Mortgage Servicing Rights (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Mortgage Servicing Rights (Additional Textual) [Abstract]
Aggregate fair value of mortgage servicing rights	5.0	4.2
Maximum [Member]
Mortgage Servicing Rights (Textual) [Abstract]
Range of fair value of mortgage servicing rights using discount rates	10.00%	10.00%
Minimum [Member]
Mortgage Servicing Rights (Textual) [Abstract]
Range of fair value of mortgage servicing rights using discount rates	5.00%	5.00%