SUPPLEMENTAL CONDENSED CONSOLIDATING FINANCIAL INFORMATION (Notes)

12 Months Ended

Dec. 31, 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 the equity in ONEOK Partners’ 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 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

	Year Ended December 31, 2017
	Parent Issuer & Guarantor			Subsidiary Issuer & Guarantor			Guarantor Subsidiary			Combined Non-Guarantor Subsidiaries			Consolidating Entries			Total
	(Millions of dollars)
Revenues
Commodity sales	$	—		$	—		$	—		$	9,862.7		$	—		$	9,862.7
Services	—			—			—			2,313.2			(2.0		)	2,311.2
Total revenues	—			—			—			12,175.9			(2.0		)	12,173.9
Cost of sales and fuel (exclusive of items shown separately below)	—			—			—			9,538.0			—			9,538.0
Operating expenses	28.7			—			9.2			1,204.0			(2.0		)	1,239.9
Impairment of long-lived assets	—			—			—			16.0			—			16.0
Gain on sale of assets	—			—			—			(0.9		)	—			(0.9		)
Operating income	(28.7		)	—			(9.2		)	1,418.8			—			1,380.9
Equity in net earnings from investments	1,236.6			1,215.7			1,224.9			100.7			(3,618.6		)	159.3
Impairment of equity investments	—			—			—			(4.3		)	—			(4.3		)
Other income (expense), net	(1.4		)	353.1			353.1			(8.0		)	(706.2		)	(9.4		)
Interest expense, net	(137.1		)	(353.1		)	(353.1		)	(348.6		)	706.2			(485.7		)
Income before income taxes	1,069.4			1,215.7			1,215.7			1,158.6			(3,618.6		)	1,040.8
Income taxes	(480.2		)	—			—			32.9			—			(447.3		)
Net income	589.2			1,215.7			1,215.7			1,191.5			(3,618.6		)	593.5
Less: Net income attributable to noncontrolling interests	201.4			—			—			4.3			—			205.7
Net income attributable to ONEOK	387.8			1,215.7			1,215.7			1,187.2			(3,618.6		)	387.8
Less: Preferred stock dividends	0.8			—			—			—			—			0.8
Net income available to common shareholders	$	387.0		$	1,215.7		$	1,215.7		$	1,187.2		$	(3,618.6	)	$	387.0

	Year Ending December 31, 2016
	Parent Issuer & Guarantor			Subsidiary Issuer & Guarantor			Guarantor Subsidiary			Combined Non-Guarantor Subsidiaries			Consolidating Entries			Total
	(Millions of dollars)
Revenues
Commodity sales	$	—		$	—		$	—		$	6,858.5		$	—		$	6,858.5
Services	—			—			—			2,064.3			(1.8		)	2,062.5
Total revenues	—			—			—			8,922.8			(1.8		)	8,921.0
Cost of sales and fuel (exclusive of items shown separately below)	—			—			—			6,496.1			—			6,496.1
Operating expenses	28.8			—			—			1,121.8			(1.8		)	1,148.8
(Gain) loss on sale of assets	0.3			—			—			(9.9		)	—			(9.6		)
Operating income	(29.1		)	—			—			1,314.8			—			1,285.7
Equity in net earnings from investments	1,063.9			1,066.8			1,066.8			69.7			(3,127.5		)	139.7
Other income (expense), net	5.1			373.5			373.5			(2.8		)	(747.0		)	2.3
Interest expense, net	(102.9		)	(373.5		)	(373.5		)	(366.8		)	747.0			(469.7		)
Income before income taxes	937.0			1,066.8			1,066.8			1,014.9			(3,127.5		)	958.0
Income taxes	(199.0		)	—			—			(13.4		)	—			(212.4		)
Income from continuing operations	738.0			1,066.8			1,066.8			1,001.5			(3,127.5		)	745.6
Income (loss) from discontinued operations, net of tax	—			—			—			(2.1		)	—			(2.1		)
Net income	738.0			1,066.8			1,066.8			999.4			(3,127.5		)	743.5
Less: Net income attributable to noncontrolling interests	386.0			—			—			5.5			—			391.5
Net income attributable to ONEOK	$	352.0		$	1,066.8		$	1,066.8		$	993.9		$	(3,127.5	)	$	352.0

