Loans and Allowance for Credit Losses - Class of loan, an aging analysis and the recorded investments in loans past due (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Loans past due	$ 74,993	$ 73,660
Current loans	7,470,755	6,917,787
Total recorded investment in loans	7,545,748	6,991,447
Real Estate Mortgage Residential
Loans past due	9,164	5,664
Current loans	95,057	100,754
Total recorded investment in loans	104,221	106,418
Owner Occupied - Commercial Real Estate
Loans past due	19,471	9,789
Current loans	965,938	878,025
Total recorded investment in loans	985,409	887,814
Other Consumer
Loans past due	9
Current loans	2,151	2,988
Total recorded investment in loans	2,160	2,988
Income Producing - Commercial Real Estate
Loans past due	15,253	35,100
Current loans	3,687,494	3,221,800
Total recorded investment in loans	3,702,747	3,256,900
Home Equity
Loans past due	815	1,164
Current loans	79,246	85,439
Total recorded investment in loans	80,061	86,603
Construction - Commercial and Residential
Loans past due	11,509	7,423
Current loans	1,113,735	1,090,189
Total recorded investment in loans	1,125,244	1,097,612
Commercial
Loans past due	18,772	14,520
Current loans	1,527,134	1,538,592
Total recorded investment in loans	1,545,906	1,553,112
30 to 59 days past due
Loans past due	19,740	22,919
30 to 59 days past due \| Real Estate Mortgage Residential
Loans past due	3,533	2,456
30 to 59 days past due \| Owner Occupied - Commercial Real Estate
Loans past due	13,008	5,051
30 to 59 days past due \| Income Producing - Commercial Real Estate
Loans past due		5,855
30 to 59 days past due \| Home Equity
Loans past due	136	630
30 to 59 days past due \| Construction - Commercial and Residential
Loans past due		4,392
30 to 59 days past due \| Commercial
Loans past due	3,063	4,535
60-89 days past due
Loans past due	6,524	34,464
60-89 days past due \| Real Estate Mortgage Residential
Loans past due		1,698
60-89 days past due \| Owner Occupied - Commercial Real Estate
Loans past due		2,370
60-89 days past due \| Other Consumer
Loans past due	9
60-89 days past due \| Income Producing - Commercial Real Estate
Loans past due	5,542	27,479
60-89 days past due \| Home Equity
Loans past due	192	47
60-89 days past due \| Commercial
Loans past due	781	2,870
90 days or more past due
Loans past due	48,729	16,277
90 days or more past due \| Real Estate Mortgage Residential
Loans past due	5,631	1,510
90 days or more past due \| Owner Occupied - Commercial Real Estate
Loans past due	6,463	2,368
90 days or more past due \| Income Producing - Commercial Real Estate
Loans past due	9,711	1,766
90 days or more past due \| Home Equity
Loans past due	487	487
90 days or more past due \| Construction - Commercial and Residential
Loans past due	11,509	3,031
90 days or more past due \| Commercial
Loans past due	$ 14,928	$ 7,115