Unrestricted Subsidiaries - Schedule of Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Schedule of Equity Method Investments
Cash and cash equivalents	$ 13.7	$ 50.5	$ 13.7	$ 50.5		$ 35.2
Accounts receivable	347.8		347.8			268.0
Inventory	447.7		447.7			498.0
Prepaid expenses and other current assets	49.0		49.0			19.2
Property, plant and equipment, net	1,526.9	1,329.4	1,526.9	1,329.4		1,482.0
Other noncurrent assets, net	414.5		414.5			439.4
Accounts payable	342.1		342.1			442.4
Accrued interest payable	41.2		41.2			34.6
Obligations under inventory financing agreements	237.9		237.9			221.8
Other current liabilities	85.2		85.2			114.5
Current portion of long-term debt	204.6		204.6			20.0
Other long-term liabilities	57.5		57.5			60.2
Long-term debt, less current portion	1,608.2		1,608.2			1,539.7
Redeemable noncontrolling interest	250.0		250.0			250.0
Total partners' capital (deficit)	(447.6)	(465.4)	(447.6)	(465.4)	$ (547.8)	(537.7)	$ (477.6)	$ (385.1)
Other operating expense	4.1	(2.5)	(4.1)	(16.8)
Interest expense	(58.7)	(41.8)	(163.7)	(136.0)
Debt extinguishment costs	(0.3)	(40.4)	(5.5)	(41.4)
Unrealized gain (loss) on derivative instruments	(36.3)	28.1	18.8	(47.5)
Net loss attributable to noncontrolling interest	(3.1)	(1.1)	(18.5)	(1.1)
Eliminations
Schedule of Equity Method Investments
Cash and cash equivalents	0.0		0.0			0.0
Accounts receivable	0.0		0.0			0.0
Inventory	0.0		0.0			0.0
Prepaid expenses and other current assets	0.0		0.0			0.0
Property, plant and equipment, net	0.0		0.0			0.0
Other noncurrent assets, net	0.0		0.0			0.0
Accounts payable	(249.2)		(249.2)			(130.8)
Accrued interest payable	0.0		0.0
Obligations under inventory financing agreements	0.0		0.0			0.0
Other current liabilities	0.0		0.0			0.0
Current portion of long-term debt	0.0		0.0			0.0
Other long-term liabilities	0.0		0.0			0.0
Long-term debt, less current portion	(100.0)		(100.0)			0.0
Redeemable noncontrolling interest	0.0		0.0			0.0
Total partners' capital (deficit)	(18.8)		(18.8)			(18.8)
Parent Company and Restricted Subsidiaries
Schedule of Equity Method Investments
Cash and cash equivalents	6.1		6.1			9.4
Accounts receivable	307.4		307.4			259.8
Inventory	345.0		345.0			370.1
Prepaid expenses and other current assets	20.7		20.7			13.2
Property, plant and equipment, net	737.9		737.9			760.7
Other noncurrent assets, net	397.0		397.0			428.8
Accounts payable	307.4		307.4			307.6
Accrued interest payable	40.2		40.2
Obligations under inventory financing agreements	166.1		166.1			158.2
Other current liabilities	73.0		73.0			100.8
Current portion of long-term debt	187.8		187.8			8.2
Other long-term liabilities	53.7		53.7			59.0
Long-term debt, less current portion	1,167.0		1,167.0			1,183.3
Redeemable noncontrolling interest	0.0		0.0			0.0
Total partners' capital (deficit)	(233.6)		(233.6)			(456.4)
Unrestricted Subsidiaries
Schedule of Equity Method Investments
Cash and cash equivalents	7.6		7.6			25.8
Accounts receivable	40.4		40.4			8.2
Inventory	102.7		102.7			127.9
Prepaid expenses and other current assets	28.3		28.3			6.0
Property, plant and equipment, net	789.0		789.0			721.3
Other noncurrent assets, net	17.5		17.5			10.6
Accounts payable	283.9		283.9			265.6
Accrued interest payable	1.0		1.0
Obligations under inventory financing agreements	71.8		71.8			63.6
Other current liabilities	12.2		12.2			13.7
Current portion of long-term debt	16.8		16.8			11.8
Other long-term liabilities	3.8		3.8			1.2
Long-term debt, less current portion	541.2		541.2			356.4
Redeemable noncontrolling interest	250.0		250.0			250.0
Total partners' capital (deficit)	(195.2)		(195.2)			$ (62.5)
Revenues	184.6	20.3	431.4	63.5
Operating costs	164.1	4.6	452.3	18.5
Other operating expense			4.0
Depreciation expense	11.7	3.8	30.7	11.3
Selling, general and administrative expense	5.8		15.1
Interest expense	(22.6)	(7.1)	(59.5)	(29.4)
Debt extinguishment costs		$ (38.3)		$ (38.3)
Other Income	0.6		0.7
Unrealized gain (loss) on derivative instruments	(4.5)		(3.2)
Net loss attributable to noncontrolling interest	$ (3.1)		$ (18.5)