Amount of cash receipt from (payment to) bank; or stock received from (issuance to) bank in the settlement of the accelerated share repurchase agreement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 25
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6405686&loc=d3e22802-112653

Name:	us-gaap_AcceleratedShareRepurchasesSettlementPaymentOrReceipt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Stockholders' Equity - Additional Information (Detail) - USD ($) $ in Billions	Oct. 05, 2017	Sep. 20, 2017
Equity, Class of Treasury Stock [Line Items]
Authorized share-repurchase program		$ 2.5
Subsequent Event [Member]
Equity, Class of Treasury Stock [Line Items]
Accelerated share repurchase agreement amount	$ 1.0