Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ (1,857.5)	$ 388.2	$ 103.0
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Depreciation and amortization	523.8	404.4	346.7
Impairment expense	91.8	0.0	0.0
Stock-based compensation	29.3	30.5	20.2
Change in fair value of catalyst obligations	11.8	9.7	(5.6)
Deferred income taxes	7.3	(8.8)	7.2
Non-cash change in inventory repurchase obligations	(12.6)	25.4	(31.8)
Non-cash lower of cost or market inventory adjustment	268.0	(250.2)	351.3
Change in fair value of contingent consideration	(79.3)	0.0	0.0
Debt extinguishment costs	22.2	0.0	0.0
Pension and other post-retirement benefit costs	55.7	44.8	47.4
Income from equity method investee	0.0	(7.9)	(17.8)
Distributions from equity method investee	0.0	7.9	17.8
Gain on sale of assets	(477.8)	(29.9)	(43.1)
Changes in operating assets and liabilities:
Accounts receivable	325.1	(115.9)	240.4
Due to/from affiliates	6.7	12.6	(3.5)
Inventories	392.2	(8.0)	(1.5)
Prepaid and other current assets	(3.0)	4.4	(2.9)
Accounts payable	(200.6)	132.0	(110.7)
Accrued expenses	111.5	209.5	(233.0)
Deferred revenue	28.2	(0.2)	9.6
Other assets and liabilities	(62.8)	(58.9)	1.3
Net cash (used in) provided by operating activities	(820.0)	789.6	695.0
Cash flows from investing activities:
Expenditures for property, plant and equipment	(183.9)	(373.1)	(277.3)
Expenditures for deferred turnaround costs	(188.1)	(299.3)	(266.0)
Expenditures for other assets	(9.1)	(44.7)	(17.0)
Proceeds from sale of assets	543.1	36.3	48.3
Equity method investment - return of capital	0.0	0.6	2.4
Net cash used in investing activities	(1,014.2)	(680.2)	(509.6)
Cash flows from financing activities:
Contributions from PBF LLC	42.4	228.5	287.0
Distributions to members	(23.1)	(121.6)	(52.6)
Proceeds from revolver borrowings	1,450.0	1,350.0	0.0
Repayments of revolver borrowings	(550.0)	(1,350.0)	(350.0)
Repayments of note payable	0.0	0.0	(5.6)
Settlements of catalyst obligations	(8.8)	(6.5)	(9.1)
Proceeds from catalyst financing arrangements	51.9	0.0	0.0
Payments on financing leases	(12.4)	0.0	0.0
Deferred financing costs and other	(34.7)	(1.4)	(12.8)
Net cash provided by (used in) financing activities	2,641.2	92.0	(149.9)
Net increase in cash and cash equivalents	807.0	201.4	35.5
Cash and cash equivalents, beginning of period	763.1	561.7	526.2
Cash and cash equivalents, end of period	1,570.1	763.1	561.7
Non-cash activities:
Accrued and unpaid capital expenditures	31.1	36.0	89.5
Assets acquired under operating and financing leases	702.0	1,194.3	0.0
Distribution of assets to PBF Energy Company LLC	0.0	169.1	13.7
Cash paid during the year for:
Interest (net of capitalized interest of $11.9, $17.6 and $9.3 in 2020, 2019 and 2018, respectively)	162.9	107.0	124.4
Income taxes	1.0	1.2	0.6
Capitalized interest	11.9	17.6	9.3
Martinez Acquisition
Cash flows from investing activities:
Acquisition of Martinez refinery	(1,176.2)	0.0	0.0
Non-cash activities:
Fair value of the Martinez Contingent Consideration at acquisition	77.3	0.0	0.0
2025 Senior Secured Notes
Cash flows from financing activities:
Proceeds from Issuance of Long-term Debt	1,250.6	0.0	0.0
2028 Senior Notes [Member]
Cash flows from financing activities:
Proceeds from Issuance of Long-term Debt	1,000.0	0.0	0.0
2023 Senior Notes [Member]
Cash flows from financing activities:
Repayments of Long-term Debt	(517.5)	0.0	0.0
Rail Term Loan [Member]
Cash flows from financing activities:
Repayments of Long-term Debt	$ (7.2)	$ (7.0)	$ (6.8)