Securities - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019 USD ($) item security	Dec. 31, 2018 USD ($)
Additional Information
The number of holdings of securities of any one issuer other than the U.S. Government and its sponsored entities | security	0
Holdings of securities as percentage of shareholders' equity, considered as threshold for disclosure purpose	10.00%
Number of securities held | security	463
Number of available for sale securities held | item	141
Number of held to maturity securities held | item	322
Number of securities with fair values below amortized cost | security	86
Total unrealized loss for securities 12 months or more	$ 856,000
Available-for-sale securities carried with an unrealized loss for over 12 months	27,534,000	$ 281,082,000
Held-to-maturity securities carried with an unrealized loss for over 12 months	$ 88,128,000	313,218,000
Municipals - exempt from Federal tax
Additional Information
Held-to-maturity securities carried with an unrealized loss for over 12 months		$ 57,301,000