Income Taxes - Income Tax Provisions (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Note 11 - Income Taxes - Income Tax Provisions (Details)
Federal tax provision, current									$ 14,178	$ 12,404	$ 9,183
Federal tax provision, deferred									(4,990)	(1,965)	(609)
Total federal tax provision									9,188	10,439	8,574
State and local tax provision, current									967	3,543	3,876
State and local tax provision, deferred									353	(1,930)	(2,055)
Total state and local tax provision									1,320	1,613	1,821
Total income tax provision	$ 417	$ 4,489	$ 5,808	$ (206)	$ 3,957	$ 2,536	$ 3,272	$ 2,287	$ 10,508	$ 12,052	$ 10,395