Equity - Additional Information (Details) - USD ($) $ in Millions			9 Months Ended
		Sep. 30, 2018	Jun. 29, 2019
Class of Stock [Line Items]
AOCI reclassifications to retained earnings, tax	[1]		$ (683)
AOCI reclassifications to retained earnings, before tax			(23)
AOCI reclassifications to retained earnings, net of tax	[1]		$ (706)
Accounting Standards Update 2018-02
Class of Stock [Line Items]
AOCI reclassifications to retained earnings, tax		$ 691
Accounting Standards Update 2016-01
Class of Stock [Line Items]
AOCI reclassifications to retained earnings, before tax		24
AOCI reclassifications to retained earnings, net of tax		$ 15

[1] At the beginning of fiscal 2019, the Company adopted new FASB accounting guidance, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, and reclassified $691 million from AOCI to retained earnings.In addition, at the beginning of fiscal 2019, the Company adopted new FASB accounting guidance, Recognition and Measurement of Financial Assets and Liabilities, and reclassified $24 million ($15 million after tax) of market value adjustments on investments previously recorded in AOCI to retained earnings.