NET INCOME PER COMMON SHARE - Potentially Dilutive Securities Excluded from Computation of Net Income Per Common Share (Details) - 7.50% Cumulative Redeemable Preferred Stock, Series E [Member]	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Schedule of Earning Per Share, Basic, by Common Class [Line Items]
Preferred stock dividend rate (in hundredths)	7.50%	7.50%
Redeemable Preferred Stock [Member]
Schedule of Earning Per Share, Basic, by Common Class [Line Items]
Preferred stock dividend rate (in hundredths)		7.50%	7.50%