Note 8 - Reinsurance Reinsurance Premiums (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Premiums Earned, Net [Abstract]
Direct Premiums Earned										$ 990,016		$ 999,093		$ 973,645
Assumed Premiums Earned										28		35		43
Ceded Premiums Earned										(57,271)		(77,359)		(57,780)
Net premiums earned—insurance		$ 245,175	$ 236,702	$ 229,096	$ 221,800	$ 233,585	$ 238,149	$ 229,085	$ 220,950	932,773		921,769		915,908
Mortgage Insurance Segment
Premiums Written, Net [Abstract]
Direct Premiums Written										1,032,735		1,000,111		1,009,409
Assumed Premiums Written										25		29		104
Ceded Premiums Written	[1]									(214,343)		(266,306)		(41,008)
Net premiums written—insurance										818,417	[2],[3]	733,834	[4]	968,505	[5]
Premiums Earned, Net [Abstract]
Direct Premiums Earned										990,016		999,093		973,645
Assumed Premiums Earned										28		35		43
Ceded Premiums Earned	[1]									(57,271)		(77,359)		(57,780)
Net premiums earned—insurance										$ 932,773		$ 921,769		$ 915,908

[1] Net of profit commission.

[2] Effective December 31, 2017, we amended the 2016 Single Premium QSR Transaction to increase the amount of ceded risk for performing loans under the agreement from 35% to 65% for the 2015 through 2017 vintages, resulting in a reduction of $145.7 million in net premiums written.

[3] Net of ceded premiums written under the QSR Transactions and the 2016 Single Premium QSR Transaction. See Note 8 for additional information.

[4] Net of ceded premiums written under the QSR Transactions and the 2016 Single Premium QSR Transaction. See Note 8 for additional information.

[5] Net of ceded premiums written under the QSR Transactions. See Note 8 for additional information.