Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial [Line Items]
Sales	$ 774.8	$ 929.6	$ 896.9	$ 851.3	$ 848.0	$ 953.5	$ 945.5	$ 750.5	$ 3,452.6	$ 3,497.5	$ 3,763.8
Gross Profit	90.8	117.8	107.1	136.0	95.8	104.3	123.4	113.2	451.7	436.7	498.2
Net income (loss) from continuing operations	(38.6)	(4.6)	(16.8)	16.4	19.1	(16.0)	(51.2)	(2.9)	(43.6)	(51.0)	(31.3)
Net loss from discontinued operations					(1.0)	(0.5)	(0.7)	(1.9)	0.0	(4.1)	(72.5)
Net income (loss)	(38.6)	(4.6)	(16.8)	16.4	18.1	(16.5)	(51.9)	(4.8)	(43.6)	(55.1)	(103.8)
Net income (loss) available to limited partners	$ (37.8)	$ (4.5)	$ (16.5)	$ 16.0	$ 17.7	$ (16.1)	$ (50.9)	$ (4.7)	$ (42.7)	$ (54.0)	$ (101.7)
Limited partners' interest basic net income (loss) per unit from continuing operations	$ (0.48)	$ (0.06)	$ (0.21)	$ 0.20	$ 0.24	$ (0.20)	$ (0.64)	$ (0.04)	$ (0.55)	$ (0.64)	$ (0.40)
Limited partners' interest basic net loss per unit from discontinued operations					(0.01)	(0.01)	(0.01)	(0.02)	0.00	(0.05)	(0.91)
Limited partners’ interest basic net income (loss) per unit	(0.48)	(0.06)	(0.21)	0.20	0.23	(0.21)	(0.65)	(0.06)	(0.55)	(0.69)	(1.31)
Limited partners' interest diluted net income (loss) per unit from continuing operations	(0.48)	(0.06)	(0.21)	0.20	0.24	(0.20)	(0.64)	(0.04)	(0.55)	(0.64)	(0.40)
Limited partners' interest diluted net loss per unit from discontinued operations	0.00	0.00	0.00	0.00	(0.01)	(0.01)	(0.01)	(0.02)	0.00	(0.05)	(0.91)
Limited partners' interest diluted net income (loss) per unit	$ (0.48)	$ (0.06)	$ (0.21)	$ 0.20	$ 0.23	$ (0.21)	$ (0.65)	$ (0.06)	$ (0.55)	$ (0.69)	$ (1.31)
Weighted average limited partner units outstanding — basic	78,332,671	78,299,472	78,212,837	78,111,551	78,086,357	77,783,879	77,730,458	78,045,360
Weighted average limited partner units outstanding — diluted	78,332,671	78,299,472	78,212,837	78,175,007	78,218,831	77,783,879	77,730,458	78,045,360