, venture capital and other activities. The Company is prohibited by banking regulations from controlling or actively managing the activities of these investments and the Company's maximum exposure to loss is restricted to its investment balance. The Company's obligation to fund alternative investments is included in Other liabilities in the Consolidated Balance Sheets. A summary of consolidated and unconsolidated alternative investments as of September 30, 2016 , December 31, 2015 and September 30, 2015 is as follows (in thousands): September 30, 2016 Loans Other assets Other liabilities Other borrowings Non-controlling interests Consolidated: Private equity funds $ — $ 18,420 $ — $ — $ 15,946 Tax credit entities 10,000 11,740 — 10,964 10,000 Other — 30,978 2,346 1,063 8,154 Total consolidated $ 10,000 $ 61,138 $ 2,346 $ 12,027 $ 34,100 Unconsolidated: Tax credit entities $ 39,849 $ 129,715 $ 57,026 $ — $ — Other — 30,272 13,653 — — Total unconsolidated $ 39,849 $ 159,987 $ 70,679 $ — $ — Dec. 31, 2015 Loans Other assets Other liabilities Other borrowings Non-controlling interests Consolidated: Private equity funds $ — $ 22,472 $ — $ — $ 17,823 Tax credit entities 10,000 12,206 — 10,964 10,000 Other — 40,453 2,198 2,831 9,260 Total consolidated $ 10,000 $ 75,131 $ 2,198 $ 13,795 $ 37,083 Unconsolidated: Tax credit entities $ 16,916 $ 85,274 $ 14,572 $ — $ — Other — 15,506 6,319 — — Total unconsolidated $ 16,916 $ 100,780 $ 20,891 $ — $ — September 30, 2015 Loans Other assets Other liabilities Other borrowings Non-controlling interests Consolidated: Private equity funds $ — $ 24,133 $ — $ — $ 19,947 Tax credit entities 10,000 12,361 — 10,964 10,000 Other — 41,197 2,774 2,788 8,989 Total consolidated $ 10,000 $ 77,691 $ 2,774 $ 13,752 $ 38,936 Unconsolidated: Tax credit entities $ 18,114 $ 94,600 $ 21,973 $ — $ — Other — 15,822 6,899 — — Total unconsolidated $ 18,114 $ 110,422 $ 28,872 $ — $ — Other Commitments and Contingencies At September 30, 2016 , Cavanal Hill Funds’ assets included U.S. Treasury, cash management and tax-free money market funds. Assets of these funds consist of highly-rated, short-term obligations of the U.S. Treasury, corporate issuers and U.S. states and municipalities. The net asset value of units in these funds was $1.00 at September 30, 2016 . An investment in these funds is not insured by the Federal Deposit Insurance Corporation or guaranteed by BOK Financial or any of its subsidiaries. BOK Financial may, but is not obligated to purchase assets from these funds to maintain the net asset value at $1.00 . No assets were purchased from the funds in 2016 or 2015 . The Company has agreed to purchase approximately $7.5 million of Oklahoma Historic State Income Tax Credits from the George Kaiser Family Foundation, a principal shareholder of BOKF. These credits will be used to reduce the Company's state income tax liability in 2016 and 2017.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2016
Stockholders' Equity Note [Abstract]
Shareholders' Equity [Text Block]	Shareholders' Equity On October 25, 2016 , the Company declared a quarterly cash dividend of $0.44 per common share on or about November 28, 2016 to shareholders of record as of November 14, 2016 . Dividends declared were $0.43 per share and $1.29 per share during the three and nine months ended September 30, 2016 and $0.42 per share and $1.26 during the three and nine months ended September 30, 2015 . 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. AOCI also includes unrealized gains on AFS securities that were transferred from AFS to investment securities in the third quarter of 2011. Such amounts are being amortized over the estimated remaining life of the security as an adjustment to yield, offsetting the related amortization of premium on the transferred securities. 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. Accumulated losses on the interest rate lock hedge of the 2005 subordinated debt issuance were reclassified into income over the ten-year life of the debt. 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 Investment Securities Transferred from AFS Employee Benefit Plans Loss on Effective Cash Flow Hedges Total Balance, Dec. 31, 2014 $ 59,239 $ 376 $ (2,868 ) $ (74 ) $ 56,673 Net change in unrealized gain (loss) 57,763 — — — 57,763 Reclassification adjustments included in earnings: Interest revenue, Investment securities, Taxable securities — (418 ) — — (418 ) Interest expense, Subordinated debentures — — — 121 121 Net impairment losses recognized in earnings 92 — — — 92 Gain on available for sale securities, net (9,926 ) — — — (9,926 ) Other comprehensive income (loss), before income taxes 47,929 (418 ) — 121 47,632 Federal and state income taxes 1 18,644 (162 ) — 47 18,529 Other comprehensive income (loss), net of income taxes 29,285 (256 ) — 74 29,103 Balance, Sept. 30, 2015 $ 88,524 $ 120 $ (2,868 ) $ — $ 85,776 Balance, Dec. 31, 2015 $ 23,284 $ 68 $ (1,765 ) $ — $ 21,587 Net change in unrealized gain (loss) 133,108 — — — 133,108 Reclassification adjustments included in earnings: Interest revenue, Investment securities, Taxable securities — (112 ) — — (112 ) Interest expense, Subordinated debentures — — — — — Net impairment losses recognized in earnings — — — — — Gain on available for sale securities, net (11,684 ) — — — (11,684 ) Other comprehensive income (loss), before income taxes 121,424 (112 ) — — 121,312 Federal and state income taxes 1 47,216 (44 ) — — 47,172 Other comprehensive income (loss), net of income taxes 74,208 (68 ) — — 74,140 Balance, Sept. 30, 2016 $ 97,492 $ — $ (1,765 ) $ — $ 95,727 1 Calculated using a 39 percent effective tax rate.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2016
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 2016 2015 2016 2015 Numerator: Net income attributable to BOK Financial Corp. shareholders $ 74,277 $ 74,891 $ 182,642 $ 228,964 Less: Earnings allocated to participating securities 916 894 2,275 2,652 Numerator for basic earnings per share – income available to common shareholders 73,361 73,997 180,367 226,312 Effect of reallocating undistributed earnings of participating securities 1 1 1 2 Numerator for diluted earnings per share – income available to common shareholders $ 73,362 $ 73,998 $ 180,368 $ 226,314 Denominator: Weighted average shares outstanding 65,895,430 68,486,376 66,031,497 68,800,419 Less: Participating securities included in weighted average shares outstanding 810,038 818,300 822,723 795,911 Denominator for basic earnings per common share 65,085,392 67,668,076 65,208,774 68,004,508 Dilutive effect of employee stock compensation plans 1 72,449 94,407 54,792 99,509 Denominator for diluted earnings per common share 65,157,841 67,762,483 65,263,566 68,104,017 Basic earnings per share $ 1.13 $ 1.09 $ 2.77 $ 3.33 Diluted earnings per share $ 1.13 $ 1.09 $ 2.76 $ 3.32 1 Excludes employee stock options with exercise prices greater than current market price. — — — —

Reportable Segments

Reportable Segments	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Reportable Segments [Text Block]	Reportable Segments Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended September 30, 2016 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 123,598 $ 22,098 $ 9,274 $ 32,876 $ 187,846 Net interest revenue (expense) from internal sources (15,052 ) 9,263 7,401 (1,612 ) — Net interest revenue 108,546 31,361 16,675 31,264 187,846 Provision for credit losses 5,601 1,157 (89 ) 3,331 10,000 Net interest revenue after provision for credit losses 102,945 30,204 16,764 27,933 177,846 Other operating revenue 49,642 64,635 73,523 3,542 191,342 Other operating expense 53,375 64,995 64,426 79,324 262,120 Net direct contribution 99,212 29,844 25,861 (47,849 ) 107,068 Loss on financial instruments, net — (1,087 ) (42 ) 1,129 — Change in fair value of mortgage servicing rights — 2,327 — (2,327 ) — Gain on repossessed assets, net 1,486 161 — (1,647 ) — Corporate expense allocations 9,054 16,905 10,912 (36,871 ) — Net income before taxes 91,644 14,340 14,907 (13,823 ) 107,068 Federal and state income taxes 35,650 5,578 5,799 (15,071 ) 31,956 Net income 55,994 8,762 9,108 1,248 75,112 Net income attributable to non-controlling interests — — — 835 835 Net income attributable to BOK Financial Corp. shareholders $ 55,994 $ 8,762 $ 9,108 $ 413 $ 74,277 Average assets $ 16,934,587 $ 8,827,816 $ 6,413,735 $ 470,335 $ 32,646,473 Average invested capital 1,170,465 275,358 244,291 1,667,437 3,357,551 Reportable segments reconciliation to the Consolidated Financial Statements for the nine months ended September 30, 2016 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 358,714 $ 65,897 $ 21,622 $ 106,797 $ 553,030 Net interest revenue (expense) from internal sources (44,259 ) 27,492 22,258 (5,491 ) — Net interest revenue 314,455 93,389 43,880 101,306 553,030 Provision for credit losses 34,024 4,177 (479 ) 27,278 65,000 Net interest revenue after provision for credit losses 280,431 89,212 44,359 74,028 488,030 Other operating revenue 146,248 181,774 218,042 (6,096 ) 539,968 Other operating expense 162,039 189,188 186,524 223,994 761,745 Net direct contribution 264,640 81,798 75,877 (156,062 ) 266,253 Gain (loss) on financial instruments, net — 30,539 (42 ) (30,497 ) — Change in fair value of mortgage servicing rights — (41,944 ) — 41,944 — Gain on repossessed assets, net 806 566 — (1,372 ) — Corporate expense allocations 26,681 49,513 31,864 (108,058 ) — Net income before taxes 238,765 21,446 43,971 (37,929 ) 266,253 Federal and state income taxes 92,880 8,342 17,105 (34,446 ) 83,881 Net income 145,885 13,104 26,866 (3,483 ) 182,372 Net loss attributable to non-controlling interests — — — (270 ) (270 ) Net income attributable to BOK Financial Corp. shareholders $ 145,885 $ 13,104 $ 26,866 $ (3,213 ) $ 182,642 Average assets $ 16,958,999 $ 8,763,564 $ 5,916,545 $ 410,075 $ 32,049,183 Average invested capital 1,161,996 267,123 238,917 1,650,563 3,318,599 Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended September 30, 2015 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 109,503 $ 21,551 $ 6,674 $ 40,908 $ 178,636 Net interest revenue (expense) from internal sources (13,450 ) 7,216 $ 5,834 400 — Net interest revenue 96,053 28,767 12,508 41,308 178,636 Provision for credit losses 997 1,431 (190 ) 5,262 7,500 Net interest revenue after provision for credit losses 95,056 27,336 12,698 36,046 171,136 Other operating revenue 45,276 57,349 66,541 (5,730 ) 163,436 Other operating expense 51,960 51,027 57,356 64,285 224,628 Net direct contribution 88,372 33,658 21,883 (33,969 ) 109,944 Gain (loss) on financial instruments, net — 7,386 (176 ) (7,210 ) — Change in fair value of mortgage servicing rights — (11,758 ) — 11,758 — Gain on repossessed assets, net 350 331 — (681 ) — Corporate expense allocations 10,723 18,921 9,841 (39,485 ) — Net income before taxes 77,999 10,696 11,866 9,383 109,944 Federal and state income taxes 30,342 4,161 4,616 (4,991 ) 34,128 Net income 47,657 6,535 7,250 14,374 75,816 Net income attributable to non-controlling interests — — — 925 925 Net income attributable to BOK Financial Corp. shareholders $ 47,657 $ 6,535 $ 7,250 $ 13,449 $ 74,891 Average assets $ 16,156,446 $ 8,843,926 $ 5,433,238 $ 336,123 $ 30,769,733 Average invested capital 1,062,053 264,540 226,477 1,808,477 3,361,547 Reportable segments reconciliation to the Consolidated Financial Statements for the nine months ended September 30, 2015 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 319,298 $ 63,993 $ 18,271 $ 120,531 $ 522,093 Net interest revenue (expense) from internal sources (38,728 ) 20,874 $ 17,400 454 — Net interest revenue 280,570 84,867 35,671 120,985 522,093 Provision for credit losses (7,952 ) 4,467 (937 ) 15,922 11,500 Net interest revenue after provision for credit losses 288,522 80,400 36,608 105,063 510,593 Other operating revenue 132,996 178,232 204,100 (9,590 ) 505,738 Other operating expense 151,908 155,844 170,113 194,141 672,006 Net direct contribution 269,610 102,788 70,595 (98,668 ) 344,325 Gain (loss) on financial instruments, net — 1,809 (204 ) (1,605 ) — Change in fair value of mortgage servicing rights — (12,269 ) — 12,269 — Gain on repossessed assets, net 336 888 — (1,224 ) — Corporate expense allocations 32,747 56,075 30,011 (118,833 ) — Net income before taxes 237,199 37,141 40,380 29,605 344,325 Federal and state income taxes 92,270 14,448 15,708 (9,284 ) 113,142 Net income 144,929 22,693 24,672 38,889 231,183 Net income attributable to non-controlling interests — — — 2,219 2,219 Net income attributable to BOK Financial Corp. shareholders $ 144,929 $ 22,693 $ 24,672 $ 36,670 $ 228,964 Average assets $ 16,229,307 $ 8,871,423 $ 5,401,433 $ (97,733 ) $ 30,404,430 Average invested capital 1,028,013 268,427 225,222 1,819,969 3,341,631

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2016
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. 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, 2016 and 2015 , respectively. Transfers between significant other observable inputs and significant unobservable inputs during the three and nine months ended September 30, 2016 and 2015 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, 2016 , December 31, 2015 or September 30, 2015 . 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, 2016 (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 $ 15,705 $ — $ 15,705 $ — U.S. government agency residential mortgage-backed securities 464,749 — 464,749 — Municipal and other tax-exempt securities 54,856 — 54,856 — Other trading securities 11,305 — 11,305 — Total trading securities 546,615 — 546,615 — Available for sale securities: U.S. Treasury 1,002 1,002 — — Municipal and other tax-exempt 42,092 — 36,379 5,713 U.S. government agency residential mortgage-backed securities 5,668,672 — 5,668,672 — Privately issued residential mortgage-backed securities 121,603 — 121,603 — Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,986,495 — 2,986,495 — Other debt securities 4,151 — — 4,151 Perpetual preferred stock 19,578 — 19,578 — Equity securities and mutual funds 18,690 3,544 15,146 — Total available for sale securities 8,862,283 4,546 8,847,873 9,864 Fair value option securities: U.S. government agency residential mortgage-backed securities — — — — U.S. Treasury 222,409 222,409 — — Total fair value option securities 222,409 222,409 — — Residential mortgage loans held for sale 447,592 — 438,291 9,301 Mortgage servicing rights 1 203,621 — — 203,621 Derivative contracts, net of cash collateral 2 655,078 5,575 649,503 — Liabilities: Derivative contracts, net of cash collateral 2 573,987 1,308 572,679 — 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 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 and energy derivative contracts, net of cash margin. The fair value of financial assets and liabilities measured on a recurring basis was as follows as of December 31, 2015 (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 $ 61,295 $ — $ 61,295 $ — U.S. government agency residential mortgage-backed securities 10,989 — 10,989 — Municipal and other tax-exempt securities 31,901 — 31,901 — Other trading securities 18,219 — 18,219 — Total trading securities 122,404 — 122,404 — Available for sale securities: U.S. Treasury 995 995 — — Municipal and other tax-exempt 56,817 — 47,207 9,610 U.S. government agency residential mortgage-backed securities 5,898,351 — 5,898,351 — Privately issued residential mortgage-backed securities 139,118 — 139,118 — Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,905,796 — 2,905,796 — Other debt securities 4,151 — — 4,151 Perpetual preferred stock 19,672 — 19,672 — Equity securities and mutual funds 17,833 3,265 14,568 — Total available for sale securities 9,042,733 4,260 9,024,712 13,761 Fair value option securities: U.S. government agency residential mortgage-backed securities 444,217 — 444,217 — U.S. Treasury — — — — Total fair value option securities 444,217 — 444,217 — Residential mortgage loans held for sale 308,439 — 300,565 7,874 Mortgage servicing rights 1 218,605 — — 218,605 Derivative contracts, net of cash collateral 2 586,270 38,530 547,740 — Liabilities: Derivative contracts, net of cash collateral 2 581,701 — 581,701 — 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 energy derivative contacts, net of cash margin. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate and agricultural derivative contracts, net of cash margin. The fair value of financial assets and liabilities measured on a recurring basis was as follows as of September 30, 2015 (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 $ 42,431 $ — $ 42,431 $ — U.S. government agency residential mortgage-backed securities 30,973 — 30,973 — Municipal and other tax-exempt securities 84,261 — 84,261 — Other trading securities 23,466 — 23,466 — Total trading securities 181,131 — 181,131 — Available for sale securities: U.S. Treasury 1,003 1,003 — — Municipal and other tax-exempt 57,960 — 48,360 9,600 U.S. government agency residential mortgage-backed securities 5,819,127 — 5,819,127 — Privately issued residential mortgage-backed securities 145,682 — 145,682 — Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,735,787 — 2,735,787 — Other debt securities 4,150 — — 4,150 Perpetual preferred stock 19,163 — 19,163 — Equity securities and mutual funds 18,217 3,505 14,712 — Total available for sale securities 8,801,089 4,508 8,782,831 13,750 Fair value option securities: U.S. government agency residential mortgage-backed securities 427,760 — 427,760 — U.S. Treasury — — — — Total fair value option securities 427,760 — 427,760 — Residential mortgage loans held for sale 357,414 — 349,381 8,033 Mortgage servicing rights 1 200,049 — — 200,049 Derivative contracts, net of cash collateral 2 726,159 4,922 721,237 — Liabilities: Derivative contracts, net of cash collateral 2 636,115 — 636,115 — 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 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) were exchange-traded interest rate derivative 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 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 monthly. 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 counterparty credit rating or equivalent loan grading, derivative contract notional size, price volatility of the underlying commodity, duration of the derivative contracts and expected loss severity. Expected loss severity is based on historical losses for similarly risk graded commercial loan customers. Decreases in counterparty credit rating or grading and increases in price volatility and expected loss severity all tend to increase the credit quality adjustment which reduces the fair value of asset contracts. The reduction in fair value is recognized in earnings during the current period. 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. The change in the fair value would be recognized in earnings in the current period. Residential Mortgage Loans Held for Sale Residential mortgage loans held for sale are carried on the balance sheet at fair value. 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. Other Assets - Private Equity Funds The fair value of the portfolio investments of the Company's two private equity funds is based upon net asset value reported by the underlying funds, as adjusted by the general partner when necessary, as a practical expedient to measure the fair value of the investments in the underlying funds. The Company's private equity funds provide customers alternative investment opportunities as limited partners of the funds. As fund of funds, the private equity funds invest in other limited partnerships or limited liability companies that invest substantially all of their assets in U.S. companies pursuing diversified investment strategies including early-stage venture capital, distressed securities and corporate or asset buy-outs. Private equity fund assets are long-term, illiquid investments. No secondary market exists for these assets. The private equity funds typically invest in funds that provide no redemption rights to investors. The fair value of the private equity investments may only be realized through cash distributions from the underlying funds. See Note 7 for disclosure of the fair value of the private equity funds using the net asset value per share of the underlying investments, as a practical expedient, included in Other assets in the Consolidated Balance Sheets of the Company. The following represents the changes for the three months ended September 30, 2016 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 Other debt securities Residential mortgage loans held for sale Balance, June 30, 2016 $ 9,600 $ 4,151 $ 9,749 Transfer to Level 3 from Level 2 — — 442 Purchases — — — Proceeds from sales — — (1,003 ) Redemptions and distributions (3,975 ) — — Gain (loss) recognized in earnings: Mortgage banking revenue — — 113 Other comprehensive income (loss): Net change in unrealized gain (loss) 88 — — Balance, Sept. 30, 2016 $ 5,713 $ 4,151 $ 9,301 The following represents the changes for the nine months ended September 30, 2016 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 Other debt securities Residential mortgage loans held for sale Balance, Dec. 31, 2015 $ 9,610 $ 4,151 $ 7,874 Transfer to Level 3 from Level 2 — — 3,982 Purchases — — — Proceeds from sales — — (2,365 ) Redemptions and distributions (3,975 ) — — Gain (loss) recognized in earnings: Mortgage banking revenue — — (190 ) Other comprehensive income (loss): Net change in unrealized gain (loss) 78 — — Balance, Sept. 30, 2016 $ 5,713 $ 4,151 $ 9,301 The following represents the changes for the three months ended September 30, 2015 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 Other debt securities Residential mortgage loans held for sale Balance, June 30, 2015 $ 9,617 $ 4,150 $ 7,973 Transfer to Level 3 from Level 2 — — 966 Purchases — — — Proceeds from sales — — (811 ) Redemptions and distributions — — — Gain (loss) recognized in earnings: Mortgage banking revenue — — (95 ) Other comprehensive income (loss): Net change in unrealized gain (loss) (17 ) — — Balance, Sept. 30, 2015 $ 9,600 $ 4,150 $ 8,033 The following represents the changes for the nine months ended September 30, 2015 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 Other debt securities Residential mortgage loans held for sale Balance, Dec. 31, 2014 $ 10,093 $ 4,150 $ 11,856 Transfer to Level 3 from Level 2 — — 2,153 Purchases — — — Proceeds from sales — — (6,099 ) Redemptions and distributions (500 ) — — Gain (loss) recognized in earnings — Mortgage banking revenue — — 123 Other comprehensive income (loss): Net change in unrealized gain (loss) 7 — — Balance, Sept. 30, 2015 $ 9,600 $ 4,150 $ 8,033 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, 2016 follows (in thousands): Par Value Amortized Cost/Unpaid Principal Balance Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Available for sale securities Municipal and other tax-exempt securities $ 6,195 $ 6,162 $ 5,713 Discounted cash flows 1 Interest rate spread 5.60%-5.90% (5.85%) 2 90.00%-93.79% (92.22%) 3 Other debt securities 4,400 4,400 4,151 Discounted cash flows 1 Interest rate spread 5.98%-6.03% (6.02%) 4 94.34% - 94.34 (94.34%) 3 Residential mortgage loans held for sale N/A 9,957 9,301 Quoted prices of loans sold in securitization transactions, with a liquidity discount applied Liquidity discount applied to the market value of a mortgage loans qualifying for sale to U.S. government agencies. 93.41% 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 Interest rate yields used to value investment grade tax-exempt securities represent a spread of 437 to 484 basis points over average yields for comparable tax-exempt securities. 3 Represents fair value as a percentage of par value. 4 Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 1 percent . A summary of quantitative information about Recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of December 31, 2015 follows (in thousands): Par Value Amortized Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Available for sale securities Municipal and other tax-exempt securities $ 10,370 $ 10,311 $ 9,610 Discounted cash flows 1 Interest rate spread 5.47%-5.77% (5.73%) 2 92.34%-92.93% (92.67%) 3 Other debt securities 4,400 4,400 4,151 Discounted cash flows 1 Interest rate spread 5.80%-5.92% (5.90%) 4 94.33% - 94.34 (94.34%) 3 Residential mortgage loans held for sale N/A 8,395 7,874 Quoted prices of loans sold in securitization transactions, with a liquidity discount applied Liquidity discount applied to the market value of a mortgage loans qualifying for sale to U.S. government agencies. 93.79% 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 Interest rate yields used to value investment grade tax-exempt securities represent a spread of 499 to 541 basis points over average yields for comparable tax-exempt securities. 3 Represents fair value as a percentage of par value. 4 Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 1 percent . A summary of quantitative information about Recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of September 30, 2015 follows (in thousands): Par Value Amortized Cost Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Available for sale securities Municipal and other tax-exempt securities $ 10,370 $ 10,310 $ 9,600 Discounted cash flows 1 Interest rate spread 5.23%-5.53% (5.49%) 2 92.35%-92.73% (92.57%) 3 Other debt securities 4,400 4,400 4,150 Discounted cash flows 1 Interest rate spread 5.65%-5.70% (5.69%) 4 94.32% - 94.33 (94.33%) 3 Residential mortgage loans held for sale N/A 8,538 8,033 Quoted prices of loans sold in securitization transactions, with a liquidity discount applied Liquidity discount applied to the market value of a mortgage loans qualifying for sale to U.S. government agencies. 94.09% 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 Interest rate yields used to value investment grade tax-exempt securities represent a spread of 510 to 538 basis points over average yields for comparable tax-exempt securities. 3 Represents fair value as a percentage of par value. 4 Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 1 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, 2016 for which the fair value was adjusted during the three and nine months ended September 30, 2016 : Fair Value Adjustments for the Carrying Value at September 30, 2016 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 expenses of repossessed assets, net Gross charge-offs against allowance for loan losses Net losses and expenses of repossessed assets, net Impaired loans $ — $ 436 $ 23,089 $ 6,334 $ — $ 30,200 $ — Real estate and other repossessed assets — 6,048 1,927 — 480 — 1,260 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, 2015 for which the fair value was adjusted during the three and nine months ended September 30, 2015 : Fair Value Adjustments for the Carrying Value at September 30, 2015 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 expenses of repossessed assets, net Gross charge-offs against allowance for loan losses Net losses and expenses of repossessed assets, net Impaired loans $ — $ 3,239 $ 12,386 $ 890 $ — $ 1,439 $ — Real estate and other repossessed assets — 12,689 702 — 670 — 1,771 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, 2016 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Impaired loans $ 23,089 Discounted cash flows Recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs 23% - 59% (43%) 1 Real estate and other repossessed assets 1,927 Appraised value, as adjusted Marketability adjustment off appraised value 2 68% - 80% (71%) 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, 2015 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Impaired loans $ 12,386 Appraised value, as adjusted Broker quotes and management's knowledge of industry and collateral N/A Real estate and other repossessed assets 702 Appraised value, as adjusted Marketability adjustments off appraised value1 66%-86% (78%) 1 Marketability adjustments include consideration of estimated costs to sell which is approximately 10% of the fair value. Fair Value of Financial Instruments The following table presents the carrying values and estimated fair values of all financial instruments, including those financial assets and liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis as of September 30, 2016 (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 $ 535,916 $ 535,916 $ 535,916 $ — $ — Interest-bearing cash and cash equivalents 2,080,978 2,080,978 2,080,978 — — Trading securities: — U.S. government agency debentures 15,705 15,705 — 15,705 — U.S. government agency residential mortgage-backed securities 464,749 464,749 — 464,749 — Municipal and other tax-exempt securities 54,856 54,856 — 54,856 — Other trading securities 11,305 11,305 — 11,305 — Total trading securities 546,615 546,615 — 546,615 — Investment securities: Municipal and other tax-exempt 323,225 327,788 — 327,788 — U.S. government agency residential mortgage-backed securities 22,166 23,452 — 23,452 — Other debt securities 201,066 229,070 — 229,070 — Total investment securities 546,457 580,310 — 580,310 — Available for sale securities: U.S. Treasury 1,002 1,002 1,002 — — Municipal and other tax-exempt 42,092 42,092 — 36,379 5,713 U.S. government agency residential mortgage-backed securities 5,668,672 5,668,672 — 5,668,672 — Privately issued residential mortgage-backed securities 121,603 121,603 — 121,603 — Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,986,495 2,986,495 — 2,986,495 — Other debt securities 4,151 4,151 — — 4,151 Perpetual preferred stock 19,578 19,578 — 19,578 — Equity securities and mutual funds 18,690 18,690 3,544 15,146 — Total available for sale securities 8,862,283 8,862,283 4,546 8,847,873 9,864 Fair value option securities: U.S. government agency residential mortgage-backed securities — — — — — U.S. Treasury 222,409 222,409 222,409 — — Total fair value option securities 222,409 222,409 222,409 — — Residential mortgage loans held for sale 447,592 447,592 — 438,291 9,301 Loans: Commercial 10,120,163 9,926,548 — — 9,926,548 Commercial real estate 3,793,598 3,769,427 — — 3,769,427 Residential mortgage 1,872,793 1,905,786 — — 1,905,786 Personal 678,232 671,421 — — 671,421 Total loans 16,464,786 16,273,182 — — 16,273,182 Allowance for loan losses (245,103 ) — — — — Loans, net of allowance 16,219,683 16,273,182 — — 16,273,182 Mortgage servicing rights 203,621 203,621 — — 203,621 Derivative instruments with positive fair value, net of cash margin 655,078 655,078 5,575 649,503 — Deposits with no stated maturity 18,925,873 18,925,873 — — 18,925,873 Time deposits 2,169,631 2,163,947 — — 2,163,947 Other borrowed funds 7,147,047 7,079,737 — — 7,079,737 Subordinated debentures 144,631 148,360 — 148,360 — Derivative instruments with negative fair value, net of cash margin 573,987 573,987 1,308 572,679 — 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, 2015 (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 $ 573,699 $ 573,699 $ 573,699 $ — $ — Interest-bearing cash and cash equivalents 2,069,900 2,069,900 2,069,900 — — Trading securities: — U.S. government agency debentures 61,295 61,295 — 61,295 — U.S. government agency residential mortgage-backed securities 10,989 10,989 — 10,989 — Municipal and other tax-exempt securities 31,901 31,901 — 31,901 — Other trading securities 18,219 18,219 — 18,219 — Total trading securities 122,404 122,404 — 122,404 — Investment securities: Municipal and other tax-exempt 365,258 368,910 — 368,910 — U.S. government agency residential mortgage-backed securi

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2016
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company evaluated events from the date of the consolidated financial statements on September 30, 2016 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 Polici20

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
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., The Milestone Group, Inc. and Cavanal Hill Investment Management Inc. Operating divisions of the Bank include Bank of Albuquerque, Bank of Arizona, Bank of Arkansas, Bank of Oklahoma, Bank of Texas, Colorado State Bank and Trust, Bank of Kansas City, 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. 2014-09, Revenue from Contracts with Customers ("ASU 2014-09") On May 28, 2014, the FASB issued ASU 2014-09 to clarify the principles for recognizing revenue by providing a more robust framework that will give greater consistency and comparability in revenue recognition practices. In the new framework, an entity recognizes revenue in an amount that reflects the consideration to which the entity expects to be entitled in exchange for goods or services. The new model requires the identification of performance obligations included in contracts with customers, a determination of the transaction price and an allocation of the price to those performance obligations. The entity recognizes revenue when performance obligations are satisfied. ASU 2014-09 is effective for the Company for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company is evaluating the impact the adoption of ASU 2014-09 will have on the Company's financial statements. FASB Accounting Standards Update No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ("ASU 2016-08") On March 17, 2016, the FASB Issued ASU 2016-08 to amend the principal versus agent implementation guidance in ASU 2014-09. The ASU clarifies that an entity should evaluate whether it is the principal or the agent for each specified good or service promised in a contract with a customer. ASU 2016-08 is effective for the Company for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company is evaluating the impact the adoption of ASU 2016-08 will have on the Company's financial statements along with ASU 2014-09. FASB Accounting Standards Update No. 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing ("ASU 2016-10") On April 14, 2016, the FASB issued ASU 2016-10 which amends certain sections of ASU 2014-09 related to identifying performance obligations and licensing implementation. ASU 2016-10 is effective for the Company for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company is evaluating the impact the adoption of ASU 2016-10 will have on the Company's financial statements along with ASU 2014-09. FASB Accounting Standards Update No. 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients ("ASU 2016-12") On May 9, 2016, the FASB issued ASU 2016-12, which amends certain aspects of the Board's new revenue standard, ASU 2014-09. The amendments clarify information regarding collectibility, presentation of sales tax and other similar taxes collected from customers, noncash consideration, contract modifications and completed contracts at transition, and transition disclosures. ASU 2016-12 is effective for the Company for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company is evaluating the impact the adoption of ASU 2016-12 will have on the Company's financial statements along with ASU 2014-09. FASB Accounting Standards Update No. 2014-16, Derivatives and Hedging (Topic 815): Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share is More Akin to Debt or to Equity ("ASU 2014-16") On November 3, 2014, the FASB issued ASU 2014-16 to eliminate the use of different methods and reduce diversity under GAAP in the accounting for hybrid financial instruments issued in the form of a share. For hybrid financial instruments issued in the form of a share, an entity should determine the nature of the host contract by considering all stated and implied substantive terms and features of the hybrid financial instrument. The entity should determine the nature of the host contract by considering the economic characteristics and risks of the entire hybrid financial instrument, including the embedded derivative feature that is being evaluated for separate accounting from the host contract. For public business entities, the ASU was effective for annual periods beginning after December 15, 2015, and interim periods within those annual periods. Adoption of ASU 2014-16 did not have a material impact on the Company's consolidated financial statements. FASB Accounting Standards Update No. 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis ("ASU 2015-02") On February 18, 2015, the FASB issued ASU 2015-02 to address concerns that current U.S. GAAP may require a reporting entity to consolidate another legal entity where the reporting entity's contractual rights do not give it the ability to act primarily on its own behalf, the reporting entity does not hold a majority of the legal entity's voting rights, or the reporting entity is not exposed to a majority of the legal entity's economic benefits or obligations. The amendments affect limited partnerships and similar legal entities, the evaluation of fees paid to a decision maker or a service provider as a variable interest, the effect of fee arrangements and related parties on the primary beneficiary determination, and certain investment funds. The ASU was effective for periods beginning after December 15, 2015 for public companies. Adoption of ASU 2015-02 did not have a material impact on the Company's consolidated financial statements. FASB Accounting Standards Update No. 2015-07, Fair Value Measurements (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent) ("ASU 2015-07") On May 1, 2015, the FASB issued ASU 2015-07 to gain consistency within the categorization of the fair value hierarchy. The update removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient. It also removes the requirement to make certain disclosures for all investments that are eligible to be measured at fair value using the net asset value per share practical expedient. The ASU was effective for the Company for interim and annual periods beginning after December 15, 2015 and should be applied retrospectively to all periods presented. Adoption of ASU 2015-07 did not have a material impact on the Company's consolidated financial statements. FASB Accounting Standards Update No. 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01") On January 5, 2016, the FASB issued ASU 2016-01 over the recognition and measurement of financial assets and liabilities. The update requires equity investments, in general, to be measured at fair value with changes in fair value recognized in earnings. It also eliminates the requirement to disclose the methods and significant assumptions used to estimate the fair value for financial instruments measured at amortized cost, requires entities to use the exit price notion when measuring fair value, requires an entity to present separately in other comprehensive income the portion of the total change in fair value of a liability resulting from a change in the instrument-specific credit risk when the fair value option has been elected, requires separate presentation of financial assets and liabilities by measurement category and form on the balance sheet or accompanying notes, clarifies that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity's other deferred tax assets, and simplifies the impairment assessment of equity investments without readily determinable fair values. The ASU is effective for the Company for interim and annual periods beginning after December 15, 2017. Upon adoption, unrealized gains and losses from equity securities will be reclassified from other comprehensive income to retained earnings. At September 30, 2016 , the Company had $3.3 million of unrealized gains included in accumulated other comprehensive income. 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 and disclosing key information about leasing arrangements. The final guidance requires lessees to put most leases on their balance sheets and may affect the presentation and timing of expense recognition, eliminates the current real estate-specific provisions, modifies the classification criteria and the accounting for sales-type and direct financing leases for lessors. The ASU is effective for the Company for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early application of the amendments is permitted. The Company is evaluating the impact the adoption of ASU 2016-02 will have on the Company's financial statements. FASB Accounting Standards Update No. 2016-05, Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships ("ASU 2016-05") On March 10, 2016, the FASB issued ASU 2016-05 which clarifies that "a change in the counterparty to a derivative instrument that has been designated as the hedging instrument in an existing hedging relationship would not, in and of itself, be considered a termination of the derivative instrument" or "a change in a critical term of the hedging relationship." If all other hedge accounting criteria in ASC 815 are met, a hedging relationship where the hedging derivative instrument is novated would not be discontinued or need to be redesignated. The ASU is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. An entity would apply the guidance prospectively unless modified retrospective transition is elected. Early adoption is permitted. Adoption of ASU 2016-05 is not expected to have a material impact on the Company's financial statements. FASB Accounting Standards Update No. 2016-07, Investments - Equity Method and Joint Ventures ("ASU 2016-07") On March 15, 2016, the FASB issued ASU 2016-07 to simplify the equity method of accounting by eliminating the requirement to retrospectively apply the equity method to an investment that subsequently qualifies for such accounting as result of an increase in the level of ownership interest or degree of influence. The ASU also requires that unrealized holding gains or losses in accumulated other comprehensive income related to an available for sale security that becomes eligible for the equity method be recognized in earnings as of the date the investment qualifies for the equity method. The ASU is effective for all entities for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted. Adoption of ASU 2016-07 is not expected to have a material impact on the Company's financial statements. FASB Accounting Standards Update No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09") On March 30, 2016, the FASB issued ASU 2016-09 to simplify multiple aspects of accounting for employee share-based payment transactions including accounting income taxes, forfeitures, and statutory tax withholding requirements. The ASU is effective for annual reporting periods beginning after December 15, 2016, including interim periods within those annual reporting periods. Implementation of ASU 2016-09 will add volatility to tax expense as stock prices change; however, we expect the impact to be insignificant. FASB Accounting Standards Update No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Assets Measured at Amortized Cost ("ASU 2016-13") On June 16, 2016, the FASB issued ASU 2016-13 in order to provide more timely recording of credit losses on loans and other financial instruments. The ASU adds an impairment model (known as the current expected credit loss ("CECL") model) that is based on expected credit losses rather than incurred credit losses. It requires an organization to measure all expected credit losses for financial assets carried at amortized cost at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. ASU 2016-13 is effective for the Company for annual reporting periods beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for annual reporting periods beginning after December 15, 2018. ASU 2016-13 will be applied through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The Company is evaluating the impact the adoption of ASU 2016-13 will have on the Company's financial statements. FASB Accounting Standards Update No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments ("ASU 2016-15") On August 26, 2016, the FASB issued ASU 2016-15, which amends guidance in ASC 230 on the classification of certain cash receipts and payments in the statement of cash flows, in order to reduce inconsistent application. The amendments address eight cash flow issues including debt repayment and extinguishment costs, settlement of zero-coupon debt instruments, contingent consideration payments following a business combination, proceeds from the settlement of insurance claims and corporate-owned life insurance policies, distributions received from equity method investees, beneficial interests in securitization transactions and separately identifiable cash flows. ASU 2016-15 is effective for the Company for annual reporting periods beginning after December 15, 2017, including interim periods within those fiscal years. Entities must apply the guidance retrospectively to all periods presented but may apply it prospectively from the earliest date practicable if retrospective application would be impracticable. Adoption of ASU 2016-15 is not expected to have a material impact on the Company's financial statements.
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. 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. As of September 30, 2016 , a decrease in BOK Financial's credit rating to below investment grade would increase our obligation to post cash margin on existing contracts by approximately $18 million . 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, and foreign exchange rates, or to take positions in derivative contracts. Customers may also manage interest rate risk through interest rate swaps used by borrowers to modify interest rate terms of their loans or to-be-announced securities used by mortgage banking customers to hedge their loan production. 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. 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 as an economic hedge of trading securities. As of September 30, 2016 , derivative contracts under the internal risk management programs were primarily used as part of the economic hedges of the change in the fair value of the mortgage servicing rights and trading securities. 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"). 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. 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 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. 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 principal balance continues to be guaranteed; 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.
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 on-going 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, 2016 . 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 ten-year 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.

