| **Investment Securities**                              | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                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| **Investments, Debt and Equity Securities [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                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| Investment Securities                                  | Investment SecuritiesSecurities designated as available-for-sale are carried at fair value.  However, the unrealized difference between amortized cost and fair value of securities available-for-sale is excluded from net income unless there is an other than temporary impairment and it is reported, net of deferred taxes, as a component of shareholders' equity as accumulated other comprehensive income (loss).  Securities designated as held-to-maturity are carried at amortized cost, as the Company has the ability, and management has the positive intent, to hold these securities to maturity.  Premiums and discounts on securities are amortized and accreted according to the interest method.Our primary objective in managing the investment portfolio is to maintain a portfolio of high quality, highly liquid investments yielding competitive returns.  We are required under federal regulations to maintain adequate liquidity to ensure safe and sound operations.  We maintain investment balances based on a continuing assessment of cash flows, the level of loan production, current interest rate risk strategies and an assessment of the potential future direction of market interest rate changes.  Investment securities differ in terms of default, interest rate, liquidity and expected rate of return risks.The following table summarizes the amortized cost and estimated fair value of investment securities and presents the related gross unrealized gains and losses:March 31, 2016        (dollars in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair ValueAvailable-for-Sale:        Residential mortgage-backed securities-GSE $278,521 $920 $2,379 $277,062Residential mortgage-backed securities-Private 31,079 399 44 31,434Commercial mortgage-backed securities-GSE 21,880 242 — 22,122Commercial mortgage-backed securities-Private 17,858 140 150 17,848Corporate notes 37,524 21 17 37,528Total available-for-sale 386,862 1,722 2,590 385,994Held-to-Maturity:        Residential mortgage-backed securities-GSE 118,194 698 109 118,783Residential mortgage-backed securities-Private 16,877 — 32 16,845Commercial mortgage-backed securities-Private 10,056 169 — 10,225     Total held-to-maturity 145,127 867 141 145,853Total investment securities $531,989 $2,589 $2,731 $531,847         December 31, 2015        (dollars in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair ValueAvailable-for-Sale:        Obligations of U.S. government sponsored enterprises $2,005 $3 $— $2,008Residential mortgage-backed securities-GSE 286,057 339 8,289 278,107Residential mortgage-backed securities-Private 33,235 578 236 33,577Commercial mortgage-backed securities-GSE 21,980 — 368 21,612Commercial mortgage-backed securities-Private 17,869 — 294 17,575Corporate notes 37,669 — 114 37,555Total available-for-sale 398,815 920 9,301 390,434Held-to-Maturity:        Residential mortgage-backed securities-GSE 120,197 — 2,310 117,887Residential mortgage-backed securities-Private 17,712 — 298 17,414Commercial mortgage-backed securities-Private 10,058 — 174 9,884     Total held-to-maturity 147,967 — 2,782 145,185Total investment securities $546,782 $920 $12,083 $535,619As a member of the Federal Home Loan Bank of Atlanta (“FHLB”), the Bank is required to own capital stock in the FHLB based generally upon the balances of total assets and FHLB advances.  FHLB capital stock is pledged to secure FHLB advances.  This investment is carried at cost since no ready market exists for FHLB stock and there is no quoted market value.  However, redemption of this stock has historically been at par value.  The Bank owned a total of $4.9 million of FHLB stock at March 31, 2016 and $6.0 million at December 31, 2015.  Due to the redemption provisions of FHLB stock, we have estimated that fair value approximated cost and that this investment was not impaired at March 31, 2016.  FHLB stock is included in other assets at its original cost basis.As a member bank of the Federal Reserve Bank of Richmond (“FRBR”), the Bank also is required to own capital stock of the FRBR based upon a percentage of the Bank's common stock and surplus.  This investment is carried at cost since no ready market exists for FRBR stock and there is no quoted market value.  At March 31, 2016 and December 31, 2015, the Bank owned a total of $9.8 million and $9.9 million of FRBR stock, respectively.  Because this investment is in an entity of the U.S. government, we have estimated that fair value approximated the cost and that this investment was not impaired at March 31, 2016.  