Troubled Debt Restructurings (Details Textual) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013 Investment	Dec. 31, 2012 Investment
Troubled Debt Restructurings (Textual)
Total number of loans classified under troubled debt restructurings (TDRs)	37	36
Total sum of loans classified as troubled debt restructurings (TDRs)	$ 12.4	$ 14.2
Number of months previous loan payment defaulted	12-month period.