Equity Securities (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule Of Investments [Line Items]
Realized and unrealized net gains on equity securities	$ (263)	$ 184
Net unrealized gains on equity securities	(237)	172
Non-Marketable Equity Securities	396	441
Cash proceeds from sale of equity securities	241	172	$ 103
Offerpad Inc [Member]
Schedule Of Investments [Line Items]
Net unrealized losses on equity securities	191
Net unrealized gains on equity securities		121
Non Marketable Equity Securities
Schedule Of Investments [Line Items]
Cost	307	215
Non-Marketable Equity Securities	396	441
Net unrealized losses on equity securities	153
Net unrealized gains on equity securities	16	$ 210
Recognized impairment charges of investments	140
Realized gain on securities	52
Cash proceeds from sale of equity securities	$ 63