ONEOK (OKE) 10-Q 2 Nov 16 2016 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 24, 2016
Document Information [Line Items]
Entity Registrant Name	ONEOK INC /NEW/
Entity Central Index Key	1,039,684
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		210,521,971
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues
Commodity sales	$ 1,840,523	$ 1,484,350	$ 4,757,306	$ 4,642,320
Services	517,384	414,596	1,509,167	1,189,984
Total revenues	2,357,907	1,898,946	6,266,473	5,832,304
Cost of sales and fuel (exclusive of items shown separately below)	1,751,593	1,360,809	4,474,654	4,307,766
Operations and maintenance	165,664	146,979	488,476	442,179
Depreciation and amortization	98,550	88,299	292,275	261,241
General taxes	18,487	17,198	64,529	66,366
(Gain) loss on sale of assets	(5,744)	726	(9,537)	610
Operating income	329,357	284,935	956,076	754,142
Equity in net earnings from investments (Note J)	35,155	32,244	100,441	93,205
Allowance for equity funds used during construction	0	177	208	1,718
Other income	4,242	71	9,351	249
Other expense	(710)	(7,508)	(2,288)	(7,754)
Interest expense (net of capitalized interest of $3,806, $8,851, $9,265 and $26,008, respectively)	(118,240)	(106,923)	(355,463)	(306,057)
Income before income taxes	249,804	202,996	708,325	535,503
Income taxes	(55,012)	(38,298)	(157,536)	(123,948)
Income from continuing operations	194,792	164,698	550,789	411,555
Income (loss) from discontinued operations, net of tax (Note M)	(576)	(3,860)	(1,755)	(4,144)
Net income	194,216	160,838	549,034	407,411
Less: Net income attributable to noncontrolling interests	102,072	78,681	287,500	187,949
Net income attributable to ONEOK	92,144	82,157	261,534	219,462
Amounts attributable to ONEOK:
Income from continuing operations	92,720	86,017	263,289	223,606
Income (loss) from discontinued operations	(576)	(3,860)	(1,755)	(4,144)
Net income attributable to ONEOK	$ 92,144	$ 82,157	$ 261,534	$ 219,462
Basic earnings per share:
Income from continuing operations (Note H)	$ 0.44	$ 0.41	$ 1.25	$ 1.06
Income (loss) from discontinued operations	0	(0.02)	(0.01)	(0.02)
Net income	0.44	0.39	1.24	1.04
Diluted earnings per share:
Income from continuing operations (Note H)	0.44	0.41	1.24	1.06
Income (loss) from discontinued operations	(0.01)	(0.02)	(0.01)	(0.02)
Net income	$ 0.43	$ 0.39	$ 1.23	$ 1.04
Average shares (thousands)
Basic	211,309	210,296	211,038	210,138
Diluted	212,870	210,524	212,123	210,509
Dividends declared per share of common stock	$ 0.615	$ 0.605	$ 1.845	$ 1.815

CONSOLIDATED STATEMENTS OF INC3

CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Interest Costs, Capitalized During Period	$ 3,806	$ 8,851	$ 9,265	$ 26,008

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 194,216	$ 160,838	$ 549,034	$ 407,411
Other comprehensive income (loss), net of tax
Unrealized gains (losses) on derivatives, net of tax of $(1,301), $(1,109), $15,033 and $(2,156), respectively	7,237	14,840	(83,580)	19,217
Realized (gains) losses on derivatives in net income, net of tax of $(811), $2,957, $1,658 and $5,621, respectively	3,083	(15,259)	(13,496)	(35,530)
Unrealized holding gains (losses) on available-for-sale securities, net of tax of $0, $0, $0 and $648, respectively	0	0	0	(955)
Change in pension and postretirement benefit plan liability, net of tax of $(1,035), $(1,599), $(3,105) and $(4,798), respectively	1,553	2,441	4,658	7,320
Other comprehensive income (loss) on investments in unconsolidated affiliates, net of tax of $108, $0, $1,840 and $0, respectively	(600)	0	(10,231)	0
Total other comprehensive income (loss), net of tax	11,273	2,022	(102,649)	(9,948)
Comprehensive income	205,489	162,860	446,385	397,463
Less: Comprehensive income attributable to noncontrolling interest	108,450	81,481	211,960	177,760
Comprehensive income attributable to ONEOK	$ 97,039	$ 81,379	$ 234,425	$ 219,703

CONSOLIDATED STATEMENTS OF COM5

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Parenthetical - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Other comprehensive income (loss), net of tax
Unrealized gains (losses) on derivatives, tax	$ (1,301)	$ (1,109)	$ 15,033	$ (2,156)
Realized (gains) losses on derivatives in net income, tax	(811)	2,957	1,658	5,621
Unrealized holding gains (losses) on available-for-sale securities, tax	0	0	0	648
Change in pension and postretirement benefit plan liability, tax	(1,035)	(1,599)	(3,105)	(4,798)
Other comprehensive income (loss) on investments in unconsolidated affiliates, tax	$ 108	$ 0	$ 1,840	$ 0

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 237,410	$ 97,619
Accounts receivable, net	737,224	593,979
Materials and supplies	81,701	76,696
Natural gas and natural gas liquids in storage	217,769	128,084
Commodity imbalances	43,770	38,681
Other current assets	50,759	39,946
Assets of discontinued operations (Note M)	658	205
Total current assets	1,369,291	975,210
Property, plant and equipment
Property, plant and equipment	14,943,225	14,530,460
Accumulated depreciation and amortization	2,416,476	2,156,471
Net property, plant and equipment	12,526,749	12,373,989
Investments and other assets
Investments in unconsolidated affiliates	943,390	948,221
Goodwill and intangible assets	1,008,334	1,017,258
Other assets	121,529	112,598
Assets of discontinued operations (Note M)	12,742	18,835
Total investments and other assets	2,085,995	2,096,912
Total assets	15,982,035	15,446,111
Current liabilities
Current maturities of long-term debt (Note E)	460,650	110,650
Short-term borrowings (Note D)	693,500	546,340
Accounts payable	711,817	615,982
Commodity imbalances	134,658	74,460
Accrued interest	104,137	129,043
Other current liabilities	214,662	132,556
Liabilities of discontinued operations (Note M)	22,540	29,235
Total current liabilities	2,341,964	1,638,266
Long-term debt, excluding current maturities (Note E)	8,320,144	8,323,582
Deferred credits and other liabilities
Deferred income taxes	1,573,950	1,436,715
Other deferred credits	296,751	264,248
Liabilities of discontinued operations (Note M)	9,012	16,964
Total deferred credits and other liabilities	1,879,713	1,717,927
Commitments and contingencies (Note L)
ONEOK shareholders' equity:
Common stock, $0.01 par value: authorized 600,000,000 shares; issued 245,811,180 shares and outstanding 210,517,586 shares at September 30, 2016; issued 245,811,180 shares and outstanding 209,731,028 shares at December 31, 2015	2,458	2,458
Paid-in capital	1,264,041	1,378,444
Accumulated other comprehensive loss (Note G)	(154,351)	(127,242)
Retained earnings	0	0
Treasury stock, at cost: 35,293,594 shares at September 30, 2016, and 36,080,152 shares at December 31, 2015	(897,852)	(917,862)
Total ONEOK shareholders' equity	214,296	335,798
Noncontrolling interests in consolidated subsidiaries	3,225,918	3,430,538
Total equity	3,440,214	3,766,336
Total liabilities and equity	$ 15,982,035	$ 15,446,111

CONSOLIDATED BALANCE SHEETS Par

CONSOLIDATED BALANCE SHEETS Parenthetical - $ / shares	Sep. 30, 2016	Dec. 31, 2015
Equity (Note F)
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)	210,517,586	209,731,028
Treasury stock, shares (in shares)	35,293,594	36,080,152

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating Activities
Net income	$ 549,034	$ 407,411
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	292,275	261,241
Equity in net earnings from investments	(100,441)	(93,205)
Distributions received from unconsolidated affiliates	106,381	92,042
Deferred income taxes	157,819	124,615
Share-based compensation expense	31,112	13,732
Pension and postretirement benefit expense, net of contributions	8,270	10,145
Allowance for equity funds used during construction	(208)	(1,718)
(Gain) loss on sale of assets	(9,537)	610
Changes in assets and liabilities:
Accounts receivable	(145,430)	157,742
Natural gas and natural gas liquids in storage	(89,685)	(8,174)
Accounts payable	138,198	(191,542)
Commodity imbalances, net	55,109	25,728
Settlement of exit activities liabilities	(16,211)	(31,207)
Accrued interest	(24,906)	3,577
Risk management assets and liabilities	(48,695)	(45,240)
Other assets and liabilities, net	18,943	(30,680)
Cash provided by operating activities	922,028	695,077
Investing Activities
Capital expenditures (less allowance for equity funds used during construction)	(491,528)	(930,316)
Contributions to unconsolidated affiliates	(55,177)	(27,540)
Distributions received from unconsolidated affiliates in excess of cumulative earnings	43,018	25,111
Proceeds from sale of assets	19,099	3,171
Other	0	(12,607)
Cash used in investing activities	(484,588)	(942,181)
Financing Activities
Dividends paid	(388,103)	(380,498)
Distributions to noncontrolling interests	(412,539)	(396,847)
Borrowing (repayment) of short-term borrowings, net	147,160	(768,024)
Issuance of long-term debt, net of discounts	1,000,000	1,291,506
Debt financing costs	(2,770)	(17,126)
Repayment of long-term debt	(656,117)	(5,795)
Issuance of common stock	14,948	13,839
Issuance of common units, net of issuance costs	0	375,660
Cash provided by (used in) financing activities	(297,421)	112,715
Change in cash and cash equivalents	140,019	(134,389)
Change in cash and cash equivalents included in discontinued operations	(228)	(52)
Change in cash and cash equivalents from continuing operations	139,791	(134,441)
Cash and cash equivalents at beginning of period	97,619	172,812
Cash and cash equivalents at end of period	$ 237,410	$ 38,371

CONSOLIDATED STATEMENT OF CHANG

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - USD ($) $ in Thousands	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]
Stockholders' equity, beginning balance at Dec. 31, 2014	$ 4,005,883	$ 2,458	$ 1,541,583	$ (136,353)	$ 138,128	$ (953,701)	$ 3,413,768
Common stock issued, beginning balance (in shares) at Dec. 31, 2014		245,811,180
Net income	407,411	$ 0	0	0	219,462	0	187,949
Other comprehensive income (loss) (Note G)	(9,948)	$ 0	0	241	0	0	(10,189)
Common stock issued (in shares)		0
Common stock issued	17,912	$ 0	(6,284)	0	0	24,196	0
Common stock dividends - $1.845 and $1.815 per share (Note F)	(380,498)	0	(22,807)	0	(357,691)	0	0
Issuance of common units of ONEOK Partners (Note K)	394,144	0	(34,446)	0	0	0	428,590
Distributions to noncontrolling interests	(396,847)	0	0	0	0	0	(396,847)
Other	(752)	0	(415)	0	101	0	(438)
Stockholders' equity, ending balance at Sep. 30, 2015	4,037,305	$ 2,458	1,477,631	(136,112)	0	(929,505)	3,622,833
Common stock issued, ending balance (in shares) at Sep. 30, 2015		245,811,180
Stockholders' equity, beginning balance at Dec. 31, 2015	3,766,336	$ 2,458	1,378,444	(127,242)	0	(917,862)	3,430,538
Common stock issued, beginning balance (in shares) at Dec. 31, 2015		245,811,180
Net income	549,034	$ 0	0	0	261,534	0	287,500
Other comprehensive income (loss) (Note G)	(102,649)	$ 0	0	(27,109)	0	0	(75,540)
Common stock issued (in shares)		0
Common stock issued	19,479	$ 0	(531)	0	0	20,010	0
Common stock dividends - $1.845 and $1.815 per share (Note F)	(388,103)	0	(126,569)	0	(261,534)	0	0
Distributions to noncontrolling interests	(412,539)	0	0	0	0	0	(412,539)
Other	8,656	0	12,697	0	0	0	(4,041)
Stockholders' equity, ending balance at Sep. 30, 2016	$ 3,440,214	$ 2,458	$ 1,264,041	$ (154,351)	$ 0	$ (897,852)	$ 3,225,918
Common stock issued, ending balance (in shares) at Sep. 30, 2016		245,811,180

CONSOLIDATED STATEMENT OF CHA10

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY Parenthetical - $ / shares	3 Months Ended			9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2016	Sep. 30, 2015
Statement of Stockholders' Equity [Abstract]
Common Stock, Dividends, Per Share, Cash Paid	$ 0.615	$ 0.615	$ 0.615	$ 1.845	$ 1.815

