Fair Value Measurements, Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	$ 2,677,511	$ 4,332,015
Equity securities with readily determinable fair values, Fair Value	6,000	5,000
Servicing Asset at Fair Value, Amount	76,570	57,158
Fair Value, Inputs, Level 1
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	113,109	122,957
Equity securities with readily determinable fair values, Fair Value	5,502	4,810
Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	2,564,402	4,209,058
Fair Value, Inputs, Level 3
Assets, Fair Value Disclosure [Abstract]
Trading assets		30
Servicing Asset at Fair Value, Amount	76,570	57,259
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	113	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Assets, Fair Value Disclosure [Abstract]
Trading assets	0	30
US Treasury Securities
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	113,109	122,957
US Treasury Securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	113,109	122,957
Agency Securities
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	13,959	14,897
Agency Securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	13,959	14,897
US States and Political Subdivisions Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	358,842	400,457
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	358,842	400,457
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	0	329,724
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	0	329,724
Residential Related Securities | FNMA/FHLMC
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	1,811,603	2,691,879
Residential Related Securities | FNMA/FHLMC | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	1,811,603	2,691,879
Residential Related Securities | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	86,238	67,780
Residential Related Securities | Government National Mortgage Association (GNMA) [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	86,238	67,780
Commercial mortgage-related securities | FNMA/FHLMC
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	18,606	350,623
Commercial mortgage-related securities | FNMA/FHLMC | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	18,606	350,623
Commercial mortgage-related securities | Government National Mortgage Association (GNMA) [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	105,680	166,799
Commercial mortgage-related securities | Government National Mortgage Association (GNMA) [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	105,680	166,799
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	161,264	177,325
Federal Family Education Loan Program (FFELP) Guaranteed Loans [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	161,264	177,325
US Government-sponsored Enterprises Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	5,281	6,580
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	5,281	6,580
Other Debt securities
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	2,929	2,994
Other Debt securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	2,929	2,994
Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	113,109	122,957
Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale	2,564,402	4,209,058
Other Debt And Other Equity Securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Assets, Fair Value Disclosure [Abstract]
Equity securities with readily determinable fair values, Fair Value	5,502	4,810
Residential loans held for sale | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Trading assets	42,676	136,638
Interest rate-related instruments — customer and mirror, net | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Trading assets	34,184	83,626
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	173,955	26,231
Foreign currency exchange forwards | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Trading assets	4,190	5,490
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	3,764	5,441
Commodity contracts | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Trading assets	0	1,264
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	0	1,248
Interest Rate Lock Commitments [Member] | Fair Value, Inputs, Level 3
Assets, Fair Value Disclosure [Abstract]
Trading assets	986	2,617
Interest Rate Lock Commitments [Member] | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Assets, Fair Value Disclosure [Abstract]
Trading assets	986	2,617
TBA securities | Fair Value, Inputs, Level 3
Assets, Fair Value Disclosure [Abstract]
Trading assets	$ 47	$ 0