Derivative Instruments and Hedging Activities - Location and Fair Values of Derivative Instruments and Hedging Activities (Detail) $ in Millions, € in Billions, ¥ in Billions	3 Months Ended
	Dec. 31, 2016	Jun. 30, 2017 USD ($) T lb Swap	Jun. 30, 2017 EUR (€) T lb Swap	Sep. 30, 2016 USD ($) T lb Swap	Sep. 30, 2016 EUR (€) T lb Swap	Sep. 30, 2016 JPY (¥) T lb Swap	Jun. 30, 2014 USD ($) Swap	Sep. 30, 2005 USD ($)
Derivative Instruments [Line Items]
Number of Interest Rate Derivatives Held | Swap		0	0	8	8	8
Number of interest rate derivatives terminated	4
Derivative assets		$ 95.0		$ 95.0
Derivative liabilities		$ 1,713.0		$ 2,980.0
Copper [Member]
Derivative Instruments [Line Items]
Derivative, Nonmonetary Notional Amount | lb		6,200,000	6,200,000	5,849,000	5,849,000	5,849,000
Polypropylene [Member]
Derivative Instruments [Line Items]
Derivative, Nonmonetary Notional Amount | lb		18,000,000	18,000,000	0	0	0
Lead [Member]
Derivative Instruments [Line Items]
Derivative, Nonmonetary Notional Amount | T		8,645	8,645	5,185	5,185	5,185
Aluminum [Member]
Derivative Instruments [Line Items]
Derivative, Nonmonetary Notional Amount | T		2,860	2,860	2,620	2,620	2,620
Tin [Member]
Derivative Instruments [Line Items]
Derivative, Nonmonetary Notional Amount | T		2,225	2,225	185	185	185
Equity swap
Derivative Instruments [Line Items]
Derivative, Amount of Hedged Item				$ 0.0
Foreign Currency Denominated Debt [Member]
Derivative Instruments [Line Items]
Notional amount | ¥						¥ 37
Treasury Lock
Derivative Instruments [Line Items]
Notional amount								$ 1,300.0
Designated as Hedging Instrument
Derivative Instruments [Line Items]
Derivative assets		$ 10.0		46.0
Derivative liabilities		1,700.0		2,957.0
Designated as Hedging Instrument | Other Current Assets | Foreign Currency Exchange Derivatives
Derivative Instruments [Line Items]
Derivative assets		7.0		41.0
Designated as Hedging Instrument | Other Current Assets | Commodity Derivatives
Derivative Instruments [Line Items]
Derivative assets		3.0		4.0
Designated as Hedging Instrument | Other Noncurrent Assets | Interest Rate Swaps
Derivative Instruments [Line Items]
Derivative assets		0.0		1.0
Designated as Hedging Instrument | Other Noncurrent Assets | Equity swap
Derivative Instruments [Line Items]
Derivative assets		0.0		0.0
Designated as Hedging Instrument | Other Current Liabilities | Foreign Currency Exchange Derivatives
Derivative Instruments [Line Items]
Derivative liabilities		6.0		48.0
Designated as Hedging Instrument | Other Current Liabilities | Commodity Derivatives
Derivative Instruments [Line Items]
Derivative liabilities		1.0		0.0
Designated as Hedging Instrument | Liabilities held for sale [Domain] | Foreign Currency Exchange Derivatives
Derivative Instruments [Line Items]
Derivative liabilities		0.0		0.0
Designated as Hedging Instrument | Current Portion of Long-Term Debt | Fixed Rate Debt Swapped to Floating
Derivative Instruments [Line Items]
Derivative liabilities		0.0		551.0
Designated as Hedging Instrument | Long-term Debt | Fixed Rate Debt Swapped to Floating
Derivative Instruments [Line Items]
Derivative liabilities		0.0		301.0
Designated as Hedging Instrument | Long-term Debt | Foreign Currency Denominated Debt [Member]
Derivative Instruments [Line Items]
Derivative liabilities		1,693.0		938.0
Designated as Hedging Instrument | Noncurrent liabilities held for sale [Domain] | Foreign Currency Exchange Derivatives
Derivative Instruments [Line Items]
Derivative liabilities		0.0		1,119.0
Not Designated as Hedging Instrument
Derivative Instruments [Line Items]
Derivative assets		85.0		49.0
Derivative liabilities		13.0		23.0
Not Designated as Hedging Instrument | Other Current Assets | Foreign Currency Exchange Derivatives
Derivative Instruments [Line Items]
Derivative assets		26.0		49.0
Not Designated as Hedging Instrument | Other Current Assets | Commodity Derivatives
Derivative Instruments [Line Items]
Derivative assets		0.0		0.0
Not Designated as Hedging Instrument | Other Noncurrent Assets | Interest Rate Swaps
Derivative Instruments [Line Items]
Derivative assets		0.0		0.0
Not Designated as Hedging Instrument | Other Noncurrent Assets | Equity swap
Derivative Instruments [Line Items]
Derivative assets		59.0		0.0
Not Designated as Hedging Instrument | Other Current Liabilities | Foreign Currency Exchange Derivatives
Derivative Instruments [Line Items]
Derivative liabilities		13.0		18.0
Not Designated as Hedging Instrument | Other Current Liabilities | Commodity Derivatives
Derivative Instruments [Line Items]
Derivative liabilities		0.0		0.0
Not Designated as Hedging Instrument | Liabilities held for sale [Domain] | Foreign Currency Exchange Derivatives
Derivative Instruments [Line Items]
Derivative liabilities		0.0		5.0
Not Designated as Hedging Instrument | Current Portion of Long-Term Debt | Fixed Rate Debt Swapped to Floating
Derivative Instruments [Line Items]
Derivative liabilities		0.0		0.0
Not Designated as Hedging Instrument | Long-term Debt | Fixed Rate Debt Swapped to Floating
Derivative Instruments [Line Items]
Derivative liabilities		0.0		0.0
Not Designated as Hedging Instrument | Long-term Debt | Foreign Currency Denominated Debt [Member]
Derivative Instruments [Line Items]
Derivative liabilities		0.0		0.0
Not Designated as Hedging Instrument | Noncurrent liabilities held for sale [Domain] | Foreign Currency Exchange Derivatives
Derivative Instruments [Line Items]
Derivative liabilities		$ 0.0		$ 0.0
1.4% due 2018 | Interest Rate Swaps
Derivative Instruments [Line Items]
Number of Interest Rate Derivatives Held | Swap							3
Notional amount							$ 300.0
2.6% due 2017 | Interest Rate Swaps
Derivative Instruments [Line Items]
Number of Interest Rate Derivatives Held | Swap							4
Notional amount							$ 400.0
7.125% due 2017 | Interest Rate Swaps
Derivative Instruments [Line Items]
Number of Interest Rate Derivatives Held | Swap							1
Notional amount							$ 150.0
One billion euro net investment hedge [Member] | Foreign Currency Denominated Debt [Member]
Derivative Instruments [Line Items]
Notional amount | €			€ 1		€ 1