Goodwill and Other Intangible Assets - Current Year Amortization Expense for Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Total intangible amortization	$ 1,598	$ 1,895
Core deposit intangibles
Finite-Lived Intangible Assets [Line Items]
Total intangible amortization	1,553	1,850
Customer relationship intangible
Finite-Lived Intangible Assets [Line Items]
Total intangible amortization	$ 45	$ 45