Fair Value Measurements, Quantitative Information (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2013		Dec. 31, 2012
Impaired Loans Under Range One [Member]
Fair value inputs [Abstract]
Valuation Technique			Discounted appraised value
Impaired Loans Under Range One [Member] | Minimum [Member]
Fair value inputs [Abstract]
Selling cost (in hundredths)			0.00%
Impaired Loans Under Range One [Member] | Maximum [Member]
Fair value inputs [Abstract]
Selling cost (in hundredths)			10.00%
Impaired Loans Under Range One [Member] | Weighted Average [Member]
Fair value inputs [Abstract]
Selling cost (in hundredths)			2.00%
Impaired Loans Under Range Two [Member]
Fair value inputs [Abstract]
Valuation Technique			Discounted appraised value
Impaired Loans Under Range Two [Member] | Minimum [Member]
Fair value inputs [Abstract]
Discount for lack of marketability and age of appraisal (in hundredths)			0.00%
Impaired Loans Under Range Two [Member] | Maximum [Member]
Fair value inputs [Abstract]
Discount for lack of marketability and age of appraisal (in hundredths)			60.00%
Impaired Loans Under Range Two [Member] | Weighted Average [Member]
Fair value inputs [Abstract]
Discount for lack of marketability and age of appraisal (in hundredths)			52.00%
Impaired Loans Under Range Three [Member]
Fair value inputs [Abstract]
Valuation Technique			Present value of cash flows
Impaired Loans Under Range Three [Member] | Minimum [Member]
Fair value inputs [Abstract]
Discount rate (in hundredths)			0.00%
Impaired Loans Under Range Three [Member] | Maximum [Member]
Fair value inputs [Abstract]
Discount rate (in hundredths)			7.50%
Impaired Loans Under Range Three [Member] | Weighted Average [Member]
Fair value inputs [Abstract]
Discount rate (in hundredths)			6.28%
Impaired Loans Under Range Four [Member]
Fair value inputs [Abstract]
Valuation Technique	Discounted appraised value
Impaired Loans Under Range Four [Member] | Maximum [Member]
Fair value inputs [Abstract]
Selling cost (in hundredths)	10.00%	[1]
Impaired Loans Under Range Five [Member]
Fair value inputs [Abstract]
Valuation Technique	Present value of cash flows
Impaired Loans Under Range Five [Member] | Minimum [Member]
Fair value inputs [Abstract]
Discount rate (in hundredths)	6.25%
Impaired Loans Under Range Five [Member] | Maximum [Member]
Fair value inputs [Abstract]
Discount rate (in hundredths)	7.75%
Impaired Loans Under Range Five [Member] | Weighted Average [Member]
Fair value inputs [Abstract]
Discount rate (in hundredths)	6.36%
Other Real Estate Owned [Member]
Fair value inputs [Abstract]
Valuation Technique	Discounted appraised value		Discounted appraised value
Other Real Estate Owned [Member] | Minimum [Member]
Fair value inputs [Abstract]
Selling cost (in hundredths)	0.00%		0.00%
Discount for lack of marketability and age of appraisal (in hundredths)	0.00%		0.00%
Other Real Estate Owned [Member] | Maximum [Member]
Fair value inputs [Abstract]
Selling cost (in hundredths)	9.95%		6.00%
Discount for lack of marketability and age of appraisal (in hundredths)	30.90%		30.90%
Other Real Estate Owned [Member] | Weighted Average [Member]
Fair value inputs [Abstract]
Selling cost (in hundredths)	2.28%		4.30%
Discount for lack of marketability and age of appraisal (in hundredths)	4.94%		4.68%

[1] Of the Company's impaired loans with specific allocations based on Level 3 inputs, only one loan was valued using fair value of collateral.