Loans and Allowances for Credit Losses Part 3 (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	$ 11,140,443,000	$ 10,789,740,000	$ 10,170,974,000
Non-Graded, Recorded Investment	1,937,411,000	2,002,524,000	1,922,590,000
Total	13,077,854,000	12,792,264,000	12,093,564,000
Related Allowance [Abstract]
Internally Risk Graded, Allowance	133,382,000	127,961,000	121,611,000
Non-Graded, Allowance	27,971,000	29,222,000	41,542,000
Allowance For Financing Receivable Total	188,318,000	185,396,000	205,965,000	215,507,000
Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	11,001,684,000	10,650,784,000	9,963,687,000
Non-Graded, Recorded Investment	1,897,379,000	1,966,324,000	1,885,993,000
Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	74,085,000	74,007,000	111,251,000
Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	64,674,000	64,949,000	96,036,000
Non-Graded, Recorded Investment	40,032,000	36,200,000	36,597,000
Commercial [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	8,029,443,000	7,888,219,000	7,400,848,000
Non-Graded, Recorded Investment	22,263,000	55,002,000	17,457,000
Total	8,051,706,000	7,943,221,000	7,418,305,000
Related Allowance [Abstract]
Internally Risk Graded, Allowance	84,333,000	78,250,000	65,320,000
Non-Graded, Allowance	913,000	930,000	1,099,000
Allowance For Financing Receivable Total	85,246,000	79,180,000	66,419,000
Commercial [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	7,972,912,000	7,841,108,000	7,319,106,000
Non-Graded, Recorded Investment	22,149,000	54,929,000	17,385,000
Commercial [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	37,598,000	30,424,000	61,953,000
Commercial [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	18,933,000	16,687,000	19,789,000
Non-Graded, Recorded Investment	114,000	73,000	72,000
Energy [Member]
Recorded Investment [Abstract]
Total	2,344,072,000	2,351,760,000	2,349,432,000
Energy [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,339,578,000	2,347,519,000	2,342,500,000
Non-Graded, Recorded Investment	0	0	0
Energy [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,735,000	2,381,000	4,555,000
Energy [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,759,000	1,860,000	2,377,000
Non-Graded, Recorded Investment	0	0	0
Services [Member]
Recorded Investment [Abstract]
Total	2,232,471,000	2,282,210,000	2,114,799,000
Services [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,213,569,000	2,265,984,000	2,074,198,000
Non-Graded, Recorded Investment	0	0	0
Services [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	14,321,000	11,304,000	31,127,000
Services [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	4,581,000	4,922,000	9,474,000
Non-Graded, Recorded Investment	0	0	0
Wholesale/retail [Member]
Recorded Investment [Abstract]
Total	1,225,990,000	1,201,364,000	1,085,000,000
Wholesale/retail [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,216,725,000	1,191,791,000	1,071,954,000
Non-Graded, Recorded Investment	0	0	0
Wholesale/retail [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,411,000	2,604,000	10,807,000
Wholesale/retail [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	6,854,000	6,969,000	2,239,000
Non-Graded, Recorded Investment	0	0	0
Manufacturing [Member]
Recorded Investment [Abstract]
Total	444,215,000	391,751,000	399,818,000
Manufacturing [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	429,523,000	381,794,000	387,346,000
Non-Graded, Recorded Investment	0	0	0
Manufacturing [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	11,127,000	9,365,000	10,624,000
Manufacturing [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	3,565,000	592,000	1,848,000
Non-Graded, Recorded Investment	0	0	0
Healthcare [Member]
Recorded Investment [Abstract]
Total	1,396,562,000	1,274,246,000	1,081,636,000
Healthcare [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,392,315,000	1,272,626,000	1,078,550,000
Non-Graded, Recorded Investment	0	0	0
Healthcare [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,804,000	34,000	124,000
Healthcare [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,443,000	1,586,000	2,962,000
Non-Graded, Recorded Investment	0	0	0
Integrated food services [Member]
Recorded Investment [Abstract]
Total	126,514,000	150,494,000	173,800,000
Integrated food services [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	122,314,000	145,758,000	173,800,000
Non-Graded, Recorded Investment	0	0	0
