Allowance for Loan and Lease Losses (Troubled Debt Restructuring) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($) loans	Jun. 30, 2017 USD ($) loans	Jun. 30, 2018 USD ($) loans	Jun. 30, 2017 USD ($) loans	Dec. 31, 2017 USD ($)
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	101	129	249	280
Financing Receivable, Modifications, Recorded Investment	$ 161,824		$ 161,824		$ 164,561
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 13,087	$ 7,850	$ 23,947	$ 18,228
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans	66	58	129	93
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 4,354	$ 3,779	$ 9,182	$ 6,686
Non-PCI Loans
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	143,025		143,025		146,126
PCI Loans
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	18,799		18,799		18,435
Commercial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	81,474		81,474		95,392
Commercial | Construction and land development
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,278		2,278		4,572
Commercial | Mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	69,181		69,181		78,221
Commercial | Other commercial real estate
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,078		1,078		1,800
Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	7,661		7,661		8,508
Commercial | Lease financing
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,106		1,106		1,770
Commercial | Other
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	170		170		521
Noncommercial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	80,350		80,350		69,169
Noncommercial | Construction and land development
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,911		2,911		0
Noncommercial | Mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	48,224		48,224		43,542
Noncommercial | Revolving mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	26,530		26,530		22,853
Noncommercial | Consumer and Other
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,685		2,685		2,774
Accruing
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	132,310		132,310		130,391
Accruing | Non-PCI Loans
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	113,764		113,764		112,228
Accruing | PCI Loans
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	18,546		18,546		18,163
Accruing | Commercial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	69,360		69,360		76,300
Accruing | Commercial | Construction and land development
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,050		2,050		4,089
Accruing | Commercial | Mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	58,877		58,877		62,358
Accruing | Commercial | Other commercial real estate
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,039		1,039		1,012
Accruing | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	6,673		6,673		7,598
Accruing | Commercial | Lease financing
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	677		677		722
Accruing | Commercial | Other
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	44		44		521
Accruing | Noncommercial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	62,950		62,950		54,091
Accruing | Noncommercial | Construction and land development
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,821		2,821		0
Accruing | Noncommercial | Mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	38,266		38,266		34,067
Accruing | Noncommercial | Revolving mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	19,752		19,752		17,673
Accruing | Noncommercial | Consumer and Other
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,111		2,111		2,351
Nonaccruing
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	29,514		29,514		34,170
Nonaccruing | Non-PCI Loans
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	29,261		29,261		33,898
Nonaccruing | PCI Loans
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	253		253		272
Nonaccruing | Commercial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	12,114		12,114		19,092
Nonaccruing | Commercial | Construction and land development
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	228		228		483
Nonaccruing | Commercial | Mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	10,304		10,304		15,863
Nonaccruing | Commercial | Other commercial real estate
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	39		39		788
Nonaccruing | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	988		988		910
Nonaccruing | Commercial | Lease financing
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	429		429		1,048
Nonaccruing | Commercial | Other
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	126		126		0
Nonaccruing | Noncommercial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	17,400		17,400		15,078
Nonaccruing | Noncommercial | Construction and land development
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	90		90		0
Nonaccruing | Noncommercial | Mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	9,958		9,958		9,475
Nonaccruing | Noncommercial | Revolving mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	6,778		6,778		5,180
Nonaccruing | Noncommercial | Consumer and Other
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 574		$ 574		$ 423
Interest only period provided
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	1	3	2	3
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 154	$ 571	$ 821	$ 571
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans	2	1	2	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 821	$ 332	$ 821	$ 332
Loan term extension
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	10	13	17	21
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 936	$ 1,397	$ 1,658	$ 2,070
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans	7	1	8	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 341	$ 32	$ 638	$ 32
Below market interest rate
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	53	73	139	159
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 9,525	$ 4,440	$ 15,873	$ 12,582
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans	33	32	64	49
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 1,702	$ 2,800	$ 3,385	$ 4,231
Discharged from bankruptcy
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	37	40	91	97
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 2,472	$ 1,442	$ 5,595	$ 3,005
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans	24	24	55	42
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 1,490	$ 615	$ 4,338	$ 2,091