Significant Restructuring Costs - Additional Information (Detail) $ in Millions	3 Months Ended			6 Months Ended		36 Months Ended
	Mar. 31, 2019 USD ($) Plant Employees	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2019 USD ($) Plant Employees	Mar. 31, 2018 USD ($)	Sep. 30, 2018 Plant Employees
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment costs | $	$ 0	$ 0	$ 154	$ 0	$ 154
Number of employees to be severed						11,300
Number of employees severed	5,100			5,100
Number of plants to be closed | Plant						12
Plants closed | Plant	10			10
Building Technologies & Solutions
Restructuring Cost and Reserve [Line Items]
Number of employees to be severed						9,100
Number of plants to be closed | Plant						12
Corporate Segment
Restructuring Cost and Reserve [Line Items]
Number of employees to be severed						2,200