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Fair Value Measurements, Financial Instruments (Details) - USD ($) $ in Thousands | Mar. 31, 2020 | Dec. 31, 2019 | Mar. 31, 2019 | Dec. 31, 2018
--- | --- | --- | --- | ---
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | $ 2,110,585 | $ 1,623,921 |  |
Investment securities, net of allowance | 272,576 | 293,418 |  |
Investment Securities, Gross Amortized Cost | 274,078 | 293,418 |  |
Investment securities, Allowance for Credit Loss | 1,502 | 0 |  |
Available for sale securities | 12,694,277 | 11,269,643 |  |
Fair value option securities | 1,703,238 | 1,098,577 |  |
Residential mortgage loans held for sale | 204,720 | 182,271 |  |
Loans | 22,463,970 | 21,750,987 |  |
Allowance for loan losses | (315,311) | (210,759) | $ (205,340) | $ (207,457)
Loans, net of allowance | 22,148,659 | 21,540,228 |  |
Mortgage servicing rights | 110,828 | 201,886 | 238,193 | 259,254
Derviative contracts, net of cash collateral, Assets, Fair value | 922,716 | 323,375 |  |
Time deposits | 2,232,473 | 2,217,849 |  |
Subordinated debentures | 275,942 | 275,923 |  |
Derivative contracts, net of cash collateral, Liabilities, Fair Value | 1,213,445 | 251,128 |  |
Commercial [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans | 14,795,975 | 14,031,650 |  |
Allowance for loan losses | (213,438) | (118,187) | (103,577) | (102,226)
Commercial real estate [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans | 4,450,085 | 4,433,783 |  |
Allowance for loan losses | (51,461) | (51,805) | $ (58,134) | $ (60,026)
Loans to individuals [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans | 3,217,910 | 2,084,172 |  |
Allowance for loan losses | (50,412) |  |  |
U.S. government agency debentures [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 37,740 | 44,264 |  |
Residential agency mortgage-backed securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 1,922,725 | 1,504,651 |  |
Investment Securities, Gross Amortized Cost | 10,253 | 10,676 |  |
Available for sale securities | 9,259,089 | 8,046,096 |  |
Fair value option securities | 1,703,238 | 1,088,660 |  |
Municipal and other tax-exempt securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 35,513 | 26,196 |  |
Investment Securities, Gross Amortized Cost | 86,212 | 93,653 |  |
Available for sale securities | 24,034 | 1,861 |  |
U.S. Treasury [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Available for sale securities | 917 | 1,600 |  |
Fair value option securities | 0 | 9,917 |  |
Residential non-agency mortgage-backed securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Available for sale securities | 34,866 | 41,609 |  |
Commercial agency mortgage-backed securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Available for sale securities | 3,374,899 | 3,178,005 |  |
Other debt securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 56,329 | 34,726 |  |
Investment Securities, Gross Amortized Cost | 177,613 | 189,089 |  |
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 | 670,500 | 735,836 |  |
Interest-bearing cash and cash equivalents | 302,577 | 522,985 |  |
Trading securities | 2,110,585 | 1,623,921 |  |
Investment securities, net of allowance | 272,576 | 293,418 |  |
Investment Securities, Gross Amortized Cost | 274,078 |  |  |
Investment securities, Allowance for Credit Loss | (1,502) |  |  |
Available for sale securities | 12,694,277 | 11,269,643 |  |
Fair value option securities | 1,703,238 | 1,098,577 |  |
Residential mortgage loans held for sale | 204,720 | 182,271 |  |
Loans | 22,463,970 | 21,750,987 |  |
Allowance for loan losses | (315,311) | (210,759) |  |
Loans, net of allowance | 22,148,659 | 21,540,228 |  |
Mortgage servicing rights | 110,828 | 201,886 |  |
Derviative contracts, net of cash collateral, Assets, Fair value | 922,716 | 323,375 |  |
Deposits with no stated maturity | 27,011,679 | 25,403,319 |  |
Time deposits | 2,232,473 | 2,217,849 |  |
Other borrowed funds | 10,113,322 | 8,345,405 |  |
Subordinated debentures | 275,942 | 275,923 |  |
Derivative contracts, net of cash collateral, Liabilities, Fair Value | 1,213,445 | 251,128 |  |
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans | 14,795,975 | 14,031,650 |  |
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial real estate [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans | 4,450,085 | 4,433,783 |  |
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Residential mortgage [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans |  | 2,084,172 |  |
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Loans to individuals [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans | 3,217,910 |  |  |
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Personal [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans |  | 1,201,382 |  |
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U.S. government agency debentures [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 37,740 | 44,264 |  |
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 | 1,922,725 | 1,504,651 |  |
Investment securities, net of allowance |  | 10,676 |  |
Investment Securities, Gross Amortized Cost | 10,253 |  |  |
Available for sale securities | 9,259,089 | 8,046,096 |  |
Fair value option securities | 1,703,238 | 1,088,660 |  |
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 35,513 | 26,196 |  |
Investment securities, net of allowance |  | 93,653 |  |
Investment Securities, Gross Amortized Cost | 86,212 |  |  |
Available for sale securities | 24,034 | 1,861 |  |
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Asset-backed securities |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 58,278 | 14,084 |  |
