STOCKHOLDERS' EQUITY - Repurchase of Common Stock (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stockholders' Equity Note [Abstract]
Number of shares authorized to be repurchased (in shares)	3,763,038
Aggregate number of shares repurchased since inception (in shares)	2,568,396
Treasury stock (in shares)	76,084	203,879
Number of shares acquired under the stock repurchase plan and subsequently reissued (in shares)	136,629	240,995	16,755
Treasury stock acquired, average cost (in dollars per share)	$ 98.54	$ 88.47	$ 83.08