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	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 statement of the results for the interim periods presented. All such adjustments are of a normal recurring nature. The 2015 year-end consolidated balance sheet data was derived from our audited financial statements but does not include all disclosures required by GAAP. Certain reclassifications have been made in the prior-year financial statements to conform to the current-year presentation. These unaudited consolidated financial statements should be read in conjunction with our audited consolidated financial statements in our Annual Report. Unless indicated otherwise, the information in the Notes to the Consolidated Financial Statements relates to our continuing operations. Our significant accounting policies are consistent with those disclosed in Note A of the Notes to Consolidated Financial Statements in our Annual Report, except as described below. Consolidation - Our consolidated financial statements include our accounts and the accounts of our subsidiaries over which we have control or are the primary beneficiary. Management’s judgment is required when: • determining whether an entity is a variable interest entity (VIE); • determining whether we are the primary beneficiary of a VIE; and • identifying events that require reconsideration of whether an entity is a VIE. As a result of adopting ASU 2015-02 described below, we have concluded that ONEOK Partners is a VIE and that we are the primary beneficiary. Therefore, we continue to consolidate ONEOK Partners. See Note K for additional information. We record noncontrolling interests in consolidated subsidiaries on our Consolidated Balance Sheets to recognize the portion of ONEOK Partners that we do not own. We reflect our ownership interest in ONEOK Partners’ accumulated other comprehensive income (loss) in our consolidated accumulated other comprehensive income (loss). The remaining portion is reflected as an adjustment to noncontrolling interests in consolidated subsidiaries. Goodwill Impairment Test - We assess our goodwill for impairment at least annually on July 1, unless events or changes in circumstances indicate an impairment may have occurred before that time. As the commodity price environment has remained relatively unchanged since 2015, we elected to perform a quantitative assessment, or Step 1 analysis, to test our goodwill for impairment. The assessment included our current commodity price assumptions, expected contractual terms, anticipated operating costs and volume estimates. Our goodwill impairment analysis performed as of July 1, 2016, did not result in an impairment charge nor did our analysis reflect any reporting units at risk. In each reporting unit, the fair value substantially exceeded the carrying value. Subsequent to that date, no event has occurred indicating that the implied fair value of each of our reporting units is less than the carrying value of its net assets. Recently Issued Accounting Standards Update - The following tables provide a brief description of recent accounting pronouncements and our analysis of the effects on our financial statements: Standard Description Date of Adoption Effect on the Financial Statements or Other Significant Matters Standards that were adopted ASU 2015-16, “Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments” The standard requires that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. First quarter 2016 There was no impact, but it could impact us in the future if we complete any acquisitions with subsequent measurement period adjustments. ASU 2015-07, “Fair Value Measurement (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent)” The standard removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient. The amendment also removes the requirement to make certain disclosures for all investments that are eligible to be measured at fair value using the net asset value per share practical expedient. First quarter 2016 The impact of adopting this standard was not material. ASU 2015-05, “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement” The standard clarifies whether a cloud computing arrangement includes a software license. If it does, the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses; if not, the customer should account for the arrangement as a service contract. First quarter 2016 The impact of adopting this standard was not material. ASU 2015-02, “Consolidation (Topic 810): Amendments to the Consolidation Analysis” The standard eliminates the presumption that a general partner should consolidate a limited partnership. It also modifies the evaluation of whether limited partnerships are variable interest entities or voting interest entities and adds requirements that limited partnerships must meet to qualify as voting interest entities. First quarter 2016 As a result of adopting this standard, we no longer consolidate ONEOK Partners under the presumption that a general partner should consolidate a limited partnership. We concluded, however, that ONEOK Partners is a VIE and ONEOK is the primary beneficiary, and we therefore consolidate ONEOK Partners under the variable interest model of consolidation. There was no financial statement impact due to the change in consolidation methodology. See Note K for additional information. Standard Description Date of Adoption Effect on the Financial Statements or Other Significant Matters Standards that are not yet adopted ASU 2015-11, “Inventory (Topic 330): Simplifying the Measurement of Inventory” The standard requires that inventory, excluding inventory measured using last-in, first-out (LIFO) or the retail inventory method, be measured at the lower of cost or net realizable value. First quarter 2017 We do not expect the adoption of this standard to materially impact us. ASU 2016-05, “Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships” The standard clarifies that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under Topic 815 does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. First quarter 2017 We do not expect the adoption of this standard to materially impact us. ASU 2016-06, “Derivatives and Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments” The standard clarifies the requirements for assessing whether a contingent call (put) option that can accelerate the payment of principal on a debt instrument is clearly and closely related to its debt host. First quarter 2017 We do not expect the adoption of this standard to materially impact us. ASU 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting” The standard provides simplified accounting for share-based payment transactions in relation to income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. First quarter 2017 We are evaluating the impact of this standard on us. ASU 2014-09, “Revenue from Contracts with Customers (Topic 606)” The standard outlines the principles an entity must apply to measure and recognize revenue for entities that enter into contracts to provide goods or services to their customers. The core principle is that an entity should recognize revenue at an amount that reflects the consideration to which the entity expects to be entitled in exchange for transferring goods or services to a customer. The amendment also requires more extensive disaggregated revenue disclosures in interim and annual financial statements. First quarter 2018 We are evaluating the impact of this standard on us. Our evaluation process includes a review of our and ONEOK Partners’ contracts and transaction types across all of the business segments. In addition, we are currently evaluating the methods of adoption and analyzing the impact of the standard on our internal controls, accounting policies and financial statements and disclosures. ASU 2016-01, “Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities” The standard requires all equity investments, other than those accounted for using the equity method of accounting or those that result in consolidation of the investee, to be measured at fair value with changes in fair value recognized in net income, eliminates the available-for-sale classification for equity securities with readily determinable fair values and eliminates the cost method for equity investments without readily determinable fair values. First quarter 2018 We are evaluating the impact of this standard on us. ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments” The standard clarifies the classification of certain cash receipts and cash payments on the statement of cash flows where diversity in practice has been identified. First quarter 2018 We are evaluating the impact of this standard on us. ASU 2016-02, “Leases (Topic 842)” The standard requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous GAAP. It also requires qualitative disclosures along with specific quantitative disclosures by lessees and lessors to meet the objective of enabling users of financial statements to assess the amount, timing and uncertainty of cash flows arising from leases. First quarter 2019 We are evaluating the impact of this standard on us. ASU 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” The standard requires a financial asset (or a group of financial assets) measured at amortized cost basis to be presented net of the allowance for credit losses to reflect the net carrying value at the amount expected to be collected on the financial asset; and the initial allowance for credit losses for purchased financial assets, including available-for-sale debt securities, to be added to the purchase price rather than being reported as a credit loss expense. First quarter 2020 We are evaluating the impact of this standard on us.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	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 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 a group 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. For certain transactions, we utilize modeling techniques using NYMEX-settled pricing data and implied forward LIBOR curves. Inputs into our fair value estimates include commodity-exchange prices, over-the-counter quotes, historical correlations of pricing data, data obtained from third-party pricing services and LIBOR and other liquid money-market instrument rates. 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 derivatives by discounting the projected future cash flows from the derivative assets and liabilities to present value using interest-rate yields to calculate present-value discount factors derived from LIBOR, Eurodollar futures and the LIBOR interest-rate swaps market. 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 monitoring the credit default swap markets. Although we use our best estimates to determine the fair value of the executed derivative contracts, the ultimate market prices realized could differ from our estimates, and the differences could be material. The fair value of forward-starting interest-rate swaps are determined using financial models that incorporate the implied forward LIBOR yield curve for the same period as the future interest-rate swap settlements. Fair Value Hierarchy - At each balance sheet date, we utilize a fair value hierarchy to classify fair value amounts recognized or disclosed in our financial statements based on the observability of inputs used to estimate such fair value. The levels of the hierarchy are described below: • Level 1 - fair value measurements are based on unadjusted quoted prices for identical securities in active markets, including NYMEX-settled prices. These balances are comprised predominantly of exchange-traded derivative contracts for natural gas and crude oil. • Level 2 - fair value measurements 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. • Level 3 - fair value measurements are based on inputs that may include one or more unobservable inputs, including internally developed natural gas basis and NGL price curves that incorporate observable and unobservable market data from broker quotes, third-party pricing services, 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. 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 has not been material. Determining the appropriate classification of our fair value measurements within the fair value hierarchy requires management’s judgment regarding the degree to which market data is observable or corroborated by observable market data. We categorize derivatives for which fair value is determined using multiple inputs within a single level, based on the lowest level input that is significant to the fair value measurement in its entirety. Recurring Fair Value Measurements - The following tables set forth our recurring fair value measurements for the periods indicated: September 30, 2016 Level 1 Level 2 Level 3 Total - Gross Netting (a) Total - Net (b) ( Thousands of dollars ) Derivative assets Commodity contracts Financial contracts $ 9,051 $ — $ 2,858 $ 11,909 $ (7,389 ) $ 4,520 Physical contracts — — 98 98 — 98 Total derivative assets $ 9,051 $ — $ 2,956 $ 12,007 $ (7,389 ) $ 4,618 Derivative liabilities Commodity contracts Financial contracts $ (12,175 ) $ — $ (9,846 ) $ (22,021 ) $ 22,021 $ — Physical contracts — — (3,173 ) (3,173 ) — (3,173 ) Interest-rate contracts — (69,103 ) — (69,103 ) — (69,103 ) Total derivative liabilities $ (12,175 ) $ (69,103 ) $ (13,019 ) $ (94,297 ) $ 22,021 $ (72,276 ) (a) - Derivative assets and liabilities are presented in our Consolidated Balance Sheets on a net basis. We net derivative assets and liabilities when a legally enforceable master-netting arrangement exists between the counterparty to a derivative contract and us. At September 30, 2016 , we held no cash and posted $27.4 million of cash with various counterparties, including $14.6 million of cash collateral that is offsetting derivative net liability positions under master-netting arrangements in the table above. The remaining $12.8 million of cash collateral in excess of derivative net liability positions is included in other current assets in our Consolidated Balance Sheets. (b) - Included in other current assets, other assets, other current liabilities or deferred credits and other liabilities in our Consolidated Balance Sheets. December 31, 2015 Level 1 Level 2 Level 3 Total - Gross Netting (a) Total - Net (b) ( Thousands of dollars ) Derivative assets Commodity contracts Financial contracts $ 38,921 $ — $ 7,253 $ 46,174 $ (42,414 ) $ 3,760 Physical contracts — — 3,591 3,591 — 3,591 Total derivative assets $ 38,921 $ — $ 10,844 $ 49,765 $ (42,414 ) $ 7,351 Derivative liabilities Commodity contracts Financial contracts $ (4,513 ) $ — $ (3,513 ) $ (8,026 ) $ 8,026 $ — Interest-rate contracts — (9,936 ) — (9,936 ) — (9,936 ) Total derivative liabilities $ (4,513 ) $ (9,936 ) $ (3,513 ) $ (17,962 ) $ 8,026 $ (9,936 ) (a) - Derivative assets and liabilities are presented in our Consolidated Balance Sheets on a net basis. We net derivative assets and liabilities when a legally enforceable master-netting arrangement exists between the counterparty to a derivative contract and us. At December 31, 2015 , we held $34.4 million of cash from various counterparties that is offsetting derivative net asset positions in the table above under master-netting arrangements and had no cash collateral posted. (b) - Included in other current assets or other current liabilities in our Consolidated Balance Sheets. The following table sets forth a reconciliation of our Level 3 fair value measurements for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, Derivative Assets (Liabilities) 2016 2015 2016 2015 ( Thousands of dollars ) Net assets (liabilities) at beginning of period $ (14,021 ) $ 10,387 $ 7,331 $ 9,285 Total realized/unrealized gains (losses): Included in earnings (a) 920 (15 ) 492 95 Included in other comprehensive income (loss) 3,038 (5,076 ) (17,886 ) (4,084 ) Net assets (liabilities) at end of period $ (10,063 ) $ 5,296 $ (10,063 ) $ 5,296 (a) - Included in commodity sales revenues in our Consolidated Statements of Income. Realized/unrealized gains (losses) include the realization of derivative contracts through maturity. During the three and nine months ended September 30, 2016 and 2015 , gains or losses included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the end of each reporting period were not material. We recognize transfers into and out of the levels in the fair value hierarchy as of the end of each reporting period. During the three and nine months ended September 30, 2016 and 2015 , there were no transfers between levels. Other Financial Instruments - The approximate fair value of cash and cash equivalents, accounts receivable, accounts payable and short-term borrowings 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 short-term borrowings are classified as Level 2 since the estimated fair value of the short-term borrowings 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 $9.3 billion and $7.4 billion at September 30, 2016 , and December 31, 2015 , respectively. The book value of our consolidated long-term debt, including current maturities, was $8.8 billion and $8.4 billion at September 30, 2016 , and December 31, 2015 , respectively. 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 ACT

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES	9 Months Ended
	Sep. 30, 2016
Derivatives, Fair Value [Line Items]
RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES	RISK-MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES Risk-Management Activities - We are sensitive to changes in natural gas, crude oil and NGL prices, principally as a result of contractual terms under which these commodities are processed, purchased and sold. We use physical-forward purchases and sales and financial derivatives to secure a certain price for a portion of our natural gas, condensate and NGL products; to reduce our exposure to commodity price and interest-rate fluctuations; and to achieve more predictable cash flows. We follow established policies and procedures to assess risk and approve, monitor and report risk-management activities. We have not used these instruments for trading purposes. We are also subject to the risk of interest-rate fluctuation in the normal course of business. Commodity price risk - Commodity price risk refers 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 the following commodity derivative instruments to mitigate the near-term commodity price risk associated with a portion of the forecasted sales of these commodities: • 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. These instruments transfer 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. We may also use other instruments including collars to mitigate commodity price risk. A collar is a combination of a purchased put option and a sold call option, which places a floor and a ceiling price for commodity sales being hedged. The Natural Gas Gathering and Processing segment is exposed to commodity price risk as a result of receiving commodities as a portion of its compensation for services associated with its POP with fee contracts. Under certain POP with fee contracts, ONEOK Partners’ fee revenues may increase or decrease if production volumes, delivery pressures or commodity prices change relative to specified thresholds. The Natural Gas Gathering and Processing segment also is exposed to basis risk between the various production and market locations where it receives and sells commodities. As part of our hedging strategy, we use the previously described commodity derivative financial instruments and physical-forward contracts to reduce the impact of price fluctuations related to natural gas, NGLs and condensate. The Natural Gas Liquids segment is exposed to location price differential risk, primarily as a result of the relative value of NGL purchases at one location and sales at another location. The Natural Gas Liquids segment also is exposed to commodity price risk resulting from the relative values of the various NGL products to each other, NGLs in storage and the relative value of NGLs to natural gas. We utilize physical-forward contracts and commodity derivative financial instruments to reduce the impact of price fluctuations related to NGLs. The Natural Gas Pipelines segment is exposed to commodity price risk because its intrastate and interstate natural gas pipelines retain natural gas from its customers for operations or as part of its fee for services provided. When the amount of natural gas consumed in operations by these pipelines differs from the amount provided by its customers, these pipelines must buy or sell natural gas, or store or use natural gas from inventory, which can expose them to commodity price risk depending on the regulatory treatment for this activity. To the extent that commodity price risk in the Natural Gas Pipelines segment is not mitigated by fuel cost-recovery mechanisms, we use physical-forward sales or purchases to reduce the impact of price fluctuations related to natural gas. At September 30, 2016 , and December 31, 2015 , there were no financial derivative instruments with respect to ONEOK Partners’ natural gas pipeline operations. Interest-rate risk - We manage interest-rate risk through the use of fixed-rate debt, floating-rate debt and interest-rate swaps. Interest-rate swaps are agreements to exchange interest payments at some future point based on specified notional amounts. As of September 30, 2016 , ONEOK Partners had interest-rate swaps with notional amounts totaling $1.0 billion to hedge the variability of ONEOK Partners’ LIBOR-based interest payments. In addition, in June 2016, ONEOK Partners entered into forward-starting interest-rate swaps with notional amounts totaling $750 million to hedge the variability of interest payments on a portion of its forecasted debt issuances that may result from changes in the benchmark interest rate before the debt is issued, resulting in total notional amounts of this type of interest-rate swap of $1.2 billion at September 30, 2016 , compared with $400 million at December 31, 2015 . All of ONEOK Partners’ interest-rate swaps are designated as cash flow hedges. Accounting T r eatment - Our accounting treatment of derivative instruments is consistent with that disclosed in Note A of the Notes to consolidated Financial Statements in our Annual Report. Fair Values of Derivative Instruments - See Note B for a discussion of the inputs associated with our fair value measurements. The following table sets forth the fair values of derivative instruments for the periods indicated: September 30, 2016 December 31, 2015 Assets (a) (Liabilities) (a) Assets (b) (Liabilities) (b) ( Thousands of dollars ) Derivatives designated as hedging instruments Commodity contracts Financial contracts $ 9,525 $ (20,376 ) $ 39,255 $ (1,440 ) Physical contracts 98 (3,173 ) 3,591 — Interest-rate contracts — (69,103 ) — (9,936 ) Total derivatives designated as hedging instruments 9,623 (92,652 ) 42,846 (11,376 ) Derivatives not designated as hedging instruments Commodity contracts Financial contracts 2,384 (1,645 ) 6,919 (6,586 ) Total derivatives not designated as hedging instruments 2,384 (1,645 ) 6,919 (6,586 ) Total derivatives $ 12,007 $ (94,297 ) $ 49,765 $ (17,962 ) (a) - Included on a net basis in other current assets, other assets, other current liabilities or deferred credits and other liabilities in our Consolidated Balance Sheets. (b) - Included on a net basis in other current assets or other current liabilities in our Consolidated Balance Sheets. Notional Quantities for Derivative Instruments - The following table sets forth the notional quantities for derivative instruments held for the periods indicated: September 30, 2016 December 31, 2015 Contract Type Purchased/ Payor Sold/ Receiver Purchased/ Payor Sold/ Receiver Derivatives designated as hedging instruments: Cash flow hedges Fixed price - Natural gas ( Bcf ) Futures and swaps — (43.3 ) — (27.1 ) - Natural gas ( Bcf ) Put options 68.3 — — — - Crude oil and NGLs ( MMBbl ) Futures, forwards — (4.6 ) — (2.3 ) Basis - Natural gas ( Bcf ) Futures and swaps — (43.3 ) — (27.1 ) Interest-rate contracts ( Millions of dollars ) Swaps $ 2,150.0 $ — $ 400.0 $ — Derivatives not designated as hedging instruments: Fixed price - NGLs ( MMBbl ) Futures, forwards 1.1 (0.9 ) 0.6 (0.6 ) 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 actual exposure to market or credit risk. Cash Flow Hedges - At September 30, 2016 , our Consolidated Balance Sheet reflected a net loss of $154.4 million in accumulated other comprehensive loss. The portion of accumulated other comprehensive loss attributable to commodity derivative financial instruments is an unrealized loss of $7.1 million , net of tax, which will be realized within the next 27 months as the forecasted transactions affect earnings. If commodity prices remain at current levels, we will realize approximately $5.6 million in net losses , net of tax, over the next 12 months and approximately $1.5 million in net losses , net of tax, thereafter. The amount deferred in accumulated other comprehensive loss attributable to settled interest-rate swaps is a loss of $45.5 million , net of tax, which will be recognized over the life of the long-term, fixed-rate debt, including losses of $6.4 million , net of tax, that will be reclassified into earnings during the next 12 months as the hedged items affect earnings. The remaining amounts in accumulated other comprehensive loss are attributable primarily to forward-starting interest-rate swaps with future settlement dates, which will be amortized to interest expense over the life of long-term, fixed-rate debt upon issuance of the debt. The following table sets forth the unrealized effect of cash flow hedges recognized in other comprehensive income (loss) for the periods indicated: Derivatives in Cash Flow Hedging Relationships Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Commodity contracts $ 7,580 $ 36,559 $ (39,396 ) $ 47,650 Interest-rate contracts 958 (20,610 ) (59,217 ) (26,277 ) Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion) $ 8,538 $ 15,949 $ (98,613 ) $ 21,373 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 Hedging Relationships Location of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Net Income (Effective Portion) Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Commodity contracts Commodity sales revenues $ 908 $ 22,770 $ 29,456 $ 54,020 Interest-rate contracts Interest expense (4,802 ) (4,554 ) (14,302 ) (12,869 ) Total gain (loss) reclassified from accumulated other comprehensive loss into net income on derivatives (effective portion) $ (3,894 ) $ 18,216 $ 15,154 $ 41,151 Ineffectiveness related to our cash flow hedges for the three and nine months ended September 30, 2016 and 2015 , was not material. In the event that it becomes probable that a forecasted transaction will not occur, we would discontinue cash flow hedge treatment, which would affect earnings. For the three and nine months ended September 30, 2016 and 2015 , there were no gains or losses due to the discontinuance of cash flow hedge treatment. 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. From time to time, ONEOK Partners may enter into financial derivative instruments that contain provisions that require it to maintain an investment-grade credit rating from S&P and/or Moody’s. If ONEOK Partners’ credit ratings on its 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. There were no financial derivative instruments with contingent features related to credit risk at September 30, 2016 . The counterparties to our derivative contracts consist primarily of major energy companies, financial institutions and commercial and industrial end users. This concentration of counterparties may affect our overall exposure to credit risk, either positively or negatively, in that the counterparties may be affected similarly 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, 2016 , the net credit exposure from our derivative assets is primarily with investment-grade companies in the financial services sector.