	Year Ending December 31, 2015
	Parent Issuer & Guarantor			Subsidiary Issuer & Guarantor			Guarantor Subsidiary			Combined Non-Guarantor Subsidiaries			Consolidating Entries			Total
	(Millions of dollars)
Revenues
Commodity sales	$	—		$	—		$	—		$	6,098.3		$	—		$	6,098.3
Services	—			—			—			1,669.8			(4.9		)	1,664.9
Total revenues	—			—			—			7,768.1			(4.9		)	7,763.2
Cost of sales and fuel (exclusive of items shown separately below)	—			—			—			5,641.1			—			5,641.1
Operating expenses	1.2			—			—			1,051.5			(4.9		)	1,047.8
Impairment of long-lived assets	—			—			—			83.7			—			83.7
Gain on sale of assets	—			—			—			(5.6		)	—			(5.6		)
Operating income	(1.2		)	—			—			997.4			—			996.2
Equity in net earnings from investments	583.8			589.5			589.5			58.4			(1,695.9		)	125.3
Impairment of equity investments	—			—			—			(180.6		)	—			(180.6		)
Other income (expense), net	4.0			371.0			371.0			(6.2		)	(742.0		)	(2.2		)
Interest expense, net	(85.1		)	(371.0		)	(371.0		)	(331.7		)	742.0			(416.8		)
Income before income taxes	501.5			589.5			589.5			537.3			(1,695.9		)	521.9
Income taxes	(130.7		)	—			—			(5.9		)	—			(136.6		)
Income from continuing operations	370.8			589.5			589.5			531.4			(1,695.9		)	385.3
Income (loss) from discontinued operations, net of tax	—			—			—			(6.1		)	—			(6.1		)
Net income	370.8			589.5			589.5			525.3			(1,695.9		)	379.2
Less: Net income attributable to noncontrolling interests	125.8			—			—			8.4			—			134.2
Net income attributable to ONEOK	$	245.0		$	589.5		$	589.5		$	516.9		$	(1,695.9	)	$	245.0

Condensed Consolidating Statements of Comprehensive Income

	Year Ended December 31, 2017
	Parent Issuer & Guarantor			Subsidiary Issuer & Guarantor			Guarantor Subsidiary			Combined Non-Guarantor Subsidiaries			Consolidating Entries			Total
	(Millions of dollars)
Net income	$	589.2		$	1,215.7		$	1,215.7		$	1,191.5		$	(3,618.6	)	$	593.5
Other comprehensive income (loss), net of tax
Unrealized gains (losses) on derivatives, net of tax	19.1			(72.2		)	(40.6		)	(8.8		)	81.1			(21.4		)
Realized (gains) losses on derivatives in net income, net of tax	2.5			86.5			69.6			44.3			(139.2		)	63.7
Change in pension and postretirement benefit plan liability, net of tax	(4.2		)	—			—			—			—			(4.2		)
Other comprehensive income (loss) on investments in unconsolidated affiliates, net of tax	—			(1.1		)	(1.1		)	(1.0		)	2.2			(1.0		)
Total other comprehensive income (loss), net of tax	17.4			13.2			27.9			34.5			(55.9		)	37.1
Comprehensive income	606.6			1,228.9			1,243.6			1,226.0			(3,674.5		)	630.6
Less: Comprehensive income attributable to noncontrolling interests	232.4			—			—			4.3			—			236.7
Comprehensive income attributable to ONEOK	$	374.2		$	1,228.9		$	1,243.6		$	1,221.7		$	(3,674.5	)	$	393.9

