Portfolio Loans - Summary of Recorded Investment by Risk Category of Portfolio Loans by Portfolio Class and Category (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	$ 3,037,705	$ 2,750,737
Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	3,038,137	2,750,446
Loans and Leases Receivable, Gross	3,037,705	2,750,737
Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	1,598,815	1,484,327
Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	340,916	342,959
Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	515,055	428,064
Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	188,856	161,061
Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	233,960	196,498
Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	160,535	137,537
Loans and Leases Receivable, Gross	160,103	137,828
Pass (1-6) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	2,829,644	2,541,405
Pass (1-6) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	1,457,729	1,356,864
Pass (1-6) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	311,427	314,791
Pass (1-6) | Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	501,228	403,820
Pass (1-6) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	179,515	146,601
Pass (1-6) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	226,287	188,269
Pass (1-6) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	153,458	131,060
Watch (7) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	109,475	149,938
Watch (7) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	63,572	90,370
Watch (7) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	25,369	24,727
Watch (7) | Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	9,549	18,868
Watch (7) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	6,050	10,114
Watch (7) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	4,224	5,138
Watch (7) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	711	721
Substandard (8) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	98,586	59,394
Substandard (8) | Non-Covered Loans | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	77,514	37,093
Substandard (8) | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	4,120	3,441
Substandard (8) | Non-Covered Loans | Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	4,278	5,376
Substandard (8) | Non-Covered Loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	3,291	4,346
Substandard (8) | Non-Covered Loans | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	3,449	3,091
Substandard (8) | Non-Covered Loans | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	5,934	6,047
Doubtful (9) | Non-Covered Loans
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	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 - owner occupied
Financing Receivable, Recorded Investment [Line Items]
Portfolio loans	0	0
Doubtful (9) | Non-Covered Loans | Commercial Real Estate Investor Owned
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	$ 0	$ 0