COMMON STOCK - Additional Information (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Intrinsic value of stock options exercised and restricted stock units vested	$ 323.5	$ 382.1	$ 281.1
Cash from exercises of stock options	79.2	110.4	103.7
Realized tax benefits from exercises of stock options and vesting of restricted stock units	72.1	85.1	62.5
Total grant date fair value of stock options vested	34.0	$ 31.2	$ 29.0
Employee stock purchase subscriptions	$ 140.9
Weighted-average remaining requisite service period	30 months