Purchased 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	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
30-89 Days Past Due	$ 3,138	$ 1,153
90 or More Days Past Due	3,687	6,404
Total Past Due	6,825	7,557
Current	96,490	38,844
Total	103,315	46,401
Commercial and industrial
Financing Receivable, Past Due [Line Items]
30-89 Days Past Due	1,525	0
90 or More Days Past Due	0	0
Total Past Due	1,525	0
Current	15,384	2,159
Total	16,909	2,159
CRE - investor owned
Financing Receivable, Past Due [Line Items]
30-89 Days Past Due	1,317	416
90 or More Days Past Due	1,917	88
Total Past Due	3,234	504
Current	38,754	23,435
Total	41,988	23,939
CRE - owner occupied
Financing Receivable, Past Due [Line Items]
30-89 Days Past Due	0	591
90 or More Days Past Due	1,381	6,279
Total Past Due	1,381	6,870
Current	21,235	2,799
Total	22,616	9,669
Construction and land development
Financing Receivable, Past Due [Line Items]
30-89 Days Past Due	70	0
90 or More Days Past Due	154	0
Total Past Due	224	0
Current	7,963	4,548
Total	8,187	4,548
Residential real estate
Financing Receivable, Past Due [Line Items]
30-89 Days Past Due	226	146
90 or More Days Past Due	235	37
Total Past Due	461	183
Current	12,911	5,899
Total	13,372	6,082
Consumer and other
Financing Receivable, Past Due [Line Items]
30-89 Days Past Due	0	0
90 or More Days Past Due	0	0
Total Past Due	0	0
Current	243	4
Total	$ 243	$ 4