Loans and Allowance for Credit Losses - Rollforward of Purchase Credit Impaired Loans (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($)
Gross Carrying Value
Gross carrying value, beginning balance	$ 29,544
Reclassification of discount to allowance for credit losses	0
Year-to-date settlements	1,691
Gross carrying value, ending balance	27,853
Accretable Yield
Accretable yield, beginning balance	(4,801)
Reclassification of discount to allowance for credit losses	0
Year-to-date settlements	1,141
Accretable yield, ending balance	(3,660)
Nonaccretable Yield
Nonaccretable yield, beginning balance	(3,828)
Reclassification of discount to allowance for credit losses	3,828
Year-to-date settlements	0
Nonaccretable yield, ending balance	0
Net Carrying Value
Net carrying value, beginning balance	20,915
Reclassification of discount to allowance for credit losses	3,828
Year-to-date settlements	550
Net carrying value, ending balance	$ 24,193