Net Loss per Share - Reconciliation (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Numerator:
Net loss attributable to common stockholder—basic	$ (57.2)	$ (67.2)	$ (104.5)	$ (133.0)
Net loss attributable to common stockholders—diluted	$ (57.2)	$ (67.2)	$ (104.5)	$ (133.0)
Denominator:
Weighted average common shares outstanding—basic (in shares)	70,721,227	69,534,731	70,502,856	69,434,971
Weighted average common shares outstanding—diluted (in shares)	70,721,227	69,534,731	70,502,856	69,434,971
Net loss per share attributable to common stockholders—basic (usd per share)	$ (0.81)	$ (0.97)	$ (1.48)	$ (1.92)
Net loss per share attributable to common stockholders—diluted (usd per share)	$ (0.81)	$ (0.97)	$ (1.48)	$ (1.92)