BUSINESS SEGMENTS - Schedule of Income and Total Assets for Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Net interest income	$ 36,515	$ 45,525	$ 119,414	$ 128,040
Noninterest income	19,354	16,383	55,988	49,605
Total income	55,869	61,908	175,402	177,645
Provision for credit losses	5,856	599	9,065	4,423
Compensation and employee benefits	25,264	22,656	76,204	66,987
Premises and equipment	5,214	4,534	14,317	13,821
FDIC insurance expense	741	510	2,181	1,484
Other operating expense	6,194	5,860	17,977	18,096
Total operating expense	43,269	34,159	119,744	104,811
INCOME BEFORE INCOME TAX EXPENSE	12,600	27,749	55,658	72,834
Income tax expense	3,845	7,623	15,403	19,167
NET INCOME	8,755	20,126	40,255	53,667
Total assets at period end	6,521,581	6,087,261	6,521,581	6,087,261	$ 6,353,593
Banking Segment [Member]
Net interest income	35,811	43,327	116,004	122,404
Noninterest income	5,120	2,955	13,027	6,645
Total income	40,931	46,282	129,031	129,049
Provision for credit losses	5,856	599	9,065	4,423
Compensation and employee benefits	18,440	15,343	54,558	47,222
Premises and equipment	4,436	3,908	12,072	11,674
FDIC insurance expense	741	510	2,181	1,484
Other operating expense	4,188	3,235	11,317	10,613
Total operating expense	33,661	23,595	89,193	75,416
INCOME BEFORE INCOME TAX EXPENSE	7,270	22,687	39,838	53,633
Income tax expense	2,275	6,193	11,021	14,117
NET INCOME	4,995	16,494	28,817	39,516
Total assets at period end	6,405,796	5,999,393	6,405,796	5,999,393
Peapack Private Segment [Member]
Net interest income	704	2,198	3,410	5,636
Noninterest income	14,234	13,428	42,961	42,960
Total income	14,938	15,626	46,371	48,596
Compensation and employee benefits	6,824	7,313	21,646	19,765
Premises and equipment	778	626	2,245	2,147
Other operating expense	2,006	2,625	6,660	7,483
Total operating expense	9,608	10,564	30,551	29,395
INCOME BEFORE INCOME TAX EXPENSE	5,330	5,062	15,820	19,201
Income tax expense	1,570	1,430	4,382	5,050
NET INCOME	3,760	3,632	11,438	14,151
Total assets at period end	$ 115,785	$ 87,868	$ 115,785	$ 87,868