| **Investment Securities (Tables)**                                 | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
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| **Investments, Debt and Equity Securities [Abstract]**             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| Schedule of Available-for-sale Securities Reconciliation           | 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, 2014        (dollars in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair ValueAvailable-for-Sale:        Obligations of:        U.S. government sponsored enterprises $2,045 $25 $— $2,070Residential mortgage-backed securities-GSE 356,022 971 19,429 337,564Residential mortgage-backed securities-Private 19,338 953 9 20,282Commercial mortgage-backed securities-GSE 22,670 — 1,080 21,590Commercial mortgage-backed securities-Private 10,398 — 554 9,844Business Development Company investment 1,753 898 — 2,651Corporate notes 8,393 74 — 8,467Total available-for-sale $420,619 $2,921 $21,072 $402,468Held-to-Maturity:        Residential mortgage-backed securities-GSE 138,991 — 7,564 131,427Commercial mortgage-backed securities-Private 10,069 — 494 9,575     Total held-to-maturity $149,060 $— $8,058 $141,002Total investment securities $569,679 $2,921 $29,130 $543,470         December 31, 2013        (dollars in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair ValueAvailable-for-Sale:        Obligations of:        U.S. government sponsored enterprises $2,051 $26 $— $2,077Residential mortgage-backed securities-GSE 364,513 974 24,340 341,147Residential mortgage-backed securities-Private 19,770 982 — 20,752Commercial mortgage-backed securities-GSE 22,767 — 1,328 21,439Commercial mortgage-backed securities-Private 10,408 — 823 9,585Business Development Company investment 1,753 984   2,737Corporate notes 16,795 82 — 16,877Total available-for-sale $438,057 $3,048 $26,491 $414,614Held-to-Maturity:        Residential mortgage-backed securities-GSE 141,724 — 9,907 131,817Commercial mortgage-backed securities-Private 10,071 — 763 9,308     Total held-to-maturity $151,795 $— $10,670 $141,125Total investment securities $589,852 $3,048 $37,161 $555,739 |
| Available-for-sale Securities, Continuous Unrealized Loss Position | 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, 2014 and December 31, 2013.  The change in unrealized losses during the three months ending March 31, 2014 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, 2014        Available-for-Sale:        Residential mortgage-backed securities-GSE$164,313$8,975 $133,699$10,454 $298,012$19,429Residential mortgage-backed securities-Private1,2979 —— 1,2979Commercial mortgage-backed securities-GSE—— 21,5911,080 21,5911,080Commercial mortgage-backed securities-Private9,843554 —— 9,843554Total available-for-sale$175,453$9,538 $155,290$11,534 $330,743$21,072Held-to-Maturity:        Residential mortgage-backed securities-GSE$131,427$7,564 $—$— $131,427$7,564Commercial mortgage-backed securities-Private9,575494 —— 9,575494Total held-to-maturity$141,002$8,058 $—$— $141,002$8,058Total$316,455$17,596 $155,290$11,534 $471,745$29,130         December 31, 2013        Available-for-Sale        Residential mortgage-backed securities-GSE$222,475$16,585 $76,501$7,755 $298,976$24,340Commercial mortgage-backed securities-GSE—— 21,4391,328 21,4391,328Commercial mortgage-backed securities-Private9,585823 —— 9,585823Total available-for-sale$232,060$17,408 $97,940$9,083 $330,000$26,491Held-to-Maturity:        Residential mortgage-backed securities-GSE$131,817$9,907 $—$— $131,817$9,907Commercial mortgage-backed securities-Private9,308763 —— 9,308763Total held-to-maturity$141,125$10,670 $—$— $141,125$10,670Total$373,185$28,078 $97,940$9,083$471,125$37,161                                                                                                                                                                                                                                                                              |
| Available-for-sale Securities, by Maturity Dates                   | The aggregate amortized cost and fair value of securities at March 31, 2014, 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 obligations.  Available-for-Sale Held-to-Maturity(dollars in thousands) Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair ValueDue in one year or less $8,393 $8,467 $— $—Due after one year through five years 2,045 2,070 — —With no stated maturity 1,753 2,652 — —Total 12,191 13,189 — —Mortgage-backed securities 408,428 389,279 149,060 141,002Total $420,619 $402,468 $149,060 $141,002                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |

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Tabular disclosure of fair value of investments in debt and equity securities in an unrealized loss position categorized neither as held-to-maturity nor trading securities.
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Tabular disclosure of maturities of an entity's investments as well as any other information pertinent to the investments.
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Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value.
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No definition available.
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