Transfers of financial assets and servicing assets - Changes in MSRs measured using the fair value method - Parenthetical (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Servicing Assets at Fair Value [Line Items]
Servicing asset at fair value amount	$ 114,964	$ 118,109	$ 127,475	$ 128,350
PB
Servicing Assets at Fair Value [Line Items]
Servicing asset at fair value amount	$ 2,000		$ 2,000