BOK Financial (BOKF) 10-K 27 Feb 15 2014 FY Annual report Financial data

Document_And_Entity_Informatio

Document And Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Jan. 31, 2015	Jun. 30, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	BOK FINANCIAL CORP ET AL
Entity Central Index Key	875357
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	Yes
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$1,782,640,442
Entity Common Stock, Shares Outstanding		69,113,013
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14

Consolidated_Statements_of_Ear

Consolidated Statements of Earnings (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest revenue [Abstract]
Loans	$502,753	$498,600	$513,429
Residential mortgage loans held for sale	10,143	8,505	8,185
Trading securities	1,945	1,962	1,419
Investment securities, Taxable securities	13,183	14,260	16,848
Investment securities, Tax-exempt securities	5,708	4,781	3,577
Total investment securities	18,891	19,041	20,425
Available for sale securities, Taxable securities	182,923	204,830	237,226
Available for sale securities, Tax-exempt securities	2,184	2,380	2,487
Total available for sale securities	185,107	207,210	239,713
Fair value option securities	3,611	3,907	8,464
Restricted equity securities	7,040	5,071	2,291
Interest-bearing cash and cash equivalents	2,749	1,075	945
Total interest revenue	732,239	745,371	794,871
Interest expense [Abstract]
Deposits	50,683	55,564	67,013
Borrowed funds	7,672	6,589	6,531
Subordinated debentures	8,690	8,741	13,778
Total interest expense	67,045	70,894	87,322
Net interest revenue	665,194	674,477	707,549
Provision for credit losses	0	-27,900	-22,000
Net interest revenue after provision for credit losses	665,194	702,377	729,549
Other operating revenue [Abstract]
Brokerage and trading revenue	134,437	125,478	126,930
Transaction card revenue	123,689	116,823	107,985
Fiduciary and asset management revenue	115,652	96,082	80,053
Deposit service charges and fees	90,911	95,110	98,917
Mortgage banking revenue	109,093	121,934	169,302
Bank-owned life insurance	9,086	10,155	11,089
Other revenue	38,451	38,262	34,604
Total fees and commissions	621,319	603,844	628,880
Loss on assets, net	-6,346	-925	-1,415
Gain (loss) on derivatives, net	2,776	-4,367	-301
Gain (loss) on fair value option securities, net	10,189	-15,212	9,230
Change in fair value of mortgage servicing rights	-16,445	22,720	-9,210
Gain on available for sale securities, net	1,539	10,720	33,845
Total other-than-temporary impairment losses	-373	-2,574	-1,144
Portion of loss recognized in (reclassified from) other comprehensive income	0	266	-6,207
Net impairment losses recognized in earnings	-373	-2,308	-7,351
Total other operating revenue	612,659	614,472	653,678
Other operating expense [Abstract]
Personnel	476,931	505,225	491,033
Business promotion	26,649	22,598	23,338
Charitable contributions to BOKF Foundation	4,267	2,062	2,062
Professional fees and services	44,440	32,552	34,015
Net occupancy and equipment	77,232	69,773	66,726
Insurance	18,578	16,122	15,356
Data processing and communications	117,049	106,075	98,904
Printing, postage and supplies	13,518	13,885	14,228
Net losses and operating expenses of repossessed assets	6,019	5,160	20,528
Amortization of intangible assets	3,965	3,428	2,927
Mortgage banking costs	29,881	31,088	44,334
Other expense	28,993	32,652	26,912
Total other operating expense	847,522	840,620	840,363
Net income before taxes	430,331	476,229	542,864
Federal and state income taxes	134,852	157,298	188,740
Net income	295,479	318,931	354,124
Net income attributable to non-controlling interests	3,044	2,322	2,933
Net income attributable to BOK Financial Corp. shareholders	$292,435	$316,609	$351,191
Earnings per share: [Abstract]
Basic (in dollars per share)	$4.23	$4.61	$5.15
Diluted (in dollars per share)	$4.22	$4.59	$5.13
Average shares used in computation: [Abstract]
Basic (in shares)	68,394,194	67,988,897	67,684,043
Diluted (in shares)	68,544,770	68,205,519	67,964,940
Dividends declared per share (in dollars per share)	$1.62	$1.54	$2.47

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$295,479		$318,931		$354,124
Other comprehensive income (loss), before income taxes: [Abstract]
Net change in unrealized gain (loss)	136,775		-275,945		66,197
Reclassification adjustments included in earnings: [Abstract]
Interest revenue, Investment securities, Taxable securities	-1,216		-3,210		-6,601
Interest expense, Subordinated debentures	296		262		453
Net impairment losses recognized in earnings	373		2,308		7,351
Gain on available for sale securities, net	-1,539		-10,720		-33,845
Other comprehensive income (loss), before income taxes	134,689		-287,305		33,555
Federal and state income taxes	-52,393	[1]	111,762	[1]	-12,614	[1]
Other comprehensive income (loss), net of income taxes	82,296		-175,543		20,941
Comprehensive income	377,775		143,388		375,065
Comprehensive income attributable to non-controlling interests	3,044		2,322		2,933
Comprehensive income attributable to BOK Financial Corp. shareholders	$374,731		$141,066		$372,132
[1]	1 Calculated using 39% effective tax rate.

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Assets [Abstract]
Cash and due from banks	$550,576		$512,931
Interest-bearing cash and cash equivalents	1,925,266		574,282
Trading securities	188,700		91,616
Investment securities	652,360	[1]	677,878	[2]
Available for sale securities	8,978,945		10,147,162
Fair value option securities	311,597		167,125
Restricted equity securities	141,494		85,240
Residential mortgage loans held for sale	304,182		200,546
Loans	14,208,037		12,792,264
Allowance for loan losses	-189,056		-185,396
Loans, net of allowance	14,018,981		12,606,868
Premises and Equipment, net	273,833		277,849
Receivables	132,408		117,126
Goodwill	377,780		359,759
Intangible assets, net	34,376		24,564
Mortgage servicing rights	171,976		153,333
Real estate and other repossessed assets, net of allowance	101,861		92,272
Derivative contracts	361,874		265,012
Cash surrender value of bank-owned life insurance	293,978		284,801
Receivable on unsettled securities sales	74,259		17,174
Other assets	195,252		359,894
Total assets	29,089,698		27,015,432
Liabilities [Abstract]
Noninterest-bearing demand deposits	8,066,357		7,316,277
Interest-bearing deposits: [Abstract]
Transaction	10,114,355		9,934,051
Savings	351,431		323,006
Time	2,608,716		2,695,993
Total deposits	21,140,859		20,269,327
Funds purchased	57,031		868,081
Repurchase agreements	1,187,489		813,454
Other borrowings	2,133,774		1,040,353
Subordinated debentures	347,983		347,802
Accrued interest, taxes and expense	120,211		194,870
Derivative contracts	354,554		247,185
Due on unsettled securities purchases	290,540		45,740
Other liabilities	121,051		133,647
Total liabilities	25,753,492		23,960,459
Shareholders' equity: [Abstract]
Common stock	4		4
Capital surplus	954,644		898,586
Retained earnings	2,530,837		2,349,428
Treasury stock	-239,979		-202,346
Accumulated other comprehensive income (loss)	56,673		-25,623
Total shareholders' equity	3,302,179		3,020,049
Non-controlling interests	34,027		34,924
Total equity	3,336,206		3,054,973
Total liabilities and equity	$29,089,698		$27,015,432
[1]	Carrying value includes $615 thousand of net unrealized gain which remains in Accumulated other comprehensive income (“AOCI”) in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.
[2]	Carrying value includes $1.8 million of net unrealized gain which remains in AOCI in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Investment securities [Abstract]
Investment securities, fair value	$673,626	$687,127
Real estate and other repossessed assets, allowance	$22,937	$24,195
Shareholders' equity: [Abstract]
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, authorized (in shares)	2,500,000,000	2,500,000,000
Common stock, shares issued (in shares)	74,003,754	73,163,275
Common stock, shares outstanding (in shares)	74,003,754	73,163,275
Treasury stock, shares at cost (in shares)	4,890,018	4,304,782

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Equity (USD $)	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total Shareholders' Equity [Member]	Non-Controlling Interests [Member]
In Thousands
Balance, beginning of period at Dec. 31, 2011	$2,786,652	$4	$818,817	$1,953,332	($150,664)	$128,979	$2,750,468	$36,184
Balances (in shares) at Dec. 31, 2011		71,533			3,380
Net income	354,124			351,191			351,191	2,933
Other comprehensive income (loss)	20,941					20,941	20,941
Repurchase of common stock (in shares)					384
Repurchase of common stock	-20,558				-20,558		-20,558
Issuance of shares for equity compensation, net (in shares)		882			324
Issuance of shares for equity compensation, net	14,650		32,311		-17,661		14,650
Tax effect from equity compensation, net	120		120				120
Share-based compensation	8,030		8,030				8,030
Issuance of shares in settlement of deferred compensation, net	0
Cash dividends on common stock	-166,982			-166,982			-166,982
Acquisition of non-controlling interest	1,645							1,645
Capital calls and distributions, net	-4,941							-4,941
Balance, end of period at Dec. 31, 2012	2,993,681	4	859,278	2,137,541	-188,883	149,920	2,957,860	35,821
Balances (in shares) at Dec. 31, 2012		72,415			4,088
Net income	318,931			316,609			316,609	2,322
Other comprehensive income (loss)	-175,543					-175,543	-175,543
Repurchase of common stock (in shares)					0
Repurchase of common stock	0				0		0
Issuance of shares for equity compensation, net (in shares)		748			217
Issuance of shares for equity compensation, net	16,566		30,029		-13,463		16,566
Tax effect from equity compensation, net	2,210		2,210				2,210
Share-based compensation	7,069		7,069				7,069
Issuance of shares in settlement of deferred compensation, net	0
Cash dividends on common stock	-104,722			-104,722			-104,722
Capital calls and distributions, net	-3,219							-3,219
Balance, end of period at Dec. 31, 2013	3,054,973	4	898,586	2,349,428	-202,346	-25,623	3,020,049	34,924
Balances (in shares) at Dec. 31, 2013		73,163			4,305
Net income	295,479			292,435			292,435	3,044
Other comprehensive income (loss)	82,296					82,296	82,296
Repurchase of common stock (in shares)					200
Repurchase of common stock	-12,337				-12,337		-12,337
Issuance of shares for equity compensation, net (in shares)		510			183
Issuance of shares for equity compensation, net	4,472		16,632		-12,160		4,472
Tax effect from equity compensation, net	8,258		8,258				8,258
Share-based compensation	9,680		9,680				9,680
Issuance of shares in settlement of deferred compensation (in shares)		331			202
Issuance of shares in settlement of deferred compensation, net	8,352		21,488		-13,136		8,352
Cash dividends on common stock	-111,026			-111,026			-111,026
Capital calls and distributions, net	-3,941							-3,941
Balance, end of period at Dec. 31, 2014	$3,336,206	$4	$954,644	$2,530,837	($239,979)	$56,673	$3,302,179	$34,027
Balances (in shares) at Dec. 31, 2014		74,004			4,890

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash Flows From Operating Activities: [Abstract]
Net income	$295,479	$318,931	$354,124
Adjustments to reconcile net income to net cash provided by (used in) operating activities: [Abstract]
Provision for credit losses	0	-27,900	-22,000
Change in fair value of mortgage servicing rights	16,445	-22,720	9,210
Net unrealized losses (gains) from derivatives	-6,495	16,256	-984
Tax effect from equity compensation, net	-8,258	-2,210	-120
Change in bank-owned life insurance	-9,086	-10,155	-11,089
Share-based compensation	9,680	7,069	8,030
Depreciation and amortization	56,032	53,261	54,935
Net amortization of securities discounts and premiums	57,202	62,274	87,769
Net realized losses (gains) on financial instruments and other assets	-1,362	-12,586	-15,097
Net gain on mortgage loans held for sale	-62,053	-84,403	-120,599
Mortgage loans originated for resale	-4,484,394	-4,081,390	-3,708,350
Proceeds from sale of mortgage loans held for resale	4,441,819	4,254,151	3,731,830
Capitalized mortgage servicing rights	-54,413	-49,431	-42,191
Change in trading and fair value option securities	-243,265	237,581	226,144
Change in receivables	-7,103	-3,122	9,244
Change in other assets	77,907	76,257	10,999
Change in accrued interest, taxes and expense	-115,772	18,192	23,424
Change in other liabilities	1,007	-13,735	-3,729
Net cash provided by (used in) operating activities	-36,630	736,320	591,550
Cash Flows From Investing Activities: [Abstract]
Proceeds from maturities or redemptions of investment securities	63,258	143,445	111,511
Proceeds from maturities or redemptions of available for sale securities	1,635,533	2,650,045	4,456,363
Purchases of investment securities	-44,723	-326,815	-172,327
Purchases of available for sale securities	-3,045,077	-4,287,146	-7,334,843
Proceeds from sales of available for sale securities	2,664,740	2,436,093	1,744,662
Change in receivables on unsettled securities sales	-57,085	193,878	-135,901
Loans originated net of principal collected	-1,346,995	-441,474	-1,077,075
Net proceeds from (payments on) derivative asset contracts	-247,726	59,390	-13,273
Acquisitions, net of cash acquired	-21,898	-7,500	-23,615
Proceeds from disposition of assets	273,271	229,405	170,907
Purchases of assets	-307,318	-212,292	-94,756
Net cash provided by (used in) investing activities	-434,020	437,029	-2,368,347
Cash Flows From Financing Activities: [Abstract]
Net change in demand deposits, transaction deposits and savings accounts	958,809	-637,734	2,830,470
Net change in time deposits	-87,277	-271,999	-413,990
Net change in other borrowings	511,776	-111,905	210,607
Repayment of subordinated debentures	0	0	-53,705
Net payments or proceeds on derivaive liability contracts	257,439	-64,724	-7,560
Net change in derivative margin accounts	84,365	51,646	39,237
Change in amount due on unsettled security purchases	244,800	-251,713	-355,918
Issuance of common and treasury stock, net	4,472	16,566	14,650
Sale of non-controlling interest	0	0	300
Tax effect from equity compensation, net	8,258	2,210	120
Repurchase of common stock	-12,337	0	-20,558
Dividends paid	-111,026	-104,722	-166,982
Net cash provided by (used in) financing activities	1,859,279	-1,372,375	2,076,671
Net increase (decrease) in cash and cash equivalents	1,388,629	-199,026	299,874
Cash and cash equivalents at beginning of period	1,087,213	1,286,239	986,365
Cash and cash equivalents at end of period	2,475,842	1,087,213	1,286,239
Cash paid for interest	65,721	69,830	90,137
Cash paid for taxes	67,199	132,176	158,703
Net loans transferred to real estate and other repossessed assets	79,464	86,868	133,502
Residential mortgage loans guaranteed by U.S. government agencies that became elgible fo repurchase during the year	144,630	127,572	121,432
Conveyance of other real estate owned guaranteed by U.S. government agencies	44,963	43,901	89,223
Issuance of shares in settlement of deferred compensation, net	$8,352	$0	$0

Significant_Accounting_Policie

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	(1) Significant Accounting Policies
	Basis of Presentation
	The Consolidated Financial Statements of BOK Financial Corporation (“BOK Financial” or “the Company”) have been prepared in conformity with accounting principles generally accepted in the United States ("U.S. GAAP"), including interpretations of U.S. GAAP issued by federal banking regulators and general practices of the banking industry. The consolidated financial statements include the accounts of BOK Financial and its subsidiaries, principally BOKF, NA (“the Bank”), BOSC, Inc., The Milestone Group, Inc. and Cavanal Hill Investment Management, Inc. All significant intercompany transactions are eliminated in consolidation. Certain prior year amounts have been reclassified to conform to the current year presentation.
	The consolidated financial statements include the assets, liabilities, non-controlling interests and results of operations of variable interest entities (“VIEs”) when BOK Financial is determined to be the primary beneficiary. 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. See additional discussion of variable interest entities at Note 14 following.
	Nature of Operations
	BOK Financial, through its subsidiaries, provides a wide range of financial services to commercial and industrial customers, other financial institutions, municipalities, and consumers. These services include depository and cash management; lending and lease financing; mortgage banking; securities brokerage, trading and underwriting; and personal and corporate trust.
	The Bank operates as Bank of Oklahoma primarily in Tulsa and Oklahoma City metropolitan areas of the state of Oklahoma and Bank of Texas primarily in the Dallas, Fort Worth and Houston metropolitan areas of the state of Texas. In addition, the Bank does business as Bank of Albuquerque in Albuquerque, New Mexico; Colorado State Bank and Trust in Denver, Colorado; Bank of Arizona in Phoenix, Arizona; Bank of Kansas City in Kansas City, Missouri/Kansas and Bank of Arkansas in Northwest Arkansas. The Bank also operates the TransFund electronic funds network.
	Use of Estimates
	Preparation of BOK Financial's consolidated financial statements requires management to make estimates of future economic activities, including loan collectability, prepayments and cash flows from customer accounts. These estimates are based upon current conditions and information available to management. Actual results may differ significantly from these estimates.
	Acquisitions
	Assets and liabilities acquired, including identifiable intangible assets, are recorded at fair value on the acquisition date. The purchase price includes consideration paid at closing and the estimated fair value of contingent consideration that will be paid in the future, subject to achieving defined performance criteria. Goodwill is recognized as the excess of the purchase price over the net fair value of assets acquired and liabilities assumed. The Consolidated Statements of Earnings include the results of operations from the acquisition date.
	Goodwill and Intangible Assets
	Goodwill and intangible assets generally result from business combinations and are evaluated for each of BOK Financial's reporting units for impairment annually or more frequently if conditions indicate impairment. The evaluation of possible impairment of goodwill and intangible assets involves significant judgment based upon short-term and long-term projections of future performance.
	Reporting units are defined by the Company as significant lines of business within each operating segment. This definition is consistent with the manner in which the chief operating decision maker assesses the performance of the Company and makes decisions concerning the allocation of resources. The Company qualitatively assesses whether it is more likely than not that the fair value of the reporting units are less than their carrying value. This assessment includes consideration of relevant events and circumstances including but not limited to macroeconomic conditions, industry and market conditions, the financial and stock performance of the Company and other relevant factors. Quantitative analysis may be undertaken to support the qualitative assessment. The fair value of BOK Financial's reporting units is estimated by the discounted future earnings method. Income growth is projected for each reporting unit and a terminal value is computed. This projected income stream is converted to current fair value by using a discount rate that reflects a rate of return required by a willing buyer. Assumptions used to determine the fair value of the reporting units are compared to observable inputs, such as the market value of BOK Financial common stock. However, determination of the fair value of individual reporting units requires the use of significant unobservable inputs. There have been no changes in the techniques used to evaluate the carrying value of goodwill.
	Intangible assets are generally composed of customer relationships, naming rights, non-compete agreements and core deposit premiums. They are amortized using accelerated or straight-line methods, as appropriate, over the estimated benefit periods. These periods range from 3 years to 20 years. The net book values of identifiable intangible assets are evaluated for impairment when economic conditions indicate impairment may exist.
	Cash Equivalents
	Due from banks, funds sold (generally federal funds sold for one day), resell agreements (which generally mature within one to 30 days) and investments in money market funds are considered cash equivalents.
	Securities
	Securities are identified as trading, investment (held to maturity) or available for sale at the time of purchase based upon the intent of management, liquidity and capital requirements, regulatory limitations and other relevant factors. Trading securities, which are acquired for profit through resale, are carried at fair value with unrealized gains and losses included in current period earnings. Investment securities are carried at amortized cost. Amortization is computed by methods that approximate level yield and is adjusted for changes in prepayment estimates. Securities identified as available for sale are carried at fair value. Unrealized gains and losses are recorded, net of deferred income taxes, as accumulated other comprehensive income in shareholders' equity. Available for sale securities are separately identified as pledged to creditors if the creditor has the right to sell or re-pledge the collateral.
	The purchase or sale of securities is recognized on a trade date basis. Realized gains and losses on sales of securities are based upon specific identification of the security sold. A receivable or payable is recognized for subsequent transaction settlement. BOK Financial will periodically commit to purchase to-be-announced residential mortgage-backed securities. These commitments are carried at fair value if they are considered derivative contracts. Investment securities may be sold or transferred to trading or available for sale classification in certain limited circumstances specified in generally accepted accounting principles. Securities meeting certain criteria may also be transferred from the available for sale classification to the investment securities portfolio at fair value on the date of transfer. The unrealized gain or loss at the date of transfer is retained in accumulated other comprehensive income and in the carrying value of the investment securities portfolio. Such amounts are amortized over the estimated remaining life of the security as an adjustment to yield, offsetting the related amortization of the premium or accretion of the discount on the transferred securities.
	On a quarterly basis, the Company performs separate evaluations of impaired debt investment and available for sale securities and equity available for sale securities to determine if the decline in fair value below the amortized cost is other-than-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 and securities portfolio management. If the Company intends to sell or it is more likely than not that it will be required to sell the impaired debt security, a charge is recognized against earnings for the entire unrealized loss. For all impaired debt securities for which there is no intent or expected requirement to sell, the evaluation considers all available evidence to assess whether it is more likely than not that all amounts due would not be collected according to the security's contractual terms. Any expected credit loss due to the inability to collect all amounts due according to the security's contractual terms is recognized as a charge against earnings. Any remaining unrealized loss related to other factors would be recognized in other comprehensive income, net of taxes.
	For equity securities, management evaluates various factors including cause, severity and duration of the decline in value of the security and prospects for recovery, as well as the Company's intent and ability not to sell the security until the fair value exceeds amortized cost. If an unrealized loss is determined to be other-than-temporary, a charge is recognized against earnings for the difference between the security's amortized cost and fair value.
	BOK Financial has elected to carry certain non-trading securities at fair value with changes in fair value recognized in current period income. These securities are held with the intent that gains or losses will offset changes in the fair value of mortgage servicing rights or certain derivative instruments.
	Restricted equity securities represent equity interests the Company is required to hold in the Federal Reserve Banks and Federal Home Loan Banks. Restricted equity securities are carried at cost as theses securities do not have a readily determined fair value because ownership of these shares is restricted and they lack a market.
	Derivative Instruments
	Derivative instruments may be used by the Company as part of its interest rate risk management programs or may be offered to customers. All derivative instruments are carried at fair value. The determination of fair value of derivative instruments considers changes in interest rates, commodity prices and foreign exchange rates. Credit risk is also considered in determining fair value. Deterioration in the credit rating of customers or other counterparties reduces the fair value of asset contracts. Deterioration of our credit rating to below investment grade or the credit ratings of other counterparties could decrease the fair value of our derivative liabilities. Changes in fair value are generally reported in income as they occur.
	Derivative instruments used to manage interest rate risk consist primarily of interest rate swaps. These contracts modify the interest income or expense of certain assets or liabilities. Amounts receivable from or payable to counterparties are reported in interest income or expense using the accrual method. Changes in fair value of interest rate swaps are reported in other operating revenue - gain (loss) on derivatives, net.
	In certain circumstances, an interest rate swap may be designated as a fair value hedge and may qualify for hedge accounting. In these circumstances, changes in the full fair value of the hedged asset or liability, not only changes in fair value due to changes in the benchmark interest rate, are also recognized in earnings and may partially or completely offset changes in fair value of the interest rate swap. A fair value hedge is considered effective if the cumulative fair value adjustment of the interest rate swap is within a range of 80% to 120% of the cumulative change in the fair value of the hedged asset or liability. Any ineffectiveness, including ineffectiveness due to credit risk or ineffectiveness created when the fixed rate of the hedged asset or liability does not match the fixed rate of the interest rate swap, is recognized in earnings and reported in Gain (loss) on derivatives, net.
	Interest rate swaps may be designated as cash flow hedges of variable rate assets or liabilities, or of anticipated transactions. Changes in the fair value of interest rate swaps designated as cash flow hedges are recorded in accumulated other comprehensive income to the extent they are effective. The amount recorded in other comprehensive income is reclassified to earnings in the same periods as the hedged cash flows impact earnings. The ineffective portion of changes in fair value is reported in current earnings.
	If a derivative instrument that had been designated as a fair value hedge is terminated or if the hedge designation is removed or deemed to no longer be effective, the difference between the hedged items carrying value and its face amount is recognized into income over the remaining original hedge period. Similarly, if a derivative instrument that had been designated as a cash flow hedge is terminated or if the hedge designation is removed or deemed to no longer be effective, the amount remaining in accumulated other comprehensive income is reclassified to earnings in the same period as the hedged item.
	BOK Financial offers programs that permit its customers to manage various risks, including fluctuations in energy, cattle and other agricultural products, interest rates and foreign exchanges rates with derivative contracts. Derivative contracts are executed between the customers and BOK Financial. Offsetting contracts are executed between BOK Financial and other selected counterparties to minimize market risk from 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.
	When bilateral netting agreements 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 counterparty basis.
	Derivative contracts may also 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.
	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 financial 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 loans guaranteed by U.S. government agencies, are as follows.
	Interest is accrued at the applicable interest rate on the outstanding principal amount. 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 90 days or more 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 received 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. 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, debt service ratio and other underwriting standards. Nonaccruing loans may also 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 an evaluation of available cash resources and collateral value. Internally risk graded loans are evaluated quarterly and charge-offs are taken in the quarter in which the loss is identified. Non-risk graded loans that are past due between 60 days and 180 days, based on the loan product type, are charged off. Loans to borrowers whose personal obligation has been discharged through Chapter 7 bankruptcy proceedings are charged off within 60 days of notice of the bankruptcy filing, regardless of payment status.
	Loan origination and commitment fees and direct loan acquisition and origination costs are deferred and amortized as an adjustment to yield over the life of the loan or over the commitment period, as applicable. Amortization does not anticipate loan prepayments. Net unamortized fees are recognized in full at time of payoff.
	Qualifying residential mortgage loans guaranteed by U.S. government agencies have been sold into GNMA pools. Under certain performance conditions specified in government programs, the Company has 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 Sheet. Guaranteed loans are considered to be 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 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 at the modified rate. U.S. government guaranteed loans may either be resold into GNMA pools after a performance period specified by the programs or foreclosed and conveyed to the guarantors.
	Allowance for Loan Losses and Accrual for Off-Balance Sheet Credit Risk
	The appropriateness of the allowance for loan losses and accrual for off-balance sheet credit risk (collectively "Allowance for Credit Losses") is assessed by management based on an ongoing quarterly evaluation of the probable estimated losses inherent in the portfolio, including probable losses on outstanding loans and unused commitments to provide financing.
	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 Credits Losses. Classes are based on the risk characteristics of the loans and the Company's method for monitoring and assessing credit risk.
	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 based on estimated loss rates by loan class and nonspecific allowances based on factors that affect more than one portfolio segment. There were no changes to the methodology for estimating general allowances during 2014 or 2013.
	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 a quarterly 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, modified in a troubled debt restructuring 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 loan's initial effective interest rate or the fair value of collateral for certain collateral dependent loans. The fair value of real property held as collateral 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 generally are not adjusted by the Company. Updated appraisals are obtained at least annually or more frequently if market conditions indicate collateral values may have declined. Collateral value of mineral rights is generally determined by our internal staff of engineers based on projected cash flows from proven oil and gas reserves under existing economic and operating conditions. The value of other collateral is generally determined by our special assets staff based on projected liquidation 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 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 an estimated loss rate by loan class. The appropriate historical gross loss rate for each loan class is determined by the greater of the current loss rate based on the most recent twelve months or a ten-year average gross loss rate. Recoveries are not directly considered in the estimation of historical 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, historical 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 weighted average risk grade. This comparison determines whether credit risk in each loan class is increasing or decreasing. Historical 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 a specific loan class which have not yet been represented in the historical 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 portfolio segment or loan class. These factors include trends in the economy in our primary lending areas, concentration in large-balance loans and other relevant factors.
	An accrual for off-balance sheet credit risk is included in Other liabilities. The appropriateness of the 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.
	Transfers of Financial Assets
	BOK Financial regularly transfers financial assets as part of its mortgage banking activities and periodically may transfer other financial assets. Transfers are recorded as sales when the criteria for surrender of control are met.
	The Company has elected to carry certain residential mortgage loans held for sale at fair value under the fair value option. Changes in fair value are recognized in net income as they occur. These loans are reported separately in the Consolidated Balance Sheets and changes in fair value are recorded in other operating revenue - mortgage banking revenue in the Consolidated Statements of Earnings.
	Fair value of conforming residential mortgage loans that will be sold to U.S. government agencies is based on sales commitments or market quotes considered Level 2 inputs. Fair value of mortgage loans that are unable to be sold to U.S. government agencies is based on Level 3 inputs using quoted prices of loans that are sold in securitization transactions with a liquidity discount applied. The fair value is corroborated with an independent third party on at least an annual basis.
	BOK Financial retains a repurchase obligation under underwriting representations and warranties related to residential mortgage loans transferred and generally retains the right to service the loans. The Company may incur a recourse obligation in limited circumstances. Separate accruals are recognized in Other liabilities in the Consolidated Balance Sheets for repurchase and recourse obligations. These reserves reflect the estimated amount of probable loss the bank will incur as a result of repurchasing a loan, indemnifications, and other settlement resolutions.
	Repurchases of loans with an origination defect that are also credit impaired are considered collateral dependent and are initially recognized at net realizable value (appraised value less the cost to sell). The difference between unpaid principal balance and net realizable value is not accreted. Repurchases of loans with an origination defect that are not credit impaired are carried at fair value as of the repurchase date. Interest income continues to accrue on these loans and the discount is accreted over the estimated life of the loan.
	The accrual for credit losses related to recourse loans for principal and interest is performed by Credit Administration and subject to oversight by the Finance/Credit Administration Allowance Committee while all other mortgage related accruals are reviewed monthly by the Mortgage Contingency Loss Accrual Committee which is subject to oversight by Finance.
	The Company may also choose to purchase GNMA loans once certain mandated delinquency criteria are met. The loans that are eligible and are chosen to be repurchased are carried at fair value based on expected cash flow discounted using the average agency guaranteed debenture rates, average actual principal loss rates and liquidity premium.
	The Company may also retain a residual interest in excess cash flows generated by the assets. All assets obtained, including cash, servicing rights and residual interests, and all liabilities incurred, including recourse obligations, are initially recognized at fair value, all assets transferred are derecognized and any gain or loss on the sale is recognized in earnings. Subsequently, servicing rights and residual interest are carried at fair value with changes in fair value recognized in earnings as they occur.
	Real Estate and Other Repossessed Assets
	Real estate and other repossessed assets are acquired in partial or total forgiveness of loans. These assets are carried at the lower of cost, which is determined by fair value at date of foreclosure less estimated disposal costs, or current fair value less estimated disposal costs. Decreases in fair value below cost are recognized as asset-specific valuation allowances which may be reversed when supported by future increases in fair value. Fair values of real estate are based on “as is” appraisals which are updated at least annually or more frequently for certain asset types or assets located in certain distressed markets. Fair values based on appraisals are generally considered to be based on significant other observable inputs. The Company also considers decreases in listing price and other relevant information in quarterly evaluations and reduces the carrying value of real estate and other repossessed assets when necessary. Fair values based on list prices and other relevant information are generally considered to be based on significant unobservable inputs. Additional costs incurred to complete real estate and other repossessed assets may increase the carrying value, up to current fair value based on “as completed” appraisals. The fair value of mineral rights included in repossessed assets are generally determined by our internal staff of engineers based on projected cash flows from proven oil and gas reserves under existing economic and operating conditions. The value of other repossessed assets is generally determined by our special assets staff based on projected liquidation cash flows under current market conditions. Income generated by these assets is recognized as received. Operating expenses are recognized as incurred. Gains or losses on sales of real estate and other repossessed assets are based on the cash proceeds received less the cost basis of the asset, net of any valuation allowances.
	Premises and Equipment
Premises and equipment are carried at cost, including capitalized interest when appropriate, less accumulated depreciation and amortization. Depreciation and amortization are computed on a straight-line basis over the estimated useful lives of the assets or, for leasehold improvements, over the shorter of the estimated useful lives or remaining lease terms. Useful lives range from 5 years to 40 years for buildings and improvements, 3 years to 10 years for software and 3 years to 10 years for furniture and equipment. Construction in progress represents facilities construction and data processing systems projects underway that have not yet been placed into service. Depreciation and amortization begin once the assets are placed into service. Repair and maintenance costs, including software maintenance and enhancement costs, are charged to expense as incurred.
Premises no longer used by the Company are transferred to real estate and other repossessed assets. The transferred amount is the lower of cost less accumulated depreciation or fair value less estimated disposal costs as of the transfer date.
Rent expense for leased premises is recognized as incurred over the lease term. The effects of rent holidays, significant rent escalations and other adjustments to rent payments are recognized on a straight-line basis over the lease term.
Mortgage Servicing Rights
Mortgage servicing rights may be purchased or may be recognized when mortgage loans are originated pursuant to an existing plan for sale or, if no such plan exists, when the mortgage loans are sold. All mortgage servicing rights are carried at fair value. Changes in the fair value are recognized in earnings as they occur.
There is no active market for trading in mortgage servicing rights after origination. A cash flow model is used to determine fair value. Key assumptions and estimates, including projected prepayment speeds and assumed servicing costs, earnings on escrow deposits, ancillary income and discount rates, used by this model are based on current market sources. Assumptions used to value mortgage servicing rights are considered significant unobservable inputs. 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. Fair value estimates from outside sources are received at least annually to corroborate the results of the valuation model.
Federal and State Income Taxes
BOK Financial and its subsidiaries file consolidated tax returns. The subsidiaries provide for income taxes on a separate return basis and remit to BOK Financial amounts determined to be currently payable. BOK Financial is agent for its subsidiaries under the Company's tax sharing agreements and has no ownership rights to any refunds received for the benefit of its subsidiaries.
Current income tax expense or benefit is based on an evaluation that considers estimated taxable income, tax credits, and statutory federal and state income tax rates. The amount of current income tax expense or benefit recognized in any period may differ from amounts reported to taxing authorities. Annually, tax returns are filed with each jurisdiction where the Company conducts business and recognized current income tax expense or benefit is adjusted to the filed tax returns.
Deferred tax assets and liabilities are based upon the differences between the values of assets and liabilities as recognized in the financial statements and their related tax basis using enacted tax rates in effect for the year in which the differences are expected to be recovered or settled. A valuation allowance is provided when it is more likely than not that some portion of the entire deferred tax asset may not be realized based on taxes previously paid in net loss carry-back periods and other factors.
BOK Financial has unrecognized tax benefits, which are included in accrued current income taxes payable, for the uncertain portion of recorded tax benefits and related interest. These uncertainties result from the application of complex tax laws, rules, regulations and interpretations, primarily in state taxing jurisdictions. Unrecognized tax benefits are assessed quarterly and may be adjusted through current income tax expense in future periods based on changing facts and circumstances, completion of examinations by taxing authorities or expiration of a statute of limitations. Estimated penalties and interest on uncertain tax positions are recognized in income tax expense.
Employee Benefit Plans
BOK Financial sponsors a defined benefit cash balance pension plan (“Pension Plan”), qualified profit sharing plan (“Thrift Plan”) and employee health care plans. Pension Plan costs, which are based upon actuarial computations of current costs, are expensed annually. Unrecognized prior service cost and net gains or losses are amortized on a straight-line basis over a period not to exceed the average remaining service periods of the participants. Employer contributions to the Pension Plan are in accordance with Federal income tax regulations. Pension Plan benefits were curtailed as of April 1, 2006. No participants may be added to the Pension Plan and no additional service benefits will be accrued.
BOK Financial recognizes the funded status of its employee benefit plans. For a pension plan, the funded status is the difference between the fair value of plan assets and the projected benefit obligation measured as of the fiscal year-end date. Adjustments required to recognize the Pension Plan's net funded status are made through accumulated other comprehensive income, net of deferred income taxes.
Employer contributions to the Thrift Plan, which matches employee contributions subject to percentage and years of service limits, are expensed when incurred. BOK Financial recognizes the expense of health care benefits on the accrual method.
Share-Based Compensation Plans
BOK Financial awards stock options and non-vested common shares as compensation to certain officers. Compensation cost is generally fixed based on the grant date fair value of the award. The grant date fair value of stock options is based on the Black-Scholes option pricing model. Stock options generally have graded vesting over 7 years. Each tranche is considered a separate award for valuation and compensation cost recognition. Grant date fair value of non-vested shares is based on the current market value of BOK Financial common stock. Non-vested shares awarded prior to 2013 generally cliff vest in 5 years. Non-vested shares awarded since January 1, 2013 generally cliff vest in 3 years and are subject to a two year holding period after vesting. Shares awarded under the Executive Incentive Plan are subject to downward adjustment at the discretion of the Incentive Compensation Committee. Compensation cost of non-vested shares granted under the Executive Incentive Plan may vary based on changes in the fair value of BOKF common shares.
Compensation cost is recognized as expense over the service period, which is generally the vesting period. Expense is reduced for estimated forfeitures over the vesting period and adjusted for actual forfeitures as they occur. Stock-based compensation awarded to certain officers has performance conditions that affect the number of awards granted. Compensation cost is adjusted based on the probable outcome of the performance conditions. Excess tax benefits from share-based payments recognized in capital surplus are determined by the excess of tax benefits recognized over the tax effect of compensation cost recognized. Dividends on non-vested shares that are not subject to forfeiture are recognized as expense.
Other Operating Revenue
Fees and commission revenue is recognized at the time the related services are provided or products are sold and may be accrued when necessary. Accrued fees and commissions are reversed against revenue if amounts are subsequently deemed to be uncollectible. Revenue is recognized on a gross basis whenever we have primary responsibility and risk in providing the services or products to our customers and on a net basis whenever we act as a broker for products or services of others.
Brokerage and trading revenue includes changes in the fair value of securities held for trading purposes and derivatives held for customer risk management programs, including credit losses on trading securities and derivatives, commissions earned from the retail sale of securities, mutual funds and other financial instruments, and underwriting and financial advisory fees.
Transaction card revenue includes merchant discounts fees, electronic funds transfer network fees and check card fees. Merchant discount fees represent fees paid by customers for account management and electronic processing of transactions. Merchant discount fees are recognized at the time the customer's transactions are processed or other services are performed. The Company also maintains the TransFund electronic funds transfer network for the benefit of its members, which includes the Bank. Electronic funds transfer fees are recognized as electronic transactions processed on behalf of its members. Check card fees represent interchange fees paid by a merchant bank for transactions processed from cards issued by the Company. Check card fees are recognized when transactions are processed.
Trust fees and commissions include revenue from asset management, custody, recordkeeping, investment advisory and administration services. Revenue is recognized on an accrual basis at the time the services are performed and may be based on either the fair value of the account or the service provided.
Deposit service charges and fees are recognized at least quarterly in accordance with a published deposit account agreements and disclosure statements for retail accounts or contractual agreements for commercial accounts. Item charges for overdraft or non-sufficient funds items are recognized as items are presented for payment. Account balance charges and activity fees are accrued monthly and collected in arrears. Commercial account activity fees may be offset by an earnings credit based on account balances.
Newly Adopted and Pending Accounting Pronouncements
Financial Accounting Standards Board ("FASB")
FASB Accounting Standards Update No. 2013-08, Financial Services – Investment Companies (Topic 946): Amendments to the Scope, Measurement, and Disclosure Requirements ("ASU 2013-08")
On June 7, 2013, the FASB issued ASU 2013-08 which amends the criteria an entity would need to meet to qualify as an investment company under ASC 946, Financial Services - Investment Companies. ASU 2013-08 also provides additional implementation guidance for the assessment and requires additional disclosures. ASU 2013-08 was effective prospectively during interim and annual periods beginning after December 15, 2013, with early adoption prohibited. The adoption of ASU 2013-08 did not have a material impact on the Company's consolidated financial statements.
FASB Accounting Standards Update No. 2014-01, Accounting for Investments in Qualified Affordable Housing Projects ("ASU 2014-01")
On January 15, 2014, the FASB issued ASU 2014-01 to simplify the amortization method an entity uses and modify the criteria to elect a measurement and presentation alternative, including the simplified amortization method, for certain investments in qualified affordable housing projects. This alternative permits the entity to present the investment's performance net of the related tax benefits as part of income tax expense. ASU 2014-01 was effective for the Company for interim and annual periods beginning after December 15, 2014. Adoption of ASU 2014-01 may affect income statement presentation, but otherwise did not have a material impact on the Company's consolidated financial statements.
FASB Accounting Standards Update No. 2014-04, Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans Upon Foreclosure ("ASU 2014-04")
On January 17, 2014, the FASB issued ASU 2014-04 to clarify when an entity is considered to have obtained physical possession (from an in-substance possession or foreclosure) of a residential real estate property collateralizing a mortgage loan. Upon physical possession of such real property, an entity is required to reclassify the nonperforming mortgage loan to other real estate owned. ASU 2014-04 was effective for the Company for interim and annual periods beginning after December 15, 2014. Adoption of ASU 2014-04 did not have a material impact on the Company's consolidated financial statements.
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, 2016, 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. 2014-14, Classification of Certain Government-Guaranteed Mortgage Loans Upon Foreclosure ("ASU 2014-14")
On August 8, 2014, the FASB issued ASU 2014-14 to give greater consistency in the classification of government-guaranteed loans upon foreclosure. ASU 2014-14 applies to all loans that contain a government guarantee that is not separable from the loan or for which the creditor has both the intent and ability to recover a fixed amount under the guarantee by conveying the property to the guarantor. Upon foreclosure, the creditor should reclassify the mortgage loan to an other receivable that is separate from loans and should measure the receivable at the amount of the loan balance expected to be recovered from the guarantor. ASU 2014-14 was effective for the Company for interim and annual periods beginning after December 15, 2014. At January 1, 2015, approximately $50 million of real estate owned was reclassified from Real estate and other repossessed assets to Receivables on the balance sheet with adoption of ASC 2014-14.
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 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 is effective for annual periods beginning after December 15, 2015, and interim periods within those annual periods. Early adoption is permitted. Adoption of ASU 2014-16 is not expected to 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 will be effective for periods beginning after December 15, 2015 for public companies. Early adoption is permitted, including adoption in an interim period. The Company is evaluating the impact the adoption of ASU 2015-02 will have on the Company's financial statements.

Securities

Securities	12 Months Ended
	Dec. 31, 2014
Marketable Securities [Abstract]
Securities [Text Block]	(2) Securities
	Trading Securities
	The fair value and net unrealized gain (loss) included in trading securities is as follows (in thousands):
			December 31, 2014								December 31, 2013
			Fair Value				Net Unrealized Gain (Loss)				Fair Value				Net Unrealized Gain (Loss)
	U.S. government agency debentures		$	85,092			$	(62	)		$	34,120			$	77
	U.S. government agency residential mortgage-backed securities		31,199				269				21,011				123
	Municipal and other tax-exempt securities		38,951				18				27,350				(182		)
	Other trading securities		33,458				(38		)		9,135				(7		)
	Total		$	188,700			$	187			$	91,616			$	11
	Investment Securities
	The amortized cost and fair values of investment securities are as follows (in thousands):
			December 31, 2014
			Amortized				Carrying				Fair				Gross Unrealized2
			Cost				Value1				Value				Gain				Loss
	Municipal and other tax-exempt securities		$	405,090			$	405,090			$	408,344			$	4,205			$	(951	)
	U.S. government agency residential mortgage-backed securities – Other		35,135				35,750				37,463				1,713				—
	Other debt securities		211,520				211,520				227,819				16,956				(657		)
	Total		$	651,745			$	652,360			$	673,626			$	22,874			$	(1,608	)
	1	Carrying value includes $615 thousand of net unrealized gain which remains in Accumulated other comprehensive income (“AOCI”) in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.
	2	Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets.
			December 31, 2013
			Amortized				Carrying				Fair				Gross Unrealized2
			Cost				Value1				Value				Gain				Loss
	Municipal and other tax-exempt securities		$	440,187			$	440,187			$	439,870			$	2,452			$	(2,769	)
	U.S. government agency residential mortgage-backed securities – Other		48,351				50,182				51,864				1,738				(56		)
	Other debt securities		187,509				187,509				195,393				8,497				(613		)
	Total		$	676,047			$	677,878			$	687,127			$	12,687			$	(3,438	)
	1	Carrying value includes $1.8 million of net unrealized gain which remains in AOCI in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.
	2	Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets.
	In 2011, the Company transferred certain U.S. government agency residential mortgage-backed securities from the available for sale portfolio to the investment securities (held-to-maturity) portfolio as the Company has the positive intent and ability to hold these securities to maturity. No gains or losses were recognized in the Consolidated Statement of Earnings at the time of the transfer. Transfers of debt securities into the investment securities portfolio (held-to-maturity) are made at fair value at the date of transfer. The unrealized holding gain or loss at the date of transfer is retained in Accumulated Other Comprehensive Income and in the carrying value of the investment securities portfolio. Such amounts are amortized over the estimated remaining life of the security as an adjustment to yield, offsetting the related amortization of the premium or accretion of the discount on the transferred securities. At the time of transfer, the fair value totaled $131 million, amortized cost totaled $118 million and the pretax unrealized gain totaled $13 million.
	The amortized cost and fair values of investment securities at December 31, 2014, by contractual maturity, are as shown in the following table (dollars in thousands):
			Less than				One to				Six to				Over				Total				Weighted
			One Year				Five Years				Ten Years				Ten Years								Average
																							Maturity²
	Municipal and other tax-exempt securities:
	Carrying value		$	44,255			$	299,934			$	22,429			$	38,472			$	405,090			3.8
	Fair value		44,381				300,434				22,666				40,863				408,344
	Nominal yield¹		1.71		%		1.74		%		3.91		%		5.37		%		2.2		%
	Other debt securities:
	Carrying value		$	15,918			$	37,726			$	58,338			$	99,538			$	211,520			9.18
	Fair value		15,925				38,509				61,430				111,955				227,819
	Nominal yield		3.32		%		4.96		%		5.19		%		6.12		%		5.45		%
	Total fixed maturity securities:
	Carrying value		$	60,173			$	337,660			$	80,767			$	138,010			$	616,610			5.65
	Fair value		60,306				338,943				84,096				152,818				636,163
	Nominal yield		2.14		%		2.1		%		4.83		%		5.91		%		3.31		%
	Residential mortgage-backed securities:
	Carrying value																		$	35,750			³
	Fair value																		37,463
	Nominal yield4																		2.74		%
	Total investment securities:
	Carrying value																		$	652,360
	Fair value																		673,626
	Nominal yield																		3.28		%
	1	Calculated on a taxable equivalent basis using a 39% 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 2.8 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):
			December 31, 2014
			Amortized				Fair				Gross Unrealized1
			Cost				Value				Gain				Loss				OTTI²
U.S. Treasury securities		$	1,005			$	1,005			$	—			$	—			$	—
Municipal and other tax-exempt securities		63,018				63,557				1,280				(741		)		—
Residential mortgage-backed securities:
U. S. government agencies:
FNMA		3,932,200				3,997,428				71,200				(5,972		)		—
FHLMC		1,810,476				1,836,870				29,043				(2,649		)		—
GNMA		801,820				807,443				8,240				(2,617		)		—
Other		4,808				5,143				335				—				—
Total U.S. government agencies		6,549,304				6,646,884				108,818				(11,238		)		—
Private issue:
Alt-A loans		65,582				71,952				6,677				—				(307		)
Jumbo-A loans		88,778				94,005				5,584				—				(357		)
Total private issue		154,360				165,957				12,261				—				(664		)
Total residential mortgage-backed securities		6,703,664				6,812,841				121,079				(11,238		)		(664		)
Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,064,091				2,048,609				4,437				(19,919		)		—
Other debt securities		9,438				9,212				26				(252		)		—
Perpetual preferred stock		22,171				24,277				2,183				(77		)		—
Equity securities and mutual funds		18,603				19,444				871				(30		)		—
Total		$	8,881,990			$	8,978,945			$	129,876			$	(32,257	)		$	(664	)
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, 2013
		Amortized				Fair				Gross Unrealized¹
		Cost				Value				Gain				Loss				OTTI²
U.S. Treasury securities		$	1,042			$	1,042			$	—			$	—			$	—
Municipal and other tax-exempt securities		73,232				73,775				1,606				(1,063		)		—
Residential mortgage-backed securities:
U. S. government agencies:
FNMA		4,224,327				4,232,332				68,154				(60,149		)		—
FHLMC		2,308,341				2,293,943				25,813				(40,211		)		—
GNMA		1,151,225				1,152,128				9,435				(8,532		)		—
Other		36,296				37,607				1,311				—				—
Total U.S. government agencies		7,720,189				7,716,010				104,713				(108,892		)		—
Private issue:
Alt-A loans		104,559				107,212				4,386				—				(1,733		)
Jumbo-A loans		109,622				113,887				4,974				—				(709		)
Total private issue		214,181				221,099				9,360				—				(2,442		)
Total residential mortgage-backed securities		7,934,370				7,937,109				114,073				(108,892		)		(2,442		)
Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,100,146				2,055,804				1,042				(45,384		)		—
Other debt securities		35,061				35,241				368				(188		)		—
Perpetual preferred stock		22,171				22,863				705				(13		)		—
Equity securities and mutual funds		19,069				21,328				2,326				(67		)		—
Total		$	10,185,091			$	10,147,162			$	120,120			$	(155,607	)		$	(2,442	)
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 December 31, 2014, by contractual maturity, are as shown in the following table (dollars in thousands):
	Less than				One to				Six to				Over				Total				Weighted
	One Year				Five Years				Ten Years				Ten Years6								Average
																					Maturity5
U.S. Treasury securities:
Amortized cost	$	1,005			$	—			$	—			$	—			$	1,005			0.13
Fair value	1,005				—				—				—				1,005
Nominal yield	0.24		%		—		%		—		%		—		%		0.24		%
Municipal and other tax-exempt securities:
Amortized cost	7,134				29,750				2,288				23,846				63,018				8.27
Fair value	7,197				30,603				2,496				23,261				63,557
Nominal yield¹	3.68		%		4.05		%		6.48		%		1.92		%		3.29		%
Commercial mortgage-backed securities:
Amortized cost	—				912,178				808,792				343,121				2,064,091				8.56
Fair value	—				906,081				803,324				339,204				2,048,609
Nominal yield	—		%		1.43		%		1.68		%		1.33		%		1.51		%
Other debt securities:
Amortized cost	5,038				—				—				4,400				9,438				15.38
Fair value	5,065				—				—				4,147				9,212
Nominal yield	2.12		%		—		%		—		%		1.71		%		1.93		%
Total fixed maturity securities:
Amortized cost	$	13,177			$	941,928			$	811,080			$	371,367			$	2,137,552			8.58
Fair value	13,267				936,684				805,820				366,612				2,122,383
Nominal yield	2.82		%		1.52		%		1.69		%		1.38		%		1.57		%
Residential mortgage-backed securities:
Amortized cost																	$	6,703,664			2
Fair value																	6,812,841
Nominal yield4																	1.95		%
Perpetual preferred stock. equity securities and mutual funds:
Amortized cost																	$	40,774			³
Fair value																	43,721
Nominal yield																	1.28		%
Total available-for-sale securities:
Amortized cost																	$	8,881,990
Fair value																	8,978,945
Nominal yield																	1.85		%
1	Calculated on a taxable equivalent basis using a 39% effective tax rate.
2	The average expected lives of mortgage-backed securities were 3.4 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):
	Year Ended December 31,
	2014				2013				2012
Proceeds	$	2,664,740			$	2,436,093			1,744,662
Gross realized gains	24,923				25,711				41,191
Gross realized losses	(23,384		)		(14,991		)		(7,346	)
Related federal and state income tax expense	599				4,170				13,166
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):
	December 31,
	2014				2013
Investment:
Carrying value	$	63,495			$	89,087
Fair value	65,855				91,804
Available for sale:
Amortized cost	5,855,220				5,171,782
Fair value	5,893,972				5,133,530
No trading securities were pledged as collateral as of December 31, 2014 or December 31, 2013.
Temporarily Impaired Securities as of December 31, 2014
(In thousands)
		Number of Securities			Less Than 12 Months								12 Months or Longer								Total
					Fair				Unrealized				Fair				Unrealized				Fair				Unrealized
					Value				Loss				Value				Loss				Value				Loss
Investment:
Municipal and other tax-exempt securities		78			$	112,677			$	426			$	60,076			$	525			$	172,753			$	951
Other debt securities		84			31,274				637				761				20				32,035				657
Total investment securities		162			$	143,951			$	1,063			$	60,837			$	545			$	204,788			$	1,608
		Number of Securities			Less Than 12 Months								12 Months or Longer								Total
					Fair				Unrealized				Fair				Unrealized				Fair				Unrealized
					Value				Loss				Value				Loss				Value				Loss
Available for sale:
Municipal and other tax-exempt securities		22			$	10,838			$	12			$	12,176			$	729			$	23,014			$	741
Residential mortgage-backed securities:
U. S. government agencies:
FNMA		24			257,854				547				454,394				5,425				712,248				5,972
FHLMC		16			62,950				37				310,834				2,612				373,784				2,649
GNMA		5			8,550				12				128,896				2,605				137,446				2,617
Total U.S. agencies		45			329,354				596				894,124				10,642				1,223,478				11,238
Private issue1:
Alt-A loans		4			11,277				307				—				—				11,277				307
Jumbo-A loans		8			—				—				10,020				357				10,020				357
Total private issue		12			11,277				307				10,020				357				21,297				664
Total residential mortgage-backed securities		57			340,631				903				904,144				10,999				1,244,775				11,902
Commercial mortgage-backed securities guaranteed by U.S. government agencies		104			223,106				454				1,238,376				19,465				1,461,482				19,919
Other debt securities		2			—				—				4,150				252				4,150				252
Perpetual preferred stock		2			2,898				77				—				—				2,898				77
Equity securities and mutual funds		68			—				—				1,205				30				1,205				30
Total available for sale securities		255			$	577,473			$	1,446			$	2,160,051			$	31,475			$	2,737,524			$	32,921
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, 2013
(In thousands)
		Number of Securities			Less Than 12 Months								12 Months or Longer								Total
					Fair				Unrealized				Fair				Unrealized				Fair				Unrealized
					Value				Loss				Value				Loss				Value				Loss
Investment:
Municipal and other tax- exempt securities		107			$	166,382			$	1,921			$	53,073			$	848			$	219,455			$	2,769
U.S. Agency residential mortgage-backed securities – Other		2			15,224				56				—				—				15,224				56
Other debt securities		30			10,932				549				777				64				11,709				613
Total investment securities		139			$	192,538			$	2,526			$	53,850			$	912			$	246,388			$	3,438
		Number of Securities			Less Than 12 Months								12 Months or Longer								Total
					Fair				Unrealized				Fair				Unrealized				Fair				Unrealized
					Value				Loss				Value				Loss				Value				Loss
Available for sale:
Municipal and other tax-exempt securities		27			$	13,286			$	245			$	17,805			$	818			$	31,091			$	1,063
Residential mortgage-backed securities:
U. S. government agencies:
FNMA		81			2,281,491				60,149				—				—				2,281,491				60,149
FHLMC		50			1,450,588				40,211				—				—				1,450,588				40,211
GNMA		27			647,058				8,532				—				—				647,058				8,532
Total U.S. agencies		158			4,379,137				108,892				—				—				4,379,137				108,892
Private issue1:
Alt-A loans		7			11,043				756				30,774				977				41,817				1,733
Jumbo-A loans		9			14,642				709				—				—				14,642				709
Total private issue		16			25,685				1,465				30,774				977				56,459				2,442
Total residential mortgage-backed securities		174			4,404,822				110,357				30,774				977				4,435,596				111,334
Commercial mortgage-backed securities guaranteed by U.S. government agencies		123			1,800,717				45,302				2,286				82				1,803,003				45,384
Other debt securities		3			4,712				188				—				—				4,712				188
Perpetual preferred stock		1			4,988				13				—				—				4,988				13
Equity securities and mutual funds		118			2,070				67				—				—				2,070				67
Total available for sale securities		446			$	6,230,595			$	156,172			$	50,865			$	1,877			$	6,281,460			$	158,049
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 December 31, 2014, we do not intend to sell any impaired available for sale securities before fair value recovers to our current amortized cost and it is more-likely-than-not that we 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 December 31, 2014.
At December 31, 2014, 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																Below Investment Grade
		U.S. Govt/GSE 1																A - BBB												Not Rated				Total
		Carrying				Fair				Carrying				Fair				Carrying				Fair				Carrying		Fair		Carrying		Fair		Carrying		Fair
		Value				Value				Value				Value				Value				Value				Value		Value		Value		Value		Value		Value
Investment:
Municipal and other tax-exempt		$	—			$	—			$	264,326			$	264,651			$	13,676			$	13,806			$	—	$	—	$	127,088	$	129,887	$	405,090	$	408,344
U.S. government agency mortgage-backed securities -- Other		35,750				37,463				—				—				—				—				—		—		—		—		35,750		37,463
Other debt securities		—				—				160,353				176,915				—				—				—		—		51,167		50,904		211,520		227,819
Total investment securities		$	35,750			$	37,463			$	424,679			$	441,566			$	13,676			$	13,806			$	—	$	—	$	178,255	$	180,791	$	652,360	$	673,626
		U.S. Govt / GSE 1								AAA - AA																Below Investment Grade				Not Rated				Total
																		A - BBB
		Amortized Cost				Fair				Amortized Cost				Fair Value				Amortized Cost				Fair Value				Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair
						Value																														Value
Available for Sale:
U.S. Treasury		$	1,005			$	1,005			$	—			$	—			$	—			$	—			$	—	$	—	$	—	$	—	$	1,005	$	1,005
Municipal and other tax-exempt		—				—				40,511				41,579				11,053				10,516				—		—		11,454		11,462		63,018		63,557
Residential mortgage-backed securities:
U. S. government agencies:
FNMA		3,932,200				3,997,428				—				—				—				—				—		—		—		—		3,932,200		3,997,428
FHLMC		1,810,476				1,836,870				—				—				—				—				—		—		—		—		1,810,476		1,836,870
GNMA		801,820				807,443				—				—				—				—				—		—		—		—		801,820		807,443
Other		4,808				5,143				—				—				—				—				—		—		—		—		4,808		5,143
Total U.S. government agencies		6,549,304				6,646,884				—				—				—				—				—		—		—		—		6,549,304		6,646,884
Private issue:
Alt-A loans		—				—				—				—				—				—				65,582		71,952		—		—		65,582		71,952
Jumbo-A loans		—				—				—				—				—				—				88,778		94,005		—		—		88,778		94,005
Total private issue		—				—				—				—				—				—				154,360		165,957		—		—		154,360		165,957
Total residential mortgage-backed securities		6,549,304				6,646,884				—				—				—				—				154,360		165,957		—		—		6,703,664		6,812,841
Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,064,091				2,048,609				—				—				—				—				—		—		—		—		2,064,091		2,048,609
Other debt securities		—				—				4,400				4,149				5,038				5,063				—		—		—		—		9,438		9,212
Perpetual preferred stock		—				—				—				—				11,406				12,508				10,765		11,769		—		—		22,171		24,277
Equity securities and mutual funds		—				—				4				517				—				—				—		—		18,599		18,927		18,603		19,444
Total available for sale securities		$	8,614,400			$	8,696,498			$	44,915			$	46,245			$	27,497			$	28,087			$	165,125	$	177,726	$	30,053	$	30,389	$	8,881,990	$	8,978,945
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 December 31, 2014, the entire portfolio of privately issued residential mortgage-backed securities was rated below investment grade by at least one of the nationally-recognized rating agencies. The gross unrealized loss on these securities totaled $664 thousand. Ratings by the nationally-recognized rating agencies are subjective in nature and accordingly ratings can vary significantly amongst the agencies. Limitations generally expressed by the rating agencies include statements that ratings do not predict the specific percentage default likelihood over any given period of time and that ratings do not opine on expected loss severity of an obligation should the issuer default. As such, the impairment of securities rated below investment grade by at least one of the nationally-recognized rating agencies was evaluated to determine if we expect not to recover the entire amortized cost basis of the security. This evaluation was based on projections of estimated cash flows based on individual loans underlying each security using current and anticipated increases in unemployment and default rates, changes in housing prices and estimated liquidation costs at foreclosure.
The primary assumptions used in this evaluation were:
	December 31,
	2014		2013
Unemployment rate	Held constant at 5.6% over the next 12 months and remain at 5.6% thereafter.		Increasing to 7.3% over the next 12 months and remain at 7.3% thereafter
Housing price appreciation/depreciation	Starting with current depreciated housing prices based on information derived from the FHFA1, appreciating 3.2% over the next 12 months, then flat for the following 12 months and then appreciating at 2% per year thereafter.		Starting with current depreciated housing prices based on information derived from the FHFA1, appreciating 4% over the next 12 months, then flat for the following 12 months and then appreciating at 2% 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.
Discount rates	Estimated cash flows were discounted at rates that range from 2.00% to 6.25% based on our current expected yields.		Estimated cash flows were discounted at rates that range from 2.00% to 6.25% based on our current expected yields.
1	Federal Housing Finance Agency
We also consider the current loan-to-value ratio and remaining credit enhancement as part of the assessment of the cash flows available to recover the amortized cost of the debt securities. Each factor is considered in the evaluation.
The Company calculates the current loan-to-value ratio for each mortgage-backed security using loan-level data. Current loan-to-value ratio is the current outstanding loan amount divided by an estimate of the current home value. The current home value is derived from FHFA data. FHFA provides historical information on home price depreciation at both the Metropolitan Statistical Area and state level. This information is matched to each loan to estimate the home price depreciation. Data is accumulated from the loan level to determine the current loan-to-value ratio for the security as a whole.
Remaining credit enhancement is the amount of credit enhancement available to absorb current projected losses within the pool of loans that support the security. The Company acquires the benefit of credit enhancement by investing in super-senior tranches for many of our residential mortgage-backed securities. Subordinated tranches held by other investors are specifically designed to absorb losses before the super-senior tranches which added an additional layer to the typical credit support for these types of bonds. Current projected losses consider depreciation of home prices based on FHFA data, estimated costs and additional losses to liquidate collateral and delinquency status of the individual loans underlying the security.
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 was charged against other comprehensive income, net of deferred taxes.
The Company recognized no credit loss impairments on private-label residential mortgage-backed securities in earnings during 2014, $938 thousand in 2013 and $5.9 million in 2012.
The Company recognized no credit loss impairment in earnings during 2014 for certain below investment grade municipal securities based on an assessment of the issuer's on-going financial difficulties and bankruptcy filing in 2011. The Company recognized $1.4 million in impairment charges on these securities in 2013 and $1.0 million of impairment losses on these securities in 2012.
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
													Year Ended
													December 31, 2014							Life-to-date
		Number of Securities			Amortized Cost				Fair Value				Number of			Amount				Number of Securities			Amount
													Securities
Alt-A		14			$	65,582			$	71,952			—			$	—			14			$	36,127
Jumbo-A		30			88,778				94,005				—			—				29			18,220
Total		44			$	154,360			$	165,957			—			$	—			43			$	54,347
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. Based on this evaluation, $373 thousand other-than-temporary impairment losses were recorded in earnings on equity securities during 2014. All remaining impairment of equity securities was considered temporary at December 31, 2014 and December 31, 2013. No other-than-temporary impairment loss related to equity securities was recorded in earnings in 2013 and $457 thousand in impairment losses were recorded in 2012.
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):
		Year Ended December 31,
		2014				2013				2012
Balance of credit-related OTTI recognized on available for sale debt, beginning of period		$	67,346			$	75,228			$	76,131
Additions for credit-related OTTI not previously recognized		—				618				113
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		—				320				6,780
Reductions for change in intent to hold before recovery		—				(3,589		)		—
Sales		(12,999		)		(5,231		)		(7,796		)
Balance of credit-related OTTI recognized on available for sale debt securities, end of period		$	54,347			$	67,346			$	75,228
Fair Value Option Securities
Fair value option securities represent securities which the Company has elected to carry at fair value and separately identified on the Consolidated Balance Sheets with changes in the fair value recognized in earnings as they occur. Certain residential mortgage-backed securities issued by U.S. government agencies and derivative contracts are held as an economic hedge of the mortgage servicing rights. In addition, certain corporate debt securities are economically hedged by derivative contracts to manage interest rate risk. Derivative contracts that have not been designated as hedging instruments effectively modify these fixed rate securities into variable rate securities.
The fair value and net unrealized gain (loss) included in Fair value option securities is as follows (in thousands):
		December 31, 2014								December 31, 2013
		Fair Value				Net Unrealized Gain (Loss)				Fair Value				Net Unrealized Gain (Loss)
U.S. agency residential mortgage-backed securities		$	311,597			$	1,624			$	157,431			$	(8,378	)
Other securities		—				—				9,694				209
Total		$	311,597			$	1,624			$	167,125			$	(8,169	)
Restricted Equity Securities
Restricted equity securities include stock we are required to hold as members of the Federal Reserve system and the Federal Home Loan Banks ("FHLB"). Restricted equity securities are carried at cost as these securities do not have a readily determined fair value because ownership of these shares is restricted and they lack a market. A summary of restricted equity securities follows (in thousands):
	December 31,
	2014				2013
Federal Reserve Bank stock	$	35,018			$	33,742
Federal Home Loan Bank stock	106,476				51,498
Total	$	141,494			$	85,240

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2014
Derivative Instrument Detail [Abstract]
Derivatives [Text Block]	(3) Derivatives
	The following table summarizes the fair values of derivative contracts recorded as “derivative contracts” assets and liabilities in the balance sheet at December 31, 2014 (in thousands):
			Assets
			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		$	13,313,615	$	94,719	$	(39,359	)	$	55,360		$	—		$	55,360
	Interest rate swaps		1,165,568		35,405		—			35,405			—			35,405
	Energy contracts		579,801		141,166		(48,624		)	92,542			(71,310		)	21,232
	Agricultural contracts		47,657		1,904		(1,256		)	648			—			648
	Foreign exchange contracts		290,965		238,395		—			238,395			—			238,395
	Equity option contracts		194,960		10,834		—			10,834			—			10,834
	Total customer risk management programs		15,592,566		522,423		(89,239		)	433,184			(71,310		)	361,874
	Interest rate risk management programs		—		—		—			—			—			—
	Total derivative contracts		$	15,592,566	$	522,423	$	(89,239	)	$	433,184		$	(71,310	)	$	361,874
			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		$	13,471,880	$	91,949	$	(39,359	)	$	52,590		$	(52,290	)	$	300
	Interest rate swaps		1,165,568		35,599		—			35,599			(18,717		)	16,882
	Energy contracts		579,801		142,839		(48,624		)	94,215			—			94,215
	Agricultural contracts		47,418		1,908		(1,256		)	652			(596		)	56
	Foreign exchange contracts		290,856		238,118		—			238,118			(6,703		)	231,415
	Equity option contracts		194,960		10,834		—			10,834			—			10,834
	Total customer risk management programs		15,750,483		521,247		(89,239		)	432,008			(78,306		)	353,702
	Interest rate risk management programs		47,000		852		—			852			—			852
	Total derivative contracts		$	15,797,483	$	522,099	$	(89,239	)	$	432,860		$	(78,306	)	$	354,554
	1	Notional amounts for commodity contracts are converted into dollar-equivalent amounts based on dollar prices at the inception of the contract.
	When bilateral netting agreements 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 counterparty basis.
	Derivative contracts may also 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. As of December 31, 2014, a decrease in credit rating to below investment grade would increase our obligation to post cash margin on existing contracts by approximately $19 million.
	The following table summarizes the fair values of derivative contracts recorded as “derivative contracts” assets and liabilities in the balance sheet at December 31, 2013 (in thousands):
			Assets
			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		$	10,817,159	$	102,921	$	(46,623	)	$	56,298		$	—		$	56,298
	Interest rate swaps		1,283,379		44,124		—			44,124			(731		)	43,393
	Energy contracts		1,263,266		48,078		(29,957		)	18,121			(2,575		)	15,546
	Agricultural contracts		100,886		2,060		(1,166		)	894			—			894
	Foreign exchange contracts		136,543		136,543		—			136,543			(2,147		)	134,396
	Equity option contracts		210,816		17,957		—			17,957			(3,472		)	14,485
	Total customer risk management programs		13,812,049		351,683		(77,746		)	273,937			(8,925		)	265,012
	Interest rate risk management programs		—		—		—			—			—			—
	Total derivative contracts		$	13,812,049	$	351,683	$	(77,746	)	$	273,937		$	(8,925	)	$	265,012
			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		$	10,982,049	$	99,830	$	(46,623	)	$	53,207		$	—		$	53,207
	Interest rate swaps		1,283,379		44,377		—			44,377			(17,853		)	26,524
	Energy contracts		1,216,426		46,095		(29,957		)	16,138			(6,055		)	10,083
	Agricultural contracts		99,191		2,009		(1,166		)	843			—			843
	Foreign exchange contracts		135,237		135,237		—			135,237			(294		)	134,943
	Equity option contracts		210,816		17,957		—			17,957			—			17,957
	Total customer risk management programs		13,927,098		345,505		(77,746		)	267,759			(24,202		)	243,557
	Interest rate risk management programs		47,000		3,628		—			3,628			—			3,628
	Total derivative contracts		$	13,974,098	$	349,133	$	(77,746	)	$	271,387		$	(24,202	)	$	247,185
	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 Consolidated Statement of Earnings (in thousands):
			Year Ended December 31,
			2014				2013						2012
			Brokerage		Gain (Loss)		Brokerage			Gain (Loss)			Brokerage			Gain (Loss)
			and Trading Revenue		on Derivatives, Net		and Trading			on Derivatives,			and Trading			on Derivatives,
					Revenue			Net			Revenue			Net
Customer risk management programs:
Interest rate contracts
To-be-announced residential mortgage-backed securities		$	27,007	$	—	$	29,614		$	—		$	25,509		$	—
Interest rate swaps		2,494		—		2,991			—			3,458			—
Energy contracts		6,572		—		8,303			—			8,171			—
Agricultural contracts		146		—		357			—			382			—
Foreign exchange contracts		1,581		—		687			—			612			—
Equity option contracts		—		—		—			—			—			—
Total customer risk management programs		37,800		—		41,952			—			38,132			—
Interest rate risk management programs		—		2,776		—			(4,367		)	—			(301		)
Total derivative contracts		$	37,800	$	2,776	$	41,952		$	(4,367	)	$	38,132		$	(301	)
At December 31, 2014, BOK Financial had interest rate swaps with a notional value of $47 million used as part of the economic hedge of the change in the fair value of mortgage servicing rights.
As discussed in Note 7, 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 7 for additional discussion of notional, fair value and impact on earnings of these contracts. Forward sales contracts are not considered swaps under the Commodity and Futures Trading Commission final rules.
None of these derivative contracts have been designated as hedging instruments.

