Trinseo (TSE) 10-Q 4 Nov 22 2022 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Oct. 28, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2022
Document Transition Report	false
Entity File Number	001-36473
Entity Registrant Name	Trinseo PLC
Entity Incorporation, State or Country Code	L2
Entity Tax Identification Number	00-0000000
Entity Address, Address Line One	440 East Swedesford Road
Entity Address, Address Line Two	Suite 301
Entity Address, Address Line Three	Wayne
Entity Address, City or Town	Wayne, PA 19087
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19087
City Area Code	610
Local Phone Number	240-3200
Title of 12(b) Security	Ordinary Shares, par value $0.01 per share
Trading Symbol	TSE
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		34,973,747
Entity Central Index Key	0001519061
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 242.8	$ 573
Accounts receivable, net of allowance for doubtful accounts (September 30, 2022: $6.0; December 31, 2021: $4.1)	673.7	740.2
Inventories	614	621
Other current assets	40.5	44.3
Total current assets	1,571	1,978.5
Investments in unconsolidated affiliates	269.2	247.8
Property, plant and equipment, net of accumulated depreciation (September 30, 2022: $579.3; December 31, 2021: $556.5)	638.3	719
Other assets
Goodwill	691.9	710.1
Other intangible assets, net	764.7	823.8
Right-of-use assets - operating, net	74.8	85.3
Deferred income tax assets	62.6	77.6
Deferred charges and other assets	59.4	70.1
Total other assets	1,653.4	1,766.9
Total assets	4,131.9	4,712.2
Current liabilities
Short-term borrowings and current portion of long-term debt	16.7	18.5
Accounts payable	442.2	590.3
Current lease liabilities - operating	17.9	18.4
Income taxes payable	25.4	52.1
Accrued expenses and other current liabilities	215.4	235.1
Total current liabilities	717.6	914.4
Noncurrent liabilities
Long-term debt, net of unamortized deferred financing fees	2,297.8	2,305.6
Noncurrent lease liabilities - operating	59.3	69.2
Deferred income tax liabilities	91.5	103.2
Other noncurrent obligations	267.6	306.7
Total noncurrent liabilities	2,716.2	2,784.7
Commitments and contingencies (Note 13)
Shareholders' equity
Ordinary shares, $0.01 nominal value, 4,000.0 shares authorized (September 30, 2022: 39.2 shares issued and 35.1 shares outstanding; December 31, 2021: 38.9 shares issued and 37.9 shares outstanding)	0.4	0.4
Preferred shares, €0.01 nominal value, 1,000.0 shares authorized (no shares issued or outstanding)
Additional paid-in-capital	483.7	468.1
Treasury shares, at cost (September 30, 2022: 4.1 shares; December 31, 2021: 1.0 shares)	(200)	(50)
Retained earnings	641	741.8
Accumulated other comprehensive loss	(227)	(147.2)
Total shareholders' equity	698.1	1,013.1
Total liabilities and shareholders' equity	$ 4,131.9	$ 4,712.2

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) shares in Thousands, $ in Millions	Sep. 30, 2022 USD ($) $ / shares shares	Sep. 30, 2022 € / shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2021 € / shares
Allowance for doubtful accounts | $	$ 6		$ 4.1
Accumulated depreciation | $	$ 579.3		$ 556.5
Ordinary shares, nominal value | $ / shares	$ 0.01		$ 0.01
Ordinary shares, shares authorized	4,000,000		4,000,000
Ordinary shares, shares issued	39,200		38,900
Ordinary shares, shares outstanding	35,100		37,900
Treasury stock, shares	4,100		1,000
Preferred stock, par value | € / shares		€ 0.01		€ 0.01
Preferred stock, shares authorized	1,000,000		1,000,000
Preferred stock, shares issued	0		0
Preferred stock, shares outstanding	0		0
Deferred Ordinary Shares
Ordinary shares, nominal value | € / shares		€ 1		€ 1
Ordinary shares, shares authorized	25		25
Ordinary shares, shares issued	25		25
Ordinary shares, shares outstanding	25		25

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Condensed Consolidated Statements of Operations
Net sales	$ 1,178.1	$ 1,269.3	$ 3,990.3	$ 3,529
Cost of sales	1,217.6	1,101	3,714.8	2,951.7
Gross profit (loss)	(39.5)	168.3	275.5	577.3
Selling, general and administrative expenses	80.5	76.4	262.8	230.4
Equity in earnings of unconsolidated affiliates	22.8	17.1	83.8	70.2
Other charges	1.9	1.2	39.5	3
Operating income (loss)	(99.1)	107.8	57	414.1
Interest expense, net	30.4	23	77.7	56.6
Acquisition purchase price hedge loss				22
Other expense (income), net	0.5	(0.1)	1.6	8.4
Income (loss) from continuing operations before income taxes	(130)	84.9	(22.3)	327.1
Provision for (benefit from) income taxes	(12.1)	5.5	41.4	48.9
Net income (loss) from continuing operations	(117.9)	79.4	(63.7)	278.2
Net income (loss) from discontinued operations, net of income taxes	(1.9)	13.7	(1.9)	38
Net income (loss)	$ (119.8)	$ 93.1	$ (65.6)	$ 316.2
Earnings Per Share
Weighted average shares- basic	35.2	38.8	36.3	38.7
Net income (loss) per share- basic: continuing operations	$ (3.35)	$ 2.04	$ (1.76)	$ 7.19
Net income (loss) per share- basic: discontinued operations	(0.06)	0.35	(0.05)	0.98
Net income (loss) per share- basic	$ (3.41)	$ 2.39	$ (1.81)	$ 8.17
Weighted average shares- diluted	35.2	39.5	36.3	39.6
Net income (loss) per share- diluted: continuing operations	$ (3.35)	$ 2.01	$ (1.76)	$ 7.03
Net income (loss) per share- diluted: discontinued operations	(0.06)	0.35	(0.05)	0.96
Net income (loss) per share- diluted	$ (3.41)	$ 2.36	$ (1.81)	$ 7.99

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Condensed Consolidated Statements of Comprehensive Income (Loss)
Net income (loss)	$ (119.8)	$ 93.1	$ (65.6)	$ 316.2
Other comprehensive income (loss), net of tax:
Cumulative translation adjustments (net of tax of $0.0, $0.0, $3.9, $0.0)	(45)	(1.7)	(84.1)	(2)
Net gain (loss) on cash flow hedges (net of tax of $0.0, $0.0, $0.6, $0.0)	(5.6)	1.2	(3.8)	5.6
Pension and other postretirement benefit plans:
Net gain arising during period (net of tax of $0.8, $1.0, $1.6, $1.0)	2.4	9.3	10	9.3
Amounts reclassified from accumulated other comprehensive income	(0.9)	(1.2)	(1.9)	0.9
Total other comprehensive income (loss), net of tax	(49.1)	7.6	(79.8)	13.8
Comprehensive income (loss)	$ (168.9)	$ 100.7	$ (145.4)	$ 330

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Condensed Consolidated Statements of Comprehensive Income (Loss)
Cumulative translation adjustments, tax	$ 0	$ 0	$ 3.9	$ 0
Net gain (loss) on cash flow hedges, tax	0	0	0.6	0
Net gain (loss) during period, tax expense	$ 0.8	$ 1	$ 1.6	$ 1

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Ordinary Shares	Additional Paid-In Capital	Treasury Shares	Total	Retained Earnings	Total
Balance at beginning of period at Dec. 31, 2020	$ 0.5	$ 579.6	$ (542.9)	$ (186.1)	$ 739.2	$ 590.3
Balance at beginning of period, shares at Dec. 31, 2020	38.4
Balance at beginning of period, Treasury shares at Dec. 31, 2020			10.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)					71.5	71.5
Other comprehensive income				6.1		6.1
Share-based compensation activity		(1.1)	$ 12.9			11.8
Share-based compensation activity, shares	0.3		(0.3)
Dividends on ordinary shares					(3.4)	(3.4)
Balance at end of period at Mar. 31, 2021	$ 0.5	578.5	$ (530)	(180)	807.3	676.3
Balance at end of period, shares at Mar. 31, 2021	38.7
Balance at end of period, Treasury shares at Mar. 31, 2021			10.1
Balance at beginning of period at Dec. 31, 2020	$ 0.5	579.6	$ (542.9)	(186.1)	739.2	590.3
Balance at beginning of period, shares at Dec. 31, 2020	38.4
Balance at beginning of period, Treasury shares at Dec. 31, 2020			10.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)						316.2
Other comprehensive income						13.8
Balance at end of period at Sep. 30, 2021	$ 0.5	582.2	$ (524.8)	(172.3)	1,036.4	922
Balance at end of period, shares at Sep. 30, 2021	38.8
Balance at end of period, Treasury shares at Sep. 30, 2021			10
Balance at beginning of period at Mar. 31, 2021	$ 0.5	578.5	$ (530)	(180)	807.3	676.3
Balance at beginning of period, shares at Mar. 31, 2021	38.7
Balance at beginning of period, Treasury shares at Mar. 31, 2021			10.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)					151.6	151.6
Other comprehensive income				0.1		0.1
Share-based compensation activity		0.2	$ 4.7			4.9
Share-based compensation activity, shares	0.1		(0.1)
Dividends on ordinary shares					(3.1)	(3.1)
Balance at end of period at Jun. 30, 2021	$ 0.5	578.7	$ (525.3)	(179.9)	955.8	829.8
Balance at end of period, shares at Jun. 30, 2021	38.8
Balance at end of period, Treasury shares at Jun. 30, 2021			10
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)					93.1	93.1
Other comprehensive income				7.6		7.6
Share-based compensation activity		3.5	$ 0.5			4
Dividends on ordinary shares					(12.5)	(12.5)
Balance at end of period at Sep. 30, 2021	$ 0.5	582.2	$ (524.8)	(172.3)	1,036.4	922
Balance at end of period, shares at Sep. 30, 2021	38.8
Balance at end of period, Treasury shares at Sep. 30, 2021			10
Balance at beginning of period at Dec. 31, 2021	$ 0.4	468.1	$ (50)	(147.2)	741.8	$ 1,013.1
Balance at beginning of period, shares at Dec. 31, 2021	37.9					37.9
Balance at beginning of period, Treasury shares at Dec. 31, 2021			1			1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)					16.7	$ 16.7
Other comprehensive income				(2.5)		(2.5)
Share-based compensation activity		7.6				7.6
Share-based compensation activity, shares	0.2
Purchase of treasury shares			$ (50)			(50)
Purchase of treasury shares, shares	(0.9)		0.9
Dividends on ordinary shares					(12.1)	(12.1)
Balance at end of period at Mar. 31, 2022	$ 0.4	475.7	$ (100)	(149.7)	746.4	972.8
Balance at end of period, shares at Mar. 31, 2022	37.2
Balance at end of period, Treasury shares at Mar. 31, 2022			1.9
Balance at beginning of period at Dec. 31, 2021	$ 0.4	468.1	$ (50)	(147.2)	741.8	$ 1,013.1
Balance at beginning of period, shares at Dec. 31, 2021	37.9					37.9
Balance at beginning of period, Treasury shares at Dec. 31, 2021			1			1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)						$ (65.6)
Other comprehensive income						(79.8)
Balance at end of period at Sep. 30, 2022	$ 0.4	483.7	$ (200)	(227)	641	$ 698.1
Balance at end of period, shares at Sep. 30, 2022	35.1					35.1
Balance at end of period, Treasury shares at Sep. 30, 2022			4.1			4.1
Balance at beginning of period at Mar. 31, 2022	$ 0.4	475.7	$ (100)	(149.7)	746.4	$ 972.8
Balance at beginning of period, shares at Mar. 31, 2022	37.2
Balance at beginning of period, Treasury shares at Mar. 31, 2022			1.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)					37.4	37.4
Other comprehensive income				(28.2)		(28.2)
Share-based compensation activity		4.4				4.4
Share-based compensation activity, shares	0.1
Purchase of treasury shares			$ (50)			(50)
Purchase of treasury shares, shares	(1)		1
Dividends on ordinary shares					(11.8)	(11.8)
Balance at end of period at Jun. 30, 2022	$ 0.4	480.1	$ (150)	(177.9)	772	924.6
Balance at end of period, shares at Jun. 30, 2022	36.3
Balance at end of period, Treasury shares at Jun. 30, 2022			2.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)					(119.8)	(119.8)
Other comprehensive income				(49.1)		(49.1)
Share-based compensation activity		3.6				3.6
Purchase of treasury shares			$ (50)			(50)
Purchase of treasury shares, shares	(1.2)		1.2
Dividends on ordinary shares					(11.2)	(11.2)
Balance at end of period at Sep. 30, 2022	$ 0.4	$ 483.7	$ (200)	$ (227)	$ 641	$ 698.1
Balance at end of period, shares at Sep. 30, 2022	35.1					35.1
Balance at end of period, Treasury shares at Sep. 30, 2022			4.1			4.1

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Shareholders' Equity (Parenthetical)) - $ / shares	3 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021
Condensed Consolidated Statement of Stockholders' Equity
Dividends on ordinary shares	$ 0.32	$ 0.32	$ 0.32	$ 0.32	$ 0.08	$ 0.08

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities
Net income (loss)	$ (65.6)	$ 316.2
Less: Net income (loss) from discontinued operations	(1.9)	38
Net income (loss) from continuing operations	(63.7)	278.2
Adjustments to reconcile net income (loss) from continuing operations to net cash provided by (used in) operating activities - continuing operations
Depreciation and amortization	147.1	111
Amortization of deferred financing fees and issuance discount	6.9	5.5
Deferred income tax	(8)	0.2
Share-based compensation expense	15.6	11
Earnings of unconsolidated affiliates, net of dividends	(21.3)	(10.2)
Unrealized net gain (loss) on foreign exchange forward contracts	1.6	(25.2)
Acquisition purchase price hedge loss		22
Pension curtailment and settlement gain	(3)	(2.1)
Asset impairment charges or write-offs	3.9	3
Changes in assets and liabilities
Accounts receivable	5.1	(280.8)
Inventories	(43.1)	(196.7)
Accounts payable and other current liabilities	(81.9)	248.7
Income taxes payable	(23.7)	22.3
Other assets, net	13.5	(9.2)
Other liabilities, net	61.8	41
Cash provided by operating activities - continuing operations	10.8	218.7
Cash provided by (used in) operating activities - discontinued operations	(1.4)	19.5
Cash provided by operating activities	9.4	238.2
Cash flows from investing activities
Capital expenditures	(94)	(64.7)
Cash paid for asset or business acquisitions, net of cash acquired ($1.0 and $12.1)	(22.2)	(1,806.6)
Proceeds from the sale of businesses and other assets	5.3	0.2
Proceeds from (payments for) the settlement of hedging instruments	1.9	(14.7)
Cash used in investing activities - continuing operations	(109)	(1,885.8)
Cash used in investing activities - discontinued operations	(0.8)	(3.3)
Cash used in investing activities	(109.8)	(1,889.1)
Cash flows from financing activities
Deferred financing fees		(35)
Short-term borrowings, net	(12.2)	(11.6)
Purchase of treasury shares	(151.9)
Dividends paid	(36.3)	(9.5)
Proceeds from exercise of option awards	2.9	10.5
Withholding taxes paid on restricted share units	(3.1)	(0.8)
Repurchases and repayments of long-term debt	(12.9)	(7.1)
Net proceeds from issuance of 2028 Term Loan B		746.3
Net proceeds from issuance of 2029 Senior Notes		450
Proceeds from draw on Accounts Receivable Securitization Facility		150
Repayments of Accounts Receivable Securitization Facility		(20)
Cash provided by (used in) financing activities	(213.5)	1,272.8
Effect of exchange rates on cash	(16.3)	(3.1)
Net change in cash, cash equivalents, and restricted cash	(330.2)	(381.2)
Cash, cash equivalents, and restricted cash-beginning of period	573	588.7
Cash, cash equivalents, and restricted cash-end of period	242.8	207.5
Cash and cash equivalents-end of period	242.8	207.5
Supplemental disclosure of cash flow information
Net cash paid	$ 1	$ 12.1

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2022
Basis of Presentation
Basis of Presentation	NOTE 1—BASIS OF PRESENTATION The unaudited interim condensed consolidated financial statements of Trinseo PLC and its subsidiaries (the “Company”) as of and for the periods ended September 30, 2022 and 2021 were prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and reflect all adjustments, consisting only of normal recurring adjustments, which, in the opinion of management, are considered necessary for the fair statement of the results for the periods presented. Because they cover interim periods, the statements and related notes to the financial statements do not include all disclosures normally provided in annual financial statements, and therefore, these statements should be read in conjunction with the 2021 audited consolidated financial statements included within the Company’s Annual Report on Form 10-K (“Annual Report”) filed with the Securities and Exchange Commission (“SEC”) on February 23, 2022. The Company’s condensed consolidated financial statements presented herein reflect the latest estimates and assumptions made by management that affect the reported amounts and related disclosures as of and for the period ended September 30, 2022. However, actual results could differ from these estimates and assumptions. The December 31, 2021 condensed consolidated balance sheet data presented herein was derived from the Company’s December 31, 2021 audited consolidated financial statements, but does not include all disclosures required by GAAP for annual periods. Certain prior year amounts have been reclassified to conform to the current year presentation. Throughout this Quarterly Report, unless otherwise indicated, amounts and activity are presented on a continuing operations basis.

