Earnings per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Numerator:
Net income (loss) attributable to common shareholders	$ (4,916)	$ (7,247)
Less: dividends paid on unvested share-based compensation	(79)	(83)
Undistributed earnings attributable to share-based compensation	0	0
Net income (loss) available to common shareholders	$ (4,995)	$ (7,330)
Denominator:
Weighted-average number of common shares-basic	60,996,196	51,009,904
Effect of dilutive share-based compensation	0	0
Weighted-average number of common shares-diluted	60,996,196	51,009,904
Net income (loss) per share attributable to common shareholders-basic	$ (0.08)	$ (0.14)
Net income (loss) per share attributable to common shareholders-diluted	$ (0.08)	$ (0.14)