Other assets and other liabilities - Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Other Assets And Other Liabilities [Abstract]
Prepaid expenses	$ 12,371	$ 7,332
Software	578	1,147
Mortgage lending receivable	12,078	14,100
Derivatives	27,384	68,938
Deferred tax asset	0	16,396
FHLB lender risk account receivable	17,130	12,729
Pledged collateral on derivative instruments	57,868	57,985
Other assets	44,827	23,512
Other assets	$ 172,236	$ 202,139