Federal Income Taxes (Details 2) (USD $)	3 Months Ended												12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 30, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Characterization of distributions paid per common share
Amount of distributions paid per common share	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.72	$ 0.72	$ 0.72
Percentage of distributions paid per common share													100.00%	100.00%	100.00%
Ordinary Income [Member]
Characterization of distributions paid per common share
Amount of distributions paid per common share													$ 0.12844	$ 0.07892	$ 0.29090
Percentage of distributions paid per common share													17.84%	10.96%	40.40%
Capital Gains [Member]
Characterization of distributions paid per common share
Amount of distributions paid per common share													$ 0.05835	$ 0.08391	$ 0.08205
Percentage of distributions paid per common share													8.10%	11.65%	11.40%
Return of Capital [Member]
Characterization of distributions paid per common share
Amount of distributions paid per common share													$ 0.53321	$ 0.55717	$ 0.34705
Percentage of distributions paid per common share													74.06%	77.39%	48.20%