Note 4 - Segment Reporting - Adjusted Pretax Operating Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted pretax operating income (loss)	$ 182,264	$ (89,730)	$ 346,098	$ 112,784
Net gains (losses) on investments and other financial instruments	15,661	47,276	10,480	25,249
Amortization and impairment of other acquired intangible assets	(863)	(979)	(1,725)	(1,958)
Consolidated pretax income (loss)	195,496	(42,224)	356,685	139,069
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net gains (losses) on investments and other financial instruments	15,661	47,276	10,480	25,249
Amortization and impairment of other acquired intangible assets	(863)	(979)	(1,725)	(1,958)
Impairment of other long-lived assets and other-non-operating items	(4,021)	(22)	(4,105)	(322)
Mortgage segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted pretax operating income (loss)	191,462	(85,821)	365,749	119,846
Total Operating Expenses Allocated to Subsidiaries From Parent Company	33,000	25,359	60,884	54,573
Depreciation	1,660	2,656	3,470	5,926
homegenius segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted pretax operating income (loss)	(9,198)	(3,909)	(19,651)	(7,062)
Total Operating Expenses Allocated to Subsidiaries From Parent Company	4,721	2,823	8,717	6,190
Depreciation	491	719	945	1,329
All Other activities segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted pretax operating income (loss)	$ 2,455	$ 1,231	$ 5,937	$ 3,316