Recent Accounting Guidance

Recent Accounting Guidance	9 Months Ended
	Sep. 30, 2022
Recent Accounting Guidance
Recent Accounting Guidance	NOTE 2—RECENT ACCOUNTING GUIDANCE As of September 30, 2022, there was no recently issued accounting standards which would have a material effect on the Company’s condensed consolidated financial statements.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2022
Acquisitions
Acquisitions	NOTE 3—ACQUISITIONS Acquisition of Heathland B.V. On January 3, 2022, the Company completed the acquisition of Heathland B.V. (“Heathland”) from Heathland Holding B.V. (“Heathland Holding”), through the purchase of all issued and outstanding shares (the “Heathland Acquisition”). The Heathland Acquisition was completed pursuant to the Sale and Purchase Agreement dated December 3, 2021 (“Heathland Agreement”), by and between the Company and Heathland Holding. Heathland is a leading collector and recycler of post-consumer and post-industrial plastic wastes in Europe. The total purchase price consideration is estimated to be $29.3 million, including an initial cash purchase price of $22.9 million, as well as $6.4 million of contingent cash consideration, representing the fair value of certain earn-out payments. The maximum amount of potential earn-out payments is $6.8 million, which amounts will become payable to Heathland Holding as and when the related performance milestones or thresholds are achieved over the three-year period following the date of acquisition. The Heathland Acquisition was funded through existing cash on hand. Additionally, the Heathland Agreement includes a service fee of approximately $4.5 million, payable to Heathland Holdings contingent upon the continued employment of certain Heathland employees for three years following the acquisition date. The Company has not included this service fee as part of the estimated purchase price and instead will accrue for the service fee as compensation expense over the three-year period in which it is earned. The Company accounted for the acquisition as a business combination pursuant to ASC 805. In accordance with ASC 805, fair values are assigned to tangible and identifiable intangible assets acquired and liabilities assumed at the acquisition date based on the information that was available as of the acquisition date. The Company allocated the purchase price of the acquisition to identifiable assets acquired and liabilities assumed based on their estimated fair values as of the acquisition date. The excess of the purchase price over the aggregate fair values was recorded as goodwill. During the third quarter of 2022, there were no changes to the purchase price allocation for the Heathland Acquisition. The table below summarizes the purchase price allocation for the assets acquired and liabilities assumed, based on their relative fair values, which have been assessed as of the January 3, 2022 acquisition date: ​ ​ ​ ​ ​ ​ ​ January 3, ​ 2022 Cash and cash equivalents ​ $ 1.0 Other current assets ​ ​ 1.2 Other intangible assets (1) ​ ​ ​ Customer relationships ​ 5.1 Tradenames ​ 0.9 Developed technology ​ ​ 0.2 Other assets ​ ​ 1.0 Total fair value of assets acquired ​ ​ 9.4 ​ ​ ​ ​ Current liabilities ​ (1.3) Noncurrent liabilities ​ ​ (1.6) Total fair value of liabilities assumed ​ ​ (2.9) Net identifiable assets acquired ​ ​ 6.5 Purchase price consideration ​ ​ 29.3 Goodwill (2) ​ $ 22.8 (1) The expected weighted average useful life of the acquired intangible assets are 7 years for customer relationships, tradenames and developed technology. (2) Goodwill largely consists of strategic and synergistic opportunities resulting from combining Heathland with the Company’s existing businesses and is allocated entirely to the Base Plastics segment. No goodwill related to this acquisition is expected to be deductible for income tax purposes. Pro forma results of operations information have not been presented as the effect of the acquisition is not material. The operating results of the Heathland acquisition are included within the Company's condensed consolidated statements of operations since the acquisition date of January 3, 2022 and were not material for the three and nine months ended September 30, 2022. Pursuant to GAAP, costs incurred to complete the Heathland Acquisition as well as costs incurred to integrate into the Company’s operations are expensed as incurred. Transaction-related costs incurred, which are included within “Selling, general, and administrative expenses” in the condensed consolidated statements of operations, were not material for the three and nine months ended September 30, 2022. Acquisition of Aristech Surfaces On September 1, 2021, the Company completed its previously announced acquisition of Aristech Surfaces LLC (“Aristech Surfaces”) from SK AA Holdings LLC (“SK AA Holdings”), the sole member of Aristech Surfaces, through purchase of 100% membership interest and intellectual property (the “Aristech Surfaces Acquisition”). The purchase price consideration for the Aristech Surfaces Acquisition was $449.5 million, all of which was paid during the year ended December 31, 2021 (of which $448.0 million was paid during the nine months ended September 30, 2021). Aristech Surfaces is a leading North America manufacturer and global provider of PMMA continuous cast and solid surface sheets, serving the wellness, architectural, transportation and industrial markets, whose results are included within the Engineered Materials segment. Aristech Surfaces’ products are used for a variety of applications, including the construction of hot tubs, swim spas, counter tops, signage, bath products and recreational vehicles. The Company allocated the purchase price of the acquisition to identifiable assets acquired and liabilities assumed based on their estimated fair values as of the acquisition date. Refer to the Annual Report for further information. During the nine months ended September 30, 2022, there were no changes to the purchase price allocation for the acquisition of the Aristech Surfaces business. As of September 1, 2022, the acquisition measurement period for the Aristech Surfaces business has ended and the values assigned to the assets acquired and liabilities assumed are final. Acquisition of the PMMA Business On May 3, 2021, the Company completed its previously-announced acquisition of the polymethyl methacrylates (“PMMA”) and activated methyl methacrylates (“MMA”) business (together, the “PMMA business”) from Arkema S.A., (“Arkema”) through the purchase of 100% of the shares of certain subsidiaries of Arkema (the “PMMA Acquisition”). The purchase price consideration for the PMMA Acquisition was $1,364.9 million, all of which was paid during the year ended December 31, 2021 (of which $1,358.6 million was paid during the nine months ended September 30, 2021). PMMA is a transparent and rigid plastic with a wide range of end uses, and is an attractive adjacent chemistry which complements Trinseo’s offerings across several end markets including automotive, building & construction, medical and consumer electronics. PMMA results are included within the Engineered Materials segment. The Company allocated the purchase price of the acquisition to identifiable assets acquired and liabilities assumed based on their estimated fair values as of the acquisition date. Refer to the Annual Report for further information. As of May 3, 2022, the acquisition measurement period for the PMMA business has ended and the values assigned to the assets acquired and liabilities assumed are final. Unaudited Pro Forma Financial Information The following unaudited pro forma financial information presents the consolidated results of operations of the Company with the PMMA business and Aristech Surfaces for the three and nine months ended September 30, 2021 as if these acquisitions had occurred on January l, 2021. The pro forma results were calculated by combining the results of Trinseo with the PMMA business and Aristech Surfaces but do not include adjustments related to cost savings or other synergies that are anticipated as a result of these acquisitions. Accordingly, these unaudited pro forma results are presented for informational purposes only and are not necessarily indicative of what the actual results of operations would have been if the acquisitions had occurred as of January 1, 2021, nor are they indicative of future results of operations. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2021 2021 Net sales $ 1,300.2 $ 3,863.8 Net income ​ $ 94.1 ​ $ 355.1 Income from continuing operations ​ $ 80.4 ​ $ 317.1 ​

Divestitures And Discontinued O

Divestitures And Discontinued Operations	9 Months Ended
	Sep. 30, 2022
Divestitures and Discontinued Operations
Divestitures and Discontinued Operations	NOTE 4—DIVESTITURES AND DISCONTINUED OPERATIONS On December 1, 2021, the Company completed the divestiture of its Synthetic Rubber business to Synthos S.A. and certain of its subsidiaries (together, “Synthos”) for a purchase price of materials used in the Synthetic Rubber business subsequent to the sale. For the three and nine months ended September 30, 2022, the Company recorded $13.8 million and $55.6 million, respectively, in net sales, and $14.5 million and $46.3 million, respectively, in cost of sales related to the supply agreement, which is recorded in continuing operations. The following table summarizes the results of the Synthetic Rubber business for the three and nine months ended September 30, 2022 and 2021, which are reflected as discontinued operations in the Company’s condensed consolidated statements of operations: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2022 2021 2022 2021 Net sales $ — $ 122.3 $ 0.1 $ 382.2 Cost of sales ​ 2.2 ​ 101.9 ​ 3.6 ​ 321.2 ​ Gross profit (loss) ​ (2.2) ​ 20.4 ​ (3.5) ​ 61.0 ​ Selling, general and administrative expenses ​ — ​ 4.9 ​ (0.3) ​ 16.7 ​ Operating income (loss) ​ (2.2) ​ 15.5 ​ (3.2) ​ 44.3 ​ Gain on sale of businesses and other assets ​ ​ — ​ ​ — ​ ​ 1.2 ​ ​ — ​ Other expense, net ​ ​ — ​ ​ 0.2 ​ ​ — ​ ​ 1.2 ​ Income (loss) from discontinued operations before income taxes ​ (2.2) ​ 15.3 ​ (2.0) ​ 43.1 ​ Provision for (benefit from) income taxes ​ (0.3) ​ 1.6 ​ (0.1) ​ 5.1 ​ Net income (loss) from discontinued operations ​ $ (1.9) ​ $ 13.7 ​ $ (1.9) ​ $ 38.0 ​ ​

Net Sales

Net Sales	9 Months Ended
	Sep. 30, 2022
Net Sales
Net Sales	NOTE 5—NET SALES Refer to the Annual Report for information on the Company's accounting policies and further background related to its net sales. The following table provides disclosure of net sales to external customers by primary geographical market (based on the location where sales originated), by segment for the three and nine months ended September 30, 2022 and 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Engineered ​ Latex ​ Base ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Materials ​ Binders ​ Plastics ​ Polystyrene ​ Feedstocks ​ Total September 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ United States ​ $ 128.9 ​ $ 105.4 ​ $ 73.7 ​ $ — ​ $ 4.5 ​ $ 312.5 ​ Europe ​ 72.5 ​ 160.1 ​ 157.1 ​ 174.0 ​ 48.9 ​ 612.6 ​ Asia-Pacific ​ 38.9 ​ 72.9 ​ 33.3 ​ 73.7 ​ — ​ 218.8 ​ Rest of World ​ 2.4 ​ 2.5 ​ 29.3 ​ — ​ — ​ 34.2 ​ Total ​ $ 242.7 ​ $ 340.9 ​ $ 293.4 ​ $ 247.7 ​ $ 53.4 ​ $ 1,178.1 ​ September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ United States ​ $ 102.4 ​ $ 86.3 ​ $ 82.3 ​ $ — ​ $ 4.0 ​ $ 275.0 ​ Europe ​ 89.6 ​ 153.5 ​ ​ 247.3 ​ 162.6 ​ 50.8 ​ 703.8 ​ Asia-Pacific ​ 35.9 ​ 73.0 ​ ​ 43.9 ​ 112.2 ​ — ​ ​ 265.0 ​ Rest of World ​ 2.9 ​ 2.8 ​ ​ 19.8 ​ — ​ — ​ 25.5 ​ Total ​ $ 230.8 ​ $ 315.6 ​ $ 393.3 ​ $ 274.8 ​ $ 54.8 ​ $ 1,269.3 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Engineered ​ Latex ​ Base ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ Materials ​ Binders ​ Plastics ​ Polystyrene ​ Feedstocks ​ Total September 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ United States ​ $ 418.0 ​ $ 290.1 ​ $ 264.3 ​ $ — ​ $ 13.0 ​ $ 985.4 ​ Europe ​ 300.1 ​ 480.4 ​ 602.2 ​ 604.5 ​ 207.3 ​ 2,194.5 ​ Asia-Pacific ​ 112.4 ​ 223.9 ​ 102.1 ​ 273.1 ​ — ​ 711.5 ​ Rest of World ​ 8.7 ​ 6.9 ​ 83.2 ​ 0.1 ​ — ​ 98.9 ​ Total ​ $ 839.2 ​ $ 1,001.3 ​ $ 1,051.8 ​ $ 877.7 ​ $ 220.3 ​ $ 3,990.3 ​ September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ United States ​ $ 174.1 ​ $ 228.2 ​ $ 216.5 ​ $ — ​ $ 10.7 ​ $ 629.5 ​ Europe ​ 190.8 ​ 431.4 ​ ​ 699.2 ​ 511.7 ​ 188.9 ​ 2,022.0 ​ Asia-Pacific ​ 108.1 ​ 211.1 ​ ​ 144.5 ​ 343.3 ​ — ​ ​ 807.0 ​ Rest of World ​ 4.5 ​ 6.9 ​ ​ 59.1 ​ — ​ — ​ 70.5 ​ Total ​ $ 477.5 ​ $ 877.6 ​ $ 1,119.3 ​ $ 855.0 ​ $ 199.6 ​ $ 3,529.0 ​ ​

Investments in Unconsolidated A

Investments in Unconsolidated Affiliates	9 Months Ended
	Sep. 30, 2022
Investments in Unconsolidated Affiliates
Investments in Unconsolidated Affiliates	NOTE 6—INVESTMENTS IN UNCONSOLIDATED AFFILIATES The Company is currently supplemented by one joint venture, Americas Styrenics LLC (“Americas Styrenics,” a styrene and polystyrene joint venture with Chevron Phillips Chemical Company LP), which is accounted for using the equity method. The results of Americas Styrenics are included within its own reporting segment. Americas Styrenics is a privately held company; therefore, a quoted market price for its equity interests is not available. The summarized financial information of the Company’s unconsolidated affiliate is shown below. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2022 2021 2022 2021 Sales $ 535.3 $ 433.4 $ 1,654.3 $ 1,351.9 ​ Gross profit ​ $ 70.6 ​ $ 49.3 ​ $ 212.2 ​ $ 189.2 ​ Net income ​ $ 48.3 ​ $ 37.2 ​ $ 164.5 ​ $ 151.8 ​ ​ As of September 30, 2022 and December 31, 2021, the Company’s investment in Americas Styrenics was $269.2 million and $247.8 million, respectively, which was $11.0 million and $9.4 million greater than the Company’s 50% share of the underlying net assets of Americas Styrenics, respectively. This amount represents the difference between the book value of assets held by the joint venture and the Company’s 50% share of the total recorded value of the joint venture’s assets, inclusive of certain adjustments to conform with the Company’s accounting policies. This difference is being amortized over a weighted average remaining useful life of approximately 2.3 years as of September 30, 2022. The Company received dividends of $25.0 million and $62.5 million from Americas Styrenics during the three and nine months ended September 30, 2022, respectively, and $20.0 million and $60.0 million during the three and nine months ended September 30, 2021, respectively.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2022
Inventories
Inventories	NOTE 7—INVENTORIES Inventories consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2022 ​ 2021 Finished goods $ 281.7 $ 279.2 Raw materials and semi-finished goods ​ 297.5 ​ 303.9 Supplies ​ 34.8 ​ 37.9 Total ​ $ 614.0 ​ $ 621.0 ​

Debt

Debt	9 Months Ended
	Sep. 30, 2022
Debt
Debt	NOTE 8—DEBT Refer to the Annual Report for definitions of capitalized terms not included herein and further background on the Company’s debt structure discussed below. The Company was in compliance with all debt related covenants as of September 30, 2022 and December 31, 2021. As of September 30, 2022 and December 31, 2021, debt consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2022 ​ December 31, 2021 ​ ​ Interest Rate as of September 30, 2022 Maturity Date Carrying Amount Unamortized Deferred Financing Fees (1) Total Debt, Less Unamortized Deferred Financing Fees Carrying Amount Unamortized Deferred Financing Fees (1) Total Debt, Less Unamortized Deferred Financing Fees ​ Senior Credit Facility ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 Term Loan B ​ 5.115% ​ September 2024 ​ $ 665.2 ​ $ (5.9) ​ $ 659.3 ​ $ 670.4 ​ $ (8.0) ​ $ 662.4 ​ 2028 Term Loan B ​ 5.615% ​ May 2028 ​ ​ 737.6 ​ ​ (15.1) ​ ​ 722.5 ​ ​ 742.8 ​ ​ (17.0) ​ ​ 725.8 ​ 2026 Revolving Facility (2) ​ Various ​ May 2026 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ 2029 Senior Notes ​ 5.125% ​ April 2029 ​ ​ 447.0 ​ ​ (13.3) ​ ​ 433.7 ​ ​ 450.0 ​ ​ (14.7) ​ ​ 435.3 ​ 2025 Senior Notes ​ 5.375% ​ September 2025 ​ ​ 500.0 ​ ​ (4.0) ​ ​ 496.0 ​ ​ 500.0 ​ ​ (5.0) ​ ​ 495.0 ​ Accounts Receivable Securitization Facility (3) ​ Various ​ November 2024 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ Other indebtedness ​ Various ​ Various ​ ​ 3.0 ​ ​ — ​ ​ 3.0 ​ ​ 5.6 ​ ​ — ​ ​ 5.6 ​ Total debt ​ ​ ​ ​ ​ $ 2,352.8 ​ $ (38.3) ​ $ 2,314.5 ​ $ 2,368.8 ​ $ (44.7) ​ $ 2,324.1 ​ Less: current portion (4) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (16.7) ​ ​ ​ ​ ​ ​ ​ ​ (18.5) ​ Total long-term debt, net of unamortized deferred financing fees ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 2,297.8 ​ ​ ​ ​ ​ ​ ​ $ 2,305.6 ​ (1) This caption does not include deferred financing fees related to the Company’s revolving facilities, which are included within “Deferred charges and other assets” on the condensed consolidated balance sheets. (2) As of September 30, 2022, under the 2026 Revolving Facility, the Company had a capacity of $375.0 million and funds available for borrowing of $369.2 million (net of $5.8 million outstanding letters of credit). Additionally, the Company is required to pay a quarterly commitment fee in respect of any unused commitments under this facility equal to 0.375% per annum. (3) As of September 30, 2022, this facility had a borrowing capacity of $150.0 million, and the Company had approximately $150.0 million of accounts receivable available to support this facility, based on the pool of eligible accounts receivable. (4) The current portion of long-term debt was primarily related to $14.5 million of the scheduled future principal payments on both the 2024 Term Loan B and 2028 Term Loan B as of September 30, 2022 and December 31, 2021.

Goodwill

Goodwill	9 Months Ended
	Sep. 30, 2022
Goodwill.
Goodwill	NOTE 9—GOODWILL The following table shows changes in the carrying amount of goodwill, by segment, from December 31, 2021 to September 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Engineered ​ Latex ​ Base ​ ​ ​ ​ ​ Americas ​ ​ ​ ​ Materials Binders Plastics Polystyrene Feedstocks Styrenics Total Balance at December 31, 2021 ​ $ 667.3 ​ $ 15.9 ​ $ 22.4 ​ $ 4.5 ​ $ — ​ $ — ​ $ 710.1 ​ Acquisitions (Note 3) ​ ​ — ​ ​ — ​ ​ 22.8 ​ ​ — ​ ​ — ​ ​ — ​ ​ 22.8 ​ Foreign currency impact ​ (31.7) ​ ​ (2.3) ​ ​ (6.3) ​ ​ (0.7) ​ ​ — ​ ​ — ​ (41.0) ​ Balance at September 30, 2022 ​ $ 635.6 ​ $ 13.6 ​ $ 38.9 ​ $ 3.8 ​ $ — ​ $ — ​ $ 691.9 ​ ​ ​ The Company tests goodwill for impairment annually as of October 1, or more frequently when events or changes in circumstances indicate that the fair value of a reporting unit is more likely than not below carrying value. As noted within Note 3 – Acquisitions and as discussed within the Annual Report, in 2021, the Company completed the PMMA Acquisition and Aristech Surfaces Acquisition, each of which represents a separate reporting unit within the Engineered Materials segment. The Company allocated the purchase price of these acquisitions to identifiable assets acquired and liabilities assumed based on their estimated fair values as of the acquisition date, with the excess of the purchase price over the aggregate fair values recorded as goodwill. As of September 30, 2022, the reporting units for the PMMA business and Aristech Surfaces had goodwill balances of approximately $503.0 million and $120.0 million, respectively. In 2022, historically high natural gas prices and depressed customer demand in Europe, COVID-19 lockdowns in China, global supply chain constraints, weakness in certain end customer applications, and an uncertain geopolitical situation in Europe, created a challenging operating environment for these businesses, negatively impacting their financial performance. In response to these conditions, the Company performed qualitative analyses over these reporting units, including consideration of current and estimated future financial results, general and industry-specific economic conditions, changes in their respective carrying values and potential changes to the assumptions used in previous fair value calculations. Based on these analyses, the Company has not identified any triggering events indicating that it is more likely than not that goodwill is impaired. However, these reporting units may be at risk for future impairment due to the limited amount of fair value in excess of carrying value as a result of their recent acquisition. Should these conditions persist, or other events occur indicating that the estimated future cash flows of these reporting units have declined, the Company may be required to record future non-cash impairment charges related to goodwill.

