Equifax Inc. Annual report pursuant to Section 13 and 15(d)

STOCK-BASED COMPENSATION - Total Stock-Based Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense, before income taxes	$ 49.7	$ 42.5	$ 38.3
Cost of services
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense, before income taxes	10.7	9.5	7.2
Selling, general and administrative expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense, before income taxes	$ 39.0	$ 33.0	$ 31.1