Loans_and_Allowances_for_Credi

Loans and Allowances for Credit Losses	12 Months Ended
	Dec. 31, 2014
Loans Receivable, Net [Abstract]
Loans [Text Block]	(4) Loans and Allowances for Credit Losses
	The portfolio segments of the loan portfolio are as follows (in thousands):
			December 31, 2014																December 31, 2013
			Fixed				Variable				Non-accrual				Total				Fixed				Variable				Non-accrual			Total
			Rate				Rate												Rate				Rate
	Commercial		$	1,736,976			$	7,345,167			$	13,527			$	9,095,670			$	1,637,620			$	6,288,841			$	16,760		$	7,943,221
	Commercial real estate		721,513				1,988,080				18,557				2,728,150				770,908				1,603,595				40,850			2,415,353
	Residential mortgage		1,698,620				202,771				48,121				1,949,512				1,783,614				226,092				42,320			2,052,026
	Consumer		102,865				331,274				566				434,705				135,494				244,951				1,219			381,664
	Total		$	4,259,974			$	9,867,292			$	80,771			$	14,208,037			$	4,327,636			$	8,363,479			$	101,149		$	12,792,264
	Accruing loans past due (90 days)1														$	125														$	1,415
	Foregone interest on nonaccrual loans														$	8,170														$	9,815
	1	Excludes residential mortgage loans guaranteed by agencies of the U.S. government.
	At December 31, 2014, loans to businesses and individuals with collateral primarily located in Texas totaled $4.9 billion or 34% of the total loan portfolio. Loans to businesses and individuals with collateral primarily located in Oklahoma totaled $3.4 billion or 24% of our total loan portfolio. Loans for which the collateral location is not relevant, such as unsecured loans and reserve-based energy loans, are distributed by the borrower’s primary operating location. These geographic concentrations subject the loan portfolio to the general economic conditions within these areas. At December 31, 2013, loans to businesses and individuals with collateral primarily located in Texas totaled $4.3 billion or 34% of the loan portfolio and loans to businesses and individuals with collateral primarily located in Oklahoma totaled $3.3 billion or 26% of the loan portfolio.
	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 December 31, 2014, commercial loans with collateral primarily located in Texas totaled $3.2 billion or 36% of the commercial loan portfolio segment and commercial loans with collateral primarily located in Oklahoma totaled $2.0 billion or 22% of the commercial loan portfolio segment. The commercial loan portfolio segment is further divided into loan classes. The energy loan class totaled $2.9 billion or 20% of total loans at December 31, 2014, including $2.5 billion of outstanding loans to energy producers. Approximately 59% of committed production loans are secured by properties primarily producing oil and 41% are secured by properties producing natural gas. The services loan class totaled $2.5 billion at December 31, 2014. Approximately $1.2 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, educational, utilities, not-for-profit and professional/technical services.
	At December 31, 2013, commercial loans with collateral primarily located in Texas totaled $2.8 billion or 36% of the commercial loan portfolio segment and commercial loans with collateral primarily located in Oklahoma totaled $1.9 billion or 23% of the commercial loan portfolio segment. The energy loan class totaled $2.4 billion and the services loan class totaled $2.3 billion. Approximately $1.1 billion of loans in the services category consisted of loans with individual balances of less than $10 million.
	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 December 31, 2014, 34% of commercial real estate loans are secured by properties primarily located in the Dallas and Houston areas of Texas. An additional 16% of commercial real estate loans are secured by properties located primarily in the Tulsa and Oklahoma City metropolitan areas of Oklahoma. At December 31, 2013, 32% of commercial real estate loans were secured by properties in Texas, 19% of commercial real estate loans were secured by properties in Oklahoma and 11% of commercial real estate loans were secured by properties located primarily in Albuquerque, New Mexico.
	Residential Mortgage and Consumer
	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. Consumer loans include direct loans secured by and for the purchase of automobiles, recreational and marine equipment as well as other unsecured loans. Consumer loans also include indirect automobile loans made through primary dealers. Residential mortgage and consumer loans are made in accordance with underwriting policies we believe to be conservative and are fully documented. 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%. Loan-to-value (“LTV”) ratios are tiered from 60% to 100%, 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 December 31, 2014 and 2013, residential mortgage loans included $206 million and $182 million, respectively, 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 $774 million at December 31, 2014 and $808 million at December 31, 2013. At December 31, 2014, 69% of the home equity loan portfolio was comprised of first lien loans and 31% of the home equity portfolio was comprised of junior lien loans. Junior lien loans were distributed 71% to amortizing term loans and 29% to revolving lines of credit. At December 31, 2013, 70% of the home equity portfolio was comprised of first lien loans and 30% of the home equity loan portfolio was comprised of junior lien loans. Junior lien loans were distributed 74% to amortizing term loans and 26% to revolving lines of credit. Home equity loans generally require a minimum FICO score of 700 and a maximum DTI of 40%. 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 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.
	At December 31, 2014, 38% of residential mortgage loans are secured by properties located in Oklahoma, 28% of residential mortgage loans are secured by properties located in Texas, 12% of residential mortgage are secured by properties located in New Mexico and 10% of residential mortgage are secured by properties located in Colorado. At December 31, 2013, 38% of residential mortgage loans were secured by properties in Oklahoma, 27% of residential mortgage were secured by properties in Texas and 10% of residential mortgage loans are secured by properties in New Mexico.
	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 December 31, 2014, outstanding commitments totaled $8.3 billion. Because some commitments are expected to expire before being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. BOK Financial uses the same credit policies in making commitments as it does loans.
	The amount of collateral obtained, if deemed necessary, is based upon management’s credit evaluation of the borrower.
	Standby letters of credit are conditional commitments issued to guarantee the performance of a customer to a third party. Because the credit risk involved in issuing standby letters of credit is essentially the same as that involved in extending loan commitments, BOK Financial uses the same credit policies in evaluating the creditworthiness of the customer. Additionally, BOK Financial uses the same evaluation process in obtaining collateral on standby letters of credit as it does for loan commitments. The term of these standby letters of credit is defined in each commitment and typically corresponds with the underlying loan commitment. At December 31, 2014, outstanding standby letters of credit totaled $448 million. Commercial letters of credit are used to facilitate customer trade transactions with the drafts being drawn when the underlying transaction is consummated. At December 31, 2014, outstanding commercial letters of credit totaled $6.7 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 7, the Company also has separate accruals related to 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 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, concentration in loans with large balances and other relevant factors.
	The activity in the allowance for loan losses and the accrual for off-balance sheet credit risk related to loan commitments and standby letters of credit for the year ended December 31, 2014 is summarized as follows (in thousands):
			Commercial				Commercial Real Estate				Residential Mortgage				Consumer				Nonspecific Allowance				Total
	Allowance for loan losses:
	Beginning balance		$	79,180			$	41,573			$	29,465			$	6,965			$	28,213			$	185,396
	Provision for loan losses		9,561				(4,084		)		(3,559		)		(892		)		(168		)		858
	Loans charged off		(3,569		)		(2,047		)		(4,448		)		(6,168		)		—				(16,232		)
	Recoveries		5,703				7,003				2,000				4,328				—				19,034
	Ending balance		$	90,875			$	42,445			$	23,458			$	4,233			$	28,045			$	189,056
	Accrual for off-balance sheet credit risk:
	Beginning balance		$	119			$	1,876			$	90			$	3			$	—			$	2,088
	Provision for off-balance sheet credit risk		356				(1,169		)		(62		)		17				—				(858		)
	Ending balance		$	475			$	707			$	28			$	20			$	—			$	1,230
	Total provision for credit losses		$	9,917			$	(5,253	)		$	(3,621	)		$	(875	)		$	(168	)		$	—
	The activity in the allowance for loan losses and the accrual for off-balance sheet credit risk related to loan commitments and standby letters of credit for the year ended December 31, 2013 is summarized as follows (in thousands):
			Commercial				Commercial Real Estate				Residential Mortgage				Consumer				Nonspecific Allowance				Total
	Allowance for loan losses:
	Beginning balance		$	65,280			$	54,884			$	41,703			$	9,453			$	44,187			$	215,507
	Provision for loan losses		12,747				(16,886		)		(8,043		)		83				(15,974		)		(28,073		)
	Loans charged off		(6,335		)		(5,845		)		(5,753		)		(7,349		)		—				(25,282		)
	Recoveries		7,488				9,420				1,558				4,778				—				23,244
	Ending balance		$	79,180			$	41,573			$	29,465			$	6,965			$	28,213			$	185,396
	Accrual for off-balance sheet credit risk:
	Beginning balance		$	475			$	1,353			$	78			$	9			$	—			$	1,915
	Provision for off-balance sheet credit risk		(356		)		523				12				(6		)		—				173
	Ending balance		$	119			$	1,876			$	90			$	3			$	—			$	2,088
	Total provision for credit losses		$	12,391			$	(16,363	)		$	(8,031	)		$	77			$	(15,974	)		$	(27,900	)
	The activity in the allowance for loan losses and the accrual for off-balance sheet credit risk related to loan commitments and standby letters of credit for the year ended December 31, 2012 is summarized as follows (in thousands):
			Commercial				Commercial Real Estate				Residential Mortgage				Consumer				Nonspecific Allowance				Total
	Allowance for loan losses:
	Beginning balance		$	83,443			$	67,034			$	46,476			$	10,178			$	46,350			$	253,481
	Provision for loan losses		(14,950		)		(6,214		)		3,346				5,327				(2,163		)		(14,654		)
Loans charged off		(9,341		)		(11,642		)		(10,047		)		(11,108		)		—				(42,138		)
Recoveries		6,128			1	5,706				1,928				5,056				—				18,818
Ending balance		$	65,280			$	54,884			$	41,703			$	9,453			$	44,187			$	215,507
Accrual for off-balance sheet credit risk:
Beginning balance		$	7,906			$	1,250			$	91			$	14			$	—			$	9,261
Provision for off-balance sheet credit risk		(7,431		)		103				(13		)		(5		)		—				(7,346		)
Ending balance		$	475			$	1,353			$	78			$	9			$	—			$	1,915
Total provision for credit losses		$	(22,381	)		$	(6,111	)		$	3,333			$	5,322			$	(2,163	)		$	(22,000	)
1	Includes $7.1 million of negative recovery related to a refund of a settlement between BOK Financial and the City of Tulsa invalidated by the Oklahoma Supreme Court.
The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at December 31, 2014 is as follows (in thousands):
		Collectively Measured								Individually Measured								Total
		for Impairment								for Impairment
		Recorded Investment				Related Allowance				Recorded Investment				Related Allowance				Recorded Investment				Related
																						Allowance
Commercial		$	9,082,143			$	90,709			$	13,527			$	166			$	9,095,670			$	90,875
Commercial real estate		2,709,593				42,404				18,557				41				2,728,150				42,445
Residential mortgage		1,901,391				23,353				48,121				105				1,949,512				23,458
Consumer		434,139				4,233				566				—				434,705				4,233
Total		14,127,266				160,699				80,771				312				14,208,037				161,011
Nonspecific allowance		—				—				—				—				—				28,045
Total		$	14,127,266			$	160,699			$	80,771			$	312			$	14,208,037			$	189,056
The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at December 31, 2013 is as follows (in thousands):
		Collectively Measured								Individually Measured								Total
		for Impairment								for Impairment
		Recorded Investment				Related Allowance				Recorded Investment				Related Allowance				Recorded Investment				Related
																						Allowance
Commercial		$	7,926,461			$	78,607			$	16,760			$	573			$	7,943,221			$	79,180
Commercial real estate		2,374,503				41,440				40,850				133				2,415,353				41,573
Residential mortgage		2,010,483				29,217				41,543				248				2,052,026				29,465
Consumer		380,445				6,965				1,219				—				381,664				6,965
Total		12,691,892				156,229				100,372				954				12,792,264				157,183
Nonspecific allowance		—				—				—				—				—				28,213
Total		$	12,691,892			$	156,229			$	100,372			$	954			$	12,792,264			$	185,396
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 December 31, 2014 is as follows (in thousands):
		Internally Risk Graded								Non-Graded								Total
		Recorded Investment				Related Allowance				Recorded Investment				Related Allowance				Recorded Investment				Related
																						Allowance
Commercial		$	9,073,030			$	90,085			$	22,640			$	790			$	9,095,670			$	90,875
Commercial real estate		2,728,150				42,445				—				—				2,728,150				42,445
Residential mortgage		192,303				2,996				1,757,209				20,462				1,949,512				23,458
Consumer		343,227				1,506				91,478				2,727				434,705				4,233
Total		12,336,710				137,032				1,871,327				23,979				14,208,037				161,011
Nonspecific allowance		—				—				—				—				—				28,045
Total		$	12,336,710			$	137,032			$	1,871,327			$	23,979			$	14,208,037			$	189,056
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, 2013 is as follows (in thousands):
		Internally Risk Graded								Non-Graded								Total
		Recorded Investment				Related Allowance				Recorded Investment				Related Allowance				Recorded Investment				Related
																						Allowance
Commercial		$	7,888,219			$	78,250			$	55,002			$	930			$	7,943,221			$	79,180
Commercial real estate		2,415,353				41,573				—				—				2,415,353				41,573
Residential mortgage		220,635				5,481				1,831,391				23,984				2,052,026				29,465
Consumer		265,533				2,657				116,131				4,308				381,664				6,965
Total		10,789,740				127,961				2,002,524				29,222				12,792,264				157,183
Nonspecific allowance		—				—				—				—				—				28,213
Total		$	10,789,740			$	127,961			$	2,002,524			$	29,222			$	12,792,264			$	185,396
Loans are considered to be performing if they are in compliance with the original terms of the agreement which is consistent with the regulatory guideline of “pass.” Performing also includes loans considered to be “other loans especially mentioned” by regulatory guidelines. Other loans especially mentioned are in compliance with the original terms of the agreement but may have a weakness that deserves management’s close attention. Performing loans also include past due residential mortgages that are guaranteed by agencies of the U.S. government.
The risk grading process identified certain criticized loans as potential problem loans. These loans 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. Known information does, however, cause concern as to the borrowers’ continued compliance with current repayment terms. Nonaccruing loans represent loans for which full collection of principal and interest in accordance with the original terms of the loan agreements 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 December 31, 2014 by the risk grade categories (in thousands):
		Internally Risk Graded												Non-Graded
		Performing				Potential Problem				Nonaccruing				Performing				Nonaccruing				Total
Commercial:
Energy		$	2,843,093			$	15,919			$	1,416			$	—			$	—			$	2,860,428
Services		2,497,888				15,140				5,201				—				—				2,518,229
Wholesale/retail		1,301,026				8,141				4,149				—				—				1,313,316
Manufacturing		527,951				4,193				450				—				—				532,594
Healthcare		1,449,024				4,565				1,380				—				—				1,454,969
Other commercial and industrial		389,378				3,293				823				22,532				108				416,134
Total commercial		9,008,360				51,251				13,419				22,532				108				9,095,670
Commercial real estate:
Residential construction and land development		127,437				10,855				5,299				—				—				143,591
Retail		662,335				628				3,926				—				—				666,889
Office		411,548				576				3,420				—				—				415,544
Multifamily		691,053				13,245				—				—				—				704,298
Industrial		428,817				—				—				—				—				428,817
Other commercial real estate		362,375				724				5,912				—				—				369,011
Total commercial real estate		2,683,565				26,028				18,557				—				—				2,728,150
Residential mortgage:
Permanent mortgage		187,520				1,773				3,010				745,813				31,835				969,951
Permanent mortgages guaranteed by U.S. government agencies		—				—				—				202,238				3,712				205,950
Home equity		—				—				—				764,047				9,564				773,611
Total residential mortgage		187,520				1,773				3,010				1,712,098				45,111				1,949,512
Consumer		343,041				19				167				91,079				399				434,705
Total		$	12,222,486			$	79,071			$	35,153			$	1,825,709			$	45,618			$	14,208,037
The following table summarizes the Company’s loan portfolio at December 31, 2013 by the risk grade categories (in thousands):
		Internally Risk Graded												Non-Graded
		Performing				Potential Problem				Nonaccruing				Performing				Nonaccruing				Total
Commercial:
Energy		$	2,347,519			$	2,381			$	1,860			$	—			$	—			$	2,351,760
Services		2,265,984				11,304				4,922				—				—				2,282,210
Wholesale/retail		1,191,791				2,604				6,969				—				—				1,201,364
Manufacturing		381,794				9,365				592				—				—				391,751
Healthcare		1,272,626				34				1,586				—				—				1,274,246
Other commercial and industrial		381,394				4,736				758				54,929				73				441,890
Total commercial		7,841,108				30,424				16,687				54,929				73				7,943,221
Commercial real estate:
Residential construction and land development		173,488				15,393				17,377				—				—				206,258
Retail		579,506				1,684				4,857				—				—				586,047
Office		403,951				1,157				6,391				—				—				411,499
Multifamily		562,800				13,695				7				—				—				576,502
Industrial		243,625				—				252				—				—				243,877
Other commercial real estate		371,628				7,576				11,966				—				—				391,170
Total commercial real estate		2,334,998				39,505				40,850				—				—				2,415,353
Residential mortgage:
Permanent mortgage		210,142				3,283				7,210				815,040				27,069				1,062,744
Permanent mortgages guaranteed by U.S. government agencies		—				—				—				180,821				777				181,598
Home equity		—				—				—				800,420				7,264				807,684
Total residential mortgage		210,142				3,283				7,210				1,796,281				35,110				2,052,026
Consumer		264,536				795				202				115,114				1,017				381,664
Total		$	10,650,784			$	74,007			$	64,949			$	1,966,324			$	36,200			$	12,792,264
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 troubled debt restructuring and all loans repurchased from GNMA pool.
A summary of impaired loans follows (in thousands):
	As of December 31, 2014																				Year Ended
					Recorded Investment																December 31, 2014
	Unpaid				Total				With No				With Allowance				Related Allowance				Average Recorded				Interest Income Recognized
	Principal								Allowance												Investment
	Balance
Commercial:
Energy	$	1,444			$	1,416			$	1,416			$	—			$	—			$	1,638			$	—
Services	8,068				5,201				4,487				714				157				5,061				—
Wholesale/retail	9,457				4,149				4,117				32				9				5,559				—
Manufacturing	737				450				450				—				—				521				—
Healthcare	2,432				1,380				1,380				—				—				1,483				—
Other commercial and industrial	8,604				931				931				—				—				881				—
Total commercial	30,742				13,527				12,781				746				166				15,143				—
Commercial real estate:
Residential construction and land development	10,071				5,299				5,192				107				23				11,338				—
Retail	5,406				3,926				3,926				—				—				4,392				—
Office	5,959				3,420				3,420				—				—				4,905				—
Multifamily	—				—				—				—				—				3				—
Industrial	—				—				—				—				—				126				—
Other commercial real estate	11,954				5,912				5,739				173				18				8,939				—
Total commercial real estate	33,390				18,557				18,277				280				41				29,703				—
Residential mortgage:
Permanent mortgage	43,463				34,845				34,675				170				105				34,561				1,418
Permanent mortgage guaranteed by U.S. government agencies1	212,684				205,950				205,950				—				—				194,017				8,342
Home equity	9,767				9,564				9,564				—				—				8,414				—
Total residential mortgage	265,914				250,359				250,189				170				105				236,992				9,760
Consumer	584				566				566				—				—				893				—
Total	$	330,630			$	283,009			$	281,813			$	1,196			$	312			$	282,731			$	9,760
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, 2014, $3.7 million of these loans are nonaccruing and $202 million are 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, have been recovered.
	As of December 31, 2013																					Year Ended
						Recorded Investment																December 31, 2013
		Unpaid				Total				With No				With Allowance				Related Allowance				Average Recorded				Interest Income Recognized
		Principal								Allowance												Investment
		Balance
Commercial:
Energy		$	1,860			$	1,860			$	1,860			$	—			$	—			$	2,160			$	—
Services		6,486				4,922				3,791				1,131				516				8,506				—
Wholesale/retail		11,009				6,969				6,937				32				9				5,023				—
Manufacturing		746				592				592				—				—				1,300				—
Healthcare		2,193				1,586				1,538				48				48				2,376				—
Other commercial and industrial		8,532				831				831				—				—				1,249				—
Total commercial		30,826				16,760				15,549				1,211				573				20,614				—
Commercial real estate:
Residential construction and land development		20,804				17,377				17,050				327				107				21,754				—
Retail		6,133				4,857				4,857				—				—				6,487				—
Office		7,848				6,391				6,383				8				8				6,610				—
Multifamily		7				7				7				—				—				1,357				—
Industrial		252				252				252				—				—				2,110				—
Other commercial real estate		14,593				11,966				11,779				187				18				12,421				—
Total commercial real estate		49,637				40,850				40,328				522				133				50,739				—
Residential mortgage:
Permanent mortgage		41,870				34,279				33,869				410				248				37,071				1,582
Permanent mortgage guaranteed by U.S. government agencies1		188,436				181,598				181,598				—				—				165,509				6,961
Home equity		7,537				7,264				7,264				—				—				6,760				—
Total residential mortgage		237,843				223,141				222,731				410				248				209,340				8,543
Consumer		1,228				1,219				1,219				—				—				1,965				—
Total		$	319,534			$	281,970			$	279,827			$	2,143			$	954			$	282,658			$	8,543
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, 2013, $777 thousand of these loans are nonaccruing and $181 million are accruing based on the guarantee by U.S. government agencies.
Troubled Debt Restructurings
A summary of troubled debt restructurings ("TDRs") by accruing status as of December 31, 2014 is as follows (in thousands):
		As of December 31, 2014
		Recorded				Performing in Accordance With Modified Terms				Not				Specific				Amounts Charged-Off During the Year Ended December 31, 2014
		Investment								Performing in Accordance With Modified Terms				Allowance
Nonaccruing TDRs:
Commercial:
Energy		$	—			$	—			$	—			$	—			$	—
Services		1,666				706				960				148				—
Wholesale/retail		3,381				3,284				97				9				—
Manufacturing		340				340				—				—				3,000
Healthcare		—				—				—				—				—
Other commercial and industrial		674				93				581				—				—
Total commercial		6,061				4,423				1,638				157				3,000
Commercial real estate:
Residential construction and land development		3,140				641				2,499				23				1,597
Retail		3,600				2,432				1,168				—				—
Office		2,324				—				2,324				—				—
Multifamily		—				—				—				—				—
Industrial		—				—				—				—				—
Other commercial real estate		1,647				1,647				—				—				—
Total commercial real estate		10,711				4,720				5,991				23				1,597
Residential mortgage:
Permanent mortgage		16,393				11,134				5,259				105				262
Permanent mortgage guaranteed by U.S. government agencies		1,597				179				1,418				—				—
Home equity		5,184				3,736				1,448				—				247
Total residential mortgage		23,174				15,049				8,125				105				509
Consumer		419				253				166				—				1
Total nonaccruing TDRs		40,365				24,445				15,920				285				5,107
Accruing TDRs:
Residential mortgage:
Permanent mortgages guaranteed by U.S. government agencies		73,985				17,274				56,711				—				—
Total residential mortgage		73,985				17,274				56,711				—				—
Total accruing TDRs		73,985				17,274				56,711				—				—
Total TDRs		$	114,350			$	41,719			$	72,631			$	285			$	5,107
A summary of troubled debt restructurings by accruing status as of December 31, 2013 is as follows (in thousands):
		As of December 31, 2013
		Recorded				Performing in Accordance With Modified Terms				Not				Specific				Amounts Charged-off During the Year Ended December 31, 2013
		Investment								Performing in Accordance With Modified Terms				Allowance
Nonaccruing TDRs:
Commercial:
Energy		$	—			$	—			$	—			$	—			$	—
Services		2,235				852				1,383				237				—
Wholesale/retail		235				89				146				9				—
Manufacturing		391				—				391				—				154
Healthcare		—				—				—				—				—
Other commercial and industrial		771				173				598				—				—
Total commercial		3,632				1,114				2,518				246				154
Commercial real estate:
Residential construction and land development		10,148				1,444				8,704				107				46
Retail		4,359				3,141				1,218				—				582
Office		5,059				3,872				1,187				—				117
Multifamily		—				—				—				—				—
Industrial		—				—				—				—				—
Other commercial real estate		5,011				2,885				2,126				—				—
Total commercial real estate		24,577				11,342				13,235				107				745
Residential mortgage:
Permanent mortgage		18,697				12,214				6,483				88				469
Home equity		4,045				3,531				514				—				112
Total residential mortgage		22,742				15,745				6,997				88				581
Consumer		1,008				758				250				—				1
Total nonaccuring TDRs		51,959				28,959				23,000				441				1,481
Accruing TDRs:
Residential mortgage:
Permanent mortgages guaranteed by U.S. government agencies		54,322				13,384				40,938				—				—
Total residential mortgage		54,322				13,384				40,938				—				—
Total accruing TDRs		54,322				13,384				40,938				—				—
Total TDRs		$	106,281			$	42,343			$	63,938			$	441			$	1,481
Troubled debt restructurings generally consist of interest rate concessions, payment stream concessions or a combination of concessions to distressed borrowers. The following table details the recorded balance of loans at December 31, 2014 by class that were restructured during the year ended December 31, 2014 by primary type of concession (in thousands):
	Year Ended December 31, 2014
	Accruing												Nonaccrual															Total
	Payment Stream				Combination & Other				Total				Interest Rate				Payment Stream				Combination & Other				Total
Commercial:
Energy	$	—			$	—			$	—			$	—			$	—			$	—			$	—		$	—
Services	—				—				—				—				—				—				—			—
Wholesale/retail	—				—				—				—				3,261				—				3,261			3,261
Manufacturing	—				—				—				—				—				—				—			—
Healthcare	—				—				—				—				—				—				—			—
Other commercial and industrial	—				—				—				—				396				81				477			477
Total commercial	—				—				—				—				3,657				81				3,738			3,738
Commercial real estate:
Residential construction and land development	—				—				—				—				—				—				—			—
Retail	—				—				—				—				—				—				—			—
Office	—				—				—				—				—				—				—			—
Multifamily	—				—				—				—				—				—				—			—
Industrial	—				—				—				—				—				—				—			—
Other commercial real estate	—				—				—				—				—				—				—			—
Total commercial real estate	—				—				—				—				—				—				—			—
Residential mortgage:
Permanent mortgage	—				—				—				—				586				3,538				4,124			4,124
Permanent mortgage guaranteed by U.S. government agencies	15,386				17,293				32,679				—				—				1,059				1,059			33,738
Home equity	—				—				—				—				—				2,534				2,534			2,534
Total residential mortgage	15,386				17,293				32,679				—				586				7,131				7,717			40,396
Consumer	—				—				—				—				—				76				76			76
Total	$	15,386			$	17,293			$	32,679			$	—			$	4,243			$	7,288			$	11,531		$	44,210
The following table details the recorded balance of loans by class that were restructured during the year ended December 31, 2013 by primary type of concession (in thousands):
	Year Ended December 31, 2013
	Accruing												Nonaccrual															Total
	Payment Stream				Combination & Other				Total				Interest Rate				Payment Stream				Combination & Other				Total
Commercial:
Energy	$	—			$	—			$	—			$	—			$	—			$	—			$	—		$	—
Services	—				—				—				—				1,080				—				1,080			1,080
Wholesale/retail	—				—				—				—				—				—				—			—
Manufacturing	—				—				—				—				391				—				391			391
Healthcare	—				—				—				—				—				—				—			—
Other commercial and industrial	—				—				—				139				—				57				196			196
Total commercial	—				—				—				139				1,471				57				1,667			1,667
Commercial real estate:
Residential construction and land development	—				—				—				—				—				—				—			—
Retail	—				—				—				—				486				—				486			486
Office	—				—				—				—				2,819				—				2,819			2,819
Multifamily	—				—				—				—				—				—				—			—
Industrial	—				—				—				—				—				—				—			—
Other commercial real estate	—				—				—				—				517				—				517			517
Total commercial real estate	—				—				—				—				3,822				—				3,822			3,822
Residential mortgage:
Permanent mortgage	—				—				—				—				1,062				1,894				2,956			2,956
Permanent mortgage guaranteed by U.S. government agencies	11,545				12,518				24,063				—				—				—				—			24,063
Home equity	—				—				—				—				—				2,800				2,800			2,800
Total residential mortgage	11,545				12,518				24,063				—				1,062				4,694				5,756			29,819
Consumer	—				—				—				75				—				638				713			713
Total	$	11,545			$	12,518			$	24,063			$	214			$	6,355			$	5,389			$	11,958		$	36,021
The following table summarizes, by loan class, the recorded investment at December 31, 2014 and 2013, respectively of loans modified as TDRs within the previous 12 months and for which there was a payment default during the years ended December 31, 2014 and 2013, respectively (in thousands):
	Year Ended
	31-Dec-14												31-Dec-13
	Accruing				Nonaccrual				Total				Accruing				Nonaccrual				Total
Commercial:
Energy	$	—			$	—			$	—			$	—			$	—			$	—
Services	—				—				—				—				1,080				1,080
Wholesale/retail	—				—				—				—				—				—
Manufacturing	—				—				—				—				391				391
Healthcare	—				—				—				—				—				—
Other commercial and industrial	—				13				13				—				164				164
Total commercial	—				13				13				—				1,635				1,635
Commercial real estate:
Residential construction and land development	—				—				—				—				—				—
Retail	—				—				—				—				486				486
Office	—				—				—				—				2,819				2,819
Multifamily	—				—				—				—				—				—
Industrial	—				—				—				—				—				—
Other commercial real estate	—				—				—				—				517				517
Total commercial real estate	—				—				—				—				3,822				3,822
Residential mortgage:
Permanent mortgage	—				2,836				2,836				—				586				586
Permanent mortgage guaranteed by U.S. government agencies	29,585				1,047				30,632				23,918				—				23,918
Home equity	—				1,101				1,101				—				590				590
Total residential mortgage	29,585				4,984				34,569				23,918				1,176				25,094
Consumer	—				25				25				—				155				155
Total	$	29,585			$	5,022			$	34,607			$	23,918			$	6,788			$	30,706
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.
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 December 31, 2014 is as follows (in thousands):
						Past Due
		Current				30 to 89				90 Days				Nonaccrual				Total
						Days				or More
Commercial:
Energy		$	2,857,082			$	1,930			$	—			$	1,416			$	2,860,428
Services		2,511,892				1,136				—				5,201				2,518,229
Wholesale/retail		1,309,167				—				—				4,149				1,313,316
Manufacturing		532,144				—				—				450				532,594
Healthcare		1,453,409				180				—				1,380				1,454,969
Other commercial and industrial		415,030				173				—				931				416,134
Total commercial		9,078,724				3,419				—				13,527				9,095,670
Commercial real estate:
Residential construction and land development		133,642				4,650				—				5,299				143,591
Retail		662,963				—				—				3,926				666,889
Office		412,124				—				—				3,420				415,544
Multifamily		704,298				—				—				—				704,298
Industrial		428,817				—				—				—				428,817
Other commercial real estate		362,529				570				—				5,912				369,011
Total commercial real estate		2,704,373				5,220				—				18,557				2,728,150
Residential mortgage:
Permanent mortgage		929,090				5,970				46				34,845				969,951
Permanent mortgages guaranteed by U.S. government agencies		26,691				23,558				151,989				3,712				205,950
Home equity		761,247				2,723				77				9,564				773,611
Total residential mortgage		1,717,028				32,251				152,112				48,121				1,949,512
Consumer		433,590				547				2				566				434,705
Total		$	13,933,715			$	41,437			$	152,114			$	80,771			$	14,208,037
A summary of loans currently performing, loans past due and accruing and nonaccrual loans as of December 31, 2013 is as follows (in thousands):
						Past Due
		Current				30 to 89				90 Days				Nonaccrual				Total
						Days				or More
Commercial:
Energy		$	2,347,267			$	2,483			$	150			$	1,860			$	2,351,760
Services		2,276,036				1,210				42				4,922				2,282,210
Wholesale/retail		1,193,905				338				152				6,969				1,201,364
Manufacturing		391,159				—				—				592				391,751
Healthcare		1,272,660				—				—				1,586				1,274,246
Other commercial and industrial		440,973				81				5				831				441,890
Total commercial		7,922,000				4,112				349				16,760				7,943,221
Commercial real estate:
Residential construction and land development		188,434				428				19				17,377				206,258
Retail		580,926				264				—				4,857				586,047
Office		404,505				603				—				6,391				411,499
Multifamily		576,495				—				—				7				576,502
Industrial		243,625				—				—				252				243,877
Other commercial real estate		376,699				1,493				1,012				11,966				391,170
Total commercial real estate		2,370,684				2,788				1,031				40,850				2,415,353
Residential mortgage:
Permanent mortgage		1,018,670				9,795				—				34,279				1,062,744
Permanent mortgages guaranteed by U.S. government agencies		21,916				17,290				141,615				777				181,598
Home equity		797,299				3,087				34				7,264				807,684
Total residential mortgage		1,837,885				30,172				141,649				42,320				2,052,026
Consumer		379,417				1,027				1				1,219				381,664
Total		$	12,509,986			$	38,099			$	143,030			$	101,149			$	12,792,264

Premises_and_Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Premises and Equipment Disclosure [Text Block]	(5) Premises and Equipment
	Premises and equipment at December 31 are summarized as follows (in thousands):
		December 31,
		2014		2013
	Land	$	71,371	$	75,859
	Buildings and improvements	225,008		221,326
	Software	120,010		103,473
	Furniture and equipment	179,513		163,013
	Construction in progress	21,805		31,027
	Subtotal	617,707		594,698
	Less accumulated depreciation	343,874		316,849
	Total	$	273,833	$	277,849
	Depreciation expense of premises and equipment was $33 million, $30 million and $33 million for the years ended December 31, 2014, 2013 and 2012, respectively.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	On February 28, 2014, the Company acquired GTRUST Financial Corporation ("GTRUST"), a Topeka-based independent trust and asset management company with approximately $631 million of assets under management or custody at the date of acquisition.
	On April 30, 2014, the Company acquired MBM Advisors, a Houston-based independent, full service retirement and pension plan investment firm and an SEC registered investment adviser with approximately $1.3 billion of assets under management at the date of acquisition.
	The purchase price for acquisitions in 2014 totaled approximately $27 million including $23 million paid in cash and $4 million of contingent consideration. The purchase price allocation included $14 million of identifiable intangible assets and $18 million of goodwill. The pro-forma impact of these transactions was not material to the Company's consolidated financial statements.
	The following table presents the original cost and accumulated amortization of intangible assets (in thousands):
		December 31,
		2014			2013
	Core deposit premiums	$	33,749		$	33,749
	Less accumulated amortization	33,088			32,656
	Net core deposit premiums	661			1,093
	Other identifiable intangible assets	50,288			36,511
	Less accumulated amortization	16,573			13,040
	Net other identifiable intangible assets	33,715			23,471
	Total intangible assets, net	$	34,376		$	24,564
	Expected amortization expense for intangible assets that will continue to be amortized (in thousands):
		Core			Other			Total
		Deposit			Identifiable
		Premiums			Intangible Assets
	2015	$	393		$	3,967		$	4,360
	2016	247			3,967			4,214
	2017	21			3,735			3,756
	2018	—			3,078			3,078
	2019	—			2,816			2,816
	Thereafter	—			16,152			16,152
		$	661		$	33,715		$	34,376
	The changes in the carrying value of goodwill by operating segment for the year ended December 31, 2014 are as follows (in thousands):
		Commercial			Consumer			Wealth		Total
								Management
	Balance, December 31, 2012
	Goodwill	$	271,162		$	39,251		$	51,794	$	362,207
	Accumulated impairment losses	—			(228		)	—		(228		)
		271,162			39,023			51,794		361,979
	Goodwill adjustments during 2013	(2,220		)	—			—		(2,220		)
	Balance, December 31, 2013
	Goodwill	268,942			39,251			51,794		359,987
	Accumulated impairment losses	—			(228		)	—		(228		)
		268,942			39,023			51,794		359,759
	Goodwill acquired during 2014	421			—			17,600		18,021
	Balance, December 31, 2014
	Goodwill	269,363			39,251			69,394		378,008
	Accumulated Impairment	—			(228		)	—		(228		)
		$	269,363		$	39,023		$	69,394	$	377,780
	The annual goodwill evaluations for 2014 and 2013 did not indicate impairment for any reporting unit. Economic conditions did not indicate that impairment existed for any identifiable intangible assets and therefore no impairment evaluation was performed.

Mortgage_Banking_Activities_Mo

Mortgage Banking Activities Mortgage Banking Activities (Notes)	12 Months Ended
	Dec. 31, 2014
Mortgage Banking [Abstract]
Mortgage Banking Activities [Text Block]	(7) 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 held for investment. All 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):
			December 31, 2014								December 31, 2013
			Unpaid Principal Balance/				Fair Value				Unpaid Principal Balance/			Fair Value
			Notional								Notional
	Residential mortgage loans held for sale		$	291,537			$	298,212			$	192,266		$	193,584
	Residential mortgage loan commitments		520,829				9,971				258,873			2,656
	Forward sales contracts		701,066				(4,001		)		435,867			4,306
							$	304,182						$	200,546
	No residential mortgage loans held for sale were 90 days or more past due or considered impaired as of December 31, 2014 or December 31, 2013. No credit losses were recognized on residential mortgage loans held for sale for the years ended December 31, 2014, 2013 and 2012.
	Mortgage banking revenue was as follows (in thousands):
			Year Ended
			2014				2013				2012
	Production revenue:
	Net realized gains on sales of mortgage loans		$	56,696			$	95,309			$	115,879
	Net change in unrealized gain on mortgage loans held for sale		5,357				(10,899		)		4,720
	Change in the fair value of mortgage loan commitments		7,315				(10,077		)		6,136
	Change in the fair value of forward sales contracts		(8,307		)		5,212				2,382
	Total production revenue		61,061				79,545				129,117
	Servicing revenue		48,032				42,389				40,185
	Total mortgage banking revenue		$	109,093			$	121,934			$	169,302
	Mortgage 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
	The Company generally retains the right to service residential mortgage loans sold and may purchase mortgage servicing rights. 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):
			December 31,
			2014				2013				2012
	Number of residential mortgage loans serviced for others		117,483				106,137				98,246
	Outstanding principal balance of residential mortgage loans serviced for others		$	16,162,887			$	13,718,942			$	11,981,624
	Weighted average interest rate		4.29		%		4.4		%		4.71		%
	Remaining term (in months)		296				292				289
	Activity in capitalized mortgage servicing rights during the three years ended December 31, 2014 is as follows (in thousands):
			Purchased				Originated				Total
	Balance, December 31, 2011		$	18,903			$	67,880			$	86,783
	Additions, net		—				42,191				42,191
	Change in fair value due to loan runoff		(4,164		)		(14,788		)		(18,952		)
	Change in fair value due to market changes		(1,763		)		(7,447		)		(9,210		)
	Balance, December 31, 2012		12,976				87,836				100,812
	Additions, net		—				49,431				49,431
	Change in fair value due to loan runoff		(3,029		)		(16,601		)		(19,630		)
	Change in fair value due to market changes		5,988				16,732				22,720
	Balance, December 31, 2013		15,935				137,398				153,333
	Additions, net		—				54,413				54,413
	Change in fair value due to loan runoff		(2,357		)		(16,968		)		(19,325		)
	Change in fair value due to market changes		(2,464		)		(13,981		)		(16,445		)
	Balance, December 31, 2014		$	11,114			$	160,862			$	171,976
	Changes in the fair value of mortgage servicing rights due to market changes are included in Other operating revenue in the Consolidated Statements of Earnings. Changes in fair value due to loan runoff are included in Mortgage banking costs.
	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 considered to be significant unobservable inputs were as follows:
			December 31,
			2014		2013
	Discount rate – risk-free rate plus a market premium		10.17%		10.21%
	Prepayment rate – based upon loan interest rate, original term and loan type		7.70% - 30.44%		6.66% - 26.19%
	Loan servicing costs – annually per loan based upon loan type:
	Performing loans		$60 - $105		$60 - $105
	Delinquent loans		$150 - $500		$150 - $500
	Loans in foreclosure		$1,000 - $4,250		$1,000 - $4,250
	Escrow earnings rate – indexed to rates paid on deposit accounts with comparable average life		1.77%		1.80%
	Stratification of the residential mortgage loan servicing portfolio and outstanding principal of loans serviced for others by interest rate at December 31, 2014 follows (in thousands):
			< 4.00%				4.00% - 4.99%				5.00% - 5.99%			> 5.99%			Total
	Fair value		$	67,412			$	80,405			$	19,383		$	4,776		$	171,976
	Outstanding principal of loans serviced for others		6,332,112				6,882,025				1,989,977			958,773			16,162,887
Weighted average prepayment rate1		7.7		%		8.58		%		14.5		%	30.44		%	10.26		%
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.
Changes in primary residential mortgage interest rates directly affect the prepayment speeds used in valuing our mortgage servicing rights. A separate third party model is used to estimate prepayment speeds based on interest rates, housing turnover rates, estimated loan curtailment, anticipated defaults and other relevant factors. The prepayment model is updated daily for changes in market conditions and adjusted to better correlate with actual performance of BOK Financial’s servicing portfolio.
The interest rate sensitivity of our mortgage servicing rights net of securities and derivative contracts held as an economic hedge is modeled over a range of +/- 50 basis points. At December 31, 2014, a 50 basis point increase in mortgage interest rates is expected to increase the fair value of our mortgage servicing rights, net of economic hedge by $4.7 million. A 50 basis point decrease in mortgage interest rates is expected to decrease the fair value of our mortgage servicing rights, net of economic hedge by $4.6 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 December 31, 2014 follows (in thousands):
						Past Due
		Current				30 to 59				60 to 89			90 Days or More			Total
						Days				Days
FHLMC		$	5,289,078			$	37,881			$	9,418		$	33,837		$	5,370,214
FNMA		5,200,509				27,089				5,736			22,087			5,255,421
GNMA		4,920,064				132,680				34,602			13,594			5,100,940
Other		422,598				6,674				1,491			5,549			436,312
Total		$	15,832,249			$	204,324			$	51,247		$	75,067		$	16,162,887
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 $180 million at December 31, 2014 and $191 million at December 31, 2013. At December 31, 2014, approximately 4% of the loans sold with recourse with an outstanding principal balance of $7.1 million were either delinquent more than 90 days, in bankruptcy or in foreclosure and 5% with an outstanding balance of $8.4 million were past due 30 to 89 days. A separate accrual for these off-balance sheet commitments is included in Other liabilities in the Consolidated Balance Sheets. 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):
	Year Ended
	2014				2013				2012
Beginning balance	$	9,562			$	13,158			$	18,683
Provision for recourse losses	354				517				(100		)
Loans charged off, net	(2,617		)		(4,113		)		(5,425		)
Ending balance	$	7,299			$	9,562			$	13,158
The Company also has off-balance sheet 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.The Company has established an accrual for credit losses related to potential loan repurchases under representations and warranties that is included in Other liabilities in the Consolidated Balance Sheets and in Mortgage banking costs in the Consolidated Statements of Earnings. For 2014, the Company has repurchased 41 loans from the agencies for $6.5 million and recognized $62 thousand of related losses. In addition, the Company has paid indemnification for 17 loans and recognized $613 thousand of related losses during 2014.
A summary of unresolved deficiency requests from the agencies follows (in thousands, except for number of unresolved deficiency requests):
	December 31,
	2014				2013
Number of unresolved deficiency requests	186				578
Aggregate outstanding principal balance subject to unresolved deficiency requests	$	15,328			$	69,288
Unpaid principal balance subject to indemnification by the Company	4,047				3,200
The activity in the accruals for mortgage losses is summarized as follows (in thousands).
	December 31,
	2014				2013
Beginning balance	$	12,716			$	8,983
Provision for losses	7,200				6,221
Charge-offs, net	(8,048		)		(2,488		)
Ending balance	$	11,868			$	12,716

Deposits

Deposits	12 Months Ended
	Dec. 31, 2014
Deposits [Abstract]
Deposits [Text Block]	(8) Deposits
	Interest expense on deposits is summarized as follows (in thousands):
		Year Ended December 31,
		2014		2013		2012
	Transaction deposits	$	9,757	$	11,155	$	14,300
	Savings	401		442		540
	Time:
	Certificates of deposits under $100,000	14,278		16,234		19,150
	Certificates of deposits $100,000 and over	11,878		12,273		16,331
	Other time deposits	14,369		15,460		16,692
	Total time	40,525		43,967		52,173
	Total	$	50,683	$	55,564	$	67,013
	The aggregate amounts of time deposits in denominations of $250,000 or more at December 31, 2014 and 2013 were $994 million and $988 million, respectively.
	Time deposit maturities are as follows:  2015 – $1.3 billion, 2016 – $519 million, 2017 – $170 million, 2018 – $201 million, 2019 – $81 million and $290 million thereafter. At December 31, 2014 and 2013, the Company had $334 million and $186 million, respectively, in fixed rate, brokered certificates of deposits. The weighted-average interest rate paid on these certificates was 2.59% in 2014 and 2.96% in 2013.
	The aggregate amount of overdrawn transaction deposits that have been reclassified as loan balances was $6.2 million at December 31, 2014 and $37 million at December 31, 2013.

Other_Borrowings

Other Borrowings	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Other borrowings [Text Block]	(9) Other Borrowings
	Information relating to other borrowings is summarized as follows (dollars in thousands):
			As of				Year Ended
			December 31, 2014				December 31, 2014
			Balance		Rate		Average Balance			Rate			Maximum
													Outstanding
													At Any
													Month End
	Parent Company and Other Non-Bank Subsidiaries:
	Other		$	—	—	%	$	—		—	%		$	—
	Total Parent Company and Other Non-Bank Subsidiaries		—				—			—
	Subsidiary Bank:
	Funds purchased		57,031		0.05		494,220			0.07			1,548,676
	Repurchase agreements		1,187,489		0.04		928,767			0.06			1,187,489
	Other borrowings:
	Federal Home Loan Bank advances		2,103,400		0.25		1,894,966			0.24			3,453,400
	GNMA repurchase liability		14,298		5.05		17,343			5.2			24,980
	Other		16,076		2.73		16,433			2.32			16,582
	Total other borrowings		2,133,774				1,928,742			0.35
	Subordinated debentures		347,983		2.35		347,892			2.5			347,983
	Total subsidiary bank		3,726,277				3,699,621			0.43
	Total other borrowed funds		$	3,726,277			$	3,699,621		0.43	%
			As of				Year Ended
			December 31, 2013				December 31, 2013
			Balance		Rate		Average Balance			Rate			Maximum
													Outstanding
													At Any
													Month End
	Parent Company and Other Non-Bank Subsidiaries:
	Other		$	—	—	%	$	326		—	%		$	—
	Total Parent Company and Other Non-Bank Subsidiaries		—				326			—
	Subsidiary Bank:
	Funds purchased		868,081		0.04		866,062			0.1			997,536
	Repurchase agreements		813,454		0.05		811,996			0.06			881,033
	Other borrowings:
	Federal Home Loan Bank advances		1,005,650		0.19		1,661,424			0.2			2,451,197
	GNMA repurchase liability		18,113		5.5		15,741			5.43			21,055
	Other		16,590		2.73		16,502			2.54			17,092
	Total other borrowings		1,040,353				1,693,667
	Subordinated debentures		347,802		2.35		347,717			2.51			347,802
	Total subsidiary bank		3,069,690				3,719,442			0.41
	Total other borrowings		$	3,069,690			$	3,719,768		0.4	%
			As of				Year Ended
			December 31, 2012				December 31, 2012
			Balance		Rate		Average Balance			Rate			Maximum
													Outstanding
													At Any
													Month End
	Parent Company and Other Non-Bank Subsidiaries:
	Other		$	10,500	1.5	%	$	394		1.11			$	10,500
	Total Parent Company and Other Non-Bank Subsidiaries		10,500				394			1.11
	Subsidiary Banks:
	Funds purchased		1,167,416		0.05		1,512,711			0.14			1,810,793
	Repurchase agreements		887,030		0.07		1,072,650			0.09			1,272,151
	Other borrowings:
	Federal Home Loan Bank advances		604,897		0.23		104,925			0.31			604,897
	GNMA repurchase liability		20,046		5.44		33,769			5.41			47,840
	Other		16,332		2.79		16,577			2.91			16,761
	Total other borrowings		641,275				155,271
	Subordinated debentures		347,633		2.4		363,699			3.79			398,897
	Total subsidiary banks		3,043,354				3,104,330			0.65
	Total other borrowings		$	3,053,854			$	3,104,724		0.65	%
	Aggregate annual principal repayments at December 31, 2014 are as follows (in thousands):
			Parent		Subsidiary
Company and Other Non-bank Subsidiaries			Bank
2015		$	—	$	3,484,519
2016		—		525
2017		—		226,732
2018		—		575
2019		—		575
Thereafter		—		13,351
Total		$	—	$	3,726,277
Funds purchased are unsecured and generally mature within one to ninety days from the transaction date. Securities repurchase agreements are recorded as secured borrowings that generally mature within ninety days and are secured by certain available for sale securities. There was no outstanding accrued interest payable related to repurchase agreements at December 31, 2014 or December 31, 2013.
Additional information relating to securities sold under agreements to repurchase and related liabilities at December 31, 2014 and 2013 is as follows (dollars in thousands):
		December 31, 2014
		Amortized		Market			Repurchase			Average
Security Sold/Maturity		Cost		Value			Liability1			Rate
U.S. Agency Securities:
Overnight1		$	1,185,345	$	1,192,361		$	1,187,445		0.04	%
Long-term		—		—			—			—	%
Total Agency Securities		$	1,185,345	$	1,192,361		$	1,187,445		0.04	%
		December 31, 2013
		Amortized		Market			Repurchase			Average
Security Sold/Maturity		Cost		Value			Liability1			Rate
U.S. Agency Securities:
Overnight1		$	1,085,893	$	1,075,821		$	813,624		0.05	%
Long-term		—		—			—			—	%
Total Agency Securities		$	1,085,893	$	1,075,821		$	813,624		0.05	%
1	BOK Financial maintains control over the securities underlying overnight repurchase agreements and generally transfers control over securities underlying longer-term dealer repurchase agreements to the respective counterparty.
Borrowings from the Federal Home Loan Banks are used for funding purposes. In accordance with policies of the Federal Home Loan Banks, BOK Financial has granted a blanket pledge of eligible assets (generally unencumbered U.S. Treasury and residential mortgage-backed securities, 1-4 family loans and multifamily loans) as collateral for these advances. The Federal Home Loan Banks have issued letters of credit totaling $315 million to secure BOK Financial’s obligations to depositors of public funds. The unused credit available to BOK Financial at December 31, 2014 pursuant to the Federal Home Loan Bank’s collateral policies is $1.9 billion.
The Company has a $100 million senior unsecured 364 day revolving credit facility with Wells Fargo Bank, National Association, administrative agent and other commercial banks (“the Credit Facility”). Interest on amounts outstanding under the Credit Facility is to be paid at a defined base rate minus 1.25% or LIBOR plus 1.00% based upon the Company’s option. Interest on amounts borrowed for certain acquisitions converted to a term loan at the Company's option is to be paid at a defined base rate minus 1.25% or LIBOR plus 1.25%. A commitment fee equal to 0.20% shall be paid quarterly on the unused portion of the credit commitment under the Credit Facility and there are no prepayment penalties. Any amounts outstanding at the end of the Credit Facility term shall be converted into a term loan which, except for amounts borrowed for certain acquisitions, shall be payable June 5, 2015. The Credit Facility contains customary representations and warranties, as well as affirmative and negative covenants, including limits on the Company’s ability to borrow additional funds, make investments or sell assets. These covenants also require BOKF to maintain minimum capital levels. At December 31, 2014, no amounts were outstanding under the Credit Facility and the Company met all of the covenants.
In addition, BOSC may borrow funds from Pershing, LLC ("Pershing"), a clearing broker/dealer and a wholly owned subsidiary of Bank of New York Mellon, for the purposes of financing securities purchases or to facilitate funding of investment banking activities, on terms to be negotiated at the time of the borrowing. BOSC had no borrowings from Pershing outstanding at December 31, 2014 or December 31, 2013.
In 2007, the Bank issued $250 million of subordinated debt due May 15, 2017. Interest on this debt was based upon a fixed rate of 5.75% through May 14, 2012 and is based on a floating rate of three-month LIBOR plus 0.69% thereafter. The proceeds of this debt were used to fund the Worth National Bank and First United Bank acquisitions and to fund continued asset growth. At December 31, 2014, and December 31, 2013 $227 million of this subordinated debt remained outstanding.
In 2005, the Bank issued $150 million of fixed rate subordinated debt due June 1, 2015. The cost of this subordinated debt, including issuance discounts and hedge loss is 5.56%. The proceeds of this debt were used to repay the unsecured revolving line of credit and to provide additional capital to support asset growth. During 2006, an interest rate swap was designated as a hedge of changes in fair value of the subordinated debt due to changes in interest rates. The Company received a fixed rate of interest and paid a variable rate based on 1-month LIBOR. This fair value hedging relationship was discontinued and the interest rate swap was terminated in April 2007. At December 31, 2014 and December 31, 2013, $122 million of this subordinated debt remains outstanding.
The Company has a liability related to the repurchase of certain delinquent residential mortgage loans previously sold into GNMA mortgage pools. Interest is payable at rates contractually due to investors.

Federal_and_State_Income_Taxes

Federal and State Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Federal and State Income Taxes	(10) Federal and State Income Taxes
	Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of deferred tax assets and liabilities are as follows (in thousands):
		December 31,
		2014				2013
	Deferred tax assets:
	Available for sale securities mark to market	$	—			$	14,751
	Share-based compensation	9,414				8,064
	Credit loss allowances	74,362				75,657
	Valuation adjustments	36,870				35,292
	Deferred compensation	23,333				60,068
	Unearned fees	11,820				10,683
	Other	26,633				22,348
	Total deferred tax assets	182,432				226,863
	Deferred tax liabilities:
	Available for sale securities mark to market	37,719				—
	Depreciation	18,601				17,333
	Mortgage servicing rights	86,752				72,235
	Lease financing	24,429				23,202
	Other	22,160				18,494
	Total deferred tax liabilities	189,661				131,264
	Net deferred tax assets (liabilities)	$	(7,229	)		$	95,599
	The company determined that no valuation allowance was necessary on deferred tax assets as of December 31, 2014 and 2013.
	The significant components of the provision for income taxes attributable to continuing operations for BOK Financial are shown below (in thousands):
		Year Ended December 31,
		2014				2013				2012
	Current income tax expense:
	Federal	$	85,990			$	125,412			$	159,706
	State	9,392				14,381				19,103
	Total current income tax expense	95,382				139,793				178,809
	Deferred income tax expense:
	Federal	36,521				15,915				8,664
	State	2,949				1,590				1,267
	Total deferred income tax expense	39,470				17,505				9,931
	Total income tax expense	$	134,852			$	157,298			$	188,740
	The reconciliations of income (loss) attributable to continuing operations at the U.S. federal statutory tax rate to income tax expense are as follows (in thousands):
		Year Ended December 31,
		2014				2013				2012
	Amount:
	Federal statutory tax	$	150,616			$	166,680			$	190,003
	Tax exempt revenue	(8,446		)		(7,361		)		(5,558		)
	Effect of state income taxes, net of federal benefit	9,054				10,937				13,684
	Utilization of tax credits	(11,107		)		(8,145		)		(5,126		)
	Bank-owned life insurance	(3,183		)		(3,596		)		(3,850		)
	Reduction of tax accrual	(2,281		)		(1,400		)		(950		)
	Other, net	199				183				537
	Total income tax expense	$	134,852			$	157,298			$	188,740
	Due to the favorable resolution of certain tax issues for the periods ended December 31, 2010 and 2009, BOK Financial reduced its tax accrual by $2.3 million and $1.4 million in 2014 and 2013, respectively, which was credited against current income tax expense.
		Year Ended December 31,
		2014			2013			2012
	Percent of pretax income:
	Federal statutory tax	35	%		35	%		35	%
	Tax exempt revenue	(2.0	)		(1.5	)		(1.0	)
	Effect of state income taxes, net of federal benefit	2.1			2.3			2.5
	Utilization of tax credits	(2.6	)		(1.7	)		(0.9	)
	Bank-owned life insurance	(0.7	)		(0.8	)		(0.7	)
	Reduction of tax accrual	(0.5	)		(0.3	)		(0.1	)
	Other, net	—			—			—
	Total	31.3	%		33	%		34.8	%
	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands):
		2014				2013				2012
	Balance as of January 1	$	12,058			$	12,275			$	12,230
	Additions for tax for current year positions	3,813				2,730				3,976
	Settlements during the period	—				—				(1,000		)
	Lapses of applicable statute of limitations	(2,497		)		(2,947		)		(2,931		)
Balance as of December 31	$	13,374			$	12,058			$	12,275
Of the above unrecognized tax benefits, $8.7 million, if recognized, would affect the effective tax rate.
BOK Financial recognizes interest and penalties accrued related to unrecognized tax benefits in income tax expense. The Company recognized $1.5 million for 2014, $1.2 million for 2013 and $1.2 million for 2012 in interest and penalties. The Company had approximately $3.6 million and $2.9 million accrued for the payment of interest and penalties at December 31, 2014 and 2013, respectively. Federal statutes remain open for federal tax returns filed in the previous three reporting periods. Various state income tax statutes remain open for the previous three to six reporting periods.
The Internal Revenue Service completed an audit of the Company's federal income tax return for the year ended December 31, 2008 during the first quarter 2012 with no adjustments. The Internal Revenue Service also completed its audit of the Company’s 2008 refund claim during the first quarter of 2013 with no adjustments.

