Financial Instruments and Fair Value Measurements - Schedule of Fair Value Hedging Relationship By Balance Sheet (Detail) - Borrowings [Member] $ in Millions	Sep. 30, 2019 USD ($)
Carrying amount of hedged item	$ 69
Cumulative hedging adjustments included in the carrying amount	$ (3)

Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4EE
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109999712-113959

Name:	us-gaap_HedgedLiabilityFairValueHedgeCumulativeIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant