Investment Securities - Allowance for Credit Losses AFS (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 269	$ 0
Credit losses on securities not previously recorded	530	269
Reduction due to sales		(142)
Net increase (decrease) in allowance on previously impaired securities	(190)	109
Ending balance, June 30, 2020	609	$ 609	$ 0
Accounting Standards Update [Extensible List]		us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201613Member
Impact of ASU 2016-13 adoption
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Beginning balance		$ 373
Ending balance, June 30, 2020			$ 373
State and political subdivisions
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Beginning balance	95	0
Credit losses on securities not previously recorded	370	77
Reduction due to sales		(142)
Net increase (decrease) in allowance on previously impaired securities	(94)	63
Ending balance, June 30, 2020	371	371	0
State and political subdivisions | Impact of ASU 2016-13 adoption
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Beginning balance		373
Ending balance, June 30, 2020			373
Other securities
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Beginning balance	174	0
Credit losses on securities not previously recorded	160	192
Reduction due to sales		0
Net increase (decrease) in allowance on previously impaired securities	(96)	46
Ending balance, June 30, 2020	$ 238	238	0
Other securities | Impact of ASU 2016-13 adoption
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Beginning balance		$ 0
Ending balance, June 30, 2020			$ 0