Investment Securities - Allowance for Credit Losses HTM (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning balance	$ 409	$ 0
Provision for credit loss expense	(102)	(62)
Ending balance, June 30, 2020	307	307
State and political subdivisions
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning balance	97	0
Provision for credit loss expense	(2)	37
Ending balance, June 30, 2020	95	95
Other securities
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning balance	312	0
Provision for credit loss expense	(100)	(99)
Ending balance, June 30, 2020	$ 212	212
Impact of ASU 2016-13 adoption
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning balance		369
Impact of ASU 2016-13 adoption | State and political subdivisions
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning balance		58
Impact of ASU 2016-13 adoption | Other securities
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning balance		$ 311