Financial Instruments (Non-Marketable Equity Securities) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Unrealized gains	$ 1,852	$ 189	$ 5,128	$ 545
Unrealized losses (including impairment)	(65)	(98)	(67)	(1,395)
Total unrealized gain (loss) for non-marketable equity securities	$ 1,787	$ 91	$ 5,061	$ (850)