ONEOK (OKE) 10-Q 6 Nov 13 2013 Q3 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 29, 2013
Document Information [Line Items]	'	'
Entity Registrant Name	'ONEOK INC /NEW/	'
Entity Central Index Key	'0001039684	'
Current Fiscal Year End Date	'--12-31	'
Entity Well-known Seasoned Issuer	'Yes	'
Entity Voluntary Filers	'No	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	206,286,720
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-13	'

CONSOLIDATED_STATEMENTS_OF_INC

CONSOLIDATED STATEMENTS OF INCOME (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues	$3,571,925	$3,028,775	$10,462,606	$8,972,635
Cost of sales and fuel	3,010,737	2,474,803	8,824,577	7,226,114
Net margin	561,188	553,972	1,638,029	1,746,521
Operating expenses	'	'	'	'
Operations and maintenance	209,019	206,048	635,915	603,055
Depreciation and amortization	94,267	81,434	276,343	249,429
Goodwill impairment	0	0	0	10,255
General Taxes	27,843	23,157	94,000	81,471
Total operating expenses	331,129	310,639	1,006,258	944,210
Gain (loss) on sale of assets	22	-420	342	603
Operating income	230,081	242,913	632,113	802,914
Equity earnings from investments (Note L)	27,468	28,591	79,744	92,380
Allowance for equity funds used during construction	6,429	3,302	21,172	6,126
Other income	6,154	5,049	16,652	11,495
Other expense	-1,077	-919	-4,479	-3,990
Interest expense (net of capitalized interest of $14,704, $11,802, $39,203 and $30,521, respectively)	-81,908	-71,364	-244,076	-218,714
Income before income taxes	187,147	207,572	501,126	690,211
Income taxes	-39,449	-42,584	-108,228	-156,835
Income from continuing operations	147,698	164,988	392,898	533,376
Income from discontinued operations, net of tax (Note C)	0	0	0	762
Gain on sale of discontinued operations, net of tax (Note C)	0	0	0	13,517
Net income	147,698	164,988	392,898	547,655
Less: Net income attributable to noncontrolling interests	85,342	99,769	217,102	298,578
Net income attributable to ONEOK	62,356	65,219	175,796	249,077
Amounts attributable to ONEOK:	'	'	'	'
Income from continuing operations	62,356	65,219	175,796	234,798
Income from discontinued operations	0	0	0	14,279
Net income	$62,356	$65,219	$175,796	$249,077
Basic earnings per share:	'	'	'	'
Income from continuing operations (Note J)	$0.30	$0.32	$0.85	$1.14
Income from discontinued operations	$0	$0	$0	$0.07
Net income	$0.30	$0.32	$0.85	$1.21
Diluted earnings per share:	'	'	'	'
Income from continuing operations (Note J)	$0.30	$0.31	$0.84	$1.11
Income from discontinued operations	$0	$0	$0	$0.07
Net income	$0.30	$0.31	$0.84	$1.18
Average shares (thousands)	'	'	'	'
Basic	206,235	205,005	205,952	206,638
Diluted	209,893	209,960	209,408	211,198
Common Stock, Dividends, Per Share, Cash Paid	$0.38	$0.33	$1.10	$0.94

CONSOLIDATED_STATEMENTS_OF_INC1

CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Interest Costs, Capitalized During Period	$14,704	$11,802	$39,203	$30,521

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Other Comprehensive Income [Abstract]	'	'	'	'
Net income	$147,698	$164,988	$392,898	$547,655
Other comprehensive income (loss), net of tax	'	'	'	'
Unrealized gains (losses) on energy marketing and risk-management assets/liabilities, net of tax of $(467), $12,244, $(10,349) and $(2,146), respectively	-2,542	-30,383	37,095	4,520
Realized (gains) losses in net income, net of tax of $333, $6,143, $(1,748) and $12,954, respectively	789	-20,973	4,694	-44,675
Unrealized holding gains (losses) on available-for-sale securities, net of tax of $277, $(57), $147 and $(132), respectively	-440	90	-234	210
Change in pension and postretirement benefit plan liability, net of tax of $4,603, $3,644, $13,651 and $10,932, respectively	-7,293	-5,778	-21,637	-17,330
Total other comprehensive income (loss), net of tax	-9,486	-57,044	19,918	-57,275
Comprehensive income	138,212	107,944	412,816	490,380
Less: Comprehensive income attributable to noncontrolling interests	83,378	77,561	239,714	275,658
Comprehensive income attributable to ONEOK	$54,834	$30,383	$173,102	$214,722

CONSOLIDATED_STATEMENTS_OF_COM1

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Parenthetical (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Other comprehensive income (loss), net of tax	'	'	'	'
Unrealized gains (losses) on energy marketing and risk-management assets/liabilities, tax	($467)	$12,244	($10,349)	($2,146)
Realized losses (gains) in net income, tax	333	6,143	-1,748	12,954
Unrealized holding gains (losses) on available-for-sale securities, tax	227	-57	147	-132
Change in pension and postretirement benefit plan liability, tax	$4,603	$3,644	$13,651	$10,932

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets	'	'
Cash and cash equivalents	$779,524	$583,618
Accounts receivable, net	1,166,994	1,349,371
Gas and natural gas liquids in storage	664,213	517,014
Commodity imbalances	94,404	90,211
Energy marketing and risk-management assets (Notes D and E)	16,437	48,577
Other current assets	160,452	175,869
Total current assets	2,882,024	2,764,660
Property, plant and equipment	'	'
Property, plant and equipment	14,944,162	13,088,991
Accumulated depreciation and amortization	3,173,366	2,974,651
Net property, plant and equipment	11,770,796	10,114,340
Investments and other assets	'	'
Investments in unconsolidated affiliates (Note L)	1,201,873	1,221,405
Goodwill and intangible assets	990,456	996,206
Other assets	765,194	758,664
Total investments and other assets	2,957,523	2,976,275
Total assets	17,610,343	15,855,275
Current liabilities	'	'
Current maturities of long-term debt	10,656	10,855
Notes payable (Note F)	562,329	817,170
Accounts payable	1,382,785	1,333,489
Commodity imbalances	227,355	272,436
Energy marketing and risk-management liabilities (Notes D and E)	5,530	9,990
Other current liabilities	433,055	369,054
Total current liabilities	2,621,710	2,812,994
Long-term debt, excluding current maturities (Note G)	7,757,159	6,515,372
Deferred credits and other liabilities	'	'
Deferred income taxes	1,776,949	1,592,802
Other deferred credits	763,879	701,657
Total deferred credits and other liabilities	2,540,828	2,294,459
Commitments and contingencies (Note N)	'	'
ONEOK shareholders' equity:	'	'
Common stock, $0.01 par value: authorized 600,000,000 shares; issued 245,811,180 shares and outstanding 206,273,200 shares at September 30, 2013; issued 245,811,180 shares and outstanding 204,935,043 shares at December 31, 2012	2,458	2,458
Paid-in capital	1,404,086	1,324,698
Accumulated other comprehensive loss (Note I)	-219,492	-216,798
Retained earnings	2,008,471	2,059,024
Treasury stock, at cost: 39,537,980 shares at September 30, 2013, and 40,876,137 shares at December 31, 2012	-1,005,829	-1,039,773
Total ONEOK shareholders' equity	2,189,694	2,129,609
Noncontrolling interests in consolidated subsidiaries	2,500,952	2,102,841
Total equity	4,690,646	4,232,450
Total liabilities and equity	$17,610,343	$15,855,275

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS Parenthetical (USD $)	Sep. 30, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]	'	'
Common stock, shares, par value (in dollars per share)	$0.01	$0.01
Common stock, shares, authorized (in shares)	600,000,000	600,000,000
Common stock, shares, issued (in shares)	245,811,180	245,811,180
Common stock, shares, outstanding (in shares)	206,273,200	204,935,043
Treasury stock, shares (in shares)	39,537,980	40,876,137

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating Activities	'	'
Net income	$392,898	$547,655
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization	276,343	249,437
Charges attributable to exit activities, net of settlements	124,610	0
Impairment of goodwill	0	10,255
Gain on sale of discontinued operations	0	-13,517
Reclassified loss on energy price risk-management assets and liabilities	0	29,861
Equity earnings from investments	-79,744	-92,380
Distributions received from unconsolidated affiliates	79,022	92,996
Deferred income taxes	107,575	170,657
Share-based compensation expense	27,634	35,970
Allowance for equity funds used during construction	-21,172	-6,126
Gain on sale of assets	-342	-603
Other	-4,047	-1,770
Changes in assets and liabilities:	'	'
Accounts receivable	182,377	350,350
Gas and natural gas liquids in storage	-147,199	-94,362
Accounts payable	82,743	-156,483
Commodity imbalances, net	-49,274	17,310
Energy marketing and risk-management assets and liabilities	-15,574	-205,008
Other assets and liabilities, net	65,696	-171,383
Cash provided by operating activities	1,021,546	762,859
Investing Activities	'	'
Capital expenditures (less allowance for equity funds used during construction)	-1,597,820	-1,238,908
Acquisition	-304,889	0
Proceeds from sale of discontinued operations, net of cash sold	0	32,946
Contributions to unconsolidated affiliates	-4,558	-21,284
Distributions received from unconsolidated affiliates	24,891	25,756
Proceeds from sale of assets	1,685	1,918
Other	0	988
Cash used in investing activities	-1,880,691	-1,198,584
Financing Activities	'	'
Borrowing of notes payable, net	-254,841	-165,235
Issuance of debt, net of discounts	1,247,822	1,994,693
Long-term debt financing costs	-10,217	-15,030
Repayment of debt	-5,802	-359,251
Repurchase of common stock	0	-150,000
Issuance of common stock	8,538	7,068
Issuance of common units, net of issuance costs	569,246	459,680
Dividends paid	-226,349	-194,443
Distributions to noncontrolling interests	-273,346	-237,744
Cash provided by financing activities	1,055,051	1,339,738
Change in cash and cash equivalents	195,906	904,013
Change in cash and cash equivalents included in discontinued operations	0	8,859
Change in cash and cash equivalents from continuing operations	195,906	912,872
Cash and cash equivalents at beginning of period	583,618	65,953
Cash and cash equivalents at end of period	$779,524	$978,825

CONSOLIDATED_STATEMENT_OF_CHAN

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY (USD $)	Total	Common Stock [Member]	Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Noncontrolling Interests in Consolidated Subsidiaries [Member]
In Thousands, except Share data
Stockholders' equity, beginning balance at Dec. 31, 2011	$3,799,732	'	'	'	'	'	$1,561,159
Net income	547,655	'	'	'	'	'	298,578
Other comprehensive income (loss)	-57,275	'	'	'	'	'	-22,920
Common stock issued	10,390	'	'	'	'	'	0
Common stock dividends - $1.10 per share	-194,443	'	'	'	'	'	0
Issuance of common units of ONEOK Partners	459,680	'	'	'	'	'	510,780
Distributions to noncontrolling interests	-237,744	'	'	'	'	'	-237,744
Other	-2,436	'	'	'	'	'	0
Stockholders' equity, ending balance at Sep. 30, 2012	4,175,559	'	'	'	'	'	2,109,853
Stockholders' equity, beginning balance at Jun. 30, 2012	4,205,988	'	'	'	'	'	2,116,448
Net income	164,988	'	'	'	'	'	99,769
Other comprehensive income (loss)	-57,044	'	'	'	'	'	-22,208
Common stock issued	3,838	'	'	'	'	'	0
Common stock dividends - $1.10 per share	-67,671	'	'	'	'	'	0
Issuance of common units of ONEOK Partners	0	'	'	'	'	'	0
Distributions to noncontrolling interests	-84,156	'	'	'	'	'	-84,156
Other	9,616	'	'	'	'	'	0
Stockholders' equity, ending balance at Sep. 30, 2012	4,175,559	'	'	'	'	'	2,109,853
Stockholders' equity, beginning balance at Dec. 31, 2012	4,232,450	2,458	1,324,698	-216,798	2,059,024	-1,039,773	2,102,841
Common stock issued, beginning balance (in shares) at Dec. 31, 2012	'	245,811,180	'	'	'	'	'
Net income	392,898	0	0	0	175,796	0	217,102
Other comprehensive income (loss)	19,918	0	0	-2,694	0	0	22,612
Common stock issued	11,892	0	-22,052	0	0	33,944	0
Common stock issued (in shares)	'	0	'	'	'	'	'
Common stock dividends - $1.10 per share	-226,349	0	0	0	-226,349	0	0
Issuance of common units of ONEOK Partners	516,201	0	84,458	0	0	0	431,743
Distributions to noncontrolling interests	-273,346	0	0	0	0	0	-273,346
Other	16,982	0	16,982	0	0	0	0
Stockholders' equity, ending balance at Sep. 30, 2013	4,690,646	2,458	1,404,086	-219,492	2,008,471	-1,005,829	2,500,952
Common stock issued, ending balance (in shares) at Sep. 30, 2013	'	245,811,180	'	'	'	'	'
Stockholders' equity, beginning balance at Jun. 30, 2013	4,174,356	'	'	'	'	'	2,089,007
Net income	147,698	'	'	'	'	'	85,342
Other comprehensive income (loss)	-9,486	'	'	'	'	'	-1,964
Common stock issued	4,142	'	'	'	'	'	0
Common stock dividends - $1.10 per share	-78,367	'	'	'	'	'	0
Issuance of common units of ONEOK Partners	501,893	'	'	'	'	'	420,391
Distributions to noncontrolling interests	-91,824	'	'	'	'	'	-91,824
Other	42,234	'	'	'	'	'	0
Stockholders' equity, ending balance at Sep. 30, 2013	$4,690,646	'	'	'	'	'	$2,500,952

CONSOLIDATED_STATEMENT_OF_CHAN1

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY Parenthetical (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Stockholders' Equity [Abstract]	'	'	'	'	'	'
Common Stock, Dividends, Per Share, Cash Paid	$0.38	$0.36	$0.36	$0.33	$1.10	$0.94

SUMMARY_OF_SIGNIFICANT_ACCOUNT

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	A.	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Our accompanying unaudited consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC. These statements have been prepared in accordance with GAAP and reflect all adjustments that, in our opinion, are necessary for a fair presentation of the results for the interim periods presented.  All such adjustments are of a normal recurring nature. The 2012 year-end consolidated balance sheet data was derived from our audited financial statements but does not include all disclosures required by GAAP.  These unaudited consolidated financial statements should be read in conjunction with our audited consolidated financial statements in our Annual Report.  Due to the seasonal nature of our business, the results of operations for the three and nine months ended September 30, 2013, are not necessarily indicative of the results that may be expected for a 12-month period.
	On July 25, 2013, we announced that our Board of Directors unanimously authorized management to pursue a plan to separate our natural gas distribution business into a standalone publicly traded company. The natural gas distribution company, named ONE Gas will consist of ONEOK’s Natural Gas Distribution segment that includes Kansas Gas Service, Oklahoma Natural Gas and Texas Gas Service.
	ONEOK and its subsidiaries will continue to be the sole general partner and own limited partner units of ONEOK Partners (NYSE: OKS), which represented a 41.3 percent interest in ONEOK Partners at September 30, 2013, and operate our Energy Services segment through the completion of the wind down process.  Under the separation plan, ONEOK shareholders will retain their current shares of ONEOK stock and receive a pro-rata dividend of shares of stock in ONE Gas in a transaction that is expected to be tax-free to ONEOK and its shareholders. The plan provides for the completion of the separation after the receipt of regulatory approvals. On October 1, 2013, ONE Gas filed a registration statement on Form 10 with the SEC. Our Board of Directors retains the discretion to determine whether and when to complete the separation.
	Our significant accounting policies are consistent with those disclosed in Note A of the Notes to Consolidated Financial Statements in our Annual Report.
	Recently Issued Accounting Standards Update - In July 2013, the FASB issued ASU 2013-10, “Inclusion of the Fed Funds Effective Swap Rate (or Overnight Index Swap Rate) as a Benchmark Interest Rate for Hedge Accounting Purposes,” which allows an entity to designate the Fed Funds Effective Swap rate (also known as the Overnight Index Swap rate, or OIS rate, in the United States) as a benchmark interest rate for hedge accounting purposes in addition to the interest rates on direct Treasury obligations of the United States government and LIBOR. In addition, this guidance removes the restriction on using different benchmark interest rates for similar hedges. This guidance is effective prospectively for qualifying new or redesigned hedging relationships entered into on or after July 17, 2013. We adopted this guidance with our September 30, 2013, Quarterly Report, and it did not impact materially our financial position or results of operations. See Notes D and E for additional disclosures.
	In February 2013, the FASB issued ASU 2013-02, “Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income,” which requires presentation in a single location, either in a single note or parenthetically on the face of the financial statements, of the effect of significant amounts reclassified from each component of accumulated other comprehensive income based on its source. This guidance is effective for our interim and annual periods beginning on January 1, 2013, and is applied prospectively. We adopted this guidance with our March 31, 2013, Quarterly Report, and it did not impact our financial position or results of operations. See Note I for additional disclosures.
	In December 2011, the FASB issued ASU 2011-11, “Disclosures about Offsetting Assets and Liabilities,” which increases disclosures about offsetting assets and liabilities. In January 2013, the FASB issued ASU 2013-01, “Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities,” which clarifies that the scope of ASU 2011-11 applies to derivatives accounted for in accordance with Topic 815, Derivatives and Hedging. New disclosures are required to enable users of financial statements to understand significant quantitative differences in balance sheets prepared under GAAP and International Financial Reporting Standards related to the offsetting of financial instruments, including derivatives. The existing GAAP guidance allowing balance sheet offsetting remains unchanged. This guidance is effective for interim and annual periods beginning on January 1, 2013, and is applied retrospectively for all comparative periods presented. We adopted this guidance beginning with our March 31, 2013, Quarterly Report, and it did not impact our financial position or results of operations. See Note D for additional disclosures.
	In July 2012, the FASB issued ASU 2012-02, “Testing Indefinite-lived Intangible Assets for Impairment,” which allows companies to perform a “qualitative” assessment to determine whether further impairment testing of indefinite-lived intangible assets is necessary.  Under the revised standard, an entity is not required to calculate the fair value of an indefinite-lived intangible asset and perform the quantitative impairment test unless the entity determines that it is more likely than not that the asset is impaired. An entity has the option to bypass the qualitative assessment and perform the quantitative impairment test for any indefinite-lived intangible assets in any period. We adopted this guidance for our annual assessments beginning in July 2013, and it did not impact our financial position or results of operations.
	Impairment of Goodwill and Indefinite-lived Intangible Assets - We assess our goodwill and indefinite-lived intangible assets for impairment at least annually as of July 1. At July 1, 2013, we assessed qualitative factors to determine whether it was more likely than not that the fair value of each of our reporting units was less than its carrying amount and to determine whether it was more likely than not that the indefinite-lived intangible asset was impaired.  After assessing qualitative factors (including macroeconomic conditions, industry and market considerations, cost factors and overall financial performance), we determined that no further testing was necessary.

EXIT_ACTIVITIES

EXIT ACTIVITIES	9 Months Ended
	Sep. 30, 2013
Restructuring Cost and Reserve [Line Items]	'
Restructuring and Related Activities Disclosure [Text Block]	'
	B.	EXIT ACTIVITIES
	In June 2013, we announced we would exit the operations of our Energy Services segment through an accelerated wind down process. Our Energy Services segment faced challenging industry conditions that showed no signs of improving. Increased natural gas supply and infrastructure, coupled with lower natural gas price volatility, narrowed seasonal and location natural gas price differentials, which resulted in limited opportunities to generate revenues to cover our fixed costs on our contracted storage and transportation capacity. We executed agreements in 2013 to release a significant portion of our nonaffiliated, third-party natural gas transportation and storage contracts to third parties effective July 1 and September 1, 2013, at current market rates that resulted in noncash charges totaling $130.2 million. In addition, pursuant to a request for proposal, our Energy Services segment assigned contracts for 18.0 Bcf of affiliated storage capacity to our Natural Gas Distribution segment in June 2013. Our Energy Services segment will continue to serve its contracted premium-services customers during the wind down, and we expect the Energy Services segment to be classified as discontinued operations, effective April 1, 2014, when substantially all operations of the segment have ceased.
	The following table summarizes the change in our liability related to released capacity contracts for the period indicated:
		Three Months Ended
		30-Sep-13
		(Millions of dollars)
	Beginning balance	$	113.8
	Noncash charges	16.4
	Settlements	(6.2		)
	Accretion	0.6
	Ending balance	$	124.6
	We recorded these noncash charges in cost of sales and fuel in our Consolidated Statements of Income. We expect to record additional noncash charges of approximately $12 million before taxes between October 1, 2013, and March 31, 2014, subject to the release or assignment of the additional natural gas transportation, storage and other energy contracts. We do not expect the total charge attributable to any severance benefits will be material. We expect future cash payments associated with released transportation and storage capacity from the wind down of our Energy Services segment to total approximately $89 million on an after-tax basis with approximately $8 million paid in the fourth quarter 2013, $33 million in 2014, $24 million in 2015 and $24 million over the period 2016 through 2023.

DISCONTINUED_OPERATIONS

DISCONTINUED OPERATIONS	9 Months Ended
	Sep. 30, 2013
Discontinued Operations [Abstract]	'
DISCONTINUED OPERATIONS	'
	C.	DISCONTINUED OPERATIONS
	On February 1, 2012, we sold ONEOK Energy Marketing Company, our retail natural gas marketing business, to Constellation Energy Group, Inc. for $22.5 million plus working capital.  We received net proceeds of approximately $32.9 million and recognized a gain on the sale of approximately $13.5 million, net of taxes of $8.3 million. The financial information of ONEOK Energy Marketing Company is reflected as discontinued operations in this Quarterly Report. For the month ended January 31, 2012, ONEOK Energy Marketing Company had revenues of $27.6 million and pre-tax income of $1.2 million.