SHORT-TERM BORROWINGS

SHORT-TERM BORROWINGS	9 Months Ended
	Sep. 30, 2016
Short-term Debt [Abstract]
SHORT-TERM BORROWINGS	SHORT-TERM BORROWINGS ONEOK Credit Agreement - In January 2016, we extended the term of the ONEOK Credit Agreement by one year to January 2020. The ONEOK Credit Agreement is a $300 million revolving credit facility and contains certain financial, operational and legal covenants. Among other things, these covenants include maintaining a ratio of indebtedness to Consolidated EBITDA (EBITDA, as defined in our ONEOK Credit Agreement) of no more than 4.0 to 1. Upon breach of certain covenants by us in the ONEOK Credit Agreement, amounts outstanding under the ONEOK Credit Agreement, if any, may become due and payable immediately. At September 30, 2016 , ONEOK’s ratio of indebtedness to Consolidated EBITDA was 2.1 to 1, and ONEOK was in compliance with all covenants under the ONEOK Credit Agreement. The ONEOK Credit Agreement includes a $50 million sublimit for the issuance of standby letters of credit and a $50 million sublimit for swingline loans. Under the terms of the ONEOK Credit Agreement, ONEOK may request an increase in the size of the facility to an aggregate of $500 million from $300 million by either commitments from new lenders or increased commitments from existing lenders. 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 interest at LIBOR plus 145 basis points , and the annual facility fee is 30 basis points . At September 30, 2016 , ONEOK had $1.1 million in letters of credit issued and no borrowings under the ONEOK Credit Agreement. ONEOK Partners Credit Agreement - In January 2016, ONEOK Partners extended the term of the ONEOK Partners Credit Agreement by one year to January 2020. The ONEOK Partners Credit Agreement is a $2.4 billion revolving credit facility and includes a $100 million sublimit for the issuance of standby letters of credit and a $150 million swingline sublimit. The ONEOK Partners Credit Agreement is available for general partnership purposes. ONEOK Partners had $14 million of letters of credit issued, no borrowings outstanding and approximately $1.7 billion capacity available at September 30, 2016 , 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 its credit rating. Under the terms of the ONEOK Partners Credit Agreement, based on ONEOK Partners’ current credit ratings, borrowings, if any, will accrue at LIBOR plus 117.5 basis points , and the annual facility fee is 20 basis points . The ONEOK Partners Credit Agreement is guaranteed fully and unconditionally by the Intermediate Partnership. Borrowings under the ONEOK Partners Credit Agreement are nonrecourse to ONEOK. 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 in which the acquisition was completed and the two following quarters. If ONEOK Partners were to breach certain covenants 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, 2016 , ONEOK Partners’ ratio of indebtedness to adjusted EBITDA was 4.1 to 1, and it was in compliance with all covenants under the ONEOK Partners Credit Agreement. 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 or other similar commitments of ONEOK. ONEOK Partners Commercial Paper Program - At September 30, 2016 , ONEOK Partners had $694 million of commercial paper outstanding under its $2.4 billion commercial paper program with a weighted-average interest rate of 1.15 percent . Amounts outstanding under ONEOK Partners’ commercial paper program reduce the borrowing capacity under the ONEOK Partners Credit Agreement.

LONG-TERM DEBT

LONG-TERM DEBT	9 Months Ended
	Sep. 30, 2016
Long-term Debt, Unclassified [Abstract]
LONG-TERM DEBT	LONG-TERM DEBT The following table sets forth our long-term debt for the periods indicated: September 30, December 31, 2016 2015 ( Thousands of dollars ) ONEOK $700,000 at 4.25% due 2022 $ 547,397 $ 547,397 $500,000 at 7.5% due 2023 500,000 500,000 $100,000 at 6.5% due 2028 87,137 87,516 $100,000 at 6.875% due 2028 100,000 100,000 $400,000 at 6.0% due 2035 400,000 400,000 Total ONEOK senior notes payable 1,634,534 1,634,913 ONEOK Partners $650,000 at 3.25% due 2016 — 650,000 $450,000 at 6.15% due 2016 450,000 450,000 $400,000 at 2.0% due 2017 400,000 400,000 $425,000 at 3.2% due 2018 425,000 425,000 $1,000,000 term loan, variable rate, due 2019 1,000,000 — $500,000 at 8.625% due 2019 500,000 500,000 $300,000 at 3.8% due 2020 300,000 300,000 $900,000 at 3.375% due 2022 900,000 900,000 $425,000 at 5.0% due 2023 425,000 425,000 $500,000 at 4.9% due 2025 500,000 500,000 $600,000 at 6.65% due 2036 600,000 600,000 $600,000 at 6.85% due 2037 600,000 600,000 $650,000 at 6.125% due 2041 650,000 650,000 $400,000 at 6.2% due 2043 400,000 400,000 Guardian Pipeline Average 7.85% due 2022 46,170 51,907 Total ONEOK Partners long-term debt 7,196,170 6,851,907 Total long-term debt 8,830,704 8,486,820 Unamortized portion of terminated swaps 20,615 21,904 Unamortized debt issuance costs and discounts (70,525 ) (74,492 ) Current maturities (460,650 ) (110,650 ) Long-term debt, excluding current maturities $ 8,320,144 $ 8,323,582 ONEOK Debt Issuance - In August 2015, we completed an underwritten public offering of $500 million , 7.5 percent senior notes due 2023. The net proceeds, after deducting underwriting discounts, commissions and other expenses, were approximately $487.1 million . We used the proceeds together with cash on hand to purchase $650 million of additional common units from ONEOK Partners. ONEOK Partners Debt Issuances and Maturities - In January 2016, ONEOK Partners entered into the $1.0 billion senior unsecured delayed-draw Term Loan Agreement with a syndicate of banks. The Term Loan Agreement matures in January 2019 and bears interest at LIBOR plus a margin that is based on the credit ratings assigned to ONEOK Partners’ senior, unsecured, long-term indebtedness. Based on ONEOK Partners’ current applicable credit rating, borrowings on the Term Loan Agreement accrue at LIBOR plus 130 basis points . At September 30, 2016 , the interest rate was 1.83 percent . The Term Loan Agreement contains an option, which may be exercised up to two times, to extend the term of the loan, in each case, for an additional one-year term, subject to approval of the banks. The Term Loan Agreement allows prepayment of all or any portion outstanding without penalty or premium and contains substantially the same covenants as the ONEOK Partners Credit Agreement. During the first quarter 2016, ONEOK Partners drew the full $1.0 billion available under the agreement and used the proceeds to repay its $650 million , 3.25 percent senior notes, to repay amounts outstanding under its commercial paper program and for general partnership purposes. At September 30, 2016 , ONEOK Partners’ $450 million , 6.15 percent senior notes due October 1, 2016, are reflected in current maturities of long-term debt in our Consolidated Balance Sheet. In October 2016, ONEOK Partners repaid its $450 million , 6.15 percent senior notes with a combination of cash on hand and short-term borrowings. In March 2015, ONEOK Partners completed an underwritten public offering of $800 million of senior notes, consisting of $300 million , 3.8 percent senior notes due 2020, and $500 million , 4.9 percent senior notes due 2025. The net proceeds, after deducting underwriting discounts, commissions and other expenses, were approximately $792.3 million . ONEOK Partners used the proceeds to repay amounts outstanding under its commercial paper program and for general partnership purposes.

EQUITY

EQUITY	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Stockholders' Equity Note Disclosure [Text Block]	EQUITY Dividends - Dividends paid on our common stock to shareholders of record at the close of business on February 1, 2016, May 2, 2016, and August 8, 2016, were $0.615 per share in each instance. A dividend of $0.615 per share was declared for shareholders of record at the close of business on October 31, 2016 , payable November 14, 2016 . See Note K for a discussion of ONEOK Partners’ issuance of common units and distributions to noncontrolling interests.

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	9 Months Ended
	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	ACCUMULATED OTHER COMPREHENSIVE LOSS The following table sets forth the balance in accumulated other comprehensive loss for the period indicated: Unrealized Gains (Losses) on Risk- Management Assets/Liabilities (a) Pension and Postretirement Benefit Plan Obligations (a) (b) Unrealized Gains (Losses) on Risk- Management Assets/Liabilities of Unconsolidated Affiliates (a) Accumulated Other Comprehensive Loss (a) ( Thousands of dollars ) January 1, 2016 $ (42,199 ) $ (84,543 ) $ (500 ) $ (127,242 ) Other comprehensive income (loss) before reclassifications (25,597 ) 9 (3,133 ) (28,721 ) Amounts reclassified from accumulated other comprehensive loss (3,037 ) 4,649 — 1,612 Net current period other comprehensive income (loss) attributable to ONEOK (28,634 ) 4,658 (3,133 ) (27,109 ) September 30, 2016 $ (70,833 ) $ (79,885 ) $ (3,633 ) $ (154,351 ) (a) All amounts are presented net of tax. (b) Includes amounts related to supplemental executive retirement plan. The following table sets forth the effect of reclassifications from accumulated other comprehensive loss in our Consolidated Statements of Income for the periods indicated: Details about Accumulated Other Comprehensive Loss Components Three Months Ended Nine Months Ended Affected Line Item in the Consolidated Statements of Income September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Unrealized gains (losses) on risk-management assets/liabilities Commodity contracts $ 908 $ 22,770 $ 29,456 $ 54,020 Commodity sales revenues Interest-rate contracts (4,802 ) (4,554 ) (14,302 ) (12,869 ) Interest expense (3,894 ) 18,216 15,154 41,151 Income before income taxes 811 (2,957 ) (1,658 ) (5,621 ) Income tax expense (3,083 ) 15,259 13,496 35,530 Net income Noncontrolling interests (1,774 ) 10,150 10,459 25,745 Less: Net income attributable to noncontrolling interests $ (1,309 ) $ 5,109 $ 3,037 $ 9,785 Net income attributable to ONEOK Pension and postretirement benefit plan obligations (a) Amortization of net loss $ (2,999 ) $ (4,422 ) $ (8,994 ) $ (13,268 ) Amortization of unrecognized prior service cost 416 392 1,246 1,176 (2,583 ) (4,030 ) (7,748 ) (12,092 ) Income before income taxes 1,033 1,612 3,099 4,837 Income tax expense $ (1,550 ) $ (2,418 ) $ (4,649 ) $ (7,255 ) Net income attributable to ONEOK Total reclassifications for the period attributable to ONEOK $ (2,859 ) $ 2,691 $ (1,612 ) $ 2,530 Net income attributable to ONEOK (a) These components of accumulated other comprehensive loss are included in the computation of net periodic benefit cost. See Note I for additional detail of our net periodic benefit cost.

EARNINGS PER SHARE

EARNINGS PER SHARE	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
EARNINGS PER SHARE	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, 2016 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 stock $ 92,720 211,309 $ 0.44 Diluted EPS from continuing operations Effect of dilutive securities — 1,561 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 92,720 212,870 $ 0.44 Three Months Ended September 30, 2015 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 stock $ 86,017 210,296 $ 0.41 Diluted EPS from continuing operations Effect of dilutive securities — 228 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 86,017 210,524 $ 0.41 Nine Months Ended September 30, 2016 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 stock $ 263,289 211,038 $ 1.25 Diluted EPS from continuing operations Effect of dilutive securities — 1,085 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 263,289 212,123 $ 1.24 Nine Months Ended September 30, 2015 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 stock $ 223,606 210,138 $ 1.06 Diluted EPS from continuing operations Effect of dilutive securities — 371 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 223,606 210,509 $ 1.06

EMPLOYEE BENEFIT PLANS

EMPLOYEE BENEFIT PLANS	9 Months Ended
	Sep. 30, 2016
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
EMPLOYEE BENEFIT PLANS	EMPLOYEE BENEFIT PLANS The following tables set forth the components of net periodic benefit cost for our pension and postretirement benefit plans for our continuing operations for the periods indicated: Pension Benefits Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Components of net periodic benefit cost Service cost $ 1,622 $ 1,887 $ 4,866 $ 5,661 Interest cost 4,946 4,546 14,840 13,638 Expected return on assets (5,077 ) (5,213 ) (15,231 ) (15,639 ) Amortization of unrecognized prior service cost — 23 — 69 Amortization of net loss 2,737 3,987 8,210 11,961 Net periodic benefit cost $ 4,228 $ 5,230 $ 12,685 $ 15,690 Postretirement Benefits Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Components of net periodic benefit cost Service cost $ 149 $ 186 $ 447 $ 558 Interest cost 601 587 1,803 1,760 Expected return on assets (531 ) (564 ) (1,593 ) (1,692 ) Amortization of unrecognized prior service cost (416 ) (415 ) (1,246 ) (1,245 ) Amortization of net loss 262 435 784 1,307 Net periodic benefit cost $ 65 $ 229 $ 195 $ 688

UNCONSOLIDATED AFFILIATES

UNCONSOLIDATED AFFILIATES	9 Months Ended
	Sep. 30, 2016
Equity Method Investments and Joint Ventures [Abstract]
UNCONSOLIDATED AFFILIATES	UNCONSOLIDATED AFFILIATES Equity in Net Earnings from Investments - The following table sets forth ONEOK Partners’ equity in net earnings from investments for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Northern Border Pipeline $ 17,854 $ 16,156 $ 52,251 $ 51,131 Overland Pass Pipeline Company 13,886 10,538 40,798 27,048 Other 3,415 5,550 7,392 15,026 Equity in net earnings from investments $ 35,155 $ 32,244 $ 100,441 $ 93,205 Unconsolidated Affiliates Financial Information - The following table sets forth summarized combined financial information of ONEOK Partners’ unconsolidated affiliates for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Income Statement Operating revenues $ 143,967 $ 135,474 $ 423,170 $ 390,793 Operating expenses $ 66,490 $ 64,786 $ 191,863 $ 178,324 Net income $ 72,672 $ 67,121 $ 214,129 $ 196,123 Distributions paid to ONEOK Partners $ 40,822 $ 36,370 $ 149,399 $ 117,153 ONEOK Partners incurred expenses in transactions with unconsolidated affiliates of $36.4 million and $28.4 million for the three months ended September 30, 2016 and 2015 , respectively, and $105.3 million and $74.2 million for the nine months ended September 30, 2016 and 2015 , respectively, primarily related to Overland Pass Pipeline Company and Northern Border Pipeline. Accounts payable to ONEOK Partners’ equity-method investees at September 30, 2016 , and December 31, 2015 , were $11.5 million and $8.0 million , respectively. Northern Border Pipeline - The Northern Border Pipeline partnership agreement provides that distributions to Northern Border Pipeline’s partners are to be made on a pro rata basis according to each partner’s percentage interest. The Northern Border Pipeline Management Committee determines the amount and timing of such distributions. Any changes to, or suspension of, the cash distribution policy of Northern Border Pipeline requires the unanimous approval of the Northern Border Pipeline Management Committee. Cash distributions are equal to 100 percent of distributable cash flow as determined from Northern Border Pipeline’s financial statements based upon EBITDA, less interest expense and maintenance capital expenditures. Loans or other advances from Northern Border Pipeline to its partners or affiliates are prohibited under its credit agreement. Overland Pass Pipeline Company - The Overland Pass Pipeline Company limited liability company agreement provides that distributions to Overland Pass Pipeline Company’s members are to be made on a pro rata basis according to each member’s percentage interest. The Overland Pass Pipeline Company Management Committee determines the amount and timing of such distributions. Any changes to, or suspension of, the cash distributions from Overland Pass Pipeline Company requires the unanimous approval of the Overland Pass Pipeline Company Management Committee. Cash distributions are equal to 100 percent of available cash as defined in the limited liability company agreement. Roadrunner Gas Transmission - In March 2015, ONEOK Partners entered into a 50-50 joint venture with a subsidiary of Fermaca Infrastructure B.V. (Fermaca), a Mexico City-based natural gas infrastructure company, to construct a pipeline to transport natural gas from the Permian Basin in West Texas to the Mexican border near El Paso, Texas. During the nine months ended September 30, 2016 , ONEOK Partners made contributions of approximately $55 million to Roadrunner, and expects to contribute approximately $10 million to Roadrunner during the remainder of 2016. The Roadrunner limited liability company agreement provides that distributions to members are made on a pro rata basis according to each member’s ownership interest. The Roadrunner Management Committee determines the amount and timing of such distributions. Any changes to, or suspension of, the cash distributions from Roadrunner requires approval of the Roadrunner Management Committee. Voting rights for the Roadrunner Management Committee are allocated on a pro rata basis according to each member’s ownership interest. Cash distributions are equal to 100 percent of available cash, as defined in the limited liability company agreement.

