ACQUISITIONS - Acquisition of Energy Labs, Inc (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Schedule of total aggregate purchase consideration      
Purchase consideration, net of cash acquired $ 0.0 $ 124.3 $ 211.4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract]      
Goodwill 605.8 634.0 $ 596.1
Acquisition of Energy Labs, Inc      
Additional Information      
Discount rate     14.80%
Schedule of total aggregate purchase consideration      
Purchase consideration - Cash 144.2    
Purchase consideration - Contingent consideration 12.8 34.5  
Purchase consideration 157.0    
Less: Cash acquired (7.5)    
Purchase consideration, net of cash acquired 149.5    
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract]      
Current assets 26.4    
Property, plant and equipment, net 23.6    
Intangible assets 73.7    
Total identifiable assets 123.7    
Current liabilities 13.3    
Deferred income taxes 23.1    
Total identifiable liabilities assumed 36.4    
Goodwill 62.2    
Purchase consideration, net of cash acquired 149.5    
Total identifiable intangible assets acquired, their useful lives and fair values      
Total finite-lived identifiable intangible assets $ 73.7    
Weighted average useful life of finite-lived intangibles (years) 8 years 10 months 24 days    
Acquisition of Energy Labs, Inc | Minimum      
Additional Information      
Decrease in fair value of contingent consideration   10.0  
Acquisition of Energy Labs, Inc | Maximum      
Additional Information      
Decrease in fair value of contingent consideration   $ 2.8  
Acquisition of Energy Labs, Inc | Customer relationships      
Total identifiable intangible assets acquired, their useful lives and fair values      
Total finite-lived identifiable intangible assets $ 59.7    
Weighted average useful life of finite-lived intangibles (years) 10 years    
Acquisition of Energy Labs, Inc | Developed Technology      
Total identifiable intangible assets acquired, their useful lives and fair values      
Total finite-lived identifiable intangible assets $ 7.5    
Weighted average useful life of finite-lived intangibles (years) 5 years    
Acquisition of Energy Labs, Inc | Trademarks      
Total identifiable intangible assets acquired, their useful lives and fair values      
Total finite-lived identifiable intangible assets $ 3.3    
Weighted average useful life of finite-lived intangibles (years) 5 years    
Acquisition of Energy Labs, Inc | Other Intangibles      
Total identifiable intangible assets acquired, their useful lives and fair values      
Total finite-lived identifiable intangible assets $ 3.2    
Weighted average useful life of finite-lived intangibles (years) 1 year