ACQUISITION OF HATTERAS - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions		12 Months Ended
	Jul. 12, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
7.625% Series E Cumulative Redeemable Preferred Stock
Business Acquisition [Line Items]
Preferred stock dividend rate, percentage	7.625%	7.625%	7.625%	7.625%
Cumulative redeemable preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Hatteras
Business Acquisition [Line Items]
Business combination aggregate consideration transferred to common stockholders	$ 1,500,000
Business acquisition, cash consideration	521,082
Hatteras | Common Stock
Business Acquisition [Line Items]
Business combination, equity consideration transfered	$ 997,707
Business acquisition, shares issued (in shares)	93.9
Hatteras
Business Acquisition [Line Items]
Preferred stock dividend rate, percentage	7.625%
Cumulative redeemable preferred stock, par value (in dollars per share)	$ 0.001