Employee_Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Employee Benefits [Text Block]	(11) Employee Benefits
	BOK Financial sponsors a defined benefit cash balance Pension Plan for all employees who satisfy certain age and service requirements. Pension Plan benefits were curtailed as of April 1, 2006. No participants may be added to the plan and no additional service benefits will be accrued. During 2014 and 2013, interest accrued on employees' account balances at a variable rate tied to the five-year trailing average of five-year Treasury Securities plus 1.5%. The rate has a floor of 3.0% and a ceiling of 5.0%. The 2014 quarterly variable rates ranged from 3.00% to 3.01%.
	The following table presents information regarding this plan (in thousands):
			December 31,
			2014				2013
	Change in projected benefit obligation:
	Projected benefit obligation at beginning of year		$	44,765			$	48,028
	Interest cost		1,685				1,532
	Actuarial loss (gain)		2,878				(1,543		)
	Benefits paid		(4,104		)		(3,252		)
	Projected benefit obligation at end of year1,2		$	45,224			$	44,765
	Change in plan assets:
	Plan assets at fair value at beginning of year		$	48,812			$	45,920
	Actual return on plan assets		4,735				6,144
	Benefits paid		(4,104		)		(3,252		)
	Plan assets at fair value at end of year		$	49,443			$	48,812
	Funded status of the plan		$	4,219			$	4,047
	Components of net periodic benefit costs:
	Interest cost		$	1,685			$	1,532
	Expected return on plan assets		(2,539		)		(2,185		)
	Recognized prior service cost		(1,175		)		(1,175		)
	Amortization of unrecognized net loss		2,584				3,830
	Net periodic pension cost		$	555			$	2,002
	1	Projected benefit obligation equals accumulated benefit obligation.
	2	Projected benefit obligation is based on January 1 measurement date.
	Weighted-average assumptions as of December 31:		2014			2013
	Discount rate		3.42	%		4.05	%
	Expected return on plan assets		6	%		6	%
	As of December 31, 2014, expected future benefit payments related to the Pension Plan were as follows (in thousands):
	2015	$	3,535
	2016	3,673
	2017	3,270
	2018	3,396
	2019	3,628
	Thereafter	44,057
		$	61,559
	Assets of the Pension Plan consist primarily of shares in the Cavanal Hill Balanced Fund. The stated objective of this fund is to provide an attractive total return through a broadly diversified mix of equities and bonds. The typical portfolio mix is approximately 60% equities and 40% bonds. The net asset value of shares in the Cavanal Hill Funds is reported daily based on market quotations for the Fund’s securities. The inception-to-date return on the fund, which is used as an indicator when setting the expected return on plan assets, was 7.44%. As of December 31, 2014, the expected return on plan assets for 2015 is 6.00%. The maximum tax deductible Pension Plan contribution for 2014 was $21 million. No minimum contribution was required for 2014, 2013 or 2012. We expect approximately $267 thousand of net pension costs currently in accumulated other comprehensive income to be recognized as net periodic pension cost in 2015.
	Employee contributions to the Thrift Plan are eligible for Company matching equal to 6% of base compensation, as defined in the plan. The Company-provided matching contribution rates range from 50% for employees with less than four years of service to 200% for employees with 15 or more years of service. Additionally, a maximum Company-provided, non-elective annual contribution of up to $750 per participant for employees whose annual base compensation is less than $40,000. Total non-elective contributions were $662 thousand for 2014, $738 thousand for 2013 and $802 thousand for 2012.
	Participants may direct investments in their accounts to a variety of options, including a BOK Financial common stock fund. Employer contributions, which are invested in accordance with the participant’s investment options, vest over five years. Thrift Plan expenses were $18.6 million for 2014, $18.1 million for 2013 and $16.8 million for 2012.
	BOK Financial offers numerous incentive compensation plans that are aligned with the Company’s growth strategy. Compensation awarded under these plans may be based on defined formulas, other performance criteria or discretionary. Incentive compensation is designed to motivate and reinforce sales and customer service behavior in all markets. Earnings were charged $111.7 million in 2014, $110.9 million in 2013, and $116.7 million in 2012 for cash incentive compensation.

ShareBased_Compensation_Plans

Share-Based Compensation Plans	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Compensation Plans [Text Block]	(12) Share-Based Compensation Plans
	The shareholders and Board of Directors of BOK Financial have approved various share-based compensation plans. An independent compensation committee of the Board of Directors determines the number of awards granted to the Chief Executive Officer and other senior executives. Share-based compensation is granted to other officers and employees as determined by the Chief Executive Officer.
	The following table presents stock options outstanding during 2014, 2013 and 2012 under these plans (in thousands, except for per share data):
			Number			Weighted-				Aggregate
						Average				Intrinsic
						Exercise				Value
						Price
	Options outstanding at December 31, 2011		2,621,347			$	47.01			$	20,769
	Options awarded		67,155			58.76
	Options exercised		(708,295	)		45.32
	Options forfeited		(22,559	)		50.36
	Options expired		(66,862	)		45.97
	Options outstanding at December 31, 2012		1,890,786			48.29				11,748
	Options awarded		81,492			55.74
	Options exercised		(608,663	)		48
	Options forfeited		(219,342	)		47.65
	Options expired		(9,168	)		50.61
	Options outstanding at December 31, 2013		1,135,105			49.09				19,564
	Options awarded		—			—
	Options exercised		(323,004	)		49.17
	Options forfeited		(15,509	)		45.71
	Options expired		(2,701	)		47.98
	Options outstanding at December 31, 2014		793,891			$	49.05			$	8,725
	Options vested at:
	December 31, 2012		601,367			$	47.99			$	3,890
	December 31, 2013		424,459			49.49				7,146
	December 31, 2014		347,633			48.85				3,889
	The following table summarizes information concerning currently outstanding and vested stock options:
			Options Outstanding							Options Vested
						Weighted							Weighted
						Average		Weighted				Weighted	Average
	Range of					Remaining		Average				Average	Remaining
	Exercise		Number			Contractual		Exercise		Number		Exercise	Contractual
	Prices		Outstanding			Life (years)		Price		Vested		Price	Life (years)
	$36.65		190,832			2.83		$36.65		65,626		$36.65	1.51
	45.15 - 47.34		33,574			0.76		47.09		33,574		47.09	0.76
	48.3		39,557			3.16		48.3		13,326		48.3	1.42
	48.46		169,422			2.16		48.46		95,415		48.46	1.49
	54.33		78,904			1.48		54.33		78,904		54.33	1.48
	55.74		78,108			5.16		55.74		8,260		55.74	2.03
	55.94		125,285			3.62		55.94		37,008		55.94	1.44
	58.76		78,209			4.35		58.76		15,520		58.76	1.59
	The aggregate intrinsic value of options exercised was $5.5 million for 2014, $8.5 million for 2013 and $8.3 million for 2012.
	The fair value of options was determined as of the date of grant using a Black-Scholes option pricing model with the following weighted average assumptions:
			2013				2012
	Average risk-free interest rate1		0.89		%		0.93		%
	Dividend yield		2.8		%		2.2		%
	Volatility factors		0.272				0.28
	Weighted average expected life		4.9 years				4.9 years
	Weighted average fair value		$	9.67			$	11.48
	1	Average risk-free interest rate represents U.S. Treasury rates matched to the expected life of the options.
	No options were granted in 2014. Compensation expense recognized on stock options totaled $826 thousand for 2014, $1.3 million for 2013 and $4.1 million for 2012. Compensation cost of stock options granted that may be recognized as compensation expense in future years totaled $980 thousand at December 31, 2014. Subject to adjustments for forfeitures, we expect to recognize compensation expense for current outstanding options of $475 thousand in 2015, $275 thousand in 2016, $152 thousand in 2017, $60 thousand in 2018, and $18 thousand in 2019.
	The following represents a summary of the non-vested stock awards as of December 31, 2014 (in thousands):
			Shares			Weighted
						Average
						Grant Date
						Fair Value
	Non-vested at January 1, 2012		503,738
	Granted		197,058			$55.63
	Vested		(76,192	)		$47.32
	Forfeited		(31,773	)		$50.45
	Non-vested at December 31, 2012		592,831
	Granted		211,791			$55.84
	Vested		(66,648	)		$35.93
Forfeited		(89,985	)		$49.95
Non-vested at December 31, 2013		647,989
Granted		206,621			$64.96
Vested		(140,820	)		$44.56
Forfeited		(25,179	)		$56.26
Non-vested at December 31, 2014		688,611
Compensation expense recognized on non-vested shares totaled $10.0 million for 2014, $6.9 million for 2013 and $5.6 million for 2012. Unrecognized compensation cost of non-vested shares totaled $15.5 million at December 31, 2014. Subject to adjustment for forfeitures, we expect to recognize compensation expense of $9.3 million in 2015, $5.7 million in 2016, $474 thousand in 2017 and $1 thousand in 2018.
On April 26, 2011 shareholders approved the BOK Financial Corporation 2011 True-Up Plan. The True-Up Plan was intended to address inequality in the Executive Incentive Plan which had been approved by shareholders in 2003. The True-Up Plan was designed to adjust performance-based incentive compensation for certain senior executives either upward or downward based on the earnings per share performance and compensation of comparable senior executives at peer banks. As of December 31, 2013, the Company had accrued $69 million for the True-Up Plan liability. The final amount distributed in May 2014 totaled $56 million, including $35 million in cash and $21 million consisting of 331 thousand shares at a price of $64.91 per share.
During January 2015, BOK Financial awarded 297,106 shares of non-vested stock with a fair value per award of $55.53. The aggregate compensation cost of these awards totaled approximately $16.5 million. This cost will be recognized over the vesting periods, subject to adjustments for forfeitures. Non-vested shares awarded in January 2015 generally cliff vest in 3 years and are subject to a 2 year holding period after vesting.

Related_Parties

Related Parties	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Parties [Text Block]	(13) Related Parties
	In compliance with applicable regulations, the Company may extend credit to certain executive officers, directors, principal shareholders and their affiliates (collectively referred to as “related parties”) in the ordinary course of business under substantially the same terms as comparable third-party lending arrangements. The Company’s loans to related parties do not involve more than the normal credit risk and there are no nonaccruing or impaired related party loans outstanding at December 31, 2014 or 2013.
	Activity in loans to related parties is summarized as follows (in thousands):
			Year Ended December 31,
			2014			2013
	Beginning balance		$	88,691		$	49,943
	Advances		712,413			292,393
	Payments		(698,149		)	(253,645		)
	Adjustments1		440			—
	Ending balance		$	103,395		$	88,691
	1	Adjustments generally consist of changes in status as a related party.
	Certain related parties are customers of the Company for services other than loans, including consumer banking, corporate banking, risk management, wealth management, brokerage and trading, or fiduciary/trust services. The Company engages in transactions with related parties in the ordinary course of business in compliance with applicable regulations.
	The Company rents office space in facilities owned by affiliates of Mr. Kaiser, its Chairman and principal shareholder. Lease payments totaled $900 thousand for 2014, $952 thousand for 2013 and $1.1 million for 2012.
	In 2008, the Company entered into a $25 million loan commitment with the Tulsa Community Foundation (“TCF”) to be secured by tax-exempt bonds purchased from the Tulsa Stadium Trust (the “Stadium Trust”) by TCF. The Stadium Trust is an Oklahoma public trust, of which the City of Tulsa is the sole beneficiary. Stacy C. Kymes, Executive Vice President and Chief Credit Officer of the Company, is Chairman of the Stadium Trust.
	Cavanal Hill Investment Management, Inc., a wholly-owned subsidiary of the Bank, is the administrator to and investment advisor for the Cavanal Hill Funds (the "Funds"), a diversified, open-ended investment company established as a business trust under the Investment Company Act of 1940 (the "1940 Act"). The Bank is custodian and BOSC, Inc. is distributor for the Funds. The Funds’ products are offered to customers, employee benefit plans, trusts and the general public in the ordinary course of business. Approximately 99% of the Funds’ assets of $3.2 billion are held for the Company's clients. A Company executive officer serves on the Funds' board of trustees and officers of the Bank serve as president and secretary of the Funds. A majority of the members of the Funds’ board of trustees are, however, independent of the Company and the Funds are managed by its board of trustees.

Commitments_and_Contingent_Lia

Commitments and Contingent Liabilities	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities [Text Block]	(14)  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 251,837 Visa Class B shares which are convertible into 103,782 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.
	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 $5.6 million at December 31, 2014. 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 type of investments.
	Consolidated tax credit entities represent the Company's interest in entities earning federal new market tax credits related to qualifying loans for which 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. The creditors underlying the other borrowings of consolidated tax credit entities do not have recourse to the general credit of BOKF.
	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 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. The Company's ability to hold these investments will be curtailed by the Volcker Rule.
	A summary of consolidated and unconsolidated alternative investments as of December 31, 2014 and December 31, 2013 is as follows (in thousands):
		December 31, 2014
		Loans		Other		Other		Other		Non-controlling
				Assets		Liabilities		Borrowings		Interests
	Consolidated:
	Private equity funds	$	—	$	25,627	$	—	$	—	$	21,921
	Tax credit entities	10,000		12,827		—		10,964		10,000
	Other	—		5,996		—		—		2,106
	Total consolidated	$	10,000	$	44,450	$	—	$	10,964	$	34,027
	Unconsolidated:
	Tax credit entities	$	18,192	$	96,721	$	28,920	$	—	$	—
	Other	—		9,471		4,050		—		—
	Total unconsolidated	$	18,192	$	106,192	$	32,970	$	—	$	—
		December 31, 2013
		Loans		Other		Other		Other		Non-controlling
				Assets		Liabilities		Borrowings		Interests
	Consolidated:
	Private equity funds	$	—	$	27,341	$	—	$	—	$	23,036
	Tax credit entities	10,000		13,448		—		10,964		9,869
	Other	—		9,178		—		—		2,019
	Total consolidated	$	10,000	$	49,967	$	—	$	10,964	$	34,924
	Unconsolidated:
	Tax credit entities	$	27,319	$	90,260	$	35,776	$	—	$	—
	Other	—		9,257		1,681		—		—
	Total unconsolidated	$	27,319	$	99,517	$	37,457	$	—	$	—
	Other Commitments and Contingencies
	At December 31, 2014, Cavanal Hill Funds’ assets included $1.1 billion of U.S. Treasury, $1.3 billion of cash management and $258 million of 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 December 31, 2014. 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 2014 or 2013.
	Cottonwood Valley Ventures, Inc. (“CVV, Inc.”), an indirectly wholly-owned subsidiary of BOK Financial, is being audited by the Oklahoma Tax Commission (“OTC”) for tax years 2007 through 2009. CVV, Inc. is a qualified venture capital company under the applicable Oklahoma statute. As authorized by the statute, CVV, Inc. guarantees transferable Oklahoma state income tax credits by providing direct debt financing to private companies which qualify as statutory business ventures. Due to certain statutory limitations on utilization of such credits, CVV, Inc. must sell the majority of the credits to provide the economic incentives provided for by the statute. During 2012, CVV, Inc. and credit purchasers settled the assessment related to the 2008 tax credits disallowed with no material adverse impact to the consolidated financial statements. Management does not anticipate that the remaining issue under audit will have a material adverse impact to the consolidated financial statements.
	Total rent expense for BOK Financial was $25.0 million in 2014, $23.5 million in 2013 and $21.7 million in 2012. At December 31, 2014, future minimum lease payments for premises under operating leases were as follows: $26.0 million in 2015, $22.9 million in 2016, $19.3 million in 2017, $15.1 million in 2018, $13.0 million in 2019 and $104.8 million thereafter. The Bank is obligated under a long-term lease for its bank premises in downtown Tulsa. The lease term, which began November 1, 1976, is for fifty-seven years with an option to terminate in 2024 with a two-year prior written notice. Premises leases may include options to renew at then current market rates and may include escalation provisions based upon changes in consumer price index or similar benchmarks.
	The Federal Reserve Bank requires member banks to maintain certain minimum average cash balances. Member banks may satisfy reserve balance requirements through it holdings of vault cash and balance maintained directly with a Federal Reserve Bank. The combined average balance of vault cash and balances held at the Federal Reserve Bank was $1.5 billion for the year ended December 31, 2014 and $830 million for the year ended December 31, 2013.
	BOSC, Inc., a wholly-owned subsidiary of BOK Financial, is an introducing broker to Pershing, LLC for retail equity investment transactions. As such, it has indemnified Pershing, LLC against losses due to a customer's failure to settle a transaction or to repay a margin loan. All unsettled transaction and margin loans are secured as required by applicable regulation. The amount of customer balances subject to indemnification totaled $72 thousand at December 31, 2014.
	The Company agreed to guarantee rents totaling $28.7 million through September of 2017 to the City as owner of a building immediately adjacent to the Bank’s main office for space currently rented by third-party tenants in the building. All rent payments are current. Remaining guaranteed rents totaled $8.4 million at December 31, 2014. In return for this guarantee, the Company will receive 80% of net cash flow as defined in an agreement with the City through September 2017 from rental of space that was vacant at the inception of the agreement. The maximum amount that the Company may receive under this agreement is $4.5 million.

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	(16)  Earnings Per Share
	The following table presents the computation of basic and diluted earnings per share (dollars in thousands, except per share data):
		Year Ended
		2014		2013		2012
	Numerator:
	Net income attributable to BOK Financial Corp. shareholders	$	292,435	$	316,609	$	351,191
	Less: Earnings allocated to participating securities	3,239		3,388		2,541
	Numerator for basic earnings per share – income available to common shareholders	289,196		313,221		348,650
	Effect of reallocating undistributed earnings of participating securities	4		7		6
	Numerator for diluted earnings per share – income available to common shareholders	$	289,200	$	313,228	$	348,656
	Denominator:
	Weighted average shares outstanding	69,159,902		68,719,069		68,221,013
	Less:  Participating securities included in weighted average shares outstanding	765,708		730,172		536,970
	Denominator for basic earnings per common share	68,394,194		67,988,897		67,684,043
	Dilutive effect of employee stock compensation plans1	150,576		216,622		280,897
	Denominator for diluted earnings per common share	68,544,770		68,205,519		67,964,940
	Basic earnings per share	$	4.23	$	4.61	$	5.15
	Diluted earnings per share	$	4.22	$	4.59	$	5.13
	1  Excludes employee stock options with exercise prices greater than current market price.	—		—		224,653

Shareholders_Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Shareholders' Equity [Text Block]	(15) Shareholders Equity
	Preferred Stock
	One billion shares of preferred stock with a par value of $0.00005 per share are authorized. The Series A Preferred Stock has no voting rights except as otherwise provided by Oklahoma corporate law and may be converted into one share of Common Stock for each 36 shares of Series A Preferred Stock at the option of the holder. Dividends are cumulative at an annual rate of ten percent of the $0.06 per share liquidation preference value when declared and are payable in cash. Aggregate liquidation preference is $15 million. No Series A Preferred Stock was outstanding in 2014, 2013 or 2012.
	Common Stock
	Common stock consists of 2.5 billion authorized shares with a $0.00006 par value. Holders of common shares are entitled to one vote per share at the election of the Board of Directors and on any question arising at any shareholders’ meeting and to receive dividends when and as declared. Additionally, regulations restrict the ability of national banks and bank holding companies to pay dividends.
	Subsidiary Bank
	The amounts of dividends that BOK Financial’s subsidiary bank can declare and the amounts of loans the subsidiary bank can extend to affiliates are limited by various federal banking regulations and state corporate law. Generally, dividends declared during a calendar year are limited to net profits, as defined, for the year plus retained profits for the preceding two years. The amounts of dividends are further restricted by minimum capital requirements. Based on the most restrictive limitations as well as management’s internal capital policy, at December 31, 2014, BOK Financial's subsidiary bank could declare up to $365 million of dividends without regulatory approval. Upon adoption of the Basel III regulatory capital framework in the first quarter of 2015, the dividend capacity of the subsidiary bank will be reduced to zero. The subsidiary bank declared and paid dividends of $75 million in 2014, $225 million in 2013 and $275 million in 2012.
	As defined by banking regulations, loan commitments and equity investments to a single affiliate may not exceed 10% of unimpaired capital and surplus and loan commitments and equity investments to all affiliates may not exceed 20% of unimpaired capital and surplus. All loans to affiliates must be fully secured by eligible collateral. At December 31, 2014, loan commitments and equity investments were limited to $245 million to a single affiliate and $490 million to all affiliates. The largest loan commitment and equity investment to a single affiliate was $220 million and the aggregate loan commitments and equity investments to all affiliates were $330 million. The largest outstanding amount to a single affiliate at December 31, 2014 was $14 million and the total outstanding amounts to all affiliates were $18 million. At December 31, 2013, total loan commitments and equity investments to all affiliates were $334 million and the total outstanding amounts to all affiliates were $27 million.
	Regulatory Capital
	BOK Financial and the Bank are subject to various capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and additional discretionary actions by regulators that could have a material effect on BOK Financial's operations. These capital requirements include quantitative measures of assets, liabilities and certain off-balance sheet items. The capital standards are also subject to qualitative judgments by regulators about components, risk weightings and other factors.
	For a banking institution to qualify as well capitalized, Tier I, Total and Leverage capital ratios must be at least 6%, 10% and 5%, respectively. Tier I capital consists primarily of common stockholders' equity, excluding unrealized gains or losses on available for sale securities, less goodwill, core deposit premiums and certain other intangible assets. Total capital consists primarily of Tier I capital plus preferred stock, subordinated debt and allowances for credit losses, subject to certain limitations. The Bank exceeded the regulatory definition of well capitalized as of December 31, 2014 and December 31, 2013.
	A summary of regulatory capital levels follows (dollars in thousands):
			December 31,
			2014						2013
	Total Capital (to Risk Weighted Assets):
	Consolidated		$	3,120,223		14.66	%		$	3,017,022			15.56	%
	BOKF, NA		2,449,078			11.56			2,293,673				11.88
	Tier I Capital (to Risk Weighted Assets):
	Consolidated		$	2,838,129		13.33	%		$	2,668,981			13.77	%
	BOKF, NA		2,168,161			10.24			1,946,247				10.08
	Tier I Capital (to Average Assets):
	Consolidated		$	2,838,129		9.96	%		$	2,668,981			10.05	%
	BOKF, NA		2,168,161			7.65			1,946,247				7.38
	Accumulated Other Comprehensive Income (Loss)
	AOCI includes unrealized gains and losses on available for sale ("AFS") securities. Unrealized gain (loss) on AFS securities also includes 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 will be amortized over the estimated remaining life of the security as an adjustment to yield. 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 will be 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, December 31, 2011		$	135,740		$	6,673			$	(12,742	)		$	(692	)	$	128,979
	Net change in unrealized gain (loss)		58,921			—				7,276				—			66,197
	Reclassification adjustments included in earnings:
	Interest revenue, Investment securities, Taxable securities		—			(6,601		)		—				—			(6,601		)
	Interest expense, Subordinated debentures		—			—				—				453			453
	Net impairment losses recognized in earnings		7,351			—				—				—			7,351
	Gain on available for sale securities, net		(33,845		)	—				—				—			(33,845		)
	Other comprehensive income (loss), before income taxes		32,427			(6,601		)		7,276				453			33,555
	Federal and state income tax1		(12,614		)	3,006				(2,830		)		(176		)	(12,614		)
	Other comprehensive income (loss), net of income taxes		19,813			(3,595		)		4,446				277			20,941
	Balance, December 31, 2012		155,553			3,078				(8,296		)		(415		)	149,920
	Net change in unrealized gain (loss)		(284,104		)	—				8,159				—			(275,945		)
	Reclassification adjustments included in earnings:
	Interest revenue, Investment securities, Taxable securities		—			(3,210		)		—				—			(3,210		)
	Interest expense, Subordinated debentures		—			—				—				262			262
	Net impairment losses recognized in earnings		2,308			—				—				—			2,308
	Gain on available for sale securities, net		(10,720		)	—				—				—			(10,720		)
	Other comprehensive income (loss), before income taxes		(292,516		)	(3,210		)		8,159				262			(287,305		)
	Federal and state income tax1		113,788			1,250				(3,174		)		(102		)	111,762
	Other comprehensive income (loss), net of income taxes		(178,728		)	(1,960		)		4,985				160			(175,543		)
	Balance, December 31, 2013		(23,175		)	1,118				(3,311		)		(255		)	(25,623		)
	Net change in unrealized gain (loss)		136,050			—				725				—			136,775
	Reclassification adjustments included in earnings:
	Interest revenue, Investment securities, Taxable securities		—			(1,216		)		—				—			(1,216		)
	Interest expense, Subordinated debentures		—			—				—				296			296
	Net impairment losses recognized in earnings		373			—				—				—			373
	Gain on available for sale securities, net		(1,539		)	—				—				—			(1,539		)
	Other comprehensive income (loss), before income taxes		134,884			(1,216		)		725				296			134,689
	Federal and state income tax1		(52,470		)	474				(282		)		(115		)	(52,393		)
	Other comprehensive income (loss), net of income taxes		82,414			(742		)		443				181			82,296
	Balance, December 31, 2014		$	59,239		$	376			$	(2,868	)		$	(74	)	$	56,673
	1	Calculated using 39% effective tax rate.

Reportable_Segments

Reportable Segments	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Reportable Segments [Text Block]	(17)  Reportable Segments
	BOK Financial operates three principal lines of business: Commercial Banking, Consumer Banking and Wealth Management. Commercial Banking includes lending, treasury and cash management services and customer risk management products to small businesses, middle market and larger commercial customers. Commercial Banking also includes the TransFund EFT network. Consumer Banking includes retail lending and deposit services, lending and deposit services to small business customers served through the consumer branch network and all mortgage banking activities. Wealth Management provides fiduciary services, private bank services and investment advisory services in all markets. Wealth Management also underwrites state and municipal securities and engages in brokerage and trading activities.
	In addition to its lines of business, BOK Financial has a Funds Management unit. The primary purpose of this unit is to manage the overall liquidity needs and interest rate risk. Each line of business borrows funds from and provides funds to the Funds Management unit as needed to support their operations. Operating results for Funds Management and other include the effect of interest rate risk positions and risk management activities, securities gains and losses including impairment charges, the provision for credit losses in excess of net loans charged off, tax planning strategies and certain executive compensation costs that are not attributed to the lines of business.
	BOK Financial allocates resources and evaluates performance of its lines of business after allocation of funds, actual net credit losses and capital costs. In addition, we measure the performance of our business lines after allocation of certain indirect expenses and taxes on statutory rates. Corporate expense allocations were updated in 2014. The allocation for the prior comparable periods have been revised on a comparable basis.
	The cost of funds borrowed from the Funds Management unit by the operating lines of business is transfer priced at rates that approximate market rates for funds with similar duration. Market rates are generally based on the applicable LIBOR or interest rate swap rates, adjusted for prepayment risk. This method of transfer-pricing funds that support assets of the operating lines of business tends to insulate them from interest rate risk.
	The value of funds provided by the operating lines of business to the Funds Management unit is based on rates which approximate the wholesale market rates for funds with similar duration and re-pricing characteristics. Market rates are generally based on LIBOR or interest rate swap rates. The funds credit formula applied to deposit products with indeterminate maturities is established based on their re-pricing characteristics reflected in a combination of the short-term LIBOR rates and a moving average of an intermediate term swap rate, with an appropriate spread applied to both. Shorter duration products are weighted towards the short-term LIBOR rate and longer duration products are weighted towards intermediate swap rates. The expected duration ranges from 30 days for certain rate-sensitive deposits to five years.
	Economic capital is assigned to the business units by a capital allocation model that reflects management's assessment of risk. This model assigns capital based upon credit, operating, interest rate and market risk inherent in our business lines and recognizes the diversification benefits among the units. The level of assigned economic capital is a combination of the risk taken by each business line, based on its actual exposures and calibrated to its own loss history where possible. Average invested capital includes economic capital and amounts we have invested in the lines of business.
	Substantially all revenue is from domestic customers. No single external customer accounts for more than 10% of total revenue.
	Net loans charged off and provision for credit losses represents net loans charged off as attributed to the lines of business and the provision for credit losses in excess of net charge-offs attributed to Funds Management and Other.
	Reportable segments reconciliation to the Consolidated Financial Statements for the year ended December 31, 2014 is as follows (in thousands):
		Commercial			Consumer			Wealth			Funds Management and Other			BOK
								Management						Financial
														Consolidated
	Net interest revenue from external sources	$	381,687		$	95,910		$	23,826		$	163,771		$	665,194
	Net interest revenue (expense) from internal sources	(43,934		)	32,170			20,578			(8,814		)	—
	Net interest revenue	337,753			128,080			44,404			154,957			665,194
	Provision for credit losses	(7,447		)	5,405			213			1,829			—
	Net interest revenue after provision for credit losses	345,200			122,675			44,191			153,128			665,194
	Other operating revenue	169,704			200,815			239,045			3,095			612,659
	Other operating expense	201,748			196,082			216,770			232,922			847,522
	Net direct contribution	313,156			127,408			66,466			(76,699		)	430,331
	Corporate expense allocations	41,338			67,040			31,375			(139,753		)	—
	Income before taxes	271,818			60,368			35,091			63,054			430,331
	Federal and state income taxes	105,737			23,483			13,650			(8,018		)	134,852
	Net income	166,081			36,885			21,441			71,072			295,479
	Net income attributable to non-controlling interests	—			—			—			3,044			3,044
	Net income attributable to BOK Financial Corp. shareholders	$	166,081		$	36,885		$	21,441		$	68,028		$	292,435
	Average assets	$	11,384,508		$	6,555,642		$	4,518,511		$	5,540,197		$	27,998,858
	Average invested capital	946,383			277,404			193,784			1,793,190			3,210,761
	Performance measurements:
	Return on average assets	1.46		%	0.56		%	0.52		%				1.04		%
	Return on average invested capital	17.58		%	13.3		%	12.07		%				9.11		%
	Efficiency ratio	39.57		%	56.58		%	75.9		%				64.5		%
	Reportable segments reconciliation to the Consolidated Financial Statements for the year ended December 31, 2013 is as follows (in thousands):
		Commercial			Consumer			Wealth			Funds Management and Other			BOK
								Management						Financial
														Consolidated
	Net interest revenue from external sources	$	363,961		$	100,153		$	25,478		$	184,885		$	674,477
	Net interest revenue (expense) from internal sources	(51,587		)	34,850			20,061			(3,324		)	—
	Net interest revenue	312,374			135,003			45,539			181,561			674,477
	Provision for credit losses	(4,372		)	5,532			1,275			(30,335		)	(27,900		)
	Net interest revenue after provision for credit losses	316,746			129,471			44,264			211,896			702,377
	Other operating revenue	163,206			225,336			211,655			14,275			614,472
	Other operating expense	190,306			189,099			197,890			263,325			840,620
	Net direct contribution	289,646			165,708			58,029			(37,154		)	476,229
	Corporate expense allocations	44,865			60,005			29,993			(134,863		)	—
	Net income before taxes	244,781			105,703			28,036			97,709			476,229
	Federal and state income taxes	95,220			41,118			10,906			10,054			157,298
	Net income	149,561			64,585			17,130			87,655			318,931
	Net income attributable to non-controlling interests	—			—			—			2,322			2,322
	Net income attributable to BOK Financial Corp. shareholders	$	149,561		$	64,585		$	17,130		$	85,333		$	316,609
	Average assets	$	10,386,235		$	6,487,255		$	4,556,132		$	5,951,472		$	27,381,094
	Average invested capital	906,717			293,736			203,914			1,606,715			3,011,082
	Performance measurements:
	Return on average assets	1.44		%	1		%	0.4		%				1.16		%
	Return on average invested capital	16.49		%	21.99		%	9		%				10.51		%
	Efficiency ratio	40.24		%	51.3		%	76.37		%				64.6		%
	Reportable segments reconciliation to the Consolidated Financial Statements for the year ended December 31, 2012 is as follows (in thousands):
		Commercial			Consumer			Wealth			Funds Management and Other			BOK
								Management						Financial
														Consolidated
	Net interest revenue from external sources	$	366,243		$	102,321		$	27,647		$	211,338		$	707,549
	Net interest revenue (expense) from internal sources	(58,835		)	36,700			21,456			679			—
	Net interest revenue	307,408			139,021			49,103			212,017			707,549
Provision for credit losses	9,463			10,588			2,284			(44,335		)	(22,000		)
Net interest revenue after provision for credit losses	297,945			128,433			46,819			256,352			729,549
Other operating revenue	162,085			271,723			197,306			22,564			653,678
Other operating expense	192,396			206,598			177,423			263,946			840,363
Net direct contribution	267,634			193,558			66,702			14,970			542,864
Corporate expense allocations	44,330			64,239			30,525			(139,094		)	—
Net income before taxes	223,304			129,319			36,177			154,064			542,864
Federal and state income taxes	86,865			50,305			14,073			37,497			188,740
Net income	136,439			79,014			22,104			116,567			354,124
Net income attributable to non-controlling interests	—			—			—			2,933			2,933
Net income attributable to BOK Financial Corp. shareholders	$	136,439		$	79,014		$	22,104		$	113,634		$	351,191
Average assets	$	9,844,145		$	6,498,193		$	4,357,641		$	5,589,171		$	26,289,150
Average invested capital	882,036			289,665			184,707			1,549,547			2,905,955
Performance measurements:
Return on average assets	1.39		%	1.22		%	0.52		%				1.34		%
Return on average invested capital	15.47		%	27.28		%	12.26		%				12.09		%
Efficiency ratio	42.26		%	49.6		%	71.19		%				62.03		%

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements	(18) 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. During 2014, $14 million of residential mortgage loans held for sale were transferred from significant other observable inputs to significant unobservable inputs. These loans cannot be sold to U.S. government agencies due to origination defects. An unobservable liquidity discount is applied to determine fair value. There were no other transfers in or out of quoted prices in active markets for identical instruments, significant other observable inputs or significant unobservable inputs during the year ended December 31, 2014 and 2013, respectively.
	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 December 31, 2014 and 2013.
	Assets and Liabilities Measured at Fair Value on a Recurring Basis
	The fair value of financial assets and liabilities that are measured on a recurring basis is as follows as of December 31, 2014 (in thousands):
			Total				Quoted Prices in Active Markets for Identical Instruments				Significant Other Observable Inputs				Significant Unobservable Inputs
	Assets:
	Trading securities:
	U.S. Government agency debentures		$	85,092			$	—			$	85,092			$	—
	U.S. agency residential mortgage-backed securities		31,199				—				31,199				—
	Municipal and other tax-exempt securities		38,951				—				38,951				—
	Other trading securities		33,458				—				33,458				—
	Total trading securities		188,700				—				188,700				—
	Available for sale securities:
	U.S. Treasury securities		1,005				1,005				—				—
	Municipal and other tax-exempt securities		63,557				—				53,464				10,093
	U.S. government agency residential mortgage-backed securities		6,646,884				—				6,646,884				—
	Privately issued residential mortgage-backed securities		165,957				—				165,957				—
	Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,048,609				—				2,048,609				—
	Other debt securities		9,212				—				5,062				4,150
	Perpetual preferred stock		24,277				—				24,277				—
	Equity securities and mutual funds		19,444				4,927				14,517				—
	Total available for sale securities		8,978,945				5,932				8,958,770				14,243
	Fair value option securities:
	U.S. government agency residential mortgage-backed securities		311,597				—				311,597				—
	Other securities		—				—				—				—
	Total fair value option securities		311,597				—				311,597				—
	Residential mortgage loans held for sale		304,182				—				292,326				11,856
	Mortgage servicing rights, net1		171,976				—				—				171,976
	Derivative contracts, net of cash margin2		361,874				17,607				344,267				—
	Other assets – private equity funds		25,627				—				—				25,627
	Liabilities:
	Derivative contracts, net of cash margin2		354,554				541				354,013				—
	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 7, Mortgage Banking Activities.
	2	See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts in asset positions were valued based on quoted prices in active markets or identical instruments (Level 1) are exchange-traded energy derivative contracts, net of cash margin. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate and agricultural derivative contracts, net of cash margin.
	The fair value of financial assets and liabilities that are measured on a recurring basis is as follows as of December 31, 2013 (in thousands):
			Total				Quoted Prices in Active Markets for Identical Instruments				Significant Other Observable Inputs				Significant Unobservable Inputs
	Assets:
	Trading securities:
	U.S. Government agency debentures		$	34,120			$	—			$	34,120			$	—
	U.S. government agency residential mortgage-backed securities		21,011				—				21,011				—
	Municipal and other tax-exempt securities		27,350				—				27,350				—
	Other trading securities		9,135				—				9,135				—
	Total trading securities		91,616				—				91,616				—
	Available for sale securities:
	U.S. Treasury securities		1,042				1,042				—				—
	Municipal and other tax-exempt securities		73,775				—				55,970				17,805
	U.S. government agency residential mortgage-backed securities		7,716,010				—				7,716,010				—
	Privately issued residential mortgage-backed securities		221,099				—				221,099				—
	Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,055,804				—				2,055,804				—
	Other debt securities		35,241				—				30,529				4,712
	Perpetual preferred stock		22,863				—				22,863				—
	Equity securities and mutual funds		21,328				—				17,121				4,207
	Total available for sale securities		10,147,162				1,042				10,119,396				26,724
	Fair value option securities:
U.S. government agency residential mortgage-backed securities		157,431				—				157,431				—
Other securities		9,694				—				9,694				—
Total fair value option securities		167,125				—				167,125				—
Residential mortgage loans held for sale		200,546				—				200,546				—
Mortgage servicing rights, net1		153,333				—				—				153,333
Derivative contracts, net of cash margin2		265,012				2,712				262,300				—
Other assets – private equity funds		27,341				—				—				27,341
Liabilities:
Derivative contracts, net of cash margin 2		247,185				—				247,185				—
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 7, 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 contracts, net of 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 reference 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 assess 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 conforming residential mortgage loans held for sale are based upon quoted market prices of such loans sold in securitization transactions, including related unfunded loan commitments. The fair value of mortgage loans that are unable to be sold to U.S. government agencies is 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 are based upon net asset value reported by the underlying funds, as adjusted by the general partner when necessary to represent the price that would be received to sell the assets. 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.
The following represents the changes related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands):
		Available for Sale Securities												Residential mortgage loans held for sale				Other assets – private equity funds
		Municipal and other tax-exempt				Other debt securities				Equity securities and mutual funds
Balance, December 31, 2012		$	40,702			$	5,399			$	2,161			$	—			$	28,169
Transfer to Level 3 from Level 2		—				—				—				—				—
Purchases and capital calls		—				—				—				—				1,415
Redemptions and distributions		(19,238		)		(500		)		—				—				(5,294		)
Gain (loss) recognized in earnings:
Gain (loss) on other assets, net		—				—				—				—				3,051
Gain on available for sale securities, net		1,216				—				—				—				—
Other-than-temporary impairment losses		(1,369		)		—				—				—				—
Other comprehensive income (loss):
Net change in unrealized gain (loss)		(3,506		)		(187		)		2,046				—				—
Balance, December 31, 2013		17,805				4,712				4,207				—				27,341
Transfer to Level 3 from Level 2		—				—				—				13,644				—
Purchases and capital calls		—				—				—				—				1,012
Redemptions and distributions		(7,487		)		(500		)		—				—				(7,473		)
Proceeds from sales		—				—				—				(1,176		)		—
Gain (loss) recognized in earnings:
Mortgage banking revenue		—				—				—				(612		)		—
Gain on other assets, net		—				—				—				—				4,747
Gain on available for sale securities, net		(235		)		—				—				—				—
Other-than-temporary impairment losses		—				—				—				—				—
Charitable contributions to BOKF Foundation		—				—				(2,420		)		—				—
Other comprehensive income (loss):
Net change in unrealized gain (loss)		10				(62		)		(1,787		)		—				—
Balance, December 31, 2014		$	10,093			$	4,150			$	—			$	11,856			$	25,627
A summary of quantitative information about assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) as of December 31, 2014 follows (in thousands):
Quantitative Information about Level 3 Recurring Fair Value Measurements
		Par				Amortized				Fair				Valuation Technique(s)		Unobservable Input		Range
		Value				Cost/Unpaid Principal Balance				Value								(Weighted Average)
Available for sale securities
Municipal and other tax-exempt securities		$	10,870			$	10,805			$	10,093			Discounted cash flows	1	Interest rate spread		4.96%-5.26% (5.21%)	2
																		92.65%-94.32% (93.09%)	3
Other debt securities		4,400				4,400				4,150				Discounted cash flows	1	Interest rate spread		5.62% - 5.67% (5.66%)	4
																		92.65% - 92.95% (92.77%)	3
Residential mortgage loans held for sale		N/A				12,468				11,856				Quoted prices of loans sold in securitization transactions, with a liquidity discount applied		Liquidity discount applied to the market value of mortgage loans qualifying for sale to U.S. government agencies		95.09%
Other assets - private equity funds		N/A				N/A				25,627				Net asset value reported by underlying fund		Net asset value reported by underlying fund		N/A
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 488 to 516 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%.
A summary of quantitative information about Recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of December 31, 2013 follows (in thousands):
Quantitative Information about Level 3 Recurring Fair Value Measurements
		Par				Amortized				Fair				Valuation Technique(s)		Unobservable Input		Range
		Value				Cost6				Value								(Weighted Average)
Available for sale securities
Municipal and other tax-exempt securities		$	18,695			$	18,624			$	17,805			Discounted cash flows	1	Interest rate spread		4.97%-5.27% (5.16%)	2
																		95.02%-95.50% (95.24%)	3
Other debt securities		4,900				4,900				4,712				Discounted cash flows	1	Interest rate spread		5.67% (5.67%)	4
																		96.16% (96.16%)	3
Equity securities and other mutual funds		N/A				2,420				4,207				Publicly announced preliminary purchase price information from acquirer		Discount for settlement uncertainty		N/A	5
Other assets - private equity funds		N/A				N/A				27,341				Net asset value reported by underlying fund		Net asset value reported by underlying fund		N/A
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 467 to 518 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%.
5	Fair value of shares of a smaller privately-held financial institution were valued using preliminary announced purchase information by a publicly-traded acquirer.
Fair Value of Assets and Liabilities Measured on a Non-Recurring Basis
Assets measured at fair value on a non-recurring basis include pension plan assets, which are based on quoted prices in active markets for identical instruments, 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. In addition, goodwill impairment is evaluated based on the fair value of the Company's reporting units.
The following represents the carrying value of assets measured at fair value on a non-recurring basis and related losses recorded during the year. The carrying value represents only those assets with the balance sheet date for which the fair value was adjusted during the year:
	Carrying Value at December 31, 2014												Fair Value Adjustments for the
													Year Ended December 31, 2014
													Recognized In:
	Quoted Prices				Significant				Significant				Gross charge-offs against allowance for loan losses				Net losses and expenses of repossessed assets, net
	in Active Markets for Identical Instruments				Other				Unobservable
					Observable				Inputs
					Inputs
Impaired loans	$	—			$	8,198			$	635			$	4,044			$	—
Real estate and other repossessed assets	—				22,594				3,691				—				3,563
	Carrying Value at December 31, 2013												Fair Value Adjustments for the
													Year Ended December 31, 2013
													Recognized In:
	Quoted Prices				Significant				Significant				Gross charge-offs against allowance for loan losses				Net losses and expenses of repossessed assets, net
	in Active Markets for Identical Instruments				Other				Unobservable
					Observable				Inputs
					Inputs
Impaired loans	$	—			$	8,380			$	4,622			$	6,598			$	—
Real estate and other repossessed assets	—				20,733				191				—				5,489
The fair value of collateral-dependent impaired loans 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 comparable assets, uncorroborated expert opinions or management's knowledge of the collateral or industry. These 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 December 31, 2014 follows (in thousands):
Quantitative Information about Level 3 Non-recurring Fair Value Measurements
		Fair Value				Valuation Technique(s)		Unobservable Input		Range
										(Weighted Average)
Impaired loans		$	635			Appraised value, as adjusted		Broker quotes and management's knowledge of industry and collateral.		N/A
Real estate and other repossessed assets		3,691				Appraised value, as adjusted		Marketability adjustments off appraised value		65%
A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of December 31, 2013 follows (in thousands):
Quantitative Information about Level 3 Non-recurring Fair Value Measurements
		Fair Value				Valuation Technique(s)		Unobservable Input		Range
										(Weighted Average)
Impaired loans		$	4,622			Appraised value, as adjusted		Broker quotes and management's knowledge of industry and collateral.		N/A
Real estate and other repossessed assets		191				Listing value, less cost to sell		Marketability adjustments off appraised value		80%-85% (82%)1
1	Marketability adjustments includes consideration of estimated costs to sell which is approximately 15% of the fair value.
The fair value of pension plan assets was approximately $49 million at both December 31, 2014 and December 31, 2013, determined by significant other observable inputs. Fair value adjustments of pension plan assets along with changes in the projected benefit obligation are recognized in other comprehensive income.
Goodwill and intangible assets, which consist primarily of core deposit intangible assets and other acquired intangibles, for each business unit are evaluated for impairment annually as of October 1st or more frequently if conditions indicate that impairment may have occurred. The evaluation of possible impairment of intangible assets involves significant judgment based upon short-term and long-term projections of future performance.
The fair value of each of our reporting units is estimated by the discounted future earnings method. Income growth is projected for each of our reporting units over five years and a terminal value is computed. The projected income stream is converted to fair value by using a discount rate that reflects a rate of return required by a willing buyer. Assumptions used to value our business units are based on growth rates, volatility, discount rate and market risk premium inherent in our current stock price.
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 (dollars in thousands):
		31-Dec-14
		Carrying				Range of Contractual Yields				Average		Discount Rate				Estimated
		Value								Re-pricing						Fair
										(in years)						Value
Cash and due from banks		$	550,576													$	550,576
Interest-bearing cash and cash equivalents		1,925,266														1,925,266
Trading securities:
U.S. Government agency debentures		85,092														85,092
U.S. government agency residential mortgage-backed securities		31,199														31,199
Municipal and other tax-exempt securities		38,951														38,951
Other trading securities		33,458														33,458
Total trading securities		188,700														188,700
Investment securities:
Municipal and other tax-exempt securities		405,090														408,344
U.S. government agency residential mortgage-backed securities		35,750														37,463
Other debt securities		211,520														227,819
Total investment securities		652,360														673,626
Available for sale securities:
U.S. Treasury securities		1,005														1,005
Municipal and other tax-exempt securities		63,557														63,557
U.S. government agency residential mortgage-backed securities		6,646,884														6,646,884
Privately issued residential mortgage-backed securities		165,957														165,957
Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,048,609														2,048,609
Other debt securities		9,212														9,212
Perpetual preferred stock		24,277														24,277
Equity securities and mutual funds		19,444														19,444
Total available for sale securities		8,978,945														8,978,945
Fair value option securities:
U.S. government agency residential mortgage-backed securities		311,597														311,597
Other securities		—														—
Total fair value option securities		311,597														311,597
Residential mortgage loans held for sale		304,182														304,182
Loans:
Commercial		9,095,670				0.17	% -	30.00%		0.65		0.51	% -	4.34%		8,948,870
Commercial real estate		2,728,150				0.38	% -	18.00%		0.84		1.09	% -	3.78%		2,704,454
Residential mortgage		1,949,512				1.2	% -	18.00%		2.5		0.64	% -	3.99%		1,985,870
Consumer		434,705				0.38	% -	21.00%		0.45		1.04	% -	3.98%		431,274
Total loans		14,208,037														14,070,468
Allowance for loan losses		(189,056		)												—
Loans, net of allowance		14,018,981														14,070,468
Mortgage servicing rights		171,976														171,976
Derivative instruments with positive fair value, net of cash margin		361,874														361,874
Other assets – private equity funds		25,627														25,627
Deposits with no stated maturity		18,532,143														18,532,143
Time deposits		2,608,716				0.02	% -	9.64%		1.92		0.76	% -	1.33%		2,612,576
Other borrowings		3,378,294				0.21	% -	1.52%		0.12		0.06	% -	2.64%		3,331,771
Subordinated debentures		347,983				0.92	% -	5.00%		1.67		2.14%				344,687
Derivative instruments with negative fair value, net of cash margin		354,554														354,554
		31-Dec-13
		Carrying				Range of Contractual Yields				Average		Discount Rate				Estimated
		Value								Re-pricing						Fair
										(in years)						Value
Cash and due from banks		$	512,931													$	512,931
Interest-bearing cash and cash equivalents		574,282														574,282
Trading securities:
U.S. Government agency debentures		34,120														34,120
U.S. government agency residential mortgage-backed securities		21,011														21,011
Municipal and other tax-exempt securities		27,350														27,350
Other trading securities		9,135														9,135
Total trading securities		91,616														91,616
Investment securities:
Municipal and other tax-exempt		440,187														439,870
U.S. government agency residential mortgage-backed securities		50,182														51,864
Other debt securities		187,509														195,393
Total investment securities		677,878														687,127
Available for sale securities:
U.S. Treasury		1,042														1,042
Municipal and other tax-exempt		73,775														73,775
U.S. government agency residential mortgage-backed securities		7,716,010														7,716,010
Privately issued residential mortgage-backed securities		221,099														221,099
Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,055,804														2,055,804
Other debt securities		35,241														35,241
Perpetual preferred stock		22,863														22,863
Equity securities and mutual funds		21,328														21,328
Total available for sale securities		10,147,162														10,147,162
Fair value option securities:
U.S. government agency residential mortgage-backed securities		157,431														157,431
Other securities		9,694														9,694
Total fair value option securities		167,125														167,125
Residential mortgage loans held for sale		200,546														200,546
Loans:
Commercial		7,943,221				0.04	% -	30.00%		0.49		0.48	% -	4.33%		7,835,325
Commercial real estate		2,415,353				0.38	% -	18.00%		0.78		1.21	% -	3.49%		2,394,443
Residential mortgage		2,052,026				0.38	% -	18.00%		2.63		0.59	% -	4.73%		2,068,690
Consumer		381,664				0.38	% -	21.00%		0.55		1.22	% -	3.75%		375,962
Total loans		12,792,264														12,674,420
Allowance for loan losses		(185,396		)												—
Loans, net of allowance		12,606,868														12,674,420
Mortgage servicing rights		153,333														153,333
Derivative instruments with positive fair value, net of cash margin		265,012														265,012
Other assets – private equity funds		27,341														27,341
Deposits with no stated maturity		17,573,334														17,573,334
Time deposits		2,695,993				0.01	% -	9.64%		2.12		0.75	% -	1.33%		2,697,290
Other borrowings		2,721,888				0.25	% -	4.78%		0.03		0.08	% -	2.64%		2,693,788
Subordinated debentures		347,802				0.95	% -	5.00%		2.63		2.22%				344,783
Derivative instruments with negative fair value, net of cash margin		247,185														247,185
Because no market exists for certain of these financial instruments and management does not intend to sell these financial instruments, the fair values shown in the tables above may not represent values at which the respective financial instruments could be sold individually or in the aggregate at the given reporting date.
The following methods and assumptions were used in estimating the fair value of these financial instruments:
Cash and Cash Equivalents
The book value reported in the consolidated balance sheet for cash and short-term instruments approximates those assets’ fair values.
Securities
The fair values of securities are generally based on Significant Other Observable Inputs such as quoted prices for comparable instruments or interest rates and credit spreads, yield curves, volatilities, prepayment speeds and loss severities.
Loans
The fair value of loans, excluding loans held for sale, are based on discounted cash flow analyses using interest rates and credit and liquidity spreads currently being offered for loans with similar remaining terms to maturity and risk, adjusted for the impact of interest rate floors and ceilings which are classified as Significant Unobservable Inputs. The fair values of loans were estimated to approximate their discounted cash flows less loan loss allowances allocated to these loans of $161 million at December 31, 2014 and $157 million at December 31, 2013.
Deposits
The fair values of time deposits are based on discounted cash flow analyses using interest rates currently being offered on similar transactions which are considered Significant Unobservable Inputs. Estimated fair value of deposits with no stated maturity, which includes demand deposits, transaction deposits, money market deposits and savings accounts, is equal to the amount payable on demand. Although market premiums paid reflect an additional value for these low cost deposits, adjusting fair value for the expected benefit of these deposits is prohibited. Accordingly, the positive effect of such deposits is not included in the tables above.
Other Borrowings and Subordinated Debentures
The fair values of these instruments are based upon discounted cash flow analyses using interest rates currently being offered on similar instruments which are considered Significant Unobservable Inputs
Off-Balance Sheet Instruments
The fair values of commercial loan commitments are based on fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements. The fair values of these off-balance sheet instruments were not significant at December 31, 2014 or December 31, 2013.
Fair Value Election
As more fully disclosed in Note 2 and Note 7 to the Consolidated Financial Statements, the Company has elected to carry all residential mortgage-backed securities which have been designated as economic hedges against changes in the fair value of mortgage servicing rights, certain corporate debt securities economically hedged by derivative contracts to manage interest rate risk and all residential mortgage loans originated for sale at fair value. Changes in the fair value of these financial instruments are recognized in earnings.

Parent_Company_Only_Financial_

Parent Company Only Financial Statements	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Parent Company Only Financial Statements [Text Block]	(19) Parent Company Only Financial Statements
	Summarized financial information for BOK Financial – Parent Company Only follows:
	Balance Sheets
	(In thousands)	December 31,
		2014			2013
	Assets
	Cash and cash equivalents	$	510,668		$	561,297
	Available for sale securities	24,794			27,526
	Investment in subsidiaries	2,774,276			2,426,495
	Other assets	1,637			12,872
	Total assets	$	3,311,375		$	3,028,190
	Liabilities and Shareholders’ Equity
	Other liabilities	$	9,196		$	8,141
	Total liabilities	9,196			8,141
	Shareholders’ equity:
	Common stock	4			4
	Capital surplus	954,644			898,586
	Retained earnings	2,530,837			2,349,428
	Treasury stock	(239,979		)	(202,346		)
	Accumulated other comprehensive income (loss)	56,673			(25,623		)
	Total shareholders’ equity	3,302,179			3,020,049
	Total liabilities and shareholders’ equity	$	3,311,375		$	3,028,190
	Statements of Earnings
	(In thousands)	Year Ended December 31,
		2014			2013			2012
	Dividends, interest and fees received from subsidiaries	$	75,412		$	225,340		$	275,330
	Other revenue	1,572			3,341			2,295
	Other-than-temporary impairment losses recognized in earnings	—			—			(1,099		)
	Total revenue	76,984			228,681			276,526
	Interest expense	293			292			269
	Charitable contributions to BOKF Foundation	2,420			2,062			2,062
	Professional fees and services	600			811			765
	Other operating expense	1,556			1,210			1,037
	Total expense	4,869			4,375			4,133
	Income before taxes and equity in undistributed income of subsidiaries	72,115			224,306			272,393
	Federal and state income taxes	(1,702		)	(1,578		)	(1,706		)
	Income before equity in undistributed income of subsidiaries	73,817			225,884			274,099
	Equity in undistributed income of subsidiaries	218,618			90,725			77,092
	Net income attributable to BOK Financial Corp. shareholders	$	292,435		$	316,609		$	351,191
	Statements of Cash Flows
	(In thousands)	Year Ended December 31,
		2014			2013			2012
	Cash Flows From Operating Activities:
	Net income	$	292,435		$	316,609		$	351,191
	Adjustments to reconcile net income to net cash provided by operating activities:
	Equity in undistributed income of subsidiaries	(218,618		)	(90,725		)	(77,092		)
	Tax effect from equity compensation, net	(8,258		)	(2,210		)	(120		)
	Change in other assets	8,726			(8,308		)	4,237
	Change in other liabilities	1,055			4,263			(4,965		)
	Net cash provided by operating activities	75,340			219,629			273,251
	Cash Flows From Investing Activities:
	Purchases of available for sale securities	—			—			(5,343		)
	Proceeds from sales of available for sale securities	—			13,600			4,781
	Investment in subsidiaries	(15,336		)	(36,000		)	(9,100		)
	Acquisitions, net of cash acquired	—			(7,500		)	(20,000		)
	Net cash used in investing activities	(15,336		)	(29,900		)	(29,662		)
	Cash Flows From Financing Activities:
	Issuance of common and treasury stock, net	4,472			16,566			14,650
	Tax effect from equity compensation, net	8,258			2,210			120
	Dividends paid	(111,026		)	(104,722		)	(166,982		)
	Repurchase of common stock	(12,337		)	—			(20,558		)
	Net cash used in financing activities	(110,633		)	(85,946		)	(172,770		)
	Net increase (decrease) in cash and cash equivalents	(50,629		)	103,783			70,819
	Cash and cash equivalents at beginning of period	561,297			457,514			386,695
Cash and cash equivalents at end of period	$	510,668		$	561,297		$	457,514
Cash paid for interest	$	293		$	292		$	269
Issuance of shares in settlement of deferred compensation, net	$	8,352		$	—		$	—

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events [Text Block]	(20) Subsequent Events
	The Company evaluated events from the date of the consolidated financial statements on December 31, 2014 through the issuance of those consolidated financial statements included in this Annual Report on Form 10-K. No events were identified requiring recognition in and/or disclosure in the consolidated financial statements.