FAIR_VALUE_MEASUREMENTS

FAIR VALUE MEASUREMENTS	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
FAIR VALUE MEASUREMENTS	'
	D.	FAIR VALUE MEASUREMENTS
	Determining Fair Value - We define fair value as the price that would be received from the sale of an asset or the transfer of a liability in an orderly transaction between market participants at the measurement date.  We use the market and income approaches to determine the fair value of our assets and liabilities and consider the markets in which the transactions are executed.  We measure the fair value of financial assets and liabilities consistent with how a market participant would price the net risk exposure at the measurement date.
	While many of the contracts in our portfolio are executed in liquid markets where price transparency exists, some contracts are executed in markets for which market prices may exist, but the market may be relatively inactive.  This results in limited price transparency that requires management’s judgment and assumptions to estimate fair values.  Inputs into our fair value estimates include commodity-exchange prices, over-the-counter quotes, volatility, historical correlations of pricing data and LIBOR and other liquid money-market instrument rates.  We also utilize internally developed basis curves that incorporate observable and unobservable market data.  We validate our valuation inputs with third-party information and settlement prices from other sources, where available.
	In addition, as prescribed by the income approach, we compute the fair value of our derivative portfolio by discounting the projected future cash flows from our derivative assets and liabilities to present value using interest-rate yields to calculate present-value discount factors derived from LIBOR, Eurodollar futures and interest-rate swaps.  We also take into consideration the potential impact on market prices of liquidating positions in an orderly manner over a reasonable period of time under current market conditions.  We consider current market data in evaluating counterparties’, as well as our own, nonperformance risk, net of collateral, by using specific and sector bond yields and also monitor the credit default swap markets.  Although we use our best estimates to determine the fair value of the derivative contracts we have executed, the ultimate market prices realized could differ from our estimates, and the differences could be material.
	Recurring Fair Value Measurements - The following tables set forth our recurring fair value measurements for our continuing and discontinued operations for the periods indicated:
		September 30, 2013
		Level 1			Level 2			Level 3			Total - Gross			Netting			Total - Net
		(Thousands of dollars)
	Assets
	Derivatives (a)
	Commodity contracts
	Financial contracts	$	50,965		$	1,790		$	8,707		$	61,462		$	(46,938	)	$	14,524
	Physical contracts	—			1,122			3,205			4,327			(541		)	3,786
	Interest-rate contracts	—			43,614			—			43,614			—			43,614
	Total derivatives	50,965			46,526			11,912			109,403			(47,479		)	61,924
	Trading securities (b)	10,193			—			—			10,193			—			10,193
	Available-for-sale investment securities (c)	1,478			—			—			1,478			—			1,478
	Total assets	$	62,636		$	46,526		$	11,912		$	121,074		$	(47,479	)	$	73,595
	Liabilities
	Derivatives (a)
	Commodity contracts
	Financial contracts	$	(26,355	)	$	(1,207	)	$	(7,679	)	$	(35,241	)	$	32,981		$	(2,260	)
	Physical contracts	—			(267		)	(3,571		)	(3,838		)	541			(3,297		)
	Total derivatives	(26,355		)	(1,474		)	(11,250		)	(39,079		)	33,522			(5,557		)
	Fair value of firm commitments (d)	—			—			(144		)	(144		)	—			(144		)
	Total liabilities	$	(26,355	)	$	(1,474	)	$	(11,394	)	$	(39,223	)	$	33,522		$	(5,701	)
	(a) - Our derivative assets and liabilities are presented in our Consolidated Balance Sheets as energy marketing and risk-management assets and liabilities, other assets and other deferred credits on a net basis. We net derivative assets and liabilities, including cash collateral, when a legally enforceable master-netting arrangement exists between the counterparty to a derivative contract and us.  At September 30, 2013, we held $14.0 million of cash collateral and posted no cash collateral with various counterparties.
	(b) - Included in our Consolidated Balance Sheets as other current assets.
	(c) - Included in our Consolidated Balance Sheets as other assets.
	(d) - Included in our Consolidated Balance Sheets as other current liabilities.
		December 31, 2012
		Level 1			Level 2			Level 3			Total - Gross			Netting			Total - Net
		(Thousands of dollars)
	Assets
	Derivatives (a)
	Commodity contracts
	Financial contracts	$	69,957		$	10,780		$	7,107		$	87,844		$	(51,602	)	$	36,242
	Physical contracts	—			2,083			2,032			4,115			(151		)	3,964
	Interest-rate contracts	—			10,923			—			10,923			—			10,923
	Total derivatives	69,957			23,786			9,139			102,882			(51,753		)	51,129
	Trading securities (b)	5,978			—			—			5,978			—			5,978
	Available-for-sale investment securities (c)	2,027			—			—			2,027			—			2,027
	Total assets	$	77,962		$	23,786		$	9,139		$	110,887		$	(51,753	)	$	59,134
	Liabilities
	Derivatives (a)
	Commodity contracts
	Financial contracts	$	(35,172	)	$	(1,737	)	$	(7,177	)	$	(44,086	)	$	33,878		$	(10,208	)
	Physical contracts	—			—			(279		)	(279		)	151			(128		)
	Total derivatives	(35,172		)	(1,737		)	(7,456		)	(44,365		)	34,029			(10,336		)
	Fair value of firm commitments (d)	—			—			(1,280		)	(1,280		)	—			(1,280		)
	Total liabilities	$	(35,172	)	$	(1,737	)	$	(8,736	)	$	(45,645	)	$	34,029		$	(11,616	)
	(a) - Our derivative assets and liabilities are presented in our Consolidated Balance Sheets as energy marketing and risk-management assets and liabilities, other assets and other deferred credits on a net basis. We net derivative assets and liabilities, including cash collateral, when a legally enforceable master-netting arrangement exists between the counterparty to a derivative contract and us. At December 31, 2012, we held $17.7 million of cash collateral and posted $4.5 million of cash collateral with various counterparties.
	(b) - Included in our Consolidated Balance Sheets as other current assets.
	(c) - Included in our Consolidated Balance Sheets as other assets.
	(d) - Included in our Consolidated Balance Sheets as other current liabilities and other deferred credits.
	Our Level 1 fair value amounts are based on unadjusted quoted prices in active markets including NYMEX-settled prices and actively quoted prices for equity securities. These balances are comprised predominantly of exchange-traded derivative contracts for natural gas and crude oil. Also included in Level 1 are equity securities.
	Our Level 2 fair value amounts are based on significant observable pricing inputs, such as NYMEX-settled prices for natural gas and crude oil, and financial models that utilize implied forward LIBOR yield curves for interest-rate swaps.
	Our Level 3 fair value amounts are based on inputs that may include one or more unobservable inputs including internally developed basis curves that incorporate observable and unobservable market data, NGL price curves from broker quotes, market volatilities derived from the most recent NYMEX close spot prices and forward LIBOR curves, and adjustments for the credit risk of our counterparties.  We corroborate the data on which our fair value estimates are based using our market knowledge of recent transactions, analysis of historical correlations and validation with independent broker quotes.  These balances categorized as Level 3 are comprised of derivatives for natural gas and NGLs.  Also included in Level 3 are the fair values of firm commitments.  We do not believe that our Level 3 fair value estimates have a material impact on our results of operations, as the majority of our derivatives are accounted for as hedges for which ineffectiveness is not material.  The significant unobservable inputs used are the unpublished forward basis and index curves.  Significant increases or decreases in either of those inputs in isolation would not have a material impact on our fair value measurements.
	The following tables set forth the reconciliation of our Level 3 fair value measurements for the periods indicated:
		Derivative			Fair Value of			Total
		Assets			Firm
		(Liabilities)			Commitments
		(Thousands of dollars)
1-Jul-13	$	8,015		$	—		$	8,015
Total realized/unrealized gains (losses):
Included in earnings (a)	(215		)	(144		)	(359		)
Included in other comprehensive income (loss)	(7,162		)	—			(7,162		)
Transfers into Level 3	24			—			24
September 30, 2013	$	662		$	(144	)	$	518
Total gains (losses) for the period included in earnings attributable to the change in	$	367		$	(42	)	$	325
unrealized gains (losses) relating to assets and liabilities still held at
September 30, 2013 (a)
(a) - Reported in revenues and cost of sales and fuel in our Consolidated Statements of Income.
	Derivative			Fair Value of			Total
	Assets			Firm
	(Liabilities)			Commitments
	(Thousands of dollars)
1-Jul-12	$	37,745		$	(4,250	)	$	33,495
Total realized/unrealized gains (losses):
Included in earnings (a)	(4,366		)	2,083			(2,283		)
Included in other comprehensive income (loss)	(20,295		)	—			(20,295		)
Transfers into Level 3	385			—			385
Transfers out of Level 3	685			—			685
September 30, 2012	$	14,154		$	(2,167	)	$	11,987
Total gains (losses) for the period included in earnings attributable to the change	$	51		$	205		$	256
in unrealized gains (losses) relating to assets and liabilities still held at
September 30, 2012 (a)
(a) - Reported in revenues and cost of sales and fuel in our Consolidated Statements of Income.
	Derivative			Fair Value of			Total
	Assets			Firm
	(Liabilities)			Commitments
	(Thousands of dollars)
1-Jan-13	$	1,683		$	(1,280	)	$	403
Total realized/unrealized gains (losses):
Included in earnings (a)	(4,343		)	1,136			(3,207		)
Included in other comprehensive income (loss)	3,487			—			3,487
Transfers out of Level 3	(165		)	—			(165		)
30-Sep-13	$	662		$	(144	)	$	518
Total gains (losses) for the period included in earnings attributable to the change in	$	(760	)	$	21		$	(739	)
unrealized gains (losses) relating to assets and liabilities still held at
September 30, 2013 (a)
(a) - Reported in revenues and cost of sales and fuel in our Consolidated Statements of Income.
	Derivative			Fair Value of			Total
	Assets			Firm
	(Liabilities)			Commitments
	(Thousands of dollars)
1-Jan-12	$	25,104		$	(7,283	)	$	17,821
Total realized/unrealized gains (losses):
Included in earnings (a)	(13,153		)	5,116			(8,037		)
Included in other comprehensive income (loss)	6,384			—			6,384
Sale of discontinued operations	(3,636		)	—			(3,636		)
Transfers out of Level 3	(545		)	—			(545		)
30-Sep-12	$	14,154		$	(2,167	)	$	11,987
Total gains (losses) for the period included in earnings attributable to the change in	$	352		$	(296	)	$	56
unrealized gains (losses) relating to assets and liabilities still held at
September 30, 2012 (a)
(a) - Reported in revenues and cost of sales and fuel in our Consolidated Statements of Income.
Realized/unrealized gains (losses) include the realization of our derivative contracts through maturity and changes in fair value of our hedged firm commitments. We recognize transfers into and out of the levels in the fair value hierarchy as of the end of each reporting period.  We had no transfers into or out of Level 1 during the periods presented.  Transfers into Level 3 represent existing assets or liabilities that were previously categorized at a higher level for which the unobservable inputs became a more significant portion of the fair value estimates.  Transfers out of Level 3 represent existing assets and liabilities that were classified previously as Level 3 for which the observable inputs became a more significant portion of the fair value estimates.
Our Level 3 fair value measurements based on unobservable inputs, excluding the portion of our fair value measurements based on third-party pricing information without adjustment, are not material at September 30, 2013.
Other Financial Instruments - The approximate fair value of cash and cash equivalents, accounts receivable, accounts payable and notes payable is equal to book value, due to the short-term nature of these items. Our cash and cash equivalents are comprised of bank and money market accounts and are classified as Level 1.  Our notes payable are classified as Level 2 since the estimated fair value of the notes payable can be determined using information available in the commercial paper market.
The estimated fair value of our consolidated long-term debt, including current maturities, was $8.1 billion at September 30, 2013, and $7.5 billion at December 31, 2012.  The book value of long-term debt, including current maturities, was $7.8 billion at September 30, 2013, and $6.5 billion at December 31, 2012.  The estimated fair value of the aggregate of ONEOK’s and ONEOK Partners’ senior notes outstanding was determined using quoted market prices for similar issues with similar terms and maturities.  The estimated fair value of our consolidated long-term debt is classified as Level 2.

RISK_MANAGEMENT_AND_HEDGING_AC

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES	'
	E.	RISK-MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES
	Our Energy Services and ONEOK Partners segments are exposed to various risks that we manage by periodically entering into derivative instruments. In June 2013, we announced we will exit the operations of our Energy Services segment. As a result, the use of derivative instruments will decrease significantly within our Energy Services segment. See Note B for additional information. These risks include the following:
	•	Commodity-price risk - We are exposed to the risk of loss in cash flows and future earnings arising from adverse changes in the price of natural gas, NGLs and condensate.  We use commodity derivative instruments such as futures, physical-forward contracts, swaps and options to mitigate the commodity-price risk associated with a portion of the forecasted purchases and sales of commodities and natural gas and natural gas liquids in storage.  Commodity-price volatility may have a significant impact on the fair value of our derivative instruments as of a given date;
	•	Basis risk - We are exposed to the risk of loss in cash flows and future earnings arising from adverse changes in the price differentials between pipeline receipt and delivery locations.  Our firm transportation capacity allows us to purchase natural gas at a pipeline receipt point and sell natural gas at a pipeline delivery point.  As market conditions permit, our Energy Services segment periodically enters into basis swaps between the transportation receipt and delivery points in order to protect the fair value of these location price differentials related to our firm commitments; and
	•	Interest-rate risk - We are also subject to fluctuations in interest rates.  We manage interest-rate risk through the use of fixed-rate debt, floating-rate debt and, at times, interest-rate swaps.
	The following derivative instruments are used to manage our exposure to these risks:
	•	Futures contracts - Standardized contracts to purchase or sell natural gas and crude oil for future delivery or settlement under the provisions of exchange regulations;
	•	Forward contracts - Nonstandardized commitments between two parties to purchase or sell natural gas, crude oil or NGLs for future physical delivery. These contracts are typically nontransferable and can only be canceled with the consent of both parties;
	•	Swaps - Exchange of one or more payments based on the value of one or more commodities. This transfers the financial risk associated with a future change in value between the counterparties of the transaction without also conveying ownership interest in the asset or liability; and
	•	Options - Contractual agreements that give the holder the right, but not the obligation, to buy or sell a fixed quantity of a commodity, at a fixed price, within a specified period of time.  Options may either be standardized and exchange traded or customized and nonexchange traded.
	Our objectives for entering into such contracts include but are not limited to:
	•	reducing the variability of cash flows by locking in the price for all or a portion of anticipated index-based physical purchases and sales, transportation fuel requirements, asset management transactions and customer-related business activities;
	•	locking in a price differential to protect the fair value between transportation receipt and delivery points and to protect the fair value of natural gas or NGLs that are purchased in one month and sold in a later month;
	•	reducing our exposure to fluctuations in interest rates; and
	•	reducing variability in cash flows from changes in interest rates associated with forecasted debt issuances.
	With respect to the net open positions that exist within our marketing operations, fluctuating commodity prices can impact our financial position and results of operations.  The net open positions are managed actively, and the impact of the changing prices on our financial condition at a point in time is not necessarily indicative of the impact of price movements throughout the year.
	Our Natural Gas Distribution segment also uses derivative instruments to hedge the cost of a portion of anticipated natural gas purchases during the winter heating months to protect our customers from upward volatility in the market price of natural gas. The use of these derivative instruments and the associated recovery of these costs have been approved by the OCC, KCC and regulatory authorities in certain of our Texas jurisdictions.
	ONEOK Partners has forward-starting interest-rate swaps designated as cash flow hedges of the variability of interest payments on a portion of forecasted debt issuances that may result from changes in the benchmark interest rate before the debt is issued. At September 30, 2013, and December 31, 2012, ONEOK Partners had forward-starting interest-rate swaps with notional amounts totaling $400 million.
	Accounting Treatment - We record all derivative instruments at fair value, with the exception of normal purchases and normal sales that are expected to result in physical delivery.  The accounting for changes in the fair value of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship and, if so, the reason for holding it.
	If certain conditions are met, we may elect to designate a derivative instrument as a hedge of exposure to changes in fair values, cash flows or foreign currency.  Certain nontrading derivative transactions, which are economic hedges of our accrual transactions such as our storage and transportation contracts, do not qualify for hedge accounting treatment.
	The table below summarizes the various ways in which we account for our derivative instruments and the impact on our consolidated financial statements:
			Recognition and Measurement
	Accounting Treatment		Balance Sheet		Income Statement
	Normal purchases and normal	-	Fair value not recorded	-	Change in fair value not recognized in earnings
	sales
	Mark-to-market	-	Recorded at fair value	-	Change in fair value recognized in earnings
	Cash flow hedge	-	Recorded at fair value	-	Ineffective portion of the gain or loss on the
					derivative instrument is recognized in earnings
		-	Effective portion of the gain or loss on the	-	Effective portion of the gain or loss on the
			derivative instrument is reported initially		derivative instrument is reclassified out of
			as a component of accumulated other		accumulated other comprehensive income (loss)
			comprehensive income (loss)		into earnings when the forecasted transaction
					affects earnings
	Fair value hedge	-	Recorded at fair value	-	The gain or loss on the derivative instrument is
					recognized in earnings
		-	Change in fair value of the hedged item is	-	Change in fair value of the hedged item is
			recorded as an adjustment to book value		recognized in earnings
	Gains or losses associated with the fair value of derivative instruments entered into by our Natural Gas Distribution segment are included in, and recoverable through, the monthly purchased-gas cost mechanism.
	We formally document all relationships between hedging instruments and hedged items, as well as risk-management objectives, strategies for undertaking various hedge transactions and methods for assessing and testing correlation and hedge ineffectiveness. We specifically identify the asset, liability, firm commitment or forecasted transaction that has been designated as the hedged item. We assess the effectiveness of hedging relationships quarterly by performing an effectiveness analysis on our cash flow and fair value hedging relationships to determine whether the hedge relationships are highly effective on a retrospective and prospective basis.  We also document our normal purchases and normal sales transactions that we expect to result in physical delivery and that we elect to exempt from derivative accounting treatment.
	The presentation of settled derivative instruments on either a gross or net basis in our Consolidated Statements of Income is dependent on the relevant facts and circumstances of our different types of activities rather than based solely on the terms of the individual contracts.  All financially settled derivative instruments, as well as derivative instruments considered held for trading purposes that result in physical delivery, are reported on a net basis in revenues in our Consolidated Statements of Income.  The realized revenues and purchase costs of derivative instruments that are not considered held for trading purposes and nonderivative contracts are reported on a gross basis. Derivatives that qualify as normal purchases or normal sales that are expected to result in physical delivery are also reported on a gross basis.
	Revenues in our Consolidated Statements of Income include financial trading margins, as well as certain physical natural gas transactions with our trading counterparties.  Revenues and cost of sales and fuel from such physical transactions are reported on a net basis.
	Cash flows from futures, forwards, options and swaps that are accounted for as hedges are included in the same category as the cash flows from the related hedged items in our Consolidated Statements of Cash Flows.
	Fair Values of Derivative Instruments - The following table sets forth the fair values of our derivative instruments for our continuing and discontinued operations for the periods indicated:
		September 30, 2013									December 31, 2012
		Fair Values of Derivatives (a)									Fair Values of Derivatives (a)
		Assets					(Liabilities)				Assets					(Liabilities)
		(Thousands of dollars)
	Derivatives designated as hedging instruments
	Commodity contracts
	Financial contracts	$	33,216		(b)		$	(4,554	)		$	47,516		(c)		$	(4,885	)
	Physical contracts	351					(2,711		)		56					(126		)
	Interest-rate contracts	43,614					—				10,923					—
	Total derivatives designated as hedging instruments	77,181					(7,265		)		58,495					(5,011		)
	Derivatives not designated as hedging instruments
	Commodity contracts
	Nontrading instruments
	Financial contracts	12,260					(15,018		)		24,970					(25,009		)
	Physical contracts	3,976					(1,127		)		4,059					(153		)
	Trading instruments
	Financial contracts	15,986					(15,669		)		15,358					(14,192		)
	Total derivatives not designated as hedging instruments	32,222					(31,814		)		44,387					(39,354		)
	Total derivatives	$	109,403				$	(39,079	)		$	102,882				$	(44,365	)
	(a) - Included on a net basis in energy marketing and risk-management assets and liabilities, other assets and other deferred credits on our Consolidated Balance Sheets.
(b) - Includes $8.0 million of derivative assets associated with cash flow hedges of inventory that were adjusted to reflect the lower of cost or market value. The deferred gains associated with these assets have been reclassified from accumulated other comprehensive income (loss).
(c) - Includes $16.9 million of derivative net assets and ineffectiveness associated with cash flow hedges of inventory related to certain financial contracts that were used to hedge forecasted purchases and sales of natural gas. The deferred gains associated with these assets have been reclassified from accumulated other comprehensive income (loss).
Notional Quantities for Derivative Instruments - The following table sets forth the notional quantities for derivative instruments held for periods indicated:
			September 30, 2013								December 31, 2012
	Contract		Purchased/				Sold/				Purchased/				Sold/
	Type		Payor				Receiver				Payor				Receiver
Derivatives designated as hedging instruments:
Cash flow hedges
Fixed price
- Natural gas (Bcf)	Futures, forwards and swaps		—				(72.4		)		—				(85.1		)
- Crude oil and NGLs (MMbbl)	Futures, forwards and swaps		—				(2.3		)		—				(1.1		)
Basis
- Natural gas (Bcf)	Futures, forwards and swaps		—				(58.0		)		—				(56.3		)
Interest-rate contracts (Millions of dollars)	Forward-starting		$	400			$	—			$	400			$	—
	swaps
Fair value hedges
Basis
- Natural gas (Bcf)	Futures, forwards and swaps		5.8				(5.8		)		59.1				(59.1		)
Derivatives not designated as hedging instruments:
Fixed price
- Natural gas (Bcf)	Futures, forwards and swaps		53				(53.1		)		60.7				(60.4		)
	Options		—				—				102.1				(100.8		)
Basis
- Natural gas (Bcf)	Futures, forwards and swaps		105.9				(105.7		)		80.2				(81.7		)
Index
- Natural gas (Bcf)	Futures, forwards and swaps		8.2				(4.8		)		20.3				(22.3		)
These notional amounts are used to summarize the volume of financial instruments; however, they do not reflect the extent to which the positions offset one another and consequently do not reflect our actual exposure to market or credit risk.
Cash Flow Hedges - Our Energy Services and ONEOK Partners segments use derivative instruments to hedge the cash flows associated with anticipated purchases and sales of natural gas, NGLs and condensate and cost of fuel used in the transportation of natural gas.  Accumulated other comprehensive income (loss) at September 30, 2013, includes gains of approximately $5.6 million, net of tax, related to these hedges that will be recognized within the next 27 months as the forecasted transactions affect earnings.  If prices remain at current levels, we will recognize $3.6 million in net gains over the next 12 months and net gains of $2.0 million thereafter.  The amount deferred in accumulated other comprehensive income (loss) attributable to our settled interest-rate swaps is a loss of $50.9 million, net of tax, which will be recognized over the life of the long-term, fixed-rate debt. We expect that losses of $5.3 million will be reclassified into earnings during the next 12 months as the hedged items affect earnings. The remaining amounts in accumulated other comprehensive income (loss) are attributable primarily to ONEOK Partners’ forward-starting interest-rate swaps with settlement dates greater than 12 months, which will be amortized to interest expense over the life of long-term, fixed-rate debt upon issuance of ONEOK Partners debt.
For the nine months ended September 30, 2013, cost of sales and fuel in our Consolidated Statements of Income includes $10.1 million reflecting an adjustment to natural gas inventory at the lower of cost or market value. We reclassified $8.0 million of deferred gains, before income taxes, on associated cash flow hedges from accumulated other comprehensive income (loss) into earnings.
For the nine months ended September 30, 2012, net margin in our Consolidated Statement of Income includes losses of $29.9 million related to certain financial contracts that were used to hedge forecasted purchases of natural gas.  As a result of the continued decline in natural gas prices, the combination of the cost basis of the forecasted purchases of inventory and the financial contracts exceeded the amount expected to be recovered through sales of that inventory after considering related sales hedges, which required reclassification of the loss from accumulated other comprehensive loss to current period earnings.
The following table sets forth the effects of cash flow hedges recognized in other comprehensive income (loss) for the periods indicated:
Derivatives in Cash Flow	Three Months Ended								Nine Months Ended
Hedging Relationships	September 30,								September 30,
	2013				2012				2013				2012
	(Thousands of dollars)
Commodity contracts	$	(8,796	)		$	(41,452	)		$	11,718			$	39,461
Interest-rate contracts	6,721				(1,175		)		35,726				(32,795		)
Total unrealized gain (loss) recognized in other comprehensive	$	(2,075	)		$	(42,627	)		$	47,444			$	6,666
income (loss) on derivatives (effective portion)
The following table sets forth the effect of cash flow hedges in our Consolidated Statements of Income for the periods indicated:
Derivatives in Cash Flow	Location of Gain (Loss) Reclassified from	Three Months Ended								Nine Months Ended
Hedging Relationships	Accumulated Other Comprehensive Income	September 30,								September 30,
	(Loss) into Net Income (Effective Portion)	2013				2012				2013				2012
		(Thousands of dollars)
Commodity contracts	Revenues	$	3,357			$	31,447			$	18,718			$	127,477
Commodity contracts	Cost of sales and fuel	(117		)		(2,503		)		(14,320		)		(65,940		)
Interest-rate contracts	Interest expense	(3,696		)		(1,828		)		(10,840		)		(3,908		)
Total gain (loss) reclassified from accumulated other comprehensive income		$	(456	)		$	27,116			$	(6,442	)		$	57,629
(loss) into net income on derivatives (effective portion)
Ineffectiveness related to our cash flow hedges was not material for the three and nine months ended September 30, 2013 and 2012.  In the event that it becomes probable that a forecasted transaction will not occur, we will discontinue cash flow hedge treatment, which will affect earnings.  For the three and nine months ended September 30, 2013, we recorded immaterial gains due to the discontinuance of cash flow hedge treatment as a result of the underlying transactions being no longer probable. For the three and nine months ended September 30, 2012, there were no gains or losses due to the discontinuance of cash flow hedge treatment as a result of the underlying transactions being no longer probable.
Other Derivative Instruments - The following table sets forth the effect of our derivative instruments that are not part of a hedging relationship in our Consolidated Statements of Income for our continuing and discontinued operations for the periods indicated:
Derivatives Not Designated as	Location of Gain (Loss)	Three Months Ended								Nine Months Ended
Hedging Instruments		September 30,								September 30,
		2013				2012				2013				2012
		(Thousands of dollars)
Commodity contracts - trading	Revenues	$	4			$	867			$	(2,054	)		$	1,673
Commodity contracts - nontrading (a)	Cost of sales and fuel	(534		)	(b)	601				(2,959		)	(b)	4,924
Total gain (loss) recognized in income on derivatives		$	(530	)		$	1,468			$	(5,013	)		$	6,597
(a) - Amounts are presented net of deferred gains (losses) associated with derivatives entered into by our Natural Gas Distribution segment.
(b) - Includes losses of $0.4 million and $2.2 million for the three and nine months ended September 30, 2013, respectively, on certain derivatives derecognized that were designated previously as fair value hedges of firm transportation commitments that no longer meet the definition of a firm commitment.
Our Natural Gas Distribution segment held natural gas call options with fair values of $4.8 million and $1.8 million at September 30, 2013, and December 31, 2012, respectively.  The premiums are recorded in other current assets as these contracts are included in, and recoverable through, the monthly purchased-gas cost mechanism.  For the three and nine months ended September 30, 2013, we recorded losses of $2.3 million and $7.4 million, respectively, which are deferred as part of our unrecovered purchased-gas costs. For the three and nine months ended September 30, 2012, we recorded gains of $2.8 million and $3.8 million, respectively, which are deferred as part of our unrecovered purchased-gas costs.
Fair Value Hedges - Our Energy Services segment uses basis swaps to hedge the fair value of location price differentials related to certain firm transportation commitments. The change in fair value of derivatives designated as fair value hedges and the related hedged firm commitments and the ineffectiveness related to these hedges were not material for the three and nine months ended September 30, 2013 and 2012.
Credit Risk - We monitor the creditworthiness of our counterparties and compliance with policies and limits established by our Risk Oversight and Strategy Committee.  We maintain credit policies with regard to our counterparties that we believe minimize overall credit risk.  These policies include an evaluation of potential counterparties’ financial condition (including credit ratings, bond yields and credit default swap rates), collateral requirements under certain circumstances and the use of standardized master-netting agreements that allow us to net the positive and negative exposures associated with a single counterparty.  We have counterparties whose credit is not rated, and for those customers we use internally developed credit ratings.
Some of our derivative instruments contain provisions that require us to maintain an investment-grade credit rating from S&P and/or Moody’s.  If our credit ratings on senior unsecured long-term debt were to decline below investment grade, the counterparties to the derivative instruments could request collateralization on derivative instruments in net liability positions. The aggregate fair value of all financial derivative instruments with contingent features related to credit risk that were in a net liability position at September 30, 2013, was $2.5 million.
The counterparties to our derivative contracts consist primarily of major energy companies, LDCs, electric utilities, financial institutions and commercial and industrial end-users.  This concentration of counterparties may impact our overall exposure to credit risk, either positively or negatively, in that the counterparties may be similarly affected by changes in economic, regulatory or other conditions.  Based on our policies, exposures, credit and other reserves, we do not anticipate a material adverse effect on our financial position or results of operations as a result of counterparty nonperformance.
At September 30, 2013, the net credit exposure from our derivative assets is primarily with investment-grade companies in the financial services sector.

