Information Regarding Troubled Debt Restructurings (Parenthetical) (Detail) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Taxi Medallion Loans [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings	$ 22.6	$ 20.4

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554

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