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2016
Marketable Securities [Abstract]
Trading Securities [Table Text Block]	The fair value and net unrealized gain (loss) included in trading securities is as follows (in thousands): September 30, 2016 December 31, 2015 September 30, 2015 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. government agency debentures $ 15,705 $ (7 ) $ 61,295 $ (71 ) $ 42,431 $ (38 ) U.S. government agency residential mortgage-backed securities 464,749 876 10,989 17 30,973 195 Municipal and other tax-exempt securities 54,856 (100 ) 31,901 210 84,261 421 Other trading securities 11,305 14 18,219 (16 ) 23,466 28 Total trading securities $ 546,615 $ 783 $ 122,404 $ 140 $ 181,131 $ 606
Investment Securities (Held-to-Maturity) [Table Text Block]	The amortized cost and fair values of investment securities are as follows (in thousands): September 30, 2016 Amortized Carrying Fair Gross Unrealized 1 Cost Value Value Gain Loss Municipal and other tax-exempt $ 323,225 $ 323,225 $ 327,788 $ 4,745 $ (182 ) U.S. government agency residential mortgage-backed securities – Other 22,166 22,166 23,452 1,286 — Other debt securities 201,066 201,066 229,070 28,014 (10 ) Total investment securities $ 546,457 $ 546,457 $ 580,310 $ 34,045 $ (192 ) 1 Gross unrealized gains and losses are not recognized in Accumulated Other Comprehensive Income "AOCI" in the Consolidated Balance Sheets. December 31, 2015 Amortized Carrying Fair Gross Unrealized 1 Cost Value Value Gain Loss Municipal and other tax-exempt $ 365,258 $ 365,258 $ 368,910 $ 3,935 $ (283 ) U.S. government agency residential mortgage-backed securities – Other 26,721 26,833 27,874 1,063 (22 ) Other debt securities 205,745 205,745 232,375 26,689 (59 ) Total investment securities $ 597,724 $ 597,836 $ 629,159 $ 31,687 $ (364 ) 1 Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets. September 30, 2015 Amortized Carrying Fair Gross Unrealized 1 Cost Value Value Gain Loss Municipal and other tax-exempt $ 379,980 $ 379,980 $ 384,310 $ 4,461 $ (131 ) U.S. government agency residential mortgage-backed securities – Other 28,456 28,653 30,080 1,427 — Other debt securities 203,751 203,751 228,701 25,063 (113 ) Total investment securities $ 612,187 $ 612,384 $ 643,091 $ 30,951 $ (244 ) 1 Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets. The amortized cost and fair values of investment securities at September 30, 2016 , 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 Maturity² Municipal and other tax-exempt: Carrying value $ 87,330 $ 195,763 $ 8,778 $ 31,354 $ 323,225 2.76 Fair value 87,331 196,864 9,023 34,570 327,788 Nominal yield¹ 1.42 % 2.01 % 3.20 % 6.08 % 2.28 % Other debt securities: Carrying value 15,047 42,314 125,955 17,750 201,066 6.84 Fair value 15,191 45,802 148,422 19,655 229,070 Nominal yield 3.49 % 5.03 % 5.88 % 4.86 % 5.43 % Total fixed maturity securities: Carrying value $ 102,377 $ 238,077 $ 134,733 $ 49,104 $ 524,291 4.32 Fair value 102,522 242,666 157,445 54,225 556,858 Nominal yield 1.72 % 2.54 % 5.70 % 5.64 % 3.48 % Residential mortgage-backed securities: Carrying value $ 22,166 ³ Fair value 23,452 Nominal yield 4 2.75 % Total investment securities: Carrying value $ 546,457 Fair value 580,310 Nominal yield 3.46 % 1 Calculated on a taxable equivalent basis using a 39 percent effective tax rate. 2 Expected maturities may differ from contractual maturities, because borrowers may have the right to call or prepay obligations with or without penalty. 3 The average expected lives of residential mortgage-backed securities were 4.3 years based upon current prepayment assumptions. 4 The nominal yield on residential mortgage-backed securities is based upon prepayment assumptions at the purchase date. Actual yields earned may differ significantly based upon actual prepayments. See Quarterly Financial Summary - Unaudited for current yields on the investment securities portfolio.
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, 2016 Amortized Fair Gross Unrealized 1 Cost Value Gain Loss OTTI ² U.S. Treasury $ 1,000 $ 1,002 $ 2 $ — $ — Municipal and other tax-exempt 41,943 42,092 602 (453 ) — Residential mortgage-backed securities: U. S. government agencies: FNMA 3,035,041 3,101,136 67,859 (1,764 ) — FHLMC 1,611,887 1,641,178 29,640 (349 ) — GNMA 924,176 926,358 3,530 (1,348 ) — Other — — — — — Total U.S. government agencies 5,571,104 5,668,672 101,029 (3,461 ) — Private issue: Alt-A loans 47,039 54,065 7,230 — (204 ) Jumbo-A loans 61,377 67,538 6,187 (26 ) — Total private issue 108,416 121,603 13,417 (26 ) (204 ) Total residential mortgage-backed securities 5,679,520 5,790,275 114,446 (3,487 ) (204 ) Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,942,988 2,986,495 45,329 (1,822 ) — Other debt securities 4,400 4,151 — (249 ) — Perpetual preferred stock 15,562 19,578 4,016 — — Equity securities and mutual funds 17,337 18,690 1,370 (17 ) — Total available for sale securities $ 8,702,750 $ 8,862,283 $ 165,765 $ (6,028 ) $ (204 ) 1 Gross unrealized gain/loss recognized in AOCI in the consolidated balance sheet. 2 Amounts represent unrealized loss that remains in AOCI after an other-than-temporary credit loss has been recognized in income. December 31, 2015 Amortized Fair Gross Unrealized¹ Cost Value Gain Loss OTTI ² U.S. Treasury $ 1,000 $ 995 $ — $ (5 ) $ — Municipal and other tax-exempt 56,681 56,817 873 (737 ) — Residential mortgage-backed securities: U. S. government agencies: FNMA 3,156,214 3,187,215 41,502 (10,501 ) — FHLMC 1,940,915 1,949,335 14,727 (6,307 ) — GNMA 763,967 761,801 2,385 (4,551 ) — Other — — — — — Total U.S. government agencies 5,861,096 5,898,351 58,614 (21,359 ) — Private issue: Alt-A loans 56,387 62,574 6,574 — (387 ) Jumbo-A loans 71,724 76,544 5,260 — (440 ) Total private issue 128,111 139,118 11,834 — (827 ) Total residential mortgage-backed securities 5,989,207 6,037,469 70,448 (21,359 ) (827 ) Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,919,044 2,905,796 5,396 (18,644 ) — Other debt securities 4,400 4,151 — (249 ) — Perpetual preferred stock 17,171 19,672 2,501 — — Equity securities and mutual funds 17,121 17,833 752 (40 ) — Total available for sale securities $ 9,004,624 $ 9,042,733 $ 79,970 $ (41,034 ) $ (827 ) 1 Gross unrealized gain/loss recognized in AOCI in the consolidated balance sheet. 2 Amounts represent unrealized loss that remains in AOCI after an other-than-temporary credit loss has been recognized in income. September 30, 2015 Amortized Fair Gross Unrealized 1 Cost Value Gain Loss OTTI ² U.S. Treasury $ 1,000 $ 1,003 $ 3 $ — $ — Municipal and other tax-exempt 57,610 57,960 1,065 (715 ) — Residential mortgage-backed securities: U. S. government agencies: FNMA 3,115,810 3,185,097 69,757 (470 ) — FHLMC 1,853,379 1,885,201 32,646 (824 ) — GNMA 741,212 744,647 4,557 (1,122 ) — Other 3,922 4,182 260 — — Total U.S. government agencies 5,714,323 5,819,127 107,220 (2,416 ) — Private issue: Alt-A loans 58,801 64,700 6,519 — (620 ) Jumbo-A loans 75,258 80,982 6,121 — (397 ) Total private issue 134,059 145,682 12,640 — (1,017 ) Total residential mortgage-backed securities 5,848,382 5,964,809 119,860 (2,416 ) (1,017 ) Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,708,931 2,735,787 28,889 (2,033 ) — Other debt securities 4,400 4,150 — (250 ) — Perpetual preferred stock 17,171 19,163 2,030 (38 ) — Equity securities and mutual funds 18,711 18,217 950 (1,444 ) — Total available for sale securities $ 8,656,205 $ 8,801,089 $ 152,797 $ (6,896 ) $ (1,017 ) 1 Gross unrealized gain/loss recognized in AOCI in the consolidated balance sheet. 2 Amounts represent unrealized loss that remains in AOCI after an other-than-temporary credit loss has been recognized in income. The amortized cost and fair values of available for sale securities at September 30, 2016 , 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 5 U.S. Treasuries: Amortized cost $ — $ 1,000 $ — $ — $ 1,000 1.29 Fair value — 1,002 — — 1,002 Nominal yield — % 0.87 % — % — % 0.87 % Municipal and other tax-exempt: Amortized cost $ 9,089 $ 13,593 $ 2,092 $ 17,169 $ 41,943 8.14 Fair value 9,190 13,858 2,109 16,935 42,092 Nominal yield¹ 4.97 % 3.85 % 3.46 % 2.36 % 6 3.46 % Commercial mortgage-backed securities: Amortized cost $ — $ 931,761 $ 1,817,166 $ 194,061 $ 2,942,988 6.82 Fair value — 942,994 1,848,462 195,039 2,986,495 Nominal yield — % 1.74 % 1.84 % 1.54 % 1.79 % Other debt securities: Amortized cost $ — $ — $ — $ 4,400 $ 4,400 30.91 Fair value — — — 4,151 4,151 Nominal yield — % — % — % 1.71 % 6 1.71 % Total fixed maturity securities: Amortized cost $ 9,089 $ 946,354 $ 1,819,258 $ 215,630 $ 2,990,331 6.87 Fair value 9,190 957,854 1,850,571 216,125 3,033,740 Nominal yield 4.97 % 1.77 % 1.85 % 1.61 % 1.81 % Residential mortgage-backed securities: Amortized cost $ 5,679,520 2 Fair value 5,790,275 Nominal yield 4 1.87 % Equity securities and mutual funds: Amortized cost $ 32,899 ³ Fair value 38,268 Nominal yield — % Total available-for-sale securities: Amortized cost $ 8,702,750 Fair value 8,862,283 Nominal yield 1.84 % 1 Calculated on a taxable equivalent basis using a 39 percent effective tax rate. 2 The average expected lives of mortgage-backed securities were 3.4 years years based upon current prepayment assumptions. 3 Primarily common stock and preferred stock of corporate issuers with no stated maturity. 4 The nominal yield on mortgage-backed securities is based upon prepayment assumptions at the purchase date. Actual yields earned may differ significantly based upon actual prepayments. See Quarterly Financial Summary –– Unaudited following for current yields on available for sale securities portfolio. 5 Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without penalty. 6 Nominal yield on municipal and other tax-exempt securities and other debt securities with contractual maturity dates over ten years are based on variable rates which generally are reset within 35 days . Sales of available for sale securities resulted in gains and losses as follows (in thousands): Three Months Ended Nine Months Ended 2016 2015 2016 2015 Proceeds $ 232,239 $ 450,765 $ 1,027,379 $ 1,164,425 Gross realized gains 2,415 3,803 11,705 13,543 Gross realized losses (21 ) (1,637 ) (21 ) (3,617 ) Related federal and state income tax expense 931 843 4,545 3,861
Securities Pledged As Collateral [Table Text Block]	A summary of investment and available for sale securities that have been pledged as collateral for repurchase agreements, public trust funds on deposit and for other purposes, as required by law was as follows (in thousands): Sept. 30,2016 Dec. 31, 2016 Sept. 30,2015 Investment: Carrying value $ 301,754 $ 231,033 $ 50,380 Fair value 307,264 234,382 52,249 Available for sale: Amortized cost 7,098,721 6,831,743 6,225,689 Fair value 7,213,520 6,849,524 6,318,330
Schedule of Unrealized Loss on Investments [Table Text Block]	Temporarily Impaired Securities as of September 30, 2016 (in thousands): 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 75 $ 100,624 $ 106 $ 4,359 $ 76 $ 104,983 $ 182 U.S. government agency residential mortgage-backed securities – Other — — — — — — — Other debt securities 3 444 6 856 4 1,300 10 Total investment securities 78 $ 101,068 $ 112 $ 5,215 $ 80 $ 106,283 $ 192 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: Municipal and other tax-exempt 20 $ 2,210 $ 3 $ 6,396 $ 450 $ 8,606 $ 453 Residential mortgage-backed securities: U. S. government agencies: FNMA 14 365,201 1,712 14,229 52 379,430 1,764 FHLMC 6 122,713 91 20,306 258 143,019 349 GNMA 16 230,043 1,157 212,705 191 442,748 1,348 Total U.S. government agencies 36 717,957 2,960 247,240 501 965,197 3,461 Private issue 1 : Alt-A loans 5 8,231 141 7,773 63 16,004 204 Jumbo-A loans 1 6,583 26 — — 6,583 26 Total private issue 6 14,814 167 7,773 63 22,587 230 Total residential mortgage-backed securities 42 732,771 3,127 255,013 564 987,784 3,691 Commercial mortgage-backed securities guaranteed by U.S. government agencies 33 372,805 1,656 60,851 166 433,656 1,822 Other debt securities 2 — — 4,151 249 4,151 249 Perpetual preferred stocks — — — — — — — Equity securities and mutual funds 33 86 — 886 17 972 17 Total available for sale securities 130 $ 1,107,872 $ 4,786 $ 327,297 $ 1,446 $ 1,435,169 $ 6,232 1 Includes securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income. Temporarily Impaired Securities as of December 31, 2015 (In thousands) 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 73 $ 127,319 $ 207 $ 13,380 $ 77 $ 140,699 $ 284 U.S. government agency residential mortgage-backed securities – Other 1 5,533 22 — — 5,533 22 Other debt securities 11 1,082 41 1,715 18 2,797 59 Total investment securities 85 $ 133,934 $ 270 $ 15,095 $ 95 $ 149,029 $ 365 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 $ 995 $ 5 $ — $ — $ 995 $ 5 Municipal and other tax-exempt 20 $ 9,909 $ 27 $ 11,664 $ 710 $ 21,573 $ 737 Residential mortgage-backed securities: U. S. government agencies: FNMA 55 1,188,022 10,262 18,236 239 1,206,258 10,501 FHLMC 40 726,713 4,827 77,545 1,480 804,258 6,307 GNMA 15 364,919 1,951 102,109 2,600 467,028 4,551 Total U.S. government agencies 110 2,279,654 17,040 197,890 4,319 2,477,544 21,359 Private issue 1 : Alt-A loans 4 — — 9,264 387 9,264 387 Jumbo-A loans 8 — — 8,482 440 8,482 440 Total private issue 12 — — 17,746 827 17,746 827 Total residential mortgage-backed securities 122 2,279,654 17,040 215,636 5,146 2,495,290 22,186 Commercial mortgage-backed securities guaranteed by U.S. government agencies 213 1,582,469 11,419 484,258 7,225 2,066,727 18,644 Other debt securities 2 — — 4,151 249 4,151 249 Perpetual preferred stocks — — — — — — — Equity securities and mutual funds 61 782 5 991 35 1,773 40 Total available for sale securities 419 $ 3,873,809 $ 28,496 $ 716,700 $ 13,365 $ 4,590,509 $ 41,861 1 Includes securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income. Temporarily Impaired Securities as of September 30, 2015 (In thousands) 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 15 $ 6,250 $ 81 $ 13,438 $ 50 $ 19,688 $ 131 U.S. government agency residential mortgage-backed securities – Other — — — — — — — Other debt securities 17 1,283 64 4,577 49 5,860 113 Total investment securities 32 $ 7,533 $ 145 $ 18,015 $ 99 $ 25,548 $ 244 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: Municipal and other tax-exempt 1 18 $ 7,868 $ 485 $ 3,800 $ 230 $ 11,668 $ 715 Residential mortgage-backed securities: U. S. government agencies: FNMA 6 155,747 470 — — 155,747 470 FHLMC 4 71,930 503 26,848 321 98,778 824 GNMA 4 54,701 562 54,701 560 109,402 1,122 Total U.S. government agencies 14 282,378 1,535 81,549 881 363,927 2,416 Private issue 1 : Alt-A loans 4 2,857 186 6,667 434 9,524 620 Jumbo-A loans 8 5,380 236 3,681 161 9,061 397 Total private issue 12 8,237 422 10,348 595 18,585 1,017 Total residential mortgage-backed securities 26 290,615 1,957 91,897 1,476 382,512 3,433 Commercial mortgage-backed securities guaranteed by U.S. government agencies 31 327,790 1,488 223,007 545 550,797 2,033 Other debt securities 2 — — 4,149 250 4,149 250 Perpetual preferred stocks 1 1,912 38 — — 1,912 38 Equity securities and mutual funds 37 4,031 1,432 526 12 4,557 1,444 Total available for sale securities 115 $ 632,216 $ 5,400 $ 323,379 $ 2,513 $ 955,595 $ 7,913 1 Includes securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income.
Investments by Lowest Credit Rating [Table Text Block]	At September 30, 2016 , the composition of the Company’s investment and available for sale securities portfolios by the lowest current credit rating assigned by any of the three nationally-recognized rating agencies is as follows (in thousands): AAA - AA A - BBB Below Investment Grade Not Rated Total Carrying Value Fair Value Carrying Value Fair Value Carrying Value Fair Value Carrying Value Fair Value Carrying Value Fair Value Investment: Municipal and other tax-exempt $ 207,881 $ 209,210 $ 5,094 $ 5,160 $ — $ — $ 110,250 $ 113,418 $ 323,225 $ 327,788 U.S. government agency residential mortgage-backed securities 1 — — — — — — 22,166 23,452 22,166 23,452 Other debt securities 140,184 164,118 — — — — 60,882 64,952 201,066 229,070 Total investment securities $ 348,065 $ 373,328 $ 5,094 $ 5,160 $ — $ — $ 193,298 $ 201,822 $ 546,457 $ 580,310 AAA - AA A - BBB Below Investment Grade Not Rated Total Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Available for Sale: U.S. Treasury $ — $ — $ — $ — $ — $ — $ 1,000 $ 1,002 $ 1,000 $ 1,002 Municipal and other tax-exempt 23,837 24,290 5,675 5,316 — — 12,431 12,486 41,943 42,092 U.S. government agency residential mortgage-backed securities 1 — — — — — — 5,571,104 5,668,672 5,571,104 5,668,672 Privately issued residential mortgage-backed securities — — — — 108,416 121,603 — — 108,416 121,603 Commercial mortgage-backed securities guaranteed by U.S. government agencies — — — — — — 2,942,988 2,986,495 2,942,988 2,986,495 Other debt securities 4,400 4,151 — — — — — — 4,400 4,151 Perpetual preferred stock — — 4,796 5,505 10,766 14,073 — — 15,562 19,578 Equity securities and mutual funds 4 591 — — — — 17,333 18,099 17,337 18,690 Total available for sale securities $ 28,241 $ 29,032 $ 10,471 $ 10,821 $ 119,182 $ 135,676 $ 8,544,856 $ 8,686,754 $ 8,702,750 $ 8,862,283 1 U.S. government and government sponsored enterprises are not rated by the nationally-recognized rating agencies as these securities are guaranteed by agencies of the U.S. government or government-sponsored enterprises.
Other-than-temporary impairement, Private Lable Mortgage-Backed Securities, Assumptions Used to Develop Projected Cash Flows [Table Text Block]	The primary assumptions used in this evaluation were: September 30, 2016 Dec. 31, 2015 September 30, 2015 Unemployment rate Moving down to 4.7 percent over the next 12 months and remain at 4.7 percent thereafter. Decreasing to 4.8 percent over the next 12 months and remain at 4.8 percent thereafter. Moving down to 5.1 percent over the next 12 months and remain at 5.1 percent thereafter. Housing price appreciation/depreciation Starting with current depreciated housing prices based on information derived from the FHFA 1 , appreciating 3.5 percent over the next 12 months, then flat for the following 12 months and then appreciating at 2 percent per year thereafter. Starting with current depreciated housing prices based on information derived from the FHFA 1 , appreciating 3.5 percent over the next 12 months, then flat for the following 12 months and then appreciating at 2 percent per year thereafter. Starting with current depreciated housing prices based on information derived from the FHFA 1 , appreciating 3.2 percent over the next 12 months, then flat for the following 12 months and then appreciating at 2 percent per year thereafter. Estimated liquidation costs Reflect actual historical liquidations costs observed on Jumbo and Alt-A residential mortgage loans in securities owned by the Company. Reflect actual historical liquidations costs observed on Jumbo and Alt-A residential mortgage loans in securities owned by the Company. Reflect actual historical liquidations costs observed on Jumbo and Alt-A residential mortgage loans in securities owned by the Company. Discount rates Estimated cash flows were discounted at rates that range from 2.00 percent to 6.25 percent based on our current expected yields. Estimated cash flows were discounted at rates that range from 2.00 percent to 6.25 percent based on our current expected yields. Estimated cash flows were discounted at rates that range from 2.00 percent to 6.25 percent based on our current expected yields. 1 Federal Housing Finance Agency
Schedule of Privately Issued Residential Mortgage-backed Securities [Table Text Block]	Credit Losses Recognized Three months ended September 30, 2016 Life-to-date Number of Securities Amortized Cost Fair Value Number of Securities Amount Number of Securities Amount Alt-A 14 $ 47,039 $ 54,065 — $ — 14 $ 36,284 Jumbo-A 30 61,377 67,538 — — 29 18,220 Total 44 $ 108,416 $ 121,603 — $ — 43 $ 54,504
Rollforward Other-than-temporary Impairment Credit Losses Recognized in Earnings [Table Text Block]	The following is a tabular roll forward of the amount of credit-related OTTI recognized on available for sale debt securities in earnings (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 Balance of credit-related OTTI recognized on available for sale debt securities, beginning of period $ 54,504 $ 54,439 $ 54,504 $ 54,347 Additions for credit-related OTTI not previously recognized — — — — Additions for increases in credit-related OTTI previously recognized when there is no intent to sell and no requirement to sell before recovery of amortized cost — — — 92 Reductions for change in intent to hold before recovery — — — — Sales — — — — Balance of credit-related OTTI recognized on available for sale debt securities, end of period $ 54,504 $ 54,439 $ 54,504 $ 54,439
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): Sept. 30,2016 Dec. 31, 2015 Sept. 30, 2015 Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) Fair Value Net Unrealized Gain (Loss) U.S. Treasury $ 222,409 $ (2,397 ) $ — $ — $ — $ — U.S. government agency residential mortgage-backed securities $ — $ — $ 444,217 $ (2,060 ) $ 427,760 $ 2,067 Total $ 222,409 $ (2,397 ) $ 444,217 $ (2,060 ) $ 427,760 $ 2,067
Schedule of Restricted Equity Securities [Table Text Block]	Sept. 30,2016 Dec. 31, 2015 Sept. 30,2015 Federal Reserve stock $ 36,283 $ 36,148 $ 35,148 Federal Home Loan Bank stock 296,907 237,365 228,268 Other 201 171 171 Total $ 333,391 $ 273,684 $ 263,587

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Sep. 30, 2016
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, 2016 (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 $ 20,078,974 $ 90,999 $ (38,678 ) $ 52,321 $ — $ 52,321 Interest rate swaps 1,323,045 49,279 — 49,279 (794 ) 48,485 Energy contracts 729,202 41,775 (28,464 ) 13,311 (288 ) 13,023 Agricultural contracts 53,002 3,950 (1,571 ) 2,379 (1,076 ) 1,303 Foreign exchange contracts 550,828 536,264 — 536,264 (7,577 ) 528,687 Equity option contracts 103,464 4,654 — 4,654 (730 ) 3,924 Total customer risk management programs 22,838,515 726,921 (68,713 ) 658,208 (10,465 ) 647,743 Internal risk management programs 2,298,038 7,335 — 7,335 — 7,335 Total derivative contracts $ 25,136,553 $ 734,256 $ (68,713 ) $ 665,543 $ (10,465 ) $ 655,078 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 $ 19,776,883 $ 86,812 $ (38,678 ) $ 48,134 $ (39,042 ) $ 9,092 Interest rate swaps 1,323,045 49,518 — 49,518 (34,457 ) 15,061 Energy contracts 695,835 40,888 (28,464 ) 12,424 (3,857 ) 8,567 Agricultural contracts 52,997 3,943 (1,571 ) 2,372 — 2,372 Foreign exchange contracts 550,943 536,660 — 536,660 (5,396 ) 531,264 Equity option contracts 103,464 4,654 — 4,654 — 4,654 Total customer risk management programs 22,503,167 722,475 (68,713 ) 653,762 (82,752 ) 571,010 Interest risk management programs 1,485,691 2,977 — 2,977 — 2,977 Total derivative contracts $ 23,988,858 $ 725,452 $ (68,713 ) $ 656,739 $ (82,752 ) $ 573,987 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, 2015 (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 $ 14,583,052 $ 43,270 $ (28,305 ) $ 14,965 $ — $ 14,965 Interest rate swaps 1,332,044 31,744 — 31,744 (1,424 ) 30,320 Energy contracts 470,613 83,045 (22,970 ) 60,075 (18,606 ) 41,469 Agricultural contracts 61,662 2,591 (1,158 ) 1,433 — 1,433 Foreign exchange contracts 546,572 498,830 — 498,830 (4,140 ) 494,690 Equity option contracts 137,278 3,780 — 3,780 (470 ) 3,310 Total customer risk management programs 17,131,221 663,260 (52,433 ) 610,827 (24,640 ) 586,187 Interest risk management programs 22,000 83 — 83 — 83 Total derivative contracts $ 17,153,221 $ 663,343 $ (52,433 ) $ 610,910 $ (24,640 ) $ 586,270 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 $ 14,168,927 $ 40,141 $ (28,305 ) $ 11,836 $ (1,308 ) $ 10,528 Interest rate swaps 1,332,044 31,928 — 31,928 (20,530 ) 11,398 Energy contracts 463,703 81,869 (22,970 ) 58,899 — 58,899 Agricultural contracts 61,657 2,579 (1,158 ) 1,421 (1,248 ) 173 Foreign exchange contracts 546,405 498,574 — 498,574 (1,951 ) 496,623 Equity option contracts 137,278 3,780 — 3,780 — 3,780 Total customer risk management programs 16,710,014 658,871 (52,433 ) 606,438 (25,037 ) 581,401 Interest risk management programs 75,000 300 — 300 — 300 Total derivative contracts $ 16,785,014 $ 659,171 $ (52,433 ) $ 606,738 $ (25,037 ) $ 581,701 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 September 30, 2015 (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 $ 16,093,704 $ 136,435 $ (50,845 ) $ 85,590 $ — $ 85,590 Interest rate swaps 1,345,779 42,636 — 42,636 — 42,636 Energy contracts 560,997 89,948 (28,535 ) 61,413 (23,089 ) 38,324 Agricultural contracts 101,321 8,064 (4,053 ) 4,011 (1,558 ) 2,453 Foreign exchange contracts 618,991 557,313 — 557,313 (3,985 ) 553,328 Equity option contracts 143,452 3,784 — 3,784 (470 ) 3,314 Total customer risk management programs 18,864,244 838,180 (83,433 ) 754,747 (29,102 ) 725,645 Interest risk management programs 47,000 514 — 514 — 514 Total derivative contracts $ 18,911,244 $ 838,694 $ (83,433 ) $ 755,261 $ (29,102 ) $ 726,159 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 $ 16,050,271 $ 133,543 $ (50,845 ) $ 82,698 $ (82,225 ) $ 473 Interest rate swaps 1,345,779 42,901 — 42,901 (26,723 ) 16,178 Energy contracts 551,989 85,856 (28,535 ) 57,321 — 57,321 Agricultural contracts 101,325 8,045 (4,053 ) 3,992 — 3,992 Foreign exchange contracts 618,770 556,890 — 556,890 (2,619 ) 554,271 Equity option contracts 143,452 3,784 — 3,784 — 3,784 Total customer risk management programs 18,811,586 831,019 (83,433 ) 747,586 (111,567 ) 636,019 Interest risk management programs 7,500 96 — 96 — 96 Total derivative contracts $ 18,819,086 $ 831,115 $ (83,433 ) $ 747,682 $ (111,567 ) $ 636,115 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, 2016 September 30, 2015 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 $ 11,584 $ — $ 7,914 $ — Interest rate swaps 710 — 411 — Energy contracts 1,222 — 771 — Agricultural contracts 25 — 44 — Foreign exchange contracts 218 — 152 — Equity option contracts — — — — Total customer risk management programs 13,759 — 9,292 — Interest risk management programs (1,608 ) 2,226 (199 ) 1,283 Total derivative contracts $ 12,151 $ 2,226 $ 9,093 $ 1,283 Nine Months Ended September 30, 2016 September 30, 2015 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 $ 28,886 $ — $ 25,942 $ — Interest rate swaps 1,758 — 1,495 — Energy contracts 4,667 — 3,138 — Agricultural contracts 86 — 86 — Foreign exchange contracts 730 — 618 — Equity option contracts — — — — Total customer risk management programs 36,127 — 31,279 — Interest risk management programs (1,617 ) 20,130 (199 ) 1,162 Total derivative contracts $ 34,510 $ 20,130 $ 31,080 $ 1,162

