Acquisition (Tables)	12 Months Ended
	Dec. 31, 2021
Acquisition [Abstract]
Summary of Consideration Paid	Purchase Price Consideration in Common Stock Landmark shares settled for stock 2,382,695Exchange ratio 0.272Total FDBC shares issued 647,990Value assigned to FDBC common share (6/30/2021 closing price) $ 54.10 Purchase price assigned to Landmark common shares exchanged for FDBC common shares $ 35,056,259 Purchase Price Consideration - Cash for Common Stock Landmark shares exchanged for cash, excluding fractional shares 2,382,695Cash consideration (per Landmark share) $ 3.26Cash portion of purchase price $ 7,767,586 Cash portion of purchase price (cash paid fractional shares) $ 5,559 Cash for outstanding Landmark stock options $ 69,250 Total consideration paid $ 42,898,654 Allocation of Purchase PriceIn thousands     Total Purchase Price $ 42,899 Estimated Fair Value of Assets Acquired Cash and cash equivalents 4,090 Investment securities 49,430 Loans 298,860 Restricted investments in bank stock 1,186 Premises and equipment 3,405 Lease property under finance leases 1,188 Core deposit intangible asset 597 Other real estate owned 488 Other assets 11,629 Total assets acquired 370,873 Estimated Fair Value of Liabilities Assumed Non-interest bearing deposits 100,472 Interest bearing deposits 208,057 Short-term borrowings 2,224 FHLB borrowings 4,602 Secured borrowings 20,619 Finance lease obligation 1,188 Other liabilities 3,387 Total liabilities assumed 340,549 Net Assets Acquired 30,324Goodwill Recorded in Acquisition $ 12,575
Summary of Fair Value Adjustments of Loans Acquired	Dollars in thousands Gross amortized cost basis at June 30, 2021 $ 309,767Interest rate fair value adjustment on pools of homogeneous loans (1,855)Credit fair value adjustment on pools of homogeneous loans (7,915)Credit fair value adjustment on purchased credit impaired loans (1,137)Fair value of acquired loans at June 30, 2021 $ 298,860
Summary of Credit Adjustment on Acquired Impaired Loans	Dollars in thousands Contractual principal and interest at acquisition $ 5,306Non-accretable difference (1,691)Expected cash flows at acquisition 3,615Accretable yield (588)Fair value of purchased impaired loans $ 3,027
Summary of Supplemental Pro Forma Financial Information	UnauditedTwelve months ended December 31,(Dollars in thousands)2021 2020Net interest income$ 68,970 $ 57,531Other income 18,959 15,978Total net interest income and other income$ 87,929 $ 73,509 Net income 29,080 18,402 Basic earnings per common share$5.15 $3.52Diluted earnings per common share$5.11 $3.50