Borrowings - Repurchase agreements accounted for as secured borrowings (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Assets Sold under Agreements to Repurchase
Repurchase liability	$ 162,450	$ 91,603
Secured Debt
Assets Sold under Agreements to Repurchase
Repurchase liability	162,450	91,603
US Treasury Securities | Secured Debt
Assets Sold under Agreements to Repurchase
Repurchase liability	58,619	78,869
US Treasury Securities | Within 30 days | Secured Debt
Assets Sold under Agreements to Repurchase
Repurchase liability	27,381	19,538
US Treasury Securities | After 30 to 90 days | Secured Debt
Assets Sold under Agreements to Repurchase
Repurchase liability	13,790	30,295
US Treasury Securities | After 90 days | Secured Debt
Assets Sold under Agreements to Repurchase
Repurchase liability	17,448	29,036
Mortgage Backed Securities | Secured Debt
Assets Sold under Agreements to Repurchase
Repurchase liability	103,552	12,455
Mortgage Backed Securities | Within 30 days | Secured Debt
Assets Sold under Agreements to Repurchase
Repurchase liability	96,572	11,733
Mortgage Backed Securities | After 90 days | Secured Debt
Assets Sold under Agreements to Repurchase
Repurchase liability	6,980	722
CMO | Secured Debt
Assets Sold under Agreements to Repurchase
Repurchase liability	279	279
CMO | Within 30 days | Secured Debt
Assets Sold under Agreements to Repurchase
Repurchase liability	$ 279	$ 279