Fair Values (Details Textuals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net upward adjustments of equity securities without readily determinable fair values	$ 377	$ 15
Fair Value, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of equity securities without readily determinable fair values	911		$ 530
Net upward adjustments of equity securities without readily determinable fair values	377	$ 15
Cumulative net unrealized gains for equity investments without readily determinable fair values	$ 728		$ 347