BUSINESS SEGMENTS - Schedule of Income and Total Assets for Reportable Segments (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Net interest income		$ 42,893	$ 33,845	$ 82,515	$ 65,638
Noninterest income		18,508	17,678	33,222	35,498
Total income		61,401	51,523	115,737	101,136
Provision for credit losses	[1]	1,449	900	3,824	1,125
Compensation and employee benefits		21,882	19,910	44,331	41,900
Premises and equipment		4,640	4,074	9,287	8,187
FDIC insurance expense		503	529	974	1,114
Other operating expense		5,634	6,171	12,236	11,077
Total operating expense		34,108	31,584	70,652	63,403
INCOME BEFORE INCOME TAX EXPENSE		27,293	19,939	45,085	37,733
Income tax expense		7,193	5,521	11,544	10,137
NET INCOME		20,100	14,418	33,541	27,596
Total assets at period end		6,151,167	5,791,688	6,151,167	5,791,688	$ 6,077,993
Banking Segment [Member]
Net interest income		41,078	32,399	79,077	62,625
Noninterest income		4,119	4,194	3,690	9,334
Total income		45,197	36,593	82,767	71,959
Provision for credit losses		1,449	900	3,824	1,125
Compensation and employee benefits		15,476	14,369	31,879	30,797
Premises and equipment		3,835	3,519	7,766	7,089
FDIC insurance expense		503	529	974	1,114
Other operating expense		3,212	3,817	7,378	6,208
Total operating expense		24,475	23,134	51,821	46,333
INCOME BEFORE INCOME TAX EXPENSE		20,722	13,459	30,946	25,626
Income tax expense		5,624	3,721	7,924	6,880
NET INCOME		15,098	9,738	23,022	18,746
Total assets at period end		6,046,082	5,700,105	6,046,082	5,700,105
Peapack Private Segment [Member]
Net interest income		1,815	1,446	3,438	3,013
Noninterest income		14,389	13,484	29,532	26,164
Total income		16,204	14,930	32,970	29,177
Compensation and employee benefits		6,406	5,541	12,452	11,103
Premises and equipment		805	555	1,521	1,098
Other operating expense		2,422	2,354	4,858	4,869
Total operating expense		9,633	8,450	18,831	17,070
INCOME BEFORE INCOME TAX EXPENSE		6,571	6,480	14,139	12,107
Income tax expense		1,569	1,800	3,620	3,257
NET INCOME		5,002	4,680	10,519	8,850
Total assets at period end		$ 105,085	$ 91,583	$ 105,085	$ 91,583

[1] Commencing on January 1, 2022, the allowance calculation is based on the current expected credit loss methodology. Prior to January 1, 2022, the calculation was based on the incurred loss methodology.