Loans - Summary of Aging of Recorded Investment in Past Due Portfolio Loans by Portfolio Class and Category (Details) - Non-Covered Loans - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 38,317
Current	6,101,734
Loans, including unearned loan fees	6,140,051	$ 5,314,337
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	29,307
Current	3,113,890
Loans, including unearned loan fees	3,143,197
CRE - investor owned
Financing Receivable, Past Due [Line Items]
Total Past Due	2,211
Current	1,307,684
Loans, including unearned loan fees	1,309,895
CRE - owner occupied
Financing Receivable, Past Due [Line Items]
Total Past Due	3,931
Current	734,618
Loans, including unearned loan fees	738,549
Construction and land development
Financing Receivable, Past Due [Line Items]
Total Past Due	58
Current	481,163
Loans, including unearned loan fees	481,221
Residential real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	2,689
Current	324,303
Loans, including unearned loan fees	326,992
Other
Financing Receivable, Past Due [Line Items]
Total Past Due	121
Current	140,076
Loans, including unearned loan fees	140,197
Financial Asset, 30 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due	10,632
Financial Asset, 30 to 89 Days Past Due [Member] | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	6,684
Financial Asset, 30 to 89 Days Past Due [Member] | CRE - investor owned
Financing Receivable, Past Due [Line Items]
Total Past Due	116
Financial Asset, 30 to 89 Days Past Due [Member] | CRE - owner occupied
Financing Receivable, Past Due [Line Items]
Total Past Due	2,723
Financial Asset, 30 to 89 Days Past Due [Member] | Construction and land development
Financing Receivable, Past Due [Line Items]
Total Past Due	58
Financial Asset, 30 to 89 Days Past Due [Member] | Residential real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	951
Financial Asset, 30 to 89 Days Past Due [Member] | Other
Financing Receivable, Past Due [Line Items]
Total Past Due	100
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due	27,685
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	22,623
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | CRE - investor owned
Financing Receivable, Past Due [Line Items]
Total Past Due	2,095
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | CRE - owner occupied
Financing Receivable, Past Due [Line Items]
Total Past Due	1,208
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Construction and land development
Financing Receivable, Past Due [Line Items]
Total Past Due	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	1,738
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Other
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 21