SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Antidilutive Options (Details) - Stock options - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Options not included in the computation of diluted earnings per share:
Excluded from the computation of diluted earnings per share (in shares)	1,086,244	843,980	697,968
Minimum
Options not included in the computation of diluted earnings per share:
Weighted Average Proceeds per Share (in dollars per share)	$ 43.09	$ 44.55	$ 39.82
Maximum
Options not included in the computation of diluted earnings per share:
Weighted Average Proceeds per Share (in dollars per share)	$ 85.68	$ 59.07	$ 47.81