Investment Securities - Maturities of Investment Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Held-to-maturity, amortized cost, one year or less	$ 2,639
Held-to-maturity, amortized cost, after one through five years	7,822
Held-to-maturity, amortized cost, after five through ten years	352,450
Held-to-maturity, amortized cost, after ten years	2,207,402
Held-to-maturity, amortized cost, securities not due on a single maturity date	1,190,781
Amortized Cost	3,761,094	$ 1,530,500
Held-to-maturity, fair value, one year or less	2,635
Held-to-maturity, fair value, after one through five years	7,660
Held-to-maturity, fair value, after five through ten years	310,335
Held-to-maturity, fair value, after ten years	1,670,555
Held-to-maturity, fair value, securities not due on a single maturity date	1,072,048
Held-to-maturity, fair value, total	3,063,233	1,517,378
Available-for-sale, amortized cost, one year or less	12,368
Available-for-sale, amortized cost, after one through five years	184,524
Available-for-sale, amortized cost, after five through ten years	258,451
Available-for-sale, amortized cost, after ten years	1,066,291
Available-for-sale, amortized cost, securities not due on a single maturity date	2,809,319
Available-for-sale, amortized cost, other securities (no maturity)	460
Amortized Cost	4,331,413	7,130,861
Available-for-sale, fair value, one year or less	12,169
Available-for-sale, fair value, after one through five years	176,836
Available-for-sale, fair value, after five through ten years	238,768
Available-for-sale, fair value, after ten years	881,720
Available-for-sale, fair value, securities not due on a single maturity date	2,542,901
Available-for-sale, fair value, other securities (no maturity)	460
Available-for-sale, fair value, total	$ 3,852,854	$ 7,113,545