STOCKHOLDERS' EQUITY - Repurchase of Common Stock (Details) - $ / shares	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	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)	2,431,767
Number of shares remaining in treasury (in shares)	232,499		706
Number of shares acquired under stock repurchase plan and subsequently reissued (in shares)	240,995	14,862
Treasury stock acquired, average cost (in dollars per share)	$ 88.47	$ 82.22