Guarantor Consolidating Financial Statements - Condensed Consolidating Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Aug. 01, 2019	Dec. 31, 2018	Dec. 31, 2017
Current Assets:
Cash and Cash Equivalents	$ 148.7		$ 70.5
Receivables, Net	500.2		570.3
Inventories, Net	1,095.9		1,014.4
Intercompany	0.0		0.0
Other Current Assets	50.1		102.1
Total Current Assets	1,794.9		1,757.3
Property, Plant, and Equipment, Net	3,253.8
Property, Plant and Equipment, Net			3,239.7
Investment in Consolidated Subsidiaries	0.0		0.0
Goodwill	1,477.0	$ 7.5	1,459.7	$ 1,323.0
Other Assets	751.0		592.1
Total Assets	7,276.7		7,048.8	4,821.3
Current Liabilities:
Short-Term Debt and Current Portion of Long-Term Debt	50.4		52.0
Accounts Payable	716.1		711.6
Intercompany	0.0		0.0
Interest Payable, Current	24.7		13.6
Other Accrued Liabilities	410.0		383.9
Total Current Liabilities	1,176.5		1,147.5
Long-Term Debt	2,809.9		2,905.1
Deferred Income Tax Liabilities	27.7		26.5
Other Noncurrent Liabilities	406.0		224.4
MEMBER'S INTEREST
Total Member's Interest	2,856.6		2,745.3	$ 1,569.3
Total Liabilities and Member's Interest	7,276.7		7,048.8
Reportable Legal Entities | Issuer
Current Assets:
Cash and Cash Equivalents	59.4		14.5
Receivables, Net	154.0		211.5
Inventories, Net	843.6		791.9
Intercompany	781.4		652.7
Other Current Assets	29.7		87.1
Total Current Assets	1,868.1		1,757.7
Property, Plant, and Equipment, Net	2,925.4
Property, Plant and Equipment, Net			2,925.4
Investment in Consolidated Subsidiaries	203.1		204.9
Goodwill	1,299.8		1,294.2
Other Assets	536.9		451.2
Total Assets	6,833.3		6,633.4
Current Liabilities:
Short-Term Debt and Current Portion of Long-Term Debt	40.6		39.8
Accounts Payable	571.4		571.9
Intercompany	0.0		0.0
Other Accrued Liabilities	315.0		311.0
Total Current Liabilities	927.0		922.7
Long-Term Debt	2,751.3		2,807.5
Deferred Income Tax Liabilities	4.8		4.0
Other Noncurrent Liabilities	293.6		153.9
MEMBER'S INTEREST
Total Member's Interest	2,856.6		2,745.3
Total Liabilities and Member's Interest	6,833.3		6,633.4
Reportable Legal Entities | Combined Guarantor Subsidiaries
Current Assets:
Cash and Cash Equivalents	0.0		0.0
Receivables, Net	0.0		0.0
Inventories, Net	0.0		0.0
Intercompany	203.0		204.8
Other Current Assets	0.0		0.0
Total Current Assets	203.0		204.8
Property, Plant, and Equipment, Net	0.1
Property, Plant and Equipment, Net			0.1
Investment in Consolidated Subsidiaries	15.5		12.6
Goodwill	0.0		0.0
Other Assets	0.0		0.0
Total Assets	218.6		217.5
Current Liabilities:
Short-Term Debt and Current Portion of Long-Term Debt	0.0		0.0
Accounts Payable	0.0		0.0
Intercompany	0.0		0.0
Other Accrued Liabilities	0.0		0.0
Total Current Liabilities	0.0		0.0
Long-Term Debt	0.0		0.0
Deferred Income Tax Liabilities	0.0		0.0
Other Noncurrent Liabilities	0.0		0.0
MEMBER'S INTEREST
Total Member's Interest	218.6		217.5
Total Liabilities and Member's Interest	218.6		217.5
Reportable Legal Entities | Combined Nonguarantor Subsidiaries
Current Assets:
Cash and Cash Equivalents	89.3		56.0
Receivables, Net	346.2		358.8
Inventories, Net	252.3		222.5
Intercompany	0.0		0.0
Other Current Assets	20.4		15.0
Total Current Assets	708.2		652.3
Property, Plant, and Equipment, Net	328.3
Property, Plant and Equipment, Net			314.2
Investment in Consolidated Subsidiaries	0.0		0.0
Goodwill	177.2		165.5
Other Assets	214.1		140.9
Total Assets	1,427.8		1,272.9
Current Liabilities:
Short-Term Debt and Current Portion of Long-Term Debt	9.8		12.2
Accounts Payable	144.7		139.7
Intercompany	1,137.4		1,081.5
Other Accrued Liabilities	95.0		72.9
Total Current Liabilities	1,386.9		1,306.3
Long-Term Debt	58.6		97.6
Deferred Income Tax Liabilities	22.9		22.5
Other Noncurrent Liabilities	112.4		70.5
MEMBER'S INTEREST
Total Member's Interest	(153.0)		(224.0)
Total Liabilities and Member's Interest	1,427.8		1,272.9
Consolidating Eliminations
Current Assets:
Cash and Cash Equivalents	0.0		0.0
Receivables, Net	0.0		0.0
Inventories, Net	0.0		0.0
Intercompany	(984.4)		(857.5)
Other Current Assets	0.0		0.0
Total Current Assets	(984.4)		(857.5)
Property, Plant, and Equipment, Net	0.0
Property, Plant and Equipment, Net			0.0
Investment in Consolidated Subsidiaries	(218.6)		(217.5)
Goodwill	0.0		0.0
Other Assets	0.0		0.0
Total Assets	(1,203.0)		(1,075.0)
Current Liabilities:
Short-Term Debt and Current Portion of Long-Term Debt	0.0		0.0
Accounts Payable	0.0		0.0
Intercompany	(1,137.4)		(1,081.5)
Other Accrued Liabilities	0.0		0.0
Total Current Liabilities	(1,137.4)		(1,081.5)
Long-Term Debt	0.0		0.0
Deferred Income Tax Liabilities	0.0		0.0
Other Noncurrent Liabilities	0.0		0.0
MEMBER'S INTEREST
Total Member's Interest	(65.6)		6.5
Total Liabilities and Member's Interest	$ (1,203.0)		$ (1,075.0)