ONEOK (OKE) 10-Q 2 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Jul. 24, 2017
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
Limited Partners' Capital Account, Units Outstanding		380,008,256
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues
Commodity sales	$ 2,161,009	$ 1,633,272	$ 4,377,726	$ 2,916,783
Services	564,763	500,835	1,097,657	991,783
Total revenues	2,725,772	2,134,107	5,475,383	3,908,566
Cost of sales and fuel (exclusive of items shown separately below)	2,091,022	1,527,323	4,234,865	2,723,061
Operations and maintenance	193,501	167,667	358,270	322,812
Depreciation and amortization	100,849	99,247	200,268	193,725
General taxes	24,304	24,172	51,457	46,042
(Gain) loss on sale of assets	(637)	413	(630)	(3,793)
Operating income	316,733	315,285	631,153	626,719
Equity in net earnings from investments (Note J)	39,363	32,372	78,927	65,286
Allowance for equity funds used during construction	22	0	35	208
Other income	4,033	4,804	8,374	5,109
Other expense	(21,843)	(941)	(22,593)	(1,578)
Interest expense (net of capitalized interest of $1,745, $2,572, $3,186 ,and $5,459, respectively)	(118,473)	(118,976)	(234,935)	(237,223)
Income before income taxes	219,835	232,544	460,961	458,521
Income taxes	(43,844)	(52,458)	(98,785)	(102,524)
Income from Continuing Operations	175,991	180,086	362,176	355,997
Income (Loss) from Discontinued Operations, Net of Tax	0	(227)	0	(1,179)
Net income	175,991	179,859	362,176	354,818
Less: Net income attributable to noncontrolling interests	104,298	93,915	203,122	185,428
Net income attributable to ONEOK	71,693	85,944	159,054	169,390
Less: Preferred Stock Dividends	217	0	217	0
Net Income	71,476	85,944	158,837	169,390
Amounts available to common shareholders
Income from Continuing Operations	71,476	86,171	158,837	170,569
Income (Loss) from Discontinued Operations	0	(227)	0	(1,179)
Net Income	$ 71,476	$ 85,944	$ 158,837	$ 169,390
Basic earnings per common share:
Income from Continuing Operations (Note H)	$ 0.34	$ 0.41	$ 0.75	$ 0.81
Income (Loss) from Discontinued Operations	0	0	0	(0.01)
Net income	0.34	0.41	0.75	0.80
Diluted earnings per common share:
Income from Continuing Operations (Note H)	0.33	0.41	0.74	0.81
Income (Loss) from Discontinued Operations	0	(0.01)	0	(0.01)
Net income	$ 0.33	$ 0.40	$ 0.74	$ 0.80
Average shares (thousands)
Basic	211,785	211,075	211,702	210,928
Diluted	214,012	212,618	213,807	211,663
Dividends declared per share of common stock	$ 0.615	$ 0.615	$ 1.230	$ 1.230

CONSOLIDATED STATEMENT OF INCOM

CONSOLIDATED STATEMENT OF INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Interest Costs, Capitalized During Period	$ 1,745	$ 2,572	$ 3,186	$ 5,459

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net income	$ 175,991	$ 179,859	$ 362,176	$ 354,818
Other comprehensive income (loss)
Unrealized gains (losses) on derivatives, net of tax of $874, $13,295, $(3,527) and $16,334, respectively	(5,123)	(73,923)	19,333	(90,817)
Realized (gains) losses on derivatives recognized in net income, net of tax of $(2,041), $1,193, $(5,406) and $2,469, respectively	9,927	(8,054)	27,210	(16,579)
Change in pension and postretirement benefit plan liability, net of tax of $(1,361), $(1,035), $(2,721) and $(2,070) respectively	2,040	1,552	4,081	3,105
Other comprehensive income (loss) on investments in unconsolidated affiliates, net of tax of $246, $848, $188 and $1,732, respectively	(1,370)	(4,714)	(1,045)	(9,631)
Total other comprehensive income (loss), net of tax	5,474	(85,139)	49,579	(113,922)
Comprehensive income	181,465	94,720	411,755	240,896
Less: Comprehensive income attributable to noncontrolling interests	106,507	33,408	234,148	103,510
Comprehensive income attributable to ONEOK	$ 74,958	$ 61,312	$ 177,607	$ 137,386

CONSOLIDATED STATEMENTS OF COM5

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (PARANTHETICAL) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Unrealized Gains (Losses) on Derivatives, Tax	$ 874	$ 13,295	$ (3,527)	$ 16,334
Realized (Gains) Losses on Derivatives in Net Income, Tax	(2,041)	1,193	(5,406)	2,469
Change in Pension and Postretirement Benefit Plan Liability, Tax	(1,361)	(1,035)	(2,721)	(2,070)
Other Comprehensive Income (Loss) on Investments in Unconsolidated Affiliates, Tax	$ 246	$ 848	$ 188	$ 1,732

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 332,371	$ 248,875
Accounts receivable, net	749,345	872,430
Materials and supplies	75,172	60,912
Natural gas and natural gas liquids in storage	200,133	140,034
Commodity imbalances	39,325	60,896
Other current assets	51,465	45,986
Asset of discontinued operations	0	551
Total current assets	1,447,811	1,429,684
Property, plant and equipment
Property, plant and equipment	15,241,140	15,078,497
Accumulated depreciation and amortization	2,694,148	2,507,094
Net property, plant and equipment	12,546,992	12,571,403
Investments and other assets
Investments in unconsolidated affiliates	944,562	958,807
Goodwill and intangible assets	999,409	1,005,359
Deferred Income Taxes	563,364	0
Other assets	170,785	162,998
Asset of discontinued operations	0	10,500
Total investments and other assets	2,678,120	2,137,664
Total assets	16,672,923	16,138,751
Current liabilities
Current maturities of long-term debt (Note E)	494,703	410,650
Short-term borrowings (Note E)	1,274,407	1,110,277
Accounts payable	696,834	874,731
Commodity imbalances	114,941	142,646
Accrued interest	111,697	112,514
Other current liabilities	167,937	166,042
Liabilities of discontinued operations	0	19,841
Liabilities, Current	2,860,519	2,836,701
Long-term debt, excluding current maturities (Note E)	7,835,606	7,919,996
Deferred income taxes	73,983	1,623,822
Other deferred credits	337,584	321,846
Liabilities of discontinued operations	0	7,471
Deferred credits and other liabilities	411,567	1,953,139
Commitments and contingencies (Note K)
Equity (Note F)
Preferred stock, $0.01 par value:issued 20,000 shares at June 30, 2017, and no shares at December 31, 2016	0	0
Common stock, $0.01 par value:authorized 1,200,000,000 shares; issued 414,732,011 shares and outstanding380,004,718 shares at June 30, 2017; issued 245,811,180 shares andoutstanding 210,681,661 shares at December 31, 2016	4,147	2,458
Additional Paid in Capital	6,463,130	1,234,314
Accumulated other comprehensive loss (Note G)	(176,085)	(154,350)
Retained Earnings	0	0
Treasury stock, at cost: 34,727,293 shares at June 30, 2017, and35,129,519 shares at December 31, 2016	(883,445)	(893,677)
Total ONEOK Shareholder' Equity	5,407,747	188,745
Noncontrolling interests in consolidated subsidiaries	157,484	3,240,170
Total equity	5,565,231	3,428,915
Total liabilities and equity	$ 16,672,923	$ 16,138,751

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 30, 2017	Dec. 31, 2016
Equity (Note F)
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares, Issued	414,732,011	245,811,180
Common Stock, Shares Authorized	1,200,000,000	600,000,000
Common Stock, Shares, Outstanding	380,004,718	210,681,661
Treasury Stock, Shares	34,727,293	35,129,519
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0
Preferred Stock, Shares Issued	20,000	0

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating activities
Net income	$ 362,176	$ 354,818
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	200,268	193,725
Noncash contribution of preferred stock, net of tax	12,600	0
Equity in net earnings from investments	(78,927)	(65,286)
Distributions received from unconsolidated affiliates	81,744	72,204
Deferred Income Taxes	90,685	105,567
Share-based Compensation	13,477	23,194
Pension and Other Postretirement Benefit Expense, Net of Contributions	(1,576)	6,172
Allowance for equity funds used during construction	(35)	(208)
(Gain) loss on sale of assets	(630)	(3,793)
Changes in assets and liabilities:
Accounts receivable	123,085	(85,435)
Natural gas and natural gas liquids in storage	(60,099)	(117,862)
Accounts payable	(134,334)	103,976
Commodity imbalances, net	(6,134)	31,465
Settlement of exit liabilities	(6,546)	(11,590)
Accrued interest	(817)	(9,269)
Risk-management assets and liabilities	66,940	(60,016)
Other assets and liabilities, net	(18,986)	(6,056)
Cash provided by operating activities	642,891	531,606
Investing activities
Capital expenditures (less allowance for equity funds used during construction)	(195,232)	(333,254)
Contributions to unconsolidated affiliates	(4,653)	(19,830)
Distributions received from unconsolidated affiliates in excess of cumulative earnings	14,936	36,373
Proceeds from sale of assets	1,218	18,232
Cash used in investing activities	(183,731)	(298,479)
Financing activities
Dividends paid	(259,758)	(258,508)
Distributions to noncontrolling interests	(273,460)	(275,259)
Borrowing (repayment) of short-term borrowings, net	164,130	29,967
Issuance of long-term debt, net of discounts	0	1,000,000
Debt financing costs	(38)	(2,770)
Repayment of long-term debt	(3,898)	(654,151)
Issuance of Common Stock	10,845	11,101
Other	(13,485)	0
Cash used in financing activities	(375,664)	(149,620)
Change in cash and cash equivalents	83,496	83,507
Change in cash and cash equivalents included in discontinued operations	0	(272)
Change in cash and cash equivalents from continuing operations	83,496	83,235
Cash and cash equivalents at beginning of period	248,875	97,619
Cash and cash equivalents at end of period	$ 332,371	$ 180,854

CONSOLIDATED STATEMENT OF CHANG

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Preferred Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Noncontrolling Interests in Consolidated Subsidiaries [Member]
Shares, Issued		245,811,180	0
Total equity	$ 3,766,336	$ 2,458	$ 0	$ 1,378,444	$ (127,242)	$ 0	$ (917,862)	$ 3,430,538
Net income	354,818	0	0	0	0	169,390	0	185,428
Other comprehensive income (loss) (Note G)	(113,922)	0	0	0	(32,004)	0	0	(81,918)
Common Stock Issued	15,462	$ 0	0	(2,034)	0	0	17,496	0
Stock Issued During Period, Shares, Other		0
Dividends, Cash	(258,508)	$ 0	0	(89,118)	0	(169,390)	0	0
Distributions to Noncontrolling Interests	(275,259)	0	0	0	0	0	0	(275,259)
Stockholders' Equity, Other	3,250	$ 0	$ 0	7,291	0	0	0	(4,041)
Shares, Issued		245,811,180	0
Total equity	3,492,177	$ 2,458	$ 0	1,294,583	(159,246)	0	(900,366)	3,254,748
Shares, Issued		245,811,180	0
Cumulative Effect of New Accounting Principle in Period of Adoption	73,368	$ 0	$ 0	0	0	73,368	0	0
Total equity	3,428,915	2,458	0	1,234,314	(154,350)	0	(893,677)	3,240,170
Net income	362,176	0	0	0	0	159,054	0	203,122
Other comprehensive income (loss) (Note G)	49,579	0	0	0	18,553	0	0	31,026
Common Stock Issued	11,431	$ 0	$ 0	1,199	0	0	10,232	0
Stock Issued During Period, Shares, Other		0	20,000
Preferred Stock Issued	20,000	$ 0	$ 0	20,000	0	0	0	0
Dividends, Cash	(259,758)	0	0	(27,336)	0	(232,422)	0	0
Dividends, Preferred Stock	(217)	0	0	(217)	0	0	0	0
Distributions to Noncontrolling Interests	(273,460)	$ 0	0	0	0	0	0	(273,460)
Stock Issued During Period, Shares, Acquisitions		168,920,831
Acquisition of ONEOK Partners’ noncontrolling interests (Note B)	2,146,462	$ 1,689	0	5,228,580	(40,288)	0	0	(3,043,519)
Stockholders' Equity, Other	6,735	$ 0	$ 0	6,590	0	0	0	145
Shares, Issued		414,732,011	20,000
Total equity	$ 5,565,231	$ 4,147	$ 0	$ 6,463,130	$ (176,085)	$ 0	$ (883,445)	$ 157,484

CONSOLIDATED STATEMENT OF CHA10

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY CONSOLIDATED STATEMENT OF CHANGES IN EQUITY Parenthetical - $ / shares	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016
Statement of Stockholders' Equity [Abstract]
Dividends paid (in dollars per share)	$ 0.615	$ 1.230	$ 1.230

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Notes)	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	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 2016 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 and our Current Report on Form 8-K filed on July 6, 2017, which updates Item 8 in our Annual Report. 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. Merger Transaction - On June 30, 2017, we completed the acquisition of all of the outstanding common units of ONEOK Partners that we did not already own. See Note B for additional information, including a discussion of the impact of the Merger Transaction on our Consolidated Financial Statements. Discontinued Operations - Beginning in 2017, the results of operations and financial position of our former energy services business are no longer reflected as discontinued operations in our Consolidated Financial Statements and Notes to the Consolidated Financial Statements, as they are not material. Recently Issued Accounting Standards Update - Changes to GAAP are established by the Financial Accounting Standards Board (FASB) in the form of ASUs to the FASB Accounting Standards Codification. We consider the applicability and impact of all ASUs. ASUs not listed below were assessed and determined to be either not applicable or clarifications of ASUs listed below. 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 2015-11, “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 As a result of adopting this guidance, we updated our accounting policy for inventory valuation accordingly. The financial impact of adopting this guidance was not material. 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 The impact of adopting this standard was not material. 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 The impact of adopting this standard was not material. 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 As a result of adopting this guidance, we recorded an adjustment increasing beginning retained earnings and deferred tax assets in the first quarter 2017 of approximately $73 million to recognize previously unrecognized cumulative excess tax benefits related to share-based payments on a modified retrospective basis. Beginning in January 2017, all share-based payment tax effects are recorded in earnings. The other effects of adopting this standard were not material. Standard Description Date of Adoption Effect on the Financial Statements or Other Significant Matters Standards that are not yet adopted 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 contracts and transaction types across all our business segments, which we have substantially completed. For the majority of our contracts, we do not expect material changes in our accounting policies or revenue recognition. However, we are reviewing the potential impact on certain contract types where there remains diversity of thought across our industry in the application of the standard. Due to this ongoing analysis, we cannot yet determine the quantitative impact on revenues or cost of sales from the adoption of Topic 606, but we do not currently believe the adoption will have a material impact on net income. We are developing our required disclosures under the standard and expect to disaggregate revenues similar to our current presentation in Note L - Segments. We have not identified material unsatisfied performance obligations that would require disclosure. We are currently evaluating methods of adoption and analyzing the impact of the standard on our internal controls. We expect to determine our method of adoption when we complete our evaluation of the quantitative impact of the standard and the implications of each adoption method. 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 do not have any equity investments classified as available-for-sale or accounted for using the cost method, therefore we do not expect adoption of this standard to have a material impact 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 2017-07, “Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost” The standard requires the service cost component of net benefit cost to be reported in the same line item or items as other compensation costs from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations. 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 our current leases and other contracts that may be considered leases under the new standard and the impact on our internal controls, accounting policies and financial statements and disclosures. Standard Description Date of Adoption Effect on the Financial Statements or Other Significant Matters Standards that are not yet adopted (continued) 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. ASU 2017-04, “Intangibles- Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment” The standard simplifies the subsequent measurement of goodwill by eliminating the requirement to calculate the implied fair value of goodwill under step 2. Instead, an entity will recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. The standard does not change step zero or step 1 assessments. First quarter 2020 We are evaluating the impact of this standard on us.

ONEOK PARTNERS ACQUISITION (Not

ONEOK PARTNERS ACQUISITION (Notes)	6 Months Ended
	Jun. 30, 2017
Business Acquisition [Line Items]
Business Acquisition, Description of Acquired Entity	ACQUISITION OF ONEOK PARTNERS On June 30, 2017, we completed the Merger Transaction at a fixed exchange ratio of 0.985 of a share of our common stock for each ONEOK Partners common unit that we did not already own. We issued 168.9 million shares of our common stock to third-party common unitholders of ONEOK Partners in exchange for all of the 171.5 million outstanding common units of ONEOK Partners that we previously did not own. No fractional shares were issued in the Merger Transaction, and ONEOK Partners common unitholders instead received cash in lieu of fractional shares. As a result of the completion of the Merger Transaction, common units of ONEOK Partners are no longer publicly traded. As we controlled ONEOK Partners and continue to control ONEOK Partners after the Merger Transaction, the change in our ownership interest was accounted for as an equity transaction, and no gain or loss was recognized in our Consolidated Statements of Income resulting from the Merger Transaction. The Merger Transaction was a taxable exchange to the ONEOK Partners unitholders resulting in a book/tax difference in the basis of the underlying assets acquired. We recorded a deferred tax asset of approximately $2.1 billion, computed as the net of the equity value exchanged of $8.8 billion and noncontrolling interests of $3.0 billion at a tax rate of 37 percent, based on a preliminary tax allocation of the transaction value. Final allocation is subject to completion of our valuation study. Prior to June 30, 2017, we and our subsidiaries owned all of the general partner interest, which included incentive distribution rights, and a portion of the limited partner interest, which, together represented a 41.2 percent ownership interest in ONEOK Partners. The equity interests in ONEOK Partners (which are consolidated in our financial statements) that were owned by the public until June 30, 2017, are reflected in “Noncontrolling interests” in our accompanying Consolidated Balance Sheet as of December 31, 2016. The earnings of ONEOK Partners that are attributed to its units held by the public until June 30, 2017, are reported as “Net income attributable to noncontrolling interest” in our accompanying Consolidated Statements of Income. Our general partner incentive distribution rights effectively terminated at the closing of the Merger Transaction. Effective with the close of the Merger Transaction, we, ONEOK Partners and the Intermediate Partnership issued, to the extent not already in place, guarantees of the indebtedness of ONEOK and ONEOK Partners. Supplemental Cash Flow Information - Our noncash balance sheet activity related to the Merger Transaction is as follows (in millions): June 30, 2017 Common stock $ 1.7 Paid-in capital $ 5,228.6 Accumulated other comprehensive loss $ (40.3 ) Noncontrolling interests in consolidated subsidiaries $ (3,043.5 ) Deferred income taxes $ (2,146.5 )

FAIR VALUE MEASUREMENTS (Notes)

FAIR VALUE MEASUREMENTS (Notes)	6 Months Ended
	Jun. 30, 2017
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 derivative 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 our derivative portfolio by discounting the projected future cash flows from our derivative assets and liabilities to present value using interest-rate yields to calculate present-value discount factors derived from LIBOR, Eurodollar futures and 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 derivative contracts we have executed, the ultimate market prices realized could differ from our estimates, and the differences could be material. The fair value of our 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 composed 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: June 30, 2017 Level 1 Level 2 Level 3 Total - Gross Netting (a) Total - Net (b) ( Thousands of dollars ) Derivative assets Commodity contracts Financial contracts $ 4,349 $ — $ 11,865 $ 16,214 $ (15,786 ) $ 428 Physical contracts — — 710 710 — 710 Interest-rate contracts — 38,006 — 38,006 — 38,006 Total derivative assets $ 4,349 $ 38,006 $ 12,575 $ 54,930 $ (15,786 ) $ 39,144 Derivative liabilities Commodity contracts Financial contracts $ (5,973 ) $ — $ (10,792 ) $ (16,765 ) $ 16,656 $ (109 ) Physical contracts — — (1,033 ) (1,033 ) — (1,033 ) Interest-rate contracts — (16,872 ) — (16,872 ) — (16,872 ) Total derivative liabilities $ (5,973 ) $ (16,872 ) $ (11,825 ) $ (34,670 ) $ 16,656 $ (18,014 ) (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 June 30, 2017 , we held no cash and posted $11.8 million of cash with various counterparties, including $0.9 million of cash collateral that is offsetting derivative net liability positions under master-netting arrangements in the table above. The remaining $10.9 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 or other current liabilities in our Consolidated Balance Sheets. December 31, 2016 Level 1 Level 2 Level 3 Total - Gross Netting (a) Total - Net (b) ( Thousands of dollars ) Derivative assets Commodity contracts Financial contracts $ 1,147 $ — $ 4,564 $ 5,711 $ (4,760 ) $ 951 Interest rate contracts — 47,457 — 47,457 — 47,457 Total derivative assets $ 1,147 $ 47,457 $ 4,564 $ 53,168 $ (4,760 ) $ 48,408 Derivative liabilities Commodity contracts Financial contracts $ (31,458 ) $ — $ (24,861 ) $ (56,319 ) $ 56,319 $ — Physical contracts — — (3,022 ) (3,022 ) — (3,022 ) Interest-rate contracts — (12,795 ) — (12,795 ) — (12,795 ) Total derivative liabilities $ (31,458 ) $ (12,795 ) $ (27,883 ) $ (72,136 ) $ 56,319 $ (15,817 ) (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, 2016 , we held no cash and posted $67.7 million of cash with various counterparties, including $51.6 million of cash collateral that is offsetting derivative net liability positions under master-netting arrangements in the table above. The remaining $16.1 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 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 Six Months Ended June 30, June 30, Derivative Assets (Liabilities) 2017 2016 2017 2016 ( Thousands of dollars ) Net assets (liabilities) at beginning of period $ (772 ) $ 34 $ (23,319 ) $ 7,331 Total realized/unrealized gains (losses): Included in earnings (a) (656 ) 318 258 (427 ) Included in other comprehensive income (loss) 2,178 (14,373 ) 23,811 (20,925 ) Net assets (liabilities) at end of period $ 750 $ (14,021 ) $ 750 $ (14,021 ) (a) - Included in commodity sales revenues in our Consolidated Statements of Income. Realized/unrealized gains (losses) include the realization of our derivative contracts through maturity. During the three and six months ended June 30, 2017 and 2016 , 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 hierarc hy as of the end of each reporting period. During the three and six months ended June 30, 2017 and 2016 , there were no tra ns fers 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 composed 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 $9.1 billion and $8.8 billion at June 30, 2017 , and December 31, 2016 , respectively. The book value of our consolidated long-term debt, including current maturities, was $8.3 billion at June 30, 2017 , and December 31, 2016 . The estimated fair value of the aggregate of our 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 (Notes)	6 Months Ended
	Jun. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
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 purchased, processed and sold. We are also subject to the risk of interest-rate fluctuation in the normal course of business. 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 our risk-management activities. We have not used these instruments for trading purposes. 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. In our Natural Gas Gathering and Processing segment, we are exposed to commodity price risk as a result of retaining a portion of the commodity sales proceeds associated with our POP with fee contracts. Under certain POP with fee contracts, our fee revenues may increase or decrease if production volumes, delivery pressures or commodity prices change relative to specified thresholds. We also are exposed to basis risk between the various production and market locations where we buy and sell 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. In our Natural Gas Liquids segment, we are 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. We are also 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. In our Natural Gas Pipelines segment, we are exposed to commodity price risk because our intrastate and interstate natural gas pipelines retain natural gas from our customers for operations or as part of our fee for services provided. When the amount of natural gas consumed in operations by these pipelines differs from the amount provided by our customers, our pipelines must buy or sell natural gas, or store or use natural gas from inventory, which may expose this segment to commodity price risk depending on the regulatory treatment for this activity. To the extent that commodity price risk in our Natural Gas Pipelines segment is not mitigated by fuel cost-recovery mechanisms, we may use physical-forward sales or purchases to reduce the impact of price fluctuations related to natural gas. At June 30, 2017 , and December 31, 2016 , there were no financial derivative instruments with respect to our 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 June 30, 2017 , and December 31, 2016 , we had interest-rate swaps with notional amounts totaling $1 billion to hedge the variability of our LIBOR-based interest payments and forward-starting interest-rate swaps with notional amounts totaling $1.2 billion to hedge the variability of interest payments on a portion of our forecasted debt issuances that may result from changes in the benchmark interest rate before the debt is issued. All of our interest-rate swaps are designated as cash flow hedges. In July 2017, we settled $400 million of our forward-starting interest-rate swaps upon the completion of our underwritten public offering of $1.2 billion senior unsecured notes and $500 million of our interest-rate swaps used to hedge our LIBOR-based interest payments. Accounting Treatment - 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 C 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: June 30, 2017 December 31, 2016 Location in our Consolidated Balance Sheets Assets (Liabilities) Assets (Liabilities) ( Thousands of dollars ) Derivatives designated as hedging instruments Commodity contracts Financial contracts Other current assets/other current liabilities $ 7,577 $ (13,082 ) $ 1,155 $ (49,938 ) Other assets/deferred credits and other liabilities 5,510 (225 ) 210 (2,142 ) Physical contracts Other current assets/other current liabilities 330 (1,033 ) — (3,022 ) Other assets 380 — — — Interest-rate contracts Other current assets/other current liabilities 493 (16,872 ) — (12,795 ) Other assets 37,513 — 47,457 — Total derivatives designated as hedging instruments 51,803 (31,212 ) 48,822 (67,897 ) Derivatives not designated as hedging instruments Commodity contracts Financial contracts Other current assets/other current liabilities 2,587 (2,967 ) 4,346 (4,239 ) Other assets/deferred credits and other liabilities 540 (491 ) — — Total derivatives not designated as hedging instruments 3,127 (3,458 ) 4,346 (4,239 ) Total derivatives $ 54,930 $ (34,670 ) $ 53,168 $ (72,136 ) Notional Quantities for Derivative Instruments - The following table sets forth the notional quantities for derivative instruments held for the periods indicated: June 30, 2017 December 31, 2016 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 — (34.3 ) — (38.4 ) - Natural gas ( Bcf ) Put options 22.5 — 49.5 — - Crude oil and NGLs ( MMBbl ) Futures, forwards and swaps 0.7 (5.0 ) — (3.6 ) Basis - Natural gas ( Bcf ) Futures and swaps — (34.3 ) — (38.4 ) Interest-rate contracts ( Millions of dollars ) Swaps $ 2,150.0 $ — $ 2,150.0 $ — Derivatives not designated as hedging instruments: Fixed price -Natural gas ( Bcf ) Futures and swaps 1.8 — 0.4 — - NGLs ( MMBbl ) Futures, forwards and swaps 0.6 (1.1 ) 0.5 (0.7 ) Basis - Natural gas ( Bcf ) Futures and swaps 1.8 — 0.4 — These notional amounts are used to summarize the volume of financial instruments; however, they do not reflect the extent to which the positions offset one another and, consequently, do not reflect our actual exposure to market or credit risk. Cash Flow Hedges - At June 30, 2017 , our Consolidated Balance Sheet reflected a net loss of $176.1 million in accumulated other comprehensive loss. The portion of accumulated other comprehensive loss attributable to our commodity derivative financial instruments is an unrealized loss of $3.1 million , net of tax, which is expected to be realized within the next 18 months as the forecasted transactions affect earnings. If commodity prices remain at current levels, we will realize approximately $6.6 million in net losses , net of tax, over the next 12 months and approximately $3.5 million in net gains , net of tax, thereafter. The amount deferred in accumulated other comprehensive loss attributable to our settled interest-rate swaps is a loss of $84.3 million , net of tax, which will be recognized over the life of the long-term, fixed-rate debt, including losses of $12.9 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 is expected to 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: Three Months Ended Six Months Ended Derivatives in Cash Flow Hedging Relationships June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Commodity contracts $ 8,998 $ (58,654 ) $ 36,326 $ (46,976 ) Interest-rate contracts (14,995 ) (28,564 ) (13,466 ) (60,175 ) Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion) $ (5,997 ) $ (87,218 ) $ 22,860 $ (107,151 ) 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 Six Months Ended June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Commodity contracts Commodity sales revenues $ (6,796 ) $ 14,049 $ (22,115 ) $ 28,548 Interest-rate contracts Interest expense (5,172 ) (4,802 ) (10,501 ) (9,500 ) Total gain (loss) reclassified from accumulated other comprehensive loss into net income on derivatives (effective portion) $ (11,968 ) $ 9,247 $ (32,616 ) $ 19,048 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, we may enter into financial derivative instruments that contain provisions that require us to maintain an investment-grade credit rating from S&P and/or Moody’s. If our credit ratings on our 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 June 30, 2017 . 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 June 30, 2017 , the net credit exposure from our derivative assets is with investment-grade companies in the financial services sector.

DEBT DEBT (Notes)

DEBT DEBT (Notes)	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Debt [Text Block]	DEBT The following table sets forth our consolidated debt for the periods indicated: June 30, December 31, ( Thousands of dollars ) ONEOK Senior unsecured obligations: $700,000 at 4.25% due February 2022 $ 547,397 $ 547,397 $500,000 at 7.5% due September 2023 500,000 500,000 $100,000 at 6.5% due September 2028 87,053 87,126 $100,000 at 6.875% due September 2028 100,000 100,000 $400,000 at 6.0% due June 2035 400,000 400,000 ONEOK Partners Commercial paper outstanding, bearing a weighted-average interest rate of 1.80% and 1.27%, respectively (a) 1,274,407 1,110,277 Senior unsecured obligations: $400,000 at 2.0% due October 2017 400,000 400,000 $425,000 at 3.2% due September 2018 425,000 425,000 $1,000,000 term loan, variable rate, due January 2019 (b) 1,000,000 1,000,000 $500,000 at 8.625% due March 2019 500,000 500,000 $300,000 at 3.8% due March 2020 300,000 300,000 $900,000 at 3.375 % due October 2022 900,000 900,000 $425,000 at 5.0 % due September 2023 425,000 425,000 $500,000 at 4.9 % due March 2025 500,000 500,000 $600,000 at 6.65% due October 2036 600,000 600,000 $600,000 at 6.85% due October 2037 600,000 600,000 $650,000 at 6.125% due February 2041 650,000 650,000 $400,000 at 6.2% due September 2043 400,000 400,000 Guardian Pipeline Weighted average 7.85% due December 2022 40,433 44,257 Total debt 9,649,290 9,489,057 Unamortized portion of terminated swaps 19,327 20,186 Unamortized debt issuance costs and discounts (63,901 ) (68,320 ) Current maturities of long-term debt (494,703 ) (410,650 ) Short-term borrowings (c) (1,274,407 ) (1,110,277 ) Long-term debt $ 7,835,606 $ 7,919,996 (a) - In July 2017, the commercial paper outstanding under the ONEOK Partners commercial paper program was repaid as it matured with a combination of proceeds from new issuances from ONEOK’s recently established $2.5 billion commercial paper program, cash on hand and proceeds from our July 2017 $1.2 billion senior notes issuance. The $2.4 billion ONEOK Partners commercial paper program was terminated in July 2017. (b) - I n July 2017, we repaid $500 million of the $1.0 billion Term Loan Agreement due 2019. (c) - Individual issuances of commercial paper under our commercial paper program generally mature in 90 days or less. These issuances are supported by and reduce the borrowing capacity under the 2017 Credit Agreement. 2017 Credit Agreement - In April 2017, we entered into the 2017 Credit Agreement with a syndicate of banks, which became effective June 30, 2017, with the close of the Merger Transaction and the terminations of the ONEOK Credit Agreement and ONEOK Partners Credit Agreement. The 2017 Credit Agreement is a $2.5 billion revolving credit facility and 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 our 2017 Credit Agreement, adjusted for all noncash charges and increased for projected EBITDA from certain lender-approved capital expansion projects) of no more than 5.75 to 1 at June 30, 2017, and for the following two quarters; 5.5 to 1 for the subsequent two quarters; and 5.0 to 1 thereafter. Once the covenant decreases to 5.0 to 1, if we consummate one or more acquisitions in which the aggregate purchase 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 is completed and the two following quarters. The 2017 Credit Agreement includes a $100 million sublimit for the issuance of standby letters of credit and a $200 million sublimit for swingline loans. Under the terms of the 2017 Credit Agreement, we may request an increase in the size of the facility to an aggregate of $3.5 billion by either commitments from new lenders or increased commitments from existing lenders. The 2017 Credit Agreement contains provisions for an applicable margin rate and an annual facility fee, both of which adjust with changes in our credit ratings. Based on our current credit ratings, borrowings, if any, will accrue at LIBOR plus 110 basis points , and the annual facility fee is 15 basis points . We have the option to request two one-year extensions, subject to lender approval, which may be used for working capital, capital expenditures, acquisitions and mergers, the issuance of letters of credit and for other general corporate purposes. At June 30, 2017, our ratio of indebtedness to adjusted EBITDA was 5.1 to 1, and we were in compliance with all covenants under the 2017 Credit Agreement. Issuances - In July 2017, we completed an underwritten public offering of $1.2 billion senior unsecured notes consisting of $500 million , 4.0 percent senior notes due 2027, and $700 million , 4.95 percent senior notes due 2047. The net proceeds, after deducting underwriting discounts, commissions and offering expenses, were approximately $1.18 billion . The proceeds were used for general corporate purposes, which included repayment of existing indebtedness and capital expenditures. In January 2016, ONEOK Partners entered into the $1.0 billion senior unsecured Term Loan Agreement with a syndicate of banks. The Term Loan Agreement matures in January 2019 and bears interest at LIBOR plus 130 basis points based on our current credit ratings. At June 30, 2017, the interest rate was 2.52 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 our 2017 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 $650 million of senior notes at maturity, to repay amounts outstanding under its commercial paper program and for general partnership purposes. In April 2017, ONEOK Partners entered into the first amendment to the Term Loan Agreement, which, among other things, added ONEOK as a guarantor to the Term Loan Agreement effective June 30, 2017, with the close of the Merger Transaction described in Note B. Repayments - In July 2017, we redeemed our 6.5 percent senior notes due 2028 at a redemption price of approximately $87 million , including the outstanding principal amount, plus accrued and unpaid interest, with cash on hand. At June 30, 2017, these notes are included in current maturities of long-term debt in our Consolidated Balance Sheet. Also in July 2017, we repaid $500 million of the $1.0 billion Term Loan Agreement due 2019. Debt Guarantees - Effective June 30, 2017, with the Merger Transaction, we, ONEOK Partners and the Intermediate Partnership issued, to the extent not already in place, guarantees of the indebtedness of ONEOK and ONEOK Partners.

EQUITY (Notes)

EQUITY (Notes)	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
EQUITY	EQUITY Ownership Interest in ONEOK Partners - At December 31, 2016, we and our subsidiaries owned all of the general partner interest, which included incentive distribution rights, and a portion of the limited partner interest, which together represented a 41.2 percent ownership interest in ONEOK Partners consisting of approximately 41.3 million common units and 73.0 million Class B units, which are convertible, at our option, into common units. The portion of ONEOK Partners that we did not own is reflected in our 2016 Consolidated Balance Sheet under the caption “Noncontrolling interests” along with the 20 percent of WTLPG that we do not own. On June 30, 2017, we completed the Merger Transaction at a fixed exchange ratio of 0.985 of a share of our common stock for each ONEOK Partners common unit that we did not already own. We issued 168.9 million shares of our common stock to third-party common unitholders of ONEOK Partners in exchange for all of the 171.5 million outstanding common units of ONEOK Partners that we previously did not own. At June 30, 2017, the caption “Noncontrolling interests” on our Consolidated Balance Sheet reflects only the 20 percent of WTLPG that we do not own. Cash Distributions - Prior to the consummation of the Merger Transaction, we received distributions from ONEOK Partners on our common and Class B units and our 2 percent general partner interest, which included our incentive distribution rights. Additional information about ONEOK Partners’ cash distributions and our incentive distribution rights for the periods prior to June 30, 2017, is included under “Cash Distributions” in Note O of the Notes to Consolidated Financial Statements in our Annual Report. Distributions paid to ONEOK Partners unitholders of record at the close of business on January 30, 2017 , and May 1, 2017 , were $0.79 per unit. As a result of the Merger Transaction, we are entitled to receive all available ONEOK Partners cash. Our incentive distribution rights effectively terminated at the close of the Merger Transaction. The following table sets forth ONEOK Partners’ distributions declared and paid during the periods indicated: Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 ( Thousands, except per unit amounts ) Distribution per unit $ 0.79 $ 0.79 $ 1.58 $ 1.58 General partner distributions $ 6,660 $ 6,660 $ 13,320 $ 13,320 Incentive distributions 100,538 100,538 201,076 201,076 Distributions to general partner 107,198 107,198 214,396 214,396 Limited partner distributions to ONEOK 90,323 90,323 180,646 180,646 Limited partner distributions to other unitholders 135,479 135,479 270,959 270,959 Total distributions paid $ 333,000 $ 333,000 $ 666,001 $ 666,001 Dividends - Holders of our common stock share equally in any dividend declared by our board of directors, subject to the rights of the holders of outstanding preferred stock. Dividends paid on our common stock to shareholders of record at the close of business on January 30, 2017, and May 1, 2017, were $0.615 per share. A dividend of $0.745 per share was declared for shareholders of record at the close of business on August 7, 2017 , payable August 14, 2017 . In April 2017, through a wholly owned subsidiary, we contributed 20,000 shares of newly issued Series E Preferred Stock, having an aggregate value of $20 million , to the Foundation for use in charitable and nonprofit causes. The contribution was recorded as a $20 million noncash expense in the second quarter 2017 and is included in other expense in our Consolidated Statements of Income. The Series E Preferred Stock pays quarterly dividends on each share of Series E Preferred Stock, when, as and if declared by our Board of Directors, at a rate of 5.5 percent per year. Dividends totaling approximately $0.4 million were declared for the Series E Preferred Stock and are payable August 14, 2017 . The $20 million issuance of the shares of Series E Preferred Stock and the related accrued dividends of approximately $0.2 million at June 30, 2017, represent noncash financing activities. Equity Issuances - In July 2017, we established an “at-the-market” equity program for the offer and sale from time to time of our common stock up to an aggregate amount of $1 billion . The program allows us to offer and sell our common stock at prices we deem appropriate through a sales agent. Sales of our common stock may be made by means of ordinary brokers’ transactions on the NYSE, in block transactions, or as otherwise agreed to between us and the sales agent. We are under no obligation to offer and sell common stock under the program. Prior to the close of the Merger Transaction, ONEOK Partners had 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 . During the six months ended June 30, 2017 , and the year ended December 31, 2016, no common units were sold through ONEOK Partners’ “at-the-market” equity program. Upon the close of the Merger Transaction on June 30, 2017, the ONEOK Partners “at-the-market” equity program terminated.

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) ACCUMULATED OTHER COMPREHENSIVE INCOME (Notes)	6 Months Ended
	Jun. 30, 2017
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, 2017 $ (52,155 ) $ (101,236 ) $ (959 ) $ (154,350 ) Other comprehensive income (loss) before reclassifications 5,728 5 (367 ) 5,366 Amounts reclassified from accumulated other comprehensive loss 9,064 4,076 47 13,187 Impact of Merger Transaction (Note B) (c) (40,288 ) — — (40,288 ) Net current-period other comprehensive income (loss) attributable to ONEOK (25,496 ) 4,081 (320 ) (21,735 ) June 30, 2017 $ (77,651 ) $ (97,155 ) $ (1,279 ) $ (176,085 ) (a) - All amounts are presented net of tax. (b) - Includes amounts related to supplemental executive retirement plan. (c) - Includes the remaining portion of ONEOK Partners’ accumulated other comprehensive loss at June 30, 2017, that we acquired in the Merger Transaction, related to commodity and interest-rate contracts. 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 Components Three Months Ended Six Months Ended Affected Line Item in the Statements of Income June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Unrealized gains (losses) on risk-management assets/liabilities Commodity contracts $ (6,796 ) $ 14,049 $ (22,115 ) $ 28,548 Commodity sales revenues Interest-rate contracts (5,172 ) (4,802 ) (10,501 ) (9,500 ) Interest expense (11,968 ) 9,247 (32,616 ) 19,048 Income before income taxes 2,041 (1,193 ) 5,406 (2,469 ) Income tax expense (9,927 ) 8,054 (27,210 ) 16,579 Net income Noncontrolling interests (6,521 ) 5,953 (18,146 ) 12,233 Less: Net income attributable to noncontrolling interests $ (3,406 ) $ 2,101 $ (9,064 ) $ 4,346 Net income attributable to ONEOK Pension and postretirement benefit plan obligations (a) Amortization of net loss $ (3,812 ) $ (2,997 ) $ (7,624 ) $ (5,995 ) Amortization of unrecognized prior service cost 415 415 830 830 (3,397 ) (2,582 ) (6,794 ) (5,165 ) Income before income taxes 1,359 1,033 2,718 2,066 Income tax expense $ (2,038 ) $ (1,549 ) $ (4,076 ) $ (3,099 ) Net income attributable to ONEOK Unrealized gains (losses) on risk-management assets/liabilities of unconsolidated affiliates $ (85 ) $ — $ (181 ) $ — Equity in net earnings from investments 13 — 28 — Income tax expense (72 ) — (153 ) — Net income Noncontrolling interests (50 ) — (106 ) — Less: Net income attributable to noncontrolling interests $ (22 ) $ — $ (47 ) $ — Net income attributable to ONEOK Total reclassifications for the period attributable to ONEOK $ (5,466 ) $ 552 $ (13,187 ) $ 1,247 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

EARNINGS PER SHARE EARNINGS PER SHARE (Notes)	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	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 June 30, 2017 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 $ 71,476 211,785 $ 0.34 Diluted EPS from continuing operations Effect of dilutive securities — 2,227 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 71,476 214,012 $ 0.33 Three Months Ended June 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 $ 86,171 211,075 $ 0.41 Diluted EPS from continuing operations Effect of dilutive securities — 1,543 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 86,171 212,618 $ 0.41 Six Months Ended June 30, 2017 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 $ 158,837 211,702 $ 0.75 Diluted EPS from continuing operations Effect of dilutive securities — 2,105 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 158,837 213,807 $ 0.74 Six Months Ended June 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 $ 170,569 210,928 $ 0.81 Diluted EPS from continuing operations Effect of dilutive securities — 735 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 170,569 211,663 $ 0.81

EMPLOYEE BENEFIT PLANS EMPLOYEE

EMPLOYEE BENEFIT PLANS EMPLOYEE BENEFIT PLANS (Notes)	6 Months Ended
	Jun. 30, 2017
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 Six Months Ended June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Components of net periodic benefit cost Service cost $ 1,722 $ 1,622 $ 3,444 $ 3,244 Interest cost 4,655 4,947 9,310 9,894 Expected return on plan assets (5,336 ) (5,077 ) (10,672 ) (10,154 ) Amortization of net loss 3,392 2,736 6,784 5,473 Net periodic benefit cost $ 4,433 $ 4,228 $ 8,866 $ 8,457 Postretirement Benefits Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Components of net periodic benefit cost Service cost $ 165 $ 149 $ 330 $ 298 Interest cost 565 601 1,130 1,202 Expected return on plan assets (564 ) (531 ) (1,128 ) (1,062 ) Amortization of prior service credit (415 ) (415 ) (830 ) (830 ) Amortization of net loss 420 261 840 522 Net periodic benefit cost $ 171 $ 65 $ 342 $ 130

UNCONSOLIDATED AFFILIATES (Note

UNCONSOLIDATED AFFILIATES (Notes)	6 Months Ended
	Jun. 30, 2017
Equity Method Investments and Joint Ventures [Abstract]
UNCONSOLIDATED AFFILIATES	UNCONSOLIDATED AFFILIATES Equity in Net Earnings from Investments - The following table sets forth our equity in net earnings from investments for the periods indicated: Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Northern Border Pipeline $ 15,622 $ 15,723 $ 34,439 $ 34,397 Overland Pass Pipeline Company 14,884 13,608 28,450 26,912 Other 8,857 3,041 16,038 3,977 Equity in net earnings from investments $ 39,363 $ 32,372 $ 78,927 $ 65,286 Unconsolidated Affiliates Financial Information - The following table sets forth summarized combined financial information of our unconsolidated affiliates for the periods indicated: Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Income Statement Operating revenues $ 157,603 $ 142,631 $ 311,883 $ 279,203 Operating expenses $ 69,465 $ 66,674 $ 136,401 $ 125,373 Net income $ 92,072 $ 69,420 $ 173,203 $ 141,457 Distributions paid to us $ 49,760 $ 62,024 $ 96,680 $ 108,577 We incurred expenses in transactions with unconsolidated affiliates of $39.4 million and $34.7 million for the three months ended June 30, 2017 and 2016 , respectively, and $76.1 million and $68.3 million for the six months ended June 30, 2017 and 2016 , respectively, primarily related to Overland Pass Pipeline Company and Northern Border Pipeline. Accounts payable to our equity-method investees at June 30, 2017 , and December 31, 2016 , were $12.9 million and $11.1 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, 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 - 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. As the operator, we have been delegated the authority to determine such distributions in accordance with, and on the frequency set forth in, the Roadrunner limited liability company agreement. Cash distributions are equal to 100 percent of available cash, as defined in the limited liability company agreement. We have an operating agreement with Roadrunner that provides for reimbursement or payment to us for management services and certain operating costs. Reimbursements and payments from Roadrunner included in operating income in our Consolidated Statements of Income for the three and six months ended June 30, 2017 and 2016 , were not material.

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Notes)	6 Months Ended
	Jun. 30, 2017
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, we 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 results of operations, financial condition or cash flows. Legal Proceedings - Gas Index Pricing Litigation - In March 2017, the United States District Court for the District of Nevada (the Court) entered an order granting summary judgment in favor of our affiliate ONEOK Energy Services Company, L.P. (OESC), the lone defendant in the previously reported Sinclair case. The Court determined that the plaintiff’s claim is barred by a release obtained in a prior lawsuit against us and OESC. Upon entry of a final judgment, Sinclair Oil Corporation may pursue an appeal of this determination to the Ninth Circuit Court of Appeals. We expect that future charges, if any, from the ultimate resolution of the Sinclair case will not be material to our results of operations, financial position or cash flows. In May 2017, the Court gave final approval to the previously announced settlements of Learjet, Inc., et al. v. ONEOK, Inc., et al. (filed in the District Court of Wyandotte, Kansas, in November 2005, transferred to MDL-1566 in the United States District Court for the District of Nevada); Arandell Corporation, et al. v. Xcel Energy, Inc., et al. (filed in the Circuit Court for Dane County, Wisconsin, in December 2006, transferred to MDL-1566 in the United States District Court for the District of Nevada); Heartland Regional Medical Center, et al. v. ONEOK, Inc., et al. (filed in the Circuit Court of Buchanan County, Missouri, in March 2007, transferred to MDL-1566 in the United States District Court for the District of Nevada); and NewPage Wisconsin System v. CMS Energy Resource Management Company, et al. (filed in the Circuit Court for Wood County, Wisconsin, in March 2009, transferred to MDL-1566 in the United States District Court for the District of Nevada and now consolidated with the Arandell case). Thereafter, the Court entered a final judgment dismissing these actions with prejudice as to us and our affiliates. The final judgment was not appealed and became final and nonappealable in July 2017. The amount paid to settle these cases was not material to our results of operations, financial position or cash flows and was paid with cash on hand. ONEOK Partners Class Action Litigation - In June 2017, ONEOK Partners settled two putative class action lawsuits captioned Juergen Krueger, Individually And On Behalf Of All Others Similarly Situated v. ONEOK Partners, L.P., et al. (filed in the United States District Court for the Northern District of Oklahoma) and Max Federman, On Behalf of Himself and All Others Similarly Situated v. ONEOK Partners, L.P., et al. (filed in the United States District Court for the Northern District of Oklahoma) by agreeing to make certain disclosures about the Merger Transaction in addition to those made in the final proxy statement filed with the SEC. The supplemental disclosure was filed with the SEC on June 12, 2017 and the Krueger and Federman actions were dismissed on June 14, 2017 as moot, with prejudice as to the named plaintiffs and without prejudice as to any other members of a putative class. In July 2017, ONEOK Partners entered into a settlement concerning attorney’s fees and expenses for plaintiffs’ counsel in an amount immaterial to our results of operations, financial position or cash flows and was paid with cash on hand. Other Legal Proceedings - We are a party to various other litigation matters and claims that have arisen in the normal course of our operations. While the results of these 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.