ONEOK PARTNERS

ONEOK PARTNERS	9 Months Ended
	Sep. 30, 2016
Related Party Transactions [Abstract]
ONEOK PARTNERS	ONEOK PARTNERS Ownership Interest in ONEOK Partners - Our ownership interest in ONEOK Partners is shown in the table below at September 30, 2016 : General partner interest 2.0 % Limited partner interest (a) 39.2 % Total ownership interest 41.2 % (a) - Represents 41.3 million common units and approximately 73.0 million Class B units, which are convertible, at our option, into common units. Consolidation - We determined ONEOK Partners is a VIE due to the limited partners’ lack of substantive voting rights under the Partnership Agreement. Substantive voting rights under a master limited partnership are either kick-out rights or participating rights, as defined by FASB Accounting Standards Codification 810-10, that can be exercised with a simple majority of the vote of the limited partners. Prior to the adoption of ASU 2015-02, ONEOK Partners was not considered a VIE but was consolidated by us under the presumption that a general partner consolidates its limited partnership. See Note A for more information on ASU 2015-02. We have determined that we are the primary beneficiary of ONEOK Partners as we have the power, through our general partner interest, to direct the operations of ONEOK Partners that impact its economic performance and the right to receive the benefits of ONEOK Partners through our general partner and limited partner interests. These interests are significant due to our 41.2 percent ownership interest in ONEOK Partners, the largest ownership interest by an individual entity, and our incentive distribution rights. As we are the primary beneficiary of ONEOK Partners, 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 from ONEOK Partners. Distributions are declared quarterly by the board of ONEOK Partners’ general partner based on the terms of the Partnership Agreement. See Note N for more information on ONEOK Partners’ results. The following table shows the carrying amount and classification of ONEOK Partners’ assets and liabilities in our Consolidated Balance Sheets: September 30, December 31, 2016 2015 ( Thousands of dollars ) Assets Total current assets $ 1,128,794 $ 883,164 Net property, plant and equipment 12,415,775 12,256,791 Total investments and other assets 1,774,989 1,787,631 Total assets $ 15,319,558 $ 14,927,586 Liabilities Total current liabilities $ 2,286,251 $ 1,580,300 Long-term debt, excluding current maturities 6,691,663 6,695,312 Total deferred credits and other liabilities 188,254 154,631 Total liabilities $ 9,166,168 $ 8,430,243 ONEOK receives distributions from ONEOK Partners through its general partner and limited partner interests, but otherwise the assets of ONEOK Partners cannot be used to settle obligations of ONEOK. ONEOK does not guarantee the debt, commercial paper or other similar commitments of ONEOK Partners, and the obligations of ONEOK Partners may only be settled using the assets of ONEOK Partners. ONEOK Partners does not guarantee the debt or other similar commitments of ONEOK. Equity Issuances - In August 2015, ONEOK Partners completed the sale to us in a private placement of 21.5 million common units at a price of $30.17 per unit. Additionally, ONEOK Partners completed a concurrent sale of approximately 3.3 million common units at a price of $30.17 per unit to funds managed by Kayne Anderson Capital Advisors in a registered direct offering, which were issued through ONEOK Partners’ existing “at-the-market” equity program. The combined offerings generated net proceeds of approximately $749 million . In conjunction with these issuances, ONEOK Partners GP contributed approximately $15.3 million in order to maintain our 2 percent general partner interest in ONEOK Partners. ONEOK Partners used the proceeds for general partnership purposes, including capital expenditures and repayment of commercial paper borrowings. No other units were sold through the “at-the-market” program during the three months ended September 30, 2015. 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 $650 million . The program allows ONEOK Partners to offer and sell its common units at prices it 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. At September 30, 2016 , ONEOK Partners had approximately $138 million of registered common units available for issuance through its “at-the-market” equity program. During the three and nine months ended September 30, 2016 , no common units were sold through ONEOK Partners’ “at-the-market” equity program. During the nine months ended September 30, 2015, ONEOK Partners sold 10.5 million common units through its “at-the-market” equity program, including the units sold to funds managed by Kayne Anderson Capital Advisors in the offering discussed above. The net proceeds, including ONEOK Partners GP’s contribution to maintain our 2 percent general partner interest in ONEOK Partners, were approximately $381.6 million , which were used for general partnership purposes, including repayment of commercial paper borrowings. 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. Cash Distributions - We receive distributions from ONEOK Partners on the common and Class B units we own and the 2 percent general partner interest, which includes our incentive distribution rights. Under the Partnership Agreement, 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 the Partnership Agreement. 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 the Partnership Agreement, 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. In October 2016, a cash distribution of $0.79 per unit ( $3.16 per unit on an annualized basis) was declared for the third quarter 2016 and will be paid on November 14, 2016 , to unitholders of record at the close of business on October 31, 2016 . The following table sets forth ONEOK Partners’ distributions paid in the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands, except per unit amounts ) Distribution per unit $ 0.79 $ 0.79 $ 2.37 $ 2.37 General partner distributions $ 6,660 $ 6,081 $ 19,980 $ 17,950 Incentive distributions 100,538 91,794 301,614 270,962 Distributions to general partner 107,198 97,875 321,594 288,912 Limited partner distributions to ONEOK 90,323 73,302 270,969 219,907 Limited partner distributions to noncontrolling interest 135,480 132,862 406,439 388,655 Total distributions paid $ 333,001 $ 304,039 $ 999,002 $ 897,474 The following table sets forth 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, 2016 2015 2016 2015 ( Thousands, except per unit amounts ) Distribution per unit $ 0.79 $ 0.79 $ 2.37 $ 2.37 General partner distributions $ 6,660 $ 6,660 $ 19,980 $ 18,696 Incentive distributions 100,538 100,538 301,614 282,221 Distributions to general partner 107,198 107,198 321,594 300,917 Limited partner distributions to ONEOK 90,323 90,323 270,969 236,927 Limited partner distributions to noncontrolling interest 135,480 135,480 406,439 396,925 Total distributions declared $ 333,001 $ 333,001 $ 999,002 $ 934,769 Affiliate Transactions - We provide and are reimbursed for a variety of services to our affiliates, including cash management and financial services, employee benefits, 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 the three months ended September 30, 2016 and 2015 , $95.2 million and $89.3 million , respectively, of ONEOK Partners’ operating expenses were incurred with us. For the nine months ended September 30, 2016 and 2015 , $285.1 million and $265.6 million , respectively, of ONEOK Partners’ operating expenses were incurred with us. ONEOK Partners has an operating agreement with Roadrunner that provides for reimbursement or payment to it for management services and certain operating costs. Charges to Roadrunner included in operating income in our Consolidated Statements of Income for the three and nine months ended September 30, 2016 , were $2.5 million and $6.9 million , respectively. Charges to Roadrunner for the three and nine months ended September 30, 2015, were not material.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Environmental Matters and Pipeline Safety - The operation of pipelines, plants and other facilities for the gathering, processing, transportation and storage of natural gas, NGLs, condensate and other products is subject to numerous and complex laws and regulations pertaining to health, safety and the environment. As an owner and/or operator of these facilities, ONEOK Partners must comply with United States laws and regulations at the federal, state and local levels that relate to air and water quality, hazardous and solid waste management and disposal, and other environmental matters. The cost of planning, designing, constructing and operating pipelines, plants and other facilities must incorporate compliance with environmental laws and regulations and safety standards. Failure to comply with these laws and regulations may trigger a variety of administrative, civil and potentially criminal enforcement measures, including citizen suits, which can include the assessment of monetary penalties, the imposition of remedial requirements and the issuance of injunctions or restrictions on operation. Management believes that, based on currently known information, compliance with these laws and regulations will not have a material adverse effect on our or ONEOK Partners’ results of operations, financial condition or cash flows. Legal Proceedings - Gas Index Pricing Litigation - In October 2016, we reached an agreement in principle to settle the claims alleged against us and our affiliate ONEOK Energy Services Company, L.P. (“OESC”) in Reorganized FLI, Inc. previously reported in our Annual Report. The amount we expect to pay to settle this case is not material to our results of operations, financial position or cash flows and is expected to be paid with cash on hand. In March 2016, we reached an agreement in principle to settle the claims alleged against us and our affiliates, OESC and Kansas Gas Marketing Company, in the following putative class action lawsuits, previously reported in our Annual Report, that claimed damages resulting from alleged market manipulation or false reporting of prices to gas index publications by us and others: Learjet , Arandell , Heartland Regional Medical Center , and NewPage . The amount we expect to pay to settle these cases is not material to our results of operations, financial position or cash flows and is expected to be paid with cash on hand. The above agreements in principle to settle do not apply to the Sinclair case, previously reported in our Annual Report. We expect that future charges, if any, from the ultimate resolution of this matter will not be material to our results of operations, financial position or cash flows. Other Legal Proceedings - We and ONEOK Partners are 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 from 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.

DISCONTINUED OPERATIONS

DISCONTINUED OPERATIONS	9 Months Ended
	Sep. 30, 2016
Discontinued Operations [Abstract]
DISCONTINUED OPERATIONS	DISCONTINUED OPERATIONS In 2014, we completed the wind down of our former energy services business. We executed agreements to release a significant portion of our nonaffiliated natural gas transportation and storage contracts to third parties that resulted in noncash charges. The following table summarizes the change in our liability related to released capacity contracts for the periods indicated: Nine Months Ended September 30, 2016 2015 ( Millions of dollars ) Beginning balance $ 36.3 $ 73.8 Settlements (16.2 ) (31.2 ) Accretion 0.4 0.8 Ending balance $ 20.5 $ 43.4 We expect future cash payments associated with released transportation and storage capacity contracts from the wind down of our former energy services business to total approximately $21 million , which consists of approximately $3 million to be paid in the remainder of 2016, $10 million in 2017, $4 million in 2018 and $4 million over the period 2019 through 2023. Results of Operations of Discontinued Operations - The results of operations for our former energy services business have been reported as discontinued operations for all periods presented. Income (loss) from discontinued operations, net of tax, in the Consolidated Statements of Income for the three and nine months ended September 30, 2016 and 2015 , includes accretion expense, net of tax benefit, on the released contracts for our former energy services business. Statement of Financial Position of Discontinued Operations - At September 30, 2016 , and December 31, 2015 , assets and liabilities of discontinued operations in our Consolidated Balance Sheets relate primarily to deferred tax assets and capacity release obligations associated with our former energy services business.

SEGMENTS

SEGMENTS	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
SEGMENTS	SEGMENTS Segment Descriptions - Our reportable business segments are based upon the following segments of ONEOK Partners: • the Natural Gas Gathering and Processing segment gathers, treats and processes natural gas; • the Natural Gas Liquids segment gathers, treats, fractionates and transports NGLs and stores, markets and distributes NGL products; and • the Natural Gas Pipelines segment operates regulated interstate and intrastate natural gas transmission pipelines and natural gas storage facilities. 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 - The accounting policies of the segments are described in Note A of the Notes to Consolidated Financial Statements in our Annual Report. Our chief operating decision-maker reviews the financial performance of each of the three segments of ONEOK Partners, as well as our financial performance, on a regular basis. Beginning in 2016, adjusted EBITDA by segment, a non-GAAP financial measure, is utilized in this evaluation. We believe this non-GAAP financial measure is useful to investors because it is used by many companies in our industry as a measurement of financial performance and is commonly employed by financial analysts and others to evaluate our financial performance and to compare our financial performance with the performance of other publicly traded partnerships within our industry. Adjusted EBITDA is defined as net income adjusted for interest expense, depreciation and amortization, noncash impairment charges, income taxes and AFUDC and other noncash items. Adjusted EBITDA should not be considered an alternative to net income, earnings per unit or any other measure of financial performance presented in accordance with GAAP. Additionally, this calculation may not be comparable with similarly titled measures of other companies. Prior period segment disclosures have been recast to reflect this change. Customers - The primary customers of the Natural Gas Gathering and Processing segment are crude oil and natural gas producers, which include both large integrated and independent exploration and production companies. The Natural Gas Liquids segment’s customers are primarily NGL and natural gas gathering and processing companies; large integrated and independent crude oil and natural gas production companies; propane distributors; ethanol producers; and petrochemical, refining and NGL marketing companies. The Natural Gas Pipelines segment’s customers are primarily local natural gas distribution companies, electric-generation companies, large industrial companies, municipalities, irrigation customers and marketing companies. For the three months and nine months ended September 30, 2016 and 2015 , we had no single customer from which we received 10 percent or more of our consolidated revenues. Operating Segment Information - The following tables set forth certain selected financial information for our operating segments for the periods indicated: Three Months Ended September 30, 2016 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Other and Total ( Thousands of dollars ) Sales to unaffiliated customers $ 361,717 $ 1,905,273 $ 90,401 $ 516 $ 2,357,907 Intersegment revenues 150,501 133,984 1,676 (286,161 ) — Total revenues 512,218 2,039,257 92,077 (285,645 ) 2,357,907 Cost of sales and fuel (exclusive of items shown separately below) 336,456 1,694,161 6,870 (285,894 ) 1,751,593 Operating costs 69,443 79,771 28,373 6,564 184,151 Depreciation and amortization 44,994 40,751 12,057 748 98,550 (Gain) loss on sale of assets (846 ) (5 ) (4,894 ) 1 (5,744 ) Operating income $ 62,171 $ 224,579 $ 49,671 $ (7,064 ) $ 329,357 Equity in net earnings from investments $ 2,596 $ 13,960 $ 18,599 $ — $ 35,155 Capital expenditures $ 99,649 $ 30,533 $ 24,495 $ 3,597 $ 158,274 (a) - The Natural Gas Liquids segment has regulated and nonregulated operations. The Natural Gas Liquids segment’s regulated operations had revenues of $299.2 million , of which $253.4 million related to sales within the segment, cost of sales and fuel of $119.6 million and operating income of $118.5 million . (b) - The Natural Gas Pipelines segment has regulated and nonregulated operations. The Natural Gas Pipelines segment’s regulated operations had revenues of $61.0 million , cost of sales and fuel of $7.8 million and operating income of $26.0 million . Three Months Ended September 30, 2015 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Other and Total ( Thousands of dollars ) Sales to unaffiliated customers $ 294,948 $ 1,522,224 $ 81,246 $ 528 $ 1,898,946 Intersegment revenues 139,388 89,230 1,751 (230,369 ) — Total revenues 434,336 1,611,454 82,997 (229,841 ) 1,898,946 Cost of sales and fuel (exclusive of items shown separately below) 293,681 1,289,682 7,628 (230,182 ) 1,360,809 Operating costs 61,162 74,464 26,674 1,877 164,177 Depreciation and amortization 37,286 39,317 10,914 782 88,299 (Gain) loss on sale of assets (132 ) 498 77 283 726 Operating income $ 42,339 $ 207,493 $ 37,704 $ (2,601 ) $ 284,935 Equity in net earnings from investments $ 4,350 $ 10,912 $ 16,982 $ — $ 32,244 Capital expenditures $ 231,835 $ 52,807 $ 14,718 $ 1,508 $ 300,868 (a) - The Natural Gas Liquids segment has regulated and nonregulated operations. The Natural Gas Liquids segment’s regulated operations had revenues of $252.8 million , of which $204.7 million related to sales within the segment, cost of sales and fuel of $112.7 million and operating income of $80.3 million . (b) - The Natural Gas Pipelines segment has regulated and nonregulated operations. The Natural Gas Pipelines segment’s regulated operations had revenues of $65.1 million , cost of sales and fuel of $7.2 million and operating income of $24.7 million . Nine Months Ended September 30, 2016 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Other and Total ( Thousands of dollars ) Sales to unaffiliated customers $ 971,834 $ 5,030,820 $ 262,276 $ 1,543 $ 6,266,473 Intersegment revenues 449,154 367,820 3,843 (820,817 ) — Total revenues 1,420,988 5,398,640 266,119 (819,274 ) 6,266,473 Cost of sales and fuel (exclusive of items shown separately below) 902,747 4,376,345 15,914 (820,352 ) 4,474,654 Operating costs 208,353 236,722 85,075 22,855 553,005 Depreciation and amortization 133,258 122,153 34,634 2,230 292,275 (Gain) loss on sale of assets (2,331 ) (12 ) (7,133 ) (61 ) (9,537 ) Operating income $ 178,961 $ 663,432 $ 137,629 $ (23,946 ) $ 956,076 Equity in net earnings from investments $ 7,987 $ 41,211 $ 51,243 $ — $ 100,441 Investments in unconsolidated affiliates $ 68,735 $ 470,635 $ 404,020 $ — $ 943,390 Total assets $ 5,268,161 $ 8,257,203 $ 1,912,951 $ 543,720 $ 15,982,035 Noncontrolling interests in consolidated subsidiaries $ — $ 158,352 $ — $ 3,067,566 $ 3,225,918 Capital expenditures $ 325,820 $ 85,519 $ 71,721 $ 8,468 $ 491,528 (a) - The Natural Gas Liquids segment has regulated and nonregulated operations. The Natural Gas Liquids segment’s regulated operations had revenues of $878.5 million , of which $742.6 million related to sales within the segment, cost of sales and fuel of $339.1 million and operating income of $354.9 million . (b) - The Natural Gas Pipelines segment has regulated and nonregulated operations. The Natural Gas Pipelines segment’s regulated operations had revenues of $172.4 million , cost of sales and fuel of $19.1 million and operating income of $72.9 million . Nine Months Ended September 30, 2015 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Other and Total ( Thousands of dollars ) Sales to unaffiliated customers $ 862,462 $ 4,726,617 $ 241,605 $ 1,620 $ 5,832,304 Intersegment revenues 487,559 229,804 5,053 (722,416 ) — Total revenues 1,350,021 4,956,421 246,658 (720,796 ) 5,832,304 Cost of sales and fuel (exclusive of items shown separately below) 947,539 4,054,039 28,059 (721,871 ) 4,307,766 Operating costs 193,922 234,120 79,156 1,347 508,545 Depreciation and amortization 109,035 118,044 32,484 1,678 261,241 (Gain) loss on sale of assets (328 ) 579 76 283 610 Operating income $ 99,853 $ 549,639 $ 106,883 $ (2,233 ) $ 754,142 Equity in net earnings from investments $ 13,511 $ 27,585 $ 52,109 $ — $ 93,205 Investments in unconsolidated affiliates $ 253,548 $ 484,403 $ 399,108 $ — $ 1,137,059 Total assets $ 5,206,987 $ 8,041,064 $ 1,845,232 $ 415,015 $ 15,508,298 Noncontrolling interests in consolidated subsidiaries $ 4,066 $ 161,210 $ — $ 3,457,557 $ 3,622,833 Capital expenditures $ 692,570 $ 185,360 $ 39,923 $ 12,463 $ 930,316 (a) - The Natural Gas Liquids segment has regulated and nonregulated operations. The Natural Gas Liquids segment’s regulated operations had revenues of $690.1 million , of which $556.4 million related to sales within the segment, cost of sales and fuel of $297.3 million and operating income of $218.8 million . (b) - The Natural Gas Pipelines segment has regulated and nonregulated operations. The Natural Gas Pipelines segment’s regulated operations had revenues of $198.5 million , cost of sales and fuel of $22.6 million and operating income of $77.8 million . Three Months Ended Nine Months Ended September 30, September 30, ( Unaudited ) 2016 2015 2016 2015 ( Thousands of dollars ) Segment Adjusted EBITDA: Natural Gas Gathering and Processing $ 109,837 $ 82,718 $ 320,170 $ 221,298 Natural Gas Liquids 279,256 255,745 826,036 692,991 Natural Gas Pipelines 80,304 65,166 223,185 201,112 Other (4,061 ) 2,228 (9,744 ) (3,473 ) Depreciation and amortization (98,550 ) (88,299 ) (292,275 ) (261,241 ) Interest expense, net of capitalized interest (118,240 ) (106,923 ) (355,463 ) (306,057 ) Income taxes (55,012 ) (38,298 ) (157,536 ) (123,948 ) AFUDC and other 1,258 (7,639 ) (3,584 ) (9,127 ) Income from continuing operations 194,792 164,698 550,789 411,555 Income (loss) from discontinued operations, net of tax (576 ) (3,860 ) (1,755 ) (4,144 ) Net income $ 194,216 $ 160,838 $ 549,034 $ 407,411