	Year Ending December 31, 2016
	Parent Issuer & Guarantor			Subsidiary Issuer & Guarantor			Guarantor Subsidiary			Combined Non-Guarantor Subsidiaries			Consolidating Entries			Total
	(Millions of dollars)
Net income	$	738.0		$	1,066.8		$	1,066.8		$	999.4		$	(3,127.5	)	$	743.5
Other comprehensive income (loss), net of tax
Unrealized gains (losses) on derivatives, net of tax	—			(35.8		)	(78.5		)	(108.8		)	192.8			(30.3		)
Realized (gains) losses on derivatives in net income, net of tax	2.1			(10.7		)	(26.4		)	(33.4		)	61.4			(7.0		)
Change in pension and postretirement benefit plan liability, net of tax	(16.7		)	—			—			—			—			(16.7		)
Other comprehensive income (loss) on investments in unconsolidated affiliates, net of tax	—			(1.8		)	(1.8		)	(3.3		)	5.4			(1.5		)
Total other comprehensive income (loss), net of tax	(14.6		)	(48.3		)	(106.7		)	(145.5		)	259.6			(55.5		)
Comprehensive income	723.4			1,018.5			960.1			853.9			(2,867.9		)	688.0
Less: Comprehensive income attributable to noncontrolling interests	357.6			—			—			5.5			—			363.1
Comprehensive income attributable to ONEOK	$	365.8		$	1,018.5		$	960.1		$	848.4		$	(2,867.9	)	$	324.9

	Year Ending December 31, 2015
	Parent Issuer & Guarantor		Subsidiary Issuer & Guarantor			Guarantor Subsidiary			Combined Non-Guarantor Subsidiaries			Consolidating Entries			Total
	(Millions of dollars)
Net income	$	370.8	$	589.5		$	589.5		$	525.3		$	(1,695.9	)	$	379.2
Other comprehensive income (loss), net of tax
Unrealized gains (losses) on derivatives, net of tax	—		47.5			70.1			111.5			(187.7		)	41.4
Realized (gains) losses on derivatives in net income, net of tax	2.1		(67.0		)	(81.1		)	(137.9		)	229.2			(54.7		)
Unrealized holding gains (losses) on available-for-sale securities, net of tax	—		—			—			(1.0		)	—			(1.0		)
Change in pension and postretirement benefit plan liability, net of tax	15.4		—			—			—			—			15.4
Other comprehensive income (loss) on investments in unconsolidated affiliates, net of tax	—		(1.9		)	(1.9		)	(3.5		)	5.7			(1.6		)
Total other comprehensive income (loss), net of tax	17.5		(21.4		)	(12.9		)	(30.9		)	47.2			(0.5		)
Comprehensive income	388.3		568.1			576.6			494.4			(1,648.7		)	378.7
Less: Comprehensive income attributable to noncontrolling interests	116.2		—			—			8.4			—			124.6
Comprehensive income attributable to ONEOK	$	272.1	$	568.1		$	576.6		$	486.0		$	(1,648.7	)	$	254.1

