Merger with AlloVir - Schedule of Number of Shares Common Stock Issued and Outstanding (Details) - Common Stock - AlloVir	Mar. 18, 2025 shares
Business Combination, Consideration Transferred, Equity Interest [Line Items]
AlloVir's common stock outstanding	5,043,652
AlloVir's restricted stock units accelerated and settled in common stock	24,022
Common stock issued to Legacy Kalaris' securityholders at the Effective Time	13,634,744
Total	18,702,418

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