Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator for EPS - continuing operations
(Loss) income from continuing operations	$ 98.5	$ 84.6	$ (208.5)	$ 239.0
Less: Income from continuing operations attributed to non-controlling interest	10.8	6.5	18.2	11.6
Numerator for diluted EPS - continuing operations attributable to Delek	87.7	78.1	(226.7)	227.4
Numerator for EPS - discontinued operations
Loss from discontinued operations	0.0	(0.8)	0.0	(0.8)
Income (loss) from discontinued operations attributed to Delek	$ 0.0	$ (0.8)	$ 0.0	$ (0.8)
Denominator:
Weighted Average Number of Shares Outstanding( denominatior for basic EPS) (in shares)	73,547,582	76,598,846	73,492,656	77,192,763
Dilutive effect of stock-based awards	480,461	681,846	0	690,522
Weighted average common shares outstanding, assuming dilution (in shares)	74,028,043	77,280,692	73,492,656	77,883,285
EPS:
Income (loss) Income from Continuing Operations (USD per share)	$ 1.19	$ 1.02	$ (3.08)	$ 2.95
(Loss) income from discontinued operations (USD per share)	0	(0.01)	0	(0.01)
Total basic income (loss) per share (USD per Share)	1.19	1.01	(3.08)	2.94
Income (Loss) from Continuing Operations (USD per share)	1.18	1.01	(3.08)	2.92
Income (loss) from discontinued operations (USD per share)	0	(0.01)	0	(0.01)
Total diluted income (loss) per share (USD per share)	$ 1.18	$ 1.00	$ (3.08)	$ 2.91
Stock Compensation Plan, Excluding Loss [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	3,922,290	1,927,150	3,328,789	2,153,411
Stock Compensation Plan, Loss [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	0	372,220	0
Share-based Payment Arrangement [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	3,922,290	1,927,150	3,701,009	2,153,411