SUMMARY OF SIGNIFICANT ACCOUN25

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
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 statement of the results for the interim periods presented. All such adjustments are of a normal recurring nature. The 2015 year-end consolidated balance sheet data was derived from our audited financial statements but does not include all disclosures required by GAAP. Certain reclassifications have been made in the prior-year financial statements to conform to the current-year presentation. These unaudited consolidated financial statements should be read in conjunction with our audited consolidated financial statements in our Annual Report. Unless indicated otherwise, the information in the Notes to the Consolidated Financial Statements relates to our continuing operations. Our significant accounting policies are consistent with those disclosed in Note A of the Notes to Consolidated Financial Statements in our Annual Report, except as described below.
Consolidation, Policy [Policy Text Block]	Consolidation - Our consolidated financial statements include our accounts and the accounts of our subsidiaries over which we have control or are the primary beneficiary. Management’s judgment is required when: • determining whether an entity is a variable interest entity (VIE); • determining whether we are the primary beneficiary of a VIE; and • identifying events that require reconsideration of whether an entity is a VIE. As a result of adopting ASU 2015-02 described below, we have concluded that ONEOK Partners is a VIE and that we are the primary beneficiary. Therefore, we continue to consolidate ONEOK Partners. See Note K for additional information. We record noncontrolling interests in consolidated subsidiaries on our Consolidated Balance Sheets to recognize the portion of ONEOK Partners that we do not own. We reflect our ownership interest in ONEOK Partners’ accumulated other comprehensive income (loss) in our consolidated accumulated other comprehensive income (loss). The remaining portion is reflected as an adjustment to noncontrolling interests in consolidated subsidiaries.
Goodwill and Intangible Assets, Policy [Policy Text Block]	We assess our goodwill for impairment at least annually on July 1, unless events or changes in circumstances indicate an impairment may have occurred before that time. As the commodity price environment has remained relatively unchanged since 2015, we elected to perform a quantitative assessment, or Step 1 analysis, to test our goodwill for impairment. The assessment included our current commodity price assumptions, expected contractual terms, anticipated operating costs and volume estimates. Our goodwill impairment analysis performed as of July 1, 2016, did not result in an impairment charge nor did our analysis reflect any reporting units at risk. In each reporting unit, the fair value substantially exceeded the carrying value. Subsequent to that date, no event has occurred indicating that the implied fair value of each of our reporting units is less than the carrying value of its net assets.
New Accounting Pronouncements, Policy [Policy Text Block]	The following tables provide a brief description of recent accounting pronouncements and our analysis of the effects on our financial statements: Standard Description Date of Adoption Effect on the Financial Statements or Other Significant Matters Standards that were adopted ASU 2015-16, “Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments” The standard requires that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. First quarter 2016 There was no impact, but it could impact us in the future if we complete any acquisitions with subsequent measurement period adjustments. ASU 2015-07, “Fair Value Measurement (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent)” The standard removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient. The amendment also removes the requirement to make certain disclosures for all investments that are eligible to be measured at fair value using the net asset value per share practical expedient. First quarter 2016 The impact of adopting this standard was not material. ASU 2015-05, “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement” The standard clarifies whether a cloud computing arrangement includes a software license. If it does, the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses; if not, the customer should account for the arrangement as a service contract. First quarter 2016 The impact of adopting this standard was not material. ASU 2015-02, “Consolidation (Topic 810): Amendments to the Consolidation Analysis” The standard eliminates the presumption that a general partner should consolidate a limited partnership. It also modifies the evaluation of whether limited partnerships are variable interest entities or voting interest entities and adds requirements that limited partnerships must meet to qualify as voting interest entities. First quarter 2016 As a result of adopting this standard, we no longer consolidate ONEOK Partners under the presumption that a general partner should consolidate a limited partnership. We concluded, however, that ONEOK Partners is a VIE and ONEOK is the primary beneficiary, and we therefore consolidate ONEOK Partners under the variable interest model of consolidation. There was no financial statement impact due to the change in consolidation methodology. See Note K for additional information. Standard Description Date of Adoption Effect on the Financial Statements or Other Significant Matters Standards that are not yet adopted ASU 2015-11, “Inventory (Topic 330): Simplifying the Measurement of Inventory” The standard requires that inventory, excluding inventory measured using last-in, first-out (LIFO) or the retail inventory method, be measured at the lower of cost or net realizable value. First quarter 2017 We do not expect the adoption of this standard to materially impact us. ASU 2016-05, “Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships” The standard clarifies that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under Topic 815 does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. First quarter 2017 We do not expect the adoption of this standard to materially impact us. ASU 2016-06, “Derivatives and Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments” The standard clarifies the requirements for assessing whether a contingent call (put) option that can accelerate the payment of principal on a debt instrument is clearly and closely related to its debt host. First quarter 2017 We do not expect the adoption of this standard to materially impact us. ASU 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting” The standard provides simplified accounting for share-based payment transactions in relation to income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. First quarter 2017 We are evaluating the impact of this standard on us. ASU 2014-09, “Revenue from Contracts with Customers (Topic 606)” The standard outlines the principles an entity must apply to measure and recognize revenue for entities that enter into contracts to provide goods or services to their customers. The core principle is that an entity should recognize revenue at an amount that reflects the consideration to which the entity expects to be entitled in exchange for transferring goods or services to a customer. The amendment also requires more extensive disaggregated revenue disclosures in interim and annual financial statements. First quarter 2018 We are evaluating the impact of this standard on us. Our evaluation process includes a review of our and ONEOK Partners’ contracts and transaction types across all of the business segments. In addition, we are currently evaluating the methods of adoption and analyzing the impact of the standard on our internal controls, accounting policies and financial statements and disclosures. ASU 2016-01, “Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities” The standard requires all equity investments, other than those accounted for using the equity method of accounting or those that result in consolidation of the investee, to be measured at fair value with changes in fair value recognized in net income, eliminates the available-for-sale classification for equity securities with readily determinable fair values and eliminates the cost method for equity investments without readily determinable fair values. First quarter 2018 We are evaluating the impact of this standard on us. ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments” The standard clarifies the classification of certain cash receipts and cash payments on the statement of cash flows where diversity in practice has been identified. First quarter 2018 We are evaluating the impact of this standard on us. ASU 2016-02, “Leases (Topic 842)” The standard requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous GAAP. It also requires qualitative disclosures along with specific quantitative disclosures by lessees and lessors to meet the objective of enabling users of financial statements to assess the amount, timing and uncertainty of cash flows arising from leases. First quarter 2019 We are evaluating the impact of this standard on us. ASU 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” The standard requires a financial asset (or a group of financial assets) measured at amortized cost basis to be presented net of the allowance for credit losses to reflect the net carrying value at the amount expected to be collected on the financial asset; and the initial allowance for credit losses for purchased financial assets, including available-for-sale debt securities, to be added to the purchase price rather than being reported as a credit loss expense. First quarter 2020 We are evaluating the impact of this standard on us.

FAIR VALUE MEASUREMENTS FAIR VA

FAIR VALUE MEASUREMENTS FAIR VALUE MEASUREMENTS (Policies)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments, Policy [Policy Text Block]	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 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 a group 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. For certain transactions, we utilize modeling techniques using NYMEX-settled pricing data and implied forward LIBOR curves. Inputs into our fair value estimates include commodity-exchange prices, over-the-counter quotes, historical correlations of pricing data, data obtained from third-party pricing services and LIBOR and other liquid money-market instrument rates. 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 derivatives by discounting the projected future cash flows from the derivative assets and liabilities to present value using interest-rate yields to calculate present-value discount factors derived from LIBOR, Eurodollar futures and the LIBOR interest-rate swaps market. 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 monitoring the credit default swap markets. Although we use our best estimates to determine the fair value of the executed derivative contracts, the ultimate market prices realized could differ from our estimates, and the differences could be material. The fair value of forward-starting interest-rate swaps are determined using financial models that incorporate the implied forward LIBOR yield curve for the same period as the future interest-rate swap settlements. Fair Value Hierarchy - At each balance sheet date, we utilize a fair value hierarchy to classify fair value amounts recognized or disclosed in our financial statements based on the observability of inputs used to estimate such fair value. The levels of the hierarchy are described below: • Level 1 - fair value measurements are based on unadjusted quoted prices for identical securities in active markets, including NYMEX-settled prices. These balances are comprised predominantly of exchange-traded derivative contracts for natural gas and crude oil. • Level 2 - fair value measurements 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. • Level 3 - fair value measurements are based on inputs that may include one or more unobservable inputs, including internally developed natural gas basis and NGL price curves that incorporate observable and unobservable market data from broker quotes, third-party pricing services, 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. 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 has not been material. Determining the appropriate classification of our fair value measurements within the fair value hierarchy requires management’s judgment regarding the degree to which market data is observable or corroborated by observable market data. We categorize derivatives for which fair value is determined using multiple inputs within a single level, based on the lowest level input that is significant to the fair value measurement in its entirety.

ONEOK PARTNERS (Policies)

ONEOK PARTNERS (Policies)	9 Months Ended
	Sep. 30, 2016
Related Party Transactions [Abstract]
Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block]	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. Consolidation - We determined ONEOK Partners is a VIE due to the limited partners’ lack of substantive voting rights under the Partnership Agreement. Substantive voting rights under a master limited partnership are either kick-out rights or participating rights, as defined by FASB Accounting Standards Codification 810-10, that can be exercised with a simple majority of the vote of the limited partners. Prior to the adoption of ASU 2015-02, ONEOK Partners was not considered a VIE but was consolidated by us under the presumption that a general partner consolidates its limited partnership. See Note A for more information on ASU 2015-02. We have determined that we are the primary beneficiary of ONEOK Partners as we have the power, through our general partner interest, to direct the operations of ONEOK Partners that impact its economic performance and the right to receive the benefits of ONEOK Partners through our general partner and limited partner interests. These interests are significant due to our 41.2 percent ownership interest in ONEOK Partners, the largest ownership interest by an individual entity, and our incentive distribution rights. As we are the primary beneficiary of ONEOK Partners, 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 from ONEOK Partners.
Cash Distributions	Cash Distributions - We receive distributions from ONEOK Partners on the common and Class B units we own and the 2 percent general partner interest, which includes our incentive distribution rights. Under the Partnership Agreement, 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 the Partnership Agreement. 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 the Partnership Agreement, 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.
Allocation of Costs Incurred by Related Party, Policy [Policy Text Block]	We provide and are reimbursed for a variety of services to our affiliates, including cash management and financial services, employee benefits, 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.

SEGMENTS SEGMENTS (Policies)

SEGMENTS SEGMENTS (Policies)	9 Months Ended
	Sep. 30, 2016
Segment Accounting Policies [Abstract]
Segments Accounting Policies [Text Block]	Accounting Policies - The accounting policies of the segments are described in Note A of the Notes to Consolidated Financial Statements in our Annual Report. Our chief operating decision-maker reviews the financial performance of each of the three segments of ONEOK Partners, as well as our financial performance, on a regular basis. Beginning in 2016, adjusted EBITDA by segment, a non-GAAP financial measure, is utilized in this evaluation. We believe this non-GAAP financial measure is useful to investors because it is used by many companies in our industry as a measurement of financial performance and is commonly employed by financial analysts and others to evaluate our financial performance and to compare our financial performance with the performance of other publicly traded partnerships within our industry. Adjusted EBITDA is defined as net income adjusted for interest expense, depreciation and amortization, noncash impairment charges, income taxes and AFUDC and other noncash items. Adjusted EBITDA should not be considered an alternative to net income, earnings per unit or any other measure of financial performance presented in accordance with GAAP. Additionally, this calculation may not be comparable with similarly titled measures of other companies. Prior period segment disclosures have been recast to reflect this change.

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Recurring Fair Value Measurments	Recurring Fair Value Measurements - The following tables set forth our recurring fair value measurements for the periods indicated: September 30, 2016 Level 1 Level 2 Level 3 Total - Gross Netting (a) Total - Net (b) ( Thousands of dollars ) Derivative assets Commodity contracts Financial contracts $ 9,051 $ — $ 2,858 $ 11,909 $ (7,389 ) $ 4,520 Physical contracts — — 98 98 — 98 Total derivative assets $ 9,051 $ — $ 2,956 $ 12,007 $ (7,389 ) $ 4,618 Derivative liabilities Commodity contracts Financial contracts $ (12,175 ) $ — $ (9,846 ) $ (22,021 ) $ 22,021 $ — Physical contracts — — (3,173 ) (3,173 ) — (3,173 ) Interest-rate contracts — (69,103 ) — (69,103 ) — (69,103 ) Total derivative liabilities $ (12,175 ) $ (69,103 ) $ (13,019 ) $ (94,297 ) $ 22,021 $ (72,276 ) (a) - Derivative assets and liabilities are presented in our Consolidated Balance Sheets on a net basis. We net derivative assets and liabilities when a legally enforceable master-netting arrangement exists between the counterparty to a derivative contract and us. At September 30, 2016 , we held no cash and posted $27.4 million of cash with various counterparties, including $14.6 million of cash collateral that is offsetting derivative net liability positions under master-netting arrangements in the table above. The remaining $12.8 million of cash collateral in excess of derivative net liability positions is included in other current assets in our Consolidated Balance Sheets. (b) - Included in other current assets, other assets, other current liabilities or deferred credits and other liabilities in our Consolidated Balance Sheets. December 31, 2015 Level 1 Level 2 Level 3 Total - Gross Netting (a) Total - Net (b) ( Thousands of dollars ) Derivative assets Commodity contracts Financial contracts $ 38,921 $ — $ 7,253 $ 46,174 $ (42,414 ) $ 3,760 Physical contracts — — 3,591 3,591 — 3,591 Total derivative assets $ 38,921 $ — $ 10,844 $ 49,765 $ (42,414 ) $ 7,351 Derivative liabilities Commodity contracts Financial contracts $ (4,513 ) $ — $ (3,513 ) $ (8,026 ) $ 8,026 $ — Interest-rate contracts — (9,936 ) — (9,936 ) — (9,936 ) Total derivative liabilities $ (4,513 ) $ (9,936 ) $ (3,513 ) $ (17,962 ) $ 8,026 $ (9,936 ) (a) - Derivative assets and liabilities are presented in our Consolidated Balance Sheets on a net basis. We net derivative assets and liabilities when a legally enforceable master-netting arrangement exists between the counterparty to a derivative contract and us. At December 31, 2015 , we held $34.4 million of cash from various counterparties that is offsetting derivative net asset positions in the table above under master-netting arrangements and had no cash collateral posted. (b) - Included in other current assets or other current liabilities in our Consolidated Balance Sheets.
Reconciliation of Level 3 Fair Value Measurements	The following table sets forth a reconciliation of our Level 3 fair value measurements for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, Derivative Assets (Liabilities) 2016 2015 2016 2015 ( Thousands of dollars ) Net assets (liabilities) at beginning of period $ (14,021 ) $ 10,387 $ 7,331 $ 9,285 Total realized/unrealized gains (losses): Included in earnings (a) 920 (15 ) 492 95 Included in other comprehensive income (loss) 3,038 (5,076 ) (17,886 ) (4,084 ) Net assets (liabilities) at end of period $ (10,063 ) $ 5,296 $ (10,063 ) $ 5,296 (a) - Included in commodity sales revenues in our Consolidated Statements of Income.

RISK MANAGEMENT AND HEDGING A30

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES (Tables)	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair value of derivatives	The following table sets forth the fair values of derivative instruments for the periods indicated: September 30, 2016 December 31, 2015 Assets (a) (Liabilities) (a) Assets (b) (Liabilities) (b) ( Thousands of dollars ) Derivatives designated as hedging instruments Commodity contracts Financial contracts $ 9,525 $ (20,376 ) $ 39,255 $ (1,440 ) Physical contracts 98 (3,173 ) 3,591 — Interest-rate contracts — (69,103 ) — (9,936 ) Total derivatives designated as hedging instruments 9,623 (92,652 ) 42,846 (11,376 ) Derivatives not designated as hedging instruments Commodity contracts Financial contracts 2,384 (1,645 ) 6,919 (6,586 ) Total derivatives not designated as hedging instruments 2,384 (1,645 ) 6,919 (6,586 ) Total derivatives $ 12,007 $ (94,297 ) $ 49,765 $ (17,962 ) (a) - Included on a net basis in other current assets, other assets, other current liabilities or deferred credits and other liabilities in our Consolidated Balance Sheets. (b) - Included on a net basis in other current assets or other current liabilities in our Consolidated Balance Sheets.
Notional amounts of derivative instruments	The following table sets forth the notional quantities for derivative instruments held for the periods indicated: September 30, 2016 December 31, 2015 Contract Type Purchased/ Payor Sold/ Receiver Purchased/ Payor Sold/ Receiver Derivatives designated as hedging instruments: Cash flow hedges Fixed price - Natural gas ( Bcf ) Futures and swaps — (43.3 ) — (27.1 ) - Natural gas ( Bcf ) Put options 68.3 — — — - Crude oil and NGLs ( MMBbl ) Futures, forwards — (4.6 ) — (2.3 ) Basis - Natural gas ( Bcf ) Futures and swaps — (43.3 ) — (27.1 ) Interest-rate contracts ( Millions of dollars ) Swaps $ 2,150.0 $ — $ 400.0 $ — Derivatives not designated as hedging instruments: Fixed price - NGLs ( MMBbl ) Futures, forwards 1.1 (0.9 ) 0.6 (0.6 )
Schedule of cash flow hedging instruments effect on comprehensive income (loss)	The following table sets forth the unrealized effect of cash flow hedges recognized in other comprehensive income (loss) for the periods indicated: Derivatives in Cash Flow Hedging Relationships Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Commodity contracts $ 7,580 $ 36,559 $ (39,396 ) $ 47,650 Interest-rate contracts 958 (20,610 ) (59,217 ) (26,277 ) Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion) $ 8,538 $ 15,949 $ (98,613 ) $ 21,373
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 Hedging Relationships Location of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Net Income (Effective Portion) Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Commodity contracts Commodity sales revenues $ 908 $ 22,770 $ 29,456 $ 54,020 Interest-rate contracts Interest expense (4,802 ) (4,554 ) (14,302 ) (12,869 ) Total gain (loss) reclassified from accumulated other comprehensive loss into net income on derivatives (effective portion) $ (3,894 ) $ 18,216 $ 15,154 $ 41,151

