CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	100,000,000	100,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	450,000,000	450,000,000
Common stock, issued	85,528,563	85,402,408
Common stock, outstanding	85,528,563	85,402,408
9.25% Series A Preferred Stock
Preferred stock, shares issued	2,000,000	2,000,000
Preferred stock, shares outstanding	2,000,000	2,000,000
Preferred stock, liquidation preference (in dollars)	$ 50,398	$ 50,398
Preferred stock, dividend rate (as a percent)	9.25%	9.25%
7.875% Series B Preferred Stock
Preferred stock, shares issued	3,000,000	3,000,000
Preferred stock, shares outstanding	3,000,000	3,000,000
Preferred stock, liquidation preference (in dollars)	75,324	75,324
Preferred stock, dividend rate (as a percent)	7.875%	7.875%
7.125% Series C Preferred Stock
Preferred stock, shares issued	3,400,000	3,400,000
Preferred stock, shares outstanding	3,400,000	3,400,000
Preferred stock, liquidation preference (in dollars)	$ 85,522	$ 85,522
Preferred stock, dividend rate (as a percent)	7.125%	7.125%