STOCKHOLDERS' EQUITY - Repurchase of Common Stock (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
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)	2,190,772
Treasury stock (in shares)	706	0
Number of shares acquired under the stock repurchase plan and subsequently reissued (in shares)	16,755	23,182
Treasury stock acquired, average cost (in dollars per share)	$ 83.08	$ 82.19