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Presentation [Policy Text Block]	Basis of Presentation
	The Consolidated Financial Statements of BOK Financial Corporation (“BOK Financial” or “the Company”) have been prepared in conformity with accounting principles generally accepted in the United States ("U.S. GAAP"), including interpretations of U.S. GAAP issued by federal banking regulators and general practices of the banking industry. The consolidated financial statements include the accounts of BOK Financial and its subsidiaries, principally BOKF, NA (“the Bank”), BOSC, Inc., The Milestone Group, Inc. and Cavanal Hill Investment Management, Inc. All significant intercompany transactions are eliminated in consolidation. Certain prior year amounts have been reclassified to conform to the current year presentation.
	The consolidated financial statements include the assets, liabilities, non-controlling interests and results of operations of variable interest entities (“VIEs”) when BOK Financial is determined to be the primary beneficiary. 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. See additional discussion of variable interest entities at Note 14 following.
Nature of Operations [Text Block]	Nature of Operations
	BOK Financial, through its subsidiaries, provides a wide range of financial services to commercial and industrial customers, other financial institutions, municipalities, and consumers. These services include depository and cash management; lending and lease financing; mortgage banking; securities brokerage, trading and underwriting; and personal and corporate trust.
	The Bank operates as Bank of Oklahoma primarily in Tulsa and Oklahoma City metropolitan areas of the state of Oklahoma and Bank of Texas primarily in the Dallas, Fort Worth and Houston metropolitan areas of the state of Texas. In addition, the Bank does business as Bank of Albuquerque in Albuquerque, New Mexico; Colorado State Bank and Trust in Denver, Colorado; Bank of Arizona in Phoenix, Arizona; Bank of Kansas City in Kansas City, Missouri/Kansas and Bank of Arkansas in Northwest Arkansas. The Bank also operates the TransFund electronic funds network.
Use of Estimates [Policy Text Block]	Use of Estimates
	Preparation of BOK Financial's consolidated financial statements requires management to make estimates of future economic activities, including loan collectability, prepayments and cash flows from customer accounts. These estimates are based upon current conditions and information available to management. Actual results may differ significantly from these estimates.
Acquisitions [Policy Text Block]	Acquisitions
	Assets and liabilities acquired, including identifiable intangible assets, are recorded at fair value on the acquisition date. The purchase price includes consideration paid at closing and the estimated fair value of contingent consideration that will be paid in the future, subject to achieving defined performance criteria. Goodwill is recognized as the excess of the purchase price over the net fair value of assets acquired and liabilities assumed. The Consolidated Statements of Earnings include the results of operations from the acquisition date.
Goodwill and Intangible Assets [Policy Text Block]	Goodwill and Intangible Assets
	Goodwill and intangible assets generally result from business combinations and are evaluated for each of BOK Financial's reporting units for impairment annually or more frequently if conditions indicate impairment. The evaluation of possible impairment of goodwill and intangible assets involves significant judgment based upon short-term and long-term projections of future performance.
	Reporting units are defined by the Company as significant lines of business within each operating segment. This definition is consistent with the manner in which the chief operating decision maker assesses the performance of the Company and makes decisions concerning the allocation of resources. The Company qualitatively assesses whether it is more likely than not that the fair value of the reporting units are less than their carrying value. This assessment includes consideration of relevant events and circumstances including but not limited to macroeconomic conditions, industry and market conditions, the financial and stock performance of the Company and other relevant factors. Quantitative analysis may be undertaken to support the qualitative assessment. The fair value of BOK Financial's reporting units is estimated by the discounted future earnings method. Income growth is projected for each reporting unit and a terminal value is computed. This projected income stream is converted to current fair value by using a discount rate that reflects a rate of return required by a willing buyer. Assumptions used to determine the fair value of the reporting units are compared to observable inputs, such as the market value of BOK Financial common stock. However, determination of the fair value of individual reporting units requires the use of significant unobservable inputs. There have been no changes in the techniques used to evaluate the carrying value of goodwill.
	Intangible assets are generally composed of customer relationships, naming rights, non-compete agreements and core deposit premiums. They are amortized using accelerated or straight-line methods, as appropriate, over the estimated benefit periods. These periods range from 3 years to 20 years. The net book values of identifiable intangible assets are evaluated for impairment when economic conditions indicate impairment may exist.
Cash and Cash Equivalents [Policy Text Block]	Cash Equivalents
	Due from banks, funds sold (generally federal funds sold for one day), resell agreements (which generally mature within one to 30 days) and investments in money market funds are considered cash equivalents.
Securities [Policy Text Block]	Securities
	Securities are identified as trading, investment (held to maturity) or available for sale at the time of purchase based upon the intent of management, liquidity and capital requirements, regulatory limitations and other relevant factors. Trading securities, which are acquired for profit through resale, are carried at fair value with unrealized gains and losses included in current period earnings. Investment securities are carried at amortized cost. Amortization is computed by methods that approximate level yield and is adjusted for changes in prepayment estimates. Securities identified as available for sale are carried at fair value. Unrealized gains and losses are recorded, net of deferred income taxes, as accumulated other comprehensive income in shareholders' equity. Available for sale securities are separately identified as pledged to creditors if the creditor has the right to sell or re-pledge the collateral.
	The purchase or sale of securities is recognized on a trade date basis. Realized gains and losses on sales of securities are based upon specific identification of the security sold. A receivable or payable is recognized for subsequent transaction settlement. BOK Financial will periodically commit to purchase to-be-announced residential mortgage-backed securities. These commitments are carried at fair value if they are considered derivative contracts. Investment securities may be sold or transferred to trading or available for sale classification in certain limited circumstances specified in generally accepted accounting principles. Securities meeting certain criteria may also be transferred from the available for sale classification to the investment securities portfolio at fair value on the date of transfer. The unrealized gain or loss at the date of transfer is retained in accumulated other comprehensive income and in the carrying value of the investment securities portfolio. Such amounts are amortized over the estimated remaining life of the security as an adjustment to yield, offsetting the related amortization of the premium or accretion of the discount on the transferred securities.
	On a quarterly basis, the Company performs separate evaluations of impaired debt investment and available for sale securities and equity available for sale securities to determine if the decline in fair value below the amortized cost is other-than-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 and securities portfolio management. If the Company intends to sell or it is more likely than not that it will be required to sell the impaired debt security, a charge is recognized against earnings for the entire unrealized loss. For all impaired debt securities for which there is no intent or expected requirement to sell, the evaluation considers all available evidence to assess whether it is more likely than not that all amounts due would not be collected according to the security's contractual terms. Any expected credit loss due to the inability to collect all amounts due according to the security's contractual terms is recognized as a charge against earnings. Any remaining unrealized loss related to other factors would be recognized in other comprehensive income, net of taxes.
	For equity securities, management evaluates various factors including cause, severity and duration of the decline in value of the security and prospects for recovery, as well as the Company's intent and ability not to sell the security until the fair value exceeds amortized cost. If an unrealized loss is determined to be other-than-temporary, a charge is recognized against earnings for the difference between the security's amortized cost and fair value.
	BOK Financial has elected to carry certain non-trading securities at fair value with changes in fair value recognized in current period income. These securities are held with the intent that gains or losses will offset changes in the fair value of mortgage servicing rights or certain derivative instruments.
	Restricted equity securities represent equity interests the Company is required to hold in the Federal Reserve Banks and Federal Home Loan Banks. Restricted equity securities are carried at cost as theses securities do not have a readily determined fair value because ownership of these shares is restricted and they lack a market.
Derivatives Instruments [Policy Text Block]	Derivative Instruments
	Derivative instruments may be used by the Company as part of its interest rate risk management programs or may be offered to customers. All derivative instruments are carried at fair value. The determination of fair value of derivative instruments considers changes in interest rates, commodity prices and foreign exchange rates. Credit risk is also considered in determining fair value. Deterioration in the credit rating of customers or other counterparties reduces the fair value of asset contracts. Deterioration of our credit rating to below investment grade or the credit ratings of other counterparties could decrease the fair value of our derivative liabilities. Changes in fair value are generally reported in income as they occur.
	Derivative instruments used to manage interest rate risk consist primarily of interest rate swaps. These contracts modify the interest income or expense of certain assets or liabilities. Amounts receivable from or payable to counterparties are reported in interest income or expense using the accrual method. Changes in fair value of interest rate swaps are reported in other operating revenue - gain (loss) on derivatives, net.
	In certain circumstances, an interest rate swap may be designated as a fair value hedge and may qualify for hedge accounting. In these circumstances, changes in the full fair value of the hedged asset or liability, not only changes in fair value due to changes in the benchmark interest rate, are also recognized in earnings and may partially or completely offset changes in fair value of the interest rate swap. A fair value hedge is considered effective if the cumulative fair value adjustment of the interest rate swap is within a range of 80% to 120% of the cumulative change in the fair value of the hedged asset or liability. Any ineffectiveness, including ineffectiveness due to credit risk or ineffectiveness created when the fixed rate of the hedged asset or liability does not match the fixed rate of the interest rate swap, is recognized in earnings and reported in Gain (loss) on derivatives, net.
	Interest rate swaps may be designated as cash flow hedges of variable rate assets or liabilities, or of anticipated transactions. Changes in the fair value of interest rate swaps designated as cash flow hedges are recorded in accumulated other comprehensive income to the extent they are effective. The amount recorded in other comprehensive income is reclassified to earnings in the same periods as the hedged cash flows impact earnings. The ineffective portion of changes in fair value is reported in current earnings.
	If a derivative instrument that had been designated as a fair value hedge is terminated or if the hedge designation is removed or deemed to no longer be effective, the difference between the hedged items carrying value and its face amount is recognized into income over the remaining original hedge period. Similarly, if a derivative instrument that had been designated as a cash flow hedge is terminated or if the hedge designation is removed or deemed to no longer be effective, the amount remaining in accumulated other comprehensive income is reclassified to earnings in the same period as the hedged item.
	BOK Financial offers programs that permit its customers to manage various risks, including fluctuations in energy, cattle and other agricultural products, interest rates and foreign exchanges rates with derivative contracts. Derivative contracts are executed between the customers and BOK Financial. Offsetting contracts are executed between BOK Financial and other selected counterparties to minimize market risk from 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.
	When bilateral netting agreements 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 counterparty basis.
	Derivative contracts may also 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.
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 financial 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 loans guaranteed by U.S. government agencies, are as follows.
	Interest is accrued at the applicable interest rate on the outstanding principal amount. 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 90 days or more 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 received 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. 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, debt service ratio and other underwriting standards. Nonaccruing loans may also 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 an evaluation of available cash resources and collateral value. Internally risk graded loans are evaluated quarterly and charge-offs are taken in the quarter in which the loss is identified. Non-risk graded loans that are past due between 60 days and 180 days, based on the loan product type, are charged off. Loans to borrowers whose personal obligation has been discharged through Chapter 7 bankruptcy proceedings are charged off within 60 days of notice of the bankruptcy filing, regardless of payment status.
	Loan origination and commitment fees and direct loan acquisition and origination costs are deferred and amortized as an adjustment to yield over the life of the loan or over the commitment period, as applicable. Amortization does not anticipate loan prepayments. Net unamortized fees are recognized in full at time of payoff.
	Qualifying residential mortgage loans guaranteed by U.S. government agencies have been sold into GNMA pools. Under certain performance conditions specified in government programs, the Company has 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 Sheet. Guaranteed loans are considered to be 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 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 at the modified rate. U.S. government guaranteed loans may either be resold into GNMA pools after a performance period specified by the programs or foreclosed and conveyed to the guarantors.
Allowance for Loan Losses and Accrual for Off-Balance Sheet Credit Losses [Policy Text Block]	Allowance for Loan Losses and Accrual for Off-Balance Sheet Credit Risk
	The appropriateness of the allowance for loan losses and accrual for off-balance sheet credit risk (collectively "Allowance for Credit Losses") is assessed by management based on an ongoing quarterly evaluation of the probable estimated losses inherent in the portfolio, including probable losses on outstanding loans and unused commitments to provide financing.
	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 Credits Losses. Classes are based on the risk characteristics of the loans and the Company's method for monitoring and assessing credit risk.
	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 based on estimated loss rates by loan class and nonspecific allowances based on factors that affect more than one portfolio segment. There were no changes to the methodology for estimating general allowances during 2014 or 2013.
	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 a quarterly 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, modified in a troubled debt restructuring 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 loan's initial effective interest rate or the fair value of collateral for certain collateral dependent loans. The fair value of real property held as collateral 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 generally are not adjusted by the Company. Updated appraisals are obtained at least annually or more frequently if market conditions indicate collateral values may have declined. Collateral value of mineral rights is generally determined by our internal staff of engineers based on projected cash flows from proven oil and gas reserves under existing economic and operating conditions. The value of other collateral is generally determined by our special assets staff based on projected liquidation 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 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 an estimated loss rate by loan class. The appropriate historical gross loss rate for each loan class is determined by the greater of the current loss rate based on the most recent twelve months or a ten-year average gross loss rate. Recoveries are not directly considered in the estimation of historical 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, historical 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 weighted average risk grade. This comparison determines whether credit risk in each loan class is increasing or decreasing. Historical 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 a specific loan class which have not yet been represented in the historical 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 portfolio segment or loan class. These factors include trends in the economy in our primary lending areas, concentration in large-balance loans and other relevant factors.
	An accrual for off-balance sheet credit risk is included in Other liabilities. The appropriateness of the 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.
Transfers of Financial Assets [Policy Text Block]	Transfers of Financial Assets
	BOK Financial regularly transfers financial assets as part of its mortgage banking activities and periodically may transfer other financial assets. Transfers are recorded as sales when the criteria for surrender of control are met.
	The Company has elected to carry certain residential mortgage loans held for sale at fair value under the fair value option. Changes in fair value are recognized in net income as they occur. These loans are reported separately in the Consolidated Balance Sheets and changes in fair value are recorded in other operating revenue - mortgage banking revenue in the Consolidated Statements of Earnings.
	Fair value of conforming residential mortgage loans that will be sold to U.S. government agencies is based on sales commitments or market quotes considered Level 2 inputs. Fair value of mortgage loans that are unable to be sold to U.S. government agencies is based on Level 3 inputs using quoted prices of loans that are sold in securitization transactions with a liquidity discount applied. The fair value is corroborated with an independent third party on at least an annual basis.
	BOK Financial retains a repurchase obligation under underwriting representations and warranties related to residential mortgage loans transferred and generally retains the right to service the loans. The Company may incur a recourse obligation in limited circumstances. Separate accruals are recognized in Other liabilities in the Consolidated Balance Sheets for repurchase and recourse obligations. These reserves reflect the estimated amount of probable loss the bank will incur as a result of repurchasing a loan, indemnifications, and other settlement resolutions.
	Repurchases of loans with an origination defect that are also credit impaired are considered collateral dependent and are initially recognized at net realizable value (appraised value less the cost to sell). The difference between unpaid principal balance and net realizable value is not accreted. Repurchases of loans with an origination defect that are not credit impaired are carried at fair value as of the repurchase date. Interest income continues to accrue on these loans and the discount is accreted over the estimated life of the loan.
	The accrual for credit losses related to recourse loans for principal and interest is performed by Credit Administration and subject to oversight by the Finance/Credit Administration Allowance Committee while all other mortgage related accruals are reviewed monthly by the Mortgage Contingency Loss Accrual Committee which is subject to oversight by Finance.
	The Company may also choose to purchase GNMA loans once certain mandated delinquency criteria are met. The loans that are eligible and are chosen to be repurchased are carried at fair value based on expected cash flow discounted using the average agency guaranteed debenture rates, average actual principal loss rates and liquidity premium.
	The Company may also retain a residual interest in excess cash flows generated by the assets. All assets obtained, including cash, servicing rights and residual interests, and all liabilities incurred, including recourse obligations, are initially recognized at fair value, all assets transferred are derecognized and any gain or loss on the sale is recognized in earnings. Subsequently, servicing rights and residual interest are carried at fair value with changes in fair value recognized in earnings as they occur.
Real Estate and Other Repossessed Assets [Policy Text Block]	Real Estate and Other Repossessed Assets
	Real estate and other repossessed assets are acquired in partial or total forgiveness of loans. These assets are carried at the lower of cost, which is determined by fair value at date of foreclosure less estimated disposal costs, or current fair value less estimated disposal costs. Decreases in fair value below cost are recognized as asset-specific valuation allowances which may be reversed when supported by future increases in fair value. Fair values of real estate are based on “as is” appraisals which are updated at least annually or more frequently for certain asset types or assets located in certain distressed markets. Fair values based on appraisals are generally considered to be based on significant other observable inputs. The Company also considers decreases in listing price and other relevant information in quarterly evaluations and reduces the carrying value of real estate and other repossessed assets when necessary. Fair values based on list prices and other relevant information are generally considered to be based on significant unobservable inputs. Additional costs incurred to complete real estate and other repossessed assets may increase the carrying value, up to current fair value based on “as completed” appraisals. The fair value of mineral rights included in repossessed assets are generally determined by our internal staff of engineers based on projected cash flows from proven oil and gas reserves under existing economic and operating conditions. The value of other repossessed assets is generally determined by our special assets staff based on projected liquidation cash flows under current market conditions. Income generated by these assets is recognized as received. Operating expenses are recognized as incurred. Gains or losses on sales of real estate and other repossessed assets are based on the cash proceeds received less the cost basis of the asset, net of any valuation allowances.
Premises and Equipment [Policy Text Block]	Premises and Equipment
	Premises and equipment are carried at cost, including capitalized interest when appropriate, less accumulated depreciation and amortization. Depreciation and amortization are computed on a straight-line basis over the estimated useful lives of the assets or, for leasehold improvements, over the shorter of the estimated useful lives or remaining lease terms. Useful lives range from 5 years to 40 years for buildings and improvements, 3 years to 10 years for software and 3 years to 10 years for furniture and equipment. Construction in progress represents facilities construction and data processing systems projects underway that have not yet been placed into service. Depreciation and amortization begin once the assets are placed into service. Repair and maintenance costs, including software maintenance and enhancement costs, are charged to expense as incurred.
	Premises no longer used by the Company are transferred to real estate and other repossessed assets. The transferred amount is the lower of cost less accumulated depreciation or fair value less estimated disposal costs as of the transfer date.
	Rent expense for leased premises is recognized as incurred over the lease term. The effects of rent holidays, significant rent escalations and other adjustments to rent payments are recognized on a straight-line basis over the lease term.
Mortgage Servicing Rights [Policy Text Block]	Mortgage Servicing Rights
	Mortgage servicing rights may be purchased or may be recognized when mortgage loans are originated pursuant to an existing plan for sale or, if no such plan exists, when the mortgage loans are sold. All mortgage servicing rights are carried at fair value. Changes in the fair value are recognized in earnings as they occur.
	There is no active market for trading in mortgage servicing rights after origination. A cash flow model is used to determine fair value. Key assumptions and estimates, including projected prepayment speeds and assumed servicing costs, earnings on escrow deposits, ancillary income and discount rates, used by this model are based on current market sources. Assumptions used to value mortgage servicing rights are considered significant unobservable inputs. 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. Fair value estimates from outside sources are received at least annually to corroborate the results of the valuation model.
Federal and State Income Taxes [Policy Text Block]	Federal and State Income Taxes
	BOK Financial and its subsidiaries file consolidated tax returns. The subsidiaries provide for income taxes on a separate return basis and remit to BOK Financial amounts determined to be currently payable. BOK Financial is agent for its subsidiaries under the Company's tax sharing agreements and has no ownership rights to any refunds received for the benefit of its subsidiaries.
	Current income tax expense or benefit is based on an evaluation that considers estimated taxable income, tax credits, and statutory federal and state income tax rates. The amount of current income tax expense or benefit recognized in any period may differ from amounts reported to taxing authorities. Annually, tax returns are filed with each jurisdiction where the Company conducts business and recognized current income tax expense or benefit is adjusted to the filed tax returns.
	Deferred tax assets and liabilities are based upon the differences between the values of assets and liabilities as recognized in the financial statements and their related tax basis using enacted tax rates in effect for the year in which the differences are expected to be recovered or settled. A valuation allowance is provided when it is more likely than not that some portion of the entire deferred tax asset may not be realized based on taxes previously paid in net loss carry-back periods and other factors.
	BOK Financial has unrecognized tax benefits, which are included in accrued current income taxes payable, for the uncertain portion of recorded tax benefits and related interest. These uncertainties result from the application of complex tax laws, rules, regulations and interpretations, primarily in state taxing jurisdictions. Unrecognized tax benefits are assessed quarterly and may be adjusted through current income tax expense in future periods based on changing facts and circumstances, completion of examinations by taxing authorities or expiration of a statute of limitations. Estimated penalties and interest on uncertain tax positions are recognized in income tax expense.
Employee Benefit Plans [Policy Text Block]	Employee Benefit Plans
	BOK Financial sponsors a defined benefit cash balance pension plan (“Pension Plan”), qualified profit sharing plan (“Thrift Plan”) and employee health care plans. Pension Plan costs, which are based upon actuarial computations of current costs, are expensed annually. Unrecognized prior service cost and net gains or losses are amortized on a straight-line basis over a period not to exceed the average remaining service periods of the participants. Employer contributions to the Pension Plan are in accordance with Federal income tax regulations. Pension Plan benefits were curtailed as of April 1, 2006. No participants may be added to the Pension Plan and no additional service benefits will be accrued.
	BOK Financial recognizes the funded status of its employee benefit plans. For a pension plan, the funded status is the difference between the fair value of plan assets and the projected benefit obligation measured as of the fiscal year-end date. Adjustments required to recognize the Pension Plan's net funded status are made through accumulated other comprehensive income, net of deferred income taxes.
	Employer contributions to the Thrift Plan, which matches employee contributions subject to percentage and years of service limits, are expensed when incurred. BOK Financial recognizes the expense of health care benefits on the accrual method.
Shared-Based Compensation Plans [Policy Text Block]	Share-Based Compensation Plans
	BOK Financial awards stock options and non-vested common shares as compensation to certain officers. Compensation cost is generally fixed based on the grant date fair value of the award. The grant date fair value of stock options is based on the Black-Scholes option pricing model. Stock options generally have graded vesting over 7 years. Each tranche is considered a separate award for valuation and compensation cost recognition. Grant date fair value of non-vested shares is based on the current market value of BOK Financial common stock. Non-vested shares awarded prior to 2013 generally cliff vest in 5 years. Non-vested shares awarded since January 1, 2013 generally cliff vest in 3 years and are subject to a two year holding period after vesting. Shares awarded under the Executive Incentive Plan are subject to downward adjustment at the discretion of the Incentive Compensation Committee. Compensation cost of non-vested shares granted under the Executive Incentive Plan may vary based on changes in the fair value of BOKF common shares.
	Compensation cost is recognized as expense over the service period, which is generally the vesting period. Expense is reduced for estimated forfeitures over the vesting period and adjusted for actual forfeitures as they occur. Stock-based compensation awarded to certain officers has performance conditions that affect the number of awards granted. Compensation cost is adjusted based on the probable outcome of the performance conditions. Excess tax benefits from share-based payments recognized in capital surplus are determined by the excess of tax benefits recognized over the tax effect of compensation cost recognized. Dividends on non-vested shares that are not subject to forfeiture are recognized as expense.
Other Operating Revenue [Policy Text Block]	Other Operating Revenue
	Fees and commission revenue is recognized at the time the related services are provided or products are sold and may be accrued when necessary. Accrued fees and commissions are reversed against revenue if amounts are subsequently deemed to be uncollectible. Revenue is recognized on a gross basis whenever we have primary responsibility and risk in providing the services or products to our customers and on a net basis whenever we act as a broker for products or services of others.
	Brokerage and trading revenue includes changes in the fair value of securities held for trading purposes and derivatives held for customer risk management programs, including credit losses on trading securities and derivatives, commissions earned from the retail sale of securities, mutual funds and other financial instruments, and underwriting and financial advisory fees.
	Transaction card revenue includes merchant discounts fees, electronic funds transfer network fees and check card fees. Merchant discount fees represent fees paid by customers for account management and electronic processing of transactions. Merchant discount fees are recognized at the time the customer's transactions are processed or other services are performed. The Company also maintains the TransFund electronic funds transfer network for the benefit of its members, which includes the Bank. Electronic funds transfer fees are recognized as electronic transactions processed on behalf of its members. Check card fees represent interchange fees paid by a merchant bank for transactions processed from cards issued by the Company. Check card fees are recognized when transactions are processed.
	Trust fees and commissions include revenue from asset management, custody, recordkeeping, investment advisory and administration services. Revenue is recognized on an accrual basis at the time the services are performed and may be based on either the fair value of the account or the service provided.
	Deposit service charges and fees are recognized at least quarterly in accordance with a published deposit account agreements and disclosure statements for retail accounts or contractual agreements for commercial accounts. Item charges for overdraft or non-sufficient funds items are recognized as items are presented for payment. Account balance charges and activity fees are accrued monthly and collected in arrears. Commercial account activity fees may be offset by an earnings credit based on account balances.
Newly Adopted and Pending Accounting Pronouncements [Policy Text Block]	Newly Adopted and Pending Accounting Pronouncements
	Financial Accounting Standards Board ("FASB")
	FASB Accounting Standards Update No. 2013-08, Financial Services – Investment Companies (Topic 946): Amendments to the Scope, Measurement, and Disclosure Requirements ("ASU 2013-08")
	On June 7, 2013, the FASB issued ASU 2013-08 which amends the criteria an entity would need to meet to qualify as an investment company under ASC 946, Financial Services - Investment Companies. ASU 2013-08 also provides additional implementation guidance for the assessment and requires additional disclosures. ASU 2013-08 was effective prospectively during interim and annual periods beginning after December 15, 2013, with early adoption prohibited. The adoption of ASU 2013-08 did not have a material impact on the Company's consolidated financial statements.
	FASB Accounting Standards Update No. 2014-01, Accounting for Investments in Qualified Affordable Housing Projects ("ASU 2014-01")
	On January 15, 2014, the FASB issued ASU 2014-01 to simplify the amortization method an entity uses and modify the criteria to elect a measurement and presentation alternative, including the simplified amortization method, for certain investments in qualified affordable housing projects. This alternative permits the entity to present the investment's performance net of the related tax benefits as part of income tax expense. ASU 2014-01 was effective for the Company for interim and annual periods beginning after December 15, 2014. Adoption of ASU 2014-01 may affect income statement presentation, but otherwise did not have a material impact on the Company's consolidated financial statements.
	FASB Accounting Standards Update No. 2014-04, Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans Upon Foreclosure ("ASU 2014-04")
	On January 17, 2014, the FASB issued ASU 2014-04 to clarify when an entity is considered to have obtained physical possession (from an in-substance possession or foreclosure) of a residential real estate property collateralizing a mortgage loan. Upon physical possession of such real property, an entity is required to reclassify the nonperforming mortgage loan to other real estate owned. ASU 2014-04 was effective for the Company for interim and annual periods beginning after December 15, 2014. Adoption of ASU 2014-04 did not have a material impact on the Company's consolidated financial statements.
	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, 2016, 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. 2014-14, Classification of Certain Government-Guaranteed Mortgage Loans Upon Foreclosure ("ASU 2014-14")
	On August 8, 2014, the FASB issued ASU 2014-14 to give greater consistency in the classification of government-guaranteed loans upon foreclosure. ASU 2014-14 applies to all loans that contain a government guarantee that is not separable from the loan or for which the creditor has both the intent and ability to recover a fixed amount under the guarantee by conveying the property to the guarantor. Upon foreclosure, the creditor should reclassify the mortgage loan to an other receivable that is separate from loans and should measure the receivable at the amount of the loan balance expected to be recovered from the guarantor. ASU 2014-14 was effective for the Company for interim and annual periods beginning after December 15, 2014. At January 1, 2015, approximately $50 million of real estate owned was reclassified from Real estate and other repossessed assets to Receivables on the balance sheet with adoption of ASC 2014-14.
	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 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 is effective for annual periods beginning after December 15, 2015, and interim periods within those annual periods. Early adoption is permitted. Adoption of ASU 2014-16 is not expected to 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 will be effective for periods beginning after December 15, 2015 for public companies. Early adoption is permitted, including adoption in an interim period. The Company is evaluating the impact the adoption of ASU 2015-02 will have on the Company's financial statements.

Securities_Tables

Securities (Tables)	12 Months Ended
	Dec. 31, 2014
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):
			December 31, 2014								December 31, 2013
			Fair Value				Net Unrealized Gain (Loss)				Fair Value				Net Unrealized Gain (Loss)
	U.S. government agency debentures		$	85,092			$	(62	)		$	34,120			$	77
	U.S. government agency residential mortgage-backed securities		31,199				269				21,011				123
	Municipal and other tax-exempt securities		38,951				18				27,350				(182		)
	Other trading securities		33,458				(38		)		9,135				(7		)
	Total		$	188,700			$	187			$	91,616			$	11
Investment Securities (Held-to-Maturity) [Table Text Block]	The amortized cost and fair values of investment securities are as follows (in thousands):
			December 31, 2014
			Amortized				Carrying				Fair				Gross Unrealized2
			Cost				Value1				Value				Gain				Loss
	Municipal and other tax-exempt securities		$	405,090			$	405,090			$	408,344			$	4,205			$	(951	)
	U.S. government agency residential mortgage-backed securities – Other		35,135				35,750				37,463				1,713				—
	Other debt securities		211,520				211,520				227,819				16,956				(657		)
	Total		$	651,745			$	652,360			$	673,626			$	22,874			$	(1,608	)
	1	Carrying value includes $615 thousand of net unrealized gain which remains in Accumulated other comprehensive income (“AOCI”) in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.
	2	Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets.
			December 31, 2013
			Amortized				Carrying				Fair				Gross Unrealized2
			Cost				Value1				Value				Gain				Loss
	Municipal and other tax-exempt securities		$	440,187			$	440,187			$	439,870			$	2,452			$	(2,769	)
	U.S. government agency residential mortgage-backed securities – Other		48,351				50,182				51,864				1,738				(56		)
	Other debt securities		187,509				187,509				195,393				8,497				(613		)
	Total		$	676,047			$	677,878			$	687,127			$	12,687			$	(3,438	)
	1	Carrying value includes $1.8 million of net unrealized gain which remains in AOCI in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.
	2	Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets.
	In 2011, the Company transferred certain U.S. government agency residential mortgage-backed securities from the available for sale portfolio to the investment securities (held-to-maturity) portfolio as the Company has the positive intent and ability to hold these securities to maturity. No gains or losses were recognized in the Consolidated Statement of Earnings at the time of the transfer. Transfers of debt securities into the investment securities portfolio (held-to-maturity) are made at fair value at the date of transfer. The unrealized holding gain or loss at the date of transfer is retained in Accumulated Other Comprehensive Income and in the carrying value of the investment securities portfolio. Such amounts are amortized over the estimated remaining life of the security as an adjustment to yield, offsetting the related amortization of the premium or accretion of the discount on the transferred securities. At the time of transfer, the fair value totaled $131 million, amortized cost totaled $118 million and the pretax unrealized gain totaled $13 million.
	The amortized cost and fair values of investment securities at December 31, 2014, by contractual maturity, are as shown in the following table (dollars in thousands):
			Less than				One to				Six to				Over				Total				Weighted
			One Year				Five Years				Ten Years				Ten Years								Average
																							Maturity²
	Municipal and other tax-exempt securities:
	Carrying value		$	44,255			$	299,934			$	22,429			$	38,472			$	405,090			3.8
	Fair value		44,381				300,434				22,666				40,863				408,344
	Nominal yield¹		1.71		%		1.74		%		3.91		%		5.37		%		2.2		%
	Other debt securities:
	Carrying value		$	15,918			$	37,726			$	58,338			$	99,538			$	211,520			9.18
	Fair value		15,925				38,509				61,430				111,955				227,819
	Nominal yield		3.32		%		4.96		%		5.19		%		6.12		%		5.45		%
	Total fixed maturity securities:
	Carrying value		$	60,173			$	337,660			$	80,767			$	138,010			$	616,610			5.65
	Fair value		60,306				338,943				84,096				152,818				636,163
	Nominal yield		2.14		%		2.1		%		4.83		%		5.91		%		3.31		%
	Residential mortgage-backed securities:
	Carrying value																		$	35,750			³
	Fair value																		37,463
	Nominal yield4																		2.74		%
	Total investment securities:
	Carrying value																		$	652,360
	Fair value																		673,626
	Nominal yield																		3.28		%
	1	Calculated on a taxable equivalent basis using a 39% 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 2.8 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):
			December 31, 2014
			Amortized				Fair				Gross Unrealized1
			Cost				Value				Gain				Loss				OTTI²
	U.S. Treasury securities		$	1,005			$	1,005			$	—			$	—			$	—
	Municipal and other tax-exempt securities		63,018				63,557				1,280				(741		)		—
	Residential mortgage-backed securities:
	U. S. government agencies:
	FNMA		3,932,200				3,997,428				71,200				(5,972		)		—
	FHLMC		1,810,476				1,836,870				29,043				(2,649		)		—
	GNMA		801,820				807,443				8,240				(2,617		)		—
	Other		4,808				5,143				335				—				—
	Total U.S. government agencies		6,549,304				6,646,884				108,818				(11,238		)		—
	Private issue:
	Alt-A loans		65,582				71,952				6,677				—				(307		)
	Jumbo-A loans		88,778				94,005				5,584				—				(357		)
	Total private issue		154,360				165,957				12,261				—				(664		)
	Total residential mortgage-backed securities		6,703,664				6,812,841				121,079				(11,238		)		(664		)
	Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,064,091				2,048,609				4,437				(19,919		)		—
	Other debt securities		9,438				9,212				26				(252		)		—
	Perpetual preferred stock		22,171				24,277				2,183				(77		)		—
	Equity securities and mutual funds		18,603				19,444				871				(30		)		—
	Total		$	8,881,990			$	8,978,945			$	129,876			$	(32,257	)		$	(664	)
	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, 2013
			Amortized				Fair				Gross Unrealized¹
			Cost				Value				Gain				Loss				OTTI²
	U.S. Treasury securities		$	1,042			$	1,042			$	—			$	—			$	—
	Municipal and other tax-exempt securities		73,232				73,775				1,606				(1,063		)		—
	Residential mortgage-backed securities:
	U. S. government agencies:
	FNMA		4,224,327				4,232,332				68,154				(60,149		)		—
	FHLMC		2,308,341				2,293,943				25,813				(40,211		)		—
	GNMA		1,151,225				1,152,128				9,435				(8,532		)		—
	Other		36,296				37,607				1,311				—				—
	Total U.S. government agencies		7,720,189				7,716,010				104,713				(108,892		)		—
	Private issue:
	Alt-A loans		104,559				107,212				4,386				—				(1,733		)
	Jumbo-A loans		109,622				113,887				4,974				—				(709		)
	Total private issue		214,181				221,099				9,360				—				(2,442		)
	Total residential mortgage-backed securities		7,934,370				7,937,109				114,073				(108,892		)		(2,442		)
	Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,100,146				2,055,804				1,042				(45,384		)		—
	Other debt securities		35,061				35,241				368				(188		)		—
	Perpetual preferred stock		22,171				22,863				705				(13		)		—
	Equity securities and mutual funds		19,069				21,328				2,326				(67		)		—
	Total		$	10,185,091			$	10,147,162			$	120,120			$	(155,607	)		$	(2,442	)
	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 December 31, 2014, by contractual maturity, are as shown in the following table (dollars in thousands):
		Less than				One to				Six to				Over				Total				Weighted
		One Year				Five Years				Ten Years				Ten Years6								Average
																						Maturity5
	U.S. Treasury securities:
	Amortized cost	$	1,005			$	—			$	—			$	—			$	1,005			0.13
	Fair value	1,005				—				—				—				1,005
	Nominal yield	0.24		%		—		%		—		%		—		%		0.24		%
	Municipal and other tax-exempt securities:
	Amortized cost	7,134				29,750				2,288				23,846				63,018				8.27
	Fair value	7,197				30,603				2,496				23,261				63,557
	Nominal yield¹	3.68		%		4.05		%		6.48		%		1.92		%		3.29		%
	Commercial mortgage-backed securities:
	Amortized cost	—				912,178				808,792				343,121				2,064,091				8.56
	Fair value	—				906,081				803,324				339,204				2,048,609
Nominal yield	—		%		1.43		%		1.68		%		1.33		%		1.51		%
Other debt securities:
Amortized cost	5,038				—				—				4,400				9,438				15.38
Fair value	5,065				—				—				4,147				9,212
Nominal yield	2.12		%		—		%		—		%		1.71		%		1.93		%
Total fixed maturity securities:
Amortized cost	$	13,177			$	941,928			$	811,080			$	371,367			$	2,137,552			8.58
Fair value	13,267				936,684				805,820				366,612				2,122,383
Nominal yield	2.82		%		1.52		%		1.69		%		1.38		%		1.57		%
Residential mortgage-backed securities:
Amortized cost																	$	6,703,664			2
Fair value																	6,812,841
Nominal yield4																	1.95		%
Perpetual preferred stock. equity securities and mutual funds:
Amortized cost																	$	40,774			³
Fair value																	43,721
Nominal yield																	1.28		%
Total available-for-sale securities:
Amortized cost																	$	8,881,990
Fair value																	8,978,945
Nominal yield																	1.85		%
1	Calculated on a taxable equivalent basis using a 39% effective tax rate.
2	The average expected lives of mortgage-backed securities were 3.4 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):
	Year Ended December 31,
	2014				2013				2012
Proceeds	$	2,664,740			$	2,436,093			1,744,662
Gross realized gains	24,923				25,711				41,191
Gross realized losses	(23,384		)		(14,991		)		(7,346	)
Related federal and state income tax expense	599				4,170				13,166
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):
		December 31,
		2014				2013
	Investment:
	Carrying value	$	63,495			$	89,087
	Fair value	65,855				91,804
	Available for sale:
	Amortized cost	5,855,220				5,171,782
	Fair value	5,893,972				5,133,530
Schedule of Unrealized Loss on Investments [Table Text Block]	Temporarily Impaired Securities as of December 31, 2014
	(In thousands)
			Number of Securities			Less Than 12 Months								12 Months or Longer								Total
						Fair				Unrealized				Fair				Unrealized				Fair				Unrealized
						Value				Loss				Value				Loss				Value				Loss
	Investment:
	Municipal and other tax-exempt securities		78			$	112,677			$	426			$	60,076			$	525			$	172,753			$	951
	Other debt securities		84			31,274				637				761				20				32,035				657
	Total investment securities		162			$	143,951			$	1,063			$	60,837			$	545			$	204,788			$	1,608
			Number of Securities			Less Than 12 Months								12 Months or Longer								Total
						Fair				Unrealized				Fair				Unrealized				Fair				Unrealized
						Value				Loss				Value				Loss				Value				Loss
	Available for sale:
	Municipal and other tax-exempt securities		22			$	10,838			$	12			$	12,176			$	729			$	23,014			$	741
	Residential mortgage-backed securities:
	U. S. government agencies:
	FNMA		24			257,854				547				454,394				5,425				712,248				5,972
	FHLMC		16			62,950				37				310,834				2,612				373,784				2,649
	GNMA		5			8,550				12				128,896				2,605				137,446				2,617
	Total U.S. agencies		45			329,354				596				894,124				10,642				1,223,478				11,238
	Private issue1:
	Alt-A loans		4			11,277				307				—				—				11,277				307
	Jumbo-A loans		8			—				—				10,020				357				10,020				357
	Total private issue		12			11,277				307				10,020				357				21,297				664
	Total residential mortgage-backed securities		57			340,631				903				904,144				10,999				1,244,775				11,902
	Commercial mortgage-backed securities guaranteed by U.S. government agencies		104			223,106				454				1,238,376				19,465				1,461,482				19,919
	Other debt securities		2			—				—				4,150				252				4,150				252
	Perpetual preferred stock		2			2,898				77				—				—				2,898				77
	Equity securities and mutual funds		68			—				—				1,205				30				1,205				30
	Total available for sale securities		255			$	577,473			$	1,446			$	2,160,051			$	31,475			$	2,737,524			$	32,921
	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, 2013
	(In thousands)
			Number of Securities			Less Than 12 Months								12 Months or Longer								Total
						Fair				Unrealized				Fair				Unrealized				Fair				Unrealized
						Value				Loss				Value				Loss				Value				Loss
	Investment:
	Municipal and other tax- exempt securities		107			$	166,382			$	1,921			$	53,073			$	848			$	219,455			$	2,769
	U.S. Agency residential mortgage-backed securities – Other		2			15,224				56				—				—				15,224				56
	Other debt securities		30			10,932				549				777				64				11,709				613
	Total investment securities		139			$	192,538			$	2,526			$	53,850			$	912			$	246,388			$	3,438
			Number of Securities			Less Than 12 Months								12 Months or Longer								Total
						Fair				Unrealized				Fair				Unrealized				Fair				Unrealized
						Value				Loss				Value				Loss				Value				Loss
	Available for sale:
	Municipal and other tax-exempt securities		27			$	13,286			$	245			$	17,805			$	818			$	31,091			$	1,063
	Residential mortgage-backed securities:
	U. S. government agencies:
	FNMA		81			2,281,491				60,149				—				—				2,281,491				60,149
	FHLMC		50			1,450,588				40,211				—				—				1,450,588				40,211
	GNMA		27			647,058				8,532				—				—				647,058				8,532
	Total U.S. agencies		158			4,379,137				108,892				—				—				4,379,137				108,892
	Private issue1:
	Alt-A loans		7			11,043				756				30,774				977				41,817				1,733
	Jumbo-A loans		9			14,642				709				—				—				14,642				709
	Total private issue		16			25,685				1,465				30,774				977				56,459				2,442
	Total residential mortgage-backed securities		174			4,404,822				110,357				30,774				977				4,435,596				111,334
	Commercial mortgage-backed securities guaranteed by U.S. government agencies		123			1,800,717				45,302				2,286				82				1,803,003				45,384
	Other debt securities		3			4,712				188				—				—				4,712				188
	Perpetual preferred stock		1			4,988				13				—				—				4,988				13
	Equity securities and mutual funds		118			2,070				67				—				—				2,070				67
	Total available for sale securities		446			$	6,230,595			$	156,172			$	50,865			$	1,877			$	6,281,460			$	158,049
	1	Includes securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income.
Schedule of Investments by Lowest Current Credit Rating [Table Text Block]	At December 31, 2014, 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																Below Investment Grade
			U.S. Govt/GSE 1																A - BBB												Not Rated				Total
			Carrying				Fair				Carrying				Fair				Carrying				Fair				Carrying		Fair		Carrying		Fair		Carrying		Fair
			Value				Value				Value				Value				Value				Value				Value		Value		Value		Value		Value		Value
	Investment:
	Municipal and other tax-exempt		$	—			$	—			$	264,326			$	264,651			$	13,676			$	13,806			$	—	$	—	$	127,088	$	129,887	$	405,090	$	408,344
	U.S. government agency mortgage-backed securities -- Other		35,750				37,463				—				—				—				—				—		—		—		—		35,750		37,463
	Other debt securities		—				—				160,353				176,915				—				—				—		—		51,167		50,904		211,520		227,819
	Total investment securities		$	35,750			$	37,463			$	424,679			$	441,566			$	13,676			$	13,806			$	—	$	—	$	178,255	$	180,791	$	652,360	$	673,626
			U.S. Govt / GSE 1								AAA - AA																Below Investment Grade				Not Rated				Total
																			A - BBB
			Amortized Cost				Fair				Amortized Cost				Fair Value				Amortized Cost				Fair Value				Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair
							Value																														Value
	Available for Sale:
	U.S. Treasury		$	1,005			$	1,005			$	—			$	—			$	—			$	—			$	—	$	—	$	—	$	—	$	1,005	$	1,005
	Municipal and other tax-exempt		—				—				40,511				41,579				11,053				10,516				—		—		11,454		11,462		63,018		63,557
	Residential mortgage-backed securities:
	U. S. government agencies:
	FNMA		3,932,200				3,997,428				—				—				—				—				—		—		—		—		3,932,200		3,997,428
	FHLMC		1,810,476				1,836,870				—				—				—				—				—		—		—		—		1,810,476		1,836,870
	GNMA		801,820				807,443				—				—				—				—				—		—		—		—		801,820		807,443
	Other		4,808				5,143				—				—				—				—				—		—		—		—		4,808		5,143
	Total U.S. government agencies		6,549,304				6,646,884				—				—				—				—				—		—		—		—		6,549,304		6,646,884
	Private issue:
	Alt-A loans		—				—				—				—				—				—				65,582		71,952		—		—		65,582		71,952
	Jumbo-A loans		—				—				—				—				—				—				88,778		94,005		—		—		88,778		94,005
	Total private issue		—				—				—				—				—				—				154,360		165,957		—		—		154,360		165,957
	Total residential mortgage-backed securities		6,549,304				6,646,884				—				—				—				—				154,360		165,957		—		—		6,703,664		6,812,841
	Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,064,091				2,048,609				—				—				—				—				—		—		—		—		2,064,091		2,048,609
	Other debt securities		—				—				4,400				4,149				5,038				5,063				—		—		—		—		9,438		9,212
	Perpetual preferred stock		—				—				—				—				11,406				12,508				10,765		11,769		—		—		22,171		24,277
	Equity securities and mutual funds		—				—				4				517				—				—				—		—		18,599		18,927		18,603		19,444
	Total available for sale securities		$	8,614,400			$	8,696,498			$	44,915			$	46,245			$	27,497			$	28,087			$	165,125	$	177,726	$	30,053	$	30,389	$	8,881,990	$	8,978,945
	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.
Schedule of Primary Assumptions Used in Other-Than-Temporary Impairment Evaluation [Table Text Block]
		December 31,
		2014		2013
	Unemployment rate	Held constant at 5.6% over the next 12 months and remain at 5.6% thereafter.		Increasing to 7.3% over the next 12 months and remain at 7.3% thereafter
	Housing price appreciation/depreciation	Starting with current depreciated housing prices based on information derived from the FHFA1, appreciating 3.2% over the next 12 months, then flat for the following 12 months and then appreciating at 2% per year thereafter.		Starting with current depreciated housing prices based on information derived from the FHFA1, appreciating 4% over the next 12 months, then flat for the following 12 months and then appreciating at 2% 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.
	Discount rates	Estimated cash flows were discounted at rates that range from 2.00% to 6.25% based on our current expected yields.		Estimated cash flows were discounted at rates that range from 2.00% to 6.25% based on our current expected yields.
Schedule of Privately Issued Residential Mortgage-backed Securities [Table Text Block]
														Credit Losses Recognized
														Year Ended
														December 31, 2014							Life-to-date
			Number of Securities			Amortized Cost				Fair Value				Number of			Amount				Number of Securities			Amount
														Securities
	Alt-A		14			$	65,582			$	71,952			—			$	—			14			$	36,127
	Jumbo-A		30			88,778				94,005				—			—				29			18,220
	Total		44			$	154,360			$	165,957			—			$	—			43			$	54,347
Rollforward Other-than-temporary Impairment Credit Losses Recognized in Earnings [Table Text Block]
			Year Ended December 31,
			2014				2013				2012
	Balance of credit-related OTTI recognized on available for sale debt, beginning of period		$	67,346			$	75,228			$	76,131
	Additions for credit-related OTTI not previously recognized		—				618				113
	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		—				320				6,780
	Reductions for change in intent to hold before recovery		—				(3,589		)		—
	Sales		(12,999		)		(5,231		)		(7,796		)
	Balance of credit-related OTTI recognized on available for sale debt securities, end of period		$	54,347			$	67,346			$	75,228
Schedule of 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):
			December 31, 2014								December 31, 2013
			Fair Value				Net Unrealized Gain (Loss)				Fair Value				Net Unrealized Gain (Loss)
	U.S. agency residential mortgage-backed securities		$	311,597			$	1,624			$	157,431			$	(8,378	)
	Other securities		—				—				9,694				209
	Total		$	311,597			$	1,624			$	167,125			$	(8,169	)
Schedule of Cost Method Investments [Table Text Block]
		December 31,
		2014				2013
	Federal Reserve Bank stock	$	35,018			$	33,742
	Federal Home Loan Bank stock	106,476				51,498
	Total	$	141,494			$	85,240

Derivatives_Tables

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2014
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 December 31, 2014 (in thousands):
			Assets
			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		$	13,313,615	$	94,719	$	(39,359	)	$	55,360		$	—		$	55,360
	Interest rate swaps		1,165,568		35,405		—			35,405			—			35,405
	Energy contracts		579,801		141,166		(48,624		)	92,542			(71,310		)	21,232
	Agricultural contracts		47,657		1,904		(1,256		)	648			—			648
	Foreign exchange contracts		290,965		238,395		—			238,395			—			238,395
	Equity option contracts		194,960		10,834		—			10,834			—			10,834
	Total customer risk management programs		15,592,566		522,423		(89,239		)	433,184			(71,310		)	361,874
	Interest rate risk management programs		—		—		—			—			—			—
	Total derivative contracts		$	15,592,566	$	522,423	$	(89,239	)	$	433,184		$	(71,310	)	$	361,874
			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		$	13,471,880	$	91,949	$	(39,359	)	$	52,590		$	(52,290	)	$	300
	Interest rate swaps		1,165,568		35,599		—			35,599			(18,717		)	16,882
	Energy contracts		579,801		142,839		(48,624		)	94,215			—			94,215
	Agricultural contracts		47,418		1,908		(1,256		)	652			(596		)	56
	Foreign exchange contracts		290,856		238,118		—			238,118			(6,703		)	231,415
	Equity option contracts		194,960		10,834		—			10,834			—			10,834
	Total customer risk management programs		15,750,483		521,247		(89,239		)	432,008			(78,306		)	353,702
	Interest rate risk management programs		47,000		852		—			852			—			852
	Total derivative contracts		$	15,797,483	$	522,099	$	(89,239	)	$	432,860		$	(78,306	)	$	354,554
	1	Notional amounts for commodity contracts are converted into dollar-equivalent amounts based on dollar prices at the inception of the contract.
	When bilateral netting agreements 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 counterparty basis.
	Derivative contracts may also 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. As of December 31, 2014, a decrease in credit rating to below investment grade would increase our obligation to post cash margin on existing contracts by approximately $19 million.
	The following table summarizes the fair values of derivative contracts recorded as “derivative contracts” assets and liabilities in the balance sheet at December 31, 2013 (in thousands):
			Assets
			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		$	10,817,159	$	102,921	$	(46,623	)	$	56,298		$	—		$	56,298
	Interest rate swaps		1,283,379		44,124		—			44,124			(731		)	43,393
	Energy contracts		1,263,266		48,078		(29,957		)	18,121			(2,575		)	15,546
	Agricultural contracts		100,886		2,060		(1,166		)	894			—			894
	Foreign exchange contracts		136,543		136,543		—			136,543			(2,147		)	134,396
	Equity option contracts		210,816		17,957		—			17,957			(3,472		)	14,485
	Total customer risk management programs		13,812,049		351,683		(77,746		)	273,937			(8,925		)	265,012
	Interest rate risk management programs		—		—		—			—			—			—
	Total derivative contracts		$	13,812,049	$	351,683	$	(77,746	)	$	273,937		$	(8,925	)	$	265,012
			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		$	10,982,049	$	99,830	$	(46,623	)	$	53,207		$	—		$	53,207
	Interest rate swaps		1,283,379		44,377		—			44,377			(17,853		)	26,524
	Energy contracts		1,216,426		46,095		(29,957		)	16,138			(6,055		)	10,083
	Agricultural contracts		99,191		2,009		(1,166		)	843			—			843
	Foreign exchange contracts		135,237		135,237		—			135,237			(294		)	134,943
	Equity option contracts		210,816		17,957		—			17,957			—			17,957
	Total customer risk management programs		13,927,098		345,505		(77,746		)	267,759			(24,202		)	243,557
	Interest rate risk management programs		47,000		3,628		—			3,628			—			3,628
	Total derivative contracts		$	13,974,098	$	349,133	$	(77,746	)	$	271,387		$	(24,202	)	$	247,185
	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 Consolidated Statement of Earnings (in thousands):
			Year Ended December 31,
			2014				2013						2012
			Brokerage		Gain (Loss)		Brokerage			Gain (Loss)			Brokerage			Gain (Loss)
			and Trading Revenue		on Derivatives, Net		and Trading			on Derivatives,			and Trading			on Derivatives,
							Revenue			Net			Revenue			Net
	Customer risk management programs:
	Interest rate contracts
	To-be-announced residential mortgage-backed securities		$	27,007	$	—	$	29,614		$	—		$	25,509		$	—
	Interest rate swaps		2,494		—		2,991			—			3,458			—
	Energy contracts		6,572		—		8,303			—			8,171			—
	Agricultural contracts		146		—		357			—			382			—
	Foreign exchange contracts		1,581		—		687			—			612			—
	Equity option contracts		—		—		—			—			—			—
	Total customer risk management programs		37,800		—		41,952			—			38,132			—
	Interest rate risk management programs		—		2,776		—			(4,367		)	—			(301		)
	Total derivative contracts		$	37,800	$	2,776	$	41,952		$	(4,367	)	$	38,132		$	(301	)

