Fair Value Measurements and Fair Value of Financial Instruments (Additional Qualitative Information about Level 3 Assets) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013		Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 13,867		$ 14,597
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	13,867		14,597
Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	8,262		9,235
Impaired Loans [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	8,262	[1]	9,235	[1]
Fair Value Measurements, Valuation Techniques	Appraisal	[1]	Appraisal	[1]
Impaired Loans [Member] | Level 3 [Member] | Minimum [Member] | Unobservable Input Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	0.00%	[2]	0.00%	[2]
Impaired Loans [Member] | Level 3 [Member] | Minimum [Member] | Unobservable Input Cost to sell [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	5.00%		5.00%
Impaired Loans [Member] | Level 3 [Member] | Maximum [Member] | Unobservable Input Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	100.00%	[2]	100.00%	[2]
Impaired Loans [Member] | Level 3 [Member] | Maximum [Member] | Unobservable Input Cost to sell [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	15.00%		25.00%
Impaired Loans [Member] | Level 3 [Member] | Weighted Average [Member] | Unobservable Input Appraisal Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	18.20%	[2]	11.00%	[2]
Impaired Loans [Member] | Level 3 [Member] | Weighted Average [Member] | Unobservable Input Cost to sell [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	6.50%		7.00%
Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	5,420		5,127
Other Real Estate Owned [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	5,420	[1]	5,127	[1]
Fair Value Measurements, Valuation Techniques	Appraisal	[1]	Appraisal	[1]
Other Real Estate Owned [Member] | Level 3 [Member] | Unobservable Inputs, Appraisal Adjustments And Cost To Sell [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	8.00%	[2]	8.00%	[2]
Other Real Estate Owned [Member] | Level 3 [Member] | Weighted Average [Member] | Unobservable Inputs, Appraisal Adjustments And Cost To Sell [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	8.00%	[2]	8.00%	[2]
Mortgage Servicing Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	185		235
Mortgage Servicing Rights [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 185		$ 235
Fair Value Measurements, Valuation Techniques	Discounted Cash Flow (3)		Discounted Cash Flow (3)	[3]

[1] (1) Includes assets directly charged-down to fair value during the year-to-date period.

[2] (2) Qualitative adjustments are discounts specific to each asset and are made as needed.

[3] (3) Valuation and inputs are determined by a third-party pricing service without adjustment.