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2022
Derivative Instruments
Derivative Instruments	NOTE 10—DERIVATIVE INSTRUMENTS The Company’s ongoing business operations expose it to various risks, including fluctuating foreign exchange rates, interest rate risk, and commodity price risk, in particular natural gas. To manage these risks, the Company periodically enters into derivative financial instruments, such as foreign exchange forward contracts, interest rate swap agreements, and commodity swaps, forward contracts, or options. The Company does not hold or enter into financial instruments for trading or speculative purposes. All derivatives are recorded on the condensed consolidated balance sheets at fair value. Foreign Exchange Forward Contracts Certain subsidiaries have assets and liabilities denominated in currencies other than their respective functional currencies, which creates foreign exchange risk. The Company’s principal strategy in managing its exposure to changes in foreign currency exchange rates is to naturally hedge the foreign currency-denominated liabilities on its balance sheet against corresponding assets of the same currency, such that any changes in liabilities due to fluctuations in exchange rates are offset by changes in their corresponding foreign currency assets. In order to further reduce this exposure, the Company also uses foreign exchange forward contracts to economically hedge the impact of the variability in exchange rates on assets and liabilities denominated in certain foreign currencies. The Company entered into a specific such foreign exchange forward contract in December 2020 in order to economically hedge the euro-denominated purchase price of the PMMA business, which was acquired on May 3, 2021, as discussed in Note 3. These derivative contracts are not designated for hedge accounting treatment. As of September 30, 2022, the Company had open foreign exchange forward contracts with a notional U.S. dollar equivalent absolute value of $547.6 million. The following table displays the notional amounts of the most significant net foreign exchange hedge positions outstanding as of September 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ Buy / (Sell) 2022 ​ Euro ​ $ (411.1) ​ Chinese Yuan ​ $ (46.4) ​ Swedish Krona ​ $ 20.7 ​ South Korean Won ​ $ (18.3) ​ New Taiwan Dollar ​ $ 15.6 ​ ​ Open foreign exchange forward contracts as of September 30, 2022 had maturities occurring over a period of two months. Foreign Exchange Cash Flow Hedges The Company also enters into forward contracts, as deemed appropriate, with the objective of managing the currency risk associated with forecasted U.S. dollar-denominated raw materials purchases by one of its subsidiaries whose functional currency is the euro. By entering into these forward contracts, which are designated as cash flow hedges, the Company buys a designated amount of U.S. dollars and sells euros at the prevailing market rate to mitigate the risk associated with the fluctuations in the euro-to-U.S. dollar foreign currency exchange rates. The qualifying hedge contracts are marked-to-market at each reporting date and any unrealized gains or losses are included in Accumulated Other Comprehensive Income (“AOCI”) to the extent effective, and reclassified to cost of sales in the period during which the transaction affects earnings or it becomes probable that the forecasted transaction will not occur. The Company had no open foreign exchange cash flow hedges as of Commodity Cash Flow Hedges The Company purchases certain commodities, primarily natural gas, to operate facilities and generate heat and steam for various manufacturing processes, which purchases are subject to price volatility. In order to manage the risk of price fluctuations associated with these commodity purchases, as deemed appropriate, the Company may enter into commodity swaps, forward contracts, or options. These commodity derivatives are designated as cash flow hedges, and as such, the contracts are marked-to-market at each reporting date and any unrealized gains or losses are included in AOCI to the extent effective, and reclassified to cost of sales in the period during which the transaction affects earnings or it becomes probable that the forecasted transaction will not occur. Open commodity cash flow hedges as of September 30, 2022 had maturities occurring over a period of three months and had a notional value of approximately 63 thousand megawatt hours of natural gas purchases. Interest Rate Swaps On September 6, 2017, the Company issued the 2024 Term Loan B, which currently bears an interest rate of LIBOR plus 2.00%, subject to a 0.00% LIBOR floor. In order to reduce the variability in interest payments associated with the Company’s variable rate debt, during 2017 the Company entered into certain interest rate swap agreements to convert a portion of these variable rate borrowings into a fixed rate obligation. These interest rate swap agreements are designated as cash flow hedges, and as such, the contracts are marked-to-market at each reporting date and any unrealized gains or losses are included in AOCI to the extent effective, and reclassified to interest expense in the period during which the transaction affects earnings or it becomes probable that the forecasted transaction will not occur. Under the terms of the swap agreements, with a net notional U.S. dollar equivalent of $200.0 million and an effective date of September 29, 2017, the Company was required to pay the counterparties a stream of fixed interest payments at a rate of 1.81%, and in turn, receives variable interest payments based on 1-month LIBOR from the counterparties. These interest rate swap agreements matured in September 2022, and the Company has no remaining open interest rate swap agreements. Net Investment Hedge The Company accounts for its cross currency swaps (“CCS”) under the spot method, meaning that changes in the fair value of the hedge included in the assessment of effectiveness (changes due to spot foreign exchange rates) are recorded within AOCI, where they remain until either the sale or substantially complete liquidation of the subsidiary subject to the hedge. Additionally, the initial value of any component excluded from the assessment of effectiveness is recognized in income using a systematic and rational method over the life of the hedging instrument and any difference between the change in the fair value of the excluded component and amounts recognized in income under that systematic and rational method is recognized in AOCI. When applicable, the Company amortizes any initial excluded component value of a CCS as a reduction of “Interest expense, net” in the condensed consolidated statements of operations using the straight-line method over the remaining term of the related CCS. Additionally, interest receipts and payments are accrued under the terms of the Company’s CCS and are recognized within “Interest expense, net” in the condensed consolidated statements of operations. The Company entered into a CCS arrangement (the “2017 CCS”) on September 1, 2017, swapping U.S. dollar principal and interest payments of $500.0 million at an interest rate of 5.375% on its 2025 Senior Notes for euro-denominated payments of €420.0 million at a weighted average interest rate of 3.45% for approximately five years. On February 26, 2020, the Company settled its 2017 CCS and replaced it with a new CCS arrangement (the “2020 CCS”) that carried substantially the same terms as the 2017 CCS. Under the 2020 CCS, the Company notionally exchanged $500.0 million at an interest rate of 5.375% for €459.3 million at a weighted average interest rate of 3.672% for approximately 2.7 years, with a final maturity of November 3, 2022. The cash flows under the 2020 CCS are aligned with the Company’s principal and interest obligations on its 5.375% 2025 Senior Notes. On April 7, 2022, the Company settled its existing 2020 CCS, which were set to mature in November 2022. Upon settlement of the 2020 CCS, the Company realized net cash proceeds of $1.9 million. ​ Summary of Derivative Instruments The following table presents the effect of the Company’s derivative instruments, including those not designated for hedge accounting treatment, on the condensed consolidated statements of operations for the three and nine months ended September 30, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Location and Amount of Gain (Loss) Recognized in Statements of Operations ​ ​ Three Months Ended ​ Three Months Ended ​ ​ September 30, 2022 ​ September 30, 2021 ​ Cost of sales ​ Interest expense, net ​ Other (expense) income, net ​ Cost of sales ​ Interest expense, net ​ Other (expense) income, net Total amount of income and (expense) line items presented in the statements of operations in which the effects of derivative instruments are recorded ​ $ (1,217.6) ​ $ (30.4) ​ $ (0.5) ​ $ (1,101.0) ​ $ (23.0) ​ $ 0.1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The effects of cash flow hedge instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign exchange cash flow hedges ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain reclassified from AOCI into income ​ $ — ​ $ — ​ $ — ​ $ 0.3 ​ $ — ​ $ — Commodity cash flow hedges ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain reclassified from AOCI into income ​ $ 2.0 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — Interest rate swaps ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain (loss) reclassified from AOCI into income ​ $ — ​ $ 0.2 ​ $ — ​ $ — ​ $ (0.9) ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The effects of net investment hedge instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cross currency swaps (CCS) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain excluded from effectiveness testing ​ $ — ​ $ — ​ $ — ​ $ — ​ $ 1.9 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The effects of derivatives not designated as hedge instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign exchange forward contracts ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain recognized in income (1) ​ $ — ​ $ — ​ $ 33.7 ​ $ — ​ $ — ​ $ 23.3 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Location and Amount of Gain (Loss) Recognized in Statements of Operations ​ ​ Nine Months Ended ​ Nine Months Ended ​ ​ September 30, 2022 ​ September 30, 2021 ​ Cost of sales ​ Interest expense, net ​ Other (expense) income, net ​ Cost of sales ​ Interest expense, net ​ Acquisition purchase price hedge gain (loss) ​ Other (expense) income, net Total amount of income and (expense) line items presented in the statements of operations in which the effects of derivative instruments are recorded ​ $ (3,714.8) ​ $ (77.7) ​ $ (1.6) ​ $ (2,951.7) ​ $ (56.6) ​ $ (22.0) ​ $ (8.4) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The effects of cash flow hedge instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity cash flow hedges ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain reclassified from AOCI into income ​ $ 2.0 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — Interest rate swaps ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of loss reclassified from AOCI into income ​ $ — ​ $ (1.2) ​ $ — ​ $ — ​ $ (2.6) ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The effects of net investment hedge instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cross currency swaps (CCS) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain excluded from effectiveness testing ​ $ — ​ $ 2.4 ​ $ — ​ $ — ​ $ 5.5 ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The effects of derivatives not designated as hedge instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign exchange forward contracts ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain (loss) recognized in income (1) ​ $ — ​ $ — ​ $ 81.6 ​ $ — ​ $ — ​ $ (22.0) ​ $ 43.4 (1) The $22.0 million loss incurred from the change in fair value of the forward currency hedge arrangement on the euro-denominated purchase price of the PMMA business during the nine months ended September 30, 2021 is presented separately in the condensed consolidated statements of operations from the gains recorded on the Company’s other foreign exchange forward contracts. The following table presents the effect of cash flow and net investment hedge accounting on AOCI for the three and nine months ended September 30, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ` ​ Gain (Loss) Recognized in AOCI on Balance Sheet ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ ​ 2022 ​ 2021 ​ 2022 ​ 2021 Designated as Cash Flow Hedges ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign exchange cash flow hedges $ — $ 0.4 $ — $ 3.1 Commodity cash flow hedges ​ ​ (5.4) ​ ​ — ​ ​ (5.4) ​ ​ — Interest rate swaps ​ ​ (0.2) ​ ​ 0.8 ​ ​ 2.2 ​ ​ 2.5 Total ​ $ (5.6) ​ $ 1.2 ​ $ (3.2) ​ $ 5.6 Designated as Net Investment Hedges ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cross currency swaps (CCS) ​ $ — ​ $ 13.1 ​ $ 15.8 ​ $ 32.1 Total ​ $ — ​ $ 13.1 ​ $ 15.8 ​ $ 32.1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gain (Loss) Recognized in Other expense, net in Statement of Operations ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2022 2021 2022 2021 Settlements and changes in the fair value of forward contracts (not designated as hedges) (1) $ 33.7 $ 23.3 $ 81.6 $ 43.4 Remeasurement of foreign currency-denominated assets and liabilities ​ $ (35.4) ​ $ (23.7) ​ $ (83.4) ​ $ (43.0) ​ Total ​ $ (1.7) ​ $ (0.4) ​ $ (1.8) ​ $ 0.4 ​ (1) Amount does not include the loss of $22.0 million recorded from the change in fair value of the forward currency hedge arrangement on the euro-denominated purchase price of the PMMA business during the nine months ended September 30, 2021. ​ The Company expects to reclassify in the next twelve months an approximate $5.4 million net loss from AOCI into earnings related to the Company’s outstanding commodity cash flow hedges as of September 30, 2022. The following tables summarize the gross and net unrealized gains and losses, as well as the balance sheet classification, of outstanding derivatives recorded in the condensed consolidated balance sheets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2022 ​ ​ Foreign ​ ​ ​ ​ ​ ​ ​ Exchange ​ Commodity ​ ​ ​ Balance Sheet ​ Forward ​ Cash Flow ​ ​ Classification Contracts ​ Hedges ​ Total Asset Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ Accounts receivable, net of allowance ​ $ 11.5 ​ $ — ​ $ 11.5 Gross derivative asset position ​ ​ 11.5 ​ ​ — ​ ​ 11.5 Less: Counterparty netting ​ ​ (0.7) ​ ​ — ​ ​ (0.7) Net derivative asset position ​ $ 10.8 ​ $ — ​ $ 10.8 Liability Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ Accounts payable ​ $ (0.7) ​ $ (1.8) ​ $ (2.5) Gross derivative liability position ​ ​ (0.7) ​ ​ (1.8) ​ ​ (2.5) Less: Counterparty netting ​ ​ 0.7 ​ ​ — ​ ​ 0.7 Net derivative liability position ​ $ — ​ $ (1.8) ​ $ (1.8) Total net derivative position ​ $ 10.8 ​ $ (1.8) ​ $ 9.0 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ Foreign ​ ​ ​ ​ ​ ​ ​ ​ Exchange ​ Interest ​ Cross ​ ​ ​ ​ Balance Sheet ​ Forward ​ Rate ​ Currency ​ ​ Classification Contracts Swaps Swaps Total Asset Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accounts receivable, net of allowance ​ $ 2.3 ​ $ — ​ $ — ​ $ 2.3 ​ Gross derivative asset position ​ ​ 2.3 ​ ​ — ​ ​ — ​ ​ 2.3 ​ Less: Counterparty netting ​ ​ (0.1) ​ ​ — ​ ​ — ​ ​ (0.1) ​ Net derivative asset position ​ $ 2.2 ​ $ — ​ $ — ​ $ 2.2 ​ Liability Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accounts payable ​ $ (1.3) ​ $ (2.2) ​ $ (17.4) ​ $ (20.9) ​ Gross derivative liability position ​ ​ (1.3) ​ ​ (2.2) ​ ​ (17.4) ​ ​ (20.9) ​ Less: Counterparty netting ​ ​ 0.1 ​ ​ — ​ ​ — ​ ​ 0.1 ​ Net derivative liability position ​ $ (1.2) ​ $ (2.2) ​ $ (17.4) ​ $ (20.8) ​ Total net derivative position ​ $ 1.0 ​ $ (2.2) ​ $ (17.4) ​ $ (18.6) ​ Forward contracts, interest rate swaps, commodity forward contracts, swaps, or options, and cross currency swaps are entered into with a limited number of counterparties, each of which allows for net settlement of all contracts through a single payment in a single currency in the event of a default on or termination of any one contract. As such, in accordance with the Company’s accounting policy, these derivative instruments are recorded on a net basis by counterparty within the condensed consolidated balance sheets. Refer to Notes 11 and 18 of the condensed consolidated financial statements for further information regarding the fair value of the Company’s derivative instruments and the related changes in AOCI.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2022
Fair Value Measurements
Fair Value Measurements	NOTE 11—FAIR VALUE MEASUREMENTS Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Assets and liabilities measured at fair value are classified using the following hierarchy, which is based upon the transparency of inputs to the valuation as of the measurement date. Level 1—Valuation is based upon quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2—Valuation is based upon quoted prices for similar assets and liabilities in active markets, or other inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. Level 3—Valuation is based upon other unobservable inputs that are significant to the fair value measurement. The following table summarizes the basis used to measure certain assets and liabilities at fair value on a recurring basis in the condensed consolidated balance sheets as of September 30, 2022 and December 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2022 ​ ​ Quoted Prices in Active Markets for Identical Items ​ Significant Other Observable Inputs ​ Significant Unobservable Inputs ​ ​ ​ Assets (Liabilities) at Fair Value (Level 1) (Level 2) (Level 3) Total Foreign exchange forward contracts—Assets $ — $ 10.8 $ — $ 10.8 ​ Commodity cash flow hedges—(Liabilities) ​ ​ — ​ ​ (1.8) ​ ​ — ​ ​ (1.8) ​ Total fair value ​ $ — ​ $ 9.0 ​ $ — ​ $ 9.0 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ Quoted Prices in Active Markets for Identical Items ​ Significant Other Observable Inputs ​ Significant Unobservable Inputs ​ ​ ​ Assets (Liabilities) at Fair Value (Level 1) (Level 2) (Level 3) Total Foreign exchange forward contracts—Assets ​ $ — $ 2.2 $ — $ 2.2 ​ Foreign exchange forward contracts—(Liabilities) ​ ​ — ​ ​ (1.2) ​ ​ — ​ ​ (1.2) ​ Interest rate swaps—(Liabilities) ​ ​ — ​ ​ (2.2) ​ ​ — ​ ​ (2.2) ​ Cross currency swaps—(Liabilities) ​ ​ — ​ ​ (17.4) ​ ​ — ​ ​ (17.4) ​ Total fair value ​ $ — ​ $ (18.6) ​ $ — ​ $ (18.6) ​ ​ The Company uses an income approach to value its derivative instruments, utilizing discounted cash flow techniques, considering the terms of the contract and observable market information available as of the reporting date, such as interest rate yield curves and currency spot and forward rates. Significant inputs to the valuation for these derivative instruments are obtained from broker quotations or from listed or over-the-counter market data, and are classified as Level 2 in the fair value hierarchy. Nonrecurring Fair Value Measurements The Company measured certain financial assets at fair value on a nonrecurring basis during the year ended December 31, 2021, which were still held as of September 30, 2022. These financial assets represent the Company’s styrene monomer assets in Boehlen, Germany, which it continues to operate. These assets were measured at fair value using underlying fixed asset records in conjunction with the use of industry experience and available market data, which are classified as Level 3 significant unobservable inputs in the fair value hierarchy. During the three and nine months ended September 30, 2022, the Company recorded additional impairment charges of $1.9 million and $3.9 million, respectively, related to capital expenditures at the Boehlen styrene monomer facility that it determined to be impaired, which are also included within “Other charges” on the condensed consolidated statements of operations. Refer to the Company’s Annual Report for further information. As of September 30, 2022 and December 31, 2021, the value of the Boehlen styrene monomer assets are recorded at $2.9 million and $3.4 million, respectively, within the Company’s condensed consolidated balance sheets herein. There were no other financial assets Fair Value of Debt Instruments The following table presents the estimated fair value of the Company’s outstanding debt not carried at fair value as of September 30, 2022 and December 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ September 30, 2022 December 31, 2021 2029 Senior Notes ​ $ 268.2 ​ $ 460.2 ​ 2028 Term Loan B ​ ​ 685.5 ​ ​ 737.4 ​ 2025 Senior Notes ​ ​ 393.7 ​ ​ 509.4 ​ 2024 Term Loan B ​ ​ 639.8 ​ ​ 667.5 ​ Total fair value ​ $ 1,987.2 ​ $ 2,374.5 ​ ​ The fair value of the Company’s debt facilities above (each Level 2 securities) is determined using over-the-counter market quotes and benchmark yields received from independent vendors. Fair value amount presented reflect the Company’s carrying value of debt, net of original issuance discount. There were no other significant financial instruments outstanding as of September 30, 2022 and December 31, 2021.

Provision For Income Taxes

Provision For Income Taxes	9 Months Ended
	Sep. 30, 2022
Provision For Income Taxes
Provision For Income Taxes	NOTE 12—PROVISION FOR INCOME TAXES ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ ​ September 30, ​ September 30, ​ ​ ​ 2022 2021 2022 2021 ​ Effective income tax rate ​ ​ 9.3 % ​ 6.5 % ​ (185.2) % ​ 14.9 % ​ ​ Provision for (benefit from) income taxes for the three and nine months ended September 30, 2022 totaled $(12.1) million and $41.4 million, respectively, resulting in an effective tax rate of 9.3% and (185.2)%, respectively. Provision for income taxes for the three and nine months ended September 30, 2021 totaled $5.5 million and $48.9 million, respectively, resulting in an effective tax rate of 6.5% and 14.9%, respectively. The most significant driver of the changes in the effective income tax rate for the three and nine months ended September 30, 2022 compared to the prior year was the change in the Company’s forecasted jurisdictional mix of earnings, where income expected to be generated in higher rate jurisdictions exceeds income expected to be generated in lower rate jurisdictions. Also impacting the effective tax rate for the three and nine months ended September 30, 2022 was the revaluation of the Company’s net deferred tax assets in Switzerland, which were originally established as part of the Swiss cantonal tax reform measures enacted in 2019. This revaluation resulted in a one-time deferred tax expense of $15.3 million recorded in the second quarter of 2022. This expense was partially offset by the release of a valuation allowance of $8.5 million during the second quarter of 2022, as a result of improvements in actual and projected future results in one of the Company’s subsidiaries in Luxembourg. Additionally, the effective income tax rate for this period was impacted by a $35.6 million charge recorded in the first quarter of 2022 related to the European Commission request for information, as described within Note 13 in the condensed consolidated financial statements, for which the Company estimates no tax benefit based on currently available information. The effective income tax rate for the three and nine months ended September 30, 2021 was significantly impacted by the release of a valuation allowance of $16.3 million, as a result of improvements in actual business operations and projected future results of one of the Company’s subsidiaries in China.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2022
Commitments and Contingencies.
Commitments and Contingencies	NOTE 13—COMMITMENTS AND CONTINGENCIES Environmental Matters Accruals for environmental matters are recorded when it is probable that a liability has been incurred and the amount of the liability can be reasonably estimated based on current law, existing technologies and other information. Pursuant to the terms of the agreement associated with the Company’s formation, the pre-closing environmental liabilities were retained by Dow, and Dow agreed, subject to temporal, monetary, and other limitations to indemnify the Company from and against environmental liabilities incurred or relating to the predecessor periods. Other than certain immaterial environmental liabilities assumed as part of the PMMA Acquisition and the Aristech Surfaces Acquisition, no environmental claims have been asserted or threatened against the Company. The Company is not a potentially responsible party for any material amounts at any Superfund Sites. As of September 30, 2022 and December 31, 2021, the Company had $4.1 million and $4.4 million, respectively, of accrued obligations for environmental remediation or restoration costs, which were recorded at fair value within the opening balance sheets of the PMMA business and Aristech Surfaces during 2021. Inherent uncertainties exist in the Company’s potential environmental liabilities primarily due to unknown conditions, whether future claims may fall outside the scope of the indemnity, changing governmental regulations and legal standards regarding liability, and evolving technologies for handling site remediation and restoration. In connection with the Company’s existing indemnification, the possibility is considered remote that environmental remediation costs will have a material adverse impact on the condensed consolidated financial statements over the next 12 months. Purchase Commitments In the normal course of business, the Company has certain raw material purchase contracts where it is required to purchase certain minimum volumes at current market prices. These commitments range from one During the three and nine months ended September 30, 2022, the Company recorded a one-time charge of approximately $19.0 million related to raw material purchase contract obligations. This estimated liability, which is subject to change, was recorded within “Cost of sales” in the condensed consolidated statements of operations. Litigation Matters From time to time, the Company may be subject to various legal claims and proceedings incidental to the normal conduct of business, relating to such matters as employees, product liability, antitrust/competition, past waste disposal practices and release of chemicals into the environment. While it is impossible at this time to determine with certainty the ultimate outcome of these routine claims, the Company does not believe that the ultimate resolution of these claims will have a material adverse effect on the Company’s results of operations, financial condition or cash flow. Legal costs, including those legal costs expected to be incurred in connection with a loss contingency, are expensed as incurred. European Commission Request for Information On June 6, 2018, Trinseo Europe GmbH, a subsidiary of the Company, received a request for information in the form of a letter from the European Commission Directorate General for Competition (the “European Commission”) related to styrene monomer commercial activity in the European Economic Area. The Company subsequently commenced an internal investigation into these commercial activities and discovered instances of inappropriate activity. On October 28, 2019, a supplemental request for information was received from the European Commission. This request was limited to historical employment, entity, and organizational structures, along with certain financial, styrene purchasing, and styrene market information, as well as certain spot styrene purchase contracts. The Company has provided all information requested and continues to fully cooperate with the European Commission. As a result of further developments in this matter, during the first quarter of 2022, the Company recorded a charge of $35.6 million which is included within “Other charges” on the condensed consolidated statements of operations. As of September 30, 2022, the estimated liability recorded on the balance sheet related to this matter was $31.2 million, adjusted for foreign exchange rate impacts. The Company is unable to predict the ultimate outcome of this matter, which remains ongoing. Based on its findings, the European Commission may decide to adopt a final decision imposing additional fines and/or request certain behavioral or structural commitments from the Company. However, any additional potential losses incurred could be material to the Company’s results of operations, balance sheet, and cash flows. ​

