Note 14 - Income Taxes (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Expense (Benefit), Total	$ 3,167,000	$ 1,700,000	$ 15,284,000	$ 9,792,000
Effective Income Tax Rate Reconciliation, Percent, Total	14.00%	7.50%	22.00%	19.50%
Effective Income Tax Rate Reconciliation, Expiration of Statute of Limitations, Amount	$ 2,064,000	$ 2,222,000	$ 2,064,000	$ 2,222,000
Effective Income Tax Rate Reconciliation, Return to Provision, Amount	$ 793,000	1,434,000	$ 793,000	1,434,000
Effective Income Tax Rate Reconciliation, Gain on Acquisition of Equity Method Investment, Amount, Total		$ 547,000		547,000
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amount, Total				$ 945,000
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent, Total				1.90%
Open Tax Year			2016