Investment Securities - Schedule of Maturities of Investment Securities Available-for-Sale and Held-to-Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Available for Sale Amortized Cost
Within one year	$ 0	$ 0
After one year but within five years	103,960	37,852
After five years but within ten years	204,186	239,845
After ten years	4,941,736	2,172,568
Amortized Cost	5,249,882	2,450,265
Available for Sale Fair Value
Within one year	0	0
After one year but within five years	107,009	39,985
After five years but within ten years	204,289	251,874
After ten years	4,894,013	2,237,198
Fair Value	5,205,311	2,529,057
Held to Maturity, Amortized Cost
Within one year	232	1,144
After one year but within five years	2,675	972
After five years but within ten years	44,137	35,967
After ten years	43,602	73,664
Amortized Cost	90,646	111,747
Held to Maturity, Fair Value
Within one year	234	1,154
After one year but within five years	2,736	990
After five years but within ten years	45,404	37,317
After ten years	45,757	76,960
Fair Value	$ 94,131	$ 116,421