Pension Plans And Other Postret

Pension Plans And Other Postretirement Benefits	9 Months Ended
	Sep. 30, 2022
Pension Plans and Other Postretirement Benefits
Pension Plans and Other Postretirement Benefits	NOTE 14—PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS The components of net periodic benefit costs for all significant plans were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Three Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ ​ Non-U.S. Defined Benefit Pension Plans ​ U.S. Defined Benefit Pension (1) ​ ​ 2022 2021 2022 2021 Net periodic benefit cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service cost ​ $ 3.0 ​ $ 4.0 $ 0.2 ​ $ 0.2 ​ Interest cost ​ 0.6 ​ 0.2 ​ 0.2 ​ 0.2 ​ Expected return on plan assets ​ (0.1) ​ (0.1) ​ (0.2) ​ (0.2) ​ Amortization of prior service credit ​ (0.1) ​ (0.5) ​ — ​ — ​ Amortization of net loss ​ 0.6 ​ 1.6 ​ — ​ — ​ Settlement and curtailment gain ​ (1.2) ​ (2.3) ​ (0.2) ​ — ​ Net periodic benefit cost ​ $ 2.8 ​ $ 2.9 ​ $ — ​ $ 0.2 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ ​ Non-U.S. Defined Benefit Pension Plans ​ U.S. Defined Benefit Pension (1) ​ ​ 2022 2021 2022 2021 Net periodic benefit cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service cost ​ $ 9.3 ​ $ 12.1 $ 0.7 ​ $ 0.3 ​ Interest cost ​ 2.0 ​ 1.1 ​ 0.5 ​ 0.3 ​ Expected return on plan assets ​ (0.2) ​ (0.2) ​ (0.7) ​ (0.4) ​ Amortization of prior service credit ​ (0.3) ​ (0.9) ​ — ​ — ​ Amortization of net loss ​ 1.9 ​ 4.7 ​ — ​ — ​ Settlement and curtailment gain ​ ​ (3.1) ​ ​ (2.3) ​ ​ (0.2) ​ ​ — ​ Net periodic benefit cost ​ $ 9.6 ​ $ 14.5 ​ $ 0.3 ​ $ 0.2 ​ (1) The Company’s U.S. defined benefit pension plans were acquired in 2021, primarily in conjunction with the PMMA Acquisition. The Company had less than $0.1 million of net periodic benefit costs for its other postretirement plans for the three and nine months ended September 30, 2022 and 2021. Service cost related to the Company’s defined benefit pension plans and other postretirement plans is included within “Cost of sales” and “Selling, general and administrative expenses,” whereas all other components of net periodic benefit cost are included within “Other expense, net” in the condensed consolidated statements of operations. As of September 30, 2022 and December 31, 2021, the Company’s benefit obligations included primarily in “Other noncurrent obligations” in the condensed consolidated balance sheets were $237.8 million and $274.7 million, respectively. The Company made cash contributions and benefit payments to unfunded plans of approximately $1.4 million and $6.1 million during the three and nine months ended September 30, 2022, respectively. The Company expects to make additional cash contributions, including benefit payments to unfunded plans, of approximately $2.7 million to its defined benefit plans for the remainder of 2022. ​

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2022
Share-Based Compensation.
Share-Based Compensation	NOTE 15—SHARE-BASED COMPENSATION Refer to the Annual Report for definitions of capitalized terms not included herein and further background on the Company’s share-based compensation programs included in the tables below. The following table summarizes the Company’s share-based compensation expense for the three and nine months ended September 30, 2022 and 2021, as well as unrecognized compensation cost as of September 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ September 30, 2022 ​ ​ ​ September 30, ​ September 30, ​ Unrecognized ​ Weighted ​ ​ 2022 2021 2022 2021 Compensation Cost Average Years ​ RSUs ​ $ 2.1 ​ $ 2.1 ​ $ 9.1 ​ $ 5.7 ​ $ 11.3 ​ 1.7 ​ Options ​ ​ 0.6 ​ ​ 1.2 ​ ​ 4.4 ​ ​ 3.5 ​ ​ 2.7 ​ 1.4 ​ PSUs ​ ​ 0.7 ​ ​ 0.7 ​ ​ 2.1 ​ ​ 1.8 ​ ​ 4.4 ​ 2.0 ​ Total share-based compensation expense ​ $ 3.4 ​ $ 4.0 ​ $ 15.6 ​ $ 11.0 ​ ​ ​ ​ ​ ​ ​ The following table summarizes awards granted and the respective weighted average grant date fair value for the nine months ended September 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ ​ ​ September 30, 2022 ​ ​ ​ Awards Granted ​ Weighted Average Grant Date Fair Value per Award ​ RSUs ​ ​ 197,986 ​ $ 52.10 ​ Options ​ ​ 192,175 ​ ​ 22.52 ​ PSUs ​ ​ 63,317 ​ ​ 57.47 ​ ​ Option Awards The following are the weighted average assumptions used within the Black-Scholes pricing model for the Company’s option awards granted during the nine months ended September 30, 2022: ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ September 30, 2022 Expected term (in years) 5.50 ​ Expected volatility 48.72 % Risk-free interest rate 1.97 % Dividend yield ​ 2.00 % ​ The expected volatility assumption is determined based on the historical volatility of the Company’s publicly traded ordinary shares. The expected term of option awards represents the period of time that option awards granted are expected to be outstanding. For the option awards granted during the nine months ended September 30, 2022, the simplified method was used to calculate the expected term, given the Company’s limited historical exercise data. The risk-free interest rate for the periods within the expected term of option awards is based on the U.S. Treasury yield curve in effect at the time of grant. The dividend yield is estimated based on historical and expected dividend activity. Performance Share Units (PSUs) The following are the weighted average assumptions used within the Monte Carlo valuation model for PSUs granted during the nine months ended September 30, 2022: ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ ​ September 30, 2022 Expected term (in years) ​ 3.00 ​ Expected volatility 57.30 % Risk-free interest rate 1.73 % Share price $ 58.64 ​ ​ Determining the fair value of PSUs requires considerable judgment, including estimating the expected volatility of the price of the Company’s ordinary shares, the correlation between the Company’s share price and that of its peer companies, and the expected rate of interest. The expected volatility for each grant is determined based on the historical volatility of the Company’s ordinary shares. The expected term of PSUs represents the length of the performance period. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for a duration equivalent to the performance period. The share price is the closing price of the Company’s ordinary shares on the grant date.

Segments

Segments	9 Months Ended
	Sep. 30, 2022
Segments
Segments	NOTE 16—SEGMENTS The Company operates under six segments: Engineered Materials, Latex Binders, Base Plastics, Polystyrene, Feedstocks, and Americas Styrenics. The Engineered Materials segment includes the Company’s compounds and blends products sold into higher growth and value applications, such as consumer electronics and medical, as well as soft thermoplastic elastomers (“TPEs”) products which are sold into markets such as footwear and automotive. Additionally, PMMA and MMA products, which are sold into a variety of applications including automotive, building & construction, medical, consumer electronics, and wellness, among others. The Latex Binders segment produces styrene-butadiene latex (“SB latex”) and other latex polymers and binders, primarily for coated paper and packaging board, carpet and artificial turf backings, as well as a number of performance latex binders applications, such as adhesive, building and construction and the technical textile paper market. The Base Plastics segment contains the results of the acrylonitrile-butadiene-styrene (“ABS”), styrene-acrylonitrile (“SAN”), and polycarbonate (“PC”) businesses, as well as compounds and blends for automotive and other applications. The Base Plastics segment also includes the results of Heathland, which was acquired in the first quarter of 2022. The Polystyrene segment includes a variety of general purpose polystyrenes (“GPPS”) and polystyrene that has been modified with polybutadiene rubber to increase its impact resistant properties (“HIPS”). The Feedstocks segment includes the Company’s production and procurement of styrene monomer outside of North America, which is used as a key raw material in many of the Company’s products, including polystyrene, SB latex, and ABS resins. Lastly, the Americas Styrenics segment consists solely of the operations of the Company’s The following table provides disclosure of the Company’s segment Adjusted EBITDA, which is used to measure segment operating performance and is defined below, for the three and nine months ended September 30, 2022 and 2021. Asset and intersegment sales information by reporting segment is not regularly reviewed or included with the Company’s reporting to the chief operating decision maker. Therefore, this information has not been disclosed below. Refer to Note 5 for the Company’s net sales to external customers by segment for the three and nine months ended September 30, 2022 and 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Engineered ​ Latex ​ Base ​ ​ ​ ​ ​ Americas Three Months Ended (1) ​ Materials ​ Binders ​ Plastics ​ Polystyrene ​ Feedstocks ​ Styrenics September 30, 2022 $ 7.5 $ 31.0 ​ $ (14.9) ​ $ 18.7 $ (78.0) $ 22.8 ​ September 30, 2021 ​ $ 32.7 ​ $ 37.1 ​ $ 87.9 ​ $ 51.2 ​ $ (27.6) ​ $ 17.1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Engineered ​ Latex ​ Base ​ ​ ​ ​ ​ Americas Nine Months Ended (1) ​ Materials ​ Binders ​ Plastics ​ Polystyrene ​ Feedstocks ​ Styrenics September 30, 2022 ​ $ 76.2 ​ $ 90.6 ​ $ 99.8 ​ $ 87.0 ​ $ (59.8) ​ $ 83.8 ​ September 30, 2021 ​ $ 68.5 ​ $ 86.2 ​ $ 235.0 ​ $ 149.6 ​ $ 58.5 ​ $ 70.2 ​ ​ (1) The Company’s primary measure of segment operating performance is Adjusted EBITDA, which is defined as income from continuing operations before interest expense, net; provision for income taxes; depreciation and amortization expense; loss on extinguishment of long-term debt; asset impairment charges; gains or losses on the dispositions of businesses and assets; restructuring charges; acquisition related costs and benefits and other items. Segment Adjusted EBITDA is a key metric that is used by management to evaluate business performance in comparison to budgets, forecasts, and prior year financial results, providing a measure that management believes reflects core operating performance by removing the impact of transactions and events that would not be considered a part of core operations. Other companies in the industry may define segment Adjusted EBITDA differently than the Company, and as a result, it may be difficult to use segment Adjusted EBITDA, or similarly named financial measures, that other companies may use to compare the performance of those companies to the Company’s segment performance. ​ The reconciliation of income from continuing operations before income taxes to segment Adjusted EBITDA is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2022 2021 2022 2021 Income from continuing operations before income taxes ​ $ (130.0) ​ $ 84.9 ​ $ (22.3) ​ $ 327.1 ​ Interest expense, net ​ 30.4 ​ 23.0 ​ 77.7 ​ 56.6 ​ Depreciation and amortization ​ 45.9 ​ 49.8 ​ ​ 147.1 ​ 111.0 ​ Corporate Unallocated (2) ​ ​ 23.7 ​ ​ 25.0 ​ ​ 72.1 ​ ​ 71.3 ​ Adjusted EBITDA Addbacks (3) ​ 17.1 ​ 15.7 ​ 103.0 ​ 102.0 ​ Segment Adjusted EBITDA ​ $ (12.9) ​ $ 198.4 ​ $ 377.6 ​ $ 668.0 ​ (2) Corporate unallocated includes corporate overhead costs and certain other income and expenses. (3) Adjusted EBITDA addbacks for the three and nine months ended September 30, 2022 and 2021 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ ​ 2022 2021 2022 2021 Net gain on disposition of businesses and assets ​ $ — ​ $ — ​ $ (1.8) ​ $ (0.2) ​ Restructuring and other charges (Note 17) ​ ​ — ​ ​ 0.2 ​ ​ (1.0) ​ ​ 6.8 ​ Acquisition transaction and integration net costs (Note 3) ​ ​ 0.4 ​ ​ 13.6 ​ ​ 6.2 ​ ​ 62.8 ​ Acquisition purchase price hedge (gain) loss (Note 10) ​ ​ — ​ ​ — ​ ​ — ​ ​ 22.0 ​ Asset impairment charges or write-offs (Note 11) ​ ​ 1.9 ​ ​ 1.2 ​ ​ 3.9 ​ ​ 3.0 ​ European Commission request for information (Note 13) ​ ​ — ​ ​ — ​ ​ 35.6 ​ ​ — ​ Other items (a) ​ ​ 14.8 ​ ​ 0.7 ​ ​ 60.1 ​ ​ 7.6 ​ Total Adjusted EBITDA Addbacks ​ $ 17.1 ​ $ 15.7 ​ $ 103.0 ​ $ 102.0 ​ (a) Other items for the three and nine months ended September 30, 2022 and 2021 primarily relate to fees incurred in conjunction with certain of the Company’s strategic initiatives, as well as our transition to a new enterprise resource planning system.

Restructuring

Restructuring	9 Months Ended
	Sep. 30, 2022
Restructuring
Restructuring	NOTE 17—RESTRUCTURING Refer to the Annual Report for further details regarding the Company’s previously announced restructuring activities included in the tables below. Restructuring charges are included within “Selling, general and administrative expenses” in the condensed consolidated statements of operations. The following table provides detail of the Company’s restructuring charges for the three and nine months ended September 30, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ Cumulative ​ ​ ​ ​ ​ September 30, ​ September 30, ​ Life-to-date ​ ​ ​ ​ ​ 2022 2021 ​ 2022 2021 ​ Charges Segment ​ Transformational Restructuring Program ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Employee termination benefits ​ $ — ​ $ 0.3 ​ $ 0.1 ​ $ 6.4 ​ $ 8.8 ​ N/A (1) ​ Transformational Restructuring Program Subtotal ​ $ — ​ $ 0.3 ​ $ 0.1 ​ $ 6.4 ​ $ 8.8 ​ ​ ​ Other Restructurings ​ ​ — ​ ​ (0.1) ​ ​ (1.1) ​ ​ — ​ ​ ​ ​ Various ​ Total Restructuring Charges ​ $ — ​ $ 0.2 ​ $ (1.0) ​ $ 6.4 ​ ​ ​ ​ ​ ​ (1) In May 2021, the Company approved a transformational restructuring program associated with the Company’s recent strategic initiatives. The Company expects to incur incremental employee termination benefit charges related to impacted employees as of September 30, 2022 of less than $1.0 million, the majority of which are expected to be paid by December 31, 2022. As this was identified as a corporate-related activity, the charges related to this restructuring program were not allocated to a specific segment, but rather included within corporate unallocated. The following table provides a roll forward of the liability balances associated with the Company’s restructuring activities as of September 30, 2022. Employee termination benefit and contract termination charges are primarily recorded within “Accrued expenses and other current liabilities” in the condensed consolidated balance sheets. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at ​ ​ ​ ​ Balance at ​ December 31, 2021 Expenses Deductions (1) September 30, 2022 Employee termination benefits ​ $ 10.0 ​ $ (1.4) ​ $ (4.4) ​ $ 4.2 ​ Decommissioning and other ​ — ​ 0.1 ​ (0.1) ​ — ​ Total ​ $ 10.0 ​ $ (1.3) ​ $ (4.5) ​ $ 4.2 ​ (1) Primarily includes payments made against the existing accrual, as well as immaterial impacts of foreign currency remeasurement.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2022
Accumulated Other Comprehensive Income (Loss).
Accumulated Other Comprehensive Income (Loss)	NOTE 18—ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) The components of AOCI, net of income taxes, consisted of: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cumulative Pension & Other ​ ​ ​ ​ ​ ​ ​ ​ Translation ​ Postretirement Benefit ​ ​ Cash Flow ​ ​ ​ ​ Three Months Ended September 30, 2022 and 2021 Adjustments Plans, Net ​ Hedges, Net Total Balance as of June 30, 2022 ​ $ (153.4) ​ $ (27.0) ​ $ 2.5 ​ $ (177.9) ​ Other comprehensive income (loss) ​ (45.0) ​ 2.4 ​ (3.4) ​ (46.0) ​ Amounts reclassified from AOCI to net income (1) ​ ​ — ​ ​ (0.9) ​ ​ (2.2) ​ ​ (3.1) ​ Balance as of September 30, 2022 ​ $ (198.4) ​ $ (25.5) ​ $ (3.1) ​ $ (227.0) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of June 30, 2021 ​ $ (109.3) ​ $ (69.8) ​ $ (0.8) ​ $ (179.9) ​ Other comprehensive income (loss) ​ (1.7) ​ 9.3 ​ 0.6 ​ 8.2 ​ Amounts reclassified from AOCI to net income (1) ​ ​ — ​ ​ (1.2) ​ ​ 0.6 ​ ​ (0.6) ​ Balance as of September 30, 2021 ​ $ (111.0) ​ $ (61.7) ​ $ 0.4 ​ $ (172.3) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cumulative Pension & Other ​ ​ ​ ​ ​ ​ ​ Translation ​ Postretirement Benefit ​ Cash Flow ​ ​ ​ ​ Nine Months Ended September 30, 2022 and 2021 ​ Adjustments Plans, Net Hedges, Net Total ​ Balance as of December 31, 2021 ​ $ (114.3) ​ $ (33.6) ​ $ 0.7 ​ $ (147.2) ​ Other comprehensive income (loss) ​ (84.1) ​ 10.0 ​ (2.7) ​ (76.8) ​ Amounts reclassified from AOCI to net income (1) ​ ​ — ​ ​ (1.9) ​ ​ (1.1) ​ ​ (3.0) ​ Balance as of September 30, 2022 ​ $ (198.4) ​ $ (25.5) ​ $ (3.1) ​ $ (227.0) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of December 31, 2020 ​ $ (109.0) ​ $ (71.9) ​ $ (5.2) ​ $ (186.1) ​ Other comprehensive income (loss) ​ (2.0) ​ 9.3 ​ 3.0 ​ 10.3 ​ Amounts reclassified from AOCI to net income (1) ​ ​ — ​ ​ 0.9 ​ ​ 2.6 ​ ​ 3.5 ​ Balance as of September 30, 2021 ​ $ (111.0) ​ $ (61.7) ​ $ 0.4 ​ $ (172.3) ​ (1) The following is a summary of amounts reclassified from AOCI to net income (loss) for the three and nine months ended September 30, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ ​ ​ September 30, ​ September 30, ​ Statements of Operations ​ AOCI Components 2022 2021 2022 2021 Classification ​ Cash flow hedging items ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign exchange cash flow hedges ​ $ — ​ $ (0.3) ​ $ — ​ $ — ​ Cost of sales ​ Commodity cash flow hedges ​ ​ (2.0) ​ ​ — ​ ​ (2.0) ​ ​ — ​ Cost of sales ​ Interest rate swaps ​ ​ (0.2) ​ ​ 0.9 ​ ​ 1.2 ​ ​ 2.6 ​ Interest expense, net ​ Total before tax ​ ​ (2.2) ​ ​ 0.6 ​ ​ (0.8) ​ ​ 2.6 ​ ​ ​ Tax effect ​ ​ — ​ ​ — ​ ​ (0.3) ​ ​ — ​ Provision for (benefit from) income taxes ​ Total, net of tax ​ $ (2.2) ​ $ 0.6 ​ $ (1.1) ​ $ 2.6 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of pension and other postretirement benefit plan items ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Prior service credit ​ $ (0.1) ​ $ (0.2) ​ $ (0.4) ​ $ (0.7) ​ (a) ​ Net actuarial loss ​ ​ 0.6 ​ ​ 1.7 ​ ​ 2.0 ​ ​ 5.3 ​ (a) ​ Net curtailment and settlement gain ​ ​ (1.4) ​ ​ (2.5) ​ ​ (3.3) ​ ​ (2.5) ​ (a) ​ Total before tax ​ ​ (0.9) ​ ​ (1.0) ​ ​ (1.7) ​ ​ 2.1 ​ ​ ​ Tax effect ​ ​ — ​ ​ (0.2) ​ ​ (0.2) ​ ​ (1.2) ​ Provision for (benefit from) income taxes ​ Total, net of tax ​ $ (0.9) ​ $ (1.2) ​ $ (1.9) ​ $ 0.9 ​ ​ ​ (a) These AOCI components are included in the computation of net periodic benefit costs (see Note 14). .

