Purchase Credit Impaired ("PCI") Loans - Summary of Aging of Recorded Investment in Past Due PCI Loans by Portfolio Class and Category (Details) - Covered Loans - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	$ 4,447	$ 3,672
90 or More Days Past Due	6,012	10,722
Total Past Due	10,459	14,394
Current	73,277	84,709
Total	83,736	99,103
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	0
90 or More Days Past Due	0	16
Total Past Due	0	16
Current	3,467	3,996
Total	3,467	4,012
CRE - owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	0
90 or More Days Past Due	543	2,759
Total Past Due	543	2,759
Current	19,465	19,936
Total	20,008	22,695
Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	4,358	878
90 or More Days Past Due	3,441	6,484
Total Past Due	7,799	7,362
Current	24,735	31,704
Total	32,534	39,066
Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	774
90 or More Days Past Due	1,975	0
Total Past Due	1,975	774
Current	5,093	6,966
Total	7,068	7,740
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	89	2,020
90 or More Days Past Due	53	1,451
Total Past Due	142	3,471
Current	20,262	21,650
Total	20,404	25,121
Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	0
90 or More Days Past Due	0	12
Total Past Due	0	12
Current	255	457
Total	$ 255	$ 469