SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) - USD ($) $ in Millions		3 Months Ended
	Jan. 01, 2020	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Revenue Recognition
Unearned revenues		$ 3.3		$ 3.8
Revenues recognized that was included in the deferred revenue balance		2.3
Trade accounts receivable
Allowance for doubtful accounts		1.1		$ 1.2
Development services contract
Revenue Recognition
Transaction price allocated to unsatisfied performance obligation		5.4
Fixed fee contract
Revenue Recognition
Transaction price allocated to unsatisfied performance obligation		$ 16.7
Fixed fee contract | Minimum | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
Revenue Recognition
Expected timing to recognize revenue, term		1 year
Fixed fee contract | Maximum | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
Revenue Recognition
Expected timing to recognize revenue, term		5 years
State Enterprise | Revenues
Summary of Significant Accounting Policies
Prior period reclassification adjustment			$ (7.4)
State Enterprise | Cost of revenues
Summary of Significant Accounting Policies
Prior period reclassification adjustment			(6.7)
Software & services | Revenues
Summary of Significant Accounting Policies
Prior period reclassification adjustment			7.4
Software & services | Cost of revenues
Summary of Significant Accounting Policies
Prior period reclassification adjustment			$ 6.7
ASU 2016-13
Recently issued accounting pronouncements
Cumulative effect adjustment	$ 0.3