Summary of Significant Accounting Policies - Distributions and Dividends and Reacquired Stock (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2012	Oct. 31, 2012	Jul. 31, 2012	Jan. 02, 2011	Dec. 31, 2010
Accounting Policies [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01			$ 0.01	$ 0.01
Distributions payable	$ 76,293,000	$ 8,545,000
Dividends in arrears outstanding	67,700,000
Preferred stock, dividends in arrears, amount paid			$ 37,700,000	$ 30,000,000