Note 9 - Subordinated Debentures - Summary of Mandatory Redeemable Trust Preferred Securities (Details) - Center Bancorp Statutory Trust II [Member] - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2003	Dec. 31, 2023	Dec. 31, 2022	Dec. 19, 2003
Securities issued		$ 5
Subordinated Debt [Member]
Securities issued		$ 5,000	$ 5,000	$ 5
Liquidation value (in dollars per share)		$ 1,000	$ 1,000
Maturity		Jan. 23, 2034	Jan. 23, 2034
Redeemable by issuer beginning		Jan. 23, 2009	Jan. 23, 2009
Subordinated Debt [Member] | Secured Overnight Financing Rate (SOFR) [Member]
Coupon rate		2.85%
Subordinated Debt [Member] | LIBOR - London Interbank Offered Rate [Member]
Coupon rate	2.85%		2.85%