Loans and Allowances for Cred23

Loans and Allowances for Credit Losses (Tables)	9 Months Ended
	Sep. 30, 2016
Loans Receivable, Net [Abstract]
Schedule of Loans by Portfolio Segment [Table Text Block]	Portfolio segments of the loan portfolio are as follows (in thousands): September 30, 2016 December 31, 2015 Fixed Rate Variable Rate Non-accrual Total Fixed Rate Variable Rate Non-accrual Total Commercial $ 1,991,423 $ 7,952,276 $ 176,464 $ 10,120,163 $ 1,850,548 $ 8,325,559 $ 76,424 $ 10,252,531 Commercial real estate 565,429 3,220,819 7,350 3,793,598 627,678 2,622,354 9,001 3,259,033 Residential mortgage 1,572,288 248,053 52,452 1,872,793 1,598,992 216,661 61,240 1,876,893 Personal 104,408 573,138 686 678,232 91,816 460,418 463 552,697 Total $ 4,233,548 $ 11,994,286 $ 236,952 $ 16,464,786 $ 4,169,034 $ 11,624,992 $ 147,128 $ 15,941,154 Accruing loans past due (90 days) 1 $ 3,839 $ 1,207 September 30, 2015 Fixed Rate Variable Rate Non-accrual Total Commercial $ 1,854,163 $ 7,909,461 $ 33,798 $ 9,797,422 Commercial real estate 588,604 2,635,507 10,956 3,235,067 Residential mortgage 1,624,759 200,136 44,100 1,868,995 Personal 100,615 364,848 494 465,957 Total $ 4,168,141 $ 11,109,952 $ 89,348 $ 15,367,441 Accruing loans past due (90 days) 1 $ 101 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, 2016 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 145,139 $ 46,745 $ 18,690 $ 6,001 $ 26,684 $ 243,259 Provision for loan losses 2,420 2,551 (466 ) 1,900 1,502 7,907 Loans charged off (6,266 ) — (285 ) (1,550 ) — (8,101 ) Recoveries 177 521 650 690 — 2,038 Ending balance $ 141,470 $ 49,817 $ 18,589 $ 7,041 $ 28,186 $ 245,103 Allowance for off-balance sheet credit losses: Beginning balance $ 8,752 $ 203 $ 62 $ 28 $ — $ 9,045 Provision for off-balance sheet credit losses 2,170 (53 ) (7 ) (17 ) — 2,093 Ending balance $ 10,922 $ 150 $ 55 $ 11 $ — $ 11,138 Total provision for credit losses $ 4,590 $ 2,498 $ (473 ) $ 1,883 $ 1,502 $ 10,000 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, 2016 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 130,334 $ 41,391 $ 19,509 $ 4,164 $ 30,126 $ 225,524 Provision for loan losses 45,995 7,538 (829 ) 4,809 (1,940 ) 55,573 Loans charged off (35,747 ) — (1,104 ) (4,086 ) — (40,937 ) Recoveries 888 888 1,013 2,154 — 4,943 Ending balance $ 141,470 $ 49,817 $ 18,589 $ 7,041 $ 28,186 $ 245,103 Allowance for off-balance sheet credit losses: Beginning balance $ 1,506 $ 153 $ 30 $ 22 $ — $ 1,711 Provision for off-balance sheet credit losses 9,416 (3 ) 25 (11 ) — 9,427 Ending balance $ 10,922 $ 150 $ 55 $ 11 $ — $ 11,138 Total provision for credit losses $ 55,411 $ 7,535 $ (804 ) $ 4,798 $ (1,940 ) $ 65,000 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, 2015 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 107,037 $ 39,744 $ 21,449 $ 3,955 $ 28,902 $ 201,087 Provision for loan losses 4,694 180 (349 ) 1,413 (1,156 ) 4,782 Loans charged off (3,497 ) — (446 ) (1,331 ) — (5,274 ) Recoveries 759 1,865 205 692 — 3,521 Ending balance $ 108,993 $ 41,789 $ 20,859 $ 4,729 $ 27,746 $ 204,116 Allowance for off-balance sheet credit losses: Beginning balance $ 595 $ 242 $ 26 $ 19 $ — $ 882 Provision for off-balance sheet credit losses 1,873 847 (2 ) — — 2,718 Ending balance $ 2,468 $ 1,089 $ 24 $ 19 $ — $ 3,600 Total provision for credit losses $ 6,567 $ 1,027 $ (351 ) $ 1,413 $ (1,156 ) $ 7,500 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, 2015 is summarized as follows (in thousands): Commercial Commercial Real Estate Residential Mortgage Personal Nonspecific Allowance Total Allowance for loan losses: Beginning balance $ 90,875 $ 42,445 $ 23,458 $ 4,233 $ 28,045 $ 189,056 Provision for loan losses 20,869 (11,571 ) (1,938 ) 2,069 (299 ) 9,130 Loans charged off (4,552 ) (44 ) (1,784 ) (3,940 ) — (10,320 ) Recoveries 1,801 10,959 1,123 2,367 — 16,250 Ending balance $ 108,993 $ 41,789 $ 20,859 $ 4,729 $ 27,746 $ 204,116 Allowance for off-balance sheet credit losses: Beginning balance $ 475 $ 707 $ 28 $ 20 $ — $ 1,230 Provision for off-balance sheet credit losses 1,993 382 (4 ) (1 ) — 2,370 Ending balance $ 2,468 $ 1,089 $ 24 $ 19 $ — $ 3,600 Total provision for credit losses $ 22,862 $ (11,189 ) $ (1,942 ) $ 2,068 $ (299 ) $ 11,500 The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at September 30, 2016 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 $ 9,943,699 $ 134,968 $ 176,464 $ 6,502 $ 10,120,163 $ 141,470 Commercial real estate 3,786,248 49,817 7,350 — 3,793,598 49,817 Residential mortgage 1,820,341 18,527 52,452 62 1,872,793 18,589 Personal 677,546 7,041 686 — 678,232 7,041 Total 16,227,834 210,353 236,952 6,564 16,464,786 216,917 Nonspecific allowance — — — — — 28,186 Total $ 16,227,834 $ 210,353 $ 236,952 $ 6,564 $ 16,464,786 $ 245,103 The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at December 31, 2015 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 $ 10,176,107 $ 114,027 $ 76,424 $ 16,307 $ 10,252,531 $ 130,334 Commercial real estate 3,250,032 41,373 9,001 18 3,259,033 41,391 Residential mortgage 1,815,653 19,441 61,240 68 1,876,893 19,509 Personal 552,234 4,164 463 — 552,697 4,164 Total 15,794,026 179,005 147,128 16,393 15,941,154 195,398 Nonspecific allowance — — — — — 30,126 Total $ 15,794,026 $ 179,005 $ 147,128 $ 16,393 $ 15,941,154 $ 225,524 The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at September 30, 2015 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 $ 9,763,624 $ 104,157 $ 33,798 $ 4,836 $ 9,797,422 $ 108,993 Commercial real estate 3,224,111 41,771 10,956 18 3,235,067 41,789 Residential mortgage 1,824,896 20,762 44,099 97 1,868,995 20,859 Personal 465,463 4,729 494 — 465,957 4,729 Total 15,278,094 171,419 89,347 4,951 15,367,441 176,370 Nonspecific allowance — — — — — 27,746 Total $ 15,278,094 $ 171,419 $ 89,347 $ 4,951 $ 15,367,441 $ 204,116
Schedule of Allowance for Loan Losses and Recorded Investment by Portfolio Segment for Risk Graded and Non-Risk Graded Loans [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, 2016 is as follows (in thousands): Internally Risk Graded Non-Graded Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 10,093,884 $ 140,552 $ 26,279 $ 918 $ 10,120,163 $ 141,470 Commercial real estate 3,793,598 49,817 — — 3,793,598 49,817 Residential mortgage 206,430 3,028 1,666,363 15,561 1,872,793 18,589 Personal 586,869 4,182 91,363 2,859 678,232 7,041 Total 14,680,781 197,579 1,784,005 19,338 16,464,786 216,917 Nonspecific allowance — — — — — 28,186 Total $ 14,680,781 $ 197,579 $ 1,784,005 $ 19,338 $ 16,464,786 $ 245,103 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, 2015 is as follows (in thousands): Internally Risk Graded Non-Graded Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 10,227,303 $ 129,426 $ 25,228 $ 908 $ 10,252,531 $ 130,334 Commercial real estate 3,259,033 41,391 — — 3,259,033 41,391 Residential mortgage 196,701 2,883 1,680,192 16,626 1,876,893 19,509 Personal 467,955 1,390 84,742 2,774 552,697 4,164 Total 14,150,992 175,090 1,790,162 20,308 15,941,154 195,398 Nonspecific allowance — — — — — 30,126 Total $ 14,150,992 $ 175,090 $ 1,790,162 $ 20,308 $ 15,941,154 $ 225,524 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, 2015 is as follows (in thousands): Internally Risk Graded Non-Graded Total Recorded Investment Related Allowance Recorded Investment Related Allowance Recorded Investment Related Allowance Commercial $ 9,771,003 $ 108,101 $ 26,419 $ 892 $ 9,797,422 $ 108,993 Commercial real estate 3,235,067 41,789 — — 3,235,067 41,789 Residential mortgage 190,361 2,938 1,678,634 17,921 1,868,995 20,859 Personal 380,376 1,790 85,581 2,939 465,957 4,729 Total 13,576,807 154,618 1,790,634 21,752 15,367,441 176,370 Nonspecific allowance — — — — — 27,746 Total $ 13,576,807 $ 154,618 $ 1,790,634 $ 21,752 $ 15,367,441 $ 204,116
Schedule of Credit Quality Indicators [Table Text Block]	The following table summarizes the Company’s loan portfolio at September 30, 2016 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 $ 1,869,598 $ 147,153 $ 361,087 $ 142,966 $ — $ — $ 2,520,804 Services 2,882,065 14,861 31,196 8,477 — — 2,936,599 Wholesale/retail 1,557,067 15,337 27,173 2,453 — — 1,602,030 Manufacturing 470,702 8,774 19,736 274 — — 499,486 Healthcare 2,022,757 42,224 19,210 855 — — 2,085,046 Other commercial and industrial 415,769 2,478 10,302 21,370 26,210 69 476,198 Total commercial 9,217,958 230,827 468,704 176,395 26,210 69 10,120,163 Commercial real estate: Residential construction and land development 155,737 — 470 3,739 — — 159,946 Retail 794,920 4,802 406 1,249 — — 801,377 Office 750,924 899 — 882 — — 752,705 Multifamily 868,501 — 5,221 51 — — 873,773 Industrial 837,945 — — 76 — — 838,021 Other commercial real estate 366,416 — 7 1,353 — — 367,776 Total commercial real estate 3,774,443 5,701 6,104 7,350 — — 3,793,598 Residential mortgage: Permanent mortgage 200,590 1,192 2,134 2,514 739,686 23,442 969,558 Permanent mortgages guaranteed by U.S. government agencies — — — — 174,877 15,432 190,309 Home equity — — — — 701,862 11,064 712,926 Total residential mortgage 200,590 1,192 2,134 2,514 1,616,425 49,938 1,872,793 Personal 585,287 228 923 431 91,108 255 678,232 Total $ 13,778,278 $ 237,948 $ 477,865 $ 186,690 $ 1,733,743 $ 50,262 $ 16,464,786 The following table summarizes the Company’s loan portfolio at December 31, 2015 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 $ 2,580,694 $ 325,663 $ 129,782 $ 61,189 $ — $ — $ 3,097,328 Services 2,763,929 3,296 6,761 10,290 — — 2,784,276 Wholesale/retail 1,394,596 18,184 6,365 2,919 — — 1,422,064 Manufacturing 534,966 19,560 1,872 331 — — 556,729 Healthcare 1,876,745 5,563 — 1,072 — — 1,883,380 Other commercial and industrial 477,551 5,479 — 496 25,101 127 508,754 Total commercial 9,628,481 377,745 144,780 76,297 25,101 127 10,252,531 Commercial real estate: Residential construction and land development 154,369 1,355 293 4,409 — — 160,426 Retail 788,708 6,046 426 1,319 — — 796,499 Office 636,210 291 555 651 — — 637,707 Multifamily 744,299 — 6,512 274 — — 751,085 Industrial 563,093 — — 76 — — 563,169 Other commercial real estate 347,864 — 11 2,272 — — 350,147 Total commercial real estate 3,234,543 7,692 7,797 9,001 — — 3,259,033 Residential mortgage: Permanent mortgage 192,367 89 1,932 2,313 721,964 26,671 945,336 Permanent mortgages guaranteed by U.S. government agencies — — — — 175,037 21,900 196,937 Home equity — — — — 724,264 10,356 734,620 Total residential mortgage 192,367 89 1,932 2,313 1,621,265 58,927 1,876,893 Personal 467,808 3 14 130 84,409 333 552,697 Total $ 13,523,199 $ 385,529 $ 154,523 $ 87,741 $ 1,730,775 $ 59,387 $ 15,941,154 The following table summarizes the Company’s loan portfolio at September 30, 2015 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 $ 2,527,543 $ 196,298 $ 96,446 $ 17,880 $ — $ — $ 2,838,167 Services 2,683,655 4,207 8,070 10,692 — — 2,706,624 Wholesale/retail 1,432,460 23,176 3,242 3,058 — — 1,461,936 Manufacturing 532,443 20,975 1,907 352 — — 555,677 Healthcare 1,734,741 5,721 — 1,218 — — 1,741,680 Other commercial and industrial 463,385 3,012 — 522 26,343 76 493,338 Total commercial 9,374,227 253,389 109,665 33,722 26,343 76 9,797,422 Commercial real estate: Residential construction and land development 146,764 1,628 370 4,748 — — 153,510 Retail 761,279 6,089 433 1,648 — — 769,449 Office 624,611 296 560 684 — — 626,151 Multifamily 750,791 — 7,682 185 — — 758,658 Industrial 563,795 — — 76 — — 563,871 Other commercial real estate 359,672 — 141 3,615 — — 363,428 Total commercial real estate 3,206,912 8,013 9,186 10,956 — — 3,235,067 Residential mortgage: Permanent mortgage 186,832 91 918 2,520 719,163 28,140 937,664 Permanent mortgages guaranteed by U.S. government agencies — — — — 188,827 3,885 192,712 Home equity — — — — 729,065 9,554 738,619 Total residential mortgage 186,832 91 918 2,520 1,637,055 41,579 1,868,995 Personal 380,216 5 15 140 85,227 354 465,957 Total $ 13,148,187 $ 261,498 $ 119,784 $ 47,338 $ 1,748,625 $ 42,009 $ 15,367,441
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 includes all nonaccruing loans, all loans modified in a TDR and all loans repurchased from GNMA pools. A summary of impaired loans follows (in thousands): As of For the For the September 30, 2016 Three Months Ended Nine Months Ended Recorded Investment September 30, 2016 September 30, 2016 Unpaid Principal Balance Total With No Allowance With Allowance Related Allowance Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial: Energy $ 179,578 $ 142,966 $ 100,300 $ 42,666 $ 6,502 $ 155,555 $ — $ 85,333 $ — Services 11,858 8,477 8,477 — — 8,932 — 9,384 — Wholesale/retail 8,528 2,453 2,453 — — 2,613 — 2,686 — Manufacturing 642 274 274 — — 284 — 303 — Healthcare 1,168 855 855 — — 865 — 964 — Other commercial and industrial 29,176 21,439 21,439 — — 10,978 — 11,031 — Total commercial 230,950 176,464 133,798 42,666 6,502 179,227 — 109,701 — Commercial real estate: Residential construction and land development 6,090 3,739 3,739 — — 4,000 — 4,074 — Retail 1,914 1,249 1,249 — — 1,257 — 1,284 — Office 1,187 882 882 — — 744 — 766 — Multifamily 1,000 51 51 — — 58 — 163 — Industrial 76 76 76 — — 76 — 76 — Other real estate loans 7,375 1,353 1,353 — — 1,430 — 1,813 — Total commercial real estate 17,642 7,350 7,350 — — 7,565 — 8,176 — Residential mortgage: Permanent mortgage 32,372 25,956 25,847 109 62 26,592 292 27,470 923 Permanent mortgage guaranteed by U.S. government agencies 1 196,162 190,309 190,309 — — 190,547 2,098 193,879 5,893 Home equity 12,099 11,064 11,064 — — 10,578 — 10,710 — Total residential mortgage 240,633 227,329 227,220 109 62 227,717 2,390 232,059 6,816 Personal 724 686 686 — — 520 — 575 — Total $ 489,949 $ 411,829 $ 369,054 $ 42,775 $ 6,564 $ 415,029 $ 2,390 $ 350,511 $ 6,816 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 September 30, 2016 , $15 million of these loans were nonaccruing and $175 million 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, 2015 follows (in thousands): Recorded Investment Unpaid Principal Balance Total With No Allowance With Allowance Related Allowance Commercial: Energy $ 63,910 $ 61,189 $ 18,330 $ 42,859 $ 16,115 Services 13,449 10,290 9,657 633 148 Wholesale/retail 8,582 2,919 2,907 12 9 Manufacturing 665 331 331 — — Healthcare 1,352 1,072 931 141 35 Other commercial and industrial 8,304 623 623 — — Total commercial 96,262 76,424 32,779 43,645 16,307 Commercial real estate: Residential construction and land development 8,963 4,409 4,409 — — Retail 1,923 1,319 1,319 — — Office 937 651 651 — — Multifamily 1,192 274 274 — — Industrial 76 76 76 — — Other real estate loans 8,363 2,272 2,113 159 18 Total commercial real estate 21,454 9,001 8,842 159 18 Residential mortgage: Permanent mortgage 37,273 28,984 28,868 116 68 Permanent mortgage guaranteed by U.S. government agencies 1 202,984 196,937 196,937 — — Home equity 10,988 10,356 10,356 — — Total residential mortgage 251,245 236,277 236,161 116 68 Personal 489 463 463 — — Total $ 369,450 $ 322,165 $ 278,245 $ 43,920 $ 16,393 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, 2015 , $22 million of these loans were nonaccruing and $175 million were accruing based on the guarantee by U.S. government agencies. A summary of impaired loans at September 30, 2015 follows (in thousands): For the For the As of September 30, 2015 Three Months Ended Nine Months Ended Recorded Investment September 30, 2015 September 30, 2015 Unpaid Principal Balance Total With No Allowance With Allowance Related Allowance Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Commercial: Energy $ 18,904 $ 17,880 $ 5,017 $ 12,863 $ 4,644 $ 12,361 $ — $ 9,648 $ — Services 13,677 10,692 10,041 651 148 10,818 — 7,946 — Wholesale/retail 8,588 3,058 3,046 12 9 3,612 — 3,603 — Manufacturing 675 352 352 — — 365 — 401 — Healthcare 1,612 1,218 1,064 154 35 1,248 — 1,299 — Other commercial and industrial 8,277 598 598 — — 611 — 765 — Total commercial 51,733 33,798 20,118 13,680 4,836 29,015 — 23,662 — Commercial real estate: Residential construction and land development 9,349 4,748 4,748 — — 7,058 — 5,023 — Retail 2,252 1,648 1,648 — — 2,737 — 2,787 — Office 2,046 684 684 — — 1,522 — 2,052 — Multifamily 192 185 185 — — 190 — 93 — Industrial 76 76 76 — — 76 — 38 — Other real estate loans 9,650 3,615 3,452 163 18 3,965 — 4,763 — Total commercial real estate 23,565 10,956 10,793 163 18 15,548 — 14,756 — Residential mortgage: Permanent mortgage 38,829 30,660 30,506 154 97 31,424 297 32,753 942 Permanent mortgage guaranteed by U.S. government agencies 1 198,905 192,712 192,712 — — 193,165 1,902 198,312 6,205 Home equity 10,085 9,554 9,554 — — 9,810 — 9,559 — Total residential mortgage 247,819 232,926 232,772 154 97 234,399 2,199 240,624 7,147 Personal 516 494 494 — — 522 — 530 — Total $ 323,633 $ 278,174 $ 264,177 $ 13,997 $ 4,951 $ 279,484 $ 2,199 $ 279,572 $ 7,147 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 September 30, 2015 , $3.9 million of these loans were nonaccruing and $189 million were accruing based on the guarantee by U.S. government agencies.
Troubled Debt Restructurings [Table Text Block]	Troubled Debt Restructurings A summary of troubled debt restructurings ("TDRs") by accruing status as of September 30, 2016 is as follows (in thousands): As of September 30, 2016 Amounts Charged Off During: Recorded Investment Performing in Accordance With Modified Terms Not Performing in Accordance With Modified Terms Specific Allowance Three Months Nine Months Ended Nonaccruing TDRs: Commercial: Energy $ 1,746 $ — $ 1,746 $ — $ 500 $ 1,000 Services 7,761 7,034 727 — — — Wholesale/retail 2,327 2,287 40 — — — Manufacturing 238 238 — — — — Healthcare 623 — 623 — — — Other commercial and industrial 497 61 436 — — 57 Total commercial 13,192 9,620 3,572 — 500 1,057 Commercial real estate: Residential construction and land development 794 359 435 — — — Retail 1,249 892 357 — — — Office 149 149 — — — — Multifamily — — — — — — Industrial — — — — — — Other real estate loans 666 666 — — — — Total commercial real estate 2,858 2,066 792 — — — Residential mortgage: Permanent mortgage 16,109 11,944 4,165 62 — 2 Permanent mortgage guaranteed by U.S. government agencies 8,220 2,331 5,889 — — — Home equity 5,168 4,667 501 — 34 153 Total residential mortgage 29,497 18,942 10,555 62 34 155 Personal 273 271 2 — 9 18 Total nonaccruing TDRs $ 45,820 $ 30,899 $ 14,921 $ 62 $ 543 $ 1,230 Accruing TDRs: Permanent mortgages guaranteed by U.S. government agencies 80,306 29,020 51,286 — — — Total TDRs $ 126,126 $ 59,919 $ 66,207 $ 62 $ 543 $ 1,230 A summary of troubled debt restructurings by accruing status as of December 31, 2015 is as follows (in thousands): As of December 31, 2015 Recorded Investment Performing in Accordance With Modified Terms Not Performing in Accordance With Modified Terms Specific Allowance Nonaccruing TDRs: Commercial: Energy $ 2,304 $ 2,304 $ — $ — Services 9,027 8,210 817 148 Wholesale/retail 2,758 2,706 52 9 Manufacturing 282 282 — — Healthcare 673 673 — — Other commercial and industrial 621 89 532 — Total commercial 15,665 14,264 1,401 157 Commercial real estate: Residential construction and land development 2,328 1,556 772 — Retail 1,319 942 377 — Office 165 165 — — Multifamily — — — — Industrial — — — — Other real estate loans 920 478 442 — Total commercial real estate 4,732 3,141 1,591 — Residential mortgage: Permanent mortgage 16,618 9,043 7,575 68 Permanent mortgage guaranteed by U.S. government agencies 11,136 139 10,997 — Home equity 5,159 4,218 941 — Total residential mortgage 32,913 13,400 19,513 68 Personal 324 297 27 — Total nonaccuring TDRs $ 53,634 $ 31,102 $ 22,532 $ 225 Accruing TDRs: Permanent mortgages guaranteed by U.S. government agencies 74,050 23,029 51,021 — Total TDRs $ 127,684 $ 54,131 $ 73,553 $ 225 A summary of troubled debt restructurings by accruing status as of September 30, 2015 is as follows (in thousands): As of September 30, 2015 Amounts Charged Off During Recorded Investment Performing in Accordance With Modified Terms Not Performing in Accordance With Modified Terms Specific Allowance Three Months Ended Nine Months Ended Nonaccruing TDRs: Commercial: Energy $ — $ — $ — $ — $ — $ — Services 9,362 8,502 860 148 — — Wholesale/retail 2,897 2,844 53 9 — — Manufacturing 296 296 — — — — Healthcare 689 689 — — — — Other commercial and industrial 590 76 514 — 100 100 Total commercial 13,834 12,407 1,427 157 100 100 Commercial real estate: Residential construction and land development 2,539 1,624 915 — — — Retail 1,356 960 396 — — — Office 169 169 — — — — Multifamily — — — — — — Industrial — — — — — — Other real estate loans 1,037 584 453 — — — Total commercial real estate 5,101 3,337 1,764 — — — Residential mortgage: Permanent mortgage 16,359 9,361 6,998 97 140 142 Permanent mortgage guaranteed by U.S. government agencies 1,944 140 1,804 — — — Home equity 4,975 4,336 639 — 10 68 Total residential mortgage 23,278 13,837 9,441 97 150 210 Personal 365 209 156 — — 2 Total nonaccruing TDRs $ 42,578 $ 29,790 $ 12,788 $ 254 $ 250 $ 312 Accruing TDRs: Permanent mortgages guaranteed by U.S. government agencies 81,598 22,352 59,246 — — — Total TDRs $ 124,176 $ 52,142 $ 72,034 $ 254 $ 250 $ 312 Troubled debt restructurings generally consist of interest rate concessions, payment stream concessions or a combination of concessions to distressed borrowers. The following tables detail the recorded balance of loans at September 30, 2016 by class that were restructured during the three months ended September 30, 2016 by primary type of concession (in thousands): Three Months Ended Accruing Nonaccrual Total Payment Stream Combination & Other Total Payment Stream Combination & Other Total Commercial: Energy $ — $ — $ — $ — $ — $ — $ — Services — — — — — — — Wholesale/retail — — — — — — — Manufacturing — — — — — — — Healthcare — — — — — — — Other commercial and industrial — — — — — — — Total commercial — — — — — — — Commercial real estate: Residential construction and land development — — — — — — — Retail — — — — — — — Office — — — — — — — Multifamily — — — — — — — Industrial — — — — — — — Other real estate loans — — — — — — — Total commercial real estate — — — — — — — Residential mortgage: Permanent mortgage — — — — 151 151 151 Permanent mortgage guaranteed by U.S. government agencies 3,527 4,211 7,738 — 287 287 8,025 Home equity — — — — 920 920 920 Total residential mortgage 3,527 4,211 7,738 — 1,358 1,358 9,096 Personal — — — — 19 19 19 Total $ 3,527 $ 4,211 $ 7,738 $ — $ 1,377 $ 1,377 $ 9,115 Troubled debt restructurings generally consist of interest rate concessions, payment stream concessions or a combination of concessions to distressed borrowers. The following tables detail the recorded balance of loans at September 30, 2016 by class that were restructured during the nine months ended September 30, 2016 by primary type of concession (in thousands): Nine Months Ended Accruing Nonaccrual Total Payment Stream Combination & Other Total Payment Stream Combination & Other Total Commercial: Energy $ — $ — $ — $ 501 $ — $ 501 $ 501 Services — — — — — — — Wholesale/retail — — — — — — — Manufacturing — — — — — — — Healthcare — — — — — — — Other commercial and industrial — — — — — — — Total commercial — — — 501 — 501 501 Commercial real estate: Residential construction and land development — — — — — — — Retail — — — — — — — Office — — — — — — — Multifamily — — — — — — — Industrial — — — — — — — Other real estate loans — — — — — — — Total commercial real estate — — — — — — — Residential mortgage: Permanent mortgage — — — 1,037 1,051 2,088 2,088 Permanent mortgage guaranteed by U.S. government agencies 9,687 9,350 19,037 — 982 982 20,019 Home equity — — — 48 1,630 1,678 1,678 Total residential mortgage 9,687 9,350 19,037 1,085 3,663 4,748 23,785 Personal — — — — 82 82 82 Total $ 9,687 $ 9,350 $ 19,037 $ 1,586 $ 3,745 $ 5,331 $ 24,368 Troubled debt restructurings generally consist of interest rate concessions, payment stream concessions or a combination of concessions to distressed borrowers. The following tables detail the recorded balance of loans by class that were restructured during three months ended September 30, 2015 by primary type of concession (in thousands): Three Months Ended Accruing Nonaccrual Total Payment Stream Combination & Other Total Interest Rate Payment Stream Combination & Other Total Commercial: Energy $ — $ — $ — $ — $ — $ — $ — $ — Services — — — — — — — — Wholesale/retail — — — — — — — — Manufacturing — — — — — — — — Healthcare — — — — — — — — Other commercial and industrial — — — — — — — — Total commercial — — — — — — — — Commercial real estate: Residential construction and land development — — — — — — — — Retail — — — — — — — — Office — — — — — — — — Multifamily — — — — — — — — Industrial — — — — — — — — Other real estate loans — — — — — — — — Total commercial real estate — — — — — — — — Residential mortgage: Permanent mortgage — — — — 1,448 150 1,598 1,598 Permanent mortgage guaranteed by U.S. government agencies 5,809 3,846 9,655 — — — — 9,655 Home equity — — — — — 447 447 447 Total residential mortgage 5,809 3,846 9,655 — 1,448 597 2,045 11,700 Personal — — — — — 18 18 18 Total $ 5,809 $ 3,846 $ 9,655 $ — $ 1,448 $ 615 $ 2,063 $ 11,718 Troubled debt restructurings generally consist of interest rate concessions, payment stream concessions or a combination of concessions to distressed borrowers. The following tables detail the recorded balance of loans by class that were restructured during nine months ended September 30, 2015 by primary type of concession (in thousands): Nine Months Ended Accruing Nonaccrual Total Payment Stream Combination & Other Total Interest Rate Payment Stream Combination & Other Total Commercial: Energy $ — $ — $ — $ — $ — $ — $ — $ — Services — — — — — 7,851 7,851 7,851 Wholesale/retail — — — — — — — — Manufacturing — — — — — — — — Healthcare — — — 689 — — 689 689 Other commercial and industrial — — — — — — — — Total commercial — — — 689 — 7,851 8,540 8,540 Commercial real estate: Residential construction and land development — — — — 329 — 329 329 Retail — — — — — — — — Office — — — — — — — — Multifamily — — — — — — — — Industrial — — — — — — — — Other real estate loans — — — — — — — — Total commercial real estate — — — — 329 — 329 329 Residential mortgage: Permanent mortgage — — — — 2,150 1,125 3,275 3,275 Permanent mortgage guaranteed by U.S. government agencies 15,858 10,397 26,255 — — 843 843 27,098 Home equity — — — 59 145 1,523 1,727 1,727 Total residential mortgage 15,858 10,397 26,255 59 2,295 3,491 5,845 32,100 Personal — — — — — 104 104 104 Total $ 15,858 $ 10,397 $ 26,255 $ 748 $ 2,624 $ 11,446 $ 14,818 $ 41,073 The following table summarizes, by loan class, the recorded investment at September 30, 2016 and 2015 , respectively, of loans modified as TDRs within the previous 12 months and for which there was a payment default during the three months ended September 30, 2016 and 2015 , respectively (in thousands): Three Months Ended Nine Months Ended Accruing Nonaccrual Total Accruing Nonaccrual Total Commercial: Energy $ — $ 1,746 $ 1,746 $ — $ 1,746 $ 1,746 Services — — — — — — Wholesale/retail — — — — — — Manufacturing — — — — — — Healthcare — — — — — — Other commercial and industrial — — — — — — Total commercial — 1,746 1,746 — 1,746 1,746 Commercial real estate: Residential construction and land development — — — — — — Retail — — — — — — Office — — — — — — Multifamily — — — — — — Industrial — — — — — — Other real estate loans — — — — — — Total commercial real estate — — — — — — Residential mortgage: Permanent mortgage — 298 298 — 542 542 Permanent mortgage guaranteed by U.S. government agencies 17,491 1,095 18,586 19,352 1,121 20,473 Home equity — 258 258 — 258 258 Total residential mortgage 17,491 1,651 19,142 19,352 1,921 21,273 Personal — 11 11 — 11 11 Total $ 17,491 $ 3,408 $ 20,899 $ 19,352 $ 3,678 $ 23,030 A payment default is defined as being 30 days or more past due. The table above includes loans that experienced a payment default during the period, but may be performing in accordance with the modified terms as of the balance sheet date. Three Months Ended Nine Months Ended Accruing Nonaccrual Total Accruing Nonaccrual Total Commercial: Energy $ — $ — $ — $ — $ — $ — Services — — — — — — Wholesale/retail — — — — — — Manufacturing — — — — — — Healthcare — — — — — — Other commercial and industrial — — — — — — Total commercial — — — — — — Commercial real estate: Residential construction and land development — 329 329 — 329 329 Retail — — — — — — Office — — — — — — Multifamily — — — — — — Industrial — — — — — — Other real estate loans — — — — — — Total commercial real estate — 329 329 — 329 329 Residential mortgage: Permanent mortgage — 2,364 2,364 — 2,543 2,543 Permanent mortgage guaranteed by U.S. government agencies 29,942 779 30,721 31,673 919 32,592 Home equity — 398 398 — 435 435 Total residential mortgage 29,942 3,541 33,483 31,673 3,897 35,570 Personal — 38 38 — 38 38 Total $ 29,942 $ 3,908 $ 33,850 $ 31,673 $ 4,264 $ 35,937
Summary of Loans by Aging Status [Table Text Block]	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, 2016 is as follows (in thousands): Past Due Current 30 to 59 Days 60 to 89 Days 90 Days or More Nonaccrual Total Commercial: Energy $ 2,365,850 $ 11,988 $ — $ — $ 142,966 $ 2,520,804 Services 2,923,874 502 39 3,707 8,477 2,936,599 Wholesale/retail 1,599,356 221 — — 2,453 1,602,030 Manufacturing 499,212 — — — 274 499,486 Healthcare 2,083,556 635 — — 855 2,085,046 Other commercial and industrial 454,538 34 68 119 21,439 476,198 Total commercial 9,926,386 13,380 107 3,826 176,464 10,120,163 Commercial real estate: Residential construction and land development 156,207 — — — 3,739 159,946 Retail 796,362 3,766 — — 1,249 801,377 Office 751,823 — — — 882 752,705 Multifamily 868,591 — 5,131 — 51 873,773 Industrial 837,945 — — — 76 838,021 Other real estate loans 366,416 7 — — 1,353 367,776 Total commercial real estate 3,777,344 3,773 5,131 — 7,350 3,793,598 Residential mortgage: Permanent mortgage 939,853 3,547 202 — 25,956 969,558 Permanent mortgages guaranteed by U.S. government agencies 41,150 17,364 12,963 103,400 15,432 190,309 Home equity 700,031 1,526 305 — 11,064 712,926 Total residential mortgage 1,681,034 22,437 13,470 103,400 52,452 1,872,793 Personal 677,194 191 148 13 686 678,232 Total $ 16,061,958 $ 39,781 $ 18,856 $ 107,239 $ 236,952 $ 16,464,786 A summary of loans currently performing, loans past due and accruing and nonaccrual loans as of December 31, 2015 is as follows (in thousands): Past Due Current 30 to 59 Days 60 to 89 Days 90 Days or More Nonaccrual Total Commercial: Energy $ 3,033,504 $ 2,635 — $ — $ 61,189 $ 3,097,328 Services 2,769,895 66 4,025 — 10,290 2,784,276 Wholesale/retail 1,418,396 49 — 700 2,919 1,422,064 Manufacturing 556,398 — — — 331 556,729 Healthcare 1,879,873 2,435 — — 1,072 1,883,380 Other commercial and industrial 507,929 84 16 102 623 508,754 Total commercial 10,165,995 5,269 4,041 802 76,424 10,252,531 Commercial real estate: Residential construction and land development 156,017 — — — 4,409 160,426 Retail 795,180 — — — 1,319 796,499 Office 637,056 — — — 651 637,707 Multifamily 742,697 8,114 — — 274 751,085 Industrial 563,093 — — — 76 563,169 Other real estate loans 347,498 — — 377 2,272 350,147 Total commercial real estate 3,241,541 8,114 — 377 9,001 3,259,033 Residential mortgage: Permanent mortgage 913,062 3,290 — — 28,984 945,336 Permanent mortgages guaranteed by U.S. government agencies 33,653 16,986 13,397 111,001 21,900 196,937 Home equity 721,149 2,379 716 20 10,356 734,620 Total residential mortgage 1,667,864 22,655 14,113 111,021 61,240 1,876,893 Personal 551,533 665 28 8 463 552,697 Total $ 15,626,933 $ 36,703 18,182 $ 112,208 $ 147,128 $ 15,941,154 A summary of loans currently performing, loans past due and accruing and nonaccrual loans as of September 30, 2015 is as follows (in thousands): Past Due Current 30 to 59 Days 60 to 89 Days 90 Days or More Nonaccrual Total Commercial: Energy $ 2,813,145 $ 7,142 — $ — $ 17,880 $ 2,838,167 Services 2,690,554 1,575 3,803 — 10,692 2,706,624 Wholesale/retail 1,458,681 197 — — 3,058 1,461,936 Manufacturing 555,325 — — — 352 555,677 Healthcare 1,740,462 — — — 1,218 1,741,680 Other commercial and industrial 492,554 65 21 100 598 493,338 Total commercial 9,750,721 8,979 3,824 100 33,798 9,797,422 Commercial real estate: Residential construction and land development 148,762 — — — 4,748 153,510 Retail 767,801 — — — 1,648 769,449 Office 625,250 217 — — 684 626,151 Multifamily 752,055 — 6,418 — 185 758,658 Industrial 563,795 — — — 76 563,871 Other real estate loans 359,813 — — — 3,615 363,428 Total commercial real estate 3,217,476 217 6,418 — 10,956 3,235,067 Residential mortgage: Permanent mortgage 903,685 3,183 135 — 30,661 937,664 Permanent mortgages guaranteed by U.S. government agencies 33,046 15,299 10,477 130,005 3,885 192,712 Home equity 725,572 2,873 619 1 9,554 738,619 Total residential mortgage 1,662,303 21,355 11,231 130,006 44,100 1,868,995 Personal 465,218 199 46 — 494 465,957 Total $ 15,095,718 $ 30,750 21,519 $ 130,106 $ 89,348 $ 15,367,441

Mortgage Banking Activities (Ta

Mortgage Banking Activities (Tables)	9 Months Ended
	Sep. 30, 2016
Mortgage Banking [Abstract]
Components of Residential Mortgage Loans Held For Sale [Table Text Block]	September 30, 2016 Dec. 31, 2015 September 30, 2015 Unpaid Principal Balance/ Notional Fair Value Unpaid Principal Balance/ Notional Fair Value Unpaid Principal Balance/ Notional Fair Value Residential mortgage loans held for sale $ 422,523 $ 433,040 $ 293,637 $ 299,505 $ 336,974 $ 348,400 Residential mortgage loan commitments 630,804 18,598 601,147 8,134 742,742 18,161 Forward sales contracts 929,907 (4,046 ) 884,710 800 1,073,343 (9,147 ) $ 447,592 $ 308,439 $ 357,414
Mortgage Banking Revenue [Table Text Block]	Mortgage banking revenue was as follows (in thousands): Three Months Ended Nine Months Ended 2016 2015 2016 2015 Production revenue: Net realized gains on sale of mortgage loans $ 27,142 $ 18,968 $ 57,126 $ 60,075 Net change in unrealized gain on mortgage loans held for sale (2,518 ) 6,666 4,649 4,751 Net change in the fair value of mortgage loan commitments (6,901 ) 9,838 10,464 8,190 Net change in the fair value of forward sales contracts 8,267 (16,755 ) (4,846 ) (5,146 ) Total production revenue 25,990 18,717 67,393 67,870 Servicing revenue 16,558 14,453 47,809 41,466 Total mortgage banking revenue $ 42,548 $ 33,170 $ 115,202 $ 109,336
Summary of Mortgage Servicing Rights [Table Text Block]	The following represents a summary of mortgage servicing rights (Dollars in thousands): September 30, Dec. 31, September 30, Number of residential mortgage loans serviced for others 139,587 131,859 128,828 Outstanding principal balance of residential mortgage loans serviced for others $ 21,851,536 $ 19,678,226 $ 18,928,726 Weighted average interest rate 4.01 % 4.12 % 4.15 % Remaining term (in months) 302 300 300
Activity in Capitalized Mortgage Servicing Rights [Table Text Block]	Activity in capitalized mortgage servicing rights during the three months ended September 30, 2016 was as follows (in thousands): Purchased Originated Total Balance, June 30, 2016 $ 4,067 $ 186,680 $ 190,747 Additions, net — 21,990 21,990 Change in fair value due to scheduled payments and full-balance payoffs (753 ) (10,690 ) (11,443 ) Change in fair value due to market assumption changes 251 2,076 2,327 Balance, Sept. 30, 2016 $ 3,565 $ 200,056 $ 203,621 Activity in capitalized mortgage servicing rights during the nine months ended September 30, 2016 was as follows (in thousands): Purchased Originated Total Balance, Dec. 31, 2015 $ 9,911 $ 208,694 $ 218,605 Additions, net — 56,345 56,345 Change in fair value due to scheduled payments and full-balance payoffs (2,109 ) (27,276 ) (29,385 ) Change in fair value due to market assumption changes (4,237 ) (37,707 ) (41,944 ) Balance, Sept. 30, 2016 $ 3,565 $ 200,056 $ 203,621 Activity in capitalized mortgage servicing rights during the three months ended September 30, 2015 was as follows (in thousands): Purchased Originated Total Balance, June 30, 2015 $ 10,730 $ 187,964 $ 198,694 Additions, net — 19,993 19,993 Change in fair value due to scheduled payments and full-balance payoffs (661 ) (6,220 ) (6,881 ) Change in fair value due to market assumption changes (656 ) (11,101 ) (11,757 ) Balance, Sept. 30, 2015 $ 9,413 $ 190,636 $ 200,049 Activity in capitalized mortgage servicing rights during the nine months ended September 30, 2015 was as follows (in thousands): Purchased Originated Total Balance, Dec. 31, 2014 $ 11,114 $ 160,862 $ 171,976 Additions, net — 62,375 62,375 Change in fair value due to scheduled payments and full-balance payoffs (2,171 ) (19,862 ) (22,033 ) Change in fair value due to market assumption changes 470 (12,739 ) (12,269 ) Balance, Sept. 30, 2015 $ 9,413 $ 190,636 $ 200,049
Assumptions to Value Mortgage Servicing Rights [Table Text Block]	There is no active market for trading in mortgage servicing rights after origination. Fair value is determined by discounting the projected net cash flows. Significant assumptions used to determine fair value based on significant unobservable inputs were as follows: September 30, Dec. 31, September 30, Discount rate – risk-free rate plus a market premium 10.08% 10.11% 10.12% Loan servicing costs – annually per loan based upon loan type: Performing loans $63-$120 $63 - $105 $63 - $105 Delinquent loans $150 - $500 $150 - $500 $150 - $500 Loans in foreclosure $650 - $4,250 $650 - $4,250 $650 - $4,250 Escrow earnings rate – indexed to rates paid on deposit accounts with comparable average life 1.18% 1.73% 1.40% Primary/secondary mortgage rate spread 115 bps 130 bps 135 bps
Stratification of Loan Servicing Portfolio [Table Text Block]	Stratification of the residential mortgage loan servicing portfolio and outstanding principal of loans serviced for others by interest rate at September 30, 2016 follows (in thousands): < 4.00% 4.00% - 4.99% 5.00% - 5.99% > 5.99% Total Fair value $ 121,802 $ 74,830 $ 4,968 $ 2,021 $ 203,621 Outstanding principal of loans serviced for others $ 12,145,996 $ 7,720,311 $ 1,215,692 $ 769,537 $ 21,851,536 Weighted average prepayment rate 1 9.16 % 12.48 % 36.75 % 47.15 % 13.20 % 1 Annual prepayment estimates based upon loan interest rate, original term and loan type. Weighted average prepayment rate is determined by weighting the prepayment speed for each loan by its unpaid principal balance.
Aging Status of Mortgage Loans Serviced For Others [Table Text Block]	The aging status of our mortgage loans serviced for others by investor at September 30, 2016 follows (in thousands): Past Due Current 30 to 59 Days 60 to 89 Days 90 Days or More Total FHLMC $ 7,760,547 $ 34,145 $ 10,399 $ 23,938 $ 7,829,029 FNMA 6,944,158 43,046 8,704 17,097 7,013,005 GNMA 6,338,155 150,386 48,790 16,624 6,553,955 Other 452,083 1,219 596 1,649 455,547 Total $ 21,494,943 $ 228,796 $ 68,489 $ 59,308 $ 21,851,536
Activity in Allowance for Losses On Loans Sold With Recourse [Table Text Block]	Three Months Ended Nine Months Ended 2016 2015 2016 2015 Beginning balance $ 4,339 $ 6,691 $ 4,649 $ 7,299 Provision for recourse losses 113 81 504 211 Loans charged off, net (235 ) (506 ) (936 ) (1,244 ) Ending balance $ 4,217 $ 6,266 $ 4,217 $ 6,266
Summary of Unresolved Deficiency Requests and Related Accrual for Credit Losses [Table Text Block]	A summary of unresolved deficiency requests from the agencies follows (in thousands, except for number of unresolved deficiency requests): September 30, 2016 2015 Number of unresolved deficiency requests 221 194 Aggregate outstanding principal balance subject to unresolved deficiency requests $ 15,750 $ 14,237 Unpaid principal balance subject to indemnification by the Company 5,399 4,604
Activity in Accruals for Mortgage Losses [Table Text Block]	The activity in the accruals for mortgage losses is summarized as follows (in thousands). Three Months Ended Nine Months Ended 2016 2015 2016 2015 Beginning balance $ 8,043 $ 8,908 $ 7,732 $ 11,868 Provision for losses 1,357 (52 ) 5,260 (3,056 ) Charge-offs, net (1,758 ) (1,262 ) (5,350 ) (1,218 ) Ending balance $ 7,642 $ 7,594 $ 7,642 $ 7,594

Commitments and Contingent Li25

Commitments and Contingent Liabilities Commitments and Contingent Liabilities - Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Schedule of Variable Interest Entities [Table Text Block]	A summary of consolidated and unconsolidated alternative investments as of September 30, 2016 , December 31, 2015 and September 30, 2015 is as follows (in thousands): September 30, 2016 Loans Other assets Other liabilities Other borrowings Non-controlling interests Consolidated: Private equity funds $ — $ 18,420 $ — $ — $ 15,946 Tax credit entities 10,000 11,740 — 10,964 10,000 Other — 30,978 2,346 1,063 8,154 Total consolidated $ 10,000 $ 61,138 $ 2,346 $ 12,027 $ 34,100 Unconsolidated: Tax credit entities $ 39,849 $ 129,715 $ 57,026 $ — $ — Other — 30,272 13,653 — — Total unconsolidated $ 39,849 $ 159,987 $ 70,679 $ — $ — Dec. 31, 2015 Loans Other assets Other liabilities Other borrowings Non-controlling interests Consolidated: Private equity funds $ — $ 22,472 $ — $ — $ 17,823 Tax credit entities 10,000 12,206 — 10,964 10,000 Other — 40,453 2,198 2,831 9,260 Total consolidated $ 10,000 $ 75,131 $ 2,198 $ 13,795 $ 37,083 Unconsolidated: Tax credit entities $ 16,916 $ 85,274 $ 14,572 $ — $ — Other — 15,506 6,319 — — Total unconsolidated $ 16,916 $ 100,780 $ 20,891 $ — $ — September 30, 2015 Loans Other assets Other liabilities Other borrowings Non-controlling interests Consolidated: Private equity funds $ — $ 24,133 $ — $ — $ 19,947 Tax credit entities 10,000 12,361 — 10,964 10,000 Other — 41,197 2,774 2,788 8,989 Total consolidated $ 10,000 $ 77,691 $ 2,774 $ 13,752 $ 38,936 Unconsolidated: Tax credit entities $ 18,114 $ 94,600 $ 21,973 $ — $ — Other — 15,822 6,899 — — Total unconsolidated $ 18,114 $ 110,422 $ 28,872 $ — $ —

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2016
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 Investment Securities Transferred from AFS Employee Benefit Plans Loss on Effective Cash Flow Hedges Total Balance, Dec. 31, 2014 $ 59,239 $ 376 $ (2,868 ) $ (74 ) $ 56,673 Net change in unrealized gain (loss) 57,763 — — — 57,763 Reclassification adjustments included in earnings: Interest revenue, Investment securities, Taxable securities — (418 ) — — (418 ) Interest expense, Subordinated debentures — — — 121 121 Net impairment losses recognized in earnings 92 — — — 92 Gain on available for sale securities, net (9,926 ) — — — (9,926 ) Other comprehensive income (loss), before income taxes 47,929 (418 ) — 121 47,632 Federal and state income taxes 1 18,644 (162 ) — 47 18,529 Other comprehensive income (loss), net of income taxes 29,285 (256 ) — 74 29,103 Balance, Sept. 30, 2015 $ 88,524 $ 120 $ (2,868 ) $ — $ 85,776 Balance, Dec. 31, 2015 $ 23,284 $ 68 $ (1,765 ) $ — $ 21,587 Net change in unrealized gain (loss) 133,108 — — — 133,108 Reclassification adjustments included in earnings: Interest revenue, Investment securities, Taxable securities — (112 ) — — (112 ) Interest expense, Subordinated debentures — — — — — Net impairment losses recognized in earnings — — — — — Gain on available for sale securities, net (11,684 ) — — — (11,684 ) Other comprehensive income (loss), before income taxes 121,424 (112 ) — — 121,312 Federal and state income taxes 1 47,216 (44 ) — — 47,172 Other comprehensive income (loss), net of income taxes 74,208 (68 ) — — 74,140 Balance, Sept. 30, 2016 $ 97,492 $ — $ (1,765 ) $ — $ 95,727 1 Calculated using a 39 percent effective tax rate.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Earnings Per Share [Table Text Block]	(In thousands, except share and per share amounts) Three Months Ended Nine Months Ended 2016 2015 2016 2015 Numerator: Net income attributable to BOK Financial Corp. shareholders $ 74,277 $ 74,891 $ 182,642 $ 228,964 Less: Earnings allocated to participating securities 916 894 2,275 2,652 Numerator for basic earnings per share – income available to common shareholders 73,361 73,997 180,367 226,312 Effect of reallocating undistributed earnings of participating securities 1 1 1 2 Numerator for diluted earnings per share – income available to common shareholders $ 73,362 $ 73,998 $ 180,368 $ 226,314 Denominator: Weighted average shares outstanding 65,895,430 68,486,376 66,031,497 68,800,419 Less: Participating securities included in weighted average shares outstanding 810,038 818,300 822,723 795,911 Denominator for basic earnings per common share 65,085,392 67,668,076 65,208,774 68,004,508 Dilutive effect of employee stock compensation plans 1 72,449 94,407 54,792 99,509 Denominator for diluted earnings per common share 65,157,841 67,762,483 65,263,566 68,104,017 Basic earnings per share $ 1.13 $ 1.09 $ 2.77 $ 3.33 Diluted earnings per share $ 1.13 $ 1.09 $ 2.76 $ 3.32 1 Excludes employee stock options with exercise prices greater than current market price. — — — —

