Parent-Only Financial Information - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income	$ 5,230	$ 4,698	$ 5,133	$ 5,261	$ 4,932	$ 5,165	$ 5,117	$ 4,706	$ 20,322	$ 19,920	$ 16,330
Net cash provided by operating activities									28,451	27,581	35,458
Cash flows from investing activities:
Proceeds from sale of investment securities available-for-sale										8,439	1,244
Purchase of investment securities									(9,972)	(20,547)	(28,292)
Net cash (used in) provided by investing activities									(95,300)	(111,373)	(31,421)
Cash flows from financing activities:
Decrease in borrowings									(5,000)
Dividends paid									(8,693)	(8,241)	(8,239)
Purchase of treasury stock									(6,459)	(9,178)	(8,108)
Exercise of stock options									396	349	65
Net cash provided by (used in) financing activities									74,678	85,951	(32,623)
Net increase in cash and due from banks									7,829	2,159	(28,586)
OceanFirst Financial Corp. [Member]
Cash flows from operating activities:
Net income									20,322	19,920	16,330
Decrease (increase) in advances to subsidiary Bank									6,580	(6,023)	3,264
Undistributed earnings of subsidiary Bank									(5,516)	(4,147)	(1,178)
Net (gain) on sales of investment securities available for sale										(1,031)	(46)
Change in other assets and other liabilities									(707)	373	(547)
Net cash provided by operating activities									20,679	9,092	17,823
Cash flows from investing activities:
Proceeds from sale of investment securities available-for-sale										8,439	1,244
Purchase of investment securities									(1,000)	(651)	(2,964)
Repayments on ESOP loan receivable									204	190	179
Cash consideration for acquisition									(127)
Net cash (used in) provided by investing activities									(923)	7,978	(1,541)
Cash flows from financing activities:
Decrease in borrowings									(5,000)
Dividends paid									(8,693)	(8,241)	(8,239)
Purchase of treasury stock									(6,459)	(9,178)	(8,108)
Exercise of stock options									396	349	65
Net cash provided by (used in) financing activities									(19,756)	(17,070)	(16,282)
Net increase in cash and due from banks									0	0	0
Cash and due from banks at beginning of year				$ 7				$ 7	7	7	7
Cash and due from banks at end of year	$ 7				$ 7				$ 7	$ 7	$ 7