Purchase Credit Impaired ("PCI") Loans - Summary of Aging of the Recorded Investment in Past Due Covered Loans by Portfolio Class and Category (Details) (Covered Loans, USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	$ 731	$ 6,466
90 or More Days Past Due	12,376	19,809
Total Past Due	13,107	26,275
Current	100,755	114,263
Total	113,862	140,538
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	338	397
90 or More Days Past Due	702	573
Total Past Due	1,040	970
Current	5,063	8,301
Total	6,103	9,271
Commercial real estate - Owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	94	255
90 or More Days Past Due	3,466	6,595
Total Past Due	3,560	6,850
Current	26,362	25,675
Total	29,922	32,525
Commercial real estate - Investor owned
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	5,143
90 or More Days Past Due	4,270	3,167
Total Past Due	4,270	8,310
Current	35,005	39,836
Total	39,275	48,146
Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	32
90 or More Days Past Due	94	4,198
Total Past Due	94	4,230
Current	7,748	10,095
Total	7,842	14,325
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	299	639
90 or More Days Past Due	3,831	5,276
Total Past Due	4,130	5,915
Current	26,158	28,583
Total	30,288	34,498
Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	0
90 or More Days Past Due	13	0
Total Past Due	13	0
Current	419	1,773
Total	$ 432	$ 1,773