Borrowings - Activity (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Assets Sold under Agreements to Repurchase [Line Items]
Long-term debt	$ 438,838	$ 304,675
Securities sold under agreements to repurchase
Assets Sold under Agreements to Repurchase [Line Items]
Long-term debt	$ 32,469	$ 23,745
Weighted Average Interest Rate	0.61%	0.89%
FHLB advances
Assets Sold under Agreements to Repurchase [Line Items]
Long-term debt	$ 200,000	$ 250,000
Weighted Average Interest Rate	0.77%	1.60%
Subordinated debt
Assets Sold under Agreements to Repurchase [Line Items]
Long-term debt	$ 189,750	$ 30,930
Weighted Average Interest Rate	5.10%	5.13%
Other Borrowings
Assets Sold under Agreements to Repurchase [Line Items]
Long-term debt	$ 16,619	$ 0
Weighted Average Interest Rate	1.88%	0.00%