CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Activities:
Net loss	$ (11.8)	$ (10.2)	$ (42.5)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	48.2	37.0	27.1
Stock-based compensation	38.8	34.4	17.9
Change in fair value of contingent consideration related to earnouts	0.0	6.7	18.1
Deferred taxes	(0.5)	(12.6)	4.4
Non-cash lease costs	2.8	2.6	7.9
Other, net	2.9	1.3	(2.1)
Changes in operating assets and liabilities, net of business combination:
Accounts receivable	10.7	(18.7)	(20.2)
Prepaid expenses and other assets	(4.4)	(0.7)	(9.6)
Accounts payable	(1.8)	(5.6)	(2.2)
Accrued expenses and other current liabilities	(2.4)	5.8	16.6
Payment of contingent consideration	(14.0)	(11.5)	0.0
Operating lease liabilities	(3.1)	(2.4)	(7.3)
Other liabilities	6.7	(1.1)	(0.9)
Net cash provided by operating activities	72.1	25.0	7.2
Investing Activities:
Capitalized software development costs	(28.8)	(27.6)	(20.7)
Purchase of property and equipment	(0.7)	(4.6)	(2.3)
Business combination, net of cash acquired	0.0	(68.1)	0.0
Net cash used in investing activities	(29.5)	(100.3)	(23.0)
Financing Activities:
Payment of contingent consideration	(16.9)	(19.0)	0.0
Proceeds from line of credit	7.5	70.0	0.0
Payments on line of credit	(7.5)	(70.0)	0.0
Payment of debt issuance costs	(1.4)	0.0	0.0
Principal repayment of subordinated promissory notes	0.0	0.0	(28.5)
Repurchase of Series A redeemable convertible preferred stock	0.0	0.0	(2.1)
Proceeds from exercise of stock options	10.2	7.7	11.0
Issuance of Class A common stock under Employee Stock Purchase Plan	3.0	4.5	0.0
Tax payments related to net-share settlements on restricted stock units	(1.1)	(0.6)	(1.9)
Proceeds from issuance of common stock upon initial public offering, net of underwriting discounts and commissions	0.0	0.0	140.0
Payment of offering costs related to initial public offering	0.0	(1.0)	(4.0)
Net cash provided by (used in) financing activities	(26.2)	(8.4)	100.2
Effect of exchange rate changes on cash and cash equivalents	0.1	(0.2)	0.0
Net increase (decrease) in cash and cash equivalents	16.5	(83.9)	84.4
Cash and Cash Equivalents:
Beginning of year	83.9	167.8	83.4
End of year	100.4	83.9	167.8
Supplemental Disclosures of Non-Cash Investing and Financing Activities:
Capitalized software development costs recorded in accounts payable and accrued expenses and other current liabilities	0.5	0.9	0.5
Purchase of property and equipment recorded in accounts payable and accrued expenses and other current liabilities	0.0	0.1	0.8
Offering costs related to initial public offering not yet paid	0.0	0.0	1.0
Supplemental Disclosures of Cash Flow Information:
Income tax payments	13.5	4.0	0.3
Cash paid for interest	0.3	1.9	2.5
Supplemental Cash Flow Disclosure Related to Operating Leases:
Cash paid for amounts included in the measurement of lease liabilities	3.7	3.1	8.2
Lease liabilities arising from obtaining right-of-use assets	0.0	0.0	7.8
Stock Options
Financing Activities:
Repurchases of common stock	0.0	0.0	(1.4)
Common Class A
Financing Activities:
Repurchases of common stock	(20.0)	0.0	(0.5)
Common Class F
Financing Activities:
Repurchases of common stock	$ 0.0	$ 0.0	$ (12.4)