Loans - Information Relating to Loans (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[1]	$ 3,817,377	$ 2,879,536
Commercial and financial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[2]	606,014	370,589
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		189,436	154,452
Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		343,125	160,116
Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		1,639,992	1,357,592
Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		1,038,810	836,787
Portfolio Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[1]	2,922,609	2,425,850
Portfolio Loans [Member] | Commercial and financial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[2]	512,430	308,731
Portfolio Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		178,826	153,434
Portfolio Loans [Member] | Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		215,315	137,480
Portfolio Loans [Member] | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		1,170,618	1,041,915
Portfolio Loans [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		845,420	784,290
PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[1]	17,417	12,996
PCI Loans [Member] | Commercial and financial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[2]	894	941
PCI Loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		0	0
PCI Loans [Member] | Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		1,121	114
PCI Loans [Member] | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		9,776	11,257
PCI Loans [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		5,626	684
PULs [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[1]	877,351	440,690
PULs [Member] | Commercial and financial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES	[2]	92,690	60,917
PULs [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		10,610	1,018
PULs [Member] | Construction and land development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		126,689	22,522
PULs [Member] | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		459,598	304,420
PULs [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
NET LOAN BALANCES		$ 187,764	$ 51,813

[1] Net loan balances at December 31, 2017 and 2016 include deferred costs of $11.5 million and $10.6 million, respectively.

[2] Commercial and financial includes leases of $30.3 million and $0 million as of December 31, 2017 and 2016, respectively.