STOCKHOLDERS' EQUITY (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Oct. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Preferred stock
Preferred stock authorized for issuance (in shares)		2,000,000	2,000,000
Preferred stock, par value (in dollars per share)		$ 0.01	$ 0.01
Common stock
Common stock authorized for issuance (in shares)		60,000,000	60,000,000
Common stock par value (in dollars per share)		$ 0.01	$ 0.01
Equity offering
Equity offering in period, new shares (in shares)	3,300,000
New shares issued, price per share (in dollars per share)	$ 260.00
Proceeds from equity offering, net of transaction costs	$ 834,000	$ 0	$ 833,911	$ 0
Payments for underwriting expense	$ 29,000