Derivative Instruments and Hedging Activities - Location and Fair Values of Derivative Instruments and Hedging Activities (Detail) € in Millions, shares in Millions, $ in Millions, ¥ in Billions	3 Months Ended		12 Months Ended
	Dec. 31, 2017 EUR (€) T Swap shares	Dec. 31, 2016	Sep. 30, 2017 EUR (€) T Swap shares	Dec. 31, 2017 USD ($) T Swap	Dec. 31, 2017 JPY (¥) T Swap	Sep. 30, 2017 USD ($) T Swap	Sep. 30, 2017 JPY (¥) T Swap	Sep. 30, 2016 USD ($) Swap
Derivative Instruments [Line Items]
Hedge Percentage For Foreign Exchange Transactional Exposures Minimum	70.00%
Hedge Percentage For Foreign Exchange Transactional Exposures Maximum	90.00%
Number of Interest Rate Derivatives Held | Swap	0		0	0	0	0	0
Number of interest rate derivatives terminated		4
Derivative, amount of hedged ordinary shares | shares	1.8		1.4
Derivative assets				$ 130		$ 91
Derivative liabilities				$ 3,023		$ 2,105
Copper [Member]
Derivative Instruments [Line Items]
Derivative, Nonmonetary Notional Amount | T	3,765		1,962	3,765	3,765	1,962	1,962
Polypropylene [Member]
Derivative Instruments [Line Items]
Derivative, Nonmonetary Notional Amount | T	21,762		19,563	21,762	21,762	19,563	19,563
Lead [Member]
Derivative Instruments [Line Items]
Derivative, Nonmonetary Notional Amount | T	13,791		24,705	13,791	13,791	24,705	24,705
Aluminum [Member]
Derivative Instruments [Line Items]
Derivative, Nonmonetary Notional Amount | T	5,295		2,169	5,295	5,295	2,169	2,169
Tin [Member]
Derivative Instruments [Line Items]
Derivative, Nonmonetary Notional Amount | T	1,655		1,715	1,655	1,655	1,715	1,715
Equity swap
Derivative Instruments [Line Items]
Derivative, Amount of Hedged Item				$ 73		$ 58
Foreign Currency Denominated Debt [Member]
Derivative Instruments [Line Items]
Notional amount | ¥					¥ 35		¥ 35
Designated as Hedging Instrument
Derivative Instruments [Line Items]
Derivative assets				41		36
Derivative liabilities				3,007		2,080
Designated as Hedging Instrument | Other Current Assets | Foreign Currency Exchange Derivatives
Derivative Instruments [Line Items]
Derivative assets				35		27
Designated as Hedging Instrument | Other Current Assets | Commodity Derivatives
Derivative Instruments [Line Items]
Derivative assets				6		9
Designated as Hedging Instrument | Other Noncurrent Assets | Equity swap
Derivative Instruments [Line Items]
Derivative assets				0		0
Designated as Hedging Instrument | Other Current Liabilities | Foreign Currency Exchange Derivatives
Derivative Instruments [Line Items]
Derivative liabilities				25		21
Designated as Hedging Instrument | Other Current Liabilities | Commodity Derivatives
Derivative Instruments [Line Items]
Derivative liabilities				1		1
Designated as Hedging Instrument | Long-term Debt | Foreign Currency Denominated Debt [Member]
Derivative Instruments [Line Items]
Derivative liabilities				2,981		2,058
Not Designated as Hedging Instrument
Derivative Instruments [Line Items]
Derivative assets				89		55
Derivative liabilities				16		25
Not Designated as Hedging Instrument | Other Current Assets | Foreign Currency Exchange Derivatives
Derivative Instruments [Line Items]
Derivative assets				21		0
Not Designated as Hedging Instrument | Other Current Assets | Commodity Derivatives
Derivative Instruments [Line Items]
Derivative assets				0		0
Not Designated as Hedging Instrument | Other Noncurrent Assets | Equity swap
Derivative Instruments [Line Items]
Derivative assets				68		55
Not Designated as Hedging Instrument | Other Current Liabilities | Foreign Currency Exchange Derivatives
Derivative Instruments [Line Items]
Derivative liabilities				16		25
Not Designated as Hedging Instrument | Other Current Liabilities | Commodity Derivatives
Derivative Instruments [Line Items]
Derivative liabilities				0		0
Not Designated as Hedging Instrument | Long-term Debt | Foreign Currency Denominated Debt [Member]
Derivative Instruments [Line Items]
Derivative liabilities				$ 0		$ 0
One Point Four Percent Due Two Thousand Eighteen | Interest Rate Swaps
Derivative Instruments [Line Items]
Number of Interest Rate Derivatives Held | Swap								3
Notional amount								$ 300
Debt Instrument, Interest Rate, Stated Percentage								1.40%
2.6% due 2017 | Interest Rate Swaps
Derivative Instruments [Line Items]
Number of Interest Rate Derivatives Held | Swap								4
Notional amount								$ 400
Debt Instrument, Interest Rate, Stated Percentage								2.60%
7.125% due 2017 | Interest Rate Swaps
Derivative Instruments [Line Items]
Number of Interest Rate Derivatives Held | Swap								1
Notional amount								$ 150
Debt Instrument, Interest Rate, Stated Percentage								7.125%
One billion euro net investment hedge [Member] | Foreign Currency Denominated Debt [Member]
Derivative Instruments [Line Items]
Notional amount | €	€ 1,000		€ 1,000
423 million euro net investment hedge [Member] | Foreign Currency Denominated Debt [Member]
Derivative Instruments [Line Items]
Notional amount | €	423		423
58 million euro net investment hedge [Member] | Foreign Currency Denominated Debt [Member]
Derivative Instruments [Line Items]
Notional amount | €	€ 58		€ 58