SEGMENTS (Notes)

SEGMENTS (Notes)	6 Months Ended
	Jun. 30, 2017
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
SEGMENTS	SEGMENTS Segment Descriptions - Our operations are divided into three reportable business segments, as follows: • our Natural Gas Gathering and Processing segment gathers, treats and processes natural gas; • our Natural Gas Liquids segment gathers, treats, fractionates and transports NGLs and stores, markets and distributes NGL products; and • our Natural Gas Pipelines segment operates regulated interstate and intrastate natural gas transmission pipelines and natural gas storage facilities. Other and eliminations consist of corporate and Merger Transaction-related costs, the operating and leasing activities of our headquarters building and related parking facility and eliminations necessary 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 our three segments, as well as our financial performance as a whole, on a regular basis. Adjusted EBITDA by segment is utilized in this evaluation. We believe this financial measure is useful to investors because it and similar measures are used by many companies in our industry as a measurement of financial performance and are commonly employed by financial analysts and others to evaluate our financial performance and to compare financial performance among companies in our industry. Adjusted EBITDA for each segment is defined as net income adjusted for interest expense, depreciation and amortization, noncash impairment charges, income taxes, allowance for equity funds used during construction, noncash equity compensation and other noncash items. This calculation may not be comparable with similarly titled measures of other companies. Customers - The primary customers of our Natural Gas Gathering and Processing segment are crude oil and natural gas producers, which include both large integrated and independent exploration and production companies. Our 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. Our 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 ended June 30, 2017 and 2016 , and the six months ended June 30, 2017 , we had no single customer from which we received 10 percent or more of our consolidated revenues. For the six months ended June 30, 2016 , we had one customer, BP p.l.c. or its affiliates, from which we received approximately 10 percent 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 June 30, 2017 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Total ( Thousands of dollars ) Sales to unaffiliated customers $ 433,088 $ 2,196,399 $ 95,755 $ 2,725,242 Intersegment revenues 252,727 153,286 2,094 408,107 Total revenues 685,815 2,349,685 97,849 3,133,349 Cost of sales and fuel (exclusive of depreciation and items shown separately below) (488,891 ) (2,003,601 ) (6,773 ) (2,499,265 ) Operating costs (73,093 ) (87,285 ) (30,877 ) (191,255 ) Equity in net earnings from investments 3,780 15,062 20,521 39,363 Other 650 (552 ) (60 ) 38 Segment adjusted EBITDA $ 128,261 $ 273,309 $ 80,660 $ 482,230 Depreciation and amortization $ (46,033 ) $ (41,427 ) $ (12,598 ) $ (100,058 ) Capital expenditures $ 37,020 $ 12,336 $ 26,846 $ 76,202 (a) - Our Natural Gas Liquids segment has regulated and nonregulated operations. Our Natural Gas Liquids segment’s regulated operations had revenues of $289.4 million , of which $249.4 million related to sales within the segment and cost of sales and fuel of $118.9 million . (b) - Our Natural Gas Pipelines segment has regulated and nonregulated operations. Our Natural Gas Pipelines segment’s regulated operations had revenues of $62.8 million and cost of sales and fuel of $8.3 million . Three Months Ended June 30, 2017 Total Segments Other and Eliminations Total ( Thousands of dollars ) Reconciliations of total segments to consolidated Sales to unaffiliated customers $ 2,725,242 $ 530 $ 2,725,772 Intersegment revenues 408,107 (408,107 ) — Total revenues $ 3,133,349 $ (407,577 ) $ 2,725,772 Cost of sales and fuel (exclusive of depreciation and operating costs) $ (2,499,265 ) $ 408,243 $ (2,091,022 ) Operating costs $ (191,255 ) $ (26,550 ) $ (217,805 ) Depreciation and amortization $ (100,058 ) $ (791 ) $ (100,849 ) Equity in net earnings from investments $ 39,363 $ — $ 39,363 Capital expenditures $ 76,202 $ 6,293 $ 82,495 Three Months Ended June 30, 2016 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Total ( Thousands of dollars ) Sales to unaffiliated customers $ 293,071 $ 1,754,122 $ 86,401 $ 2,133,594 Intersegment revenues 183,688 117,871 1,668 303,227 Total revenues 476,759 1,871,993 88,069 2,436,821 Cost of sales and fuel (exclusive of depreciation and items shown separately below) (299,991 ) (1,525,234 ) (5,112 ) (1,830,337 ) Operating costs (69,304 ) (83,769 ) (29,189 ) (182,262 ) Equity in net earnings from investments 2,576 13,904 15,892 32,372 Other 258 (283 ) (1,118 ) (1,143 ) Segment adjusted EBITDA $ 110,298 $ 276,611 $ 68,542 $ 455,451 Depreciation and amortization $ (46,413 ) $ (40,696 ) $ (11,398 ) $ (98,507 ) Capital expenditures $ 84,674 $ 20,779 $ 29,278 $ 134,731 (a) - Our Natural Gas Liquids segment has regulated and nonregulated operations. Our Natural Gas Liquids segment’s regulated operations had revenues of $297.5 million , of which $258.4 million related to sales within the segment and cost of sales and fuel of $112.7 million . (b) - Our Natural Gas Pipelines segment has regulated and nonregulated operations. Our Natural Gas Pipelines segment’s regulated operations had revenues of $56.6 million and cost of sales and fuel of $5.7 million . Three Months Ended June 30, 2016 Total Segments Other and Eliminations Total ( Thousands of dollars ) Reconciliations of total segments to consolidated Sales to unaffiliated customers $ 2,133,594 $ 513 $ 2,134,107 Intersegment revenues 303,227 (303,227 ) — Total revenues $ 2,436,821 $ (302,714 ) $ 2,134,107 Cost of sales and fuel (exclusive of depreciation and operating costs) $ (1,830,337 ) $ 303,014 $ (1,527,323 ) Operating costs $ (182,262 ) $ (9,577 ) $ (191,839 ) Depreciation and amortization $ (98,507 ) $ (740 ) $ (99,247 ) Equity in net earnings from investments $ 32,372 $ — $ 32,372 Capital expenditures $ 134,731 $ 2,112 $ 136,843 Six Months Ended June 30, 2017 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Total ( Thousands of dollars ) Sales to unaffiliated customers $ 833,237 $ 4,440,399 $ 200,679 $ 5,474,315 Intersegment revenues 513,854 301,270 3,988 819,112 Total revenues 1,347,091 4,741,669 204,667 6,293,427 Cost of sales and fuel (exclusive of depreciation and items shown separately below) (977,275 ) (4,052,294 ) (23,376 ) (5,052,945 ) Operating costs (144,882 ) (166,028 ) (62,630 ) (373,540 ) Equity in net earnings from investments 6,410 28,784 43,733 78,927 Other 884 (593 ) 1,224 1,515 Segment adjusted EBITDA $ 232,228 $ 551,538 $ 163,618 $ 947,384 Depreciation and amortization $ (91,001 ) $ (82,542 ) $ (25,141 ) $ (198,684 ) Total assets $ 5,310,946 $ 8,168,567 $ 1,951,423 $ 15,430,936 Capital expenditures $ 100,171 $ 32,789 $ 51,860 $ 184,820 (a) - Our Natural Gas Liquids segment has regulated and nonregulated operations. Our Natural Gas Liquids segment’s regulated operations had revenues of $585.7 million , of which $502.3 million related to sales within the segment and cost of sales and fuel of $235.4 million . (b) - Our Natural Gas Pipelines segment has regulated and nonregulated operations. Our Natural Gas Pipelines segment’s regulated operations had revenues of $131.7 million and cost of sales and fuel of $22.4 million . Six Months Ended June 30, 2017 Total Segments Other and Eliminations Total ( Thousands of dollars ) Reconciliations of total segments to consolidated Sales to unaffiliated customers $ 5,474,315 $ 1,068 $ 5,475,383 Intersegment revenues 819,112 (819,112 ) — Total revenues $ 6,293,427 $ (818,044 ) $ 5,475,383 Cost of sales and fuel (exclusive of depreciation and operating costs) $ (5,052,945 ) $ 818,080 $ (4,234,865 ) Operating costs $ (373,540 ) $ (36,187 ) $ (409,727 ) Depreciation and amortization $ (198,684 ) $ (1,584 ) $ (200,268 ) Equity in net earnings from investments $ 78,927 $ — $ 78,927 Total assets $ 15,430,936 $ 1,241,987 $ 16,672,923 Capital expenditures $ 184,820 $ 10,412 $ 195,232 Six Months Ended June 30, 2016 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Total ( Thousands of dollars ) Sales to unaffiliated customers $ 610,117 $ 3,125,547 $ 171,875 $ 3,907,539 Intersegment revenues 298,653 233,836 2,167 534,656 Total revenues 908,770 3,359,383 174,042 4,442,195 Cost of sales and fuel (exclusive of depreciation and items shown separately below) (566,291 ) (2,682,184 ) (9,044 ) (3,257,519 ) Operating costs (138,910 ) (156,951 ) (56,702 ) (352,563 ) Equity in net earnings from investments 5,391 27,251 32,644 65,286 Other 1,373 (719 ) 1,941 2,595 Segment adjusted EBITDA $ 210,333 $ 546,780 $ 142,881 $ 899,994 Depreciation and amortization $ (88,264 ) $ (81,402 ) $ (22,577 ) $ (192,243 ) Total assets $ 5,222,225 $ 8,289,089 $ 1,856,128 $ 15,367,442 Capital expenditures $ 226,171 $ 54,986 $ 47,226 $ 328,383 (a) - Our Natural Gas Liquids segment has regulated and nonregulated operations. Our Natural Gas Liquids segment’s regulated operations had revenues of $579.3 million , of which $489.2 million related to sales within the segment and cost of sales and fuel of $219.5 million . (b) - Our Natural Gas Pipelines segment has regulated and nonregulated operations. Our Natural Gas Pipelines segment’s regulated operations had revenues of $111.4 million and cost of sales and fuel of $11.3 million . Six Months Ended June 30, 2016 Total Segments Other and Eliminations Total ( Thousands of dollars ) Reconciliations of total segments to consolidated Sales to unaffiliated customers $ 3,907,539 $ 1,027 $ 3,908,566 Intersegment revenues 534,656 (534,656 ) — Total revenues $ 4,442,195 $ (533,629 ) $ 3,908,566 Cost of sales and fuel (exclusive of depreciation and operating costs) $ (3,257,519 ) $ 534,458 $ (2,723,061 ) Operating costs $ (352,563 ) $ (16,291 ) $ (368,854 ) Depreciation and amortization $ (192,243 ) $ (1,482 ) $ (193,725 ) Equity in net earnings from investments $ 65,286 $ — $ 65,286 Total assets $ 15,367,442 $ 455,458 $ 15,822,900 Capital expenditures $ 328,383 $ 4,871 $ 333,254 Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 Reconciliation of income from continuing operations to total segment adjusted EBITDA ( Thousands of dollars ) Income from continuing operations $ 175,991 $ 180,086 $ 362,176 $ 355,997 Add: Interest expense, net of capitalized interest 118,473 118,976 234,935 237,223 Depreciation and amortization 100,849 99,247 200,268 193,725 Income taxes 43,844 52,458 98,785 102,524 Other corporate costs and noncash items (a) 43,073 4,684 51,220 10,525 Total segment adjusted EBITDA $ 482,230 $ 455,451 $ 947,384 $ 899,994 (a) - Includes our April 2017, $20 million contribution of Series E Preferred Stock to the Foundation and costs related to the Merger Transaction of $22.8 million and $29.5 million for the three and six months ended June 30, 2017, respectively.

SUPPLEMENTAL CONDENSED CONSOLID

SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION (Notes)	6 Months Ended
	Jun. 30, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Supplemental Condensed Consolidating Financial Information	SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION ONEOK and ONEOK Partners are issuers of certain public debt securities. Effective with the Merger Transaction, we, ONEOK Partners and the Intermediate Partnership issued, to the extent not already in place, guarantees of the indebtedness of ONEOK and ONEOK Partners. The Intermediate Partnership holds all of ONEOK Partners’ partnership interests and equity in its subsidiaries, as well as a 50 percent interest in Northern Border Pipeline. In lieu of providing separate financial statements for each subsidiary issuer and guarantor, we have included the accompanying condensed consolidating financial statements based on Rule 3-10 of the SEC’s Regulation S-X. We have presented each of the parent and subsidiary issuers in separate columns in this single set of condensed consolidating financial statements. For purposes of the following footnote: • we are referred to as “Parent Issuer and Guarantor”; • ONEOK Partners is referred to as “Subsidiary Issuer and Guarantor”; • the Intermediate Partnership is referred to as “Guarantor Subsidiary”; and • the “Non-Guarantor Subsidiaries” are all subsidiaries other than the Guarantor Subsidiary and Subsidiary Issuer and Guarantor. The following unaudited supplemental condensed consolidating financial information is presented on an equity-method basis reflecting the separate accounts of ONEOK, ONEOK Partners and the Intermediate Partnership, the combined accounts of the Non-Guarantor Subsidiaries, the combined consolidating adjustments and eliminations, and our consolidated amounts for the periods indicated. Condensed Consolidating Statements of Income Three Months Ended June 30, 2017 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Revenues Commodity sales $ — $ — $ — $ 2,161.0 $ — $ 2,161.0 Services — — — 565.8 (1.0 ) 564.8 Total revenues — — — 2,726.8 (1.0 ) 2,725.8 Cost of sales and fuel (exclusive of items shown separately below) — — — 2,091.0 — 2,091.0 Operating expenses 20.5 — 6.2 293.0 (1.0 ) 318.7 (Gain) loss on sale of assets — — — (0.6 ) — (0.6 ) Operating income (20.5 ) — (6.2 ) 343.4 — 316.7 Equity in net earnings from investments 275.2 278.5 284.7 23.8 (822.8 ) 39.4 Other income (expense), net (17.4 ) 94.9 94.9 (0.4 ) (189.8 ) (17.8 ) Interest expense, net (24.5 ) (94.9 ) (94.9 ) (94.0 ) 189.8 (118.5 ) Income before income taxes 212.8 278.5 278.5 272.8 (822.8 ) 219.8 Income taxes 37.7 — — 6.1 — 43.8 Net income 175.1 278.5 278.5 266.7 (822.8 ) 176.0 Less: Net income attributable to noncontrolling interests 103.4 — — 0.9 — 104.3 Net income attributable to ONEOK 71.7 278.5 278.5 265.8 (822.8 ) 71.7 Less: Preferred stock dividends 0.2 — — — — 0.2 Net income available to common shareholders $ 71.5 $ 278.5 $ 278.5 $ 265.8 $ (822.8 ) $ 71.5 Three Months Ended June 30, 2016 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Revenues Commodity sales $ — $ — $ — $ 1,633.3 $ — $ 1,633.3 Services — — — 501.3 (0.5 ) 500.8 Total revenues — — — 2,134.6 (0.5 ) 2,134.1 Cost of sales and fuel (exclusive of items shown separately below) — — — 1,527.3 — 1,527.3 Operating expenses 9.8 — — 281.8 (0.5 ) 291.1 (Gain) loss on sale of assets — — — 0.4 — 0.4 Operating income (9.8 ) — — 325.1 — 315.3 Equity in net earnings from investments 260.9 261.5 261.5 16.7 (768.2 ) 32.4 Other income (expense), net 4.3 94.9 94.9 (0.5 ) (189.8 ) 3.8 Interest expense, net (25.7 ) (94.9 ) (94.9 ) (93.3 ) 189.8 (119.0 ) Income before income taxes 229.7 261.5 261.5 248.0 (768.2 ) 232.5 Income taxes (50.3 ) — — (2.1 ) — (52.4 ) Income from continuing operations 179.4 261.5 261.5 245.9 (768.2 ) 180.1 Income (loss) from discontinued operations, net of tax — — — (0.2 ) — (0.2 ) Net income 179.4 261.5 261.5 245.7 (768.2 ) 179.9 Less: Net income attributable to noncontrolling interests 93.5 — — 0.5 — 94.0 Net income attributable to ONEOK $ 85.9 $ 261.5 $ 261.5 $ 245.2 $ (768.2 ) $ 85.9 Six Months Ended June 30, 2017 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Revenues Commodity sales $ — $ — $ — $ 4,377.7 $ — $ 4,377.7 Services — — — 1,098.7 (1.0 ) 1,097.7 Total revenues — — — 5,476.4 (1.0 ) 5,475.4 Cost of sales and fuel (exclusive of items shown separately below) — — — 4,234.9 — 4,234.9 Operating expenses 30.1 — 6.2 574.6 (1.0 ) 609.9 (Gain) loss on sale of assets — — — (0.6 ) — (0.6 ) Operating income (30.1 ) — (6.2 ) 667.5 — 631.2 Equity in net earnings from investments 544.0 547.6 553.8 44.5 (1,611.0 ) 78.9 Other income (expense), net (14.2 ) 186.1 186.1 — (372.2 ) (14.2 ) Interest expense, net (50.3 ) (186.1 ) (186.1 ) (184.6 ) 372.2 (234.9 ) Income before income taxes 449.4 547.6 547.6 527.4 (1,611.0 ) 461.0 Income taxes (89.0 ) — — (9.8 ) — (98.8 ) Net income 360.4 547.6 547.6 517.6 (1,611.0 ) 362.2 Less: Net income attributable to noncontrolling interests 201.3 — — 1.8 — 203.1 Net income attributable to ONEOK 159.1 547.6 547.6 515.8 (1,611.0 ) 159.1 Less: Preferred stock dividends 0.2 — — — — 0.2 Net income available to common shareholders $ 158.9 $ 547.6 $ 547.6 $ 515.8 $ (1,611.0 ) $ 158.9 Six Months Ended June 30, 2016 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Revenues Commodity sales $ — $ — $ — $ 2,916.8 $ — $ 2,916.8 Services — — — 992.8 (1.0 ) 991.8 Total revenues — — — 3,909.6 (1.0 ) 3,908.6 Cost of sales and fuel (exclusive of items shown separately below) — — — 2,723.1 — 2,723.1 Operating expenses 16.4 — — 547.2 (1.0 ) 562.6 (Gain) loss on sale of assets — — — (3.8 ) — (3.8 ) Operating income (16.4 ) — — 643.1 — 626.7 Equity in net earnings from investments 513.3 515.0 515.0 30.9 (1,508.9 ) 65.3 Other income (expense), net 4.4 189.3 189.3 (0.7 ) (378.6 ) 3.7 Interest expense, net (51.4 ) (189.3 ) (189.3 ) (185.8 ) 378.6 (237.2 ) Income before income taxes 449.9 515.0 515.0 487.5 (1,508.9 ) 458.5 Income taxes (98.4 ) — — (4.1 ) — (102.5 ) Income from continuing operations 351.5 515.0 515.0 483.4 (1,508.9 ) 356.0 Income (loss) from discontinued operations, net of tax — — — (1.2 ) — (1.2 ) Net income 351.5 515.0 515.0 482.2 (1,508.9 ) 354.8 Less: Net income attributable to noncontrolling interests 182.1 — — 3.3 — 185.4 Net income attributable to ONEOK $ 169.4 $ 515.0 $ 515.0 $ 478.9 $ (1,508.9 ) $ 169.4 Condensed Consolidating Statements of Comprehensive Income Three Months Ended June 30, 2017 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Net income $ 175.1 $ 278.5 $ 278.5 $ 266.7 $ (822.8 ) $ 176.0 Other comprehensive income (loss), net of tax Unrealized gains (losses) on derivatives, net of tax (0.3 ) (5.7 ) 9.0 9.8 (17.9 ) (5.1 ) Realized (gains) losses on derivatives in net income, net of tax 0.5 11.1 6.8 5.1 (13.6 ) 9.9 Change in pension and postretirement benefit plan liability, net of tax 2.1 — — — — 2.1 Other comprehensive income (loss) on investments in unconsolidated affiliates, net of tax — (1.6 ) (1.6 ) (1.4 ) 3.2 (1.4 ) Total other comprehensive income (loss) 2.3 3.8 14.2 13.5 (28.3 ) 5.5 Comprehensive income 177.4 282.3 292.7 280.2 (851.1 ) 181.5 Less: Comprehensive income attributable to noncontrolling interests 105.6 — — 0.9 — 106.5 Comprehensive income attributable to ONEOK $ 71.8 $ 282.3 $ 292.7 $ 279.3 $ (851.1 ) $ 75.0 Three Months Ended June 30, 2016 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Net income $ 179.4 $ 261.5 $ 261.5 $ 245.7 $ (768.2 ) $ 179.9 Other comprehensive income (loss), net of tax Unrealized gains (losses) on derivatives, net of tax — (87.2 ) (58.7 ) (132.6 ) 204.6 (73.9 ) Realized (gains) losses on derivatives in net income, net of tax 0.6 (10.1 ) (14.0 ) (21.5 ) 36.9 (8.1 ) Change in pension and postretirement benefit plan liability, net of tax 1.5 — — — — 1.5 Other comprehensive income (loss) on investments in unconsolidated affiliates, net of tax — (5.6 ) (5.6 ) (10.3 ) 16.8 (4.7 ) Total other comprehensive income (loss) 2.1 (102.9 ) (78.3 ) (164.4 ) 258.3 (85.2 ) Comprehensive income 181.5 158.6 183.2 81.3 (509.9 ) 94.7 Less: Comprehensive income attributable to noncontrolling interests 32.9 — — 0.5 — 33.4 Comprehensive income attributable to ONEOK $ 148.6 $ 158.6 $ 183.2 $ 80.8 $ (509.9 ) $ 61.3 Six Months Ended June 30, 2017 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Net income $ 360.4 $ 547.6 $ 547.6 $ 517.6 $ (1,611.0 ) $ 362.2 Other comprehensive income (loss), net of tax Unrealized gains (losses) on derivatives, net of tax (0.3 ) 23.1 36.3 32.8 (72.6 ) 19.3 Realized (gains) losses on derivatives in net income, net of tax 1.0 30.9 22.1 17.4 (44.2 ) 27.2 Change in pension and postretirement benefit plan liability, net of tax 4.1 — — — — 4.1 Other comprehensive income (loss) on investments in unconsolidated affiliates, net of tax — (1.2 ) (1.2 ) (1.0 ) 2.4 (1.0 ) Total other comprehensive income (loss) 4.8 52.8 57.2 49.2 (114.4 ) 49.6 Comprehensive income 365.2 600.4 604.8 566.8 (1,725.4 ) 411.8 Less: Comprehensive income attributable to noncontrolling interests 232.4 — — 1.8 — 234.2 Comprehensive income attributable to ONEOK $ 132.8 $ 600.4 $ 604.8 $ 565.0 $ (1,725.4 ) $ 177.6 Six Months Ended June 30, 2016 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Net income $ 351.5 $ 515.0 $ 515.0 $ 482.2 $ (1,508.9 ) $ 354.8 Other comprehensive income (loss), net of tax Unrealized gains (losses) on derivatives, net of tax — (107.1 ) (47.0 ) (137.8 ) 201.1 (90.8 ) Realized (gains) losses on derivatives in net income, net of tax 1.1 (20.8 ) (28.5 ) (44.0 ) 75.6 (16.6 ) Change in pension and postretirement benefit plan liability, net of tax 3.1 — — — — 3.1 Other comprehensive income (loss) on investments in unconsolidated affiliates, net of tax — (11.4 ) (11.4 ) (21.0 ) 34.2 (9.6 ) Total other comprehensive income (loss) 4.2 (139.3 ) (86.9 ) (202.8 ) 310.9 (113.9 ) Comprehensive income 355.7 375.7 428.1 279.4 (1,198.0 ) 240.9 Less: Comprehensive income attributable to noncontrolling interests 100.2 — — 3.3 — 103.5 Comprehensive income attributable to ONEOK $ 255.5 $ 375.7 $ 428.1 $ 276.1 $ (1,198.0 ) $ 137.4 Condensed Consolidating Balance Sheets June 30, 2017 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total Assets ( Millions of dollars ) Current assets Cash and cash equivalents $ 321.0 $ — $ 11.4 $ — $ — $ 332.4 Accounts receivable, net — — — 749.3 — 749.3 Natural gas and natural gas liquids in storage — — — 200.1 — 200.1 Other current assets 12.9 0.5 — 152.6 — 166.0 Total current assets 333.9 0.5 11.4 1,102.0 — 1,447.8 Property, plant and equipment Property, plant and equipment 139.8 — — 15,101.3 — 15,241.1 Accumulated depreciation and amortization 94.3 — — 2,599.8 — 2,694.1 Net property, plant and equipment 45.5 — — 12,501.5 — 12,547.0 Investments and other assets Investments 5,936.9 3,160.9 7,376.1 622.7 (16,152.0 ) 944.6 Intercompany notes receivable 253.7 10,791.6 6,565.0 — (17,610.3 ) — Other assets 763.6 19.7 — 1,017.9 (67.7 ) 1,733.5 Total investments and other assets 6,954.2 13,972.2 13,941.1 1,640.6 (33,830.0 ) 2,678.1 Total assets $ 7,333.6 $ 13,972.7 $ 13,952.5 $ 15,244.1 $ (33,830.0 ) $ 16,672.9 Liabilities and equity Current liabilities Current maturities of long-term debt $ 87.1 $ 400.0 $ — $ 7.7 $ — $ 494.8 Short-term borrowings — 1,274.4 — — — 1,274.4 Accounts payable 19.9 — — 676.9 — 696.8 Other current liabilities 57.7 86.3 — 250.5 — 394.5 Total current liabilities 164.7 1,760.7 — 935.1 — 2,860.5 Intercompany debt — — 10,791.6 6,818.7 (17,610.3 ) — Long-term debt, excluding current maturities 1,545.0 6,257.9 — 32.7 — 7,835.6 Deferred credits and other liabilities 216.2 — — 263.1 (67.7 ) 411.6 Commitments and contingencies Equity Equity excluding noncontrolling interests in consolidated subsidiaries 5,407.7 5,954.1 3,160.9 7,037.0 (16,152.0 ) 5,407.7 Noncontrolling interests in consolidated subsidiaries — — — 157.5 — 157.5 Total equity 5,407.7 5,954.1 3,160.9 7,194.5 (16,152.0 ) 5,565.2 Total liabilities and equity $ 7,333.6 $ 13,972.7 $ 13,952.5 $ 15,244.1 $ (33,830.0 ) $ 16,672.9 December 31, 2016 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total Assets ( Millions of dollars ) Current assets Cash and cash equivalents $ 248.5 $ — $ 0.4 $ — $ — $ 248.9 Accounts receivable, net — — — 872.4 — 872.4 Natural gas and natural gas liquids in storage — — — 140.0 — 140.0 Other current assets 7.2 — — 160.6 — 167.8 Assets of discontinued operations — — — 0.6 — 0.6 Total current assets 255.7 — 0.4 1,173.6 — — 1,429.7 Property, plant and equipment Property, plant and equipment 139.8 — — 14,938.7 — 15,078.5 Accumulated depreciation and amortization 90.4 — — 2,416.7 — 2,507.1 Net property, plant and equipment 49.4 — — 12,522.0 — 12,571.4 Investments and other assets Investments 2,931.9 3,222.1 6,805.4 631.1 (12,631.7 ) 958.8 Intercompany notes receivable 205.2 10,615.0 7,031.3 — (17,851.5 ) — Other assets 103.4 47.5 — 1,028.0 — 1,178.9 Total investments and other assets 3,240.5 13,884.6 13,836.7 1,659.1 (30,483.2 ) 2,137.7 Total assets $ 3,545.6 $ 13,884.6 $ 13,837.1 $ 15,354.7 $ (30,483.2 ) $ 16,138.8 Liabilities and equity Current liabilities Current maturities of long-term debt $ 3.0 $ 400.0 $ — $ 7.7 $ — $ 410.7 Short-term borrowings — 1,110.3 — — — 1,110.3 Accounts payable 13.0 — — 861.7 — 874.7 Other current liabilities 44.7 99.9 — 296.5 — 441.1 Total current liabilities 60.7 1,610.2 — 1,165.9 — 2,836.8 Intercompany debt — — 10,615.0 7,236.5 (17,851.5 ) — Long-term debt, excluding current maturities 1,628.7 6,254.7 — 36.6 — 7,920.0 Deferred credits and other liabilities 1,667.5 — — 285.6 — 1,953.1 Commitments and contingencies Equity Equity excluding noncontrolling interests in consolidated subsidiaries 188.7 6,019.7 3,222.1 6,472.0 (15,713.8 ) 188.7 Noncontrolling interests in consolidated subsidiaries — — — 158.1 3,082.1 3,240.2 Total equity 188.7 6,019.7 3,222.1 6,630.1 (12,631.7 ) 3,428.9 Total liabilities and equity $ 3,545.6 $ 13,884.6 $ 13,837.1 $ 15,354.7 $ (30,483.2 ) $ 16,138.8 Condensed Consolidating Statements of Cash Flows Six Months Ended June 30, 2017 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Operating activities Cash provided by operating activities $ 355.0 $ 675.2 $ 28.2 $ 645.5 $ (1,061.0 ) $ 642.9 Investing activities Capital expenditures (0.1 ) — — (195.1 ) — (195.2 ) Other investing activities — — 6.7 4.8 — 11.5 Cash provided by (used in) investing activities (0.1 ) — 6.7 (190.3 ) — (183.7 ) Financing activities Dividends paid (259.8 ) (666.0 ) (666.0 ) — 1,332.0 (259.8 ) Distributions to noncontrolling interests — — — (2.5 ) (271.0 ) (273.5 ) Intercompany borrowings (advances), net (27.1 ) (166.1 ) 642.1 (448.9 ) — — Borrowing (repayment) of short-term borrowings, net — 164.1 — — — 164.1 Repayment of long-term debt (0.1 ) — — (3.8 ) — (3.9 ) Issuance of common stock 10.8 — — — — 10.8 Other (6.2 ) (7.2 ) — — — (13.4 ) Cash used in financing activities (282.4 ) (675.2 ) (23.9 ) — (455.2 ) 1,061.0 (375.7 ) Change in cash and cash equivalents 72.5 — 11.0 — — 83.5 Cash and cash equivalents at beginning of period 248.5 — 0.4 — — 248.9 Cash and cash equivalents at end of period $ 321.0 $ — $ 11.4 $ — $ — $ 332.4 Six Months Ended June 30, 2016 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Operating activities Cash provided by operating activities $ 363.1 $ 668.6 $ 34.4 $ 526.5 $ (1,061.0 ) $ 531.6 Investing activities Capital expenditures — — — (333.3 ) — (333.3 ) Other investing activities — — 24.9 9.9 — 34.8 Cash provided by (used in) investing activities — — 24.9 (323.4 ) — (298.5 ) Financing activities Dividends paid (258.5 ) (666.0 ) (666.0 ) — 1,332.0 (258.5 ) Distributions to noncontrolling interests — — — (4.3 ) (271.0 ) (275.3 ) Intercompany borrowings (advances), net (30.5 ) (379.8 ) 605.3 (195.0 ) — — Borrowing (repayment) of short-term borrowings, net — 30.0 — — — 30.0 Issuance of long-term debt, net of discounts — 1,000.0 — — — 1,000.0 Debt financing costs — (2.8 ) — — — (2.8 ) Repayment of long-term debt (0.3 ) (650.0 ) — (3.8 ) — (654.1 ) Issuance of common stock 11.1 — — — — 11.1 Cash used in financing activities (278.2 ) (668.6 ) (60.7 ) (203.1 ) 1,061.0 (149.6 ) Change in cash and cash equivalents 84.9 — (1.4 ) — — 83.5 Change in cash and cash equivalents included in discontinued operations (0.2 ) — — — — (0.2 ) Change in cash and cash equivalents included in continuing operations 84.7 — (1.4 ) — — 83.3 Cash and cash equivalents at beginning of period 92.5 — 5.1 — — 97.6 Cash and cash equivalents at end of period $ 177.2 $ — $ 3.7 $ — $ — $ 180.9

