Debt Securities Available for Sale - AFS debt securities in a continuous unrealized loss position (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	$ 2,385,549	$ 287,277
Less than 12 months Gross Unrealized Losses	27,848	5,566
12 months or more Fair Value	8,771,666	12,455,131
12 months or more Gross Unrealized Losses	1,246,136	1,367,947
Total Fair Value	11,157,215	12,742,408
Total Gross Unrealized Losses	1,273,984	1,373,513
US Treasury Securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	2,309,894	244,925
Less than 12 months Gross Unrealized Losses	24,646	5,126
12 months or more Fair Value	3,638,092	6,550,941
12 months or more Gross Unrealized Losses	85,010	257,662
Total Fair Value	5,947,986	6,795,866
Total Gross Unrealized Losses	109,656	262,788
Collateralized Mortgage Obligations - Federal agencies
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	4,878	5,234
Less than 12 months Gross Unrealized Losses	27	35
12 months or more Fair Value	102,160	124,930
12 months or more Gross Unrealized Losses	9,861	11,992
Total Fair Value	107,038	130,164
Total Gross Unrealized Losses	9,888	12,027
Mortgage Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	70,777	37,118
Less than 12 months Gross Unrealized Losses	3,175	405
12 months or more Fair Value	5,031,414	5,779,260
12 months or more Gross Unrealized Losses	1,151,265	1,098,293
Total Fair Value	5,102,191	5,816,378
Total Gross Unrealized Losses	$ 1,154,440	$ 1,098,698