Note 11 - Subordinated Debentures - Summary of Mandatory Redeemable Trust Preferred Securities (Details) - Center Bancorp Statutory Trust II [Member] - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022	Dec. 19, 2003
Securities issued	$ 5,000,000
Subordinated Debt [Member]
Securities issued	$ 5,000,000,000	$ 5,000,000	$ 5,000,000
Liquidation value (in dollars per share)	$ 1,000	$ 1,000
Coupon rate	2.85%	2.85%
Maturity	Jan. 23, 2034	Jan. 23, 2034
Redeemable by issuer beginning	Jan. 23, 2009	Jan. 23, 2009