SUMMARY OF SIGNIFICANT ACCOUN24

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Basis of Accounting, Policy [Policy Text Block]	Our accompanying unaudited consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC. These statements have been prepared in accordance with GAAP and reflect all adjustments that, in our opinion, are necessary for a fair statement of the results for the interim periods presented. All such adjustments are of a normal recurring nature. The 2016 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 and our Current Report on Form 8-K filed on July 6, 2017, which updates Item 8 in our Annual Report.
Discontinued Operations, Policy [Policy Text Block]	Discontinued Operations - Beginning in 2017, the results of operations and financial position of our former energy services business are no longer reflected as discontinued operations in our Consolidated Financial Statements and Notes to the Consolidated Financial Statements, as they are not material.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Issued Accounting Standards Update - Changes to GAAP are established by the Financial Accounting Standards Board (FASB) in the form of ASUs to the FASB Accounting Standards Codification. We consider the applicability and impact of all ASUs. ASUs not listed below were assessed and determined to be either not applicable or clarifications of ASUs listed below. 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 2015-11, “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 As a result of adopting this guidance, we updated our accounting policy for inventory valuation accordingly. The financial impact of adopting this guidance was not material. 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 The impact of adopting this standard was not material. 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 The impact of adopting this standard was not material. 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 As a result of adopting this guidance, we recorded an adjustment increasing beginning retained earnings and deferred tax assets in the first quarter 2017 of approximately $73 million to recognize previously unrecognized cumulative excess tax benefits related to share-based payments on a modified retrospective basis. Beginning in January 2017, all share-based payment tax effects are recorded in earnings. The other effects of adopting this standard were not material. Standard Description Date of Adoption Effect on the Financial Statements or Other Significant Matters Standards that are not yet adopted 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 contracts and transaction types across all our business segments, which we have substantially completed. For the majority of our contracts, we do not expect material changes in our accounting policies or revenue recognition. However, we are reviewing the potential impact on certain contract types where there remains diversity of thought across our industry in the application of the standard. Due to this ongoing analysis, we cannot yet determine the quantitative impact on revenues or cost of sales from the adoption of Topic 606, but we do not currently believe the adoption will have a material impact on net income. We are developing our required disclosures under the standard and expect to disaggregate revenues similar to our current presentation in Note L - Segments. We have not identified material unsatisfied performance obligations that would require disclosure. We are currently evaluating methods of adoption and analyzing the impact of the standard on our internal controls. We expect to determine our method of adoption when we complete our evaluation of the quantitative impact of the standard and the implications of each adoption method. 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 do not have any equity investments classified as available-for-sale or accounted for using the cost method, therefore we do not expect adoption of this standard to have a material impact 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 2017-07, “Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost” The standard requires the service cost component of net benefit cost to be reported in the same line item or items as other compensation costs from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations. 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 our current leases and other contracts that may be considered leases under the new standard and the impact on our internal controls, accounting policies and financial statements and disclosures. Standard Description Date of Adoption Effect on the Financial Statements or Other Significant Matters Standards that are not yet adopted (continued) 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. ASU 2017-04, “Intangibles- Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment” The standard simplifies the subsequent measurement of goodwill by eliminating the requirement to calculate the implied fair value of goodwill under step 2. Instead, an entity will recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. The standard does not change step zero or step 1 assessments. 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)	6 Months Ended
	Jun. 30, 2017
Fair Value Accounting Policy [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 derivative 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 our derivative portfolio by discounting the projected future cash flows from our derivative assets and liabilities to present value using interest-rate yields to calculate present-value discount factors derived from LIBOR, Eurodollar futures and 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 derivative contracts we have executed, the ultimate market prices realized could differ from our estimates, and the differences could be material. The fair value of our 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 composed 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.

EQUITY (Policies)

EQUITY (Policies)	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Partnership agreement	Cash Distributions - Prior to the consummation of the Merger Transaction, we received distributions from ONEOK Partners on our common and Class B units and our 2 percent general partner interest, which included our incentive distribution rights.

SEGMENTS SEGMENTS (Policies)

SEGMENTS SEGMENTS (Policies)	6 Months Ended
	Jun. 30, 2017
Segment Reporting [Abstract]
Segment Accounting Policy [Policy 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 our three segments, as well as our financial performance as a whole, on a regular basis. Adjusted EBITDA by segment is utilized in this evaluation. We believe this financial measure is useful to investors because it and similar measures are used by many companies in our industry as a measurement of financial performance and are commonly employed by financial analysts and others to evaluate our financial performance and to compare financial performance among companies in our industry. Adjusted EBITDA for each segment is defined as net income adjusted for interest expense, depreciation and amortization, noncash impairment charges, income taxes, allowance for equity funds used during construction, noncash equity compensation and other noncash items. This calculation may not be comparable with similarly titled measures of other companies.

ONEOK PARTNERS ACQUISITION (Tab

ONEOK PARTNERS ACQUISITION (Tables)	6 Months Ended
	Jun. 30, 2017
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Cash Flow, Supplemental Disclosures [Text Block]	Our noncash balance sheet activity related to the Merger Transaction is as follows (in millions): June 30, 2017 Common stock $ 1.7 Paid-in capital $ 5,228.6 Accumulated other comprehensive loss $ (40.3 ) Noncontrolling interests in consolidated subsidiaries $ (3,043.5 ) Deferred income taxes $ (2,146.5 )

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Recurring Fair Value Measurements	The following tables set forth our recurring fair value measurements for the periods indicated: June 30, 2017 Level 1 Level 2 Level 3 Total - Gross Netting (a) Total - Net (b) ( Thousands of dollars ) Derivative assets Commodity contracts Financial contracts $ 4,349 $ — $ 11,865 $ 16,214 $ (15,786 ) $ 428 Physical contracts — — 710 710 — 710 Interest-rate contracts — 38,006 — 38,006 — 38,006 Total derivative assets $ 4,349 $ 38,006 $ 12,575 $ 54,930 $ (15,786 ) $ 39,144 Derivative liabilities Commodity contracts Financial contracts $ (5,973 ) $ — $ (10,792 ) $ (16,765 ) $ 16,656 $ (109 ) Physical contracts — — (1,033 ) (1,033 ) — (1,033 ) Interest-rate contracts — (16,872 ) — (16,872 ) — (16,872 ) Total derivative liabilities $ (5,973 ) $ (16,872 ) $ (11,825 ) $ (34,670 ) $ 16,656 $ (18,014 ) (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 June 30, 2017 , we held no cash and posted $11.8 million of cash with various counterparties, including $0.9 million of cash collateral that is offsetting derivative net liability positions under master-netting arrangements in the table above. The remaining $10.9 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 or other current liabilities in our Consolidated Balance Sheets. December 31, 2016 Level 1 Level 2 Level 3 Total - Gross Netting (a) Total - Net (b) ( Thousands of dollars ) Derivative assets Commodity contracts Financial contracts $ 1,147 $ — $ 4,564 $ 5,711 $ (4,760 ) $ 951 Interest rate contracts — 47,457 — 47,457 — 47,457 Total derivative assets $ 1,147 $ 47,457 $ 4,564 $ 53,168 $ (4,760 ) $ 48,408 Derivative liabilities Commodity contracts Financial contracts $ (31,458 ) $ — $ (24,861 ) $ (56,319 ) $ 56,319 $ — Physical contracts — — (3,022 ) (3,022 ) — (3,022 ) Interest-rate contracts — (12,795 ) — (12,795 ) — (12,795 ) Total derivative liabilities $ (31,458 ) $ (12,795 ) $ (27,883 ) $ (72,136 ) $ 56,319 $ (15,817 ) (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, 2016 , we held no cash and posted $67.7 million of cash with various counterparties, including $51.6 million of cash collateral that is offsetting derivative net liability positions under master-netting arrangements in the table above. The remaining $16.1 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 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 Six Months Ended June 30, June 30, Derivative Assets (Liabilities) 2017 2016 2017 2016 ( Thousands of dollars ) Net assets (liabilities) at beginning of period $ (772 ) $ 34 $ (23,319 ) $ 7,331 Total realized/unrealized gains (losses): Included in earnings (a) (656 ) 318 258 (427 ) Included in other comprehensive income (loss) 2,178 (14,373 ) 23,811 (20,925 ) Net assets (liabilities) at end of period $ 750 $ (14,021 ) $ 750 $ (14,021 ) (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)	6 Months Ended
	Jun. 30, 2017
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: June 30, 2017 December 31, 2016 Location in our Consolidated Balance Sheets Assets (Liabilities) Assets (Liabilities) ( Thousands of dollars ) Derivatives designated as hedging instruments Commodity contracts Financial contracts Other current assets/other current liabilities $ 7,577 $ (13,082 ) $ 1,155 $ (49,938 ) Other assets/deferred credits and other liabilities 5,510 (225 ) 210 (2,142 ) Physical contracts Other current assets/other current liabilities 330 (1,033 ) — (3,022 ) Other assets 380 — — — Interest-rate contracts Other current assets/other current liabilities 493 (16,872 ) — (12,795 ) Other assets 37,513 — 47,457 — Total derivatives designated as hedging instruments 51,803 (31,212 ) 48,822 (67,897 ) Derivatives not designated as hedging instruments Commodity contracts Financial contracts Other current assets/other current liabilities 2,587 (2,967 ) 4,346 (4,239 ) Other assets/deferred credits and other liabilities 540 (491 ) — — Total derivatives not designated as hedging instruments 3,127 (3,458 ) 4,346 (4,239 ) Total derivatives $ 54,930 $ (34,670 ) $ 53,168 $ (72,136 )
Notional Amounts of Derivative Instruments	The following table sets forth the notional quantities for derivative instruments held for the periods indicated: June 30, 2017 December 31, 2016 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 — (34.3 ) — (38.4 ) - Natural gas ( Bcf ) Put options 22.5 — 49.5 — - Crude oil and NGLs ( MMBbl ) Futures, forwards and swaps 0.7 (5.0 ) — (3.6 ) Basis - Natural gas ( Bcf ) Futures and swaps — (34.3 ) — (38.4 ) Interest-rate contracts ( Millions of dollars ) Swaps $ 2,150.0 $ — $ 2,150.0 $ — Derivatives not designated as hedging instruments: Fixed price -Natural gas ( Bcf ) Futures and swaps 1.8 — 0.4 — - NGLs ( MMBbl ) Futures, forwards and swaps 0.6 (1.1 ) 0.5 (0.7 ) Basis - Natural gas ( Bcf ) Futures and swaps 1.8 — 0.4 —
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: Three Months Ended Six Months Ended Derivatives in Cash Flow Hedging Relationships June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Commodity contracts $ 8,998 $ (58,654 ) $ 36,326 $ (46,976 ) Interest-rate contracts (14,995 ) (28,564 ) (13,466 ) (60,175 ) Total unrealized gain (loss) recognized in other comprehensive income (loss) on derivatives (effective portion) $ (5,997 ) $ (87,218 ) $ 22,860 $ (107,151 )
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 Six Months Ended June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Commodity contracts Commodity sales revenues $ (6,796 ) $ 14,049 $ (22,115 ) $ 28,548 Interest-rate contracts Interest expense (5,172 ) (4,802 ) (10,501 ) (9,500 ) Total gain (loss) reclassified from accumulated other comprehensive loss into net income on derivatives (effective portion) $ (11,968 ) $ 9,247 $ (32,616 ) $ 19,048

DEBT DEBT (Tables)

DEBT DEBT (Tables)	6 Months Ended
	Jun. 30, 2017
Debt Instrument [Line Items]
Debt [Table Text Block]	The following table sets forth our consolidated debt for the periods indicated: June 30, December 31, ( Thousands of dollars ) ONEOK Senior unsecured obligations: $700,000 at 4.25% due February 2022 $ 547,397 $ 547,397 $500,000 at 7.5% due September 2023 500,000 500,000 $100,000 at 6.5% due September 2028 87,053 87,126 $100,000 at 6.875% due September 2028 100,000 100,000 $400,000 at 6.0% due June 2035 400,000 400,000 ONEOK Partners Commercial paper outstanding, bearing a weighted-average interest rate of 1.80% and 1.27%, respectively (a) 1,274,407 1,110,277 Senior unsecured obligations: $400,000 at 2.0% due October 2017 400,000 400,000 $425,000 at 3.2% due September 2018 425,000 425,000 $1,000,000 term loan, variable rate, due January 2019 (b) 1,000,000 1,000,000 $500,000 at 8.625% due March 2019 500,000 500,000 $300,000 at 3.8% due March 2020 300,000 300,000 $900,000 at 3.375 % due October 2022 900,000 900,000 $425,000 at 5.0 % due September 2023 425,000 425,000 $500,000 at 4.9 % due March 2025 500,000 500,000 $600,000 at 6.65% due October 2036 600,000 600,000 $600,000 at 6.85% due October 2037 600,000 600,000 $650,000 at 6.125% due February 2041 650,000 650,000 $400,000 at 6.2% due September 2043 400,000 400,000 Guardian Pipeline Weighted average 7.85% due December 2022 40,433 44,257 Total debt 9,649,290 9,489,057 Unamortized portion of terminated swaps 19,327 20,186 Unamortized debt issuance costs and discounts (63,901 ) (68,320 ) Current maturities of long-term debt (494,703 ) (410,650 ) Short-term borrowings (c) (1,274,407 ) (1,110,277 ) Long-term debt $ 7,835,606 $ 7,919,996 (a) - In July 2017, the commercial paper outstanding under the ONEOK Partners commercial paper program was repaid as it matured with a combination of proceeds from new issuances from ONEOK’s recently established $2.5 billion commercial paper program, cash on hand and proceeds from our July 2017 $1.2 billion senior notes issuance. The $2.4 billion ONEOK Partners commercial paper program was terminated in July 2017. (b) - I n July 2017, we repaid $500 million of the $1.0 billion Term Loan Agreement due 2019. (c) - Individual issuances of commercial paper under our commercial paper program generally mature in 90 days or less. These issuances are supported by and reduce the borrowing capacity under the 2017 Credit Agreement.

EQUITY (Tables)

EQUITY (Tables)	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Schedule of distributions declared to general or limited partner	The following table sets forth ONEOK Partners’ distributions declared and paid during the periods indicated: Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 ( Thousands, except per unit amounts ) Distribution per unit $ 0.79 $ 0.79 $ 1.58 $ 1.58 General partner distributions $ 6,660 $ 6,660 $ 13,320 $ 13,320 Incentive distributions 100,538 100,538 201,076 201,076 Distributions to general partner 107,198 107,198 214,396 214,396 Limited partner distributions to ONEOK 90,323 90,323 180,646 180,646 Limited partner distributions to other unitholders 135,479 135,479 270,959 270,959 Total distributions paid $ 333,000 $ 333,000 $ 666,001 $ 666,001

ACCUMULATED OTHER COMPREHENSI33

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) ACCUMULATED OTHER COMPREHENSIVE INCOME (Tables)	6 Months Ended
	Jun. 30, 2017
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, 2017 $ (52,155 ) $ (101,236 ) $ (959 ) $ (154,350 ) Other comprehensive income (loss) before reclassifications 5,728 5 (367 ) 5,366 Amounts reclassified from accumulated other comprehensive loss 9,064 4,076 47 13,187 Impact of Merger Transaction (Note B) (c) (40,288 ) — — (40,288 ) Net current-period other comprehensive income (loss) attributable to ONEOK (25,496 ) 4,081 (320 ) (21,735 ) June 30, 2017 $ (77,651 ) $ (97,155 ) $ (1,279 ) $ (176,085 ) (a) - All amounts are presented net of tax. (b) - Includes amounts related to supplemental executive retirement plan. (c) - Includes the remaining portion of ONEOK Partners’ accumulated other comprehensive loss at June 30, 2017, that we acquired in the Merger Transaction, related to commodity and interest-rate contracts.
Reclassification out of Accumulated Other Comprehensive Income (Loss)	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 Components Three Months Ended Six Months Ended Affected Line Item in the Statements of Income June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Unrealized gains (losses) on risk-management assets/liabilities Commodity contracts $ (6,796 ) $ 14,049 $ (22,115 ) $ 28,548 Commodity sales revenues Interest-rate contracts (5,172 ) (4,802 ) (10,501 ) (9,500 ) Interest expense (11,968 ) 9,247 (32,616 ) 19,048 Income before income taxes 2,041 (1,193 ) 5,406 (2,469 ) Income tax expense (9,927 ) 8,054 (27,210 ) 16,579 Net income Noncontrolling interests (6,521 ) 5,953 (18,146 ) 12,233 Less: Net income attributable to noncontrolling interests $ (3,406 ) $ 2,101 $ (9,064 ) $ 4,346 Net income attributable to ONEOK Pension and postretirement benefit plan obligations (a) Amortization of net loss $ (3,812 ) $ (2,997 ) $ (7,624 ) $ (5,995 ) Amortization of unrecognized prior service cost 415 415 830 830 (3,397 ) (2,582 ) (6,794 ) (5,165 ) Income before income taxes 1,359 1,033 2,718 2,066 Income tax expense $ (2,038 ) $ (1,549 ) $ (4,076 ) $ (3,099 ) Net income attributable to ONEOK Unrealized gains (losses) on risk-management assets/liabilities of unconsolidated affiliates $ (85 ) $ — $ (181 ) $ — Equity in net earnings from investments 13 — 28 — Income tax expense (72 ) — (153 ) — Net income Noncontrolling interests (50 ) — (106 ) — Less: Net income attributable to noncontrolling interests $ (22 ) $ — $ (47 ) $ — Net income attributable to ONEOK Total reclassifications for the period attributable to ONEOK $ (5,466 ) $ 552 $ (13,187 ) $ 1,247 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 P34

EARNINGS PER SHARE EARNINGS PER SHARE (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 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 $ 71,476 211,785 $ 0.34 Diluted EPS from continuing operations Effect of dilutive securities — 2,227 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 71,476 214,012 $ 0.33 Three Months Ended June 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 $ 86,171 211,075 $ 0.41 Diluted EPS from continuing operations Effect of dilutive securities — 1,543 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 86,171 212,618 $ 0.41 Six Months Ended June 30, 2017 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 $ 158,837 211,702 $ 0.75 Diluted EPS from continuing operations Effect of dilutive securities — 2,105 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 158,837 213,807 $ 0.74 Six Months Ended June 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 $ 170,569 210,928 $ 0.81 Diluted EPS from continuing operations Effect of dilutive securities — 735 Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents $ 170,569 211,663 $ 0.81

EMPLOYEE BENEFIT PLANS EMPLOY35

EMPLOYEE BENEFIT PLANS EMPLOYEE BENEFIT PLANS (Tables)	6 Months Ended
	Jun. 30, 2017
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Components of net periodic benefit cost for pension and postretirement 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 Six Months Ended June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Components of net periodic benefit cost Service cost $ 1,722 $ 1,622 $ 3,444 $ 3,244 Interest cost 4,655 4,947 9,310 9,894 Expected return on plan assets (5,336 ) (5,077 ) (10,672 ) (10,154 ) Amortization of net loss 3,392 2,736 6,784 5,473 Net periodic benefit cost $ 4,433 $ 4,228 $ 8,866 $ 8,457 Postretirement Benefits Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Components of net periodic benefit cost Service cost $ 165 $ 149 $ 330 $ 298 Interest cost 565 601 1,130 1,202 Expected return on plan assets (564 ) (531 ) (1,128 ) (1,062 ) Amortization of prior service credit (415 ) (415 ) (830 ) (830 ) Amortization of net loss 420 261 840 522 Net periodic benefit cost $ 171 $ 65 $ 342 $ 130

