Note 2 - Summary of Significant Accounting Policies - Valuation Assumptions (Details)		6 Months Ended
		Jun. 30, 2018		Jun. 30, 2017
Dividend yield(1)		0.00%
Expected volatility		28.22%	[1]	45.50%	[2]
Risk-free interest rate(4)	[3]			1.89%
Expected life (in years)(5) (Year)	[4]	6 years 91 days		5 years 182 days
Assumed forfeiture rate(6)	[5]	4.00%
Maximum [Member]
Dividend yield(1)	[6]	0.00%		0.00%
Expected volatility	[2]			50.09%
Risk-free interest rate(4)	[3]	2.91%		2.26%
Expected life (in years)(5) (Year)	[4]			7 years
Assumed forfeiture rate(6)	[5]			6.00%
Minimum [Member]
Risk-free interest rate(4)	[3]	2.35%

[1] The expected volatility was based on the historical volatility of the Company’s common stock price as adjusted for certain historical periods of extraordinary volatility in order to provide a basis for a reasonable estimate of fair value.

[2] Expected volatility is based on Bloomberg’s five and one-half to seven year volatility calculation for "FRBK" stock.

[3] The risk-free interest rate is based on the five to seven year Treasury bond.

[4] The expected life reflects a 1 to 4 year vesting period, the maximum ten year term and review of historical behavior.

[5] Forfeiture rate is determined through forfeited and expired options as a percentage of options granted over the current three year period.

[6] A dividend yield of 0.0% is utilized because cash dividends have never been paid.