Note 3 - Segment Reporting Reconciliation of Segment to Consolidated Results Pretax (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Assets		$ 6,139,488		$ 6,139,488		$ 5,900,881
Adjusted pretax operating income (loss)		191,009	$ 163,736	355,112	$ 289,017
Net gains (losses) on investments and other financial instruments		(7,404)	5,331	(26,291)	2,480
Loss on induced conversion and debt extinguishment		0	(1,247)	0	(5,703)
Acquisition-related (expenses) benefits	[1]	(416)	(64)	(416)	(72)
Goodwill, Impairment Loss		0	(184,374)	0	(184,374)
Increase (Decrease) in Goodwill and Intangible Assets		(2,748)	(18,856)	(5,496)	(22,152)
Impairment of Long-Lived Assets Held-for-use	[2]	130	0	104	0
Pretax income (loss)		180,571	(35,474)	323,013	79,196
Mortgage Insurance Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue from Related Parties		885	2,173
Assets		5,949,845		5,949,845		5,733,918
Adjusted pretax operating income (loss)	[3]	197,440	170,361	369,151	304,994
Costs and Expenses, Related Party				1,887	4,235
Mortgage and Real Estate Services Segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue from Related Parties		885	2,173	1,887	4,235
Assets		189,643		189,643		166,963
Adjusted pretax operating income (loss)	[3]	$ (6,431)	$ (6,625)	(14,039)	$ (15,977)
Goodwill, Impairment Loss				$ 0		$ (184,374)

[1] Acquisition-related expenses represent expenses incurred to effect the acquisition of a business, net of adjustments to accruals previously recorded for acquisition expenses.

[2] Included within restructuring and other exit costs. See Note 1.

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