Investment Securities (Details 3) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Investment Securities, Available-for-Sale, Amortized Cost
Due in one year or less	$ 54,301
Due after one year through five years	635,456
Due after five years through ten years	3,526,824
Due after ten years	6,386,937
Available-for-sale Securities, Amortized Cost Basis	10,603,518	$ 4,996,970
Investment Securities, Available-for-Sale, Estimated Fair Value
Due in one year or less	54,685
Due after one year through five years	662,377
Due after five years through ten years	3,544,687
Due after ten years	6,432,709
Debt Securities, Available-for-sale	$ 10,694,458	$ 5,235,591