Fair Value Measurements, Fair Value Of Financial Instruments as Measured On a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021	Dec. 31, 2020
Assets [Abstract]
Trading securities	$ 5,193,505		$ 4,464,161
Available for sale securities	12,286,681		11,493,860
Fair value option securities	20,671		296,590
Mortgage servicing rights	293,884		277,608		$ 163,198	$ 101,172
Derivative contracts, net of cash margin, Assets, Fair Value	410,304		880,343
Liabilities [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	587,473		554,900
U.S. government securities [Member]
Assets [Abstract]
Trading securities	10,959		9,823
Residential agency mortgage-backed securities [Member]
Assets [Abstract]
Trading securities	5,105,137		4,406,848
Available for sale securities	6,834,720		5,814,496
Fair value option securities	20,671		296,590
Municipal securities [Member]
Assets [Abstract]
Trading securities	37,413		21,484
Available for sale securities	502,833		624,500
U.S. Treasury [Member]
Assets [Abstract]
Available for sale securities	925		898
Residential non-agency mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	799,877		577,576
Commercial agency mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	4,147,853		4,475,917
Other debt securities [Member]
Assets [Abstract]
Trading securities	39,996		26,006
Available for sale securities	473		473
Fair Value, Recurring [Member]
Assets [Abstract]
Trading securities	5,193,505		4,464,161
Available for sale securities	12,286,681		11,493,860
Residential mortgage loans held for sale	56,935	[1]	75,272	[2]
Mortgage servicing rights	293,884	[3]	277,608	[4]
Derivative contracts, net of cash margin, Assets, Fair Value	410,304	[5]	880,343	[6]
Liabilities [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	587,473	[5]	554,900	[6]
Fair Value, Recurring [Member] | U.S. government securities [Member]
Assets [Abstract]
Trading securities	10,959		9,823
Fair Value, Recurring [Member] | Residential agency mortgage-backed securities [Member]
Assets [Abstract]
Trading securities	5,105,137		4,406,848
Available for sale securities	6,834,720		5,814,496
Fair value option securities	20,671		296,590
Fair Value, Recurring [Member] | Municipal securities [Member]
Assets [Abstract]
Trading securities	37,413		21,484
Available for sale securities	502,833		624,500
Fair Value, Recurring [Member] | U.S. Treasury [Member]
Assets [Abstract]
Available for sale securities	925		898
Fair Value, Recurring [Member] | Residential non-agency mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	799,877		577,576
Fair Value, Recurring [Member] | Commercial agency mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	4,147,853		4,475,917
Fair Value, Recurring [Member] | Other debt securities [Member]
Assets [Abstract]
Available for sale securities	473		473
Fair Value, Recurring [Member] | Other trading securities [Member]
Assets [Abstract]
Trading securities	39,996		26,006
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets [Abstract]
Trading securities	9,017		4,970
Available for sale securities	925		898
Residential mortgage loans held for sale	0	[1]	0	[2]
Mortgage servicing rights	0	[3]	0	[4]
Derivative contracts, net of cash margin, Assets, Fair Value	0	[5]	2,110	[6]
Liabilities [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	2,607	[5]	16	[6]
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. government securities [Member]
Assets [Abstract]
Trading securities	9,017		4,970
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Residential agency mortgage-backed securities [Member]
Assets [Abstract]
Trading securities	0		0
Available for sale securities	0		0
Fair value option securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal securities [Member]
Assets [Abstract]
Trading securities	0		0
Available for sale securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Treasury [Member]
Assets [Abstract]
Available for sale securities	925		898
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Residential non-agency mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial agency mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other debt securities [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other trading securities [Member]
Assets [Abstract]
Trading securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets [Abstract]
Trading securities	5,184,488		4,459,191
Available for sale securities	12,285,283		11,492,489
Residential mortgage loans held for sale	49,749	[1]	68,054	[2]
Mortgage servicing rights	0	[3]	0	[4]
Derivative contracts, net of cash margin, Assets, Fair Value	410,304	[5]	878,233	[6]
Liabilities [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	584,866	[5]	554,884	[6]
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. government securities [Member]
Assets [Abstract]
Trading securities	1,942		4,853
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential agency mortgage-backed securities [Member]
Assets [Abstract]
Trading securities	5,105,137		4,406,848
Available for sale securities	6,834,720		5,814,496
Fair value option securities	20,671		296,590
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal securities [Member]
Assets [Abstract]
Trading securities	37,413		21,484
Available for sale securities	502,833		624,500
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Treasury [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential non-agency mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	799,877		577,576
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial agency mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	4,147,853		4,475,917
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other debt securities [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other trading securities [Member]
Assets [Abstract]
Trading securities	39,996		26,006
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets [Abstract]
Trading securities	0		0
Available for sale securities	473		473
Residential mortgage loans held for sale	7,186	[1]	7,218	[2]
Mortgage servicing rights	293,884	[3]	277,608	[4]
Derivative contracts, net of cash margin, Assets, Fair Value	$ 0	[5]	$ 0	[6]
Liquidity Discount on Mortgage Loans Qualifying for Sale to US Govt Agencies	77.74%		77.55%
Liabilities [Abstract]
Derivative contracts, net of cash margin, Liabilities, Fair Value	$ 0	[5]	$ 0	[6]
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. government securities [Member]
Assets [Abstract]
Trading securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Residential agency mortgage-backed securities [Member]
Assets [Abstract]
Trading securities	0		0
Available for sale securities	0		0
Fair value option securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal securities [Member]
Assets [Abstract]
Trading securities	0		0
Available for sale securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Treasury [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Residential non-agency mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial agency mortgage-backed securities [Member]
Assets [Abstract]
Available for sale securities	0		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other debt securities [Member]
Assets [Abstract]
Available for sale securities	473		473
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other trading securities [Member]
Assets [Abstract]
Trading securities	$ 0		$ 0

[1] Residential mortgage loans held for sale measured at fair value on a recurring basis using significant unobservable inputs (Level 3) consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards and are valued at 77.74% of the unpaid principal balance.

[2] Residential mortgage loans held for sale measured at fair value on a recurring basis using significant unobservable inputs (Level 3) consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards and are valued at 77.55% of the unpaid principal balance.

[3] A reconciliation of the beginning and ending fair value of mortgage servicing rights and disclosures of significant assumptions used to determine fair value are presented in Note 7, Mortgage Banking Activities.

[4] A reconciliation of the beginning and ending fair value of mortgage servicing rights and disclosures of significant assumptions used to determine fair value are presented in Note 7, Mortgage Banking Activities.

[5] See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts in asset and liability positions that were valued based on quoted prices in active markets for identical instruments (Level 1) are primarily exchange-traded interest rate derivative contracts held for trading purposes.

[6] See Note 3 for detail of fair value of derivative contracts by contract type. Derivative contracts in asset and liability positions that were valued based on quoted prices in active markets for identical instruments (Level 1) are primarily exchange-traded interest rate derivative contracts held for trading purposes.