Financial Instruments (Measurement Alternative Investments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity Securities, FV-NI, Gain (Loss), Alternative [Abstract]
Net gain (loss) on equity securities sold during the period	$ (301)	$ 1,458
Unrealized gain (loss) on equity securities held as of the end of the period	2,950	4,002
Total gain (loss) recognized in other income (expense), net	2,649	5,460	$ 73
Total unrealized gain (loss) for non-marketable equity securities	$ 1,791	$ 4,107