Reportable Segments (Tables)

Reportable Segments (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Reportable Segments [Table Text Block]	Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended September 30, 2016 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 123,598 $ 22,098 $ 9,274 $ 32,876 $ 187,846 Net interest revenue (expense) from internal sources (15,052 ) 9,263 7,401 (1,612 ) — Net interest revenue 108,546 31,361 16,675 31,264 187,846 Provision for credit losses 5,601 1,157 (89 ) 3,331 10,000 Net interest revenue after provision for credit losses 102,945 30,204 16,764 27,933 177,846 Other operating revenue 49,642 64,635 73,523 3,542 191,342 Other operating expense 53,375 64,995 64,426 79,324 262,120 Net direct contribution 99,212 29,844 25,861 (47,849 ) 107,068 Loss on financial instruments, net — (1,087 ) (42 ) 1,129 — Change in fair value of mortgage servicing rights — 2,327 — (2,327 ) — Gain on repossessed assets, net 1,486 161 — (1,647 ) — Corporate expense allocations 9,054 16,905 10,912 (36,871 ) — Net income before taxes 91,644 14,340 14,907 (13,823 ) 107,068 Federal and state income taxes 35,650 5,578 5,799 (15,071 ) 31,956 Net income 55,994 8,762 9,108 1,248 75,112 Net income attributable to non-controlling interests — — — 835 835 Net income attributable to BOK Financial Corp. shareholders $ 55,994 $ 8,762 $ 9,108 $ 413 $ 74,277 Average assets $ 16,934,587 $ 8,827,816 $ 6,413,735 $ 470,335 $ 32,646,473 Average invested capital 1,170,465 275,358 244,291 1,667,437 3,357,551 Reportable segments reconciliation to the Consolidated Financial Statements for the nine months ended September 30, 2016 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 358,714 $ 65,897 $ 21,622 $ 106,797 $ 553,030 Net interest revenue (expense) from internal sources (44,259 ) 27,492 22,258 (5,491 ) — Net interest revenue 314,455 93,389 43,880 101,306 553,030 Provision for credit losses 34,024 4,177 (479 ) 27,278 65,000 Net interest revenue after provision for credit losses 280,431 89,212 44,359 74,028 488,030 Other operating revenue 146,248 181,774 218,042 (6,096 ) 539,968 Other operating expense 162,039 189,188 186,524 223,994 761,745 Net direct contribution 264,640 81,798 75,877 (156,062 ) 266,253 Gain (loss) on financial instruments, net — 30,539 (42 ) (30,497 ) — Change in fair value of mortgage servicing rights — (41,944 ) — 41,944 — Gain on repossessed assets, net 806 566 — (1,372 ) — Corporate expense allocations 26,681 49,513 31,864 (108,058 ) — Net income before taxes 238,765 21,446 43,971 (37,929 ) 266,253 Federal and state income taxes 92,880 8,342 17,105 (34,446 ) 83,881 Net income 145,885 13,104 26,866 (3,483 ) 182,372 Net loss attributable to non-controlling interests — — — (270 ) (270 ) Net income attributable to BOK Financial Corp. shareholders $ 145,885 $ 13,104 $ 26,866 $ (3,213 ) $ 182,642 Average assets $ 16,958,999 $ 8,763,564 $ 5,916,545 $ 410,075 $ 32,049,183 Average invested capital 1,161,996 267,123 238,917 1,650,563 3,318,599 Reportable segments reconciliation to the Consolidated Financial Statements for the three months ended September 30, 2015 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 109,503 $ 21,551 $ 6,674 $ 40,908 $ 178,636 Net interest revenue (expense) from internal sources (13,450 ) 7,216 $ 5,834 400 — Net interest revenue 96,053 28,767 12,508 41,308 178,636 Provision for credit losses 997 1,431 (190 ) 5,262 7,500 Net interest revenue after provision for credit losses 95,056 27,336 12,698 36,046 171,136 Other operating revenue 45,276 57,349 66,541 (5,730 ) 163,436 Other operating expense 51,960 51,027 57,356 64,285 224,628 Net direct contribution 88,372 33,658 21,883 (33,969 ) 109,944 Gain (loss) on financial instruments, net — 7,386 (176 ) (7,210 ) — Change in fair value of mortgage servicing rights — (11,758 ) — 11,758 — Gain on repossessed assets, net 350 331 — (681 ) — Corporate expense allocations 10,723 18,921 9,841 (39,485 ) — Net income before taxes 77,999 10,696 11,866 9,383 109,944 Federal and state income taxes 30,342 4,161 4,616 (4,991 ) 34,128 Net income 47,657 6,535 7,250 14,374 75,816 Net income attributable to non-controlling interests — — — 925 925 Net income attributable to BOK Financial Corp. shareholders $ 47,657 $ 6,535 $ 7,250 $ 13,449 $ 74,891 Average assets $ 16,156,446 $ 8,843,926 $ 5,433,238 $ 336,123 $ 30,769,733 Average invested capital 1,062,053 264,540 226,477 1,808,477 3,361,547 Reportable segments reconciliation to the Consolidated Financial Statements for the nine months ended September 30, 2015 is as follows (in thousands): Commercial Consumer Wealth Management Funds Management and Other BOK Financial Consolidated Net interest revenue from external sources $ 319,298 $ 63,993 $ 18,271 $ 120,531 $ 522,093 Net interest revenue (expense) from internal sources (38,728 ) 20,874 $ 17,400 454 — Net interest revenue 280,570 84,867 35,671 120,985 522,093 Provision for credit losses (7,952 ) 4,467 (937 ) 15,922 11,500 Net interest revenue after provision for credit losses 288,522 80,400 36,608 105,063 510,593 Other operating revenue 132,996 178,232 204,100 (9,590 ) 505,738 Other operating expense 151,908 155,844 170,113 194,141 672,006 Net direct contribution 269,610 102,788 70,595 (98,668 ) 344,325 Gain (loss) on financial instruments, net — 1,809 (204 ) (1,605 ) — Change in fair value of mortgage servicing rights — (12,269 ) — 12,269 — Gain on repossessed assets, net 336 888 — (1,224 ) — Corporate expense allocations 32,747 56,075 30,011 (118,833 ) — Net income before taxes 237,199 37,141 40,380 29,605 344,325 Federal and state income taxes 92,270 14,448 15,708 (9,284 ) 113,142 Net income 144,929 22,693 24,672 38,889 231,183 Net income attributable to non-controlling interests — — — 2,219 2,219 Net income attributable to BOK Financial Corp. shareholders $ 144,929 $ 22,693 $ 24,672 $ 36,670 $ 228,964 Average assets $ 16,229,307 $ 8,871,423 $ 5,401,433 $ (97,733 ) $ 30,404,430 Average invested capital 1,028,013 268,427 225,222 1,819,969 3,341,631

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
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, 2016 (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 $ 15,705 $ — $ 15,705 $ — U.S. government agency residential mortgage-backed securities 464,749 — 464,749 — Municipal and other tax-exempt securities 54,856 — 54,856 — Other trading securities 11,305 — 11,305 — Total trading securities 546,615 — 546,615 — Available for sale securities: U.S. Treasury 1,002 1,002 — — Municipal and other tax-exempt 42,092 — 36,379 5,713 U.S. government agency residential mortgage-backed securities 5,668,672 — 5,668,672 — Privately issued residential mortgage-backed securities 121,603 — 121,603 — Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,986,495 — 2,986,495 — Other debt securities 4,151 — — 4,151 Perpetual preferred stock 19,578 — 19,578 — Equity securities and mutual funds 18,690 3,544 15,146 — Total available for sale securities 8,862,283 4,546 8,847,873 9,864 Fair value option securities: U.S. government agency residential mortgage-backed securities — — — — U.S. Treasury 222,409 222,409 — — Total fair value option securities 222,409 222,409 — — Residential mortgage loans held for sale 447,592 — 438,291 9,301 Mortgage servicing rights 1 203,621 — — 203,621 Derivative contracts, net of cash collateral 2 655,078 5,575 649,503 — Liabilities: Derivative contracts, net of cash collateral 2 573,987 1,308 572,679 — 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 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 and energy derivative contracts, net of cash margin. The fair value of financial assets and liabilities measured on a recurring basis was as follows as of December 31, 2015 (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 $ 61,295 $ — $ 61,295 $ — U.S. government agency residential mortgage-backed securities 10,989 — 10,989 — Municipal and other tax-exempt securities 31,901 — 31,901 — Other trading securities 18,219 — 18,219 — Total trading securities 122,404 — 122,404 — Available for sale securities: U.S. Treasury 995 995 — — Municipal and other tax-exempt 56,817 — 47,207 9,610 U.S. government agency residential mortgage-backed securities 5,898,351 — 5,898,351 — Privately issued residential mortgage-backed securities 139,118 — 139,118 — Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,905,796 — 2,905,796 — Other debt securities 4,151 — — 4,151 Perpetual preferred stock 19,672 — 19,672 — Equity securities and mutual funds 17,833 3,265 14,568 — Total available for sale securities 9,042,733 4,260 9,024,712 13,761 Fair value option securities: U.S. government agency residential mortgage-backed securities 444,217 — 444,217 — U.S. Treasury — — — — Total fair value option securities 444,217 — 444,217 — Residential mortgage loans held for sale 308,439 — 300,565 7,874 Mortgage servicing rights 1 218,605 — — 218,605 Derivative contracts, net of cash collateral 2 586,270 38,530 547,740 — Liabilities: Derivative contracts, net of cash collateral 2 581,701 — 581,701 — 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 energy derivative contacts, net of cash margin. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate and agricultural derivative contracts, net of cash margin. The fair value of financial assets and liabilities measured on a recurring basis was as follows as of September 30, 2015 (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 $ 42,431 $ — $ 42,431 $ — U.S. government agency residential mortgage-backed securities 30,973 — 30,973 — Municipal and other tax-exempt securities 84,261 — 84,261 — Other trading securities 23,466 — 23,466 — Total trading securities 181,131 — 181,131 — Available for sale securities: U.S. Treasury 1,003 1,003 — — Municipal and other tax-exempt 57,960 — 48,360 9,600 U.S. government agency residential mortgage-backed securities 5,819,127 — 5,819,127 — Privately issued residential mortgage-backed securities 145,682 — 145,682 — Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,735,787 — 2,735,787 — Other debt securities 4,150 — — 4,150 Perpetual preferred stock 19,163 — 19,163 — Equity securities and mutual funds 18,217 3,505 14,712 — Total available for sale securities 8,801,089 4,508 8,782,831 13,750 Fair value option securities: U.S. government agency residential mortgage-backed securities 427,760 — 427,760 — U.S. Treasury — — — — Total fair value option securities 427,760 — 427,760 — Residential mortgage loans held for sale 357,414 — 349,381 8,033 Mortgage servicing rights 1 200,049 — — 200,049 Derivative contracts, net of cash collateral 2 726,159 4,922 721,237 — Liabilities: Derivative contracts, net of cash collateral 2 636,115 — 636,115 — 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 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) were exchange-traded interest rate derivative 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 months ended September 30, 2016 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 Other debt securities Residential mortgage loans held for sale Balance, June 30, 2016 $ 9,600 $ 4,151 $ 9,749 Transfer to Level 3 from Level 2 — — 442 Purchases — — — Proceeds from sales — — (1,003 ) Redemptions and distributions (3,975 ) — — Gain (loss) recognized in earnings: Mortgage banking revenue — — 113 Other comprehensive income (loss): Net change in unrealized gain (loss) 88 — — Balance, Sept. 30, 2016 $ 5,713 $ 4,151 $ 9,301 The following represents the changes for the nine months ended September 30, 2016 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 Other debt securities Residential mortgage loans held for sale Balance, Dec. 31, 2015 $ 9,610 $ 4,151 $ 7,874 Transfer to Level 3 from Level 2 — — 3,982 Purchases — — — Proceeds from sales — — (2,365 ) Redemptions and distributions (3,975 ) — — Gain (loss) recognized in earnings: Mortgage banking revenue — — (190 ) Other comprehensive income (loss): Net change in unrealized gain (loss) 78 — — Balance, Sept. 30, 2016 $ 5,713 $ 4,151 $ 9,301 The following represents the changes for the three months ended September 30, 2015 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 Other debt securities Residential mortgage loans held for sale Balance, June 30, 2015 $ 9,617 $ 4,150 $ 7,973 Transfer to Level 3 from Level 2 — — 966 Purchases — — — Proceeds from sales — — (811 ) Redemptions and distributions — — — Gain (loss) recognized in earnings: Mortgage banking revenue — — (95 ) Other comprehensive income (loss): Net change in unrealized gain (loss) (17 ) — — Balance, Sept. 30, 2015 $ 9,600 $ 4,150 $ 8,033 The following represents the changes for the nine months ended September 30, 2015 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 Other debt securities Residential mortgage loans held for sale Balance, Dec. 31, 2014 $ 10,093 $ 4,150 $ 11,856 Transfer to Level 3 from Level 2 — — 2,153 Purchases — — — Proceeds from sales — — (6,099 ) Redemptions and distributions (500 ) — — Gain (loss) recognized in earnings — Mortgage banking revenue — — 123 Other comprehensive income (loss): Net change in unrealized gain (loss) 7 — — Balance, Sept. 30, 2015 $ 9,600 $ 4,150 $ 8,033
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, 2016 follows (in thousands): Par Value Amortized Cost/Unpaid Principal Balance Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Available for sale securities Municipal and other tax-exempt securities $ 6,195 $ 6,162 $ 5,713 Discounted cash flows 1 Interest rate spread 5.60%-5.90% (5.85%) 2 90.00%-93.79% (92.22%) 3 Other debt securities 4,400 4,400 4,151 Discounted cash flows 1 Interest rate spread 5.98%-6.03% (6.02%) 4 94.34% - 94.34 (94.34%) 3 Residential mortgage loans held for sale N/A 9,957 9,301 Quoted prices of loans sold in securitization transactions, with a liquidity discount applied Liquidity discount applied to the market value of a mortgage loans qualifying for sale to U.S. government agencies. 93.41% 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 Interest rate yields used to value investment grade tax-exempt securities represent a spread of 437 to 484 basis points over average yields for comparable tax-exempt securities. 3 Represents fair value as a percentage of par value. 4 Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 1 percent . A summary of quantitative information about Recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of December 31, 2015 follows (in thousands): Par Value Amortized Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Available for sale securities Municipal and other tax-exempt securities $ 10,370 $ 10,311 $ 9,610 Discounted cash flows 1 Interest rate spread 5.47%-5.77% (5.73%) 2 92.34%-92.93% (92.67%) 3 Other debt securities 4,400 4,400 4,151 Discounted cash flows 1 Interest rate spread 5.80%-5.92% (5.90%) 4 94.33% - 94.34 (94.34%) 3 Residential mortgage loans held for sale N/A 8,395 7,874 Quoted prices of loans sold in securitization transactions, with a liquidity discount applied Liquidity discount applied to the market value of a mortgage loans qualifying for sale to U.S. government agencies. 93.79% 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 Interest rate yields used to value investment grade tax-exempt securities represent a spread of 499 to 541 basis points over average yields for comparable tax-exempt securities. 3 Represents fair value as a percentage of par value. 4 Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 1 percent . A summary of quantitative information about Recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of September 30, 2015 follows (in thousands): Par Value Amortized Cost Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Available for sale securities Municipal and other tax-exempt securities $ 10,370 $ 10,310 $ 9,600 Discounted cash flows 1 Interest rate spread 5.23%-5.53% (5.49%) 2 92.35%-92.73% (92.57%) 3 Other debt securities 4,400 4,400 4,150 Discounted cash flows 1 Interest rate spread 5.65%-5.70% (5.69%) 4 94.32% - 94.33 (94.33%) 3 Residential mortgage loans held for sale N/A 8,538 8,033 Quoted prices of loans sold in securitization transactions, with a liquidity discount applied Liquidity discount applied to the market value of a mortgage loans qualifying for sale to U.S. government agencies. 94.09% 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 Interest rate yields used to value investment grade tax-exempt securities represent a spread of 510 to 538 basis points over average yields for comparable tax-exempt securities. 3 Represents fair value as a percentage of par value. 4 Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 1 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, 2016 for which the fair value was adjusted during the three and nine months ended September 30, 2016 : Fair Value Adjustments for the Carrying Value at September 30, 2016 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 expenses of repossessed assets, net Gross charge-offs against allowance for loan losses Net losses and expenses of repossessed assets, net Impaired loans $ — $ 436 $ 23,089 $ 6,334 $ — $ 30,200 $ — Real estate and other repossessed assets — 6,048 1,927 — 480 — 1,260 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, 2015 for which the fair value was adjusted during the three and nine months ended September 30, 2015 : Fair Value Adjustments for the Carrying Value at September 30, 2015 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 expenses of repossessed assets, net Gross charge-offs against allowance for loan losses Net losses and expenses of repossessed assets, net Impaired loans $ — $ 3,239 $ 12,386 $ 890 $ — $ 1,439 $ — Real estate and other repossessed assets — 12,689 702 — 670 — 1,771
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, 2016 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Impaired loans $ 23,089 Discounted cash flows Recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs 23% - 59% (43%) 1 Real estate and other repossessed assets 1,927 Appraised value, as adjusted Marketability adjustment off appraised value 2 68% - 80% (71%) 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, 2015 follows (in thousands): Fair Value Valuation Technique(s) Unobservable Input Range (Weighted Average) Impaired loans $ 12,386 Appraised value, as adjusted Broker quotes and management's knowledge of industry and collateral N/A Real estate and other repossessed assets 702 Appraised value, as adjusted Marketability adjustments off appraised value1 66%-86% (78%) 1 Marketability adjustments include consideration of estimated costs to sell which is approximately 10% of the fair value.
Fair Value of Financial Instruments [Table Text Block]	The following table presents the carrying values and estimated fair values of all financial instruments, including those financial assets and liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis as of September 30, 2016 (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 $ 535,916 $ 535,916 $ 535,916 $ — $ — Interest-bearing cash and cash equivalents 2,080,978 2,080,978 2,080,978 — — Trading securities: — U.S. government agency debentures 15,705 15,705 — 15,705 — U.S. government agency residential mortgage-backed securities 464,749 464,749 — 464,749 — Municipal and other tax-exempt securities 54,856 54,856 — 54,856 — Other trading securities 11,305 11,305 — 11,305 — Total trading securities 546,615 546,615 — 546,615 — Investment securities: Municipal and other tax-exempt 323,225 327,788 — 327,788 — U.S. government agency residential mortgage-backed securities 22,166 23,452 — 23,452 — Other debt securities 201,066 229,070 — 229,070 — Total investment securities 546,457 580,310 — 580,310 — Available for sale securities: U.S. Treasury 1,002 1,002 1,002 — — Municipal and other tax-exempt 42,092 42,092 — 36,379 5,713 U.S. government agency residential mortgage-backed securities 5,668,672 5,668,672 — 5,668,672 — Privately issued residential mortgage-backed securities 121,603 121,603 — 121,603 — Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,986,495 2,986,495 — 2,986,495 — Other debt securities 4,151 4,151 — — 4,151 Perpetual preferred stock 19,578 19,578 — 19,578 — Equity securities and mutual funds 18,690 18,690 3,544 15,146 — Total available for sale securities 8,862,283 8,862,283 4,546 8,847,873 9,864 Fair value option securities: U.S. government agency residential mortgage-backed securities — — — — — U.S. Treasury 222,409 222,409 222,409 — — Total fair value option securities 222,409 222,409 222,409 — — Residential mortgage loans held for sale 447,592 447,592 — 438,291 9,301 Loans: Commercial 10,120,163 9,926,548 — — 9,926,548 Commercial real estate 3,793,598 3,769,427 — — 3,769,427 Residential mortgage 1,872,793 1,905,786 — — 1,905,786 Personal 678,232 671,421 — — 671,421 Total loans 16,464,786 16,273,182 — — 16,273,182 Allowance for loan losses (245,103 ) — — — — Loans, net of allowance 16,219,683 16,273,182 — — 16,273,182 Mortgage servicing rights 203,621 203,621 — — 203,621 Derivative instruments with positive fair value, net of cash margin 655,078 655,078 5,575 649,503 — Deposits with no stated maturity 18,925,873 18,925,873 — — 18,925,873 Time deposits 2,169,631 2,163,947 — — 2,163,947 Other borrowed funds 7,147,047 7,079,737 — — 7,079,737 Subordinated debentures 144,631 148,360 — 148,360 — Derivative instruments with negative fair value, net of cash margin 573,987 573,987 1,308 572,679 — 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, 2015 (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 $ 573,699 $ 573,699 $ 573,699 $ — $ — Interest-bearing cash and cash equivalents 2,069,900 2,069,900 2,069,900 — — Trading securities: — U.S. government agency debentures 61,295 61,295 — 61,295 — U.S. government agency residential mortgage-backed securities 10,989 10,989 — 10,989 — Municipal and other tax-exempt securities 31,901 31,901 — 31,901 — Other trading securities 18,219 18,219 — 18,219 — Total trading securities 122,404 122,404 — 122,404 — Investment securities: Municipal and other tax-exempt 365,258 368,910 — 368,910 — U.S. government agency residential mortgage-backed securities 26,833 27,874 — 27,874 — Other debt securities 205,745 232,375 — 232,375 — Total investment securities 597,836 629,159 — 629,159 — Available for sale securities: U.S. Treasury 995 995 995 — — Municipal and other tax-exempt 56,817 56,817 — 47,207 9,610 U.S. government agency residential mortgage-backed securities 5,898,351 5,898,351 — 5,898,351 — Privately issued residential mortgage-backed securities 139,118 139,118 — 139,118 — Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,905,796 2,905,796 — 2,905,796 — Other debt securities 4,151 4,151 — — 4,151 Perpetual preferred stock 19,672 19,672 — 19,672 — Equity securities and mutual funds 17,833 17,833 3,265 14,568 — Total available for sale securities 9,042,733 9,042,733 4,260 9,024,712 13,761 Fair value option securities: U.S. government agency residential mortgage-backed securities 444,217 444,217 — 444,217 — U.S. Treasury — — — — — Total fair value option securities 444,217 444,217 — 444,217 — Residential mortgage loans held for sale 308,439 308,439 — 300,565 7,874 Loans: Commercial 10,252,531 10,053,952 — — 10,053,952 Commercial real estate 3,259,033 3,233,476 — — 3,233,476 Residential mortgage 1,876,893 1,902,976 — — 1,902,976 Personal 552,697 549,068 — — 549,068 Total loans 15,941,154 15,739,472 — — 15,739,472 Allowance for loan losses (225,524 ) — — — — Loans, net of allowance 15,715,630 15,739,472 — — 15,739,472 Mortgage servicing rights 218,605 218,605 — — 218,605 Derivative instruments with positive fair value, net of cash margin 586,270 586,270 38,530 547,740 — Deposits with no stated maturity 18,682,094 18,682,094 — — 18,682,094 Time deposits 2,406,064 2,394,562 — — 2,394,562 Other borrowed funds 6,051,515 5,600,932 — — 5,600,932 Subordinated debentures 226,350 223,758 — — 223,758 Derivative instruments with negative fair value, net of cash margin 581,701 581,701 — 581,701 — 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, 2015 (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 $ 489,268 $ 489,268 $ 489,268 $ — $ — Interest-bearing cash and cash equivalents 1,830,105 1,830,105 1,830,105 — — Trading securities: — U.S. government agency debentures 42,431 42,431 — 42,431 — U.S. government agency residential mortgage-backed securities 30,973 30,973 — 30,973 — Municipal and other tax-exempt securities 84,261 84,261 — 84,261 — Other trading securities 23,466 23,466 — 23,466 — Total trading securities 181,131 181,131 — 181,131 — Investment securities: Municipal and other tax-exempt 379,980 384,310 — 384,310 — U.S. government agency residential mortgage-backed securities 28,653 30,080 — 30,080 — Other debt securities 203,751 228,701 — 228,701 — Total investment securities 612,384 643,091 — 643,091 — Available for sale securities: U.S. Treasury 1,003 1,003 1,003 — — Municipal and other tax-exempt 57,960 57,960 — 48,360 9,600 U.S. government agency residential mortgage-backed securities 5,819,127 5,819,127 — 5,819,127 — Privately issued residential mortgage-backed securities 145,682 145,682 — 145,682 — Commercial mortgage-backed securities guaranteed by U.S. government agencies 2,735,787 2,735,787 — 2,735,787 — Other debt securities 4,150 4,150 — — 4,150 Perpetual preferred stock 19,163 19,163 — 19,163 — Equity securities and mutual funds 18,217 18,217 3,505 14,712 — Total available for sale securities 8,801,089 8,801,089 4,508 8,782,831 13,750 Fair value option securities: U.S. government agency residential mortgage-backed securities 427,760 427,760 — 427,760 — U.S. Treasury — — — — — Total fair value option securities 427,760 427,760 — 427,760 — Residential mortgage loans held for sale 357,414 357,414 — 349,381 8,033 Loans: Commercial 9,797,422 9,530,437 — — 9,530,437 Commercial real estate 3,235,067 3,330,298 — — 3,330,298 Residential mortgage 1,868,995 1,906,585 — — 1,906,585 Personal 465,957 462,266 — — 462,266 Total loans 15,367,441 15,229,586 — — 15,229,586 Allowance for loan losses (204,116 ) — — — — Loans, net of allowance 15,163,325 15,229,586 — — 15,229,586 Mortgage servicing rights 200,049 200,049 — — 200,049 Derivative instruments with positive fair value, net of cash margin 726,159 726,159 4,922 721,237 — Deposits with no stated maturity 18,120,912 18,120,912 — — 18,120,912 Time deposits 2,498,531 2,500,469 — — 2,500,469 Other borrowed funds 5,253,124 5,239,400 — — 5,239,400 Subordinated debentures 226,314 223,334 — — 223,334 Derivative instruments with negative fair value, net of cash margin 636,115 636,115 — 636,115 —
Fair Value Inputs, Financial Instruments, Quantitative Information [Table Text Block]	Range of Contractual Yields Average Re-pricing (in years) Discount Rate Minimum Maximum Average Minimum Maximum September 30, 2016 Commercial 0.38 % 30.00 % 0.69 0.54 % 3.93 % Commercial real estate 0.38 % 18.00 % 0.72 0.80 % 3.90 % Residential mortgage 1.74 % 18.00 % 1.95 1.57 % 3.55 % Consumer 0.25 % 21.00 % 0.35 0.75 % 4.15 % Time deposits 0.03 % 9.65 % 2.10 1.37 % 1.66 % Other borrowings 0.25 % 3.81 % 0.02 0.29 % 2.99 % Subordinated debentures 5.38 % 5.38 % 18.37 5.38 % 5.38 % December 31, 2015 Commercial 0.25 % 30.00 % 0.62 0.52 % 4.34 % Commercial real estate 0.38 % 18.00 % 0.73 0.95 % 3.93 % Residential mortgage 1.67 % 18.00 % 2.42 0.86 % 4.25 % Consumer 0.38 % 21.00 % 0.37 1.19 % 4.11 % Time deposits 0.02 % 5.50 % 1.78 1.11 % 1.57 % Other borrowings 0.25 % 3.40 % 0.00 0.20 % 2.89 % Subordinated debentures 1.05 % 1.05 % 1.37 2.12 % 2.12 % September 30, 2015 Commercial 0.19 % 30.00 % 0.63 0.47 % 4.06 % Commercial real estate 0.38 % 18.00 % 0.77 0.92 % 3.60 % Residential mortgage 1.25 % 18.00 % 2.34 0.86 % 3.94 % Consumer 0.38 % 21.00 % 0.40 0.89 % 3.86 % Time deposits 0.02 % 9.64 % 1.75 0.85 % 1.25 % Other borrowings 0.25 % 3.34 % 0.02 0.07 % 2.66 % Subordinated debentures 1.01 % 1.01 % 1.63 1.83 % 1.83 %

Significant Accounting Polici30

Significant Accounting Policies Loans and Allowance for Credit Losses (Details)	9 Months Ended
	Sep. 30, 2016
Loans and Allowance for Credit Losses [Abstract]
Loans, Number of Days Past Due for a Non-Risk Graded Loan to be Placed on Nonaccruing Status	90 days
Loans, Number of Days After Notification of Chapter 7 Bankruptcy Non-Risk Graded Loan is Placed on Nonaccruing Status	60 days
Loans and Allowances for Credit Losses, Minimum No of Days After Which Past Due Non-Risk Graded Loans Are Charged Off	60 days
Loans and Allowances for Credit Losses, Maximum No of Days After Which Past Due Non-Risk Graded Loans Are Charged Off	180 days
Loans, Number of Days After Notification of Chapter 7 Bankruptcy Non-Risk Graded Loan is Charged Off	60 days

Trading Securities (Details)

Trading Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Schedule of Trading Securities [Line Items]
Trading Securities, Fair Value	$ 546,615	$ 122,404	$ 181,131
Trading Securities, Net Unrealized Gain (Loss)	783	140	606
U.S. government agency debentures
Schedule of Trading Securities [Line Items]
Trading Securities, Fair Value	15,705	61,295	42,431
Trading Securities, Net Unrealized Gain (Loss)	(7)	(71)	(38)
U.S. government agency residential mortgage-backed securities
Schedule of Trading Securities [Line Items]
Trading Securities, Fair Value	464,749	10,989	30,973
Trading Securities, Net Unrealized Gain (Loss)	876	17	195
Municipal and other tax-exempt securities
Schedule of Trading Securities [Line Items]
Trading Securities, Fair Value	54,856	31,901	84,261
Trading Securities, Net Unrealized Gain (Loss)	(100)	210	421
Other trading securities
Schedule of Trading Securities [Line Items]
Trading Securities, Fair Value	11,305	18,219	23,466
Trading Securities, Net Unrealized Gain (Loss)	$ 14	$ (16)	$ 28

Investment (Held-to-Maturity) S

Investment (Held-to-Maturity) Securities (Details) $ in Thousands		9 Months Ended
		Sep. 30, 2016USD ($)		Dec. 31, 2015USD ($)		Sep. 30, 2015USD ($)
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Amortized Cost		$ 546,457		$ 597,724		$ 612,187
Investments Securities, Carrying Value		546,457		597,836		612,384
Investment Securities, fair value		580,310		629,159		643,091
Investment Securities, Gross Unrealized Gain		34,045	[1]	31,687	[2]	30,951	[3]
Investment Securities, Gross Unrealized Loss		(192)	[1]	(364)	[2]	(244)	[3]
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investments Securities, Debt Maturities, Carrying Value		546,457		597,836		612,384
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Fair Value		$ 580,310		629,159		643,091
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Nominal Yield		3.46%
Investment Securities, Pledged as Collateral [Abstract]
Investment Securities, Pledged as Collateral, Carrying Value		$ 301,754		231,033		50,380
Investment Securities, Pledged as Collateral, Fair Value		$ 307,264		$ 234,382		$ 52,249
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		78		85		32
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 101,068		$ 133,934		$ 7,533
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		5,215		15,095		18,015
Investment Securities, Continuous Unrealized Loss Position, Fair Value		106,283		149,029		25,548
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		112		270		145
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		80		95		99
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss		192		365		244
Other than Temporary Impairment Losses, Investment Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Investment Securities, Portfolio Concentration Rated AAA to AA, Carrying Value		348,065
Investment Securities, Portfolio Concentration Rated AAA to AA, Fair Value		373,328
Investment Securities, Portfolio Concentration Rated A to BBB, Carrying Value		5,094
Investment Securities, Portfolio Concentration Rated A to BBB, Fair Value		5,160
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Carrying Value		0
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value		0
Investment Securities, Portfolio Concentration Not Rated, Carrying Value		193,298
Investment Securities, Portfolio Concentration Not Rated, Fair Value		201,822
Fixed Maturity Securities [Member]
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Net Carrying Value		102,377
Investment Securities, Debt Maturities, One to Five Years, Net Carrying Value		238,077
Investment Securities, Debt Maturities, Six to Ten Years, Net Carrying Value		134,733
Investment Securities, Debt Maturities, Over Ten Years, Net Carrying Value		49,104
Investment Securities, Debt Maturities, Single Maturity Date, Net Carrying Value		524,291
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Fair Value		102,522
Investment Securities, Debt Maturities, One to Five Years, Fair Value		242,666
Investment Securities, Debt Maturities, Six to Ten Years, Fair Value		157,445
Investment Securities, Debt Maturities, Over Ten Years, Fair Value		54,225
Investment Securities, Debt Maturities, Single Maturity Date, Fair Value		$ 556,858
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Nominal Yield		1.72%
Investment Securities, Debt Maturities, One to Five Years, Nominal Yield		2.54%
Investment Securities, Debt Maturities, Six to Ten Years, Nominal Yield		5.70%
Investment Securities, Debt Maturities, Over Ten Years, Nominal Yield		5.64%
Investment Securities, Debt Maturities, Nominal Yield		3.48%
Investment Securities, Debt Maturities, Weighted Average Maturity	[4]	4.32
Municipal and other tax-exempt securities
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Amortized Cost		$ 323,225		365,258		379,980
Investments Securities, Carrying Value		323,225		365,258		379,980
Investment Securities, fair value		327,788		368,910		384,310
Investment Securities, Gross Unrealized Gain		4,745	[1]	3,935	[2]	4,461	[3]
Investment Securities, Gross Unrealized Loss		(182)	[1]	(283)	[2]	(131)	[3]
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Net Carrying Value		87,330
Investment Securities, Debt Maturities, One to Five Years, Net Carrying Value		195,763
Investment Securities, Debt Maturities, Six to Ten Years, Net Carrying Value		8,778
Investment Securities, Debt Maturities, Over Ten Years, Net Carrying Value		31,354
Investment Securities, Debt Maturities, Single Maturity Date, Net Carrying Value		323,225
Investments Securities, Debt Maturities, Carrying Value		323,225		365,258		379,980
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Fair Value		87,331
Investment Securities, Debt Maturities, One to Five Years, Fair Value		196,864
Investment Securities, Debt Maturities, Six to Ten Years, Fair Value		9,023
Investment Securities, Debt Maturities, Over Ten Years, Fair Value		34,570
Investment Securities, Debt Maturities, Single Maturity Date, Fair Value		327,788
Investment Securities, Debt Maturities, Fair Value		$ 327,788		$ 368,910		$ 384,310
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Nominal Yield	[5]	1.42%
Investment Securities, Debt Maturities, One to Five Years, Nominal Yield	[5]	2.01%
Investment Securities, Debt Maturities, Six to Ten Years, Nominal Yield	[5]	3.20%
Investment Securities, Debt Maturities, Over Ten Years, Nominal Yield	[5]	6.08%
Investment Securities, Debt Maturities, Nominal Yield	[5]	2.28%
Investment Securities, Debt Maturities, Weighted Average Maturity	[4]	2.76
Investment Securities,Debt Maturities, Effective tax rate for nominal yield calculation		39.00%
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		75		73		15
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 100,624		$ 127,319		$ 6,250
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		4,359		13,380		13,438
Investment Securities, Continuous Unrealized Loss Position, Fair Value		104,983		140,699		19,688
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		106		207		81
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		76		77		50
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss		182		284		131
Other than Temporary Impairment Losses, Investment Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Investment Securities, Portfolio Concentration Rated AAA to AA, Carrying Value		207,881
Investment Securities, Portfolio Concentration Rated AAA to AA, Fair Value		209,210
Investment Securities, Portfolio Concentration Rated A to BBB, Carrying Value		5,094
Investment Securities, Portfolio Concentration Rated A to BBB, Fair Value		5,160
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Carrying Value		0
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value		0
Investment Securities, Portfolio Concentration Not Rated, Carrying Value		110,250
Investment Securities, Portfolio Concentration Not Rated, Fair Value		113,418
Other debt securities
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Amortized Cost		201,066		205,745		203,751
Investments Securities, Carrying Value		201,066		205,745		203,751
Investment Securities, fair value		229,070		232,375		228,701
Investment Securities, Gross Unrealized Gain		28,014	[1]	26,689	[2]	25,063	[3]
Investment Securities, Gross Unrealized Loss		(10)	[1]	(59)	[2]	(113)	[3]
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Net Carrying Value		15,047
Investment Securities, Debt Maturities, One to Five Years, Net Carrying Value		42,314
Investment Securities, Debt Maturities, Six to Ten Years, Net Carrying Value		125,955
Investment Securities, Debt Maturities, Over Ten Years, Net Carrying Value		17,750
Investment Securities, Debt Maturities, Single Maturity Date, Net Carrying Value		201,066
Investments Securities, Debt Maturities, Carrying Value		201,066		205,745		203,751
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Fair Value		15,191
Investment Securities, Debt Maturities, One to Five Years, Fair Value		45,802
Investment Securities, Debt Maturities, Six to Ten Years, Fair Value		148,422
Investment Securities, Debt Maturities, Over Ten Years, Fair Value		19,655
Investment Securities, Debt Maturities, Single Maturity Date, Fair Value		229,070
Investment Securities, Debt Maturities, Fair Value		$ 229,070		$ 232,375		$ 228,701
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Nominal Yield		3.49%
Investment Securities, Debt Maturities, One to Five Years, Nominal Yield		5.03%
Investment Securities, Debt Maturities, Six to Ten Years, Nominal Yield		5.88%
Investment Securities, Debt Maturities, Over Ten Years, Nominal Yield		4.86%
Investment Securities, Debt Maturities, Nominal Yield		5.43%
Investment Securities, Debt Maturities, Weighted Average Maturity	[4]	6.84
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		3		11		17
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 444		$ 1,082		$ 1,283
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		856		1,715		4,577
Investment Securities, Continuous Unrealized Loss Position, Fair Value		1,300		2,797		5,860
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		6		41		64
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		4		18		49
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss		10		59		113
Other than Temporary Impairment Losses, Investment Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Investment Securities, Portfolio Concentration Rated AAA to AA, Carrying Value		140,184
Investment Securities, Portfolio Concentration Rated AAA to AA, Fair Value		164,118
Investment Securities, Portfolio Concentration Rated A to BBB, Carrying Value		0
Investment Securities, Portfolio Concentration Rated A to BBB, Fair Value		0
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Carrying Value		0
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value		0
Investment Securities, Portfolio Concentration Not Rated, Carrying Value		60,882
Investment Securities, Portfolio Concentration Not Rated, Fair Value		64,952
U.S. government agency residential mortgage-backed securities
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investment Securities, Debt Maturities, without Single Maturity Date, Net Carrying Value		22,166
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, without Single Maturity Date, Fair Value		$ 23,452
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Nominal Yield	[6]	2.75%
Investment Securities, Debt Maturities, Average Expected Life of Mortgage-backed Securities		4 years 109 days
U.S. government agency residential mortgage-backed securities | Other [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Amortized Cost		$ 22,166		26,721		28,456
Investments Securities, Carrying Value		22,166	[7]	26,833		28,653
Investment Securities, fair value		23,452	[7]	27,874		30,080
Investment Securities, Gross Unrealized Gain		1,286	[1]	1,063	[2]	1,427	[3]
Investment Securities, Gross Unrealized Loss		0	[1]	(22)	[2]	0	[3]
Investment Securities, Debt Maturities, Net Carrying Value [Abstract]
Investments Securities, Debt Maturities, Carrying Value		22,166	[7]	26,833		28,653
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Fair Value		$ 23,452	[7]	$ 27,874		$ 30,080
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		0		1		0
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 0		$ 5,533		$ 0
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0		0		0
Investment Securities, Continuous Unrealized Loss Position, Fair Value		0		5,533		0
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0		22		0
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0		0		0
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss		0		$ 22		$ 0
Other than Temporary Impairment Losses, Investment Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Investment Securities, Portfolio Concentration Rated AAA to AA, Carrying Value	[7]	0
Investment Securities, Portfolio Concentration Rated AAA to AA, Fair Value	[7]	0
Investment Securities, Portfolio Concentration Rated A to BBB, Carrying Value	[7]	0
Investment Securities, Portfolio Concentration Rated A to BBB, Fair Value	[7]	0
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Carrying Value	[7]	0
Investment Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	[7]	0
Investment Securities, Portfolio Concentration Not Rated, Carrying Value	[7]	22,166
Investment Securities, Portfolio Concentration Not Rated, Fair Value	[7]	$ 23,452
[1]	Gross unrealized gains and losses are not recognized in Accumulated Other Comprehensive Income "AOCI" in the Consolidated Balance Sheets.
[2]	Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets.
[3]	Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets.
[4]	Expected maturities may differ from contractual maturities, because borrowers may have the right to call or prepay obligations with or without penalty.
[5]	Calculated on a taxable equivalent basis using a 39 percent effective tax rate.
[6]	The nominal yield on residential mortgage-backed securities is based upon prepayment assumptions at the purchase date. Actual yields earned may differ significantly based upon actual prepayments. See Quarterly Financial Summary - Unaudited for current yields on the investment securities portfolio.
[7]	U.S. government and government sponsored enterprises are not rated by the nationally-recognized rating agencies as these securities are guaranteed by agencies of the U.S. government or government-sponsored enterprises.

