Consolidated Statements of Operations - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Sales		$ 3,452.6	$ 3,497.5	$ 3,763.8
Cost of sales		3,000.9	3,060.8	3,265.6
Gross profit		451.7	436.7	498.2
Operating costs and expenses:
Selling		53.1	58.2	65.7
General and administrative		136.7	122.5	138.7
Transportation		122.9	137.2	137.1
Taxes other than income taxes		20.5	18.1	24.1
Loss on impairment and disposal of assets		37.0	0.0	207.3
Gain (Loss) on sale of business, net		(8.7)	4.8	236.0
Other operating (income)		(3.5)	(17.4)
Other operating expense				3.3
Operating income		76.3	122.9	158.0
Other income (expense):
Interest expense		(134.6)	(155.5)	(183.1)
Debt extinguishment costs		(2.2)	(58.8)	0.0
Gain (loss) on derivative instruments		9.0	33.8	(9.6)
Gain (loss) from unconsolidated affiliates		(3.8)	3.7	0.0
Gain on sale of unconsolidated affiliates		1.2	0.2	0.0
Other		3.4	10.8	3.3
Total other expense		(119.4)	(173.2)	(189.4)
Net loss from continuing operations before income taxes		(43.1)	(50.3)	(31.4)
Income tax expense (benefit) from continuing operations		0.5	0.7	(0.1)
Net loss from continuing operations		(43.6)	(51.0)	(31.3)
Net loss from discontinued operations		0.0	(4.1)	(72.5)
Allocation of net loss:
Net loss		(43.6)	(55.1)	(103.8)
Less:
General partners’ interest in net loss		(0.9)	(1.1)	(2.1)
Net loss available to limited partners		$ (42.7)	$ (54.0)	$ (101.7)
Weighted average limited partner units outstanding:
Weighted Average Number of Shares Outstanding, Basic and Diluted	[1]	78,212,136	77,943,992	77,598,950
Limited partners' interest basic net loss per unit from continuing operations		$ (0.55)	$ (0.64)	$ (0.40)
Limited partners' interest basic net loss per unit from discontinued operations		0.00	(0.05)	(0.91)
Limited partners’ interest basic net income (loss) per unit		(0.55)	(0.69)	(1.31)
Limited partners' interest diluted net loss per unit from continuing operations		(0.55)	(0.64)	(0.40)
Limited partners' interest diluted net loss per unit from discontinued operations		0.00	(0.05)	(0.91)
Limited partners' interest diluted net income (loss) per unit		$ (0.55)	$ (0.69)	$ (1.31)

[1] Total diluted weighted average limited partner units outstanding includes 0.1 million of potentially dilutive phantom units which would have been anti-dilutive for the year ended December 31, 2019 and 0.2 million potentially dilutive phantom units which would be anti-dilutive in the years ended December 31, 2018 and 2017.