LONG-TERM DEBT LONG-TERM DEBT (

LONG-TERM DEBT LONG-TERM DEBT (Tables)	9 Months Ended
	Sep. 30, 2016
Debt Instrument [Line Items]
Schedule of Debt [Table Text Block]	The following table sets forth our long-term debt for the periods indicated: September 30, December 31, 2016 2015 ( Thousands of dollars ) ONEOK $700,000 at 4.25% due 2022 $ 547,397 $ 547,397 $500,000 at 7.5% due 2023 500,000 500,000 $100,000 at 6.5% due 2028 87,137 87,516 $100,000 at 6.875% due 2028 100,000 100,000 $400,000 at 6.0% due 2035 400,000 400,000 Total ONEOK senior notes payable 1,634,534 1,634,913 ONEOK Partners $650,000 at 3.25% due 2016 — 650,000 $450,000 at 6.15% due 2016 450,000 450,000 $400,000 at 2.0% due 2017 400,000 400,000 $425,000 at 3.2% due 2018 425,000 425,000 $1,000,000 term loan, variable rate, due 2019 1,000,000 — $500,000 at 8.625% due 2019 500,000 500,000 $300,000 at 3.8% due 2020 300,000 300,000 $900,000 at 3.375% due 2022 900,000 900,000 $425,000 at 5.0% due 2023 425,000 425,000 $500,000 at 4.9% due 2025 500,000 500,000 $600,000 at 6.65% due 2036 600,000 600,000 $600,000 at 6.85% due 2037 600,000 600,000 $650,000 at 6.125% due 2041 650,000 650,000 $400,000 at 6.2% due 2043 400,000 400,000 Guardian Pipeline Average 7.85% due 2022 46,170 51,907 Total ONEOK Partners long-term debt 7,196,170 6,851,907 Total long-term debt 8,830,704 8,486,820 Unamortized portion of terminated swaps 20,615 21,904 Unamortized debt issuance costs and discounts (70,525 ) (74,492 ) Current maturities (460,650 ) (110,650 ) Long-term debt, excluding current maturities $ 8,320,144 $ 8,323,582

ACCUMULATED OTHER COMPREHENSI32

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Tables)	9 Months Ended
	Sep. 30, 2016
Accumulated other comprehensive income (loss)	The following table sets forth the balance in accumulated other comprehensive loss for the period indicated: Unrealized Gains (Losses) on Risk- Management Assets/Liabilities (a) Pension and Postretirement Benefit Plan Obligations (a) (b) Unrealized Gains (Losses) on Risk- Management Assets/Liabilities of Unconsolidated Affiliates (a) Accumulated Other Comprehensive Loss (a) ( Thousands of dollars ) January 1, 2016 $ (42,199 ) $ (84,543 ) $ (500 ) $ (127,242 ) Other comprehensive income (loss) before reclassifications (25,597 ) 9 (3,133 ) (28,721 ) Amounts reclassified from accumulated other comprehensive loss (3,037 ) 4,649 — 1,612 Net current period other comprehensive income (loss) attributable to ONEOK (28,634 ) 4,658 (3,133 ) (27,109 ) September 30, 2016 $ (70,833 ) $ (79,885 ) $ (3,633 ) $ (154,351 ) (a) All amounts are presented net of tax. (b) Includes amounts related to supplemental executive retirement plan.
Disclosure of Reclassification Amount [Text Block]	The following table sets forth the effect of reclassifications from accumulated other comprehensive loss in our Consolidated Statements of Income for the periods indicated: Details about Accumulated Other Comprehensive Loss Components Three Months Ended Nine Months Ended Affected Line Item in the Consolidated Statements of Income September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Unrealized gains (losses) on risk-management assets/liabilities Commodity contracts $ 908 $ 22,770 $ 29,456 $ 54,020 Commodity sales revenues Interest-rate contracts (4,802 ) (4,554 ) (14,302 ) (12,869 ) Interest expense (3,894 ) 18,216 15,154 41,151 Income before income taxes 811 (2,957 ) (1,658 ) (5,621 ) Income tax expense (3,083 ) 15,259 13,496 35,530 Net income Noncontrolling interests (1,774 ) 10,150 10,459 25,745 Less: Net income attributable to noncontrolling interests $ (1,309 ) $ 5,109 $ 3,037 $ 9,785 Net income attributable to ONEOK Pension and postretirement benefit plan obligations (a) Amortization of net loss $ (2,999 ) $ (4,422 ) $ (8,994 ) $ (13,268 ) Amortization of unrecognized prior service cost 416 392 1,246 1,176 (2,583 ) (4,030 ) (7,748 ) (12,092 ) Income before income taxes 1,033 1,612 3,099 4,837 Income tax expense $ (1,550 ) $ (2,418 ) $ (4,649 ) $ (7,255 ) Net income attributable to ONEOK Total reclassifications for the period attributable to ONEOK $ (2,859 ) $ 2,691 $ (1,612 ) $ 2,530 Net income attributable to ONEOK (a) These components of accumulated other comprehensive loss are included in the computation of net periodic benefit cost. See Note I for additional detail of our net periodic benefit cost.

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2016
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, 2016 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 stock $ 92,720 211,309 $ 0.44 Diluted EPS from continuing operations Effect of dilutive securities — 1,561 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 92,720 212,870 $ 0.44 Three Months Ended September 30, 2015 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 stock $ 86,017 210,296 $ 0.41 Diluted EPS from continuing operations Effect of dilutive securities — 228 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 86,017 210,524 $ 0.41 Nine Months Ended September 30, 2016 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 stock $ 263,289 211,038 $ 1.25 Diluted EPS from continuing operations Effect of dilutive securities — 1,085 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 263,289 212,123 $ 1.24 Nine Months Ended September 30, 2015 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 stock $ 223,606 210,138 $ 1.06 Diluted EPS from continuing operations Effect of dilutive securities — 371 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 223,606 210,509 $ 1.06

EMPLOYEE BENEFIT PLANS (Tables)

EMPLOYEE BENEFIT PLANS (Tables)	9 Months Ended
	Sep. 30, 2016
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 our continuing operations for the periods indicated: Pension Benefits Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Components of net periodic benefit cost Service cost $ 1,622 $ 1,887 $ 4,866 $ 5,661 Interest cost 4,946 4,546 14,840 13,638 Expected return on assets (5,077 ) (5,213 ) (15,231 ) (15,639 ) Amortization of unrecognized prior service cost — 23 — 69 Amortization of net loss 2,737 3,987 8,210 11,961 Net periodic benefit cost $ 4,228 $ 5,230 $ 12,685 $ 15,690 Postretirement Benefits Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Components of net periodic benefit cost Service cost $ 149 $ 186 $ 447 $ 558 Interest cost 601 587 1,803 1,760 Expected return on assets (531 ) (564 ) (1,593 ) (1,692 ) Amortization of unrecognized prior service cost (416 ) (415 ) (1,246 ) (1,245 ) Amortization of net loss 262 435 784 1,307 Net periodic benefit cost $ 65 $ 229 $ 195 $ 688

UNCONSOLIDATED AFFILIATES (Tabl

UNCONSOLIDATED AFFILIATES (Tables)	9 Months Ended
	Sep. 30, 2016
Equity In Net Earnings From Investments [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	The following table sets forth ONEOK Partners’ equity in net earnings from investments for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Northern Border Pipeline $ 17,854 $ 16,156 $ 52,251 $ 51,131 Overland Pass Pipeline Company 13,886 10,538 40,798 27,048 Other 3,415 5,550 7,392 15,026 Equity in net earnings from investments $ 35,155 $ 32,244 $ 100,441 $ 93,205
Summarized Financial Information Of Unconsolidated Affiliates [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	The following table sets forth summarized combined financial information of ONEOK Partners’ unconsolidated affiliates for the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands of dollars ) Income Statement Operating revenues $ 143,967 $ 135,474 $ 423,170 $ 390,793 Operating expenses $ 66,490 $ 64,786 $ 191,863 $ 178,324 Net income $ 72,672 $ 67,121 $ 214,129 $ 196,123 Distributions paid to ONEOK Partners $ 40,822 $ 36,370 $ 149,399 $ 117,153

ONEOK PARTNERS (Tables)

ONEOK PARTNERS (Tables)	9 Months Ended
	Sep. 30, 2016
Related Party Transaction [Line Items]
ONEOK Partners' transactions	Ownership Interest in ONEOK Partners - Our ownership interest in ONEOK Partners is shown in the table below at September 30, 2016 : General partner interest 2.0 % Limited partner interest (a) 39.2 % Total ownership interest 41.2 % (a) - Represents 41.3 million common units and approximately 73.0 million Class B units, which are convertible, at our option, into common units.
Consolidated Variable Interest Entity Assets and Liabilities	The following table shows the carrying amount and classification of ONEOK Partners’ assets and liabilities in our Consolidated Balance Sheets: September 30, December 31, 2016 2015 ( Thousands of dollars ) Assets Total current assets $ 1,128,794 $ 883,164 Net property, plant and equipment 12,415,775 12,256,791 Total investments and other assets 1,774,989 1,787,631 Total assets $ 15,319,558 $ 14,927,586 Liabilities Total current liabilities $ 2,286,251 $ 1,580,300 Long-term debt, excluding current maturities 6,691,663 6,695,312 Total deferred credits and other liabilities 188,254 154,631 Total liabilities $ 9,166,168 $ 8,430,243
ONEOK Partners' Distributions Paid	The following table sets forth ONEOK Partners’ distributions paid in the periods indicated: Three Months Ended Nine Months Ended September 30, September 30, 2016 2015 2016 2015 ( Thousands, except per unit amounts ) Distribution per unit $ 0.79 $ 0.79 $ 2.37 $ 2.37 General partner distributions $ 6,660 $ 6,081 $ 19,980 $ 17,950 Incentive distributions 100,538 91,794 301,614 270,962 Distributions to general partner 107,198 97,875 321,594 288,912 Limited partner distributions to ONEOK 90,323 73,302 270,969 219,907 Limited partner distributions to noncontrolling interest 135,480 132,862 406,439 388,655 Total distributions paid $ 333,001 $ 304,039 $ 999,002 $ 897,474
ONEOK Partners' Distributions Declared	The following table sets forth 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, 2016 2015 2016 2015 ( Thousands, except per unit amounts ) Distribution per unit $ 0.79 $ 0.79 $ 2.37 $ 2.37 General partner distributions $ 6,660 $ 6,660 $ 19,980 $ 18,696 Incentive distributions 100,538 100,538 301,614 282,221 Distributions to general partner 107,198 107,198 321,594 300,917 Limited partner distributions to ONEOK 90,323 90,323 270,969 236,927 Limited partner distributions to noncontrolling interest 135,480 135,480 406,439 396,925 Total distributions declared $ 333,001 $ 333,001 $ 999,002 $ 934,769

DISCONTINUED OPERATIONS (Tables

DISCONTINUED OPERATIONS (Tables)	9 Months Ended
	Sep. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring and Related Costs [Table Text Block]	The following table summarizes the change in our liability related to released capacity contracts for the periods indicated: Nine Months Ended September 30, 2016 2015 ( Millions of dollars ) Beginning balance $ 36.3 $ 73.8 Settlements (16.2 ) (31.2 ) Accretion 0.4 0.8 Ending balance $ 20.5 $ 43.4

SEGMENTS (Tables)

SEGMENTS (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Reporting Information [Line Items]
Segments	The following tables set forth certain selected financial information for our operating segments for the periods indicated: Three Months Ended September 30, 2016 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Other and Total ( Thousands of dollars ) Sales to unaffiliated customers $ 361,717 $ 1,905,273 $ 90,401 $ 516 $ 2,357,907 Intersegment revenues 150,501 133,984 1,676 (286,161 ) — Total revenues 512,218 2,039,257 92,077 (285,645 ) 2,357,907 Cost of sales and fuel (exclusive of items shown separately below) 336,456 1,694,161 6,870 (285,894 ) 1,751,593 Operating costs 69,443 79,771 28,373 6,564 184,151 Depreciation and amortization 44,994 40,751 12,057 748 98,550 (Gain) loss on sale of assets (846 ) (5 ) (4,894 ) 1 (5,744 ) Operating income $ 62,171 $ 224,579 $ 49,671 $ (7,064 ) $ 329,357 Equity in net earnings from investments $ 2,596 $ 13,960 $ 18,599 $ — $ 35,155 Capital expenditures $ 99,649 $ 30,533 $ 24,495 $ 3,597 $ 158,274 (a) - The Natural Gas Liquids segment has regulated and nonregulated operations. The Natural Gas Liquids segment’s regulated operations had revenues of $299.2 million , of which $253.4 million related to sales within the segment, cost of sales and fuel of $119.6 million and operating income of $118.5 million . (b) - The Natural Gas Pipelines segment has regulated and nonregulated operations. The Natural Gas Pipelines segment’s regulated operations had revenues of $61.0 million , cost of sales and fuel of $7.8 million and operating income of $26.0 million . Three Months Ended September 30, 2015 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Other and Total ( Thousands of dollars ) Sales to unaffiliated customers $ 294,948 $ 1,522,224 $ 81,246 $ 528 $ 1,898,946 Intersegment revenues 139,388 89,230 1,751 (230,369 ) — Total revenues 434,336 1,611,454 82,997 (229,841 ) 1,898,946 Cost of sales and fuel (exclusive of items shown separately below) 293,681 1,289,682 7,628 (230,182 ) 1,360,809 Operating costs 61,162 74,464 26,674 1,877 164,177 Depreciation and amortization 37,286 39,317 10,914 782 88,299 (Gain) loss on sale of assets (132 ) 498 77 283 726 Operating income $ 42,339 $ 207,493 $ 37,704 $ (2,601 ) $ 284,935 Equity in net earnings from investments $ 4,350 $ 10,912 $ 16,982 $ — $ 32,244 Capital expenditures $ 231,835 $ 52,807 $ 14,718 $ 1,508 $ 300,868 (a) - The Natural Gas Liquids segment has regulated and nonregulated operations. The Natural Gas Liquids segment’s regulated operations had revenues of $252.8 million , of which $204.7 million related to sales within the segment, cost of sales and fuel of $112.7 million and operating income of $80.3 million . (b) - The Natural Gas Pipelines segment has regulated and nonregulated operations. The Natural Gas Pipelines segment’s regulated operations had revenues of $65.1 million , cost of sales and fuel of $7.2 million and operating income of $24.7 million . Nine Months Ended September 30, 2016 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Other and Total ( Thousands of dollars ) Sales to unaffiliated customers $ 971,834 $ 5,030,820 $ 262,276 $ 1,543 $ 6,266,473 Intersegment revenues 449,154 367,820 3,843 (820,817 ) — Total revenues 1,420,988 5,398,640 266,119 (819,274 ) 6,266,473 Cost of sales and fuel (exclusive of items shown separately below) 902,747 4,376,345 15,914 (820,352 ) 4,474,654 Operating costs 208,353 236,722 85,075 22,855 553,005 Depreciation and amortization 133,258 122,153 34,634 2,230 292,275 (Gain) loss on sale of assets (2,331 ) (12 ) (7,133 ) (61 ) (9,537 ) Operating income $ 178,961 $ 663,432 $ 137,629 $ (23,946 ) $ 956,076 Equity in net earnings from investments $ 7,987 $ 41,211 $ 51,243 $ — $ 100,441 Investments in unconsolidated affiliates $ 68,735 $ 470,635 $ 404,020 $ — $ 943,390 Total assets $ 5,268,161 $ 8,257,203 $ 1,912,951 $ 543,720 $ 15,982,035 Noncontrolling interests in consolidated subsidiaries $ — $ 158,352 $ — $ 3,067,566 $ 3,225,918 Capital expenditures $ 325,820 $ 85,519 $ 71,721 $ 8,468 $ 491,528 (a) - The Natural Gas Liquids segment has regulated and nonregulated operations. The Natural Gas Liquids segment’s regulated operations had revenues of $878.5 million , of which $742.6 million related to sales within the segment, cost of sales and fuel of $339.1 million and operating income of $354.9 million . (b) - The Natural Gas Pipelines segment has regulated and nonregulated operations. The Natural Gas Pipelines segment’s regulated operations had revenues of $172.4 million , cost of sales and fuel of $19.1 million and operating income of $72.9 million . Nine Months Ended September 30, 2015 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Other and Total ( Thousands of dollars ) Sales to unaffiliated customers $ 862,462 $ 4,726,617 $ 241,605 $ 1,620 $ 5,832,304 Intersegment revenues 487,559 229,804 5,053 (722,416 ) — Total revenues 1,350,021 4,956,421 246,658 (720,796 ) 5,832,304 Cost of sales and fuel (exclusive of items shown separately below) 947,539 4,054,039 28,059 (721,871 ) 4,307,766 Operating costs 193,922 234,120 79,156 1,347 508,545 Depreciation and amortization 109,035 118,044 32,484 1,678 261,241 (Gain) loss on sale of assets (328 ) 579 76 283 610 Operating income $ 99,853 $ 549,639 $ 106,883 $ (2,233 ) $ 754,142 Equity in net earnings from investments $ 13,511 $ 27,585 $ 52,109 $ — $ 93,205 Investments in unconsolidated affiliates $ 253,548 $ 484,403 $ 399,108 $ — $ 1,137,059 Total assets $ 5,206,987 $ 8,041,064 $ 1,845,232 $ 415,015 $ 15,508,298 Noncontrolling interests in consolidated subsidiaries $ 4,066 $ 161,210 $ — $ 3,457,557 $ 3,622,833 Capital expenditures $ 692,570 $ 185,360 $ 39,923 $ 12,463 $ 930,316 (a) - The Natural Gas Liquids segment has regulated and nonregulated operations. The Natural Gas Liquids segment’s regulated operations had revenues of $690.1 million , of which $556.4 million related to sales within the segment, cost of sales and fuel of $297.3 million and operating income of $218.8 million . (b) - The Natural Gas Pipelines segment has regulated and nonregulated operations. The Natural Gas Pipelines segment’s regulated operations had revenues of $198.5 million , cost of sales and fuel of $22.6 million and operating income of $77.8 million . Three Months Ended Nine Months Ended September 30, September 30, ( Unaudited ) 2016 2015 2016 2015 ( Thousands of dollars ) Segment Adjusted EBITDA: Natural Gas Gathering and Processing $ 109,837 $ 82,718 $ 320,170 $ 221,298 Natural Gas Liquids 279,256 255,745 826,036 692,991 Natural Gas Pipelines 80,304 65,166 223,185 201,112 Other (4,061 ) 2,228 (9,744 ) (3,473 ) Depreciation and amortization (98,550 ) (88,299 ) (292,275 ) (261,241 ) Interest expense, net of capitalized interest (118,240 ) (106,923 ) (355,463 ) (306,057 ) Income taxes (55,012 ) (38,298 ) (157,536 ) (123,948 ) AFUDC and other 1,258 (7,639 ) (3,584 ) (9,127 ) Income from continuing operations 194,792 164,698 550,789 411,555 Income (loss) from discontinued operations, net of tax (576 ) (3,860 ) (1,755 ) (4,144 ) Net income $ 194,216 $ 160,838 $ 549,034 $ 407,411

