Parent-Only Financial Information - Condensed Statements of Cash Flows (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net income	$ 19,920us-gaap_NetIncomeLoss	$ 16,330us-gaap_NetIncomeLoss	$ 20,020us-gaap_NetIncomeLoss
Net cash provided by operating activities	27,581	35,458	30,888
Cash flows from investing activities:
Proceeds from sale of investment securities available-for-sale	8,439	1,244	1,221
Purchase of investment securities	(20,547)	(28,292)	(74,390)
Net cash (used in) provided by investing activities	(111,373)	(31,421)	7,243
Cash flows from financing activities:
Dividends paid	(8,241)us-gaap_PaymentsOfDividendsCommonStock	(8,239)us-gaap_PaymentsOfDividendsCommonStock	(8,579)us-gaap_PaymentsOfDividendsCommonStock
Purchase of treasury stock	(9,178)	(8,108)	(11,897)
Exercise of stock options	349	65	419
Net cash provided by (used in) financing activities	85,951	(32,623)	(53,114)
Net increase (decrease) in cash and due from banks	2,159	(28,586)	(14,983)
OceanFirst Financial Corp. [Member]
Cash flows from operating activities:
Net income	19,920	16,330	20,020
(Increase) decrease in advances to subsidiary Bank	(6,023)	3,264	(1,921)
Undistributed earnings of subsidiary Bank	(4,147)	(1,178)	(309)
Net (gain) on sales of investment securities available for sale	(1,031)	(46)	(226)
Change in other assets and other liabilities	373	(547)	2,799
Net cash provided by operating activities	9,092	17,823	20,363
Cash flows from investing activities:
Proceeds from sale of investment securities available-for-sale	8,439	1,244	1,221
Purchase of investment securities	(651)	(2,964)	(1,694)
Repayments on ESOP loan receivable	190	179	167
Net cash (used in) provided by investing activities	7,978	(1,541)	(306)
Cash flows from financing activities:
Dividends paid	(8,241)	(8,239)	(8,579)
Purchase of treasury stock	(9,178)	(8,108)	(11,897)
Exercise of stock options	349	65	419
Net cash provided by (used in) financing activities	(17,070)	(16,282)	(20,057)
Net increase (decrease) in cash and due from banks	0	0	0
Cash and due from banks at beginning of year	7	7	7
Cash and due from banks at end of year	$ 7	$ 7	$ 7

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