CREDIT_FACILITIES_AND_SHORTTER

CREDIT FACILITIES AND SHORT-TERM NOTES PAYABLE	9 Months Ended
	Sep. 30, 2013
Short-term Debt [Abstract]	'
CREDIT FACILITIES AND SHORT-TERM NOTES PAYABLE	'
	F.	CREDIT FACILITIES AND SHORT-TERM NOTES PAYABLE
	ONEOK Credit Agreement - The ONEOK Credit Agreement, which is scheduled to expire in March 2018, contains certain financial, operational and legal covenants.  Among other things, these covenants include maintaining ONEOK’s stand-alone debt-to-capital ratio of no more than 67.5 percent at the end of any calendar quarter, limitations on the ratio of indebtedness secured by liens and indebtedness of subsidiaries to consolidated net tangible assets, a requirement that ONEOK maintains the power to control the management and policies of ONEOK Partners, and a limit on new investments in master limited partnerships. The ONEOK Credit Agreement also contains customary affirmative and negative covenants, including covenants relating to liens, investments, fundamental changes in the nature of ONEOK’s businesses, transactions with affiliates, the use of proceeds and a covenant that limits ONEOK’s ability to restrict its subsidiaries’ ability to pay dividends.  The debt covenant calculations in the ONEOK Credit Agreement exclude the debt of ONEOK Partners.  In the event of a breach of certain covenants by ONEOK, amounts outstanding under the ONEOK Credit Agreement may become due and payable immediately. At September 30, 2013, ONEOK’s stand-alone debt-to-capital ratio, as defined by the ONEOK Credit Agreement, was 48.2 percent, and ONEOK was in compliance with all covenants under the ONEOK Credit Agreement.
	Under the terms of the ONEOK Credit Agreement, ONEOK may request an increase in the size of the facility to an aggregate of $1.7 billion from $1.2 billion by either commitments from new lenders or increased commitments from existing lenders. The ONEOK Credit Agreement is available for general corporate purposes, including repayment of ONEOK’s commercial paper notes, if necessary.  Amounts outstanding under the commercial paper program reduce the borrowing capacity under the ONEOK Credit Agreement. The ONEOK Credit Agreement contains provisions for an applicable margin rate and an annual facility fee, both of which adjust with changes in our credit rating. Based on our current credit rating, borrowings, if any, will accrue at LIBOR plus 117.5 basis points, and the annual facility fee is 20 basis points.
	At September 30, 2013, ONEOK had $515.3 million of commercial paper outstanding and $1.9 million in letters of credit issued, leaving approximately $682.8 million of credit available under the ONEOK Credit Agreement.
	In March 2013, we amended the ONEOK Credit Agreement to extend its maturity to March 28, 2018, from April 5, 2016, and reduce the facility fee and interest-rate margins for any borrowings after the amendment’s effective date.
	ONEOK Partners Credit Agreement - The ONEOK Partners Credit Agreement contains certain financial, operational and legal covenants.  Among other things, these covenants include maintaining a ratio of indebtedness to adjusted EBITDA (EBITDA, as defined in the ONEOK Partners Credit Agreement, adjusted for all noncash charges and increased for projected EBITDA from certain lender-approved capital expansion projects) of no more than 5.0 to 1.  If ONEOK Partners consummates one or more acquisitions in which the aggregate purchase price is $25 million or more, the allowable ratio of indebtedness to adjusted EBITDA will increase to 5.5 to 1 for the quarter of the acquisition and the two following quarters.  As a result of ONEOK Partners’ Sage Creek acquisition on September 30, 2013, its allowable ratio of indebtedness to adjusted EBITDA increased to 5.5 to 1 for the current quarter and will remain at that level through the first quarter 2014. Upon breach of certain covenants by ONEOK Partners in the ONEOK Partners Credit Agreement, amounts outstanding under the ONEOK Partners Credit Agreement, if any, may become due and payable immediately.  At September 30, 2013, ONEOK Partners’ ratio of indebtedness to adjusted EBITDA was 4.2 to 1, and ONEOK Partners was in compliance with all covenants under the ONEOK Partners Credit Agreement.
	The ONEOK Partners Credit Agreement includes a $100 million sublimit for the issuance of standby letters of credit and also features an option that allows ONEOK Partners to request an increase in the size of the facility to an aggregate of $1.7 billion from $1.2 billion by either commitments from new lenders or increased commitments from existing lenders.  The ONEOK Partners Credit Agreement is available for general partnership purposes, including repayment of ONEOK Partners’ commercial paper notes, if necessary.  Amounts outstanding under ONEOK Partners’ commercial paper program reduce the borrowing capacity under the ONEOK Partners Credit Agreement.  At September 30, 2013, ONEOK Partners had $47.0 million in commercial paper outstanding, no letters of credit issued and no borrowings under the ONEOK Partners Credit Agreement.
	The ONEOK Partners Credit Agreement contains provisions for an applicable margin rate and an annual facility fee, both of which adjust with changes in ONEOK Partners’ credit rating. Based on ONEOK Partners’ current credit rating, borrowings, if any, will accrue at LIBOR plus 130 basis points, and the annual facility fee is 20 basis points. ONEOK Partners Credit Agreement is guaranteed fully and unconditionally by the Intermediate Partnership. Borrowings under the ONEOK Partners Credit Agreement are nonrecourse to ONEOK.
	Neither ONEOK nor ONEOK Partners guarantees the debt or other similar commitments of unaffiliated parties. ONEOK does not guarantee the debt, commercial paper or other similar commitments of ONEOK Partners, and ONEOK Partners does not guarantee the debt, commercial paper or other similar commitments of ONEOK.

LONGTERM_DEBT

LONG-TERM DEBT	9 Months Ended
	Sep. 30, 2013
Long-term Debt, Unclassified [Abstract]	'
LONG-TERM DEBT	'
	G.	LONG-TERM DEBT
	In September 2013, ONEOK Partners completed an underwritten public offering of $1.25 billion of senior notes, consisting of $425 million, 3.2-percent senior notes due 2018, $425 million, 5.0-percent senior notes due 2023 and $400 million, 6.2-percent senior notes due 2043. A portion of the net proceeds from the offering of approximately $1.24 billion was used to repay amounts outstanding under its commercial paper program, and the balance will be used for general partnership purposes, including but not limited to capital expenditures.
	These notes are governed by an indenture, dated as of September 25, 2006, between ONEOK Partners and Wells Fargo Bank, N.A., the trustee, as supplemented.  The indenture does not limit the aggregate principal amount of debt securities that may be issued and provides that debt securities may be issued from time to time in one or more additional series.  The indenture contains covenants including, among other provisions, limitations on ONEOK Partners’ ability to place liens on its property or assets and to sell and lease back its property.  The indenture includes an event of default upon acceleration of other indebtedness of $100 million or more.  Such an event of default would entitle the trustee or the holders of 25 percent in aggregate principal amount of any of ONEOK Partners’ outstanding senior notes to declare those notes immediately due and payable in full.
	ONEOK Partners may redeem its 3.2 percent senior notes due 2018, its 5.0 percent senior notes due 2023, and its 6.2 percent senior notes due 2043 from the September 2013 offering at par, plus accrued and unpaid interest to the redemption date, starting one month, three months, and six months, respectively, before their maturity dates.  Prior to these dates, ONEOK Partners may redeem these notes, in whole or in part, at a redemption price equal to the principal amount, plus accrued and unpaid interest and a make-whole premium.  The redemption price will never be less than 100 percent of the principal amount of the respective note plus accrued and unpaid interest to the redemption date.  ONEOK Partners’ senior notes are senior unsecured obligations, ranking equally in right of payment with all of ONEOK Partners’ existing and future unsecured senior indebtedness, and structurally subordinate to any of the existing and future debt and other liabilities of any ONEOK Partners’ nonguarantor subsidiaries.
	In September 2012, ONEOK Partners completed an underwritten public offering of $1.3 billion of senior notes, consisting of $400 million, 2.0 percent senior notes due 2017 and $900 million, 3.375 percent senior notes due 2022. A portion of the net proceeds from the offering of approximately $1.29 billion was used to repay amounts outstanding under its commercial paper program, and the balance was used for general partnership purposes, including but not limited to capital expenditures.
	ONEOK Partners repaid its $350 million, 5.9 percent senior notes at maturity in April 2012 with a portion of the proceeds from its March 2012 equity issuance.

EQUITY

EQUITY	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Stockholders' Equity Note Disclosure [Text Block]	'
	H.	EQUITY
	The following table sets forth the changes in equity attributable to us and our noncontrolling interests, including other comprehensive income, net of tax, for the periods indicated:
		Three Months Ended									Three Months Ended
		30-Sep-13									30-Sep-12
		ONEOK			Noncontrolling			Total			ONEOK			Noncontrolling			Total
		Shareholders’			Interests in			Equity			Shareholders’			Interests in			Equity
		Equity			Consolidated						Equity			Consolidated
					Subsidiaries									Subsidiaries
		(Thousands of dollars)
	Beginning balance	$	2,085,349		$	2,089,007		$	4,174,356		$	2,089,540		$	2,116,448		$	4,205,988
	Net income	62,356			85,342			147,698			65,219			99,769			164,988
	Other comprehensive income	(7,522		)	(1,964		)	(9,486		)	(34,836		)	(22,208		)	(57,044		)
	(loss)
	Repurchase of common stock	—			—			—			—			—			—
	Common stock issued	4,142			—			4,142			3,838			—			3,838
	Common stock dividends	(78,367		)	—			(78,367		)	(67,671		)	—			(67,671		)
	Issuance of common units of	81,502			420,391			501,893			—			—			—
	ONEOK Partners
	Distributions to noncontrolling	—			(91,824		)	(91,824		)	—			(84,156		)	(84,156		)
	interests
	Other	42,234			—			42,234			9,616			—			9,616
	Ending balance	$	2,189,694		$	2,500,952		$	4,690,646		$	2,065,706		$	2,109,853		$	4,175,559
		Nine Months Ended									Nine Months Ended
		September 30, 2013									September 30, 2012
		ONEOK			Noncontrolling			Total			ONEOK			Noncontrolling			Total
		Shareholders’			Interests in			Equity			Shareholders’			Interests in			Equity
		Equity			Consolidated						Equity			Consolidated
					Subsidiaries									Subsidiaries
		(Thousands of dollars)
	Beginning balance	$	2,129,609		$	2,102,841		$	4,232,450		$	2,238,573		$	1,561,159		$	3,799,732
	Net income	175,796			217,102			392,898			249,077			298,578			547,655
	Other comprehensive income	(2,694		)	22,612			19,918			(34,355		)	(22,920		)	(57,275		)
	(loss)
	Repurchase of common stock	—			—			—			(150,000		)	—			(150,000		)
	Common stock issued	11,892			—			11,892			10,390			—			10,390
	Common stock dividends	(226,349		)	—			(226,349		)	(194,443		)	—			(194,443		)
	Issuance of common units of	84,458			431,743			516,201			(51,100		)	510,780			459,680
	ONEOK Partners
	Distributions to noncontrolling	—			(273,346		)	(273,346		)	—			(237,744		)	(237,744		)
	interests
	Other	16,982			—			16,982			(2,436		)	—			(2,436		)
	Ending balance	$	2,189,694		$	2,500,952		$	4,690,646		$	2,065,706		$	2,109,853		$	4,175,559
	Dividends - Dividends paid on our common stock to shareholders of record at the close of business on January 31, 2013, April 30, 2013, and August 5, 2013 were $0.36 per share, $0.36 per share, and $0.38 per share respectively.  A dividend of $0.38 per share was declared for shareholders of record on November 4, 2013, payable November 14, 2013.
	See Note M for a discussion of ONEOK Partners’ issuance of common units and distributions to noncontrolling interests.

ACCUMULATED_OTHER_COMPREHENSIV

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	9 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	'
	I.	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)
	The following table sets forth the balance in accumulated other comprehensive income (loss) for the period indicated:
		Unrealized Gains				Unrealized				Pension and			Accumulated
		(Losses) on Energy				Holding Gains				Postretirement			Other
		Marketing and				(Losses)				Benefit Plan			Comprehensive
		Risk-Management				on Investment				Obligations (a)			Income (Loss) (a)
		Assets/Liabilities (a)				Securities (a)
		(Thousands of dollars)
	1-Jan-13	$	(55,030	)		$	1,034			$	(162,802	)	$	(216,798	)
	Other comprehensive income (loss) before	16,406				(234		)		(56,164		)	(39,992		)
	reclassifications
	Amounts reclassified from accumulated other	2,771				—				34,527			37,298
	comprehensive income (loss)
	Other comprehensive income	19,177				(234		)		(21,637		)	(2,694		)
	(loss) attributable to ONEOK
	September 30, 2013	$	(35,853	)		$	800			$	(184,439	)	$	(219,492	)
	(a) All amounts are presented net of tax.
	The following table sets forth the effect of reclassifications from accumulated other comprehensive income (loss) on our Consolidated Statements of Income for the periods indicated:
		Details about Accumulated Other		Three Months Ended				Nine Months Ended				Affected Line Item
		Comprehensive Income (Loss) Components		30-Sep-13				30-Sep-13				in the Consolidated
												Statements of Income
				(Thousand of dollars)
		Unrealized (gains) losses on energy marketing and risk-management assets/liabilities
		Commodity contracts		$	(3,357	)		$	(18,718	)		Revenues
		Commodity contracts		117				14,320				Cost of sales and fuel
		Interest-rate contracts		3,696				10,840				Interest expense
				456				6,442				Income before income taxes
				333				(1,748		)		Income tax expense
				789				4,694				Net income
		Noncontrolling interest		1,317				1,923				Less: Net income attributable to
												noncontrolling interest
				$	(528	)		$	2,771			Net income attributable to ONEOK
		Pension and postretirement benefit plan
		obligations (a)
		Amortization of net loss		$	19,729			$	59,183
		Amortization of unrecognized prior service		(1,438		)		(4,314		)
		cost
		Amortization of unrecognized net asset at		71				213
		adoption
		Settlement charge		275				1,225
				18,637				56,307				Income before income taxes
				(7,210		)		(21,780		)		Income tax expense
				$	11,427			$	34,527			Net income attributable to ONEOK
		Total reclassifications for the period		$	10,899			$	37,298			Net income attributable to ONEOK
		attributable to ONEOK
	(a) These components of accumulated other comprehensive income (loss) are included in the computation of net periodic benefit cost. See Note K for additional detail of our net periodic benefit cost.

EARNINGS_PER_SHARE

EARNINGS PER SHARE	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
EARNINGS PER SHARE	'
	J.	EARNINGS PER SHARE
	The following tables set forth the computation of basic and diluted EPS from continuing operations for the periods indicated:
		Three Months Ended September 30, 2013
		Income		Shares	Per Share
					Amount
		(Thousands, except per share amounts)
	Basic EPS from continuing operations
	Income from continuing operations attributable to ONEOK available for common	$	62,356	206,235	$	0.3
	stock
	Diluted EPS from continuing operations
	Effect of dilutive securities	—		3,658
	Income from continuing operations attributable to ONEOK available for common	$	62,356	209,893	$	0.3
	stock and common stock equivalents
		Three Months Ended September 30, 2012
		Income		Shares	Per Share
					Amount
		(Thousands, except per share amounts)
	Basic EPS from continuing operations
	Income from continuing operations attributable to ONEOK available for common	$	65,219	205,005	$	0.32
	stock
	Diluted EPS from continuing operations
	Effect of dilutive securities	—		4,955
	Income from continuing operations attributable to ONEOK available for common	$	65,219	209,960	$	0.31
	stock and common stock equivalents
		Nine Months Ended September 30, 2013
		Income		Shares	Per Share
					Amount
		(Thousands, except per share amounts)
	Basic EPS from continuing operations
	Income from continuing operations attributable to ONEOK available for common	$	175,796	205,952	$	0.85
	stock
	Diluted EPS from continuing operations
	Effect of dilutive securities	—		3,456
	Income from continuing operations attributable to ONEOK available for common	$	175,796	209,408	$	0.84
	stock and common stock equivalents
		Nine Months Ended September 30, 2012
		Income		Shares	Per Share
					Amount
		(Thousands, except per share amounts)
	Basic EPS from continuing operations
	Income from continuing operations attributable to ONEOK available for common	$	234,798	206,638	$	1.14
	stock
	Diluted EPS from continuing operations
	Effect of dilutive securities	—		4,560
	Income from continuing operations attributable to ONEOK available for common	$	234,798	211,198	$	1.11
	stock and common stock equivalents
	There were no option shares excluded from the calculation of diluted EPS for the three and nine months ended September 30, 2013 and 2012.