FAIR VALUE MEASUREMENTS - Part

FAIR VALUE MEASUREMENTS - Part 1 (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash held - offsetting derivative net asset positions under master-netting arrangements	$ 0	$ 34,400
Cash posted - total	27,400
Cash posted - offsetting derivative net liability positions under master-netting arrangements	14,600	0
Cash posted - remaining in excess of derivative net liability positions included in consolidated Balance Sheets	12,800
Derivative liabilities
Long-term Debt, Fair Value	9,300,000	7,400,000
Long-term Debt, Book Value	8,800,000	8,400,000
Fair Value, Measurements, Recurring [Member]
Derivative assets
Commodity contracts - financial	4,520	3,760
Commodity contracts - physical	98	3,591
Total derivatives assets	4,618	7,351
Derivative assets netting	(7,389)	(42,414)
Derivative liabilities
Commodity contracts - financial	0	0
Commodity contracts - physical	(3,173)
Interest-rate contracts	(69,103)	(9,936)
Total derivative liabilities	(72,276)	(9,936)
Derivative liabilities netting	22,021	8,026
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative assets
Commodity contracts - financial	9,051	38,921
Commodity contracts - physical	0	0
Total derivatives assets	9,051	38,921
Derivative liabilities
Commodity contracts - financial	(12,175)	(4,513)
Commodity contracts - physical	0
Interest-rate contracts	0	0
Total derivative liabilities	(12,175)	(4,513)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative assets
Commodity contracts - financial	0	0
Commodity contracts - physical	0	0
Total derivatives assets	0	0
Derivative liabilities
Commodity contracts - financial	0	0
Commodity contracts - physical	0
Interest-rate contracts	(69,103)	(9,936)
Total derivative liabilities	(69,103)	(9,936)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative assets
Commodity contracts - financial	2,858	7,253
Commodity contracts - physical	98	3,591
Total derivatives assets	2,956	10,844
Derivative liabilities
Commodity contracts - financial	(9,846)	(3,513)
Commodity contracts - physical	(3,173)
Interest-rate contracts	0	0
Total derivative liabilities	(13,019)	(3,513)
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Derivative assets
Commodity contracts - financial	11,909	46,174
Commodity contracts - physical	98	3,591
Total derivatives assets	12,007	49,765
Derivative liabilities
Commodity contracts - financial	(22,021)	(8,026)
Commodity contracts - physical	(3,173)
Interest-rate contracts	(69,103)	(9,936)
Total derivative liabilities	$ (94,297)	$ (17,962)

FAIR VALUE MEASUREMENTS - Par40

FAIR VALUE MEASUREMENTS - Part 2 (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net assets (liabilities) at beginning of period	$ (14,021)	$ 10,387	$ 7,331	$ 9,285
Total realized/unrealized gains (losses):
Included in earnings	920	(15)	492	95
Included in other comprehensive income (loss)	3,038	(5,076)	(17,886)	(4,084)
Net assets (liabilities) at end of period	(10,063)	5,296	(10,063)	5,296
Transfers between levels	$ 0	$ 0	$ 0	$ 0

RISK MANAGEMENT AND HEDGING A41

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES Part 1 (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Assets	$ 12,007,000	$ 49,765,000
Liabilities	(94,297,000)	(17,962,000)
Derivative, Net Liability Position, Aggregate Fair Value	0
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Assets	9,623,000	42,846,000
Liabilities	(92,652,000)	(11,376,000)
Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	(69,103,000)	(9,936,000)
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Assets	2,384,000	6,919,000
Liabilities	(1,645,000)	(6,586,000)
Physical Derivative Instrument [Member] | Designated as Hedging Instrument [Member] | Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Assets	98,000	3,591,000
Liabilities	(3,173,000)	0
Financial Derivative Instrument [Member] | Designated as Hedging Instrument [Member] | Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Assets	9,525,000	39,255,000
Liabilities	(20,376,000)	(1,440,000)
Financial Derivative Instrument [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Assets	2,384,000	6,919,000
Liabilities	(1,645,000)	(6,586,000)
Natural Gas Pipelines [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net	$ 0	$ 0

RISK MANAGEMENT AND HEDGING A42

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES Part 2 (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)MMcfMMBbls	Dec. 31, 2015USD ($)MMcfMMBbls
Forward Contracts [Member] | Cash Flow Hedging [Member] | Interest Rate Contract [Member] | LIBOR Based Interest Payments [Member]
Derivative [Line Items]
Derivative, Notional Amount | $	$ 1,000
Forward Contracts [Member] | Cash Flow Hedging [Member] | Interest Rate Contract [Member] | Forecasted Debt Issuances [Member]
Derivative [Line Items]
Derivative, Notional Amount | $	1,200	$ 400
Derivative, Notional Amount, New Contracts | $	$ 750
Futures and swaps [Member] | Designated as Hedging Instrument [Member] | Fixed Price [Member] | Purchased [Member] | Natural Gas [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	0	0
Futures and swaps [Member] | Designated as Hedging Instrument [Member] | Fixed Price [Member] | Sold [Member] | Natural Gas [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(43,300)	(27,100)
Futures and swaps [Member] | Designated as Hedging Instrument [Member] | Basis [Member] | Purchased [Member] | Natural Gas [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	0	0
Futures and swaps [Member] | Designated as Hedging Instrument [Member] | Basis [Member] | Sold [Member] | Natural Gas [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	(43,300)	(27,100)
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Purchased [Member]
Derivative [Line Items]
Derivative, Notional Amount | $	$ 2,150	$ 400
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Sold [Member]
Derivative [Line Items]
Derivative, Notional Amount | $	$ 0	$ 0
Options [Member] | Designated as Hedging Instrument [Member] | Fixed Price [Member] | Purchased [Member] | Natural Gas [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	68,300	0
Options [Member] | Designated as Hedging Instrument [Member] | Fixed Price [Member] | Sold [Member] | Natural Gas [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	0	0
Futures, forwards and swaps [Member] | Not Designated as Hedging Instrument [Member] | Fixed Price [Member] | Purchased [Member] | Crude Oil and NGL [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | MMBbls	1.1	0.6
Futures, forwards and swaps [Member] | Not Designated as Hedging Instrument [Member] | Fixed Price [Member] | Sold [Member] | Crude Oil and NGL [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | MMBbls	(0.9)	(0.6)
Futures, forwards and swaps [Member] | Designated as Hedging Instrument [Member] | Fixed Price [Member] | Purchased [Member] | Crude Oil and NGL [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | MMBbls	0	0
Futures, forwards and swaps [Member] | Designated as Hedging Instrument [Member] | Fixed Price [Member] | Sold [Member] | Crude Oil and NGL [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | MMBbls	(4.6)	(2.3)

RISK MANAGEMENT AND HEDGING A43

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES Part 3 (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (154,351)		$ (154,351)		$ (127,242)
Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion)			(25,597)
Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion)	8,538	$ 15,949	(98,613)	$ 21,373
Total gain (loss) reclassified from accumulated other comprehensive income (loss) into net income on derivatives (effective portion)	(3,894)	18,216	15,154	41,151
Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net	0	0	0	0
Commodity Contract [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Commodity cash flow hedge gain (loss) to be reclassified	(7,100)		(7,100)
Price Risk Cash Flow Hedge Unrealized Gain (Loss) to be Reclassified During Next 12 Months	(5,600)		(5,600)
Commodity Cash Flow Hedge Gain (Loss) To Be Reclassified After Next 12 Months Net	(1,500)		(1,500)
Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion)	7,580	36,559	(39,396)	47,650
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)	908	22,770	29,456	54,020
Interest Rate Contract [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of accumulated other comprehensive income (loss) attributable primarily to settled interest-rate swaps.	(45,500)		(45,500)
Amount of loss to be recognized in the next 12 months	(6,400)		(6,400)
Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion)	958	(20,610)	(59,217)	(26,277)
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)	$ (4,802)	$ (4,554)	$ (14,302)	$ (12,869)

SHORT-TERM BORROWINGS (Details)

SHORT-TERM BORROWINGS (Details)	9 Months Ended
	Sep. 30, 2016USD ($)Rate
ONEOK Credit Agreement [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 300,000,000
Indebtedness To Adjusted EBITDA Maximum	4
Indebtedness To Adjusted EBITDA Current	2.1
Line of Credit Facility Letter of Credit Sublimit	$ 50,000,000
Line of Credit Facility Swingline Sublimit	50,000,000
Line Of Credit Facility Option To Increase Borrowing Capacity	$ 500,000,000
Interest rate description	borrowings, if any, will accrue interest at LIBOR plus 145 basis points
Line Of Credit Facility, Annual Facility Fee Description	the annual facility fee is 30 basis points
Letters of credit issued	$ 1,100,000
Borrowings outstanding under Partnership Credit Agreement	0
Partnership Credit Agreement [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 2,400,000,000
Indebtedness To Adjusted EBITDA Maximum	5
Indebtedness To Adjusted EBITDA Current	4.1
Line of Credit Facility Letter of Credit Sublimit	$ 100,000,000
Line of Credit Facility Swingline Sublimit	$ 150,000,000
Interest rate description	borrowings, if any, will accrue at LIBOR plus 117.5 basis points
Line Of Credit Facility, Annual Facility Fee Description	the annual facility fee is 20 basis points
Letters of credit issued	$ 14,000,000
Borrowings outstanding under Partnership Credit Agreement	0
Line of Credit Facility, Remaining Borrowing Capacity	$ 1,700,000,000
Indebtedness To Adjusted EBITDA From Acquisitions Maximum	5.5
Acquisition price threshold for increase in permitted debt to EBITDA covenant ratio	$ 25,000,000
Commercial Paper [Member]
Line of Credit Facility [Line Items]
Commercial paper outstanding	694,000,000
Maximum Amount Of Commercial Paper	$ 2,400,000,000
Short-term Debt, Weighted Average Interest Rate | Rate	1.15%

LONG-TERM DEBT (Details)

LONG-TERM DEBT (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 8,830,704	$ 8,486,820
Unamortized Portion of Terminated Swaps	20,615	21,904
Unamortized debt issuance costs and discounts	(70,525)	(74,492)
Long-term Debt, Current Maturities	(460,650)	(110,650)
Long-term debt, excluding current maturities	8,320,144	8,323,582
Payments to Acquire Interest in Subsidiaries and Affiliates		650,000
Parent Company [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 1,634,534	1,634,913
Parent Company [Member] | Note Payable from Public Offering Due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.25%
Long-term Debt, Gross	$ 547,397	$ 547,397
Parent Company [Member] | Note Payable Due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.50%	7.50%
Long-term Debt, Gross	$ 500,000	$ 500,000
Proceeds from Debt, Net of Issuance Costs		487,100
Parent Company [Member] | Note Payables 1 due 2028 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.50%
Long-term Debt, Gross	$ 87,137	87,516
Parent Company [Member] | Note Payables 2 due 2028 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.875%
Long-term Debt, Gross	$ 100,000	100,000
Parent Company [Member] | Notes Payables due 2035 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.00%
Long-term Debt, Gross	$ 400,000	400,000
Partnership Interest [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 7,196,170	6,851,907
Partnership Interest [Member] | Note Payable from Public Offering Due 2016 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.25%
Long-term Debt, Gross	$ 0	650,000
Partnership Interest [Member] | Notes Payable due 2016 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.15%
Long-term Debt, Gross	$ 450,000	450,000
Partnership Interest [Member] | Note Payable from Public Offering Due 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.00%
Long-term Debt, Gross	$ 400,000	400,000
Partnership Interest [Member] | Note Payable from Public Offering Due 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.20%
Long-term Debt, Gross	$ 425,000	425,000
Partnership Interest [Member] | Term Loan Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	1,000,000	0
Delayed-Draw Unsecured Senior Term Loan	$ 1,000,000
Debt Instrument, Interest Rate Terms	LIBOR plus 130 basis points
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	1.83%
Proceeds from Debt, Net of Issuance Costs	$ 1,000,000
Partnership Interest [Member] | Notes Payables due 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	8.625%
Long-term Debt, Gross	$ 500,000	$ 500,000
Partnership Interest [Member] | Note Payable from Public Offering Due 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.80%	3.80%
Long-term Debt, Gross	$ 300,000	$ 300,000
Partnership Interest [Member] | Note Payable 2 from Public Offering Due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.375%
Long-term Debt, Gross	$ 900,000	900,000
Partnership Interest [Member] | Note Payable from Public Offering Due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.00%
Long-term Debt, Gross	$ 425,000	$ 425,000
Partnership Interest [Member] | Note Payable from Public Offering Due 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.90%	4.90%
Long-term Debt, Gross	$ 500,000	$ 500,000
Partnership Interest [Member] | Notes Payables due 2036 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.65%
Long-term Debt, Gross	$ 600,000	600,000
Partnership Interest [Member] | Notes Payables due 2037 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.85%
Long-term Debt, Gross	$ 600,000	600,000
Partnership Interest [Member] | Note Payable from Public Offering Due 2041 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.125%
Long-term Debt, Gross	$ 650,000	650,000
Partnership Interest [Member] | Note Payable from Public Offering Due 2043 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.20%
Long-term Debt, Gross	$ 400,000	400,000
Guardian Pipeline [Member] | Notes Payables 1 due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Weighted Average Interest Rate	7.85%
Long-term Debt, Gross	$ 46,170	51,907
Senior Notes [Member] | Partnership Interest [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent		800,000
Proceeds from Debt, Net of Issuance Costs		$ 792,300

EQUITY (Details)

EQUITY (Details) - $ / shares	3 Months Ended					9 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Common Stock, Dividends, Per Share, Cash Paid		$ 0.615	$ 0.615	$ 0.615		$ 1.845	$ 1.815
Common Stock, Dividends, Per Share, Declared		$ 0.615			$ 0.605	$ 1.845	$ 1.815
Subsequent Event [Member]
Common Stock, Dividends, Per Share, Declared	$ 0.615
Dividends Payable, Date of Record	Oct. 31, 2016
Dividends Payable, Date to be Paid	Nov. 14, 2016

ACCUMULATED OTHER COMPREHENSI47

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Unrealized gains (losses) on risk-management assets/liabilities - January 1, 2016			$ (42,199)
Pension and postretirement benefit plan obligation - January 1, 2016			(84,543)
Unrealized gains (losses) on risk-management assets/liabilities of unconsolidated affiliates - January 1, 2016			(500)
Accumulated other comprehensive loss - January 1, 2016			(127,242)
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net			(25,597)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments, Net of Tax			9
Other Comprehensive Income (Loss), Amount Attributable to Equity Method Investments, before Reclassification Adjustments, Net of Tax			(3,133)
Other comprehensive income (loss) before reclassifications			(28,721)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	$ 3,083	$ (15,259)	(13,496)	$ (35,530)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Other Comprehensive Income Attributable to Equity Method Investments, Net of Tax			0
Other Comprehensive Income (Loss), Reclassification Adjustment included in Net Income, Net of Tax	2,859	(2,691)	1,612	(2,530)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent			(28,634)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	1,553	2,441	4,658	7,320
Other Comprehensive Income (Loss), Portion Attributable to Equity Method Investments, Net of Tax			(3,133)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent			(27,109)
Unrealized gains (losses) on risk-management assets/liabilities - September 30, 2016	(70,833)		(70,833)
Pension and postretirement benefit plan obligation - September 30, 2016	(79,885)		(79,885)
Unrealized gains (losses) on risk-management assets/liabilities of unconsolidated affiliates - September 30, 2016	(3,633)		(3,633)
Accumulated other comprehensive loss - September 30, 2016	(154,351)		(154,351)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	(811)	2,957	1,658	5,621
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	1,309	(5,109)	(3,037)	(9,785)
Accumulated Defined Benefit Plans Adjustment [Member]
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax	1,550	2,418	4,649	7,255
Defined Benefit Plan, Future Amortization of Gain (Loss)	2,999	4,422	8,994	13,268
Defined Benefit Plan, Future Amortization of Prior Service Cost (Credit)	(416)	(392)	(1,246)	(1,176)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax	2,583	4,030	7,748	12,092
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), Tax	(1,033)	(1,612)	(3,099)	(4,837)
Total before tax [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	3,894	(18,216)	(15,154)	(41,151)
Tax Expense [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	(811)	2,957	1,658	5,621
Net of tax [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	3,083	(15,259)	(13,496)	(35,530)
Net income attributable to noncontrolling interest [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Noncontrolling Interest	1,774	(10,150)	(10,459)	(25,745)
Commodity Contract [Member] | Sales [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(908)	(22,770)	(29,456)	(54,020)
Interest Rate Contract [Member] | Interest Expense [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ 4,802	$ 4,554	$ 14,302	$ 12,869