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2022
Earnings Per Share
Earnings Per Share	NOTE 19—EARNINGS PER SHARE Basic earnings per ordinary share (“basic EPS”) is computed by dividing net income available to ordinary shareholders by the weighted average number of the Company’s ordinary shares outstanding for the applicable period. Diluted earnings per ordinary share (“diluted EPS”) is calculated using net income available to ordinary shareholders divided by diluted weighted average ordinary shares outstanding during each period, which includes unvested RSUs, option awards, and PSUs. Diluted EPS considers the impact of potentially dilutive securities except in periods in which there is a loss from continuing operations because the inclusion of the potential ordinary shares would have an anti-dilutive effect. The following table presents basic EPS and diluted EPS for the three and nine months ended September 30, 2022 and 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ (in millions, except per share data) 2022 2021 2022 2021 Earnings: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) from continuing operations ​ $ (117.9) ​ $ 79.4 ​ $ (63.7) ​ $ 278.2 ​ Net income (loss) from discontinued operations ​ ​ (1.9) ​ ​ 13.7 ​ ​ (1.9) ​ ​ 38.0 ​ Net income (loss) ​ $ (119.8) ​ $ 93.1 ​ $ (65.6) ​ $ 316.2 ​ Shares: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average ordinary shares outstanding ​ 35.2 ​ 38.8 ​ 36.3 ​ 38.7 ​ Dilutive effect of RSUs, option awards, and PSUs (1) ​ — ​ 0.7 ​ — ​ 0.9 ​ Diluted weighted average ordinary shares outstanding ​ 35.2 ​ 39.5 ​ 36.3 ​ 39.6 ​ Income (loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income (loss) per share—basic: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Continuing operations ​ $ (3.35) ​ $ 2.04 ​ $ (1.76) ​ $ 7.19 ​ Discontinued operations ​ ​ (0.06) ​ ​ 0.35 ​ ​ (0.05) ​ ​ 0.98 ​ Income (loss) per share—basic ​ $ (3.41) ​ $ 2.39 ​ $ (1.81) ​ $ 8.17 ​ Income (loss) per share—diluted: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Continuing operations ​ $ (3.35) ​ $ 2.01 ​ $ (1.76) ​ $ 7.03 ​ Discontinued operations ​ ​ (0.06) ​ ​ 0.35 ​ ​ (0.05) ​ ​ 0.96 ​ Income (loss) per share—diluted ​ $ (3.41) ​ $ 2.36 ​ $ (1.81) ​ $ 7.99 ​ (1) Refer to Note 15 for discussion of RSUs, option awards, and PSUs granted to certain Company directors and employees. As the Company recorded a net loss from continuing operations for the three and nine months ended September 30, 2022, potential shares related to equity-based awards have been excluded from the calculation of diluted EPS, as doing so would be anti-dilutive. There were 0.6 million anti-dilutive shares that have been excluded from the computation of diluted earnings per share for the three and nine months ended September 30, 2021.

Other Charges

Other Charges	9 Months Ended
	Sep. 30, 2022
Other Charges
Other Charges	NOTE 20—OTHER CHARGES ​ Other charges consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2022 2021 2022 2021 Asset impairment charges or write-offs (Note 11) ​ $ 1.9 ​ $ 1.2 ​ $ 3.9 ​ $ 3.0 European Commission request for information (Note 13) ​ ​ — ​ ​ — ​ ​ 35.6 ​ ​ — Total ​ $ 1.9 ​ $ 1.2 ​ $ 39.5 ​ $ 3.0 ​

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2022
Basis of Presentation
Basis of Presentation	The unaudited interim condensed consolidated financial statements of Trinseo PLC and its subsidiaries (the “Company”) as of and for the periods ended September 30, 2022 and 2021 were prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and reflect all adjustments, consisting only of normal recurring adjustments, which, in the opinion of management, are considered necessary for the fair statement of the results for the periods presented. Because they cover interim periods, the statements and related notes to the financial statements do not include all disclosures normally provided in annual financial statements, and therefore, these statements should be read in conjunction with the 2021 audited consolidated financial statements included within the Company’s Annual Report on Form 10-K (“Annual Report”) filed with the Securities and Exchange Commission (“SEC”) on February 23, 2022. The Company’s condensed consolidated financial statements presented herein reflect the latest estimates and assumptions made by management that affect the reported amounts and related disclosures as of and for the period ended September 30, 2022. However, actual results could differ from these estimates and assumptions. The December 31, 2021 condensed consolidated balance sheet data presented herein was derived from the Company’s December 31, 2021 audited consolidated financial statements, but does not include all disclosures required by GAAP for annual periods. Certain prior year amounts have been reclassified to conform to the current year presentation. Throughout this Quarterly Report, unless otherwise indicated, amounts and activity are presented on a continuing operations basis.

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2022
Business Acquisition [Line Items]
Schedule of unaudited pro forma financial information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2021 2021 Net sales $ 1,300.2 $ 3,863.8 Net income ​ $ 94.1 ​ $ 355.1 Income from continuing operations ​ $ 80.4 ​ $ 317.1
Heathland B.V.
Business Acquisition [Line Items]
Schedule of purchase price allocation	​ ​ ​ ​ ​ ​ ​ January 3, ​ 2022 Cash and cash equivalents ​ $ 1.0 Other current assets ​ ​ 1.2 Other intangible assets (1) ​ ​ ​ Customer relationships ​ 5.1 Tradenames ​ 0.9 Developed technology ​ ​ 0.2 Other assets ​ ​ 1.0 Total fair value of assets acquired ​ ​ 9.4 ​ ​ ​ ​ Current liabilities ​ (1.3) Noncurrent liabilities ​ ​ (1.6) Total fair value of liabilities assumed ​ ​ (2.9) Net identifiable assets acquired ​ ​ 6.5 Purchase price consideration ​ ​ 29.3 Goodwill (2) ​ $ 22.8 (1) The expected weighted average useful life of the acquired intangible assets are 7 years for customer relationships, tradenames and developed technology. (2) Goodwill largely consists of strategic and synergistic opportunities resulting from combining Heathland with the Company’s existing businesses and is allocated entirely to the Base Plastics segment. No goodwill related to this acquisition is expected to be deductible for income tax purposes.

Divestitures And Discontinued_2

Divestitures And Discontinued Operations (Tables)	9 Months Ended
	Sep. 30, 2022
Emulsion Polymers, Synthetic Rubber | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Summary of the assets and liabilities classified as held-for-sale and results reflected as discontinued operations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2022 2021 2022 2021 Net sales $ — $ 122.3 $ 0.1 $ 382.2 Cost of sales ​ 2.2 ​ 101.9 ​ 3.6 ​ 321.2 ​ Gross profit (loss) ​ (2.2) ​ 20.4 ​ (3.5) ​ 61.0 ​ Selling, general and administrative expenses ​ — ​ 4.9 ​ (0.3) ​ 16.7 ​ Operating income (loss) ​ (2.2) ​ 15.5 ​ (3.2) ​ 44.3 ​ Gain on sale of businesses and other assets ​ ​ — ​ ​ — ​ ​ 1.2 ​ ​ — ​ Other expense, net ​ ​ — ​ ​ 0.2 ​ ​ — ​ ​ 1.2 ​ Income (loss) from discontinued operations before income taxes ​ (2.2) ​ 15.3 ​ (2.0) ​ 43.1 ​ Provision for (benefit from) income taxes ​ (0.3) ​ 1.6 ​ (0.1) ​ 5.1 ​ Net income (loss) from discontinued operations ​ $ (1.9) ​ $ 13.7 ​ $ (1.9) ​ $ 38.0 ​

Net Sales (Tables)

Net Sales (Tables)	9 Months Ended
	Sep. 30, 2022
Net Sales
Disaggregation of Revenue [Table Text Block]	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Engineered ​ Latex ​ Base ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Materials ​ Binders ​ Plastics ​ Polystyrene ​ Feedstocks ​ Total September 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ United States ​ $ 128.9 ​ $ 105.4 ​ $ 73.7 ​ $ — ​ $ 4.5 ​ $ 312.5 ​ Europe ​ 72.5 ​ 160.1 ​ 157.1 ​ 174.0 ​ 48.9 ​ 612.6 ​ Asia-Pacific ​ 38.9 ​ 72.9 ​ 33.3 ​ 73.7 ​ — ​ 218.8 ​ Rest of World ​ 2.4 ​ 2.5 ​ 29.3 ​ — ​ — ​ 34.2 ​ Total ​ $ 242.7 ​ $ 340.9 ​ $ 293.4 ​ $ 247.7 ​ $ 53.4 ​ $ 1,178.1 ​ September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ United States ​ $ 102.4 ​ $ 86.3 ​ $ 82.3 ​ $ — ​ $ 4.0 ​ $ 275.0 ​ Europe ​ 89.6 ​ 153.5 ​ ​ 247.3 ​ 162.6 ​ 50.8 ​ 703.8 ​ Asia-Pacific ​ 35.9 ​ 73.0 ​ ​ 43.9 ​ 112.2 ​ — ​ ​ 265.0 ​ Rest of World ​ 2.9 ​ 2.8 ​ ​ 19.8 ​ — ​ — ​ 25.5 ​ Total ​ $ 230.8 ​ $ 315.6 ​ $ 393.3 ​ $ 274.8 ​ $ 54.8 ​ $ 1,269.3 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Engineered ​ Latex ​ Base ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ Materials ​ Binders ​ Plastics ​ Polystyrene ​ Feedstocks ​ Total September 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ United States ​ $ 418.0 ​ $ 290.1 ​ $ 264.3 ​ $ — ​ $ 13.0 ​ $ 985.4 ​ Europe ​ 300.1 ​ 480.4 ​ 602.2 ​ 604.5 ​ 207.3 ​ 2,194.5 ​ Asia-Pacific ​ 112.4 ​ 223.9 ​ 102.1 ​ 273.1 ​ — ​ 711.5 ​ Rest of World ​ 8.7 ​ 6.9 ​ 83.2 ​ 0.1 ​ — ​ 98.9 ​ Total ​ $ 839.2 ​ $ 1,001.3 ​ $ 1,051.8 ​ $ 877.7 ​ $ 220.3 ​ $ 3,990.3 ​ September 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ United States ​ $ 174.1 ​ $ 228.2 ​ $ 216.5 ​ $ — ​ $ 10.7 ​ $ 629.5 ​ Europe ​ 190.8 ​ 431.4 ​ ​ 699.2 ​ 511.7 ​ 188.9 ​ 2,022.0 ​ Asia-Pacific ​ 108.1 ​ 211.1 ​ ​ 144.5 ​ 343.3 ​ — ​ ​ 807.0 ​ Rest of World ​ 4.5 ​ 6.9 ​ ​ 59.1 ​ — ​ — ​ 70.5 ​ Total ​ $ 477.5 ​ $ 877.6 ​ $ 1,119.3 ​ $ 855.0 ​ $ 199.6 ​ $ 3,529.0 ​

Investments in Unconsolidated_2

Investments in Unconsolidated Affiliates (Tables)	9 Months Ended
	Sep. 30, 2022
Investments in Unconsolidated Affiliates
Summarized Financial Information of Unconsolidated Affiliates	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2022 2021 2022 2021 Sales $ 535.3 $ 433.4 $ 1,654.3 $ 1,351.9 ​ Gross profit ​ $ 70.6 ​ $ 49.3 ​ $ 212.2 ​ $ 189.2 ​ Net income ​ $ 48.3 ​ $ 37.2 ​ $ 164.5 ​ $ 151.8 ​

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2022
Inventories
Schedule of Inventories	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2022 ​ 2021 Finished goods $ 281.7 $ 279.2 Raw materials and semi-finished goods ​ 297.5 ​ 303.9 Supplies ​ 34.8 ​ 37.9 Total ​ $ 614.0 ​ $ 621.0

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2022
Debt
Schedule of Debt [Table Text Block]	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2022 ​ December 31, 2021 ​ ​ Interest Rate as of September 30, 2022 Maturity Date Carrying Amount Unamortized Deferred Financing Fees (1) Total Debt, Less Unamortized Deferred Financing Fees Carrying Amount Unamortized Deferred Financing Fees (1) Total Debt, Less Unamortized Deferred Financing Fees ​ Senior Credit Facility ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 Term Loan B ​ 5.115% ​ September 2024 ​ $ 665.2 ​ $ (5.9) ​ $ 659.3 ​ $ 670.4 ​ $ (8.0) ​ $ 662.4 ​ 2028 Term Loan B ​ 5.615% ​ May 2028 ​ ​ 737.6 ​ ​ (15.1) ​ ​ 722.5 ​ ​ 742.8 ​ ​ (17.0) ​ ​ 725.8 ​ 2026 Revolving Facility (2) ​ Various ​ May 2026 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ 2029 Senior Notes ​ 5.125% ​ April 2029 ​ ​ 447.0 ​ ​ (13.3) ​ ​ 433.7 ​ ​ 450.0 ​ ​ (14.7) ​ ​ 435.3 ​ 2025 Senior Notes ​ 5.375% ​ September 2025 ​ ​ 500.0 ​ ​ (4.0) ​ ​ 496.0 ​ ​ 500.0 ​ ​ (5.0) ​ ​ 495.0 ​ Accounts Receivable Securitization Facility (3) ​ Various ​ November 2024 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ Other indebtedness ​ Various ​ Various ​ ​ 3.0 ​ ​ — ​ ​ 3.0 ​ ​ 5.6 ​ ​ — ​ ​ 5.6 ​ Total debt ​ ​ ​ ​ ​ $ 2,352.8 ​ $ (38.3) ​ $ 2,314.5 ​ $ 2,368.8 ​ $ (44.7) ​ $ 2,324.1 ​ Less: current portion (4) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (16.7) ​ ​ ​ ​ ​ ​ ​ ​ (18.5) ​ Total long-term debt, net of unamortized deferred financing fees ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 2,297.8 ​ ​ ​ ​ ​ ​ ​ $ 2,305.6 ​ (1) This caption does not include deferred financing fees related to the Company’s revolving facilities, which are included within “Deferred charges and other assets” on the condensed consolidated balance sheets. (2) As of September 30, 2022, under the 2026 Revolving Facility, the Company had a capacity of $375.0 million and funds available for borrowing of $369.2 million (net of $5.8 million outstanding letters of credit). Additionally, the Company is required to pay a quarterly commitment fee in respect of any unused commitments under this facility equal to 0.375% per annum. (3) As of September 30, 2022, this facility had a borrowing capacity of $150.0 million, and the Company had approximately $150.0 million of accounts receivable available to support this facility, based on the pool of eligible accounts receivable. (4) The current portion of long-term debt was primarily related to $14.5 million of the scheduled future principal payments on both the 2024 Term Loan B and 2028 Term Loan B as of September 30, 2022 and December 31, 2021.

Goodwill (Tables)

Goodwill (Tables)	9 Months Ended
	Sep. 30, 2022
Goodwill.
Changes in Carrying Amount of Goodwill, by Segment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Engineered ​ Latex ​ Base ​ ​ ​ ​ ​ Americas ​ ​ ​ ​ Materials Binders Plastics Polystyrene Feedstocks Styrenics Total Balance at December 31, 2021 ​ $ 667.3 ​ $ 15.9 ​ $ 22.4 ​ $ 4.5 ​ $ — ​ $ — ​ $ 710.1 ​ Acquisitions (Note 3) ​ ​ — ​ ​ — ​ ​ 22.8 ​ ​ — ​ ​ — ​ ​ — ​ ​ 22.8 ​ Foreign currency impact ​ (31.7) ​ ​ (2.3) ​ ​ (6.3) ​ ​ (0.7) ​ ​ — ​ ​ — ​ (41.0) ​ Balance at September 30, 2022 ​ $ 635.6 ​ $ 13.6 ​ $ 38.9 ​ $ 3.8 ​ $ — ​ $ — ​ $ 691.9 ​

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2022
Derivative Instruments
Notional Amounts of Most Significant Net Foreign Exchange Hedge Positions Outstanding	​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ Buy / (Sell) 2022 ​ Euro ​ $ (411.1) ​ Chinese Yuan ​ $ (46.4) ​ Swedish Krona ​ $ 20.7 ​ South Korean Won ​ $ (18.3) ​ New Taiwan Dollar ​ $ 15.6 ​
Schedule of Effect of Derivative Instruments on Statements of Operations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Location and Amount of Gain (Loss) Recognized in Statements of Operations ​ ​ Three Months Ended ​ Three Months Ended ​ ​ September 30, 2022 ​ September 30, 2021 ​ Cost of sales ​ Interest expense, net ​ Other (expense) income, net ​ Cost of sales ​ Interest expense, net ​ Other (expense) income, net Total amount of income and (expense) line items presented in the statements of operations in which the effects of derivative instruments are recorded ​ $ (1,217.6) ​ $ (30.4) ​ $ (0.5) ​ $ (1,101.0) ​ $ (23.0) ​ $ 0.1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The effects of cash flow hedge instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign exchange cash flow hedges ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain reclassified from AOCI into income ​ $ — ​ $ — ​ $ — ​ $ 0.3 ​ $ — ​ $ — Commodity cash flow hedges ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain reclassified from AOCI into income ​ $ 2.0 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — Interest rate swaps ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain (loss) reclassified from AOCI into income ​ $ — ​ $ 0.2 ​ $ — ​ $ — ​ $ (0.9) ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The effects of net investment hedge instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cross currency swaps (CCS) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain excluded from effectiveness testing ​ $ — ​ $ — ​ $ — ​ $ — ​ $ 1.9 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The effects of derivatives not designated as hedge instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign exchange forward contracts ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain recognized in income (1) ​ $ — ​ $ — ​ $ 33.7 ​ $ — ​ $ — ​ $ 23.3 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Location and Amount of Gain (Loss) Recognized in Statements of Operations ​ ​ Nine Months Ended ​ Nine Months Ended ​ ​ September 30, 2022 ​ September 30, 2021 ​ Cost of sales ​ Interest expense, net ​ Other (expense) income, net ​ Cost of sales ​ Interest expense, net ​ Acquisition purchase price hedge gain (loss) ​ Other (expense) income, net Total amount of income and (expense) line items presented in the statements of operations in which the effects of derivative instruments are recorded ​ $ (3,714.8) ​ $ (77.7) ​ $ (1.6) ​ $ (2,951.7) ​ $ (56.6) ​ $ (22.0) ​ $ (8.4) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The effects of cash flow hedge instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity cash flow hedges ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain reclassified from AOCI into income ​ $ 2.0 ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — Interest rate swaps ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of loss reclassified from AOCI into income ​ $ — ​ $ (1.2) ​ $ — ​ $ — ​ $ (2.6) ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The effects of net investment hedge instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cross currency swaps (CCS) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain excluded from effectiveness testing ​ $ — ​ $ 2.4 ​ $ — ​ $ — ​ $ 5.5 ​ $ — ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The effects of derivatives not designated as hedge instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign exchange forward contracts ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount of gain (loss) recognized in income (1) ​ $ — ​ $ — ​ $ 81.6 ​ $ — ​ $ — ​ $ (22.0) ​ $ 43.4 (1) The $22.0 million loss incurred from the change in fair value of the forward currency hedge arrangement on the euro-denominated purchase price of the PMMA business during the nine months ended September 30, 2021 is presented separately in the condensed consolidated statements of operations from the gains recorded on the Company’s other foreign exchange forward contracts. ​
Schedule of Effect of Hedges on AOCI	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ` ​ Gain (Loss) Recognized in AOCI on Balance Sheet ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ ​ 2022 ​ 2021 ​ 2022 ​ 2021 Designated as Cash Flow Hedges ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign exchange cash flow hedges $ — $ 0.4 $ — $ 3.1 Commodity cash flow hedges ​ ​ (5.4) ​ ​ — ​ ​ (5.4) ​ ​ — Interest rate swaps ​ ​ (0.2) ​ ​ 0.8 ​ ​ 2.2 ​ ​ 2.5 Total ​ $ (5.6) ​ $ 1.2 ​ $ (3.2) ​ $ 5.6 Designated as Net Investment Hedges ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cross currency swaps (CCS) ​ $ — ​ $ 13.1 ​ $ 15.8 ​ $ 32.1 Total ​ $ — ​ $ 13.1 ​ $ 15.8 ​ $ 32.1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gain (Loss) Recognized in Other expense, net in Statement of Operations ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2022 2021 2022 2021 Settlements and changes in the fair value of forward contracts (not designated as hedges) (1) $ 33.7 $ 23.3 $ 81.6 $ 43.4 Remeasurement of foreign currency-denominated assets and liabilities ​ $ (35.4) ​ $ (23.7) ​ $ (83.4) ​ $ (43.0) ​ Total ​ $ (1.7) ​ $ (0.4) ​ $ (1.8) ​ $ 0.4 ​ (1) Amount does not include the loss of $22.0 million recorded from the change in fair value of the forward currency hedge arrangement on the euro-denominated purchase price of the PMMA business during the nine months ended September 30, 2021. ​
Schedule of Gross and Net Unrealized Gains and Losses and Balance Sheet Classification	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2022 ​ ​ Foreign ​ ​ ​ ​ ​ ​ ​ Exchange ​ Commodity ​ ​ ​ Balance Sheet ​ Forward ​ Cash Flow ​ ​ Classification Contracts ​ Hedges ​ Total Asset Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ Accounts receivable, net of allowance ​ $ 11.5 ​ $ — ​ $ 11.5 Gross derivative asset position ​ ​ 11.5 ​ ​ — ​ ​ 11.5 Less: Counterparty netting ​ ​ (0.7) ​ ​ — ​ ​ (0.7) Net derivative asset position ​ $ 10.8 ​ $ — ​ $ 10.8 Liability Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ Accounts payable ​ $ (0.7) ​ $ (1.8) ​ $ (2.5) Gross derivative liability position ​ ​ (0.7) ​ ​ (1.8) ​ ​ (2.5) Less: Counterparty netting ​ ​ 0.7 ​ ​ — ​ ​ 0.7 Net derivative liability position ​ $ — ​ $ (1.8) ​ $ (1.8) Total net derivative position ​ $ 10.8 ​ $ (1.8) ​ $ 9.0 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ Foreign ​ ​ ​ ​ ​ ​ ​ ​ Exchange ​ Interest ​ Cross ​ ​ ​ ​ Balance Sheet ​ Forward ​ Rate ​ Currency ​ ​ Classification Contracts Swaps Swaps Total Asset Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accounts receivable, net of allowance ​ $ 2.3 ​ $ — ​ $ — ​ $ 2.3 ​ Gross derivative asset position ​ ​ 2.3 ​ ​ — ​ ​ — ​ ​ 2.3 ​ Less: Counterparty netting ​ ​ (0.1) ​ ​ — ​ ​ — ​ ​ (0.1) ​ Net derivative asset position ​ $ 2.2 ​ $ — ​ $ — ​ $ 2.2 ​ Liability Derivatives: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accounts payable ​ $ (1.3) ​ $ (2.2) ​ $ (17.4) ​ $ (20.9) ​ Gross derivative liability position ​ ​ (1.3) ​ ​ (2.2) ​ ​ (17.4) ​ ​ (20.9) ​ Less: Counterparty netting ​ ​ 0.1 ​ ​ — ​ ​ — ​ ​ 0.1 ​ Net derivative liability position ​ $ (1.2) ​ $ (2.2) ​ $ (17.4) ​ $ (20.8) ​ Total net derivative position ​ $ 1.0 ​ $ (2.2) ​ $ (17.4) ​ $ (18.6) ​

