Loans (Summary of the Aging Status of the Recorded Investment in Loans by Portfolio Segment/Class) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule representing the aging status of the recorded investment in loans by classes
Total loans	$ 12,990,779	$ 7,271,147
Commercial
Schedule representing the aging status of the recorded investment in loans by classes
Total loans		1,905,879
Commercial real estate
Schedule representing the aging status of the recorded investment in loans by classes
Total loans		2,112,162
Real estate construction and land development
Schedule representing the aging status of the recorded investment in loans by classes
Total loans		232,076
Residential mortgage
Schedule representing the aging status of the recorded investment in loans by classes
Total loans		1,429,636
Consumer installment
Schedule representing the aging status of the recorded investment in loans by classes
Total loans		877,457
Home equity
Schedule representing the aging status of the recorded investment in loans by classes
Total loans		713,937
Originated Portfolio
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	51,633	42,643
Current	7,406,768	5,765,291
Total loans	7,458,401	5,807,934
Financing receivable, recorded investment accruing loans past due 90 days or more	1,283	2,287
Originated Portfolio | 30-59 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	29,928	29,827
Originated Portfolio | 60-89 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	8,560	10,529
Originated Portfolio | 90 days or more past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	13,145	2,287
Originated Portfolio | Commercial
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	18,904	15,000
Current	1,882,622	1,506,515
Total loans	1,901,526	1,521,515
Financing receivable, recorded investment accruing loans past due 90 days or more	11	364
Originated Portfolio | Commercial | 30-59 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	10,421	9,393
Originated Portfolio | Commercial | 60-89 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	4,842	5,243
Originated Portfolio | Commercial | 90 days or more past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	3,641	364
Originated Portfolio | Commercial real estate
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	13,305	9,457
Current	1,908,494	1,414,602
Total loans	1,921,799	1,424,059
Financing receivable, recorded investment accruing loans past due 90 days or more	277	254
Originated Portfolio | Commercial real estate | 30-59 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	6,551	6,941
Originated Portfolio | Commercial real estate | 60-89 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	1,589	2,262
Originated Portfolio | Commercial real estate | 90 days or more past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	5,165	254
Originated Portfolio | Real estate construction and land development
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	3,220	596
Current	278,504	184,551
Total loans	281,724	185,147
Financing receivable, recorded investment accruing loans past due 90 days or more	0	0
Originated Portfolio | Real estate construction and land development | 30-59 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	2,721	596
Originated Portfolio | Real estate construction and land development | 60-89 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	499	0
Originated Portfolio | Real estate construction and land development | 90 days or more past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	0	0
Originated Portfolio | Residential mortgage
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	4,961	9,047
Current	1,470,381	1,207,928
Total loans	1,475,342	1,216,975
Financing receivable, recorded investment accruing loans past due 90 days or more	0	402
Originated Portfolio | Residential mortgage | 30-59 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	3,147	7,475
Originated Portfolio | Residential mortgage | 60-89 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	62	1,170
Originated Portfolio | Residential mortgage | 90 days or more past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	1,752	402
Originated Portfolio | Consumer installment
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	4,904	4,088
Current	1,277,684	865,338
Total loans	1,282,588	869,426
Financing receivable, recorded investment accruing loans past due 90 days or more	0	0
Originated Portfolio | Consumer installment | 30-59 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	3,991	3,347
Originated Portfolio | Consumer installment | 60-89 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	675	741
Originated Portfolio | Consumer installment | 90 days or more past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	238	0
Originated Portfolio | Home equity
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	6,339	4,455
Current	589,083	586,357
Total loans	595,422	590,812
Financing receivable, recorded investment accruing loans past due 90 days or more	995	1,267
Originated Portfolio | Home equity | 30-59 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	3,097	2,075
Originated Portfolio | Home equity | 60-89 days past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	893	1,113
Originated Portfolio | Home equity | 90 days or more past due
Schedule representing the aging status of the recorded investment in loans by classes
Total past due	$ 2,349	$ 1,267