Note 9 - Stockholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Millions		11 Months Ended	12 Months Ended
	Feb. 13, 2020	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Feb. 14, 2019
Common Stock, Shares Authorized		37,000,000	37,000,000	37,000,000
Preferred Stock, Shares Authorized		3,000,000	3,000,000	3,000,000
Preferred Stock, Shares Outstanding, Ending Balance		0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized			5,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period			10 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		7,118,003	7,118,003
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		1,089,749	1,089,749
Share Price		$ 35.95	$ 35.95	$ 23.64
Common Stock, Dividends, Per Share, Declared			$ 0.34	$ 0.28	$ 0.22
Subsequent Event [Member]
Common Stock, Dividends, Per Share, Declared	$ 0.095
Dividends Payable	$ 1.9
Dividends Payable, Date Declared	Feb. 13, 2020
Dividends Payable, Date to be Paid	Mar. 19, 2020
Dividends Payable, Date of Record	Mar. 03, 2020
Stock Repurchase Program [Member] | Common Stock [Member]
Stock Repurchase Program, Authorized Amount						$ 10.0
Treasury Stock, Shares, Acquired		0
Share-based Payment Arrangement, Option [Member] | Share-based Payment Arrangement, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			4 years
Share-based Payment Arrangement, Option [Member] | Share-based Payment Arrangement, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			5 years
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value			$ 2.1	$ 1.9	$ 1.9
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total		$ 10.4	$ 10.4
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition			3 years 292 days