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2022
Fair Value Measurements
Schedule of Assets and Liabilities at Fair Value on Recurring Basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2022 ​ ​ Quoted Prices in Active Markets for Identical Items ​ Significant Other Observable Inputs ​ Significant Unobservable Inputs ​ ​ ​ Assets (Liabilities) at Fair Value (Level 1) (Level 2) (Level 3) Total Foreign exchange forward contracts—Assets $ — $ 10.8 $ — $ 10.8 ​ Commodity cash flow hedges—(Liabilities) ​ ​ — ​ ​ (1.8) ​ ​ — ​ ​ (1.8) ​ Total fair value ​ $ — ​ $ 9.0 ​ $ — ​ $ 9.0 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ Quoted Prices in Active Markets for Identical Items ​ Significant Other Observable Inputs ​ Significant Unobservable Inputs ​ ​ ​ Assets (Liabilities) at Fair Value (Level 1) (Level 2) (Level 3) Total Foreign exchange forward contracts—Assets ​ $ — $ 2.2 $ — $ 2.2 ​ Foreign exchange forward contracts—(Liabilities) ​ ​ — ​ ​ (1.2) ​ ​ — ​ ​ (1.2) ​ Interest rate swaps—(Liabilities) ​ ​ — ​ ​ (2.2) ​ ​ — ​ ​ (2.2) ​ Cross currency swaps—(Liabilities) ​ ​ — ​ ​ (17.4) ​ ​ — ​ ​ (17.4) ​ Total fair value ​ $ — ​ $ (18.6) ​ $ — ​ $ (18.6) ​
Estimated Fair Value of Outstanding Debt Not Carried at Fair Value	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ As of ​ September 30, 2022 December 31, 2021 2029 Senior Notes ​ $ 268.2 ​ $ 460.2 ​ 2028 Term Loan B ​ ​ 685.5 ​ ​ 737.4 ​ 2025 Senior Notes ​ ​ 393.7 ​ ​ 509.4 ​ 2024 Term Loan B ​ ​ 639.8 ​ ​ 667.5 ​ Total fair value ​ $ 1,987.2 ​ $ 2,374.5 ​

Provision For Income Taxes (Tab

Provision For Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2022
Provision For Income Taxes
Schedule of Effective Tax Rate	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ ​ September 30, ​ September 30, ​ ​ ​ 2022 2021 2022 2021 ​ Effective income tax rate ​ ​ 9.3 % ​ 6.5 % ​ (185.2) % ​ 14.9 % ​

Pension Plans and Other Postr_2

Pension Plans and Other Postretirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2022
Pension Plans and Other Postretirement Benefits
Schedule of Net Periodic Benefit Costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Three Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ ​ Non-U.S. Defined Benefit Pension Plans ​ U.S. Defined Benefit Pension (1) ​ ​ 2022 2021 2022 2021 Net periodic benefit cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service cost ​ $ 3.0 ​ $ 4.0 $ 0.2 ​ $ 0.2 ​ Interest cost ​ 0.6 ​ 0.2 ​ 0.2 ​ 0.2 ​ Expected return on plan assets ​ (0.1) ​ (0.1) ​ (0.2) ​ (0.2) ​ Amortization of prior service credit ​ (0.1) ​ (0.5) ​ — ​ — ​ Amortization of net loss ​ 0.6 ​ 1.6 ​ — ​ — ​ Settlement and curtailment gain ​ (1.2) ​ (2.3) ​ (0.2) ​ — ​ Net periodic benefit cost ​ $ 2.8 ​ $ 2.9 ​ $ — ​ $ 0.2 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ ​ Non-U.S. Defined Benefit Pension Plans ​ U.S. Defined Benefit Pension (1) ​ ​ 2022 2021 2022 2021 Net periodic benefit cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service cost ​ $ 9.3 ​ $ 12.1 $ 0.7 ​ $ 0.3 ​ Interest cost ​ 2.0 ​ 1.1 ​ 0.5 ​ 0.3 ​ Expected return on plan assets ​ (0.2) ​ (0.2) ​ (0.7) ​ (0.4) ​ Amortization of prior service credit ​ (0.3) ​ (0.9) ​ — ​ — ​ Amortization of net loss ​ 1.9 ​ 4.7 ​ — ​ — ​ Settlement and curtailment gain ​ ​ (3.1) ​ ​ (2.3) ​ ​ (0.2) ​ ​ — ​ Net periodic benefit cost ​ $ 9.6 ​ $ 14.5 ​ $ 0.3 ​ $ 0.2 ​ (1) The Company’s U.S. defined benefit pension plans were acquired in 2021, primarily in conjunction with the PMMA Acquisition.

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Share-Based Compensation Expense and Unrecognized Compensation Cost	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ September 30, 2022 ​ ​ ​ September 30, ​ September 30, ​ Unrecognized ​ Weighted ​ ​ 2022 2021 2022 2021 Compensation Cost Average Years ​ RSUs ​ $ 2.1 ​ $ 2.1 ​ $ 9.1 ​ $ 5.7 ​ $ 11.3 ​ 1.7 ​ Options ​ ​ 0.6 ​ ​ 1.2 ​ ​ 4.4 ​ ​ 3.5 ​ ​ 2.7 ​ 1.4 ​ PSUs ​ ​ 0.7 ​ ​ 0.7 ​ ​ 2.1 ​ ​ 1.8 ​ ​ 4.4 ​ 2.0 ​ Total share-based compensation expense ​ $ 3.4 ​ $ 4.0 ​ $ 15.6 ​ $ 11.0 ​ ​ ​ ​ ​ ​
Summary of Awards Granted and Weighted Average Grant-Date Fair Value	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ ​ ​ September 30, 2022 ​ ​ ​ Awards Granted ​ Weighted Average Grant Date Fair Value per Award ​ RSUs ​ ​ 197,986 ​ $ 52.10 ​ Options ​ ​ 192,175 ​ ​ 22.52 ​ PSUs ​ ​ 63,317 ​ ​ 57.47 ​
Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Weighted-average Assumptions	​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ September 30, 2022 Expected term (in years) 5.50 ​ Expected volatility 48.72 % Risk-free interest rate 1.97 % Dividend yield ​ 2.00 %
Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Weighted-average Assumptions	​ ​ ​ ​ ​ ​ ​ Nine Months Ended ​ ​ September 30, 2022 Expected term (in years) ​ 3.00 ​ Expected volatility 57.30 % Risk-free interest rate 1.73 % Share price $ 58.64 ​

Segments (Tables)

Segments (Tables)	9 Months Ended
	Sep. 30, 2022
Segments
Reconciliation of Segment Reporting to Consolidated	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Engineered ​ Latex ​ Base ​ ​ ​ ​ ​ Americas Three Months Ended (1) ​ Materials ​ Binders ​ Plastics ​ Polystyrene ​ Feedstocks ​ Styrenics September 30, 2022 $ 7.5 $ 31.0 ​ $ (14.9) ​ $ 18.7 $ (78.0) $ 22.8 ​ September 30, 2021 ​ $ 32.7 ​ $ 37.1 ​ $ 87.9 ​ $ 51.2 ​ $ (27.6) ​ $ 17.1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Engineered ​ Latex ​ Base ​ ​ ​ ​ ​ Americas Nine Months Ended (1) ​ Materials ​ Binders ​ Plastics ​ Polystyrene ​ Feedstocks ​ Styrenics September 30, 2022 ​ $ 76.2 ​ $ 90.6 ​ $ 99.8 ​ $ 87.0 ​ $ (59.8) ​ $ 83.8 ​ September 30, 2021 ​ $ 68.5 ​ $ 86.2 ​ $ 235.0 ​ $ 149.6 ​ $ 58.5 ​ $ 70.2 ​ ​ (1) The Company’s primary measure of segment operating performance is Adjusted EBITDA, which is defined as income from continuing operations before interest expense, net; provision for income taxes; depreciation and amortization expense; loss on extinguishment of long-term debt; asset impairment charges; gains or losses on the dispositions of businesses and assets; restructuring charges; acquisition related costs and benefits and other items. Segment Adjusted EBITDA is a key metric that is used by management to evaluate business performance in comparison to budgets, forecasts, and prior year financial results, providing a measure that management believes reflects core operating performance by removing the impact of transactions and events that would not be considered a part of core operations. Other companies in the industry may define segment Adjusted EBITDA differently than the Company, and as a result, it may be difficult to use segment Adjusted EBITDA, or similarly named financial measures, that other companies may use to compare the performance of those companies to the Company’s segment performance.
Reconciliation of IBT to Adjusted EBITDA	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2022 2021 2022 2021 Income from continuing operations before income taxes ​ $ (130.0) ​ $ 84.9 ​ $ (22.3) ​ $ 327.1 ​ Interest expense, net ​ 30.4 ​ 23.0 ​ 77.7 ​ 56.6 ​ Depreciation and amortization ​ 45.9 ​ 49.8 ​ ​ 147.1 ​ 111.0 ​ Corporate Unallocated (2) ​ ​ 23.7 ​ ​ 25.0 ​ ​ 72.1 ​ ​ 71.3 ​ Adjusted EBITDA Addbacks (3) ​ 17.1 ​ 15.7 ​ 103.0 ​ 102.0 ​ Segment Adjusted EBITDA ​ $ (12.9) ​ $ 198.4 ​ $ 377.6 ​ $ 668.0 ​ (2) Corporate unallocated includes corporate overhead costs and certain other income and expenses. (3) Adjusted EBITDA addbacks for the three and nine months ended September 30, 2022 and 2021 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ ​ ​ 2022 2021 2022 2021 Net gain on disposition of businesses and assets ​ $ — ​ $ — ​ $ (1.8) ​ $ (0.2) ​ Restructuring and other charges (Note 17) ​ ​ — ​ ​ 0.2 ​ ​ (1.0) ​ ​ 6.8 ​ Acquisition transaction and integration net costs (Note 3) ​ ​ 0.4 ​ ​ 13.6 ​ ​ 6.2 ​ ​ 62.8 ​ Acquisition purchase price hedge (gain) loss (Note 10) ​ ​ — ​ ​ — ​ ​ — ​ ​ 22.0 ​ Asset impairment charges or write-offs (Note 11) ​ ​ 1.9 ​ ​ 1.2 ​ ​ 3.9 ​ ​ 3.0 ​ European Commission request for information (Note 13) ​ ​ — ​ ​ — ​ ​ 35.6 ​ ​ — ​ Other items (a) ​ ​ 14.8 ​ ​ 0.7 ​ ​ 60.1 ​ ​ 7.6 ​ Total Adjusted EBITDA Addbacks ​ $ 17.1 ​ $ 15.7 ​ $ 103.0 ​ $ 102.0 ​ (a) Other items for the three and nine months ended September 30, 2022 and 2021 primarily relate to fees incurred in conjunction with certain of the Company’s strategic initiatives, as well as our transition to a new enterprise resource planning system.

Restructuring (Tables)

Restructuring (Tables)	9 Months Ended
	Sep. 30, 2022
Restructuring
Detail of Restructuring Charges	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ Cumulative ​ ​ ​ ​ ​ September 30, ​ September 30, ​ Life-to-date ​ ​ ​ ​ ​ 2022 2021 ​ 2022 2021 ​ Charges Segment ​ Transformational Restructuring Program ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Employee termination benefits ​ $ — ​ $ 0.3 ​ $ 0.1 ​ $ 6.4 ​ $ 8.8 ​ N/A (1) ​ Transformational Restructuring Program Subtotal ​ $ — ​ $ 0.3 ​ $ 0.1 ​ $ 6.4 ​ $ 8.8 ​ ​ ​ Other Restructurings ​ ​ — ​ ​ (0.1) ​ ​ (1.1) ​ ​ — ​ ​ ​ ​ Various ​ Total Restructuring Charges ​ $ — ​ $ 0.2 ​ $ (1.0) ​ $ 6.4 ​ ​ ​ ​ ​ ​ (1) In May 2021, the Company approved a transformational restructuring program associated with the Company’s recent strategic initiatives. The Company expects to incur incremental employee termination benefit charges related to impacted employees as of September 30, 2022 of less than $1.0 million, the majority of which are expected to be paid by December 31, 2022. As this was identified as a corporate-related activity, the charges related to this restructuring program were not allocated to a specific segment, but rather included within corporate unallocated.
Rollforward of Liability Balances	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at ​ ​ ​ ​ Balance at ​ December 31, 2021 Expenses Deductions (1) September 30, 2022 Employee termination benefits ​ $ 10.0 ​ $ (1.4) ​ $ (4.4) ​ $ 4.2 ​ Decommissioning and other ​ — ​ 0.1 ​ (0.1) ​ — ​ Total ​ $ 10.0 ​ $ (1.3) ​ $ (4.5) ​ $ 4.2 ​ (1) Primarily includes payments made against the existing accrual, as well as immaterial impacts of foreign currency remeasurement.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2022
Accumulated Other Comprehensive Income (Loss).
Components of AOCI, Net of Income Taxes	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cumulative Pension & Other ​ ​ ​ ​ ​ ​ ​ ​ Translation ​ Postretirement Benefit ​ ​ Cash Flow ​ ​ ​ ​ Three Months Ended September 30, 2022 and 2021 Adjustments Plans, Net ​ Hedges, Net Total Balance as of June 30, 2022 ​ $ (153.4) ​ $ (27.0) ​ $ 2.5 ​ $ (177.9) ​ Other comprehensive income (loss) ​ (45.0) ​ 2.4 ​ (3.4) ​ (46.0) ​ Amounts reclassified from AOCI to net income (1) ​ ​ — ​ ​ (0.9) ​ ​ (2.2) ​ ​ (3.1) ​ Balance as of September 30, 2022 ​ $ (198.4) ​ $ (25.5) ​ $ (3.1) ​ $ (227.0) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of June 30, 2021 ​ $ (109.3) ​ $ (69.8) ​ $ (0.8) ​ $ (179.9) ​ Other comprehensive income (loss) ​ (1.7) ​ 9.3 ​ 0.6 ​ 8.2 ​ Amounts reclassified from AOCI to net income (1) ​ ​ — ​ ​ (1.2) ​ ​ 0.6 ​ ​ (0.6) ​ Balance as of September 30, 2021 ​ $ (111.0) ​ $ (61.7) ​ $ 0.4 ​ $ (172.3) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cumulative Pension & Other ​ ​ ​ ​ ​ ​ ​ Translation ​ Postretirement Benefit ​ Cash Flow ​ ​ ​ ​ Nine Months Ended September 30, 2022 and 2021 ​ Adjustments Plans, Net Hedges, Net Total ​ Balance as of December 31, 2021 ​ $ (114.3) ​ $ (33.6) ​ $ 0.7 ​ $ (147.2) ​ Other comprehensive income (loss) ​ (84.1) ​ 10.0 ​ (2.7) ​ (76.8) ​ Amounts reclassified from AOCI to net income (1) ​ ​ — ​ ​ (1.9) ​ ​ (1.1) ​ ​ (3.0) ​ Balance as of September 30, 2022 ​ $ (198.4) ​ $ (25.5) ​ $ (3.1) ​ $ (227.0) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of December 31, 2020 ​ $ (109.0) ​ $ (71.9) ​ $ (5.2) ​ $ (186.1) ​ Other comprehensive income (loss) ​ (2.0) ​ 9.3 ​ 3.0 ​ 10.3 ​ Amounts reclassified from AOCI to net income (1) ​ ​ — ​ ​ 0.9 ​ ​ 2.6 ​ ​ 3.5 ​ Balance as of September 30, 2021 ​ $ (111.0) ​ $ (61.7) ​ $ 0.4 ​ $ (172.3) ​ (1) The following is a summary of amounts reclassified from AOCI to net income (loss) for the three and nine months ended September 30, 2022 and 2021:
Summary of amounts reclassified from AOCI to net income (loss)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ ​ ​ September 30, ​ September 30, ​ Statements of Operations ​ AOCI Components 2022 2021 2022 2021 Classification ​ Cash flow hedging items ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign exchange cash flow hedges ​ $ — ​ $ (0.3) ​ $ — ​ $ — ​ Cost of sales ​ Commodity cash flow hedges ​ ​ (2.0) ​ ​ — ​ ​ (2.0) ​ ​ — ​ Cost of sales ​ Interest rate swaps ​ ​ (0.2) ​ ​ 0.9 ​ ​ 1.2 ​ ​ 2.6 ​ Interest expense, net ​ Total before tax ​ ​ (2.2) ​ ​ 0.6 ​ ​ (0.8) ​ ​ 2.6 ​ ​ ​ Tax effect ​ ​ — ​ ​ — ​ ​ (0.3) ​ ​ — ​ Provision for (benefit from) income taxes ​ Total, net of tax ​ $ (2.2) ​ $ 0.6 ​ $ (1.1) ​ $ 2.6 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of pension and other postretirement benefit plan items ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Prior service credit ​ $ (0.1) ​ $ (0.2) ​ $ (0.4) ​ $ (0.7) ​ (a) ​ Net actuarial loss ​ ​ 0.6 ​ ​ 1.7 ​ ​ 2.0 ​ ​ 5.3 ​ (a) ​ Net curtailment and settlement gain ​ ​ (1.4) ​ ​ (2.5) ​ ​ (3.3) ​ ​ (2.5) ​ (a) ​ Total before tax ​ ​ (0.9) ​ ​ (1.0) ​ ​ (1.7) ​ ​ 2.1 ​ ​ ​ Tax effect ​ ​ — ​ ​ (0.2) ​ ​ (0.2) ​ ​ (1.2) ​ Provision for (benefit from) income taxes ​ Total, net of tax ​ $ (0.9) ​ $ (1.2) ​ $ (1.9) ​ $ 0.9 ​ ​ ​ (a) These AOCI components are included in the computation of net periodic benefit costs (see Note 14).

