Equity method investment - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Schedule of Equity Method Investments [Line Items]
Technology, trade name and customer relationship intangibles	$ 25,881		$ 27,465
Amortization of Intangible Assets	1,584	$ 1,794
Dividends received from equity method investment	3,601	23,961
Loans	33,162,873		32,676,091
Bankers Healthcare Group, LLC
Schedule of Equity Method Investments [Line Items]
Technology, trade name and customer relationship intangibles	5,900		6,000
Amortization of Intangible Assets	59	87
Accretion income	39	95
Dividends received from equity method investment	3,600	24,000
Payments to Acquire Loans Held-for-investment	0	$ 0
Loans	$ 245,800		$ 263,000