Mortgage Banking Activities (Details 3)	12 Months Ended
	Dec. 31, 2012 Rate	Dec. 31, 2011 Rate
Key economic assumptions in measuring the value of mortgage servicing rights
Weighted average prepayment rate	401	475
Weighted average life (in years)	3 years 11 months 5 days	3 years 8 months 12 days
Weighted average discount rate	8.00%	8.00%