Contract and Other Deferred Assets - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contract assets (total revenue in excess of billings)	$ 1,694	$ 1,684	$ 1,233
Deferred inventory costs	179	360	$ 276
Non-recurring engineering costs	21	0
Contract and other deferred assets	1,894	2,044
Revenue recognized from performance obligations satisfied in previous periods	26	44
Long-term product service agreements
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contract assets (total revenue in excess of billings)	609	589
Long-term equipment contract
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contract assets (total revenue in excess of billings)	$ 1,085	$ 1,095