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other trading securities |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 56,329 | 34,726 |  |
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 | 917 | 1,600 |  |
Fair value option securities | 0 | 9,917 |  |
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 | 34,866 | 41,609 |  |
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Commercial agency mortgage-backed securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Available for sale securities | 3,374,899 | 3,178,005 |  |
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Other debt securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investment securities, net of allowance |  | 189,089 |  |
Investment Securities, Gross Amortized Cost | 177,613 |  |  |
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 | 670,500 | 735,836 |  |
Interest-bearing cash and cash equivalents | 302,577 | 522,985 |  |
Trading securities | 2,110,585 | 1,623,921 |  |
Investment securities, net of allowance | 296,402 | 314,402 |  |
Investment Securities, Gross Amortized Cost | 296,402 |  |  |
Investment securities, Allowance for Credit Loss | 0 |  |  |
Available for sale securities | 12,694,277 | 11,269,643 |  |
Fair value option securities | 1,703,238 | 1,098,577 |  |
Residential mortgage loans held for sale | 204,720 | 182,271 |  |
Loans | 22,440,081 | 21,689,329 |  |
Allowance for loan losses | 0 | 0 |  |
Loans, net of allowance | 22,440,081 | 21,689,329 |  |
Mortgage servicing rights | 110,828 | 201,886 |  |
Derviative contracts, net of cash collateral, Assets, Fair value | 922,716 | 323,375 |  |
Deposits with no stated maturity | 27,011,679 | 25,403,319 |  |
Time deposits | 2,257,136 | 2,212,467 |  |
Other borrowed funds | 10,110,076 | 8,315,860 |  |
Subordinated debentures | 263,674 | 284,627 |  |
Derivative contracts, net of cash collateral, Liabilities, Fair Value | 1,213,445 | 251,128 |  |
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans | 14,733,781 | 13,966,221 |  |
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial real estate [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans | 4,469,491 | 4,422,717 |  |
Estimate of Fair Value, Fair Value Disclosure [Member] | Residential mortgage [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans |  | 2,098,093 |  |
Estimate of Fair Value, Fair Value Disclosure [Member] | Loans to individuals [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans | 3,236,809 |  |  |
Estimate of Fair Value, Fair Value Disclosure [Member] | Personal [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans |  | 1,202,298 |  |
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 37,740 | 44,264 |  |
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 | 1,922,725 | 1,504,651 |  |
Investment securities, net of allowance |  | 11,164 |  |
Investment Securities, Gross Amortized Cost | 11,099 |  |  |
Available for sale securities | 9,259,089 | 8,046,096 |  |
Fair value option securities | 1,703,238 | 1,088,660 |  |
Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 35,513 | 26,196 |  |
Investment securities, net of allowance |  | 96,897 |  |
Investment Securities, Gross Amortized Cost | 89,359 |  |  |
Available for sale securities | 24,034 | 1,861 |  |
Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed securities |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 58,278 | 14,084 |  |
Estimate of Fair Value, Fair Value Disclosure [Member] | Other trading securities |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 56,329 | 34,726 |  |
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 | 917 | 1,600 |  |
Fair value option securities | 0 | 9,917 |  |
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 | 34,866 | 41,609 |  |
Estimate of Fair Value, Fair Value Disclosure [Member] | Commercial agency mortgage-backed securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Available for sale securities | 3,374,899 | 3,178,005 |  |
Estimate of Fair Value, Fair Value Disclosure [Member] | Other debt securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Investment securities, net of allowance |  | 206,341 |  |
Investment Securities, Gross Amortized Cost | 195,944 |  |  |
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 | 670,500 | 735,836 |  |
Interest-bearing cash and cash equivalents | 302,577 | 522,985 |  |
Trading securities | 0 | 0 |  |
Investment securities, net of allowance | 0 | 0 |  |
Investment Securities, Gross Amortized Cost | 0 |  |  |
Investment securities, Allowance for Credit Loss | 0 |  |  |
Available for sale securities | 917 | 1,600 |  |
Fair value option securities | 0 | 9,917 |  |
Residential mortgage loans held for sale | 0 | 0 |  |
Loans | 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 | 83,268 | 8,944 |  |
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 | 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 | 0 | 0 |  |
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential mortgage [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans |  | 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 | 0 |  |  |
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Personal [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans |  | 0 |  |
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures [Member] |  |  |  |
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] | Residential agency mortgage-backed securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 0 | 0 |  |
Investment securities, net of allowance |  | 0 |  |
Investment Securities, Gross Amortized Cost | 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 and other tax-exempt securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 0 | 0 |  |