Condensed Consolidating Balance Sheets

	December 31, 2017
	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	$	37.2	$	—	$	—	$	—	$	—		$	37.2
Accounts receivable, net	—		—		—		1,203.0		—			1,203.0
Materials and supplies	—		—		—		90.3		—			90.3
Natural gas and natural gas liquids in storage	—		—		—		342.3		—			342.3
Other current assets	9.8		1.3		—		80.6		—			91.7
Total current assets	47.0		1.3		—		1,716.2		—			1,764.5
Property, plant and equipment
Property, plant and equipment	128.3		—		—		15,431.3		—			15,559.6
Accumulated depreciation and amortization	86.4		—		—		2,775.1		—			2,861.5
Net property, plant and equipment	41.9		—		—		12,656.2		—			12,698.1
Investments and other assets
Investments	5,752.1		3,133.7		8,058.4		803.0		(16,744.0		)	1,003.2
Intercompany notes receivable	2,926.9		8,627.8		3,703.1		—		(15,257.8		)	—
Other assets	416.9		0.2		—		1,007.4		(44.4		)	1,380.1
Total investments and other assets	9,095.9		11,761.7		11,761.5		1,810.4		(32,046.2		)	2,383.3
Total assets	$	9,184.8	$	11,763.0	$	11,761.5	$	16,182.8	$	(32,046.2	)	$	16,845.9
Liabilities and equity
Current liabilities
Current maturities of long-term debt	$	—	$	425.0	$	—	$	7.7	$	—		$	432.7
Short-term borrowings	614.7		—		—		—		—			614.7
Accounts payable	12.0		—		—		1,128.6		—			1,140.6
Other current liabilities	65.9		85.0		—		328.4		—			479.3
Total current liabilities	692.6		510.0		—		1,464.7		—			2,667.3
Intercompany debt	—		—		8,627.8		6,630.0		(15,257.8		)	—
Long-term debt, excluding current maturities	2,726.4		5,336.4		—		28.8		—			8,091.6
Deferred credits and other liabilities	237.9		—		—		208.1		(44.4		)	401.6
Commitments and contingencies
Equity
Equity excluding noncontrolling interests in consolidated subsidiaries	5,527.9		5,916.6		3,133.7		7,693.7		(16,744.0		)	5,527.9
Noncontrolling interests in consolidated subsidiaries	—		—		—		157.5		—			157.5
Total equity	5,527.9		5,916.6		3,133.7		7,851.2		(16,744.0		)	5,685.4
Total liabilities and equity	$	9,184.8	$	11,763.0	$	11,761.5	$	16,182.8	$	(32,046.2	)	$	16,845.9

	December 31, 2016
	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
Materials and supplies	—		—		—		60.9		—			60.9
Natural gas and natural gas liquids in storage	—		—		—		140.0		—			140.0
Other current assets	7.2		—		—		99.7		—			106.9
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		)	—
Goodwill and intangible assets	—		—		—		1,005.4		—			1,005.4
Other assets	103.4		47.5		—		12.1		—			163.0
Assets of discontinued operations	—		—		—		10.5		—			10.5
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
Commodity imbalances	—		—		—		142.6		—			142.6
Accrued interest	25.4		87.1		—		—		—			112.5
Other current liabilities	19.3		12.8		—		134.1		—			166.2
Liabilities of discontinued operations	—		—		—		19.8		—			19.8
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

	Year Ended December 31, 2017
	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	$	947.4		$	1,348.3		$	59.0		$	1,353.7		$	(2,393.0	)	$	1,315.4
Investing activities
Capital expenditures	—			—			—			(512.4		)	—			(512.4		)
Contributions to unconsolidated affiliates	—			—			(83.0		)	(4.9		)	—			(87.9		)
Other investing activities	—			—			14.8			17.9			—			32.7
Cash used in investing activities	—			—			(68.2		)	(499.4		)	—			(567.6		)
Financing activities
Dividends paid	(829.4		)	(1,332.0		)	(1,332.0		)	—			2,664.0			(829.4		)
Distributions to noncontrolling interests	—			—			—			(5.3		)	(271.0		)	(276.3		)
Intercompany borrowings (advances), net	(2,500.7		)	2,001.2			1,340.8			(841.3		)	—			—
Borrowing (repayment) of short-term borrowings, net	614.7			(1,110.3		)	—			—			—			(495.6		)
Issuance of long-term debt, net of discounts	1,190.5			—			—			—			—			1,190.5
Repayment of long-term debt	(87.1		)	(900.0		)	—			(7.7		)	—			(994.8		)
Issuance of common stock	471.4			—			—			—			—			471.4
Other	(18.1		)	(7.2		)	—			—			—			(25.3		)
Cash provided by (used in) financing activities	(1,158.7		)	(1,348.3		)	8.8			(854.3		)	2,393.0			(959.5		)
Change in cash and cash equivalents	(211.3		)	—			(0.4		)	—			—			(211.7		)
Cash and cash equivalents at beginning of period	248.5			—			0.4			—			—			248.9
Cash and cash equivalents at end of period	$	37.2		$	—		$	—		$	—		$	—		$	37.2

