Long-Term Obligations and Notes Payable - Outstanding Borrowings Schedule (Details) - USD ($) $ in Millions		Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Long-term Debt		$ 1,761.1	$ 1,783.3
Current portion of long-term debt		32.0	32.0
Long-term debt, net of current portion		1,729.1	1,751.3
Delek Revolving Credit Facility | Line of credit
Debt Instrument [Line Items]
Long-term Debt			300.0
Delek Term Loan Credit Facility | Term loan
Debt Instrument [Line Items]
Long-term Debt	[1]	680.9	682.9
Footnote [Abstract]
Deferred financing costs		4.2	3.5
Debt discount		7.9	8.4
DKL Notes | Senior notes
Debt Instrument [Line Items]
Long-term Debt	[2]	244.0	243.7
Footnote [Abstract]
Deferred financing costs		4.6	4.8
Debt discount		1.4	1.5
Promissory Notes
Debt Instrument [Line Items]
Long-term Debt		45.0	70.0
Revolving credit facility | Line of credit
Debt Instrument [Line Items]
Long-term Debt		300.0
Revolving credit facility | DKL Revolver | Line of credit
Debt Instrument [Line Items]
Long-term Debt		461.2	456.7
Revolving credit facility | Reliant Bank Revolver | Line of credit
Debt Instrument [Line Items]
Long-term Debt		$ 30.0	$ 30.0

[1] The Term Loan Credit Facility is net of deferred financing costs of $4.2 million and $3.5 million, respectively, and debt discount of $7.9 million and $8.4 million at March 31, 2019 and December 31, 2018.

[2] The Delek Logistics Notes are net of deferred financing costs of $4.6 million and $4.8 million, respectively, and debt discount of $1.4 million and $1.5 million, respectively, at March 31, 2019 and December 31, 2018.