Note 7 - Reinsurance Net Premiums Written and Earned, Insurance (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Premiums Earned, Net [Abstract]
Net premiums earned—insurance		$ 258,431	$ 236,702	$ 752,325	$ 687,598
Mortgage Insurance Segment
Premiums Written, Net [Abstract]
Direct Premiums Written		278,118	265,927	819,812	766,219
Ceded Premiums Written	[1]	(24,291)	(18,117)	(76,047)	(52,437)
Net premiums written—insurance	[2]	253,827	247,810	743,765	713,782
Premiums Earned, Net [Abstract]
Direct Premiums Earned		271,487	250,541	795,811	729,832
Assumed Premiums Earned		6	7	19	21
Ceded Premiums Earned	[1]	(16,011)	(13,846)	(48,830)	(42,255)
Net premiums earned—insurance		$ 255,482	$ 236,702	$ 747,000	$ 687,598

[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.