Note 7 - Reinsurance Reinsurance Premiums Written and Earned (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Premiums Earned, Net [Abstract]
Net premiums earned-insurance		$ 251,344	$ 229,096	$ 493,894	$ 450,896
Mortgage Insurance Segment
Premiums Written, Net [Abstract]
Direct Premiums Written		283,783	260,647	541,694	500,292
Ceded Premiums Written	[1]	(31,825)	(19,340)	(51,756)	(34,320)
Net premiums written	[2]	251,958	241,307	489,938	465,972
Premiums Earned, Net [Abstract]
Direct Premiums Earned		265,581	243,229	524,324	479,291
Assumed Premiums Earned		7	7	13	14
Ceded Premiums Earned	[1]	(16,620)	(14,140)	(32,819)	(28,409)
Net premiums earned-insurance		$ 248,968	$ 229,096	$ 491,518	$ 450,896

[1] Net of profit commission.

[2] Net of ceded premiums written under the QSR Program and the Single Premium QSR Program. See Note 7 for additional information.