Parent-Only Financial Information - Condensed Statements of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Interest expense - borrowings									$ (3,402)	$ (4,919)	$ (6,556)
Operating expenses	(14,396)	(14,431)	(14,830)	(14,107)	(19,611)	(13,784)	(13,724)	(12,666)	(57,764)	(59,244)	(52,389)
Benefit for income taxes	(2,491)	(2,790)	(2,767)	(2,563)	(784)	(2,658)	(2,774)	(2,397)	(10,611)	(8,613)	(10,927)
Net income	4,932	5,165	5,117	4,706	1,939	4,968	4,987	4,436	19,920	16,330	20,020
OceanFirst Financial Corp. [Member]
Condensed Financial Statements, Captions [Line Items]
Dividend income - subsidiary Bank									16,000	16,000	20,500
Dividend income - investment securities									279	287	227
Net gain on sales of investment securities available-for-sale									1,031	46	226
Interest income - advances to subsidiary Bank									44	40	39
Interest income - ESOP loan receivable									322	336	349
Total income									17,676	16,709	21,341
Interest expense - borrowings									767	766	818
Operating expenses									1,365	1,358	1,323
Income before income taxes and undistributed earnings of subsidiary Bank									15,544	14,585	19,200
Benefit for income taxes									229	567	511
Income before undistributed earnings of subsidiary Bank									15,773	15,152	19,711
Undistributed earnings of subsidiary Bank									4,147	1,178	309
Net income									$ 19,920	$ 16,330	$ 20,020