FRBR stock is included in other assets at its original cost basis.At March 31, 2016, $161.4 million of the investment securities portfolio was pledged to secure public deposits, $16.9 million was pledged to retail repurchase agreements and $156.3 million was pledged to others, leaving $196.5 million available as pledgeable collateral.The Bank did not sell any investment securities during the three months ended March 31, 2016 or the three months ended March 31, 2015.The following tables show our investments' estimated fair value and gross unrealized losses, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position, at March 31, 2016 and December 31, 2015.  The change in unrealized losses during the three months ending March 31, 2016 was attributed to changes in interest rates and not to changes in the credit quality of these securities.  All unrealized losses on investment securities are considered by management to be temporary given the credit quality of these investment securities or the short duration of the unrealized loss, or both. Less than 12 Months 12 Months or More Total(dollars in thousands)Estimated Fair ValueGross Unrealized Losses Estimated Fair ValueGross Unrealized Losses Estimated Fair ValueGross Unrealized LossesMarch 31, 2016        Available-for-Sale:        Residential mortgage-backed securities-GSE$—$— $189,610$2,379 $189,610$2,379Residential mortgage-backed securities-Private2,97032 62112 3,59144Commercial mortgage-backed securities-GSE—— —— ——Commercial mortgage-backed securities-Private7,399150 —— 7,399150Corporate Notes10,2244 9,99413 20,21817Total available-for-sale20,593186 200,2252,404 220,8182,590Held-to-Maturity:        Residential mortgage-backed securities-GSE—— 13,628109 13,628109Residential mortgage-backed securities-Private16,84532 —— 16,84532Total held-to-maturity16,84532 13,628109 30,473141Total$37,438$218 $213,853$2,513 $251,291$2,731         December 31, 2015        Available-for-Sale        Residential mortgage-backed securities-GSE$137,998$2,560 $132,148$5,729 $270,146$8,289Residential mortgage-backed securities-Private26,265231 6365 26,901236Commercial mortgage-backed securities-GSE21,612368 —— 21,612368Commercial mortgage-backed securities-Private17,575294 —— 17,575294Corporate notes30,523114 —— 30,523114Total available-for-sale233,9733,567 132,7845,734 366,7579,301Held-to-Maturity:        Residential mortgage-backed securities-GSE83,0141,481 34,872829 117,8862,310Residential mortgage-backed securities-Private17,414298 —— 17,414298Commercial mortgage-backed securities-Private9,884174 —— 9,884174Total held-to-maturity110,3121,953 34,872829 145,1842,782Total$344,285$5,520 $167,656$6,563$511,941$12,083At March 31, 2016 and December 31, 2015, there were 28 and 18 securities that were in a continuous unrealized loss position for 12 months or more, respectively.We analyzed our securities portfolio at March 31, 2016, and considered ratings, fair value, cash flows and other factors to determine if any of the securities were other than temporarily impaired. Since none of the unrealized losses relate to the marketability of the securities or the issuer’s ability to honor redemption obligations, and we have determined that it is not more likely than not that we will be required to sell the security before recovery of its amortized cost basis, none of the securities are deemed to be other than temporarily impaired.The aggregate amortized cost and fair value of securities at March 31, 2016, by remaining contractual maturity, are shown in the following table.  Actual expected maturities may differ from contractual maturities because issuers may have the right to call or prepay the obligations.  Mortgage backed securities are grouped based on stated maturity date, but actual maturity will vary based on the actual repayment of the underlying mortgage loans.  Available-for-Sale Held-to-Maturity(dollars in thousands) Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair ValueU.S. government sponsored agencies        Due in one year or less $— $— $— $—Residential mortgage-backed securities-GSE        Due after five years through 10 years 1,670 1,716 — —Due after ten years 276,851 275,346 118,194 118,783Residential mortgage-backed securities-Private        Due after ten years 31,079 31,434 16,877 16,845Commercial mortgage-backed securities-GSE        Due after one year through five years 21,880 22,122 — —Commercial mortgage-backed securities-Private        Due after ten years 17,858 17,848 10,056 10,225Corporate notes        Due in one year or less 20,465 20,461 — —Due after one year through five years 17,059 17,067 — —Total $386,862 $385,994 $145,127 $145,853 |

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The entire disclosure for  investments in certain debt and equity securities.
+ References
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