SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Basic:
Net income	$ 280.2	$ 274.7	$ 242.3	$ 249.7	$ 7.0	$ 225.9	$ 282.7	$ 206.6	$ 1,046.9	$ 722.2	$ 583.6
Weighted-average shares outstanding (in shares)									208.3	209.2	210.9
Basic earnings per share (in dollars per share)	$ 1.34	$ 1.32	$ 1.16	$ 1.20	$ 0.03	$ 1.08	$ 1.35	$ 0.98	$ 5.03	$ 3.45	$ 2.77
Diluted:
Net income	$ 280.2	$ 274.7	$ 242.3	$ 249.7	$ 7.0	$ 225.9	$ 282.7	$ 206.6	$ 1,046.9	$ 722.2	$ 583.6
Weighted-average shares outstanding (in shares)									208.3	209.2	210.9
Dilutive effect of stock plans (in shares)									3.9	4.4	5.0
Dilutive weighted-average shares outstanding (in shares)									212.2	213.6	215.9
Diluted earnings per share (in dollars per share)	$ 1.32	$ 1.30	$ 1.14	$ 1.18	$ 0.03	$ 1.06	$ 1.32	$ 0.96	$ 4.93	$ 3.38	$ 2.70