Disclosures about Fair Value of Assets and Liabilities - Fair Value Measurements of Assets and Liabilities Recognized on a Recurring Basis (Detail) (USD $) | Mar. 31, 2014 | Dec. 31, 2013 |
In Thousands, unless otherwise specified |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | $519,430 | $508,591 |
U.S. Treasury and federal agencies [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 42,641 | 43,134 |
State and municipal [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 178,333 | 177,898 |
Federal agency collateralized mortgage obligations [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 114,836 | 114,706 |
Federal agency mortgage-backed pools [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 181,573 | 170,894 |
Private labeled mortgage-backed pools [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 1,056 | 1,226 |
Corporate notes [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 991 | 733 |
Recurring Basis [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 519,430 | 508,591 |
Recurring Basis [Member] | U.S. Treasury and federal agencies [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 42,641 | 43,134 |
Recurring Basis [Member] | State and municipal [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 178,333 | 177,898 |
Recurring Basis [Member] | Federal agency collateralized mortgage obligations [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 114,836 | 114,706 |
Recurring Basis [Member] | Federal agency mortgage-backed pools [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 181,573 | 170,894 |
Recurring Basis [Member] | Private labeled mortgage-backed pools [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 1,056 | 1,226 |
Recurring Basis [Member] | Hedged Loans [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | 100,564 | 95,372 |
Recurring Basis [Member] | Forward Sale Commitments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | 470 | 212 |
Recurring Basis [Member] | Interest Rate Swap Agreements [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | -3,205 | -2,773 |
Recurring Basis [Member] | Commitments to Originate Loans [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | -39 | -22 |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Treasury and federal agencies [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | State and municipal [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Federal agency collateralized mortgage obligations [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Federal agency mortgage-backed pools [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Private labeled mortgage-backed pools [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Hedged Loans [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | ' | ' |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Forward Sale Commitments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | ' | ' |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest Rate Swap Agreements [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | ' | ' |
Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commitments to Originate Loans [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | ' | ' |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 519,430 | 508,591 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. Treasury and federal agencies [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 42,641 | 43,134 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | State and municipal [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 178,333 | 177,898 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Federal agency collateralized mortgage obligations [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 114,836 | 114,706 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Federal agency mortgage-backed pools [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 181,573 | 170,894 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Private labeled mortgage-backed pools [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 1,056 | 1,226 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Hedged Loans [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | 100,564 | 95,372 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Forward Sale Commitments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | 470 | 212 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Swap Agreements [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | -3,205 | -2,773 |
Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commitments to Originate Loans [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | -39 | -22 |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | U.S. Treasury and federal agencies [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | State and municipal [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Federal agency collateralized mortgage obligations [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Federal agency mortgage-backed pools [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Private labeled mortgage-backed pools [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Hedged Loans [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | ' | ' |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Forward Sale Commitments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | ' | ' |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Swap Agreements [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | ' | ' |
Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commitments to Originate Loans [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Available-for-sale securities | ' | ' |
Recurring Basis [Member] | Corporate notes [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 991 | 733 |
Recurring Basis [Member] | Corporate notes [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |
Recurring Basis [Member] | Corporate notes [Member] | Significant Other Observable Inputs (Level 2) [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | 991 | 733 |
Recurring Basis [Member] | Corporate notes [Member] | Significant Unobservable Inputs (Level 3) [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Total available-for-sale securities, Fair Value | ' | ' |