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Loans and Loans Held for Sale - Summary of Restructured Loans (Details) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2017 USD ($) tdr | Mar. 31, 2016 USD ($) tdr | Dec. 31, 2016 USD ($)
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans | [1] | $ 438 | $ 2,614 |
Number of troubled debt restructuring loans returned back to accruing status | tdr |  | 0 | 0 |
Performing |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | $ 13,086 |  | $ 13,423
Performing | Commercial Real Estate |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 2,715 |  | 2,994
Performing | Commercial And Industrial |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 1,361 |  | 1,387
Performing | Commercial Construction |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 2,959 |  | 2,966
Performing | Residential Mortgage |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 2,242 |  | 2,375
Performing | Home Equity Loan |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 3,793 |  | 3,683
Performing | Installment And Other Consumer |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 16 |  | 18
Nonperforming |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 10,324 |  | 11,598
Nonperforming | Commercial Real Estate |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 625 |  | 646
Nonperforming | Commercial And Industrial |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 3,942 |  | 4,493
Nonperforming | Commercial Construction |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 427 |  | 430
Nonperforming | Residential Mortgage |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 4,321 |  | 5,068
Nonperforming | Home Equity Loan |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 1,003 |  | 954
Nonperforming | Installment And Other Consumer |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 6 |  | 7
Financing Receivable |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 23,410 |  | 25,021
Financing Receivable | Commercial Real Estate |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 3,340 |  | 3,640
Financing Receivable | Commercial And Industrial |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 5,303 |  | 5,880
Financing Receivable | Commercial Construction |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 3,386 |  | 3,396
Financing Receivable | Residential Mortgage |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 6,563 |  | 7,443
Financing Receivable | Home Equity Loan |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | 4,796 |  | 4,637
Financing Receivable | Installment And Other Consumer |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Restructured loans |  | $ 22 |  | $ 25
[1] | Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.

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