Loans and Allowance for Loan Losses, Financing Receivables Past Due (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		$ 22,330	$ 19,977
Nonperforming	[1]	27,577	29,359
Current and performing		8,400,018	6,493,899
Total Loans		8,449,925	6,543,235
Currently performing impaired loans		16,700	19,000
30-89 Days Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		21,196	18,208
90 Days or More Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		1,134	1,769
Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		3,505	0
Nonperforming	[1]	4,254	5,103
Current and performing		1,347,134	1,078,394
Total Loans		1,354,893	1,083,497
Commercial Real Estate Owner Occupied [Member] | 30-89 Days Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		3,505	0
Commercial Real Estate Owner Occupied [Member] | 90 Days or More Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		0	0
Commercial Real Estate Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		0	0
Nonperforming	[1]	667	718
Current and performing		1,837,936	1,191,268
Total Loans		1,838,603	1,191,986
Commercial Real Estate Other [Member] | 30-89 Days Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		0	0
Commercial Real Estate Other [Member] | 90 Days or More Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		0	0
Consumer Real Estate - Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		3,891	7,776
Nonperforming	[1]	8,073	9,346
Current and performing		1,173,953	1,029,395
Total Loans		1,185,917	1,046,517
Consumer Real Estate - Mortgage [Member] | 30-89 Days Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		3,838	6,380
Consumer Real Estate - Mortgage [Member] | 90 Days or More Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		53	1,396
Construction and Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		2,210	309
Nonperforming	[1]	6,613	7,607
Current and performing		903,850	739,781
Total Loans		912,673	747,697
Construction and Land Development [Member] | 30-89 Days Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		2,210	309
Construction and Land Development [Member] | 90 Days or More Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		0	0
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		4,475	4,798
Nonperforming	[1]	7,495	1,683
Current and performing		2,879,740	2,222,061
Total Loans		2,891,710	2,228,542
Commercial and Industrial [Member] | 30-89 Days Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		4,475	4,798
Commercial and Industrial [Member] | 90 Days or More Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		0	0
Consumer and Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		8,249	7,094
Nonperforming	[1]	475	4,902
Current and performing		257,405	233,000
Total Loans		266,129	244,996
Consumer and Other [Member] | 30-89 Days Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		7,168	6,721
Consumer and Other [Member] | 90 Days or More Past Due and Performing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due and performing		$ 1,081	$ 373

[1] Approximately $16.7 million and $19.0 million of nonaccrual loans as of December 31, 2016 and 2015, respectively, are currently performing pursuant to their contractual terms.