Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Available-for-Sale, Amortized Cost	$ 1,524,555	$ 1,566,779
Held to Maturity, Fair Value, Total	$ 1,384,430	$ 1,524,710
Preferred Stock, par value	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	1,000,000	1,000,000
Preferred Stock, shares outstanding	0	0
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	75,000,000	75,000,000
Common Stock, Shares, Outstanding	44,141,973	45,641,238
Common Stock, Shares, Issued	44,141,973	45,641,238
Common Stock, unvested restricted Stock awards	162,464	135,712
Shares Held in Rabbi Trust	81,943	80,965
Junior Subordinated Debt [Member]
Unamortized debt issuance expense	$ 31	$ 33
Subordinated Debt [Member]
Unamortized debt issuance expense	$ 43	$ 115