EMPLOYEE_BENEFIT_PLANS

EMPLOYEE BENEFIT PLANS	9 Months Ended
	Sep. 30, 2013
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]	'
EMPLOYEE BENEFIT PLANS	'
	K.	EMPLOYEE BENEFIT PLANS
	The following tables set forth the components of net periodic benefit cost for our pension and postretirement benefit plans for the periods indicated:
		Pension Benefits						Pension Benefits
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
		(Thousands of dollars)
	Components of net periodic benefit cost
	Service cost	$	5,735		$	5,325		$	17,207		$	15,975
	Interest cost	13,612			14,809			40,836			44,427
	Expected return on assets	(20,318		)	(20,689		)	(60,954		)	(62,067		)
	Amortization of unrecognized prior service cost	230			242			690			726
	Amortization of net loss	16,572			12,111			49,712			36,333
	Settlement charge	275			—			1,225			—
	Net periodic benefit cost	$	16,106		$	11,798		$	48,716		$	35,394
		Postretirement Benefits						Postretirement Benefits
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
		(Thousands of dollars)
	Components of net periodic benefit cost
	Service cost	$	1,145		$	1,239		$	3,435		$	3,716
	Interest cost	2,910			3,473			8,732			10,419
	Expected return on assets	(3,065		)	(2,671		)	(9,195		)	(8,013		)
	Amortization of unrecognized net asset at adoption	71			718			213			2,154
	Amortization of unrecognized prior service cost	(1,668		)	(2,063		)	(5,004		)	(6,189		)
	Amortization of net loss	3,157			3,296			9,471			9,888
	Net periodic benefit cost	$	2,550		$	3,992		$	7,652		$	11,975

UNCONSOLIDATED_AFFILIATES

UNCONSOLIDATED AFFILIATES	9 Months Ended
	Sep. 30, 2013
Equity Method Investments and Joint Ventures [Abstract]	'
UNCONSOLIDATED AFFILIATES	'
	L.	UNCONSOLIDATED AFFILIATES
	Equity Earnings from Investments - The following table sets forth our equity earnings from investments for the periods indicated.  All amounts in the table below are equity earnings from investments in our ONEOK Partners segment:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
		(Thousands of dollars)
	Northern Border Pipeline	$	16,464	$	18,185	$	48,133	$	54,493
	Overland Pass Pipeline Company	5,783		4,490		14,210		15,786
	Fort Union Gas Gathering	2,946		4,091		9,895		11,494
	Bighorn Gas Gathering	559		1,157		1,897		3,118
	Other	1,716		668		5,609		7,489
	Equity earnings from investments	$	27,468	$	28,591	$	79,744	$	92,380
	Unconsolidated Affiliates Financial Information - The following table sets forth summarized combined financial information of our unconsolidated affiliates for the periods indicated:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
		(Thousands of dollars)
	Income Statement
	Operating revenues	$	131,959	$	125,828	$	391,912	$	373,038
	Operating expenses	$	63,971	$	60,937	$	189,366	$	173,232
	Net income	$	61,630	$	55,721	$	185,580	$	180,787
	Distributions paid to ONEOK Partners	$	34,409	$	34,557	$	103,913	$	118,752
	ONEOK and ONEOK Partners incurred expenses in transactions with unconsolidated affiliates of $15.9 million and $9.0 million for the three months ended September 30, 2013 and 2012, respectively, and $36.3 million and $27.7 million for the nine months ended September 30, 2013 and 2012, respectively, primarily related to Overland Pass Pipeline Company, which are included in cost of sales and fuel in our Consolidated Statements of Income. Accounts payable to our equity method investees at September 30, 2013, and December 31, 2012, were not material.
	In January 2013, the FERC approved a settlement between Northern Border Pipeline and its customers that modified its transportation rates, effective January 1, 2013. The new long-term transportation rates are approximately 11 percent lower than previous rates, which reduced ONEOK Partners’ equity earnings from Northern Border Pipeline for the three and nine months ended September 30, 2013, compared with the same periods last year, and are expected to reduce equity earnings and cash distributions from Northern Border Pipeline in the future.
	Low natural gas prices and the relatively higher crude oil and NGL prices, compared with natural gas on a heating-value basis, have caused producers primarily to focus development efforts on crude oil and NGL-rich supply basins rather than areas with dry natural gas production, such as the coal-bed methane areas in the Powder River Basin.  The reduced coal-bed methane development activities and natural production declines in the dry natural gas formations of the Powder River Basin have resulted in lower dry natural gas volumes available to be gathered.  While the reserve potential in the dry natural gas formations of the Powder River Basin still exists, future drilling and development will be affected by commodity prices and producers’ alternative prospects.
	Due to recent reductions in producer activity and declines in natural gas volumes gathered in the Powder River Basin on the Bighorn Gas Gathering system, in which ONEOK Partners owns a 49 percent interest, ONEOK Partners tested its investment for impairment at March 31, 2013. The estimated fair value exceeded the carrying value; however, a decline of 10 percent or more in the fair value of ONEOK Partners’ investment in Bighorn Gas Gathering would result in a noncash impairment charge. ONEOK Partners is not able to reasonably estimate a range of potential future impairment charges, as many of the assumptions that would be used in its estimate of fair value are dependent upon events beyond its control. There were no impairment indicators identified in the third quarter 2013. The carrying amount of ONEOK Partners’ investment at September 30, 2013, was $88.7 million, which includes $53.4 million in equity method goodwill.

ONEOK_PARTNERS

ONEOK PARTNERS	9 Months Ended
	Sep. 30, 2013
Related Party Transactions [Abstract]	'
ONEOK PARTNERS	'
	M.	ONEOK PARTNERS
	Equity Issuances - In August 2013, ONEOK Partners completed an underwritten public offering of 11.5 million common units at a public offering price of $49.61 per common unit, generating net proceeds of approximately $553.4 million. In conjunction with this issuance, ONEOK Partners GP contributed approximately $11.6 million in order to maintain our 2 percent general partner interest in ONEOK Partners. ONEOK Partners used a portion of the proceeds from its August 2013 equity issuance to repay amounts outstanding under its $1.2 billion commercial paper program and the balance was used for general partnership purposes.
	ONEOK Partners has an “at-the-market” equity program for the offer and sale from time to time of its common units up to an aggregate amount of $300 million. The program allows ONEOK Partners to offer and sell its common units at prices ONEOK Partners deems appropriate through a sales agent. Sales of common units are made by means of ordinary brokers’ transactions on the NYSE, in block transactions, or as otherwise agreed to between ONEOK Partners and the sales agent. ONEOK Partners is under no obligation to offer and sell common units under the program. During the three months ended March 31, 2013, ONEOK Partners sold common units through this program that resulted in net proceeds, including ONEOK Partners GP’s contribution to maintain our 2 percent general partner interest in ONEOK Partners, of approximately $16.3 million. ONEOK Partners used the proceeds for general partnership purposes. ONEOK Partners did not sell any units under this program in the second or third quarter 2013.
	As a result of these transactions, our aggregate ownership interest in ONEOK Partners decreased to 41.3 percent at September 30, 2013, from 43.4 percent at December 31, 2012.
	In March 2012, ONEOK Partners completed an underwritten public offering of 8.0 million common units at a public offering price of $59.27 per common unit, generating net proceeds of approximately $460 million.  ONEOK Partners also sold 8.0 million common units to us in a private placement, generating net proceeds of approximately $460 million.  In conjunction with the issuances, ONEOK Partners GP contributed approximately $19 million in order to maintain our 2 percent general partner interest in ONEOK Partners.
	We account for the difference between the carrying amount of our investment in ONEOK Partners and the underlying book value arising from issuance of common units by ONEOK Partners as an equity transaction.  If ONEOK Partners issues common units at a price different than our carrying value per unit, we account for the premium or deficiency as an adjustment to paid-in capital. As a result of ONEOK Partners’ issuance of common units, we recognized an increase to paid-in capital of approximately $84.5 million, net of taxes of $53.0 million, in 2013.
	Ownership Interest in ONEOK Partners - Our ownership interest in ONEOK Partners is shown in the table below at September 30, 2013:
	General partner interest	2	%
	Limited partner interest (a)	39.3	%
	Total ownership interest	41.3	%
	(a) - Represents 19.8 million common units and approximately 73.0 million Class B units, which are convertible, at our option, into common units.
	Cash Distributions - We receive distributions from ONEOK Partners on our common and Class B units and our 2 percent general partner interest, which includes our incentive distribution rights.  Under ONEOK Partners’ partnership agreement, as amended, distributions are made to the partners with respect to each calendar quarter in an amount equal to 100 percent of available cash as defined in ONEOK Partners’ partnership agreement, as amended.  Available cash generally will be distributed 98 percent to limited partners and 2 percent to the general partner.  The general partner’s percentage interest in quarterly distributions is increased after certain specified target levels are met during the quarter.  Under the incentive distribution provisions, as set forth in ONEOK Partners’ partnership agreement, as amended, the general partner receives:
	•	15 percent of amounts distributed in excess of $0.3025 per unit;
	•	25 percent of amounts distributed in excess of $0.3575 per unit; and
	•	50 percent of amounts distributed in excess of $0.4675 per unit.
	The following table shows ONEOK Partners’ distributions paid in the periods indicated:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
		(Thousands, except per unit amounts)
	Distribution per unit	$	0.72	$	0.66	$	2.145	$	1.905
	General partner distributions	$	4,512	$	3,979	$	13,399	$	11,019
	Incentive distributions	62,634		49,886		184,647		130,968
	Distributions to general partner	67,146		53,865		198,046		141,987
	Limited partner distributions to ONEOK	66,807		61,240		199,031		171,882
	Limited partner distributions to noncontrolling interest	91,676		83,838		272,904		237,109
	Total distributions paid	$	225,629	$	198,943	$	669,981	$	550,978
	The following table shows ONEOK Partners’ distributions declared for the periods indicated and paid within 45 days of the end of the period:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
		(Thousands, except per unit amounts)
	Distribution per unit	$	0.725	$	0.685	$	2.16	$	1.98
	General partner distributions	$	4,795	$	4,199	$	13,776	$	11,937
	Incentive distributions	67,017		55,162		191,226		149,658
	Distributions to general partner	71,812		59,361		205,002		161,595
	Limited partner distributions to ONEOK	67,271		63,560		200,422		183,721
	Limited partner distributions to noncontrolling interest	100,650		87,014		283,365		251,514
	Total distributions declared	$	239,733	$	209,935	$	688,789	$	596,830
	Acquisition - On September 30, 2013, ONEOK Partners completed the acquisition of a business comprised of natural gas gathering and processing and natural gas liquids facilities in Converse and Campbell counties, Wyoming, in the NGL-rich Niobrara Shale formation of the Powder River Basin for $305 million, subject to customary purchase price adjustments. The Sage Creek acquisition consists primarily of a 50 MMcf/d natural gas processing facility, the Sage Creek plant, and related natural gas gathering and natural gas liquids infrastructure. Included in the acquisition were supply contracts providing for long-term acreage dedications from producers in the area, which are structured with POP and fee-based contractual terms. The acquisition is complementary to ONEOK Partners’ existing natural gas liquids assets and provides additional natural gas gathering and processing and natural gas liquids gathering capacity in a region where producers are actively drilling for crude oil and NGL-rich natural gas.
	ONEOK Partners accounted for this transaction using the acquisition method of accounting, which requires, among other things, that the assets acquired and liabilities assumed be recognized on the balance sheet at their fair values as of the acquisition date. ONEOK Partners is developing a preliminary purchase price allocation, which will be adjusted as additional information relative to the fair value of assets and liabilities, which could include intangible assets and goodwill, becomes available. As ONEOK Partners has not completed the purchase price allocation for this transaction, the purchase price has been recorded in property, plant and equipment in our consolidated balance sheet at September 30, 2013.
	Relationship - We consolidate ONEOK Partners in our consolidated financial statements; however, we are restricted from the assets and cash flows of ONEOK Partners except for the distributions we receive.  Distributions are declared quarterly by ONEOK Partners’ general partner based on the terms of the ONEOK Partners partnership agreement.  See Note O for more information on ONEOK Partners’ results.
	Affiliate Transactions - We have certain transactions with ONEOK Partners and its subsidiaries, which collectively comprise our ONEOK Partners segment.
	ONEOK Partners sells natural gas from its natural gas gathering and processing operations to our Energy Services segment.  In addition, a portion of ONEOK Partners’ revenues from its natural gas pipelines business is from our Energy Services and Natural Gas Distribution segments, which contract with ONEOK Partners for natural gas transportation and storage services. ONEOK Partners also purchases natural gas from our Energy Services segment for its natural gas liquids and its natural gas gathering and processing operations. As a result of the wind down activities discussed in Note B, our Energy Services segment will not execute affiliate transactions with ONEOK Partners after the wind down is completed. ONEOK Partners expects to continue providing midstream services, including marketing natural gas, NGLs and condensate as a service for third parties or other ONEOK affiliates. ONEOK Partners expects to enter into future commodity derivative financial contracts with unaffiliated third parties or ONEOK affiliates.
	We provide a variety of services to our affiliates, including cash management and financial services, legal and administrative services by our employees and management, insurance and office space leased in our headquarters building and other field locations.  Where costs are incurred specifically on behalf of an affiliate, the costs are billed directly to the affiliate by us.  In other situations, the costs may be allocated to the affiliates through a variety of methods, depending upon the nature of the expenses and the activities of the affiliates.  For example, a service that applies equally to all employees is allocated based upon the number of employees in each affiliate.  However, an expense benefiting the consolidated company but having no direct basis for allocation is allocated by the modified Distrigas method, a method using a combination of ratios that include gross plant and investment, operating income and payroll expense.  It is not practicable to determine what these general overhead costs would be on a stand-alone basis.
	The following table shows ONEOK Partners’ transactions with us for the periods indicated:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
		(Thousands of dollars)
	Revenues	$	81,324	$	91,096	$	255,298	$	247,851
	Expenses
	Cost of sales and fuel	$	9,562	$	7,831	$	27,855	$	22,875
	Administrative and general expenses	58,549		60,020		192,906		179,017
	Total expenses	$	68,111	$	67,851	$	220,761	$	201,892

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
COMMITMENTS AND CONTINGENCIES	'
	N.	COMMITMENTS AND CONTINGENCIES
	Environmental Matters - We are subject to multiple historical preservation, wildlife preservation and environmental laws and/or regulations that affect many aspects of our present and future operations.  Regulated activities include, but are not limited to, those involving air emissions, storm water and wastewater discharges, handling and disposal of solid and hazardous wastes, wetland preservation, hazardous materials transportation, and pipeline and facility construction.  These laws and regulations require us to obtain and/or comply with a wide variety of environmental clearances, registrations, licenses, permits and other approvals.  Failure to comply with these laws, regulations, licenses and permits may expose us to fines, penalties and/or interruptions in our operations that could be material to our results of operations.  For example, if a leak or spill of hazardous substances or petroleum products occurs from pipelines or facilities that we own, operate or otherwise use, we could be held jointly and severally liable for all resulting liabilities, including response, investigation and cleanup costs, which could affect materially our results of operations and cash flows.  In addition, emissions controls and/or other regulatory or permitting mandates under the Clean Air Act and other similar federal and state laws could require unexpected capital expenditures at our facilities.  We cannot assure that existing environmental statutes and regulations will not be revised or that new regulations will not be adopted or become applicable to us.
	In June 2013, the Executive Office of the President of the United States issued the President’s Climate Action Plan, which includes, among other things, plans for further regulatory actions to reduce carbon emissions from various sources. The impact of any such regulatory actions on our facilities and operations is unknown. Revised or additional statutes or regulations that result in increased compliance costs or additional operating restrictions could have a significant impact on our business, financial position, results of operations and cash flows.
	We own or retain legal responsibility for the environmental conditions at 12 former manufactured natural gas sites in Kansas. These sites contain potentially harmful materials that are subject to control or remediation under various environmental laws and regulations. A consent agreement with KDHE presently governs all work at these sites. The terms of the consent agreement allow us to investigate these sites and set remediation activities based upon the results of the investigations and risk analysis. Remediation typically involves the management of contaminated soils and may involve removal of structures and monitoring and/or remediation of groundwater.
	Of the 12 sites, we have begun soil remediation on 11 sites.  Regulatory closure has been achieved at three locations, and we have completed or are near completion of soil remediation at eight sites.  We have begun site assessment at the remaining site where no active remediation has occurred.
	Our expenditures for environmental assessment, mitigation, remediation and compliance to date have not been significant in relation to our financial position, results of operations or cash flows, and our expenditures related to environmental matters have had no material effects on earnings or cash flows during the three and nine months ended September 30, 2013, or in 2012.
	The EPA’s “Tailoring Rule” regulates greenhouse gas emissions at new or modified facilities that meet certain criteria. Affected facilities are required to review best available control technology, conduct air-quality analysis, impact analysis and public reviews with respect to such emissions.  At current emissions threshold levels, this rule has had a minimal impact on our existing facilities.  The EPA has stated it will consider lowering the threshold levels over the next five years, which could increase the impact on our existing facilities; however, potential costs, fees or expenses associated with the potential adjustments are unknown.
	The EPA’s rule on air-quality standards, titled “National Emissions Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines,” also known as RICE NESHAP, initially included a compliance date in 2013.  Subsequent industry appeals and settlements with the EPA have extended timelines for compliance associated with the final RICE NESHAP rule. While the rule could require capital expenditures for the purchase and installation of new emissions-control equipment, we do not expect these expenditures will have a material impact on our results of operations, financial position or cash flows.
	In July 2011, the EPA issued a proposed rule that would change the air emissions New Source Performance Standards, also known as NSPS, and Maximum Achievable Control Technology requirements applicable to the oil and natural gas industry, including natural gas production, processing, transmission and underground storage sectors. In April 2012, the EPA released the final rule, which includes new NSPS and air toxic standards for a variety of sources within natural gas processing plants, oil and natural gas production facilities and natural gas transmission stations. The rule also regulates emissions from the hydraulic fracturing of wells for the first time. The EPA’s final rule reflects significant changes from the proposal issued in 2011 and allows for more manageable compliance options. The NSPS final rule became effective in October 2012, but the dates for compliance vary and depend in part upon the type of affected facility and the date of construction, reconstruction or modification.
	In March 2013, the EPA issued proposed rulemaking to amend the NSPS for the crude oil and natural gas industry, pursuant to various industry comments, administrative petitions for reconsideration and/or judicial appeals of portions of the NSPS final rule. Beyond the March 2013 proposed amendments, the EPA indicated it would provide additional responses, amendments and/or policy guidance to amend or clarify other portions of the final rule in 2013. The rule was most recently amended in September 2013. Based on the amendments and our understanding of pending stakeholder responses to the NSPS rule, we anticipate a reduction in our anticipated capital, operations and maintenance costs resulting from compliance with the regulation. However, the EPA may issue additional responses, amendments and/or policy guidance on the final rule, which could alter our present expectations. Generally, the NSPS rule will require expenditures for updated emissions controls, monitoring and record-keeping requirements at affected facilities in the crude oil and natural gas industry. We do not expect these expenditures will have a material impact on our results of operations, financial position or cash flows.
	Pipeline Safety - We are subject to PHMSA regulations, including integrity-management regulations.  The Pipeline Safety Improvement Act of 2002 requires pipeline companies operating high-pressure pipelines to perform integrity assessments on pipeline segments that pass through densely populated areas or near specifically designated high-consequence areas.  In January 2012, The Pipeline Safety, Regulatory Certainty and Job Creation Act of 2011 was signed into law.  The law increased maximum penalties for violating federal pipeline safety regulations and directs the DOT and Secretary of Transportation to conduct further review or studies on issues that may or may not be material to us. These issues include but are not limited to the following:
	•	an evaluation on whether hazardous natural gas liquids and natural gas pipeline integrity-management requirements should be expanded beyond current high-consequence areas;
	•	a review of all natural gas and hazardous natural gas liquids gathering pipeline exemptions;
	•	a verification of records for pipelines in class 3 and 4 locations and high-consequence areas to confirm maximum allowable operating pressures; and
	•	a requirement to test previously untested pipelines operating above 30 percent yield strength in high-consequence areas.
	The potential capital and operating expenditures related to this legislation, the associated regulations or other new pipeline safety regulations are unknown.
	Financial Markets Legislation - The Dodd-Frank Act represents a far-reaching overhaul of the framework for regulation of United States financial markets. The CFTC has issued final regulations for most of the provisions of the Dodd-Frank Act, and we have implemented measures to comply with the regulations that are applicable to our businesses. We expect to be able to continue to participate in financial markets for hedging certain risks inherent in our business, including commodity-price and interest-rate risks; however, the capital requirements and costs of hedging may increase as a result of the regulations. These requirements could affect adversely market liquidity and pricing of derivative contracts, making it more difficult to execute our risk-management strategies in the future. Also, the anticipated increased costs of compliance by dealers and counterparties likely will be passed on to customers, which could decrease the benefits of hedging to us and could reduce our profitability and liquidity.
	Legal Proceedings - Gas Index Pricing Litigation - As previously reported, ONEOK and its subsidiary, ONEOK Energy Services Company L.P. (OESC), along with several other energy companies, are defending multiple lawsuits arising from alleged market manipulation or false reporting of natural gas prices to natural gas-index publications. On April 10, 2013, the United States Court of Appeals for the Ninth Circuit reversed the summary judgments that had been granted in favor of ONEOK, OESC and other unaffiliated defendants in the following cases: Reorganized FLI, Learjet, Arandell, Heartland and NewPage. The Ninth Circuit also reversed the summary judgment that had been granted in favor of OESC on all state law claims asserted in the Sinclair case. The Ninth Circuit directed the removal of the cases back to the United States District Court for the District of Nevada for further proceedings. ONEOK, OESC and the other unaffiliated defendants filed a Petition for Writ of Certiorari with the United States Supreme Court on August 26, 2013. The Ninth Circuit has ordered the cases stayed until the final disposition of the Petition for Writ of Certiorari.
	Because of the uncertainty surrounding the Gas Index Pricing Litigation, including an insufficient description of the purported classes and other related matters, we cannot reasonably estimate a range of potential exposures at this time. However, it is reasonably possible that the ultimate resolution of these matters could result in future charges that may be material to our results of operations.
	Other Legal Proceedings - We are a party to various other litigation matters and claims that have arisen in the normal course of our operations. While the results of these various other litigation matters and claims cannot be predicted with certainty, we believe the reasonably possible losses on such matters, individually and in the aggregate, are not material. Additionally, we believe the probable final outcome of such matters will not have a material adverse effect on our consolidated results of operations, financial position or cash flows.

