v3.24.4
Summary of Significant Accounting Policies - Schedule of Changes in Fair Value of Liabilities (Q3) (Details) - USD ($)
$ in Thousands
 9 Months Ended 12 Months Ended
Sep. 30, 2024
Dec. 31, 2023
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value recurring, basis unobservable input reconciliation, liability gain (loss), statement of other comprehensive income, extensible list, not disclosed flag Change in Fair Value Change in Fair Value
Fair Value, Inputs, Level 3 | Fair Value, Recurring    
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value at beginning of period $ 3 $ 10,564
Change in Fair Value   (561)
Fair value at end of period   3
Fair Value, Inputs, Level 3 | Warrant Liability (Level 3) | Fair Value, Recurring    
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value at beginning of period 3 564
Change in Fair Value 0 (561)
Fair value at end of period $ 3 $ 3