Other Financial Information - Schedule of Other Noncurrent Liabilities and Deferred Credits (Parenthetical) (Detail) - Foreign Corrupt Practices Act Investigation [Member] $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)
Other Liabilities And Deferred Credits [Line Items]
Fines and penalties	$ 384
Fines and penalties paid	236
Fines and penalties payable	148
Fines and penalties installment amount	$ 74