| Document and Entity Information | Nov. 02, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Nov. 02, 2022 |
| 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, Adress Line Two | Suite 301 |
| Entity Address, City or Town | Wayne |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 19087 |
| City Area Code | 610 |
| Local Phone Number | 240-3200 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Ordinary Shares, par value $0.01 per share |
| Trading Symbol | TSE |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001519061 |
| Amendment Flag | false |
