Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income (loss)	$ (14.1)	$ (956.1)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	221.3	229.4
Stock-based compensation	14.0	16.4
Change in fair value of catalyst obligations	4.2	(6.6)
Deferred income taxes	(13.8)	9.8
Non-cash change in inventory repurchase obligations	42.2	(25.7)
Non-cash lower of cost or market inventory adjustment	(669.6)	701.4
Change in fair value of contingent consideration	24.3	(65.4)
Debt extinguishment costs	0.0	22.2
Pension and other post-retirement benefit costs	25.3	27.3
Gain on sale of assets	(0.6)	(471.1)
Changes in operating assets and liabilities:
Accounts receivable	(501.1)	403.7
Due to/from affiliates	6.5	6.3
Inventories	(280.4)	24.8
Prepaid and other current assets	(82.4)	(54.6)
Accounts payable	373.4	(185.9)
Accrued expenses	892.5	(360.4)
Deferred revenue	(18.8)	1.1
Other assets and liabilities	(46.0)	(24.5)
Net cash used in operating activities	(23.1)	(707.9)
Cash flows from investing activities:
Expenditures for property, plant and equipment	(81.1)	(112.6)
Expenditures for deferred turnaround costs	(38.5)	(159.2)
Expenditures for other assets	(16.5)	(7.2)
Acquisition of Martinez refinery	0.0	(1,176.2)
Proceeds from sale of assets	0.0	529.4
Net cash used in investing activities	(136.1)	(925.8)
Cash flows from financing activities:
Contributions from PBF LLC	18.9	24.4
Payments of Capital Distribution	(2.0)	(21.1)
Proceeds from revolver borrowings	0.0	1,150.0
Repayments of revolver borrowings	0.0	(550.0)
Settlement of catalyst obligations	0.0	(8.8)
Payments on financing leases	(7.1)	(5.7)
Proceeds from insurance premium financing	28.0	33.8
Deferred financing costs and other	0.4	(27.8)
Net cash provided by financing activities	33.8	2,073.7
Net (decrease) increase in cash and cash equivalents	(125.4)	440.0
Cash and cash equivalents, beginning of period	1,570.1	763.1
Cash and cash equivalents, end of period	1,444.7	1,203.1
Non-cash activities:
Accrued and unpaid capital expenditures	45.5	29.8
Assets acquired or remeasured under operating and financing leases	(127.9)	224.3
Fair value of the Martinez Contingent Consideration at acquisition	0.0	77.3
Cash paid during the period for:
Interest (net of capitalized interest of $4.8 million and $5.6 million in 2021 and 2020, respectively)	130.7	49.2
Capitalized interest	4.8	5.6
Income taxes	0.6	0.1
Collins Pipeline Company and T&M Terminal Company
Cash flows from financing activities:
Payments of Capital Distribution	(0.7)	0.0
2025 Senior Secured Notes [Member]
Cash flows from financing activities:
Proceeds from Issuance of Long-term Debt	0.0	1,000.0
2028 Senior Notes [Member]
Cash flows from financing activities:
Proceeds from Issuance of Long-term Debt	0.0	1,000.0
2023 Senior Notes [Member]
Cash flows from financing activities:
Repayments of Long-term Debt	0.0	(517.5)
Rail Term Loan [Member]
Cash flows from financing activities:
Repayments of Long-term Debt	$ (3.7)	$ (3.6)