SEGMENTS

SEGMENTS	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
SEGMENTS	'
	O.	SEGMENTS
	Segment Descriptions - Our operations are divided into three reportable business segments as follows:
	•	our ONEOK Partners segment reflects the consolidated operations of ONEOK Partners.  At September 30, 2013, we have a 41.3 percent ownership interest and control ONEOK Partners through our ownership of its general partner. ONEOK Partners gathers, processes, treats, transports, stores and sells natural gas and gathers, treats, fractionates, stores, distributes and markets NGLs and NGL products.  We and ONEOK Partners maintain significant financial and corporate governance separations.  We seek to receive increasing cash distributions as a result of our investment in ONEOK Partners, and our investment decisions are made based on the anticipated returns from ONEOK Partners in total, not specific to any of its businesses individually;
	•	our Natural Gas Distribution segment is comprised of our regulated public utilities that deliver natural gas to residential, commercial and industrial customers, and transport natural gas; and
	•	our Energy Services segment markets natural gas to wholesale customers.
	Other and eliminations consist of the operating and leasing operations of our headquarters building and related parking facility and other amounts needed to reconcile our reportable segments to our consolidated financial statements.
	Accounting Policies - We evaluate performance based principally on each segment’s operating income and equity earnings. The accounting policies of the segments are the same as those described in Note A of the Notes to Consolidated Financial Statements in our Annual Report.  Intersegment sales are recorded on the same basis as sales to unaffiliated customers and are discussed in further detail in Note M.  Net margin is comprised of total revenues less cost of sales and fuel.  Cost of sales and fuel includes commodity purchases, fuel, and storage and transportation costs.
	Customers - For the three and nine months ended September 30, 2013 and 2012, we had no single external customer from which we received 10 percent or more of our consolidated gross revenues.
	Operating Segment Information - The following tables set forth certain selected financial information for our operating segments for the periods indicated:
	Three Months Ended	ONEOK			Natural Gas		Energy			Other and			Total
	30-Sep-13	Partners (a)			Distribution		Services			Eliminations
		(Thousands of dollars)
	Sales to unaffiliated customers	$	3,053,409		$	219,724	$	298,146		$	646		$	3,571,925
	Intersegment revenues	81,324			1		34,050			(115,375		)	—
	Total revenues	$	3,134,733		$	219,725	$	332,196		$	(114,729	)	$	3,571,925
	Net margin	$	423,574		$	159,233	$	(22,265	)	$	646		$	561,188
	Operating costs	122,362			109,304		2,369			2,827			236,862
	Depreciation and amortization	61,182			32,347		69			669			94,267
	Gain on sale of assets	22			—		—			—			22
	Operating income (loss)	$	240,052		$	17,582	$	(24,703	)	$	(2,850	)	$	230,081
	Equity earnings from investments	$	27,468		$	—	$	—		$	—		$	27,468
	Capital expenditures	$	449,072		$	83,783	$	—		$	4,632		$	537,487
	(a) - Our ONEOK Partners segment has regulated and nonregulated operations.  Our ONEOK Partners segment’s regulated operations had revenues of $204.6 million, net margin of $142.3 million and operating income of $76.0 million.
	Three Months Ended	ONEOK			Natural Gas		Energy			Other and			Total
	30-Sep-12	Partners (a)			Distribution		Services			Eliminations
		(Thousands of dollars)
	Sales to unaffiliated customers	$	2,456,364		$	204,930	$	366,955		$	526		$	3,028,775
	Intersegment revenues	91,096			2		(3,116		)	(87,982		)	—
	Total revenues	$	2,547,460		$	204,932	$	363,839		$	(87,456	)	$	3,028,775
	Net margin	$	419,737		$	150,987	$	(17,275	)	$	523		$	553,972
	Operating costs	121,176			103,373		4,424			232			229,205
	Depreciation and amortization	49,754			31,962		78			(360		)	81,434
	Gain on sale of assets	(420		)	—		—			—			(420		)
	Operating income (loss)	$	248,387		$	15,652	$	(21,777	)	$	651		$	242,913
	Equity earnings from investments	$	28,591		$	—	$	—		$	—		$	28,591
	Capital expenditures	$	375,291		$	74,287	$	—		$	8,633		$	458,211
	(a) - Our ONEOK Partners segment has regulated and nonregulated operations.  Our ONEOK Partners segment’s regulated operations had revenues of $181.6 million, net margin of $122.9 million and operating income of $63.6 million.
	Nine Months Ended	ONEOK			Natural Gas		Energy			Other and			Total
	30-Sep-13	Partners (a)			Distribution		Services			Eliminations
		(Thousands of dollars)
	Sales to unaffiliated customers	$	8,165,061		$	1,167,261	$	1,128,325		$	1,959		$	10,462,606
	Intersegment revenues	255,298			5		162,376			(417,679		)	—
	Total revenues	$	8,420,359		$	1,167,266	$	1,290,701		$	(415,720	)	$	10,462,606
	Net margin	$	1,206,126		$	589,354	$	(159,406	)	$	1,955		$	1,638,029
	Operating costs	384,602			330,465		10,930			3,918			729,915
	Depreciation and amortization	174,086			100,118		209			1,930			276,343
	Gain on sale of assets	342			—		—			—			342
	Operating income (loss)	$	647,780		$	158,771	$	(170,545	)	$	(3,893	)	$	632,113
	Equity earnings from investments	$	79,744		$	—	$	—		$	—		$	79,744
	Investments in unconsolidated affiliates	$	1,201,873		$	—	$	—		$	—		$	1,201,873
	Total assets	$	12,863,326		$	3,597,730	$	362,438		$	786,849		$	17,610,343
	Noncontrolling interests in consolidated subsidiaries	$	4,588		$	—	$	—		$	2,496,364		$	2,500,952
	Capital expenditures	$	1,373,904		$	206,372	$	—		$	17,544		$	1,597,820
	(a) - Our ONEOK Partners segment has regulated and nonregulated operations.  Our ONEOK Partners segment’s regulated operations had revenues of $558.9 million, net margin of $390.3 million and operating income of $196.0 million.
	Nine Months Ended	ONEOK			Natural Gas		Energy			Other and			Total
	30-Sep-12	Partners (a)			Distribution		Services			Eliminations
		(Thousands of dollars)
	Sales to unaffiliated customers	$	7,018,503		$	943,034	$	1,009,550		$	1,548		$	8,972,635
	Intersegment revenues	247,851			845		84,022			(332,718		)	—
	Total revenues	$	7,266,354		$	943,879	$	1,093,572		$	(331,170	)	$	8,972,635
	Net margin	$	1,242,289		$	545,823	$	(43,133	)	$	1,542		$	1,746,521
	Operating costs	360,410			312,133		13,889			(1,906		)	684,526
	Depreciation and amortization	150,024			97,481		284			1,640			249,429
Goodwill impairment	—			—		10,255			—			10,255
Gain on sale of assets	603			—		—			—			603
Operating income (loss)	$	732,458		$	136,209	$	(67,561	)	$	1,808		$	802,914
Equity earnings from investments	$	92,380		$	—	$	—		$	—		$	92,380
Investments in unconsolidated affiliates	$	1,218,282		$	—	$	—		$	—		$	1,218,282
Total assets	$	10,792,593		$	3,258,320	$	450,899		$	862,495		$	15,364,307
Noncontrolling interests in consolidated subsidiaries	$	4,812		$	—	$	—		$	2,105,041		$	2,109,853
Capital expenditures	$	1,011,527		$	205,652	$	—		$	21,729		$	1,238,908
(a) - Our ONEOK Partners segment has regulated and nonregulated operations.  Our ONEOK Partners segment’s regulated operations had revenues of $513.0 million, net margin of $359.7 million and operating income of $182.3 million.

SUMMARY_OF_SIGNIFICANT_ACCOUNT1

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2013
New Accounting Pronouncements or Change in Accounting Principle [Line Items]	'
Basis of Accounting, Policy [Policy Text Block]	'
	Our accompanying unaudited consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC. These statements have been prepared in accordance with GAAP and reflect all adjustments that, in our opinion, are necessary for a fair presentation of the results for the interim periods presented.  All such adjustments are of a normal recurring nature. The 2012 year-end consolidated balance sheet data was derived from our audited financial statements but does not include all disclosures required by GAAP.  These unaudited consolidated financial statements should be read in conjunction with our audited consolidated financial statements in our Annual Report.  Due to the seasonal nature of our business, the results of operations for the three and nine months ended September 30, 2013, are not necessarily indicative of the results that may be expected for a 12-month period.
	On July 25, 2013, we announced that our Board of Directors unanimously authorized management to pursue a plan to separate our natural gas distribution business into a standalone publicly traded company. The natural gas distribution company, named ONE Gas will consist of ONEOK’s Natural Gas Distribution segment that includes Kansas Gas Service, Oklahoma Natural Gas and Texas Gas Service.
	ONEOK and its subsidiaries will continue to be the sole general partner and own limited partner units of ONEOK Partners (NYSE: OKS), which represented a 41.3 percent interest in ONEOK Partners at September 30, 2013, and operate our Energy Services segment through the completion of the wind down process.  Under the separation plan, ONEOK shareholders will retain their current shares of ONEOK stock and receive a pro-rata dividend of shares of stock in ONE Gas in a transaction that is expected to be tax-free to ONEOK and its shareholders. The plan provides for the completion of the separation after the receipt of regulatory approvals. On October 1, 2013, ONE Gas filed a registration statement on Form 10 with the SEC. Our Board of Directors retains the discretion to determine whether and when to complete the separation.
	Our significant accounting policies are consistent with those disclosed in Note A of the Notes to Consolidated Financial Statements in our Annual Report.
Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]	'
	We assess our goodwill and indefinite-lived intangible assets for impairment at least annually as of July 1. At July 1, 2013, we assessed qualitative factors to determine whether it was more likely than not that the fair value of each of our reporting units was less than its carrying amount and to determine whether it was more likely than not that the indefinite-lived intangible asset was impaired.  After assessing qualitative factors (including macroeconomic conditions, industry and market considerations, cost factors and overall financial performance), we determined that no further testing was necessary.
Accounting Standards Update 2013-10 [Member]	'
New Accounting Pronouncements or Change in Accounting Principle [Line Items]	'
New Accounting Pronouncement or Change in Accounting Principle, Description	'In July 2013, the FASB issued ASU 2013-10, bInclusion of the Fed Funds Effective Swap Rate (or Overnight Index Swap Rate) as a Benchmark Interest Rate for Hedge Accounting Purposes,b which allows an entity to designate the Fed Funds Effective Swap rate (also known as the Overnight Index Swap rate, or OIS rate, in the United States) as a benchmark interest rate for hedge accounting purposes in addition to the interest rates on direct Treasury obligations of the United States government and LIBOR. In addition, this guidance removes the restriction on using different benchmark interest rates for similar hedges. This guidance is effective prospectively for qualifying new or redesigned hedging relationships entered into on or after July 17, 2013. We adopted this guidance with our September 30, 2013, Quarterly Report, and it did not impact materially our financial position or results of operations. See Notes D and E for additional disclosures.
Accounting Standards Update 2013-02 [Member]	'
New Accounting Pronouncements or Change in Accounting Principle [Line Items]	'
New Accounting Pronouncement or Change in Accounting Principle, Description	'In February 2013, the FASB issued ASU 2013-02, bReporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income,b which requires presentation in a single location, either in a single note or parenthetically on the face of the financial statements, of the effect of significant amounts reclassified from each component of accumulated other comprehensive income based on its source. This guidance is effective for our interim and annual periods beginning on January 1, 2013, and is applied prospectively. We adopted this guidance with our March 31, 2013, Quarterly Report, and it did not impact our financial position or results of operations. See Note I for additional disclosures.
Accounting Standards Update 2011-11 [Member]	'
New Accounting Pronouncements or Change in Accounting Principle [Line Items]	'
New Accounting Pronouncement or Change in Accounting Principle, Description	'In December 2011, the FASB issued ASU 2011-11, bDisclosures about Offsetting Assets and Liabilities,b which increases disclosures about offsetting assets and liabilities. In January 2013, the FASB issued ASU 2013-01, bClarifying the Scope of Disclosures about Offsetting Assets and Liabilities,b which clarifies that the scope of ASU 2011-11 applies to derivatives accounted for in accordance with Topic 815, Derivatives and Hedging. New disclosures are required to enable users of financial statements to understand significant quantitative differences in balance sheets prepared under GAAP and International Financial Reporting Standards related to the offsetting of financial instruments, including derivatives. The existing GAAP guidance allowing balance sheet offsetting remains unchanged. This guidance is effective for interim and annual periods beginning on January 1, 2013, and is applied retrospectively for all comparative periods presented. We adopted this guidance beginning with our March 31, 2013, Quarterly Report, and it did not impact our financial position or results of operations. See Note D for additional disclosures.
Accounting Standards Update 2012-02 [Member]	'
New Accounting Pronouncements or Change in Accounting Principle [Line Items]	'
New Accounting Pronouncement or Change in Accounting Principle, Description	'In July 2012, the FASB issued ASU 2012-02, bTesting Indefinite-lived Intangible Assets for Impairment,b which allows companies to perform a bqualitativeb assessment to determine whether further impairment testing of indefinite-lived intangible assets is necessary.B Under the revised standard, an entity is not required to calculate the fair value of an indefinite-lived intangible asset and perform the quantitative impairment test unless the entity determines that it is more likely than not that the asset is impaired. An entity has the option to bypass the qualitative assessment and perform the quantitative impairment test for any indefinite-lived intangible assets in any period. We adopted this guidance for our annual assessments beginning in July 2013, and it did not impact our financial position or results of operations.Impairment of Goodwill and Indefinite-lived Intangible Assets - We assess our goodwill and indefinite-lived intangible assets for impairment at least annually as of July 1. At July 1, 2013, we assessed qualitative factors to determine whether it was more likely than not that the fair value of each of our reporting units was less than its carrying amount and to determine whether it was more likely than not that the indefinite-lived intangible asset was impaired.B After assessing qualitative factors (including macroeconomic conditions, industry and market considerations, cost factors and overall financial performance), we determined that no further testing was necessary.

RISK_MANAGEMENT_AND_HEDGING_AC1

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES (Policies)	9 Months Ended
	Sep. 30, 2013
RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES [Abstract]	'
Accounting treatment for derivative instruments	'
	Accounting Treatment - We record all derivative instruments at fair value, with the exception of normal purchases and normal sales that are expected to result in physical delivery.  The accounting for changes in the fair value of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship and, if so, the reason for holding it.
	If certain conditions are met, we may elect to designate a derivative instrument as a hedge of exposure to changes in fair values, cash flows or foreign currency.  Certain nontrading derivative transactions, which are economic hedges of our accrual transactions such as our storage and transportation contracts, do not qualify for hedge accounting treatment.
	The table below summarizes the various ways in which we account for our derivative instruments and the impact on our consolidated financial statements:
			Recognition and Measurement
	Accounting Treatment		Balance Sheet		Income Statement
	Normal purchases and normal	-	Fair value not recorded	-	Change in fair value not recognized in earnings
	sales
	Mark-to-market	-	Recorded at fair value	-	Change in fair value recognized in earnings
	Cash flow hedge	-	Recorded at fair value	-	Ineffective portion of the gain or loss on the
					derivative instrument is recognized in earnings
		-	Effective portion of the gain or loss on the	-	Effective portion of the gain or loss on the
			derivative instrument is reported initially		derivative instrument is reclassified out of
			as a component of accumulated other		accumulated other comprehensive income (loss)
			comprehensive income (loss)		into earnings when the forecasted transaction
					affects earnings
	Fair value hedge	-	Recorded at fair value	-	The gain or loss on the derivative instrument is
					recognized in earnings
		-	Change in fair value of the hedged item is	-	Change in fair value of the hedged item is
			recorded as an adjustment to book value		recognized in earnings
	Gains or losses associated with the fair value of derivative instruments entered into by our Natural Gas Distribution segment are included in, and recoverable through, the monthly purchased-gas cost mechanism.
	We formally document all relationships between hedging instruments and hedged items, as well as risk-management objectives, strategies for undertaking various hedge transactions and methods for assessing and testing correlation and hedge ineffectiveness. We specifically identify the asset, liability, firm commitment or forecasted transaction that has been designated as the hedged item. We assess the effectiveness of hedging relationships quarterly by performing an effectiveness analysis on our cash flow and fair value hedging relationships to determine whether the hedge relationships are highly effective on a retrospective and prospective basis.  We also document our normal purchases and normal sales transactions that we expect to result in physical delivery and that we elect to exempt from derivative accounting treatment.
	The presentation of settled derivative instruments on either a gross or net basis in our Consolidated Statements of Income is dependent on the relevant facts and circumstances of our different types of activities rather than based solely on the terms of the individual contracts.  All financially settled derivative instruments, as well as derivative instruments considered held for trading purposes that result in physical delivery, are reported on a net basis in revenues in our Consolidated Statements of Income.  The realized revenues and purchase costs of derivative instruments that are not considered held for trading purposes and nonderivative contracts are reported on a gross basis. Derivatives that qualify as normal purchases or normal sales that are expected to result in physical delivery are also reported on a gross basis.
	Revenues in our Consolidated Statements of Income include financial trading margins, as well as certain physical natural gas transactions with our trading counterparties.  Revenues and cost of sales and fuel from such physical transactions are reported on a net basis.
	Cash flows from futures, forwards, options and swaps that are accounted for as hedges are included in the same category as the cash flows from the related hedged items in our Consolidated Statements of Cash Flows.

ONEOK_PARTNERS_Policies

ONEOK PARTNERS (Policies)	9 Months Ended
	Sep. 30, 2013
Related Party Transactions [Abstract]	'
Cash Distributions	'
	Cash Distributions - We receive distributions from ONEOK Partners on our common and Class B units and our 2 percent general partner interest, which includes our incentive distribution rights.  Under ONEOK Partners’ partnership agreement, as amended, distributions are made to the partners with respect to each calendar quarter in an amount equal to 100 percent of available cash as defined in ONEOK Partners’ partnership agreement, as amended.  Available cash generally will be distributed 98 percent to limited partners and 2 percent to the general partner.  The general partner’s percentage interest in quarterly distributions is increased after certain specified target levels are met during the quarter.  Under the incentive distribution provisions, as set forth in ONEOK Partners’ partnership agreement, as amended, the general partner receives:
	•	15 percent of amounts distributed in excess of $0.3025 per unit;
	•	25 percent of amounts distributed in excess of $0.3575 per unit; and
	•	50 percent of amounts distributed in excess of $0.4675 per unit.

SEGMENTS_Policies

SEGMENTS (Policies)	9 Months Ended
	Sep. 30, 2013
Segment Accounting Policies [Abstract]	'
Segments Accounting Policies [Text Block]	'
	We evaluate performance based principally on each segment’s operating income and equity earnings. The accounting policies of the segments are the same as those described in Note A of the Notes to Consolidated Financial Statements in our Annual Report.  Intersegment sales are recorded on the same basis as sales to unaffiliated customers and are discussed in further detail in Note M.  Net margin is comprised of total revenues less cost of sales and fuel.  Cost of sales and fuel includes commodity purchases, fuel, and storage and transportation costs.

EXIT_ACTIVITIES_Tables

EXIT ACTIVITIES (Tables)	9 Months Ended
	Sep. 30, 2013
Restructuring Cost and Reserve [Line Items]	'
Schedule of Restructuring and Related Costs [Table Text Block]	'
	The following table summarizes the change in our liability related to released capacity contracts for the period indicated:
		Three Months Ended
		30-Sep-13
		(Millions of dollars)
	Beginning balance	$	113.8
	Noncash charges	16.4
	Settlements	(6.2		)
	Accretion	0.6
	Ending balance	$	124.6

FAIR_VALUE_MEASUREMENTS_Tables

FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Recurring Fair Value Measurments	'
	Recurring Fair Value Measurements - The following tables set forth our recurring fair value measurements for our continuing and discontinued operations for the periods indicated:
		September 30, 2013
		Level 1			Level 2			Level 3			Total - Gross			Netting			Total - Net
		(Thousands of dollars)
	Assets
	Derivatives (a)
	Commodity contracts
	Financial contracts	$	50,965		$	1,790		$	8,707		$	61,462		$	(46,938	)	$	14,524
	Physical contracts	—			1,122			3,205			4,327			(541		)	3,786
	Interest-rate contracts	—			43,614			—			43,614			—			43,614
	Total derivatives	50,965			46,526			11,912			109,403			(47,479		)	61,924
	Trading securities (b)	10,193			—			—			10,193			—			10,193
	Available-for-sale investment securities (c)	1,478			—			—			1,478			—			1,478
	Total assets	$	62,636		$	46,526		$	11,912		$	121,074		$	(47,479	)	$	73,595
	Liabilities
	Derivatives (a)
	Commodity contracts
	Financial contracts	$	(26,355	)	$	(1,207	)	$	(7,679	)	$	(35,241	)	$	32,981		$	(2,260	)
	Physical contracts	—			(267		)	(3,571		)	(3,838		)	541			(3,297		)
	Total derivatives	(26,355		)	(1,474		)	(11,250		)	(39,079		)	33,522			(5,557		)
	Fair value of firm commitments (d)	—			—			(144		)	(144		)	—			(144		)
	Total liabilities	$	(26,355	)	$	(1,474	)	$	(11,394	)	$	(39,223	)	$	33,522		$	(5,701	)
	(a) - Our derivative assets and liabilities are presented in our Consolidated Balance Sheets as energy marketing and risk-management assets and liabilities, other assets and other deferred credits on a net basis. We net derivative assets and liabilities, including cash collateral, when a legally enforceable master-netting arrangement exists between the counterparty to a derivative contract and us.  At September 30, 2013, we held $14.0 million of cash collateral and posted no cash collateral with various counterparties.
	(b) - Included in our Consolidated Balance Sheets as other current assets.
	(c) - Included in our Consolidated Balance Sheets as other assets.
	(d) - Included in our Consolidated Balance Sheets as other current liabilities.
		December 31, 2012
		Level 1			Level 2			Level 3			Total - Gross			Netting			Total - Net
		(Thousands of dollars)
	Assets
	Derivatives (a)
	Commodity contracts
	Financial contracts	$	69,957		$	10,780		$	7,107		$	87,844		$	(51,602	)	$	36,242
	Physical contracts	—			2,083			2,032			4,115			(151		)	3,964
	Interest-rate contracts	—			10,923			—			10,923			—			10,923
	Total derivatives	69,957			23,786			9,139			102,882			(51,753		)	51,129
	Trading securities (b)	5,978			—			—			5,978			—			5,978
	Available-for-sale investment securities (c)	2,027			—			—			2,027			—			2,027
	Total assets	$	77,962		$	23,786		$	9,139		$	110,887		$	(51,753	)	$	59,134
	Liabilities
	Derivatives (a)
	Commodity contracts
	Financial contracts	$	(35,172	)	$	(1,737	)	$	(7,177	)	$	(44,086	)	$	33,878		$	(10,208	)
	Physical contracts	—			—			(279		)	(279		)	151			(128		)
	Total derivatives	(35,172		)	(1,737		)	(7,456		)	(44,365		)	34,029			(10,336		)
	Fair value of firm commitments (d)	—			—			(1,280		)	(1,280		)	—			(1,280		)
	Total liabilities	$	(35,172	)	$	(1,737	)	$	(8,736	)	$	(45,645	)	$	34,029		$	(11,616	)
	(a) - Our derivative assets and liabilities are presented in our Consolidated Balance Sheets as energy marketing and risk-management assets and liabilities, other assets and other deferred credits on a net basis. We net derivative assets and liabilities, including cash collateral, when a legally enforceable master-netting arrangement exists between the counterparty to a derivative contract and us. At December 31, 2012, we held $17.7 million of cash collateral and posted $4.5 million of cash collateral with various counterparties.
	(b) - Included in our Consolidated Balance Sheets as other current assets.
	(c) - Included in our Consolidated Balance Sheets as other assets.
	(d) - Included in our Consolidated Balance Sheets as other current liabilities and other deferred credits.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	'
	The following tables set forth the reconciliation of our Level 3 fair value measurements for the periods indicated:
		Derivative			Fair Value of			Total
		Assets			Firm
		(Liabilities)			Commitments
		(Thousands of dollars)
	1-Jul-13	$	8,015		$	—		$	8,015
	Total realized/unrealized gains (losses):
	Included in earnings (a)	(215		)	(144		)	(359		)
	Included in other comprehensive income (loss)	(7,162		)	—			(7,162		)
	Transfers into Level 3	24			—			24
	September 30, 2013	$	662		$	(144	)	$	518
	Total gains (losses) for the period included in earnings attributable to the change in	$	367		$	(42	)	$	325
	unrealized gains (losses) relating to assets and liabilities still held at
	September 30, 2013 (a)
	(a) - Reported in revenues and cost of sales and fuel in our Consolidated Statements of Income.
		Derivative			Fair Value of			Total
		Assets			Firm
		(Liabilities)			Commitments
		(Thousands of dollars)
	1-Jul-12	$	37,745		$	(4,250	)	$	33,495
	Total realized/unrealized gains (losses):
	Included in earnings (a)	(4,366		)	2,083			(2,283		)
	Included in other comprehensive income (loss)	(20,295		)	—			(20,295		)
	Transfers into Level 3	385			—			385
	Transfers out of Level 3	685			—			685
	September 30, 2012	$	14,154		$	(2,167	)	$	11,987
	Total gains (losses) for the period included in earnings attributable to the change	$	51		$	205		$	256
	in unrealized gains (losses) relating to assets and liabilities still held at
	September 30, 2012 (a)
	(a) - Reported in revenues and cost of sales and fuel in our Consolidated Statements of Income.
		Derivative			Fair Value of			Total
		Assets			Firm
		(Liabilities)			Commitments
		(Thousands of dollars)
	1-Jan-13	$	1,683		$	(1,280	)	$	403
	Total realized/unrealized gains (losses):
	Included in earnings (a)	(4,343		)	1,136			(3,207		)
	Included in other comprehensive income (loss)	3,487			—			3,487
	Transfers out of Level 3	(165		)	—			(165		)
	30-Sep-13	$	662		$	(144	)	$	518
	Total gains (losses) for the period included in earnings attributable to the change in	$	(760	)	$	21		$	(739	)
	unrealized gains (losses) relating to assets and liabilities still held at
	September 30, 2013 (a)
	(a) - Reported in revenues and cost of sales and fuel in our Consolidated Statements of Income.
		Derivative			Fair Value of			Total
		Assets			Firm
		(Liabilities)			Commitments
		(Thousands of dollars)
	1-Jan-12	$	25,104		$	(7,283	)	$	17,821
	Total realized/unrealized gains (losses):
	Included in earnings (a)	(13,153		)	5,116			(8,037		)
	Included in other comprehensive income (loss)	6,384			—			6,384
	Sale of discontinued operations	(3,636		)	—			(3,636		)
	Transfers out of Level 3	(545		)	—			(545		)
	30-Sep-12	$	14,154		$	(2,167	)	$	11,987
	Total gains (losses) for the period included in earnings attributable to the change in	$	352		$	(296	)	$	56
	unrealized gains (losses) relating to assets and liabilities still held at
	September 30, 2012 (a)
	(a) - Reported in revenues and cost of sales and fuel in our Consolidated Statements of Income.

