Stockholders' Equity (Details 2) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Dividends
Preferred stock dividends declared (in dollars per share)			$ 0.50	$ 2.00
Common stock dividends declared (in dollars per share)	$ 0.36	$ 0.51	$ 0.10
Dividends declared (in dollars per share)		$ 2.510	$ 2.600	$ 4.000
Series A Cumulative Redeemable Preferred Stock
Dividends
Preferred stock dividends declared (in dollars per share)			$ 0.50	$ 2.00
Series D Cumulative Redeemable Preferred Stock
Dividends
Preferred stock dividends declared (in dollars per share)		$ 2.00	$ 2.00	$ 2.00
Common Stock
Dividends
Common stock dividends declared (in dollars per share)		$ 0.51	$ 0.10