Transfers of financial assets and servicing assets - Changes in MSRs measured using the fair value method - Parenthetical (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Servicing Assets at Fair Value [Line Items]
Servicing asset at fair value amount	$ 108,827	$ 118,109	$ 119,030	$ 128,350
PB
Servicing Assets at Fair Value [Line Items]
Servicing asset at fair value amount	$ 1,800		$ 1,900