Note 8 - Reinsurance - Net Premiums Written and Earned, Insurance (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Premiums Written, Net [Abstract]
Direct premiums written	$ 269,240	$ 287,000	$ 820,267	$ 828,022
Assumed premiums written	2,942	2,608	9,585	7,528
Ceded premiums written	(9,789)	(15,455)	(72,912)	(39,900)
Net premiums written	262,393	274,153	756,940	795,650
Premiums Earned, Net [Abstract]
Direct premiums earned	328,728	305,493	945,287	919,507
Assumed premiums earned	2,946	2,614	9,599	7,545
Ceded premiums earned	(45,203)	(26,922)	(141,705)	(83,189)
Net premiums earned	286,471	281,185	813,181	843,863
Ceded Credit Risk [Line Items]
Ceding commissions earned	17,038	12,153	40,457	37,191
Ceded losses	10,189	771	51,786	4,326
Deferred ceding commissions	$ 59,200	$ 77,800	$ 59,200	$ 77,800