Summary of Significant Accounting Policies - Receivables Purchase Agreement (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2026	Dec. 31, 2025	Jun. 27, 2025
Summary of Significant Accounting Policies
Maximum amount of trade receivables that can be sold			$ 35.0
Cash inflow from factoring arrangement	$ 230.2
Customer payments remitted to the factor	237.0
Fees incurred	1.2
Cash collections on behalf of factor	9.9	$ 13.8
Deferred purchase price on the sold receivables	$ 1.1	$ 1.2

No definition available.

Name:	us-gaap_AccountingPoliciesAbstract
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Amount remitted to Factor under the receivable purchase agreement.

No definition available.

Name:	wch_AccountsReceivableAmountRemitted
Namespace Prefix:	wch_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of fees incurred associated with the sale of receivables under the receivable purchase agreement.

No definition available.

Name:	wch_AccountsReceivableSaleFeesIncurred
Namespace Prefix:	wch_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of cash collections on behalf of the Factor that are yet to be remitted under the receivable purchase agreement.

No definition available.

Name:	wch_CashCollectionsOnBehalfOfFactor
Namespace Prefix:	wch_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of deferred purchase price balance on the sold receivables outstanding.

No definition available.

Name:	wch_FactoringAgreementsDeferredPurchasePrice
Namespace Prefix:	wch_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The maximum amount of accounts receivable that can be sold on a nonrecourse basis to the Factor under the receivable purchase agreement.

No definition available.

Name:	wch_MaximumAmountOfAccountsReceivableThatCanBeSold
Namespace Prefix:	wch_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of cash inflow from sale of accounts receivables.

No definition available.

Name:	wch_ProceedsFromSaleOfAccountsReceivables
Namespace Prefix:	wch_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration