Investment Securities - Allowance for Credit Losses for HTM Securities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning Balance	$ 0
Provision for HTM Securities	218
Ending Balance	392
Day one impact for adoption of amendment
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning Balance	174
Municipal bonds and notes
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning Balance	0
Provision for HTM Securities	218
Ending Balance	392
Municipal bonds and notes | Day one impact for adoption of amendment
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Beginning Balance	$ 174