Investment Securities - Additional Information (Details)	Mar. 31, 2019 USD ($) Security	Dec. 31, 2018 USD ($) Security
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Number of debt securities with unrealized losses | Security	104	142
Aggregate depreciation percentage of gross unrealized losses from amortized cost	1.45%	2.05%
Maximum
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Percentage of unrealized loss on amortized cost	4.22%	9.79%
Unrealized loss of amortized cost basis	$ 70,000	$ 98,000
Unrealized dollar loss of amortized cost basis	$ 127,000	$ 189,000
Percentage of unrealized dollar loss on amortized cost	3.73%	5.34%