RISK_MANAGEMENT_AND_HEDGING_AC2

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Fair value of derivatives	'
	Fair Values of Derivative Instruments - The following table sets forth the fair values of our derivative instruments for our continuing and discontinued operations for the periods indicated:
		September 30, 2013									December 31, 2012
		Fair Values of Derivatives (a)									Fair Values of Derivatives (a)
		Assets					(Liabilities)				Assets					(Liabilities)
		(Thousands of dollars)
	Derivatives designated as hedging instruments
	Commodity contracts
	Financial contracts	$	33,216		(b)		$	(4,554	)		$	47,516		(c)		$	(4,885	)
	Physical contracts	351					(2,711		)		56					(126		)
	Interest-rate contracts	43,614					—				10,923					—
	Total derivatives designated as hedging instruments	77,181					(7,265		)		58,495					(5,011		)
	Derivatives not designated as hedging instruments
	Commodity contracts
	Nontrading instruments
	Financial contracts	12,260					(15,018		)		24,970					(25,009		)
	Physical contracts	3,976					(1,127		)		4,059					(153		)
	Trading instruments
	Financial contracts	15,986					(15,669		)		15,358					(14,192		)
	Total derivatives not designated as hedging instruments	32,222					(31,814		)		44,387					(39,354		)
	Total derivatives	$	109,403				$	(39,079	)		$	102,882				$	(44,365	)
	(a) - Included on a net basis in energy marketing and risk-management assets and liabilities, other assets and other deferred credits on our Consolidated Balance Sheets.
	(b) - Includes $8.0 million of derivative assets associated with cash flow hedges of inventory that were adjusted to reflect the lower of cost or market value. The deferred gains associated with these assets have been reclassified from accumulated other comprehensive income (loss).
	(c) - Includes $16.9 million of derivative net assets and ineffectiveness associated with cash flow hedges of inventory related to certain financial contracts that were used to hedge forecasted purchases and sales of natural gas. The deferred gains associated with these assets have been reclassified from accumulated other comprehensive income (loss).
Notional amounts of derivative instruments	'
	Notional Quantities for Derivative Instruments - The following table sets forth the notional quantities for derivative instruments held for periods indicated:
				September 30, 2013								December 31, 2012
		Contract		Purchased/				Sold/				Purchased/				Sold/
		Type		Payor				Receiver				Payor				Receiver
	Derivatives designated as hedging instruments:
	Cash flow hedges
	Fixed price
	- Natural gas (Bcf)	Futures, forwards and swaps		—				(72.4		)		—				(85.1		)
	- Crude oil and NGLs (MMbbl)	Futures, forwards and swaps		—				(2.3		)		—				(1.1		)
	Basis
	- Natural gas (Bcf)	Futures, forwards and swaps		—				(58.0		)		—				(56.3		)
	Interest-rate contracts (Millions of dollars)	Forward-starting		$	400			$	—			$	400			$	—
		swaps
	Fair value hedges
	Basis
	- Natural gas (Bcf)	Futures, forwards and swaps		5.8				(5.8		)		59.1				(59.1		)
	Derivatives not designated as hedging instruments:
	Fixed price
	- Natural gas (Bcf)	Futures, forwards and swaps		53				(53.1		)		60.7				(60.4		)
		Options		—				—				102.1				(100.8		)
	Basis
	- Natural gas (Bcf)	Futures, forwards and swaps		105.9				(105.7		)		80.2				(81.7		)
	Index
	- Natural gas (Bcf)	Futures, forwards and swaps		8.2				(4.8		)		20.3				(22.3		)
Schedule of cash flow hedging instruments effect on comprehensive income (loss)	'
	The following table sets forth the effects of cash flow hedges recognized in other comprehensive income (loss) for the periods indicated:
	Derivatives in Cash Flow	Three Months Ended								Nine Months Ended
	Hedging Relationships	September 30,								September 30,
		2013				2012				2013				2012
		(Thousands of dollars)
	Commodity contracts	$	(8,796	)		$	(41,452	)		$	11,718			$	39,461
	Interest-rate contracts	6,721				(1,175		)		35,726				(32,795		)
	Total unrealized gain (loss) recognized in other comprehensive	$	(2,075	)		$	(42,627	)		$	47,444			$	6,666
	income (loss) on derivatives (effective portion)
Schedule of cash flow hedging instruments effect on income	'
	The following table sets forth the effect of cash flow hedges in our Consolidated Statements of Income for the periods indicated:
	Derivatives in Cash Flow	Location of Gain (Loss) Reclassified from	Three Months Ended								Nine Months Ended
	Hedging Relationships	Accumulated Other Comprehensive Income	September 30,								September 30,
		(Loss) into Net Income (Effective Portion)	2013				2012				2013				2012
			(Thousands of dollars)
	Commodity contracts	Revenues	$	3,357			$	31,447			$	18,718			$	127,477
	Commodity contracts	Cost of sales and fuel	(117		)		(2,503		)		(14,320		)		(65,940		)
	Interest-rate contracts	Interest expense	(3,696		)		(1,828		)		(10,840		)		(3,908		)
	Total gain (loss) reclassified from accumulated other comprehensive income		$	(456	)		$	27,116			$	(6,442	)		$	57,629
	(loss) into net income on derivatives (effective portion)
Schedule of derivatives not designated as hedging effect on income	'
	Other Derivative Instruments - The following table sets forth the effect of our derivative instruments that are not part of a hedging relationship in our Consolidated Statements of Income for our continuing and discontinued operations for the periods indicated:
	Derivatives Not Designated as	Location of Gain (Loss)	Three Months Ended								Nine Months Ended
	Hedging Instruments		September 30,								September 30,
			2013				2012				2013				2012
			(Thousands of dollars)
	Commodity contracts - trading	Revenues	$	4			$	867			$	(2,054	)		$	1,673
	Commodity contracts - nontrading (a)	Cost of sales and fuel	(534		)	(b)	601				(2,959		)	(b)	4,924
	Total gain (loss) recognized in income on derivatives		$	(530	)		$	1,468			$	(5,013	)		$	6,597
	(a) - Amounts are presented net of deferred gains (losses) associated with derivatives entered into by our Natural Gas Distribution segment.
	(b) - Includes losses of $0.4 million and $2.2 million for the three and nine months ended September 30, 2013, respectively, on certain derivatives derecognized that were designated previously as fair value hedges of firm transportation commitments that no longer meet the definition of a firm commitment.

EQUITY_Tables

EQUITY (Tables)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Changes in equity, including other comprehensive income, net of tax	'
	The following table sets forth the changes in equity attributable to us and our noncontrolling interests, including other comprehensive income, net of tax, for the periods indicated:
		Three Months Ended									Three Months Ended
		30-Sep-13									30-Sep-12
		ONEOK			Noncontrolling			Total			ONEOK			Noncontrolling			Total
		Shareholders’			Interests in			Equity			Shareholders’			Interests in			Equity
		Equity			Consolidated						Equity			Consolidated
					Subsidiaries									Subsidiaries
		(Thousands of dollars)
	Beginning balance	$	2,085,349		$	2,089,007		$	4,174,356		$	2,089,540		$	2,116,448		$	4,205,988
	Net income	62,356			85,342			147,698			65,219			99,769			164,988
	Other comprehensive income	(7,522		)	(1,964		)	(9,486		)	(34,836		)	(22,208		)	(57,044		)
	(loss)
	Repurchase of common stock	—			—			—			—			—			—
	Common stock issued	4,142			—			4,142			3,838			—			3,838
	Common stock dividends	(78,367		)	—			(78,367		)	(67,671		)	—			(67,671		)
	Issuance of common units of	81,502			420,391			501,893			—			—			—
	ONEOK Partners
	Distributions to noncontrolling	—			(91,824		)	(91,824		)	—			(84,156		)	(84,156		)
	interests
	Other	42,234			—			42,234			9,616			—			9,616
	Ending balance	$	2,189,694		$	2,500,952		$	4,690,646		$	2,065,706		$	2,109,853		$	4,175,559
		Nine Months Ended									Nine Months Ended
		September 30, 2013									September 30, 2012
		ONEOK			Noncontrolling			Total			ONEOK			Noncontrolling			Total
		Shareholders’			Interests in			Equity			Shareholders’			Interests in			Equity
		Equity			Consolidated						Equity			Consolidated
					Subsidiaries									Subsidiaries
		(Thousands of dollars)
	Beginning balance	$	2,129,609		$	2,102,841		$	4,232,450		$	2,238,573		$	1,561,159		$	3,799,732
	Net income	175,796			217,102			392,898			249,077			298,578			547,655
	Other comprehensive income	(2,694		)	22,612			19,918			(34,355		)	(22,920		)	(57,275		)
	(loss)
	Repurchase of common stock	—			—			—			(150,000		)	—			(150,000		)
	Common stock issued	11,892			—			11,892			10,390			—			10,390
	Common stock dividends	(226,349		)	—			(226,349		)	(194,443		)	—			(194,443		)
	Issuance of common units of	84,458			431,743			516,201			(51,100		)	510,780			459,680
	ONEOK Partners
	Distributions to noncontrolling	—			(273,346		)	(273,346		)	—			(237,744		)	(237,744		)
	interests
	Other	16,982			—			16,982			(2,436		)	—			(2,436		)
	Ending balance	$	2,189,694		$	2,500,952		$	4,690,646		$	2,065,706		$	2,109,853		$	4,175,559

ACCUMULATED_OTHER_COMPREHENSIV1

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables)	9 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
Accumulated other comprehensive income (loss)	'
	The following table sets forth the balance in accumulated other comprehensive income (loss) for the period indicated:
		Unrealized Gains				Unrealized				Pension and			Accumulated
		(Losses) on Energy				Holding Gains				Postretirement			Other
		Marketing and				(Losses)				Benefit Plan			Comprehensive
		Risk-Management				on Investment				Obligations (a)			Income (Loss) (a)
		Assets/Liabilities (a)				Securities (a)
		(Thousands of dollars)
	1-Jan-13	$	(55,030	)		$	1,034			$	(162,802	)	$	(216,798	)
	Other comprehensive income (loss) before	16,406				(234		)		(56,164		)	(39,992		)
	reclassifications
	Amounts reclassified from accumulated other	2,771				—				34,527			37,298
	comprehensive income (loss)
	Other comprehensive income	19,177				(234		)		(21,637		)	(2,694		)
	(loss) attributable to ONEOK
	September 30, 2013	$	(35,853	)		$	800			$	(184,439	)	$	(219,492	)
	(a) All amounts are presented net of tax.
Statement [Line Items]	'
Disclosure of Reclassification Amount [Text Block]	'
	The following table sets forth the effect of reclassifications from accumulated other comprehensive income (loss) on our Consolidated Statements of Income for the periods indicated:
		Details about Accumulated Other		Three Months Ended				Nine Months Ended				Affected Line Item
		Comprehensive Income (Loss) Components		30-Sep-13				30-Sep-13				in the Consolidated
												Statements of Income
				(Thousand of dollars)
		Unrealized (gains) losses on energy marketing and risk-management assets/liabilities
		Commodity contracts		$	(3,357	)		$	(18,718	)		Revenues
		Commodity contracts		117				14,320				Cost of sales and fuel
		Interest-rate contracts		3,696				10,840				Interest expense
				456				6,442				Income before income taxes
				333				(1,748		)		Income tax expense
				789				4,694				Net income
		Noncontrolling interest		1,317				1,923				Less: Net income attributable to
												noncontrolling interest
				$	(528	)		$	2,771			Net income attributable to ONEOK
		Pension and postretirement benefit plan
		obligations (a)
		Amortization of net loss		$	19,729			$	59,183
		Amortization of unrecognized prior service		(1,438		)		(4,314		)
		cost
		Amortization of unrecognized net asset at		71				213
		adoption
		Settlement charge		275				1,225
				18,637				56,307				Income before income taxes
				(7,210		)		(21,780		)		Income tax expense
				$	11,427			$	34,527			Net income attributable to ONEOK
		Total reclassifications for the period		$	10,899			$	37,298			Net income attributable to ONEOK
		attributable to ONEOK
	(a) These components of accumulated other comprehensive income (loss) are included in the computation of net periodic benefit cost. See Note K for additional detail of our net periodic benefit cost.

EARNINGS_PER_SHARE_Tables

EARNINGS PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	The following tables set forth the computation of basic and diluted EPS from continuing operations for the periods indicated:
		Three Months Ended September 30, 2013
		Income		Shares	Per Share
					Amount
		(Thousands, except per share amounts)
	Basic EPS from continuing operations
	Income from continuing operations attributable to ONEOK available for common	$	62,356	206,235	$	0.3
	stock
	Diluted EPS from continuing operations
	Effect of dilutive securities	—		3,658
	Income from continuing operations attributable to ONEOK available for common	$	62,356	209,893	$	0.3
	stock and common stock equivalents
		Three Months Ended September 30, 2012
		Income		Shares	Per Share
					Amount
		(Thousands, except per share amounts)
	Basic EPS from continuing operations
	Income from continuing operations attributable to ONEOK available for common	$	65,219	205,005	$	0.32
	stock
	Diluted EPS from continuing operations
	Effect of dilutive securities	—		4,955
	Income from continuing operations attributable to ONEOK available for common	$	65,219	209,960	$	0.31
	stock and common stock equivalents
		Nine Months Ended September 30, 2013
		Income		Shares	Per Share
					Amount
		(Thousands, except per share amounts)
	Basic EPS from continuing operations
	Income from continuing operations attributable to ONEOK available for common	$	175,796	205,952	$	0.85
	stock
	Diluted EPS from continuing operations
	Effect of dilutive securities	—		3,456
	Income from continuing operations attributable to ONEOK available for common	$	175,796	209,408	$	0.84
	stock and common stock equivalents
		Nine Months Ended September 30, 2012
		Income		Shares	Per Share
					Amount
		(Thousands, except per share amounts)
	Basic EPS from continuing operations
	Income from continuing operations attributable to ONEOK available for common	$	234,798	206,638	$	1.14
	stock
	Diluted EPS from continuing operations
	Effect of dilutive securities	—		4,560
	Income from continuing operations attributable to ONEOK available for common	$	234,798	211,198	$	1.11
	stock and common stock equivalents

EMPLOYEE_BENEFIT_PLANS_Tables

EMPLOYEE BENEFIT PLANS (Tables)	9 Months Ended
	Sep. 30, 2013
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]	'
The components of net periodic benefit cost	'
	The following tables set forth the components of net periodic benefit cost for our pension and postretirement benefit plans for the periods indicated:
		Pension Benefits						Pension Benefits
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
		(Thousands of dollars)
	Components of net periodic benefit cost
	Service cost	$	5,735		$	5,325		$	17,207		$	15,975
	Interest cost	13,612			14,809			40,836			44,427
	Expected return on assets	(20,318		)	(20,689		)	(60,954		)	(62,067		)
	Amortization of unrecognized prior service cost	230			242			690			726
	Amortization of net loss	16,572			12,111			49,712			36,333
	Settlement charge	275			—			1,225			—
	Net periodic benefit cost	$	16,106		$	11,798		$	48,716		$	35,394
		Postretirement Benefits						Postretirement Benefits
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
		(Thousands of dollars)
	Components of net periodic benefit cost
	Service cost	$	1,145		$	1,239		$	3,435		$	3,716
	Interest cost	2,910			3,473			8,732			10,419
	Expected return on assets	(3,065		)	(2,671		)	(9,195		)	(8,013		)
	Amortization of unrecognized net asset at adoption	71			718			213			2,154
	Amortization of unrecognized prior service cost	(1,668		)	(2,063		)	(5,004		)	(6,189		)
	Amortization of net loss	3,157			3,296			9,471			9,888
	Net periodic benefit cost	$	2,550		$	3,992		$	7,652		$	11,975

UNCONSOLIDATED_AFFILIATES_Tabl

UNCONSOLIDATED AFFILIATES (Tables)	9 Months Ended
	Sep. 30, 2013
Equity Method Investments and Joint Ventures [Abstract]	'
Equity Earnings from Investments	'
	Equity Earnings from Investments - The following table sets forth our equity earnings from investments for the periods indicated.  All amounts in the table below are equity earnings from investments in our ONEOK Partners segment:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
		(Thousands of dollars)
	Northern Border Pipeline	$	16,464	$	18,185	$	48,133	$	54,493
	Overland Pass Pipeline Company	5,783		4,490		14,210		15,786
	Fort Union Gas Gathering	2,946		4,091		9,895		11,494
	Bighorn Gas Gathering	559		1,157		1,897		3,118
	Other	1,716		668		5,609		7,489
	Equity earnings from investments	$	27,468	$	28,591	$	79,744	$	92,380
Unconsolidated Affiliates Financial Information [Table Text Block]	'
	Unconsolidated Affiliates Financial Information - The following table sets forth summarized combined financial information of our unconsolidated affiliates for the periods indicated:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
		(Thousands of dollars)
	Income Statement
	Operating revenues	$	131,959	$	125,828	$	391,912	$	373,038
	Operating expenses	$	63,971	$	60,937	$	189,366	$	173,232
	Net income	$	61,630	$	55,721	$	185,580	$	180,787
	Distributions paid to ONEOK Partners	$	34,409	$	34,557	$	103,913	$	118,752

ONEOK_PARTNERS_Tables

ONEOK PARTNERS (Tables)	9 Months Ended
	Sep. 30, 2013
Related Party Transactions [Abstract]	'
Ownership interest in ONEOK Partners	'
	Ownership Interest in ONEOK Partners - Our ownership interest in ONEOK Partners is shown in the table below at September 30, 2013:
	General partner interest	2	%
	Limited partner interest (a)	39.3	%
	Total ownership interest	41.3	%
	(a) - Represents 19.8 million common units and approximately 73.0 million Class B units, which are convertible, at our option, into common units.
ONEOK Partners' Distributions Paid	'
	The following table shows ONEOK Partners’ distributions paid in the periods indicated:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
		(Thousands, except per unit amounts)
	Distribution per unit	$	0.72	$	0.66	$	2.145	$	1.905
	General partner distributions	$	4,512	$	3,979	$	13,399	$	11,019
	Incentive distributions	62,634		49,886		184,647		130,968
	Distributions to general partner	67,146		53,865		198,046		141,987
	Limited partner distributions to ONEOK	66,807		61,240		199,031		171,882
	Limited partner distributions to noncontrolling interest	91,676		83,838		272,904		237,109
	Total distributions paid	$	225,629	$	198,943	$	669,981	$	550,978
ONEOK Partners' Distributions Declared	'
	The following table shows ONEOK Partners’ distributions declared for the periods indicated and paid within 45 days of the end of the period:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
		(Thousands, except per unit amounts)
	Distribution per unit	$	0.725	$	0.685	$	2.16	$	1.98
	General partner distributions	$	4,795	$	4,199	$	13,776	$	11,937
	Incentive distributions	67,017		55,162		191,226		149,658
	Distributions to general partner	71,812		59,361		205,002		161,595
	Limited partner distributions to ONEOK	67,271		63,560		200,422		183,721
	Limited partner distributions to noncontrolling interest	100,650		87,014		283,365		251,514
	Total distributions declared	$	239,733	$	209,935	$	688,789	$	596,830
ONEOK Partners' transactions	'
	The following table shows ONEOK Partners’ transactions with us for the periods indicated:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
		(Thousands of dollars)
	Revenues	$	81,324	$	91,096	$	255,298	$	247,851
	Expenses
	Cost of sales and fuel	$	9,562	$	7,831	$	27,855	$	22,875
	Administrative and general expenses	58,549		60,020		192,906		179,017
	Total expenses	$	68,111	$	67,851	$	220,761	$	201,892

SEGMENTS_Tables

SEGMENTS (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segments	'
	Operating Segment Information - The following tables set forth certain selected financial information for our operating segments for the periods indicated:
	Three Months Ended	ONEOK			Natural Gas		Energy			Other and			Total
	30-Sep-13	Partners (a)			Distribution		Services			Eliminations
		(Thousands of dollars)
	Sales to unaffiliated customers	$	3,053,409		$	219,724	$	298,146		$	646		$	3,571,925
	Intersegment revenues	81,324			1		34,050			(115,375		)	—
	Total revenues	$	3,134,733		$	219,725	$	332,196		$	(114,729	)	$	3,571,925
	Net margin	$	423,574		$	159,233	$	(22,265	)	$	646		$	561,188
	Operating costs	122,362			109,304		2,369			2,827			236,862
	Depreciation and amortization	61,182			32,347		69			669			94,267
	Gain on sale of assets	22			—		—			—			22
	Operating income (loss)	$	240,052		$	17,582	$	(24,703	)	$	(2,850	)	$	230,081
	Equity earnings from investments	$	27,468		$	—	$	—		$	—		$	27,468
	Capital expenditures	$	449,072		$	83,783	$	—		$	4,632		$	537,487
	(a) - Our ONEOK Partners segment has regulated and nonregulated operations.  Our ONEOK Partners segment’s regulated operations had revenues of $204.6 million, net margin of $142.3 million and operating income of $76.0 million.
	Three Months Ended	ONEOK			Natural Gas		Energy			Other and			Total
	30-Sep-12	Partners (a)			Distribution		Services			Eliminations
		(Thousands of dollars)
	Sales to unaffiliated customers	$	2,456,364		$	204,930	$	366,955		$	526		$	3,028,775
	Intersegment revenues	91,096			2		(3,116		)	(87,982		)	—
	Total revenues	$	2,547,460		$	204,932	$	363,839		$	(87,456	)	$	3,028,775
	Net margin	$	419,737		$	150,987	$	(17,275	)	$	523		$	553,972
	Operating costs	121,176			103,373		4,424			232			229,205
	Depreciation and amortization	49,754			31,962		78			(360		)	81,434
	Gain on sale of assets	(420		)	—		—			—			(420		)
	Operating income (loss)	$	248,387		$	15,652	$	(21,777	)	$	651		$	242,913
	Equity earnings from investments	$	28,591		$	—	$	—		$	—		$	28,591
	Capital expenditures	$	375,291		$	74,287	$	—		$	8,633		$	458,211
	(a) - Our ONEOK Partners segment has regulated and nonregulated operations.  Our ONEOK Partners segment’s regulated operations had revenues of $181.6 million, net margin of $122.9 million and operating income of $63.6 million.
	Nine Months Ended	ONEOK			Natural Gas		Energy			Other and			Total
	30-Sep-13	Partners (a)			Distribution		Services			Eliminations
		(Thousands of dollars)
	Sales to unaffiliated customers	$	8,165,061		$	1,167,261	$	1,128,325		$	1,959		$	10,462,606
	Intersegment revenues	255,298			5		162,376			(417,679		)	—
	Total revenues	$	8,420,359		$	1,167,266	$	1,290,701		$	(415,720	)	$	10,462,606
	Net margin	$	1,206,126		$	589,354	$	(159,406	)	$	1,955		$	1,638,029
	Operating costs	384,602			330,465		10,930			3,918			729,915
	Depreciation and amortization	174,086			100,118		209			1,930			276,343
	Gain on sale of assets	342			—		—			—			342
	Operating income (loss)	$	647,780		$	158,771	$	(170,545	)	$	(3,893	)	$	632,113
	Equity earnings from investments	$	79,744		$	—	$	—		$	—		$	79,744
	Investments in unconsolidated affiliates	$	1,201,873		$	—	$	—		$	—		$	1,201,873
	Total assets	$	12,863,326		$	3,597,730	$	362,438		$	786,849		$	17,610,343
	Noncontrolling interests in consolidated subsidiaries	$	4,588		$	—	$	—		$	2,496,364		$	2,500,952
	Capital expenditures	$	1,373,904		$	206,372	$	—		$	17,544		$	1,597,820
	(a) - Our ONEOK Partners segment has regulated and nonregulated operations.  Our ONEOK Partners segment’s regulated operations had revenues of $558.9 million, net margin of $390.3 million and operating income of $196.0 million.
	Nine Months Ended	ONEOK			Natural Gas		Energy			Other and			Total
	30-Sep-12	Partners (a)			Distribution		Services			Eliminations
		(Thousands of dollars)
	Sales to unaffiliated customers	$	7,018,503		$	943,034	$	1,009,550		$	1,548		$	8,972,635
	Intersegment revenues	247,851			845		84,022			(332,718		)	—
	Total revenues	$	7,266,354		$	943,879	$	1,093,572		$	(331,170	)	$	8,972,635
	Net margin	$	1,242,289		$	545,823	$	(43,133	)	$	1,542		$	1,746,521
	Operating costs	360,410			312,133		13,889			(1,906		)	684,526
	Depreciation and amortization	150,024			97,481		284			1,640			249,429
	Goodwill impairment	—			—		10,255			—			10,255
	Gain on sale of assets	603			—		—			—			603
	Operating income (loss)	$	732,458		$	136,209	$	(67,561	)	$	1,808		$	802,914
	Equity earnings from investments	$	92,380		$	—	$	—		$	—		$	92,380
	Investments in unconsolidated affiliates	$	1,218,282		$	—	$	—		$	—		$	1,218,282
	Total assets	$	10,792,593		$	3,258,320	$	450,899		$	862,495		$	15,364,307
	Noncontrolling interests in consolidated subsidiaries	$	4,812		$	—	$	—		$	2,105,041		$	2,109,853
	Capital expenditures	$	1,011,527		$	205,652	$	—		$	21,729		$	1,238,908
(a) - Our ONEOK Partners segment has regulated and nonregulated operations.  Our ONEOK Partners segment’s regulated operations had revenues of $513.0 million, net margin of $359.7 million and operating income of $182.3 million.

