Goodwill and Other Intangible Assets - Current Year Amortization Expense for Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Finite-Lived Intangible Assets [Line Items]
Total intangible amortization	$ 1,481	$ 1,733	$ 4,618	$ 5,462
Core deposit intangibles
Finite-Lived Intangible Assets [Line Items]
Total intangible amortization	1,436	1,688	4,482	5,326
Customer relationship intangible
Finite-Lived Intangible Assets [Line Items]
Total intangible amortization	$ 45	$ 45	$ 136	$ 136