Goodwill and Intangible Assets - Carrying Amount (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Finite-lived Intangible Assets [Roll Forward]
Balance, beginning of period	$ 14,550	$ 14,550
Acquisition of PFG	1,370	0
Balance, gross core deposit intangible	15,920	14,550
Less: accumulated amortization	(4,140)	(2,971)
Total	$ 11,780	$ 11,579