Available for Sale Securities (

Available for Sale Securities (Details) $ in Thousands		3 Months Ended						9 Months Ended				93 Months Ended
		Sep. 30, 2016USD ($)		Dec. 31, 2015USD ($)		Sep. 30, 2015USD ($)		Sep. 30, 2016USD ($)		Sep. 30, 2015USD ($)		Sep. 30, 2016USD ($)
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		$ 8,702,750		$ 9,004,624		$ 8,656,205		$ 8,702,750		$ 8,656,205		$ 8,702,750
Available-for-sale Securities, Fair Value		8,862,283		9,042,733		8,801,089		8,862,283		8,801,089		8,862,283
Available-for-sale Securities, Gross Unrealized Gain		165,765	[1]	79,970	[2]	152,797	[3]	165,765	[1]	152,797	[3]	165,765	[1]
Available-for-sale Securities, Gross Unrealized Loss		(6,028)	[1]	(41,034)	[2]	(6,896)	[3]	(6,028)	[1]	(6,896)	[3]	(6,028)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		(204)	[4]	(827)	[5]	(1,017)	[6]	(204)	[4]	(1,017)	[6]	(204)	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Amortized Cost		8,702,750		9,004,624		8,656,205		8,702,750		8,656,205		8,702,750
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Fair Value		$ 8,862,283		9,042,733		8,801,089		$ 8,862,283		8,801,089		$ 8,862,283
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Nominal Yield		1.84%						1.84%				1.84%
Available-for-sale Securities, Gross Realized Gain (Loss), Disclosures [Abstract]
Available-for-sale Securities, Proceeds		$ 232,239				450,765		$ 1,027,379		1,164,425
Available-for-sale Securities, Gross realized gains		2,415				3,803		11,705		13,543
Available-for-sale Securities, Gross realized losses		(21)				(1,637)		(21)		(3,617)
Available-for-sale Securities, Related federal and state income tax expense		931				843		4,545		3,861
Available-for-sale Securities, Pledged as Collateral [Abstract]
Available-for-sale Securities, Pledged As Collateral, Amortized cost		7,098,721		6,831,743		6,225,689		7,098,721		6,225,689		$ 7,098,721
Available-for-sale Securities, Pledged As Collateral, Fair value		$ 7,213,520		$ 6,849,524		$ 6,318,330		$ 7,213,520		$ 6,318,330		$ 7,213,520
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		130		419		115		130		115		130
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 1,107,872		$ 3,873,809		$ 632,216		$ 1,107,872		$ 632,216		$ 1,107,872
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		327,297		716,700		323,379		327,297		323,379		327,297
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		1,435,169		4,590,509		955,595		1,435,169		955,595		1,435,169
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		4,786		28,496		5,400		4,786		5,400		4,786
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		1,446		13,365		2,513		1,446		2,513		1,446
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		6,232		41,861		7,913		6,232		7,913		6,232
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost		28,241						28,241				28,241
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value		29,032						29,032				29,032
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost		10,471						10,471				10,471
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value		10,821						10,821				10,821
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost		119,182						119,182				119,182
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value		135,676						135,676				135,676
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost		8,544,856						8,544,856				8,544,856
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value		8,686,754						8,686,754				8,686,754
Fixed Maturity Securities [Member]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost Basis		9,089						9,089				9,089
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost Basis		946,354						946,354				946,354
Available-for-sale Securities, Debt Maturities, Six To Ten Years, Amortized Cost Basis		1,819,258						1,819,258				1,819,258
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost Basis		215,630						215,630				215,630
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis		2,990,331						2,990,331				2,990,331
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Fair Value		9,190						9,190				9,190
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value		957,854						957,854				957,854
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value		1,850,571						1,850,571				1,850,571
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value		216,125						216,125				216,125
Available-for-sale Securities, Debt Maturities, Single Maturity Date		$ 3,033,740						$ 3,033,740				$ 3,033,740
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield		4.97%						4.97%				4.97%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield		1.77%						1.77%				1.77%
Available-for-sale Securities, Debt Maturities, Six To Ten Years, Nominal Yield		1.85%						1.85%				1.85%
Available-for-sale Securities, Debt Maturities, Over Ten Years, Nominal Yield		1.61%						1.61%				1.61%
Available-for-sale Securities, Debt Maturities, Nominal Yield		1.81%						1.81%				1.81%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	[7]	6.87						6.87				6.87
U.S. Treasury
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		$ 1,000		1,000		1,000		$ 1,000		1,000		$ 1,000
Available-for-sale Securities, Fair Value		1,002		995		1,003		1,002		1,003		1,002
Available-for-sale Securities, Gross Unrealized Gain		2	[1]	0	[2]	3	[3]	2	[1]	3	[3]	2	[1]
Available-for-sale Securities, Gross Unrealized Loss		0	[1]	(5)	[2]	0	[3]	0	[1]	0	[3]	0	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		0	[4]	0	[5]	0	[6]	0	[4]	0	[6]	0	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost Basis		0						0				0
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost Basis		1,000						1,000				1,000
Available-for-sale Securities, Debt Maturities, Six To Ten Years, Amortized Cost Basis		0						0				0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost Basis		0						0				0
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis		1,000						1,000				1,000
Available-for-sale Securities, Debt Maturities, Amortized Cost		1,000		1,000		1,000		1,000		1,000		1,000
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Fair Value		0						0				0
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value		1,002						1,002				1,002
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value		0						0				0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value		0						0				0
Available-for-sale Securities, Debt Maturities, Single Maturity Date		1,002						1,002				1,002
Available-for-sale Securities, Debt Maturities, Fair Value		$ 1,002		$ 995		1,003		$ 1,002		1,003		$ 1,002
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield		0.00%						0.00%				0.00%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield		0.87%						0.87%				0.87%
Available-for-sale Securities, Debt Maturities, Six To Ten Years, Nominal Yield		0.00%						0.00%				0.00%
Available-for-sale Securities, Debt Maturities, Over Ten Years, Nominal Yield		0.00%						0.00%				0.00%
Available-for-sale Securities, Debt Maturities, Nominal Yield		0.87%						0.87%				0.87%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	[7]	1.29						1.29				1.29
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions				1
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value				$ 995
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value				0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value				995
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss				5
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss				0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss				5
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost		$ 0						$ 0				$ 0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost		1,000						1,000				1,000
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value		1,002						1,002				1,002
Municipal and other tax-exempt securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		41,943		56,681		57,610		41,943		57,610		41,943
Available-for-sale Securities, Fair Value		42,092		56,817		57,960		42,092		57,960		42,092
Available-for-sale Securities, Gross Unrealized Gain		602	[1]	873	[2]	1,065	[3]	602	[1]	1,065	[3]	602	[1]
Available-for-sale Securities, Gross Unrealized Loss		(453)	[1]	(737)	[2]	(715)	[3]	(453)	[1]	(715)	[3]	(453)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		0	[4]	0	[5]	0	[6]	0	[4]	0	[6]	0	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost Basis		9,089						9,089				9,089
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost Basis		13,593						13,593				13,593
Available-for-sale Securities, Debt Maturities, Six To Ten Years, Amortized Cost Basis		2,092						2,092				2,092
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost Basis		17,169						17,169				17,169
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis		41,943						41,943				41,943
Available-for-sale Securities, Debt Maturities, Amortized Cost		41,943		56,681		57,610		41,943		57,610		41,943
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Fair Value		9,190						9,190				9,190
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value		13,858						13,858				13,858
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value		2,109						2,109				2,109
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value		16,935						16,935				16,935
Available-for-sale Securities, Debt Maturities, Single Maturity Date		42,092						42,092				42,092
Available-for-sale Securities, Debt Maturities, Fair Value		$ 42,092		$ 56,817		$ 57,960		$ 42,092		$ 57,960		$ 42,092
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield	[8]	4.97%						4.97%				4.97%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	[8]	3.85%						3.85%				3.85%
Available-for-sale Securities, Debt Maturities, Six To Ten Years, Nominal Yield	[8]	3.46%						3.46%				3.46%
Available-for-sale Securities, Debt Maturities, Over Ten Years, Nominal Yield	[8],[9]	2.36%						2.36%				2.36%
Available-for-sale Securities, Debt Maturities, Nominal Yield	[8]	3.46%						3.46%				3.46%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	[7]	8.14						8.14				8.14
Available-for-sale Securities, Debt Maturities, Effective tax rate for nominal yield calculation		39.00%						39.00%				39.00%
Available-for-sale Securities, Debt Maturities, Number of days for interest rates to reset		35 days
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		20		20		18		20		18		20
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 2,210		$ 9,909		$ 7,868		$ 2,210		$ 7,868		$ 2,210
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		6,396		11,664		3,800		6,396		3,800		6,396
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		8,606		21,573		11,668		8,606		11,668		8,606
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		3		27		485		3		485		3
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		450		710		230		450		230		450
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		453		737		715		453		715		453
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost		23,837						23,837				23,837
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value		24,290						24,290				24,290
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost		5,675						5,675				5,675
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value		5,316						5,316				5,316
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost		12,431						12,431				12,431
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value		12,486						12,486				12,486
Commercial mortgage-backed securities guaranteed by U.S. government agencies
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		2,942,988		2,919,044		2,708,931		2,942,988		2,708,931		2,942,988
Available-for-sale Securities, Fair Value		2,986,495		2,905,796		2,735,787		2,986,495		2,735,787		2,986,495
Available-for-sale Securities, Gross Unrealized Gain		45,329	[1]	5,396	[2]	28,889	[3]	45,329	[1]	28,889	[3]	45,329	[1]
Available-for-sale Securities, Gross Unrealized Loss		(1,822)	[1]	(18,644)	[2]	(2,033)	[3]	(1,822)	[1]	(2,033)	[3]	(1,822)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		0	[4]	0	[5]	0	[6]	0	[4]	0	[6]	0	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost Basis		0						0				0
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost Basis		931,761						931,761				931,761
Available-for-sale Securities, Debt Maturities, Six To Ten Years, Amortized Cost Basis		1,817,166						1,817,166				1,817,166
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost Basis		194,061						194,061				194,061
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis		2,942,988						2,942,988				2,942,988
Available-for-sale Securities, Debt Maturities, Amortized Cost		2,942,988		2,919,044		2,708,931		2,942,988		2,708,931		2,942,988
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Fair Value		0						0				0
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value		942,994						942,994				942,994
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value		1,848,462						1,848,462				1,848,462
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value		195,039						195,039				195,039
Available-for-sale Securities, Debt Maturities, Single Maturity Date		2,986,495						2,986,495				2,986,495
Available-for-sale Securities, Debt Maturities, Fair Value		$ 2,986,495		$ 2,905,796		$ 2,735,787		$ 2,986,495		$ 2,735,787		$ 2,986,495
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield		0.00%						0.00%				0.00%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield		1.74%						1.74%				1.74%
Available-for-sale Securities, Debt Maturities, Six To Ten Years, Nominal Yield		1.84%						1.84%				1.84%
Available-for-sale Securities, Debt Maturities, Over Ten Years, Nominal Yield		1.54%						1.54%				1.54%
Available-for-sale Securities, Debt Maturities, Nominal Yield		1.79%						1.79%				1.79%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	[7]	6.82						6.82				6.82
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		33		213		31		33		31		33
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 372,805		$ 1,582,469		$ 327,790		$ 372,805		$ 327,790		$ 372,805
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		60,851		484,258		223,007		60,851		223,007		60,851
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		433,656		2,066,727		550,797		433,656		550,797		433,656
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		1,656		11,419		1,488		1,656		1,488		1,656
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		166		7,225		545		166		545		166
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		1,822		18,644		2,033		1,822		2,033		1,822
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost		2,942,988						2,942,988				2,942,988
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value		2,986,495						2,986,495				2,986,495
Other debt securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		4,400		4,400		4,400		4,400		4,400		4,400
Available-for-sale Securities, Fair Value		4,151		4,151		4,150		4,151		4,150		4,151
Available-for-sale Securities, Gross Unrealized Gain		0	[1]	0	[2]	0	[3]	0	[1]	0	[3]	0	[1]
Available-for-sale Securities, Gross Unrealized Loss		(249)	[1]	(249)	[2]	(250)	[3]	(249)	[1]	(250)	[3]	(249)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		0	[4]	0	[5]	0	[6]	0	[4]	0	[6]	0	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost Basis		0						0				0
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost Basis		0						0				0
Available-for-sale Securities, Debt Maturities, Six To Ten Years, Amortized Cost Basis		0						0				0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost Basis		4,400						4,400				4,400
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis		4,400						4,400				4,400
Available-for-sale Securities, Debt Maturities, Amortized Cost		4,400		4,400		4,400		4,400		4,400		4,400
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Fair Value		0						0				0
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value		0						0				0
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value		0						0				0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value		4,151						4,151				4,151
Available-for-sale Securities, Debt Maturities, Single Maturity Date		4,151						4,151				4,151
Available-for-sale Securities, Debt Maturities, Fair Value		$ 4,151		$ 4,151		$ 4,150		$ 4,151		$ 4,150		$ 4,151
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield		0.00%						0.00%				0.00%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield		0.00%						0.00%				0.00%
Available-for-sale Securities, Debt Maturities, Six To Ten Years, Nominal Yield		0.00%						0.00%				0.00%
Available-for-sale Securities, Debt Maturities, Over Ten Years, Nominal Yield	[9]	1.71%						1.71%				1.71%
Available-for-sale Securities, Debt Maturities, Nominal Yield		1.71%						1.71%				1.71%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	[7]	30.91						30.91				30.91
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		2		2		2		2		2		2
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 0		$ 0		$ 0		$ 0		$ 0		$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		4,151		4,151		4,149		4,151		4,149		4,151
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		4,151		4,151		4,149		4,151		4,149		4,151
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0		0		0		0		0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		249		249		250		249		250		249
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		249		249		250		249		250		249
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost		4,400						4,400				4,400
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value		4,151						4,151				4,151
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value		0						0				0
Residential Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		5,679,520		5,989,207		5,848,382		5,679,520		5,848,382		5,679,520
Available-for-sale Securities, Fair Value		5,790,275		6,037,469		5,964,809		5,790,275		5,964,809		5,790,275
Available-for-sale Securities, Gross Unrealized Gain		114,446	[1]	70,448	[2]	119,860	[3]	114,446	[1]	119,860	[3]	114,446	[1]
Available-for-sale Securities, Gross Unrealized Loss		(3,487)	[1]	(21,359)	[2]	(2,416)	[3]	(3,487)	[1]	(2,416)	[3]	(3,487)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		(204)	[4]	(827)	[5]	(1,017)	[6]	(204)	[4]	(1,017)	[6]	(204)	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis		5,679,520						5,679,520				5,679,520
Available-for-sale Securities, Debt Maturities, Amortized Cost		5,679,520		5,989,207		5,848,382		5,679,520		5,848,382		5,679,520
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value		5,790,275						5,790,275				5,790,275
Available-for-sale Securities, Debt Maturities, Fair Value		$ 5,790,275		$ 6,037,469		$ 5,964,809		$ 5,790,275		$ 5,964,809		$ 5,790,275
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Nominal Yield	[10]	1.87%						1.87%				1.87%
Available-for-sale Securities, Debt Maturities, Average Expected Life of Mortgage-backed Securities								3 years 164 days
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		42		122		26		42		26		42
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 732,771		$ 2,279,654		$ 290,615		$ 732,771		$ 290,615		$ 732,771
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		255,013		215,636		91,897		255,013		91,897		255,013
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		987,784		2,495,290		382,512		987,784		382,512		987,784
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		3,127		17,040		1,957		3,127		1,957		3,127
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		564		5,146		1,476		564		1,476		564
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		3,691		22,186		3,433		3,691		3,433		3,691
U.S. government agency residential mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		5,571,104	[11]	5,861,096		5,714,323		5,571,104	[11]	5,714,323		5,571,104	[11]
Available-for-sale Securities, Fair Value		5,668,672	[11]	5,898,351		5,819,127		5,668,672	[11]	5,819,127		5,668,672	[11]
Available-for-sale Securities, Gross Unrealized Gain		101,029	[1]	58,614	[2]	107,220	[3]	101,029	[1]	107,220	[3]	101,029	[1]
Available-for-sale Securities, Gross Unrealized Loss		(3,461)	[1]	(21,359)	[2]	(2,416)	[3]	(3,461)	[1]	(2,416)	[3]	(3,461)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		0	[4]	0	[5]	0	[6]	0	[4]	0	[6]	0	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Amortized Cost		5,571,104	[11]	5,861,096		5,714,323		5,571,104	[11]	5,714,323		5,571,104	[11]
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Fair Value		$ 5,668,672	[11]	$ 5,898,351		$ 5,819,127		$ 5,668,672	[11]	$ 5,819,127		$ 5,668,672	[11]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		36		110		14		36		14		36
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 717,957		$ 2,279,654		$ 282,378		$ 717,957		$ 282,378		$ 717,957
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		247,240		197,890		81,549		247,240		81,549		247,240
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		965,197		2,477,544		363,927		965,197		363,927		965,197
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		2,960		17,040		1,535		2,960		1,535		2,960
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		501		4,319		881		501		881		501
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		3,461		21,359		2,416		3,461		2,416		3,461
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	[11]	0						0				0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	[11]	0						0				0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	[11]	0						0				0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	[11]	0						0				0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	[11]	0						0				0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	[11]	0						0				0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	[11]	5,571,104						5,571,104				5,571,104
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	[11]	5,668,672						5,668,672				5,668,672
U.S. government agency residential mortgage-backed securities | Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		3,035,041		3,156,214		3,115,810		3,035,041		3,115,810		3,035,041
Available-for-sale Securities, Fair Value		3,101,136		3,187,215		3,185,097		3,101,136		3,185,097		3,101,136
Available-for-sale Securities, Gross Unrealized Gain		67,859	[1]	41,502	[2]	69,757	[3]	67,859	[1]	69,757	[3]	67,859	[1]
Available-for-sale Securities, Gross Unrealized Loss		(1,764)	[1]	(10,501)	[2]	(470)	[3]	(1,764)	[1]	(470)	[3]	(1,764)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		0	[4]	0	[5]	0	[6]	0	[4]	0	[6]	0	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Amortized Cost		3,035,041		3,156,214		3,115,810		3,035,041		3,115,810		3,035,041
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Fair Value		$ 3,101,136		$ 3,187,215		$ 3,185,097		$ 3,101,136		$ 3,185,097		$ 3,101,136
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		14		55		6		14		6		14
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 365,201		$ 1,188,022		$ 155,747		$ 365,201		$ 155,747		$ 365,201
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		14,229		18,236		0		14,229		0		14,229
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		379,430		1,206,258		155,747		379,430		155,747		379,430
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		1,712		10,262		470		1,712		470		1,712
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		52		239		0		52		0		52
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		1,764		10,501		470		1,764		470		1,764
U.S. government agency residential mortgage-backed securities | Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		1,611,887		1,940,915		1,853,379		1,611,887		1,853,379		1,611,887
Available-for-sale Securities, Fair Value		1,641,178		1,949,335		1,885,201		1,641,178		1,885,201		1,641,178
Available-for-sale Securities, Gross Unrealized Gain		29,640	[1]	14,727	[2]	32,646	[3]	29,640	[1]	32,646	[3]	29,640	[1]
Available-for-sale Securities, Gross Unrealized Loss		(349)	[1]	(6,307)	[2]	(824)	[3]	(349)	[1]	(824)	[3]	(349)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		0	[4]	0	[5]	0	[6]	0	[4]	0	[6]	0	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Amortized Cost		1,611,887		1,940,915		1,853,379		1,611,887		1,853,379		1,611,887
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Fair Value		$ 1,641,178		$ 1,949,335		$ 1,885,201		$ 1,641,178		$ 1,885,201		$ 1,641,178
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		6		40		4		6		4		6
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 122,713		$ 726,713		$ 71,930		$ 122,713		$ 71,930		$ 122,713
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		20,306		77,545		26,848		20,306		26,848		20,306
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		143,019		804,258		98,778		143,019		98,778		143,019
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		91		4,827		503		91		503		91
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		258		1,480		321		258		321		258
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		349		6,307		824		349		824		349
U.S. government agency residential mortgage-backed securities | Government National Mortgage Association Certificates and Obligations (GNMA) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		924,176		763,967		741,212		924,176		741,212		924,176
Available-for-sale Securities, Fair Value		926,358		761,801		744,647		926,358		744,647		926,358
Available-for-sale Securities, Gross Unrealized Gain		3,530	[1]	2,385	[2]	4,557	[3]	3,530	[1]	4,557	[3]	3,530	[1]
Available-for-sale Securities, Gross Unrealized Loss		(1,348)	[1]	(4,551)	[2]	(1,122)	[3]	(1,348)	[1]	(1,122)	[3]	(1,348)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		0	[4]	0	[5]	0	[6]	0	[4]	0	[6]	0	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Amortized Cost		924,176		763,967		741,212		924,176		741,212		924,176
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Fair Value		$ 926,358		$ 761,801		$ 744,647		$ 926,358		$ 744,647		$ 926,358
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		16		15		4		16		4		16
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 230,043		$ 364,919		$ 54,701		$ 230,043		$ 54,701		$ 230,043
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		212,705		102,109		54,701		212,705		54,701		212,705
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		442,748		467,028		109,402		442,748		109,402		442,748
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		1,157		1,951		562		1,157		562		1,157
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		191		2,600		560		191		560		191
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		1,348		4,551		1,122		1,348		1,122		1,348
U.S. government agency residential mortgage-backed securities | Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		0		0		3,922		0		3,922		0
Available-for-sale Securities, Fair Value		0		0		4,182		0		4,182		0
Available-for-sale Securities, Gross Unrealized Gain		0	[1]	0	[2]	260	[3]	0	[1]	260	[3]	0	[1]
Available-for-sale Securities, Gross Unrealized Loss		0	[1]	0	[2]	0	[3]	0	[1]	0	[3]	0	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		0	[4]	0	[5]	0	[6]	0	[4]	0	[6]	0	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Amortized Cost		0		0		3,922		0		3,922		0
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Fair Value		0		0		4,182		0		4,182		0
Privately issued residential mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		108,416		128,111		134,059		108,416		134,059		108,416
Available-for-sale Securities, Fair Value		121,603		139,118		145,682		121,603		145,682		121,603
Available-for-sale Securities, Gross Unrealized Gain		13,417	[1]	11,834	[2]	12,640	[3]	13,417	[1]	12,640	[3]	13,417	[1]
Available-for-sale Securities, Gross Unrealized Loss		(26)	[1]	0	[2]	0	[3]	(26)	[1]	0	[3]	(26)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		(204)	[4]	(827)	[5]	(1,017)	[6]	(204)	[4]	(1,017)	[6]	(204)	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Amortized Cost		108,416		128,111		134,059		108,416		134,059		108,416
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Fair Value		$ 121,603		$ 139,118		$ 145,682		$ 121,603		$ 145,682		$ 121,603
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		6	[12]	12	[13]	12	[14]	6	[12]	12	[14]	6	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 14,814	[12]	$ 0	[13]	$ 8,237	[14]	$ 14,814	[12]	$ 8,237	[14]	$ 14,814	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		7,773	[12]	17,746	[13]	10,348	[14]	7,773	[12]	10,348	[14]	7,773	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		22,587	[12]	17,746	[13]	18,585	[14]	22,587	[12]	18,585	[14]	22,587	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		167	[12]	0	[13]	422	[14]	167	[12]	422	[14]	167	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		63	[12]	827	[13]	595	[14]	63	[12]	595	[14]	63	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		230	[12]	$ 827	[13]	$ 1,017	[14]	230	[12]	1,017	[14]	230	[12]
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost		108,416						108,416				108,416
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value		121,603						121,603				121,603
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value		$ 0						$ 0				$ 0
Other Than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Assumptions Used to Develop Projected Cash Flows [Abstract]
Unemployment rate		Moving down to 4.7 percent over the next 12 months and remain at 4.7 percent thereafter.		Decreasing to 4.8 percent over the next 12 months and remain at 4.8 percent thereafter.		Moving down to 5.1 percent over the next 12 months and remain at 5.1 percent thereafter.
Housing price appreciation/depreciation	[15]	Starting with current depreciated housing prices based on information derived from the FHFA1, appreciating 3.5 percent over the next 12 months, then flat for the following 12 months and then appreciating at 2 percent per year thereafter.		Starting with current depreciated housing prices based on information derived from the FHFA1, appreciating 3.5 percent over the next 12 months, then flat for the following 12 months and then appreciating at 2 percent per year thereafter.		Starting with current depreciated housing prices based on information derived from the FHFA1, appreciating 3.2 percent over the next 12 months, then flat for the following 12 months and then appreciating at 2 percent per year thereafter.
Estimated liquidation costs		Reflect actual historical liquidations costs observed on Jumbo and Alt-A residential mortgage loans in securities owned by the Company.		Reflect actual historical liquidations costs observed on Jumbo and Alt-A residential mortgage loans in securities owned by the Company.		Reflect actual historical liquidations costs observed on Jumbo and Alt-A residential mortgage loans in securities owned by the Company.
Discount rates		Estimated cash flows were discounted at rates that range from 2.00 percent to 6.25 percent based on our current expected yields.		Estimated cash flows were discounted at rates that range from 2.00 percent to 6.25 percent based on our current expected yields.		Estimated cash flows were discounted at rates that range from 2.00 percent to 6.25 percent based on our current expected yields.
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized in Earnings, Net Qualitative Disclosures, Privately Issued Mortgage-backed Securities [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities		44						44				44
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Credit losses Recognized [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities with Credit Losses In Current Period		0										43
Amount of Credit Losses Recognized in Current Period		$ 0										$ 54,504
Privately issued residential mortgage-backed securities | Alt A loans Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		47,039		$ 56,387		$ 58,801		$ 47,039		58,801		47,039
Available-for-sale Securities, Fair Value		54,065		62,574		64,700		54,065		64,700		54,065
Available-for-sale Securities, Gross Unrealized Gain		7,230	[1]	6,574	[2]	6,519	[3]	7,230	[1]	6,519	[3]	7,230	[1]
Available-for-sale Securities, Gross Unrealized Loss		0	[1]	0	[2]	0	[3]	0	[1]	0	[3]	0	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		(204)	[4]	(387)	[5]	(620)	[6]	(204)	[4]	(620)	[6]	(204)	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Amortized Cost		47,039		56,387		58,801		47,039		58,801		47,039
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Fair Value		$ 54,065		$ 62,574		$ 64,700		$ 54,065		$ 64,700		$ 54,065
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		5	[12]	4	[13]	4	[14]	5	[12]	4	[14]	5	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 8,231	[12]	$ 0	[13]	$ 2,857	[14]	$ 8,231	[12]	$ 2,857	[14]	$ 8,231	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		7,773	[12]	9,264	[13]	6,667	[14]	7,773	[12]	6,667	[14]	7,773	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		16,004	[12]	9,264	[13]	9,524	[14]	16,004	[12]	9,524	[14]	16,004	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		141	[12]	0	[13]	186	[14]	141	[12]	186	[14]	141	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		63	[12]	387	[13]	434	[14]	63	[12]	434	[14]	63	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		$ 204	[12]	387	[13]	620	[14]	$ 204	[12]	620	[14]	$ 204	[12]
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized in Earnings, Net Qualitative Disclosures, Privately Issued Mortgage-backed Securities [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities		14						14				14
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Credit losses Recognized [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities with Credit Losses In Current Period		0										14
Amount of Credit Losses Recognized in Current Period		$ 0										$ 36,284
Privately issued residential mortgage-backed securities | Jumbo A loans [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		61,377		71,724		75,258		$ 61,377		75,258		61,377
Available-for-sale Securities, Fair Value		67,538		76,544		80,982		67,538		80,982		67,538
Available-for-sale Securities, Gross Unrealized Gain		6,187	[1]	5,260	[2]	6,121	[3]	6,187	[1]	6,121	[3]	6,187	[1]
Available-for-sale Securities, Gross Unrealized Loss		(26)	[1]	0	[2]	0	[3]	(26)	[1]	0	[3]	(26)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		0	[4]	(440)	[5]	(397)	[6]	0	[4]	(397)	[6]	0	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Amortized Cost		61,377		71,724		75,258		61,377		75,258		61,377
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Fair Value		$ 67,538		$ 76,544		$ 80,982		$ 67,538		$ 80,982		$ 67,538
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		1	[12]	8	[13]	8	[14]	1	[12]	8	[14]	1	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 6,583	[12]	$ 0	[13]	$ 5,380	[14]	$ 6,583	[12]	$ 5,380	[14]	$ 6,583	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0	[12]	8,482	[13]	3,681	[14]	0	[12]	3,681	[14]	0	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		6,583	[12]	8,482	[13]	9,061	[14]	6,583	[12]	9,061	[14]	6,583	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		26	[12]	0	[13]	236	[14]	26	[12]	236	[14]	26	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0	[12]	440	[13]	161	[14]	0	[12]	161	[14]	0	[12]
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		$ 26	[12]	440	[13]	397	[14]	$ 26	[12]	397	[14]	$ 26	[12]
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized in Earnings, Net Qualitative Disclosures, Privately Issued Mortgage-backed Securities [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities		30						30				30
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Credit losses Recognized [Abstract]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities with Credit Losses In Current Period		0										29
Amount of Credit Losses Recognized in Current Period		$ 0										$ 18,220
Perpetual Preferred, Equity Securities and Mutual Funds [Member]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis		32,899						$ 32,899				32,899
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value		$ 38,268						$ 38,268				$ 38,268
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Nominal Yield		0.00%						0.00%				0.00%
Perpetual preferred stock
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		$ 15,562		17,171		17,171		$ 15,562		17,171		$ 15,562
Available-for-sale Securities, Fair Value		19,578		19,672		19,163		19,578		19,163		19,578
Available-for-sale Securities, Gross Unrealized Gain		4,016	[1]	2,501	[2]	2,030	[3]	4,016	[1]	2,030	[3]	4,016	[1]
Available-for-sale Securities, Gross Unrealized Loss		0	[1]	0	[2]	(38)	[3]	0	[1]	(38)	[3]	0	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		0	[4]	0	[5]	0	[6]	0	[4]	0	[6]	0	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Amortized Cost		15,562		17,171		17,171		15,562		17,171		15,562
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Fair Value		$ 19,578		$ 19,672		$ 19,163		$ 19,578		$ 19,163		$ 19,578
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		0		0		1		0		1		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 0		$ 0		$ 1,912		$ 0		$ 1,912		$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0		0		0		0		0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		0		0		1,912		0		1,912		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0		0		38		0		38		0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0		0		0		0		0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		0		0		38		0		38		0
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost		4,796						4,796				4,796
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value		5,505						5,505				5,505
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost		10,766						10,766				10,766
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value		14,073						14,073				14,073
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value		0						0				0
Equity securities and mutual funds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost		17,337		17,121		18,711		17,337		18,711		17,337
Available-for-sale Securities, Fair Value		18,690		17,833		18,217		18,690		18,217		18,690
Available-for-sale Securities, Gross Unrealized Gain		1,370	[1]	752	[2]	950	[3]	1,370	[1]	950	[3]	1,370	[1]
Available-for-sale Securities, Gross Unrealized Loss		(17)	[1]	(40)	[2]	(1,444)	[3]	(17)	[1]	(1,444)	[3]	(17)	[1]
Available-for-Sale Securities, Other Than Temporary Impairments		0	[4]	0	[5]	0	[6]	0	[4]	0	[6]	0	[4]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Amortized Cost		17,337		17,121		18,711		17,337		18,711		17,337
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Fair Value		$ 18,690		$ 17,833		$ 18,217		$ 18,690		$ 18,217		$ 18,690
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions		33		61		37		33		37		33
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		$ 86		$ 782		$ 4,031		$ 86		$ 4,031		$ 86
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		886		991		526		886		526		886
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		972		1,773		4,557		972		4,557		972
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0		5		1,432		0		1,432		0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		17		35		12		17		12		17
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		17		$ 40		$ 1,444		17		$ 1,444		17
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities, Portion Recognized In Earnings, Net Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost		4						4				4
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value		591						591				591
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost		0						0				0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value		0						0				0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost		17,333						17,333				17,333
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value		$ 18,099						$ 18,099				$ 18,099
[1]	Gross unrealized gain/loss recognized in AOCI in the consolidated balance sheet.
[2]	Gross unrealized gain/loss recognized in AOCI in the consolidated balance sheet.
[3]	Gross unrealized gain/loss recognized in AOCI in the consolidated balance sheet.
[4]	Amounts represent unrealized loss that remains in AOCI after an other-than-temporary credit loss has been recognized in income.
[5]	Amounts represent unrealized loss that remains in AOCI after an other-than-temporary credit loss has been recognized in income.
[6]	Amounts represent unrealized loss that remains in AOCI after an other-than-temporary credit loss has been recognized in income.
[7]	Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without penalty.
[8]	Calculated on a taxable equivalent basis using a 39 percent effective tax rate.
[9]	Nominal yield on municipal and other tax-exempt securities and other debt securities with contractual maturity dates over ten years are based on variable rates which generally are reset within 35 days.
[10]	The nominal yield on mortgage-backed securities is based upon prepayment assumptions at the purchase date. Actual yields earned may differ significantly based upon actual prepayments. See Quarterly Financial Summary –– Unaudited following for current yields on available for sale securities portfolio.
[11]	U.S. government and government sponsored enterprises are not rated by the nationally-recognized rating agencies as these securities are guaranteed by agencies of the U.S. government or government-sponsored enterprises.
[12]	Includes securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income.
[13]	Includes securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income.
[14]	Includes securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income.
[15]	Federal Housing Finance Agency

Rollforward of Credit-Related O

Rollforward of Credit-Related Other-than-temporary Impairment Recognized in Earnings (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance of credit-related OTTI recognized on available for sale debt securities, beginning of period	$ 54,504	$ 54,439	$ 54,504	$ 54,347
Additions for credit-related OTTI not previously recognized	0	0	0	0
Additions for increases in credit-related OTTI previously recognized when there is no itnent to sell and no requirement to sell before recovery of amortized cost	0	0	0	92
Reductions for change in intent to hold before recovery	0	0	0	0
Sales	0	0	0	0
Balance of credit-related OTTI recognized on available for sale debt securities, end of period	$ 54,504	$ 54,439	$ 54,504	$ 54,439

Securities Fair Value Option Se

Securities Fair Value Option Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Schedule of Fair Value Option Securities [Line Items]
Fair Value Option Securities, Fair Value	$ 222,409	$ 444,217	$ 427,760
Fair Value Option Securities, Net Unrealized Gain or Loss	(2,397)	(2,060)	2,067
U.S. Treasury
Schedule of Fair Value Option Securities [Line Items]
Fair Value Option Securities, Fair Value	222,409	0	0
Fair Value Option Securities, Net Unrealized Gain or Loss	(2,397)	0	0
U.S. government agency residential mortgage-backed securities
Schedule of Fair Value Option Securities [Line Items]
Fair Value Option Securities, Fair Value	0	444,217	427,760
Fair Value Option Securities, Net Unrealized Gain or Loss	$ 0	$ (2,060)	$ 2,067

Securities Restricted Equity Se

Securities Restricted Equity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Restricted Equity Securities [Abstract]
Federal Reserve stock	$ 36,283	$ 36,148	$ 35,148
Federal Home Loan Bank stock	296,907	237,365	228,268
Other	201	171	171
Total	$ 333,391	$ 273,684	$ 263,587