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2022
Earnings Per Share
Schedule of Earnings per Share Basic and Diluted	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ ​ September 30, ​ September 30, ​ (in millions, except per share data) 2022 2021 2022 2021 Earnings: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) from continuing operations ​ $ (117.9) ​ $ 79.4 ​ $ (63.7) ​ $ 278.2 ​ Net income (loss) from discontinued operations ​ ​ (1.9) ​ ​ 13.7 ​ ​ (1.9) ​ ​ 38.0 ​ Net income (loss) ​ $ (119.8) ​ $ 93.1 ​ $ (65.6) ​ $ 316.2 ​ Shares: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average ordinary shares outstanding ​ 35.2 ​ 38.8 ​ 36.3 ​ 38.7 ​ Dilutive effect of RSUs, option awards, and PSUs (1) ​ — ​ 0.7 ​ — ​ 0.9 ​ Diluted weighted average ordinary shares outstanding ​ 35.2 ​ 39.5 ​ 36.3 ​ 39.6 ​ Income (loss) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income (loss) per share—basic: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Continuing operations ​ $ (3.35) ​ $ 2.04 ​ $ (1.76) ​ $ 7.19 ​ Discontinued operations ​ ​ (0.06) ​ ​ 0.35 ​ ​ (0.05) ​ ​ 0.98 ​ Income (loss) per share—basic ​ $ (3.41) ​ $ 2.39 ​ $ (1.81) ​ $ 8.17 ​ Income (loss) per share—diluted: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Continuing operations ​ $ (3.35) ​ $ 2.01 ​ $ (1.76) ​ $ 7.03 ​ Discontinued operations ​ ​ (0.06) ​ ​ 0.35 ​ ​ (0.05) ​ ​ 0.96 ​ Income (loss) per share—diluted ​ $ (3.41) ​ $ 2.36 ​ $ (1.81) ​ $ 7.99 ​ (1) Refer to Note 15 for discussion of RSUs, option awards, and PSUs granted to certain Company directors and employees. As the Company recorded a net loss from continuing operations for the three and nine months ended September 30, 2022, potential shares related to equity-based awards have been excluded from the calculation of diluted EPS, as doing so would be anti-dilutive. There were 0.6 million anti-dilutive shares that have been excluded from the computation of diluted earnings per share for the three and nine months ended September 30, 2021.

Other Charges (Tables)

Other Charges (Tables)	9 Months Ended
	Sep. 30, 2022
Other Charges
Schedule of Other Charges	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2022 2021 2022 2021 Asset impairment charges or write-offs (Note 11) ​ $ 1.9 ​ $ 1.2 ​ $ 3.9 ​ $ 3.0 European Commission request for information (Note 13) ​ ​ — ​ ​ — ​ ​ 35.6 ​ ​ — Total ​ $ 1.9 ​ $ 1.2 ​ $ 39.5 ​ $ 3.0

Acquisitions - Heathland B.V (D

Acquisitions - Heathland B.V (Details) - USD ($) $ in Millions	Jan. 03, 2022	Sep. 30, 2022	Dec. 31, 2021
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Goodwill		$ 691.9	$ 710.1
Heathland B.V.
Business Acquisition [Line Items]
Contingent payments to be paid	$ 6.4
Consideration paid upon signing the agreement	$ 22.9
Expected life	7 years
Contingent service fee	$ 4.5
Continuous employment period	3 years
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Cash and cash equivalents	$ 1
Other current assets	1.2
Other assets	1
Total fair value of assets acquired	9.4
Current liabilities	(1.3)
Noncurrent liabilities	(1.6)
Total fair value of liabilities assumed	(2.9)
Net identifiable assets acquired	6.5
Purchase price consideration	29.3
Goodwill	22.8
Heathland B.V. | Maximum
Business Acquisition [Line Items]
Consideration paid upon signing the agreement	6.8
Heathland B.V. | Customer Relationships
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Other intangible assets	5.1
Heathland B.V. | Trade Names
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Other intangible assets	0.9
Heathland B.V. | Developed Technology
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Other intangible assets	$ 0.2

Acquisitions - Aristech (Detail

Acquisitions - Aristech (Details) - USD ($) $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Sep. 01, 2021	May 03, 2021
Aristech Surfaces L L C
Business Acquisition [Line Items]
Equity interest acquired				100%
Purchase price consideration		$ 448	$ 449.5
Changes to purchase price allocation	$ 0
PMMA Business
Business Acquisition [Line Items]
Equity interest acquired					100%
Purchase price consideration		$ 1,358.6	$ 1,364.9

Acquisitions - Pro Forma and tr

Acquisitions - Pro Forma and transaction costs (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
Business Acquisition, Pro Forma Information [Abstract]
Net sales	$ 1,300.2	$ 3,863.8
Net income	94.1	355.1
Income from continuing operations	$ 80.4	$ 317.1

Divestitures and Discontinued_3

Divestitures and Discontinued Operations (Details) - Emulsion Polymers, Synthetic Rubber - Disposal Group, Disposed of by Sale, Not Discontinued Operations $ in Millions	Dec. 01, 2021 USD ($)
Disclosures by disposal group
Consideration	$ 402.4
Pension and other postretirement benefits	41.6
Working capital target	$ 47

Divestitures and Discontinued_4

Divestitures and Discontinued Operations - Results (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Discontinued Operation, Income (Loss) from Discontinued Operation Disclosures [Abstract]
Net income (loss) from discontinued operations	$ (1.9)	$ 13.7	$ (1.9)	$ 38
Emulsion Polymers, Synthetic Rubber | Discontinued Operations, Held-for-sale
Discontinued Operation, Income (Loss) from Discontinued Operation Disclosures [Abstract]
Net sales		122.3	0.1	382.2
Cost of sales	2.2	101.9	3.6	321.2
Gross profit (loss)	(2.2)	20.4	(3.5)	61
Selling, general and administrative expenses		4.9	(0.3)	16.7
Operating income (loss)	(2.2)	15.5	(3.2)	44.3
Gain on sale of businesses and other assets			1.2
Other expense, net		(0.2)		(1.2)
Income (loss) from discontinued operations before income taxes	(2.2)	15.3	(2)	43.1
Provision for (benefit from) income taxes	(0.3)	1.6	(0.1)	5.1
Net income (loss) from discontinued operations	(1.9)	$ 13.7	(1.9)	$ 38
Emulsion Polymers, Synthetic Rubber | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Discontinued Operation, Income (Loss) from Discontinued Operation Disclosures [Abstract]
Net sales related to supply agreement	13.8		55.6
Cost of sales related to supply agreement	$ 14.5		$ 46.3

Net Sales (Details)

Net Sales (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation of Revenue [Line Items]
Net sales	$ 1,178.1	$ 1,269.3	$ 3,990.3	$ 3,529
Engineered Materials
Disaggregation of Revenue [Line Items]
Net sales	242.7	230.8	839.2	477.5
Latex Binders
Disaggregation of Revenue [Line Items]
Net sales	340.9	315.6	1,001.3	877.6
Base Plastics
Disaggregation of Revenue [Line Items]
Net sales	293.4	393.3	1,051.8	1,119.3
Polystyrene
Disaggregation of Revenue [Line Items]
Net sales	247.7	274.8	877.7	855
Feedstocks
Disaggregation of Revenue [Line Items]
Net sales	53.4	54.8	220.3	199.6
United States
Disaggregation of Revenue [Line Items]
Net sales	312.5	275	985.4	629.5
United States | Engineered Materials
Disaggregation of Revenue [Line Items]
Net sales	128.9	102.4	418	174.1
United States | Latex Binders
Disaggregation of Revenue [Line Items]
Net sales	105.4	86.3	290.1	228.2
United States | Base Plastics
Disaggregation of Revenue [Line Items]
Net sales	73.7	82.3	264.3	216.5
United States | Feedstocks
Disaggregation of Revenue [Line Items]
Net sales	4.5	4	13	10.7
Europe
Disaggregation of Revenue [Line Items]
Net sales	612.6	703.8	2,194.5	2,022
Europe | Engineered Materials
Disaggregation of Revenue [Line Items]
Net sales	72.5	89.6	300.1	190.8
Europe | Latex Binders
Disaggregation of Revenue [Line Items]
Net sales	160.1	153.5	480.4	431.4
Europe | Base Plastics
Disaggregation of Revenue [Line Items]
Net sales	157.1	247.3	602.2	699.2
Europe | Polystyrene
Disaggregation of Revenue [Line Items]
Net sales	174	162.6	604.5	511.7
Europe | Feedstocks
Disaggregation of Revenue [Line Items]
Net sales	48.9	50.8	207.3	188.9
Asia-Pacific
Disaggregation of Revenue [Line Items]
Net sales	218.8	265	711.5	807
Asia-Pacific | Engineered Materials
Disaggregation of Revenue [Line Items]
Net sales	38.9	35.9	112.4	108.1
Asia-Pacific | Latex Binders
Disaggregation of Revenue [Line Items]
Net sales	72.9	73	223.9	211.1
Asia-Pacific | Base Plastics
Disaggregation of Revenue [Line Items]
Net sales	33.3	43.9	102.1	144.5
Asia-Pacific | Polystyrene
Disaggregation of Revenue [Line Items]
Net sales	73.7	112.2	273.1	343.3
Rest of World
Disaggregation of Revenue [Line Items]
Net sales	34.2	25.5	98.9	70.5
Rest of World | Engineered Materials
Disaggregation of Revenue [Line Items]
Net sales	2.4	2.9	8.7	4.5
Rest of World | Latex Binders
Disaggregation of Revenue [Line Items]
Net sales	2.5	2.8	6.9	6.9
Rest of World | Base Plastics
Disaggregation of Revenue [Line Items]
Net sales	$ 29.3	$ 19.8	83.2	$ 59.1
Rest of World | Polystyrene
Disaggregation of Revenue [Line Items]
Net sales			$ 0.1

Investments in Unconsolidated_3

Investments in Unconsolidated Affiliates (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($) item	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) item	Sep. 30, 2021 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of joint ventures | item	1		1
Summarized Financial Information, Net Income
Gross profit	$ (39.5)	$ 168.3	$ 275.5	$ 577.3
Net income			(65.6)	316.2
AmSty
Summarized Financial Information, Net Income
Sales	535.3	433.4	1,654.3	1,351.9
Gross profit	70.6	49.3	212.2	189.2
Net income	$ 48.3	$ 37.2	$ 164.5	$ 151.8

Investments in Unconsolidated_4

Investments in Unconsolidated Affiliates - Americas Styrenics (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Investments in Unconsolidated Affiliates
Investments in unconsolidated affiliates	$ 269.2		$ 269.2		$ 247.8
AmSty
Investments in Unconsolidated Affiliates
Investments in unconsolidated affiliates	$ 269.2		$ 269.2		$ 247.8
Percentage of ownership underlying net assets	50%		50%		50%
Amortized weighted average remaining useful life			2.3
Dividends received from operating activities	$ 25	$ 20	$ 62.5	$ 60
Unconsolidated affiliates
Investments in Unconsolidated Affiliates
Investment in unconsolidated affiliates-difference between carrying amount and underlying equity	$ 11		$ 11		$ 9.4

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Inventories
Finished goods	$ 281.7	$ 279.2
Raw materials and semi-finished goods	297.5	303.9
Supplies	34.8	37.9
Total	$ 614	$ 621

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) € in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)	Feb. 26, 2020 USD ($)	Feb. 26, 2020 EUR (€)	Sep. 01, 2017 USD ($)
Debt Instruments
Carrying amount	$ 2,352.8	$ 2,368.8
Unamortized deferred financing fees	(38.3)	(44.7)
Total Debt, Less Unamortized Deferred Financing Fees, Current and Noncurrent	2,314.5	2,324.1
Less: current portion	(16.7)	(18.5)
Total long-term debt, net of unamortized deferred financing fees	2,297.8	2,305.6
Term Loan B
Debt Instruments
Less: current portion	$ (14.5)	(14.5)
2024 Term Loan B
Debt Instruments
Interest rate at end of period (as a percent)	5.115%
Carrying amount	$ 665.2	670.4
Unamortized deferred financing fees	(5.9)	(8)
Total Debt, Less Unamortized Deferred Financing Fees, Current and Noncurrent	$ 659.3	662.4
2028 Term Loan B
Debt Instruments
Interest rate at end of period (as a percent)	5.615%
Carrying amount	$ 737.6	742.8
Unamortized deferred financing fees	(15.1)	(17)
Total Debt, Less Unamortized Deferred Financing Fees, Current and Noncurrent	722.5	725.8
2026 Revolving Facility
Debt Instruments
Funds available for borrowings	369.2
Letters of credit, amount outstanding	$ 5.8
Commitment fee (as a percent)	0.375%
Maximum borrowing capacity	$ 375
2029 Senior Notes
Debt Instruments
Interest rate	5.125%
Carrying amount	$ 447	450
Unamortized deferred financing fees	(13.3)	(14.7)
Total Debt, Less Unamortized Deferred Financing Fees, Current and Noncurrent	$ 433.7	435.3
2025 Senior Notes
Debt Instruments
Interest rate	5.375%		5.375%	5.375%	5.375%
Carrying amount	$ 500	500
Unamortized deferred financing fees	(4)	(5)
Total Debt, Less Unamortized Deferred Financing Fees, Current and Noncurrent	496	495	$ 500	€ 459.3	$ 500
Accounts Receivable Securitization Facility
Debt Instruments
Carrying amount	0	0
Unamortized deferred financing fees	0	0
Total Debt, Less Unamortized Deferred Financing Fees, Current and Noncurrent	0	0
Maximum borrowing capacity	150
Accounts receivable available to support facility	150
Other Indebtedness
Debt Instruments
Carrying amount	3	5.6
Total Debt, Less Unamortized Deferred Financing Fees, Current and Noncurrent	$ 3	$ 5.6

Goodwill - Schedule of Carrying

Goodwill - Schedule of Carrying Amount of Goodwill (Details) $ in Millions	9 Months Ended
	Sep. 30, 2022 USD ($)
Goodwill [Roll Forward]
Beginning Balance	$ 710.1
Acquisitions	22.8
Foreign currency impact	(41)
Ending Balance	691.9
Engineered Materials
Goodwill [Roll Forward]
Beginning Balance	667.3
Foreign currency impact	(31.7)
Ending Balance	635.6
Latex Binders
Goodwill [Roll Forward]
Beginning Balance	15.9
Foreign currency impact	(2.3)
Ending Balance	13.6
Base Plastics
Goodwill [Roll Forward]
Beginning Balance	22.4
Acquisitions	22.8
Foreign currency impact	(6.3)
Ending Balance	38.9
Polystyrene
Goodwill [Roll Forward]
Beginning Balance	4.5
Foreign currency impact	(0.7)
Ending Balance	$ 3.8

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Goodwill [Line Items]
Goodwill	$ 691.9	$ 710.1
PMMA Business
Goodwill [Line Items]
Goodwill	503
Aristech Surfaces L L C
Goodwill [Line Items]
Goodwill	$ 120

Derivative Instruments (Details

Derivative Instruments (Details) MWh in Thousands, € in Millions, $ in Millions				9 Months Ended
	Apr. 07, 2022 USD ($)	Feb. 26, 2020 USD ($)	Sep. 01, 2017 USD ($)	Sep. 30, 2022 USD ($) MWh item	Dec. 31, 2021 USD ($)	Feb. 26, 2020 EUR (€)	Sep. 01, 2017 EUR (€)
Derivative Instruments
Total debt				$ 2,314.5	$ 2,324.1
Foreign Exchange Forward Contracts
Derivative Instruments
Derivative term				2 months
Foreign Exchange Forward Contracts | Not Designated as Hedging Instruments
Derivative Instruments
Derivative contracts, notional amount				$ 547.6
Foreign Exchange Forward Contracts | Designated as Hedging Instrument
Derivative Instruments
Number of subsidiaries participating | item				1
Foreign Exchange Forward Contracts | Designated as Hedging Instrument | Cash Flow Hedges
Derivative Instruments
Amount hedged				$ 0
Cross Currency Swap
Derivative Instruments
Derivative contracts, notional amount | €							€ 420
Derivative term		2 years 8 months 12 days	5 years
Cross currency swap weighted average interest rate (as a percent)		3.672%	3.45%
Cash proceeds	$ 1.9
Interest Rate Swap
Derivative Instruments
Derivative contracts, notional amount				$ 200
Fixed interest rate per agreement (as a percent)				1.81%
Commodity Contract | Cash Flow Hedges
Derivative Instruments
Derivative term				3 months
Number of megawatt hours of natural gas purchases | MWh				63
2025 Senior Notes
Derivative Instruments
Total debt		$ 500	$ 500	$ 496	495	€ 459.3
Interest rate		5.375%	5.375%	5.375%		5.375%	5.375%
2024 Term Loan B
Derivative Instruments
Total debt				$ 659.3	$ 662.4
2024 Term Loan B | LIBOR
Derivative Instruments
Debt instrument, margin rate				2%
Variable rate floor (as a percent)				0%
Euro | (Sell)
Derivative Instruments
Derivative contracts, notional amount				$ 411.1
Chinese Yuan | (Sell)
Derivative Instruments
Derivative contracts, notional amount				46.4
Swedish Krona | Buy
Derivative Instruments
Derivative contracts, notional amount				20.7
South Korean Won | (Sell)
Derivative Instruments
Derivative contracts, notional amount				18.3
New Taiwan Dollar | (Sell)
Derivative Instruments
Derivative contracts, notional amount				$ 15.6

Derivative Instruments - Income

Derivative Instruments - Income Statements (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Cost of Sales	$ (1,217.6)	$ (1,101)	$ (3,714.8)	$ (2,951.7)
Interest expense, net	30.4	23	77.7	56.6
Gain (Loss) on Derivative Instruments, Net, Pretax				(22)
Other expense (income), net	0.5	(0.1)	1.6	8.4
Amount of gain (loss) recognized in income, not designated				(22)
Cost of Sales
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Cost of Sales	(1,217.6)	(1,101)	(3,714.8)	(2,951.7)
Interest Expense, Net
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Interest expense, net	(30.4)	(23)	(77.7)	(56.6)
Acquisition purchase price hedge gain (loss)
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Gain (Loss) on Derivative Instruments, Net, Pretax		0.1		(22)
Other expense, net
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Other expense (income), net	(0.5)		(1.6)	(8.4)
Foreign Exchange Forward Contracts | Not Designated as Hedging Instruments
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Amount of gain (loss) recognized in income, not designated	33.7	23.3	81.6	43.4
Foreign Exchange Forward Contracts | Not Designated as Hedging Instruments | Acquisition purchase price hedge gain (loss)
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Amount of gain (loss) recognized in income, not designated		23.3	(22)
Foreign Exchange Forward Contracts | Not Designated as Hedging Instruments | Other expense, net
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Amount of gain (loss) recognized in income, not designated	33.7
Foreign Exchange Forward Contracts | Designated as Hedging Instrument | Cost of Sales
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Amount of gain (loss) reclassified from AOCI into income, foreign exchange cash flow hedges		0.3
Foreign Exchange Forward Contracts | Designated as Hedging Instrument | Acquisition purchase price hedge gain (loss)
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Gain (Loss) on Derivative Instruments, Net, Pretax				(22)
Foreign Exchange Forward Contracts | Designated as Hedging Instrument | Other expense, net
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Other expense (income), net			81.6	43.4
Cross Currency Swap | Interest Expense, Net
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Interest expense, net			2.4	5.5
Amount of gain excluded from effectiveness testing		1.9
Interest Rate Swap | Interest Expense, Net
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Amount of gain (loss) reclassified from AOCI into income, interest rate cash flow hedges	0.2	$ (0.9)
Interest Rate Swap | Cash Flow Hedges | Interest Expense, Net
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Interest expense, net			(1.2)	$ (2.6)
Commodity Contract | Cash Flow Hedges | Cost of Sales
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Amount of gain reclassified from AOCI into income, commodity cash flow hedges	$ 2		$ 2

Derivative Instruments - Effect

Derivative Instruments - Effect on AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative Instruments
Gain (Loss) Recognized in AOCI, Cash flow hedges	$ (5.6)	$ 1.2	$ (3.8)	$ 5.6
Gain (Loss) Recognized in AOCI, Cash flow hedges	(5.6)	1.2	(3.2)	5.6
Gain (Loss) Recognized in AOCI, Net investment hedges		13.1	15.8	32.1
Foreign Exchange Forward Contracts
Derivative Instruments
Gain (Loss) Recognized in AOCI, Cash flow hedges		0.4	3.1
Commodity Contract
Derivative Instruments
Gain (Loss) Recognized in AOCI, Cash flow hedges	(5.4)		(5.4)
Interest Rate Swap
Derivative Instruments
Gain (Loss) Recognized in AOCI, Cash flow hedges	$ (0.2)	0.8	2.2	2.5
Cross Currency Swap
Derivative Instruments
Gain (Loss) Recognized in AOCI, Net investment hedges		$ 13.1	$ 15.8	$ 32.1

