Allowance for Credit Losses (Troubled Debt Restructuring) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	$ 212,975	$ 208,180
Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	152,017	157,364
Nonaccruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	60,958	50,816
Non-PCD Loans | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	104,881	101,739
Non-PCD Loans | Commercial | Construction and land development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	379	632
Non-PCD Loans | Commercial | Owner occupied commercial mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	56,916	48,463
Non-PCD Loans | Commercial | Non-owner occupied commercial mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	23,785	19,985
Non-PCD Loans | Commercial | Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	23,801	32,659
Non-PCD Loans | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	66,522	81,478
Non-PCD Loans | Consumer | Construction and land development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	2,662	1,582
Non-PCD Loans | Consumer | Consumer auto
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	2,524	2,714
Non-PCD Loans | Consumer | Mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	37,043	48,838
Non-PCD Loans | Consumer | Revolving mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	23,458	27,252
Non-PCD Loans | Consumer | Consumer and Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	835	1,092
Non-PCD Loans | Accruing | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	79,129	85,619
Non-PCD Loans | Accruing | Commercial | Construction and land development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	346	578
Non-PCD Loans | Accruing | Commercial | Owner occupied commercial mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	46,255	37,574
Non-PCD Loans | Accruing | Commercial | Non-owner occupied commercial mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	20,022	18,336
Non-PCD Loans | Accruing | Commercial | Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	12,506	29,131
Non-PCD Loans | Accruing | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	43,681	54,128
Non-PCD Loans | Accruing | Consumer | Construction and land development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	2,380	1,573
Non-PCD Loans | Accruing | Consumer | Consumer auto
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	1,888	2,018
Non-PCD Loans | Accruing | Consumer | Mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	22,106	29,458
Non-PCD Loans | Accruing | Consumer | Revolving mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	16,533	20,124
Non-PCD Loans | Accruing | Consumer | Consumer and Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	774	955
Non-PCD Loans | Nonaccruing | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	25,752	16,120
Non-PCD Loans | Nonaccruing | Commercial | Construction and land development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	33	54
Non-PCD Loans | Nonaccruing | Commercial | Owner occupied commercial mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	10,661	10,889
Non-PCD Loans | Nonaccruing | Commercial | Non-owner occupied commercial mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	3,763	1,649
Non-PCD Loans | Nonaccruing | Commercial | Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	11,295	3,528
Non-PCD Loans | Nonaccruing | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	22,841	27,350
Non-PCD Loans | Nonaccruing | Consumer | Construction and land development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	282	9
Non-PCD Loans | Nonaccruing | Consumer | Consumer auto
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	636	696
Non-PCD Loans | Nonaccruing | Consumer | Mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	14,937	19,380
Non-PCD Loans | Nonaccruing | Consumer | Revolving mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	6,925	7,128
Non-PCD Loans | Nonaccruing | Consumer | Consumer and Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	61	137
PCD Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	41,572	24,963
PCD Loans | Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	29,207	17,617
PCD Loans | Nonaccruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	$ 12,365	$ 7,346