Derivatives, Fair Value of Deri

Derivatives, Fair Value of Derivatives Contracts (Details) - USD ($) $ in Thousands		Sep. 30, 2016		Dec. 31, 2015		Sep. 30, 2015
Derivative Assets, Fair Value, Net [Abstract]
Derviative contracts, net of cash collateral, Assets, Fair value		$ 655,078		$ 586,270		$ 726,159
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Fair Value, Net of Cash Collateral		573,987		581,701		636,115
Increase in cash margin obligation for derivative holdings with a decrease in credit rating from A1 to below investment grade		18,000
Not Designated as Hedging Instrument [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	[1]	25,136,553		17,153,221		18,911,244
Derivative Liabilities, Notional		23,988,858	[2]	16,785,014	[1]	18,819,086	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value		734,256		663,343		838,694
Derivative Assets, Netting Adjustments		(68,713)		(52,433)		(83,433)
Derivative Assets, Net Fair Value Before Cash Collateral		665,543		610,910		755,261
Derivative Assets, Cash Collateral		(10,465)		(24,640)		(29,102)
Derviative contracts, net of cash collateral, Assets, Fair value		655,078		586,270		726,159
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value		725,452		659,171		831,115
Derivative Liabilities, Netting Adjustments		(68,713)		(52,433)		(83,433)
Derivative Liabilities, Net Fair Value Before Cash Collateral		656,739		606,738		747,682
Derivative Liabilities, Cash Collateral		(82,752)		(25,037)		(111,567)
Derivative Liabilities, Fair Value, Net of Cash Collateral		573,987		581,701		636,115
Not Designated as Hedging Instrument [Member] | To-be-announced residential mortgage-backed securities
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	[1]	20,078,974		14,583,052		16,093,704
Derivative Liabilities, Notional		19,776,883	[2]	14,168,927	[3]	16,050,271	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value		90,999		43,270		136,435
Derivative Assets, Netting Adjustments		(38,678)		(28,305)		(50,845)
Derivative Assets, Net Fair Value Before Cash Collateral		52,321		14,965		85,590
Derivative Assets, Cash Collateral		0		0		0
Derviative contracts, net of cash collateral, Assets, Fair value		52,321		14,965		85,590
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value		86,812		40,141		133,543
Derivative Liabilities, Netting Adjustments		(38,678)		(28,305)		(50,845)
Derivative Liabilities, Net Fair Value Before Cash Collateral		48,134		11,836		82,698
Derivative Liabilities, Cash Collateral		(39,042)		(1,308)		(82,225)
Derivative Liabilities, Fair Value, Net of Cash Collateral		9,092		10,528		473
Not Designated as Hedging Instrument [Member] | Interest rate swaps
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	[3]	1,323,045		1,332,044		1,345,779
Derivative Liabilities, Notional		1,323,045	[2]	1,332,044	[3]	1,345,779	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value		49,279		31,744		42,636
Derivative Assets, Netting Adjustments		0		0		0
Derivative Assets, Net Fair Value Before Cash Collateral		49,279		31,744		42,636
Derivative Assets, Cash Collateral		(794)		(1,424)		0
Derviative contracts, net of cash collateral, Assets, Fair value		48,485		30,320		42,636
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value		49,518		31,928		42,901
Derivative Liabilities, Netting Adjustments		0		0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral		49,518		31,928		42,901
Derivative Liabilities, Cash Collateral		(34,457)		(20,530)		(26,723)
Derivative Liabilities, Fair Value, Net of Cash Collateral		15,061		11,398		16,178
Not Designated as Hedging Instrument [Member] | Energy contracts
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	[1]	729,202		470,613		560,997
Derivative Liabilities, Notional		695,835	[2]	463,703	[3]	551,989	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value		41,775		83,045		89,948
Derivative Assets, Netting Adjustments		(28,464)		(22,970)		(28,535)
Derivative Assets, Net Fair Value Before Cash Collateral		13,311		60,075		61,413
Derivative Assets, Cash Collateral		(288)		(18,606)		(23,089)
Derviative contracts, net of cash collateral, Assets, Fair value		13,023		41,469		38,324
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value		40,888		81,869		85,856
Derivative Liabilities, Netting Adjustments		(28,464)		(22,970)		(28,535)
Derivative Liabilities, Net Fair Value Before Cash Collateral		12,424		58,899		57,321
Derivative Liabilities, Cash Collateral		(3,857)		0		0
Derivative Liabilities, Fair Value, Net of Cash Collateral		8,567		58,899		57,321
Not Designated as Hedging Instrument [Member] | Agricultural contracts
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	[1]	53,002		61,662		101,321
Derivative Liabilities, Notional		52,997	[2]	61,657	[3]	101,325	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value		3,950		2,591		8,064
Derivative Assets, Netting Adjustments		(1,571)		(1,158)		(4,053)
Derivative Assets, Net Fair Value Before Cash Collateral		2,379		1,433		4,011
Derivative Assets, Cash Collateral		(1,076)		0		(1,558)
Derviative contracts, net of cash collateral, Assets, Fair value		1,303		1,433		2,453
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value		3,943		2,579		8,045
Derivative Liabilities, Netting Adjustments		(1,571)		(1,158)		(4,053)
Derivative Liabilities, Net Fair Value Before Cash Collateral		2,372		1,421		3,992
Derivative Liabilities, Cash Collateral		0		(1,248)		0
Derivative Liabilities, Fair Value, Net of Cash Collateral		2,372		173		3,992
Not Designated as Hedging Instrument [Member] | Foreign exchange contracts
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	[1]	550,828		546,572		618,991
Derivative Liabilities, Notional		550,943	[2]	546,405	[3]	618,770	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value		536,264		498,830		557,313
Derivative Assets, Netting Adjustments		0		0		0
Derivative Assets, Net Fair Value Before Cash Collateral		536,264		498,830		557,313
Derivative Assets, Cash Collateral		(7,577)		(4,140)		(3,985)
Derviative contracts, net of cash collateral, Assets, Fair value		528,687		494,690		553,328
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value		536,660		498,574		556,890
Derivative Liabilities, Netting Adjustments		0		0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral		536,660		498,574		556,890
Derivative Liabilities, Cash Collateral		(5,396)		(1,951)		(2,619)
Derivative Liabilities, Fair Value, Net of Cash Collateral		531,264		496,623		554,271
Not Designated as Hedging Instrument [Member] | Equity option contracts
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	[1]	103,464		137,278		143,452
Derivative Liabilities, Notional		103,464	[2]	137,278	[3]	143,452	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value		4,654		3,780		3,784
Derivative Assets, Netting Adjustments		0		0		0
Derivative Assets, Net Fair Value Before Cash Collateral		4,654		3,780		3,784
Derivative Assets, Cash Collateral		(730)		(470)		(470)
Derviative contracts, net of cash collateral, Assets, Fair value		3,924		3,310		3,314
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value		4,654		3,780		3,784
Derivative Liabilities, Netting Adjustments		0		0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral		4,654		3,780		3,784
Derivative Liabilities, Cash Collateral		0		0		0
Derivative Liabilities, Fair Value, Net of Cash Collateral		4,654		3,780		3,784
Not Designated as Hedging Instrument [Member] | Total customer risk management programs
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	[1]	22,838,515		17,131,221		18,864,244
Derivative Liabilities, Notional		22,503,167	[2]	16,710,014	[3]	18,811,586	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value		726,921		663,260		838,180
Derivative Assets, Netting Adjustments		(68,713)		(52,433)		(83,433)
Derivative Assets, Net Fair Value Before Cash Collateral		658,208		610,827		754,747
Derivative Assets, Cash Collateral		(10,465)		(24,640)		(29,102)
Derviative contracts, net of cash collateral, Assets, Fair value		647,743		586,187		725,645
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value		722,475		658,871		831,019
Derivative Liabilities, Netting Adjustments		(68,713)		(52,433)		(83,433)
Derivative Liabilities, Net Fair Value Before Cash Collateral		653,762		606,438		747,586
Derivative Liabilities, Cash Collateral		(82,752)		(25,037)		(111,567)
Derivative Liabilities, Fair Value, Net of Cash Collateral		571,010		581,401		636,019
Not Designated as Hedging Instrument [Member] | Internal risk management programs
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	[1]	2,298,038		22,000		47,000
Derivative Liabilities, Notional		1,485,691	[2]	75,000	[3]	7,500	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value		7,335		83		514
Derivative Assets, Netting Adjustments		0		0		0
Derivative Assets, Net Fair Value Before Cash Collateral		7,335		83		514
Derivative Assets, Cash Collateral		0		0		0
Derviative contracts, net of cash collateral, Assets, Fair value		7,335		83		514
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Gross Fair Value		2,977		300		96
Derivative Liabilities, Netting Adjustments		0		0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral		2,977		300		96
Derivative Liabilities, Cash Collateral		0		0		0
Derivative Liabilities, Fair Value, Net of Cash Collateral		$ 2,977		$ 300		$ 96
[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.
[3]	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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	$ 12,151	$ 9,093	$ 34,510	$ 31,080
Gain (Loss) on Derivatives, Net	2,226	1,283	20,130	1,162
To-be-announced residential mortgage-backed securities
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	11,584	7,914	28,886	25,942
Gain (Loss) on Derivatives, Net	0	0	0	0
Interest rate swaps
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	710	411	1,758	1,495
Gain (Loss) on Derivatives, Net	0	0	0	0
Energy contracts
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	1,222	771	4,667	3,138
Gain (Loss) on Derivatives, Net	0	0	0	0
Agricultural contracts
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	25	44	86	86
Gain (Loss) on Derivatives, Net	0	0	0	0
Foreign exchange contracts
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	218	152	730	618
Gain (Loss) on Derivatives, Net	0	0	0	0
Equity option contracts
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	13,759	9,292	36,127	31,279
Gain (Loss) on Derivatives, Net	0	0	0	0
Internal risk management programs
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Brokergage and Trading Revenue	(1,608)	(199)	(1,617)	(199)
Gain (Loss) on Derivatives, Net	$ 2,226	$ 1,283	$ 20,130	$ 1,162

Loans and Allowance for Credit

Loans and Allowance for Credit Losses, Loans by Portfolio Type (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest		$ 4,233,548	$ 4,169,034	$ 4,168,141
Loans, variable rate of interest		11,994,286	11,624,992	11,109,952
Loans, non-accrual		236,952	147,128	89,348
Total		16,464,786	15,941,154	15,367,441
Accruing loans past due (90 days)	[1]	3,839	1,207	101
Credit Commitments [Abstract]
Outstanding commitments to extend credit		8,700,000
Outstanding standby letters of credit		500,000
Outstanding commercial letters of credit		5,200
Texas [Member] | Geographic Concentration Risk [Member]
Loan receivables disclosure [Abstract]
Total		$ 5,300,000
Loans receivable, other information [Abstract]
Percentage of loan portfolio attributed to Texas (in hundredths)		32.00%
Oklahoma [Member] | Geographic Concentration Risk [Member]
Loan receivables disclosure [Abstract]
Total		$ 3,700,000
Loans receivable, other information [Abstract]
Percentage of loan portfolio attributed to Oklahoma (in hundredths)		22.00%
Commercial
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest		$ 1,991,423	1,850,548	1,854,163
Loans, variable rate of interest		7,952,276	8,325,559	7,909,461
Loans, non-accrual		176,464	76,424	33,798
Total		10,120,163	10,252,531	9,797,422
Commercial | Texas [Member] | Geographic Concentration Risk [Member]
Loan receivables disclosure [Abstract]
Total		$ 3,300,000
Loans receivable, other information [Abstract]
Percentage of loan portfolio attributed to Texas (in hundredths)		33.00%
Commercial | Oklahoma [Member] | Geographic Concentration Risk [Member]
Loan receivables disclosure [Abstract]
Total		$ 2,300,000
Loans receivable, other information [Abstract]
Percentage of loan portfolio attributed to Oklahoma (in hundredths)		23.00%
Commercial | Energy [Member]
Loan receivables disclosure [Abstract]
Total		$ 2,520,804	3,097,328	2,838,167
Commercial | Energy [Member] | Credit Concentration Risk [Member]
Loan receivables disclosure [Abstract]
Total		$ 2,500,000
Loans receivable, other information [Abstract]
Percentage of loan class to total loans		15.00%
Commercial | Energy Producers [Member] | Credit Concentration Risk [Member]
Loan receivables disclosure [Abstract]
Total		$ 2,000,000
Loans receivable, other information [Abstract]
Percentage of committed energy production loans secured by oil		57.00%
Percentage of committed energy production loans secured by natural gas		43.00%
Commercial | Services [Member]
Loan receivables disclosure [Abstract]
Total		$ 2,936,599	2,784,276	2,706,624
Commercial | Services [Member] | Credit Concentration Risk [Member]
Loan receivables disclosure [Abstract]
Total		$ 2,900,000
Loans receivable, other information [Abstract]
Percentage of loan class to total loans		18.00%
Amount of loans with individual balances less than $10 million		$ 1,300,000
Maximum loan amount for certain individual loans in category		10,000
Commercial | Healthcare [Member]
Loan receivables disclosure [Abstract]
Total		2,085,046	1,883,380	1,741,680
Commercial | Healthcare [Member] | Credit Concentration Risk [Member]
Loan receivables disclosure [Abstract]
Total		$ 2,100,000
Loans receivable, other information [Abstract]
Percentage of loan class to total loans		13.00%
Commercial real estate
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest		$ 565,429	627,678	588,604
Loans, variable rate of interest		3,220,819	2,622,354	2,635,507
Loans, non-accrual		7,350	9,001	10,956
Total		$ 3,793,598	3,259,033	3,235,067
Commercial real estate | Texas [Member] | Geographic Concentration Risk [Member]
Loans receivable, other information [Abstract]
Percentage of loan portfolio secured by property in Texas (in hundredths)		30.00%
Commercial real estate | Oklahoma [Member] | Geographic Concentration Risk [Member]
Loans receivable, other information [Abstract]
Percentage of loan portfolio secured by property in Oklahoma (in hundredths)		12.00%
Residential mortgage
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest		$ 1,572,288	1,598,992	1,624,759
Loans, variable rate of interest		248,053	216,661	200,136
Loans, non-accrual		52,452	61,240	44,100
Total		1,872,793	1,876,893	1,868,995
Residential mortgage | Permanent mortgage [Member]
Loan receivables disclosure [Abstract]
Total		$ 969,558	945,336	937,664
Loans receivable, other information [Abstract]
Minimum FICO required for jumbo loan approval		720
Maximum debt-to-income ratio on jumbo loans (in hundredths)		38.00%
Minimum loan-to-value ratio on jumbo loans (in hundredths)		60.00%
Maximum loan-to-value ratio on jumbo loans (in hundredths)		100.00%
Minimum period for fixed rate on variable rate jumbo loans (in years)		3 years
Maximum period for fixed rate on variable rate jumbo loans (in years)		10 years
Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Loan receivables disclosure [Abstract]
Total		$ 190,309	196,937	192,712
Loans receivable, other information [Abstract]
Amount of loans guaranteed by US government and previously sold into GNMA mortgage pools		190,000
Residential mortgage | Home equity {Member]
Loan receivables disclosure [Abstract]
Total		$ 712,926	734,620	738,619
Loans receivable, other information [Abstract]
Percentage of home equity portfolio comprised of first lien loans		66.00%
Percentage of home equity portfolio comprised of junior lien loans		34.00%
Percentage of junior lien home equity loans that are amortizing term loans		58.00%
Percentage of junior lien home equity loans that are revolving lines of credit		42.00%
Home equity loans, description		Home equity loans generally require a minimum FICO score of 700 and a maximum DTI of 40 percent.
Home equity loans, maximum		$ 400
Home equity loans, revolving period		5 years
Home equity loans, amortization period following revolving period		15 years
Home equity loans, discretionary additional revolving period		5 years
Personal
Loan receivables disclosure [Abstract]
Loans, fixed rate of interest		$ 104,408	91,816	100,615
Loans, variable rate of interest		573,138	460,418	364,848
Loans, non-accrual		686	463	494
Total		$ 678,232	$ 552,697	$ 465,957
[1]	Excludes residential mortgage loans guaranteed by agencies of the U.S. government

Loans and Allowances for Cred40

Loans and Allowances for Credit Losses, Activity in Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Allowance for loan losses [Roll Forward]
Beginning balance	$ 243,259	$ 201,087	$ 225,524	$ 189,056
Provision for loan losses	7,907	4,782	55,573	9,130
Loans charged off	(8,101)	(5,274)	(40,937)	(10,320)
Recoveries	2,038	3,521	4,943	16,250
Ending balance	245,103	204,116	245,103	204,116
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance	9,045	882	1,711	1,230
Provision for off-balance sheet credit losses	2,093	2,718	9,427	2,370
Ending balance	11,138	3,600	11,138	3,600
Total provision for credit losses	10,000	7,500	65,000	11,500
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					$ 16,227,834	$ 15,794,026	$ 15,278,094
Individually measured for impairment, recorded investment					236,952	147,128	89,347
Total					16,464,786	15,941,154	15,367,441
Related allowance [Abstract]
Collectively measured for impairment, related allowance					210,353	179,005	171,419
Individually measured for impairment, related allowance					6,564	16,393	4,951
Total	243,259	201,087	225,524	189,056	245,103	225,524	204,116
Commercial
Allowance for loan losses [Roll Forward]
Beginning balance	145,139	107,037	130,334	90,875
Provision for loan losses	2,420	4,694	45,995	20,869
Loans charged off	(6,266)	(3,497)	(35,747)	(4,552)
Recoveries	177	759	888	1,801
Ending balance	141,470	108,993	141,470	108,993
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance	8,752	595	1,506	475
Provision for off-balance sheet credit losses	2,170	1,873	9,416	1,993
Ending balance	10,922	2,468	10,922	2,468
Total provision for credit losses	4,590	6,567	55,411	22,862
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					9,943,699	10,176,107	9,763,624
Individually measured for impairment, recorded investment					176,464	76,424	33,798
Total					10,120,163	10,252,531	9,797,422
Related allowance [Abstract]
Collectively measured for impairment, related allowance					134,968	114,027	104,157
Individually measured for impairment, related allowance					6,502	16,307	4,836
Total	145,139	107,037	130,334	90,875	141,470	130,334	108,993
Commercial real estate
Allowance for loan losses [Roll Forward]
Beginning balance	46,745	39,744	41,391	42,445
Provision for loan losses	2,551	180	7,538	(11,571)
Loans charged off	0	0	0	(44)
Recoveries	521	1,865	888	10,959
Ending balance	49,817	41,789	49,817	41,789
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance	203	242	153	707
Provision for off-balance sheet credit losses	(53)	847	(3)	382
Ending balance	150	1,089	150	1,089
Total provision for credit losses	2,498	1,027	7,535	(11,189)
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					3,786,248	3,250,032	3,224,111
Individually measured for impairment, recorded investment					7,350	9,001	10,956
Total					3,793,598	3,259,033	3,235,067
Related allowance [Abstract]
Collectively measured for impairment, related allowance					49,817	41,373	41,771
Individually measured for impairment, related allowance					0	18	18
Total	46,745	39,744	41,391	42,445	49,817	41,391	41,789
Residential mortgage
Allowance for loan losses [Roll Forward]
Beginning balance	18,690	21,449	19,509	23,458
Provision for loan losses	(466)	(349)	(829)	(1,938)
Loans charged off	(285)	(446)	(1,104)	(1,784)
Recoveries	650	205	1,013	1,123
Ending balance	18,589	20,859	18,589	20,859
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance	62	26	30	28
Provision for off-balance sheet credit losses	(7)	(2)	25	(4)
Ending balance	55	24	55	24
Total provision for credit losses	(473)	(351)	(804)	(1,942)
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					1,820,341	1,815,653	1,824,896
Individually measured for impairment, recorded investment					52,452	61,240	44,099
Total					1,872,793	1,876,893	1,868,995
Related allowance [Abstract]
Collectively measured for impairment, related allowance					18,527	19,441	20,762
Individually measured for impairment, related allowance					62	68	97
Total	18,690	21,449	19,509	23,458	18,589	19,509	20,859
Personal
Allowance for loan losses [Roll Forward]
Beginning balance	6,001	3,955	4,164	4,233
Provision for loan losses	1,900	1,413	4,809	2,069
Loans charged off	(1,550)	(1,331)	(4,086)	(3,940)
Recoveries	690	692	2,154	2,367
Ending balance	7,041	4,729	7,041	4,729
Allowance for off-balance sheet credit losses [Roll Forward]
Beginning balance	28	19	22	20
Provision for off-balance sheet credit losses	(17)	0	(11)	(1)
Ending balance	11	19	11	19
Total provision for credit losses	1,883	1,413	4,798	2,068
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					677,546	552,234	465,463
Individually measured for impairment, recorded investment					686	463	494
Total					678,232	552,697	465,957
Related allowance [Abstract]
Collectively measured for impairment, related allowance					7,041	4,164	4,729
Individually measured for impairment, related allowance					0	0	0
Total	6,001	3,955	4,164	4,233	7,041	4,164	4,729
Specific Allowance [Member]
Allowance for loan losses [Roll Forward]
Beginning balance			195,398
Ending balance	216,917	176,370	216,917	176,370
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					16,227,834	15,794,026	15,278,094
Individually measured for impairment, recorded investment					236,952	147,128	89,347
Total					16,464,786	15,941,154	15,367,441
Related allowance [Abstract]
Collectively measured for impairment, related allowance					210,353	179,005	171,419
Individually measured for impairment, related allowance					6,564	16,393	4,951
Total	216,917	176,370	195,398	176,370	216,917	195,398	176,370
Nonspecific Allowance [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	26,684	28,902	30,126	28,045
Provision for loan losses	1,502	(1,156)	(1,940)	(299)
Loans charged off	0	0	0	0
Recoveries	0	0	0	0
Ending balance	28,186	27,746	28,186	27,746
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	1,502	(1,156)	(1,940)	(299)
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment					0	0	0
Individually measured for impairment, recorded investment					0	0	0
Total					0	0	0
Related allowance [Abstract]
Collectively measured for impairment, related allowance					0	0	0
Individually measured for impairment, related allowance					0	0	0
Total	$ 26,684	$ 28,902	$ 30,126	$ 28,045	$ 28,186	$ 30,126	$ 27,746

Loans and Allowances for Cred41

Loans and Allowances for Credit Losses, Credit Quality Indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	$ 14,680,781		$ 14,150,992	$ 13,576,807
Non-Graded, Recorded Investment	1,784,005		1,790,162	1,790,634
Total	16,464,786		15,941,154	15,367,441
Related Allowance [Abstract]
Internally Risk Graded, Allowance	197,579		175,090	154,618
Non-Graded, Allowance	19,338		20,308	21,752
Total	245,103	$ 243,259	225,524	204,116	$ 201,087	$ 189,056
Commercial
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	10,093,884		10,227,303	9,771,003
Non-Graded, Recorded Investment	26,279		25,228	26,419
Total	10,120,163		10,252,531	9,797,422
Related Allowance [Abstract]
Internally Risk Graded, Allowance	140,552		129,426	108,101
Non-Graded, Allowance	918		908	892
Total	141,470	145,139	130,334	108,993	107,037	90,875
Commercial | Energy [Member]
Recorded Investment [Abstract]
Total	2,520,804		3,097,328	2,838,167
Commercial | Services [Member]
Recorded Investment [Abstract]
Total	2,936,599		2,784,276	2,706,624
Commercial | Wholesale/retail [Member]
Recorded Investment [Abstract]
Total	1,602,030		1,422,064	1,461,936
Commercial | Manufacturing [Member]
Recorded Investment [Abstract]
Total	499,486		556,729	555,677
Commercial | Healthcare [Member]
Recorded Investment [Abstract]
Total	2,085,046		1,883,380	1,741,680
Commercial | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Total	476,198		508,754	493,338
Commercial real estate
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	3,793,598		3,259,033	3,235,067
Non-Graded, Recorded Investment	0		0	0
Total	3,793,598		3,259,033	3,235,067
Related Allowance [Abstract]
Internally Risk Graded, Allowance	49,817		41,391	41,789
Non-Graded, Allowance	0		0	0
Total	49,817	46,745	41,391	41,789	39,744	42,445
Commercial real estate | Residential construction and land development [Member]
Recorded Investment [Abstract]
Total	159,946		160,426	153,510
Commercial real estate | Retail [Member]
Recorded Investment [Abstract]
Total	801,377		796,499	769,449
Commercial real estate | Office [Member]
Recorded Investment [Abstract]
Total	752,705		637,707	626,151
Commercial real estate | Multifamily [Member]
Recorded Investment [Abstract]
Total	873,773		751,085	758,658
Commercial real estate | Industrial [Member]
Recorded Investment [Abstract]
Total	838,021		563,169	563,871
Commercial real estate | Other commercial real estate [Member]
Recorded Investment [Abstract]
Total	367,776		350,147	363,428
Residential mortgage
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	206,430		196,701	190,361
Non-Graded, Recorded Investment	1,666,363		1,680,192	1,678,634
Total	1,872,793		1,876,893	1,868,995
Related Allowance [Abstract]
Internally Risk Graded, Allowance	3,028		2,883	2,938
Non-Graded, Allowance	15,561		16,626	17,921
Total	18,589	18,690	19,509	20,859	21,449	23,458
Residential mortgage | Permanent mortgage [Member]
Recorded Investment [Abstract]
Total	969,558		945,336	937,664
Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Recorded Investment [Abstract]
Total	190,309		196,937	192,712
Residential mortgage | Home equity {Member]
Recorded Investment [Abstract]
Total	712,926		734,620	738,619
Personal
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	586,869		467,955	380,376
Non-Graded, Recorded Investment	91,363		84,742	85,581
Total	678,232		552,697	465,957
Related Allowance [Abstract]
Internally Risk Graded, Allowance	4,182		1,390	1,790
Non-Graded, Allowance	2,859		2,774	2,939
Total	7,041	6,001	4,164	4,729	3,955	4,233
Specific Allowance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	14,680,781		14,150,992	13,576,807
Non-Graded, Recorded Investment	1,784,005		1,790,162	1,790,634
Total	16,464,786		15,941,154	15,367,441
Related Allowance [Abstract]
Internally Risk Graded, Allowance	197,579		175,090	154,618
Non-Graded, Allowance	19,338		20,308	21,752
Total	216,917		195,398	176,370
Nonspecific Allowance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0	0
Non-Graded, Recorded Investment	0		0	0
Total	0		0	0
Related Allowance [Abstract]
Internally Risk Graded, Allowance	0		0	0
Non-Graded, Allowance	0		0	0
Total	28,186	$ 26,684	30,126	27,746	$ 28,902	$ 28,045
Performing [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	1,733,743		1,730,775	1,748,625
Performing [Member] | Commercial
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	26,210		25,101	26,343
Performing [Member] | Commercial | Energy [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0	0
Performing [Member] | Commercial | Services [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0	0
Performing [Member] | Commercial | Wholesale/retail [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0	0
Performing [Member] | Commercial | Manufacturing [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0	0
Performing [Member] | Commercial | Healthcare [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0	0
Performing [Member] | Commercial | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	26,210		25,101	26,343
Performing [Member] | Commercial real estate
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0	0
Performing [Member] | Commercial real estate | Residential construction and land development [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0	0
Performing [Member] | Commercial real estate | Retail [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0	0
Performing [Member] | Commercial real estate | Office [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0	0
Performing [Member] | Commercial real estate | Multifamily [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0	0
Performing [Member] | Commercial real estate | Industrial [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0	0
Performing [Member] | Commercial real estate | Other commercial real estate [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	0		0	0
Performing [Member] | Residential mortgage
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	1,616,425		1,621,265	1,637,055
Performing [Member] | Residential mortgage | Permanent mortgage [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	739,686		721,964	719,163
Performing [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	174,877		175,037	188,827
Performing [Member] | Residential mortgage | Home equity {Member]
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	701,862		724,264	729,065
Performing [Member] | Personal
Recorded Investment [Abstract]
Non-Graded, Recorded Investment	91,108		84,409	85,227
Performing [Member] | Pass [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	13,778,278		13,523,199	13,148,187
Performing [Member] | Pass [Member] | Commercial
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	9,217,958		9,628,481	9,374,227
Performing [Member] | Pass [Member] | Commercial | Energy [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,869,598		2,580,694	2,527,543
Performing [Member] | Pass [Member] | Commercial | Services [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,882,065		2,763,929	2,683,655
Performing [Member] | Pass [Member] | Commercial | Wholesale/retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,557,067		1,394,596	1,432,460
Performing [Member] | Pass [Member] | Commercial | Manufacturing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	470,702		534,966	532,443
Performing [Member] | Pass [Member] | Commercial | Healthcare [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,022,757		1,876,745	1,734,741
Performing [Member] | Pass [Member] | Commercial | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	415,769		477,551	463,385
Performing [Member] | Pass [Member] | Commercial real estate
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	3,774,443		3,234,543	3,206,912
Performing [Member] | Pass [Member] | Commercial real estate | Residential construction and land development [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	155,737		154,369	146,764
Performing [Member] | Pass [Member] | Commercial real estate | Retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	794,920		788,708	761,279
Performing [Member] | Pass [Member] | Commercial real estate | Office [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	750,924		636,210	624,611
Performing [Member] | Pass [Member] | Commercial real estate | Multifamily [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	868,501		744,299	750,791
Performing [Member] | Pass [Member] | Commercial real estate | Industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	837,945		563,093	563,795
Performing [Member] | Pass [Member] | Commercial real estate | Other commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	366,416		347,864	359,672
Performing [Member] | Pass [Member] | Residential mortgage
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	200,590		192,367	186,832
Performing [Member] | Pass [Member] | Residential mortgage | Permanent mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	200,590		192,367	186,832
Performing [Member] | Pass [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0	0
Performing [Member] | Pass [Member] | Residential mortgage | Home equity {Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0	0
Performing [Member] | Pass [Member] | Personal
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	585,287		467,808	380,216
Performing [Member] | Other Loans Especially Mentioned [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	237,948		385,529	261,498
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	230,827		377,745	253,389
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial | Energy [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	147,153		325,663	196,298
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial | Services [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	14,861		3,296	4,207
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial | Wholesale/retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	15,337		18,184	23,176
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial | Manufacturing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	8,774		19,560	20,975
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial | Healthcare [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	42,224		5,563	5,721
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,478		5,479	3,012
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	5,701		7,692	8,013
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate | Residential construction and land development [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		1,355	1,628
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate | Retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	4,802		6,046	6,089
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate | Office [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	899		291	296
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate | Multifamily [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0	0
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate | Industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0	0
Performing [Member] | Other Loans Especially Mentioned [Member] | Commercial real estate | Other commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0	0
Performing [Member] | Other Loans Especially Mentioned [Member] | Residential mortgage
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,192		89	91
Performing [Member] | Other Loans Especially Mentioned [Member] | Residential mortgage | Permanent mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,192		89	91
Performing [Member] | Other Loans Especially Mentioned [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0	0
Performing [Member] | Other Loans Especially Mentioned [Member] | Residential mortgage | Home equity {Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0	0
Performing [Member] | Other Loans Especially Mentioned [Member] | Personal
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	228		3	5
Performing [Member] | Substandard [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	477,865		154,523	119,784
Performing [Member] | Substandard [Member] | Commercial
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	468,704		144,780	109,665
Performing [Member] | Substandard [Member] | Commercial | Energy [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	361,087		129,782	96,446
Performing [Member] | Substandard [Member] | Commercial | Services [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	31,196		6,761	8,070
Performing [Member] | Substandard [Member] | Commercial | Wholesale/retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	27,173		6,365	3,242
Performing [Member] | Substandard [Member] | Commercial | Manufacturing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	19,736		1,872	1,907
Performing [Member] | Substandard [Member] | Commercial | Healthcare [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	19,210		0	0
Performing [Member] | Substandard [Member] | Commercial | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	10,302		0	0
Performing [Member] | Substandard [Member] | Commercial real estate
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	6,104		7,797	9,186
Performing [Member] | Substandard [Member] | Commercial real estate | Residential construction and land development [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	470		293	370
Performing [Member] | Substandard [Member] | Commercial real estate | Retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	406		426	433
Performing [Member] | Substandard [Member] | Commercial real estate | Office [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		555	560
Performing [Member] | Substandard [Member] | Commercial real estate | Multifamily [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	5,221		6,512	7,682
Performing [Member] | Substandard [Member] | Commercial real estate | Industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0	0
Performing [Member] | Substandard [Member] | Commercial real estate | Other commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	7		11	141
Performing [Member] | Substandard [Member] | Residential mortgage
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,134		1,932	918
Performing [Member] | Substandard [Member] | Residential mortgage | Permanent mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,134		1,932	918
Performing [Member] | Substandard [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0	0
Performing [Member] | Substandard [Member] | Residential mortgage | Home equity {Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0	0
Performing [Member] | Substandard [Member] | Personal
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	923		14	15
Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	186,690		87,741	47,338
Non-Graded, Recorded Investment	50,262		59,387	42,009
Nonaccrual [Member] | Commercial
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	176,395		76,297	33,722
Non-Graded, Recorded Investment	69		127	76
Nonaccrual [Member] | Commercial | Energy [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	142,966		61,189	17,880
Non-Graded, Recorded Investment	0		0	0
Nonaccrual [Member] | Commercial | Services [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	8,477		10,290	10,692
Non-Graded, Recorded Investment	0		0	0
Nonaccrual [Member] | Commercial | Wholesale/retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,453		2,919	3,058
Non-Graded, Recorded Investment	0		0	0
Nonaccrual [Member] | Commercial | Manufacturing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	274		331	352
Non-Graded, Recorded Investment	0		0	0
Nonaccrual [Member] | Commercial | Healthcare [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	855		1,072	1,218
Non-Graded, Recorded Investment	0		0	0
Nonaccrual [Member] | Commercial | Other commercial and industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	21,370		496	522
Non-Graded, Recorded Investment	69		127	76
Nonaccrual [Member] | Commercial real estate
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	7,350		9,001	10,956
Non-Graded, Recorded Investment	0		0	0
Nonaccrual [Member] | Commercial real estate | Residential construction and land development [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	3,739		4,409	4,748
Non-Graded, Recorded Investment	0		0	0
Nonaccrual [Member] | Commercial real estate | Retail [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,249		1,319	1,648
Non-Graded, Recorded Investment	0		0	0
Nonaccrual [Member] | Commercial real estate | Office [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	882		651	684
Non-Graded, Recorded Investment	0		0	0
Nonaccrual [Member] | Commercial real estate | Multifamily [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	51		274	185
Non-Graded, Recorded Investment	0		0	0
Nonaccrual [Member] | Commercial real estate | Industrial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	76		76	76
Non-Graded, Recorded Investment	0		0	0
Nonaccrual [Member] | Commercial real estate | Other commercial real estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,353		2,272	3,615
Non-Graded, Recorded Investment	0		0	0
Nonaccrual [Member] | Residential mortgage
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,514		2,313	2,520
Non-Graded, Recorded Investment	49,938		58,927	41,579
Nonaccrual [Member] | Residential mortgage | Permanent mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,514		2,313	2,520
Non-Graded, Recorded Investment	23,442		26,671	28,140
Nonaccrual [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0	0
Non-Graded, Recorded Investment	15,432		21,900	3,885
Nonaccrual [Member] | Residential mortgage | Home equity {Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0		0	0
Non-Graded, Recorded Investment	11,064		10,356	9,554
Nonaccrual [Member] | Personal
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	431		130	140
Non-Graded, Recorded Investment	$ 255		$ 333	$ 354

Loans and Allowance for Credi42

Loans and Allowance for Credit Losses, Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2016		Sep. 30, 2015		Sep. 30, 2016		Sep. 30, 2015		Dec. 31, 2015
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	$ 489,949		$ 323,633		$ 489,949		$ 323,633		$ 369,450
Impaired loans, recorded investment, total	411,829		278,174		411,829		278,174		322,165
Impaired loans, recorded investment with no related allowance	369,054		264,177		369,054		264,177		278,245
Impaired loans, recorded investment with related allowance	42,775		13,997		42,775		13,997		43,920
Impaired loans, related allowance	6,564		4,951		6,564		4,951		16,393
Impaired loans, average recorded investment	415,029		279,484		350,511		279,572
Impaired loans, interest income recognized	2,390		2,199		6,816		7,147
Commercial
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	230,950		51,733		230,950		51,733		96,262
Impaired loans, recorded investment, total	176,464		33,798		176,464		33,798		76,424
Impaired loans, recorded investment with no related allowance	133,798		20,118		133,798		20,118		32,779
Impaired loans, recorded investment with related allowance	42,666		13,680		42,666		13,680		43,645
Impaired loans, related allowance	6,502		4,836		6,502		4,836		16,307
Impaired loans, average recorded investment	179,227		29,015		109,701		23,662
Impaired loans, interest income recognized	0		0		0		0
Commercial | Energy [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	179,578		18,904		179,578		18,904		63,910
Impaired loans, recorded investment, total	142,966		17,880		142,966		17,880		61,189
Impaired loans, recorded investment with no related allowance	100,300		5,017		100,300		5,017		18,330
Impaired loans, recorded investment with related allowance	42,666		12,863		42,666		12,863		42,859
Impaired loans, related allowance	6,502		4,644		6,502		4,644		16,115
Impaired loans, average recorded investment	155,555		12,361		85,333		9,648
Impaired loans, interest income recognized	0		0		0		0
Commercial | Services [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	11,858		13,677		11,858		13,677		13,449
Impaired loans, recorded investment, total	8,477		10,692		8,477		10,692		10,290
Impaired loans, recorded investment with no related allowance	8,477		10,041		8,477		10,041		9,657
Impaired loans, recorded investment with related allowance	0		651		0		651		633
Impaired loans, related allowance	0		148		0		148		148
Impaired loans, average recorded investment	8,932		10,818		9,384		7,946
Impaired loans, interest income recognized	0		0		0		0
Commercial | Wholesale/retail [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	8,528		8,588		8,528		8,588		8,582
Impaired loans, recorded investment, total	2,453		3,058		2,453		3,058		2,919
Impaired loans, recorded investment with no related allowance	2,453		3,046		2,453		3,046		2,907
Impaired loans, recorded investment with related allowance	0		12		0		12		12
Impaired loans, related allowance	0		9		0		9		9
Impaired loans, average recorded investment	2,613		3,612		2,686		3,603
Impaired loans, interest income recognized	0		0		0		0
Commercial | Manufacturing [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	642		675		642		675		665
Impaired loans, recorded investment, total	274		352		274		352		331
Impaired loans, recorded investment with no related allowance	274		352		274		352		331
Impaired loans, recorded investment with related allowance	0		0		0		0		0
Impaired loans, related allowance	0		0		0		0		0
Impaired loans, average recorded investment	284		365		303		401
Impaired loans, interest income recognized	0		0		0		0
Commercial | Healthcare [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	1,168		1,612		1,168		1,612		1,352
Impaired loans, recorded investment, total	855		1,218		855		1,218		1,072
Impaired loans, recorded investment with no related allowance	855		1,064		855		1,064		931
Impaired loans, recorded investment with related allowance	0		154		0		154		141
Impaired loans, related allowance	0		35		0		35		35
Impaired loans, average recorded investment	865		1,248		964		1,299
Impaired loans, interest income recognized	0		0		0		0
Commercial | Other commercial and industrial [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	29,176		8,277		29,176		8,277		8,304
Impaired loans, recorded investment, total	21,439		598		21,439		598		623
Impaired loans, recorded investment with no related allowance	21,439		598		21,439		598		623
Impaired loans, recorded investment with related allowance	0		0		0		0		0
Impaired loans, related allowance	0		0		0		0		0
Impaired loans, average recorded investment	10,978		611		11,031		765
Impaired loans, interest income recognized	0		0		0		0
Commercial real estate
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	17,642		23,565		17,642		23,565		21,454
Impaired loans, recorded investment, total	7,350		10,956		7,350		10,956		9,001
Impaired loans, recorded investment with no related allowance	7,350		10,793		7,350		10,793		8,842
Impaired loans, recorded investment with related allowance	0		163		0		163		159
Impaired loans, related allowance	0		18		0		18		18
Impaired loans, average recorded investment	7,565		15,548		8,176		14,756
Impaired loans, interest income recognized	0		0		0		0
Commercial real estate | Residential construction and land development [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	6,090		9,349		6,090		9,349		8,963
Impaired loans, recorded investment, total	3,739		4,748		3,739		4,748		4,409
Impaired loans, recorded investment with no related allowance	3,739		4,748		3,739		4,748		4,409
Impaired loans, recorded investment with related allowance	0		0		0		0		0
Impaired loans, related allowance	0		0		0		0		0
Impaired loans, average recorded investment	4,000		7,058		4,074		5,023
Impaired loans, interest income recognized	0		0		0		0
Commercial real estate | Retail [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	1,914		2,252		1,914		2,252		1,923
Impaired loans, recorded investment, total	1,249		1,648		1,249		1,648		1,319
Impaired loans, recorded investment with no related allowance	1,249		1,648		1,249		1,648		1,319
Impaired loans, recorded investment with related allowance	0		0		0		0		0
Impaired loans, related allowance	0		0		0		0		0
Impaired loans, average recorded investment	1,257		2,737		1,284		2,787
Impaired loans, interest income recognized	0		0		0		0
Commercial real estate | Office [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	1,187		2,046		1,187		2,046		937
Impaired loans, recorded investment, total	882		684		882		684		651
Impaired loans, recorded investment with no related allowance	882		684		882		684		651
Impaired loans, recorded investment with related allowance	0		0		0		0		0
Impaired loans, related allowance	0		0		0		0		0
Impaired loans, average recorded investment	744		1,522		766		2,052
Impaired loans, interest income recognized	0		0		0		0
Commercial real estate | Multifamily [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	1,000		192		1,000		192		1,192
Impaired loans, recorded investment, total	51		185		51		185		274
Impaired loans, recorded investment with no related allowance	51		185		51		185		274
Impaired loans, recorded investment with related allowance	0		0		0		0		0
Impaired loans, related allowance	0		0		0		0		0
Impaired loans, average recorded investment	58		190		163		93
Impaired loans, interest income recognized	0		0		0		0
Commercial real estate | Industrial [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	76		76		76		76		76
Impaired loans, recorded investment, total	76		76		76		76		76
Impaired loans, recorded investment with no related allowance	76		76		76		76		76
Impaired loans, recorded investment with related allowance	0		0		0		0		0
Impaired loans, related allowance	0		0		0		0		0
Impaired loans, average recorded investment	76		76		76		38
Impaired loans, interest income recognized	0		0		0		0
Commercial real estate | Other commercial real estate [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	7,375		9,650		7,375		9,650		8,363
Impaired loans, recorded investment, total	1,353		3,615		1,353		3,615		2,272
Impaired loans, recorded investment with no related allowance	1,353		3,452		1,353		3,452		2,113
Impaired loans, recorded investment with related allowance	0		163		0		163		159
Impaired loans, related allowance	0		18		0		18		18
Impaired loans, average recorded investment	1,430		3,965		1,813		4,763
Impaired loans, interest income recognized	0		0		0		0
Residential mortgage
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	240,633		247,819		240,633		247,819		251,245
Impaired loans, recorded investment, total	227,329		232,926		227,329		232,926		236,277
Impaired loans, recorded investment with no related allowance	227,220		232,772		227,220		232,772		236,161
Impaired loans, recorded investment with related allowance	109		154		109		154		116
Impaired loans, related allowance	62		97		62		97		68
Impaired loans, average recorded investment	227,717		234,399		232,059		240,624
Impaired loans, interest income recognized	2,390		2,199		6,816		7,147
Residential mortgage | Permanent mortgage [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	32,372		38,829		32,372		38,829		37,273
Impaired loans, recorded investment, total	25,956		30,660		25,956		30,660		28,984
Impaired loans, recorded investment with no related allowance	25,847		30,506		25,847		30,506		28,868
Impaired loans, recorded investment with related allowance	109		154		109		154		116
Impaired loans, related allowance	62		97		62		97		68
Impaired loans, average recorded investment	26,592		31,424		27,470		32,753
Impaired loans, interest income recognized	292		297		923		942
Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	196,162	[1]	198,905	[2]	196,162	[1]	198,905	[2]	202,984	[3]
Impaired loans, recorded investment, total	190,309	[1]	192,712	[2]	190,309	[1]	192,712	[2]	196,937	[3]
Impaired loans, recorded investment with no related allowance	190,309	[1]	192,712	[2]	190,309	[1]	192,712	[2]	196,937	[3]
Impaired loans, recorded investment with related allowance	0	[1]	0	[2]	0	[1]	0	[2]	0	[3]
Impaired loans, related allowance	0	[1]	0	[2]	0	[1]	0	[2]	0	[3]
Impaired loans, average recorded investment	190,547	[1]	193,165	[2]	193,879	[1]	198,312	[2]
Impaired loans, interest income recognized	2,098	[1]	1,902	[2]	5,893	[1]	6,205	[2]
Residential mortgage | Home equity {Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	12,099		10,085		12,099		10,085		10,988
Impaired loans, recorded investment, total	11,064		9,554		11,064		9,554		10,356
Impaired loans, recorded investment with no related allowance	11,064		9,554		11,064		9,554		10,356
Impaired loans, recorded investment with related allowance	0		0		0		0		0
Impaired loans, related allowance	0		0		0		0		0
Impaired loans, average recorded investment	10,578		9,810		10,710		9,559
Impaired loans, interest income recognized	0		0		0		0
Personal
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	724		516		724		516		489
Impaired loans, recorded investment, total	686		494		686		494		463
Impaired loans, recorded investment with no related allowance	686		494		686		494		463
Impaired loans, recorded investment with related allowance	0		0		0		0		0
Impaired loans, related allowance	0		0		0		0		$ 0
Impaired loans, average recorded investment	520		522		575		530
Impaired loans, interest income recognized	$ 0		$ 0		$ 0		$ 0
[1]	All permanent mortgage loans guaranteed by U.S. government agencies are considered impaired as we do not expect full collection of contractual principal and interest. At September 30, 2016, $15 million of these loans were nonaccruing and $175 million were accruing based on the guarantee by U.S. government agencies.
[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, 2015, $3.9 million of these loans were nonaccruing and $189 million 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, 2015, $22 million of these loans were nonaccruing and $175 million were accruing based on the guarantee by U.S. government agencies.