EXIT_ACTIVITIES_Details

EXIT ACTIVITIES (Details) (USD $)	3 Months Ended	6 Months Ended	9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Sep. 30, 2013	Sep. 30, 2012
			MMcf
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Assigned storage capacity	'	'	18,000	'
Restructuring and Related Cost, Cost Incurred to Date	$16,400,000	$113,800,000	$130,200,000	'
Settlements	-6,200,000	'	'	'
Restructuring and Related Cost, Expected Cost	'	'	12,000,000	'
Effect on Future Cash Flows, Amount	'	'	89,000,000	'
Accretion	600,000	'	'	'
Ending balance	'	'	124,610,000	0
2013 [Member]	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Effect on Future Cash Flows, Amount	'	'	8,000,000	'
2014 [Member]	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Effect on Future Cash Flows, Amount	'	'	33,000,000	'
2015 [Member]	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Effect on Future Cash Flows, Amount	'	'	24,000,000	'
2016 - 2023 [Member]	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Effect on Future Cash Flows, Amount	'	'	$24,000,000	'

DISCONTINUED_OPERATIONS_Detail

DISCONTINUED OPERATIONS (Details) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jan. 31, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'	'	'
Gain on sale of business, tax impact	'	'	'	'	'	$8,300,000
Description and timing of discontinued operations	'	'	'	'	'	'On February 1, 2012, we sold ONEOK Energy Marketing Company, our retail natural gas marketing business, to Constellation Energy Group, Inc. for $22.5 million plus working capital.
Proceeds from sale of business	'	'	'	'	'	32,900,000
Discontinued Operation, Gain on Disposal of Discontinued Operation, Net of Tax	'	0	0	0	13,517,000	13,500,000
Revenues	27,600,000	'	'	'	'	'
Operating income	$1,200,000	'	'	'	'	'

FAIR_VALUE_MEASUREMENTS_Part_1

FAIR VALUE MEASUREMENTS - Part 1 (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Other	'	'
Cash collateral held	$14,000,000	$17,700,000
Cash collateral posted	0	4,500,000
Fair Value, Measurements, Recurring [Member]	'	'
Derivatives	'	'
Commodity contracts - financial	14,524,000	36,242,000
Commodity contracts - physical	3,786,000	3,964,000
Interest-rate contracts	43,614,000	10,923,000
Total derivatives assets	61,924,000	51,129,000
Other	'	'
Trading securities	10,193,000	5,978,000
Available-for-sale investment securities	1,478,000	2,027,000
Total assets	73,595,000	59,134,000
Derivatives	'	'
Commodity contracts - financial	-2,260,000	-10,208,000
Commodity contracts - physical	-3,297,000	-128,000
Total derivative liabilities	-5,557,000	-10,336,000
Other	'	'
Fair value of firm commitments	-144,000	-1,280,000
Total liabilities	-5,701,000	-11,616,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Derivatives	'	'
Commodity contracts - financial	50,965,000	69,957,000
Commodity contracts - physical	0	0
Interest-rate contracts	0	0
Total derivatives assets	50,965,000	69,957,000
Other	'	'
Trading securities	10,193,000	5,978,000
Available-for-sale investment securities	1,478,000	2,027,000
Total assets	62,636,000	77,962,000
Derivatives	'	'
Commodity contracts - financial	-26,355,000	-35,172,000
Commodity contracts - physical	0	0
Total derivative liabilities	-26,355,000	-35,172,000
Other	'	'
Fair value of firm commitments	0	0
Total liabilities	-26,355,000	-35,172,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Derivatives	'	'
Commodity contracts - financial	1,790,000	10,780,000
Commodity contracts - physical	1,122,000	2,083,000
Interest-rate contracts	43,614,000	10,923,000
Total derivatives assets	46,526,000	23,786,000
Other	'	'
Trading securities	0	0
Available-for-sale investment securities	0	0
Total assets	46,526,000	23,786,000
Derivatives	'	'
Commodity contracts - financial	-1,207,000	-1,737,000
Commodity contracts - physical	-267,000	0
Total derivative liabilities	-1,474,000	-1,737,000
Other	'	'
Fair value of firm commitments	0	0
Total liabilities	-1,474,000	-1,737,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Derivatives	'	'
Commodity contracts - financial	8,707,000	7,107,000
Commodity contracts - physical	3,205,000	2,032,000
Interest-rate contracts	0	0
Total derivatives assets	11,912,000	9,139,000
Other	'	'
Trading securities	0	0
Available-for-sale investment securities	0	0
Total assets	11,912,000	9,139,000
Derivatives	'	'
Commodity contracts - financial	-7,679,000	-7,177,000
Commodity contracts - physical	-3,571,000	-279,000
Total derivative liabilities	-11,250,000	-7,456,000
Other	'	'
Fair value of firm commitments	-144,000	-1,280,000
Total liabilities	-11,394,000	-8,736,000
Fair Value, Measurements, Recurring [Member] | Total Gross, Fair Value Disclosure [Member]	'	'
Derivatives	'	'
Commodity contracts - financial	61,462,000	87,844,000
Commodity contracts - physical	4,327,000	4,115,000
Interest-rate contracts	43,614,000	10,923,000
Total derivatives assets	109,403,000	102,882,000
Other	'	'
Trading securities	10,193,000	5,978,000
Available-for-sale investment securities	1,478,000	2,027,000
Total assets	121,074,000	110,887,000
Derivatives	'	'
Commodity contracts - financial	-35,241,000	-44,086,000
Commodity contracts - physical	-3,838,000	-279,000
Total derivative liabilities	-39,079,000	-44,365,000
Other	'	'
Fair value of firm commitments	-144,000	-1,280,000
Total liabilities	-39,223,000	-45,645,000
Fair Value, Measurements, Recurring [Member] | Netting and Collateral [Member]	'	'
Derivatives	'	'
Commodity contracts - financial	-46,938,000	-51,602,000
Commodity contracts - physical	-541,000	-151,000
Interest-rate contracts	0	0
Total derivatives assets	-47,479,000	-51,753,000
Other	'	'
Trading securities	0	0
Available-for-sale investment securities	0	0
Total assets	-47,479,000	-51,753,000
Derivatives	'	'
Commodity contracts - financial	32,981,000	33,878,000
Commodity contracts - physical	541,000	151,000
Total derivative liabilities	33,522,000	34,029,000
Other	'	'
Fair value of firm commitments	0	0
Total liabilities	$33,522,000	$34,029,000

FAIR_VALUE_MEASUREMENTS_Fair_V

FAIR VALUE MEASUREMENTS, Fair Value Measurements - Part 2 (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation Calculation [Roll Forward]	'	'	'	'
Balance, beginning	$8,015	$33,495	$403	$17,821
Total realized/unrealized gains (losses):	'	'	'	'
Included in earnings	-359	-2,283	-3,207	-8,037
Included in other comprehensive income (loss)	-7,162	-20,295	3,487	6,384
Sale of discontinued operations	'	'	'	-3,636
Transfers into Level 3	24	385	'	'
Transfers out of Level 3	'	685	-165	-545
Balance, ending	518	11,987	518	11,987
Total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets and liabilities still held as of September 30	325	256	-739	56
Derivative Financial Instruments, Assets Liabilities [Member]	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation Calculation [Roll Forward]	'	'	'	'
Balance, beginning	8,015	37,745	1,683	25,104
Total realized/unrealized gains (losses):	'	'	'	'
Included in earnings	-215	-4,366	-4,343	-13,153
Included in other comprehensive income (loss)	-7,162	-20,295	3,487	6,384
Sale of discontinued operations	'	'	'	-3,636
Transfers into Level 3	24	385	'	'
Transfers out of Level 3	'	685	-165	-545
Balance, ending	662	14,154	662	14,154
Total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets and liabilities still held as of September 30	367	51	-760	352
Firm Commitments [Member]	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation Calculation [Roll Forward]	'	'	'	'
Balance, beginning	0	-4,250	-1,280	-7,283
Total realized/unrealized gains (losses):	'	'	'	'
Included in earnings	-144	2,083	1,136	5,116
Included in other comprehensive income (loss)	0	0	0	0
Sale of discontinued operations	'	'	'	0
Transfers into Level 3	0	0	'	'
Transfers out of Level 3	'	0	0	0
Balance, ending	-144	-2,167	-144	-2,167
Total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets and liabilities still held as of September 30	-42	205	21	-296
Fair Value, Inputs, Level 1 [Member]	'	'	'	'
Fair Value, Assets And Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'	'
Transfers into or out of Level 1	$0	$0	$0	$0

FAIR_VALUE_MEASUREMENTS_Fair_V1

FAIR VALUE MEASUREMENTS, Fair Value - Part 3 (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Billions, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term Debt, Fair Value	$8.10	$7.50
Long-term Debt, Book Value	$7.80	$6.50

RISK_MANAGEMENT_AND_HEDGING_AC3

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES Part 1 (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Derivatives, Fair Value [Line Items]	'	'
Inventory cash flow hedges derivative assets	$8,000,000	$16,900,000
Assets	109,403,000	102,882,000
(Liabilities)	-39,079,000	-44,365,000
Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Assets	77,181,000	58,495,000
(Liabilities)	-7,265,000	-5,011,000
Not Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Assets	32,222,000	44,387,000
(Liabilities)	-31,814,000	-39,354,000
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Assets	43,614,000	10,923,000
(Liabilities)	0	0
Financial Derivative Instrument [Member] | Commodity Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Assets	33,216,000	47,516,000
(Liabilities)	-4,554,000	-4,885,000
Physical Derivative Instrument [Member] | Commodity Contract [Member] | Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Assets	351,000	56,000
(Liabilities)	-2,711,000	-126,000
Non Trading [Member] | Financial Derivative Instrument [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Assets	12,260,000	24,970,000
(Liabilities)	-15,018,000	-25,009,000
Non Trading [Member] | Physical Derivative Instrument [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Assets	3,976,000	4,059,000
(Liabilities)	-1,127,000	-153,000
Trading [Member] | Financial Derivative Instrument [Member] | Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Assets	15,986,000	15,358,000
(Liabilities)	-15,669,000	-14,192,000
ONEOK Partners [Member] | Cash Flow Hedging [Member] | Forward Starting Interest Rate Swap [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional Amount Of Cash Flow Hedge Instruments Greater Than 12 Months	$400,000,000	$400,000,000

RISK_MANAGEMENT_AND_HEDGING_AC4

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES Part 2 (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	MMcf	MMcf
Not Designated as Hedging Instrument [Member] | Fixed Price [Member] | Sold [Member] | Natural Gas [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	53,100	60,400
Not Designated as Hedging Instrument [Member] | Fixed Price [Member] | Sold [Member] | Natural Gas [Member] | Options [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	0	100,800
Not Designated as Hedging Instrument [Member] | Fixed Price [Member] | Purchased [Member] | Natural Gas [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	53,000	60,700
Not Designated as Hedging Instrument [Member] | Fixed Price [Member] | Purchased [Member] | Natural Gas [Member] | Options [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	0	102,100
Not Designated as Hedging Instrument [Member] | Basis [Member] | Sold [Member] | Natural Gas [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	105,700	81,700
Not Designated as Hedging Instrument [Member] | Basis [Member] | Purchased [Member] | Natural Gas [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	105,900	80,200
Not Designated as Hedging Instrument [Member] | Index [Member] | Sold [Member] | Natural Gas [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	4,800	22,300
Not Designated as Hedging Instrument [Member] | Index [Member] | Purchased [Member] | Natural Gas [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	8,200	20,300
Cash Flow Hedging [Member] | Fixed Price [Member] | Sold [Member] | Natural Gas [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	72,400	85,100
Cash Flow Hedging [Member] | Fixed Price [Member] | Sold [Member] | Crude oil and NGLs [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	2.3	1.1
Cash Flow Hedging [Member] | Fixed Price [Member] | Purchased [Member] | Natural Gas [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	0	0
Cash Flow Hedging [Member] | Fixed Price [Member] | Purchased [Member] | Crude oil and NGLs [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	0	0
Cash Flow Hedging [Member] | Basis [Member] | Sold [Member] | Natural Gas [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	58,000	56,300
Cash Flow Hedging [Member] | Basis [Member] | Purchased [Member] | Natural Gas [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	0	0
Cash Flow Hedging [Member] | Interest Rate Contract [Member] | Sold [Member] | Forward-Starting Swaps [Member]	'	'
Derivative [Line Items]	'	'
Notional amount of cash flow hedge instruments	0	0
Cash Flow Hedging [Member] | Interest Rate Contract [Member] | Purchased [Member] | Forward-Starting Swaps [Member]	'	'
Derivative [Line Items]	'	'
Notional amount of cash flow hedge instruments	400	400
Fair Value Hedging [Member] | Basis [Member] | Sold [Member] | Natural Gas [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	5,800	59,100
Fair Value Hedging [Member] | Basis [Member] | Purchased [Member] | Natural Gas [Member] | Futures, Forward and Swaps Contracts [Member]	'	'
Derivative [Line Items]	'	'
Derivative nonmonetary notional amount	5,800	59,100

RISK_MANAGEMENT_AND_HEDGING_AC5

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES Part 3 (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'
Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion)	'	'	$16,406,000	'	'
Natural gas cash flow hedge losses	'	'	0	29,861,000	'
Not Designated as Hedging Instrument [Member]	'	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'
Fair value of natural gas call options held	4,800,000	'	4,800,000	'	1,800,000
Gains (losses) associated with the change in value of natural gas contracts held deferred in other current assets	2,300,000	-2,800,000	7,400,000	-3,800,000	'
Total gain (loss) recognized in income on derivatives	-530,000	1,468,000	-5,013,000	6,597,000	'
Cash Flow Hedging [Member]	'	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'
Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net	'	0	'	0	'
Total gain (loss) reclassified from accumulated other comprehensive income (loss) into net income on derivatives (effective portion)	-456,000	27,116,000	-6,442,000	57,629,000	'
Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion)	-2,075,000	-42,627,000	47,444,000	6,666,000	'
Cash Flow Hedge Gain Reclassified to Earnings	'	'	8,000,000	'	'
Cost of Sales and Fuel [Member]	'	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'
Adjustment to natural gas inventory at the lower of cost or market value reflected in cost of sales and fuel	'	'	10,100,000	'	'
Commodity Contract [Member] | Cash Flow Hedging [Member]	'	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'
Net unrealized gain in accumulated other comprehensive income (loss)	5,600,000	'	5,600,000	'	'
Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion)	-8,796,000	-41,452,000	11,718,000	39,461,000	'
Amount of gain (loss) to be recognized in the next 12 months	3,600,000	'	3,600,000	'	'
Amount of gain (loss) to be recognized after the next 12 months	2,000,000	'	2,000,000	'	'
Natural gas cash flow hedge losses	'	'	'	29,900,000	'
Commodity Contract [Member] | Revenues [Member] | Cash Flow Hedging [Member]	'	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'
Total gain (loss) reclassified from accumulated other comprehensive income (loss) into net income on derivatives (effective portion)	3,357,000	31,447,000	18,718,000	127,477,000	'
Commodity Contract [Member] | Cost of Sales and Fuel [Member] | Cash Flow Hedging [Member]	'	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'
Total gain (loss) reclassified from accumulated other comprehensive income (loss) into net income on derivatives (effective portion)	-117,000	-2,503,000	-14,320,000	-65,940,000	'
Interest Rate Contract [Member] | Cash Flow Hedging [Member]	'	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'
Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion)	6,721,000	-1,175,000	35,726,000	-32,795,000	'
Amount of accumulated other comprehensive income (loss) attributable primarily to settled interest-rate swaps.	50,900,000	'	50,900,000	'	'
Amount of loss to be recognized in the next 12 months	-5,300,000	'	-5,300,000	'	'
Interest Rate Contract [Member] | Interest Expense [Member] | Cash Flow Hedging [Member]	'	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'
Total gain (loss) reclassified from accumulated other comprehensive income (loss) into net income on derivatives (effective portion)	-3,696,000	-1,828,000	-10,840,000	-3,908,000	'
Trading [Member] | Commodity Contract [Member] | Revenues [Member] | Not Designated as Hedging Instrument [Member]	'	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'
Total gain (loss) recognized in income on derivatives	4,000	867,000	-2,054,000	1,673,000	'
Non Trading [Member] | Commodity Contract [Member] | Cost of Sales and Fuel [Member] | Not Designated as Hedging Instrument [Member]	'	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'
Losses on certain derivatives derecognized that were previously designated as fair values hedges of firm transportation commitments	-400,000	'	-2,200,000	'	'
Total gain (loss) recognized in income on derivatives	($534,000)	$601,000	($2,959,000)	$4,924,000	'

RISK_MANAGEMENT_AND_HEDGING_AC6

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES Part 4 (Details) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Derivative Credit Exposure [Line Items]	'
Derivative, Net Liability Position, Aggregate Fair Value	$2.50

CREDIT_FACILITIES_AND_SHORTTER1

CREDIT FACILITIES AND SHORT-TERM NOTES PAYABLE (Details) (USD $)	9 Months Ended
	Sep. 30, 2013
ONEOK Credit Agreement [Member]	'
Line of Credit Facility [Line Items]	'
Maximum debt-to-capital ratio (in hundredths)	67.50%
Current debt-to-capital ratio (in hundredths)	48.20%
Line Of Credit Facility Option To Increase Borrowing Capacity	$1,700,000,000
Commercial paper	515,300,000
Letters of credit issued	1,900,000
Remaining available borrowing capacity to meet liquidity needs	682,800,000
Interest rate description	'borrowings, if any, will accrue at LIBOR plus 117.5 basis points
Annual fee descripton	'the annual facility fee is 20 basis points
Expiration date	28-Mar-18
Maximum borrowing capacity	1,200,000,000
ONEOK Partners Credit Agreement [Member]	'
Line of Credit Facility [Line Items]	'
Line Of Credit Facility Option To Increase Borrowing Capacity	1,700,000,000
Commercial paper	47,000,000
Letters of credit issued	0
Interest rate description	'borrowings, if any, will accrue at LIBOR plus 130 basis points
Annual fee descripton	'the annual facility fee is 20 basis points
Indebtedness To Adjusted EBITDA Maximum	5
Acquisition price threshold for increase in permitted debt to EBITDA covenant ratio	25,000,000
Indebtedness To Adjusted EBITDA From Acquisitions Maximum	5.5
Indebtedness To Adjusted EBITDA Current	4.2
Partnership Credit Agreement sublimit for issuance of standby letters of credit	100,000,000
Maximum borrowing capacity	1,200,000,000
Short-term Bank Loans and Notes Payable	$0

LONGTERM_DEBT_Details

LONG-TERM DEBT (Details) (USD $)	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
	ONEOK Partners [Member]	ONEOK Partners [Member]	ONEOK Partners [Member]	ONEOK Partners [Member]	ONEOK Partners [Member]	Senior Notes [Member]	Senior Notes [Member]	ONEOK Partners [Member]
	Note Payable from Public Offering Due 2018 [Member]	Note Payable from Public Offering Due 2023 [Member]	Note Payable from Public Offering Due 2043 [Member]	Note Payable from Public Offering Due 2017 [Member]	Note Payable from Public Offering Due 2022 [Member]	ONEOK Partners [Member]	ONEOK Partners [Member]	Notes Payables due 2012 [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'
Debt Instrument, Covenant Description	'	'	'	'	'	'These notes are governed by an indenture, dated as of September 25, 2006, between ONEOK Partners and Wells Fargo Bank, N.A., the trustee, as supplemented.B B The indenture does not limit the aggregate principal amount of debt securities that may be issued and provides that debt securities may be issued from time to time in one or more additional series.B B The indenture contains covenants including, among other provisions, limitations on ONEOK Partnersb ability to place liens on its property or assets and to sell and lease back its property.B B The indenture includes an event of default upon acceleration of other indebtedness of $100 million or more.B B Such an event of default would entitle the trustee or the holders of 25 percent in aggregate principal amount of any of ONEOK Partnersb outstanding senior notes to declare those notes immediately due and payable in full.	'	'
Long-term Debt, Gross	$425,000,000	$425,000,000	$400,000,000	$400,000,000	$900,000,000	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	3.20%	5.00%	6.20%	2.00%	3.38%	'	'	'
Face Value	'	'	'	'	'	'	'	350,000,000
Interest rate (in hundredths)	'	'	'	'	'	'	'	5.90%
Underwritten public offering	'	'	'	'	'	1,250,000,000	1,300,000,000	'
Net proceeds from public offering	'	'	'	'	'	$1,240,000,000	$1,290,000,000	'
Maturity date	'	'	'	'	'	'	'	1-Apr-12
Debt Instrument, Call Feature	'	'	'	'	'	'ONEOK Partners may redeem its 3.2 percent senior notes due 2018, its 5.0 percent senior notes due 2023, and its 6.2 percent senior notes due 2043 from the September 2013 offering at par, plus accrued and unpaid interest to the redemption date, starting one month, three months, and six months, respectively, before their maturity dates.B B Prior to these dates, ONEOK Partners may redeem these notes, in whole or in part, at a redemption price equal to the principal amount, plus accrued and unpaid interest and a make-whole premium.B B The redemption price will never be less than 100 percent of the principal amount of the respective note plus accrued and unpaid interest to the redemption date.B B ONEOK Partnersb senior notes are senior unsecured obligations, ranking equally in right of payment with all of ONEOK Partnersb existing and future unsecured senior indebtedness, and structurally subordinate to any of the existing and future debt and other liabilities of any ONEOK Partnersb nonguarantor subsidiaries.	'	'

