Portfolio Loans - Summary of Recorded Investment by Risk Category of Portfolio Loans by Portfolio Class and Category (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, including unearned loan fees	$ 2,750,737	$ 2,433,916
Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	2,750,446	2,433,021
Portfolio loans, including unearned loan fees	2,750,737	2,433,916
Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	1,484,327	1,264,487
Non-Covered Loans | CRE - investor owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	342,959	344,003
Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	428,064	396,751
Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	161,061	143,878
Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	196,498	185,252
Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	137,537	98,650
Portfolio loans, including unearned loan fees	137,828	99,545
Pass (1-6) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, including unearned loan fees	2,541,405	2,229,430
Pass (1-6) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	1,356,864	1,161,979
Pass (1-6) | Non-Covered Loans | CRE - investor owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	314,791	322,725
Pass (1-6) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	403,820	361,991
Pass (1-6) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	146,601	122,365
Pass (1-6) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	188,269	168,543
Pass (1-6) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, including unearned loan fees	131,060	91,827
Watch (7) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, including unearned loan fees	149,938	128,484
Watch (7) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	90,370	62,315
Watch (7) | Non-Covered Loans | CRE - investor owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	24,727	18,025
Watch (7) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	18,868	18,640
Watch (7) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	10,114	12,993
Watch (7) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	5,138	11,012
Watch (7) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, including unearned loan fees	721	5,499
Substandard (8) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, including unearned loan fees	59,394	76,002
Substandard (8) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	37,093	40,193
Substandard (8) | Non-Covered Loans | CRE - investor owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	3,441	3,253
Substandard (8) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	5,376	16,120
Substandard (8) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	4,346	8,520
Substandard (8) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	3,091	5,697
Substandard (8) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, including unearned loan fees	6,047	2,219
Doubtful (9) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, including unearned loan fees	0	0
Doubtful (9) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	0	0
Doubtful (9) | Non-Covered Loans | CRE - investor owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	0	0
Doubtful (9) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	0	0
Doubtful (9) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	0	0
Doubtful (9) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio Loans	0	0
Doubtful (9) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans, including unearned loan fees	$ 0	$ 0