Employee Benefits - Summary of Stock-Based Compensation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based Compensation Expense	$ 649	$ 380	$ 382
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	(280)	(104)	(131)
Stock-based compensation expense, Net of Tax	369	276	251
Cost of Sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based Compensation Expense	24	14	11
Research and Development Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based Compensation Expense	232	176	173
Selling, General and Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based Compensation Expense	$ 393	$ 190	$ 198