Note 12 - Employee Benefit Plans (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee Benefit Plans [Line Items]
Defined contribution plan, plan name	QNB Bank Retirement Savings Plan
Matching company contribution	3.00%
Safe harbor non-elective contributions	5.00%
Matching contribution, amount	$ 309	$ 271	$ 259
Safe harbor contribution, amount	$ 553	$ 494	$ 478
Employee Stock Purchase Plan 2016 [Member]
Employee Benefit Plans [Line Items]
Discount rate on common stock	10.00%
Shares authorized for issuance	30,000
Shares issued	10,325
Expiration date	May 31, 2021