Long-term Debt Payable to Westlake (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Dec. 31, 2021
Related Party Transaction [Line Items]
Long-term debt payable to Westlake	$ 22,619	$ 399,674
Debt, Long-term and Short-term, Combined Amount	$ 399,674
Weighted average interest rate	2.20%	2.10%
Debt payable to Westlake	$ 377,055	$ 0
Limited Partner \| OpCo Revolver \| Senior Unsecured Revolving Credit Facility
Related Party Transaction [Line Items]
Long-term debt payable to Westlake	$ 22,619	22,619
Limited Partner \| OpCo Revolver \| Senior Unsecured Revolving Credit Facility \| LIBOR [Member]
Related Party Transaction [Line Items]
Basis spread on variable rate, percent	2.00%
Limited Partner \| MLP Revolver \| Senior Unsecured Revolving Credit Facility
Related Party Transaction [Line Items]
Long-term debt payable to Westlake		$ 377,055
Debt payable to Westlake	$ 377,055
Limited Partner \| MLP Revolver \| Senior Unsecured Revolving Credit Facility \| LIBOR [Member]
Related Party Transaction [Line Items]
Basis spread on variable rate, percent	2.00%

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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