Financial Statements for Guarantors of the Senior Notes - Balance Sheet (Details) - USD ($) $ in Millions	Jun. 30, 2018		Dec. 31, 2017
Assets:
Cash and cash equivalents	$ 612.7	[1]	$ 778.6
Short-term marketable securities	25.0	[1]	319.5
Receivables, net of allowance	356.1	[1]	369.7
Income tax receivable	34.6	[1]	29.0
Inventory	586.4	[1]	640.6
Property, plant, and equipment, net	6,488.2	[1]	6,134.7
Investments in and advances to subsidiaries	0.0		0.0
Restricted cash	142.2	[1]	195.2
Goodwill and other assets	1,109.5		1,075.9
Total assets	9,354.7	[1]	9,543.2
Liabilities:
Accounts payable	205.3	[1]	175.4
Accrued liabilities	435.0	[1]	440.0
Debt	3,227.3	[1]	3,242.4
Deferred income	19.1	[1]	20.5
Deferred income taxes	734.0	[1]	743.2
Advances from subsidiaries	0.0		0.0
Other liabilities	66.2	[1]	63.7
Total stockholders' equity	4,667.8	[1]	4,858.0
Total liabilities and stockholders' equity	9,354.7	[1]	9,543.2
Reportable legal entities | Parent
Assets:
Cash and cash equivalents	590.8		763.9
Short-term marketable securities	25.0		319.5
Receivables, net of allowance	0.0		1.1
Income tax receivable	29.7		24.0
Inventory	0.0		0.0
Property, plant, and equipment, net	45.7		47.6
Investments in and advances to subsidiaries	5,719.3		5,515.2
Restricted cash	0.0		0.0
Goodwill and other assets	180.4		159.2
Total assets	6,590.9		6,830.5
Liabilities:
Accounts payable	10.5		7.5
Accrued liabilities	247.9		236.5
Debt	397.2		838.1
Deferred income	0.0		0.0
Deferred income taxes	0.0		53.8
Advances from subsidiaries	1,203.5		775.2
Other liabilities	64.0		61.4
Total stockholders' equity	4,667.8		4,858.0
Total liabilities and stockholders' equity	6,590.9		6,830.5
Reportable legal entities | Combined Guarantor Subsidiaries
Assets:
Cash and cash equivalents	2.7		1.6
Short-term marketable securities	0.0		0.0
Receivables, net of allowance	159.0		204.2
Income tax receivable	0.0		0.0
Inventory	339.7		413.6
Property, plant, and equipment, net	2,063.3		2,310.7
Investments in and advances to subsidiaries	3,443.9		3,049.7
Restricted cash	0.0		0.0
Goodwill and other assets	592.8		590.9
Total assets	6,601.4		6,570.7
Liabilities:
Accounts payable	68.7		65.9
Accrued liabilities	55.1		59.1
Debt	26.8		28.3
Deferred income	17.8		19.1
Deferred income taxes	724.4		683.2
Advances from subsidiaries	0.0		0.0
Other liabilities	0.7		0.7
Total stockholders' equity	5,707.9		5,714.4
Total liabilities and stockholders' equity	6,601.4		6,570.7
Reportable legal entities | Combined Non-Guarantor Subsidiaries
Assets:
Cash and cash equivalents	50.7		65.3
Short-term marketable securities	0.0		0.0
Receivables, net of allowance	197.6		164.4
Income tax receivable	4.9		5.0
Inventory	255.1		236.8
Property, plant, and equipment, net	4,898.9		4,293.0
Investments in and advances to subsidiaries	352.1		255.5
Restricted cash	110.7		143.0
Goodwill and other assets	342.7		326.3
Total assets	6,212.7		5,489.3
Liabilities:
Accounts payable	126.7		102.2
Accrued liabilities	132.0		144.9
Debt	2,803.3		2,376.0
Deferred income	1.3		1.4
Deferred income taxes	28.7		5.9
Advances from subsidiaries	0.0		0.0
Other liabilities	1.5		1.6
Total stockholders' equity	3,119.2		2,857.3
Total liabilities and stockholders' equity	6,212.7		5,489.3
Eliminations
Assets:
Cash and cash equivalents	(31.5)		(52.2)
Short-term marketable securities	0.0		0.0
Receivables, net of allowance	(0.5)		0.0
Income tax receivable	0.0		0.0
Inventory	(8.4)		(9.8)
Property, plant, and equipment, net	(519.7)		(516.6)
Investments in and advances to subsidiaries	(9,515.3)		(8,820.4)
Restricted cash	31.5		52.2
Goodwill and other assets	(6.4)		(0.5)
Total assets	(10,050.3)		(9,347.3)
Liabilities:
Accounts payable	(0.6)		(0.2)
Accrued liabilities	0.0		(0.5)
Debt	0.0		0.0
Deferred income	0.0		0.0
Deferred income taxes	(19.1)		0.3
Advances from subsidiaries	(1,203.5)		(775.2)
Other liabilities	0.0		0.0
Total stockholders' equity	(8,827.1)		(8,571.7)
Total liabilities and stockholders' equity	$ (10,050.3)		$ (9,347.3)

[1] (unaudited)