Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Numerator for EPS - continuing operations
Income (loss) from continuing operations	$ 154.4	$ (17.3)	[1]
Less: Income from continuing operations attributed to non-controlling interest	5.1	6.8
Numerator for diluted EPS - continuing operations attributable to Delek	149.3	(24.1)
Numerator for EPS - discontinued operations
Income (loss) from discontinued operations	0.0	(8.2)	[1]
Less: Income from discontinued operations attributed to non-controlling interest	0.0	8.1
Income (loss) from discontinued operations attributed to Delek	$ 0.0	$ (16.3)
Denominator:
Weighted Average Number of Shares Outstanding( denominatior for basic EPS) (in shares)	77,793,278	82,252,405	[1]
Dilutive effect of stock-based awards	653,412	0
Weighted average common shares outstanding, assuming dilution (in shares)	78,446,690	82,252,405	[1]
EPS:
Income (loss) Income from Continuing Operations (USD per share)	$ 1.92	$ (0.29)	[1]
Loss from discontinued operations (USD per share)	0	(0.20)	[1]
Total basic income (loss) per share (USD per Share)	1.92	(0.49)	[1]
Income (Loss) from Continuing Operations (USD per share)	1.90	(0.29)	[1]
Income (loss) from discontinued operations (USD per share)	0	(0.20)	[1]
Total diluted income (loss) per share (USD per share)	$ 1.90	$ (0.49)	[1]
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)	2,173,510	820,730
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	1,112,419
Stock Compensation Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,173,510	1,933,149
Convertible Debt Securities, 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	1,458,780
Warrants, 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	161,344

[1] Income tax benefit for the quarter ended March 31, 2018 reflects a correction made in our 2018 Annual Report on Form 10-K (filed on March 1, 2019) to record additional deferred tax expense totaling $5.5 million related to the recognition of a valuation allowance on deferred tax assets recognized in connection with the Big Spring Logistic Assets Acquisition (see Note 5) not previously reported in our March 31, 2018 Quarterly Report on Form 10-Q filed on May 10, 2018. Such amount is not considered material to the financial statements or the trend of earnings for that period. See Note 23 to our annual audited consolidated financial statements included in Part II, Item 8 of our 2018 Annual Report on Form 10-K filed on March 1, 2019 for further discussion.