Integrated food services [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	4,200,000	4,736,000	0
Integrated food services [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0	0
Non-Graded, Recorded Investment	0	0	0
Other commercial and industrial [Member]
Recorded Investment [Abstract]
Total	281,882,000	291,396,000	213,820,000
Other commercial and industrial [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	258,888,000	235,636,000	190,758,000
Non-Graded, Recorded Investment	22,149,000	54,929,000	17,385,000
Other commercial and industrial [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0	4,716,000
Other commercial and industrial [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	731,000	758,000	889,000
Non-Graded, Recorded Investment	114,000	73,000	72,000
Commercial Real Estate [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,631,407,000	2,415,353,000	2,285,160,000
Non-Graded, Recorded Investment	0	0	0
Total	2,631,407,000	2,415,353,000	2,285,160,000
Related Allowance [Abstract]
Internally Risk Graded, Allowance	41,589,000	41,573,000	48,528,000
Non-Graded, Allowance	0	0	0
Allowance For Financing Receivable Total	41,589,000	41,573,000	48,528,000
Commercial Real Estate [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,558,346,000	2,334,998,000	2,178,491,000
Non-Graded, Recorded Investment	0	0	0
Commercial Real Estate [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	33,756,000	39,505,000	41,494,000
Commercial Real Estate [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	39,305,000	40,850,000	65,175,000
Non-Graded, Recorded Investment	0	0	0
Residential construction and land development [Member]
Recorded Investment [Abstract]
Total	184,820,000	206,258,000	237,829,000
Residential construction and land development [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	153,836,000	173,488,000	194,944,000
Non-Graded, Recorded Investment	0	0	0
Residential construction and land development [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	14,437,000	15,393,000	19,423,000
Residential construction and land development [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	16,547,000	17,377,000	23,462,000
Non-Graded, Recorded Investment	0	0	0
Retail [Member]
Recorded Investment [Abstract]
Total	640,506,000	586,047,000	584,279,000
Retail [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	634,253,000	579,506,000	572,761,000
Non-Graded, Recorded Investment	0	0	0
Retail [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,627,000	1,684,000	2,597,000
Retail [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	4,626,000	4,857,000	8,921,000
Non-Graded, Recorded Investment	0	0	0
Office [Member]
Recorded Investment [Abstract]
Total	436,264,000	411,499,000	420,644,000
Office [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	428,815,000	403,951,000	401,070,000
Non-Graded, Recorded Investment	0	0	0
Office [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	1,148,000	1,157,000	6,723,000
Office [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	6,301,000	6,391,000	12,851,000
Non-Graded, Recorded Investment	0	0	0
Multifamily [Member]
Recorded Investment [Abstract]
Total	662,674,000	576,502,000	460,474,000
Multifamily [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	648,999,000	562,800,000	453,822,000
Non-Graded, Recorded Investment	0	0	0
Multifamily [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	13,675,000	13,695,000	2,151,000
Multifamily [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	7,000	4,501,000
Non-Graded, Recorded Investment	0	0	0
Industrial [Member]
Recorded Investment [Abstract]
Total	305,207,000	243,877,000	237,049,000
Industrial [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	304,321,000	243,625,000	234,590,000
Non-Graded, Recorded Investment	0	0	0
Industrial [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0	261,000
Industrial [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	886,000	252,000	2,198,000
Non-Graded, Recorded Investment	0	0	0
Other commercial real estate [Member]
Recorded Investment [Abstract]
Total	401,936,000	391,170,000	344,885,000
Other commercial real estate [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	388,122,000	371,628,000	321,304,000
Non-Graded, Recorded Investment	0	0	0
Other commercial real estate [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,869,000	7,576,000	10,339,000
