EQUITY - Preferred Stock (Details) - USD ($)		3 Months Ended
	Mar. 21, 2013	Mar. 31, 2018	Jun. 01, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Shares of preferred stock issued (in shares)	5,750,000.00	5,750,000		5,750,000
Preferred stock dividend rate	7.125%
Price per share of preferred stock (in dollars per share)	$ 25.00
Net proceeds from preferred stock offering	$ 138,300,000
Preferred stock dividends in arrears		$ 0
Shares of preferred stock outstanding (in shares)		5,750,000		5,750,000
Scenario, Forecast
Class of Stock [Line Items]
Redemption price (in dollars per share)			$ 25.00