Loans and Allowance for Credit Losses (Details 5) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Loans past due	$ 59,680	$ 73,660
Current loans	7,332,935	6,917,787
Real Estate Mortgage Residential [Member]
Loans past due	5,640	5,664
Current loans	99,551	100,754
Total recorded investment in loans	105,191	106,418
Owner Occupied - Commercial Real Estate - [Member]
Loans past due	5,609	9,789
Current loans	965,241	878,025
Total recorded investment in loans	970,850	887,814
Other Consumer [Member]
Loans past due	31
Current loans	1,967	2,988
Total recorded investment in loans	1,998	2,988
Income Producing - Commercial Real Estate [Member]
Loans past due	11,472	35,100
Current loans	3,655,343	3,221,800
Total recorded investment in loans	3,666,815	3,256,900
Home Equity [Member]
Loans past due	1,947	1,164
Current loans	81,500	85,439
Total recorded investment in loans	83,447	86,603
Construction - Commercial and Residential [Member]
Loans past due	13,032	7,423
Current loans	1,076,081	1,090,189
Total recorded investment in loans	1,089,113	1,097,612
Commercial [Member]
Loans past due	21,949	14,520
Current loans	1,453,252	1,538,592
Total recorded investment in loans	1,475,201	1,553,112
Financing Receivables, 30 to 59 Days Past Due [Member]
Loans past due	10,927	22,919
Financing Receivables, 30 to 59 Days Past Due [Member] \| Real Estate Mortgage Residential [Member]
Loans past due	0	2,456
Financing Receivables, 30 to 59 Days Past Due [Member] \| Owner Occupied - Commercial Real Estate - [Member]
Loans past due	445	5,051
Financing Receivables, 30 to 59 Days Past Due [Member] \| Other Consumer [Member]
Loans past due	21
Financing Receivables, 30 to 59 Days Past Due [Member] \| Income Producing - Commercial Real Estate [Member]
Loans past due	2,253	5,855
Financing Receivables, 30 to 59 Days Past Due [Member] \| Home Equity [Member]
Loans past due	1,413	630
Financing Receivables, 30 to 59 Days Past Due [Member] \| Construction - Commercial and Residential [Member]
Loans past due	2,011	4,392
Financing Receivables, 30 to 59 Days Past Due [Member] \| Commercial [Member]
Loans past due	4,784	4,535
Financing Receivables, 60 to 89 Days Past Due [Member]
Loans past due	11,345	34,464
Financing Receivables, 60 to 89 Days Past Due [Member] \| Real Estate Mortgage Residential [Member]
Loans past due		1,698
Financing Receivables, 60 to 89 Days Past Due [Member] \| Owner Occupied - Commercial Real Estate - [Member]
Loans past due	3,654	2,370
Financing Receivables, 60 to 89 Days Past Due [Member] \| Income Producing - Commercial Real Estate [Member]
Loans past due	4,656	27,479
Financing Receivables, 60 to 89 Days Past Due [Member] \| Home Equity [Member]
Loans past due	47	47
Financing Receivables, 60 to 89 Days Past Due [Member] \| Construction - Commercial and Residential [Member]
Loans past due	1,866
Financing Receivables, 60 to 89 Days Past Due [Member] \| Commercial [Member]
Loans past due	1,112	2,870
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans past due	37,408	16,277
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] \| Real Estate Mortgage Residential [Member]
Loans past due	5,640	1,510
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] \| Owner Occupied - Commercial Real Estate - [Member]
Loans past due	1,510	2,368
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] \| Income Producing - Commercial Real Estate [Member]
Loans past due	4,563	1,766
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] \| Home Equity [Member]
Loans past due	487	487
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] \| Construction - Commercial and Residential [Member]
Loans past due	9,155	3,031
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] \| Commercial [Member]
Loans past due	$ 16,053	$ 7,115