Stock-Based Compensation Expense and Employee Benefit Plans - Employee Stock Purchase Plan (Details) - 2018 ESPP - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock ownership plan (ESOP), compensation expense	$ 0.1	$ 4.3	$ 12.5	$ 11.2
Number of shares issued (in shares)	426,170	339,055	875,695	759,744
Number of additional shares authorized (in shares)			2,239,563	12,055,792
Number of common stock reserved for issuance (in shares)	15,204,584		15,204,584		13,840,716
Unrecognized stock-based compensation cost	$ 12.1		$ 12.1		$ 12.0
Expense expected to be recognized over a weighted-average period			1 year 1 month 6 days		7 months 6 days