BUSINESS SEGMENTS - Schedule of Income and Total Assets for Reportable Segments (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Net interest income (expense)		$ 45,525	$ 35,211	$ 128,040	$ 100,849
Noninterest income		16,383	17,781	49,605	53,279
Total income		61,908	52,992	177,645	154,128
Provision for credit losses	[1]	599	1,600	4,423	2,725
Compensation and employee benefits		22,656	19,859	66,987	61,759
Premises and equipment		4,534	4,459	13,821	12,646
FDIC insurance expense		510	555	1,484	1,669
Other operating expense		5,860	7,312	18,096	18,389
Total operating expense		34,159	33,785	104,811	97,188
INCOME BEFORE INCOME TAX EXPENSE		27,749	19,207	72,834	56,940
Income tax expense		7,623	5,036	19,167	15,173
NET INCOME		20,126	14,171	53,667	41,767
Total assets at period end		6,087,261	6,240,285	6,087,261	6,240,285	$ 6,077,993
Banking Segment [Member]
Net interest income (expense)		43,327	33,780	122,404	96,405
Noninterest income		2,955	3,476	6,645	12,810
Total income		46,282	37,256	129,049	109,215
Provision for credit losses		599	1,600	4,423	2,725
Compensation and employee benefits		15,343	13,079	47,222	43,876
Premises and equipment		3,908	3,861	11,674	10,950
FDIC insurance expense		510	555	1,484	1,669
Other operating expense		3,235	4,657	10,613	10,865
Total operating expense		23,595	23,752	75,416	70,085
INCOME BEFORE INCOME TAX EXPENSE		22,687	13,504	53,633	39,130
Income tax expense		6,193	3,556	14,117	10,436
NET INCOME		16,494	9,948	39,516	28,694
Total assets at period end		5,999,393	6,144,190	5,999,393	6,144,190
Peapack Private Segment [Member]
Net interest income (expense)		2,198	1,431	5,636	4,444
Noninterest income		13,428	14,305	42,960	40,469
Total income		15,626	15,736	48,596	44,913
Compensation and employee benefits		7,313	6,780	19,765	17,883
Premises and equipment		626	598	2,147	1,696
Other operating expense		2,625	2,655	7,483	7,524
Total operating expense		10,564	10,033	29,395	27,103
INCOME BEFORE INCOME TAX EXPENSE		5,062	5,703	19,201	17,810
Income tax expense		1,430	1,480	5,050	4,737
NET INCOME		3,632	4,223	14,151	13,073
Total assets at period end		$ 87,868	$ 96,095	$ 87,868	$ 96,095

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