Loans and Allowances for Cred43

Loans and Allowances for Credit Losses, Troubled Debt Restructurings (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	$ 126,126	$ 124,176	$ 126,126	$ 124,176	$ 127,684
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	59,919	52,142	59,919	52,142	54,131
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	66,207	72,034	66,207	72,034	73,553
Troubled Debt Restructuring, Specific allowance	62	254	62	254	225
Troubled Debt Restructuring, Charge-offs	543	250	1,230	312
Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	45,820	42,578	45,820	42,578	53,634
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	30,899	29,790	30,899	29,790	31,102
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	14,921	12,788	14,921	12,788	22,532
Troubled Debt Restructuring, Specific allowance	62	254	62	254	225
Troubled Debt Restructuring, Charge-offs	543	250	1,230	312
Nonaccrual [Member] | Commercial
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	13,192	13,834	13,192	13,834	15,665
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	9,620	12,407	9,620	12,407	14,264
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	3,572	1,427	3,572	1,427	1,401
Troubled Debt Restructuring, Specific allowance	0	157	0	157	157
Troubled Debt Restructuring, Charge-offs	500	100	1,057	100
Nonaccrual [Member] | Commercial | Energy [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	1,746	0	1,746	0	2,304
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0	0	0	2,304
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	1,746	0	1,746	0	0
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	500	0	1,000	0
Nonaccrual [Member] | Commercial | Services [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	7,761	9,362	7,761	9,362	9,027
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	7,034	8,502	7,034	8,502	8,210
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	727	860	727	860	817
Troubled Debt Restructuring, Specific allowance	0	148	0	148	148
Troubled Debt Restructuring, Charge-offs	0	0	0	0
Nonaccrual [Member] | Commercial | Wholesale/retail [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	2,327	2,897	2,327	2,897	2,758
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	2,287	2,844	2,287	2,844	2,706
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	40	53	40	53	52
Troubled Debt Restructuring, Specific allowance	0	9	0	9	9
Troubled Debt Restructuring, Charge-offs	0	0	0	0
Nonaccrual [Member] | Commercial | Manufacturing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	238	296	238	296	282
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	238	296	238	296	282
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0	0	0	0
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	0	0	0	0
Nonaccrual [Member] | Commercial | Healthcare [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	623	689	623	689	673
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	689	0	689	673
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	623	0	623	0	0
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	0	0	0	0
Nonaccrual [Member] | Commercial | Other commercial and industrial [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	497	590	497	590	621
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	61	76	61	76	89
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	436	514	436	514	532
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	0	100	57	100
Nonaccrual [Member] | Commercial real estate
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	2,858	5,101	2,858	5,101	4,732
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	2,066	3,337	2,066	3,337	3,141
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	792	1,764	792	1,764	1,591
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Residential construction and land development [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	794	2,539	794	2,539	2,328
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	359	1,624	359	1,624	1,556
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	435	915	435	915	772
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Retail [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	1,249	1,356	1,249	1,356	1,319
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	892	960	892	960	942
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	357	396	357	396	377
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Office [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	149	169	149	169	165
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	149	169	149	169	165
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0	0	0	0
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Multifamily [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	0	0	0	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0	0	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0	0	0	0
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Industrial [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	0	0	0	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0	0	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0	0	0	0
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Other commercial real estate [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	666	1,037	666	1,037	920
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	666	584	666	584	478
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	453	0	453	442
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	0	0	0	0
Nonaccrual [Member] | Residential mortgage
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	29,497	23,278	29,497	23,278	32,913
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	18,942	13,837	18,942	13,837	13,400
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	10,555	9,441	10,555	9,441	19,513
Troubled Debt Restructuring, Specific allowance	62	97	62	97	68
Troubled Debt Restructuring, Charge-offs	34	150	155	210
Nonaccrual [Member] | Residential mortgage | Permanent mortgage [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	16,109	16,359	16,109	16,359	16,618
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	11,944	9,361	11,944	9,361	9,043
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	4,165	6,998	4,165	6,998	7,575
Troubled Debt Restructuring, Specific allowance	62	97	62	97	68
Troubled Debt Restructuring, Charge-offs	0	140	2	142
Nonaccrual [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	8,220	1,944	8,220	1,944	11,136
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	2,331	140	2,331	140	139
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	5,889	1,804	5,889	1,804	10,997
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	0	0	0	0
Nonaccrual [Member] | Residential mortgage | Home equity {Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	5,168	4,975	5,168	4,975	5,159
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	4,667	4,336	4,667	4,336	4,218
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	501	639	501	639	941
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	34	10	153	68
Nonaccrual [Member] | Personal
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	273	365	273	365	324
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	271	209	271	209	297
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	2	156	2	156	27
Troubled Debt Restructuring, Specific allowance	0	0	0	0	0
Troubled Debt Restructuring, Charge-offs	9	0	18	2
Accruing [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	80,306	81,598	80,306	81,598	74,050
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	29,020	22,352	29,020	22,352	23,029
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	51,286	59,246	51,286	59,246	51,021
Troubled Debt Restructuring, Specific allowance	0	0	0	0	$ 0
Troubled Debt Restructuring, Charge-offs	$ 0	$ 0	$ 0	$ 0

Loans and Allowances for Cred44

Loans and Allowances for Credit Losses, Troubled Debt Restructurings, Modifications (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	$ 9,115	$ 11,718	$ 24,368	$ 41,073
Troubled Debt Restructurings, Recorded Balance With Payment Default	20,899	33,850	23,030	35,937
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	501	8,540
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,746	0	1,746	0
Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	501	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,746	0	1,746	0
Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	7,851
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	689
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	329
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	329	0	329
Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	329
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	329	0	329
Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	9,096	11,700	23,785	32,100
Troubled Debt Restructurings, Recorded Balance With Payment Default	19,142	33,483	21,273	35,570
Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	151	1,598	2,088	3,275
Troubled Debt Restructurings, Recorded Balance With Payment Default	298	2,364	542	2,543
Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	8,025	9,655	20,019	27,098
Troubled Debt Restructurings, Recorded Balance With Payment Default	18,586	30,721	20,473	32,592
Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	920	447	1,678	1,727
Troubled Debt Restructurings, Recorded Balance With Payment Default	258	398	258	435
Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	19	18	82	104
Troubled Debt Restructurings, Recorded Balance With Payment Default	11	38	11	38
Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	7,738	9,655	19,037	26,255
Troubled Debt Restructurings, Recorded Balance With Payment Default	17,491	29,942	19,352	31,673
Accruing [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0		0
Accruing [Member] | Commercial | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance With Payment Default			0
Accruing [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	7,738	9,655	19,037	26,255
Troubled Debt Restructurings, Recorded Balance With Payment Default	17,491	29,942	19,352	31,673
Accruing [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	7,738	9,655	19,037	26,255
Troubled Debt Restructurings, Recorded Balance With Payment Default	17,491	29,942	19,352	31,673
Accruing [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Accruing [Member] | Payment Stream [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	3,527	5,809	9,687	15,858
Accruing [Member] | Payment Stream [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	3,527	5,809	9,687	15,858
Accruing [Member] | Payment Stream [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	3,527	5,809	9,687	15,858
Accruing [Member] | Payment Stream [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Payment Stream [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	4,211	3,846	9,350	10,397
Accruing [Member] | Combination & Other [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	4,211	3,846	9,350	10,397
Accruing [Member] | Combination & Other [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	4,211	3,846	9,350	10,397
Accruing [Member] | Combination & Other [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Accruing [Member] | Combination & Other [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	1,377	2,063	5,331	14,818
Troubled Debt Restructurings, Recorded Balance With Payment Default	3,408	3,908	3,678	4,264
Nonaccrual [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	501	8,540
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,746	0	1,746	0
Nonaccrual [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	501	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,746	0	1,746	0
Nonaccrual [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	7,851
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	689
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	329
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	329	0	329
Nonaccrual [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	329
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	329	0	329
Nonaccrual [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0	0	0
Nonaccrual [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	1,358	2,045	4,748	5,845
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,651	3,541	1,921	3,897
Nonaccrual [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	151	1,598	2,088	3,275
Troubled Debt Restructurings, Recorded Balance With Payment Default	298	2,364	542	2,543
Nonaccrual [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	287	0	982	843
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,095	779	1,121	919
Nonaccrual [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	920	447	1,678	1,727
Troubled Debt Restructurings, Recorded Balance With Payment Default	258	398	258	435
Nonaccrual [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	19	18	82	104
Troubled Debt Restructurings, Recorded Balance With Payment Default	11	38	11	38
Nonaccrual [Member] | Interest Rate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		748
Nonaccrual [Member] | Interest Rate [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		689
Nonaccrual [Member] | Interest Rate [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		689
Nonaccrual [Member] | Interest Rate [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		59
Nonaccrual [Member] | Interest Rate [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Interest Rate [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		59
Nonaccrual [Member] | Interest Rate [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period		0		0
Nonaccrual [Member] | Payment Stream [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	1,448	1,586	2,624
Nonaccrual [Member] | Payment Stream [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	501	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	501	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	329
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	329
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	1,448	1,085	2,295
Nonaccrual [Member] | Payment Stream [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	1,448	1,037	2,150
Nonaccrual [Member] | Payment Stream [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Payment Stream [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	48	145
Nonaccrual [Member] | Payment Stream [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	1,377	615	3,745	11,446
Nonaccrual [Member] | Combination & Other [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	7,851
Nonaccrual [Member] | Combination & Other [Member] | Commercial | Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial | Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	7,851
Nonaccrual [Member] | Combination & Other [Member] | Commercial | Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial | Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial | Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial | Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate | Residential construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate | Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate | Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate | Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate | Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Commercial real estate | Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0	0	0
Nonaccrual [Member] | Combination & Other [Member] | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	1,358	597	3,663	3,491
Nonaccrual [Member] | Combination & Other [Member] | Residential mortgage | Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	151	150	1,051	1,125
Nonaccrual [Member] | Combination & Other [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	287	0	982	843
Nonaccrual [Member] | Combination & Other [Member] | Residential mortgage | Home equity {Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	920	447	1,630	1,523
Nonaccrual [Member] | Combination & Other [Member] | Personal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	$ 19	$ 18	$ 82	$ 104

Loans and Allowances for Cred45

Loans and Allowances for Credit Losses, By Aging Category (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Financing receivable, recorded investment, aging [Abstract]
Current	$ 16,061,958	$ 15,626,933	$ 15,095,718
Nonaccrual	236,952	147,128	89,348
Total	16,464,786	15,941,154	15,367,441
Commercial
Financing receivable, recorded investment, aging [Abstract]
Current	9,926,386	10,165,995	9,750,721
Nonaccrual	176,464	76,424	33,798
Total	10,120,163	10,252,531	9,797,422
Commercial | Energy [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	2,365,850	3,033,504	2,813,145
Nonaccrual	142,966	61,189	17,880
Total	2,520,804	3,097,328	2,838,167
Commercial | Services [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	2,923,874	2,769,895	2,690,554
Nonaccrual	8,477	10,290	10,692
Total	2,936,599	2,784,276	2,706,624
Commercial | Wholesale/retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	1,599,356	1,418,396	1,458,681
Nonaccrual	2,453	2,919	3,058
Total	1,602,030	1,422,064	1,461,936
Commercial | Manufacturing [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	499,212	556,398	555,325
Nonaccrual	274	331	352
Total	499,486	556,729	555,677
Commercial | Healthcare [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	2,083,556	1,879,873	1,740,462
Nonaccrual	855	1,072	1,218
Total	2,085,046	1,883,380	1,741,680
Commercial | Other commercial and industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	454,538	507,929	492,554
Nonaccrual	21,439	623	598
Total	476,198	508,754	493,338
Commercial real estate
Financing receivable, recorded investment, aging [Abstract]
Current	3,777,344	3,241,541	3,217,476
Nonaccrual	7,350	9,001	10,956
Total	3,793,598	3,259,033	3,235,067
Commercial real estate | Residential construction and land development [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	156,207	156,017	148,762
Nonaccrual	3,739	4,409	4,748
Total	159,946	160,426	153,510
Commercial real estate | Retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	796,362	795,180	767,801
Nonaccrual	1,249	1,319	1,648
Total	801,377	796,499	769,449
Commercial real estate | Office [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	751,823	637,056	625,250
Nonaccrual	882	651	684
Total	752,705	637,707	626,151
Commercial real estate | Multifamily [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	868,591	742,697	752,055
Nonaccrual	51	274	185
Total	873,773	751,085	758,658
Commercial real estate | Industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	837,945	563,093	563,795
Nonaccrual	76	76	76
Total	838,021	563,169	563,871
Commercial real estate | Other commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	366,416	347,498	359,813
Nonaccrual	1,353	2,272	3,615
Total	367,776	350,147	363,428
Residential mortgage
Financing receivable, recorded investment, aging [Abstract]
Current	1,681,034	1,667,864	1,662,303
Nonaccrual	52,452	61,240	44,100
Total	1,872,793	1,876,893	1,868,995
Residential mortgage | Permanent mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	939,853	913,062	903,685
Nonaccrual	25,956	28,984	30,661
Total	969,558	945,336	937,664
Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	41,150	33,653	33,046
Nonaccrual	15,432	21,900	3,885
Total	190,309	196,937	192,712
Residential mortgage | Home equity {Member]
Financing receivable, recorded investment, aging [Abstract]
Current	700,031	721,149	725,572
Nonaccrual	11,064	10,356	9,554
Total	712,926	734,620	738,619
Personal
Financing receivable, recorded investment, aging [Abstract]
Current	677,194	551,533	465,218
Nonaccrual	686	463	494
Total	678,232	552,697	465,957
30 to 59 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	39,781	36,703	30,750
30 to 59 Days [Member] | Commercial
Financing receivable, recorded investment, aging [Abstract]
Past Due	13,380	5,269	8,979
30 to 59 Days [Member] | Commercial | Energy [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	11,988	2,635	7,142
30 to 59 Days [Member] | Commercial | Services [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	502	66	1,575
30 to 59 Days [Member] | Commercial | Wholesale/retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	221	49	197
30 to 59 Days [Member] | Commercial | Manufacturing [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
30 to 59 Days [Member] | Commercial | Healthcare [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	635	2,435	0
30 to 59 Days [Member] | Commercial | Other commercial and industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	34	84	65
30 to 59 Days [Member] | Commercial real estate
Financing receivable, recorded investment, aging [Abstract]
Past Due	3,773	8,114	217
30 to 59 Days [Member] | Commercial real estate | Residential construction and land development [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
30 to 59 Days [Member] | Commercial real estate | Retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	3,766	0	0
30 to 59 Days [Member] | Commercial real estate | Office [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	217
30 to 59 Days [Member] | Commercial real estate | Multifamily [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	8,114	0
30 to 59 Days [Member] | Commercial real estate | Industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
30 to 59 Days [Member] | Commercial real estate | Other commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	7	0	0
30 to 59 Days [Member] | Residential mortgage
Financing receivable, recorded investment, aging [Abstract]
Past Due	22,437	22,655	21,355
30 to 59 Days [Member] | Residential mortgage | Permanent mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	3,547	3,290	3,183
30 to 59 Days [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	17,364	16,986	15,299
30 to 59 Days [Member] | Residential mortgage | Home equity {Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	1,526	2,379	2,873
30 to 59 Days [Member] | Personal
Financing receivable, recorded investment, aging [Abstract]
Past Due	191	665	199
60 to 89 Days [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	18,856	18,182	21,519
60 to 89 Days [Member] | Commercial
Financing receivable, recorded investment, aging [Abstract]
Past Due	107	4,041	3,824
60 to 89 Days [Member] | Commercial | Energy [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
60 to 89 Days [Member] | Commercial | Services [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	39	4,025	3,803
60 to 89 Days [Member] | Commercial | Wholesale/retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
60 to 89 Days [Member] | Commercial | Manufacturing [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
60 to 89 Days [Member] | Commercial | Healthcare [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
60 to 89 Days [Member] | Commercial | Other commercial and industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	68	16	21
60 to 89 Days [Member] | Commercial real estate
Financing receivable, recorded investment, aging [Abstract]
Past Due	5,131	0	6,418
60 to 89 Days [Member] | Commercial real estate | Residential construction and land development [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
60 to 89 Days [Member] | Commercial real estate | Retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
60 to 89 Days [Member] | Commercial real estate | Office [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
60 to 89 Days [Member] | Commercial real estate | Multifamily [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	5,131	0	6,418
60 to 89 Days [Member] | Commercial real estate | Industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
60 to 89 Days [Member] | Commercial real estate | Other commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
60 to 89 Days [Member] | Residential mortgage
Financing receivable, recorded investment, aging [Abstract]
Past Due	13,470	14,113	11,231
60 to 89 Days [Member] | Residential mortgage | Permanent mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	202	0	135
60 to 89 Days [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	12,963	13,397	10,477
60 to 89 Days [Member] | Residential mortgage | Home equity {Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	305	716	619
60 to 89 Days [Member] | Personal
Financing receivable, recorded investment, aging [Abstract]
Past Due	148	28	46
90 Days or More [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	107,239	112,208	130,106
90 Days or More [Member] | Commercial
Financing receivable, recorded investment, aging [Abstract]
Past Due	3,826	802	100
90 Days or More [Member] | Commercial | Energy [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
90 Days or More [Member] | Commercial | Services [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	3,707	0	0
90 Days or More [Member] | Commercial | Wholesale/retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	700	0
90 Days or More [Member] | Commercial | Manufacturing [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
90 Days or More [Member] | Commercial | Healthcare [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
90 Days or More [Member] | Commercial | Other commercial and industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	119	102	100
90 Days or More [Member] | Commercial real estate
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	377	0
90 Days or More [Member] | Commercial real estate | Residential construction and land development [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
90 Days or More [Member] | Commercial real estate | Retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
90 Days or More [Member] | Commercial real estate | Office [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
90 Days or More [Member] | Commercial real estate | Multifamily [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
90 Days or More [Member] | Commercial real estate | Industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
90 Days or More [Member] | Commercial real estate | Other commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	377	0
90 Days or More [Member] | Residential mortgage
Financing receivable, recorded investment, aging [Abstract]
Past Due	103,400	111,021	130,006
90 Days or More [Member] | Residential mortgage | Permanent mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	0	0
90 Days or More [Member] | Residential mortgage | Permanent mortgages guaranteed by US government agencies [Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	103,400	111,001	130,005
90 Days or More [Member] | Residential mortgage | Home equity {Member]
Financing receivable, recorded investment, aging [Abstract]
Past Due	0	20	1
90 Days or More [Member] | Personal
Financing receivable, recorded investment, aging [Abstract]
Past Due	$ 13	$ 8	$ 0

Acquisitions (Details)

Acquisitions (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Business Acquisition [Line Items]
Purchase Price Allocation, Goodwill	$ 382,739	$ 385,461	$ 385,461
MBT Bancshares [Member]
Business Acquisition [Line Items]
Agreed to purchase price amount of acquisition target	102,500
Series of Individually Immaterial Business Acquisitions [Member]
Business Acquisition [Line Items]
Purchase Price	7,700	18,000
Purchase Price Allocation, Intangible Assets	5,300	11,000
Purchase Price Allocation, Goodwill	$ 3,300	$ 2,700

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, 2016	Sep. 30, 2015	Dec. 31, 2015
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	90 days
Residential mortgage loans held for sale, nonperforming	$ 0	$ 0	$ 0
Credit losses recognized on residential mortgage loans held for sale	0	0	0
Components of Residential Mortgage Loans Held for Sale [Abstract]
Unpaid principal balance	422,523	336,974	293,637
Residential mortgage loans held for sale, Fair value	433,040	348,400	299,505
Total residential mortgage loans held for sale and mortgage loan commitments, net of forward sales contracts	$ 447,592	$ 357,414	$ 308,439
Residential mortgage loan commitments [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	60 days
General number of days outstanding for residential mortgage commitments, maximum (in days)	90 days	90 days	90 days
Forward sales contracts [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	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	90 days
Not Designated as Hedging Instrument [Member] | Residential mortgage loan commitments [Member]
Components of Residential Mortgage Loans Held for Sale [Abstract]
Notional	$ 630,804	$ 742,742	$ 601,147
Derivative, Net fair value	18,598	18,161	8,134
Not Designated as Hedging Instrument [Member] | Forward sales contracts [Member]
Components of Residential Mortgage Loans Held for Sale [Abstract]
Notional	929,907	1,073,343	884,710
Derivative, Net fair value	$ (4,046)	$ (9,147)	$ 800

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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Mortgage Banking Revenue [Abstract]
Net realized gains on sale of mortgage loans	$ 27,142	$ 18,968	$ 57,126	$ 60,075
Net change in unrealized gain on mortgage loans held for sale	(2,518)	6,666	4,649	4,751
Net change in the fair value of mortgage loan commitments	(6,901)	9,838	10,464	8,190
Net change in the fair value of forward sales contracts	8,267	(16,755)	(4,846)	(5,146)
Total production revenue	25,990	18,717	67,393	67,870
Servicing revenue	16,558	14,453	47,809	41,466
Total mortgage banking revenue	$ 42,548	$ 33,170	$ 115,202	$ 109,336

Mortgage Banking Activities, Mo

Mortgage Banking Activities, Mortgage Servicing Rights (Details)	3 Months Ended			9 Months Ended
	Sep. 30, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)
Summary of Mortgage Servicing Rights [Abstract]
Number of residential mortgage loans serviced for others	139,587	131,859	128,828	139,587	128,828
Outstanding principal balance of residential mortgage loans serviced for others	$ 21,851,536,000	$ 19,678,226,000	$ 18,928,726,000	$ 21,851,536,000	$ 18,928,726,000
Weighted average interest rate	4.01%	4.12%	4.15%	4.01%	4.15%
Remaining term (in months)	302 months	300 months	300 months
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 190,747,000	$ 200,049,000	$ 198,694,000	$ 218,605,000	$ 171,976,000
Additions, net	21,990,000		19,993,000	56,345,000	62,375,000
Change in fair value due to scheduled payments and full-balance payoffs	(11,443,000)		(6,881,000)	(29,385,000)	(22,033,000)
Change in fair value due to market assumption changes	2,327,000		(11,757,000)	(41,944,000)	(12,269,000)
Ending balance	$ 203,621,000	$ 218,605,000	$ 200,049,000	$ 203,621,000	$ 200,049,000
Servicing Assets at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Discount rate - risk-free rate plus a market premium (in hundredths)	10.08%	10.11%	10.12%
Loan servicing costs - annually per loan based upon loan type, performing, minimum (in dollars per loan)	$ 63	$ 63	$ 63
Loan servicing costs - annually per loan based upon loan type, performing, maximum (in dollars per loan)	120	105	105
Loan servicing costs - annually per loan based upon loan type, delinquent, minimum (in dollars per loan)	150	150	150
Loan servicing costs - annually per loan based upon loan type, delinquent, maximum (in dollars per loan)	500	500	500
Loan servicing costs - annually per loan based upon loan type, foreclosure, minimum (in dollars per loan)	650	650	650
Loan servicing costs - annually per loan based upon loan type, foreclosure, maximum (in dollars per loan)	$ 4,250	$ 4,250	$ 4,250
Escrow earnings rate - indexed to rates paid on deposit accounts with comparable average life (in hundredths)	1.18%	1.73%	1.40%
Primary secondary mortgage rate spread (in basis points)	115	130	135	115	135
Purchased [Member]
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 4,067,000	$ 9,413,000	$ 10,730,000	$ 9,911,000	$ 11,114,000
Additions, net	0		0	0	0
Change in fair value due to scheduled payments and full-balance payoffs	(753,000)		(661,000)	(2,109,000)	(2,171,000)
Change in fair value due to market assumption changes	251,000		(656,000)	(4,237,000)	470,000
Ending balance	3,565,000	9,911,000	9,413,000	3,565,000	9,413,000
Originated [Member]
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	186,680,000	190,636,000	187,964,000	208,694,000	160,862,000
Additions, net	21,990,000		19,993,000	56,345,000	62,375,000
Change in fair value due to scheduled payments and full-balance payoffs	(10,690,000)		(6,220,000)	(27,276,000)	(19,862,000)
Change in fair value due to market assumption changes	2,076,000		(11,101,000)	(37,707,000)	(12,739,000)
Ending balance	$ 200,056,000	$ 208,694,000	$ 190,636,000	$ 200,056,000	$ 190,636,000

Mortgage Banking Activities, Lo

Mortgage Banking Activities, Loan Servicing Portfolio (Details) $ in Thousands		Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Dec. 31, 2014USD ($)
Stratification of Mortgage Loan Servicing Portfolio [Line Items]
Fair value		$ 203,621	$ 190,747	$ 218,605	$ 200,049	$ 198,694	$ 171,976
Outstanding principal of loans serviced for others		$ 21,851,536
Weighted average prepayment rate (in hundredths)	[1]	13.20%
Economic hedge threshold for interest rate sensitivity for mortgage servicing rights and securities held (in basis points)		50
Dollar decrease in fair value of mortgage servicing rights due to a 50 basis point decrease in mortgage interest rates		$ 52,600
Dollar increase in fair value of mortgage servicing rights Due To 50 Basis Point Increase In Mortgage Interest Rates		30,600
Interest Rate Range Less than 4.00% [Member]
Stratification of Mortgage Loan Servicing Portfolio [Line Items]
Fair value		121,802
Outstanding principal of loans serviced for others		$ 12,145,996
Weighted average prepayment rate (in hundredths)	[1]	9.16%
Interest Rate Range 4.00% to 4.99% [Member]
Stratification of Mortgage Loan Servicing Portfolio [Line Items]
Fair value		$ 74,830
Outstanding principal of loans serviced for others		$ 7,720,311
Weighted average prepayment rate (in hundredths)	[1]	12.48%
Interest Rate Range 5.00% to 5.99% [Member]
Stratification of Mortgage Loan Servicing Portfolio [Line Items]
Fair value		$ 4,968
Outstanding principal of loans serviced for others		$ 1,215,692
Weighted average prepayment rate (in hundredths)	[1]	36.75%
Interest Rate Range Greater than 5.99% [Member]
Stratification of Mortgage Loan Servicing Portfolio [Line Items]
Fair value		$ 2,021
Outstanding principal of loans serviced for others		$ 769,537
Weighted average prepayment rate (in hundredths)	[1]	47.15%
[1]	Annual prepayment estimates based upon loan interest rate, original term and loan type. Weighted average prepayment rate is determined by weighting the prepayment speed for each loan by its unpaid principal balance.

Mortgage Banking Activities M51

Mortgage Banking Activities Mortgage Banking Activities, Loans Serviced for Others (Details) $ in Thousands	Sep. 30, 2016USD ($)
Financing Receivable, Recorded Investment, Aging [Abstract]
Current	$ 21,494,943
30 to 59 Days Past Due	228,796
60 to 89 Days Past Due	68,489
90 Days or More Past Due	59,308
Total	21,851,536
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Current	7,760,547
30 to 59 Days Past Due	34,145
60 to 89 Days Past Due	10,399
90 Days or More Past Due	23,938
Total	7,829,029
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Current	6,944,158
30 to 59 Days Past Due	43,046
60 to 89 Days Past Due	8,704
90 Days or More Past Due	17,097
Total	7,013,005
Government National Mortgage Association Certificates and Obligations (GNMA) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Current	6,338,155
30 to 59 Days Past Due	150,386
60 to 89 Days Past Due	48,790
90 Days or More Past Due	16,624
Total	6,553,955
Other Investor Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Current	452,083
30 to 59 Days Past Due	1,219
60 to 89 Days Past Due	596
90 Days or More Past Due	1,649
Total	$ 455,547

Mortgage Banking Activities, 52

Mortgage Banking Activities, Loans Sold With Recourse (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)
Residential Mortgage Loans Sold With Recourse [Abstract]
Carrying amount of residential mortgage loans sold and subject to recourse	$ 139,000	$ 162,000	$ 139,000	$ 162,000	$ 155,000
Percentage of loans sold with recourse and either more than 90 days past due or in bankruptcy or foreclosure (in hundredths)	2.00%		2.00%
Principal balance of loans sold with recourse and either 90 days or more past due or in bankruptcy or foreclosure	$ 3,300		$ 3,300
Percentage of loans sold with recourse and 30 to 89 days past due (in hundredths)	5.00%		5.00%
Principal balance of loans sold with recourse and 30 to 89 days past due	$ 7,100		$ 7,100
Activity in the accrual for losses on loans sold with recourse [Roll forward]
Beginning balance	4,339	6,691	4,649	7,299
Provision for recourse losses	113	81	504	211
Loans charged off, net	(235)	(506)	(936)	(1,244)
Ending balance	$ 4,217	$ 6,266	$ 4,217	$ 6,266
Residential Mortgage Loan Repurchase and Servicing Losses [Abstract]
Number of mortgages purchased under repurchase agreement with government sponsored entities.	2
Purchase price of loans purchased under repurchase agreement with government sponsored entities	$ 309
Number of loans sold under standard representations and warranties indemnified	0
Number of unresolved deficiency requests	221	194	221	194
Aggregate outstanding principal balance subject to unresolved deficiency requests	$ 15,750	$ 14,237	$ 15,750	$ 14,237
Unpaid principal balance subject to indemnification by the Company	5,399	4,604	5,399	4,604
Activity in accrual for mortgage losses [Rollforward]
Beginning balance	8,043	8,908	7,732	11,868
Provision for losses	1,357	(52)	5,260	(3,056)
Charge-offs, net	(1,758)	(1,262)	(5,350)	(1,218)
Ending balance	$ 7,642	$ 7,594	$ 7,642	$ 7,594

Commitments and Contingent Li53

Commitments and Contingent Liabilities (Details)	3 Months Ended
	Sep. 30, 2016USD ($)shares
Visa Membership [Member]
Loss Contingencies [Line Items]
Number of Visa Class B Shares Owned by Entity (in shares) | shares	252,233
Number of Visa Class A Shares Visa Class B Shares Are Convertible To (in shares) | shares	415,755
BOKF Equity, LLC [Member]
Litigation Settlement [Abstract]
Number of Private Equity Funds of which the Entity is a General Partner	2
Contingent Obligations For Additional Investments in Private Equity Funds	$ 4,600,000
Cavanal Hill Funds [Member]
Litigation Settlement [Abstract]
The Net Asset Value of Units in Mutual Funds (per unit)	1
Settled Litigation [Member] | Deposit Account Posting Class Action [Member]
Litigation Settlement [Abstract]
Litigation Settlement, Amount	$ 7,800,000
Settled Litigation [Member] | Municipal Bond Purchase by Elected Treasurer [Member]
Litigation Settlement [Abstract]
Litigation Settlement, Amount	125,000
Judicial Ruling [Member] | Misuse of Revenues Pledged to Municipal Bonds [Member]
Litigation Settlement [Abstract]
Litigation Settlement, Amount	600,000
Outstanding principal, accrued interest and other amounts required by bond documents	73,000,000
Disgorged fees	$ 1,067,721
Pending Litigation [Member] | Misuse of Revenues Pledged to Municipal Bonds [Member]
Litigation Settlement [Abstract]
Loss Contingency, Number of Plaintiffs	2
Pending Litigation [Member] | Bank Participation in Fraudulent Sale of Securities by Principals [Member]
Litigation Settlement [Abstract]
Loss Contingency, Number of Plaintiffs	19
Pending Litigation [Member] | Municipal Bond Purchase by Elected Treasurer [Member]
Litigation Settlement [Abstract]
Loss Contingency, Damages Sought, Value	$ 5,600,000

Commitments and Contingent Li54

Commitments and Contingent Liabilities Variable Interest Entities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Loans Receivable [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	$ 10,000	$ 10,000	$ 10,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	39,849	16,916	18,114
Loans Receivable [Member] | Private equity funds [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0	0
Loans Receivable [Member] | Tax credit entities [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	10,000	10,000	10,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	39,849	16,916	18,114
Loans Receivable [Member] | Other [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0	0
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0	0
Other Assets [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	61,138	75,131	77,691
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	159,987	100,780	110,422
Other Assets [Member] | Private equity funds [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	18,420	22,472	24,133
Other Assets [Member] | Tax credit entities [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	11,740	12,206	12,361
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	129,715	85,274	94,600
Other Assets [Member] | Other [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	30,978	40,453	41,197
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	30,272	15,506	15,822
Other Liabilities [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	2,346	2,198	2,774
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	70,679	20,891	28,872
Other Liabilities [Member] | Private equity funds [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0	0
Other Liabilities [Member] | Tax credit entities [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0	0
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	57,026	14,572	21,973
Other Liabilities [Member] | Other [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	2,346	2,198	2,774
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	13,653	6,319	6,899
Other borrowings [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	12,027	13,795	13,752
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0	0
Other borrowings [Member] | Private equity funds [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0	0
Other borrowings [Member] | Tax credit entities [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	10,964	10,964	10,964
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0	0
Other borrowings [Member] | Other [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	1,063	2,831	2,788
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0	0
Non-Controlling Interests [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	34,100	37,083	38,936
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0	0
Non-Controlling Interests [Member] | Private equity funds [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	15,946	17,823	19,947
Non-Controlling Interests [Member] | Tax credit entities [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	10,000	10,000	10,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0	0
Non-Controlling Interests [Member] | Other [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	8,154	9,260	8,989
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	$ 0	$ 0	$ 0

Commitments and Contingent Li55

Commitments and Contingent Liabilities Commitments (Details) $ in Millions	Sep. 30, 2016USD ($)
Oklahoma Historic State Income Tax Credit [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Purchase Commitment, Remaining Minimum Amount Committed	$ 7.5

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands		Oct. 25, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016		Sep. 30, 2015
Dividends declared (in dollars per share)			$ 0.43	$ 0.42	$ 1.29		$ 1.26
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period					$ 21,587		$ 56,673
Net change in unrealized gain (loss)			$ (33,458)	$ 57,892	133,108		57,763
Reclassification adjustments included in earnings:
Interest revenue, Investment securities, Taxable securities			0	(105)	(112)		(418)
Interest expense, Subordinated debentures			0	0	0		121
Net impairment losses recognized in earnings			0	0	0		92
Gain on available for sale securities, net			(2,394)	(2,166)	(11,684)		(9,926)
Other comprehensive income (loss), before income taxes			(35,852)	55,621	121,312		47,632
Federal and state income taxes			(13,947)	21,637	47,172	[1]	18,529	[1]
Other comprehensive income (loss), net of income taxes			(21,905)	33,984	74,140		29,103
Balance, End of Period			95,727	85,776	95,727		85,776
Accumulated Net Unrealized Gain (Loss) on Available for Sale Securities [Member]
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period					23,284		59,239
Net change in unrealized gain (loss)					133,108		57,763
Reclassification adjustments included in earnings:
Interest revenue, Investment securities, Taxable securities					0		0
Interest expense, Subordinated debentures					0		0
Net impairment losses recognized in earnings					0		92
Gain on available for sale securities, net					(11,684)		(9,926)
Other comprehensive income (loss), before income taxes					121,424		47,929
Federal and state income taxes	[1]				47,216		18,644
Other comprehensive income (loss), net of income taxes					74,208		29,285
Balance, End of Period			97,492	88,524	97,492		88,524
Accumulated Unrealized Gain on Investment Securities Transferred from AFS [Member]
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period					68		376
Net change in unrealized gain (loss)					0		0
Reclassification adjustments included in earnings:
Interest revenue, Investment securities, Taxable securities					(112)		(418)
Interest expense, Subordinated debentures					0		0
Net impairment losses recognized in earnings					0		0
Gain on available for sale securities, net					0		0
Other comprehensive income (loss), before income taxes					(112)		(418)
Federal and state income taxes	[1]				(44)		(162)
Other comprehensive income (loss), net of income taxes					(68)		(256)
Balance, End of Period			0	120	0		120
Accumulated Unrealized Gain (Loss) on Employee Benefit Plans [Member]
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period					(1,765)		(2,868)
Net change in unrealized gain (loss)					0		0
Reclassification adjustments included in earnings:
Interest revenue, Investment securities, Taxable securities					0		0
Interest expense, Subordinated debentures					0		0
Net impairment losses recognized in earnings					0		0
Gain on available for sale securities, net					0		0
Other comprehensive income (loss), before income taxes					0		0
Federal and state income taxes	[1]				0		0
Other comprehensive income (loss), net of income taxes					0		0
Balance, End of Period			(1,765)	(2,868)	(1,765)		(2,868)
Accumulated Loss on Effective Cash Flow Hedges [Member]
Schedule of Accumulated Other Income (Loss) [Abstract]
Balance, Beginning of Period					0		(74)
Net change in unrealized gain (loss)					0		0
Reclassification adjustments included in earnings:
Interest revenue, Investment securities, Taxable securities					0		0
Interest expense, Subordinated debentures					0		121
Net impairment losses recognized in earnings					0		0
Gain on available for sale securities, net					0		0
Other comprehensive income (loss), before income taxes					0		121
Federal and state income taxes	[1]				0		47
Other comprehensive income (loss), net of income taxes					0		74
Balance, End of Period			$ 0	$ 0	$ 0		$ 0
Subsequent Event [Member]
Dividends Payable, Date Declared		Oct. 25, 2016
Dividends declared (in dollars per share)		$ 0.44
Dividends Payable, Date to be Paid		Nov. 28, 2016
Dividends Payable, Date of Record		Nov. 14, 2016
[1]	Calculated using a 39 percent effective tax rate.