Investment securities, net of allowance |  | 0 |  |
Investment Securities, Gross Amortized Cost | 0 |  |  |
Available for sale securities | 0 | 0 |  |
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed 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] | 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 | 917 | 1,600 |  |
Fair value option securities | 0 | 9,917 |  |
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] |  |  |  |
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] |  |  |  |
Investment securities, net of allowance |  | 0 |  |
Investment Securities, Gross Amortized Cost | 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 | 2,110,585 | 1,623,921 |  |
Investment securities, net of allowance | 109,005 | 116,267 |  |
Investment Securities, Gross Amortized Cost | 109,005 |  |  |
Investment securities, Allowance for Credit Loss | 0 |  |  |
Available for sale securities | 12,692,888 | 11,267,571 |  |
Fair value option securities | 1,703,238 | 1,088,660 |  |
Residential mortgage loans held for sale | 195,146 | 173,958 |  |
Loans | 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 | 839,448 | 314,431 |  |
Deposits with no stated maturity | 0 | 0 |  |
Time deposits | 0 | 0 |  |
Other borrowed funds | 0 | 0 |  |
Subordinated debentures | 263,674 | 284,627 |  |
Derivative contracts, net of cash collateral, Liabilities, Fair Value | 1,213,445 | 251,128 |  |
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 | 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 | 0 | 0 |  |
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential mortgage [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans |  | 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 | 0 |  |  |
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Personal [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans |  | 0 |  |
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 37,740 | 44,264 |  |
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 | 1,922,725 | 1,504,651 |  |
Investment securities, net of allowance |  | 11,164 |  |
Investment Securities, Gross Amortized Cost | 11,099 |  |  |
Available for sale securities | 9,259,089 | 8,046,096 |  |
Fair value option securities | 1,703,238 | 1,088,660 |  |
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal and other tax-exempt securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 35,513 | 26,196 |  |
Investment securities, net of allowance |  | 96,897 |  |
Investment Securities, Gross Amortized Cost | 89,359 |  |  |
Available for sale securities | 24,034 | 1,861 |  |
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed securities |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 58,278 | 14,084 |  |
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 | 56,329 | 34,726 |  |
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 option 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 | 34,866 | 41,609 |  |
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] |  |  |  |
Available for sale securities | 3,374,899 | 3,178,005 |  |
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] |  |  |  |
Investment securities, net of allowance |  | 8,206 |  |
Investment Securities, Gross Amortized Cost | 8,547 |  |  |
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 |  |
Investment securities, net of allowance | 187,397 | 198,135 |  |
Investment Securities, Gross Amortized Cost | 187,397 |  |  |
Investment securities, Allowance for Credit Loss | 0 |  |  |
Available for sale securities | 472 | 472 |  |
Fair value option securities | 0 | 0 |  |
Residential mortgage loans held for sale | 9,574 | 8,313 |  |
Loans | 22,440,081 | 21,689,329 |  |
Allowance for loan losses | 0 | 0 |  |
Loans, net of allowance | 22,440,081 | 21,689,329 |  |
Mortgage servicing rights | 110,828 | 201,886 |  |
Derviative contracts, net of cash collateral, Assets, Fair value | 0 | 0 |  |
Deposits with no stated maturity | 27,011,679 | 25,403,319 |  |
Time deposits | 2,257,136 | 2,212,467 |  |
Other borrowed funds | 10,110,076 | 8,315,860 |  |
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 | 14,733,781 | 13,966,221 |  |
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 | 4,469,491 | 4,422,717 |  |
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Residential mortgage [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans |  | 2,098,093 |  |
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 | 3,236,809 |  |  |
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Personal [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Loans |  | 1,202,298 |  |
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. government agency debentures [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 |  |
Investment securities, net of allowance |  | 0 |  |
Investment Securities, Gross Amortized Cost | 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 and other tax-exempt securities [Member] |  |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |  |
Trading securities | 0 | 0 |  |
Investment securities, net of allowance |  | 0 |  |
Investment Securities, Gross Amortized Cost | 0 |  |  |
Available for sale securities | 0 | 0 |  |
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed 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] | 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 option 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] |  |  |  |
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] |  |  |  |
Investment securities, net of allowance |  | 198,135 |  |
Investment Securities, Gross Amortized Cost | 187,397 |  |  |
Available for sale securities | $ 472 | $ 472 |  |

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