Derivative Instruments - Gains

Derivative Instruments - Gains and Losses in Other expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Amount of gain (loss) recognized in income, not designated				$ (22)
Foreign exchange transaction gains (losses)	$ (35.4)	$ (23.7)	$ (83.4)	(43)
Derivative, Gain (Loss) on Derivative, Net, Total	$ (1.7)	$ (0.4)	$ (1.8)	$ 0.4
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Reclassification expected during next 12 months			$ 5.4
Foreign Exchange Forward Contracts | Not Designated as Hedging Instruments
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Amount of gain (loss) recognized in income, not designated	$ 33.7	$ 23.3	81.6	$ 43.4
Foreign Exchange Forward Contracts | Not Designated as Hedging Instruments | Other expense, net
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Amount of gain (loss) recognized in income, not designated	$ 33.7
Foreign Exchange Forward Contracts | Not Designated as Hedging Instruments | Acquisition purchase price hedge gain (loss)
Derivative, Gain (Loss) on Derivative, Net [Abstract]
Amount of gain (loss) recognized in income, not designated		$ 23.3	$ (22)

Derivative Instruments - Financ

Derivative Instruments - Financial Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Derivatives, Financial Assets and Liabilities
Gross derivative asset position		$ 2.3
Counterparty netting, derivative assets		(0.1)
Net derivative asset position		$ 2.2
Liabilities at fair value	$ (2.5)
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accounts Payable, Current	Accounts Payable, Current
Gross derivative liability position	$ (2.5)	$ (20.9)
Counterparty netting, derivative liabilities	0.7	0.1
Net derivative liability position	(1.8)	(20.8)
Total net derivative position	9	(18.6)
Accounts Receivable
Derivatives, Financial Assets and Liabilities
Gross derivative asset position	11.5	2.3
Counterparty netting, derivative assets	(0.7)
Net derivative asset position	10.8
Foreign Exchange Forward Contracts | Not Designated as Hedging Instruments
Derivatives, Financial Assets and Liabilities
Gross derivative asset position		2.3
Counterparty netting, derivative assets		(0.1)
Net derivative asset position		$ 2.2
Liabilities at fair value	(0.7)
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Accounts Payable, Current
Gross derivative liability position	(0.7)	$ (1.3)
Counterparty netting, derivative liabilities	0.7	0.1
Net derivative liability position		(1.2)
Total net derivative position	10.8	1
Foreign Exchange Forward Contracts | Not Designated as Hedging Instruments | Accounts Receivable
Derivatives, Financial Assets and Liabilities
Gross derivative asset position	11.5	$ 2.3
Counterparty netting, derivative assets	(0.7)
Net derivative asset position	10.8
Interest Rate Swap
Derivatives, Financial Assets and Liabilities
Liabilities at fair value	(1.8)
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Accounts Payable, Current
Gross derivative liability position	(1.8)	$ (2.2)
Net derivative liability position	(1.8)	(2.2)
Total net derivative position	$ (1.8)	$ (2.2)
Cross Currency Swap
Derivatives, Financial Assets and Liabilities
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Accounts Payable, Current
Gross derivative liability position		$ (17.4)
Net derivative liability position		(17.4)
Total net derivative position		$ (17.4)

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities at Fair Value, Recurring (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022	Dec. 31, 2021
Fair Value Measurements
Liabilities at fair value	$ (2.5)	$ (2.5)
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accounts Payable, Current	Accounts Payable, Current	Accounts Payable, Current
Total net derivative position	$ 9	$ 9	$ (18.6)
Impairment, Long-Lived Asset, Held-for-Use, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Cost and Expense, Operating	Other Cost and Expense, Operating
Boehlen Location
Fair Value Measurements
Impairment loss on assets	$ 1.9	$ 3.9
Property Plant And Equipment At Fair Value | Boehlen Location
Fair Value Measurements
Assets at fair value, nonrecurring	2.9	2.9	$ 3.4
Interest Rate Swap
Fair Value Measurements
Liabilities at fair value	(1.8)	(1.8)
Derivative Liability, Statement of Financial Position [Extensible Enumeration]			Accounts Payable, Current
Total net derivative position	$ (1.8)	$ (1.8)	$ (2.2)
Cross Currency Swap
Fair Value Measurements
Derivative Liability, Statement of Financial Position [Extensible Enumeration]			Accounts Payable, Current
Total net derivative position			$ (17.4)
Not Designated as Hedging Instruments | Foreign Exchange Forward Contracts
Fair Value Measurements
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Accounts and Other Receivables, Net, Current	Accounts and Other Receivables, Net, Current	Accounts and Other Receivables, Net, Current
Liabilities at fair value	$ (0.7)	$ (0.7)
Derivative Liability, Statement of Financial Position [Extensible Enumeration]			Accounts Payable, Current
Total net derivative position	$ 10.8	$ 10.8	$ 1
Not Designated as Hedging Instruments | Interest Rate Swap
Fair Value Measurements
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Accounts and Other Receivables, Net, Current	Accounts and Other Receivables, Net, Current
Recurring
Fair Value Measurements
Total net derivative position	$ 9	$ 9	(18.6)
Recurring | Interest Rate Swap
Fair Value Measurements
Liabilities at fair value			(2.2)
Recurring | Cross Currency Swap
Fair Value Measurements
Liabilities at fair value			(17.4)
Recurring | Level 2
Fair Value Measurements
Total net derivative position	9	9	(18.6)
Recurring | Level 2 | Interest Rate Swap
Fair Value Measurements
Liabilities at fair value			(2.2)
Recurring | Level 2 | Cross Currency Swap
Fair Value Measurements
Liabilities at fair value			(17.4)
Recurring | Not Designated as Hedging Instruments | Foreign Exchange Forward Contracts
Fair Value Measurements
Assets at fair value	10.8	10.8	2.2
Liabilities at fair value			(1.2)
Recurring | Not Designated as Hedging Instruments | Interest Rate Swap
Fair Value Measurements
Assets at fair value	(1.8)	(1.8)
Recurring | Not Designated as Hedging Instruments | Level 2 | Foreign Exchange Forward Contracts
Fair Value Measurements
Assets at fair value	10.8	10.8	2.2
Liabilities at fair value			(1.2)
Recurring | Not Designated as Hedging Instruments | Level 2 | Interest Rate Swap
Fair Value Measurements
Assets at fair value	$ (1.8)	$ (1.8)
Nonrecurring
Fair Value Measurements
Assets at fair value, nonrecurring			0
Liabilities at fair value, nonrecurring			$ 0

Fair Value Measurements - Items

Fair Value Measurements - Items not at Fair Value (Details) - Level 2 - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Fair Value of Debt Instruments
Total fair value of long term debt	$ 1,987.2	$ 2,374.5
2029 Senior Notes
Fair Value of Debt Instruments
Total fair value of long term debt	268.2	460.2
2028 Term Loan B
Fair Value of Debt Instruments
Total fair value of long term debt	685.5	737.4
2025 Senior Notes
Fair Value of Debt Instruments
Total fair value of long term debt	393.7	509.4
2024 Term Loan B
Fair Value of Debt Instruments
Total fair value of long term debt	$ 639.8	$ 667.5

Provision For Income Taxes (Det

Provision For Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Provision For Income Taxes
Effective income tax rate	9.30%			6.50%	(185.20%)	14.90%
Swiss tax reform		$ 15.3
Valuation allowance, provision against tax benefit expected to expire		$ 8.5
Tax benefits			$ 0
Provision for (benefit from) income taxes	$ (12.1)			$ 5.5	$ 41.4	$ 48.9
Change in valuation allowances			$ 35.6
Valuation Allowance				$ 16.3		$ 16.3

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	Sep. 30, 2022 USD ($) item	Dec. 31, 2021 USD ($)
Commitments and Contingencies.
Accrued obligations for environmental remediation and restoration costs | $	$ 4.1	$ 4.4
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities and Other Liabilities, Other Liabilities, Noncurrent	Accrued Liabilities and Other Liabilities, Other Liabilities, Noncurrent
Environmental claims asserted | item	0

Commitments and Contingencies -

Commitments and Contingencies - Purchase Commitments (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2022	Sep. 30, 2022
Loss Contingencies [Line Items]
Amount related to raw material purchase contract obligation		$ 19
European Commission investigation	$ 35.6	35.6
Estimated Liability relating to European Commission Request for Information		$ 31.2
Maximum
Loss Contingencies [Line Items]
Purchase commitment period		5 years
Minimum
Loss Contingencies [Line Items]
Purchase commitment period		1 year

Pension Plans and Other Postr_3

Pension Plans and Other Postretirement Benefits - Net Periodic Benefit Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Net periodic benefit cost
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]			Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]			Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Settlement and Curtailment Gain (Loss), Statement of Income or Comprehensive Income [Extensible List]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Net settlement and curtailment loss, Statements of Operations location	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
U.S. Plans And Non-U.S. Plans
Net periodic benefit cost
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Pension plans | Non-U.S. Plans
Net periodic benefit cost
Service cost	$ 3	$ 4	$ 9.3	$ 12.1
Interest cost	0.6	0.2	2	1.1
Expected return on plan assets	(0.1)	(0.1)	(0.2)	(0.2)
Amortization of prior service cost	(0.1)	(0.5)	(0.3)	(0.9)
Amortization of net (gain) loss	0.6	1.6	1.9	4.7
Net curtailment and settlement gain	(1.2)	(2.3)	(3.1)	(2.3)
Net periodic benefit cost	2.8	2.9	9.6	14.5
Pension plans | United States
Net periodic benefit cost
Service cost	0.2	0.2	0.7	0.3
Interest cost	0.2	0.2	0.5	0.3
Expected return on plan assets	(0.2)	(0.2)	(0.7)	(0.4)
Net curtailment and settlement gain	(0.2)		(0.2)
Net periodic benefit cost		0.2	$ 0.3	$ 0.2
Other Postretirement Benefit Plans | Maximum
Net periodic benefit cost
Net periodic benefit cost	$ 0.1	$ 0.1

Pension Plans and Other Postr_4

Pension Plans and Other Postretirement Benefits - Net Amounts Recognized (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022	Dec. 31, 2021
Net amounts recognized in the balance sheets at December 31
Benefit obligations	$ 237.8	$ 237.8	$ 274.7
Cash contributions and benefit payments to unfunded plans	1.4	6.1
Additional cash contributions, including benefit payments to unfunded plans	$ 2.7	$ 2.7

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Expense (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	$ 3.4	$ 4	$ 15.6	$ 11
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	2.1	2.1	9.1	5.7
Unrecognized compensation cost	11.3		$ 11.3
Weighted-average period of recognition			1 year 8 months 12 days
Option Awards
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	0.6	1.2	$ 4.4	3.5
Unrecognized compensation cost, options	2.7		$ 2.7
Weighted-average period of recognition			1 year 4 months 24 days
Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation expense	0.7	$ 0.7	$ 2.1	$ 1.8
Unrecognized compensation cost	$ 4.4		$ 4.4
Weighted-average period of recognition			2 years

Share-Based Compensation - RSU

Share-Based Compensation - RSU Options and PSUs (Details)	9 Months Ended
	Sep. 30, 2022 $ / shares shares
Restricted Stock Units
Other-than-Options, Shares Activity
Granted, Shares | shares	197,986
Other-than-Options, FV Activity
Granted, Weighted-Average Grant Date Fair Value per Share	$ 52.10
Option Awards
Options Outstanding Roll Forward
Granted, Options | shares	192,175
Fair Value Assumptions
Expected term (in years)	5 years 6 months
Expected volatility	48.72%
Risk-free interest rate	1.97%
Dividend yield	2%
Options granted, Weighted average grant date fair value	$ 22.52
Performance Share Units
Fair Value Assumptions
Expected term (in years)	3 years
Expected volatility	57.30%
Risk-free interest rate	1.73%
Share Price	$ 58.64
Other-than-Options, Shares Activity
Granted, Shares | shares	63,317
Other-than-Options, FV Activity
Granted, Weighted-Average Grant Date Fair Value per Share	$ 57.47

Segments - Reconciliation of Se

Segments - Reconciliation of Segment Reporting to Consolidated (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) segment	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment			6
Adjusted EBITDA	$ (12.9)	$ 198.4	$ 377.6	$ 668
Equity in earnings of unconsolidated affiliates	22.8	17.1	83.8	70.2
Investment in unconsolidated affiliates	269.2		269.2		$ 247.8
Capital expenditures			94	64.7
Engineered Materials
Segment Reporting Information [Line Items]
Adjusted EBITDA	7.5	32.7	76.2	68.5
Latex Binders
Segment Reporting Information [Line Items]
Adjusted EBITDA	31	37.1	90.6	86.2
Base Plastics
Segment Reporting Information [Line Items]
Adjusted EBITDA	(14.9)	87.9	99.8	235
Polystyrene
Segment Reporting Information [Line Items]
Adjusted EBITDA	18.7	51.2	87	149.6
Feedstocks
Segment Reporting Information [Line Items]
Adjusted EBITDA	(78)	(27.6)	(59.8)	58.5
Americas Styrenics [Member]
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 22.8	$ 17.1	$ 83.8	$ 70.2
AmSty
Segment Reporting Information [Line Items]
Percentage of ownership underlying net assets	50%		50%		50%
Investment in unconsolidated affiliates	$ 269.2		$ 269.2		$ 247.8
AmSty | Americas Styrenics [Member]
Segment Reporting Information [Line Items]
Percentage of ownership underlying net assets	50%		50%

Segments - Reconciliation of Ne

Segments - Reconciliation of Net Income to Segment Adjusted EBITDA (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Income (loss) from continuing operations before income taxes	$ (130)	$ 84.9	$ (22.3)	$ 327.1
Interest expense, net	(30.4)	(23)	(77.7)	(56.6)
Depreciation and amortization	45.9	49.8	147.1	111
Corporate Unallocated	23.7	25	72.1	71.3
Adjusted EBITDA addbacks	17.1	15.7	103	102
Adjusted EBITDA	(12.9)	198.4	377.6	668
Net gain on disposition of businesses and assets			(1.8)	(0.2)
Restructuring and other charges		0.2	(1)	6.8
Acquisition transactions and integration net costs (benefit)	0.4	13.6	6.2	62.8
Acquisition purchase price hedge loss (gain)				22
Asset impairment charges or write-offs	1.9	1.2	3.9	3
European Commission Request for Information (Note 13)			35.6
Other items	14.8	0.7	60.1	7.6
Corporate Unallocated
Segment Reporting Information [Line Items]
Interest expense, net	$ 30.4	$ 23	$ 77.7	$ 56.6

Restructuring (Details)

Restructuring (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		$ 0.2	$ (1)	$ 6.4
Restructuring, Incurred Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Selling, General and Administrative Expense	Selling, General and Administrative Expense	Selling, General and Administrative Expense	Selling, General and Administrative Expense
Restructuring Reserve [Roll Forward]
Accrued charges/Balance at beginning of period			$ 10
Expenses			(1.3)
Deductions			(4.5)
Accrued charges/Balance at end of period	$ 4.2		4.2
Transformational Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		$ 0.3	0.1	$ 6.4
Cumulative life-to-date charges	8.8		8.8
Other Restructurings
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		(0.1)	(1.1)
Employee termination benefits
Restructuring Reserve [Roll Forward]
Accrued charges/Balance at beginning of period			10
Expenses			(1.4)
Deductions			(4.4)
Accrued charges/Balance at end of period	4.2		4.2
Employee termination benefits | Transformational Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		$ 0.3	0.1	$ 6.4
Cumulative life-to-date charges	8.8		8.8
Employee termination benefits | Transformational Restructuring Program | Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring charges	$ 1		1
Decommissioning and other
Restructuring Reserve [Roll Forward]
Expenses			0.1
Deductions			$ (0.1)

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) - Components (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	$ 924.6	$ 829.8	$ 1,013.1	$ 590.3
Balance at end of period	698.1	922	698.1	922
Cumulative Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(153.4)	(109.3)	(114.3)	(109)
Other comprehensive income (loss)	(45)	(1.7)	(84.1)	(2)
Balance at end of period	(198.4)	(111)	(198.4)	(111)
Pension & Other Postretirement Benefit Plans, Net
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(27)	(69.8)	(33.6)	(71.9)
Other comprehensive income (loss)	2.4	9.3	10	9.3
Amounts reclassified from AOCI to net income	(0.9)	(1.2)	(1.9)	0.9
Balance at end of period	(25.5)	(61.7)	(25.5)	(61.7)
Cash Flow Hedges, Net
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	2.5	(0.8)	0.7	(5.2)
Other comprehensive income (loss)	(3.4)	0.6	(2.7)	3
Amounts reclassified from AOCI to net income	(2.2)	0.6	(1.1)	2.6
Balance at end of period	(3.1)	0.4	(3.1)	0.4
Total
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at beginning of period	(177.9)	(179.9)	(147.2)	(186.1)
Other comprehensive income (loss)	(46)	8.2	(76.8)	10.3
Amounts reclassified from AOCI to net income	(3.1)	(0.6)	(3)	3.5
Balance at end of period	$ (227)	$ (172.3)	$ (227)	$ (172.3)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Loss) - Reclassification (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	$ 1,217.6			$ 1,101			$ 3,714.8	$ 2,951.7
Interest expense, net	$ 30.4			$ 23			$ 77.7	$ 56.6
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]							Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]							Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Settlement and Curtailment Gain (Loss), Statement of Income or Comprehensive Income [Extensible List]	Other Nonoperating Income (Expense)			Other Nonoperating Income (Expense)			Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Income before income taxes	$ 130			$ (84.9)			$ 22.3	$ (327.1)
Provision for income taxes	(12.1)			5.5			41.4	48.9
Net income	119.8	$ (37.4)	$ (16.7)	(93.1)	$ (151.6)	$ (71.5)	65.6	(316.2)
Reclassified from AOCI to net income (loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net curtailment and settlement gain	(1.4)			(2.5)			(3.3)	(2.5)
Pension & Other Postretirement Benefit Plans, Net | Reclassified from AOCI to net income (loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	(0.9)			(1)			(1.7)	2.1
Provision for income taxes				(0.2)			(0.2)	(1.2)
Net income	(0.9)			(1.2)			$ (1.9)	$ 0.9
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]							Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] | Reclassified from AOCI to net income (loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Prior service credit	(0.1)			(0.2)			$ (0.4)	$ (0.7)
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]							Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member] | Reclassified from AOCI to net income (loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net actuarial loss	0.6			1.7			$ 2	$ 5.3
Cash Flow Hedges, Net | Reclassified from AOCI to net income (loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales				(0.3)
Interest expense, net	(0.2)			0.9			1.2	2.6
Income before income taxes	(2.2)			0.6			(0.8)	2.6
Provision for income taxes							(0.3)
Net income	(2.2)			$ 0.6			(1.1)	$ 2.6
Cash Flow Hedges, Net | Reclassified from AOCI to net income (loss) | Commodity Contract
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	$ (2)						$ (2)

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings:
Net income (loss) from continuing operations	$ (117.9)			$ 79.4			$ (63.7)	$ 278.2
Net income (loss) from discontinued operations, net of income taxes	(1.9)			13.7			(1.9)	38
Net income (loss)	$ (119.8)	$ 37.4	$ 16.7	$ 93.1	$ 151.6	$ 71.5	$ (65.6)	$ 316.2
Shares:
Weighted average ordinary shares outstanding	35.2			38.8			36.3	38.7
Dilutive effect of RSUs, option awards and PSUs				0.7				0.9
Diluted weighted average ordinary shares outstanding	35.2			39.5			36.3	39.6
Income (loss) per share
Income (loss) per share-basic, Continuing operations	$ (3.35)			$ 2.04			$ (1.76)	$ 7.19
Income (loss) per share-basic, Discontinued operations	(0.06)			0.35			(0.05)	0.98
Income (loss) per share-basic	(3.41)			2.39			(1.81)	8.17
Income (loss) per share-diluted, Continuing operations	(3.35)			2.01			(1.76)	7.03
Income (loss) per share-diluted, Discontinued operations	(0.06)			0.35			(0.05)	0.96
Income (loss) per share- diluted	$ (3.41)			$ 2.36			$ (1.81)	$ 7.99
Anti-dilutive shares excluded				0.6				0.6

Other Charges (Details)

Other Charges (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Other Charges
Asset impairment charges or write-offs (Note 11)	$ 1.9		$ 1.2	$ 3.9	$ 3
European Commission Request for Information (Note 13)		$ 35.6		35.6
Total	$ 1.9		$ 1.2	$ 39.5	$ 3