Employee Benefit Plans - Additional Information (Detail) $ in Millions	3 Months Ended
	Dec. 31, 2018 USD ($) Plan
Defined Benefit Plan Disclosure [Line Items]
Number of foreign defined benefit plans | Plan	1
Reduction in net pension obligations	$ (30)
Pre-tax gain from net pension obligations	6
Settlement credit	5
Plan assets remain to be transferred.	8
Additional charge on defined benefit plan actuarial gain (loss)	$ 3
Pay out period for additional charge payment	5 years
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Curtailment credit	$ 1