Summary of Significant Accounting Policies (Details 4) (USD $)			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Preferred stock Series A	Dec. 31, 2013 Preferred stock Series B	Dec. 31, 2013 Preferred stock Series C	Dec. 31, 2013 Preferred stock Series D	Dec. 31, 2013 Preferred stock Series E
Preferred stock
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Preferred stock, liquidation preference (in dollars per share)			$ 10.00	$ 10.00	$ 13.00	$ 1,000	$ 1,000
Preferred stock conversion price (In dollars per share)					$ 13.00
Preferred stock dividend rate (as a percent)			5.00%	5.00%	5.00%	5.00%	5.00%