Acquisitions and Divestitures - 2015 Acquisitions - Additional Information (Detail) $ / shares in Units, € in Millions	1 Months Ended			3 Months Ended								5 Months Ended	12 Months Ended
	Jul. 31, 2015 USD ($) shares	Mar. 31, 2015 EUR (€) Employees shares	Mar. 31, 2015 USD ($) Employees shares	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) Tranche shares	Dec. 31, 2014 USD ($) Employees	Dec. 31, 2013 USD ($)	Mar. 31, 2015 USD ($) $ / shares	Mar. 06, 2015 $ / shares
Business Acquisition [Line Items]
Cash paid for business acquisition													$ 205,000,000	$ 2,458,000,000
Goodwill				$ 5,401,000,000				$ 5,247,000,000				$ 5,401,000,000	5,401,000,000	5,247,000,000	$ 3,415,000,000
Common stock conversion transaction value				870,000,000				610,000,000				870,000,000	870,000,000	610,000,000
Sale generated in last annual period prior to divestiture				5,245,000,000	$ 5,573,000,000	$ 5,897,000,000	$ 5,819,000,000	$ 6,377,000,000	$ 6,239,000,000	$ 5,836,000,000	$ 5,454,000,000		22,534,000,000	23,906,000,000	23,032,000,000
After-tax operating income (ATOI)													1,906,000,000	$ 1,968,000,000	$ 1,267,000,000
TITAL [Member]
Business Acquisition [Line Items]
Number of employees | Employees		650	650
Cash paid for business acquisition		€ 188	$ 204,000,000
Business acquisition transaction cost		€ 1														$ 1,000,000
Goodwill																118,000,000
RTI [Member]
Business Acquisition [Line Items]
Number of employees | Employees														2,600
Goodwill				240,000,000								240,000,000	240,000,000
Common stock conversion transaction value	$ 870,000,000															$ 870,000,000
Business acquisition common stock issued, price per share | $ / shares																$ 9.96	$ 14.48
Number of shares to be issued upon conversion | $ / shares																$ 2.8315
Acquisition price per share | $ / shares																	$ 41
Number of common stock shares issued in a part of acquisition | shares	87,000,000	87,397,414	87,397,414
Professional fees and costs			$ 25,000,000
Professional fees and costs , after tax			$ 19,000,000
Sale generated in last annual period prior to divestiture														$ 794,000,000
Third-party sales												309,000,000
Goodwill deductible for income tax purpose				0								0	0
Intangible assets				$ 73,000,000								73,000,000	$ 73,000,000
RTI [Member] | Convertible Notes [Member]
Business Acquisition [Line Items]
Number of repayment tranches | Tranche													2
Convertible debt, due date of first tranche													Dec. 01, 2015
Convertible debt, due date of second tranche													Dec. 31, 2019
RTI [Member] | Maximum [Member]
Business Acquisition [Line Items]
After-tax operating income (ATOI)												$ (1,000,000)
RTI [Member] | Maximum [Member] | Convertible Notes [Member]
Business Acquisition [Line Items]
Conversion of notes to common stock | shares													27,990,966