Equity method investment - Financial Position and Results of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Schedule of Equity Method Investments [Line Items]
Total assets	$ 48,894,196		$ 47,959,883
Total liabilities	42,790,345		41,924,095
Liabilities and Equity	48,894,196		47,959,883
Bankers Healthcare Group, LLC
Schedule of Equity Method Investments [Line Items]
Total assets	3,948,225		4,304,835
Total liabilities	3,369,034		3,749,821
Equity interests	579,191		555,014
Liabilities and Equity	3,948,225		$ 4,304,835
Revenues	277,260	$ 301,951
Net income	$ 32,803	$ 46,643