Earnings Per Share - Schedule of Antidilutive Shares (FY) (Details) - shares |
3 Months Ended | 9 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|---|
Sep. 30, 2024 |
Sep. 30, 2023 |
Sep. 30, 2024 |
Sep. 30, 2023 |
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||||
| Total (in shares) | 34,492,238 | 954,882 | 34,531,214 | 893,757 | 6,479,149 | 555,015 |
| Options and unvested stock units outstanding | ||||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||||
| Total (in shares) | 106,097 | 296,861 | 145,073 | 235,736 | 243,911 | 127,116 |
| Warrants outstanding | ||||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||||
| Total (in shares) | 30,017,768 | 629,271 | 30,017,768 | 629,271 | 6,206,488 | 399,149 |
| Contingent Sponsor Earnout Shares | ||||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||||
| Total (in shares) | 28,750 | 28,750 | 28,750 | 28,750 | 28,750 | 28,750 |