Investment Securities - Investments in Debt and Equity Securities Reported Less than Historical Cost (Details) - Investments reported at less than historical cost - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Schedule of Investments [Line Items]
Historical cost	$ 1,655,027	$ 658,858
Fair value	1,535,489	645,218
Gross unrealized losses	$ 119,538	$ 13,640
Percent of the Corporation's investments available for sale	71.00%	27.50%