Borrowings - Repurchase agreements accounted for as secured borrowings (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase liability	$ 123,499	$ 148,609
Secured Debt
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase liability	123,499	148,609
US Treasury Securities | Secured Debt
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase liability	47,916	48,670
US Treasury Securities | Within 30 days | Secured Debt
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase liability	17,521	410
US Treasury Securities | After 30 to 90 days | Secured Debt
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase liability	21,607	30,739
US Treasury Securities | After 90 days | Secured Debt
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase liability	8,788	17,521
Mortgage Backed Securities | Secured Debt
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase liability	75,371	99,775
Mortgage Backed Securities | Within 30 days | Secured Debt
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase liability	25,106	98,984
Mortgage Backed Securities | After 30 to 90 days | Secured Debt
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase liability	791	791
Mortgage Backed Securities | After 90 days | Secured Debt
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase liability	49,474	0
CMO | Secured Debt
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase liability	212	164
CMO | Within 30 days | Secured Debt
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase liability	$ 212	$ 164