EARNINGS PER SHARE (Details)

EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Basic EPS from Continuing Operations [Abstract]
Income from continuing operations attributable to ONEOK available for common stock	$ 92,720	$ 86,017	$ 263,289	$ 223,606
Weighted Average number of share, basic (in shares)	211,309	210,296	211,038	210,138
Per share amount, basic (in dollars per shares)	$ 0.44	$ 0.41	$ 1.25	$ 1.06
Diluted EPS from continuing operations [Abstract]
Effect of dilutive securities	$ 0	$ 0	$ 0	$ 0
Effect of dilutive securities, number of shares (in shares)	1,561	228	1,085	371
Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents	$ 92,720	$ 86,017	$ 263,289	$ 223,606
Weighted Average number of share, diluted (in shares)	212,870	210,524	212,123	210,509
Per Share amount, diluted (in dollars per share)	$ 0.44	$ 0.41	$ 1.24	$ 1.06

EMPLOYEE BENEFIT PLANS (Details

EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Pension Benefits [Member]
Components of net periodic benefit cost
Service cost	$ 1,622	$ 1,887	$ 4,866	$ 5,661
Interest cost	4,946	4,546	14,840	13,638
Expected return on assets	(5,077)	(5,213)	(15,231)	(15,639)
Amortization of unrecognized prior service cost	0	23	0	69
Amortization of net loss	2,737	3,987	8,210	11,961
Net periodic benefit cost	4,228	5,230	12,685	15,690
Postretirement Benefits [Member]
Components of net periodic benefit cost
Service cost	149	186	447	558
Interest cost	601	587	1,803	1,760
Expected return on assets	(531)	(564)	(1,593)	(1,692)
Amortization of unrecognized prior service cost	(416)	(415)	(1,246)	(1,245)
Amortization of net loss	262	435	784	1,307
Net periodic benefit cost	$ 65	$ 229	$ 195	$ 688

UNCONSOLIDATED AFFILIATES (Deta

UNCONSOLIDATED AFFILIATES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	$ 35,155	$ 32,244	$ 100,441	$ 93,205
Accounts Payable, Related Parties, Current	11,500		11,500			$ 8,000
Income Statement
Operating revenues	143,967	135,474	423,170	390,793
Operating expenses	66,490	64,786	191,863	178,324
Net income	72,672	67,121	214,129	196,123
Proceeds from Equity Method Investment, Dividends or Distributions, Total	40,822	36,370	149,399	117,153
Roadrunner Gas Transmission [Member]
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Equity Method Investments			55,000
Northern Border Pipeline [Member]
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	17,854	16,156	52,251	51,131
Overland Pass Pipeline Company [Member]
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	13,886	10,538	40,798	27,048
Other Unconsolidated Affiliate [Member]
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	3,415	5,550	7,392	15,026
Unconsolidated Affiliates [Member]
Income Statement
Costs and operating expenses with equity method investees	$ 36,400	$ 28,400	$ 105,300	$ 74,200
Scenario, Forecast [Member] | Roadrunner Gas Transmission [Member]
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Equity Method Investments					$ 10,000

ONEOK PARTNERS (Details)

ONEOK PARTNERS (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Related Party Transaction [Line Items]
Ownership Interest			41.20%
Common units	41.3		41.3
Class B units	73		73
Assets, Current	$ 1,369,291		$ 1,369,291		$ 975,210
Property, Plant and Equipment, Net	12,526,749		12,526,749		12,373,989
Investments and Other Noncurrent Assets	2,085,995		2,085,995		2,096,912
Assets	15,982,035	$ 15,508,298	15,982,035	$ 15,508,298	15,446,111
Liabilities, Current	2,341,964		2,341,964		1,638,266
Long-term debt, excluding current maturities	8,320,144		8,320,144		8,323,582
Liabilities, Other than Long-term Debt, Noncurrent	1,879,713		1,879,713		1,717,927
Aggregate Amount Of Common Units Available For Issuance And Sale Under Equity Distribution Agreement			650,000
Remaining Capacity of At The Market Equity Program	138,000		$ 138,000
Key Provisions of Operating or Partnership Agreement, Description			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 the Partnership Agreement, 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 the Partnership Agreement. 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 the Partnership Agreement 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.
Roadrunner Gas Transmission [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction	2,500		$ 6,900
ONEOK [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	95,200	$ 89,300	$ 285,100	$ 265,600
General Partner [Member]
Related Party Transaction [Line Items]
Ownership Interest			2.00%
Limited Partner [Member]
Related Party Transaction [Line Items]
Ownership Interest			39.20%
Assets, Current	1,128,794		$ 1,128,794		883,164
Property, Plant and Equipment, Net	12,415,775		12,415,775		12,256,791
Investments and Other Noncurrent Assets	1,774,989		1,774,989		1,787,631
Assets	15,319,558		15,319,558		14,927,586
Liabilities, Current	2,286,251		2,286,251		1,580,300
Long-term debt, excluding current maturities	6,691,663		6,691,663		6,695,312
Liabilities, Other than Long-term Debt, Noncurrent	188,254		188,254		154,631
Liabilities	$ 9,166,168		$ 9,166,168		$ 8,430,243
Distribution Paid [Member]
Related Party Transaction [Line Items]
Distribution per unit	$ 0.79	$ 0.79	$ 2.37	$ 2.37
General Partners' Capital Account, Period Distribution Amount	$ 107,198	$ 97,875	$ 321,594	$ 288,912
Total distributions	333,001	304,039	999,002	897,474
Distribution Paid [Member] | ONEOK [Member]
Related Party Transaction [Line Items]
Limited partner distributions to ONEOK	90,323	73,302	270,969	219,907
Distribution Paid [Member] | General Partner [Member]
Related Party Transaction [Line Items]
General partner distributions	6,660	6,081	19,980	17,950
Incentive distributions	100,538	91,794	301,614	270,962
Distribution Paid [Member] | Limited Partner [Member]
Related Party Transaction [Line Items]
Partners Capital Account Distributions to Other Unitholders	$ 135,480	$ 132,862	$ 406,439	$ 388,655
Distribution Declared [Member]
Related Party Transaction [Line Items]
Distribution per unit	$ 0.79	$ 0.79	$ 2.37	$ 2.37
Distribution Made To Member Or Limited Parter Annualized Quarterly Distribution	$ 3.16
Distribution Made to Limited Partner, Distribution Date	Nov. 14, 2016
Distribution Made to Limited Partner, Date of Record	Oct. 31, 2016
General Partners' Capital Account, Period Distribution Amount	$ 107,198	$ 107,198	$ 321,594	$ 300,917
Total distributions	333,001	333,001	999,002	934,769
Distribution Declared [Member] | ONEOK [Member]
Related Party Transaction [Line Items]
Limited partner distributions to ONEOK	90,323	90,323	270,969	236,927
Distribution Declared [Member] | General Partner [Member]
Related Party Transaction [Line Items]
General partner distributions	6,660	6,660	19,980	18,696
Incentive distributions	100,538	100,538	301,614	282,221
Distribution Declared [Member] | Limited Partner [Member]
Related Party Transaction [Line Items]
Partners Capital Account Distributions to Other Unitholders	$ 135,480	$ 135,480	$ 406,439	$ 396,925
Private Placement [Member]
Related Party Transaction [Line Items]
Partners' Capital Account, Units, Sold in Private Placement					21.5
Per Unit Offering Price Under Private Placement					$ 30.17
Partners' Capital Account, Contributions					$ 15,300
Partners Capital Account Units Sold Under Equity Distribution Agreement					3.3
Proceeds from Sale of Interest in Partnership Unit					$ 749,000
Issued Under Equity Distribution Agreement [Member]
Related Party Transaction [Line Items]
Partners Capital Account Units Sold Under Equity Distribution Agreement	0		0		10.5
Proceeds from Sale of Interest in Partnership Unit					$ 381,600
General Partner [Member]
Related Party Transaction [Line Items]
Ownership Interest			2.00%

DISCONTINUED OPERATIONS (Detail

DISCONTINUED OPERATIONS (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accumulated charges attributable to exit activities, at beginning of period	$ 36.3	$ 73.8
Settlements	(16.2)	(31.2)
Accretion	0.4	0.8
Accumulated charges attributable to exit activities, at end of period	20.5	$ 43.4
Effect on future cash flows, amount	21
2016 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Effect on future cash flows, amount	3
2017 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Effect on future cash flows, amount	10
2018 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Effect on future cash flows, amount	4
2019 - 2023 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Effect on future cash flows, amount	$ 4

SEGMENTS Part 1 (Details)

SEGMENTS Part 1 (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Segment Reporting, Disclosure of Major Customers	For the three months ended September 30, 2016, ONEOK Partners had no single customer from which we received 10 percent or more of our consolidated revenues.	For the three months ended September 30, 2015, ONEOK Partners had had no single customer from which we received 10 percent or more of our consolidated revenues.	For the nine months ended September 30, 2016, ONEOK Partners had had no single customer from which we received 10 percent or more of our consolidated revenues.	For the nine months ended September 30, 2015, ONEOK Partners had had no single customer from which we received 10 percent or more of our consolidated revenues.
Total revenues	$ 2,357,907	$ 1,898,946	$ 6,266,473	$ 5,832,304
Cost of sales and fuel (exclusive of items shown separately below)	1,751,593	1,360,809	4,474,654	4,307,766
Operating costs	184,151	164,177	553,005	508,545
Depreciation and amortization	98,550	88,299	292,275	261,241
(Gain) loss on sale of assets	(5,744)	726	(9,537)	610
Operating Income	329,357	284,935	956,076	754,142
Equity in net earnings from investments	35,155	32,244	100,441	93,205
Investments in unconsolidated affiliates	943,390	1,137,059	943,390	1,137,059	$ 948,221
Total Assets	15,982,035	15,508,298	15,982,035	15,508,298	15,446,111
Noncontrolling interests in consolidated subsidiaries	3,225,918	3,622,833	3,225,918	3,622,833	$ 3,430,538
Capital expenditures	158,274	300,868	491,528	930,316
Natural Gas Gathering And Processing [Member]
Segment Reporting Information [Line Items]
Total revenues	512,218	434,336	1,420,988	1,350,021
Cost of sales and fuel (exclusive of items shown separately below)	336,456	293,681	902,747	947,539
Operating costs	69,443	61,162	208,353	193,922
Depreciation and amortization	44,994	37,286	133,258	109,035
(Gain) loss on sale of assets	(846)	(132)	(2,331)	(328)
Operating Income	62,171	42,339	178,961	99,853
Equity in net earnings from investments	2,596	4,350	7,987	13,511
Investments in unconsolidated affiliates	68,735	253,548	68,735	253,548
Total Assets	5,268,161	5,206,987	5,268,161	5,206,987
Noncontrolling interests in consolidated subsidiaries	0	4,066	0	4,066
Capital expenditures	99,649	231,835	325,820	692,570
Natural Gas Liquids [Member]
Segment Reporting Information [Line Items]
Total revenues	2,039,257	1,611,454	5,398,640	4,956,421
Cost of sales and fuel (exclusive of items shown separately below)	1,694,161	1,289,682	4,376,345	4,054,039
Operating costs	79,771	74,464	236,722	234,120
Depreciation and amortization	40,751	39,317	122,153	118,044
(Gain) loss on sale of assets	(5)	498	(12)	579
Operating Income	224,579	207,493	663,432	549,639
Equity in net earnings from investments	13,960	10,912	41,211	27,585
Investments in unconsolidated affiliates	470,635	484,403	470,635	484,403
Total Assets	8,257,203	8,041,064	8,257,203	8,041,064
Noncontrolling interests in consolidated subsidiaries	158,352	161,210	158,352	161,210
Capital expenditures	30,533	52,807	85,519	185,360
Natural Gas Liquids [Member] | Natural Gas Liquids Regulated [Member]
Segment Reporting Information [Line Items]
Total revenues	299,200	252,800	878,500	690,100
Cost of sales and fuel (exclusive of items shown separately below)	119,600	112,700	339,100	297,300
Operating Income	118,500	80,300	354,900	218,800
Natural Gas Pipelines [Member]
Segment Reporting Information [Line Items]
Total revenues	92,077	82,997	266,119	246,658
Cost of sales and fuel (exclusive of items shown separately below)	6,870	7,628	15,914	28,059
Operating costs	28,373	26,674	85,075	79,156
Depreciation and amortization	12,057	10,914	34,634	32,484
(Gain) loss on sale of assets	(4,894)	77	(7,133)	76
Operating Income	49,671	37,704	137,629	106,883
Equity in net earnings from investments	18,599	16,982	51,243	52,109
Investments in unconsolidated affiliates	404,020	399,108	404,020	399,108
Total Assets	1,912,951	1,845,232	1,912,951	1,845,232
Noncontrolling interests in consolidated subsidiaries	0	0	0	0
Capital expenditures	24,495	14,718	71,721	39,923
Natural Gas Pipelines [Member] | Natural Gas Pipelines Regulated [Member]
Segment Reporting Information [Line Items]
Total revenues	61,000	65,100	172,400	198,500
Cost of sales and fuel (exclusive of items shown separately below)	7,800	7,200	19,100	22,600
Operating Income	26,000	24,700	72,900	77,800
Corporate Elimination [Member]
Segment Reporting Information [Line Items]
Total revenues	(285,645)	(229,841)	(819,274)	(720,796)
Cost of sales and fuel (exclusive of items shown separately below)	(285,894)	(230,182)	(820,352)	(721,871)
Operating costs	6,564	1,877	22,855	1,347
Depreciation and amortization	748	782	2,230	1,678
(Gain) loss on sale of assets	1	283	(61)	283
Operating Income	(7,064)	(2,601)	(23,946)	(2,233)
Equity in net earnings from investments	0	0	0	0
Investments in unconsolidated affiliates	0	0	0	0
Total Assets	543,720	415,015	543,720	415,015
Noncontrolling interests in consolidated subsidiaries	3,067,566	3,457,557	3,067,566	3,457,557
Capital expenditures	3,597	1,508	8,468	12,463
Sales to unaffiliated customers
Segment Reporting Information [Line Items]
Total revenues	2,357,907	1,898,946	6,266,473	5,832,304
Sales to unaffiliated customers | Natural Gas Gathering And Processing [Member]
Segment Reporting Information [Line Items]
Total revenues	361,717	294,948	971,834	862,462
Sales to unaffiliated customers | Natural Gas Liquids [Member]
Segment Reporting Information [Line Items]
Total revenues	1,905,273	1,522,224	5,030,820	4,726,617
Sales to unaffiliated customers | Natural Gas Pipelines [Member]
Segment Reporting Information [Line Items]
Total revenues	90,401	81,246	262,276	241,605
Sales to unaffiliated customers | Corporate Elimination [Member]
Segment Reporting Information [Line Items]
Total revenues	516	528	1,543	1,620
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Operating Segments [Member] | Natural Gas Gathering And Processing [Member]
Segment Reporting Information [Line Items]
Total revenues	150,501	139,388	449,154	487,559
Operating Segments [Member] | Natural Gas Liquids [Member]
Segment Reporting Information [Line Items]
Total revenues	133,984	89,230	367,820	229,804
Operating Segments [Member] | Natural Gas Liquids [Member] | Natural Gas Liquids Regulated [Member]
Segment Reporting Information [Line Items]
Total revenues	253,400	204,700	742,600	556,400
Operating Segments [Member] | Natural Gas Pipelines [Member]
Segment Reporting Information [Line Items]
Total revenues	1,676	1,751	3,843	5,053
Operating Segments [Member] | Corporate Elimination [Member]
Segment Reporting Information [Line Items]
Total revenues	$ (286,161)	$ (230,369)	$ (820,817)	$ (722,416)

SEGMENTS SEGMENTS Part 2 (Detai

SEGMENTS SEGMENTS Part 2 (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Reconciliation of Adjusted EBITDA to Net Income [Line Items]
Depreciation and amortization	$ (98,550)	$ (88,299)	$ (292,275)	$ (261,241)
Interest expense (net of capitalized interest)	(118,240)	(106,923)	(355,463)	(306,057)
Income taxes	(55,012)	(38,298)	(157,536)	(123,948)
AFUDC and other	1,258	(7,639)	(3,584)	(9,127)
Income from continuing operations	194,792	164,698	550,789	411,555
Income (loss) from discontinued operations, net of tax	(576)	(3,860)	(1,755)	(4,144)
Net income	194,216	160,838	549,034	407,411
Natural Gas Gathering And Processing [Member]
Reconciliation of Adjusted EBITDA to Net Income [Line Items]
Adjusted EBITDA	109,837	82,718	320,170	221,298
Depreciation and amortization	(44,994)	(37,286)	(133,258)	(109,035)
Natural Gas Liquids [Member]
Reconciliation of Adjusted EBITDA to Net Income [Line Items]
Adjusted EBITDA	279,256	255,745	826,036	692,991
Depreciation and amortization	(40,751)	(39,317)	(122,153)	(118,044)
Natural Gas Pipelines [Member]
Reconciliation of Adjusted EBITDA to Net Income [Line Items]
Adjusted EBITDA	80,304	65,166	223,185	201,112
Depreciation and amortization	(12,057)	(10,914)	(34,634)	(32,484)
Other Segments [Member]
Reconciliation of Adjusted EBITDA to Net Income [Line Items]
Adjusted EBITDA	$ (4,061)	$ 2,228	$ (9,744)	$ (3,473)