Allowance for Credit Losses (Troubled Debt Restructuring) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	$ 216,946	$ 208,180
Nonaccruing	194,534	191,483
Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	160,551	157,364
Nonaccruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccruing	56,395	50,816
Non-PCD Loans | Commercial | Construction and land development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	570	632
Non-PCD Loans | Commercial | Owner occupied commercial mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	48,955	48,463
Non-PCD Loans | Commercial | Non-owner occupied commercial mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	21,876	19,985
Non-PCD Loans | Commercial | Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	37,507	32,659
Non-PCD Loans | Commercial | Total commercial loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	108,908	101,739
Non-PCD Loans | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	77,609	81,478
Non-PCD Loans | Consumer | Construction and land development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	1,510	1,582
Non-PCD Loans | Consumer | Consumer auto
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	2,841	2,714
Non-PCD Loans | Consumer | Mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	46,125	48,838
Non-PCD Loans | Consumer | Revolving mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	26,060	27,252
Non-PCD Loans | Consumer | Consumer and Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	1,073	1,092
Non-PCD Loans | Accruing | Commercial | Construction and land development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	529	578
Non-PCD Loans | Accruing | Commercial | Owner occupied commercial mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	38,969	37,574
Non-PCD Loans | Accruing | Commercial | Non-owner occupied commercial mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	20,541	18,336
Non-PCD Loans | Accruing | Commercial | Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	30,956	29,131
Non-PCD Loans | Accruing | Commercial | Total commercial loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	90,995	85,619
Non-PCD Loans | Accruing | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	48,636	54,128
Non-PCD Loans | Accruing | Consumer | Construction and land development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	1,501	1,573
Non-PCD Loans | Accruing | Consumer | Consumer auto
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	2,173	2,018
Non-PCD Loans | Accruing | Consumer | Mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	25,323	29,458
Non-PCD Loans | Accruing | Consumer | Revolving mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	18,729	20,124
Non-PCD Loans | Accruing | Consumer | Consumer and Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	910	955
Non-PCD Loans | Nonaccruing | Commercial | Construction and land development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccruing	41	54
Non-PCD Loans | Nonaccruing | Commercial | Owner occupied commercial mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccruing	9,986	10,889
Non-PCD Loans | Nonaccruing | Commercial | Non-owner occupied commercial mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccruing	1,335	1,649
Non-PCD Loans | Nonaccruing | Commercial | Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccruing	6,551	3,528
Non-PCD Loans | Nonaccruing | Commercial | Total commercial loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccruing	17,913	16,120
Non-PCD Loans | Nonaccruing | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccruing	28,973	27,350
Non-PCD Loans | Nonaccruing | Consumer | Construction and land development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccruing	9	9
Non-PCD Loans | Nonaccruing | Consumer | Consumer auto
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccruing	668	696
Non-PCD Loans | Nonaccruing | Consumer | Mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccruing	20,802	19,380
Non-PCD Loans | Nonaccruing | Consumer | Revolving mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccruing	7,331	7,128
Non-PCD Loans | Nonaccruing | Consumer | Consumer and Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccruing	163	137
PCD Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	30,429	24,963
PCD Loans | Accruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructuring	20,920	17,617
PCD Loans | Nonaccruing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccruing	$ 9,509	$ 7,346