Note 3 - Segment Reporting Adjusted Pretax Operating Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted pretax operating income (loss)		$ 200,800	$ 199,706
Net gains (losses) on investments and other financial instruments		(22,027)	21,913
Amortization and impairment of other acquired intangible assets		(979)	(2,187)
Impairment of other long-lived assets and other-non-operating items		(300)	(5,660)
Consolidated pretax income (loss)		181,293	216,136
Mortgage segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Operating Expenses Allocated to Subsidiaries From Parent Company		29,100	25,600
Depreciation		3,700	3,900
Adjusted pretax operating income (loss)	[1]	205,667	203,631
Real Estate segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total Operating Expenses Allocated to Subsidiaries From Parent Company		3,800	2,800
Depreciation		700	600
Adjusted pretax operating income (loss)	[2]	(4,867)	(3,925)
All Other activities segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted pretax operating income (loss)		$ 3,799	$ 2,364

[1] For the three months ended March 31, 2020, includes allocated corporate operating expenses and depreciation expense of $29.1 million and $3.7 million, respectively. For the three months ended March 31, 2019, includes allocated corporate operating expenses and depreciation expense of $25.6 million and $3.9 million, respectively.

[2] For the three months ended March 31, 2020, includes allocated corporate operating expenses and depreciation expense of $3.8 million and $0.7 million, respectively. For the three months ended March 31, 2019, includes allocated corporate operating expenses and depreciation expense of $2.8 million and $0.6 million, respectively.