CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Activities
Net income (loss)	$ 1,296.7	$ (969.9)	$ (11.3)
Adjustments to reconcile net income (loss) to net cash and cash equivalents provided by (used for) operating activities:
Goodwill impairment	0.0	699.8	0.0
Gain on disposition of non-consolidated affiliate	0.0	0.0	(11.2)
Gains on disposition of property, plant and equipment	(1.4)	0.0	0.0
Stock-based compensation	8.3	13.6	10.7
Loss on Extinguishment of Debt	152.2	20.4	0.0
Depreciation and amortization	582.5	568.4	597.4
Deferred income taxes	(42.7)	(18.4)	(45.5)
Write-off of equipment and facility included in restructuring charges	0.0	0.0	58.9
Qualified pension plan contributions	(1.1)	(2.1)	(14.9)
Qualified pension plan income	27.8	11.4	9.3
Change in assets and liabilities:
Receivables	(360.0)	(0.3)	12.3
Income taxes receivable/payable	105.1	(11.2)	(10.7)
Inventories	(206.0)	28.6	13.0
Other current assets	(22.3)	(24.8)	7.4
Accounts payable and accrued liabilities	240.1	149.3	(11.0)
Other assets	(13.3)	(20.2)	(1.3)
Other noncurrent liabilities	26.2	8.6	30.5
Other operating activities	4.5	2.6	2.3
Net operating activities	1,741.0	433.0	617.3
Investing Activities
Capital expenditures	(200.6)	(298.9)	(385.6)
Payments under ethylene long-term supply contracts	0.0	461.0	0.0
Payments under other long-term supply contracts	0.0	(75.8)	0.0
Proceeds from disposition of property, plant and equipment	3.2	0.0	0.0
Proceeds from disposition of non-consolidated affiliate	0.0	0.0	20.0
Net investing activities	(197.4)	(835.7)	(365.6)
Long-term debt:
Borrowings	540.0	1,827.5	825.0
Repayments	1,643.1	1,307.2	744.2
Debt early redemption premiums	(137.7)	(14.6)	0.0
Common stock repurchased and retired	(251.9)	0.0	(145.9)
Stock options exercised	72.4	1.9	1.7
Dividends paid	(127.8)	(126.3)	(129.3)
Debt issuance costs	(3.9)	(10.3)	(16.6)
Net financing activities	(1,552.0)	371.0	(209.3)
Effect of exchange rate changes on cash and cash equivalents	(0.8)	0.5	(0.3)
Net (decrease) increase in cash and cash equivalents	(9.2)	(31.2)	42.1
Cash and cash equivalents, beginning of year	189.7	220.9	178.8
Cash and cash equivalents, end of year	180.5	189.7	220.9
Cash paid (received) for interest and income taxes:
Interest, net	345.2	286.4	198.3
Income taxes, net of refunds	$ 169.6	$ (9.6)	$ 36.3