ACQUISITIONS - Aggregate Purchase Price Paid for Acquisitions and Other Adjustments to Consideration (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Business Acquisition [Line Items]
Cash, net of cash acquired	$ 39.6	$ 23.8
Series of individual business acquisitions
Business Acquisition [Line Items]
Cash, net of cash acquired	39.6
Promissory notes	27.5
Deferred consideration	0.6
Contingent consideration	(0.4)
Total purchase price	67.3
Series of individual business acquisitions | Current Period Acquisitions
Business Acquisition [Line Items]
Cash, net of cash acquired	39.6
Promissory notes	27.5
Deferred consideration	0.6
Total purchase price	67.7
Series of individual business acquisitions | Restatement adjustment
Business Acquisition [Line Items]
Contingent consideration	(0.4)
Total purchase price	$ (0.4)