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator: [Abstract]
Net income attributable to BOK Financial Corp. shareholders	$ 74,277	$ 74,891	$ 182,642	$ 228,964
Less: Earnings allocated to participating securities	916	894	2,275	2,652
Numerator for basic earnings per share – income available to common shareholders	73,361	73,997	180,367	226,312
Effect of reallocating undistributed earnings of participating securities	1	1	1	2
Numerator for diluted earnings per share – income available to common shareholders	$ 73,362	$ 73,998	$ 180,368	$ 226,314
Denominator: [Abstract]
Weighted average shares outstanding (in shares)	65,895,430	68,486,376	66,031,497	68,800,419
Less: Participating securities included in weighted average shares (in shares)	810,038	818,300	822,723	795,911
Denominator for basic earnings per common share (in shares)	65,085,392	67,668,076	65,208,774	68,004,508
Dilutive effect of employee stock compensation plans (in shares)	72,449	94,407	54,792	99,509
Denominator for diluted earnings per common share (in shares)	65,157,841	67,762,483	65,263,566	68,104,017
Basic earnings per share (per share)	$ 1.13	$ 1.09	$ 2.77	$ 3.33
Diluted earnings per share (per share)	$ 1.13	$ 1.09	$ 2.76	$ 3.32
1 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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Net interest revenue from external sources	$ 187,846	$ 178,636	$ 553,030	$ 522,093
Net interest revenue (expense) from internal sources	0	0	0	0
Net interest revenue	187,846	178,636	553,030	522,093
Provision for credit losses	10,000	7,500	65,000	11,500
Net interest revenue after provision for credit losses	177,846	171,136	488,030	510,593
Other operating revenue	191,342	163,436	539,968	505,738
Other operating expense	262,120	224,628	761,745	672,006
Net direct contribution	107,068	109,944	266,253	344,325
Gain (loss) on financial instruments, net	0	0	0	0
Change in fair value of mortgage servicing rights	0	0	0	0
Gain on repossessed assets, net	0	0	0	0
Corporate expense allocations	0	0	0	0
Net income before taxes	107,068	109,944	266,253	344,325
Federal and state income taxes	31,956	34,128	83,881	113,142
Net income	75,112	75,816	182,372	231,183
Net income (loss) attributable to non-controlling interests	835	925	(270)	2,219
Net income attributable to BOK Financial Corp. shareholders	74,277	74,891	182,642	228,964
Average assets	32,646,473	30,769,733	32,049,183	30,404,430
Average invested capital	3,357,551	3,361,547	3,318,599	3,341,631
Operating Segments [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	123,598	109,503	358,714	319,298
Net interest revenue (expense) from internal sources	(15,052)	(13,450)	(44,259)	(38,728)
Net interest revenue	108,546	96,053	314,455	280,570
Provision for credit losses	5,601	997	34,024	(7,952)
Net interest revenue after provision for credit losses	102,945	95,056	280,431	288,522
Other operating revenue	49,642	45,276	146,248	132,996
Other operating expense	53,375	51,960	162,039	151,908
Net direct contribution	99,212	88,372	264,640	269,610
Gain (loss) on financial instruments, net	0	0	0	0
Change in fair value of mortgage servicing rights	0	0	0	0
Gain on repossessed assets, net	1,486	350	806	336
Corporate expense allocations	9,054	10,723	26,681	32,747
Net income before taxes	91,644	77,999	238,765	237,199
Federal and state income taxes	35,650	30,342	92,880	92,270
Net income	55,994	47,657	145,885	144,929
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	55,994	47,657	145,885	144,929
Average assets	16,934,587	16,156,446	16,958,999	16,229,307
Average invested capital	1,170,465	1,062,053	1,161,996	1,028,013
Operating Segments [Member] | Consumer [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	22,098	21,551	65,897	63,993
Net interest revenue (expense) from internal sources	9,263	7,216	27,492	20,874
Net interest revenue	31,361	28,767	93,389	84,867
Provision for credit losses	1,157	1,431	4,177	4,467
Net interest revenue after provision for credit losses	30,204	27,336	89,212	80,400
Other operating revenue	64,635	57,349	181,774	178,232
Other operating expense	64,995	51,027	189,188	155,844
Net direct contribution	29,844	33,658	81,798	102,788
Gain (loss) on financial instruments, net	(1,087)	7,386	30,539	1,809
Change in fair value of mortgage servicing rights	2,327	(11,758)	(41,944)	(12,269)
Gain on repossessed assets, net	161	331	566	888
Corporate expense allocations	16,905	18,921	49,513	56,075
Net income before taxes	14,340	10,696	21,446	37,141
Federal and state income taxes	5,578	4,161	8,342	14,448
Net income	8,762	6,535	13,104	22,693
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	8,762	6,535	13,104	22,693
Average assets	8,827,816	8,843,926	8,763,564	8,871,423
Average invested capital	275,358	264,540	267,123	268,427
Operating Segments [Member] | Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	9,274	6,674	21,622	18,271
Net interest revenue (expense) from internal sources	7,401	5,834	22,258	17,400
Net interest revenue	16,675	12,508	43,880	35,671
Provision for credit losses	(89)	(190)	(479)	(937)
Net interest revenue after provision for credit losses	16,764	12,698	44,359	36,608
Other operating revenue	73,523	66,541	218,042	204,100
Other operating expense	64,426	57,356	186,524	170,113
Net direct contribution	25,861	21,883	75,877	70,595
Gain (loss) on financial instruments, net	(42)	(176)	(42)	(204)
Change in fair value of mortgage servicing rights	0	0	0	0
Gain on repossessed assets, net	0	0	0	0
Corporate expense allocations	10,912	9,841	31,864	30,011
Net income before taxes	14,907	11,866	43,971	40,380
Federal and state income taxes	5,799	4,616	17,105	15,708
Net income	9,108	7,250	26,866	24,672
Net income (loss) attributable to non-controlling interests	0	0	0	0
Net income attributable to BOK Financial Corp. shareholders	9,108	7,250	26,866	24,672
Average assets	6,413,735	5,433,238	5,916,545	5,401,433
Average invested capital	244,291	226,477	238,917	225,222
Corporate, Non-Segment [Member] | Funds Management and Other [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	32,876	40,908	106,797	120,531
Net interest revenue (expense) from internal sources	(1,612)	400	(5,491)	454
Net interest revenue	31,264	41,308	101,306	120,985
Provision for credit losses	3,331	5,262	27,278	15,922
Net interest revenue after provision for credit losses	27,933	36,046	74,028	105,063
Other operating revenue	3,542	(5,730)	(6,096)	(9,590)
Other operating expense	79,324	64,285	223,994	194,141
Net direct contribution	(47,849)	(33,969)	(156,062)	(98,668)
Gain (loss) on financial instruments, net	1,129	(7,210)	(30,497)	(1,605)
Change in fair value of mortgage servicing rights	(2,327)	11,758	41,944	12,269
Gain on repossessed assets, net	(1,647)	(681)	(1,372)	(1,224)
Corporate expense allocations	(36,871)	(39,485)	(108,058)	(118,833)
Net income before taxes	(13,823)	9,383	(37,929)	29,605
Federal and state income taxes	(15,071)	(4,991)	(34,446)	(9,284)
Net income	1,248	14,374	(3,483)	38,889
Net income (loss) attributable to non-controlling interests	835	925	(270)	2,219
Net income attributable to BOK Financial Corp. shareholders	413	13,449	(3,213)	36,670
Average assets	470,335	336,123	410,075	(97,733)
Average invested capital	$ 1,667,437	$ 1,808,477	$ 1,650,563	$ 1,819,969

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, 2016		Jun. 30, 2016	Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015	Dec. 31, 2014
Assets: [Abstract]
Trading securities	$ 546,615			$ 122,404		$ 181,131
Available for sale securities	8,862,283			9,042,733		8,801,089
Fair value option securities	222,409			444,217		427,760
Mortgage servicing rights	203,621		$ 190,747	218,605		200,049		$ 198,694	$ 171,976
Derviative contracts, net of cash collateral, Assets, Fair value	655,078			586,270		726,159
Liabilities: [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	573,987			581,701		636,115
U.S. government agency debentures
Assets: [Abstract]
Trading securities	15,705			61,295		42,431
U.S. government agency residential mortgage-backed securities
Assets: [Abstract]
Trading securities	464,749			10,989		30,973
Available for sale securities	5,668,672	[1]		5,898,351		5,819,127
Fair value option securities	0			444,217		427,760
Municipal and other tax-exempt securities
Assets: [Abstract]
Trading securities	54,856			31,901		84,261
Available for sale securities	42,092			56,817		57,960
Other trading securities
Assets: [Abstract]
Trading securities	11,305			18,219		23,466
U.S. Treasury
Assets: [Abstract]
Available for sale securities	1,002			995		1,003
Fair value option securities	222,409			0		0
Privately issued residential mortgage-backed securities
Assets: [Abstract]
Available for sale securities	121,603			139,118		145,682
Commercial mortgage-backed securities guaranteed by U.S. government agencies
Assets: [Abstract]
Available for sale securities	2,986,495			2,905,796		2,735,787
Other debt securities
Assets: [Abstract]
Available for sale securities	4,151			4,151		4,150
Perpetual preferred stock
Assets: [Abstract]
Available for sale securities	19,578			19,672		19,163
Equity securities and mutual funds
Assets: [Abstract]
Available for sale securities	18,690			17,833		18,217
Fair Value, Measurements, Recurring [Member]
Assets: [Abstract]
Trading securities	546,615			122,404		181,131
Available for sale securities	8,862,283			9,042,733		8,801,089
Fair value option securities	222,409			444,217		427,760
Residential mortgage loans held for sale	447,592			308,439		357,414
Mortgage servicing rights	203,621	[2]		218,605	[3]	200,049	[4]
Derviative contracts, net of cash collateral, Assets, Fair value	655,078	[5]		586,270	[6]	726,159	[7]
Liabilities: [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	573,987	[5]		581,701	[6]	636,115	[7]
Fair Value, Measurements, Recurring [Member] | U.S. government agency debentures
Assets: [Abstract]
Trading securities	15,705			61,295		42,431
Fair Value, Measurements, Recurring [Member] | U.S. government agency residential mortgage-backed securities
Assets: [Abstract]
Trading securities	464,749			10,989		30,973
Available for sale securities	5,668,672			5,898,351		5,819,127
Fair value option securities	0			444,217		427,760
Fair Value, Measurements, Recurring [Member] | Municipal and other tax-exempt securities
Assets: [Abstract]
Trading securities	54,856			31,901		84,261
Available for sale securities	42,092			56,817		57,960
Fair Value, Measurements, Recurring [Member] | Other trading securities
Assets: [Abstract]
Trading securities	11,305			18,219		23,466
Fair Value, Measurements, Recurring [Member] | U.S. Treasury
Assets: [Abstract]
Available for sale securities	1,002			995		1,003
Fair value option securities	222,409			0		0
Fair Value, Measurements, Recurring [Member] | Privately issued residential mortgage-backed securities
Assets: [Abstract]
Available for sale securities	121,603			139,118		145,682
Fair Value, Measurements, Recurring [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies
Assets: [Abstract]
Available for sale securities	2,986,495			2,905,796		2,735,787
Fair Value, Measurements, Recurring [Member] | Other debt securities
Assets: [Abstract]
Available for sale securities	4,151			4,151		4,150
Fair Value, Measurements, Recurring [Member] | Perpetual preferred stock
Assets: [Abstract]
Available for sale securities	19,578			19,672		19,163
Fair Value, Measurements, Recurring [Member] | Equity securities and mutual funds
Assets: [Abstract]
Available for sale securities	18,690			17,833		18,217
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets: [Abstract]
Trading securities	0			0		0
Available for sale securities	4,546			4,260		4,508
Fair value option securities	222,409			0		0
Residential mortgage loans held for sale	0			0		0
Mortgage servicing rights	0			0		0
Derviative contracts, net of cash collateral, Assets, Fair value	5,575			38,530		4,922
Liabilities: [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	1,308			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. government agency debentures
Assets: [Abstract]
Trading securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. government agency residential mortgage-backed securities
Assets: [Abstract]
Trading securities	0			0		0
Available for sale securities	0			0		0
Fair value option securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal and other tax-exempt securities
Assets: [Abstract]
Trading securities	0			0		0
Available for sale securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other trading securities
Assets: [Abstract]
Trading securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Treasury
Assets: [Abstract]
Available for sale securities	1,002			995		1,003
Fair value option securities	222,409			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Privately issued residential mortgage-backed securities
Assets: [Abstract]
Available for sale securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies
Assets: [Abstract]
Available for sale securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other debt securities
Assets: [Abstract]
Available for sale securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Perpetual preferred stock
Assets: [Abstract]
Available for sale securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Equity securities and mutual funds
Assets: [Abstract]
Available for sale securities	3,544			3,265		3,505
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets: [Abstract]
Trading securities	546,615			122,404		181,131
Available for sale securities	8,847,873			9,024,712		8,782,831
Fair value option securities	0			444,217		427,760
Residential mortgage loans held for sale	438,291			300,565		349,381
Mortgage servicing rights	0			0		0
Derviative contracts, net of cash collateral, Assets, Fair value	649,503			547,740		721,237
Liabilities: [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	572,679			581,701		636,115
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. government agency debentures
Assets: [Abstract]
Trading securities	15,705			61,295		42,431
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. government agency residential mortgage-backed securities
Assets: [Abstract]
Trading securities	464,749			10,989		30,973
Available for sale securities	5,668,672			5,898,351		5,819,127
Fair value option securities	0			444,217		427,760
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal and other tax-exempt securities
Assets: [Abstract]
Trading securities	54,856			31,901		84,261
Available for sale securities	36,379			47,207		48,360
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other trading securities
Assets: [Abstract]
Trading securities	11,305			18,219		23,466
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Treasury
Assets: [Abstract]
Available for sale securities	0			0		0
Fair value option securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Privately issued residential mortgage-backed securities
Assets: [Abstract]
Available for sale securities	121,603			139,118		145,682
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies
Assets: [Abstract]
Available for sale securities	2,986,495			2,905,796		2,735,787
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other debt securities
Assets: [Abstract]
Available for sale securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Perpetual preferred stock
Assets: [Abstract]
Available for sale securities	19,578			19,672		19,163
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Equity securities and mutual funds
Assets: [Abstract]
Available for sale securities	15,146			14,568		14,712
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets: [Abstract]
Trading securities	0			0		0
Available for sale securities	9,864			13,761		13,750
Fair value option securities	0			0		0
Residential mortgage loans held for sale	9,301			7,874		8,033
Mortgage servicing rights	203,621			218,605		200,049
Derviative contracts, net of cash collateral, Assets, Fair value	0			0		0
Liabilities: [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. government agency debentures
Assets: [Abstract]
Trading securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. government agency residential mortgage-backed securities
Assets: [Abstract]
Trading securities	0			0		0
Available for sale securities	0			0		0
Fair value option securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal and other tax-exempt securities
Assets: [Abstract]
Trading securities	0			0		0
Available for sale securities	5,713			9,610		9,600
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other trading securities
Assets: [Abstract]
Trading securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Treasury
Assets: [Abstract]
Available for sale securities	0			0		0
Fair value option securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Privately issued residential mortgage-backed securities
Assets: [Abstract]
Available for sale securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies
Assets: [Abstract]
Available for sale securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other debt securities
Assets: [Abstract]
Available for sale securities	4,151			4,151		4,150
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Perpetual preferred stock
Assets: [Abstract]
Available for sale securities	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Equity securities and mutual funds
Assets: [Abstract]
Available for sale securities	$ 0			$ 0		$ 0
[1]	U.S. government and government sponsored enterprises are not rated by the nationally-recognized rating agencies as these securities are guaranteed by agencies of the U.S. government or government-sponsored enterprises.
[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]	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.
[4]	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.
[5]	See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts in asset positions that were valued based on quoted prices in active markets for identical instruments (Level 1) are primarily exchange-traded energy and 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 and energy derivative contracts, net of cash margin.
[6]	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 energy derivative contacts, net of cash margin. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate and agricultural derivative contracts, net of cash margin.
[7]	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 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) were exchange-traded interest rate derivative contracts, fully offset by cash margin.

Fair Value Measurements, Measur

Fair Value Measurements, Measured On Recurring Basis Significant Unobservable Inputs (Details) - Fair Value, Measurements, Recurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Available-for-sale securities [Member] | Municipal and other tax-exempt securities
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period	$ 9,600	$ 9,617	$ 9,610	$ 10,093
Transfer to Level 3 from Level 2	0	0	0	0
Purchases	0	0	0	0
Proceeds from sales	0	0	0	0
Redemptions and distributions	(3,975)	0	(3,975)	(500)
Other comprehensive income (loss)	88	(17)	78	7
Balance, end of period	5,713	9,600	5,713	9,600
Available-for-sale securities [Member] | Municipal and other tax-exempt securities | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0	0	0
Available-for-sale securities [Member] | Other debt securities
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period	4,151	4,150	4,151	4,150
Transfer to Level 3 from Level 2	0	0	0	0
Purchases	0	0	0	0
Proceeds from sales	0	0	0	0
Redemptions and distributions	0	0	0	0
Other comprehensive income (loss)	0	0	0	0
Balance, end of period	4,151	4,150	4,151	4,150
Available-for-sale securities [Member] | Other debt securities | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0	0	0
Residential mortgage loans held for sale [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period	9,749	7,973	7,874	11,856
Transfer to Level 3 from Level 2	442	966	3,982	2,153
Purchases	0	0	0	0
Proceeds from sales	(1,003)	(811)	(2,365)	(6,099)
Redemptions and distributions	0	0	0	0
Other comprehensive income (loss)	0	0	0	0
Balance, end of period	9,301	8,033	9,301	8,033
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	$ 113	$ (95)	$ (190)	$ 123

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Measurements, Financial Instruments Measured On a Recurring Basis, Quantitative Information (Details) - Fair Value, Measurements, Recurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	9 Months Ended				12 Months Ended
	Sep. 30, 2016		Sep. 30, 2015		Dec. 31, 2015
Available-for-sale securities [Member] | Municipal and other tax-exempt securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Asset, Par Value	$ 6,195		$ 10,370		$ 10,370
Fair Value Inputs, Asset, Amortized Cost	6,162		10,310		10,311
Fair Value Inputs, Asset, Fair Value	$ 5,713		$ 9,600		$ 9,610
Fair Value Measurements, Valuation Techniques	Discounted cash flows	[1]	Discounted cash flows	[2]	Discounted cash flows	[3]
Fair Value Measurements, Significant Unobservable Input	Interest rate spread		Interest rate spread		Interest rate spread
Fair Value Inputs, Assets, Discount Rate, Minimum	5.60%	[4]	5.23%	[5]	5.47%	[6]
Fair Value Inputs, Assets, Discount Rate, Maximum	5.90%	[4]	5.53%	[5]	5.77%	[6]
Fair Value Inputs, Assets, Discount Rate, Weighted Average	5.85%	[4]	5.49%	[5]	5.73%	[6]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Minimum	90.00%	[7]	92.35%	[8]	92.34%	[9]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Maximum	93.79%	[7]	92.73%	[8]	92.93%	[9]
Fair Value Inputs, Fair Value As Percentage of Par Value, Weighted Average	92.22%	[7]	92.57%	[8]	92.67%	[9]
Investment Grade Tax Exempt Securities Yield Spread Over Comparable Securities Minimum	437		510		499
Investment Grade Tax Exempt Securities Yield Spread Over Comparable Securities Maximum	484		538		541
Available-for-sale securities [Member] | Other debt securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Asset, Par Value	$ 4,400		$ 4,400		$ 4,400
Fair Value Inputs, Asset, Amortized Cost	4,400		4,400		4,400
Fair Value Inputs, Asset, Fair Value	$ 4,151		$ 4,150		$ 4,151
Fair Value Measurements, Valuation Techniques	Discounted cash flows	[1]	Discounted cash flows	[2]	Discounted cash flows	[3]
Fair Value Measurements, Significant Unobservable Input	Interest rate spread		Interest rate spread		Interest rate spread
Fair Value Inputs, Assets, Discount Rate, Minimum	5.98%	[10]	5.65%	[11]	5.80%	[12]
Fair Value Inputs, Assets, Discount Rate, Maximum	6.03%	[10]	5.70%	[11]	5.92%	[12]
Fair Value Inputs, Assets, Discount Rate, Weighted Average	6.02%	[10]	5.69%	[11]	5.90%	[12]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Minimum	94.34%	[7]	94.32%	[8]	94.33%	[9]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value, Maximum	94.34%	[7]	94.33%	[8]	94.34%	[9]
Fair Value Inputs, Fair Value As Percentage of Par Value, Weighted Average	94.34%	[7]	94.33%	[8]	94.34%	[9]
Average Yields On Comparable Short-term Taxable Securities Maximum	1.00%		1.00%		1.00%
Residential mortgage loans held for sale [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Asset, Amortized Cost	$ 9,957		$ 8,538		$ 8,395
Fair Value Inputs, Asset, Fair Value	$ 9,301		$ 8,033		$ 7,874
Fair Value Measurements, Valuation Techniques	Quoted prices of loans sold in securitization transactions, with a liquidity discount applied		Quoted prices of loans sold in securitization transactions, with a liquidity discount applied		Quoted prices of loans sold in securitization transactions, with a liquidity discount applied
Fair Value Measurements, Significant Unobservable Input	Liquidity discount applied to the market value of a mortgage loans qualifying for sale to U.S. government agencies.		Liquidity discount applied to the market value of a mortgage loans qualifying for sale to U.S. government agencies.		Liquidity discount applied to the market value of a mortgage loans qualifying for sale to U.S. government agencies.
Liquidity Discount on Mortgage Loans Qualifying for Sale to US Govt Agencies	93.41%		94.09%		93.79%
[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]	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
[3]	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
[4]	Interest rate yields used to value investment grade tax-exempt securities represent a spread of 437 to 484 basis points over average yields for comparable tax-exempt securities.
[5]	Interest rate yields used to value investment grade tax-exempt securities represent a spread of 510 to 538 basis points over average yields for comparable tax-exempt securities.
[6]	Interest rate yields used to value investment grade tax-exempt securities represent a spread of 499 to 541 basis points over average yields for comparable tax-exempt securities.
[7]	Represents fair value as a percentage of par value.
[8]	Represents fair value as a percentage of par value.
[9]	Represents fair value as a percentage of par value.
[10]	Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 1 percent.
[11]	Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 1 percent.
[12]	Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 1 percent.

Fair Value Measurements, Fair62

Fair Value Measurements, Fair Value Measured On a Nonrecurring Basis (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross charge-offs against allowance for loan losses	$ 6,334	$ 890	$ 30,200	$ 1,439
Net losses 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 and expenses of repossessed assets, net	480	670	1,260	1,771
Fair Value, Inputs, Level 1 [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	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]
Carrying Value	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]
Carrying Value	436	3,239	436	3,239
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]
Carrying Value	6,048	12,689	6,048	12,689
Fair Value, Inputs, Level 3 [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	23,089	12,386	23,089	12,386
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]
Carrying Value	$ 1,927	$ 702	$ 1,927	$ 702

Fair Value Measurements Fair 63

Fair Value Measurements Fair Value Measurement, Measured On Non-Recurring Basis, Signfiicant Unobservable Inputs, Quantitative Information (Details) - Fair Value, Measurements, Nonrecurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands		3 Months Ended
		Sep. 30, 2016		Sep. 30, 2015
Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Carrying Value		$ 23,089		$ 12,386
Fair Value Measurements, Valuation Techniques		Discounted cash flows		Appraised value, as adjusted
Fair Value Measurements, Significant Unobservable Input		Recoverable oil and gas reserves, forward-looking commodity prices, estimated operating costs		Broker quotes and management's knowledge of industry and collateral
Fair Value of Impaired Loans as a Percentage of Unpaid Principal Balance [Abstract]
Fair Value Measurements, Fair Value of Impaired Loans as a Percentage of Unpaid Principal Balance, Minimum	[1]	23.00%
Fair Value Measurements, Fair Value of Impaired Loans as a Percentage of Unpaid Principal Balance, Maximum	[1]	59.00%
Fair Value of Impaired Loans as a Percentage of Unpaid Principal Balance, Weighted Average	[1]	43.00%
Real estate and other repossessed assets [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Carrying Value		$ 1,927		$ 702
Fair Value Measurements, Valuation Techniques		Appraised value, as adjusted		Appraised value, as adjusted
Fair Value Measurements, Significant Unobservable Input		Marketability adjustment off appraised value2	[2]	Marketability adjustments off appraised value1	[3]
Fair Value of Real Estate and Other Repossessed Assets as a Percentage of Appraised Value [Abstract]
Fair Value Measurement, Percentage of Appraised Value. Minimum		68.00%		66.00%
Fair Value Measurement, Percentage of Appraised Value, Maximum		80.00%		86.00%
Fair Value Measurement, Percentage of Appraised Value, Weighted Average		71.00%		78.00%
[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.
[3]	Marketability adjustments include consideration of estimated costs to sell which is approximately 10% of the fair value.

Fair Value Measurements, Financ

Fair Value Measurements, Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2016		Jun. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest-bearing cash and cash equivalents	$ 2,080,978			$ 2,069,900	$ 1,830,105
Trading securities	546,615			122,404	181,131
Investment securities	546,457			597,836	612,384
Available for sale securities	8,862,283			9,042,733	8,801,089
Fair value option securities	222,409			444,217	427,760
Residential mortgage loans held for sale	447,592			308,439	357,414
Loans	16,464,786			15,941,154	15,367,441
Allowance for loan losses	(245,103)		$ (243,259)	(225,524)	(204,116)	$ (201,087)	$ (189,056)
Loans, net of allowance	16,219,683			15,715,630	15,163,325
Mortgage servicing rights	203,621		190,747	218,605	200,049	198,694	171,976
Derviative contracts, net of cash collateral, Assets, Fair value	655,078			586,270	726,159
Time deposits	2,169,631			2,406,064	2,498,531
Subordinated debentures	144,631			226,350	226,314
Derivative contracts, net of cash margin, Liabilities, Fair Value	573,987			581,701	636,115
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Specific allocation of allowance for loan losses included in fair value of loans	217,000			195,000	176,000
Commercial
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	10,120,163			10,252,531	9,797,422
Allowance for loan losses	(141,470)		(145,139)	(130,334)	(108,993)	(107,037)	(90,875)
Commercial real estate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	3,793,598			3,259,033	3,235,067
Allowance for loan losses	(49,817)		(46,745)	(41,391)	(41,789)	(39,744)	(42,445)
Residential mortgage
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,872,793			1,876,893	1,868,995
Allowance for loan losses	(18,589)		(18,690)	(19,509)	(20,859)	(21,449)	(23,458)
Personal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	678,232			552,697	465,957
Allowance for loan losses	(7,041)		$ (6,001)	(4,164)	(4,729)	$ (3,955)	$ (4,233)
U.S. government agency debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	15,705			61,295	42,431
U.S. government agency residential mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	464,749			10,989	30,973
Available for sale securities	5,668,672	[1]		5,898,351	5,819,127
Fair value option securities	0			444,217	427,760
Municipal and other tax-exempt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	54,856			31,901	84,261
Investment securities	323,225			365,258	379,980
Available for sale securities	42,092			56,817	57,960
Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	11,305			18,219	23,466
U.S. Treasury
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	1,002			995	1,003
Fair value option securities	222,409			0	0
Privately issued residential mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	121,603			139,118	145,682
Commercial mortgage-backed securities guaranteed by U.S. government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,986,495			2,905,796	2,735,787
Other debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	201,066			205,745	203,751
Available for sale securities	4,151			4,151	4,150
Perpetual preferred stock
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	19,578			19,672	19,163
Equity securities and mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	18,690			17,833	18,217
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	535,916			573,699	489,268
Interest-bearing cash and cash equivalents	2,080,978			2,069,900	1,830,105
Trading securities	546,615			122,404	181,131
Investment securities	546,457			597,836	612,384
Available for sale securities	8,862,283			9,042,733	8,801,089
Fair value option securities	222,409			444,217	427,760
Residential mortgage loans held for sale	447,592			308,439	357,414
Loans	16,464,786			15,941,154	15,367,441
Allowance for loan losses	(245,103)			(225,524)	(204,116)
Loans, net of allowance	16,219,683			15,715,630	15,163,325
Mortgage servicing rights	203,621			218,605	200,049
Derviative contracts, net of cash collateral, Assets, Fair value	655,078			586,270	726,159
Deposits with no stated maturity	18,925,873			18,682,094	18,120,912
Time deposits	2,169,631			2,406,064	2,498,531
Other borrowed funds	7,147,047			6,051,515	5,253,124
Subordinated debentures	144,631			226,350	226,314
Derivative contracts, net of cash margin, Liabilities, Fair Value	573,987			581,701	636,115
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	10,120,163			10,252,531	9,797,422
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial real estate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	3,793,598			3,259,033	3,235,067
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Residential mortgage
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,872,793			1,876,893	1,868,995
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Personal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	678,232			552,697	465,957
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. government agency debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	15,705			61,295	42,431
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. government agency residential mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	464,749			10,989	30,973
Investment securities	22,166			26,833	28,653
Available for sale securities	5,668,672			5,898,351	5,819,127
Fair value option securities	0			444,217	427,760
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	54,856			31,901	84,261
Investment securities	323,225			365,258	379,980
Available for sale securities	42,092			56,817	57,960
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	11,305			18,219	23,466
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. Treasury
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	1,002			995	1,003
Fair value option securities	222,409			0	0
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Privately issued residential mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	121,603			139,118	145,682
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,986,495			2,905,796	2,735,787
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	201,066			205,745	203,751
Available for sale securities	4,151			4,151	4,150
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Perpetual preferred stock
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	19,578			19,672	19,163
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Equity securities and mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	18,690			17,833	18,217
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	535,916			573,699	489,268
Interest-bearing cash and cash equivalents	2,080,978			2,069,900	1,830,105
Trading securities	546,615			122,404	181,131
Investment securities	580,310			629,159	643,091
Available for sale securities	8,862,283			9,042,733	8,801,089
Fair value option securities	222,409			444,217	427,760
Residential mortgage loans held for sale	447,592			308,439	357,414
Loans	16,273,182			15,739,472	15,229,586
Allowance for loan losses	0			0	0
Loans, net of allowance	16,273,182			15,739,472	15,229,586
Mortgage servicing rights	203,621			218,605	200,049
Derviative contracts, net of cash collateral, Assets, Fair value	655,078			586,270	726,159
Deposits with no stated maturity	18,925,873			18,682,094	18,120,912
Time deposits	2,163,947			2,394,562	2,500,469
Other borrowed funds	7,079,737			5,600,932	5,239,400
Subordinated debentures	148,360			223,758	223,334
Derivative contracts, net of cash margin, Liabilities, Fair Value	573,987			581,701	636,115
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	9,926,548			10,053,952	9,530,437
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	3,769,427			3,233,476	3,330,298
Estimate of Fair Value, Fair Value Disclosure [Member] | Residential mortgage
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,905,786			1,902,976	1,906,585
Estimate of Fair Value, Fair Value Disclosure [Member] | Personal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	671,421			549,068	462,266
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	15,705			61,295	42,431
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency residential mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	464,749			10,989	30,973
Investment securities	23,452			27,874	30,080
Available for sale securities	5,668,672			5,898,351	5,819,127
Fair value option securities	0			444,217	427,760
Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	54,856			31,901	84,261
Investment securities	327,788			368,910	384,310
Available for sale securities	42,092			56,817	57,960
Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	11,305			18,219	23,466
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	1,002			995	1,003
Fair value option securities	222,409			0	0
Estimate of Fair Value, Fair Value Disclosure [Member] | Privately issued residential mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	121,603			139,118	145,682
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,986,495			2,905,796	2,735,787
Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	229,070			232,375	228,701
Available for sale securities	4,151			4,151	4,150
Estimate of Fair Value, Fair Value Disclosure [Member] | Perpetual preferred stock
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	19,578			19,672	19,163
Estimate of Fair Value, Fair Value Disclosure [Member] | Equity securities and mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	18,690			17,833	18,217
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	535,916			573,699	489,268
Interest-bearing cash and cash equivalents	2,080,978			2,069,900	1,830,105
Trading securities	0			0	0
Investment securities	0			0	0
Available for sale securities	4,546			4,260	4,508
Fair value option securities	222,409			0	0
Residential mortgage loans held for sale	0			0	0
Loans	0			0	0
Allowance for loan losses	0			0	0
Loans, net of allowance	0			0	0
Mortgage servicing rights	0			0	0
Derviative contracts, net of cash collateral, Assets, Fair value	5,575			38,530	4,922
Deposits with no stated maturity	0			0	0
Time deposits	0			0	0
Other borrowed funds	0			0	0
Subordinated debentures	0			0	0
Derivative contracts, net of cash margin, Liabilities, Fair Value	1,308			0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0			0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0			0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential mortgage
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0			0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Personal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0			0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency residential mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0	0
Investment securities	0			0	0
Available for sale securities	0			0	0
Fair value option securities	0			0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0	0
Investment securities	0			0	0
Available for sale securities	0			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	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	1,002			995	1,003
Fair value option securities	222,409			0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Privately issued residential mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	0			0	0
Available for sale securities	0			0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Perpetual preferred stock
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0	0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Equity securities and mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	3,544			3,265	3,505
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	0
Interest-bearing cash and cash equivalents	0			0	0
Trading securities	546,615			122,404	181,131
Investment securities	580,310			629,159	643,091
Available for sale securities	8,847,873			9,024,712	8,782,831
Fair value option securities	0			444,217	427,760
Residential mortgage loans held for sale	438,291			300,565	349,381
Loans	0			0	0
Allowance for loan losses	0			0	0
Loans, net of allowance	0			0	0
Mortgage servicing rights	0			0	0
Derviative contracts, net of cash collateral, Assets, Fair value	649,503			547,740	721,237
Deposits with no stated maturity	0			0	0
Time deposits	0			0	0
Other borrowed funds	0			0	0
Subordinated debentures	148,360			0	0
Derivative contracts, net of cash margin, Liabilities, Fair Value	572,679			581,701	636,115
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0			0	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0			0	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential mortgage
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0			0	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Personal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	0			0	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	15,705			61,295	42,431
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency residential mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	464,749			10,989	30,973
Investment securities	23,452			27,874	30,080
Available for sale securities	5,668,672			5,898,351	5,819,127
Fair value option securities	0			444,217	427,760
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	54,856			31,901	84,261
Investment securities	327,788			368,910	384,310
Available for sale securities	36,379			47,207	48,360
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	11,305			18,219	23,466
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0	0
Fair value option securities	0			0	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Privately issued residential mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	121,603			139,118	145,682
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,986,495			2,905,796	2,735,787
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	229,070			232,375	228,701
Available for sale securities	0			0	0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Perpetual preferred stock
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	19,578			19,672	19,163
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Equity securities and mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	15,146			14,568	14,712
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	0
Interest-bearing cash and cash equivalents	0			0	0
Trading securities	0			0	0
Investment securities	0			0	0
Available for sale securities	9,864			13,761	13,750
Fair value option securities	0			0	0
Residential mortgage loans held for sale	9,301			7,874	8,033
Loans	16,273,182			15,739,472	15,229,586
Allowance for loan losses	0			0	0
Loans, net of allowance	16,273,182			15,739,472	15,229,586
Mortgage servicing rights	203,621			218,605	200,049
Derviative contracts, net of cash collateral, Assets, Fair value	0			0	0
Deposits with no stated maturity	18,925,873			18,682,094	18,120,912
Time deposits	2,163,947			2,394,562	2,500,469
Other borrowed funds	7,079,737			5,600,932	5,239,400
Subordinated debentures	0			223,758	223,334
Derivative contracts, net of cash margin, Liabilities, Fair Value	0			0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	9,926,548			10,053,952	9,530,437
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	3,769,427			3,233,476	3,330,298
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential mortgage
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,905,786			1,902,976	1,906,585
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Personal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	671,421			549,068	462,266
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency residential mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0	0
Investment securities	0			0	0
Available for sale securities	0			0	0
Fair value option securities	0			0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0	0
Investment securities	0			0	0
Available for sale securities	5,713			9,610	9,600
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	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0	0
Fair value option securities	0			0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Privately issued residential mortgage-backed securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	0			0	0
Available for sale securities	4,151			4,151	4,150
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Perpetual preferred stock
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0	0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Equity securities and mutual funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	$ 0			$ 0	$ 0
[1]	U.S. government and government sponsored enterprises are not rated by the nationally-recognized rating agencies as these securities are guaranteed by agencies of the U.S. government or government-sponsored enterprises.

Fair Value Measurements Financi

Fair Value Measurements Financial Instruments, Quantitative Information (Details)	9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Time deposits [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	0.03%	0.02%	0.02%
Contractual Yield, Maximum	9.65%	9.64%	5.50%
Repricing (in years)	2 years 37 days	1 year 274 days	1 year 285 days
Discount Rate, Minimum	1.37%	0.85%	1.11%
Discount Rate, Maximum	1.66%	1.25%	1.57%
Other borrowings [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	0.25%	0.25%	0.25%
Contractual Yield, Maximum	3.81%	3.34%	3.40%
Repricing (in years)	7 days	7 days	1 day
Discount Rate, Minimum	0.29%	0.07%	0.20%
Discount Rate, Maximum	2.99%	2.66%	2.89%
Subordinated debentures [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	5.38%	1.01%	1.05%
Contractual Yield, Maximum	5.38%	1.01%	1.05%
Repricing (in years)	18 years 135 days	1 year 230 days	1 year 135 days
Discount Rate, Minimum	5.38%	1.83%	2.12%
Discount Rate, Maximum	5.38%	1.83%	2.12%
Commercial | Loans Receivable [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	0.38%	0.19%	0.25%
Contractual Yield, Maximum	30.00%	30.00%	30.00%
Repricing (in years)	252 days	230 days	226 days
Discount Rate, Minimum	0.54%	0.47%	0.52%
Discount Rate, Maximum	3.93%	4.06%	4.34%
Commercial real estate | Loans Receivable [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	0.38%	0.38%	0.38%
Contractual Yield, Maximum	18.00%	18.00%	18.00%
Repricing (in years)	263 days	281 days	266 days
Discount Rate, Minimum	0.80%	0.92%	0.95%
Discount Rate, Maximum	3.90%	3.60%	3.93%
Residential mortgage | Loans Receivable [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	1.74%	1.25%	1.67%
Contractual Yield, Maximum	18.00%	18.00%	18.00%
Repricing (in years)	1 year 347 days	2 years 124 days	2 years 153 days
Discount Rate, Minimum	1.57%	0.86%	0.86%
Discount Rate, Maximum	3.55%	3.94%	4.25%
Personal | Loans Receivable [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	0.25%	0.38%	0.38%
Contractual Yield, Maximum	21.00%	21.00%	21.00%
Repricing (in years)	128 days	146 days	135 days
Discount Rate, Minimum	0.75%	0.89%	1.19%
Discount Rate, Maximum	4.15%	3.86%	4.11%