SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Loans Held-for-Sale (Detail) - USD ($)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Loans Held for Sale
Loans Held-for-Sale
Period of originated loans within which they are transferred or sold	60 days
Loans held for sale carried at lower of cost or fair value	$ 0	$ 0
Loans, non-accrual status	$ 0	$ 0
Mortgage Loans
Loans Held-for-Sale
Period of originated loans within which they are transferred or sold	60 days

Amount of financing receivable on nonaccrual status.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5111-111524

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919258-210447

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