Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Net Loss Attributable to Parent	$ (27,310)	$ (12,415)	$ (44,126)	$ (49,785)
Dividends	6,342	6,260	19,091	18,773
Dividends attributable to common stockholders under the two class method	6,202	6,100	18,526	18,202
Net loss available to common stockholders, basic	$ (27,450)	$ (12,575)	$ (44,691)	$ (50,356)
Weighted Average Number of Shares Outstanding, Basic and Diluted	49,630,369	48,806,334	49,423,548	48,561,428
Earnings Per Share, Basic and Diluted	$ (0.55)	$ (0.26)	$ (0.90)	$ (1.04)