	Year Ending December 31, 2016
	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	$	717.0		$	1,334.5		$	70.0		$	1,353.9		$	(2,122.1	)	$	1,353.3
Investing activities
Capital expenditures	(0.2		)	—			—			(624.4		)	—			(624.6		)
Other investing activities	—			—			34.9			(25.7		)	—			9.2
Cash provided by (used in) investing activities	(0.2		)	—			34.9			(650.1		)	—			(615.4		)
Financing activities
Dividends paid	(517.6		)	(1,332.0		)	(1,332.0		)	—			2,664.0			(517.6		)
Distributions to noncontrolling interests	—			—			—			(7.5		)	(541.9		)	(549.4		)
Intercompany borrowings (advances), net	(63.1		)	(470.8		)	1,222.4			(688.5		)	—			—
Borrowing (repayment) of short-term borrowings, net	—			563.9			—			—			—			563.9
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		)	(1,100.0		)	—			(7.7		)	—			(1,108.0		)
Issuance of common stock	22.0			—			—			—			—			22.0
Other	(1.7		)	7.2			—			(0.1		)	—			5.4
Cash used in financing activities	(560.7		)	(1,334.5		)	(109.6		)	(703.8		)	2,122.1			(586.5		)
Change in cash and cash equivalents	156.1			—			(4.7		)	—			—			151.4
Change in cash and cash equivalents included in discontinued operations	(0.1		)	—			—			—			—			(0.1		)
Change in cash and cash equivalents included in continuing operations	156.0			—			(4.7		)	—			—			151.3
Cash and cash equivalents at beginning of period	92.5			—			5.1			—			—			97.6
Cash and cash equivalents at end of period	$	248.5		$	—		$	0.4		$	—		$	—		$	248.9

	Year Ending December 31, 2015
	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	$	650.3		$	1,196.7		$	66.9		$	1,045.7		$	(1,936.8	)	$	1,022.8
Investing activities
Capital expenditures	(0.1		)	—			—			(1,188.2		)	—			(1,188.3		)
Contributions to investments	(671.0		)	—			—			(27.5		)	671.0			(27.5		)
Other investing activities	—			—			24.1			1.0			—			25.1
Cash provided by (used in) investing activities	(671.1		)	—			24.1			(1,214.7		)	671.0			(1,190.7		)
Financing activities
Dividends paid	(509.2		)	(1,230.5		)	(1,230.5		)	—			2,461.0			(509.2		)
Distributions to noncontrolling interests	—			—			—			(11.7		)	(524.2		)	(535.9		)
Intercompany borrowings (advances), net	4.6			(1,295.1		)	1,102.1			188.4			—			—
Borrowing (repayment) of short-term borrowings, net	—			(509.0		)	—			—			—			(509.0		)
Issuance of long-term debt, net of discounts	492.6			798.9			—			—			—			1,291.5
Debt financing costs	(9.8		)	(7.7		)	—			—			—			(17.5		)
Repayment of long-term debt	(0.1		)	—			—			(7.7		)	—			(7.8		)
Issuance of common stock	20.7			—			—			—			—			20.7
Issuance of common units, net of issuance costs	—			1,025.7			—			—			(650.0		)	375.7
Contribution from general partner	—			21.0			—			—			(21.0		)	—
Other	(15.8		)	—			—			—			—			(15.8		)
Cash provided by (used) in financing activities	(17.0		)	(1,196.7		)	(128.4		)	169.0			1,265.8			92.7
Change in cash and cash equivalents	(37.8		)	—			(37.4		)	—			—			(75.2		)
Cash and cash equivalents at beginning of period	130.3			—			42.5			—			—			172.8
Cash and cash equivalents at end of period	$	92.5		$	—		$	5.1		$	—		$	—		$	97.6