Receivables - Additional Information (Detail)		9 Months Ended	12 Months Ended
	Mar. 30, 2012 USD ($)	Sep. 30, 2017 USD ($) Agreement	Dec. 31, 2016 USD ($)
Schedule Of Financial Receivables [Line Items]
Number of arrangement with different financial institution to sell customer receivables | Agreement		3
Sale of customer receivables	$ 304,000,000
Cash received for receivables	50,000,000
Deferred purchase program receivable	$ 254,000,000	$ 238,000,000	$ 83,000,000
Net cash funding received since inception		300,000,000
Amount of cash draws under arrangement since inception		2,208,000,000
Amount of cash repayments under arrangement since inception		1,908,000,000
Net cash funding received during the period		0
Amount of cash draws under arrangement during the period		450,000,000
Amount of cash repayments under arrangement during the period		450,000,000
Accounts receivables		34,004,000,000
Cash collections of other receivables		33,416,000,000
Minimum [Member]
Schedule Of Financial Receivables [Line Items]
Funding of customer receivables sold		200,000,000
Maximum [Member]
Schedule Of Financial Receivables [Line Items]
Funding of customer receivables sold		$ 400,000,000