CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues
Commodity sales	$ 9,862,652	$ 6,858,456	$ 6,098,343
Services	2,311,255	2,062,478	1,664,863
Total revenues	12,173,907	8,920,934	7,763,206
Cost of sales and fuel (exclusive of items shown separately below)	9,538,045	6,496,124	5,641,052
Operations and maintenance	735,190	668,335	605,748
Depreciation and amortization	406,335	391,585	354,620
Impairment of long-lived assets (Note E)	15,970	0	83,673
General taxes	98,396	88,849	87,583
Gain on sale of assets	(924)	(9,635)	(5,629)
Operating income	1,380,895	1,285,676	996,159
Equity in net earnings from investments (Note N)	159,278	139,690	125,300
Impairment of equity investments (Note N)	(4,270)	0	(180,583)
Allowance for equity funds used during construction	107	209	2,179
Other income	15,385	6,091	368
Other expense	(24,936)	(4,059)	(4,760)
Interest expense (net of capitalized interest of $5,510, $10,591 and $36,572, respectively)	(485,658)	(469,651)	(416,787)
Income before income taxes	1,040,801	957,956	521,876
Income taxes (Note M)	(447,282)	(212,406)	(136,600)
Income from continuing operations	593,519	745,550	385,276
Income (loss) from discontinued operations, net of tax	0	(2,051)	(6,081)
Net income	593,519	743,499	379,195
Less: Net income attributable to noncontrolling interests	205,678	391,460	134,218
Net income attributable to ONEOK	387,841	352,039	244,977
Less: Preferred stock dividends	767	0	0
Net Income Available to Common Stockholders	387,074	352,039	244,977
Amounts available to common shareholders:
Income from continuing operations	387,074	354,090	251,058
Income (loss) from discontinued operations	0	(2,051)	(6,081)
Net Income Available to Common Stockholders	$ 387,074	$ 352,039	$ 244,977
Basic earnings per common share:
Income from continuing operations (Note J)	$ 1.30	$ 1.68	$ 1.19
Income (loss) from discontinued operations	0.00	(0.01)	(0.02)
Net income	1.30	1.67	1.17
Diluted earnings per common share:
Income from continuing operations (Note J)	1.29	1.67	1.19
Income (loss) from discontinued operations	0.00	(0.01)	(0.03)
Net income	$ 1.29	$ 1.66	$ 1.16
Average shares (thousands)
Basic	297,477	211,128	210,208
Diluted	299,780	212,383	210,541
Dividends declared per share of common stock	$ 2.72	$ 2.46	$ 2.43