Loans_and_Allowances_for_Credi1

Loans and Allowances for Credit Losses (Tables)	12 Months Ended
	Dec. 31, 2014
Loans Receivable, Net [Abstract]
Schedule of the Loans by Portfolio Segment [Table Text Block]	The portfolio segments of the loan portfolio are as follows (in thousands):
			December 31, 2014																December 31, 2013
			Fixed				Variable				Non-accrual				Total				Fixed				Variable				Non-accrual			Total
			Rate				Rate												Rate				Rate
	Commercial		$	1,736,976			$	7,345,167			$	13,527			$	9,095,670			$	1,637,620			$	6,288,841			$	16,760		$	7,943,221
	Commercial real estate		721,513				1,988,080				18,557				2,728,150				770,908				1,603,595				40,850			2,415,353
	Residential mortgage		1,698,620				202,771				48,121				1,949,512				1,783,614				226,092				42,320			2,052,026
	Consumer		102,865				331,274				566				434,705				135,494				244,951				1,219			381,664
	Total		$	4,259,974			$	9,867,292			$	80,771			$	14,208,037			$	4,327,636			$	8,363,479			$	101,149		$	12,792,264
	Accruing loans past due (90 days)1														$	125														$	1,415
	Foregone interest on nonaccrual loans														$	8,170														$	9,815
	1	Excludes residential mortgage loans guaranteed by agencies of the U.S. government
Rollforward of Allowance For Loan Losses And Accrual for Off-Balnace Sheet Credit Losses [Table Text Block]	The activity in the allowance for loan losses and the accrual for off-balance sheet credit risk related to loan commitments and standby letters of credit for the year ended December 31, 2014 is summarized as follows (in thousands):
			Commercial				Commercial Real Estate				Residential Mortgage				Consumer				Nonspecific Allowance				Total
	Allowance for loan losses:
	Beginning balance		$	79,180			$	41,573			$	29,465			$	6,965			$	28,213			$	185,396
	Provision for loan losses		9,561				(4,084		)		(3,559		)		(892		)		(168		)		858
	Loans charged off		(3,569		)		(2,047		)		(4,448		)		(6,168		)		—				(16,232		)
	Recoveries		5,703				7,003				2,000				4,328				—				19,034
	Ending balance		$	90,875			$	42,445			$	23,458			$	4,233			$	28,045			$	189,056
	Accrual for off-balance sheet credit risk:
	Beginning balance		$	119			$	1,876			$	90			$	3			$	—			$	2,088
	Provision for off-balance sheet credit risk		356				(1,169		)		(62		)		17				—				(858		)
	Ending balance		$	475			$	707			$	28			$	20			$	—			$	1,230
	Total provision for credit losses		$	9,917			$	(5,253	)		$	(3,621	)		$	(875	)		$	(168	)		$	—
	The activity in the allowance for loan losses and the accrual for off-balance sheet credit risk related to loan commitments and standby letters of credit for the year ended December 31, 2013 is summarized as follows (in thousands):
			Commercial				Commercial Real Estate				Residential Mortgage				Consumer				Nonspecific Allowance				Total
	Allowance for loan losses:
	Beginning balance		$	65,280			$	54,884			$	41,703			$	9,453			$	44,187			$	215,507
	Provision for loan losses		12,747				(16,886		)		(8,043		)		83				(15,974		)		(28,073		)
	Loans charged off		(6,335		)		(5,845		)		(5,753		)		(7,349		)		—				(25,282		)
	Recoveries		7,488				9,420				1,558				4,778				—				23,244
	Ending balance		$	79,180			$	41,573			$	29,465			$	6,965			$	28,213			$	185,396
	Accrual for off-balance sheet credit risk:
	Beginning balance		$	475			$	1,353			$	78			$	9			$	—			$	1,915
	Provision for off-balance sheet credit risk		(356		)		523				12				(6		)		—				173
	Ending balance		$	119			$	1,876			$	90			$	3			$	—			$	2,088
	Total provision for credit losses		$	12,391			$	(16,363	)		$	(8,031	)		$	77			$	(15,974	)		$	(27,900	)
	The activity in the allowance for loan losses and the accrual for off-balance sheet credit risk related to loan commitments and standby letters of credit for the year ended December 31, 2012 is summarized as follows (in thousands):
			Commercial				Commercial Real Estate				Residential Mortgage				Consumer				Nonspecific Allowance				Total
	Allowance for loan losses:
	Beginning balance		$	83,443			$	67,034			$	46,476			$	10,178			$	46,350			$	253,481
	Provision for loan losses		(14,950		)		(6,214		)		3,346				5,327				(2,163		)		(14,654		)
	Loans charged off		(9,341		)		(11,642		)		(10,047		)		(11,108		)		—				(42,138		)
	Recoveries		6,128			1	5,706				1,928				5,056				—				18,818
	Ending balance		$	65,280			$	54,884			$	41,703			$	9,453			$	44,187			$	215,507
	Accrual for off-balance sheet credit risk:
	Beginning balance		$	7,906			$	1,250			$	91			$	14			$	—			$	9,261
	Provision for off-balance sheet credit risk		(7,431		)		103				(13		)		(5		)		—				(7,346		)
	Ending balance		$	475			$	1,353			$	78			$	9			$	—			$	1,915
	Total provision for credit losses		$	(22,381	)		$	(6,111	)		$	3,333			$	5,322			$	(2,163	)		$	(22,000	)
Schedule of Allowance for Loan Losses and Recorded Investment by Impairment Methodology [Table Text Block]	The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at December 31, 2014 is as follows (in thousands):
			Collectively Measured								Individually Measured								Total
			for Impairment								for Impairment
			Recorded Investment				Related Allowance				Recorded Investment				Related Allowance				Recorded Investment				Related
																							Allowance
	Commercial		$	9,082,143			$	90,709			$	13,527			$	166			$	9,095,670			$	90,875
	Commercial real estate		2,709,593				42,404				18,557				41				2,728,150				42,445
	Residential mortgage		1,901,391				23,353				48,121				105				1,949,512				23,458
	Consumer		434,139				4,233				566				—				434,705				4,233
	Total		14,127,266				160,699				80,771				312				14,208,037				161,011
	Nonspecific allowance		—				—				—				—				—				28,045
	Total		$	14,127,266			$	160,699			$	80,771			$	312			$	14,208,037			$	189,056
	The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at December 31, 2013 is as follows (in thousands):
			Collectively Measured								Individually Measured								Total
			for Impairment								for Impairment
			Recorded Investment				Related Allowance				Recorded Investment				Related Allowance				Recorded Investment				Related
																							Allowance
	Commercial		$	7,926,461			$	78,607			$	16,760			$	573			$	7,943,221			$	79,180
	Commercial real estate		2,374,503				41,440				40,850				133				2,415,353				41,573
	Residential mortgage		2,010,483				29,217				41,543				248				2,052,026				29,465
	Consumer		380,445				6,965				1,219				—				381,664				6,965
	Total		12,691,892				156,229				100,372				954				12,792,264				157,183
	Nonspecific allowance		—				—				—				—				—				28,213
	Total		$	12,691,892			$	156,229			$	100,372			$	954			$	12,792,264			$	185,396
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 December 31, 2014 is as follows (in thousands):
			Internally Risk Graded								Non-Graded								Total
			Recorded Investment				Related Allowance				Recorded Investment				Related Allowance				Recorded Investment				Related
																							Allowance
	Commercial		$	9,073,030			$	90,085			$	22,640			$	790			$	9,095,670			$	90,875
	Commercial real estate		2,728,150				42,445				—				—				2,728,150				42,445
	Residential mortgage		192,303				2,996				1,757,209				20,462				1,949,512				23,458
	Consumer		343,227				1,506				91,478				2,727				434,705				4,233
	Total		12,336,710				137,032				1,871,327				23,979				14,208,037				161,011
	Nonspecific allowance		—				—				—				—				—				28,045
	Total		$	12,336,710			$	137,032			$	1,871,327			$	23,979			$	14,208,037			$	189,056
	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, 2013 is as follows (in thousands):
			Internally Risk Graded								Non-Graded								Total
			Recorded Investment				Related Allowance				Recorded Investment				Related Allowance				Recorded Investment				Related
																							Allowance
	Commercial		$	7,888,219			$	78,250			$	55,002			$	930			$	7,943,221			$	79,180
	Commercial real estate		2,415,353				41,573				—				—				2,415,353				41,573
	Residential mortgage		220,635				5,481				1,831,391				23,984				2,052,026				29,465
	Consumer		265,533				2,657				116,131				4,308				381,664				6,965
	Total		10,789,740				127,961				2,002,524				29,222				12,792,264				157,183
	Nonspecific allowance		—				—				—				—				—				28,213
	Total		$	10,789,740			$	127,961			$	2,002,524			$	29,222			$	12,792,264			$	185,396
Schedule of Credit Quality Indicators [Table Text Block]	The following table summarizes the Company’s loan portfolio at December 31, 2014 by the risk grade categories (in thousands):
			Internally Risk Graded												Non-Graded
			Performing				Potential Problem				Nonaccruing				Performing				Nonaccruing				Total
	Commercial:
	Energy		$	2,843,093			$	15,919			$	1,416			$	—			$	—			$	2,860,428
	Services		2,497,888				15,140				5,201				—				—				2,518,229
	Wholesale/retail		1,301,026				8,141				4,149				—				—				1,313,316
	Manufacturing		527,951				4,193				450				—				—				532,594
	Healthcare		1,449,024				4,565				1,380				—				—				1,454,969
	Other commercial and industrial		389,378				3,293				823				22,532				108				416,134
	Total commercial		9,008,360				51,251				13,419				22,532				108				9,095,670
	Commercial real estate:
	Residential construction and land development		127,437				10,855				5,299				—				—				143,591
	Retail		662,335				628				3,926				—				—				666,889
	Office		411,548				576				3,420				—				—				415,544
	Multifamily		691,053				13,245				—				—				—				704,298
	Industrial		428,817				—				—				—				—				428,817
	Other commercial real estate		362,375				724				5,912				—				—				369,011
	Total commercial real estate		2,683,565				26,028				18,557				—				—				2,728,150
	Residential mortgage:
	Permanent mortgage		187,520				1,773				3,010				745,813				31,835				969,951
	Permanent mortgages guaranteed by U.S. government agencies		—				—				—				202,238				3,712				205,950
	Home equity		—				—				—				764,047				9,564				773,611
	Total residential mortgage		187,520				1,773				3,010				1,712,098				45,111				1,949,512
	Consumer		343,041				19				167				91,079				399				434,705
	Total		$	12,222,486			$	79,071			$	35,153			$	1,825,709			$	45,618			$	14,208,037
	The following table summarizes the Company’s loan portfolio at December 31, 2013 by the risk grade categories (in thousands):
			Internally Risk Graded												Non-Graded
			Performing				Potential Problem				Nonaccruing				Performing				Nonaccruing				Total
	Commercial:
	Energy		$	2,347,519			$	2,381			$	1,860			$	—			$	—			$	2,351,760
	Services		2,265,984				11,304				4,922				—				—				2,282,210
	Wholesale/retail		1,191,791				2,604				6,969				—				—				1,201,364
	Manufacturing		381,794				9,365				592				—				—				391,751
	Healthcare		1,272,626				34				1,586				—				—				1,274,246
	Other commercial and industrial		381,394				4,736				758				54,929				73				441,890
	Total commercial		7,841,108				30,424				16,687				54,929				73				7,943,221
	Commercial real estate:
	Residential construction and land development		173,488				15,393				17,377				—				—				206,258
	Retail		579,506				1,684				4,857				—				—				586,047
	Office		403,951				1,157				6,391				—				—				411,499
	Multifamily		562,800				13,695				7				—				—				576,502
	Industrial		243,625				—				252				—				—				243,877
	Other commercial real estate		371,628				7,576				11,966				—				—				391,170
	Total commercial real estate		2,334,998				39,505				40,850				—				—				2,415,353
	Residential mortgage:
	Permanent mortgage		210,142				3,283				7,210				815,040				27,069				1,062,744
	Permanent mortgages guaranteed by U.S. government agencies		—				—				—				180,821				777				181,598
	Home equity		—				—				—				800,420				7,264				807,684
	Total residential mortgage		210,142				3,283				7,210				1,796,281				35,110				2,052,026
	Consumer		264,536				795				202				115,114				1,017				381,664
	Total		$	10,650,784			$	74,007			$	64,949			$	1,966,324			$	36,200			$	12,792,264
Summary of Impaired Loans [Table Text Block]
		As of December 31, 2014																				Year Ended
						Recorded Investment																December 31, 2014
		Unpaid				Total				With No				With Allowance				Related Allowance				Average Recorded				Interest Income Recognized
		Principal								Allowance												Investment
		Balance
	Commercial:
	Energy	$	1,444			$	1,416			$	1,416			$	—			$	—			$	1,638			$	—
	Services	8,068				5,201				4,487				714				157				5,061				—
	Wholesale/retail	9,457				4,149				4,117				32				9				5,559				—
	Manufacturing	737				450				450				—				—				521				—
	Healthcare	2,432				1,380				1,380				—				—				1,483				—
	Other commercial and industrial	8,604				931				931				—				—				881				—
	Total commercial	30,742				13,527				12,781				746				166				15,143				—
	Commercial real estate:
	Residential construction and land development	10,071				5,299				5,192				107				23				11,338				—
	Retail	5,406				3,926				3,926				—				—				4,392				—
	Office	5,959				3,420				3,420				—				—				4,905				—
	Multifamily	—				—				—				—				—				3				—
	Industrial	—				—				—				—				—				126				—
	Other commercial real estate	11,954				5,912				5,739				173				18				8,939				—
	Total commercial real estate	33,390				18,557				18,277				280				41				29,703				—
	Residential mortgage:
	Permanent mortgage	43,463				34,845				34,675				170				105				34,561				1,418
	Permanent mortgage guaranteed by U.S. government agencies1	212,684				205,950				205,950				—				—				194,017				8,342
	Home equity	9,767				9,564				9,564				—				—				8,414				—
	Total residential mortgage	265,914				250,359				250,189				170				105				236,992				9,760
	Consumer	584				566				566				—				—				893				—
	Total	$	330,630			$	283,009			$	281,813			$	1,196			$	312			$	282,731			$	9,760
	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, 2014, $3.7 million of these loans are nonaccruing and $202 million are 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, have been recovered.
		As of December 31, 2013																					Year Ended
							Recorded Investment																December 31, 2013
			Unpaid				Total				With No				With Allowance				Related Allowance				Average Recorded				Interest Income Recognized
			Principal								Allowance												Investment
			Balance
	Commercial:
	Energy		$	1,860			$	1,860			$	1,860			$	—			$	—			$	2,160			$	—
	Services		6,486				4,922				3,791				1,131				516				8,506				—
	Wholesale/retail		11,009				6,969				6,937				32				9				5,023				—
	Manufacturing		746				592				592				—				—				1,300				—
	Healthcare		2,193				1,586				1,538				48				48				2,376				—
	Other commercial and industrial		8,532				831				831				—				—				1,249				—
	Total commercial		30,826				16,760				15,549				1,211				573				20,614				—
	Commercial real estate:
	Residential construction and land development		20,804				17,377				17,050				327				107				21,754				—
	Retail		6,133				4,857				4,857				—				—				6,487				—
	Office		7,848				6,391				6,383				8				8				6,610				—
	Multifamily		7				7				7				—				—				1,357				—
	Industrial		252				252				252				—				—				2,110				—
	Other commercial real estate		14,593				11,966				11,779				187				18				12,421				—
	Total commercial real estate		49,637				40,850				40,328				522				133				50,739				—
	Residential mortgage:
	Permanent mortgage		41,870				34,279				33,869				410				248				37,071				1,582
	Permanent mortgage guaranteed by U.S. government agencies1		188,436				181,598				181,598				—				—				165,509				6,961
	Home equity		7,537				7,264				7,264				—				—				6,760				—
	Total residential mortgage		237,843				223,141				222,731				410				248				209,340				8,543
	Consumer		1,228				1,219				1,219				—				—				1,965				—
	Total		$	319,534			$	281,970			$	279,827			$	2,143			$	954			$	282,658			$	8,543
	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, 2013, $777 thousand of these loans are nonaccruing and $181 million are accruing based on the guarantee by U.S. government agencies.
Troubled Debt Restructurings [Table Text Block]	A summary of troubled debt restructurings ("TDRs") by accruing status as of December 31, 2014 is as follows (in thousands):
			As of December 31, 2014
			Recorded				Performing in Accordance With Modified Terms				Not				Specific				Amounts Charged-Off During the Year Ended December 31, 2014
			Investment								Performing in Accordance With Modified Terms				Allowance
	Nonaccruing TDRs:
	Commercial:
	Energy		$	—			$	—			$	—			$	—			$	—
	Services		1,666				706				960				148				—
	Wholesale/retail		3,381				3,284				97				9				—
	Manufacturing		340				340				—				—				3,000
	Healthcare		—				—				—				—				—
	Other commercial and industrial		674				93				581				—				—
	Total commercial		6,061				4,423				1,638				157				3,000
	Commercial real estate:
	Residential construction and land development		3,140				641				2,499				23				1,597
	Retail		3,600				2,432				1,168				—				—
	Office		2,324				—				2,324				—				—
	Multifamily		—				—				—				—				—
	Industrial		—				—				—				—				—
	Other commercial real estate		1,647				1,647				—				—				—
	Total commercial real estate		10,711				4,720				5,991				23				1,597
	Residential mortgage:
	Permanent mortgage		16,393				11,134				5,259				105				262
	Permanent mortgage guaranteed by U.S. government agencies		1,597				179				1,418				—				—
	Home equity		5,184				3,736				1,448				—				247
	Total residential mortgage		23,174				15,049				8,125				105				509
	Consumer		419				253				166				—				1
	Total nonaccruing TDRs		40,365				24,445				15,920				285				5,107
	Accruing TDRs:
	Residential mortgage:
	Permanent mortgages guaranteed by U.S. government agencies		73,985				17,274				56,711				—				—
	Total residential mortgage		73,985				17,274				56,711				—				—
	Total accruing TDRs		73,985				17,274				56,711				—				—
	Total TDRs		$	114,350			$	41,719			$	72,631			$	285			$	5,107
	A summary of troubled debt restructurings by accruing status as of December 31, 2013 is as follows (in thousands):
			As of December 31, 2013
			Recorded				Performing in Accordance With Modified Terms				Not				Specific				Amounts Charged-off During the Year Ended December 31, 2013
			Investment								Performing in Accordance With Modified Terms				Allowance
	Nonaccruing TDRs:
	Commercial:
	Energy		$	—			$	—			$	—			$	—			$	—
	Services		2,235				852				1,383				237				—
	Wholesale/retail		235				89				146				9				—
	Manufacturing		391				—				391				—				154
	Healthcare		—				—				—				—				—
	Other commercial and industrial		771				173				598				—				—
	Total commercial		3,632				1,114				2,518				246				154
	Commercial real estate:
	Residential construction and land development		10,148				1,444				8,704				107				46
	Retail		4,359				3,141				1,218				—				582
	Office		5,059				3,872				1,187				—				117
	Multifamily		—				—				—				—				—
	Industrial		—				—				—				—				—
	Other commercial real estate		5,011				2,885				2,126				—				—
	Total commercial real estate		24,577				11,342				13,235				107				745
	Residential mortgage:
	Permanent mortgage		18,697				12,214				6,483				88				469
	Home equity		4,045				3,531				514				—				112
	Total residential mortgage		22,742				15,745				6,997				88				581
	Consumer		1,008				758				250				—				1
	Total nonaccuring TDRs		51,959				28,959				23,000				441				1,481
	Accruing TDRs:
	Residential mortgage:
	Permanent mortgages guaranteed by U.S. government agencies		54,322				13,384				40,938				—				—
Total residential mortgage		54,322				13,384				40,938				—				—
Total accruing TDRs		54,322				13,384				40,938				—				—
Total TDRs		$	106,281			$	42,343			$	63,938			$	441			$	1,481
Troubled debt restructurings generally consist of interest rate concessions, payment stream concessions or a combination of concessions to distressed borrowers. The following table details the recorded balance of loans at December 31, 2014 by class that were restructured during the year ended December 31, 2014 by primary type of concession (in thousands):
	Year Ended December 31, 2014
	Accruing												Nonaccrual															Total
	Payment Stream				Combination & Other				Total				Interest Rate				Payment Stream				Combination & Other				Total
Commercial:
Energy	$	—			$	—			$	—			$	—			$	—			$	—			$	—		$	—
Services	—				—				—				—				—				—				—			—
Wholesale/retail	—				—				—				—				3,261				—				3,261			3,261
Manufacturing	—				—				—				—				—				—				—			—
Healthcare	—				—				—				—				—				—				—			—
Other commercial and industrial	—				—				—				—				396				81				477			477
Total commercial	—				—				—				—				3,657				81				3,738			3,738
Commercial real estate:
Residential construction and land development	—				—				—				—				—				—				—			—
Retail	—				—				—				—				—				—				—			—
Office	—				—				—				—				—				—				—			—
Multifamily	—				—				—				—				—				—				—			—
Industrial	—				—				—				—				—				—				—			—
Other commercial real estate	—				—				—				—				—				—				—			—
Total commercial real estate	—				—				—				—				—				—				—			—
Residential mortgage:
Permanent mortgage	—				—				—				—				586				3,538				4,124			4,124
Permanent mortgage guaranteed by U.S. government agencies	15,386				17,293				32,679				—				—				1,059				1,059			33,738
Home equity	—				—				—				—				—				2,534				2,534			2,534
Total residential mortgage	15,386				17,293				32,679				—				586				7,131				7,717			40,396
Consumer	—				—				—				—				—				76				76			76
Total	$	15,386			$	17,293			$	32,679			$	—			$	4,243			$	7,288			$	11,531		$	44,210
The following table details the recorded balance of loans by class that were restructured during the year ended December 31, 2013 by primary type of concession (in thousands):
	Year Ended December 31, 2013
	Accruing												Nonaccrual															Total
	Payment Stream				Combination & Other				Total				Interest Rate				Payment Stream				Combination & Other				Total
Commercial:
Energy	$	—			$	—			$	—			$	—			$	—			$	—			$	—		$	—
Services	—				—				—				—				1,080				—				1,080			1,080
Wholesale/retail	—				—				—				—				—				—				—			—
Manufacturing	—				—				—				—				391				—				391			391
Healthcare	—				—				—				—				—				—				—			—
Other commercial and industrial	—				—				—				139				—				57				196			196
Total commercial	—				—				—				139				1,471				57				1,667			1,667
Commercial real estate:
Residential construction and land development	—				—				—				—				—				—				—			—
Retail	—				—				—				—				486				—				486			486
Office	—				—				—				—				2,819				—				2,819			2,819
Multifamily	—				—				—				—				—				—				—			—
Industrial	—				—				—				—				—				—				—			—
Other commercial real estate	—				—				—				—				517				—				517			517
Total commercial real estate	—				—				—				—				3,822				—				3,822			3,822
Residential mortgage:
Permanent mortgage	—				—				—				—				1,062				1,894				2,956			2,956
Permanent mortgage guaranteed by U.S. government agencies	11,545				12,518				24,063				—				—				—				—			24,063
Home equity	—				—				—				—				—				2,800				2,800			2,800
Total residential mortgage	11,545				12,518				24,063				—				1,062				4,694				5,756			29,819
Consumer	—				—				—				75				—				638				713			713
Total	$	11,545			$	12,518			$	24,063			$	214			$	6,355			$	5,389			$	11,958		$	36,021
The following table summarizes, by loan class, the recorded investment at December 31, 2014 and 2013, respectively of loans modified as TDRs within the previous 12 months and for which there was a payment default during the years ended December 31, 2014 and 2013, respectively (in thousands):
	Year Ended
	31-Dec-14												31-Dec-13
	Accruing				Nonaccrual				Total				Accruing				Nonaccrual				Total
Commercial:
Energy	$	—			$	—			$	—			$	—			$	—			$	—
Services	—				—				—				—				1,080				1,080
Wholesale/retail	—				—				—				—				—				—
Manufacturing	—				—				—				—				391				391
Healthcare	—				—				—				—				—				—
Other commercial and industrial	—				13				13				—				164				164
Total commercial	—				13				13				—				1,635				1,635
Commercial real estate:
Residential construction and land development	—				—				—				—				—				—
Retail	—				—				—				—				486				486
Office	—				—				—				—				2,819				2,819
Multifamily	—				—				—				—				—				—
Industrial	—				—				—				—				—				—
Other commercial real estate	—				—				—				—				517				517
Total commercial real estate	—				—				—				—				3,822				3,822
Residential mortgage:
Permanent mortgage	—				2,836				2,836				—				586				586
Permanent mortgage guaranteed by U.S. government agencies	29,585				1,047				30,632				23,918				—				23,918
Home equity	—				1,101				1,101				—				590				590
Total residential mortgage	29,585				4,984				34,569				23,918				1,176				25,094
Consumer	—				25				25				—				155				155
Total	$	29,585			$	5,022			$	34,607			$	23,918			$	6,788			$	30,706
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.
Summary of Loans by Aging Status [Table Text Block]	A summary of loans currently performing, loans past due and accruing and nonaccrual loans as of December 31, 2014 is as follows (in thousands):
							Past Due
			Current				30 to 89				90 Days				Nonaccrual				Total
							Days				or More
	Commercial:
	Energy		$	2,857,082			$	1,930			$	—			$	1,416			$	2,860,428
	Services		2,511,892				1,136				—				5,201				2,518,229
	Wholesale/retail		1,309,167				—				—				4,149				1,313,316
	Manufacturing		532,144				—				—				450				532,594
	Healthcare		1,453,409				180				—				1,380				1,454,969
	Other commercial and industrial		415,030				173				—				931				416,134
	Total commercial		9,078,724				3,419				—				13,527				9,095,670
	Commercial real estate:
	Residential construction and land development		133,642				4,650				—				5,299				143,591
	Retail		662,963				—				—				3,926				666,889
	Office		412,124				—				—				3,420				415,544
	Multifamily		704,298				—				—				—				704,298
	Industrial		428,817				—				—				—				428,817
	Other commercial real estate		362,529				570				—				5,912				369,011
	Total commercial real estate		2,704,373				5,220				—				18,557				2,728,150
	Residential mortgage:
	Permanent mortgage		929,090				5,970				46				34,845				969,951
	Permanent mortgages guaranteed by U.S. government agencies		26,691				23,558				151,989				3,712				205,950
	Home equity		761,247				2,723				77				9,564				773,611
	Total residential mortgage		1,717,028				32,251				152,112				48,121				1,949,512
	Consumer		433,590				547				2				566				434,705
	Total		$	13,933,715			$	41,437			$	152,114			$	80,771			$	14,208,037
	A summary of loans currently performing, loans past due and accruing and nonaccrual loans as of December 31, 2013 is as follows (in thousands):
							Past Due
			Current				30 to 89				90 Days				Nonaccrual				Total
							Days				or More
	Commercial:
	Energy		$	2,347,267			$	2,483			$	150			$	1,860			$	2,351,760
	Services		2,276,036				1,210				42				4,922				2,282,210
	Wholesale/retail		1,193,905				338				152				6,969				1,201,364
	Manufacturing		391,159				—				—				592				391,751
	Healthcare		1,272,660				—				—				1,586				1,274,246
	Other commercial and industrial		440,973				81				5				831				441,890
	Total commercial		7,922,000				4,112				349				16,760				7,943,221
	Commercial real estate:
	Residential construction and land development		188,434				428				19				17,377				206,258
	Retail		580,926				264				—				4,857				586,047
	Office		404,505				603				—				6,391				411,499
	Multifamily		576,495				—				—				7				576,502
	Industrial		243,625				—				—				252				243,877
	Other commercial real estate		376,699				1,493				1,012				11,966				391,170
	Total commercial real estate		2,370,684				2,788				1,031				40,850				2,415,353
	Residential mortgage:
	Permanent mortgage		1,018,670				9,795				—				34,279				1,062,744
	Permanent mortgages guaranteed by U.S. government agencies		21,916				17,290				141,615				777				181,598
	Home equity		797,299				3,087				34				7,264				807,684
	Total residential mortgage		1,837,885				30,172				141,649				42,320				2,052,026
	Consumer		379,417				1,027				1				1,219				381,664
	Total		$	12,509,986			$	38,099			$	143,030			$	101,149			$	12,792,264

Premises_and_Equipment_Premise

Premises and Equipment Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Premises and Equipment [Table Text Block]	Premises and equipment at December 31 are summarized as follows (in thousands):
		December 31,
		2014		2013
	Land	$	71,371	$	75,859
	Buildings and improvements	225,008		221,326
	Software	120,010		103,473
	Furniture and equipment	179,513		163,013
	Construction in progress	21,805		31,027
	Subtotal	617,707		594,698
	Less accumulated depreciation	343,874		316,849
	Total	$	273,833	$	277,849

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets [Table Text Block]	The following table presents the original cost and accumulated amortization of intangible assets (in thousands):
		December 31,
		2014			2013
	Core deposit premiums	$	33,749		$	33,749
	Less accumulated amortization	33,088			32,656
	Net core deposit premiums	661			1,093
	Other identifiable intangible assets	50,288			36,511
	Less accumulated amortization	16,573			13,040
	Net other identifiable intangible assets	33,715			23,471
	Total intangible assets, net	$	34,376		$	24,564
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	Expected amortization expense for intangible assets that will continue to be amortized (in thousands):
		Core			Other			Total
		Deposit			Identifiable
		Premiums			Intangible Assets
	2015	$	393		$	3,967		$	4,360
	2016	247			3,967			4,214
	2017	21			3,735			3,756
	2018	—			3,078			3,078
	2019	—			2,816			2,816
	Thereafter	—			16,152			16,152
		$	661		$	33,715		$	34,376
Schedule of Goodwill [Table Text Block]	The changes in the carrying value of goodwill by operating segment for the year ended December 31, 2014 are as follows (in thousands):
		Commercial			Consumer			Wealth		Total
								Management
	Balance, December 31, 2012
	Goodwill	$	271,162		$	39,251		$	51,794	$	362,207
	Accumulated impairment losses	—			(228		)	—		(228		)
		271,162			39,023			51,794		361,979
	Goodwill adjustments during 2013	(2,220		)	—			—		(2,220		)
	Balance, December 31, 2013
	Goodwill	268,942			39,251			51,794		359,987
	Accumulated impairment losses	—			(228		)	—		(228		)
		268,942			39,023			51,794		359,759
	Goodwill acquired during 2014	421			—			17,600		18,021
	Balance, December 31, 2014
	Goodwill	269,363			39,251			69,394		378,008
	Accumulated Impairment	—			(228		)	—		(228		)
		$	269,363		$	39,023		$	69,394	$	377,780

Mortgage_Banking_Activities_Ta

Mortgage Banking Activities (Tables)	12 Months Ended
	Dec. 31, 2014
Mortgage Banking [Abstract]
Components of Residential Mortgage Loans Held For Sale	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):
			December 31, 2014								December 31, 2013
			Unpaid Principal Balance/				Fair Value				Unpaid Principal Balance/			Fair Value
			Notional								Notional
	Residential mortgage loans held for sale		$	291,537			$	298,212			$	192,266		$	193,584
	Residential mortgage loan commitments		520,829				9,971				258,873			2,656
	Forward sales contracts		701,066				(4,001		)		435,867			4,306
							$	304,182						$	200,546
Mortgage Banking Revenue [Table Text Block]	Mortgage banking revenue was as follows (in thousands):
			Year Ended
			2014				2013				2012
	Production revenue:
	Net realized gains on sales of mortgage loans		$	56,696			$	95,309			$	115,879
	Net change in unrealized gain on mortgage loans held for sale		5,357				(10,899		)		4,720
	Change in the fair value of mortgage loan commitments		7,315				(10,077		)		6,136
	Change in the fair value of forward sales contracts		(8,307		)		5,212				2,382
	Total production revenue		61,061				79,545				129,117
	Servicing revenue		48,032				42,389				40,185
	Total mortgage banking revenue		$	109,093			$	121,934			$	169,302
Summary of Mortgage Servicing Rights
			December 31,
			2014				2013				2012
	Number of residential mortgage loans serviced for others		117,483				106,137				98,246
	Outstanding principal balance of residential mortgage loans serviced for others		$	16,162,887			$	13,718,942			$	11,981,624
	Weighted average interest rate		4.29		%		4.4		%		4.71		%
	Remaining term (in months)		296				292				289
Activity in Capitalized Mortgage Servicing Rights	Activity in capitalized mortgage servicing rights during the three years ended December 31, 2014 is as follows (in thousands):
			Purchased				Originated				Total
	Balance, December 31, 2011		$	18,903			$	67,880			$	86,783
	Additions, net		—				42,191				42,191
	Change in fair value due to loan runoff		(4,164		)		(14,788		)		(18,952		)
	Change in fair value due to market changes		(1,763		)		(7,447		)		(9,210		)
	Balance, December 31, 2012		12,976				87,836				100,812
	Additions, net		—				49,431				49,431
	Change in fair value due to loan runoff		(3,029		)		(16,601		)		(19,630		)
	Change in fair value due to market changes		5,988				16,732				22,720
	Balance, December 31, 2013		15,935				137,398				153,333
	Additions, net		—				54,413				54,413
	Change in fair value due to loan runoff		(2,357		)		(16,968		)		(19,325		)
	Change in fair value due to market changes		(2,464		)		(13,981		)		(16,445		)
	Balance, December 31, 2014		$	11,114			$	160,862			$	171,976
Assumptions to Value Mortgage Servicing Rights [Table Text Block]	Significant assumptions used to determine fair value considered to be significant unobservable inputs were as follows:
			December 31,
			2014		2013
	Discount rate – risk-free rate plus a market premium		10.17%		10.21%
	Prepayment rate – based upon loan interest rate, original term and loan type		7.70% - 30.44%		6.66% - 26.19%
	Loan servicing costs – annually per loan based upon loan type:
	Performing loans		$60 - $105		$60 - $105
	Delinquent loans		$150 - $500		$150 - $500
	Loans in foreclosure		$1,000 - $4,250		$1,000 - $4,250
	Escrow earnings rate – indexed to rates paid on deposit accounts with comparable average life		1.77%		1.80%
Stratification of Loan Servicing Portfolio	Stratification of the residential mortgage loan servicing portfolio and outstanding principal of loans serviced for others by interest rate at December 31, 2014 follows (in thousands):
			< 4.00%				4.00% - 4.99%				5.00% - 5.99%			> 5.99%			Total
	Fair value		$	67,412			$	80,405			$	19,383		$	4,776		$	171,976
	Outstanding principal of loans serviced for others		6,332,112				6,882,025				1,989,977			958,773			16,162,887
	Weighted average prepayment rate1		7.7		%		8.58		%		14.5		%	30.44		%	10.26		%
	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	The aging status of our mortgage loans serviced for others by investor at December 31, 2014 follows (in thousands):
							Past Due
			Current				30 to 59				60 to 89			90 Days or More			Total
							Days				Days
	FHLMC		$	5,289,078			$	37,881			$	9,418		$	33,837		$	5,370,214
	FNMA		5,200,509				27,089				5,736			22,087			5,255,421
	GNMA		4,920,064				132,680				34,602			13,594			5,100,940
	Other		422,598				6,674				1,491			5,549			436,312
	Total		$	15,832,249			$	204,324			$	51,247		$	75,067		$	16,162,887
Activity in Accrual for Losses On Loans Sold With Recourse	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):
		Year Ended
		2014				2013				2012
	Beginning balance	$	9,562			$	13,158			$	18,683
	Provision for recourse losses	354				517				(100		)
	Loans charged off, net	(2,617		)		(4,113		)		(5,425		)
	Ending balance	$	7,299			$	9,562			$	13,158
Summary of Unresolved Deficiency Requests [Table Text Block]	A summary of unresolved deficiency requests from the agencies follows (in thousands, except for number of unresolved deficiency requests):
		December 31,
		2014				2013
	Number of unresolved deficiency requests	186				578
	Aggregate outstanding principal balance subject to unresolved deficiency requests	$	15,328			$	69,288
	Unpaid principal balance subject to indemnification by the Company	4,047				3,200
Activity in Accruals for Mortgage Losses [Table Text Block]	The activity in the accruals for mortgage losses is summarized as follows (in thousands).
		December 31,
		2014				2013
	Beginning balance	$	12,716			$	8,983
	Provision for losses	7,200				6,221
	Charge-offs, net	(8,048		)		(2,488		)
	Ending balance	$	11,868			$	12,716

Deposits_Tables

Deposits (Tables)	12 Months Ended
	Dec. 31, 2014
Deposits [Abstract]
Interest Expense on Deposits [Table Text Block]	Interest expense on deposits is summarized as follows (in thousands):
		Year Ended December 31,
		2014		2013		2012
	Transaction deposits	$	9,757	$	11,155	$	14,300
	Savings	401		442		540
	Time:
	Certificates of deposits under $100,000	14,278		16,234		19,150
	Certificates of deposits $100,000 and over	11,878		12,273		16,331
	Other time deposits	14,369		15,460		16,692
	Total time	40,525		43,967		52,173
	Total	$	50,683	$	55,564	$	67,013

Other_Borrowings_Other_Borrowi

Other Borrowings Other Borrowings (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Schedule of Other Borrowings [Table Text Block]	Information relating to other borrowings is summarized as follows (dollars in thousands):
			As of				Year Ended
			December 31, 2014				December 31, 2014
			Balance		Rate		Average Balance			Rate			Maximum
													Outstanding
													At Any
													Month End
	Parent Company and Other Non-Bank Subsidiaries:
	Other		$	—	—	%	$	—		—	%		$	—
	Total Parent Company and Other Non-Bank Subsidiaries		—				—			—
	Subsidiary Bank:
	Funds purchased		57,031		0.05		494,220			0.07			1,548,676
	Repurchase agreements		1,187,489		0.04		928,767			0.06			1,187,489
	Other borrowings:
	Federal Home Loan Bank advances		2,103,400		0.25		1,894,966			0.24			3,453,400
	GNMA repurchase liability		14,298		5.05		17,343			5.2			24,980
	Other		16,076		2.73		16,433			2.32			16,582
	Total other borrowings		2,133,774				1,928,742			0.35
	Subordinated debentures		347,983		2.35		347,892			2.5			347,983
	Total subsidiary bank		3,726,277				3,699,621			0.43
	Total other borrowed funds		$	3,726,277			$	3,699,621		0.43	%
			As of				Year Ended
			December 31, 2013				December 31, 2013
			Balance		Rate		Average Balance			Rate			Maximum
													Outstanding
													At Any
													Month End
	Parent Company and Other Non-Bank Subsidiaries:
	Other		$	—	—	%	$	326		—	%		$	—
	Total Parent Company and Other Non-Bank Subsidiaries		—				326			—
	Subsidiary Bank:
	Funds purchased		868,081		0.04		866,062			0.1			997,536
	Repurchase agreements		813,454		0.05		811,996			0.06			881,033
	Other borrowings:
	Federal Home Loan Bank advances		1,005,650		0.19		1,661,424			0.2			2,451,197
	GNMA repurchase liability		18,113		5.5		15,741			5.43			21,055
	Other		16,590		2.73		16,502			2.54			17,092
	Total other borrowings		1,040,353				1,693,667
	Subordinated debentures		347,802		2.35		347,717			2.51			347,802
	Total subsidiary bank		3,069,690				3,719,442			0.41
	Total other borrowings		$	3,069,690			$	3,719,768		0.4	%
			As of				Year Ended
			December 31, 2012				December 31, 2012
			Balance		Rate		Average Balance			Rate			Maximum
													Outstanding
													At Any
													Month End
	Parent Company and Other Non-Bank Subsidiaries:
	Other		$	10,500	1.5	%	$	394		1.11			$	10,500
	Total Parent Company and Other Non-Bank Subsidiaries		10,500				394			1.11
	Subsidiary Banks:
	Funds purchased		1,167,416		0.05		1,512,711			0.14			1,810,793
	Repurchase agreements		887,030		0.07		1,072,650			0.09			1,272,151
	Other borrowings:
	Federal Home Loan Bank advances		604,897		0.23		104,925			0.31			604,897
	GNMA repurchase liability		20,046		5.44		33,769			5.41			47,840
	Other		16,332		2.79		16,577			2.91			16,761
	Total other borrowings		641,275				155,271
	Subordinated debentures		347,633		2.4		363,699			3.79			398,897
	Total subsidiary banks		3,043,354				3,104,330			0.65
	Total other borrowings		$	3,053,854			$	3,104,724		0.65	%
Schedule of Maturities of Other Borrowings [Table Text Block]	Aggregate annual principal repayments at December 31, 2014 are as follows (in thousands):
			Parent		Subsidiary
			Company and Other Non-bank Subsidiaries		Bank
	2015		$	—	$	3,484,519
	2016		—		525
	2017		—		226,732
	2018		—		575
	2019		—		575
	Thereafter		—		13,351
	Total		$	—	$	3,726,277
Schedule of Repurchase Agreements [Table Text Block]	Additional information relating to securities sold under agreements to repurchase and related liabilities at December 31, 2014 and 2013 is as follows (dollars in thousands):
			December 31, 2014
			Amortized		Market			Repurchase			Average
	Security Sold/Maturity		Cost		Value			Liability1			Rate
	U.S. Agency Securities:
	Overnight1		$	1,185,345	$	1,192,361		$	1,187,445		0.04	%
	Long-term		—		—			—			—	%
	Total Agency Securities		$	1,185,345	$	1,192,361		$	1,187,445		0.04	%
			December 31, 2013
			Amortized		Market			Repurchase			Average
	Security Sold/Maturity		Cost		Value			Liability1			Rate
	U.S. Agency Securities:
	Overnight1		$	1,085,893	$	1,075,821		$	813,624		0.05	%
	Long-term		—		—			—			—	%
	Total Agency Securities		$	1,085,893	$	1,075,821		$	813,624		0.05	%
	1	BOK Financial maintains control over the securities underlying overnight repurchase agreements and generally transfers control over securities underlying longer-term dealer repurchase agreements to the respective counterparty.

Federal_and_State_Income_Taxes1

Federal and State Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of deferred tax assets and liabilities are as follows (in thousands):
		December 31,
		2014				2013
	Deferred tax assets:
	Available for sale securities mark to market	$	—			$	14,751
	Share-based compensation	9,414				8,064
	Credit loss allowances	74,362				75,657
	Valuation adjustments	36,870				35,292
	Deferred compensation	23,333				60,068
	Unearned fees	11,820				10,683
	Other	26,633				22,348
	Total deferred tax assets	182,432				226,863
	Deferred tax liabilities:
	Available for sale securities mark to market	37,719				—
	Depreciation	18,601				17,333
	Mortgage servicing rights	86,752				72,235
	Lease financing	24,429				23,202
	Other	22,160				18,494
	Total deferred tax liabilities	189,661				131,264
	Net deferred tax assets (liabilities)	$	(7,229	)		$	95,599
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	The significant components of the provision for income taxes attributable to continuing operations for BOK Financial are shown below (in thousands):
		Year Ended December 31,
		2014				2013				2012
	Current income tax expense:
	Federal	$	85,990			$	125,412			$	159,706
	State	9,392				14,381				19,103
	Total current income tax expense	95,382				139,793				178,809
	Deferred income tax expense:
	Federal	36,521				15,915				8,664
	State	2,949				1,590				1,267
	Total deferred income tax expense	39,470				17,505				9,931
	Total income tax expense	$	134,852			$	157,298			$	188,740
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	The reconciliations of income (loss) attributable to continuing operations at the U.S. federal statutory tax rate to income tax expense are as follows (in thousands):
		Year Ended December 31,
		2014				2013				2012
	Amount:
	Federal statutory tax	$	150,616			$	166,680			$	190,003
	Tax exempt revenue	(8,446		)		(7,361		)		(5,558		)
	Effect of state income taxes, net of federal benefit	9,054				10,937				13,684
	Utilization of tax credits	(11,107		)		(8,145		)		(5,126		)
	Bank-owned life insurance	(3,183		)		(3,596		)		(3,850		)
	Reduction of tax accrual	(2,281		)		(1,400		)		(950		)
	Other, net	199				183				537
	Total income tax expense	$	134,852			$	157,298			$	188,740
	Due to the favorable resolution of certain tax issues for the periods ended December 31, 2010 and 2009, BOK Financial reduced its tax accrual by $2.3 million and $1.4 million in 2014 and 2013, respectively, which was credited against current income tax expense.
		Year Ended December 31,
		2014			2013			2012
	Percent of pretax income:
	Federal statutory tax	35	%		35	%		35	%
	Tax exempt revenue	(2.0	)		(1.5	)		(1.0	)
	Effect of state income taxes, net of federal benefit	2.1			2.3			2.5
	Utilization of tax credits	(2.6	)		(1.7	)		(0.9	)
	Bank-owned life insurance	(0.7	)		(0.8	)		(0.7	)
	Reduction of tax accrual	(0.5	)		(0.3	)		(0.1	)
	Other, net	—			—			—
	Total	31.3	%		33	%		34.8	%
Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands):
		2014				2013				2012
	Balance as of January 1	$	12,058			$	12,275			$	12,230
	Additions for tax for current year positions	3,813				2,730				3,976
	Settlements during the period	—				—				(1,000		)
	Lapses of applicable statute of limitations	(2,497		)		(2,947		)		(2,931		)
	Balance as of December 31	$	13,374			$	12,058			$	12,275

Employee_Benefits_Tables

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Change in benefit obligation, plan assets funded status and net periodic pension cost (benefit) [Table Text Block]	The following table presents information regarding this plan (in thousands):
			December 31,
			2014				2013
	Change in projected benefit obligation:
	Projected benefit obligation at beginning of year		$	44,765			$	48,028
	Interest cost		1,685				1,532
	Actuarial loss (gain)		2,878				(1,543		)
	Benefits paid		(4,104		)		(3,252		)
	Projected benefit obligation at end of year1,2		$	45,224			$	44,765
	Change in plan assets:
	Plan assets at fair value at beginning of year		$	48,812			$	45,920
	Actual return on plan assets		4,735				6,144
	Benefits paid		(4,104		)		(3,252		)
	Plan assets at fair value at end of year		$	49,443			$	48,812
	Funded status of the plan		$	4,219			$	4,047
	Components of net periodic benefit costs:
	Interest cost		$	1,685			$	1,532
	Expected return on plan assets		(2,539		)		(2,185		)
	Recognized prior service cost		(1,175		)		(1,175		)
	Amortization of unrecognized net loss		2,584				3,830
	Net periodic pension cost		$	555			$	2,002
	1	Projected benefit obligation equals accumulated benefit obligation.
	2	Projected benefit obligation is based on January 1 measurement date.
Valuation assumptions used [Table Text Block]
	Weighted-average assumptions as of December 31:		2014			2013
	Discount rate		3.42	%		4.05	%
	Expected return on plan assets		6	%		6	%
Expected future benefit payments [Table Text Block]	As of December 31, 2014, expected future benefit payments related to the Pension Plan were as follows (in thousands):
	2015	$	3,535
	2016	3,673
	2017	3,270
	2018	3,396
	2019	3,628
	Thereafter	44,057
		$	61,559

ShareBased_Compensation_Plans_

Share-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]	The following table presents stock options outstanding during 2014, 2013 and 2012 under these plans (in thousands, except for per share data):
			Number			Weighted-				Aggregate
						Average				Intrinsic
						Exercise				Value
						Price
	Options outstanding at December 31, 2011		2,621,347			$	47.01			$	20,769
	Options awarded		67,155			58.76
	Options exercised		(708,295	)		45.32
	Options forfeited		(22,559	)		50.36
	Options expired		(66,862	)		45.97
	Options outstanding at December 31, 2012		1,890,786			48.29				11,748
	Options awarded		81,492			55.74
	Options exercised		(608,663	)		48
	Options forfeited		(219,342	)		47.65
	Options expired		(9,168	)		50.61
	Options outstanding at December 31, 2013		1,135,105			49.09				19,564
	Options awarded		—			—
	Options exercised		(323,004	)		49.17
	Options forfeited		(15,509	)		45.71
	Options expired		(2,701	)		47.98
	Options outstanding at December 31, 2014		793,891			$	49.05			$	8,725
	Options vested at:
	December 31, 2012		601,367			$	47.99			$	3,890
	December 31, 2013		424,459			49.49				7,146
	December 31, 2014		347,633			48.85				3,889
Schedule of Share-based Compensation, Outstanding and Vested Stock Options [Table Text Block]	The following table summarizes information concerning currently outstanding and vested stock options:
			Options Outstanding							Options Vested
						Weighted							Weighted
						Average		Weighted				Weighted	Average
	Range of					Remaining		Average				Average	Remaining
	Exercise		Number			Contractual		Exercise		Number		Exercise	Contractual
	Prices		Outstanding			Life (years)		Price		Vested		Price	Life (years)
	$36.65		190,832			2.83		$36.65		65,626		$36.65	1.51
	45.15 - 47.34		33,574			0.76		47.09		33,574		47.09	0.76
	48.3		39,557			3.16		48.3		13,326		48.3	1.42
	48.46		169,422			2.16		48.46		95,415		48.46	1.49
	54.33		78,904			1.48		54.33		78,904		54.33	1.48
	55.74		78,108			5.16		55.74		8,260		55.74	2.03
	55.94		125,285			3.62		55.94		37,008		55.94	1.44
	58.76		78,209			4.35		58.76		15,520		58.76	1.59
Schedule of Share-based Compensation, Stock Options, Valuation Assumptions [Table Text Block]	The fair value of options was determined as of the date of grant using a Black-Scholes option pricing model with the following weighted average assumptions:
			2013				2012
	Average risk-free interest rate1		0.89		%		0.93		%
	Dividend yield		2.8		%		2.2		%
	Volatility factors		0.272				0.28
	Weighted average expected life		4.9 years				4.9 years
	Weighted average fair value		$	9.67			$	11.48
	1	Average risk-free interest rate represents U.S. Treasury rates matched to the expected life of the options.
Schedule of Nonvested Share Activity [Table Text Block]	The following represents a summary of the non-vested stock awards as of December 31, 2014 (in thousands):
			Shares			Weighted
						Average
						Grant Date
						Fair Value
	Non-vested at January 1, 2012		503,738
	Granted		197,058			$55.63
	Vested		(76,192	)		$47.32
	Forfeited		(31,773	)		$50.45
	Non-vested at December 31, 2012		592,831
	Granted		211,791			$55.84
	Vested		(66,648	)		$35.93
	Forfeited		(89,985	)		$49.95
	Non-vested at December 31, 2013		647,989
	Granted		206,621			$64.96
	Vested		(140,820	)		$44.56
	Forfeited		(25,179	)		$56.26
	Non-vested at December 31, 2014		688,611

Related_Parties_Related_Partie

Related Parties Related Parties (Tables)	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Schedule of Related Party Transactions [Table Text Block]	Activity in loans to related parties is summarized as follows (in thousands):
			Year Ended December 31,
			2014			2013
	Beginning balance		$	88,691		$	49,943
	Advances		712,413			292,393
	Payments		(698,149		)	(253,645		)
	Adjustments1		440			—
	Ending balance		$	103,395		$	88,691
	1	Adjustments generally consist of changes in status as a related party.

Commitments_and_Contingent_Lia1

Commitments and Contingent Liabilities Commitments and Contingent Liabilities - Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of Variable Interest Entities [Table Text Block]
		December 31, 2014
		Loans		Other		Other		Other		Non-controlling
				Assets		Liabilities		Borrowings		Interests
	Consolidated:
	Private equity funds	$	—	$	25,627	$	—	$	—	$	21,921
	Tax credit entities	10,000		12,827		—		10,964		10,000
	Other	—		5,996		—		—		2,106
	Total consolidated	$	10,000	$	44,450	$	—	$	10,964	$	34,027
	Unconsolidated:
	Tax credit entities	$	18,192	$	96,721	$	28,920	$	—	$	—
	Other	—		9,471		4,050		—		—
	Total unconsolidated	$	18,192	$	106,192	$	32,970	$	—	$	—
		December 31, 2013
		Loans		Other		Other		Other		Non-controlling
				Assets		Liabilities		Borrowings		Interests
	Consolidated:
	Private equity funds	$	—	$	27,341	$	—	$	—	$	23,036
	Tax credit entities	10,000		13,448		—		10,964		9,869
	Other	—		9,178		—		—		2,019
	Total consolidated	$	10,000	$	49,967	$	—	$	10,964	$	34,924
	Unconsolidated:
	Tax credit entities	$	27,319	$	90,260	$	35,776	$	—	$	—
	Other	—		9,257		1,681		—		—
	Total unconsolidated	$	27,319	$	99,517	$	37,457	$	—	$	—
	A summary of consolidated and unconsolidated alternative investments as of December 31, 2014 and December 31, 2013 is as follows (in thousands):
		December 31, 2014
		Loans		Other		Other		Other		Non-controlling
				Assets		Liabilities		Borrowings		Interests
	Consolidated:
	Private equity funds	$	—	$	25,627	$	—	$	—	$	21,921
	Tax credit entities	10,000		12,827		—		10,964		10,000
	Other	—		5,996		—		—		2,106
	Total consolidated	$	10,000	$	44,450	$	—	$	10,964	$	34,027
	Unconsolidated:
	Tax credit entities	$	18,192	$	96,721	$	28,920	$	—	$	—
	Other	—		9,471		4,050		—		—
	Total unconsolidated	$	18,192	$	106,192	$	32,970	$	—	$	—
		December 31, 2013
		Loans		Other		Other		Other		Non-controlling
				Assets		Liabilities		Borrowings		Interests
	Consolidated:
	Private equity funds	$	—	$	27,341	$	—	$	—	$	23,036
	Tax credit entities	10,000		13,448		—		10,964		9,869
	Other	—		9,178		—		—		2,019
	Total consolidated	$	10,000	$	49,967	$	—	$	10,964	$	34,924
	Unconsolidated:
	Tax credit entities	$	27,319	$	90,260	$	35,776	$	—	$	—
	Other	—		9,257		1,681		—		—
	Total unconsolidated	$	27,319	$	99,517	$	37,457	$	—	$	—

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings Per Share [Table Text Block]	The following table presents the computation of basic and diluted earnings per share (dollars in thousands, except per share data):
		Year Ended
		2014		2013		2012
	Numerator:
	Net income attributable to BOK Financial Corp. shareholders	$	292,435	$	316,609	$	351,191
	Less: Earnings allocated to participating securities	3,239		3,388		2,541
	Numerator for basic earnings per share – income available to common shareholders	289,196		313,221		348,650
	Effect of reallocating undistributed earnings of participating securities	4		7		6
	Numerator for diluted earnings per share – income available to common shareholders	$	289,200	$	313,228	$	348,656
	Denominator:
	Weighted average shares outstanding	69,159,902		68,719,069		68,221,013
	Less:  Participating securities included in weighted average shares outstanding	765,708		730,172		536,970
	Denominator for basic earnings per common share	68,394,194		67,988,897		67,684,043
	Dilutive effect of employee stock compensation plans1	150,576		216,622		280,897
	Denominator for diluted earnings per common share	68,544,770		68,205,519		67,964,940
	Basic earnings per share	$	4.23	$	4.61	$	5.15
	Diluted earnings per share	$	4.22	$	4.59	$	5.13
	1  Excludes employee stock options with exercise prices greater than current market price.	—		—		224,653

Shareholders_Equity_Tables

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Summary of Regulatory Capital Levels [Table Text Block]	A summary of regulatory capital levels follows (dollars in thousands):
			December 31,
			2014						2013
	Total Capital (to Risk Weighted Assets):
	Consolidated		$	3,120,223		14.66	%		$	3,017,022			15.56	%
	BOKF, NA		2,449,078			11.56			2,293,673				11.88
	Tier I Capital (to Risk Weighted Assets):
	Consolidated		$	2,838,129		13.33	%		$	2,668,981			13.77	%
	BOKF, NA		2,168,161			10.24			1,946,247				10.08
	Tier I Capital (to Average Assets):
	Consolidated		$	2,838,129		9.96	%		$	2,668,981			10.05	%
	BOKF, NA		2,168,161			7.65			1,946,247				7.38
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, December 31, 2011		$	135,740		$	6,673			$	(12,742	)		$	(692	)	$	128,979
	Net change in unrealized gain (loss)		58,921			—				7,276				—			66,197
	Reclassification adjustments included in earnings:
	Interest revenue, Investment securities, Taxable securities		—			(6,601		)		—				—			(6,601		)
	Interest expense, Subordinated debentures		—			—				—				453			453
	Net impairment losses recognized in earnings		7,351			—				—				—			7,351
	Gain on available for sale securities, net		(33,845		)	—				—				—			(33,845		)
	Other comprehensive income (loss), before income taxes		32,427			(6,601		)		7,276				453			33,555
	Federal and state income tax1		(12,614		)	3,006				(2,830		)		(176		)	(12,614		)
	Other comprehensive income (loss), net of income taxes		19,813			(3,595		)		4,446				277			20,941
	Balance, December 31, 2012		155,553			3,078				(8,296		)		(415		)	149,920
	Net change in unrealized gain (loss)		(284,104		)	—				8,159				—			(275,945		)
	Reclassification adjustments included in earnings:
	Interest revenue, Investment securities, Taxable securities		—			(3,210		)		—				—			(3,210		)
	Interest expense, Subordinated debentures		—			—				—				262			262
	Net impairment losses recognized in earnings		2,308			—				—				—			2,308
	Gain on available for sale securities, net		(10,720		)	—				—				—			(10,720		)
	Other comprehensive income (loss), before income taxes		(292,516		)	(3,210		)		8,159				262			(287,305		)
	Federal and state income tax1		113,788			1,250				(3,174		)		(102		)	111,762
	Other comprehensive income (loss), net of income taxes		(178,728		)	(1,960		)		4,985				160			(175,543		)
	Balance, December 31, 2013		(23,175		)	1,118				(3,311		)		(255		)	(25,623		)
	Net change in unrealized gain (loss)		136,050			—				725				—			136,775
	Reclassification adjustments included in earnings:
	Interest revenue, Investment securities, Taxable securities		—			(1,216		)		—				—			(1,216		)
	Interest expense, Subordinated debentures		—			—				—				296			296
	Net impairment losses recognized in earnings		373			—				—				—			373
	Gain on available for sale securities, net		(1,539		)	—				—				—			(1,539		)
	Other comprehensive income (loss), before income taxes		134,884			(1,216		)		725				296			134,689
	Federal and state income tax1		(52,470		)	474				(282		)		(115		)	(52,393		)
	Other comprehensive income (loss), net of income taxes		82,414			(742		)		443				181			82,296
	Balance, December 31, 2014		$	59,239		$	376			$	(2,868	)		$	(74	)	$	56,673
	1	Calculated using 39% effective tax rate.

Reportable_Segments_Tables

Reportable Segments (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Reportable Segments [Table Text Block]	Reportable segments reconciliation to the Consolidated Financial Statements for the year ended December 31, 2014 is as follows (in thousands):
		Commercial			Consumer			Wealth			Funds Management and Other			BOK
								Management						Financial
														Consolidated
	Net interest revenue from external sources	$	381,687		$	95,910		$	23,826		$	163,771		$	665,194
	Net interest revenue (expense) from internal sources	(43,934		)	32,170			20,578			(8,814		)	—
	Net interest revenue	337,753			128,080			44,404			154,957			665,194
	Provision for credit losses	(7,447		)	5,405			213			1,829			—
	Net interest revenue after provision for credit losses	345,200			122,675			44,191			153,128			665,194
	Other operating revenue	169,704			200,815			239,045			3,095			612,659
	Other operating expense	201,748			196,082			216,770			232,922			847,522
	Net direct contribution	313,156			127,408			66,466			(76,699		)	430,331
	Corporate expense allocations	41,338			67,040			31,375			(139,753		)	—
	Income before taxes	271,818			60,368			35,091			63,054			430,331
	Federal and state income taxes	105,737			23,483			13,650			(8,018		)	134,852
	Net income	166,081			36,885			21,441			71,072			295,479
	Net income attributable to non-controlling interests	—			—			—			3,044			3,044
	Net income attributable to BOK Financial Corp. shareholders	$	166,081		$	36,885		$	21,441		$	68,028		$	292,435
	Average assets	$	11,384,508		$	6,555,642		$	4,518,511		$	5,540,197		$	27,998,858
	Average invested capital	946,383			277,404			193,784			1,793,190			3,210,761
	Performance measurements:
	Return on average assets	1.46		%	0.56		%	0.52		%				1.04		%
	Return on average invested capital	17.58		%	13.3		%	12.07		%				9.11		%
	Efficiency ratio	39.57		%	56.58		%	75.9		%				64.5		%
	Reportable segments reconciliation to the Consolidated Financial Statements for the year ended December 31, 2013 is as follows (in thousands):
		Commercial			Consumer			Wealth			Funds Management and Other			BOK
								Management						Financial
														Consolidated
	Net interest revenue from external sources	$	363,961		$	100,153		$	25,478		$	184,885		$	674,477
	Net interest revenue (expense) from internal sources	(51,587		)	34,850			20,061			(3,324		)	—
	Net interest revenue	312,374			135,003			45,539			181,561			674,477
	Provision for credit losses	(4,372		)	5,532			1,275			(30,335		)	(27,900		)
	Net interest revenue after provision for credit losses	316,746			129,471			44,264			211,896			702,377
	Other operating revenue	163,206			225,336			211,655			14,275			614,472
	Other operating expense	190,306			189,099			197,890			263,325			840,620
	Net direct contribution	289,646			165,708			58,029			(37,154		)	476,229
	Corporate expense allocations	44,865			60,005			29,993			(134,863		)	—
	Net income before taxes	244,781			105,703			28,036			97,709			476,229
	Federal and state income taxes	95,220			41,118			10,906			10,054			157,298
	Net income	149,561			64,585			17,130			87,655			318,931
	Net income attributable to non-controlling interests	—			—			—			2,322			2,322
	Net income attributable to BOK Financial Corp. shareholders	$	149,561		$	64,585		$	17,130		$	85,333		$	316,609
	Average assets	$	10,386,235		$	6,487,255		$	4,556,132		$	5,951,472		$	27,381,094
	Average invested capital	906,717			293,736			203,914			1,606,715			3,011,082
	Performance measurements:
	Return on average assets	1.44		%	1		%	0.4		%				1.16		%
	Return on average invested capital	16.49		%	21.99		%	9		%				10.51		%
	Efficiency ratio	40.24		%	51.3		%	76.37		%				64.6		%
	Reportable segments reconciliation to the Consolidated Financial Statements for the year ended December 31, 2012 is as follows (in thousands):
		Commercial			Consumer			Wealth			Funds Management and Other			BOK
								Management						Financial
														Consolidated
	Net interest revenue from external sources	$	366,243		$	102,321		$	27,647		$	211,338		$	707,549
	Net interest revenue (expense) from internal sources	(58,835		)	36,700			21,456			679			—
	Net interest revenue	307,408			139,021			49,103			212,017			707,549
	Provision for credit losses	9,463			10,588			2,284			(44,335		)	(22,000		)
	Net interest revenue after provision for credit losses	297,945			128,433			46,819			256,352			729,549
	Other operating revenue	162,085			271,723			197,306			22,564			653,678
	Other operating expense	192,396			206,598			177,423			263,946			840,363
	Net direct contribution	267,634			193,558			66,702			14,970			542,864
	Corporate expense allocations	44,330			64,239			30,525			(139,094		)	—
	Net income before taxes	223,304			129,319			36,177			154,064			542,864
	Federal and state income taxes	86,865			50,305			14,073			37,497			188,740
	Net income	136,439			79,014			22,104			116,567			354,124
Net income attributable to non-controlling interests	—			—			—			2,933			2,933
Net income attributable to BOK Financial Corp. shareholders	$	136,439		$	79,014		$	22,104		$	113,634		$	351,191
Average assets	$	9,844,145		$	6,498,193		$	4,357,641		$	5,589,171		$	26,289,150
Average invested capital	882,036			289,665			184,707			1,549,547			2,905,955
Performance measurements:
Return on average assets	1.39		%	1.22		%	0.52		%				1.34		%
Return on average invested capital	15.47		%	27.28		%	12.26		%				12.09		%
Efficiency ratio	42.26		%	49.6		%	71.19		%				62.03		%

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2014
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 that are measured on a recurring basis is as follows as of December 31, 2014 (in thousands):
			Total				Quoted Prices in Active Markets for Identical Instruments				Significant Other Observable Inputs				Significant Unobservable Inputs
	Assets:
	Trading securities:
	U.S. Government agency debentures		$	85,092			$	—			$	85,092			$	—
	U.S. agency residential mortgage-backed securities		31,199				—				31,199				—
	Municipal and other tax-exempt securities		38,951				—				38,951				—
	Other trading securities		33,458				—				33,458				—
	Total trading securities		188,700				—				188,700				—
	Available for sale securities:
	U.S. Treasury securities		1,005				1,005				—				—
	Municipal and other tax-exempt securities		63,557				—				53,464				10,093
	U.S. government agency residential mortgage-backed securities		6,646,884				—				6,646,884				—
	Privately issued residential mortgage-backed securities		165,957				—				165,957				—
	Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,048,609				—				2,048,609				—
	Other debt securities		9,212				—				5,062				4,150
	Perpetual preferred stock		24,277				—				24,277				—
	Equity securities and mutual funds		19,444				4,927				14,517				—
	Total available for sale securities		8,978,945				5,932				8,958,770				14,243
	Fair value option securities:
	U.S. government agency residential mortgage-backed securities		311,597				—				311,597				—
	Other securities		—				—				—				—
	Total fair value option securities		311,597				—				311,597				—
	Residential mortgage loans held for sale		304,182				—				292,326				11,856
	Mortgage servicing rights, net1		171,976				—				—				171,976
	Derivative contracts, net of cash margin2		361,874				17,607				344,267				—
	Other assets – private equity funds		25,627				—				—				25,627
	Liabilities:
	Derivative contracts, net of cash margin2		354,554				541				354,013				—
	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 7, Mortgage Banking Activities.
	2	See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts in asset positions were valued based on quoted prices in active markets or identical instruments (Level 1) are exchange-traded energy derivative contracts, net of cash margin. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate and agricultural derivative contracts, net of cash margin.
	The fair value of financial assets and liabilities that are measured on a recurring basis is as follows as of December 31, 2013 (in thousands):
			Total				Quoted Prices in Active Markets for Identical Instruments				Significant Other Observable Inputs				Significant Unobservable Inputs
	Assets:
	Trading securities:
	U.S. Government agency debentures		$	34,120			$	—			$	34,120			$	—
	U.S. government agency residential mortgage-backed securities		21,011				—				21,011				—
	Municipal and other tax-exempt securities		27,350				—				27,350				—
	Other trading securities		9,135				—				9,135				—
	Total trading securities		91,616				—				91,616				—
	Available for sale securities:
	U.S. Treasury securities		1,042				1,042				—				—
	Municipal and other tax-exempt securities		73,775				—				55,970				17,805
	U.S. government agency residential mortgage-backed securities		7,716,010				—				7,716,010				—
	Privately issued residential mortgage-backed securities		221,099				—				221,099				—
	Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,055,804				—				2,055,804				—
	Other debt securities		35,241				—				30,529				4,712
	Perpetual preferred stock		22,863				—				22,863				—
	Equity securities and mutual funds		21,328				—				17,121				4,207
	Total available for sale securities		10,147,162				1,042				10,119,396				26,724
	Fair value option securities:
	U.S. government agency residential mortgage-backed securities		157,431				—				157,431				—
	Other securities		9,694				—				9,694				—
	Total fair value option securities		167,125				—				167,125				—
	Residential mortgage loans held for sale		200,546				—				200,546				—
	Mortgage servicing rights, net1		153,333				—				—				153,333
	Derivative contracts, net of cash margin2		265,012				2,712				262,300				—
	Other assets – private equity funds		27,341				—				—				27,341
	Liabilities:
	Derivative contracts, net of cash margin 2		247,185				—				247,185				—
	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 7, 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 contracts, net of cash margin.
Fair Value Assets Measured On Recurring Basis Significant Unobservable Inputs [Table Text Block]	The following represents the changes related to assets measured at fair value on a recurring basis using significant unobservable inputs (in thousands):
			Available for Sale Securities												Residential mortgage loans held for sale				Other assets – private equity funds
			Municipal and other tax-exempt				Other debt securities				Equity securities and mutual funds
	Balance, December 31, 2012		$	40,702			$	5,399			$	2,161			$	—			$	28,169
	Transfer to Level 3 from Level 2		—				—				—				—				—
	Purchases and capital calls		—				—				—				—				1,415
	Redemptions and distributions		(19,238		)		(500		)		—				—				(5,294		)
	Gain (loss) recognized in earnings:
	Gain (loss) on other assets, net		—				—				—				—				3,051
	Gain on available for sale securities, net		1,216				—				—				—				—
	Other-than-temporary impairment losses		(1,369		)		—				—				—				—
	Other comprehensive income (loss):
	Net change in unrealized gain (loss)		(3,506		)		(187		)		2,046				—				—
	Balance, December 31, 2013		17,805				4,712				4,207				—				27,341
	Transfer to Level 3 from Level 2		—				—				—				13,644				—
	Purchases and capital calls		—				—				—				—				1,012
	Redemptions and distributions		(7,487		)		(500		)		—				—				(7,473		)
	Proceeds from sales		—				—				—				(1,176		)		—
	Gain (loss) recognized in earnings:
	Mortgage banking revenue		—				—				—				(612		)		—
	Gain on other assets, net		—				—				—				—				4,747
	Gain on available for sale securities, net		(235		)		—				—				—				—
	Other-than-temporary impairment losses		—				—				—				—				—
	Charitable contributions to BOKF Foundation		—				—				(2,420		)		—				—
	Other comprehensive income (loss):
	Net change in unrealized gain (loss)		10				(62		)		(1,787		)		—				—
	Balance, December 31, 2014		$	10,093			$	4,150			$	—			$	11,856			$	25,627
Fair Value Inputs, Assets, 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 December 31, 2014 follows (in thousands):
	Quantitative Information about Level 3 Non-recurring Fair Value Measurements
			Fair Value				Valuation Technique(s)		Unobservable Input		Range
											(Weighted Average)
	Impaired loans		$	635			Appraised value, as adjusted		Broker quotes and management's knowledge of industry and collateral.		N/A
	Real estate and other repossessed assets		3,691				Appraised value, as adjusted		Marketability adjustments off appraised value		65%
	A summary of quantitative information about Non-recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of December 31, 2013 follows (in thousands):
	Quantitative Information about Level 3 Non-recurring Fair Value Measurements
			Fair Value				Valuation Technique(s)		Unobservable Input		Range
											(Weighted Average)
	Impaired loans		$	4,622			Appraised value, as adjusted		Broker quotes and management's knowledge of industry and collateral.		N/A
	Real estate and other repossessed assets		191				Listing value, less cost to sell		Marketability adjustments off appraised value		80%-85% (82%)1
	1	Marketability adjustments includes consideration of estimated costs to sell which is approximately 15% of the fair value.
	A summary of quantitative information about assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) as of December 31, 2014 follows (in thousands):
	Quantitative Information about Level 3 Recurring Fair Value Measurements
			Par				Amortized				Fair				Valuation Technique(s)		Unobservable Input		Range
			Value				Cost/Unpaid Principal Balance				Value								(Weighted Average)
	Available for sale securities
	Municipal and other tax-exempt securities		$	10,870			$	10,805			$	10,093			Discounted cash flows	1	Interest rate spread		4.96%-5.26% (5.21%)	2
																			92.65%-94.32% (93.09%)	3
	Other debt securities		4,400				4,400				4,150				Discounted cash flows	1	Interest rate spread		5.62% - 5.67% (5.66%)	4
																			92.65% - 92.95% (92.77%)	3
	Residential mortgage loans held for sale		N/A				12,468				11,856				Quoted prices of loans sold in securitization transactions, with a liquidity discount applied		Liquidity discount applied to the market value of mortgage loans qualifying for sale to U.S. government agencies		95.09%
	Other assets - private equity funds		N/A				N/A				25,627				Net asset value reported by underlying fund		Net asset value reported by underlying fund		N/A
	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 488 to 516 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%.
	A summary of quantitative information about Recurring Fair Value Measurements based on Significant Unobservable Inputs (Level 3) as of December 31, 2013 follows (in thousands):
	Quantitative Information about Level 3 Recurring Fair Value Measurements
			Par				Amortized				Fair				Valuation Technique(s)		Unobservable Input		Range
			Value				Cost6				Value								(Weighted Average)
	Available for sale securities
	Municipal and other tax-exempt securities		$	18,695			$	18,624			$	17,805			Discounted cash flows	1	Interest rate spread		4.97%-5.27% (5.16%)	2
																			95.02%-95.50% (95.24%)	3
	Other debt securities		4,900				4,900				4,712				Discounted cash flows	1	Interest rate spread		5.67% (5.67%)	4
																			96.16% (96.16%)	3
	Equity securities and other mutual funds		N/A				2,420				4,207				Publicly announced preliminary purchase price information from acquirer		Discount for settlement uncertainty		N/A	5
	Other assets - private equity funds		N/A				N/A				27,341				Net asset value reported by underlying fund		Net asset value reported by underlying fund		N/A
	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 467 to 518 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%.
	5	Fair value of shares of a smaller privately-held financial institution were valued using preliminary announced purchase information by a publicly-traded acquirer.
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 recorded during the year. The carrying value represents only those assets with the balance sheet date for which the fair value was adjusted during the year:
		Carrying Value at December 31, 2014												Fair Value Adjustments for the
														Year Ended December 31, 2014
														Recognized In:
		Quoted Prices				Significant				Significant				Gross charge-offs against allowance for loan losses				Net losses and expenses of repossessed assets, net
		in Active Markets for Identical Instruments				Other				Unobservable
						Observable				Inputs
						Inputs
	Impaired loans	$	—			$	8,198			$	635			$	4,044			$	—
	Real estate and other repossessed assets	—				22,594				3,691				—				3,563
		Carrying Value at December 31, 2013												Fair Value Adjustments for the
														Year Ended December 31, 2013
														Recognized In:
		Quoted Prices				Significant				Significant				Gross charge-offs against allowance for loan losses				Net losses and expenses of repossessed assets, net
		in Active Markets for Identical Instruments				Other				Unobservable
						Observable				Inputs
						Inputs
	Impaired loans	$	—			$	8,380			$	4,622			$	6,598			$	—
	Real estate and other repossessed assets	—				20,733				191				—				5,489
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 (dollars in thousands):
			31-Dec-14
			Carrying				Range of Contractual Yields				Average		Discount Rate				Estimated
			Value								Re-pricing						Fair
											(in years)						Value
	Cash and due from banks		$	550,576													$	550,576
	Interest-bearing cash and cash equivalents		1,925,266														1,925,266
	Trading securities:
	U.S. Government agency debentures		85,092														85,092
	U.S. government agency residential mortgage-backed securities		31,199														31,199
	Municipal and other tax-exempt securities		38,951														38,951
	Other trading securities		33,458														33,458
	Total trading securities		188,700														188,700
	Investment securities:
	Municipal and other tax-exempt securities		405,090														408,344
	U.S. government agency residential mortgage-backed securities		35,750														37,463
	Other debt securities		211,520														227,819
	Total investment securities		652,360														673,626
	Available for sale securities:
	U.S. Treasury securities		1,005														1,005
	Municipal and other tax-exempt securities		63,557														63,557
	U.S. government agency residential mortgage-backed securities		6,646,884														6,646,884
	Privately issued residential mortgage-backed securities		165,957														165,957
	Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,048,609														2,048,609
	Other debt securities		9,212														9,212
	Perpetual preferred stock		24,277														24,277
	Equity securities and mutual funds		19,444														19,444
	Total available for sale securities		8,978,945														8,978,945
	Fair value option securities:
	U.S. government agency residential mortgage-backed securities		311,597														311,597
	Other securities		—														—
	Total fair value option securities		311,597														311,597
	Residential mortgage loans held for sale		304,182														304,182
	Loans:
	Commercial		9,095,670				0.17	% -	30.00%		0.65		0.51	% -	4.34%		8,948,870
	Commercial real estate		2,728,150				0.38	% -	18.00%		0.84		1.09	% -	3.78%		2,704,454
	Residential mortgage		1,949,512				1.2	% -	18.00%		2.5		0.64	% -	3.99%		1,985,870
	Consumer		434,705				0.38	% -	21.00%		0.45		1.04	% -	3.98%		431,274
	Total loans		14,208,037														14,070,468
	Allowance for loan losses		(189,056		)												—
	Loans, net of allowance		14,018,981														14,070,468
	Mortgage servicing rights		171,976														171,976
	Derivative instruments with positive fair value, net of cash margin		361,874														361,874
	Other assets – private equity funds		25,627														25,627
	Deposits with no stated maturity		18,532,143														18,532,143
	Time deposits		2,608,716				0.02	% -	9.64%		1.92		0.76	% -	1.33%		2,612,576
	Other borrowings		3,378,294				0.21	% -	1.52%		0.12		0.06	% -	2.64%		3,331,771
	Subordinated debentures		347,983				0.92	% -	5.00%		1.67		2.14%				344,687
	Derivative instruments with negative fair value, net of cash margin		354,554														354,554
			31-Dec-13
			Carrying				Range of Contractual Yields				Average		Discount Rate				Estimated
			Value								Re-pricing						Fair
											(in years)						Value
	Cash and due from banks		$	512,931													$	512,931
	Interest-bearing cash and cash equivalents		574,282														574,282
	Trading securities:
	U.S. Government agency debentures		34,120														34,120
	U.S. government agency residential mortgage-backed securities		21,011														21,011
	Municipal and other tax-exempt securities		27,350														27,350
	Other trading securities		9,135														9,135
	Total trading securities		91,616														91,616
	Investment securities:
	Municipal and other tax-exempt		440,187														439,870
	U.S. government agency residential mortgage-backed securities		50,182														51,864
Other debt securities		187,509														195,393
Total investment securities		677,878														687,127
Available for sale securities:
U.S. Treasury		1,042														1,042
Municipal and other tax-exempt		73,775														73,775
U.S. government agency residential mortgage-backed securities		7,716,010														7,716,010
Privately issued residential mortgage-backed securities		221,099														221,099
Commercial mortgage-backed securities guaranteed by U.S. government agencies		2,055,804														2,055,804
Other debt securities		35,241														35,241
Perpetual preferred stock		22,863														22,863
Equity securities and mutual funds		21,328														21,328
Total available for sale securities		10,147,162														10,147,162
Fair value option securities:
U.S. government agency residential mortgage-backed securities		157,431														157,431
Other securities		9,694														9,694
Total fair value option securities		167,125														167,125
Residential mortgage loans held for sale		200,546														200,546
Loans:
Commercial		7,943,221				0.04	% -	30.00%		0.49		0.48	% -	4.33%		7,835,325
Commercial real estate		2,415,353				0.38	% -	18.00%		0.78		1.21	% -	3.49%		2,394,443
Residential mortgage		2,052,026				0.38	% -	18.00%		2.63		0.59	% -	4.73%		2,068,690
Consumer		381,664				0.38	% -	21.00%		0.55		1.22	% -	3.75%		375,962
Total loans		12,792,264														12,674,420
Allowance for loan losses		(185,396		)												—
Loans, net of allowance		12,606,868														12,674,420
Mortgage servicing rights		153,333														153,333
Derivative instruments with positive fair value, net of cash margin		265,012														265,012
Other assets – private equity funds		27,341														27,341
Deposits with no stated maturity		17,573,334														17,573,334
Time deposits		2,695,993				0.01	% -	9.64%		2.12		0.75	% -	1.33%		2,697,290
Other borrowings		2,721,888				0.25	% -	4.78%		0.03		0.08	% -	2.64%		2,693,788
Subordinated debentures		347,802				0.95	% -	5.00%		2.63		2.22%				344,783
Derivative instruments with negative fair value, net of cash margin		247,185														247,185
Fair Value Inputs, Financial Instruments, Quantitative Information [Table Text Block]
		Range of						Average Re-pricing (in years)		Discount
		Contractual								Rate
		Yields
		Minimum			Maximum					Minimum			Maximum
	December 31, 2014
	Loans:
	Commercial	0.17	%		30	%		0.65		0.51	%		4.34	%
	Commercial real estate	0.38	%		18	%		0.84		1.09	%		3.78	%
	Residential mortgage	1.2	%		18	%		2.5		0.64	%		3.99	%
	Consumer	0.38	%		21	%		0.45		1.04	%		3.98	%
	Time deposits	0.02	%		9.64	%		1.92		0.76	%		1.33	%
	Other borrowings	0.21	%		1.52	%		0.12		0.06	%		2.64	%
	Subordinated debentures	0.92	%		5	%		1.67		2.14	%		2.14	%
	December 31, 2013
	Loans:
	Commercial	0.04	%		30	%		0.49		0.48	%		4.33	%
	Commercial real estate	0.38	%		18	%		0.78		1.21	%		3.49	%
	Residential mortgage	0.38	%		18	%		2.63		0.59	%		4.73	%
	Consumer	0.38	%		21	%		0.55		1.22	%		3.75	%
	Time deposits	0.01	%		9.64	%		2.12		0.75	%		1.33	%
	Other borrowings	0.25	%		4.78	%		0.03		0.08	%		2.64	%
	Subordinated debentures	0.95	%		5	%		2.63		2.22	%		2.22	%

