Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Time certificates of deposit least amount	$ 100,000	$ 100,000
Held to Maturity, Fair Value, Total	$ 517,555,000	$ 494,194,000
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, unvested restricted Stock awards	169,904	177,191
Shares Held in Rabbi Trust	155,373.53	164,438
Common Stock Outstanding
Common Stock, Shares, Outstanding	27,512,328	27,450,190
Junior Subordinated Debt [Member]
Unamortized Debt Issuance Expense	$ 124,000	$ 125,000
Subordinated Debt [Member]
Unamortized Debt Issuance Expense	$ 307,000	$ 318,000