Fair Value Measurements - Summary of Estimated Fair Value of Derivative Liabilities Related to Redemption Features (Details)	Jan. 10, 2025 yr	Dec. 31, 2024 yr	Mar. 31, 2024 yr
Expected Term (in years) \| Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0.2	0.2	0.4
Expected Term (in years) \| Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0.3	0.4	1.3
Probability of Achievement \| Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0	0	0
Probability of Achievement \| Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0.80	0.80	0.90
Discount Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0.085	0.09
Discount Rate \| Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			0.095
Discount Rate \| Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities			0.187

Kalaris Therapeutics, Inc. 10-Q