Available For Sale And Held To Maturity Securities Amount Callable Amortized Cost

No definition available.

Name:	ocfc_AvailableForSaleAndHeldToMaturitySecuritiesAmountCallableAmortizedCost
Namespace Prefix:	ocfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Available For Sale And Held To Maturity Securities Amount Callable Fair Value Disclosure

+ References

No definition available.

+ Details

Name:	ocfc_AvailableForSaleAndHeldToMaturitySecuritiesAmountCallableFairValueDisclosure
Namespace Prefix:	ocfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Equity Investments

+ References

No definition available.

+ Details

Name:	ocfc_EquityInvestments
Namespace Prefix:	ocfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Other Comprehensive Income Reclassification Adjustment For Held To Maturity Transferred From Available For Sale Securities Before Tax

+ References

No definition available.

+ Details

Name:	ocfc_OtherComprehensiveIncomeReclassificationAdjustmentForHeldToMaturityTransferredFromAvailableForSaleSecuritiesBeforeTax
Namespace Prefix:	ocfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Securities Transferred From Available For Sale To Held To Maturity

+ References

No definition available.

+ Details

Name:	ocfc_SecuritiesTransferredFromAvailableForSaleToHeldToMaturity
Namespace Prefix:	ocfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27357-111563

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleRealizedGain
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27357-111563

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of realized gain (loss) from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=120269885&loc=SL75117546-209714

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(3)(d))
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

+ Details

Name:	us-gaap_EquitySecuritiesFvNiRealizedGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The fair value, as of the date of each statement of financial position presented, of securities that are restricted as collateral for the payment of other debt obligations, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66007379&loc=d3e113888-111728

+ Details

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

- Definition

The fair value, as of the date of each statement of financial position presented, of securities which are owned but transferred to serve as collateral for the payment of repurchase agreements, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.

+ References

+ Details

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ScheduleOfInvestmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_FinancialInstrumentAxis=ocfc_ReverseRepurchaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Securities - Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
Securities - Additional Information (Details) - USD ($)	Sep. 30, 2013	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2013
Investment [Line Items]
Available-for-sale securities transferred to held-to-maturity securities	$ 536,000,000.0			$ 536,000,000.0
Unrealized net loss on securities reclassified from available-for-sale to held-to-maturity, Gross	$ 13,300,000			$ 13,300,000
Realized gains on sale of investment securities		$ 476,000
Debt securities, available-for-sale, realized gain (loss)			$ 0
Less: Net gains recognized on equity securities sold		5,401,000	0
Corporate debt securities, callable, amortized cost		53,800,000
Corporate debt securities, callable, estimated fair value		52,900,000
Estimated fair value of securities pledged for deposits and other purposes		435,900,000	475,600,000
Equity investments, at estimated fair value		107,079,000	10,136,000
Reverse Repurchase Agreements
Investment [Line Items]
Estimated fair value of securities pledged for reverse repurchase agreements		$ 152,700,000	$ 81,400,000