Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Time certificates of deposit least amount	$ 100,000	$ 100,000
Securities held to maturity, fair value	$ 752,177,000	$ 753,263,000
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, shares issued	32,965,692	34,377,388
Common stock, shares outstanding	32,965,692	34,377,388
Common stock, unvested restricted Stock awards	135,205	147,184
Shares held in rabbit trust at cost	84,126	143,820
Common Stock Outstanding
Common stock, shares outstanding	32,965,692	34,377,388
Subordinated Debt [Member]
Unamortized Debt Issuance Expense	$ 304,000	$ 399,000
Long-term Debt [Member]
Unamortized Debt Issuance Expense	$ 40,000	$ 94,000