Parent_Company_Only_Financial_1

Parent Company Only Financial Statements Parent Company Only Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Financial Statements [Table Text Block]	Summarized financial information for BOK Financial – Parent Company Only follows:
	Balance Sheets
	(In thousands)	December 31,
		2014			2013
	Assets
	Cash and cash equivalents	$	510,668		$	561,297
	Available for sale securities	24,794			27,526
	Investment in subsidiaries	2,774,276			2,426,495
	Other assets	1,637			12,872
	Total assets	$	3,311,375		$	3,028,190
	Liabilities and Shareholders’ Equity
	Other liabilities	$	9,196		$	8,141
	Total liabilities	9,196			8,141
	Shareholders’ equity:
	Common stock	4			4
	Capital surplus	954,644			898,586
	Retained earnings	2,530,837			2,349,428
	Treasury stock	(239,979		)	(202,346		)
	Accumulated other comprehensive income (loss)	56,673			(25,623		)
	Total shareholders’ equity	3,302,179			3,020,049
	Total liabilities and shareholders’ equity	$	3,311,375		$	3,028,190
	Statements of Earnings
	(In thousands)	Year Ended December 31,
		2014			2013			2012
	Dividends, interest and fees received from subsidiaries	$	75,412		$	225,340		$	275,330
	Other revenue	1,572			3,341			2,295
	Other-than-temporary impairment losses recognized in earnings	—			—			(1,099		)
	Total revenue	76,984			228,681			276,526
	Interest expense	293			292			269
	Charitable contributions to BOKF Foundation	2,420			2,062			2,062
	Professional fees and services	600			811			765
	Other operating expense	1,556			1,210			1,037
	Total expense	4,869			4,375			4,133
	Income before taxes and equity in undistributed income of subsidiaries	72,115			224,306			272,393
	Federal and state income taxes	(1,702		)	(1,578		)	(1,706		)
	Income before equity in undistributed income of subsidiaries	73,817			225,884			274,099
	Equity in undistributed income of subsidiaries	218,618			90,725			77,092
	Net income attributable to BOK Financial Corp. shareholders	$	292,435		$	316,609		$	351,191
	Statements of Cash Flows
	(In thousands)	Year Ended December 31,
		2014			2013			2012
	Cash Flows From Operating Activities:
	Net income	$	292,435		$	316,609		$	351,191
	Adjustments to reconcile net income to net cash provided by operating activities:
	Equity in undistributed income of subsidiaries	(218,618		)	(90,725		)	(77,092		)
	Tax effect from equity compensation, net	(8,258		)	(2,210		)	(120		)
	Change in other assets	8,726			(8,308		)	4,237
	Change in other liabilities	1,055			4,263			(4,965		)
	Net cash provided by operating activities	75,340			219,629			273,251
	Cash Flows From Investing Activities:
	Purchases of available for sale securities	—			—			(5,343		)
	Proceeds from sales of available for sale securities	—			13,600			4,781
	Investment in subsidiaries	(15,336		)	(36,000		)	(9,100		)
	Acquisitions, net of cash acquired	—			(7,500		)	(20,000		)
	Net cash used in investing activities	(15,336		)	(29,900		)	(29,662		)
	Cash Flows From Financing Activities:
	Issuance of common and treasury stock, net	4,472			16,566			14,650
	Tax effect from equity compensation, net	8,258			2,210			120
	Dividends paid	(111,026		)	(104,722		)	(166,982		)
	Repurchase of common stock	(12,337		)	—			(20,558		)
	Net cash used in financing activities	(110,633		)	(85,946		)	(172,770		)
	Net increase (decrease) in cash and cash equivalents	(50,629		)	103,783			70,819
	Cash and cash equivalents at beginning of period	561,297			457,514			386,695
	Cash and cash equivalents at end of period	$	510,668		$	561,297		$	457,514
Cash paid for interest	$	293		$	292		$	269
Issuance of shares in settlement of deferred compensation, net	$	8,352		$	—		$	—

Significant_Accounting_Policie2

Significant Accounting Policies Goodwill and Intangible Assets (Details)	12 Months Ended
	Dec. 31, 2014
Minimum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	3 years
Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	20 years

Significant_Accounting_Policie3

Significant Accounting Policies Cash Equivalents (Details)	12 Months Ended
	Dec. 31, 2014
Cash and Cash Equivalents [Abstract]
Maturity of Federal Funds Sold Considered Cash Equivalents	1 day
Maturity of Resell Agreement Considered Cash Equivalents, Minimum	1 day
Maturity of Resell Agreements Considered Cash Equivalents, Maximum	30 days

Significant_Accounting_Policie4

Significant Accounting Policies Derivative Instruments (Details)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments [Abstract]
Effective Fair Value Hedge, Fair Value Adjustment of Interest Rate Swap to Cumulative Change in Fair Value of Hedged Item, Minimum	80.00%
Effective Fair Value Hedge, Fair Value Adjustment of Interest Rate Swap to Cumulative Change in Fair Value of Hedged Item, Maximum	120.00%

Significant_Accounting_Policie5

Significant Accounting Policies Loans (Details)	12 Months Ended
	Dec. 31, 2014
Loans [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, Minimum Number of Days After Which Past Due Non-Risk Graded Loans Are Charged Off	60 days
Loans, Maximum Number of Days After Which Past Due Non-Risk Graded Loans Are Charged Off	180 days
Loans, Number of Days After Notification of Chapter 7 Bankruptcy Non-Risk Graded Loan is Charged Off	60 days

Significant_Accounting_Policie6

Significant Accounting Policies Premises and Equipment (Details)	12 Months Ended
	Dec. 31, 2014
Building and improvements [Member] | Minimum [Member]
Premises and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Building and improvements [Member] | Maximum [Member]
Premises and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	40 years
Software and Software Development Costs [Member] | Minimum [Member]
Premises and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Software and Software Development Costs [Member] | Maximum [Member]
Premises and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Furniture and equipment [Member] | Minimum [Member]
Premises and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Furniture and equipment [Member] | Maximum [Member]
Premises and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years

Significant_Accounting_Policie7

Significant Accounting Policies Share-Based Compensation (Details)	12 Months Ended
	Dec. 31, 2014
Stock Options [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Vesting period (in years)	7 years
Prior to 2013 [Member] | Non-vested Common Stock [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Vesting period (in years)	5 years
2013 Plan [Member] | Non-vested Common Stock [Member]
Share-based Compensation Arrangements by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Required Holding Period	2 years

Trading_Securities_Details

Trading Securities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Schedule of Trading Securities [Line Items]
Trading Securities, Fair Value	$188,700,000	$91,616,000
Trading Securities, Net Unrealized Gain (Loss)	187,000	11,000
Trading Securities Pledged as Collateral	0	0
U.S. government agency debentures [Member]
Schedule of Trading Securities [Line Items]
Trading Securities, Fair Value	85,092,000	34,120,000
Trading Securities, Net Unrealized Gain (Loss)	-62,000	77,000
U.S. government agency residential mortgage-backed securities [Member]
Schedule of Trading Securities [Line Items]
Trading Securities, Fair Value	31,199,000	21,011,000
Trading Securities, Net Unrealized Gain (Loss)	269,000	123,000
Municipal and other tax-exempt securities [Member]
Schedule of Trading Securities [Line Items]
Trading Securities, Fair Value	38,951,000	27,350,000
Trading Securities, Net Unrealized Gain (Loss)	18,000	-182,000
Other trading securities [Member]
Schedule of Trading Securities [Line Items]
Trading Securities, Fair Value	33,458,000	9,135,000
Trading Securities, Net Unrealized Gain (Loss)	($38,000)	($7,000)

Investment_HeldtoMaturity_Secu

Investment (Held-to-Maturity) Securities (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Sep. 30, 2011
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Amortized Cost	$651,745,000		$676,047,000
Investment Securities, Debt Maturities, Carrying Value	652,360,000	[1]	677,878,000	[2]
Investment Securities, Fair Value	673,626,000		687,127,000
Investment Securities, Gross Unrealized Gain	22,874,000	[3]	12,687,000	[3]
Investment Securities, Gross Unrealized Loss	-1,608,000	[3]	-3,438,000	[3]
Investment Securities, Debt Maturities, Carrying Value [Abstract]
Investment Securities, Debt Maturities, Carrying Value	652,360,000	[1]	677,878,000	[2]
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Fair Value	673,626,000		687,127,000
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Nominal Yield	3.28%
Investment Securities, Pledged as Collateral [Abstract]
Investment Securities, Pledged as Collateral, Carrying Value	63,495,000		89,087,000
Investment Securities, Pledged as Collateral, Fair Value	65,855,000		91,804,000
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	162		139
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	143,951,000		192,538,000
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	60,837,000		53,850,000
Investment Securities, Continuous Unrealized Loss Position, Fair Value	204,788,000		246,388,000
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	1,063,000		2,526,000
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	545,000		912,000
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss	1,608,000		3,438,000
Other than Temporary Impairment Losses, Investment Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Carrying Value	35,750,000	[4]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	37,463,000	[4]
Investment Securities, Portfolio Concentration Rated AAA to AA, Carrying Value	424,679,000
Investment Securities, Portfolio Concentration Rated AAA to AA, Fair Value	441,566,000
Investment Securities, Portfolio Concentration Rated A to BBB, Carrying Value	13,676,000
Investment Securities, Portfolio Concentration Rated A to BBB, Fair Value	13,806,000
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	178,255,000
Investment Securities, Portfolio Concentration Not Rated, Fair Value	180,791,000
Fixed maturity securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Debt Maturities, Carrying Value	616,610,000
Investment Securities, Fair Value	636,163,000
Investment Securities, Debt Maturities, Carrying Value [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Carrying Value	60,173,000
Investment Securities, Debt Maturities, One to Five Years, Carrying Value	337,660,000
Investment Securities, Debt Maturities, Six to Ten Years, Carrying Value	80,767,000
Investment Securities, Debt Maturities, Over Ten Years, Carrying Value	138,010,000
Investment Securities, Debt Maturities, Carrying Value	616,610,000
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Fair Value	60,306,000
Investment Securities, Debt Maturities, One to Five Years, Fair Value	338,943,000
Investment Securities, Debt Maturities, Six to Ten Years, Fair Value	84,096,000
Investment Securities, Debt Maturities, Over Ten Years, Fair Value	152,818,000
Investment Securities, Fair Value	636,163,000
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Nominal Yield	2.14%
Investment Securities, Debt Maturities, One to Five Years, Nominal Yield	2.10%
Investment Securities, Debt Maturities, Six to Ten Years, Nominal Yield	4.83%
Investment Securities, Debt Maturities, Over Ten Years, Nominal Yield	5.91%
Investment Securities, Debt Maturities, Nominal Yield	3.31%
Investment Securities, Debt Maturities, Weighted Average Maturity	5.65	[5]
Municipal and other tax-exempt securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Amortized Cost	405,090,000		440,187,000
Investment Securities, Debt Maturities, Carrying Value	405,090,000	[1]	440,187,000	[2]
Investment Securities, Fair Value	408,344,000		439,870,000
Investment Securities, Gross Unrealized Gain	4,205,000	[3]	2,452,000	[3]
Investment Securities, Gross Unrealized Loss	-951,000	[3]	-2,769,000	[3]
Investment Securities, Debt Maturities, Carrying Value [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Carrying Value	44,255,000
Investment Securities, Debt Maturities, One to Five Years, Carrying Value	299,934,000
Investment Securities, Debt Maturities, Six to Ten Years, Carrying Value	22,429,000
Investment Securities, Debt Maturities, Over Ten Years, Carrying Value	38,472,000
Investment Securities, Debt Maturities, Carrying Value	405,090,000	[1]	440,187,000	[2]
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Fair Value	44,381,000
Investment Securities, Debt Maturities, One to Five Years, Fair Value	300,434,000
Investment Securities, Debt Maturities, Six to Ten Years, Fair Value	22,666,000
Investment Securities, Debt Maturities, Over Ten Years, Fair Value	40,863,000
Investment Securities, Fair Value	408,344,000		439,870,000
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Nominal Yield	1.71%	[6]
Investment Securities, Debt Maturities, One to Five Years, Nominal Yield	1.74%	[6]
Investment Securities, Debt Maturities, Six to Ten Years, Nominal Yield	3.91%	[6]
Investment Securities, Debt Maturities, Over Ten Years, Nominal Yield	5.37%	[6]
Investment Securities, Debt Maturities, Nominal Yield	2.20%	[6]
Investment Securities, Debt Maturities, Weighted Average Maturity	3.8	[5]
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 Securities	78		107
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	112,677,000		166,382,000
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	60,076,000		53,073,000
Investment Securities, Continuous Unrealized Loss Position, Fair Value	172,753,000		219,455,000
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	426,000		1,921,000
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	525,000		848,000
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss	951,000		2,769,000
Other than Temporary Impairment Losses, Investment Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Carrying Value	0	[4]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[4]
Investment Securities, Portfolio Concentration Rated AAA to AA, Carrying Value	264,326,000
Investment Securities, Portfolio Concentration Rated AAA to AA, Fair Value	264,651,000
Investment Securities, Portfolio Concentration Rated A to BBB, Carrying Value	13,676,000
Investment Securities, Portfolio Concentration Rated A to BBB, Fair Value	13,806,000
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	127,088,000
Investment Securities, Portfolio Concentration Not Rated, Fair Value	129,887,000
Other debt securities [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Amortized Cost	211,520,000		187,509,000
Investment Securities, Debt Maturities, Carrying Value	211,520,000	[1]	187,509,000	[2]
Investment Securities, Fair Value	227,819,000		195,393,000
Investment Securities, Gross Unrealized Gain	16,956,000	[3]	8,497,000	[3]
Investment Securities, Gross Unrealized Loss	-657,000	[3]	-613,000	[3]
Investment Securities, Debt Maturities, Carrying Value [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Carrying Value	15,918,000
Investment Securities, Debt Maturities, One to Five Years, Carrying Value	37,726,000
Investment Securities, Debt Maturities, Six to Ten Years, Carrying Value	58,338,000
Investment Securities, Debt Maturities, Over Ten Years, Carrying Value	99,538,000
Investment Securities, Debt Maturities, Carrying Value	211,520,000	[1]	187,509,000	[2]
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Debt Maturities, Less than One Year, Fair Value	15,925,000
Investment Securities, Debt Maturities, One to Five Years, Fair Value	38,509,000
Investment Securities, Debt Maturities, Six to Ten Years, Fair Value	61,430,000
Investment Securities, Debt Maturities, Over Ten Years, Fair Value	111,955,000
Investment Securities, Fair Value	227,819,000		195,393,000
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Less Than One Year, Nominal Yield	3.32%
Investment Securities, Debt Maturities, One to Five Years, Nominal Yield	4.96%
Investment Securities, Debt Maturities, Six to Ten Years, Nominal Yield	5.19%
Investment Securities, Debt Maturities, Over Ten Years, Nominal Yield	6.12%
Investment Securities, Debt Maturities, Nominal Yield	5.45%
Investment Securities, Debt Maturities, Weighted Average Maturity	9.18	[5]
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	84		30
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	31,274,000		10,932,000
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	761,000		777,000
Investment Securities, Continuous Unrealized Loss Position, Fair Value	32,035,000		11,709,000
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	637,000		549,000
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	20,000		64,000
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss	657,000		613,000
Other than Temporary Impairment Losses, Investment Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Carrying Value	0	[4]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[4]
Investment Securities, Portfolio Concentration Rated AAA to AA, Carrying Value	160,353,000
Investment Securities, Portfolio Concentration Rated AAA to AA, Fair Value	176,915,000
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	51,167,000
Investment Securities, Portfolio Concentration Not Rated, Fair Value	50,904,000
U.S. government agency residential mortgage-backed securities [Member] | Other [Member]
Schedule of Investment (Held-to-Maturity) Securities [Line Items]
Investment Securities, Amortized Cost	35,135,000		48,351,000
Investment Securities, Debt Maturities, Carrying Value	35,750,000	[1]	50,182,000	[2]
Investment Securities, Fair Value	37,463,000		51,864,000
Investment Securities, Gross Unrealized Gain	1,713,000	[3]	1,738,000	[3]
Investment Securities, Gross Unrealized Loss	0	[3]	-56,000	[3]
Investments Securities, Transfers [Abstract]
Investment Securities, Transferred From Available For Sale Securities Portfolio, Fair Value					131,000,000
Investment Securities, Transferred From Available For Sale Securities Portfolio, Amortized Cost					118,000,000
Investment Securities, Transferred From Available For Sale Securities Portfolio, Net Unrealized Gain	615,000		1,800,000		13,000,000
Investment Securities, Debt Maturities, Carrying Value [Abstract]
Investment Securities, Debt Maturities, Carrying Value	35,750,000	[1]	50,182,000	[2]
Investment Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Investment Securities, Fair Value	37,463,000		51,864,000
Investment Securities, Debt Maturities, Nominal Yield [Abstract]
Investment Securities, Debt Maturities, Nominal Yield	2.74%	[7]
Investment Securities, Debt Maturities, Average Expected Life of Mortgage-backed Securities	2 years 10 months
Investment Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Investment Securities, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities			2
Investment Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value			15,224,000
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value			0
Investment Securities, Continuous Unrealized Loss Position, Fair Value			15,224,000
Investment Securities, Continuous Unrealized Loss Position, Aggregate Losses [Abstract]
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses			56,000
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses			0
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss			56,000
Other than Temporary Impairment Losses, Investment Securities, Portion Recognized in Earnings, Net, Qualitative Disclosures, Lowest Current Credit Rating [Abstract]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Carrying Value	35,750,000	[4]
Investment Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	37,463,000	[4]
Investment Securities, Portfolio Concentration Rated AAA to AA, Carrying Value	0
Investment Securities, Portfolio Concentration Rated AAA to AA, Fair Value	0
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	0
Investment Securities, Portfolio Concentration Not Rated, Fair Value	$0
[1]	Carrying value includes $615 thousand of net unrealized gain which remains in Accumulated other comprehensive income (“AOCI”) in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.
[2]	Carrying value includes $1.8 million of net unrealized gain which remains in AOCI in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.
[3]	Gross unrealized gains and losses are not recognized in AOCI in the Consolidated Balance Sheets.
[4]	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.
[5]	Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without penalty.
[6]	Calculated on a taxable equivalent basis using a 39% effective tax rate.
[7]	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_

Available for Sale Securities (Details) (USD $)	12 Months Ended					72 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	$8,881,990		$10,185,091			$8,881,990
Available-for-sale Securities, Fair Value	8,978,945		10,147,162			8,978,945
Available-for-sale Securities, Gross Unrealized Gain	129,876	[1]	120,120	[1]		129,876	[1]
Available-for-sale Securities, Gross Unrealized Loss	-32,257	[1]	-155,607	[1]		-32,257	[1]
Available-for-sale Securities, Other Than Temporary Impairments	-664	[2]	-2,442	[2]		-664	[2]
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.85%					1.85%
Available-for-sale Securities, Gross Realized Gain (Loss), Disclosures [Abstract]
Available-for-sale Securities, Proceeds	2,664,740		2,436,093		1,744,662
Available-for-sale Securities, Gross realized gains	24,923		25,711		41,191
Available-for-sale Securities, Gross realized losses	-23,384		-14,991		-7,346
Available-for-sale Securites, Related federal and state income tax expense	599		4,170		13,166
Available-for-sale Securities, Pledged as Collateral [Abstract]
Available-for-sale Securities, Pledged As Collateral, Amortized cost	5,855,220		5,171,782			5,855,220
Available-for-sale Securities, Pledged As Collateral, Fair value	5,893,972		5,133,530			5,893,972
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	255		446			255
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	577,473		6,230,595			577,473
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	2,160,051		50,865			2,160,051
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,737,524		6,281,460			2,737,524
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	1,446		156,172			1,446
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	31,475		1,877			31,475
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	32,921		158,049			32,921
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 US Govt or GSE Securities Not Rated, Amortized Cost	8,614,400	[3]				8,614,400	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	8,696,498	[3]				8,696,498	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	44,915					44,915
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	46,245					46,245
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	27,497					27,497
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	28,087					28,087
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	165,125					165,125
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	177,726					177,726
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	30,053					30,053
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	30,389					30,389
Fixed maturity securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	2,137,552					2,137,552
Available-for-sale Securities, Fair Value	2,122,383					2,122,383
Available-for-sale Securities, Debt Maturities, Amortized Cost, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost	13,177					13,177
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost	941,928					941,928
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost	811,080					811,080
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost	371,367					371,367
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less Than One Year, Fair Value	13,267					13,267
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value	936,684					936,684
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value	805,820					805,820
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value	366,612					366,612
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield	2.82%					2.82%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	1.52%					1.52%
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Nominal Yield	1.69%					1.69%
Available-for-sale Securities, Debt Maturities, Greater Than Ten Years, Nominal Yield	1.38%					1.38%
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.57%					1.57%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	8.58	[4]				8.58	[4]
U.S. Treasury securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	1,005		1,042			1,005
Available-for-sale Securities, Fair Value	1,005		1,042			1,005
Available-for-sale Securities, Gross Unrealized Gain	0	[1]	0	[1]		0	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	0	[1]		0	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Debt Maturities, Amortized Cost, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost	1,005					1,005
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost	0					0
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost	0					0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost	0					0
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less Than One Year, Fair Value	1,005					1,005
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value	0					0
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value	0					0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value	0					0
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield	0.24%					0.24%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	0.00%					0.00%
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Nominal Yield	0.00%					0.00%
Available-for-sale Securities, Debt Maturities, Greater Than Ten Years, Nominal Yield	0.00%					0.00%
Available-for-sale Securities, Debt Maturities, Nominal Yield	0.24%					0.24%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	0.13	[4]				0.13	[4]
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 US Govt or GSE Securities Not Rated, Amortized Cost	1,005	[3]				1,005	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	1,005	[3]				1,005	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
Municipal and other tax-exempt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	63,018		73,232			63,018
Available-for-sale Securities, Fair Value	63,557		73,775			63,557
Available-for-sale Securities, Gross Unrealized Gain	1,280	[1]	1,606	[1]		1,280	[1]
Available-for-sale Securities, Gross Unrealized Loss	-741	[1]	-1,063	[1]		-741	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Debt Maturities, Amortized Cost, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost	7,134					7,134
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost	29,750					29,750
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost	2,288					2,288
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost	23,846					23,846
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less Than One Year, Fair Value	7,197					7,197
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value	30,603					30,603
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value	2,496					2,496
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value	23,261					23,261
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield	3.68%	[5]				3.68%	[5]
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	4.05%	[5]				4.05%	[5]
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Nominal Yield	6.48%	[5]				6.48%	[5]
Available-for-sale Securities, Debt Maturities, Greater Than Ten Years, Nominal Yield	1.92%	[5],[6]				1.92%	[5],[6]
Available-for-sale Securities, Debt Maturities, Nominal Yield	3.29%	[5]				3.29%	[5]
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	8.27	[4]				8.27	[4]
Available-for-sale Securities, Debt Maturities, Effective tax rate for nominal yield calculation	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 Securities	22		27			22
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	10,838		13,286			10,838
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	12,176		17,805			12,176
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	23,014		31,091			23,014
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	12		245			12
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	729		818			729
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	741		1,063			741
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 US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	40,511					40,511
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	41,579					41,579
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	11,053					11,053
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	10,516					10,516
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	11,454					11,454
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	11,462					11,462
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]
Available-for-sale Securities, Other than Temporary Impairment Losses, Credit Losses Recognized	0		1,400		1,000
Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	2,064,091		2,100,146			2,064,091
Available-for-sale Securities, Fair Value	2,048,609		2,055,804			2,048,609
Available-for-sale Securities, Gross Unrealized Gain	4,437	[1]	1,042	[1]		4,437	[1]
Available-for-sale Securities, Gross Unrealized Loss	-19,919	[1]	-45,384	[1]		-19,919	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Debt Maturities, Amortized Cost, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost	0					0
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost	912,178					912,178
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost	808,792					808,792
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost	343,121					343,121
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
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value	906,081					906,081
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value	803,324					803,324
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value	339,204					339,204
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%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	1.43%					1.43%
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Nominal Yield	1.68%					1.68%
Available-for-sale Securities, Debt Maturities, Greater Than Ten Years, Nominal Yield	1.33%					1.33%
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.51%					1.51%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	8.56	[4]				8.56	[4]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	104		123			104
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	223,106		1,800,717			223,106
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1,238,376		2,286			1,238,376
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,461,482		1,803,003			1,461,482
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	454		45,302			454
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	19,465		82			19,465
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	19,919		45,384			19,919
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 US Govt or GSE Securities Not Rated, Amortized Cost	2,064,091	[3]				2,064,091	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	2,048,609	[3]				2,048,609	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
Other debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	9,438		35,061			9,438
Available-for-sale Securities, Fair Value	9,212		35,241			9,212
Available-for-sale Securities, Gross Unrealized Gain	26	[1]	368	[1]		26	[1]
Available-for-sale Securities, Gross Unrealized Loss	-252	[1]	-188	[1]		-252	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Debt Maturities, Amortized Cost, Rolling Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Amortized Cost	5,038					5,038
Available-for-sale Securities, Debt Maturities, One to Five Years, Amortized Cost	0					0
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Amortized Cost	0					0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Amortized Cost	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	5,065					5,065
Available-for-sale Securities, Debt Maturities, One to Five Years, Fair Value	0					0
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Fair Value	0					0
Available-for-sale Securities, Debt Maturities, Over Ten Years, Fair Value	4,147					4,147
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Less than One Year, Nominal Yield	2.12%					2.12%
Available-for-sale Securities, Debt Maturities, One to Five Years, Nominal Yield	0.00%					0.00%
Available-for-sale Securities, Debt Maturities, Six to Ten Years, Nominal Yield	0.00%					0.00%
Available-for-sale Securities, Debt Maturities, Greater Than Ten Years, Nominal Yield	1.71%					1.71%
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.93%					1.93%
Available-for-sale Securities, Debt Maturities, Weighted Average Maturity	15.38	[4]				15.38	[4]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	2		3			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		4,712			0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	4,150		0			4,150
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	4,150		4,712			4,150
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		188			0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	252		0			252
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	252		188			252
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 US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	4,400					4,400
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	4,149					4,149
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	5,038					5,038
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	5,063					5,063
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
Residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	6,703,664		7,934,370			6,703,664
Available-for-sale Securities, Fair Value	6,812,841		7,937,109			6,812,841
Available-for-sale Securities, Gross Unrealized Gain	121,079	[1]	114,073	[1]		121,079	[1]
Available-for-sale Securities, Gross Unrealized Loss	-11,238	[1]	-108,892	[1]		-11,238	[1]
Available-for-sale Securities, Other Than Temporary Impairments	-664	[2]	-2,442	[2]		-664	[2]
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.95%	[7]				1.95%	[7]
Available-for-sale Securities, Debt Maturities, Average Expected Life of Mortgage-backed Securities	3 years 5 months
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	57		174			57
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	340,631		4,404,822			340,631
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	904,144		30,774			904,144
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,244,775		4,435,596			1,244,775
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	903		110,357			903
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	10,999		977			10,999
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	11,902		111,334			11,902
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 US Govt or GSE Securities Not Rated, Amortized Cost	6,549,304	[3]				6,549,304	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	6,646,884	[3]				6,646,884	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	154,360					154,360
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	165,957					165,957
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
U.S. government agency residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	6,549,304		7,720,189			6,549,304
Available-for-sale Securities, Fair Value	6,646,884		7,716,010			6,646,884
Available-for-sale Securities, Gross Unrealized Gain	108,818	[1]	104,713	[1]		108,818	[1]
Available-for-sale Securities, Gross Unrealized Loss	-11,238	[1]	-108,892	[1]		-11,238	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	45		158			45
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	329,354		4,379,137			329,354
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	894,124		0			894,124
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,223,478		4,379,137			1,223,478
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	596		108,892			596
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	10,642		0			10,642
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	11,238		108,892			11,238
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 US Govt or GSE Securities Not Rated, Amortized Cost	6,549,304	[3]				6,549,304	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	6,646,884	[3]				6,646,884	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
U.S. government agency residential mortgage-backed securities [Member] | Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	3,932,200		4,224,327			3,932,200
Available-for-sale Securities, Fair Value	3,997,428		4,232,332			3,997,428
Available-for-sale Securities, Gross Unrealized Gain	71,200	[1]	68,154	[1]		71,200	[1]
Available-for-sale Securities, Gross Unrealized Loss	-5,972	[1]	-60,149	[1]		-5,972	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	24		81			24
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	257,854		2,281,491			257,854
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	454,394		0			454,394
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	712,248		2,281,491			712,248
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	547		60,149			547
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	5,425		0			5,425
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	5,972		60,149			5,972
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 US Govt or GSE Securities Not Rated, Amortized Cost	3,932,200	[3]				3,932,200	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	3,997,428	[3]				3,997,428	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
U.S. government agency residential mortgage-backed securities [Member] | Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	1,810,476		2,308,341			1,810,476
Available-for-sale Securities, Fair Value	1,836,870		2,293,943			1,836,870
Available-for-sale Securities, Gross Unrealized Gain	29,043	[1]	25,813	[1]		29,043	[1]
Available-for-sale Securities, Gross Unrealized Loss	-2,649	[1]	-40,211	[1]		-2,649	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	16		50			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	62,950		1,450,588			62,950
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	310,834		0			310,834
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	373,784		1,450,588			373,784
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	37		40,211			37
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	2,612		0			2,612
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	2,649		40,211			2,649
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 US Govt or GSE Securities Not Rated, Amortized Cost	1,810,476	[3]				1,810,476	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	1,836,870	[3]				1,836,870	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
U.S. government agency residential mortgage-backed securities [Member] | Government National Mortgage Association Certificates and Obligations (GNMA) [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	801,820		1,151,225			801,820
Available-for-sale Securities, Fair Value	807,443		1,152,128			807,443
Available-for-sale Securities, Gross Unrealized Gain	8,240	[1]	9,435	[1]		8,240	[1]
Available-for-sale Securities, Gross Unrealized Loss	-2,617	[1]	-8,532	[1]		-2,617	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	5		27			5
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	8,550		647,058			8,550
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	128,896		0			128,896
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	137,446		647,058			137,446
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	12		8,532			12
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	2,605		0			2,605
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	2,617		8,532			2,617
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 US Govt or GSE Securities Not Rated, Amortized Cost	801,820	[3]				801,820	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	807,443	[3]				807,443	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
U.S. government agency residential mortgage-backed securities [Member] | Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	4,808		36,296			4,808
Available-for-sale Securities, Fair Value	5,143		37,607			5,143
Available-for-sale Securities, Gross Unrealized Gain	335	[1]	1,311	[1]		335	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	0	[1]		0	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
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 US Govt or GSE Securities Not Rated, Amortized Cost	4,808	[3]				4,808	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	5,143	[3]				5,143	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
Privately issued residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	154,360		214,181			154,360
Available-for-sale Securities, Fair Value	165,957		221,099			165,957
Available-for-sale Securities, Gross Unrealized Gain	12,261	[1]	9,360	[1]		12,261	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	0	[1]		0	[1]
Available-for-sale Securities, Other Than Temporary Impairments	-664	[2]	-2,442	[2]		-664	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	12	[8]	16	[8]		12	[8]
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	11,277	[8]	25,685	[8]		11,277	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	10,020	[8]	30,774	[8]		10,020	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	21,297	[8]	56,459	[8]		21,297	[8]
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	307	[8]	1,465	[8]		307	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	357	[8]	977	[8]		357	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	664	[8]	2,442	[8]		664	[8]
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 US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	154,360					154,360
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	165,957					165,957
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	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	Held constant at 5.6% over the next 12 months and remain at 5.6% thereafter.		Increasing to 7.3% over the next 12 months and remain at 7.3% thereafter
Housing price appreciation/depreciation	Starting with current depreciated housing prices based on information derived from the FHFA1, appreciating 3.2% over the next 12 months, then flat for the following 12 months and then appreciating at 2% per year thereafter.	[9]	Starting with current depreciated housing prices based on information derived from the FHFA1, appreciating 4% over the next 12 months, then flat for the following 12 months and then appreciating at 2% per year thereafter.	[9]
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.
Discount rates	Estimated cash flows were discounted at rates that range from 2.00% to 6.25% based on our current expected yields.		Estimated cash flows were discounted at rates that range from 2.00% to 6.25% based on our current expected yields.
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities	44					44
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities with Credit Losses	0					43
Available-for-sale Securities, Other than Temporary Impairment Losses, Credit Losses Recognized	0		938		5,900	54,347
Privately issued residential mortgage-backed securities [Member] | Alt A loans [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	65,582		104,559			65,582
Available-for-sale Securities, Fair Value	71,952		107,212			71,952
Available-for-sale Securities, Gross Unrealized Gain	6,677	[1]	4,386	[1]		6,677	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	0	[1]		0	[1]
Available-for-sale Securities, Other Than Temporary Impairments	-307	[2]	-1,733	[2]		-307	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	4	[8]	7	[8]		4	[8]
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	11,277	[8]	11,043	[8]		11,277	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0	[8]	30,774	[8]		0	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	11,277	[8]	41,817	[8]		11,277	[8]
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	307	[8]	756	[8]		307	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	[8]	977	[8]		0	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	307	[8]	1,733	[8]		307	[8]
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 US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	65,582					65,582
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	71,952					71,952
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	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]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities	14					14
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities with Credit Losses	0					14
Available-for-sale Securities, Other than Temporary Impairment Losses, Credit Losses Recognized	0					36,127
Privately issued residential mortgage-backed securities [Member] | Jumbo A Loans [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	88,778		109,622			88,778
Available-for-sale Securities, Fair Value	94,005		113,887			94,005
Available-for-sale Securities, Gross Unrealized Gain	5,584	[1]	4,974	[1]		5,584	[1]
Available-for-sale Securities, Gross Unrealized Loss	0	[1]	0	[1]		0	[1]
Available-for-sale Securities, Other Than Temporary Impairments	-357	[2]	-709	[2]		-357	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	8	[8]	9	[8]		8	[8]
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	[8]	14,642	[8]		0	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	10,020	[8]	0	[8]		10,020	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	10,020	[8]	14,642	[8]		10,020	[8]
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	[8]	709	[8]		0	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	357	[8]	0	[8]		357	[8]
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	357	[8]	709	[8]		357	[8]
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 US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	88,778					88,778
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	94,005					94,005
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	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]
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities	30					30
Available-for-sale Securities, Privately Issued Residential Mortgage-backed Securities, Number of Securities with Credit Losses	0					29
Available-for-sale Securities, Other than Temporary Impairment Losses, Credit Losses Recognized	0					18,220
Perpetual preferred stock, equity securities and mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	40,774					40,774
Available-for-sale Securities, Fair Value	43,721					43,721
Available-for-sale Securities, Debt Maturities, Nominal Yield [Abstract]
Available-for-sale Securities, Debt Maturities, Nominal Yield	1.28%					1.28%
Perpetual preferred stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	22,171		22,171			22,171
Available-for-sale Securities, Fair Value	24,277		22,863			24,277
Available-for-sale Securities, Gross Unrealized Gain	2,183	[1]	705	[1]		2,183	[1]
Available-for-sale Securities, Gross Unrealized Loss	-77	[1]	-13	[1]		-77	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	2		1			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	2,898		4,988			2,898
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0		0			0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,898		4,988			2,898
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	77		13			77
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0		0			0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	77		13			77
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 US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	11,406					11,406
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	12,508					12,508
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	10,765					10,765
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	11,769					11,769
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	0					0
Equity securities and mutual funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	18,603		19,069			18,603
Available-for-sale Securities, Fair Value	19,444		21,328			19,444
Available-for-sale Securities, Gross Unrealized Gain	871	[1]	2,326	[1]		871	[1]
Available-for-sale Securities, Gross Unrealized Loss	-30	[1]	-67	[1]		-30	[1]
Available-for-sale Securities, Other Than Temporary Impairments	0	[2]	0	[2]		0	[2]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Securities	68		118			68
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		2,070			0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1,205		0			1,205
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,205		2,070			1,205
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		67			0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	30		0			30
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	30		67			30
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 US Govt or GSE Securities Not Rated, Amortized Cost	0	[3]				0	[3]
Available-for-sale Securities, Portfolio Concentration US Govt or GSE Securities Not Rated, Fair Value	0	[3]				0	[3]
Available-for-sale securities, Portfolio Concentration Rated AAA To AA, Amortized Cost	4					4
Available-for-sale Securities, Portfolio Concentration Rated AAA To AA, Fair Value	517					517
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated A To BBB, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Amortized Cost	0					0
Available-for-sale Securities, Portfolio Concentration Rated Below Investment Grade, Fair Value	0					0
Available-for-sale Securities, Portfolio Concentration Not Rated, Amortized Cost	18,599					18,599
Available-for-sale Securities, Portfolio Concentration Not Rated, Fair Value	18,927					18,927
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]
Available-for-sale Securities, Other than Temporary Impairment Losses, Credit Losses Recognized	$373		$0		$457
[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.
[3]	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.
[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% effective tax rate.
[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.
[7]	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.
[8]	Includes securities for which an unrealized loss remains in AOCI after an other-than-temporary credit loss has been recognized in income.
[9]	Federal Housing Finance Agency

Rollforward_of_CreditRelated_O

Rollforward of Credit-Related Other-than-temporary Impairment Recognized in Earnings (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
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	$67,346	$75,228	$76,131
Additions for credit-related OTTI not previously recognized	0	618	113
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	0	320	6,780
Reductions for change in intent to hold before recovery	0	-3,589	0
Sales	-12,999	-5,231	-7,796
Balance of credit related OTTI recognized on available for sale debt securities, end of period	$54,347	$67,346	$75,228

Securities_Fair_Value_Option_S

Securities Fair Value Option Securities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Fair Value Option Securities [Line Items]
Fair Value Option Securities, Fair Value	$311,597	$167,125
Fair Value Option Securities, Net Unrealized Gain (Loss)	1,624	-8,169
U.S. government agency residential mortgage-backed securities [Member]
Schedule of Fair Value Option Securities [Line Items]
Fair Value Option Securities, Fair Value	311,597	157,431
Fair Value Option Securities, Net Unrealized Gain (Loss)	1,624	-8,378
Other securities [Member]
Schedule of Fair Value Option Securities [Line Items]
Fair Value Option Securities, Fair Value	0	9,694
Fair Value Option Securities, Net Unrealized Gain (Loss)	$0	$209

Securities_Restricted_Equity_S

Securities Restricted Equity Securities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Restricted Equity Securities [Abstract]
Federal Reserve Bank Stock	$35,018	$33,742
Federal Home Loan Bank Stock	106,476	51,498
Total	$141,494	$85,240

Derivatives_Fair_Value_of_Deri

Derivatives, Fair Value of Derivatives Contracts (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013
Derivative Assets, Fair Value, Net [Abstract]
Derivative contracts, net of cash margin, Assets, Fair Value	$361,874,000		$265,012,000
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	354,554,000		247,185,000
Increase in cash margin obligation for derivative holdings with a decrease in credit rating from A1 to below investment grade	19,000,000
Not Designated as Hedging Instrument [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	15,592,566,000	[1]	13,812,049,000	[1]
Derivative Liabilities, Notional	15,797,483,000	[1]	13,974,098,000	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	522,423,000		351,683,000
Derivative Assets, Netting Adjustments	-89,239,000		-77,746,000
Derivative Assets, Net Fair Value Before Cash Collateral	433,184,000		273,937,000
Derivative Assets, Fair Value, Cash Collateral	-71,310,000		-8,925,000
Derivative contracts, net of cash margin, Assets, Fair Value	361,874,000		265,012,000
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Fair Value, Gross Liability	522,099,000		349,133,000
Derivative Liabilities, Netting Adjustments	-89,239,000		-77,746,000
Derivative Liabilities, Net Fair Value Before Cash Collateral	432,860,000		271,387,000
Derivative Liabilities, Fair Value, Cash Collateral	-78,306,000		-24,202,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	354,554,000		247,185,000
Not Designated as Hedging Instrument [Member] | To-be-announced residential mortgage-backed securities [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	13,313,615,000	[1]	10,817,159,000	[1]
Derivative Liabilities, Notional	13,471,880,000	[1]	10,982,049,000	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	94,719,000		102,921,000
Derivative Assets, Netting Adjustments	-39,359,000		-46,623,000
Derivative Assets, Net Fair Value Before Cash Collateral	55,360,000		56,298,000
Derivative Assets, Fair Value, Cash Collateral	0		0
Derivative contracts, net of cash margin, Assets, Fair Value	55,360,000		56,298,000
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Fair Value, Gross Liability	91,949,000		99,830,000
Derivative Liabilities, Netting Adjustments	-39,359,000		-46,623,000
Derivative Liabilities, Net Fair Value Before Cash Collateral	52,590,000		53,207,000
Derivative Liabilities, Fair Value, Cash Collateral	-52,290,000		0
Derivative contracts, net of cash margin, Liabilities, Fair Value	300,000		53,207,000
Not Designated as Hedging Instrument [Member] | Interest rate swaps [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	1,165,568,000	[1]	1,283,379,000	[1]
Derivative Liabilities, Notional	1,165,568,000	[1]	1,283,379,000	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	35,405,000		44,124,000
Derivative Assets, Netting Adjustments	0		0
Derivative Assets, Net Fair Value Before Cash Collateral	35,405,000		44,124,000
Derivative Assets, Fair Value, Cash Collateral	0		-731,000
Derivative contracts, net of cash margin, Assets, Fair Value	35,405,000		43,393,000
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Fair Value, Gross Liability	35,599,000		44,377,000
Derivative Liabilities, Netting Adjustments	0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral	35,599,000		44,377,000
Derivative Liabilities, Fair Value, Cash Collateral	-18,717,000		-17,853,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	16,882,000		26,524,000
Not Designated as Hedging Instrument [Member] | Energy contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	579,801,000	[1]	1,263,266,000	[1]
Derivative Liabilities, Notional	579,801,000	[1]	1,216,426,000	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	141,166,000		48,078,000
Derivative Assets, Netting Adjustments	-48,624,000		-29,957,000
Derivative Assets, Net Fair Value Before Cash Collateral	92,542,000		18,121,000
Derivative Assets, Fair Value, Cash Collateral	-71,310,000		-2,575,000
Derivative contracts, net of cash margin, Assets, Fair Value	21,232,000		15,546,000
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Fair Value, Gross Liability	142,839,000		46,095,000
Derivative Liabilities, Netting Adjustments	-48,624,000		-29,957,000
Derivative Liabilities, Net Fair Value Before Cash Collateral	94,215,000		16,138,000
Derivative Liabilities, Fair Value, Cash Collateral	0		-6,055,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	94,215,000		10,083,000
Not Designated as Hedging Instrument [Member] | Agricultural contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	47,657,000	[1]	100,886,000	[1]
Derivative Liabilities, Notional	47,418,000	[1]	99,191,000	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	1,904,000		2,060,000
Derivative Assets, Netting Adjustments	-1,256,000		-1,166,000
Derivative Assets, Net Fair Value Before Cash Collateral	648,000		894,000
Derivative Assets, Fair Value, Cash Collateral	0		0
Derivative contracts, net of cash margin, Assets, Fair Value	648,000		894,000
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Fair Value, Gross Liability	1,908,000		2,009,000
Derivative Liabilities, Netting Adjustments	-1,256,000		-1,166,000
Derivative Liabilities, Net Fair Value Before Cash Collateral	652,000		843,000
Derivative Liabilities, Fair Value, Cash Collateral	-596,000		0
Derivative contracts, net of cash margin, Liabilities, Fair Value	56,000		843,000
Not Designated as Hedging Instrument [Member] | Foreign exchange contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	290,965,000	[1]	136,543,000	[1]
Derivative Liabilities, Notional	290,856,000	[1]	135,237,000	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	238,395,000		136,543,000
Derivative Assets, Netting Adjustments	0		0
Derivative Assets, Net Fair Value Before Cash Collateral	238,395,000		136,543,000
Derivative Assets, Fair Value, Cash Collateral	0		-2,147,000
Derivative contracts, net of cash margin, Assets, Fair Value	238,395,000		134,396,000
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Fair Value, Gross Liability	238,118,000		135,237,000
Derivative Liabilities, Netting Adjustments	0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral	238,118,000		135,237,000
Derivative Liabilities, Fair Value, Cash Collateral	-6,703,000		-294,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	231,415,000		134,943,000
Not Designated as Hedging Instrument [Member] | Equity option contracts [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	194,960,000	[1]	210,816,000	[1]
Derivative Liabilities, Notional	194,960,000	[1]	210,816,000	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	10,834,000		17,957,000
Derivative Assets, Netting Adjustments	0		0
Derivative Assets, Net Fair Value Before Cash Collateral	10,834,000		17,957,000
Derivative Assets, Fair Value, Cash Collateral	0		-3,472,000
Derivative contracts, net of cash margin, Assets, Fair Value	10,834,000		14,485,000
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Fair Value, Gross Liability	10,834,000		17,957,000
Derivative Liabilities, Netting Adjustments	0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral	10,834,000		17,957,000
Derivative Liabilities, Fair Value, Cash Collateral	0		0
Derivative contracts, net of cash margin, Liabilities, Fair Value	10,834,000		17,957,000
Not Designated as Hedging Instrument [Member] | Customer risk management programs [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	15,592,566,000	[1]	13,812,049,000	[1]
Derivative Liabilities, Notional	15,750,483,000	[1]	13,927,098,000	[1]
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	522,423,000		351,683,000
Derivative Assets, Netting Adjustments	-89,239,000		-77,746,000
Derivative Assets, Net Fair Value Before Cash Collateral	433,184,000		273,937,000
Derivative Assets, Fair Value, Cash Collateral	-71,310,000		-8,925,000
Derivative contracts, net of cash margin, Assets, Fair Value	361,874,000		265,012,000
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Fair Value, Gross Liability	521,247,000		345,505,000
Derivative Liabilities, Netting Adjustments	-89,239,000		-77,746,000
Derivative Liabilities, Net Fair Value Before Cash Collateral	432,008,000		267,759,000
Derivative Liabilities, Fair Value, Cash Collateral	-78,306,000		-24,202,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	353,702,000		243,557,000
Not Designated as Hedging Instrument [Member] | Interest rate risk management programs [Member]
Notional Amount of Derivatives [Abstract]
Derivative Assets, Notional	0	[1]	0	[1]
Derivative Liabilities, Notional	47,000,000	[1]	47,000,000	[1]
Derivative, Notional Amount	47,000,000
Derivative Assets, Fair Value, Net [Abstract]
Derivative Assets, Gross Fair Value	0		0
Derivative Assets, Netting Adjustments	0		0
Derivative Assets, Net Fair Value Before Cash Collateral	0		0
Derivative Assets, Fair Value, Cash Collateral	0		0
Derivative contracts, net of cash margin, Assets, Fair Value	0		0
Derivative Liabilities, Fair Value, Net [Abstract]
Derivative Liabilities, Fair Value, Gross Liability	852,000		3,628,000
Derivative Liabilities, Netting Adjustments	0		0
Derivative Liabilities, Net Fair Value Before Cash Collateral	852,000		3,628,000
Derivative Liabilities, Fair Value, Cash Collateral	0		0
Derivative contracts, net of cash margin, Liabilities, Fair Value	$852,000		$3,628,000
[1]	Notional amounts for commodity contracts are converted into dollar-equivalent amounts based on dollar prices at the inception of the contract.

Loans_and_Allowances_for_Credi2

Loans and Allowances for Credit Losses, Loans by Portfolio Segment (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Loans receivables disclosure [Abstract]
Loans receivables with fixed rate of interest	$4,259,974,000		$4,327,636,000
Loans receivables with variable rate of interest	9,867,292,000		8,363,479,000
Loan receivable non-accrual	80,771,000		101,149,000
Total	14,208,037,000		12,792,264,000
Accruing loans past due (90 days)	125,000	[1]	1,415,000	[1]
Loans Receivable, Impaired, Foregone Interest on Nonaccrual Loans	8,170,000		9,815,000
Credit Commitments [Abstract]
Outstanding commitments to extend credit	8,300,000,000
Outstanding standby letters of credit	448,000,000
Outstanding commercial letters of credit	6,700,000
Commercial [Member]
Loans receivables disclosure [Abstract]
Loans receivables with fixed rate of interest	1,736,976,000		1,637,620,000
Loans receivables with variable rate of interest	7,345,167,000		6,288,841,000
Loan receivable non-accrual	13,527,000		16,760,000
Total	9,095,670,000		7,943,221,000
Energy [Member]
Loans receivables disclosure [Abstract]
Total	2,860,428,000		2,351,760,000
Services [Member]
Loans receivables disclosure [Abstract]
Total	2,518,229,000		2,282,210,000
Commercial Real Estate [Member]
Loans receivables disclosure [Abstract]
Loans receivables with fixed rate of interest	721,513,000		770,908,000
Loans receivables with variable rate of interest	1,988,080,000		1,603,595,000
Loan receivable non-accrual	18,557,000		40,850,000
Total	2,728,150,000		2,415,353,000
Residential Mortgage [Member]
Loans receivables disclosure [Abstract]
Loans receivables with fixed rate of interest	1,698,620,000		1,783,614,000
Loans receivables with variable rate of interest	202,771,000		226,092,000
Loan receivable non-accrual	48,121,000		42,320,000
Total	1,949,512,000		2,052,026,000
Permanent mortgage [Member]
Loans receivables disclosure [Abstract]
Total	969,951,000		1,062,744,000
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
Permanent mortgages guaranteed by U.S. government agencies [Member]
Loans receivables disclosure [Abstract]
Total	205,950,000		181,598,000
Home equity
Loans receivables disclosure [Abstract]
Total	773,611,000		807,684,000
Loans receivable, other information [Abstract]
Percentage of home equity portfolio comprised of first lien loans	69.00%		70.00%
Percentage of home equity portfolio comprised of junior lien loans	31.00%		30.00%
Percentage of junior lien home equity loans that are amortizing term loans	71.00%		74.00%
Percentage of junior lien home equity loans that are revolving lines of credit	29.00%		26.00%
Home equity loans, description	Home equity loans generally require a minimum FICO score of 700 and a maximum DTI of 40%.
Home equity loans, maximum	400,000
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
Consumer [Member]
Loans receivables disclosure [Abstract]
Loans receivables with fixed rate of interest	102,865,000		135,494,000
Loans receivables with variable rate of interest	331,274,000		244,951,000
Loan receivable non-accrual	566,000		1,219,000
Total	434,705,000		381,664,000
Geographic Concentration Risk [Member] | Texas [Member]
Loans receivables disclosure [Abstract]
Total	4,900,000,000		4,300,000,000
Loans receivable, other information [Abstract]
Percentage of loan portfolio attributed to Texas	34.00%		34.00%
Geographic Concentration Risk [Member] | Texas [Member] | Commercial [Member]
Loans receivables disclosure [Abstract]
Total	3,200,000,000		2,800,000,000
Loans receivable, other information [Abstract]
Percentage of loan portfolio attributed to Texas	36.00%		36.00%
Geographic Concentration Risk [Member] | Texas [Member] | Commercial Real Estate [Member]
Loans receivable, other information [Abstract]
Percentage of loan portfolio secured by property in Texas (in hundredths)	34.00%		32.00%
Geographic Concentration Risk [Member] | Texas [Member] | Residential Mortgage [Member]
Loans receivable, other information [Abstract]
Percentage of loan portfolio secured by property in Texas (in hundredths)	28.00%		27.00%
Geographic Concentration Risk [Member] | Oklahoma [Member]
Loans receivables disclosure [Abstract]
Total	3,400,000,000		3,300,000,000
Loans receivable, other information [Abstract]
Percentage of loan portfolio attributed to Oklahoma	24.00%		26.00%
Geographic Concentration Risk [Member] | Oklahoma [Member] | Commercial [Member]
Loans receivables disclosure [Abstract]
Total	2,000,000,000		1,900,000,000
Loans receivable, other information [Abstract]
Percentage of loan portfolio attributed to Oklahoma	22.00%		23.00%
Geographic Concentration Risk [Member] | Oklahoma [Member] | Commercial Real Estate [Member]
Loans receivable, other information [Abstract]
Percentage of loan portfolio secured by property in Oklahoma (in hundredths)	16.00%		19.00%
Geographic Concentration Risk [Member] | Oklahoma [Member] | Residential Mortgage [Member]
Loans receivable, other information [Abstract]
Percentage of loan portfolio secured by property in Oklahoma (in hundredths)	38.00%		38.00%
Geographic Concentration Risk [Member] | New Mexico [Memnber] | Commercial Real Estate [Member]
Loans receivable, other information [Abstract]
Percentage of loan portfolio secured by property in New Mexico (in hundredths)			11.00%
Geographic Concentration Risk [Member] | New Mexico [Memnber] | Residential Mortgage [Member]
Loans receivable, other information [Abstract]
Percentage of loan portfolio secured by property in New Mexico (in hundredths)	12.00%		10.00%
Geographic Concentration Risk [Member] | Colorado [Member] | Residential Mortgage [Member]
Loans receivable, other information [Abstract]
Percentage of loan portfolio secured by property in Colorado (in hundredths)	10.00%
Credit Concentration Risk [Member] | Energy [Member]
Loans receivables disclosure [Abstract]
Total	2,900,000,000		2,400,000,000
Loans receivable, other information [Abstract]
Percentage of energy loans in loan portfolio	20.00%
Credit Concentration Risk [Member] | Energy Producers [Member]
Loans receivables disclosure [Abstract]
Total	2,500,000,000
Loans receivable, other information [Abstract]
Percentage of committed energy production loans secured by oil	59.00%
Percentage of committed energy production loans secured by natural gas	41.00%
Credit Concentration Risk [Member] | Services [Member]
Loans receivables disclosure [Abstract]
Total	2,500,000,000		2,300,000,000
Loans receivable, other information [Abstract]
Amount of loans with individual balances less than $10 million	1,200,000,000		1,100,000,000
Maximum loan amount for certain individual loans in category	$10,000,000		$10,000,000
[1]	Excludes residential mortgage loans guaranteed by agencies of the U.S. government

Derivatives_Derivatives_Instru

Derivatives, Derivatives Instruments Gain (Loss) in Income Statement (Details) (Not Designated as Hedging Instrument [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Trading Activity, Gains and Losses, Net [Line Items]
Brokerage and Trading Revenue	$37,800	$41,952	$38,132
Gain (Loss) on Derivatives, Net	2,776	-4,367	-301
To-be-announced residential mortgage-backed securities [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Brokerage and Trading Revenue	27,007	29,614	25,509
Gain (Loss) on Derivatives, Net	0	0	0
Interest rate swaps [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Brokerage and Trading Revenue	2,494	2,991	3,458
Gain (Loss) on Derivatives, Net	0	0	0
Energy contracts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Brokerage and Trading Revenue	6,572	8,303	8,171
Gain (Loss) on Derivatives, Net	0	0	0
Agricultural contracts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Brokerage and Trading Revenue	146	357	382
Gain (Loss) on Derivatives, Net	0	0	0
Foreign exchange contracts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Brokerage and Trading Revenue	1,581	687	612
Gain (Loss) on Derivatives, Net	0	0	0
Equity option contracts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Brokerage and Trading Revenue	0	0	0
Gain (Loss) on Derivatives, Net	0	0	0
Customer risk management programs [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Brokerage and Trading Revenue	37,800	41,952	38,132
Gain (Loss) on Derivatives, Net	0	0	0
Interest rate risk management programs [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Brokerage and Trading Revenue	0	0	0
Gain (Loss) on Derivatives, Net	$2,776	($4,367)	($301)

Loans_and_Allowances_for_Credi3

Loans and Allowances for Credit Losses, Activity in Allowance for Credit Losses (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for loan losses [Roll Forward]
Beginning balance	$185,396,000	$215,507,000	$253,481,000
Provision for loan losses	858,000	-28,073,000	-14,654,000
Loans charged off	-16,232,000	-25,282,000	-42,138,000
Recoveries	19,034,000	23,244,000	18,818,000
Ending balance	189,056,000	185,396,000	215,507,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance	2,088,000	1,915,000	9,261,000
Provision for off-balance sheet credit risk	-858,000	173,000	-7,346,000
Ending balance	1,230,000	2,088,000	1,915,000
Total provision for credit losses	0	-27,900,000	-22,000,000
Negative recovery related to invalidated settlement agreement			7,100,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	14,127,266,000	12,691,892,000
Individually measured for impairment, recorded investment	80,771,000	100,372,000
Total	14,208,037,000	12,792,264,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	160,699,000	156,229,000
Individually measured for impairment, related allowance	312,000	954,000
Total measured for impairment, related allowance	189,056,000	185,396,000	215,507,000
Commercial [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	79,180,000	65,280,000	83,443,000
Provision for loan losses	9,561,000	12,747,000	-14,950,000
Loans charged off	-3,569,000	-6,335,000	-9,341,000
Recoveries	5,703,000	7,488,000	6,128,000	[1]
Ending balance	90,875,000	79,180,000	65,280,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance	119,000	475,000	7,906,000
Provision for off-balance sheet credit risk	356,000	-356,000	-7,431,000
Ending balance	475,000	119,000	475,000
Total provision for credit losses	9,917,000	12,391,000	-22,381,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	9,082,143,000	7,926,461,000
Individually measured for impairment, recorded investment	13,527,000	16,760,000
Total	9,095,670,000	7,943,221,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	90,709,000	78,607,000
Individually measured for impairment, related allowance	166,000	573,000
Total measured for impairment, related allowance	90,875,000	79,180,000	65,280,000
Commercial Real Estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	41,573,000	54,884,000	67,034,000
Provision for loan losses	-4,084,000	-16,886,000	-6,214,000
Loans charged off	-2,047,000	-5,845,000	-11,642,000
Recoveries	7,003,000	9,420,000	5,706,000
Ending balance	42,445,000	41,573,000	54,884,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance	1,876,000	1,353,000	1,250,000
Provision for off-balance sheet credit risk	-1,169,000	523,000	103,000
Ending balance	707,000	1,876,000	1,353,000
Total provision for credit losses	-5,253,000	-16,363,000	-6,111,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	2,709,593,000	2,374,503,000
Individually measured for impairment, recorded investment	18,557,000	40,850,000
Total	2,728,150,000	2,415,353,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	42,404,000	41,440,000
Individually measured for impairment, related allowance	41,000	133,000
Total measured for impairment, related allowance	42,445,000	41,573,000	54,884,000
Residential Mortgage [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	29,465,000	41,703,000	46,476,000
Provision for loan losses	-3,559,000	-8,043,000	3,346,000
Loans charged off	-4,448,000	-5,753,000	-10,047,000
Recoveries	2,000,000	1,558,000	1,928,000
Ending balance	23,458,000	29,465,000	41,703,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance	90,000	78,000	91,000
Provision for off-balance sheet credit risk	-62,000	12,000	-13,000
Ending balance	28,000	90,000	78,000
Total provision for credit losses	-3,621,000	-8,031,000	3,333,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	1,901,391,000	2,010,483,000
Individually measured for impairment, recorded investment	48,121,000	41,543,000
Total	1,949,512,000	2,052,026,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	23,353,000	29,217,000
Individually measured for impairment, related allowance	105,000	248,000
Total measured for impairment, related allowance	23,458,000	29,465,000	41,703,000
Consumer [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	6,965,000	9,453,000	10,178,000
Provision for loan losses	-892,000	83,000	5,327,000
Loans charged off	-6,168,000	-7,349,000	-11,108,000
Recoveries	4,328,000	4,778,000	5,056,000
Ending balance	4,233,000	6,965,000	9,453,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance	3,000	9,000	14,000
Provision for off-balance sheet credit risk	17,000	-6,000	-5,000
Ending balance	20,000	3,000	9,000
Total provision for credit losses	-875,000	77,000	5,322,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	434,139,000	380,445,000
Individually measured for impairment, recorded investment	566,000	1,219,000
Total	434,705,000	381,664,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	4,233,000	6,965,000
Individually measured for impairment, related allowance	0	0
Total measured for impairment, related allowance	4,233,000	6,965,000	9,453,000
Specific Allowance [Member]
Allowance for loan losses [Roll Forward]
Ending balance	161,011,000	157,183,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	14,127,266,000	12,691,892,000
Individually measured for impairment, recorded investment	80,771,000	100,372,000
Total	14,208,037,000	12,792,264,000
Related allowance [Abstract]
Collectively measured for impairment, related allowance	160,699,000	156,229,000
Individually measured for impairment, related allowance	312,000	954,000
Total measured for impairment, related allowance	161,011,000	157,183,000
Nonspecific allowance [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	28,213,000	44,187,000	46,350,000
Provision for loan losses	-168,000	-15,974,000	-2,163,000
Loans charged off	0	0	0
Recoveries	0	0	0
Ending balance	28,045,000	28,213,000	44,187,000
Accrual for off-balance sheet credit losses [Roll Forward]
Beginning balance	0	0	0
Provision for off-balance sheet credit risk	0	0	0
Ending balance	0	0	0
Total provision for credit losses	-168,000	-15,974,000	-2,163,000
Recorded investment [Abstract]
Collectively measured for impairment, recorded investment	0	0
Individually measured for impairment, recorded investment	0	0
Total	0	0
Related allowance [Abstract]
Collectively measured for impairment, related allowance	0	0
Individually measured for impairment, related allowance	0	0
Total measured for impairment, related allowance	$28,045,000	$28,213,000	$44,187,000
[1]	Includes $7.1 million of negative recovery related to a refund of a settlement between BOK Financial and the City of Tulsa invalidated by the Oklahoma Supreme Court.

