Allowance for Loan and Lease Losses (Troubled Debt Restructuring) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($) loans	Jun. 30, 2018 USD ($) loans	Jun. 30, 2019 USD ($) loans	Jun. 30, 2018 USD ($) loans	Dec. 31, 2018 USD ($)
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	115	101	239	249
Financing Receivable, Modifications, Recorded Investment	$ 164,857		$ 164,857		$ 156,130
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 17,374	$ 13,087	$ 24,522	$ 23,947
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans	62	66	120	129
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 5,901	$ 4,354	$ 12,330	$ 9,182
PCI Loans
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	18,000		18,000		18,200
Commercial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	74,470		74,470		74,560
Commercial | Construction and land development
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,193		2,193		2,298
Commercial | Mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	59,260		59,260		61,065
Commercial | Other commercial real estate
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	506		506		860
Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	12,196		12,196		10,046
Commercial | Other
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	315		315		291
Noncommercial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	90,387		90,387		81,570
Noncommercial | Construction and land development
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	3,060		3,060		2,337
Noncommercial | Mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	54,099		54,099		47,524
Noncommercial | Revolving mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	30,122		30,122		28,688
Noncommercial | Consumer and Other
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	3,106		3,106		3,021
Accruing
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	123,800		123,800		127,093
Accruing | Commercial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	62,405		62,405		64,171
Accruing | Commercial | Construction and land development
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	567		567		1,946
Accruing | Commercial | Mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	51,374		51,374		53,270
Accruing | Commercial | Other commercial real estate
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	506		506		851
Accruing | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	9,851		9,851		7,986
Accruing | Commercial | Other
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	107		107		118
Accruing | Noncommercial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	61,395		61,395		62,922
Accruing | Noncommercial | Construction and land development
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,495		1,495		2,227
Accruing | Noncommercial | Mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	36,260		36,260		37,903
Accruing | Noncommercial | Revolving mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	21,203		21,203		20,492
Accruing | Noncommercial | Consumer and Other
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,437		2,437		2,300
Nonaccruing
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	41,057		41,057		29,037
Nonaccruing | Commercial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	12,065		12,065		10,389
Nonaccruing | Commercial | Construction and land development
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,626		1,626		352
Nonaccruing | Commercial | Mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	7,886		7,886		7,795
Nonaccruing | Commercial | Other commercial real estate
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	0		0		9
Nonaccruing | Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,345		2,345		2,060
Nonaccruing | Commercial | Other
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	208		208		173
Nonaccruing | Noncommercial
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	28,992		28,992		18,648
Nonaccruing | Noncommercial | Construction and land development
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,565		1,565		110
Nonaccruing | Noncommercial | Mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	17,839		17,839		9,621
Nonaccruing | Noncommercial | Revolving mortgage
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	8,919		8,919		8,196
Nonaccruing | Noncommercial | Consumer and Other
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 669		$ 669		$ 721
Interest only period provided
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	4	1	4	2
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 4,343	$ 154	$ 4,343	$ 821
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans	0	2	2	2
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0	$ 821	$ 3,203	$ 821
Loan term extension
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	4	10	8	17
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 998	$ 936	$ 1,437	$ 1,658
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans	2	7	4	8
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 183	$ 341	$ 534	$ 638
Below market interest rate
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	67	53	125	139
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 6,979	$ 9,525	$ 11,063	$ 15,873
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans	30	33	61	64
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 2,612	$ 1,702	$ 4,645	$ 3,385
Discharged from bankruptcy
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | loans	40	37	102	91
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 5,054	$ 2,472	$ 7,679	$ 5,595
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans	30	24	53	55
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 3,106	$ 1,490	$ 3,948	$ 4,338