Investment in Affordable Housing Projects - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Equity Method Investments [Line Items]
Year in which investments are expected to be paid	2021
Tax credits and other benefits recognized	$ 504,000	$ 422,000	$ 402,000
Losses from investments in affordable housing projects	266,000	209,000	$ 267,000
Other Assets [Member]
Schedule Of Equity Method Investments [Line Items]
Investments in affordable housing projects	4,500,000	3,800,000
Other Liabilities [Member]
Schedule Of Equity Method Investments [Line Items]
Capital call for investments in affordable housing projects	$ 1,200,000	$ 1,000,000