Regulatory Matters - Summary of Regulatory Capital Amounts and Ratios (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 capital (to average assets), Actual Ratio	4.00%
Common equity Tier 1 (to risk-weighted asset), Actual Ratio	4.50%
Tier 1 capital (to risk-weighted assets), Actual Ratio	5.00%
Tier 1 capital (to average assets), For capital adequacy purposes Ratio	6.00%
Total capital (to risk-weighted assets) For capital adequacy purposes Ratio	8.00%
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	8.00%
Total capital (to risk-weighted assets), To be well capitalized under prompt corrective action Ratio	10.00%
OceanFirst Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 capital (to average assets), Actual Amount	$ 229,306	$ 223,573
Common equity Tier 1 (to risk-weighted asset), Actual Amount	229,306
Tier 1 capital (to risk-weighted assets), Actual Amount	229,306	223,573
Total capital (to risk-weighted assets), Actual Amount	$ 246,106	$ 239,940
Tier 1 capital (to average assets), Actual Ratio	8.91%	9.46%
Common equity Tier 1 (to risk-weighted asset), Actual Ratio	12.72%
Tier 1 capital (to risk-weighted assets), Actual Ratio	12.72%	14.05%
Total capital (to risk-weighted assets), Actual Ratio	13.65%	15.08%
Tier 1 capital (to average assets), For capital adequacy purposes Amount	$ 102,935	$ 94,573
Common equity Tier 1 (to risk-weighted asset), For capital adequacy purposes Amount	81,114
Tier 1 capital (to risk-weighted assets), For capital adequacy purposes Amount	108,152	63,663
Total capital (to risk-weighted assets), For capital adequacy purposes Amount	$ 144,203	$ 127,325
Tier 1 capital (to average assets), For capital adequacy purposes Ratio	4.00%	4.00%
Common equity Tier 1 (to risk-weighted asset), For capital adequacy purposes Ratio	4.50%
Tier 1 capital (to risk-weighted assets), For capital adequacy purposes Ratio	6.00%	4.00%
Total capital (to risk-weighted assets) For capital adequacy purposes Ratio	8.00%	8.00%
Tier 1 capital (to average assets), To be well capitalized under prompt corrective action Amount	$ 128,669	$ 118,217
Common equity Tier 1 (to risk-weighted asset), To be well capitalized under prompt corrective action Amount	117,165
Tier 1 capital (to risk-weighted assets), To be well capitalized under prompt corrective action Amount	144,203	95,494
Total capital (to risk-weighted assets), To be well capitalized under prompt corrective action Amount	$ 180,253	$ 159,157
Tier 1 capital (to average assets), To be well capitalized under prompt corrective action Ratio	5.00%	5.00%
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	8.00%	6.00%
Total capital (to risk-weighted assets), To be well capitalized under prompt corrective action Ratio	10.00%	10.00%
OceanFirst Financial Corp. [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 capital (to average assets), Actual Amount	$ 250,324
Common equity Tier 1 (to risk-weighted asset), Actual Amount	241,856
Tier 1 capital (to risk-weighted assets), Actual Amount	250,324
Total capital (to risk-weighted assets), Actual Amount	$ 267,124
Tier 1 capital (to average assets), Actual Ratio	9.72%
Common equity Tier 1 (to risk-weighted asset), Actual Ratio	13.40%
Tier 1 capital (to risk-weighted assets), Actual Ratio	13.87%
Total capital (to risk-weighted assets), Actual Ratio	14.80%
Tier 1 capital (to average assets), For capital adequacy purposes Amount	$ 102,984
Common equity Tier 1 (to risk-weighted asset), For capital adequacy purposes Amount	81,234
Tier 1 capital (to risk-weighted assets), For capital adequacy purposes Amount	108,312
Total capital (to risk-weighted assets), For capital adequacy purposes Amount	$ 144,416
Tier 1 capital (to average assets), For capital adequacy purposes Ratio	4.00%
Common equity Tier 1 (to risk-weighted asset), For capital adequacy purposes Ratio	4.50%
Tier 1 capital (to risk-weighted assets), For capital adequacy purposes Ratio	6.00%
Total capital (to risk-weighted assets) For capital adequacy purposes Ratio	8.00%
Tier 1 capital (to average assets), To be well capitalized under prompt corrective action Amount	$ 128,730
Common equity Tier 1 (to risk-weighted asset), To be well capitalized under prompt corrective action Amount	117,338
Tier 1 capital (to risk-weighted assets), To be well capitalized under prompt corrective action Amount	144,416
Total capital (to risk-weighted assets), To be well capitalized under prompt corrective action Amount	$ 180,520
Tier 1 capital (to average assets), To be well capitalized under prompt corrective action Ratio	5.00%
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	8.00%
Total capital (to risk-weighted assets), To be well capitalized under prompt corrective action Ratio	10.00%