Note E - Stock Based Compensation - Summary of Nonvested Restricted Stock (Details) - Restricted Stock [Member]	6 Months Ended
	Jun. 30, 2018 $ / shares shares
Nonvested (in shares) | shares	104,150
Nonvested - weighted average grant date fair value (in dollars per share) | $ / shares	$ 17.14	[1]
Granted (in shares) | shares	1,932
Granted - weighted average grant date fair value (in dollars per share) | $ / shares	$ 36.35	[1]
Canceled/forfeited/expired (in shares) | shares
Canceled/forfeited/expired - weighted average grant date fair value (in dollars per share) | $ / shares		[1]
Vested (in shares) | shares	(36,515)
Vested - weighted average grant date fair value (in dollars per share) | $ / shares	$ 17.93	[1]
Nonvested (in shares) | shares	69,567
Nonvested - weighted average grant date fair value (in dollars per share) | $ / shares	$ 17.26	[1]

[1] The weighted-average grant date fair value was based on the closing price of the Company's stock on the date of the grant.