Estimated Fair Value of Financial Instruments - Balances of Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total other real estate owned	$ 745	$ 579
Quoted Market Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total impaired loans
Internal Models with Significant Observable Market Parameters (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total impaired loans
Internal Models with Significant Unobservable Market Parameters (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total impaired loans	913,057
Internal Models with Significant Unobservable Market Parameters (Level 3) | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total impaired loans	1,334	21,986
Total other real estate owned		579
Internal Models with Significant Unobservable Market Parameters (Level 3) | Commercial real estate | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total impaired loans	1,334	11,241
Total other real estate owned		304
Internal Models with Significant Unobservable Market Parameters (Level 3) | Commercial | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total impaired loans		289
Internal Models with Significant Unobservable Market Parameters (Level 3) | Residential Real Estate | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total impaired loans		5,231
Total other real estate owned		275
Internal Models with Significant Unobservable Market Parameters (Level 3) | Home equity loans | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total impaired loans		4,464
Internal Models with Significant Unobservable Market Parameters (Level 3) | Indirect | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total impaired loans		443
Internal Models with Significant Unobservable Market Parameters (Level 3) | Consumer | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total impaired loans		$ 318