Loans_and_Allowances_for_Credi4

Loans and Allowances for Credit Losses, Credit Quality Indicators (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	$12,336,710	$10,789,740
Non-Graded, Recorded Investment	1,871,327	2,002,524
Total	14,208,037	12,792,264
Related Allowance [Abstract]
Internally Risk Graded, Related Allowance	137,032	127,961
Non-Graded, Related Allowance	23,979	29,222
Total, Related Allowance	189,056	185,396	215,507	253,481
Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	12,222,486	10,650,784
Non-Graded, Recorded Investment	1,825,709	1,966,324
Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	79,071	74,007
Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	35,153	64,949
Non-Graded, Recorded Investment	45,618	36,200
Commercial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	9,073,030	7,888,219
Non-Graded, Recorded Investment	22,640	55,002
Total	9,095,670	7,943,221
Related Allowance [Abstract]
Internally Risk Graded, Related Allowance	90,085	78,250
Non-Graded, Related Allowance	790	930
Total, Related Allowance	90,875	79,180
Commercial [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	9,008,360	7,841,108
Non-Graded, Recorded Investment	22,532	54,929
Commercial [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	51,251	30,424
Commercial [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	13,419	16,687
Non-Graded, Recorded Investment	108	73
Energy [Member]
Recorded Investment [Abstract]
Total	2,860,428	2,351,760
Energy [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,843,093	2,347,519
Non-Graded, Recorded Investment	0	0
Energy [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	15,919	2,381
Energy [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,416	1,860
Non-Graded, Recorded Investment	0	0
Services [Member]
Recorded Investment [Abstract]
Total	2,518,229	2,282,210
Services [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,497,888	2,265,984
Non-Graded, Recorded Investment	0	0
Services [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	15,140	11,304
Services [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	5,201	4,922
Non-Graded, Recorded Investment	0	0
Wholesale/retail [Member]
Recorded Investment [Abstract]
Total	1,313,316	1,201,364
Wholesale/retail [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,301,026	1,191,791
Non-Graded, Recorded Investment	0	0
Wholesale/retail [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	8,141	2,604
Wholesale/retail [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	4,149	6,969
Non-Graded, Recorded Investment	0	0
Manufacturing [Member]
Recorded Investment [Abstract]
Total	532,594	391,751
Manufacturing [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	527,951	381,794
Non-Graded, Recorded Investment	0	0
Manufacturing [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	4,193	9,365
Manufacturing [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	450	592
Non-Graded, Recorded Investment	0	0
Healthcare [Member]
Recorded Investment [Abstract]
Total	1,454,969	1,274,246
Healthcare [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,449,024	1,272,626
Non-Graded, Recorded Investment	0	0
Healthcare [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	4,565	34
Healthcare [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,380	1,586
Non-Graded, Recorded Investment	0	0
Other commercial and industrial [Member]
Recorded Investment [Abstract]
Total	416,134	441,890
Other commercial and industrial [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	389,378	381,394
Non-Graded, Recorded Investment	22,532	54,929
Other commercial and industrial [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	3,293	4,736
Other commercial and industrial [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	823	758
Non-Graded, Recorded Investment	108	73
Commercial Real Estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,728,150	2,415,353
Non-Graded, Recorded Investment	0	0
Total	2,728,150	2,415,353
Related Allowance [Abstract]
Internally Risk Graded, Related Allowance	42,445	41,573
Non-Graded, Related Allowance	0	0
Total, Related Allowance	42,445	41,573
Commercial Real Estate [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,683,565	2,334,998
Non-Graded, Recorded Investment	0	0
Commercial Real Estate [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	26,028	39,505
Commercial Real Estate [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	18,557	40,850
Non-Graded, Recorded Investment	0	0
Residential construction and land development [Member]
Recorded Investment [Abstract]
Total	143,591	206,258
Residential construction and land development [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	127,437	173,488
Non-Graded, Recorded Investment	0	0
Residential construction and land development [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	10,855	15,393
Residential construction and land development [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	5,299	17,377
Non-Graded, Recorded Investment	0	0
Retail [Member]
Recorded Investment [Abstract]
Total	666,889	586,047
Retail [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	662,335	579,506
Non-Graded, Recorded Investment	0	0
Retail [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	628	1,684
Retail [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	3,926	4,857
Non-Graded, Recorded Investment	0	0
Office [Member]
Recorded Investment [Abstract]
Total	415,544	411,499
Office [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	411,548	403,951
Non-Graded, Recorded Investment	0	0
Office [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	576	1,157
Office [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	3,420	6,391
Non-Graded, Recorded Investment	0	0
Multifamily [Member]
Recorded Investment [Abstract]
Total	704,298	576,502
Multifamily [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	691,053	562,800
Non-Graded, Recorded Investment	0	0
Multifamily [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	13,245	13,695
Multifamily [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	7
Non-Graded, Recorded Investment	0	0
Industrial [Member]
Recorded Investment [Abstract]
Total	428,817	243,877
Industrial [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	428,817	243,625
Non-Graded, Recorded Investment	0	0
Industrial [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0
Industrial [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	252
Non-Graded, Recorded Investment	0	0
Other commercial real estate [Member]
Recorded Investment [Abstract]
Total	369,011	391,170
Other commercial real estate [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	362,375	371,628
Non-Graded, Recorded Investment	0	0
Other commercial real estate [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	724	7,576
Other commercial real estate [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	5,912	11,966
Non-Graded, Recorded Investment	0	0
Residential Mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	192,303	220,635
Non-Graded, Recorded Investment	1,757,209	1,831,391
Total	1,949,512	2,052,026
Related Allowance [Abstract]
Internally Risk Graded, Related Allowance	2,996	5,481
Non-Graded, Related Allowance	20,462	23,984
Total, Related Allowance	23,458	29,465
Residential Mortgage [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	187,520	210,142
Non-Graded, Recorded Investment	1,712,098	1,796,281
Residential Mortgage [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,773	3,283
Residential Mortgage [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	3,010	7,210
Non-Graded, Recorded Investment	45,111	35,110
Permanent mortgage [Member]
Recorded Investment [Abstract]
Total	969,951	1,062,744
Permanent mortgage [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	187,520	210,142
Non-Graded, Recorded Investment	745,813	815,040
Permanent mortgage [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,773	3,283
Permanent mortgage [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	3,010	7,210
Non-Graded, Recorded Investment	31,835	27,069
Permanent mortgages guaranteed by U.S. government agencies [Member]
Recorded Investment [Abstract]
Total	205,950	181,598
Permanent mortgages guaranteed by U.S. government agencies [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0
Non-Graded, Recorded Investment	202,238	180,821
Permanent mortgages guaranteed by U.S. government agencies [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0
Permanent mortgages guaranteed by U.S. government agencies [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0
Non-Graded, Recorded Investment	3,712	777
Home equity
Recorded Investment [Abstract]
Total	773,611	807,684
Home equity | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0
Non-Graded, Recorded Investment	764,047	800,420
Home equity | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0
Home equity | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0
Non-Graded, Recorded Investment	9,564	7,264
Consumer [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	343,227	265,533
Non-Graded, Recorded Investment	91,478	116,131
Total	434,705	381,664
Related Allowance [Abstract]
Internally Risk Graded, Related Allowance	1,506	2,657
Non-Graded, Related Allowance	2,727	4,308
Total, Related Allowance	4,233	6,965
Consumer [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	343,041	264,536
Non-Graded, Recorded Investment	91,079	115,114
Consumer [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	19	795
Consumer [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	167	202
Non-Graded, Recorded Investment	399	1,017
Specific Allowance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	12,336,710	10,789,740
Non-Graded, Recorded Investment	1,871,327	2,002,524
Total	14,208,037	12,792,264
Related Allowance [Abstract]
Internally Risk Graded, Related Allowance	137,032	127,961
Non-Graded, Related Allowance	23,979	29,222
Total, Related Allowance	161,011	157,183
Nonspecific allowance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0
Non-Graded, Recorded Investment	0	0
Total	0	0
Related Allowance [Abstract]
Internally Risk Graded, Related Allowance	0	0
Non-Graded, Related Allowance	0	0
Total, Related Allowance	$28,045	$28,213	$44,187	$46,350

Loans_and_Allowances_for_Credi5

Loans and Allowances for Credit Losses, Impaired Loans (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	$330,630		$319,534
Impaired loans, recorded investment, total	283,009		281,970
Impaired loans, recorded investment with no related allowance	281,813		279,827
Impaired loans, recorded investment with related allowance	1,196		2,143
Impaired loans, related allowance	312		954
Impaired loans, average recorded investment	282,731		282,658
Impaired loans, interest income recognized	9,760		8,543
Commercial [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	30,742		30,826
Impaired loans, recorded investment, total	13,527		16,760
Impaired loans, recorded investment with no related allowance	12,781		15,549
Impaired loans, recorded investment with related allowance	746		1,211
Impaired loans, related allowance	166		573
Impaired loans, average recorded investment	15,143		20,614
Impaired loans, interest income recognized	0		0
Energy [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	1,444		1,860
Impaired loans, recorded investment, total	1,416		1,860
Impaired loans, recorded investment with no related allowance	1,416		1,860
Impaired loans, recorded investment with related allowance	0		0
Impaired loans, related allowance	0		0
Impaired loans, average recorded investment	1,638		2,160
Impaired loans, interest income recognized	0		0
Services [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	8,068		6,486
Impaired loans, recorded investment, total	5,201		4,922
Impaired loans, recorded investment with no related allowance	4,487		3,791
Impaired loans, recorded investment with related allowance	714		1,131
Impaired loans, related allowance	157		516
Impaired loans, average recorded investment	5,061		8,506
Impaired loans, interest income recognized	0		0
Wholesale/retail [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	9,457		11,009
Impaired loans, recorded investment, total	4,149		6,969
Impaired loans, recorded investment with no related allowance	4,117		6,937
Impaired loans, recorded investment with related allowance	32		32
Impaired loans, related allowance	9		9
Impaired loans, average recorded investment	5,559		5,023
Impaired loans, interest income recognized	0		0
Manufacturing [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	737		746
Impaired loans, recorded investment, total	450		592
Impaired loans, recorded investment with no related allowance	450		592
Impaired loans, recorded investment with related allowance	0		0
Impaired loans, related allowance	0		0
Impaired loans, average recorded investment	521		1,300
Impaired loans, interest income recognized	0		0
Healthcare [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	2,432		2,193
Impaired loans, recorded investment, total	1,380		1,586
Impaired loans, recorded investment with no related allowance	1,380		1,538
Impaired loans, recorded investment with related allowance	0		48
Impaired loans, related allowance	0		48
Impaired loans, average recorded investment	1,483		2,376
Impaired loans, interest income recognized	0		0
Other commercial and industrial [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	8,604		8,532
Impaired loans, recorded investment, total	931		831
Impaired loans, recorded investment with no related allowance	931		831
Impaired loans, recorded investment with related allowance	0		0
Impaired loans, related allowance	0		0
Impaired loans, average recorded investment	881		1,249
Impaired loans, interest income recognized	0		0
Commercial Real Estate [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	33,390		49,637
Impaired loans, recorded investment, total	18,557		40,850
Impaired loans, recorded investment with no related allowance	18,277		40,328
Impaired loans, recorded investment with related allowance	280		522
Impaired loans, related allowance	41		133
Impaired loans, average recorded investment	29,703		50,739
Impaired loans, interest income recognized	0		0
Residential construction and land development [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	10,071		20,804
Impaired loans, recorded investment, total	5,299		17,377
Impaired loans, recorded investment with no related allowance	5,192		17,050
Impaired loans, recorded investment with related allowance	107		327
Impaired loans, related allowance	23		107
Impaired loans, average recorded investment	11,338		21,754
Impaired loans, interest income recognized	0		0
Retail [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	5,406		6,133
Impaired loans, recorded investment, total	3,926		4,857
Impaired loans, recorded investment with no related allowance	3,926		4,857
Impaired loans, recorded investment with related allowance	0		0
Impaired loans, related allowance	0		0
Impaired loans, average recorded investment	4,392		6,487
Impaired loans, interest income recognized	0		0
Office [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	5,959		7,848
Impaired loans, recorded investment, total	3,420		6,391
Impaired loans, recorded investment with no related allowance	3,420		6,383
Impaired loans, recorded investment with related allowance	0		8
Impaired loans, related allowance	0		8
Impaired loans, average recorded investment	4,905		6,610
Impaired loans, interest income recognized	0		0
Multifamily [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	0		7
Impaired loans, recorded investment, total	0		7
Impaired loans, recorded investment with no related allowance	0		7
Impaired loans, recorded investment with related allowance	0		0
Impaired loans, related allowance	0		0
Impaired loans, average recorded investment	3		1,357
Impaired loans, interest income recognized	0		0
Industrial [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	0		252
Impaired loans, recorded investment, total	0		252
Impaired loans, recorded investment with no related allowance	0		252
Impaired loans, recorded investment with related allowance	0		0
Impaired loans, related allowance	0		0
Impaired loans, average recorded investment	126		2,110
Impaired loans, interest income recognized	0		0
Other commercial real estate [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	11,954		14,593
Impaired loans, recorded investment, total	5,912		11,966
Impaired loans, recorded investment with no related allowance	5,739		11,779
Impaired loans, recorded investment with related allowance	173		187
Impaired loans, related allowance	18		18
Impaired loans, average recorded investment	8,939		12,421
Impaired loans, interest income recognized	0		0
Residential Mortgage [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	265,914		237,843
Impaired loans, recorded investment, total	250,359		223,141
Impaired loans, recorded investment with no related allowance	250,189		222,731
Impaired loans, recorded investment with related allowance	170		410
Impaired loans, related allowance	105		248
Impaired loans, average recorded investment	236,992		209,340
Impaired loans, interest income recognized	9,760		8,543
Permanent mortgage [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	43,463		41,870
Impaired loans, recorded investment, total	34,845		34,279
Impaired loans, recorded investment with no related allowance	34,675		33,869
Impaired loans, recorded investment with related allowance	170		410
Impaired loans, related allowance	105		248
Impaired loans, average recorded investment	34,561		37,071
Impaired loans, interest income recognized	1,418		1,582
Permanent mortgages guaranteed by U.S. government agencies [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	212,684	[1]	188,436	[2]
Impaired loans, recorded investment, total	205,950	[1]	181,598	[2]
Impaired loans, recorded investment with no related allowance	205,950	[1]	181,598	[2]
Impaired loans, recorded investment with related allowance	0	[1]	0	[2]
Impaired loans, related allowance	0	[1]	0	[2]
Impaired loans, average recorded investment	194,017	[1]	165,509	[2]
Impaired loans, interest income recognized	8,342	[1]	6,961	[2]
Home equity
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	9,767		7,537
Impaired loans, recorded investment, total	9,564		7,264
Impaired loans, recorded investment with no related allowance	9,564		7,264
Impaired loans, recorded investment with related allowance	0		0
Impaired loans, related allowance	0		0
Impaired loans, average recorded investment	8,414		6,760
Impaired loans, interest income recognized	0		0
Consumer [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	584		1,228
Impaired loans, recorded investment, total	566		1,219
Impaired loans, recorded investment with no related allowance	566		1,219
Impaired loans, recorded investment with related allowance	0		0
Impaired loans, related allowance	0		0
Impaired loans, average recorded investment	893		1,965
Impaired loans, interest income recognized	$0		$0
[1]	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, 2014, $3.7 million of these loans are nonaccruing and $202 million are accruing based on the guarantee by U.S. government agencies.
[2]	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, 2013, $777 thousand of these loans are nonaccruing and $181 million are accruing based on the guarantee by U.S. government agencies.

Loans_and_Allowances_for_Credi6

Loans and Allowances for Credit Losses, Troubled Debt Restructurings (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	$114,350	$106,281
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	41,719	42,343
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	72,631	63,938
Troubled Debt Restructuring, Specific allowance	285	441
Troubled Debt Restructuring, Charge-offs	5,107	1,481
Accruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	73,985	54,322
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	17,274	13,384
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	56,711	40,938
Troubled Debt Restructuring, Specific allowance	0	0
Troubled Debt Restructuring, Charge-offs	0	0
Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	40,365	51,959
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	24,445	28,959
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	15,920	23,000
Troubled Debt Restructuring, Specific allowance	285	441
Troubled Debt Restructuring, Charge-offs	5,107	1,481
Commercial [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	6,061	3,632
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	4,423	1,114
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	1,638	2,518
Troubled Debt Restructuring, Specific allowance	157	246
Troubled Debt Restructuring, Charge-offs	3,000	154
Energy [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Specific allowance	0	0
Troubled Debt Restructuring, Charge-offs	0	0
Services [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	1,666	2,235
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	706	852
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	960	1,383
Troubled Debt Restructuring, Specific allowance	148	237
Troubled Debt Restructuring, Charge-offs	0	0
Wholesale/retail [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	3,381	235
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	3,284	89
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	97	146
Troubled Debt Restructuring, Specific allowance	9	9
Troubled Debt Restructuring, Charge-offs	0	0
Manufacturing [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	340	391
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	340	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	391
Troubled Debt Restructuring, Specific allowance	0	0
Troubled Debt Restructuring, Charge-offs	3,000	154
Healthcare [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Specific allowance	0	0
Troubled Debt Restructuring, Charge-offs	0	0
Other commercial and industrial [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	674	771
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	93	173
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	581	598
Troubled Debt Restructuring, Specific allowance	0	0
Troubled Debt Restructuring, Charge-offs	0	0
Commercial Real Estate [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	10,711	24,577
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	4,720	11,342
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	5,991	13,235
Troubled Debt Restructuring, Specific allowance	23	107
Troubled Debt Restructuring, Charge-offs	1,597	745
Residential construction and land development [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	3,140	10,148
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	641	1,444
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	2,499	8,704
Troubled Debt Restructuring, Specific allowance	23	107
Troubled Debt Restructuring, Charge-offs	1,597	46
Retail [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	3,600	4,359
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	2,432	3,141
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	1,168	1,218
Troubled Debt Restructuring, Specific allowance	0	0
Troubled Debt Restructuring, Charge-offs	0	582
Office [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	2,324	5,059
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	3,872
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	2,324	1,187
Troubled Debt Restructuring, Specific allowance	0	0
Troubled Debt Restructuring, Charge-offs	0	117
Multifamily [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Specific allowance	0	0
Troubled Debt Restructuring, Charge-offs	0	0
Industrial [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Specific allowance	0	0
Troubled Debt Restructuring, Charge-offs	0	0
Other commercial real estate [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	1,647	5,011
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	1,647	2,885
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	2,126
Troubled Debt Restructuring, Specific allowance	0	0
Troubled Debt Restructuring, Charge-offs	0	0
Residential Mortgage [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	23,174	22,742
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	15,049	15,745
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	8,125	6,997
Troubled Debt Restructuring, Specific allowance	105	88
Troubled Debt Restructuring, Charge-offs	509	581
Permanent mortgage [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	16,393	18,697
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	11,134	12,214
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	5,259	6,483
Troubled Debt Restructuring, Specific allowance	105	88
Troubled Debt Restructuring, Charge-offs	262	469
Permanent mortgages guaranteed by U.S. government agencies [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	73,985	54,322
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	17,274	13,384
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	56,711	40,938
Troubled Debt Restructuring, Specific allowance	0	0
Troubled Debt Restructuring, Charge-offs	0	0
Permanent mortgages guaranteed by U.S. government agencies [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	1,597
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	179
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	1,418
Troubled Debt Restructuring, Specific allowance	0
Troubled Debt Restructuring, Charge-offs	0
Home equity | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	5,184	4,045
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	3,736	3,531
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	1,448	514
Troubled Debt Restructuring, Specific allowance	0	0
Troubled Debt Restructuring, Charge-offs	247	112
Consumer [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	419	1,008
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	253	758
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	166	250
Troubled Debt Restructuring, Specific allowance	0	0
Troubled Debt Restructuring, Charge-offs	$1	$1

Loans_and_Allowances_for_Credi7

Loans and Allowances for Credit Losses, Troubled Debt Restructurings, Modifications (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	$44,210	$36,021
Troubled Debt Restructurings, Recorded Balance With Payment Default	34,607	30,706
Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	32,679	24,063
Troubled Debt Restructurings, Recorded Balance With Payment Default	29,585	23,918
Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	15,386	11,545
Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	17,293	12,518
Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	11,531	11,958
Troubled Debt Restructurings, Recorded Balance With Payment Default	5,022	6,788
Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	214
Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	4,243	6,355
Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	7,288	5,389
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	3,738	1,667
Troubled Debt Restructurings, Recorded Balance With Payment Default	13	1,635
Commercial [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Commercial [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Commercial [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Commercial [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	3,738	1,667
Troubled Debt Restructurings, Recorded Balance With Payment Default	13	1,635
Commercial [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	139
Commercial [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	3,657	1,471
Commercial [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	81	57
Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Energy [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Energy [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Energy [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Energy [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Energy [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Energy [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Energy [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	1,080
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	1,080
Services [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Services [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Services [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Services [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	1,080
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	1,080
Services [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Services [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	1,080
Services [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Wholesale/retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	3,261	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Wholesale/retail [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Wholesale/retail [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Wholesale/retail [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Wholesale/retail [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	3,261	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Wholesale/retail [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Wholesale/retail [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	3,261	0
Wholesale/retail [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	391
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	391
Manufacturing [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Manufacturing [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Manufacturing [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Manufacturing [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	391
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	391
Manufacturing [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Manufacturing [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	391
Manufacturing [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Healthcare [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Healthcare [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Healthcare [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Healthcare [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Healthcare [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Healthcare [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Healthcare [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Healthcare [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Other commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	477	196
Troubled Debt Restructurings, Recorded Balance With Payment Default	13	164
Other commercial and industrial [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Other commercial and industrial [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Other commercial and industrial [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Other commercial and industrial [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	477	196
Troubled Debt Restructurings, Recorded Balance With Payment Default	13	164
Other commercial and industrial [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	139
Other commercial and industrial [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	396	0
Other commercial and industrial [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	81	57
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	3,822
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	3,822
Commercial Real Estate [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Commercial Real Estate [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Commercial Real Estate [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Commercial Real Estate [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	3,822
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	3,822
Commercial Real Estate [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Commercial Real Estate [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	3,822
Commercial Real Estate [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
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
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Residential construction and land development [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Residential construction and land development [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Residential construction and land development [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Residential construction and land development [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Residential construction and land development [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Residential construction and land development [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Residential construction and land development [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Retail [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	486
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	486
Retail [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Retail [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Retail [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Retail [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	486
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	486
Retail [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Retail [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	486
Retail [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Office [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	2,819
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	2,819
Office [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Office [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Office [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Office [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	2,819
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	2,819
Office [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Office [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	2,819
Office [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Multifamily [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Multifamily [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Multifamily [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Multifamily [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Multifamily [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Multifamily [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Multifamily [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Industrial [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Industrial [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Industrial [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Industrial [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Industrial [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Industrial [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Industrial [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Other commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	517
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	517
Other commercial real estate [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Other commercial real estate [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Other commercial real estate [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Other commercial real estate [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	517
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	517
Other commercial real estate [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Other commercial real estate [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	517
Other commercial real estate [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	40,396	29,819
Troubled Debt Restructurings, Recorded Balance With Payment Default	34,569	25,094
Residential Mortgage [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	32,679	24,063
Troubled Debt Restructurings, Recorded Balance With Payment Default	29,585	23,918
Residential Mortgage [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	15,386	11,545
Residential Mortgage [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	17,293	12,518
Residential Mortgage [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	7,717	5,756
Troubled Debt Restructurings, Recorded Balance With Payment Default	4,984	1,176
Residential Mortgage [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Residential Mortgage [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	586	1,062
Residential Mortgage [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	7,131	4,694
Permanent mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	4,124	2,956
Troubled Debt Restructurings, Recorded Balance With Payment Default	2,836	586
Permanent mortgage [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Permanent mortgage [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Permanent mortgage [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Permanent mortgage [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	4,124	2,956
Troubled Debt Restructurings, Recorded Balance With Payment Default	2,836	586
Permanent mortgage [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Permanent mortgage [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	586	1,062
Permanent mortgage [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	3,538	1,894
Permanent mortgages guaranteed by U.S. government agencies [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	33,738	24,063
Troubled Debt Restructurings, Recorded Balance With Payment Default	30,632	23,918
Permanent mortgages guaranteed by U.S. government agencies [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	32,679	24,063
Troubled Debt Restructurings, Recorded Balance With Payment Default	29,585	23,918
Permanent mortgages guaranteed by U.S. government agencies [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	15,386	11,545
Permanent mortgages guaranteed by U.S. government agencies [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	17,293	12,518
Permanent mortgages guaranteed by U.S. government agencies [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	1,059	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,047	0
Permanent mortgages guaranteed by U.S. government agencies [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Permanent mortgages guaranteed by U.S. government agencies [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Permanent mortgages guaranteed by U.S. government agencies [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	1,059	0
Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	2,534	2,800
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,101	590
Home equity | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Home equity | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Home equity | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Home equity | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	2,534	2,800
Troubled Debt Restructurings, Recorded Balance With Payment Default	1,101	590
Home equity | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Home equity | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Home equity | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	2,534	2,800
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	76	713
Troubled Debt Restructurings, Recorded Balance With Payment Default	25	155
Consumer [Member] | Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Troubled Debt Restructurings, Recorded Balance With Payment Default	0	0
Consumer [Member] | Accruing [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Consumer [Member] | Accruing [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Consumer [Member] | Nonaccrual [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	76	713
Troubled Debt Restructurings, Recorded Balance With Payment Default	25	155
Consumer [Member] | Nonaccrual [Member] | Interest Rate Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	75
Consumer [Member] | Nonaccrual [Member] | Payment Stream Modification [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	0	0
Consumer [Member] | Nonaccrual [Member] | Combination & Other Modifications [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled Debt Restructurings, Recorded Balance Modified During The Period	$76	$638

Loans_and_Allowances_for_Credi8

Loans and Allowances for Credit Losses, By Aging Category (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Financing receivable, recorded investment, aging [Abstract]
Current	$13,933,715	$12,509,986
Past due 30 to 89 days	41,437	38,099
Past due 90 days or more	152,114	143,030
Nonaccrual	80,771	101,149
Total	14,208,037	12,792,264
Commercial [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	9,078,724	7,922,000
Past due 30 to 89 days	3,419	4,112
Past due 90 days or more	0	349
Nonaccrual	13,527	16,760
Total	9,095,670	7,943,221
Energy [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	2,857,082	2,347,267
Past due 30 to 89 days	1,930	2,483
Past due 90 days or more	0	150
Nonaccrual	1,416	1,860
Total	2,860,428	2,351,760
Services [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	2,511,892	2,276,036
Past due 30 to 89 days	1,136	1,210
Past due 90 days or more	0	42
Nonaccrual	5,201	4,922
Total	2,518,229	2,282,210
Wholesale/retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	1,309,167	1,193,905
Past due 30 to 89 days	0	338
Past due 90 days or more	0	152
Nonaccrual	4,149	6,969
Total	1,313,316	1,201,364
Manufacturing [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	532,144	391,159
Past due 30 to 89 days	0	0
Past due 90 days or more	0	0
Nonaccrual	450	592
Total	532,594	391,751
Healthcare [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	1,453,409	1,272,660
Past due 30 to 89 days	180	0
Past due 90 days or more	0	0
Nonaccrual	1,380	1,586
Total	1,454,969	1,274,246
Other commercial and industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	415,030	440,973
Past due 30 to 89 days	173	81
Past due 90 days or more	0	5
Nonaccrual	931	831
Total	416,134	441,890
Commercial Real Estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	2,704,373	2,370,684
Past due 30 to 89 days	5,220	2,788
Past due 90 days or more	0	1,031
Nonaccrual	18,557	40,850
Total	2,728,150	2,415,353
Residential construction and land development [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	133,642	188,434
Past due 30 to 89 days	4,650	428
Past due 90 days or more	0	19
Nonaccrual	5,299	17,377
Total	143,591	206,258
Retail [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	662,963	580,926
Past due 30 to 89 days	0	264
Past due 90 days or more	0	0
Nonaccrual	3,926	4,857
Total	666,889	586,047
Office [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	412,124	404,505
Past due 30 to 89 days	0	603
Past due 90 days or more	0	0
Nonaccrual	3,420	6,391
Total	415,544	411,499
Multifamily [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	704,298	576,495
Past due 30 to 89 days	0	0
Past due 90 days or more	0	0
Nonaccrual	0	7
Total	704,298	576,502
Industrial [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	428,817	243,625
Past due 30 to 89 days	0	0
Past due 90 days or more	0	0
Nonaccrual	0	252
Total	428,817	243,877
Other commercial real estate [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	362,529	376,699
Past due 30 to 89 days	570	1,493
Past due 90 days or more	0	1,012
Nonaccrual	5,912	11,966
Total	369,011	391,170
Residential Mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	1,717,028	1,837,885
Past due 30 to 89 days	32,251	30,172
Past due 90 days or more	152,112	141,649
Nonaccrual	48,121	42,320
Total	1,949,512	2,052,026
Permanent mortgage [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	929,090	1,018,670
Past due 30 to 89 days	5,970	9,795
Past due 90 days or more	46	0
Nonaccrual	34,845	34,279
Total	969,951	1,062,744
Permanent mortgages guaranteed by U.S. government agencies [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	26,691	21,916
Past due 30 to 89 days	23,558	17,290
Past due 90 days or more	151,989	141,615
Nonaccrual	3,712	777
Total	205,950	181,598
Home equity
Financing receivable, recorded investment, aging [Abstract]
Current	761,247	797,299
Past due 30 to 89 days	2,723	3,087
Past due 90 days or more	77	34
Nonaccrual	9,564	7,264
Total	773,611	807,684
Consumer [Member]
Financing receivable, recorded investment, aging [Abstract]
Current	433,590	379,417
Past due 30 to 89 days	547	1,027
Past due 90 days or more	2	1
Nonaccrual	566	1,219
Total	$434,705	$381,664

Premises_and_Equipment_Premise1

Premises and Equipment Premises and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Premises and Equipment [Line Items]
Premises and Equipment, Gross	$617,707,000	$594,698,000
Premises and Equipment, Accumulated depreciation	343,874,000	316,849,000
Premises and Equipment, net	273,833,000	277,849,000
Depreciation Expense	33,000,000	30,000,000	33,000,000
Land [Member]
Premises and Equipment [Line Items]
Premises and Equipment, Gross	71,371,000	75,859,000
Building and improvements [Member]
Premises and Equipment [Line Items]
Premises and Equipment, Gross	225,008,000	221,326,000
Software [Member]
Premises and Equipment [Line Items]
Premises and Equipment, Gross	120,010,000	103,473,000
Furniture and equipment [Member]
Premises and Equipment [Line Items]
Premises and Equipment, Gross	179,513,000	163,013,000
Construction in progress [Member]
Premises and Equipment [Line Items]
Premises and Equipment, Gross	$21,805,000	$31,027,000

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets Acquisitions (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 28, 2014	Apr. 30, 2014
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Goodwill Amount	$377,780,000	$359,759,000	$361,979,000
GTrust Financial Corporation [Member]
Business Acquisition [Line Items]
Assets Under Management at time of acquisition				631,000,000
MBM Advisors [Member]
Business Acquisition [Line Items]
Assets Under Management at time of acquisition					1,300,000,000
Series of Individually Immaterial Business Acquisitions [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Purchase Price	27,000,000
Business Acquisition, Cost of Acquired Entity, Cash Paid	23,000,000
Business Combination, Contingent Consideration, Liability	4,000,000
Business Acquisition, Purchase Price Allocation, Intangible Assets Other than Goodwill	14,000,000
Business Acquisition, Purchase Price Allocation, Goodwill Amount	$18,000,000

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	$34,376	$24,564
Finite-Lived Intangible Assets-Future Amortization Expense [Abstract]
2015	4,360
2016	4,214
2017	3,756
2018	3,078
2019	2,816
Thereafter	16,152
Goodwill [Roll Forward]
Goodwill, Gross Beginning Balance	359,987	362,207
Goodwill, Accumulated Impairment Beginning Balance	-228	-228
Goodwill, Net Beginning Balance	359,759	361,979
Goodwill adjustmens during 2013		-2,220
Goodwill acquired during 2014	18,021
Goodwill, Gross Ending Balance	378,008	359,987
Goodwill, Accumulated Impairment Ending Balance	-228	-228
Goodwill, Net Ending Balance	377,780	359,759
Commercial [Member]
Goodwill [Roll Forward]
Goodwill, Gross Beginning Balance	268,942	271,162
Goodwill, Accumulated Impairment Beginning Balance	0	0
Goodwill, Net Beginning Balance	268,942	271,162
Goodwill adjustmens during 2013		-2,220
Goodwill acquired during 2014	421
Goodwill, Gross Ending Balance	269,363	268,942
Goodwill, Accumulated Impairment Ending Balance	0	0
Goodwill, Net Ending Balance	269,363	268,942
Consumer [Member]
Goodwill [Roll Forward]
Goodwill, Gross Beginning Balance	39,251	39,251
Goodwill, Accumulated Impairment Beginning Balance	-228	-228
Goodwill, Net Beginning Balance	39,023	39,023
Goodwill adjustmens during 2013		0
Goodwill acquired during 2014	0
Goodwill, Gross Ending Balance	39,251	39,251
Goodwill, Accumulated Impairment Ending Balance	-228	-228
Goodwill, Net Ending Balance	39,023	39,023
Wealth Management [Member]
Goodwill [Roll Forward]
Goodwill, Gross Beginning Balance	51,794	51,794
Goodwill, Accumulated Impairment Beginning Balance	0	0
Goodwill, Net Beginning Balance	51,794	51,794
Goodwill adjustmens during 2013		0
Goodwill acquired during 2014	17,600
Goodwill, Gross Ending Balance	69,394	51,794
Goodwill, Accumulated Impairment Ending Balance	0	0
Goodwill, Net Ending Balance	69,394	51,794
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	33,749	33,749
Accumulated amortization	33,088	32,656
Finite-lived intangible assets, net	661	1,093
Finite-Lived Intangible Assets-Future Amortization Expense [Abstract]
2015	393
2016	247
2017	21
2018	0
2019	0
Thereafter	0
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	50,288	36,511
Accumulated amortization	16,573	13,040
Finite-lived intangible assets, net	33,715	23,471
Finite-Lived Intangible Assets-Future Amortization Expense [Abstract]
2015	3,967
2016	3,967
2017	3,735
2018	3,078
2019	2,816
Thereafter	$16,152

Mortgage_Banking_Activities_Co

Mortgage Banking Activities, Components of Loans Held For Sale (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Components of Residential Mortgage Loans Held for Sale [Abstract]
Residential mortgages loans held for sale, Fair Value	$304,182	$200,546
Mortgage Banking Revenue [Abstract]
Net realized gains on sales of mortgage loans	56,696	95,309	115,879
Net change in unrealized gain on mortgage loans held for sale	5,357	-10,899	4,720
Change in fair value of mortgage loan commitments	7,315	-10,077	6,136
Change in the fair value of forward sales commitments	-8,307	5,212	2,382
Total production revenue	61,061	79,545	129,117
Servicing revenue	48,032	42,389	40,185
Total mortgage banking revenue	109,093	121,934	169,302
Residential mortgage loans held for sale [Member]
Schedule of Residential Mortgage Loans Held For Sale [Line Items]
Number of days for past due for loan to be considered nonperforming (in days)	90 days	90 days
Residential mortgage loans held for sale, nonperforming	0	0
Credit losses recognized on residential mortgage loans held for sale	0	0
Components of Residential Mortgage Loans Held for Sale [Abstract]
Residential mortgage loans held for sale, Unpaid Principal Balance	291,537	192,266
Residential mortgages loans held for sale, Fair Value	298,212	193,584
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
General number of days outstanding for residential mortgage commitments, maximum (in days)	90 days	90 days
Components of Residential Mortgage Loans Held for Sale [Abstract]
Residential mortgage loans held for sale, Derivative contracts, Notional	520,829	258,873
Residential mortgages loans held for sale, Fair Value	9,971	2,656
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
General number of days for delivery of loans, for which the price is set by forward sales contracts, maximum (in days)	90 days	90 days
Components of Residential Mortgage Loans Held for Sale [Abstract]
Residential mortgage loans held for sale, Derivative contracts, Notional	701,066	435,867
Residential mortgages loans held for sale, Fair Value	($4,001)	$4,306

Mortgage_Banking_Activities_Mo1

Mortgage Banking Activities, Mortgage Servicing Rights (Details) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2011	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of Mortgage Servicing Rights [Abstract]
Number of residential mortgage loans serviced		117,483	106,137	98,246
Outstanding principal balance of residential mortgage loans serviced for others		$16,162,887,000	$13,718,942,000	$11,981,624,000
Weighted average interest rate (in hundredths)		4.29%	4.40%	4.71%
Remaining term (in months)		296 months	292 months	289 months
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance		153,333,000	100,812,000	86,783,000
Additions, net		54,413,000	49,431,000	42,191,000
Change in fair value due to loan runoff		-19,325,000	-19,630,000	-18,952,000
Change in fair value due to market changes		-16,445,000	22,720,000	-9,210,000
Ending balance		171,976,000	153,333,000	100,812,000
Servicing Assets at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Discount rate - risk-free rate plus a market premium (in hundredths)		10.17%	10.21%
Prepayment rate - estimated based upon loan interest rate, original term and loan type, minimum (in hundredths)		7.70%	6.66%
Prepayment rate - estimated based upon loan interest rate, original term and loan type, maximum (in hundredths)		30.44%	26.19%
Loan servicing costs - annually per loan based upon loan type, Performing, minimum (in dollars per loan)		60	60
Loan servicing costs - annually per loan based upon loan type, Performing, maximum (in dollars per loan)		105	105
Loan servicing costs - annually per loan based upon loan type, Delinquent loans, Minimum (in dollars per loan)		150	150
Loan servicing costs - annually per loan based upon loan type, Delinquent loans, Maximum (in dollars per loan)		500	500
Loan servicing costs - annually per loan based upon loan type, Loans in foreclosure, Minimum (in dollars per loan)		1,000	1,000
Loan servicing costs - annually per loan based upon loan type, Loans in foreclosure, Maximum (in dollars per loan)		4,250	4,250
Escrow earnings rate - indexed to rates paid on deposit accounts with comparable average life (in hundredths)		1.77%	1.80%
Purchased [Member]
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance		15,935,000	12,976,000	18,903,000
Additions, net		0	0	0
Change in fair value due to loan runoff		-2,357,000	-3,029,000	-4,164,000
Change in fair value due to market changes		-2,464,000	5,988,000	-1,763,000
Ending balance		11,114,000	15,935,000	12,976,000
Originated [Member]
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance		137,398,000	87,836,000	67,880,000
Additions, net		54,413,000	49,431,000	42,191,000
Change in fair value due to loan runoff		-16,968,000	-16,601,000	-14,788,000
Change in fair value due to market changes		-13,981,000	16,732,000	-7,447,000
Ending balance		$160,862,000	$137,398,000	$87,836,000

Mortgage_Banking_Activities_Lo

Mortgage Banking Activities, Loan Servicing Portfolio (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stratification of Mortgage Loan Servicing Portfolio [Line Items]
Fair value	$171,976,000		$153,333,000	$100,812,000	$86,783,000
Outstanding principal of loans serviced others	16,162,887,000
Weighted average prepayment rate (in hundredths)	10.26%	[1]
Economic hedge threshold for interest rate sensitivity for mortgage servicing rights and securities held (in basis points)	50
Dollar increase in fair value, net of economic hedge, of mortgage servicing rights due to 50 basis point increase in mortgage interest rates	4,700,000
Dollar decrease in fair value, net of economic hedge, of mortgage servicing rights due to 50 basis point decrease in mortgage interest rates	4,600,000
Interest Rate Range Less than 4.00% [Member]
Stratification of Mortgage Loan Servicing Portfolio [Line Items]
Fair value	67,412,000
Outstanding principal of loans serviced others	6,332,112,000
Weighted average prepayment rate (in hundredths)	7.70%	[1]
Interest Rate Range 4.00% to 4.99% [Member]
Stratification of Mortgage Loan Servicing Portfolio [Line Items]
Fair value	80,405,000
Outstanding principal of loans serviced others	6,882,025,000
Weighted average prepayment rate (in hundredths)	8.58%	[1]
Interest Rate Range 5.00% to 5.99% [Member]
Stratification of Mortgage Loan Servicing Portfolio [Line Items]
Fair value	19,383,000
Outstanding principal of loans serviced others	1,989,977,000
Weighted average prepayment rate (in hundredths)	14.50%	[1]
Interest Rate Range Greater than 5.99% [Member]
Stratification of Mortgage Loan Servicing Portfolio [Line Items]
Fair value	4,776,000
Outstanding principal of loans serviced others	$958,773,000
Weighted average prepayment rate (in hundredths)	30.44%	[1]
[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_Mo2

Mortgage Banking Activities Mortgage Banking Activities, Loans Serviced for Others (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Financing Receivable, Recorded Investment, Aging [Abstract]
Mortgage Loans Serviced For Others, Current	$15,832,249
Mortgage Loans Serviced For Others, 30 To 59 Days Past Due	204,324
Mortgage Loans Serviced For Others, 60 To 89 Days Past Due	51,247
Mortgage Loans Serviced For Others, Greater Than 90 Days or More Past Due	75,067
Mortgage Loans Serviced For Others	16,162,887
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Mortgage Loans Serviced For Others, Current	5,289,078
Mortgage Loans Serviced For Others, 30 To 59 Days Past Due	37,881
Mortgage Loans Serviced For Others, 60 To 89 Days Past Due	9,418
Mortgage Loans Serviced For Others, Greater Than 90 Days or More Past Due	33,837
Mortgage Loans Serviced For Others	5,370,214
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Mortgage Loans Serviced For Others, Current	5,200,509
Mortgage Loans Serviced For Others, 30 To 59 Days Past Due	27,089
Mortgage Loans Serviced For Others, 60 To 89 Days Past Due	5,736
Mortgage Loans Serviced For Others, Greater Than 90 Days or More Past Due	22,087
Mortgage Loans Serviced For Others	5,255,421
Government National Mortgage Association Certificates and Obligations (GNMA) [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Mortgage Loans Serviced For Others, Current	4,920,064
Mortgage Loans Serviced For Others, 30 To 59 Days Past Due	132,680
Mortgage Loans Serviced For Others, 60 To 89 Days Past Due	34,602
Mortgage Loans Serviced For Others, Greater Than 90 Days or More Past Due	13,594
Mortgage Loans Serviced For Others	5,100,940
Other Investor Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Mortgage Loans Serviced For Others, Current	422,598
Mortgage Loans Serviced For Others, 30 To 59 Days Past Due	6,674
Mortgage Loans Serviced For Others, 60 To 89 Days Past Due	1,491
Mortgage Loans Serviced For Others, Greater Than 90 Days or More Past Due	5,549
Mortgage Loans Serviced For Others	$436,312

Mortgage_Banking_Activities_Lo1

Mortgage Banking Activities, Loans Sold With Recourse (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Residential mortgage loans sold with recourse [Abstract]
Carrying amount of residential mortgage loans sold and subject to recourse	$180,000,000	$191,000,000
Percentage of loans sold with recourse and either more than 90 days past due or in bankruptcy of foreclosure (in hundreths)	4.00%
Principal balance of loans sold with recourse and either 90 days or more past due or in bankruptcy or foreclosure	7,100,000
Percentage of loans sold with recourse and 30 to 89 days past due (in hundreths)	5.00%
Principal balance of loans sold with recourse and 30 to 89 days past due	8,400,000
Activity in the allowance for losses on loans sold with recourse [Abstract]
Beginning balance	9,562,000	13,158,000	18,683,000
Provision for recourse losses	354,000	517,000	-100,000
Loans charged off, net	-2,617,000	-4,113,000	-5,425,000
Ending balance	7,299,000	9,562,000	13,158,000
Residential Mortgage Loans Subject to Repurchase Under Standard Representations and Warranties [Abstract]
Number of mortgages purchased under repurchase agreement with US government sponsored entities	41
Purchase price of loans purchased under repurchase agreement with government sponsored entities	6,500,000
Losses incurred on actual repurchased loans from governmental sponsored entities with warranties	62,000
Number of loans sold under standard representation and warranties indemnified	17
Losses on mortgage loans indemnified during period	613,000
Number of loans with unresolved deficiency requests	186	578
Principal balance of loans with unresolved deficiency requests	15,328,000	69,288,000
Unpaid principal balance of mortgage loans subject to indemnification under standard representations and warranties	4,047,000	3,200,000
Activity in Accruals for Mortgage Losses [Roll Forward]
Beginning balance	12,716,000	8,983,000
Provision for losses	7,200,000	6,221,000
Charge-offs, net	-8,048,000	-2,488,000
Ending balance	$11,868,000	$12,716,000	$8,983,000

Deposits_Details

Deposits (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest expense on deposits [Abstract]
Transaction deposits	$9,757,000	$11,155,000	$14,300,000
Savings	401,000	442,000	540,000
Time Deposit, Interest Expense [Abstract]
Certificates of deposits under $100,000	14,278,000	16,234,000	19,150,000
Certificates of deposits $100,000 and over	11,878,000	12,273,000	16,331,000
Other time deposits	14,369,000	15,460,000	16,692,000
Total time	40,525,000	43,967,000	52,173,000
Total	50,683,000	55,564,000	67,013,000
Time Deposits [Abstract]
Time Deposits, $250,000 or More, Domestic	994,000,000	988,000,000
Time Deposit Maturities [Abstract]
2015	1,300,000,000
2016	519,000,000
2017	170,000,000
2018	201,000,000
2019	81,000,000
Thereafter	290,000,000
Fixed rate, brokered certificates of deposits	334,000,000	186,000,000
Weighted-average interest rate paid on fixed rate, brokered certificates of deposits (in hundredths)	2.59%	2.96%
Other Deposits Information [Abstract]
Overdrawn transaction deposits reclassified as loan balances	$6,200,000	$37,000,000

Other_Borrowings_Details

Other Borrowings (Details) (USD $)	12 Months Ended					0 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Jun. 05, 2015	15-May-17	Jun. 01, 2015
Other Borrowings [Line Items]
Balance	$3,726,277,000		$3,069,690,000		$3,053,854,000
Average balance	3,699,621,000		3,719,768,000		3,104,724,000
Weighted Average Interest Rate During Period	0.43%		0.40%		0.65%
US Agency Securities [Member]
Repurchase Agreements, Security Sold/Maturity [Abstract]
Amortized Cost	1,185,345,000		1,085,893,000
Market Value	1,192,361,000		1,075,821,000
Repurchase Liability	1,187,445,000	[1]	813,624,000	[1]
Average Rate (in hundredths)	0.04%		0.05%
US Agency Securities [Member] | Overnight [Member]
Repurchase Agreements, Security Sold/Maturity [Abstract]
Amortized Cost	1,185,345,000		1,085,893,000
Market Value	1,192,361,000		1,075,821,000
Repurchase Liability	1,187,445,000	[1]	813,624,000	[1]
Average Rate (in hundredths)	0.04%		0.05%
US Agency Securities [Member] | Long-term [Member]
Repurchase Agreements, Security Sold/Maturity [Abstract]
Amortized Cost	0		0
Market Value	0		0
Repurchase Liability	0	[1]	0	[1]
Average Rate (in hundredths)	0.00%		0.00%
Parent Company and other non-bank subsidiaries [Member]
Other Borrowings [Line Items]
Balance	0		0		10,500,000
Average balance	0		326,000		394,000
Weighted Average Interest Rate During Period	0.00%		0.00%		1.11%
Other borrowings, Maturities [Abstract]
2015	0
2016	0
2017	0
2018	0
2019	0
Thereafter	0
Parent Company and other non-bank subsidiaries [Member] | Senior Unsecured Revolving Credit Facility [Member]
Other Borrowings [Line Items]
Balance	0		0
Other borrowings, Other Disclosures [Abstract]
Maturity date						5-Jun-15
Senior Unsecured Revolving Credit Facility [Abstract]
Senior unsecured revolving credit facility, borrowing capacity	100,000,000
Senior unsecured revolving credit facility, revolving period	364
Senior unsecured revolving credit facility, interest rate description	defined base rate minus 1.25% or LIBOR plus 1.00% based upon the Company’s option
Senior unsecured revolving credit facility, Term loan, interest rate description	defined base rate minus 1.25% or LIBOR plus 1.25%
Senior unsecured revolving credit facility, unused capacity, commitment fee percentage	0.20%
Parent Company and other non-bank subsidiaries [Member] | Other Borrowings [Member]
Other Borrowings [Line Items]
Balance	0		0		10,500,000
Weighted Average Interest Rate	0.00%		0.00%		1.50%
Average balance	0		326,000		394,000
Weighted Average Interest Rate During Period	0.00%		0.00%		1.11%
Maximum Outstanding At Any Month End	0		0		10,500,000
Subsidiary Bank [Member]
Other Borrowings [Line Items]
Balance	3,726,277,000		3,069,690,000		3,043,354,000
Average balance	3,699,621,000		3,719,442,000		3,104,330,000
Weighted Average Interest Rate During Period	0.43%		0.41%		0.65%
Other borrowings, Maturities [Abstract]
2015	3,484,519,000
2016	525,000
2017	226,732,000
2018	575,000
2019	575,000
Thereafter	13,351,000
Subsidiary Bank [Member] | Funds Purchased [Member]
Other Borrowings [Line Items]
Balance	57,031,000		868,081,000		1,167,416,000
Weighted Average Interest Rate	0.05%		0.04%		0.05%
Average balance	494,220,000		866,062,000		1,512,711,000
Weighted Average Interest Rate During Period	0.07%		0.10%		0.14%
Maximum Outstanding At Any Month End	1,548,676,000		997,536,000		1,810,793,000
Other borrowings, Other Disclosures [Abstract]
Number of days to maturity, minimum	1 day
Number of days to maturity, maximum	90 days
Subsidiary Bank [Member] | Repurchase Agreements [Member]
Other Borrowings [Line Items]
Balance	1,187,489,000		813,454,000		887,030,000
Weighted Average Interest Rate	0.04%		0.05%		0.07%
Average balance	928,767,000		811,996,000		1,072,650,000
Weighted Average Interest Rate During Period	0.06%		0.06%		0.09%
Maximum Outstanding At Any Month End	1,187,489,000		881,033,000		1,272,151,000
Other borrowings, Other Disclosures [Abstract]
Number of days to maturity, maximum	90 days
Accrued interest payable	0		0
Subsidiary Bank [Member] | Other Borrowings [Member]
Other Borrowings [Line Items]
Balance	2,133,774,000		1,040,353,000		641,275,000
Average balance	1,928,742,000		1,693,667,000		155,271,000
Weighted Average Interest Rate During Period	0.35%
Subsidiary Bank [Member] | Federal Home Loan Bank Advances [Member]
Other Borrowings [Line Items]
Balance	2,103,400,000		1,005,650,000		604,897,000
Weighted Average Interest Rate	0.25%		0.19%		0.23%
Average balance	1,894,966,000		1,661,424,000		104,925,000
Weighted Average Interest Rate During Period	0.24%		0.20%		0.31%
Maximum Outstanding At Any Month End	3,453,400,000		2,451,197,000		604,897,000
Other borrowings, Other Disclosures [Abstract]
Federal Home Loan Banks, Letters of credit issued to secure public funds	315,000,000
Unused credit available pursuant to the FHLB's collateral policies	1,900,000,000
Subsidiary Bank [Member] | GNMA Repurchase Liability [Member]
Other Borrowings [Line Items]
Balance	14,298,000		18,113,000		20,046,000
Weighted Average Interest Rate	5.05%		5.50%		5.44%
Average balance	17,343,000		15,741,000		33,769,000
Weighted Average Interest Rate During Period	5.20%		5.43%		5.41%
Maximum Outstanding At Any Month End	24,980,000		21,055,000		47,840,000
Subsidiary Bank [Member] | Other [Member]
Other Borrowings [Line Items]
Balance	16,076,000		16,590,000		16,332,000
Weighted Average Interest Rate	2.73%		2.73%		2.79%
Average balance	16,433,000		16,502,000		16,577,000
Weighted Average Interest Rate During Period	2.32%		2.54%		2.91%
Maximum Outstanding At Any Month End	16,582,000		17,092,000		16,761,000
Subsidiary Bank [Member] | Subordinated Debentures [Member]
Other Borrowings [Line Items]
Balance	347,983,000		347,802,000		347,633,000
Weighted Average Interest Rate	2.35%		2.35%		2.40%
Average balance	347,892,000		347,717,000		363,699,000
Weighted Average Interest Rate During Period	2.50%		2.51%		3.79%
Maximum Outstanding At Any Month End	347,983,000		347,802,000		398,897,000
Subsidiary Bank [Member] | Subordinated Debentures, 2007 Issuance [Member]
Other Borrowings [Line Items]
Balance	227,000,000
Other borrowings, Other Disclosures [Abstract]
Amount of debt issuance	250,000,000
Maturity date							15-May-17
Interest rate description	fixed rate of 5.75% through May 14, 2012 and is based on a floating rate of three-month LIBOR plus 0.69% thereafter
Subsidiary Bank [Member] | Subordinated Debentures, 2005 Issuance [Member]
Other Borrowings [Line Items]
Balance	122,000,000
Weighted Average Interest Rate	5.56%
Other borrowings, Other Disclosures [Abstract]
Amount of debt issuance	$150,000,000
Maturity date								1-Jun-15
[1]	1 BOK Financial maintains control over the securities underlying overnight repurchase agreements and generally transfers control over securities underlying longer-term dealer repurchase agreements to the respective counterparty.

Federal_and_State_Income_Taxes2

Federal and State Income Taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets [Abstract]
Available for sale securities mark to market	$0	$14,751,000
Share-based compensation	9,414,000	8,064,000
Credit loss allowances	74,362,000	75,657,000
Valuation adjustments	36,870,000	35,292,000
Deferred compensation	23,333,000	60,068,000
Unearned fees	11,820,000	10,683,000
Other	26,633,000	22,348,000
Total deferred tax assets	182,432,000	226,863,000
Deferred tax liabilities [Abstract]
Available for sale securities mark to market	37,719,000	0
Depreciation	18,601,000	17,333,000
Mortgage servicing rights	86,752,000	72,235,000
Lease financing	24,429,000	23,202,000
Other	22,160,000	18,494,000
Total deferred tax liabilities	189,661,000	131,264,000
Net deferred tax assets (liabilities)	-7,229,000	95,599,000
Current income tax expense [Abstract]
Federal	85,990,000	125,412,000	159,706,000
State	9,392,000	14,381,000	19,103,000
Total current income tax expense	95,382,000	139,793,000	178,809,000
Deferred income tax expense [Abstract]
Federal	36,521,000	15,915,000	8,664,000
State	2,949,000	1,590,000	1,267,000
Total deferred income tax expense	39,470,000	17,505,000	9,931,000
Total income tax expense	134,852,000	157,298,000	188,740,000
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Federal statutory tax	150,616,000	166,680,000	190,003,000
Tax exempt revenue	-8,446,000	-7,361,000	-5,558,000
Effect of state income taxes, net of federal benefit	9,054,000	10,937,000	13,684,000
Utilization of tax credits	-11,107,000	-8,145,000	-5,126,000
Bank-owned life insurance	-3,183,000	-3,596,000	-3,850,000
Reduction of tax accrual	-2,281,000	-1,400,000	-950,000
Other, net	199,000	183,000	537,000
Total income tax expense	134,852,000	157,298,000	188,740,000
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Federal statutory tax (in hundredths)	35.00%	35.00%	35.00%
Tax exempt revenue (in hundredths)	-2.00%	-1.50%	-1.00%
Effect of state income taxes, net of federal benefit (in hundredths)	2.10%	2.30%	2.50%
Utilization of tax credits (in hundredths)	-2.60%	-1.70%	-0.90%
Bank-owned life insurance (in hundredths)	-0.70%	-0.80%	-0.70%
Reduction of tax accrual (in hundredths)	-0.50%	-0.30%	-0.10%
Other, net (in hundredths)	0.00%	0.00%	0.00%
Total (in hundredths)	31.30%	33.00%	34.80%
Tax accrual reduction	2,300,000	1,400,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance as of January 1	12,058,000	12,275,000	12,230,000
Additions for tax for current year positions	3,813,000	2,730,000	3,976,000
Settlements during the period	0	0	-1,000,000
Lapses of applicable statute of limitations	-2,497,000	-2,947,000	-2,931,000
Balance as of December 31	13,374,000	12,058,000	12,275,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	8,700,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	1,500,000	1,200,000	1,200,000
Unrecognized Tax Benefits, Penalties and Interest Accrued	$3,600,000	$2,900,000
Unrecognized Tax Benefits, Number of Reporting Periods Open for Examination, Federal	3 years
Unrecognized Tax Benefits, Number of Reporting Periods Open for Examination, State, Minimum	3 years
Unrecognized Tax Benefits, Number of Reporting Periods Open for Examination, State, Maximum	6 years

Employee_Benefits_Details

Employee Benefits (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest percentage added to the five-year trailing average of five-year Treasury Securities	1.50%
Interest percentage accrued on employee account balances, Minimum	3.00%
Interest percentage accrued on employee account balances, Maximum	5.00%
Interest percentage accrued on employee account balances, Lower end of range for current year	3.00%
Interest percentage accrued on employee accounts balances, Upper end of range for current year	3.01%
Thrift Plan - Defined Contribution [Abstract]
Employee base compensation company match employee contributions (in hundredths)	6.00%
Employer matching rate for employee contributions minimum (in hundredths)	50.00%
Minimum years of service for employees to obtain maximum employer matching (in years)	P4Y
Employer matching rate for employee contributions maximum (in hundredths)	200.00%
Maximum years of service for employees to obtain minimum employer matching (in years)	15 years
Non-elective annual contribution for qualified employees	$750
Annual base employee compensation to qualify for non-elective employer contributions maximum	40,000
Employer discretionary contribution amount	662,000		738,000		802,000
Vesting period for employer contributions (in years)	5 years
Thrift Plan expenses	18,600,000		18,100,000		16,800,000
Incentive compensation plans [Abstract]
Expense related to cash-based incentive compensation plans	111,700,000		110,900,000		116,700,000
Pension Plan [Member]
Change in projected benefit obligation [Roll Forward]
Projected benefit obligation at beginning of year	44,765,000	[1],[2]	48,028,000
Interest cost	1,685,000		1,532,000
Actuarial loss (gain)	2,878,000		-1,543,000
Benefits paid	-4,104,000		-3,252,000
Projected benefit obligation at end of year	45,224,000	[1],[2]	44,765,000	[1],[2]
Change in plan assets [Roll Forward]
Plan assets at fair value at beginning of year	48,812,000		45,920,000
Actual return on plan assets	4,735,000		6,144,000
Benefits paid	-4,104,000		-3,252,000
Plan assets at fair value at end of year	49,443,000		48,812,000
Defined Benefit Plan, Funded Status of Plan [Abstract]
Funded status of the plan	4,219,000		4,047,000
Components of net periodic benefit costs [Abstract]
Interest cost	1,685,000		1,532,000
Expected return on plan assets	-2,539,000		-2,185,000
Recognized prior service cost	1,175,000		1,175,000
Amortization of unrecognized net loss	2,584,000		3,830,000
Net periodic pension cost	555,000		2,002,000
Weighted-average assumptions [Abstract]
Discount rate (in hundredths)	3.42%		4.05%
Expected return on plan assets (in hundredths)	6.00%		6.00%
Estimated Future Benefit Payments [Abstract]
2015	3,535,000
2016	3,673,000
2017	3,270,000
2018	3,396,000
2019	3,628,000
Thereafter	44,057,000
Total estimated future benefit payments	61,559,000
Defined Benefit Plan, Information about Plan Assets [Abstract]
Inception to date return (in hundredths)	7.44%
Maximum allowable contributions to defined benefit plan	21,000,000
Net pension costs currently in accumulated other comprehensive income to be recognized as net periodic pension cost in next fiscal year	$267,000
Equity Securities [Member] | Pension Plan [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of equities and bonds included in portfolio mix of fund used for defined benefit plan (in hundredths)	60.00%
Bonds [Member] | Pension Plan [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of equities and bonds included in portfolio mix of fund used for defined benefit plan (in hundredths)	40.00%
[1]	Projected benefit obligation is based on January 1 measurement date.
[2]	Projected benefit obligation equals accumulated benefit obligation.

