Debt Securities Available for Sale - AFS debt securities in a continuous unrealized loss position (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale
Less than 12 months Fair Value	$ 15,608,338	$ 15,393,537
Less than 12 months Gross Unrealized Losses	1,236,007	273,007
12 months or more Fair Value	8,352,045	596,135
12 months or more Gross Unrealized Losses	1,574,203	25,341
Total Fair Value	23,960,383	15,989,672
Total Gross Unrealized Losses	2,810,210	298,348
US Treasury Securities
Debt Securities, Available-for-sale
Less than 12 months Fair Value	13,636,522	9,590,448
Less than 12 months Gross Unrealized Losses	1,054,349	102,059
12 months or more Fair Value	3,617,608	0
12 months or more Gross Unrealized Losses	402,153	0
Total Fair Value	17,254,130	9,590,448
Total Gross Unrealized Losses	1,456,502	102,059
Collateralized Mortgage Obligations - Federal agencies
Debt Securities, Available-for-sale
Less than 12 months Fair Value	160,914	35,533
Less than 12 months Gross Unrealized Losses	11,468	334
12 months or more Fair Value	12,509	1,084
12 months or more Gross Unrealized Losses	2,301	29
Total Fair Value	173,423	36,617
Total Gross Unrealized Losses	13,769	363
Mortgage Backed Securities
Debt Securities, Available-for-sale
Less than 12 months Fair Value	1,810,828	5,767,556
Less than 12 months Gross Unrealized Losses	170,187	170,614
12 months or more Fair Value	4,721,928	595,051
12 months or more Gross Unrealized Losses	1,169,749	25,312
Total Fair Value	6,532,756	6,362,607
Total Gross Unrealized Losses	1,339,936	$ 195,926
Other
Debt Securities, Available-for-sale
Less than 12 months Fair Value	74
Less than 12 months Gross Unrealized Losses	3
12 months or more Fair Value	0
12 months or more Gross Unrealized Losses	0
Total Fair Value	74
Total Gross Unrealized Losses	$ 3