Financial Statements for Guarantors of the Senior Notes - Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Assets:
Cash and cash equivalents	$ 213.2	$ 166.2
Receivables, net of allowance	297.8	260.1
Income tax receivable	389.1	14.7
Inventory	442.0	433.4
Property, plant, and equipment, net	7,118.7	7,110.6
Investments in and advances to subsidiaries	0.0	0.0
Restricted cash	96.3	111.4
Goodwill and other assets	445.8	605.0
Assets	9,002.9	8,701.4
Liabilities:
Accounts payable	208.5	203.9
Accrued liabilities	348.5	342.1
Debt	4,870.2	4,881.9
Deferred Income Taxes and Other Tax Liabilities, Noncurrent	1,016.1	798.3
Advances from subsidiaries	0.0	0.0
Other liabilities	93.5	96.3
Total stockholders' equity	2,466.1	2,378.9	$ 2,565.1	$ 2,562.0
Total liabilities and stockholders' equity	9,002.9	8,701.4
Reportable legal entities | Parent
Assets:
Cash and cash equivalents	199.7	155.1
Receivables, net of allowance	0.7	1.3
Income tax receivable	389.0	14.6
Inventory	0.0	0.0
Property, plant, and equipment, net	31.3	37.8
Investments in and advances to subsidiaries	4,611.6	4,600.0
Restricted cash	0.0	0.0
Goodwill and other assets	148.6	190.9
Assets	5,380.9	4,999.7
Liabilities:
Accounts payable	13.3	5.3
Accrued liabilities	160.5	166.7
Debt	527.9	522.8
Deferred Income Taxes and Other Tax Liabilities, Noncurrent	126.7	0.0
Advances from subsidiaries	2,033.5	1,871.8
Other liabilities	52.9	54.2
Total stockholders' equity	2,466.1	2,378.9
Total liabilities and stockholders' equity	5,380.9	4,999.7
Reportable legal entities | Combined Guarantor Subsidiaries
Assets:
Cash and cash equivalents	5.6	0.1
Receivables, net of allowance	211.2	185.7
Income tax receivable	0.0	0.0
Inventory	405.2	398.8
Property, plant, and equipment, net	1,459.4	1,320.7
Investments in and advances to subsidiaries	3,202.2	3,136.2
Restricted cash	0.0	0.0
Goodwill and other assets	230.2	394.4
Assets	5,513.8	5,435.9
Liabilities:
Accounts payable	116.7	109.1
Accrued liabilities	29.6	23.2
Debt	0.0	0.0
Deferred Income Taxes and Other Tax Liabilities, Noncurrent	898.0	844.6
Advances from subsidiaries	0.0	0.0
Other liabilities	39.6	40.9
Total stockholders' equity	4,429.9	4,418.1
Total liabilities and stockholders' equity	5,513.8	5,435.9
Reportable legal entities | Combined Non-Guarantor Subsidiaries
Assets:
Cash and cash equivalents	27.3	36.3
Receivables, net of allowance	85.9	74.0
Income tax receivable	0.1	0.1
Inventory	36.8	34.7
Property, plant, and equipment, net	6,433.2	6,595.8
Investments in and advances to subsidiaries	318.3	347.0
Restricted cash	76.9	86.1
Goodwill and other assets	68.3	58.6
Assets	7,046.8	7,232.6
Liabilities:
Accounts payable	78.6	90.6
Accrued liabilities	159.6	152.9
Debt	4,342.3	4,359.1
Deferred Income Taxes and Other Tax Liabilities, Noncurrent	(8.7)	(8.2)
Advances from subsidiaries	0.0	0.0
Other liabilities	1.0	1.2
Total stockholders' equity	2,474.0	2,637.0
Total liabilities and stockholders' equity	7,046.8	7,232.6
Eliminations
Assets:
Cash and cash equivalents	(19.4)	(25.3)
Receivables, net of allowance	0.0	(0.9)
Income tax receivable	0.0	0.0
Inventory	0.0	(0.1)
Property, plant, and equipment, net	(805.2)	(843.7)
Investments in and advances to subsidiaries	(8,132.1)	(8,083.2)
Restricted cash	19.4	25.3
Goodwill and other assets	(1.3)	(38.9)
Assets	(8,938.6)	(8,966.8)
Liabilities:
Accounts payable	(0.1)	(1.1)
Accrued liabilities	(1.2)	(0.7)
Debt	0.0	0.0
Deferred Income Taxes and Other Tax Liabilities, Noncurrent	0.1	(38.1)
Advances from subsidiaries	(2,033.5)	(1,871.8)
Other liabilities	0.0	0.0
Total stockholders' equity	(6,903.9)	(7,055.1)
Total liabilities and stockholders' equity	$ (8,938.6)	$ (8,966.8)