Mortgage banking activities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Mortgage servicing rights fair value adjustments			$ (5,384)	$ (8,342)
Total trading account profit	$ 277	$ 35	638	413
Total mortgage banking activities	5,723	2,316	10,083	9,716
Mortgage banking activities
Mortgage servicing fees	7,602	8,369	15,353	17,058
Mortgage servicing rights fair value adjustments	(1,945)	(6,216)	(5,384)	(7,592)
Total mortgage servicing fees, net of fair value adjustments	5,657	2,153	9,969	9,466
Net gain (loss) on sale of loans, including valuation on loans held-for-sale	2	(61)	76	202
Unrealized gains on outstanding derivative positions	56	246	157	115
Realized gains on closed derivative positions	9	111	12	167
Total trading account profit	65	357	169	282
Losses on repurchased loans, including interest advances	(1)	(133)	(131)	(234)
Total mortgage banking activities	$ 5,723	$ 2,316	$ 10,083	$ 9,716