UNCONSOLIDATED AFFILIATES (Tabl

UNCONSOLIDATED AFFILIATES (Tables)	6 Months Ended
	Jun. 30, 2017
Equity In Net Earnings From Investments [Member]
Schedule of Equity Method Investments [Line Items]
Schedule of Equity Method Investments [Table Text Block]	The following table sets forth our equity in net earnings from investments for the periods indicated: Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Northern Border Pipeline $ 15,622 $ 15,723 $ 34,439 $ 34,397 Overland Pass Pipeline Company 14,884 13,608 28,450 26,912 Other 8,857 3,041 16,038 3,977 Equity in net earnings from investments $ 39,363 $ 32,372 $ 78,927 $ 65,286
Summarized Financial Information Of Unconsolidated Affiliates [Member]
Schedule of Equity Method Investments [Line Items]
Schedule of Equity Method Investments [Table Text Block]	The following table sets forth summarized combined financial information of our unconsolidated affiliates for the periods indicated: Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 ( Thousands of dollars ) Income Statement Operating revenues $ 157,603 $ 142,631 $ 311,883 $ 279,203 Operating expenses $ 69,465 $ 66,674 $ 136,401 $ 125,373 Net income $ 92,072 $ 69,420 $ 173,203 $ 141,457 Distributions paid to us $ 49,760 $ 62,024 $ 96,680 $ 108,577

SEGMENTS (Tables)

SEGMENTS (Tables)	6 Months Ended
	Jun. 30, 2017
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Segments	The following tables set forth certain selected financial information for our operating segments for the periods indicated: Three Months Ended June 30, 2017 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Total ( Thousands of dollars ) Sales to unaffiliated customers $ 433,088 $ 2,196,399 $ 95,755 $ 2,725,242 Intersegment revenues 252,727 153,286 2,094 408,107 Total revenues 685,815 2,349,685 97,849 3,133,349 Cost of sales and fuel (exclusive of depreciation and items shown separately below) (488,891 ) (2,003,601 ) (6,773 ) (2,499,265 ) Operating costs (73,093 ) (87,285 ) (30,877 ) (191,255 ) Equity in net earnings from investments 3,780 15,062 20,521 39,363 Other 650 (552 ) (60 ) 38 Segment adjusted EBITDA $ 128,261 $ 273,309 $ 80,660 $ 482,230 Depreciation and amortization $ (46,033 ) $ (41,427 ) $ (12,598 ) $ (100,058 ) Capital expenditures $ 37,020 $ 12,336 $ 26,846 $ 76,202 (a) - Our Natural Gas Liquids segment has regulated and nonregulated operations. Our Natural Gas Liquids segment’s regulated operations had revenues of $289.4 million , of which $249.4 million related to sales within the segment and cost of sales and fuel of $118.9 million . (b) - Our Natural Gas Pipelines segment has regulated and nonregulated operations. Our Natural Gas Pipelines segment’s regulated operations had revenues of $62.8 million and cost of sales and fuel of $8.3 million . Three Months Ended June 30, 2017 Total Segments Other and Eliminations Total ( Thousands of dollars ) Reconciliations of total segments to consolidated Sales to unaffiliated customers $ 2,725,242 $ 530 $ 2,725,772 Intersegment revenues 408,107 (408,107 ) — Total revenues $ 3,133,349 $ (407,577 ) $ 2,725,772 Cost of sales and fuel (exclusive of depreciation and operating costs) $ (2,499,265 ) $ 408,243 $ (2,091,022 ) Operating costs $ (191,255 ) $ (26,550 ) $ (217,805 ) Depreciation and amortization $ (100,058 ) $ (791 ) $ (100,849 ) Equity in net earnings from investments $ 39,363 $ — $ 39,363 Capital expenditures $ 76,202 $ 6,293 $ 82,495 Three Months Ended June 30, 2016 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Total ( Thousands of dollars ) Sales to unaffiliated customers $ 293,071 $ 1,754,122 $ 86,401 $ 2,133,594 Intersegment revenues 183,688 117,871 1,668 303,227 Total revenues 476,759 1,871,993 88,069 2,436,821 Cost of sales and fuel (exclusive of depreciation and items shown separately below) (299,991 ) (1,525,234 ) (5,112 ) (1,830,337 ) Operating costs (69,304 ) (83,769 ) (29,189 ) (182,262 ) Equity in net earnings from investments 2,576 13,904 15,892 32,372 Other 258 (283 ) (1,118 ) (1,143 ) Segment adjusted EBITDA $ 110,298 $ 276,611 $ 68,542 $ 455,451 Depreciation and amortization $ (46,413 ) $ (40,696 ) $ (11,398 ) $ (98,507 ) Capital expenditures $ 84,674 $ 20,779 $ 29,278 $ 134,731 (a) - Our Natural Gas Liquids segment has regulated and nonregulated operations. Our Natural Gas Liquids segment’s regulated operations had revenues of $297.5 million , of which $258.4 million related to sales within the segment and cost of sales and fuel of $112.7 million . (b) - Our Natural Gas Pipelines segment has regulated and nonregulated operations. Our Natural Gas Pipelines segment’s regulated operations had revenues of $56.6 million and cost of sales and fuel of $5.7 million . Three Months Ended June 30, 2016 Total Segments Other and Eliminations Total ( Thousands of dollars ) Reconciliations of total segments to consolidated Sales to unaffiliated customers $ 2,133,594 $ 513 $ 2,134,107 Intersegment revenues 303,227 (303,227 ) — Total revenues $ 2,436,821 $ (302,714 ) $ 2,134,107 Cost of sales and fuel (exclusive of depreciation and operating costs) $ (1,830,337 ) $ 303,014 $ (1,527,323 ) Operating costs $ (182,262 ) $ (9,577 ) $ (191,839 ) Depreciation and amortization $ (98,507 ) $ (740 ) $ (99,247 ) Equity in net earnings from investments $ 32,372 $ — $ 32,372 Capital expenditures $ 134,731 $ 2,112 $ 136,843 Six Months Ended June 30, 2017 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Total ( Thousands of dollars ) Sales to unaffiliated customers $ 833,237 $ 4,440,399 $ 200,679 $ 5,474,315 Intersegment revenues 513,854 301,270 3,988 819,112 Total revenues 1,347,091 4,741,669 204,667 6,293,427 Cost of sales and fuel (exclusive of depreciation and items shown separately below) (977,275 ) (4,052,294 ) (23,376 ) (5,052,945 ) Operating costs (144,882 ) (166,028 ) (62,630 ) (373,540 ) Equity in net earnings from investments 6,410 28,784 43,733 78,927 Other 884 (593 ) 1,224 1,515 Segment adjusted EBITDA $ 232,228 $ 551,538 $ 163,618 $ 947,384 Depreciation and amortization $ (91,001 ) $ (82,542 ) $ (25,141 ) $ (198,684 ) Total assets $ 5,310,946 $ 8,168,567 $ 1,951,423 $ 15,430,936 Capital expenditures $ 100,171 $ 32,789 $ 51,860 $ 184,820 (a) - Our Natural Gas Liquids segment has regulated and nonregulated operations. Our Natural Gas Liquids segment’s regulated operations had revenues of $585.7 million , of which $502.3 million related to sales within the segment and cost of sales and fuel of $235.4 million . (b) - Our Natural Gas Pipelines segment has regulated and nonregulated operations. Our Natural Gas Pipelines segment’s regulated operations had revenues of $131.7 million and cost of sales and fuel of $22.4 million . Six Months Ended June 30, 2017 Total Segments Other and Eliminations Total ( Thousands of dollars ) Reconciliations of total segments to consolidated Sales to unaffiliated customers $ 5,474,315 $ 1,068 $ 5,475,383 Intersegment revenues 819,112 (819,112 ) — Total revenues $ 6,293,427 $ (818,044 ) $ 5,475,383 Cost of sales and fuel (exclusive of depreciation and operating costs) $ (5,052,945 ) $ 818,080 $ (4,234,865 ) Operating costs $ (373,540 ) $ (36,187 ) $ (409,727 ) Depreciation and amortization $ (198,684 ) $ (1,584 ) $ (200,268 ) Equity in net earnings from investments $ 78,927 $ — $ 78,927 Total assets $ 15,430,936 $ 1,241,987 $ 16,672,923 Capital expenditures $ 184,820 $ 10,412 $ 195,232 Six Months Ended June 30, 2016 Natural Gas Gathering and Processing Natural Gas Liquids (a) Natural Gas Pipelines (b) Total ( Thousands of dollars ) Sales to unaffiliated customers $ 610,117 $ 3,125,547 $ 171,875 $ 3,907,539 Intersegment revenues 298,653 233,836 2,167 534,656 Total revenues 908,770 3,359,383 174,042 4,442,195 Cost of sales and fuel (exclusive of depreciation and items shown separately below) (566,291 ) (2,682,184 ) (9,044 ) (3,257,519 ) Operating costs (138,910 ) (156,951 ) (56,702 ) (352,563 ) Equity in net earnings from investments 5,391 27,251 32,644 65,286 Other 1,373 (719 ) 1,941 2,595 Segment adjusted EBITDA $ 210,333 $ 546,780 $ 142,881 $ 899,994 Depreciation and amortization $ (88,264 ) $ (81,402 ) $ (22,577 ) $ (192,243 ) Total assets $ 5,222,225 $ 8,289,089 $ 1,856,128 $ 15,367,442 Capital expenditures $ 226,171 $ 54,986 $ 47,226 $ 328,383 (a) - Our Natural Gas Liquids segment has regulated and nonregulated operations. Our Natural Gas Liquids segment’s regulated operations had revenues of $579.3 million , of which $489.2 million related to sales within the segment and cost of sales and fuel of $219.5 million . (b) - Our Natural Gas Pipelines segment has regulated and nonregulated operations. Our Natural Gas Pipelines segment’s regulated operations had revenues of $111.4 million and cost of sales and fuel of $11.3 million . Six Months Ended June 30, 2016 Total Segments Other and Eliminations Total ( Thousands of dollars ) Reconciliations of total segments to consolidated Sales to unaffiliated customers $ 3,907,539 $ 1,027 $ 3,908,566 Intersegment revenues 534,656 (534,656 ) — Total revenues $ 4,442,195 $ (533,629 ) $ 3,908,566 Cost of sales and fuel (exclusive of depreciation and operating costs) $ (3,257,519 ) $ 534,458 $ (2,723,061 ) Operating costs $ (352,563 ) $ (16,291 ) $ (368,854 ) Depreciation and amortization $ (192,243 ) $ (1,482 ) $ (193,725 ) Equity in net earnings from investments $ 65,286 $ — $ 65,286 Total assets $ 15,367,442 $ 455,458 $ 15,822,900 Capital expenditures $ 328,383 $ 4,871 $ 333,254 Three Months Ended Six Months Ended June 30, June 30, 2017 2016 2017 2016 Reconciliation of income from continuing operations to total segment adjusted EBITDA ( Thousands of dollars ) Income from continuing operations $ 175,991 $ 180,086 $ 362,176 $ 355,997 Add: Interest expense, net of capitalized interest 118,473 118,976 234,935 237,223 Depreciation and amortization 100,849 99,247 200,268 193,725 Income taxes 43,844 52,458 98,785 102,524 Other corporate costs and noncash items (a) 43,073 4,684 51,220 10,525 Total segment adjusted EBITDA $ 482,230 $ 455,451 $ 947,384 $ 899,994 (a) - Includes our April 2017, $20 million contribution of Series E Preferred Stock to the Foundation and costs related to the Merger Transaction of $22.8 million and $29.5 million for the three and six months ended June 30, 2017, respectively.

SUPPLEMENTAL CONDENSED CONSOL38

SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION (Tables)	6 Months Ended
	Jun. 30, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Consolidating Statements of Income	Condensed Consolidating Statements of Income Three Months Ended June 30, 2017 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Revenues Commodity sales $ — $ — $ — $ 2,161.0 $ — $ 2,161.0 Services — — — 565.8 (1.0 ) 564.8 Total revenues — — — 2,726.8 (1.0 ) 2,725.8 Cost of sales and fuel (exclusive of items shown separately below) — — — 2,091.0 — 2,091.0 Operating expenses 20.5 — 6.2 293.0 (1.0 ) 318.7 (Gain) loss on sale of assets — — — (0.6 ) — (0.6 ) Operating income (20.5 ) — (6.2 ) 343.4 — 316.7 Equity in net earnings from investments 275.2 278.5 284.7 23.8 (822.8 ) 39.4 Other income (expense), net (17.4 ) 94.9 94.9 (0.4 ) (189.8 ) (17.8 ) Interest expense, net (24.5 ) (94.9 ) (94.9 ) (94.0 ) 189.8 (118.5 ) Income before income taxes 212.8 278.5 278.5 272.8 (822.8 ) 219.8 Income taxes 37.7 — — 6.1 — 43.8 Net income 175.1 278.5 278.5 266.7 (822.8 ) 176.0 Less: Net income attributable to noncontrolling interests 103.4 — — 0.9 — 104.3 Net income attributable to ONEOK 71.7 278.5 278.5 265.8 (822.8 ) 71.7 Less: Preferred stock dividends 0.2 — — — — 0.2 Net income available to common shareholders $ 71.5 $ 278.5 $ 278.5 $ 265.8 $ (822.8 ) $ 71.5 Three Months Ended June 30, 2016 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Revenues Commodity sales $ — $ — $ — $ 1,633.3 $ — $ 1,633.3 Services — — — 501.3 (0.5 ) 500.8 Total revenues — — — 2,134.6 (0.5 ) 2,134.1 Cost of sales and fuel (exclusive of items shown separately below) — — — 1,527.3 — 1,527.3 Operating expenses 9.8 — — 281.8 (0.5 ) 291.1 (Gain) loss on sale of assets — — — 0.4 — 0.4 Operating income (9.8 ) — — 325.1 — 315.3 Equity in net earnings from investments 260.9 261.5 261.5 16.7 (768.2 ) 32.4 Other income (expense), net 4.3 94.9 94.9 (0.5 ) (189.8 ) 3.8 Interest expense, net (25.7 ) (94.9 ) (94.9 ) (93.3 ) 189.8 (119.0 ) Income before income taxes 229.7 261.5 261.5 248.0 (768.2 ) 232.5 Income taxes (50.3 ) — — (2.1 ) — (52.4 ) Income from continuing operations 179.4 261.5 261.5 245.9 (768.2 ) 180.1 Income (loss) from discontinued operations, net of tax — — — (0.2 ) — (0.2 ) Net income 179.4 261.5 261.5 245.7 (768.2 ) 179.9 Less: Net income attributable to noncontrolling interests 93.5 — — 0.5 — 94.0 Net income attributable to ONEOK $ 85.9 $ 261.5 $ 261.5 $ 245.2 $ (768.2 ) $ 85.9 Six Months Ended June 30, 2017 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Revenues Commodity sales $ — $ — $ — $ 4,377.7 $ — $ 4,377.7 Services — — — 1,098.7 (1.0 ) 1,097.7 Total revenues — — — 5,476.4 (1.0 ) 5,475.4 Cost of sales and fuel (exclusive of items shown separately below) — — — 4,234.9 — 4,234.9 Operating expenses 30.1 — 6.2 574.6 (1.0 ) 609.9 (Gain) loss on sale of assets — — — (0.6 ) — (0.6 ) Operating income (30.1 ) — (6.2 ) 667.5 — 631.2 Equity in net earnings from investments 544.0 547.6 553.8 44.5 (1,611.0 ) 78.9 Other income (expense), net (14.2 ) 186.1 186.1 — (372.2 ) (14.2 ) Interest expense, net (50.3 ) (186.1 ) (186.1 ) (184.6 ) 372.2 (234.9 ) Income before income taxes 449.4 547.6 547.6 527.4 (1,611.0 ) 461.0 Income taxes (89.0 ) — — (9.8 ) — (98.8 ) Net income 360.4 547.6 547.6 517.6 (1,611.0 ) 362.2 Less: Net income attributable to noncontrolling interests 201.3 — — 1.8 — 203.1 Net income attributable to ONEOK 159.1 547.6 547.6 515.8 (1,611.0 ) 159.1 Less: Preferred stock dividends 0.2 — — — — 0.2 Net income available to common shareholders $ 158.9 $ 547.6 $ 547.6 $ 515.8 $ (1,611.0 ) $ 158.9 Six Months Ended June 30, 2016 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Revenues Commodity sales $ — $ — $ — $ 2,916.8 $ — $ 2,916.8 Services — — — 992.8 (1.0 ) 991.8 Total revenues — — — 3,909.6 (1.0 ) 3,908.6 Cost of sales and fuel (exclusive of items shown separately below) — — — 2,723.1 — 2,723.1 Operating expenses 16.4 — — 547.2 (1.0 ) 562.6 (Gain) loss on sale of assets — — — (3.8 ) — (3.8 ) Operating income (16.4 ) — — 643.1 — 626.7 Equity in net earnings from investments 513.3 515.0 515.0 30.9 (1,508.9 ) 65.3 Other income (expense), net 4.4 189.3 189.3 (0.7 ) (378.6 ) 3.7 Interest expense, net (51.4 ) (189.3 ) (189.3 ) (185.8 ) 378.6 (237.2 ) Income before income taxes 449.9 515.0 515.0 487.5 (1,508.9 ) 458.5 Income taxes (98.4 ) — — (4.1 ) — (102.5 ) Income from continuing operations 351.5 515.0 515.0 483.4 (1,508.9 ) 356.0 Income (loss) from discontinued operations, net of tax — — — (1.2 ) — (1.2 ) Net income 351.5 515.0 515.0 482.2 (1,508.9 ) 354.8 Less: Net income attributable to noncontrolling interests 182.1 — — 3.3 — 185.4 Net income attributable to ONEOK $ 169.4 $ 515.0 $ 515.0 $ 478.9 $ (1,508.9 ) $ 169.4
Condensed Consolidating Statements of Comprehensive Income	Condensed Consolidating Statements of Comprehensive Income Three Months Ended June 30, 2017 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Net income $ 175.1 $ 278.5 $ 278.5 $ 266.7 $ (822.8 ) $ 176.0 Other comprehensive income (loss), net of tax Unrealized gains (losses) on derivatives, net of tax (0.3 ) (5.7 ) 9.0 9.8 (17.9 ) (5.1 ) Realized (gains) losses on derivatives in net income, net of tax 0.5 11.1 6.8 5.1 (13.6 ) 9.9 Change in pension and postretirement benefit plan liability, net of tax 2.1 — — — — 2.1 Other comprehensive income (loss) on investments in unconsolidated affiliates, net of tax — (1.6 ) (1.6 ) (1.4 ) 3.2 (1.4 ) Total other comprehensive income (loss) 2.3 3.8 14.2 13.5 (28.3 ) 5.5 Comprehensive income 177.4 282.3 292.7 280.2 (851.1 ) 181.5 Less: Comprehensive income attributable to noncontrolling interests 105.6 — — 0.9 — 106.5 Comprehensive income attributable to ONEOK $ 71.8 $ 282.3 $ 292.7 $ 279.3 $ (851.1 ) $ 75.0 Three Months Ended June 30, 2016 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Net income $ 179.4 $ 261.5 $ 261.5 $ 245.7 $ (768.2 ) $ 179.9 Other comprehensive income (loss), net of tax Unrealized gains (losses) on derivatives, net of tax — (87.2 ) (58.7 ) (132.6 ) 204.6 (73.9 ) Realized (gains) losses on derivatives in net income, net of tax 0.6 (10.1 ) (14.0 ) (21.5 ) 36.9 (8.1 ) Change in pension and postretirement benefit plan liability, net of tax 1.5 — — — — 1.5 Other comprehensive income (loss) on investments in unconsolidated affiliates, net of tax — (5.6 ) (5.6 ) (10.3 ) 16.8 (4.7 ) Total other comprehensive income (loss) 2.1 (102.9 ) (78.3 ) (164.4 ) 258.3 (85.2 ) Comprehensive income 181.5 158.6 183.2 81.3 (509.9 ) 94.7 Less: Comprehensive income attributable to noncontrolling interests 32.9 — — 0.5 — 33.4 Comprehensive income attributable to ONEOK $ 148.6 $ 158.6 $ 183.2 $ 80.8 $ (509.9 ) $ 61.3 Six Months Ended June 30, 2017 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Net income $ 360.4 $ 547.6 $ 547.6 $ 517.6 $ (1,611.0 ) $ 362.2 Other comprehensive income (loss), net of tax Unrealized gains (losses) on derivatives, net of tax (0.3 ) 23.1 36.3 32.8 (72.6 ) 19.3 Realized (gains) losses on derivatives in net income, net of tax 1.0 30.9 22.1 17.4 (44.2 ) 27.2 Change in pension and postretirement benefit plan liability, net of tax 4.1 — — — — 4.1 Other comprehensive income (loss) on investments in unconsolidated affiliates, net of tax — (1.2 ) (1.2 ) (1.0 ) 2.4 (1.0 ) Total other comprehensive income (loss) 4.8 52.8 57.2 49.2 (114.4 ) 49.6 Comprehensive income 365.2 600.4 604.8 566.8 (1,725.4 ) 411.8 Less: Comprehensive income attributable to noncontrolling interests 232.4 — — 1.8 — 234.2 Comprehensive income attributable to ONEOK $ 132.8 $ 600.4 $ 604.8 $ 565.0 $ (1,725.4 ) $ 177.6 Six Months Ended June 30, 2016 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Net income $ 351.5 $ 515.0 $ 515.0 $ 482.2 $ (1,508.9 ) $ 354.8 Other comprehensive income (loss), net of tax Unrealized gains (losses) on derivatives, net of tax — (107.1 ) (47.0 ) (137.8 ) 201.1 (90.8 ) Realized (gains) losses on derivatives in net income, net of tax 1.1 (20.8 ) (28.5 ) (44.0 ) 75.6 (16.6 ) Change in pension and postretirement benefit plan liability, net of tax 3.1 — — — — 3.1 Other comprehensive income (loss) on investments in unconsolidated affiliates, net of tax — (11.4 ) (11.4 ) (21.0 ) 34.2 (9.6 ) Total other comprehensive income (loss) 4.2 (139.3 ) (86.9 ) (202.8 ) 310.9 (113.9 ) Comprehensive income 355.7 375.7 428.1 279.4 (1,198.0 ) 240.9 Less: Comprehensive income attributable to noncontrolling interests 100.2 — — 3.3 — 103.5 Comprehensive income attributable to ONEOK $ 255.5 $ 375.7 $ 428.1 $ 276.1 $ (1,198.0 ) $ 137.4
Condensed Consolidating Balance Sheets	Condensed Consolidating Balance Sheets June 30, 2017 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total Assets ( Millions of dollars ) Current assets Cash and cash equivalents $ 321.0 $ — $ 11.4 $ — $ — $ 332.4 Accounts receivable, net — — — 749.3 — 749.3 Natural gas and natural gas liquids in storage — — — 200.1 — 200.1 Other current assets 12.9 0.5 — 152.6 — 166.0 Total current assets 333.9 0.5 11.4 1,102.0 — 1,447.8 Property, plant and equipment Property, plant and equipment 139.8 — — 15,101.3 — 15,241.1 Accumulated depreciation and amortization 94.3 — — 2,599.8 — 2,694.1 Net property, plant and equipment 45.5 — — 12,501.5 — 12,547.0 Investments and other assets Investments 5,936.9 3,160.9 7,376.1 622.7 (16,152.0 ) 944.6 Intercompany notes receivable 253.7 10,791.6 6,565.0 — (17,610.3 ) — Other assets 763.6 19.7 — 1,017.9 (67.7 ) 1,733.5 Total investments and other assets 6,954.2 13,972.2 13,941.1 1,640.6 (33,830.0 ) 2,678.1 Total assets $ 7,333.6 $ 13,972.7 $ 13,952.5 $ 15,244.1 $ (33,830.0 ) $ 16,672.9 Liabilities and equity Current liabilities Current maturities of long-term debt $ 87.1 $ 400.0 $ — $ 7.7 $ — $ 494.8 Short-term borrowings — 1,274.4 — — — 1,274.4 Accounts payable 19.9 — — 676.9 — 696.8 Other current liabilities 57.7 86.3 — 250.5 — 394.5 Total current liabilities 164.7 1,760.7 — 935.1 — 2,860.5 Intercompany debt — — 10,791.6 6,818.7 (17,610.3 ) — Long-term debt, excluding current maturities 1,545.0 6,257.9 — 32.7 — 7,835.6 Deferred credits and other liabilities 216.2 — — 263.1 (67.7 ) 411.6 Commitments and contingencies Equity Equity excluding noncontrolling interests in consolidated subsidiaries 5,407.7 5,954.1 3,160.9 7,037.0 (16,152.0 ) 5,407.7 Noncontrolling interests in consolidated subsidiaries — — — 157.5 — 157.5 Total equity 5,407.7 5,954.1 3,160.9 7,194.5 (16,152.0 ) 5,565.2 Total liabilities and equity $ 7,333.6 $ 13,972.7 $ 13,952.5 $ 15,244.1 $ (33,830.0 ) $ 16,672.9 December 31, 2016 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total Assets ( Millions of dollars ) Current assets Cash and cash equivalents $ 248.5 $ — $ 0.4 $ — $ — $ 248.9 Accounts receivable, net — — — 872.4 — 872.4 Natural gas and natural gas liquids in storage — — — 140.0 — 140.0 Other current assets 7.2 — — 160.6 — 167.8 Assets of discontinued operations — — — 0.6 — 0.6 Total current assets 255.7 — 0.4 1,173.6 — — 1,429.7 Property, plant and equipment Property, plant and equipment 139.8 — — 14,938.7 — 15,078.5 Accumulated depreciation and amortization 90.4 — — 2,416.7 — 2,507.1 Net property, plant and equipment 49.4 — — 12,522.0 — 12,571.4 Investments and other assets Investments 2,931.9 3,222.1 6,805.4 631.1 (12,631.7 ) 958.8 Intercompany notes receivable 205.2 10,615.0 7,031.3 — (17,851.5 ) — Other assets 103.4 47.5 — 1,028.0 — 1,178.9 Total investments and other assets 3,240.5 13,884.6 13,836.7 1,659.1 (30,483.2 ) 2,137.7 Total assets $ 3,545.6 $ 13,884.6 $ 13,837.1 $ 15,354.7 $ (30,483.2 ) $ 16,138.8 Liabilities and equity Current liabilities Current maturities of long-term debt $ 3.0 $ 400.0 $ — $ 7.7 $ — $ 410.7 Short-term borrowings — 1,110.3 — — — 1,110.3 Accounts payable 13.0 — — 861.7 — 874.7 Other current liabilities 44.7 99.9 — 296.5 — 441.1 Total current liabilities 60.7 1,610.2 — 1,165.9 — 2,836.8 Intercompany debt — — 10,615.0 7,236.5 (17,851.5 ) — Long-term debt, excluding current maturities 1,628.7 6,254.7 — 36.6 — 7,920.0 Deferred credits and other liabilities 1,667.5 — — 285.6 — 1,953.1 Commitments and contingencies Equity Equity excluding noncontrolling interests in consolidated subsidiaries 188.7 6,019.7 3,222.1 6,472.0 (15,713.8 ) 188.7 Noncontrolling interests in consolidated subsidiaries — — — 158.1 3,082.1 3,240.2 Total equity 188.7 6,019.7 3,222.1 6,630.1 (12,631.7 ) 3,428.9 Total liabilities and equity $ 3,545.6 $ 13,884.6 $ 13,837.1 $ 15,354.7 $ (30,483.2 ) $ 16,138.8
Condensed Consolidating Statements of Cash Flows	Condensed Consolidating Statements of Cash Flows Six Months Ended June 30, 2017 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Operating activities Cash provided by operating activities $ 355.0 $ 675.2 $ 28.2 $ 645.5 $ (1,061.0 ) $ 642.9 Investing activities Capital expenditures (0.1 ) — — (195.1 ) — (195.2 ) Other investing activities — — 6.7 4.8 — 11.5 Cash provided by (used in) investing activities (0.1 ) — 6.7 (190.3 ) — (183.7 ) Financing activities Dividends paid (259.8 ) (666.0 ) (666.0 ) — 1,332.0 (259.8 ) Distributions to noncontrolling interests — — — (2.5 ) (271.0 ) (273.5 ) Intercompany borrowings (advances), net (27.1 ) (166.1 ) 642.1 (448.9 ) — — Borrowing (repayment) of short-term borrowings, net — 164.1 — — — 164.1 Repayment of long-term debt (0.1 ) — — (3.8 ) — (3.9 ) Issuance of common stock 10.8 — — — — 10.8 Other (6.2 ) (7.2 ) — — — (13.4 ) Cash used in financing activities (282.4 ) (675.2 ) (23.9 ) — (455.2 ) 1,061.0 (375.7 ) Change in cash and cash equivalents 72.5 — 11.0 — — 83.5 Cash and cash equivalents at beginning of period 248.5 — 0.4 — — 248.9 Cash and cash equivalents at end of period $ 321.0 $ — $ 11.4 $ — $ — $ 332.4 Six Months Ended June 30, 2016 ( Unaudited ) Parent Issuer & Guarantor Subsidiary Issuer & Guarantor Guarantor Subsidiary Combined Non-Guarantor Subsidiaries Consolidating Entries Total ( Millions of dollars ) Operating activities Cash provided by operating activities $ 363.1 $ 668.6 $ 34.4 $ 526.5 $ (1,061.0 ) $ 531.6 Investing activities Capital expenditures — — — (333.3 ) — (333.3 ) Other investing activities — — 24.9 9.9 — 34.8 Cash provided by (used in) investing activities — — 24.9 (323.4 ) — (298.5 ) Financing activities Dividends paid (258.5 ) (666.0 ) (666.0 ) — 1,332.0 (258.5 ) Distributions to noncontrolling interests — — — (4.3 ) (271.0 ) (275.3 ) Intercompany borrowings (advances), net (30.5 ) (379.8 ) 605.3 (195.0 ) — — Borrowing (repayment) of short-term borrowings, net — 30.0 — — — 30.0 Issuance of long-term debt, net of discounts — 1,000.0 — — — 1,000.0 Debt financing costs — (2.8 ) — — — (2.8 ) Repayment of long-term debt (0.3 ) (650.0 ) — (3.8 ) — (654.1 ) Issuance of common stock 11.1 — — — — 11.1 Cash used in financing activities (278.2 ) (668.6 ) (60.7 ) (203.1 ) 1,061.0 (149.6 ) Change in cash and cash equivalents 84.9 — (1.4 ) — — 83.5 Change in cash and cash equivalents included in discontinued operations (0.2 ) — — — — (0.2 ) Change in cash and cash equivalents included in continuing operations 84.7 — (1.4 ) — — 83.3 Cash and cash equivalents at beginning of period 92.5 — 5.1 — — 97.6 Cash and cash equivalents at end of period $ 177.2 $ — $ 3.7 $ — $ — $ 180.9

