Significant Restructuring Costs - Additional Information (Detail) $ in Millions	3 Months Ended		9 Months Ended		45 Months Ended
	Jun. 30, 2020 USD ($) Employees Plant	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) Employees Plant	Jun. 30, 2019 USD ($)	Jun. 30, 2020 Employees Plant
Restructuring Cost and Reserve [Line Items]
Goodwill, Impairment Loss | $			$ 424
Restructuring and impairment costs | $	$ 610	$ 235	$ 783	$ 235
Number of employees to be severed					16,400
Number of employees severed	10,300		10,300		10,300
Number of plants to be closed | Plant					9
Plants closed | Plant	8		8		8
Building Technologies & Solutions
Restructuring Cost and Reserve [Line Items]
Number of employees to be severed					14,100
Number of plants to be closed | Plant					9
Corporate Segment
Restructuring Cost and Reserve [Line Items]
Number of employees to be severed					2,300
Building Solutions North America
Restructuring Cost and Reserve [Line Items]
Goodwill, Impairment Loss | $	$ 424		$ 424