Regulatory Matters - Summary of Regulatory Capital Amounts and Ratios (Details) $ in Thousands	12 Months Ended
Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 capital (to average assets), Actual Ratio	0.040
Common equity Tier 1 (to risk-weighted assets), Actual Ratio	7.00%
Tier 1 capital (to risk-weighted assets), Actual Ratio	0.050
Tier 1 capital (to average assets), For capital adequacy purposes Ratio	0.085	0.0400
Total capital (to risk-weighted assets) For capital adequacy purposes Ratio	0.105
Tier 1 capital (to average assets), To be well capitalized under prompt corrective action Ratio		0.0500
Common equity Tier 1 (to risk-weighted asset), To be well capitalized under prompt corrective action Ratio	6.50%
Tier 1 capital (to risk-weighted assets), To be well capitalized under prompt corrective action Ratio	0.080
Total capital (to risk-weighted assets), To be well capitalized under prompt corrective action Ratio	0.100
Capital conservation buffer (as a percent)	2.50%
OceanFirst Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 capital (to average assets), Actual Amount	$ 1,027,660	$ 942,122
Common equity Tier 1 (to risk-weighted asset), Actual Amount	1,027,660	942,122
Tier 1 capital (to risk-weighted assets), Actual Amount	1,027,660	942,122
Total capital (to risk-weighted assets), Actual Amount	$ 1,079,766	$ 1,004,480
Tier 1 capital (to average assets), Actual Ratio	0.0908	0.0848
Common equity Tier 1 (to risk-weighted assets), Actual Ratio	11.62%	12.11%
Tier 1 capital (to risk-weighted assets), Actual Ratio	0.1162	0.1211
Total capital (to risk-weighted assets), Actual Ratio	0.1221	0.1291
Tier 1 capital (to average assets), For capital adequacy purposes Amount	$ 452,669	$ 444,648
Common equity Tier 1 (to risk-weighted asset), For capital adequacy purposes Amount	619,178	544,625
Tier 1 capital (to risk-weighted assets), For capital adequacy purposes Amount	751,860	661,331
Total capital (to risk-weighted assets), For capital adequacy purposes Amount	$ 928,768	$ 816,938
Tier 1 capital (to average assets), For capital adequacy purposes Ratio	0.0400
Common equity Tier 1 (to risk-weighted assets), For capital adequacy purposes Ratio	7.00%	7.00%
Tier 1 capital (to risk-weighted assets), For capital adequacy purposes Ratio	0.0850	0.0850
Total capital (to risk-weighted assets) For capital adequacy purposes Ratio	0.1050	0.1050
Tier 1 capital (to average assets), To be well capitalized under prompt corrective action Amount	$ 565,836	$ 555,810
Common equity Tier 1 (to risk-weighted asset), To be well capitalized under prompt corrective action Amount	574,951	505,724
Tier 1 capital (to risk-weighted assets), To be well capitalized under prompt corrective action Amount	707,633	622,429
Total capital (to risk-weighted assets), To be well capitalized under prompt corrective action Amount	$ 884,541	$ 778,036
Tier 1 capital (to average assets), To be well capitalized under prompt corrective action Ratio	0.0500
Common equity Tier 1 (to risk-weighted asset), To be well capitalized under prompt corrective action Ratio	6.50%	6.50%
Tier 1 capital (to risk-weighted assets), To be well capitalized under prompt corrective action Ratio	0.0800	0.0800
Total capital (to risk-weighted assets), To be well capitalized under prompt corrective action Ratio	0.1000	0.1000
OceanFirst Financial Corp.
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 capital (to average assets), Actual Amount	$ 1,044,518	$ 998,273
Common equity Tier 1 (to risk-weighted asset), Actual Amount	917,088	871,385
Tier 1 capital (to risk-weighted assets), Actual Amount	1,044,518	998,273
Total capital (to risk-weighted assets), Actual Amount	$ 1,257,372	$ 1,230,370
Tier 1 capital (to average assets), Actual Ratio	0.0922	0.0944
Common equity Tier 1 (to risk-weighted assets), Actual Ratio	10.26%	11.05%
Tier 1 capital (to risk-weighted assets), Actual Ratio	0.1168	0.1266
Total capital (to risk-weighted assets), Actual Ratio	0.1406	0.1560
Tier 1 capital (to average assets), For capital adequacy purposes Amount	$ 453,087	$ 423,028
Common equity Tier 1 (to risk-weighted asset), For capital adequacy purposes Amount	625,801	552,075
Tier 1 capital (to risk-weighted assets), For capital adequacy purposes Amount	759,902	670,377
Total capital (to risk-weighted assets), For capital adequacy purposes Amount	$ 938,702	$ 828,113
Tier 1 capital (to average assets), For capital adequacy purposes Ratio	0.0400	0.0400
Common equity Tier 1 (to risk-weighted assets), For capital adequacy purposes Ratio	7.00%	7.00%
Tier 1 capital (to risk-weighted assets), For capital adequacy purposes Ratio	0.0850	0.0850
Total capital (to risk-weighted assets) For capital adequacy purposes Ratio	0.1050	0.1050

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Common Equity Tier One Capital Required For Capital Adequacy To Risk Weighted Assets Amount

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Common Equity Tier One Capital To Risk Weighted Assets

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Amount of total capital as defined by regulatory framework.

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Amount of minimum total risk-based capital required for capital adequacy as defined by regulatory framework.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 505
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