ONEOK PARTNERS ACQUISITION (Det

ONEOK PARTNERS ACQUISITION (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Business Acquisition [Line Items]
Common Stock	$ 10,845	$ 11,101
Business Acquisition, Date of Acquisition Agreement	Jun. 30, 2017
Business Acquisition, Description of Acquired Entity	we completed the Merger Transaction at a fixed exchange ratio of 0.985 of a share of our common stock for each ONEOK Partners common unit that we did not already own. We issued 168.9 million shares of our common stock to third-party common unitholders of ONEOK Partners in exchange for all of the 171.5 million outstanding common units of ONEOK Partners that we previously did not own. No fractional shares were issued in the Merger Transaction, and ONEOK Partners common unitholders instead received cash in lieu of fractional shares. As a result of the completion of the Merger Transaction, common units of ONEOK Partners are no longer publicly traded.
Deferred Tax Assets, Gross, Current	$ 2,100,000
Deferred Tax Asset, Tax Basis	8,800,000
Deferred Tax Asset, Book Basis	$ 3,000,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	37.00%
General partnership ownership interest	41.20%
Accumulated other comprehensive loss	$ (40,288)
Noncontrolling Interest in Consolidated Subsidiaries	2,146,462
ONEOK [Member]
Business Acquisition [Line Items]
Common Stock	1,700
Paid-in Capital	5,228,600
Accumulated other comprehensive loss	(40,300)
Noncontrolling Interest in Consolidated Subsidiaries	(3,043,500)
Deferred Income Taxes	$ (2,146,500)

FAIR VALUE MEASUREMENTS - Part

FAIR VALUE MEASUREMENTS - Part 1 (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
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	$ 0
Cash posted - total	11,800	67,700
Cash posted - offsetting derivative net liability positions under master-netting arrangements	900	51,600
Cash posted - remaining in excess of derivative net liability positions included in consolidated Balance Sheets	10,900	16,100
Long-term debt, Fair Value	9,100,000	8,800,000
Long-term debt	8,300,000	8,300,000
Fair Value, Measurements, Recurring [Member]
Derivative assets
Commodity contracts - financial	428	951
Commodity contracts - physical	710
Interest rate contracts	38,006	47,457
Total derivative assets	39,144	48,408
Derivative assets netting	(15,786)	(4,760)
Derivative liabilities
Commodity contracts - financial	(109)	0
Commodity contracts - physical	(1,033)	(3,022)
Interest-rate contracts	(16,872)	(12,795)
Total derivative liabilities	(18,014)	(15,817)
Derivative liabilities netting	16,656	56,319
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Derivative assets
Commodity contracts - financial	16,214	5,711
Commodity contracts - physical	710
Interest rate contracts	38,006	47,457
Total derivative assets	54,930	53,168
Derivative liabilities
Commodity contracts - financial	(16,765)	(56,319)
Commodity contracts - physical	(1,033)	(3,022)
Interest-rate contracts	(16,872)	(12,795)
Total derivative liabilities	(34,670)	(72,136)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative assets
Commodity contracts - financial	4,349	1,147
Commodity contracts - physical	0
Interest rate contracts	0	0
Total derivative assets	4,349	1,147
Derivative liabilities
Commodity contracts - financial	(5,973)	(31,458)
Commodity contracts - physical	0	0
Interest-rate contracts	0	0
Total derivative liabilities	(5,973)	(31,458)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative assets
Commodity contracts - financial	0	0
Commodity contracts - physical	0
Interest rate contracts	38,006	47,457
Total derivative assets	38,006	47,457
Derivative liabilities
Commodity contracts - financial	0	0
Commodity contracts - physical	0	0
Interest-rate contracts	(16,872)	(12,795)
Total derivative liabilities	(16,872)	(12,795)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative assets
Commodity contracts - financial	11,865	4,564
Commodity contracts - physical	710
Interest rate contracts	0	0
Total derivative assets	12,575	4,564
Derivative liabilities
Commodity contracts - financial	(10,792)	(24,861)
Commodity contracts - physical	(1,033)	(3,022)
Interest-rate contracts	0	0
Total derivative liabilities	$ (11,825)	$ (27,883)

FAIR VALUE MEASUREMENTS - Par41

FAIR VALUE MEASUREMENTS - Part 2 (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Fair Value, Assets And Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract]
Net assets (liabilities) at beginning of period	$ (772)	$ 34	$ (23,319)	$ 7,331
Total realized/unrealized gains (losses):
Included in earnings	(656)	318	258	(427)
Included in other comprehensive income (loss)	2,178	(14,373)	23,811	(20,925)
Net assets (liabilities) at end of period	750	(14,021)	750	(14,021)
Transfers between levels	$ 0	$ 0	$ 0	$ 0

RISK MANAGEMENT AND HEDGING A42

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES Part 1 (Details) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Derivative, Fair Value [Line Items]
Assets	$ 54,930,000	$ 53,168,000
(Liabilities)	(34,670,000)	(72,136,000)
Derivative, Net Liability Position, Aggregate Fair Value	0
Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
Assets	51,803,000	48,822,000
(Liabilities)	(31,212,000)	(67,897,000)
Not Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
Assets	3,127,000	4,346,000
(Liabilities)	(3,458,000)	(4,239,000)
Natural Gas Pipelines [Member]
Derivative, Fair Value [Line Items]
Derivative, Fair Value, Net	0	0
Other Current Assets [Member] | Commodity Contract [Member] | Financial Derivative Instrument [Member] | Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
Assets	7,577,000	1,155,000
Other Current Assets [Member] | Commodity Contract [Member] | Financial Derivative Instrument [Member] | Not Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
Assets	2,587,000	4,346,000
Other Current Assets [Member] | Commodity Contract [Member] | Physical Derivative Instrument [Member] | Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
Assets	330,000	0
Other Current Assets [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
Assets	493,000	0
Other Current Liabilities [Member] | Commodity Contract [Member] | Financial Derivative Instrument [Member] | Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
(Liabilities)	(13,082,000)	(49,938,000)
Other Current Liabilities [Member] | Commodity Contract [Member] | Financial Derivative Instrument [Member] | Not Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
(Liabilities)	(2,967,000)	(4,239,000)
Other Current Liabilities [Member] | Commodity Contract [Member] | Physical Derivative Instrument [Member] | Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
(Liabilities)	(1,033,000)	(3,022,000)
Other Current Liabilities [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
(Liabilities)	(16,872,000)	(12,795,000)
Other Assets [Member] | Commodity Contract [Member] | Financial Derivative Instrument [Member] | Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
Assets	5,510,000	210,000
Other Assets [Member] | Commodity Contract [Member] | Financial Derivative Instrument [Member] | Not Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
Assets	540,000	0
Other Assets [Member] | Commodity Contract [Member] | Physical Derivative Instrument [Member] | Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
Assets	380,000	0
Other Assets [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
Assets	37,513,000	47,457,000
Other Liabilities [Member] | Commodity Contract [Member] | Financial Derivative Instrument [Member] | Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
(Liabilities)	(225,000)	(2,142,000)
Other Liabilities [Member] | Commodity Contract [Member] | Financial Derivative Instrument [Member] | Not Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
(Liabilities)	(491,000)	0
Other Liabilities [Member] | Commodity Contract [Member] | Physical Derivative Instrument [Member] | Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
(Liabilities)	0	0
Other Liabilities [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivative, Fair Value [Line Items]
(Liabilities)	$ 0	$ 0

RISK MANAGEMENT AND HEDGING A43

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES, Part 2 (Details) $ in Thousands	Jun. 30, 2017USD ($)MMcfMMBbls	Dec. 31, 2016USD ($)MMcfMMBbls
Derivative [Line Items]
Long-term Debt, Gross | $	$ 9,649,290	$ 9,489,057
Senior Notes, Noncurrent | $	$ 1,200,000
Designated as Hedging Instrument [Member] | Futures, forwards and swaps [Member] | Crude Oil and NGL [Member] | Fixed Price [Member] | Purchased [Member]
Derivative [Line Items]
Notional Amount | MMBbls	0.7	0
Designated as Hedging Instrument [Member] | Futures, forwards and swaps [Member] | Crude Oil and NGL [Member] | Fixed Price [Member] | Sold [Member]
Derivative [Line Items]
Notional Amount | MMBbls	(5)	(3.6)
Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Purchased [Member]
Derivative [Line Items]
Derivative, Notional Amount | $	$ 2,150,000	$ 2,150,000
Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Sold [Member]
Derivative [Line Items]
Derivative, Notional Amount | $	$ 0	$ 0
Designated as Hedging Instrument [Member] | Futures and swaps [Member] | Natural Gas [Member] | Fixed Price [Member] | Purchased [Member]
Derivative [Line Items]
Notional Amount	0	0
Designated as Hedging Instrument [Member] | Futures and swaps [Member] | Natural Gas [Member] | Fixed Price [Member] | Sold [Member]
Derivative [Line Items]
Notional Amount	(34,300)	(38,400)
Designated as Hedging Instrument [Member] | Futures and swaps [Member] | Natural Gas [Member] | Basis [Member] | Purchased [Member]
Derivative [Line Items]
Notional Amount	0	0
Designated as Hedging Instrument [Member] | Futures and swaps [Member] | Natural Gas [Member] | Basis [Member] | Sold [Member]
Derivative [Line Items]
Notional Amount	(34,300)	(38,400)
Designated as Hedging Instrument [Member] | Options [Member] | Natural Gas [Member] | Fixed Price [Member] | Purchased [Member]
Derivative [Line Items]
Notional Amount	22,500	49,500
Designated as Hedging Instrument [Member] | Options [Member] | Natural Gas [Member] | Fixed Price [Member] | Sold [Member]
Derivative [Line Items]
Notional Amount	0	0
Not Designated as Hedging Instrument [Member] | Futures, forwards and swaps [Member] | Crude Oil and NGL [Member] | Fixed Price [Member] | Purchased [Member]
Derivative [Line Items]
Notional Amount | MMBbls	0.6	0.5
Not Designated as Hedging Instrument [Member] | Futures, forwards and swaps [Member] | Crude Oil and NGL [Member] | Fixed Price [Member] | Sold [Member]
Derivative [Line Items]
Notional Amount | MMBbls	(1.1)	(0.7)
Not Designated as Hedging Instrument [Member] | Futures and swaps [Member] | Natural Gas [Member] | Fixed Price [Member] | Purchased [Member]
Derivative [Line Items]
Notional Amount	1,800	400
Not Designated as Hedging Instrument [Member] | Futures and swaps [Member] | Natural Gas [Member] | Fixed Price [Member] | Sold [Member]
Derivative [Line Items]
Notional Amount	0	0
Not Designated as Hedging Instrument [Member] | Futures and swaps [Member] | Natural Gas [Member] | Basis [Member] | Purchased [Member]
Derivative [Line Items]
Notional Amount	1,800	400
Not Designated as Hedging Instrument [Member] | Futures and swaps [Member] | Natural Gas [Member] | Basis [Member] | Sold [Member]
Derivative [Line Items]
Notional Amount	0	0
LIBOR Based Interest Payments [Member] | Cash Flow Hedging [Member] | Forward Contracts [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Derivative, Notional Amount | $	$ 1,000,000	$ 1,000,000
Forecasted Debt Issuances [Member] | Cash Flow Hedging [Member] | Forward Contracts [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Derivative, Notional Amount | $	1,200,000	1,200,000
ONEOK Partners [Member]
Derivative [Line Items]
Long-term Debt, Gross | $	500,000
ONEOK Partners [Member] | Note Payable from Public Offering Due 2017 [Member]
Derivative [Line Items]
Long-term Debt, Gross | $	$ 400,000	$ 400,000

RISK MANAGEMENT AND HEDGING A44

RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES Part 3 (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (176,085)		$ (176,085)		$ (154,350)
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net			5,728
Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	(5,997)	$ (87,218)	22,860	$ (107,151)
Total Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Net Income (Effective Portion)	(11,968)	9,247	(32,616)	19,048
Commodity Contract [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) On Cash Flow Hedges Net Of Tax Accumulated Other Comprehensive Income Loss	(3,100)		(3,100)
Price Risk Cash Flow Hedge Unrealized Gain (Loss) to be Reclassified During Next 12 Months	(6,600)		(6,600)
Commodity Cash Flow Hedge Gain (Loss) To Be Reclassified After Next 12 Months Net	3,500		3,500
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	8,998	(58,654)	36,326	(46,976)
Commodity Contract [Member] | Sales [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total Gain (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) into Net Income (Effective Portion)	(6,796)	14,049	(22,115)	28,548
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.	(84,300)		(84,300)
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	(12,900)		(12,900)
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	(14,995)	(28,564)	(13,466)	(60,175)
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 (Effective Portion)	$ (5,172)	$ (4,802)	$ (10,501)	$ (9,500)

DEBT DEBT (Details)

DEBT DEBT (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017USD ($)Rate	Dec. 31, 2016USD ($)Rate	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 9,649,290	$ 9,489,057
Unamortized Portion of Terminated Swaps	19,327	20,186
Unamortized debt issuance costs and discounts	(63,901)	(68,320)
Current maturities	(494,703)	(410,650)
Short-term Debt	(1,274,407)	(1,110,277)
Long-term debt	$ 7,835,606	7,919,996
Indebtedness To Adjusted Ebitda Current	5.1
Senior Notes, Noncurrent	$ 1,200,000
Redemption Price, Senior Notes	87,000
Commercial Paper [Member]
Debt Instrument [Line Items]
Commercial Paper	$ 1,274,407	$ 1,110,277
Short-term Debt, Weighted Average Interest Rate | Rate	1.80%	1.27%
ONEOK Partners Commercial Paper Program [Domain]
Debt Instrument [Line Items]
Maximum Amount Of Commercial Paper	$ 2,400,000
ONEOK, Inc. Commercial Paper Program [Domain]
Debt Instrument [Line Items]
Maximum Amount Of Commercial Paper	$ 2,500,000
Partnership Credit Agreement [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate Description	borrowings, if any, will accrue at LIBOR plus 110 basis points
Line Of Credit Facility, Annual Facility Fee Description	the annual facility fee is 15 basis points
ONEOK Credit Agreement 2017 [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,500,000
Senior Notes [Member]
Debt Instrument [Line Items]
Proceeds from Debt, Net of Issuance Costs	1,180,000
Note Payable from Public Offering Due 2027 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 500,000
Interest Rate (in hundredths) | Rate	4.00%
Note Payable from Public Offering Due 2047 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 700,000
Interest Rate (in hundredths) | Rate	5.00%
Parent Company | Note Payable from Public Offering Due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 547,397	$ 547,397
Interest Rate (in hundredths) | Rate	4.25%
Parent Company | Note Payable Due 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 500,000	500,000
Interest Rate (in hundredths) | Rate	7.50%
Parent Company | Note Payables 1 due 2028 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 87,053	87,126
Interest Rate (in hundredths) | Rate	6.50%
Parent Company | Note Payables 2 due 2028 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 100,000	100,000
Interest Rate (in hundredths) | Rate	6.875%
Parent Company | Notes Payables due 2035 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 400,000	400,000
Interest Rate (in hundredths) | Rate	6.00%
ONEOK Partners [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 500,000
ONEOK Partners [Member] | Note Payable from Public Offering Due 2016 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross			$ 650,000
ONEOK Partners [Member] | Note Payable from Public Offering Due 2017 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 400,000	400,000
Interest Rate (in hundredths) | Rate	2.00%
ONEOK Partners [Member] | Note Payable from Public Offering Due 2018 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 425,000	425,000
Interest Rate (in hundredths) | Rate	3.20%
ONEOK Partners [Member] | Term Loan Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 1,000,000	1,000,000
Delayed-Draw Unsecured Senior Term Loan		1,000,000
Proceeds from Debt, Net of Issuance Costs	$ 500,000	1,000,000
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate | Rate	2.52%
ONEOK Partners [Member] | Notes Payables due 2019 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 500,000	500,000
Interest Rate (in hundredths) | Rate	8.625%
ONEOK Partners [Member] | Note Payable from Public Offering Due 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 300,000	300,000
Interest Rate (in hundredths) | Rate	3.80%
ONEOK Partners [Member] | Note Payable 2 from Public Offering Due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 900,000	900,000
Interest Rate (in hundredths) | Rate	3.375%
ONEOK Partners [Member] | Note Payable from Public Offering Due 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 425,000	425,000
Interest Rate (in hundredths) | Rate	5.00%
ONEOK Partners [Member] | Note Payable from Public Offering Due 2025 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 500,000	500,000
Interest Rate (in hundredths) | Rate	4.90%
ONEOK Partners [Member] | Notes Payables due 2036 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 600,000	600,000
Interest Rate (in hundredths) | Rate	6.65%
ONEOK Partners [Member] | Notes Payables due 2037 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 600,000	600,000
Interest Rate (in hundredths) | Rate	6.85%
ONEOK Partners [Member] | Note Payable from Public Offering Due 2041 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 650,000	650,000
Interest Rate (in hundredths) | Rate	6.125%
ONEOK Partners [Member] | Note Payable from Public Offering Due 2043 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 400,000	400,000
Interest Rate (in hundredths) | Rate	6.20%
Guardian Pipeline [Member] | Notes Payables 1 due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 40,433	$ 44,257
Weighed Average Interest Rate (in hundredths) | Rate	7.85%
Subsequent Event [Member] | ONEOK Credit Agreement 2017 [Member]
Debt Instrument [Line Items]
Line of credit facility sublimit	$ 100,000
Line Of Credit Facility Option To Increase Borrowing Capacity	3,500,000
Line of Credit Facility Swingline Subfacility	$ 200,000
Debt Instrument, Covenant Description	Among other things, these covenants include maintaining a ratio of indebtedness to adjusted EBITDA (EBITDA, as defined in our 2017 Credit Agreement, adjusted for all noncash charges and increased for projected EBITDA from certain lender-approved capital expansion projects) of no more than 5.75 to 1 at June 30,2017 and for the following two quarters; 5.5 to 1 for the subsequent two quarters; and 5.0 to 1 thereafter. Once the covenant decreases to 5.0 to 1, if we consummate one or more acquisitions in which the aggregate purchase 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 is completed and the two following quarters. The 2017 Credit Agreement includes a $100 million sublimit for the issuance of standby letters of credit and a $200 million sublimit for swingline loans. Under the terms of the 2017 Credit Agreement, we may request an increase in the size of the facility to an aggregate of $3.5 billion by either commitments from new lenders or increased commitments from existing lenders. The 2017 Credit Agreement contains provisions for an applicable margin rate and an annual facility fee, both of which adjust with changes in our credit ratings. Based on our current credit ratings, borrowings, if any, will accrue at LIBOR plus 110 basis points, and the annual facility fee is 15 basis points. We have the option to request two one-year extensions, subject to lender approval, which may be used for working capital, capital expenditures, acquisitions and mergers, the issuance of letters of credit and for other general corporate purposes. At June 30, 2017, our ratio of indebtedness to adjusted EBITDA was 5.1 to 1, and we were in compliance with all covenants under the 2017 Credit Agreement.

EQUITY (Details)

EQUITY (Details) - USD ($)	3 Months Ended				6 Months Ended		12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Partnership Capital Distributions [Line Items]
Common Stock, Dividends, Per Share, Cash Paid		$ 0.615			$ 1.230	$ 1.230
General partnership ownership interest					41.20%
Number of common units owned by related party		41,300,000			41,300,000
Number Of Class B Units Owned By Related Party		73,000,000			73,000,000
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners		20.00%			20.00%
Common Stock, Shares, Issued		414,732,011			414,732,011		245,811,180
Common Stock, Dividends, Per Share, Declared		$ 0.615		$ 0.615	$ 1.230	$ 1.230
Dividends, Preferred Stock, Cash					$ 200,000
Noncash Contribution Expense					12,600,000	$ 0
Preferred Stock, Dividends Per Share, Declared					$ (217,000)
General Partner [Member]
Partnership Capital Distributions [Line Items]
General partnership ownership interest					2.00%
Distribution Paid [Member]
Partnership Capital Distributions [Line Items]
Distribution per Limited Partnership and General Partnership Unit, Outstanding, Basic		$ 0.79		$ 0.79	$ 1.58	$ 1.58
Total distributions		$ 333,000,000		$ 333,000,000	$ 666,001,000	$ 666,001,000
Distribution Declared [Member]
Partnership Capital Distributions [Line Items]
Distribution per Limited Partnership and General Partnership Unit, Outstanding, Basic		$ 0.79
Distribution Made to Member or Limited Partner, Distribution Date		May 1, 2017	Jan. 30, 2017
Issued Under Equity Distribution Agreement [Member]
Partnership Capital Distributions [Line Items]
Partners Capital Account Units Sold Under Equity Distribution Agreement					0		0
ONEOK [Member]
Partnership Capital Distributions [Line Items]
Common Stock, Shares, Issued		168,920,998			168,920,998
Aggregate Amount Of Common Shares Available For Issuance And Sale Under Equity Distribution Agreement					$ 1,000,000,000
Oneok Partners [Member]
Partnership Capital Distributions [Line Items]
Aggregate Amount Of Common Units Available For Issuance And Sale Under The Equity Distribution Agreement					$ 650,000,000
Common Unit, Issued		171,493,399			171,493,399
Limited Partner [Member] | Distribution Paid [Member]
Partnership Capital Distributions [Line Items]
Partners Capital Account Distributions to Other Unitholders		$ 135,479,000		135,479,000	$ 270,959,000	270,959,000
ONEOK [Member] | Distribution Paid [Member]
Partnership Capital Distributions [Line Items]
Limited partner distributions to ONEOK		90,323,000		90,323,000	180,646,000	180,646,000
General Partner [Member] | Distribution Paid [Member]
Partnership Capital Distributions [Line Items]
General Partner Distributions		6,660,000		6,660,000	13,320,000	13,320,000
Incentive distributions		100,538,000		100,538,000	201,076,000	201,076,000
Distributions to general partner		$ 107,198,000		$ 107,198,000	$ 214,396,000	$ 214,396,000
Subsequent Event [Member]
Partnership Capital Distributions [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.745
Dividends Payable, Date of Record	Aug. 7, 2017
Dividends Payable, Date to be Paid	Aug. 14, 2017
Preferred Stock, Dividends Per Share, Declared	$ 352,000
Series E Preferred Stock [Member] | Subsequent Event [Member]
Partnership Capital Distributions [Line Items]
Stock Issued During Period, Shares, New Issues		20,000
Stock Issued During Period, Value, New Issues		$ 20,000,000
Noncash Contribution Expense		$ 20,000,000
Preferred Stock, Dividend Rate, Percentage		5.50%

ACCUMULATED OTHER COMPREHENSI47

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Unrealized gains (losses) on risk management assets/liabilities - January 1			$ (52,155)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax- January 1			(101,236)
Unrealized gains (losses) on risk-management assets/liabilities of unconsolidated affiliates - January 1			(959)
Accumulated other comprehensive loss - January 1			(154,350)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax			5,728
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments, Net of Tax			5
Other Comprehensive Income (Loss), Amount Attributable to Equity Method Investments, before Reclassification Adjustments, Net of Tax			(367)
Other comprehensive income (loss) before reclassifications			5,366
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	$ 9,927	$ (8,054)	27,210	$ (16,579)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Other Comprehensive Income Attributable to Equity Method Investments, Net of Tax			47
Other Comprehensive Income (Loss), Reclassification Adjustment included in Net Income, Net of Tax	5,466	(552)	13,187	(1,247)
Impact of Merger Transaction On Unrealized Gains (Losses) on Risk Management Assets/Liabilities			(40,288)
Impact of Merger Transaction on Pension and Postretirement Benefit Plan Obligations			0
Impact of Merger Transaction on Unrealized Gains (Losses) on Risk Management Assets/Liabilities of Unconsolidated Affiliates			0
Impact of Merger Transaction on AOCI, Total			(40,288)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent			(25,496)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	2,040	1,552	4,081	3,105
Other comprehensive income (loss) on investment in unconsolidated affiliates			(320)
Net current-period other comprehensive income (loss) attributable to ONEOK Partners			(21,735)
Unrealized gains (losses) on risk management assets/liabilities - June 30	(77,651)		(77,651)
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax - June 30	(97,155)		(97,155)
Unrealized gains (losses) on risk-management assets/liabilities of unconsolidated affiliates - June 30	(1,279)		(1,279)
Accumulated other comprehensive loss - June 30	(176,085)		(176,085)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	2,041	(1,193)	5,406	(2,469)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	3,406	(2,101)	9,064	(4,346)
Accumulated Other Comprehensive Income from Investments in Unconsolidated Affiliates Attributable to Parent [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Other Comprehensive Income Attributable to Equity Method Investments, Before Tax	(85)	0	(181)	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Other Comprehensive Income Attributable to Equity Method Investments, Net of Tax	22	0	47	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Other Comprehensive Income Attributable to Equity Method Investments, Tax	13	0	28	0
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Defined Benefit Plan, Future Amortization of Gain (Loss)	(3,812)	(2,997)	(7,624)	(5,995)
Defined Benefit Plan, Future Amortization of Prior Service Cost (Credit)	415	415	830	830
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax	(3,397)	(2,582)	(6,794)	(5,165)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), Tax	1,359	1,033	2,718	2,066
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax	2,038	1,549	4,076	3,099
Interest Expense [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate Contract [Member]
Amounts reclassified from accumulated other comprehensive income (loss)	(5,172)	(4,802)	(10,501)	(9,500)
Total before tax [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Amounts reclassified from accumulated other comprehensive income (loss)	(11,968)	9,247	(32,616)	19,048
Tax Expense [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	2,041	(1,193)	5,406	(2,469)
Net of tax [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	9,927	(8,054)	27,210	(16,579)
Net of tax [Member] | Accumulated Other Comprehensive Income from Investments in Unconsolidated Affiliates Attributable to Parent [Member]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Other Comprehensive Income Attributable to Equity Method Investments, Net of Tax	72	0	153	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Other Comprehensive Income Attributable to Equity Method Investments, Net of Tax, Portion Attributable to Noncont Interests	(50)	0	(106)	0
Net income attributable to noncontrolling interest [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Noncontrolling Interest	(6,521)	5,953	(18,146)	12,233
Sales [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Commodity Contract [Member]
Amounts reclassified from accumulated other comprehensive income (loss)	$ (6,796)	$ 14,049	$ (22,115)	$ 28,548

EARNINGS PER SHARE EARNINGS P48

EARNINGS PER SHARE EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Basic EPS from Continuing Operations [Abstract]
Income from continuing operations attributable to ONEOK available for common stock	$ 71,476	$ 86,171	$ 158,837	$ 170,569
Shares	211,785	211,075	211,702	210,928
Basic (in dollars per share)	$ 0.34	$ 0.41	$ 0.75	$ 0.81
Diluted EPS from Continuing Operations [Abstract]
Effect of options and other dilutive securities	$ 0	$ 0	$ 0	$ 0
Effect of options and other dilutive securities, number of shares, shares	2,227	1,543	2,105	735
Income from continuing operations attributable to ONEOK available for common stock and common stock equivalents	$ 71,476	$ 86,171	$ 158,837	$ 170,569
Shares	214,012	212,618	213,807	211,663
Diluted (in dollars per share)	$ 0.33	$ 0.41	$ 0.74	$ 0.81

EMPLOYEE BENEFIT PLANS EMPLOY49

EMPLOYEE BENEFIT PLANS EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Pension Plan [Member]
Components of net periodic benefit cost
Service Cost	$ 1,722	$ 1,622	$ 3,444	$ 3,244
Interest Cost	4,655	4,947	9,310	9,894
Expected Return on Plan Assets	(5,336)	(5,077)	(10,672)	(10,154)
Amortization of net loss	3,392	2,736	6,784	5,473
Net periodic benefit cost	4,433	4,228	8,866	8,457
Other Postretirement Benefit Plan [Member]
Components of net periodic benefit cost
Service Cost	165	149	330	298
Interest Cost	565	601	1,130	1,202
Expected Return on Plan Assets	(564)	(531)	(1,128)	(1,062)
Amortization of prior service credit	(415)	(415)	(830)	(830)
Amortization of net loss	420	261	840	522
Net periodic benefit cost	$ 171	$ 65	$ 342	$ 130

UNCONSOLIDATED AFFILIATES (Deta

UNCONSOLIDATED AFFILIATES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	$ 39,363	$ 32,372	$ 78,927	$ 65,286
Accounts Payable, Related Parties, Current	12,900		12,900		$ 11,100
Income Statement [Abstract]
Operating revenues	157,603	142,631	311,883	279,203
Operating expenses	69,465	66,674	136,401	125,373
Net income	92,072	69,420	173,203	141,457
Equity Method Investment, Dividends or Distributions, Total	49,760	62,024	96,680	108,577
Unconsolidated Affiliates [Member]
Schedule of Equity Method Investments [Line Items]
Related Party Transaction, Expenses from Transactions with Related Parties	39,400	34,700	76,100	68,300
Northern Border Pipeline [Member]
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	15,622	15,723	34,439	34,397
Overland Pass Pipeline Company [Member]
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	14,884	13,608	28,450	26,912
Other Unconsolidated Affiliate [Member]
Schedule of Equity Method Investments [Line Items]
Equity in net earnings from investments	$ 8,857	$ 3,041	$ 16,038	$ 3,977

SEGMENTS (Details)

SEGMENTS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 175,991	$ 179,859	$ 362,176	$ 354,818
Segment disclosure [Abstract]
Segment Reporting, Disclosure of Major Customers	For the three months ended June 30, 2017, we had no single customer from which we received 10 percent or more of our consolidated revenues.	For the three months ended June 30, 2016, we had no single customer from which we received 10 percent or more of our consolidated revenues.	For the six months ended June 30, 2017, we had no single customer from which we received 10 percent or more of our consolidated revenues.	For the six months ended June 30, 2016, we had one customer, BP p.l.c. or its affiliates, from which we received approximately 10 percent of our consolidated revenues.
Revenues	$ 2,725,772	$ 2,134,107	$ 5,475,383	$ 3,908,566
Cost of sales and fuel (exclusive of depreciation and items shown separately below)	(2,091,022)	(1,527,323)	(4,234,865)	(2,723,061)
Operating costs	(217,805)	(191,839)	(409,727)	(368,854)
Equity in net earnings from investments	39,363	32,372	78,927	65,286
Depreciation and amortization	(100,849)	(99,247)	(200,268)	(193,725)
Total assets	16,672,923	15,822,900	16,672,923	15,822,900	$ 16,138,751
Capital expenditures	82,495	136,843	195,232	333,254
Income from Continuing Operations	175,991	180,086	362,176	355,997
Interest Expense, Net of Capitalized Interest	118,473	118,976	234,935	237,223
Income Taxes	43,844	52,458	98,785	102,524
Other Corporate Costs and Noncash Items	43,073	4,684	51,220	10,525
Noncash Contribution Expense			12,600	0
Business Combination, Acquisition Related Costs	22,800		29,500
Natural Gas Gathering and Processing [Member]
Segment disclosure [Abstract]
Revenues	685,815	476,759	1,347,091	908,770
Cost of sales and fuel (exclusive of depreciation and items shown separately below)	(488,891)	(299,991)	(977,275)	(566,291)
Operating costs	(73,093)	(69,304)	(144,882)	(138,910)
Equity in net earnings from investments	3,780	2,576	6,410	5,391
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity and Other	650	258	884	1,373
Adjusted EBITDA	128,261	110,298	232,228	210,333
Depreciation and amortization	(46,033)	(46,413)	(91,001)	(88,264)
Total assets	5,310,946	5,222,225	5,310,946	5,222,225
Capital expenditures	37,020	84,674	100,171	226,171
Natural Gas Liquids [Member]
Segment disclosure [Abstract]
Revenues	2,349,685	1,871,993	4,741,669	3,359,383
Cost of sales and fuel (exclusive of depreciation and items shown separately below)	(2,003,601)	(1,525,234)	(4,052,294)	(2,682,184)
Operating costs	(87,285)	(83,769)	(166,028)	(156,951)
Equity in net earnings from investments	15,062	13,904	28,784	27,251
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity and Other	(552)	(283)	(593)	(719)
Adjusted EBITDA	273,309	276,611	551,538	546,780
Depreciation and amortization	(41,427)	(40,696)	(82,542)	(81,402)
Total assets	8,168,567	8,289,089	8,168,567	8,289,089
Capital expenditures	12,336	20,779	32,789	54,986
Natural Gas Liquids [Member] | Natural Gas Liquids Regulated [Member]
Segment disclosure [Abstract]
Revenues	289,400	297,500	585,700	579,300
Cost of sales and fuel (exclusive of depreciation and items shown separately below)	(118,900)	(112,700)	(235,400)	(219,500)
Natural Gas Pipelines [Member]
Segment disclosure [Abstract]
Revenues	97,849	88,069	204,667	174,042
Cost of sales and fuel (exclusive of depreciation and items shown separately below)	(6,773)	(5,112)	(23,376)	(9,044)
Operating costs	(30,877)	(29,189)	(62,630)	(56,702)
Equity in net earnings from investments	20,521	15,892	43,733	32,644
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity and Other	(60)	(1,118)	1,224	1,941
Adjusted EBITDA	80,660	68,542	163,618	142,881
Depreciation and amortization	(12,598)	(11,398)	(25,141)	(22,577)
Total assets	1,951,423	1,856,128	1,951,423	1,856,128
Capital expenditures	26,846	29,278	51,860	47,226
Natural Gas Pipelines [Member] | Natural Gas Pipelines Regulated [Member]
Segment disclosure [Abstract]
Revenues	62,800	56,600	131,700	111,400
Cost of sales and fuel (exclusive of depreciation and items shown separately below)	(8,300)	(5,700)	(22,400)	(11,300)
Total Segments [Member]
Segment disclosure [Abstract]
Revenues	3,133,349	2,436,821	6,293,427	4,442,195
Cost of sales and fuel (exclusive of depreciation and items shown separately below)	(2,499,265)	(1,830,337)	(5,052,945)	(3,257,519)
Operating costs	(191,255)	(182,262)	(373,540)	(352,563)
Equity in net earnings from investments	39,363	32,372	78,927	65,286
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity and Other	38	(1,143)	1,515	2,595
Adjusted EBITDA	482,230	455,451	947,384	899,994
Depreciation and amortization	(100,058)	(98,507)	(198,684)	(192,243)
Total assets	15,430,936	15,367,442	15,430,936	15,367,442
Capital expenditures	76,202	134,731	184,820	328,383
Other and Eliminations
Segment disclosure [Abstract]
Revenues	(407,577)	(302,714)	(818,044)	(533,629)
Cost of sales and fuel (exclusive of depreciation and items shown separately below)	408,243	303,014	818,080	534,458
Operating costs	(26,550)	(9,577)	(36,187)	(16,291)
Equity in net earnings from investments	0	0	0	0
Depreciation and amortization	(791)	(740)	(1,584)	(1,482)
Total assets	1,241,987	455,458	1,241,987	455,458
Capital expenditures	6,293	2,112	10,412	4,871
Unaffiliated entity [Member]
Segment disclosure [Abstract]
Revenues	2,725,772	2,134,107	5,475,383	3,908,566
Unaffiliated entity [Member] | Natural Gas Gathering and Processing [Member]
Segment disclosure [Abstract]
Revenues	433,088	293,071	833,237	610,117
Unaffiliated entity [Member] | Natural Gas Liquids [Member]
Segment disclosure [Abstract]
Revenues	2,196,399	1,754,122	4,440,399	3,125,547
Unaffiliated entity [Member] | Natural Gas Pipelines [Member]
Segment disclosure [Abstract]
Revenues	95,755	86,401	200,679	171,875
Unaffiliated entity [Member] | Total Segments [Member]
Segment disclosure [Abstract]
Revenues	2,725,242	2,133,594	5,474,315	3,907,539
Unaffiliated entity [Member] | Other and Eliminations
Segment disclosure [Abstract]
Revenues	530	513	1,068	1,027
Operating Segments [Member]
Segment disclosure [Abstract]
Revenues	0	0	0	0
Operating Segments [Member] | Natural Gas Gathering and Processing [Member]
Segment disclosure [Abstract]
Revenues	252,727	183,688	513,854	298,653
Operating Segments [Member] | Natural Gas Liquids [Member]
Segment disclosure [Abstract]
Revenues	153,286	117,871	301,270	233,836
Operating Segments [Member] | Natural Gas Liquids [Member] | Natural Gas Liquids Regulated [Member]
Segment disclosure [Abstract]
Revenues	249,400	258,400	502,300	489,200
Operating Segments [Member] | Natural Gas Pipelines [Member]
Segment disclosure [Abstract]
Revenues	2,094	1,668	3,988	2,167
Operating Segments [Member] | Total Segments [Member]
Segment disclosure [Abstract]
Revenues	408,107	303,227	819,112	534,656
Operating Segments [Member] | Other and Eliminations
Segment disclosure [Abstract]
Revenues	(408,107)	$ (303,227)	$ (819,112)	$ (534,656)
Series E Preferred Stock [Member] | Subsequent Event [Member]
Segment disclosure [Abstract]
Noncash Contribution Expense	$ 20,000

SUPPLEMENTAL CONDENSED CONSOL52

SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION, Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Condensed Financial Statements, Captions [Line Items]
Commodity sales	$ 2,161,009	$ 1,633,272	$ 4,377,726	$ 2,916,783
Services	564,763	500,835	1,097,657	991,783
Total revenues	2,725,772	2,134,107	5,475,383	3,908,566
Cost of sales and fuel (exclusive of items shown separately below)	2,091,022	1,527,323	4,234,865	2,723,061
(Gain) loss on sale of assets	(637)	413	(630)	(3,793)
Operating income	316,733	315,285	631,153	626,719
Equity in net earnings from investments	39,363	32,372	78,927	65,286
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	22	0	35	208
Interest expense, net	(118,473)	(118,976)	(234,935)	(237,223)
Income before income taxes	219,835	232,544	460,961	458,521
Income taxes	(43,844)	(52,458)	(98,785)	(102,524)
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	175,991	180,086	362,176	355,997
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	0	227	0	1,179
Net income	175,991	179,859	362,176	354,818
Less: Net income attributable to noncontrolling interests	104,298	93,915	203,122	185,428
Net Income (Loss) Attributable to Parent	71,693	85,944	159,054	169,390
Less: Preferred Stock Dividends	217	0	217	0
Net Income Available to Common Stockholders	$ 71,476	85,944	$ 158,837	169,390
Northern Border Pipeline [Member]
Condensed Financial Statements, Captions [Line Items]
Equity Method Investment, Ownership Percentage	50.00%		50.00%
Equity in net earnings from investments	$ 15,622	15,723	$ 34,439	34,397
Consolidation Entries
Condensed Financial Statements, Captions [Line Items]
Commodity sales	0	0	0	0
Services	(1,000)	(500)	(1,000)	(1,000)
Total revenues	(1,000)	(500)	(1,000)	(1,000)
Cost of sales and fuel (exclusive of items shown separately below)	0	0	0	0
Operating expenses	(1,000)	(500)	(1,000)	(1,000)
(Gain) loss on sale of assets	0	0	0	0
Operating income	0	0	0	0
Equity in net earnings from investments	(822,800)	(768,200)	(1,611,000)	(1,508,900)
Other income (expense), net	(189,800)	(189,800)	(372,200)	(378,600)
Interest expense, net	189,800	189,800	372,200	378,600
Income before income taxes	(822,800)	(768,200)	(1,611,000)	(1,508,900)
Income taxes	0	0	0	0
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		(768,200)		(1,508,900)
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		0		0
Net income	(822,800)	(768,200)	(1,611,000)	(1,508,900)
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net Income (Loss) Attributable to Parent	(822,800)	(768,200)	(1,611,000)	(1,508,900)
Less: Preferred Stock Dividends	0		0
Net Income Available to Common Stockholders	(822,800)		(1,611,000)
Reportable Legal Entities | Parent Company
Condensed Financial Statements, Captions [Line Items]
Commodity sales	0	0	0	0
Services	0	0	0	0
Total revenues	0	0	0	0
Cost of sales and fuel (exclusive of items shown separately below)	0	0	0	0
Operating expenses	20,500	9,800	30,100	16,400
(Gain) loss on sale of assets	0	0	0	0
Operating income	(20,500)	(9,800)	(30,100)	(16,400)
Equity in net earnings from investments	275,200	260,900	544,000	513,300
Other income (expense), net	(17,400)	4,300	(14,200)	4,400
Interest expense, net	(24,500)	(25,700)	(50,300)	(51,400)
Income before income taxes	212,800	229,700	449,400	449,900
Income taxes	37,700	(50,300)	(89,000)	(98,400)
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		179,400		351,500
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		0		0
Net income	175,100	179,400	360,400	351,500
Less: Net income attributable to noncontrolling interests	103,400	93,500	201,300	182,100
Net Income (Loss) Attributable to Parent	71,700	85,900	159,100	169,400
Less: Preferred Stock Dividends	200		200
Net Income Available to Common Stockholders	71,500		158,900
Reportable Legal Entities | Issuer and Guarantor Subsidiary [Member]
Condensed Financial Statements, Captions [Line Items]
Commodity sales	0	0	0	0
Services	0	0	0	0
Total revenues	0	0	0	0
Cost of sales and fuel (exclusive of items shown separately below)	0	0	0	0
Operating expenses	0	0	0	0
(Gain) loss on sale of assets	0	0	0	0
Operating income	0	0	0	0
Equity in net earnings from investments	278,500	261,500	547,600	515,000
Other income (expense), net	94,900	94,900	186,100	189,300
Interest expense, net	(94,900)	(94,900)	(186,100)	(189,300)
Income before income taxes	278,500	261,500	547,600	515,000
Income taxes	0	0	0	0
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		261,500		515,000
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		0		0
Net income	278,500	261,500	547,600	515,000
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net Income (Loss) Attributable to Parent	278,500	261,500	547,600	515,000
Less: Preferred Stock Dividends	0		0
Net Income Available to Common Stockholders	278,500		547,600
Reportable Legal Entities | Guarantor Subsidiary
Condensed Financial Statements, Captions [Line Items]
Commodity sales	0	0	0	0
Services	0	0	0	0
Total revenues	0	0	0	0
Cost of sales and fuel (exclusive of items shown separately below)	0	0	0	0
Operating expenses	6,200	0	6,200	0
(Gain) loss on sale of assets	0	0	0	0
Operating income	(6,200)	0	(6,200)	0
Equity in net earnings from investments	284,700	261,500	553,800	515,000
Other income (expense), net	94,900	94,900	186,100	189,300
Interest expense, net	(94,900)	(94,900)	(186,100)	(189,300)
Income before income taxes	278,500	261,500	547,600	515,000
Income taxes	0	0	0	0
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		261,500		515,000
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		0		0
Net income	278,500	261,500	547,600	515,000
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net Income (Loss) Attributable to Parent	278,500	261,500	547,600	515,000
Less: Preferred Stock Dividends	0		0
Net Income Available to Common Stockholders	278,500		547,600
Reportable Legal Entities | Combined Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Commodity sales	2,161,000	1,633,300	4,377,700	2,916,800
Services	565,800	501,300	1,098,700	992,800
Total revenues	2,726,800	2,134,600	5,476,400	3,909,600
Cost of sales and fuel (exclusive of items shown separately below)	2,091,000	1,527,300	4,234,900	2,723,100
Operating expenses	293,000	281,800	574,600	547,200
(Gain) loss on sale of assets	(600)	400	(600)	(3,800)
Operating income	343,400	325,100	667,500	643,100
Equity in net earnings from investments	23,800	16,700	44,500	30,900
Other income (expense), net	(400)	(500)	0	(700)
Interest expense, net	(94,000)	(93,300)	(184,600)	(185,800)
Income before income taxes	272,800	248,000	527,400	487,500
Income taxes	6,100	(2,100)	(9,800)	(4,100)
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		245,900		483,400
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		(200)		(1,200)
Net income	266,700	245,700	517,600	482,200
Less: Net income attributable to noncontrolling interests	900	500	1,800	3,300
Net Income (Loss) Attributable to Parent	265,800	245,200	515,800	478,900
Less: Preferred Stock Dividends	0		0
Net Income Available to Common Stockholders	265,800		515,800
Reportable Legal Entities | Total
Condensed Financial Statements, Captions [Line Items]
Commodity sales	2,161,000	1,633,300	4,377,700	2,916,800
Services	564,800	500,800	1,097,700	991,800
Total revenues	2,725,800	2,134,100	5,475,400	3,908,600
Cost of sales and fuel (exclusive of items shown separately below)	2,091,000	1,527,300	4,234,900	2,723,100
Operating expenses	318,700	291,100	609,900	562,600
(Gain) loss on sale of assets	(600)	400	(600)	(3,800)
Operating income	316,700	315,300	631,200	626,700
Equity in net earnings from investments	39,400	32,400	78,900	65,300
Other income (expense), net	(17,800)	3,800	(14,200)	3,700
Interest expense, net	(118,500)	(119,000)	(234,900)	(237,200)
Income before income taxes	219,800	232,500	461,000	458,500
Income taxes	43,800	(52,400)	(98,800)	(102,500)
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		180,100		356,000
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		(200)		(1,200)
Net income	176,000	179,900	362,200	354,800
Less: Net income attributable to noncontrolling interests	104,300	94,000	203,100	185,400
Net Income (Loss) Attributable to Parent	71,700	$ 85,900	159,100	$ 169,400
Less: Preferred Stock Dividends	200		200
Net Income Available to Common Stockholders	$ 71,500		$ 158,900

