Securities - Cost of Restricted Stock (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Total restricted stock	$ 7,796	$ 5,247	[1]
FRB stock
Schedule of Investments [Line Items]
Total restricted stock	5,045	3,621
FHLB stock
Schedule of Investments [Line Items]
Total restricted stock	$ 2,751	$ 1,626

[1] Derived from audited consolidated financial statements.