Segment Reporting - Adjusted Pretax Operating Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net gains (losses) on investments and other financial instruments	$ (236)	$ (41,869)	$ 5,349	$ (71,326)
Amortization of other acquired intangible assets	(1,370)	(849)	(2,741)	(1,698)
Pretax income	182,676	259,880	386,687	494,020
Corporate, Non-Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted pretax operating income (loss)	11,046	3,203	19,515	3,816
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	(331)	(41,869)	5,174	(71,326)
Amortization of other acquired intangible assets	(1,370)	(849)	(2,741)	(1,698)
Impairment of other long-lived assets and other non-operating items	2	565	16	63
Mortgage
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted pretax operating income (loss)	197,750	316,520	412,185	594,361
Allocated corporate operating expenses	37,081	33,237	71,910	69,446
Direct depreciation expense	2,045	2,241	4,169	4,569
Mortgage | Depreciation Expense
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Allocated corporate operating expenses	700	700	1,500	1,500
homegenius
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted pretax operating income (loss)	(24,421)	(17,690)	(47,462)	(31,196)
Allocated corporate operating expenses	4,954	5,719	9,612	10,999
Direct depreciation expense	628	642	1,208	1,286
homegenius | Depreciation Expense
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Allocated corporate operating expenses	100	200	200	300
Mortgage and homegenius segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted pretax operating income (loss)	$ 173,329	$ 298,830	$ 364,723	$ 563,165