Other commercial real estate [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	10,945,000	11,966,000	13,242,000
Non-Graded, Recorded Investment	0	0	0
Residential Mortgage [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	209,608,000	220,635,000	247,814,000
Non-Graded, Recorded Investment	1,809,067,000	1,831,391,000	1,764,636,000
Total	2,018,675,000	2,052,026,000	2,012,450,000
Related Allowance [Abstract]
Internally Risk Graded, Allowance	4,695,000	5,481,000	4,600,000
Non-Graded, Allowance	23,612,000	23,984,000	35,622,000
Allowance For Financing Receivable Total	28,307,000	29,465,000	40,222,000
Residential Mortgage [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	200,662,000	210,142,000	230,595,000
Non-Graded, Recorded Investment	1,769,929,000	1,796,281,000	1,729,874,000
Residential Mortgage [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,704,000	3,283,000	6,555,000
Residential Mortgage [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	6,242,000	7,210,000	10,664,000
Non-Graded, Recorded Investment	39,138,000	35,110,000	34,762,000
Permanent mortage [Member]
Recorded Investment [Abstract]
Total	1,033,572,000	1,062,744,000	1,091,575,000
Permanent mortage [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	200,662,000	210,142,000	230,595,000
Non-Graded, Recorded Investment	793,864,000	815,040,000	816,272,000
Permanent mortage [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	2,704,000	3,283,000	6,555,000
Permanent mortage [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	6,242,000	7,210,000	10,664,000
Non-Graded, Recorded Investment	30,100,000	27,069,000	27,489,000
Permanent mortgages guaranteed by US govenment agencies [Member]
Recorded Investment [Abstract]
Total	184,822,000	181,598,000	162,419,000
Permanent mortgages guaranteed by US govenment agencies [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0	0
Non-Graded, Recorded Investment	183,250,000	180,821,000	162,205,000
Permanent mortgages guaranteed by US govenment agencies [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0	0
Permanent mortgages guaranteed by US govenment agencies [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0	0
Non-Graded, Recorded Investment	1,572,000	777,000	214,000
Home equity {Member]
Recorded Investment [Abstract]
Total	800,281,000	807,684,000	758,456,000
Home equity {Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0	0
Non-Graded, Recorded Investment	792,815,000	800,420,000	751,397,000
Home equity {Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0	0
Home equity {Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0	0
Non-Graded, Recorded Investment	7,466,000	7,264,000	7,059,000
Consumer [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	269,985,000	265,533,000	237,152,000
Non-Graded, Recorded Investment	106,081,000	116,131,000	140,497,000
Total	376,066,000	381,664,000	377,649,000
Related Allowance [Abstract]
Internally Risk Graded, Allowance	2,765,000	2,657,000	3,163,000
Non-Graded, Allowance	3,446,000	4,308,000	4,821,000
Allowance For Financing Receivable Total	6,211,000	6,965,000	7,984,000
Consumer [Member] | Performing [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	269,764,000	264,536,000	235,495,000
Non-Graded, Recorded Investment	105,301,000	115,114,000	138,734,000
Consumer [Member] | Potential Problem [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	27,000	795,000	1,249,000
Consumer [Member] | Nonaccrual [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	194,000	202,000	408,000
Non-Graded, Recorded Investment	780,000	1,017,000	1,763,000
Specific Allowance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	11,140,443,000	10,789,740,000	10,170,974,000
Non-Graded, Recorded Investment	1,937,411,000	2,002,524,000	1,922,590,000
Total	13,077,854,000	12,792,264,000	12,093,564,000
Related Allowance [Abstract]
Internally Risk Graded, Allowance	133,382,000	127,961,000	121,611,000
Non-Graded, Allowance	27,971,000	29,222,000	41,542,000
Allowance For Financing Receivable Total	161,353,000	157,183,000	163,153,000
Nonspecific Allowance [Member]
Recorded Investment [Abstract]
Internally Risk Graded, Recorded Investment	0	0	0
Non-Graded, Recorded Investment	0	0	0
Total	0	0	0
Related Allowance [Abstract]
Internally Risk Graded, Allowance	0	0	0
Non-Graded, Allowance	0	0	0
Allowance For Financing Receivable Total	$ 26,965,000	$ 28,213,000	$ 42,812,000	$ 44,187,000