EQUITY_Details

EQUITY (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Common Stock, Dividends, Per Share, Cash Paid	$0.38	$0.36	$0.36	$0.33	$1.10	$0.94
Stockholders' equity, beginning balance	$4,174,356	'	$4,232,450	$4,205,988	$4,232,450	$3,799,732
Net income	147,698	'	'	164,988	392,898	547,655
Other comprehensive income (loss)	-9,486	'	'	-57,044	19,918	-57,275
Repurchase of common stock	0	'	'	0	0	-150,000
Common stock issued	4,142	'	'	3,838	11,892	10,390
Common stock dividends	-78,367	'	'	-67,671	-226,349	-194,443
Issuance of common units of ONEOK Partners	501,893	'	'	0	516,201	459,680
Distributions to noncontrolling interests	-91,824	'	'	-84,156	-273,346	-237,744
Other	42,234	'	'	9,616	16,982	-2,436
Stockholders' equity, ending balance	4,690,646	4,174,356	'	4,175,559	4,690,646	4,175,559
Dividends declared per share of common stock	$0.38	'	'	'	'	'
Dividends Payable, Date of Record	4-Nov-13	'	'	'	'	'
Dividends Payable, Date to be Paid	14-Nov-13	'	'	'	'	'
ONEOK Shareholders' Equity [Member]	'	'	'	'	'	'
Stockholders' equity, beginning balance	2,085,349	'	2,129,609	2,089,540	2,129,609	2,238,573
Net income	62,356	'	'	65,219	175,796	249,077
Other comprehensive income (loss)	-7,522	'	'	-34,836	-2,694	-34,355
Repurchase of common stock	0	'	'	0	0	-150,000
Common stock issued	4,142	'	'	3,838	11,892	10,390
Common stock dividends	-78,367	'	'	-67,671	-226,349	-194,443
Issuance of common units of ONEOK Partners	81,502	'	'	0	84,458	-51,100
Distributions to noncontrolling interests	0	'	'	0	0	0
Other	42,234	'	'	9,616	16,982	-2,436
Stockholders' equity, ending balance	2,189,694	'	'	2,065,706	2,189,694	2,065,706
Noncontrolling Interests in Consolidated Subsidiaries [Member]	'	'	'	'	'	'
Stockholders' equity, beginning balance	2,089,007	'	2,102,841	2,116,448	2,102,841	1,561,159
Net income	85,342	'	'	99,769	217,102	298,578
Other comprehensive income (loss)	-1,964	'	'	-22,208	22,612	-22,920
Repurchase of common stock	0	'	'	0	0	0
Common stock issued	0	'	'	0	0	0
Common stock dividends	0	'	'	0	0	0
Issuance of common units of ONEOK Partners	420,391	'	'	0	431,743	510,780
Distributions to noncontrolling interests	-91,824	'	'	-84,156	-273,346	-237,744
Other	0	'	'	0	0	0
Stockholders' equity, ending balance	$2,500,952	'	'	$2,109,853	$2,500,952	$2,109,853

ACCUMULATED_OTHER_COMPREHENSIV2

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Part 1 (Details) (USD $)	3 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012
Balance of Accumulated Other Comprehensive Income (Loss) [Abstract]	'	'	'
Unrealized Gains (Losses) on Energy Marketing and Risk Management Assets/Liabilities	($35,853)	($35,853)	($55,030)
Unrealized Holding Gains (Losses) on Investment Securities	800	800	1,034
Pension and Postretirement Benefit Plan Obligations	-184,439	-184,439	-162,802
Accumulated Other Comprehensive Income (Loss)	-219,492	-219,492	-216,798
Other comprehensive income (loss) attributable to ONEOK [Abstract]	'	'	'
Unrealized Gains (Losses) on Energy Marketing and Risk Management Assets/Liabilities, Before Reclassifications	'	16,406	'
Unrealized Gains (Losses) on Energy Marketing and Risk Management Assets/Liabilities, Reclassification Adjustment	'	2,771	'
Unrealized Gains (Losses) on Energy Marketing and Risk Management Assets/Liabilities, Net of Reclassifications	'	19,177	'
Unrealized Holding Gains (Losses) on Investment Securities, Before Reclassifications	'	-234	'
Unrealized Holding Gains (Losses) on Investment Securities, Reclassification Adjustment	'	0	'
Unrealized Holding Gains (Losses) on Investment Securities, Net of Reclassifications	'	-234	'
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Before Reclassifications	'	-56,164	'
Pension and Postretirement Benefit Plan Obligations, Reclassification Adjustment	'	34,527	'
Pension and Postretirement Benefit Plan Obligations, Net of Reclassications	'	-21,637	'
Other Comprehensive Income (Loss), Before Reclassifications	'	-39,992	'
Total reclassifications for the period attributable to ONEOK	10,899	37,298	'
Other Comprehensive Income (Loss), Net of Reclassifications	'	($2,694)	'

ACCUMULATED_OTHER_COMPREHENSIV3

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Part 2 (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Total reclassifications for the period attributable to ONEOK	$10,899	'	$37,298	'
Unrealized (gains) losses on derivatives [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Tax	-333	-6,143	1,748	-12,954
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	-789	20,973	-4,694	44,675
Pension and postretirement benefit plan obligations [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized, Net of Tax	'	'	34,527	'
Accumulated Defined Benefit Plans Adjustment [Member]	'	'	'	'
Pension and postretirement benefit plan obligations [Abstract]	'	'	'	'
Amortization of net loss	19,729	'	59,183	'
Amortization of unrecognized prior service cost	-1,438	'	-4,314	'
Amortization of unrecognized net asset at adoption	71	'	213	'
Settlement charge	275	'	1,225	'
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized, before Tax	18,637	'	56,307	'
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized, Tax	-7,210	'	-21,780	'
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized, Net of Tax	11,427	'	34,527	'
Sales [Member] | Commodity Contract [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	'	'	'	'
Unrealized (gains) losses on derivatives [Abstract]	'	'	'	'
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion	-3,357	'	-18,718	'
Cost of Sales and Fuel [Member] | Commodity Contract [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	'	'	'	'
Unrealized (gains) losses on derivatives [Abstract]	'	'	'	'
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion	117	'	14,320	'
Interest Expense [Member] | Interest Rate Contract [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	'	'	'	'
Unrealized (gains) losses on derivatives [Abstract]	'	'	'	'
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion	3,696	'	10,840	'
Total before tax [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	'	'	'	'
Unrealized (gains) losses on derivatives [Abstract]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	456	'	6,442	'
Tax benefit [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	'	'	'	'
Unrealized (gains) losses on derivatives [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Tax	333	'	-1,748	'
Cash Flow Hedging [Member]	'	'	'	'
Unrealized (gains) losses on derivatives [Abstract]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	456	-27,116	6,442	-57,629
Cash Flow Hedging [Member] | Sales [Member] | Commodity Contract [Member]	'	'	'	'
Unrealized (gains) losses on derivatives [Abstract]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	-3,357	-31,447	-18,718	-127,477
Cash Flow Hedging [Member] | Cost of Sales and Fuel [Member] | Commodity Contract [Member]	'	'	'	'
Unrealized (gains) losses on derivatives [Abstract]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	117	2,503	14,320	65,940
Cash Flow Hedging [Member] | Interest Expense [Member] | Interest Rate Contract [Member]	'	'	'	'
Unrealized (gains) losses on derivatives [Abstract]	'	'	'	'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	3,696	1,828	10,840	3,908
Cash Flow Hedging [Member] | Net of tax [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	'	'	'	'
Unrealized (gains) losses on derivatives [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	789	'	4,694	'
Cash Flow Hedging [Member] | Net income attributable to noncontrolling interest [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]	'	'	'	'
Unrealized (gains) losses on derivatives [Abstract]	'	'	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	-528	'	2,771	'
Other Comprehensive Income (Loss), Reclassification, Derivatives, Net of Tax, Portion Attributable to Noncontrolling Interest	1,317	'	1,923	'
Pension Benefits [Member]	'	'	'	'
Pension and postretirement benefit plan obligations [Abstract]	'	'	'	'
Settlement charge	$275	$0	$1,225	$0

EARNINGS_PER_SHARE_Details

EARNINGS PER SHARE (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Basic EPS from continuing operations [Abstract]	'	'	'	'
Income from continuing operations attributable to ONEOK available for common stock	$62,356	$65,219	$175,796	$234,798
Weighted Average number of share, basic (in shares)	206,235	205,005	205,952	206,638
Per share amount, basic (in dollars per shares)	$0.30	$0.32	$0.85	$1.14
Diluted EPS from continuing operations [Abstract]	'	'	'	'
Effect of options and other dilutive securities	0	0	0	0
Effect of options and other dilutive securities, number of shares (in shares)	3,658	4,955	3,456	4,560
Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents	$62,356	$65,219	$175,796	$234,798
Weighted Average number of share, diluted (in shares)	209,893	209,960	209,408	211,198
Per Share amount, diluted (in dollars per share)	$0.30	$0.31	$0.84	$1.11
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	0	0	0

EMPLOYEE_BENEFIT_PLANS_Details

EMPLOYEE BENEFIT PLANS (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pension Benefits [Member]	'	'	'	'
Components of net periodic benefit cost	'	'	'	'
Service cost	$5,735	$5,325	$17,207	$15,975
Interest cost	13,612	14,809	40,836	44,427
Expected return on assets	-20,318	-20,689	-60,954	-62,067
Amortization of unrecognized prior service cost	230	242	690	726
Amortization of net loss	16,572	12,111	49,712	36,333
Settlement charge	275	0	1,225	0
Net periodic benefit cost	16,106	11,798	48,716	35,394
Postretirement Benefits [Member]	'	'	'	'
Components of net periodic benefit cost	'	'	'	'
Service cost	1,145	1,239	3,435	3,716
Interest cost	2,910	3,473	8,732	10,419
Expected return on assets	-3,065	-2,671	-9,195	-8,013
Amortization of unrecognized net asset at adoption	71	718	213	2,154
Amortization of unrecognized prior service cost	-1,668	-2,063	-5,004	-6,189
Amortization of net loss	3,157	3,296	9,471	9,888
Net periodic benefit cost	2,550	3,992	7,652	11,975
Accumulated Defined Benefit Plans Adjustment [Member]	'	'	'	'
Components of net periodic benefit cost	'	'	'	'
Settlement charge	$275	'	$1,225	'

UNCONSOLIDATED_AFFILIATES_Deta

UNCONSOLIDATED AFFILIATES (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'
Equity earnings from investments	$27,468,000	$28,591,000	$79,744,000	$92,380,000	'
Investments in unconsolidated affiliates	1,201,873,000	1,218,282,000	1,201,873,000	1,218,282,000	1,221,405,000
Income Statement	'	'	'	'	'
Operating revenues	131,959,000	125,828,000	391,912,000	373,038,000	'
Operating expenses	63,971,000	60,937,000	189,366,000	173,232,000	'
Net income	61,630,000	55,721,000	185,580,000	180,787,000	'
Distributions paid to ONEOK Partners	34,409,000	34,557,000	103,913,000	118,752,000	'
Northern Border Pipeline [Member]	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'
Equity earnings from investments	16,464,000	18,185,000	48,133,000	54,493,000	'
Percentage decrease in long-term transportation rates	'	'	11.00%	'	'
Overland Pass Pipeline Company [Member]	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'
Equity earnings from investments	5,783,000	4,490,000	14,210,000	15,786,000	'
Fort Union Gas Gathering, L.L.C. [Member]	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'
Equity earnings from investments	2,946,000	4,091,000	9,895,000	11,494,000	'
Bighorn Gas Gathering L.L.C. [Member]	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'
Equity earnings from investments	559,000	1,157,000	1,897,000	3,118,000	'
Ownership in Bighorn Gas Gathering, LLC	49.00%	'	49.00%	'	'
Investments in unconsolidated affiliates	88,700,000	'	88,700,000	'	'
Equity medthod goodwill included in Bighorn Gas Gathering, LLC	53,400,000	'	53,400,000	'	'
Other Unconsolidated Affiliate [Member]	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'
Equity earnings from investments	1,716,000	668,000	5,609,000	7,489,000	'
Unconsolidated Affiliates [Member]	'	'	'	'	'
Schedule of Equity Method Investments [Line Items]	'	'	'	'	'
Related Party Transaction, Expenses from Transactions with Related Party	$15,900,000	$9,000,000	$36,300,000	$27,700,000	'

ONEOK_PARTNERS_Details

ONEOK PARTNERS (Details) (USD $)	3 Months Ended				9 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2012	Mar. 31, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Related Party Transaction [Line Items]	'	'	'	'	'	'	'
Payments to Acquire Businesses, Net of Cash Acquired	'	'	'	'	$304,889,000	$0	'
Proceeds from Other Equity	11,600,000	'	'	'	'	'	'
Partners' Capital Account, Units, Sold in Public Offering	11.5	'	'	'	'	'	'
Public offering price of common units	$49.61	'	'	'	'	'	'
Ownership interest (in hundreths)	41.30%	'	'	'	41.30%	'	43.40%
Aggregate amount of common units available for issuance and sale under Equity Distribution Agreement	'	'	'	'	300,000,000	'	'
Proceeds from Sale of Interest in Partnership Unit	553,400,000	16,300,000	'	'	'	'	'
Issuance of common units (in dollars per unit)	'	'	'	$59.27	'	'	'
Issuance of common units (in units)	'	'	'	8	'	'	'
Issuance of common units (in value)	'	'	'	460,000,000	569,246,000	459,680,000	'
Issuance of Common Units Sold in Private Placement (in units)	'	'	'	8	'	'	'
Issuance of Common Units Sold in Private Placement (in value)	'	'	'	460,000,000	'	'	'
Noncontrolling Interest, Increase from Equity Issuance or Sale of Parent Equity Interest	501,893,000	'	0	'	516,201,000	459,680,000	'
ONEOK [Member]	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'
Revenues	81,324,000	'	91,096,000	'	255,298,000	247,851,000	'
Expenses	'	'	'	'	'	'	'
Cost of sales and fuel	9,562,000	'	7,831,000	'	27,855,000	22,875,000	'
Administrative and general expenses	58,549,000	'	60,020,000	'	192,906,000	179,017,000	'
Total expenses	68,111,000	'	67,851,000	'	220,761,000	201,892,000	'
General Partner [Member]	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest	'	'	'	'	2.00%	'	'
Ownership interest (in hundreths)	2.00%	'	'	'	2.00%	'	'
Contribution from general partner	'	'	'	19,000,000	'	'	'
Limited Partner [Member]	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'
Ownership interest (in hundreths)	39.30%	'	'	'	39.30%	'	'
Common units	19.8	'	'	'	19.8	'	'
Class B units	73	'	'	'	73	'	'
Distribution Declared [Member]	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'
Distribution per unit	$0.73	'	$0.69	'	$2.16	$1.98	'
General partner distributions	71,812,000	'	59,361,000	'	205,002,000	161,595,000	'
Total distributions	239,733,000	'	209,935,000	'	688,789,000	596,830,000	'
Distribution Declared [Member] | General Partner [Member]	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'
General partner distributions	4,795,000	'	4,199,000	'	13,776,000	11,937,000	'
Incentive distributions	67,017,000	'	55,162,000	'	191,226,000	149,658,000	'
Distribution Declared [Member] | Limited Partner [Member]	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'
Limited partner distributions to ONEOK	67,271,000	'	63,560,000	'	200,422,000	183,721,000	'
Limited partner distributions to noncontrolling interest	100,650,000	'	87,014,000	'	283,365,000	251,514,000	'
Distribution Paid [Member]	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'
Distribution per unit	$0.72	'	$0.66	'	$2.15	$1.91	'
General partner distributions	67,146,000	'	53,865,000	'	198,046,000	141,987,000	'
Total distributions	225,629,000	'	198,943,000	'	669,981,000	550,978,000	'
Distribution Paid [Member] | General Partner [Member]	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'
General partner distributions	4,512,000	'	3,979,000	'	13,399,000	11,019,000	'
Incentive distributions	62,634,000	'	49,886,000	'	184,647,000	130,968,000	'
Distribution Paid [Member] | Limited Partner [Member]	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'
Limited partner distributions to ONEOK	66,807,000	'	61,240,000	'	199,031,000	171,882,000	'
Limited partner distributions to noncontrolling interest	91,676,000	'	83,838,000	'	272,904,000	237,109,000	'
Paid-in Capital [Member]	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'
Noncontrolling Interest, Increase from Equity Issuance or Sale of Parent Equity Interest	'	'	'	'	84,458,000	'	'
Noncontrolling Interest, Increase from Equity Issuance or Sale of Parent Equity Interest, Tax	'	'	'	'	53,000,000	'	'
Partnership Credit Agreement [Member]	'	'	'	'	'	'	'
Related Party Transaction [Line Items]	'	'	'	'	'	'	'
Maximum borrowing capacity	$1,200,000,000	'	'	'	$1,200,000,000	'	'

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Details)	Sep. 30, 2013
	Y
Total Commitments and Contingencies [Abstract]	'
Number of former manufactured gas sites in Kansas where we own or retain legal responsibility for environmental conditions	12
Number of sites where soil remediation has begun	11
Number of sites where regulatory closure has been achieved	3
Number of sites soil remediation is completed or near completion	8
Number of years of consideration for EPA lowering threshold levels for greenhouse gas emissions	5

SEGMENTS_Details

SEGMENTS (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]	'	'	'	'	'
Segment Reporting, Disclosure of Major Customers	'we had no single external customer from which we received 10 percent or more of our consolidated gross revenues	'we had no single external customer from which we received 10 percent or more of our consolidated gross revenues	'we had no single external customer from which we received 10 percent or more of our consolidated gross revenues	'we had no single external customer from which we received 10 percent or more of our consolidated gross revenues	'
Ownership interest (in hundreths)	41.30%	'	41.30%	'	43.40%
Sales to unaffiliated customers	$3,571,925	$3,028,775	$10,462,606	$8,972,635	'
Intersegment revenues	0	0	0	0	'
Total revenues	3,571,925	3,028,775	10,462,606	8,972,635	'
Net margin	561,188	553,972	1,638,029	1,746,521	'
Operating costs	236,862	229,205	729,915	684,526	'
Depreciation and amortization	94,267	81,434	276,343	249,429	'
Goodwill impairment	0	0	0	10,255	'
Gain on sale of assets	22	-420	342	603	'
Operating income (loss)	230,081	242,913	632,113	802,914	'
Equity earnings from investments	27,468	28,591	79,744	92,380	'
Investments in unconsolidated affiliates	1,201,873	1,218,282	1,201,873	1,218,282	1,221,405
Total assets	17,610,343	15,364,307	17,610,343	15,364,307	15,855,275
Noncontrolling interests in consolidated subsidiaries	2,500,952	2,109,853	2,500,952	2,109,853	2,102,841
Capital expenditures	537,487	458,211	1,597,820	1,238,908	'
ONEOK Partners [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Sales to unaffiliated customers	3,053,409	2,456,364	8,165,061	7,018,503	'
Intersegment revenues	81,324	91,096	255,298	247,851	'
Total revenues	3,134,733	2,547,460	8,420,359	7,266,354	'
Net margin	423,574	419,737	1,206,126	1,242,289	'
Operating costs	122,362	121,176	384,602	360,410	'
Depreciation and amortization	61,182	49,754	174,086	150,024	'
Goodwill impairment	'	'	'	0	'
Gain on sale of assets	22	-420	342	603	'
Operating income (loss)	240,052	248,387	647,780	732,458	'
Equity earnings from investments	27,468	28,591	79,744	92,380	'
Investments in unconsolidated affiliates	1,201,873	1,218,282	1,201,873	1,218,282	'
Total assets	12,863,326	10,792,593	12,863,326	10,792,593	'
Noncontrolling interests in consolidated subsidiaries	4,588	4,812	4,588	4,812	'
Capital expenditures	449,072	375,291	1,373,904	1,011,527	'
ONEOK Partners [Member] | Regulated Segment [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Total revenues	204,600	181,600	558,900	513,000	'
Net margin	142,300	122,900	390,300	359,700	'
Operating income (loss)	76,000	63,600	196,000	182,300	'
Natural Gas Distribution Regulated Segment [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Sales to unaffiliated customers	219,724	204,930	1,167,261	943,034	'
Intersegment revenues	1	2	5	845	'
Total revenues	219,725	204,932	1,167,266	943,879	'
Net margin	159,233	150,987	589,354	545,823	'
Operating costs	109,304	103,373	330,465	312,133	'
Depreciation and amortization	32,347	31,962	100,118	97,481	'
Goodwill impairment	'	'	'	0	'
Gain on sale of assets	0	0	0	0	'
Operating income (loss)	17,582	15,652	158,771	136,209	'
Equity earnings from investments	0	0	0	0	'
Investments in unconsolidated affiliates	0	0	0	0	'
Total assets	3,597,730	3,258,320	3,597,730	3,258,320	'
Noncontrolling interests in consolidated subsidiaries	0	0	0	0	'
Capital expenditures	83,783	74,287	206,372	205,652	'
Energy Services [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Sales to unaffiliated customers	298,146	366,955	1,128,325	1,009,550	'
Intersegment revenues	34,050	-3,116	162,376	84,022	'
Total revenues	332,196	363,839	1,290,701	1,093,572	'
Net margin	-22,265	-17,275	-159,406	-43,133	'
Operating costs	2,369	4,424	10,930	13,889	'
Depreciation and amortization	69	78	209	284	'
Goodwill impairment	'	'	'	10,255	'
Gain on sale of assets	0	0	0	0	'
Operating income (loss)	-24,703	-21,777	-170,545	-67,561	'
Equity earnings from investments	0	0	0	0	'
Investments in unconsolidated affiliates	0	0	0	0	'
Total assets	362,438	450,899	362,438	450,899	'
Noncontrolling interests in consolidated subsidiaries	0	0	0	0	'
Capital expenditures	0	0	0	0	'
Corporate Elimination [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Sales to unaffiliated customers	646	526	1,959	1,548	'
Intersegment revenues	-115,375	-87,982	-417,679	-332,718	'
Total revenues	-114,729	-87,456	-415,720	-331,170	'
Net margin	646	523	1,955	1,542	'
Operating costs	2,827	232	3,918	-1,906	'
Depreciation and amortization	669	-360	1,930	1,640	'
Goodwill impairment	'	'	'	0	'
Gain on sale of assets	0	0	0	0	'
Operating income (loss)	-2,850	651	-3,893	1,808	'
Equity earnings from investments	0	0	0	0	'
Investments in unconsolidated affiliates	0	0	0	0	'
Total assets	786,849	862,495	786,849	862,495	'
Noncontrolling interests in consolidated subsidiaries	2,496,364	2,105,041	2,496,364	2,105,041	'
Capital expenditures	$4,632	$8,633	$17,544	$21,729	'