Investment Securities - Allowance for Credit Losses for HTM Securities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($)
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning Balance / Day One Impact of adopting ASC 326	$ 0
Provision for Credit Losses	56
Ending Balance	230
Municipal bonds and notes
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning Balance / Day One Impact of adopting ASC 326	0
Provision for Credit Losses	56
Ending Balance	230
Cumulative adjustment for the adoption of amendment
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning Balance / Day One Impact of adopting ASC 326	174
Cumulative adjustment for the adoption of amendment | Municipal bonds and notes
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning Balance / Day One Impact of adopting ASC 326	$ 174