Fair Value (Policy)	9 Months Ended
Sep. 30, 2019
Fair Value [Abstract]
Fair Value	Fair value is the exchange price that would be received for an asset or paid to transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. FASB ASC Topic 820, Fair Value Measurements and Disclosures, establishes a fair value hierarchy based on the nature of data inputs for fair value determinations, under which DNB is required to value each asset within its scope using assumptions that market participations would utilize to value that asset. When DNB uses its own assumptions, it is required to disclose additional information about the assumptions used and the effect of the measurement on earnings or the net change in assets for the period. The three levels of the fair value hierarchy under FASB ASC Topic 820 are as follows: Level 1—Quoted prices in active markets for identical securities. Level 2—Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active and model derived valuations whose inputs are observable or whose significant value drivers are observable. Level 3—Instruments whose significant value drivers are unobservable. A description of the valuation methodologies used for assets measured at fair value is set forth below: DNB’s available-for-sale investment securities, which generally include U.S. government agencies and mortgage backed securities, collateralized mortgage obligations, corporate bonds and equity securities are reported at fair value. These securities are valued by an independent third party (“preparer”). The preparer’s evaluations are based on market data. They utilize evaluated pricing models that vary by asset and incorporate available trade, bid and other market information. For securities that do not trade on a daily basis, their evaluated pricing applications apply available information such as benchmarking and matrix pricing. The market inputs normally sought in the evaluation of securities include benchmark yields, reported trades, broker/dealer quotes (only obtained from market makers or broker/dealers recognized as market participants), issuer spreads, two-sided markets, benchmark securities, bid, offers and reference data. For certain securities additional inputs may be used or some market inputs may not be applicable. Inputs are prioritized differently on any given day based on market conditions. U.S. Government agencies are evaluated and priced using multi‑dimensional relational models and option adjusted spreads. State and municipal securities are evaluated on a series of matrices including reported trades and material event notices. Mortgage backed securities are evaluated using matrix correlation to treasury or floating index benchmarks, prepayment speeds, monthly payment information and other benchmarks. Other securities are evaluated using a broker-quote based application, including quotes from issuers. Impaired loans are those loans that the Bank has measured impairment generally based on the fair value of the loan’s collateral. Fair value is generally determined based upon independent third-party appraisals of the properties, or discounted cash flows based upon the expected proceeds. These assets are included as Level 3 fair values, based upon the lowest level of input that is significant to the fair value measurements. OREO assets are adjusted to fair value less estimated selling costs upon transfer of the loans to OREO establishing a new cost basis. Subsequently, OREO assets are carried at the lower of carrying value or fair value. Fair value is based upon independent market prices, appraised values of the collateral or management’s estimation of the value of the collateral. When recorded at fair value, these assets are included as Level 3 fair values.

Fair value is the exchange price that would be received for an asset or paid to transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. FASB ASC Topic 820, Fair Value Measurements and Disclosures, establishes a fair value hierarchy based on the nature of data inputs for fair value determinations, under which DNB is required to value each asset within its scope using assumptions that market participations would utilize to value that asset. When DNB uses its own assumptions, it is required to disclose additional information about the assumptions used and the effect of the measurement on earnings or the net change in assets for the period.

The three levels of the fair value hierarchy under FASB ASC Topic 820 are as follows:

Level 1—Quoted prices in active markets for identical securities.

Level 2—Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active and model derived valuations whose inputs are observable or whose significant value drivers are observable.

Level 3—Instruments whose significant value drivers are unobservable.

A description of the valuation methodologies used for assets measured at fair value is set forth below:

DNB’s available-for-sale investment securities, which generally include U.S. government agencies and mortgage backed securities, collateralized mortgage obligations, corporate bonds and equity securities are reported at fair value. These securities are valued by an independent third party (“preparer”). The preparer’s evaluations are based on market data. They utilize evaluated pricing models that vary by asset and incorporate available trade, bid and other market information. For securities that do not trade on a daily basis, their evaluated pricing applications apply available information such as benchmarking and matrix pricing. The market inputs normally sought in the evaluation of securities include benchmark yields, reported trades, broker/dealer quotes (only obtained from market makers or broker/dealers recognized as market participants), issuer spreads, two-sided markets, benchmark securities, bid, offers and reference data. For certain securities additional inputs may be used or some market inputs may not be applicable. Inputs are prioritized differently on any given day based on market conditions.

U.S. Government agencies are evaluated and priced using multi‑dimensional relational models and option adjusted spreads. State and municipal securities are evaluated on a series of matrices including reported trades and material event notices. Mortgage backed securities are evaluated using matrix correlation to treasury or floating index benchmarks, prepayment speeds, monthly payment information and other benchmarks. Other securities are evaluated using a broker-quote based application, including quotes from issuers.

Impaired loans are those loans that the Bank has measured impairment generally based on the fair value of the loan’s collateral. Fair value is generally determined based upon independent third-party appraisals of the properties, or discounted cash flows based upon the expected proceeds. These assets are included as Level 3 fair values, based upon the lowest level of input that is significant to the fair value measurements.

OREO assets are adjusted to fair value less estimated selling costs upon transfer of the loans to OREO establishing a new cost basis. Subsequently, OREO assets are carried at the lower of carrying value or fair value. Fair value is based upon independent market prices, appraised values of the collateral or management’s estimation of the value of the collateral. When recorded at fair value, these assets are included as Level 3 fair values.