Restructuring Charges - Additional Information (Detail) $ in Millions	3 Months Ended		12 Months Ended
	Sep. 30, 2015 USD ($) Position	Sep. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) Position
Restructuring Cost and Reserve [Line Items]
Restructuring charges | $	$ 0
Phone Hardware Integration Plan
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated			19,000
Completion date	Jun. 30, 2015
Restructuring charges | $		$ 1,000	$ 1,300
Phone Hardware Integration Plan | Nokia Devices And Services Business
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated			13,000
Phone Hardware Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Completion date	Jun. 30, 2016
Restructuring charge to date | $	$ 780
Phone Hardware Restructuring Plan | Upper Limit
Restructuring Cost and Reserve [Line Items]
Number of positions expected to be eliminated in fiscal year 2016	7,800