Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 22, 2017	Dec. 01, 2017
Operating Loss Carryforwards [Line Items]
Net deferred tax assets		$ 25,417,000	$ 60,818,000		$ 34,000,000
Deferred Tax Assets Related to State Net Operating Losses		5,600,000
Deferred Tax Assets, Operating Loss Carryforwards, Domestic		4,755,000	28,089,000
Deferred Tax Assets, Unrealized Losses on Available-for-Sale Securities, Gross		1,429,000	4,616,000
Amortization Method Qualified Affordable Housing Project Investments, Amortization		713,000	39,000
Affordable Housing Program Obligation Unfunded		$ 10,000,000	$ 8,300,000
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		35.00%	35.00%	35.00%
Deferred Income Tax Assets, Net					8,600,000	$ 25,400,000
Deferred Tax Assets, Net		$ 25,417,000	$ 60,818,000		$ 34,000,000
Scenario, Plan [Member]
Operating Loss Carryforwards [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Minimum [Member]
Operating Loss Carryforwards [Line Items]
Annual income before taxes		2,200,000
U.S. Federal [Member]
Operating Loss Carryforwards [Line Items]
Net deferred tax assets		15,400,000
Deferred Tax Assets, Net		$ 15,400,000
U.S. Federal [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carry forwards Expiration Period		2032
U.S. Federal [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carry forwards Expiration Period		2029
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net deferred tax assets		$ 10,000,000
Deferred Tax Assets, Net		$ 10,000,000
State and Local Jurisdiction [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carry forwards Expiration Period		2034
State and Local Jurisdiction [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carry forwards Expiration Period		2029