Note 3 - Segment Reporting Schedule of Segment Reporting Information by Segment (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) segment	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of Operating Segments | segment				2
Net premiums earned—insurance		$ 258,431	$ 236,702	$ 752,325	$ 687,598
Services revenue		36,566	39,571	106,558	115,400
Net investment income		38,995	32,540	110,424	93,643
Other income		1,174	760	2,997	2,118
Policy acquisition costs		5,667	5,554	18,780	18,406
Cost of services		25,854	27,240	73,185	81,250
Other operating expenses before corporate allocations		70,125	64,195	203,552	201,322
Restructuring and other exit costs		4,464	12,038	5,940	12,038
Adjusted pretax operating income (loss)		196,699	155,619	551,811	444,636
Net gains (losses) on investments and other financial instruments		(4,480)	2,480	(30,771)	4,960
Total assets		6,269,484		6,269,484		$ 5,900,881
Mortgage Insurance Segment
Segment Reporting Information [Line Items]
Net premiums written—insurance	[1]	253,827	247,810	743,765	713,782
(Increase) decrease in unearned premiums		1,655	(11,108)	3,235	(26,184)
Net premiums earned—insurance		255,482	236,702	747,000	687,598
Net investment income		38,824	32,540	110,227	93,643
Other income		725	760	2,153	2,118
Total	[2]	295,031	270,002	859,380	783,359
Provision for losses		20,715	35,980	77,468	100,926
Policy acquisition costs		5,667	5,554	18,780	18,406
Other operating expenses before corporate allocations		33,152	36,941	98,302	114,169
Total	[3]	59,534	78,475	194,550	233,501
Adjusted pretax operating income (loss) before corporate allocations		235,497	191,527	664,830	549,858
Allocation of corporate operating expenses		19,794	11,737	58,507	41,817
Allocation of interest expense		11,083	11,282	32,552	34,539
Adjusted pretax operating income (loss)	[4]	204,620	168,508	573,771	473,502
Inter-segment expenses		766	1,491	2,653	5,726
Total assets		6,095,101		6,095,101		5,733,918
Mortgage and Real Estate Services Segment
Segment Reporting Information [Line Items]
Corporate Cash and Investments Allocated to Segments		0		0
Net premiums earned—insurance	[5]	2,949	0	5,325	0
Services revenue	[6]	37,332	41,062	109,211	121,126
Net investment income	[5]	171	0	197	0
Other income	[5]	449	0	844	0
Total	[6]	40,901	41,062	115,577	121,126
Provision for losses	[5]	242	0	295	0
Cost of services		26,001	27,544	73,628	82,196
Other operating expenses before corporate allocations		14,772	12,781	39,531	38,188
Restructuring and other exit costs	[7]	407	5,463	1,987	5,463
Total		41,422	45,788	115,441	125,847
Adjusted pretax operating income (loss) before corporate allocations		(521)	(4,726)	136	(4,721)
Allocation of corporate operating expenses		2,948	3,730	8,742	10,852
Allocation of interest expense		4,452	4,433	13,354	13,293
Adjusted pretax operating income (loss)	[4]	(7,921)	(12,889)	(21,960)	(28,866)
Inter-segment revenues		766	$ 1,491	2,653	$ 5,726
Total assets		174,383		174,383		$ 166,963
Senior Notes | Senior Notes Due 2019
Segment Reporting Information [Line Items]
Debt Instrument, Face Amount		$ 300,000		$ 300,000

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

[2] Excludes net losses on investments and other financial instruments of $4.5 million and $30.8 million for the three and nine months ended September 30, 2018, and net gains on investments and other financial instruments of $2.5 million and $5.0 million for the three and nine months ended September 30, 2017, not included in adjusted pretax operating income.

[3] Includes inter-segment expenses as follows:   Three Months Ended
September 30,   Nine Months Ended
September 30, (In thousands) 2018   2017   2018   2017 Inter-segment expenses $ 766
  $ 1,491
  $ 2,653
  $ 5,726

[4] Includes inter-segment expenses and revenues as listed in the notes to the preceding tables.

[5] Results from inclusion of the operations of EnTitle Direct, a national title insurance and settlement services company, acquired in March 2018.

[6] Includes inter-segment revenues as follows:   Three Months Ended
September 30,   Nine Months Ended
September 30, (In thousands) 2018   2017   2018   2017 Inter-segment revenues $ 766
  $ 1,491
  $ 2,653
  $ 5,726

[7] Does not include impairment of long-lived assets and loss from the sale of a business line, which are not components of adjusted pretax operating income.