SUPPLEMENTAL CONDENSED CONSOL53

SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION, Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Condensed Financial Statements, Captions [Line Items]
Net income	$ 175,991	$ 179,859	$ 362,176	$ 354,818
Other comprehensive income (loss)
Unrealized gains (losses) on derivatives	(5,123)	(73,923)	19,333	(90,817)
Realized (gains) losses on derivatives recognized in net income	(9,927)	8,054	(27,210)	16,579
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(2,040)	(1,552)	(4,081)	(3,105)
Other comprehensive income (loss) on investment in unconsolidated affiliates	(1,370)	(4,714)	(1,045)	(9,631)
Total other comprehensive income (loss)	5,474	(85,139)	49,579	(113,922)
Comprehensive income	181,465	94,720	411,755	240,896
Less: Comprehensive income attributable to noncontrolling interests	106,507	33,408	234,148	103,510
Comprehensive income attributable to ONEOK	74,958	61,312	177,607	137,386
Reportable Legal Entities | Parent Company
Condensed Financial Statements, Captions [Line Items]
Net income	175,100	179,400	360,400	351,500
Other comprehensive income (loss)
Unrealized gains (losses) on derivatives	(300)	0	(300)	0
Realized (gains) losses on derivatives recognized in net income	500	600	1,000	1,100
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	2,100	1,500	4,100	3,100
Other comprehensive income (loss) on investment in unconsolidated affiliates	0	0	0	0
Total other comprehensive income (loss)	2,300	2,100	4,800	4,200
Comprehensive income	177,400	181,500	365,200	355,700
Less: Comprehensive income attributable to noncontrolling interests	105,600	32,900	232,400	100,200
Comprehensive income attributable to ONEOK	71,800	148,600	132,800	255,500
Reportable Legal Entities | Issuer and Guarantor Subsidiary [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	278,500	261,500	547,600	515,000
Other comprehensive income (loss)
Unrealized gains (losses) on derivatives	(5,700)	(87,200)	23,100	(107,100)
Realized (gains) losses on derivatives recognized in net income	11,100	(10,100)	30,900	(20,800)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	0	0	0	0
Other comprehensive income (loss) on investment in unconsolidated affiliates	(1,600)	(5,600)	(1,200)	(11,400)
Total other comprehensive income (loss)	3,800	(102,900)	52,800	(139,300)
Comprehensive income	282,300	158,600	600,400	375,700
Less: Comprehensive income attributable to noncontrolling interests	0	0	0	0
Comprehensive income attributable to ONEOK	282,300	158,600	600,400	375,700
Reportable Legal Entities | Guarantor Subsidiary
Condensed Financial Statements, Captions [Line Items]
Net income	278,500	261,500	547,600	515,000
Other comprehensive income (loss)
Unrealized gains (losses) on derivatives	9,000	(58,700)	36,300	(47,000)
Realized (gains) losses on derivatives recognized in net income	6,800	(14,000)	22,100	(28,500)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	0	0	0	0
Other comprehensive income (loss) on investment in unconsolidated affiliates	(1,600)	(5,600)	(1,200)	(11,400)
Total other comprehensive income (loss)	14,200	(78,300)	57,200	(86,900)
Comprehensive income	292,700	183,200	604,800	428,100
Less: Comprehensive income attributable to noncontrolling interests	0	0	0	0
Comprehensive income attributable to ONEOK	292,700	183,200	604,800	428,100
Reportable Legal Entities | Combined Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net income	266,700	245,700	517,600	482,200
Other comprehensive income (loss)
Unrealized gains (losses) on derivatives	9,800	(132,600)	32,800	(137,800)
Realized (gains) losses on derivatives recognized in net income	5,100	(21,500)	17,400	(44,000)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	0	0	0	0
Other comprehensive income (loss) on investment in unconsolidated affiliates	(1,400)	(10,300)	(1,000)	(21,000)
Total other comprehensive income (loss)	13,500	(164,400)	49,200	(202,800)
Comprehensive income	280,200	81,300	566,800	279,400
Less: Comprehensive income attributable to noncontrolling interests	900	500	1,800	3,300
Comprehensive income attributable to ONEOK	279,300	80,800	565,000	276,100
Reportable Legal Entities | Total
Condensed Financial Statements, Captions [Line Items]
Net income	176,000	179,900	362,200	354,800
Other comprehensive income (loss)
Unrealized gains (losses) on derivatives	(5,100)	(73,900)	19,300	(90,800)
Realized (gains) losses on derivatives recognized in net income	9,900	(8,100)	27,200	(16,600)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	2,100	1,500	4,100	3,100
Other comprehensive income (loss) on investment in unconsolidated affiliates	(1,400)	(4,700)	(1,000)	(9,600)
Total other comprehensive income (loss)	5,500	(85,200)	49,600	(113,900)
Comprehensive income	181,500	94,700	411,800	240,900
Less: Comprehensive income attributable to noncontrolling interests	106,500	33,400	234,200	103,500
Comprehensive income attributable to ONEOK	75,000	61,300	177,600	137,400
Consolidation Entries
Condensed Financial Statements, Captions [Line Items]
Net income	(822,800)	(768,200)	(1,611,000)	(1,508,900)
Other comprehensive income (loss)
Unrealized gains (losses) on derivatives	(17,900)	204,600	(72,600)	201,100
Realized (gains) losses on derivatives recognized in net income	(13,600)	36,900	(44,200)	75,600
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	0	0	0	0
Other comprehensive income (loss) on investment in unconsolidated affiliates	3,200	16,800	2,400	34,200
Total other comprehensive income (loss)	(28,300)	258,300	(114,400)	310,900
Comprehensive income	(851,100)	(509,900)	(1,725,400)	(1,198,000)
Less: Comprehensive income attributable to noncontrolling interests	0	0	0	0
Comprehensive income attributable to ONEOK	$ (851,100)	$ (509,900)	$ (1,725,400)	$ (1,198,000)

SUPPLEMENTAL CONDENSED CONSOL54

SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION, Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 332,371	$ 248,875	$ 180,854	$ 97,619
Accounts receivable, net	749,345	872,430
Natural gas and natural gas liquids in storage	200,133	140,034
Materials and supplies	75,172	60,912
Other current assets	51,465	45,986
Asset of discontinued operations	0	551
Assets, Current	1,447,811	1,429,684
Property, plant and equipment
Property, plant and equipment	15,241,140	15,078,497
Accumulated depreciation and amortization	2,694,148	2,507,094
Net property, plant and equipment	12,546,992	12,571,403
Investments and other assets
Investments	944,562	958,807
Goodwill and intangible assets	999,409	1,005,359
Other assets	170,785	162,998
Asset of discontinued operations	0	10,500
Total investments and other assets	2,678,120	2,137,664
Total assets	16,672,923	16,138,751	15,822,900
Current liabilities
Current maturities of long-term debt	494,703	410,650
Short-term borrowings	1,274,407	1,110,277
Accounts payable	696,834	874,731
Commodity imbalances	114,941	142,646
Accrued interest	111,697	112,514
Other current liabilities	167,937	166,042
Liabilities of discontinued operations	0	19,841
Total current liabilities	2,860,519	2,836,701
Long-term debt, excluding current maturities	7,835,606	7,919,996
Deferred credits and other liabilities	411,567	1,953,139
Commitments and contingencies
Equity
Total ONEOK Shareholder' Equity	5,407,747	188,745
Noncontrolling interests in consolidated subsidiaries	157,484	3,240,170
Total equity	5,565,231	3,428,915	3,492,177	3,766,336
Total liabilities and equity	16,672,923	16,138,751
Reportable Legal Entities | Parent Company
Current assets
Cash and cash equivalents	321,000	248,500	177,200	92,500
Accounts receivable, net	0	0
Natural gas and natural gas liquids in storage	0	0
Other current assets	12,900	7,200
Asset of discontinued operations		0
Assets, Current	333,900	255,700
Property, plant and equipment
Property, plant and equipment	139,800	139,800
Accumulated depreciation and amortization	94,300	90,400
Net property, plant and equipment	45,500	49,400
Investments and other assets
Investments	5,936,900	2,931,900
Intercompany notes receivable	253,700	205,200
Other assets	763,600	103,400
Total investments and other assets	6,954,200	3,240,500
Total assets	7,333,600	3,545,600
Current liabilities
Current maturities of long-term debt	87,100	3,000
Short-term borrowings	0	0
Accounts payable	19,900	13,000
Other current liabilities	57,700	44,700
Total current liabilities	164,700	60,700
Intercompany Debt	0	0
Long-term debt, excluding current maturities	1,545,000	1,628,700
Deferred credits and other liabilities	216,200	1,667,500
Equity
Total ONEOK Shareholder' Equity	5,407,700	188,700
Noncontrolling interests in consolidated subsidiaries	0	0
Total equity	5,407,700	188,700
Total liabilities and equity	7,333,600	3,545,600
Reportable Legal Entities | Issuer and Guarantor Subsidiary [Member]
Current assets
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	0	0
Natural gas and natural gas liquids in storage	0	0
Other current assets	500	0
Asset of discontinued operations		0
Assets, Current	500	0
Property, plant and equipment
Property, plant and equipment	0	0
Accumulated depreciation and amortization	0	0
Net property, plant and equipment	0	0
Investments and other assets
Investments	3,160,900	3,222,100
Intercompany notes receivable	10,791,600	10,615,000
Other assets	19,700	47,500
Total investments and other assets	13,972,200	13,884,600
Total assets	13,972,700	13,884,600
Current liabilities
Current maturities of long-term debt	400,000	400,000
Short-term borrowings	1,274,400	1,110,300
Accounts payable	0	0
Other current liabilities	86,300	99,900
Total current liabilities	1,760,700	1,610,200
Intercompany Debt	0	0
Long-term debt, excluding current maturities	6,257,900	6,254,700
Deferred credits and other liabilities	0	0
Equity
Total ONEOK Shareholder' Equity	5,954,100	6,019,700
Noncontrolling interests in consolidated subsidiaries	0	0
Total equity	5,954,100	6,019,700
Total liabilities and equity	13,972,700	13,884,600
Reportable Legal Entities | Guarantor Subsidiary
Current assets
Cash and cash equivalents	11,400	400	3,700	5,100
Accounts receivable, net	0	0
Natural gas and natural gas liquids in storage	0	0
Other current assets	0	0
Asset of discontinued operations		0
Assets, Current	11,400	400
Property, plant and equipment
Property, plant and equipment	0	0
Accumulated depreciation and amortization	0	0
Net property, plant and equipment	0	0
Investments and other assets
Investments	7,376,100	6,805,400
Intercompany notes receivable	6,565,000	7,031,300
Other assets	0	0
Total investments and other assets	13,941,100	13,836,700
Total assets	13,952,500	13,837,100
Current liabilities
Current maturities of long-term debt	0	0
Short-term borrowings	0	0
Accounts payable	0	0
Other current liabilities	0	0
Total current liabilities	0	0
Intercompany Debt	10,791,600	10,615,000
Long-term debt, excluding current maturities	0	0
Deferred credits and other liabilities	0	0
Equity
Total ONEOK Shareholder' Equity	3,160,900	3,222,100
Noncontrolling interests in consolidated subsidiaries	0	0
Total equity	3,160,900	3,222,100
Total liabilities and equity	13,952,500	13,837,100
Reportable Legal Entities | Combined Non-Guarantor Subsidiaries
Current assets
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	749,300	872,400
Natural gas and natural gas liquids in storage	200,100	140,000
Other current assets	152,600	160,600
Asset of discontinued operations		600
Assets, Current	1,102,000	1,173,600
Property, plant and equipment
Property, plant and equipment	15,101,300	14,938,700
Accumulated depreciation and amortization	2,599,800	2,416,700
Net property, plant and equipment	12,501,500	12,522,000
Investments and other assets
Investments	622,700	631,100
Intercompany notes receivable	0	0
Other assets	1,017,900	1,028,000
Total investments and other assets	1,640,600	1,659,100
Total assets	15,244,100	15,354,700
Current liabilities
Current maturities of long-term debt	7,700	7,700
Short-term borrowings	0	0
Accounts payable	676,900	861,700
Other current liabilities	250,500	296,500
Total current liabilities	935,100	1,165,900
Intercompany Debt	6,818,700	7,236,500
Long-term debt, excluding current maturities	32,700	36,600
Deferred credits and other liabilities	263,100	285,600
Equity
Total ONEOK Shareholder' Equity	7,037,000	6,472,000
Noncontrolling interests in consolidated subsidiaries	157,500	158,100
Total equity	7,194,500	6,630,100
Total liabilities and equity	15,244,100	15,354,700
Reportable Legal Entities | Total
Current assets
Cash and cash equivalents	332,400	248,900	180,900	97,600
Accounts receivable, net	749,300	872,400
Natural gas and natural gas liquids in storage	200,100	140,000
Other current assets	166,000	167,800
Asset of discontinued operations		600
Assets, Current	1,447,800	1,429,700
Property, plant and equipment
Property, plant and equipment	15,241,100	15,078,500
Accumulated depreciation and amortization	2,694,100	2,507,100
Net property, plant and equipment	12,547,000	12,571,400
Investments and other assets
Investments	944,600	958,800
Intercompany notes receivable	0	0
Other assets	1,733,500	1,178,900
Total investments and other assets	2,678,100	2,137,700
Total assets	16,672,900	16,138,800
Current liabilities
Current maturities of long-term debt	494,800	410,700
Short-term borrowings	1,274,400	1,110,300
Accounts payable	696,800	874,700
Other current liabilities	394,500	441,100
Total current liabilities	2,860,500	2,836,800
Intercompany Debt	0	0
Long-term debt, excluding current maturities	7,835,600	7,920,000
Deferred credits and other liabilities	411,600	1,953,100
Equity
Total ONEOK Shareholder' Equity	5,407,700	188,700
Noncontrolling interests in consolidated subsidiaries	157,500	3,240,200
Total equity	5,565,200	3,428,900
Total liabilities and equity	16,672,900	16,138,800
Consolidation Entries
Current assets
Cash and cash equivalents	0	0	$ 0	$ 0
Accounts receivable, net	0	0
Natural gas and natural gas liquids in storage	0	0
Other current assets	0	0
Asset of discontinued operations		0
Assets, Current	0	0
Property, plant and equipment
Property, plant and equipment	0	0
Accumulated depreciation and amortization	0	0
Net property, plant and equipment	0	0
Investments and other assets
Investments	(16,152,000)	(12,631,700)
Intercompany notes receivable	(17,610,300)	(17,851,500)
Other assets	(67,700)	0
Total investments and other assets	(33,830,000)	(30,483,200)
Total assets	(33,830,000)	(30,483,200)
Current liabilities
Current maturities of long-term debt	0	0
Short-term borrowings	0	0
Accounts payable	0	0
Other current liabilities	0	0
Total current liabilities	0	0
Intercompany Debt	(17,610,300)	(17,851,500)
Long-term debt, excluding current maturities	0	0
Deferred credits and other liabilities	(67,700)	0
Equity
Total ONEOK Shareholder' Equity	(16,152,000)	(15,713,800)
Noncontrolling interests in consolidated subsidiaries	0	3,082,100
Total equity	(16,152,000)	(12,631,700)
Total liabilities and equity	$ (33,830,000)	$ (30,483,200)

SUPPLEMENTAL CONDENSED CONSOL55

SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION, Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Operating activities
Cash provided by operating activities			$ 642,891	$ 531,606
Investing activities
Capital expenditures	$ (82,495)	$ (136,843)	(195,232)	(333,254)
Cash provided by (used in) investing activities			(183,731)	(298,479)
Financing activities
Dividends paid			(259,758)	(258,508)
Distributions to noncontrolling interests			(273,460)	(275,259)
Borrowing (repayment) of short-term borrowings, net			164,130	29,967
Issuance of long-term debt, net of discounts			0	1,000,000
Debt financing costs			(38)	(2,770)
Repayment of long-term debt			(3,898)	(654,151)
Issuance of Common Stock			10,845	11,101
Other			(13,485)	0
Cash used in financing activities			(375,664)	(149,620)
Change in cash and cash equivalents			83,496	83,507
Change in cash and cash equivalents included in discontinued operations			0	272
Change in cash and cash equivalents from continuing operations			83,496	83,235
Cash and cash equivalents at beginning of period			248,875	97,619
Cash and cash equivalents at end of period	332,371	180,854	332,371	180,854
Consolidation Entries
Operating activities
Cash provided by operating activities			(1,061,000)	(1,061,000)
Investing activities
Capital expenditures			0	0
Other investing activities			0	0
Cash provided by (used in) investing activities			0	0
Financing activities
Dividends paid			1,332,000	1,332,000
Distributions to noncontrolling interests			(271,000)	(271,000)
Intercompany borrowings (advances), net			0	0
Borrowing (repayment) of short-term borrowings, net			0	0
Issuance of long-term debt, net of discounts				0
Debt financing costs				0
Repayment of long-term debt			0	0
Issuance of Common Stock			0	0
Other			0
Cash used in financing activities			1,061,000	1,061,000
Change in cash and cash equivalents			0	0
Change in cash and cash equivalents included in discontinued operations				0
Change in cash and cash equivalents from continuing operations				0
Cash and cash equivalents at beginning of period			0	0
Cash and cash equivalents at end of period	0	0	0	0
Reportable Legal Entities | Parent Company
Operating activities
Cash provided by operating activities			355,000	363,100
Investing activities
Capital expenditures			(100)	0
Other investing activities			0	0
Cash provided by (used in) investing activities			(100)	0
Financing activities
Dividends paid			(259,800)	(258,500)
Distributions to noncontrolling interests			0	0
Intercompany borrowings (advances), net			(27,100)	(30,500)
Borrowing (repayment) of short-term borrowings, net			0	0
Issuance of long-term debt, net of discounts				0
Debt financing costs				0
Repayment of long-term debt			(100)	(300)
Issuance of Common Stock			10,800	11,100
Other			(6,200)
Cash used in financing activities			(282,400)	(278,200)
Change in cash and cash equivalents			72,500	84,900
Change in cash and cash equivalents included in discontinued operations				(200)
Change in cash and cash equivalents from continuing operations				84,700
Cash and cash equivalents at beginning of period			248,500	92,500
Cash and cash equivalents at end of period	321,000	177,200	321,000	177,200
Reportable Legal Entities | Issuer and Guarantor Subsidiary [Member]
Operating activities
Cash provided by operating activities			675,200	668,600
Investing activities
Capital expenditures			0	0
Other investing activities			0	0
Cash provided by (used in) investing activities			0	0
Financing activities
Dividends paid			(666,000)	(666,000)
Distributions to noncontrolling interests			0	0
Intercompany borrowings (advances), net			(166,100)	(379,800)
Borrowing (repayment) of short-term borrowings, net			164,100	30,000
Issuance of long-term debt, net of discounts				1,000,000
Debt financing costs				(2,800)
Repayment of long-term debt			0	(650,000)
Issuance of Common Stock			0	0
Other			(7,200)
Cash used in financing activities			(675,200)	(668,600)
Change in cash and cash equivalents			0	0
Change in cash and cash equivalents included in discontinued operations				0
Change in cash and cash equivalents from continuing operations				0
Cash and cash equivalents at beginning of period			0	0
Cash and cash equivalents at end of period	0	0	0	0
Reportable Legal Entities | Guarantor Subsidiary
Operating activities
Cash provided by operating activities			28,200	34,400
Investing activities
Capital expenditures			0	0
Other investing activities			6,700	24,900
Cash provided by (used in) investing activities			6,700	24,900
Financing activities
Dividends paid			(666,000)	(666,000)
Distributions to noncontrolling interests			0	0
Intercompany borrowings (advances), net			642,100	605,300
Borrowing (repayment) of short-term borrowings, net			0	0
Issuance of long-term debt, net of discounts				0
Debt financing costs				0
Repayment of long-term debt			0	0
Issuance of Common Stock			0	0
Other			0
Cash used in financing activities			(23,900)	(60,700)
Change in cash and cash equivalents			11,000	(1,400)
Change in cash and cash equivalents included in discontinued operations				0
Change in cash and cash equivalents from continuing operations				(1,400)
Cash and cash equivalents at beginning of period			400	5,100
Cash and cash equivalents at end of period	11,400	3,700	11,400	3,700
Reportable Legal Entities | Combined Non-Guarantor Subsidiaries
Operating activities
Cash provided by operating activities			645,500	526,500
Investing activities
Capital expenditures			(195,100)	(333,300)
Other investing activities			4,800	9,900
Cash provided by (used in) investing activities			(190,300)	(323,400)
Financing activities
Dividends paid			0	0
Distributions to noncontrolling interests			(2,500)	(4,300)
Intercompany borrowings (advances), net			(448,900)	(195,000)
Borrowing (repayment) of short-term borrowings, net			0	0
Issuance of long-term debt, net of discounts				0
Debt financing costs				0
Repayment of long-term debt			(3,800)	(3,800)
Issuance of Common Stock			0	0
Other			0
Cash used in financing activities			(455,200)	(203,100)
Change in cash and cash equivalents			0	0
Change in cash and cash equivalents included in discontinued operations				0
Change in cash and cash equivalents from continuing operations				0
Cash and cash equivalents at beginning of period			0	0
Cash and cash equivalents at end of period	0	0	0	0
Reportable Legal Entities | Total
Operating activities
Cash provided by operating activities			642,900	531,600
Investing activities
Capital expenditures			(195,200)	(333,300)
Other investing activities			11,500	34,800
Cash provided by (used in) investing activities			(183,700)	(298,500)
Financing activities
Dividends paid			(259,800)	(258,500)
Distributions to noncontrolling interests			(273,500)	(275,300)
Intercompany borrowings (advances), net			0	0
Borrowing (repayment) of short-term borrowings, net			164,100	30,000
Issuance of long-term debt, net of discounts				1,000,000
Debt financing costs				(2,800)
Repayment of long-term debt			(3,900)	(654,100)
Issuance of Common Stock			10,800	11,100
Other			(13,400)
Cash used in financing activities			(375,700)	(149,600)
Change in cash and cash equivalents			83,500	83,500
Change in cash and cash equivalents included in discontinued operations				(200)
Change in cash and cash equivalents from continuing operations				83,300
Cash and cash equivalents at beginning of period			248,900	97,600
Cash and cash equivalents at end of period	$ 332,400	$ 180,900	$ 332,400	$ 180,900