Investment in Affordable Housing Projects - Additional Information (Details)	3 Months Ended
	Mar. 31, 2019 USD ($) Investment	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Schedule Of Equity Method Investments [Line Items]
Number of limited liability partnerships with investments | Investment	7
Year in which investments are expected to be paid	2021
Tax credits and other benefits recognized	$ 140,000	$ 126,000
Losses from investments in affordable housing projects	83,000	$ 80,000
Other Assets [Member]
Schedule Of Equity Method Investments [Line Items]
Investments in affordable housing projects	4,400,000		$ 4,500,000
Other Liabilities [Member]
Schedule Of Equity Method Investments [Line Items]
Capital call for investments in affordable housing projects	$ 1,100,000		$ 1,200,000