ShareBased_Compensation_Plans_1

Share-Based Compensation Plans (Details) (USD $)	12 Months Ended					1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013		Dec. 31, 2012		Jan. 31, 2015	31-May-14	Dec. 31, 2011
Share-based Compensation, Deferred Compensation Plans, 2011 True-Up Plan [Abstract]
Additional Compensation Accrued for Certain Senior Executive Related to 2011 True-Up Plan		$69,000,000
Total Amount Distributed Under 2011 True-Up Plan							56,000,000
Cash Distributed Related to 2011 True-Up Plan							35,000,000
Dollar Value of Shares Distributed Related to 2011 True-Up Plan							21,000,000
Number of Shares Distributed Related to 2011 True-Up Plan							331,000
Price Per Share of Shares Distributed Related to 2011 True-Up Plan							$64.91
Stock Options [Member]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Outstanding, Number of Options [Abstract]
Number of options outstanding, Beginning balance (in shares)	1,135,105	1,890,786		2,621,347
Options awarded (in shares)	0	81,492		67,155
Options exercised (in shares)	-323,004	-608,663		-708,295
Options forfeited (in shares)	-15,509	-219,342		-22,559
Options expired (in shares)	-2,701	-9,168		-66,862
Number of options outstanding, Ending balance (in shares)	793,891	1,135,105		1,890,786
Options shares vested (in shares)	347,633	424,459		601,367
Share-based Compensation Arrangements by Share-based Payment Award, Options, Weighted Average Exercise Price [Abstract]
Options outstanding, weighted average exercise price, beginning balance (in dollars per share)	$49.09	$48.29		$47.01
Options awarded, weighted average exercise price (in dollars per share)	$0	$55.74		$58.76
Options exercised, weighted average exercise price (in dollars per share)	$49.17	$48		$45.32
Options forfeited, weighted average exercise price (in dollars per share)	$45.71	$47.65		$50.36
Options expired, weighted average exercise price (in dollars per share)	$47.98	$50.61		$45.97
Options outstanding, weighted average exercise price, ending balance (in dollars per share)	$49.05	$49.09		$48.29
Options vested, weighted average exercise price (in dollars per share)	$48.85	$49.49		$47.99
Share-based Compensation Arrangements by Share-based Payment Award, Options, Intrinsic Value [Abstract]
Options outstanding, aggregate intrinsic value	8,725,000	19,564,000		11,748,000				20,769,000
Options vested, aggregate intrinsic value	3,889,000	7,146,000		3,890,000
Options exercised, aggregate intrinsic value	5,500,000	8,500,000		8,300,000
Weighted average assumptions used to determine fair value of stock options awarded [Abstract]
Average risk-free interest rate (in hundredths)		0.89%	[1]	0.93%	[1]
Dividend yield (in hundredths)		2.80%		2.20%
Volatility factors		27.20%		28.00%
Weighted average expected life (in years)		4 years 10 months 24 days		4 years 10 months 24 days
Weighted average fair value (in dollars per share)		$9.67		$11.48
Share-based Compensation Expense Recognized	826,000	1,300,000		4,100,000
Share-based Compensation Costs, Including Costs That May Be Recognized As Future Expense [Abstract]
Unrecognized compensation cost of unvested awards, for future periods	980,000
Unrecognized compensation cost of unvested awards, Amount to be expensed in 2015	475,000
Unrecognized compensation cost of unvested awards, Amount to be expensed in 2016	275,000
Unrecognized compensation cost of unvested awards, Amount to be expensed in 2017	152,000
Unrecognized compensation cost of unvested awards, Amount to be expensed in 2018	60,000
Unrecognized compensation cost of unvested awards, Amount to be Expensed in 2019	18,000
Share-based Compensation, Deferred Compensation Plans, 2011 True-Up Plan [Abstract]
Vesting period (in years)	7 years
Stock Options [Member] | Exercise Price 36.65 [Member]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Outstanding, Number of Options [Abstract]
Number of options outstanding, Ending balance (in shares)	190,832
Options shares vested (in shares)	65,626
Weighted average remaining contractual life of options vested (in years)	1 year 6 months 5 days
Share-based Compensation Arrangements by Share-based Payment Award, Options, Weighted Average Exercise Price [Abstract]
Options outstanding, weighted average exercise price, ending balance (in dollars per share)	$36.65
Options vested, weighted average exercise price (in dollars per share)	$36.65
Share-based Compensation Arrangements by Share-based Payment Award, Options, Intrinsic Value [Abstract]
Weighted average remaining contractual life (in years)	2 years 10 months
Stock Options [Member] | Exercise Price 45.15 - 47.34 [Member]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Outstanding, Number of Options [Abstract]
Number of options outstanding, Ending balance (in shares)	33,574
Options shares vested (in shares)	33,574
Weighted average remaining contractual life of options vested (in years)	9 months 2 days
Share-based Compensation Arrangements by Share-based Payment Award, Options, Weighted Average Exercise Price [Abstract]
Options outstanding, weighted average exercise price, ending balance (in dollars per share)	$47.09
Options vested, weighted average exercise price (in dollars per share)	$47.09
Share-based Compensation Arrangements by Share-based Payment Award, Options, Intrinsic Value [Abstract]
Weighted average remaining contractual life (in years)	9 months 2 days
Stock Options [Member] | Exercise Price 48.30 [Member]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Outstanding, Number of Options [Abstract]
Number of options outstanding, Ending balance (in shares)	39,557
Options shares vested (in shares)	13,326
Weighted average remaining contractual life of options vested (in years)	1 year 5 months
Share-based Compensation Arrangements by Share-based Payment Award, Options, Weighted Average Exercise Price [Abstract]
Options outstanding, weighted average exercise price, ending balance (in dollars per share)	$48.30
Options vested, weighted average exercise price (in dollars per share)	$48.30
Share-based Compensation Arrangements by Share-based Payment Award, Options, Intrinsic Value [Abstract]
Weighted average remaining contractual life (in years)	3 years 1 month 27 days
Stock Options [Member] | Exercise Price 48.46 [Member]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Outstanding, Number of Options [Abstract]
Number of options outstanding, Ending balance (in shares)	169,422
Options shares vested (in shares)	95,415
Weighted average remaining contractual life of options vested (in years)	1 year 5 months 25 days
Share-based Compensation Arrangements by Share-based Payment Award, Options, Weighted Average Exercise Price [Abstract]
Options outstanding, weighted average exercise price, ending balance (in dollars per share)	$48.46
Options vested, weighted average exercise price (in dollars per share)	$48.46
Share-based Compensation Arrangements by Share-based Payment Award, Options, Intrinsic Value [Abstract]
Weighted average remaining contractual life (in years)	2 years 1 month 27 days
Stock Options [Member] | Exercise Price 54.33 [Member]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Outstanding, Number of Options [Abstract]
Number of options outstanding, Ending balance (in shares)	78,904
Options shares vested (in shares)	78,904
Weighted average remaining contractual life of options vested (in years)	1 year 5 months 22 days
Share-based Compensation Arrangements by Share-based Payment Award, Options, Weighted Average Exercise Price [Abstract]
Options outstanding, weighted average exercise price, ending balance (in dollars per share)	$54.33
Options vested, weighted average exercise price (in dollars per share)	$54.33
Share-based Compensation Arrangements by Share-based Payment Award, Options, Intrinsic Value [Abstract]
Weighted average remaining contractual life (in years)	1 year 5 months 22 days
Stock Options [Member] | Exercise Price 55.74 [Member]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Outstanding, Number of Options [Abstract]
Number of options outstanding, Ending balance (in shares)	78,108
Options shares vested (in shares)	8,260
Weighted average remaining contractual life of options vested (in years)	2 years 10 days
Share-based Compensation Arrangements by Share-based Payment Award, Options, Weighted Average Exercise Price [Abstract]
Options outstanding, weighted average exercise price, ending balance (in dollars per share)	$55.74
Options vested, weighted average exercise price (in dollars per share)	$55.74
Share-based Compensation Arrangements by Share-based Payment Award, Options, Intrinsic Value [Abstract]
Weighted average remaining contractual life (in years)	5 years 1 month 27 days
Stock Options [Member] | Exercise Price 55.94 [Member]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Outstanding, Number of Options [Abstract]
Number of options outstanding, Ending balance (in shares)	125,285
Options shares vested (in shares)	37,008
Weighted average remaining contractual life of options vested (in years)	1 year 5 months 8 days
Share-based Compensation Arrangements by Share-based Payment Award, Options, Weighted Average Exercise Price [Abstract]
Options outstanding, weighted average exercise price, ending balance (in dollars per share)	$55.94
Options vested, weighted average exercise price (in dollars per share)	$55.94
Share-based Compensation Arrangements by Share-based Payment Award, Options, Intrinsic Value [Abstract]
Weighted average remaining contractual life (in years)	3 years 7 months 12 days
Stock Options [Member] | Exercise Price 58.76 [Member]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Outstanding, Number of Options [Abstract]
Number of options outstanding, Ending balance (in shares)	78,209
Options shares vested (in shares)	15,520
Weighted average remaining contractual life of options vested (in years)	1 year 7 months 2 days
Share-based Compensation Arrangements by Share-based Payment Award, Options, Weighted Average Exercise Price [Abstract]
Options outstanding, weighted average exercise price, ending balance (in dollars per share)	$58.76
Options vested, weighted average exercise price (in dollars per share)	$58.76
Share-based Compensation Arrangements by Share-based Payment Award, Options, Intrinsic Value [Abstract]
Weighted average remaining contractual life (in years)	4 years 4 months 5 days
Non-vested Common Stock [Member]
Weighted average assumptions used to determine fair value of stock options awarded [Abstract]
Share-based Compensation Expense Recognized	10,000,000	6,900,000		5,600,000
Share-based Compensation Costs, Including Costs That May Be Recognized As Future Expense [Abstract]
Unrecognized compensation cost of unvested awards, for future periods	15,500,000
Unrecognized compensation cost of unvested awards, Amount to be expensed in 2015	9,300,000
Unrecognized compensation cost of unvested awards, Amount to be expensed in 2016	5,700,000
Unrecognized compensation cost of unvested awards, Amount to be expensed in 2017	474,000
Unrecognized compensation cost of unvested awards, Amount to be expensed in 2018	1,000
Share-based Compensation Arrangements by Share-based Payment Award, Restricted Stock, Nonvested, Number of Shares [Roll Forward]
Non-vested common shares awarded, beginning of period (in shares)	647,989	592,831		503,738
Non-vested common shares awarded during period (in shares)	206,621	211,791		197,058
Non-vested shares that vested during period (in shares)	-140,820	-66,648		-76,192
Non-vested shares that forfeited during period (in shares)	-25,179	-89,985		-31,773
Non-vested common shares awarded, end of period (in shares)	688,611	647,989		592,831
Share-based Compensation Arrangements by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted Average Grant Date Fair Value, Granted	$64.96	$55.84		$55.63
Weighted Average Grant Date Fair Value, Vested	$44.56	$35.93		$47.32
Weighted average grant date fair value non-vested stock awards forfeited (in dollars per share)	$56.26	$49.95		$50.45
2015 Restricted Common Stock Award [Member] | Non-vested Common Stock [Member]
Share-based Compensation Costs, Including Costs That May Be Recognized As Future Expense [Abstract]
Unrecognized compensation cost of unvested awards, for future periods						$16,500,000
Share-based Compensation, Deferred Compensation Plans, 2011 True-Up Plan [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period						297,106
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value						$55.53
Vesting period (in years)						3 years
Share Based Compensation Arrangement By Share Based Payment Award Award Retention of Shares Period						2 years
[1]	Average risk-free interest rate represents U.S. Treasury rates matched to the expected life of the options.

Related_Parties_Related_Partie1

Related Parties Related Parties (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loans and Leases Receivable, Related Parties [Roll Forward]
Lease payments on office space in facilities owned by related party afffiliates	$25,000,000	$23,500,000	$21,700,000
Management [Member]
Loans and Leases Receivable, Related Parties [Roll Forward]
Beginning balance	88,691,000	49,943,000
Advances	712,413,000	292,393,000
Payments	-698,149,000	-253,645,000
Adjustments	440,000	0
Ending balance	103,395,000	88,691,000
Board of Directors Chairman [Member]
Loans and Leases Receivable, Related Parties [Roll Forward]
Lease payments on office space in facilities owned by related party afffiliates	900,000	952,000	1,100,000
Executive Officer [Member]
Loans and Leases Receivable, Related Parties [Roll Forward]
Loan commitment secured by tax-exempt bonds purchased from a trust of which the related party is chairman of the trust	25,000,000
Percentage of investment funds' assets held by clients	99.00%
Assets Held in Cavanal Hill Funds	$3,200,000,000

Commitments_and_Contingent_Lia2

Commitments and Contingent Liabilities (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loss Contingencies [Line Items]
Operating Leases, Rent Expense, Net	$25,000,000	$23,500,000	$21,700,000
Operating Leases, Future Minimum Payments, Due in 2015	26,000,000
Operating Leases, Future Minimum Payments, Due in 2016	22,900,000
Operating Leases, Future Minimum Payments, Due in 2017	19,300,000
Operating Leases, Future Minimum Payments, Due in 2018	15,100,000
Operating Leases, Future Minimum Payments, Due in 2019	13,000,000
Operating Leases, Future Minimum Payments, Due Thereafter	104,800,000
Minimum Average Cash Balance Required to be Maintained at Federal Reserve by Subsidiary Bank	1,500,000,000	830,000,000
Parent Company [Member] | Visa Membership [Member]
Loss Contingencies [Line Items]
Number of Visa Class B Shares Owned by Entity (in shares)	251,837
Number of Visa Class A Shares Visa Class B Shares Are Convertible To (in shares)	103,782
Cavanal Hill Funds [Member]
Loss Contingencies [Line Items]
Mutual Fund Investment in US Treasury Securities	1,100,000,000
Mutual Fund Investment in Cash Management	1,300,000,000
Mutual Fund Investment in Tax-Free Money Market Funds	$258,000,000
The Net Asset Value of Units in Mutual Funds (per unit)	1

Commitments_and_Contingent_Lia3

Commitments and Contingent Liabilities Variable Interest Entities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Loans [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	$10,000,000	$10,000,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	18,192,000	27,319,000
Other Assets VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	44,450,000	49,967,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	106,192,000	99,517,000
Other Liabilities VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	32,970,000	37,457,000
Other Borrowings VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	10,964,000	10,964,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Non-controlling Interest [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	34,027,000	34,924,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Private equity funds [Member] | Loans [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Private equity funds [Member] | Other Assets VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	25,627,000	27,341,000
Private equity funds [Member] | Other Liabilities VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Private equity funds [Member] | Other Borrowings VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Private equity funds [Member] | Non-controlling Interest [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	21,921,000	23,036,000
Tax credit entities [Member] | Loans [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	10,000,000	10,000,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	18,192,000	27,319,000
Tax credit entities [Member] | Other Assets VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	12,827,000	13,448,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	96,721,000	90,260,000
Tax credit entities [Member] | Other Liabilities VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	28,920,000	35,776,000
Tax credit entities [Member] | Other Borrowings VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	10,964,000	10,964,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Tax credit entities [Member] | Non-controlling Interest [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	10,000,000	9,869,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Other [Member] | Loans [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Other [Member] | Other Assets VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	5,996,000	9,178,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	9,471,000	9,257,000
Other [Member] | Other Liabilities VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	4,050,000	1,681,000
Other [Member] | Other Borrowings VIE [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
Other [Member] | Non-controlling Interest [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net	2,106,000	2,019,000
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net	0	0
BOKF Equity, LLC [Member]
Variable Interest Entity [Line Items]
Number of Private Equity Funds of which the Entity is a General Partner	2
Contingent Obligation For Additional Investments In Private Equity Funds	$5,600,000

Commitments_and_Contingent_Lia4

Commitments and Contingent Liabilities Guarantor Obligations (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
Property Lease Guarantee [Member]
Guarantor Obligations [Line Items]
Total amount of guaranteed rents	$28,700,000
Contingent Obligation For Guaranteed Rents	8,400,000
Guaranteed Percentage To Be Received	80.00%
Maximum Amount To Be Received Under Rent Agreement With City Of Tulsa	4,500,000
BOSC, Inc. [Member]
Guarantor Obligations [Line Items]
Customer balances subject to indemnification by Pershing, LLC	$72,000

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Numerator: [Abstract]:
Net income attributable to BOK Financial Corp. shareholders	$292,435	$316,609	$351,191
Less: Earnings allocated to participating securities	3,239	3,388	2,541
Numerator for basic earnings per share - income available to common shareholders	289,196	313,221	348,650
Effect of reallocating undistributed earnings of participating securities	-4	-7	-6
Numerator for diluted earnings per share - income available to common shareholders	$289,200	$313,228	$348,656
Denominator: [Abstract]
Weighted average shares outstanding	69,159,902	68,719,069	68,221,013
Less: Participating securities included in weighted average shares outstanding (in shares)	765,708	730,172	536,970
Denominator for basic earnings per common share (in shares)	68,394,194	67,988,897	67,684,043
Dilutive effect of employee stock compensation plans (in shares)	150,576	216,622	280,897
Denominator for diluted earnings per common share (in shares)	68,544,770	68,205,519	67,964,940
Basic earnings per share (per share)	$4.23	$4.61	$5.15
Diluted earnings per share (per share)	$4.22	$4.59	$5.13
Excludes employee stock options with exercise prices greater than current market price.	0	0	224,653

Shareholders_Equity_Details

Shareholders' Equity (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Jan. 01, 2015
Common stock, authorized (in shares)	2,500,000,000		2,500,000,000
Common stock, par value (in dollars per share)	$0.00		$0.00
Dividends declared and paid	$111,026,000		$104,722,000		$166,982,000
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	-25,623,000		149,920,000		128,979,000
Net change in unrealized gain (loss)	136,775,000		-275,945,000		66,197,000
Reclassification adjustments included in earnings: [Abstract]
Interest revenue, Investment securities, Taxable securities	-1,216,000		-3,210,000		-6,601,000
Interest expense, Subordinated debentures	296,000		262,000		453,000
Net impairment losses recognized in earnings	373,000		2,308,000		7,351,000
Gain on available for sale securities, net	-1,539,000		-10,720,000		-33,845,000
Other comprehensive income (loss), before income taxes	134,689,000		-287,305,000		33,555,000
Federal and state income taxes	-52,393,000	[1]	111,762,000	[1]	-12,614,000	[1]
Other comprehensive income (loss), net of income taxes	82,296,000		-175,543,000		20,941,000
Ending balance	56,673,000		-25,623,000		149,920,000
Total Capital (to Risk Weighted Assets) [Abstract]
Total Capital Ratio Required to be Well Capitalized	10.00%		10.00%
Total Capital	3,120,223,000		3,017,022,000
Total Capital to Risk Weighted Assets	14.66%		15.56%
Tier I Capital (to Risk Weighted Assets) [Abstract]
Tier I Capital Ratio Required to be Well Capitalized	6.00%		6.00%
Tier I Capital	2,838,129,000		2,668,981,000
Tier I Capital to Risk Weighted Assets	13.33%		13.77%
Tier I Capital (to Average Assets) [Abstract]
Leverage Ratio Required to be Well Capitalized	5.00%		5.00%
Tier I Capital to Average Assets	9.96%		10.05%
Accumulated Net Unrealized Gain (Loss) on Available for Sale Securities [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	-23,175,000		155,553,000		135,740,000
Net change in unrealized gain (loss)	136,050,000		-284,104,000		58,921,000
Reclassification adjustments included in earnings: [Abstract]
Interest revenue, Investment securities, Taxable securities	0		0		0
Interest expense, Subordinated debentures	0		0		0
Net impairment losses recognized in earnings	373,000		2,308,000		7,351,000
Gain on available for sale securities, net	-1,539,000		-10,720,000		-33,845,000
Other comprehensive income (loss), before income taxes	134,884,000		-292,516,000		32,427,000
Federal and state income taxes	-52,470,000	[1]	113,788,000	[1]	-12,614,000	[1]
Other comprehensive income (loss), net of income taxes	82,414,000		-178,728,000		19,813,000
Ending balance	59,239,000		-23,175,000		155,553,000
Accumulated Unrealized Gain on Investment Securities Transferred from AFS [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	1,118,000		3,078,000		6,673,000
Net change in unrealized gain (loss)	0		0		0
Reclassification adjustments included in earnings: [Abstract]
Interest revenue, Investment securities, Taxable securities	-1,216,000		-3,210,000		-6,601,000
Interest expense, Subordinated debentures	0		0		0
Net impairment losses recognized in earnings	0		0		0
Gain on available for sale securities, net	0		0		0
Other comprehensive income (loss), before income taxes	-1,216,000		-3,210,000		-6,601,000
Federal and state income taxes	474,000	[1]	1,250,000	[1]	3,006,000	[1]
Other comprehensive income (loss), net of income taxes	-742,000		-1,960,000		-3,595,000
Ending balance	376,000		1,118,000		3,078,000
Accumulated Unrealized Gain (Loss) on Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	-3,311,000		-8,296,000		-12,742,000
Net change in unrealized gain (loss)	725,000		8,159,000		7,276,000
Reclassification adjustments included in earnings: [Abstract]
Interest revenue, Investment securities, Taxable securities	0		0		0
Interest expense, Subordinated debentures	0		0		0
Net impairment losses recognized in earnings	0		0		0
Gain on available for sale securities, net	0		0		0
Other comprehensive income (loss), before income taxes	725,000		8,159,000		7,276,000
Federal and state income taxes	-282,000	[1]	-3,174,000	[1]	-2,830,000	[1]
Other comprehensive income (loss), net of income taxes	443,000		4,985,000		4,446,000
Ending balance	-2,868,000		-3,311,000		-8,296,000
Accumulated Loss on Effective Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	-255,000		-415,000		-692,000
Net change in unrealized gain (loss)	0		0		0
Reclassification adjustments included in earnings: [Abstract]
Interest revenue, Investment securities, Taxable securities	0		0		0
Interest expense, Subordinated debentures	296,000		262,000		453,000
Net impairment losses recognized in earnings	0		0		0
Gain on available for sale securities, net	0		0		0
Other comprehensive income (loss), before income taxes	296,000		262,000		453,000
Federal and state income taxes	-115,000	[1]	-102,000	[1]	-176,000	[1]
Other comprehensive income (loss), net of income taxes	181,000		160,000		277,000
Ending balance	-74,000		-255,000		-415,000
BOKF, NA [Member]
Allowed dividends without regulatory approval	365,000,000
Available dividend capacity of subsidiary bank upon implementation of Basel III Capital Rules							0
Dividends declared and paid	75,000,000		225,000,000		275,000,000
Maximum percentage of unimpaired capital on loan commitments and equity investments to a single affiliate (in hundredths)	10.00%
Maximum percentage of unimpaired capital on loan commitments and equity investments to all affiliates (in hundredths)	20.00%
Maximum loan commitments and equity investments to a single affiliate	245,000,000
Maximum loan commitments and equity investments to all affiliates	490,000,000
Largest loan commitment and equity investment to a single affiliate	220,000,000
Aggregate loan commitment and equity investment to all affiliates	330,000,000		334,000,000
Largest amount outstanding to a single affiliate	14,000,000
Outstanding amounts to all affiliates	18,000,000		27,000,000
Total Capital (to Risk Weighted Assets) [Abstract]
Total Capital	2,449,078,000		2,293,673,000
Total Capital to Risk Weighted Assets	11.56%		11.88%
Tier I Capital (to Risk Weighted Assets) [Abstract]
Tier I Capital	2,168,161,000		1,946,247,000
Tier I Capital to Risk Weighted Assets	10.24%		10.08%
Tier I Capital (to Average Assets) [Abstract]
Tier I Capital to Average Assets	7.65%		7.38%
Perpetual stock [Member]
Preferred stock, authorized (in shares)	1,000,000,000
Preferred stock at par value (in dollars per share)	$0.00
Preferred stock conversion rate	one share of Common Stock for each 36 shares of Series A Preferred Stock at the option of the holder
Preferred stock, Rate of annual cumulative dividends (in hundredths)	10.00%
Preferred stock, Liquidation preference per share	$0.06
Preferred stock, Aggregate liquidation preference	$15,000,000
Preferred Stock, Shares Outstanding	0		0		0
Common Stock [Member]
Common stock, authorized (in shares)	2,500,000,000
Common stock, par value (in dollars per share)	$0.00
Common stock, number of vote per share	$1
[1]	1 Calculated using 39% effective tax rate.

Reportable_Segments_Details

Reportable Segments (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Net interest revenue from external sources	$665,194	$674,477	$707,549
Net interest revenue (expense) from internal sources	0	0	0
Net interest revenue	665,194	674,477	707,549
Provision for credit losses	0	-27,900	-22,000
Net interest revenue after provision for credit losses	665,194	702,377	729,549
Other operating revenue	612,659	614,472	653,678
Operating expense	847,522	840,620	840,363
Net direct contribution	430,331	476,229	542,864
Corporate expense allocations	0	0	0
Net income before taxes	430,331	476,229	542,864
Federal and state income taxes	134,852	157,298	188,740
Net income	295,479	318,931	354,124
Net income attributable to non-controlling interests	3,044	2,322	2,933
Net income attributable to BOK Financial Corp. shareholders	292,435	316,609	351,191
Average assets	27,998,858	27,381,094	26,289,150
Average invested capital	3,210,761	3,011,082	2,905,955
Performance measurements: [Abstract]
Return on average assets	1.04%	1.16%	1.34%
Return on average invested capital	9.11%	10.51%	12.09%
Efficiency ratio	64.50%	64.60%	62.03%
Operating Segments [Member] | Commercial [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	381,687	363,961	366,243
Net interest revenue (expense) from internal sources	-43,934	-51,587	-58,835
Net interest revenue	337,753	312,374	307,408
Provision for credit losses	-7,447	-4,372	9,463
Net interest revenue after provision for credit losses	345,200	316,746	297,945
Other operating revenue	169,704	163,206	162,085
Operating expense	201,748	190,306	192,396
Net direct contribution	313,156	289,646	267,634
Corporate expense allocations	41,338	44,865	44,330
Net income before taxes	271,818	244,781	223,304
Federal and state income taxes	105,737	95,220	86,865
Net income	166,081	149,561	136,439
Net income attributable to non-controlling interests	0	0	0
Net income attributable to BOK Financial Corp. shareholders	166,081	149,561	136,439
Average assets	11,384,508	10,386,235	9,844,145
Average invested capital	946,383	906,717	882,036
Performance measurements: [Abstract]
Return on average assets	1.46%	1.44%	1.39%
Return on average invested capital	17.58%	16.49%	15.47%
Efficiency ratio	39.57%	40.24%	42.26%
Operating Segments [Member] | Consumer [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	95,910	100,153	102,321
Net interest revenue (expense) from internal sources	32,170	34,850	36,700
Net interest revenue	128,080	135,003	139,021
Provision for credit losses	5,405	5,532	10,588
Net interest revenue after provision for credit losses	122,675	129,471	128,433
Other operating revenue	200,815	225,336	271,723
Operating expense	196,082	189,099	206,598
Net direct contribution	127,408	165,708	193,558
Corporate expense allocations	67,040	60,005	64,239
Net income before taxes	60,368	105,703	129,319
Federal and state income taxes	23,483	41,118	50,305
Net income	36,885	64,585	79,014
Net income attributable to non-controlling interests	0	0	0
Net income attributable to BOK Financial Corp. shareholders	36,885	64,585	79,014
Average assets	6,555,642	6,487,255	6,498,193
Average invested capital	277,404	293,736	289,665
Performance measurements: [Abstract]
Return on average assets	0.56%	1.00%	1.22%
Return on average invested capital	13.30%	21.99%	27.28%
Efficiency ratio	56.58%	51.30%	49.60%
Operating Segments [Member] | Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	23,826	25,478	27,647
Net interest revenue (expense) from internal sources	20,578	20,061	21,456
Net interest revenue	44,404	45,539	49,103
Provision for credit losses	213	1,275	2,284
Net interest revenue after provision for credit losses	44,191	44,264	46,819
Other operating revenue	239,045	211,655	197,306
Operating expense	216,770	197,890	177,423
Net direct contribution	66,466	58,029	66,702
Corporate expense allocations	31,375	29,993	30,525
Net income before taxes	35,091	28,036	36,177
Federal and state income taxes	13,650	10,906	14,073
Net income	21,441	17,130	22,104
Net income attributable to non-controlling interests	0	0	0
Net income attributable to BOK Financial Corp. shareholders	21,441	17,130	22,104
Average assets	4,518,511	4,556,132	4,357,641
Average invested capital	193,784	203,914	184,707
Performance measurements: [Abstract]
Return on average assets	0.52%	0.40%	0.52%
Return on average invested capital	12.07%	9.00%	12.26%
Efficiency ratio	75.90%	76.37%	71.19%
Corporate, Non-Segment [Member] | Funds Management and Other [Member]
Segment Reporting Information [Line Items]
Net interest revenue from external sources	163,771	184,885	211,338
Net interest revenue (expense) from internal sources	-8,814	-3,324	679
Net interest revenue	154,957	181,561	212,017
Provision for credit losses	1,829	-30,335	-44,335
Net interest revenue after provision for credit losses	153,128	211,896	256,352
Other operating revenue	3,095	14,275	22,564
Operating expense	232,922	263,325	263,946
Net direct contribution	-76,699	-37,154	14,970
Corporate expense allocations	-139,753	-134,863	-139,094
Net income before taxes	63,054	97,709	154,064
Federal and state income taxes	-8,018	10,054	37,497
Net income	71,072	87,655	116,567
Net income attributable to non-controlling interests	3,044	2,322	2,933
Net income attributable to BOK Financial Corp. shareholders	68,028	85,333	113,634
Average assets	5,540,197	5,951,472	5,589,171
Average invested capital	$1,793,190	$1,606,715	$1,549,547

Fair_Value_Measurements_Fair_V

Fair Value Measurements, Fair Value Of Financial Instruments as Measured On a Recurring Basis (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Assets [Abstract]
Trading securities	$188,700		$91,616
Available for sale securities	8,978,945		10,147,162
Fair value option securities	311,597		167,125
Mortgage servicing rights	171,976		153,333		100,812	86,783
Derivative contracts, net of cash margin, Assets, Fair Value	361,874		265,012
Liabilities [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	354,554		247,185
U.S. government agency debentures [Member]
Assets [Abstract]
Trading securities	85,092		34,120
U.S. government agency residential mortgage-backed securities [Member]
Assets [Abstract]
Trading securities	31,199		21,011
Available for sale securities	6,646,884		7,716,010
Fair value option securities	311,597		157,431
Municipal and other tax-exempt securities [Member]
Assets [Abstract]
Trading securities	38,951		27,350
Available for sale securities	63,557		73,775
Other trading securities [Member]
Assets [Abstract]
Trading securities	33,458		9,135
U.S. Treasury securities [Member]
Assets [Abstract]
Available for sale securities	1,005		1,042
Privately issued residential mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	165,957		221,099
Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Assets [Abstract]
Available for sale securities	2,048,609		2,055,804
Other debt securities [Member]
Assets [Abstract]
Available for sale securities	9,212		35,241
Fair value option securities	0		9,694
Perpetual preferred stock [Member]
Assets [Abstract]
Available for sale securities	24,277		22,863
Equity securities and mutual funds [Member]
Assets [Abstract]
Available for sale securities	19,444		21,328
Fair Value, Measurements, Recurring [Member]
Assets [Abstract]
Trading securities	188,700		91,616
Available for sale securities	8,978,945		10,147,162
Fair value option securities	311,597		167,125
Residential mortgage loans held for sale	304,182		200,546
Mortgage servicing rights	171,976	[1]	153,333	[1]
Derivative contracts, net of cash margin, Assets, Fair Value	361,874	[2]	265,012	[3]
Other assets, private equity funds	25,627		27,341
Liabilities [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	354,554	[2]	247,185	[3]
Fair Value, Measurements, Recurring [Member] | U.S. government agency debentures [Member]
Assets [Abstract]
Trading securities	85,092		34,120
Fair Value, Measurements, Recurring [Member] | U.S. government agency residential mortgage-backed securities [Member]
Assets [Abstract]
Trading securities	31,199		21,011
Available for sale securities	6,646,884		7,716,010
Fair value option securities	311,597		157,431
Fair Value, Measurements, Recurring [Member] | Municipal and other tax-exempt securities [Member]
Assets [Abstract]
Trading securities	38,951		27,350
Available for sale securities	63,557		73,775
Fair Value, Measurements, Recurring [Member] | Other trading securities [Member]
Assets [Abstract]
Trading securities	33,458		9,135
Fair Value, Measurements, Recurring [Member] | U.S. Treasury securities [Member]
Assets [Abstract]
Available for sale securities	1,005		1,042
Fair Value, Measurements, Recurring [Member] | Privately issued residential mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	165,957		221,099
Fair Value, Measurements, Recurring [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Assets [Abstract]
Available for sale securities	2,048,609		2,055,804
Fair Value, Measurements, Recurring [Member] | Other debt securities [Member]
Assets [Abstract]
Available for sale securities	9,212		35,241
Fair value option securities	0		9,694
Fair Value, Measurements, Recurring [Member] | Perpetual preferred stock [Member]
Assets [Abstract]
Available for sale securities	24,277		22,863
Fair Value, Measurements, Recurring [Member] | Equity securities and mutual funds [Member]
Assets [Abstract]
Available for sale securities	19,444		21,328
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets [Abstract]
Trading securities	0		0
Available for sale securities	5,932		1,042
Fair value option securities	0		0
Residential mortgage loans held for sale	0		0
Mortgage servicing rights	0	[1]	0	[1]
Derivative contracts, net of cash margin, Assets, Fair Value	17,607	[2]	2,712	[3]
Other assets, private equity funds	0		0
Liabilities [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	541	[2]	0	[3]
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. government agency debentures [Member]
Assets [Abstract]
Trading securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. government agency residential mortgage-backed securities [Member]
Assets [Abstract]
Trading securities	0		0
Available for sale securities	0		0
Fair value option securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal and other tax-exempt securities [Member]
Assets [Abstract]
Trading securities	0		0
Available for sale securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other trading securities [Member]
Assets [Abstract]
Trading securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Treasury securities [Member]
Assets [Abstract]
Available for sale securities	1,005		1,042
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Privately issued residential mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other debt securities [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair value option securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Perpetual preferred stock [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Equity securities and mutual funds [Member]
Assets [Abstract]
Available for sale securities	4,927		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets [Abstract]
Trading securities	188,700		91,616
Available for sale securities	8,958,770		10,119,396
Fair value option securities	311,597		167,125
Residential mortgage loans held for sale	292,326		200,546
Mortgage servicing rights	0	[1]	0	[1]
Derivative contracts, net of cash margin, Assets, Fair Value	344,267	[2]	262,300	[3]
Other assets, private equity funds	0		0
Liabilities [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	354,013	[2]	247,185	[3]
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. government agency debentures [Member]
Assets [Abstract]
Trading securities	85,092		34,120
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. government agency residential mortgage-backed securities [Member]
Assets [Abstract]
Trading securities	31,199		21,011
Available for sale securities	6,646,884		7,716,010
Fair value option securities	311,597		157,431
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal and other tax-exempt securities [Member]
Assets [Abstract]
Trading securities	38,951		27,350
Available for sale securities	53,464		55,970
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other trading securities [Member]
Assets [Abstract]
Trading securities	33,458		9,135
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Treasury securities [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Privately issued residential mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	165,957		221,099
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Assets [Abstract]
Available for sale securities	2,048,609		2,055,804
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other debt securities [Member]
Assets [Abstract]
Available for sale securities	5,062		30,529
Fair value option securities	0		9,694
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Perpetual preferred stock [Member]
Assets [Abstract]
Available for sale securities	24,277		22,863
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Equity securities and mutual funds [Member]
Assets [Abstract]
Available for sale securities	14,517		17,121
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets [Abstract]
Trading securities	0		0
Available for sale securities	14,243		26,724
Fair value option securities	0		0
Residential mortgage loans held for sale	11,856		0
Mortgage servicing rights	171,976	[1]	153,333	[1]
Derivative contracts, net of cash margin, Assets, Fair Value	0	[2]	0	[3]
Other assets, private equity funds	25,627		27,341
Liabilities [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	0	[2]	0	[3]
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. government agency debentures [Member]
Assets [Abstract]
Trading securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. government agency residential mortgage-backed securities [Member]
Assets [Abstract]
Trading securities	0		0
Available for sale securities	0		0
Fair value option securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal and other tax-exempt securities [Member]
Assets [Abstract]
Trading securities	0		0
Available for sale securities	10,093		17,805
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other trading securities [Member]
Assets [Abstract]
Trading securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Treasury securities [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Privately issued residential mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other debt securities [Member]
Assets [Abstract]
Available for sale securities	4,150		4,712
Fair value option securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Perpetual preferred stock [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Equity securities and mutual funds [Member]
Assets [Abstract]
Available for sale securities	$0		$4,207
[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 7, Mortgage Banking Activities.
[2]	See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts in asset positions were valued based on quoted prices in active markets or identical instruments (Level 1) are exchange-traded energy derivative contracts, net of cash margin. Derivative contracts in liability positions that were valued using quoted prices in active markets for identical instruments (Level 1) are exchange-traded interest rate and agricultural derivative contracts, net of cash margin.
[3]	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 contracts, net of cash margin.

Fair_Value_Measurements_Measur

Fair Value Measurements, Measured On Recurring Basis Significant Unobservable Inputs (Details) (Fair Value, Inputs, Level 3 [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Available for sale Securities [Member] | Municipal and other tax-exempt securities [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance at beginning of period	$17,805,000	$40,702,000
Transfers to Level 3 from Level 2	0	0
Purchases and capital calls	0	0
Redemptions and distributions	-7,487,000	-19,238,000
Proceeds from sales	0
Other comprehensive gain (loss)	10,000	-3,506,000
Balance at end of period	10,093,000	17,805,000
Available for sale Securities [Member] | Municipal and other tax-exempt securities [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0
Available for sale Securities [Member] | Municipal and other tax-exempt securities [Member] | Gain (loss) on assets [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0
Available for sale Securities [Member] | Municipal and other tax-exempt securities [Member] | Gain on available for sale securities, net [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	-235,000	1,216,000
Available for sale Securities [Member] | Municipal and other tax-exempt securities [Member] | Other-than-temporary impairment losses [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	-1,369,000
Available for sale Securities [Member] | Municipal and other tax-exempt securities [Member] | Charitable Contributions to BOKF Foundation [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0
Available for sale Securities [Member] | Other debt securities [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance at beginning of period	4,712,000	5,399,000
Transfers to Level 3 from Level 2	0	0
Purchases and capital calls	0	0
Redemptions and distributions	-500,000	-500,000
Proceeds from sales	0
Other comprehensive gain (loss)	-62,000	-187,000
Balance at end of period	4,150,000	4,712,000
Available for sale Securities [Member] | Other debt securities [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0
Available for sale Securities [Member] | Other debt securities [Member] | Gain (loss) on assets [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0
Available for sale Securities [Member] | Other debt securities [Member] | Gain on available for sale securities, net [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0
Available for sale Securities [Member] | Other debt securities [Member] | Other-than-temporary impairment losses [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0
Available for sale Securities [Member] | Other debt securities [Member] | Charitable Contributions to BOKF Foundation [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0
Available for sale Securities [Member] | Equity securities and mutual funds [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance at beginning of period	4,207,000	2,161,000
Transfers to Level 3 from Level 2	0	0
Purchases and capital calls	0	0
Redemptions and distributions	0	0
Proceeds from sales	0
Other comprehensive gain (loss)	-1,787,000	2,046,000
Balance at end of period	0	4,207,000
Available for sale Securities [Member] | Equity securities and mutual funds [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0
Available for sale Securities [Member] | Equity securities and mutual funds [Member] | Gain (loss) on assets [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0
Available for sale Securities [Member] | Equity securities and mutual funds [Member] | Gain on available for sale securities, net [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0
Available for sale Securities [Member] | Equity securities and mutual funds [Member] | Other-than-temporary impairment losses [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0
Available for sale Securities [Member] | Equity securities and mutual funds [Member] | Charitable Contributions to BOKF Foundation [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	-2,420,000
Residential Mortgage Loans Held for Sale [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance at beginning of period	0	0
Transfers to Level 3 from Level 2	13,644,000	0
Purchases and capital calls	0	0
Redemptions and distributions	0	0
Proceeds from sales	-1,176,000
Other comprehensive gain (loss)	0	0
Balance at end of period	11,856,000	0
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	-612,000
Residential Mortgage Loans Held for Sale [Member] | Gain (loss) on assets [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0
Residential Mortgage Loans Held for Sale [Member] | Gain on available for sale securities, net [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0
Residential Mortgage Loans Held for Sale [Member] | Other-than-temporary impairment losses [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0
Residential Mortgage Loans Held for Sale [Member] | Charitable Contributions to BOKF Foundation [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0
Other Assets [Member] | Private equity funds [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance at beginning of period	27,341,000	28,169,000
Transfers to Level 3 from Level 2	0	0
Purchases and capital calls	1,012,000	1,415,000
Redemptions and distributions	-7,473,000	-5,294,000
Proceeds from sales	0
Other comprehensive gain (loss)	0	0
Balance at end of period	25,627,000	27,341,000
Other Assets [Member] | Private equity funds [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0
Other Assets [Member] | Private equity funds [Member] | Gain (loss) on assets [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	4,747,000	3,051,000
Other Assets [Member] | Private equity funds [Member] | Gain on available for sale securities, net [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0
Other Assets [Member] | Private equity funds [Member] | Other-than-temporary impairment losses [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	0	0
Other Assets [Member] | Private equity funds [Member] | Charitable Contributions to BOKF Foundation [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings	$0

Fair_Value_Measurements_Fair_V1

Fair Value Measurements Fair Value Measurements, Financial Instruments Measured On a Recurring Basis, Quantitative Information (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	$8,978,945		$10,147,162
Municipal and other tax-exempt securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	63,557		73,775
Other debt securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	9,212		35,241
Equity securities and mutual funds [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	19,444		21,328
Fair Value, Inputs, Level 3 [Member] | Available for sale Securities [Member] | Municipal and other tax-exempt securities [Member] | External Credit Rating, Investment Grade [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Asset, Par Value	10,870		18,695
Fair Value Inputs, Asset, Amortized Cost	10,805		18,624
Fair Value Inputs, Asset, Fair Value	10,093		17,805
Fair Value Measurements, Valuation Techniques	Discounted cash flows	[1]	Discounted cash flows	[1]
Fair Value Measurements, Significant Unobservable Input	Interest rate spread		Interest rate spread
Fair Value Inputs, Assets, Discount Rate, Minimum	4.96%	[2]	4.97%	[3]
Fair Value Inputs, Assets, Discount Rate, Maximum	5.26%	[2]	5.27%	[3]
Fair Value Inputs, Assets, Discount Rate, Weighted Average	5.21%	[2]	5.16%	[3]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value or Principal Balance, Minimum	92.65%	[4]	95.02%	[4]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value or Principal Balance, Maximum	94.32%	[4]	95.50%	[4]
Fair Value Inputs, Asset, Fair Value As Percentage of Par Value or Unpaid Principal Balance, Weighted Average	93.09%	[4]	95.24%	[4]
Investment Grade Tax Exempt Securities Yield Spread Over Comparable Securities Minimum	488		467
Investment Grade Tax Exempt Securities Yield Spread Over Comparable Securities Maximum	516		518
Fair Value, Inputs, Level 3 [Member] | Available for sale Securities [Member] | Other debt securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Asset, Par Value	4,400		4,900
Fair Value Inputs, Asset, Amortized Cost	4,400		4,900
Fair Value Inputs, Asset, Fair Value	4,150		4,712
Fair Value Measurements, Valuation Techniques	Discounted cash flows	[1]	Discounted cash flows	[1]
Fair Value Measurements, Significant Unobservable Input	Interest rate spread		Interest rate spread
Fair Value Inputs, Assets, Discount Rate, Minimum	5.62%	[5]	5.67%	[5]
Fair Value Inputs, Assets, Discount Rate, Maximum	5.67%	[5]	5.67%	[5]
Fair Value Inputs, Assets, Discount Rate, Weighted Average	5.66%	[5]	5.67%	[5]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value or Principal Balance, Minimum	92.65%	[4]	96.16%	[4]
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value or Principal Balance, Maximum	92.95%	[4]	96.16%	[4]
Fair Value Inputs, Asset, Fair Value As Percentage of Par Value or Unpaid Principal Balance, Weighted Average	92.77%	[4]	96.16%	[4]
Average Yields On Comparable Short-term Taxable Securities Maximum	1.00%		1.00%
Fair Value, Inputs, Level 3 [Member] | Available for sale Securities [Member] | Equity securities and mutual funds [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Measurements, Valuation Techniques			Publicly announced preliminary purchase price information from acquirer
Fair Value Measurements, Significant Unobservable Input			Discount for settlement uncertainty
Fair Value, Inputs, Level 3 [Member] | Residential Mortgage Loans Held for Sale [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Asset, Amortized Cost	12,468
Fair Value Inputs, Asset, Fair Value	11,856
Fair Value Measurements, Valuation Techniques	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 mortgage loans qualifying for sale to U.S. government agencies
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value or Principal Balance, Minimum	95.09%
Fair Value Inputs, Assets, Fair Value As Percentage of Par Value or Principal Balance, Maximum	95.09%
Fair Value Inputs, Asset, Fair Value As Percentage of Par Value or Unpaid Principal Balance, Weighted Average	95.90%
Fair Value, Inputs, Level 3 [Member] | Other assets - private equity funds [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Measurements, Valuation Techniques	Net asset value reported by underlying fund		Net asset value reported by underlying fund
Fair Value Measurements, Significant Unobservable Input	Net asset value reported by underlying fund		Net asset value reported by underlying fund
Fair Value, Measurements, Recurring [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	8,978,945		10,147,162
Other assets, private equity funds	25,627		27,341
Fair Value, Measurements, Recurring [Member] | Municipal and other tax-exempt securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	63,557		73,775
Fair Value, Measurements, Recurring [Member] | Other debt securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	9,212		35,241
Fair Value, Measurements, Recurring [Member] | Equity securities and mutual funds [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	19,444		21,328
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	14,243		26,724
Other assets, private equity funds	25,627		27,341
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal and other tax-exempt securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	10,093		17,805
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other debt securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	4,150		4,712
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Equity securities and mutual funds [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	0		4,207
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	8,958,770		10,119,396
Other assets, private equity funds	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal and other tax-exempt securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	53,464		55,970
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other debt securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	5,062		30,529
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Equity securities and mutual funds [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available for sale securities	$14,517		$17,121
[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 488 to 516 basis points over average yields for comparable tax-exempt securities.
[3]	Interest rate yields used to value investment grade tax-exempt securities represent a spread of 467 to 518 basis points over average yields for comparable tax-exempt securities.
[4]	Represents fair value as a percentage of par value
[5]	Interest rate yields used to value investment grade taxable securities based on comparable short-term taxable securities which are generally yielding less than 1%.

Fair_Value_Measurements_Fair_V2

Fair Value Measurements, Fair Value Measured On a Nonrecurring Basis (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross charge-offs against allowance for loan losses	$4,044	$6,598
Net losses and expenses of repossessed assets, net	0	0
Fair Value, Measurements, Nonrecurring [Member] | 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
Net losses and expenses of repossessed assets, net	3,563	5,489
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	0	0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member] | Real estate and other repossessed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	0	0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	8,198	8,380
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member] | Real estate and other repossessed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	22,594	20,733
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	635	4,622
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Real estate and other repossessed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	3,691	191
Pension Plan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	49,443	48,812	45,920
Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$49,000	$48,812

Fair_Value_Measurements_Fair_V3

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 $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$635	$4,622
Fair Value Measurements, Valuation Techniques	Appraised value, as adjusted	Appraised value, as adjusted
Fair Value Measurements, Significant Unobservable Input	Broker quotes and management's knowledge of industry and collateral.	Broker quotes and management's knowledge of industry and collateral.
Real estate and other repossessed assets [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$3,691	$191
Fair Value Measurements, Valuation Techniques	Appraised value, as adjusted	Listing value, less cost to sell
Fair Value Measurements, Significant Unobservable Input	Marketability adjustments off appraised value	Marketability adjustments off appraised value
Fair Value Measurement, Percentage of Appraised Value, Minimum	65.00%	80.00%	[1]
Fair Value Measurement, Percentage of Appraised Value, Maximum	65.00%	85.00%	[1]
Fair Value Measurement, Percentage of Appraised Value, Weighted Average	65.00%	82.00%	[1]
Fair Value Measurement, Marketability adjustment as perecentage of appraised value		15.00%
[1]	Marketability adjustments includes consideration of estimated costs to sell which is approximately 15% of the fair value.

Fair_Value_Measurements_Financ

Fair Value Measurements, Financial Instruments (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	$550,576,000		$512,931,000
Interest-bearing cash and cash equivalents	1,925,266,000		574,282,000
Trading securities	188,700,000		91,616,000
Investment securities	652,360,000	[1]	677,878,000	[2]
Available for sale securities	8,978,945,000		10,147,162,000
Fair value option securities	311,597,000		167,125,000
Residential mortgage loans held for sale	304,182,000		200,546,000
Loans	14,208,037,000		12,792,264,000
Allowance for loan losses	-189,056,000		-185,396,000		-215,507,000	-253,481,000
Loans, net of allowance	14,018,981,000		12,606,868,000
Mortgage servicing rights	171,976,000		153,333,000		100,812,000	86,783,000
Derivative contracts, net of cash margin, Assets, Fair Value	361,874,000		265,012,000
Time deposits	2,608,716,000		2,695,993,000
Subordinated debentures	347,983,000		347,802,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	354,554,000		247,185,000
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Specific allocation of allowance for loan losses included in fair value of loans	161,000,000		157,000,000
Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	9,095,670,000		7,943,221,000
Allowance for loan losses	-90,875,000		-79,180,000		-65,280,000	-83,443,000
Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,728,150,000		2,415,353,000
Allowance for loan losses	-42,445,000		-41,573,000		-54,884,000	-67,034,000
Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,949,512,000		2,052,026,000
Allowance for loan losses	-23,458,000		-29,465,000		-41,703,000	-46,476,000
Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	434,705,000		381,664,000
Allowance for loan losses	-4,233,000		-6,965,000		-9,453,000	-10,178,000
U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	85,092,000		34,120,000
U.S. government agency residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	31,199,000		21,011,000
Available for sale securities	6,646,884,000		7,716,010,000
Fair value option securities	311,597,000		157,431,000
Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	38,951,000		27,350,000
Investment securities	405,090,000	[1]	440,187,000	[2]
Available for sale securities	63,557,000		73,775,000
Other trading securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	33,458,000		9,135,000
U.S. Treasury securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	1,005,000		1,042,000
Privately issued residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	165,957,000		221,099,000
Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,048,609,000		2,055,804,000
Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	211,520,000	[1]	187,509,000	[2]
Available for sale securities	9,212,000		35,241,000
Fair value option securities	0		9,694,000
Perpetual preferred stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	24,277,000		22,863,000
Equity securities and mutual funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	19,444,000		21,328,000
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	550,576,000		512,931,000
Interest-bearing cash and cash equivalents	1,925,266,000		574,282,000
Trading securities	188,700,000		91,616,000
Investment securities	652,360,000		677,878,000
Available for sale securities	8,978,945,000		10,147,162,000
Fair value option securities	311,597,000		167,125,000
Residential mortgage loans held for sale	304,182,000		200,546,000
Loans	14,208,037,000		12,792,264,000
Allowance for loan losses	-189,056,000		-185,396,000
Loans, net of allowance	14,018,981,000		12,606,868,000
Mortgage servicing rights	171,976,000		153,333,000
Derivative contracts, net of cash margin, Assets, Fair Value	361,874,000		265,012,000
Other assets, private equity funds	25,627,000		27,341,000
Deposits with no stated maturity	18,532,143,000		17,573,334,000
Time deposits	2,608,716,000		2,695,993,000
Other borrowings	3,378,294,000		2,721,888,000
Subordinated debentures	347,983,000		347,802,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	354,554,000		247,185,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	9,095,670,000		7,943,221,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,728,150,000		2,415,353,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,949,512,000		2,052,026,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	434,705,000		381,664,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	85,092,000		34,120,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. government agency residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	31,199,000		21,011,000
Investment securities	35,750,000		50,182,000
Available for sale securities	6,646,884,000		7,716,010,000
Fair value option securities	311,597,000		157,431,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	38,951,000		27,350,000
Investment securities	405,090,000		440,187,000
Available for sale securities	63,557,000		73,775,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other trading securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	33,458,000		9,135,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. Treasury securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	1,005,000		1,042,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Privately issued residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	165,957,000		221,099,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,048,609,000		2,055,804,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	211,520,000		187,509,000
Available for sale securities	9,212,000		35,241,000
Fair value option securities	0		9,694,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Perpetual preferred stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	24,277,000		22,863,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Equity securities and mutual funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	19,444,000		21,328,000
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	550,576,000		512,931,000
Interest-bearing cash and cash equivalents	1,925,266,000		574,282,000
Trading securities	188,700,000		91,616,000
Investment securities	673,626,000		687,127,000
Available for sale securities	8,978,945,000		10,147,162,000
Fair value option securities	311,597,000		167,125,000
Residential mortgage loans held for sale	304,182,000		200,546,000
Loans	14,070,468,000		12,674,420,000
Allowance for loan losses	0		0
Loans, net of allowance	14,070,468,000		12,674,420,000
Mortgage servicing rights	171,976,000		153,333,000
Derivative contracts, net of cash margin, Assets, Fair Value	361,874,000		265,012,000
Other assets, private equity funds	25,627,000		27,341,000
Deposits with no stated maturity	18,532,143,000		17,573,334,000
Time deposits	2,612,576,000		2,697,290,000
Other borrowings	3,331,771,000		2,693,788,000
Subordinated debentures	344,687,000		344,783,000
Derivative contracts, net of cash margin, Liabilities, Fair Value	354,554,000		247,185,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	8,948,870,000		7,835,325,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	2,704,454,000		2,394,443,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	1,985,870,000		2,068,690,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Consumer [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans	431,274,000		375,962,000
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	85,092,000		34,120,000
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	31,199,000		21,011,000
Investment securities	37,463,000		51,864,000
Available for sale securities	6,646,884,000		7,716,010,000
Fair value option securities	311,597,000		157,431,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	38,951,000		27,350,000
Investment securities	408,344,000		439,870,000
Available for sale securities	63,557,000		73,775,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	33,458,000		9,135,000
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	1,005,000		1,042,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Privately issued residential mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	165,957,000		221,099,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial mortgage-backed securities guaranteed by U.S. government agencies [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	2,048,609,000		2,055,804,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	227,819,000		195,393,000
Available for sale securities	9,212,000		35,241,000
Fair value option securities	0		9,694,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Perpetual preferred stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	24,277,000		22,863,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Equity securities and mutual funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	$19,444,000		$21,328,000
[1]	Carrying value includes $615 thousand of net unrealized gain which remains in Accumulated other comprehensive income (“AOCI”) in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.
[2]	Carrying value includes $1.8 million of net unrealized gain which remains in AOCI in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.

Fair_Value_Measurements_Fair_V4

Fair Value Measurements Fair Value Measurements, Financial Instruments, Quantitative Information (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Loans [Member] | Commercial [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	0.17%	0.04%
Contractual Yield, Maximum	30.00%	30.00%
Repricing (in years)	7 months 23 days	5 months 26 days
Discount Rate, Minimum	0.51%	0.48%
Discount Rate, Maximum	4.34%	4.33%
Loans [Member] | Commercial Real Estate [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	0.38%	0.38%
Contractual Yield, Maximum	18.00%	18.00%
Repricing (in years)	10 months 3 days	9 months 10 days
Discount Rate, Minimum	1.09%	1.21%
Discount Rate, Maximum	3.78%	3.49%
Loans [Member] | Residential Portfolio Segment [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	1.20%	0.38%
Contractual Yield, Maximum	18.00%	18.00%
Repricing (in years)	2 years 6 months	2 years 7 months 16 days
Discount Rate, Minimum	0.64%	0.59%
Discount Rate, Maximum	3.99%	4.73%
Loans [Member] | Consumer Portfolio Segment [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	0.38%	0.38%
Contractual Yield, Maximum	21.00%	21.00%
Repricing (in years)	5 months 12 days	6 months 18 days
Discount Rate, Minimum	1.04%	1.22%
Discount Rate, Maximum	3.98%	3.75%
Time Deposits [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	0.02%	0.01%
Contractual Yield, Maximum	9.64%	9.64%
Repricing (in years)	1 year 11 months 1 day	2 years 1 month 12 days
Discount Rate, Minimum	0.76%	0.75%
Discount Rate, Maximum	1.33%	1.33%
Other borrowings [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	0.21%	0.25%
Contractual Yield, Maximum	1.52%	4.78%
Repricing (in years)	1 month 12 days	10 days
Discount Rate, Minimum	0.06%	0.08%
Discount Rate, Maximum	2.64%	2.64%
Subordinated debentures [Member]
Fair Value Inputs, Financial Instruments, Quantitative Information [Line Items]
Contractual Yield, Minimum	0.92%	0.95%
Contractual Yield, Maximum	5.00%	5.00%
Repricing (in years)	1 year 8 months 1 day	2 years 7 months 16 days
Discount Rate, Minimum	2.14%
Discount Rate, Maximum	2.14%	2.22%

Parent_Company_Only_Financial_2

Parent Company Only Financial Statements Parent Company Only Financial Statements (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets [Abstract]
Cash and cash equivalents	$2,475,842	$1,087,213	$1,286,239
Available for sale securities	8,978,945	10,147,162
Other assets	195,252	359,894
Total assets	29,089,698	27,015,432
Liabilities and Equity [Abstract]
Other liabilities	121,051	133,647
Total liabilities	25,753,492	23,960,459
Shareholders' equity: [Abstract]
Common stock	4	4
Capital surplus	954,644	898,586
Retained earnings	2,530,837	2,349,428
Treasury stock	-239,979	-202,346
Accumulated other comprehensive income (loss)	56,673	-25,623	149,920	128,979
Total shareholders' equity	3,302,179	3,020,049
Total liabilities and equity	29,089,698	27,015,432
Income Statement [Abstract]
Other revenue	38,451	38,262	34,604
Net impairment losses recognized in earnings	-373	-2,308	-7,351
Interest expense	67,045	70,894	87,322
Charitable contributions to BOKF Foundation	4,267	2,062	2,062
Professional fees and services	44,440	32,552	34,015
Other operating expense	847,522	840,620	840,363
Federal and state income taxes	134,852	157,298	188,740
Net income attributable to BOK Financial Corp. shareholders	292,435	316,609	351,191
Cash Flows From Operating Activities: [Abstract]
Net income	295,479	318,931	354,124
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Tax effect from equity compensation, net	-8,258	-2,210	-120
Change in other assets	-77,907	-76,257	-10,999
Change in other liabilities	1,007	-13,735	-3,729
Net cash provided by operating activities	-36,630	736,320	591,550
Cash Flows From Investing Activities: [Abstract]
Purchases of available for sale securities	-3,045,077	-4,287,146	-7,334,843
Proceeds from sales of available for sale securities	2,664,740	2,436,093	1,744,662
Acquisitions, net of cash acquired	-21,898	-7,500	-23,615
Net cash used in investing activities	-434,020	437,029	-2,368,347
Cash Flows From Financing Activities: [Abstract]
Issuance of common and treasury stock, net	4,472	16,566	14,650
Tax effect from equity compensation, net	8,258	2,210	120
Dividends paid	-111,026	-104,722	-166,982
Repurchase of common stock	-12,337	0	-20,558
Net cash used in financing activities	1,859,279	-1,372,375	2,076,671
Net increase (decrease) in cash and cash equivalents	1,388,629	-199,026	299,874
Cash and cash equivalents at beginning of period	1,087,213	1,286,239	986,365
Cash and cash equivalents at end of period	2,475,842	1,087,213	1,286,239
Cash paid for interest	65,721	69,830	90,137
Issuance of shares in settlement of deferred compensation, net	8,352	0	0
Parent Company [Member]
Assets [Abstract]
Cash and cash equivalents	510,668	561,297	457,514
Available for sale securities	24,794	27,526
Investments in subsidiaries	2,774,276	2,426,495
Other assets	1,637	12,872
Total assets	3,311,375	3,028,190
Liabilities and Equity [Abstract]
Other liabilities	9,196	8,141
Total liabilities	9,196	8,141
Shareholders' equity: [Abstract]
Common stock	4	4
Capital surplus	954,644	898,586
Retained earnings	2,530,837	2,349,428
Treasury stock	-239,979	-202,346
Accumulated other comprehensive income (loss)	56,673	-25,623
Total shareholders' equity	3,302,179	3,020,049
Total liabilities and equity	3,311,375	3,028,190
Income Statement [Abstract]
Dividends, interest and fees received from subsidiaries	75,412	225,340	275,330
Other revenue	1,572	3,341	2,295
Net impairment losses recognized in earnings	0	0	-1,099
Total revenue	76,984	228,681	276,526
Interest expense	293	292	269
Charitable contributions to BOKF Foundation	2,420	2,062	2,062
Professional fees and services	600	811	765
Other operating expense	1,556	1,210	1,037
Total expenses	4,869	4,375	4,133
Income before taxes and equity in undistributed income of subsidiaries	72,115	224,306	272,393
Federal and state income taxes	-1,702	-1,578	-1,706
Income before equity in undistributed earnings of subsidiaries	73,817	225,884	274,099
Equity in undistributed income of subsidiaries	218,618	90,725	77,092
Net income attributable to BOK Financial Corp. shareholders	292,435	316,609	351,191
Cash Flows From Operating Activities: [Abstract]
Net income	292,435	316,609	351,191
Adjustments to reconcile net income to net cash provided by operating activities: [Abstract]
Equity in undistributed income of subsidiaries	218,618	90,725	77,092
Tax effect from equity compensation, net	-8,258	-2,210	-120
Change in other assets	8,726	-8,308	4,237
Change in other liabilities	1,055	4,263	-4,965
Net cash provided by operating activities	75,340	219,629	273,251
Cash Flows From Investing Activities: [Abstract]
Purchases of available for sale securities	0	0	-5,343
Proceeds from sales of available for sale securities	0	13,600	4,781
Investment in subsidiaries	-15,336	-36,000	-9,100
Acquisitions, net of cash acquired	0	-7,500	-20,000
Net cash used in investing activities	-15,336	-29,900	-29,662
Cash Flows From Financing Activities: [Abstract]
Issuance of common and treasury stock, net	4,472	16,566	14,650
Tax effect from equity compensation, net	8,258	2,210	120
Dividends paid	-111,026	-104,722	-166,982
Repurchase of common stock	-12,337	0	-20,558
Net cash used in financing activities	-110,633	-85,946	-172,770
Net increase (decrease) in cash and cash equivalents	-50,629	103,783	70,819
Cash and cash equivalents at beginning of period	561,297	457,514	386,695
Cash and cash equivalents at end of period	510,668	561,297	457,514
Cash paid for interest	293	292	269
Issuance of shares in settlement of deferred compensation, net	$8,352	$0	$0