REVENUE - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred contract asset	$ 92.8	$ 92.8	$ 63.0
Deferred revenue	22.8	22.8	22.3
Contract with customer, assets, net	11.6	11.6	11.4
Deferred revenue, revenue recognized	5.8	15.9
Deferred commissions	21.0	21.0	18.9
Accounts receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred contract asset	69.5	69.5	40.2
Prepaid expenses and other current assets
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred contract asset	8.9	8.9	7.6
Other assets
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred contract asset	$ 14.4	$ 14.4	$ 15.2