Goodwill and Other Intangible Assets - Current Year Amortization Expense for Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Finite-Lived Intangible Assets [Line Items]
Total intangible amortization	$ 1,834	$ 2,053	$ 3,729	$ 4,163
Core deposit intangibles
Finite-Lived Intangible Assets [Line Items]
Total intangible amortization	1,789	2,020	3,639	4,097
Customer relationship intangible
Finite-Lived Intangible Assets [Line Items]
Total intangible amortization	$ 45	$ 33	$ 90	$ 66