Quarterly report pursuant to Section 13 or 15(d)

Fair Values of Assets and Liabilities (Recurring basis) (Details)

v3.2.0.727
Fair Values of Assets and Liabilities (Recurring basis) (Details) - USD ($)
$ in Thousands
Jun. 30, 2015
Dec. 31, 2014
Assets measured at fair value on a recurring basis    
Trading account securities $ 59,146 $ 42,191
Available-for-sale and other securities 10,254,871 9,384,670
Liabilities measured at fair value on a recurring basis    
Short-term borrowings (16,037) (2,295)
Level 2 [Member]    
Liabilities measured at fair value on a recurring basis    
Short-term borrowings (16,037)  
Recurring Basis [Member]    
Assets measured at fair value on a recurring basis    
Mortgage loans held for sale 453,489 354,888
Trading account securities 59,146 42,191
Available-for-sale and other securities 9,922,776 9,053,111
Automobile loans 3,998 10,590
MSR's 20,681 22,786
Derivative assets 377,629 352,642
Liabilities measured at fair value on a recurring basis    
Derivatives 293,144 284,255
Other liabilities 16,037  
Recurring Basis [Member] | U.S. Treasury [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 0 0
Available-for-sale and other securities 12,600 5,452
Recurring Basis [Member] | Federal agencies - mortgage backed securities [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 0 0
Available-for-sale and other securities 6,161,270 5,322,701
Recurring Basis [Member] | Federal agencies: Other agencies [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 8,506 2,857
Available-for-sale and other securities 329,184 351,543
Recurring Basis [Member] | Municipal securities [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 4,182 5,098
Available-for-sale and other securities 2,118,365 1,868,569
Recurring Basis [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 38,004 41,926
Recurring Basis [Member] | Asset-backed Securities [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 791,317 955,998
Recurring Basis [Member] | Covered Bonds [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Corporate debt [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 454,584 486,176
Recurring Basis [Member] | Other securities [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 46,458 34,236
Available-for-sale and other securities 17,452 20,746
Recurring Basis [Member] | Level 1 [Member]    
Assets measured at fair value on a recurring basis    
Mortgage loans held for sale 0 0
Trading account securities 32,908 33,121
Available-for-sale and other securities 26,155 22,882
Automobile loans 0 0
MSR's 0 0
Derivative assets 0 0
Liabilities measured at fair value on a recurring basis    
Derivatives 0 0
Other liabilities 0  
Recurring Basis [Member] | Level 1 [Member] | U.S. Treasury [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 0 0
Available-for-sale and other securities 12,600 5,452
Recurring Basis [Member] | Level 1 [Member] | Federal agencies - mortgage backed securities [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 0 0
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 1 [Member] | Federal agencies: Other agencies [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 0 0
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 1 [Member] | Municipal securities [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 0 0
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 1 [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 1 [Member] | Asset-backed Securities [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 1 [Member] | Covered Bonds [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 1 [Member] | Corporate debt [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 1 [Member] | Other securities [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 32,908 33,121
Available-for-sale and other securities 13,555 17,430
Recurring Basis [Member] | Level 2 [Member]    
Assets measured at fair value on a recurring basis    
Mortgage loans held for sale 453,489 354,888
Trading account securities 26,238 9,070
Available-for-sale and other securities 8,048,276 7,499,434
Automobile loans 0 0
MSR's 0 0
Derivative assets 469,106 449,775
Liabilities measured at fair value on a recurring basis    
Derivatives 313,377 335,524
Short-term borrowings   (2,295)
Recurring Basis [Member] | Level 2 [Member] | U.S. Treasury [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 0 0
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 2 [Member] | Federal agencies - mortgage backed securities [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 0 0
Available-for-sale and other securities 6,161,270 5,322,701
Recurring Basis [Member] | Level 2 [Member] | Federal agencies: Other agencies [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 8,506 2,857
Available-for-sale and other securities 329,184 351,543
Recurring Basis [Member] | Level 2 [Member] | Municipal securities [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 4,182 5,098
Available-for-sale and other securities 401,520 450,976
Recurring Basis [Member] | Level 2 [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 8,575 11,462
Recurring Basis [Member] | Level 2 [Member] | Asset-backed Securities [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 689,246 873,260
Recurring Basis [Member] | Level 2 [Member] | Covered Bonds [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 2 [Member] | Corporate debt [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 454,584 486,176
Recurring Basis [Member] | Level 2 [Member] | Other securities [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 13,550 1,115
Available-for-sale and other securities 3,897 3,316
Recurring Basis [Member] | Level 3 [Member]    
Assets measured at fair value on a recurring basis    
Mortgage loans held for sale 0 0
Trading account securities 0 0
Available-for-sale and other securities 1,848,345 1,530,795
Automobile loans 3,998 10,590
MSR's 20,681 22,786
Derivative assets 6,399 4,064
Liabilities measured at fair value on a recurring basis    
Derivatives 1,233 704
Other liabilities 0  
Recurring Basis [Member] | Level 3 [Member] | U.S. Treasury [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 0 0
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 3 [Member] | Federal agencies - mortgage backed securities [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 0 0
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 3 [Member] | Federal agencies: Other agencies [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 0 0
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 3 [Member] | Municipal securities [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 0 0
Available-for-sale and other securities 1,716,845 1,417,593
Recurring Basis [Member] | Level 3 [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 29,429 30,464
Recurring Basis [Member] | Level 3 [Member] | Asset-backed Securities [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 102,071 82,738
Recurring Basis [Member] | Level 3 [Member] | Covered Bonds [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 3 [Member] | Corporate debt [Member]    
Assets measured at fair value on a recurring basis    
Available-for-sale and other securities 0 0
Recurring Basis [Member] | Level 3 [Member] | Other securities [Member]    
Assets measured at fair value on a recurring basis    
Trading account securities 0 0
Available-for-sale and other securities $ 0 $ 0