Acquisitions and Divestitures - 2015 Acquisitions (Detail) $ / shares in Units, € in Millions				1 Months Ended			3 Months Ended								4 Months Ended	5 Months Ended	12 Months Ended				14 Months Ended
	Oct. 05, 2016 shares	Jul. 23, 2015 shares	Jul. 22, 2015 shares	Jul. 31, 2015 USD ($) $ / shares shares	Mar. 31, 2015 USD ($) employee	Mar. 31, 2015 EUR (€) employee	Dec. 31, 2017 USD ($) $ / shares	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($) $ / shares	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Apr. 29, 2016 USD ($) employee	Dec. 31, 2015 USD ($)	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) Tranche company	Dec. 31, 2014 USD ($) employee	Oct. 04, 2016 shares	Sep. 30, 2015 USD ($)	Sep. 30, 2015 EUR (€)	Mar. 06, 2015 $ / shares
Business Acquisition [Line Items]
Goodwill							$ 4,535,000,000				$ 5,148,000,000					$ 5,249,000,000	$ 4,535,000,000	$ 5,148,000,000	$ 5,249,000,000
Common stock conversion transaction value							0				0					870,000,000	0	0	870,000,000
Common stock sold per share (usd per share) | $ / shares									$ 35.91
Sales revenue, goods, net							$ 3,271,000,000	$ 3,236,000,000	$ 3,261,000,000	$ 3,192,000,000	$ 2,967,000,000	$ 3,138,000,000	$ 3,234,000,000	$ 3,055,000,000			12,960,000,000	12,394,000,000	12,413,000,000
Adjusted EBITDA																	$ 2,144,000,000	$ 2,063,000,000	1,894,000,000
TITAL
Business Acquisition [Line Items]
Cash paid for business acquisition					$ 204,000,000	€ 188
Business acquisition transaction cost																						$ 1,000,000	€ 1
Number of employees | employee					650	650
Goodwill					$ 118,000,000									117,000,000
Goodwill, purchase accounting adjustments														$ 1,000,000
RTI
Business Acquisition [Line Items]
Number of employees | employee															330
Goodwill																298,000,000			298,000,000
Goodwill deductible for income tax purpose					$ 0											0			$ 0
Common stock conversion transaction value				$ 870,000,000
Common stock sold per share (usd per share) | $ / shares				$ 9.96																				$ 14.48
Debt instrument, convertible, conversion price | $ / shares				$ 2.8315
Number of common stock shares issued in a part of acquisition (in shares) | shares	29,000,000	87,397,414	29,132,471	29,132,471																	87,000,000
Acquisition price per share (USD per share) | $ / shares																								$ 41
Professional fees and costs				$ 25,000,000
Professional fees and costs, after tax				$ 19,000,000
Sales revenue, goods, net															$ 20,000,000	309,000,000
Synergy from merger and acquisition, number of companies | company																			2
RTI | Convertible Notes
Business Acquisition [Line Items]
Debt instrument, convertible, conversion price | $ / shares				$ 28.1596
Number of repayment tranches | Tranche																			2
Debt instrument, amount received upon maturity per one thousand dollars in principal amount of notes held				$ 1,000
RTI | Tranche Due December 2015
Business Acquisition [Line Items]
Long-term debt due within one year				115,000,000
RTI | Tranche Due October 2019
Business Acquisition [Line Items]
Long-term debt due within one year				$ 403,000,000												403,000,000			$ 403,000,000
RTI | 1.63% Convertible Notes, Due 2019 | Convertible Notes
Business Acquisition [Line Items]
Debt instrument, convertible, conversion price | $ / shares							$ 28.1596										$ 28.1596
Conversion of notes to common stock (in shares) | shares																	14,294,000
Debt instrument, convertible, conversion rate per bond							0.0355119										0.0355119
RTI | Customer Relationships
Business Acquisition [Line Items]
Finite-lived intangible assets acquired																			$ 37,000,000
Weighted average amortization period of intangible asset																			20 years
Maximum | RTI
Business Acquisition [Line Items]
Adjusted EBITDA																$ 21,000,000
RTI
Business Acquisition [Line Items]
Number of employees | employee																				2,600
Sales revenue, goods, net																				$ 794,000,000