Debt Securities Available for Sale - AFS debt securities in a continuous unrealized loss position (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale
Less than 12 months Fair Value	$ 18,572,166	$ 15,393,537
Less than 12 months Gross Unrealized Losses	1,172,209	273,007
12 months or more Fair Value	4,842,396	596,135
12 months or more Gross Unrealized Losses	767,814	25,341
Total Fair Value	23,414,562	15,989,672
Total Gross Unrealized Losses	1,940,023	298,348
US Treasury Securities
Debt Securities, Available-for-sale
Less than 12 months Fair Value	15,450,643	9,590,448
Less than 12 months Gross Unrealized Losses	945,084	102,059
12 months or more Fair Value	664,811	0
12 months or more Gross Unrealized Losses	41,286	0
Total Fair Value	16,115,454	9,590,448
Total Gross Unrealized Losses	986,370	102,059
Collateralized Mortgage Obligations - Federal agencies
Debt Securities, Available-for-sale
Less than 12 months Fair Value	148,922	35,533
Less than 12 months Gross Unrealized Losses	8,166	334
12 months or more Fair Value	852	1,084
12 months or more Gross Unrealized Losses	97	29
Total Fair Value	149,774	36,617
Total Gross Unrealized Losses	8,263	363
Mortgage Backed Securities
Debt Securities, Available-for-sale
Less than 12 months Fair Value	2,972,601	5,767,556
Less than 12 months Gross Unrealized Losses	218,959	170,614
12 months or more Fair Value	4,176,733	595,051
12 months or more Gross Unrealized Losses	726,431	25,312
Total Fair Value	7,149,334	6,362,607
Total Gross Unrealized Losses	$ 945,390	$ 195,926