Product Revenue and Accounts Receivable - Additional Information (Details)	Mar. 31, 2026 Customers
Product Revenues and Accounts Receivable, net [Abstract]
Number of customers with accounts receivable greater than ten percent	2
Number of other customers with accounts receivable greater than ten percent	0

Number of other customers with accounts receivable greater than ten percent.

No definition available.

Name:	kalv_NumberOfOtherCustomersWithAccountsReceivableGreaterThanTenPercent
Namespace Prefix:	kalv_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant