Investment Securities Available for Sale (Schedule of Gross Unrealized Losses on Investment Securities and Fair Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	$ 3,871,993	$ 6,596,065
Less than 12 months, gross unrealized losses	(433,377)	(96,227)
12 months or longer, fair value	5,690,956	1,523,383
12 months or longer, gross unrealized losses	(1,255,812)	(43,377)
Total, fair value	9,562,949	8,119,448
Total, gross unrealized losses	(1,689,189)	(139,604)
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	359,580	49,648
Less than 12 months, gross unrealized losses	(31,435)	(379)
12 months or longer, fair value	83,875	47,590
12 months or longer, gross unrealized losses	(15,999)	(2,248)
Total, fair value	443,455	97,238
Total, gross unrealized losses	(47,434)	(2,627)
U.S. Government agency securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	48,311	21,760
Less than 12 months, gross unrealized losses	(3,842)	(387)
12 months or longer, fair value	0	0
12 months or longer, gross unrealized losses	0	0
Total, fair value	48,311	21,760
Total, gross unrealized losses	(3,842)	(387)
Mortgage-backed securities issued by U.S. Government agencies
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	220,484	461,078
Less than 12 months, gross unrealized losses	(12,059)	(5,858)
12 months or longer, fair value	502,128	244,264
12 months or longer, gross unrealized losses	(106,064)	(5,606)
Total, fair value	722,612	705,342
Total, gross unrealized losses	(118,123)	(11,464)
Mortgage-backed securities issued by U.S. Government sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	2,371,537	5,729,476
Less than 12 months, gross unrealized losses	(331,934)	(82,671)
12 months or longer, fair value	4,461,403	643,758
12 months or longer, gross unrealized losses	(1,009,768)	(19,409)
Total, fair value	6,832,940	6,373,234
Total, gross unrealized losses	(1,341,702)	(102,080)
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	171,343	187,431
Less than 12 months, gross unrealized losses	(13,315)	(3,981)
12 months or longer, fair value	513,165	504,238
12 months or longer, gross unrealized losses	(93,487)	(12,745)
Total, fair value	684,508	691,669
Total, gross unrealized losses	(106,802)	(16,726)
Commercial mortgage-backed securities issued by U.S. Government agencies or sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	682,610	146,672
Less than 12 months, gross unrealized losses	(40,538)	(2,951)
12 months or longer, fair value	130,385	83,533
12 months or longer, gross unrealized losses	(30,494)	(3,369)
Total, fair value	812,995	230,205
Total, gross unrealized losses	(71,032)	$ (6,320)
Corporate debt securities and other debt securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	18,128
Less than 12 months, gross unrealized losses	(254)
12 months or longer, fair value	0
12 months or longer, gross unrealized losses	0
Total, fair value	18,128
Total, gross unrealized losses	$ (254)