Fair Values (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Obligations of states and political subdivisions [Member]
Quantitative information about Level 3 fair value measurements
Fair Value Measurements, Obligations of states and political subdivisions	$ 1,131
Fair Value Measurements, Valuation Techniques	Discounted cash flow
Fair Value Measurements, Unobservable Input	Risk adjusted discount rate
Other investment securities [Member]
Quantitative information about Level 3 fair value measurements
Fair Value Measurements, Other investment securities	$ 13,747
Fair Value Measurements, Valuation Techniques	Discounted cash flow
Fair Value Measurements, Unobservable Input	Constant prepayment rate Probability of default Loss Severity