Fair Value Measurements, Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2022		Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	$ 2,859,444			$ 9,136,813
Debt Securities, Held-to-maturity, gross	2,903,116			210,999
Investment securities, Allowance for Credit Loss	(717)	[1]		(555)
Investment Securities, Amortized Cost, After Allowance for Credit Loss	2,902,399			210,444
Available for sale securities	10,152,663			13,157,817
Fair value option securities	37,927			43,770
Residential mortgage loans held for sale	182,726			192,295
Loans and Leases Receivable, Gross	21,291,148			20,205,680
Allowance for loan losses	(241,114)			(256,421)
Loans, net of allowance	21,050,034			19,949,259
Mortgage servicing rights	270,312		$ 209,563	163,198	$ 117,629	$ 132,915	$ 101,172
Derviative contracts, net of cash collateral, Assets, Fair value	1,992,977			1,097,297
Time deposits	1,369,599			1,704,328
Subordinated debentures	131,223			131,226
Derivative contracts, net of cash collateral, Liabilities, Fair Value	214,576			275,625
Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	13,578,697			12,506,465
Allowance for loan losses	(137,562)			(162,056)
Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	4,106,148			3,831,325
Allowance for loan losses	(62,997)			(58,553)
Paycheck Protection Program [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	43,140			276,341
Allowance for loan losses	0			0
Loans to individuals [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	3,563,163			3,591,549
Allowance for loan losses	(40,555)			(35,812)
U.S. government securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	8,357			23,610
Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	2,807,950			9,068,900
Debt Securities, Held-to-maturity, gross	2,709,094			6,939
Available for sale securities	4,913,245			8,006,616
Fair value option securities	37,927			43,770
Municipal securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	18,825			25,783
Debt Securities, Held-to-maturity, gross	175,974			203,772
Available for sale securities	638,305			508,365
U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	927			1,000
Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	519,613			24,339
Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity, gross	17,260
Available for sale securities	4,080,101			4,617,025
Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	24,312			18,520
Debt Securities, Held-to-maturity, gross	788			288
Available for sale securities	472			472
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	1,313,563			712,067
Interest-bearing cash and cash equivalents	723,787			2,125,343
Trading securities	2,859,444			9,136,813
Debt Securities, Held-to-maturity, gross	2,638,062			210,999
Investment securities, Allowance for Credit Loss	(717)			(555)
Investment Securities, Amortized Cost, After Allowance for Credit Loss	2,637,345			210,444
Available for sale securities	10,152,663			13,157,817
Residential mortgage loans held for sale	182,726			192,295
Loans and Leases Receivable, Gross	21,291,148			20,205,680
Allowance for loan losses	(241,114)			(256,421)
Loans, net of allowance	21,050,034			19,949,259
Mortgage servicing rights	270,312			163,198
Derviative contracts, net of cash collateral, Assets, Fair value	1,992,977			1,097,297
Deposits with no stated maturity	37,249,319			39,537,731
Time deposits	1,369,599			1,704,328
Other borrowed funds	712,535			2,363,202
Subordinated debentures	131,223			131,226
Derivative contracts, net of cash collateral, Liabilities, Fair Value	214,576			275,625
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	13,578,697			12,506,465
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	4,106,148			3,831,325
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Paycheck Protection Program [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	43,140			276,341
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Loans to individuals [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	3,563,163			3,591,549
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. government securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	8,357			23,610
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	2,807,950			9,068,900
Debt Securities, Held-to-maturity, gross	2,445,845			6,939
Available for sale securities	4,913,245			8,006,616
Fair value option securities	37,927			43,770
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Municipal securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	18,825			25,783
Debt Securities, Held-to-maturity, gross	175,974			203,772
Available for sale securities	638,305			508,365
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	24,312			18,520
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	927			1,000
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	519,613			24,339
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity, gross	15,455
Available for sale securities	4,080,101			4,617,025
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity, gross	788			288
Available for sale securities	472			472
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	1,313,563			712,067
Interest-bearing cash and cash equivalents	723,787			2,125,343
Trading securities	2,859,444			9,136,813
Debt Securities, Held-to-maturity, gross	2,607,757			231,395
Investment securities, Allowance for Credit Loss	0			0
Investment Securities, Amortized Cost, After Allowance for Credit Loss	2,607,757			231,395
Available for sale securities	10,152,663			13,157,817
Residential mortgage loans held for sale	182,726			192,295
Loans and Leases Receivable, Gross	20,791,911			20,039,221
Allowance for loan losses	0			0
Loans, net of allowance	20,791,911			20,039,221
Mortgage servicing rights	270,312			163,198
Derviative contracts, net of cash collateral, Assets, Fair value	1,992,977			1,097,297
Deposits with no stated maturity	37,249,319			39,537,731
Time deposits	1,346,175			1,703,886
Other borrowed funds	710,004			2,360,746
Subordinated debentures	130,136			141,761
Derivative contracts, net of cash collateral, Liabilities, Fair Value	214,576			275,625
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	13,334,931			12,395,664
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	3,991,292			3,786,767
Estimate of Fair Value, Fair Value Disclosure [Member] | Paycheck Protection Program [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	43,140			269,912
Estimate of Fair Value, Fair Value Disclosure [Member] | Loans to individuals [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	3,422,548			3,586,878
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	8,357			23,610
Estimate of Fair Value, Fair Value Disclosure [Member] | Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	2,807,950			9,068,900
Debt Securities, Held-to-maturity, gross	2,410,926			7,500
Available for sale securities	4,913,245			8,006,616
Fair value option securities	37,927			43,770
Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	18,825			25,783
Debt Securities, Held-to-maturity, gross	180,783			223,609
Available for sale securities	638,305			508,365
Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	24,312			18,520
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	927			1,000
Estimate of Fair Value, Fair Value Disclosure [Member] | Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	519,613			24,339
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity, gross	15,279
Available for sale securities	4,080,101			4,617,025
Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity, gross	769			286
Available for sale securities	472			472
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	1,313,563			712,067
Interest-bearing cash and cash equivalents	723,787			2,125,343
Trading securities	8,357			4,999
Debt Securities, Held-to-maturity, gross	0			0
Investment securities, Allowance for Credit Loss	0			0
Investment Securities, Amortized Cost, After Allowance for Credit Loss	0			0
Available for sale securities	927			1,000
Residential mortgage loans held for sale	0			0
Loans and Leases Receivable, Gross	0			0
Allowance for loan losses	0			0
Loans, net of allowance	0			0
Mortgage servicing rights	0			0
Derviative contracts, net of cash collateral, Assets, Fair value	0			8,331
Deposits with no stated maturity	0			0
Time deposits	0			0
Other borrowed funds	0			0
Subordinated debentures	0			0
Derivative contracts, net of cash collateral, Liabilities, Fair Value	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Paycheck Protection Program [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Loans to individuals [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	8,357			4,999
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Debt Securities, Held-to-maturity, gross	0			0
Available for sale securities	0			0
Fair value option securities	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Debt Securities, Held-to-maturity, gross	0			0
Available for sale securities	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	927			1,000
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity, gross	0
Available for sale securities	0			0
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity, gross	0			0
Available for sale securities	0			0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	0			0
Interest-bearing cash and cash equivalents	0			0
Trading securities	2,851,087			9,131,814
Debt Securities, Held-to-maturity, gross	2,468,472			65,484
Investment securities, Allowance for Credit Loss	0			0
Investment Securities, Amortized Cost, After Allowance for Credit Loss	2,468,472			65,484
Available for sale securities	10,151,264			13,156,345
Residential mortgage loans held for sale	174,600			185,969
Loans and Leases Receivable, Gross	0			0
Allowance for loan losses	0			0
Loans, net of allowance	0			0
Mortgage servicing rights	0			0
Derviative contracts, net of cash collateral, Assets, Fair value	1,992,977			1,088,966
Deposits with no stated maturity	0			0
Time deposits	0			0
Other borrowed funds	0			0
Subordinated debentures	130,136			141,761
Derivative contracts, net of cash collateral, Liabilities, Fair Value	214,576			275,625
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	0			0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	0			0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Paycheck Protection Program [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	0			0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Loans to individuals [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	0			0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			18,611
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	2,807,950			9,068,900
Debt Securities, Held-to-maturity, gross	2,410,926			7,500
Available for sale securities	4,913,245			8,006,616
Fair value option securities	37,927			43,770
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	18,825			25,783
Debt Securities, Held-to-maturity, gross	41,498			57,698
Available for sale securities	638,305			508,365
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	24,312			18,520
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	519,613			24,339
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity, gross	15,279
Available for sale securities	4,080,101			4,617,025
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity, gross	769			286
Available for sale securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	0			0
Interest-bearing cash and cash equivalents	0			0
Trading securities	0			0
Debt Securities, Held-to-maturity, gross	139,285			165,911
Investment securities, Allowance for Credit Loss	0			0
Investment Securities, Amortized Cost, After Allowance for Credit Loss	139,285			165,911
Available for sale securities	472			472
Residential mortgage loans held for sale	8,126			6,326
Loans and Leases Receivable, Gross	20,791,911			20,039,221
Allowance for loan losses	0			0
Loans, net of allowance	20,791,911			20,039,221
Mortgage servicing rights	270,312			163,198
Derviative contracts, net of cash collateral, Assets, Fair value	0			0
Deposits with no stated maturity	37,249,319			39,537,731
Time deposits	1,346,175			1,703,886
Other borrowed funds	710,004			2,360,746
Subordinated debentures	0			0
Derivative contracts, net of cash collateral, Liabilities, Fair Value	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	13,334,931			12,395,664
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	3,991,292			3,786,767
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Paycheck Protection Program [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	43,140			269,912
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Loans to individuals [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Gross	3,422,548			3,586,878
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Debt Securities, Held-to-maturity, gross	0			0
Available for sale securities	0			0
Fair value option securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Debt Securities, Held-to-maturity, gross	139,285			165,911
Available for sale securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Treasury [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential non-agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial agency mortgage-backed securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity, gross	0
Available for sale securities	0			0
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity, gross	0			0
Available for sale securities	$ 472			$ 472

[1] Carrying value includes $265 million of net unrealized loss which remains in Accumulated other comprehensive income ("AOCI") in the Consolidated Balance Sheets related to certain securities transferred from the Available for Sale securities portfolio to the Investment securities portfolio as discussed in greater detail following.