XML 45 R35.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Securities - Carrying Value of Held-to-Maturity Investment Securities (Detail) - USD ($) $ in Thousands | 9 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Sep. 30, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract] |  |  |
Amortized Cost |  | $ 888,848 | $ 772,060
Net loss on date of transfer from available-for-sale | $ (13,347) | (13,347) |
Accretion of net unrealized loss on securities reclassified as held-to-maturity | 8,039 | 5,349 |
Carrying value | $ 883,540 | $ 764,062 |

X
- Definition Unrealized holding gain (loss) related to transfers of securities into held-to-maturity classification and out of the available-for-sale classification. + References No definition available. + Details
Name: | ocfc_OtherComprehensiveIncomeLossTransfersFromAvailableForSaleSecuritiesToHeldToMaturity
Namespace Prefix: | ocfc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Other comprehensive income reclassification of accretion of net unrealized losses to held to maturity securities. + References No definition available. + Details
Name: | ocfc_OtherComprehensiveIncomeReclassificationOfAccretionOfNetUnrealizedLossesToHeldToMaturitySecurities
Namespace Prefix: | ocfc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26610-111562 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563 + Details
Name: | us-gaap_HeldToMaturitySecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, before other-than-temporary impairment (OTTI) accretion, of investment in debt securities measured at amortized cost (held-to-maturity). + References No definition available. + Details
Name: | us-gaap_HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration