Allowance for Loan and Lease Losses (Troubled Debt Restructuring) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
TDRs
Financing Receivable, Modifications [Line Items]
Accruing	$ 147,598	$ 175,955
Nonaccruing	22,890	30,801
Financing Receivable, Modifications, Recorded Investment	170,488	206,756
Originated Loans
Financing Receivable, Modifications [Line Items]
Nonaccruing	47,778	53,170
Originated Loans | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	92,928	85,126
Nonaccruing	17,817	19,322
Financing Receivable, Modifications, Recorded Investment	110,745	104,448
Acquired Loans | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	54,670	90,829
Nonaccruing	5,073	11,479
Financing Receivable, Modifications, Recorded Investment	59,743
Commercial | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	117,117	147,712
Nonaccruing	20,004	26,681
Financing Receivable, Modifications, Recorded Investment	137,121	174,393
Commercial | Construction and land development | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	3,518	21,032
Nonaccruing	213	1,002
Financing Receivable, Modifications, Recorded Investment	3,731	22,034
Commercial | Construction and land development | Originated Loans
Financing Receivable, Modifications [Line Items]
Nonaccruing	258	544
Commercial | Mortgage | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	100,114	113,323
Nonaccruing	17,866	23,387
Financing Receivable, Modifications, Recorded Investment	117,980	136,710
Commercial | Mortgage | Originated Loans
Financing Receivable, Modifications [Line Items]
Nonaccruing	30,279	33,529
Commercial | Other commercial real estate | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	3,085	3,470
Nonaccruing	1,229	1,150
Financing Receivable, Modifications, Recorded Investment	4,314	4,620
Commercial | Other commercial real estate | Originated Loans
Financing Receivable, Modifications [Line Items]
Nonaccruing	1,401	1,610
Commercial | Commercial and industrial | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	10,079	9,838
Nonaccruing	696	1,142
Financing Receivable, Modifications, Recorded Investment	10,775	10,980
Commercial | Commercial and industrial | Originated Loans
Financing Receivable, Modifications [Line Items]
Nonaccruing	1,696	1,428
Commercial | Lease financing | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	281	49
Nonaccruing	0	0
Financing Receivable, Modifications, Recorded Investment	281	49
Commercial | Lease financing | Originated Loans
Financing Receivable, Modifications [Line Items]
Nonaccruing	410	832
Commercial | Other | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	40	0
Nonaccruing	0	0
Financing Receivable, Modifications, Recorded Investment	40	0
Noncommerical | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	30,481	28,243
Nonaccruing	2,886	4,120
Financing Receivable, Modifications, Recorded Investment	33,367	32,363
Noncommerical | Mortgage | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	24,444	23,343
Nonaccruing	2,886	3,663
Financing Receivable, Modifications, Recorded Investment	27,330	27,006
Noncommerical | Mortgage | Originated Loans
Financing Receivable, Modifications [Line Items]
Nonaccruing	13,713	14,701
Noncommerical | Construction and land development | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	1,498	651
Nonaccruing	0	457
Financing Receivable, Modifications, Recorded Investment	1,498	1,108
Noncommerical | Construction and land development | Originated Loans
Financing Receivable, Modifications [Line Items]
Nonaccruing	0	457
Noncommerical | Revolving mortgage | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	3,497	3,095
Nonaccruing	0	0
Financing Receivable, Modifications, Recorded Investment	3,497	3,095
Noncommerical | Revolving mortgage | Originated Loans
Financing Receivable, Modifications [Line Items]
Nonaccruing	0	0
Noncommerical | Consumer and Other | TDRs
Financing Receivable, Modifications [Line Items]
Accruing	1,042	1,154
Nonaccruing	0	0
Financing Receivable, Modifications, Recorded Investment	1,042	1,154
Loss Share Agreement [Member] | Acquired Loans | TDRs
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 38,476	$ 102,308