Loans - Summary of Aging of Recorded Investment in Past Due Portfolio Loans by Portfolio Class and Category (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 9,269,176	$ 9,017,642
Non-Covered Loans
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	9,275,788	9,026,780
Loans, including unearned loan fees	9,269,176	9,017,642
Non-Covered Loans | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	3,597,225	3,396,590
Loans, including unearned loan fees	3,596,701	3,392,375
Non-Covered Loans | CRE - investor owned
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,173,640	2,141,143
Loans, including unearned loan fees	2,173,640	2,141,143
Non-Covered Loans | CRE - owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,120,735	2,035,785
Loans, including unearned loan fees	2,120,735	2,035,785
Non-Covered Loans | Construction and land development
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	724,163	734,073
Loans, including unearned loan fees	724,163	734,073
Non-Covered Loans | Residential real estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	413,727	454,052
Loans, including unearned loan fees	413,727	454,052
Non-Covered Loans | Other
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	246,298	265,137
Loans, including unearned loan fees	240,210	260,214
Total Past Due | Non-Covered Loans
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	29,369	57,402
Total Past Due | Non-Covered Loans | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	16,187	38,605
Total Past Due | Non-Covered Loans | CRE - investor owned
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,856	3,880
Total Past Due | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	6,251	10,359
Total Past Due | Non-Covered Loans | Construction and land development
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	24
Total Past Due | Non-Covered Loans | Residential real estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,032	4,486
Total Past Due | Non-Covered Loans | Other
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	43	48
30-89 Days Past Due | Non-Covered Loans
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	23,468	41,639
30-89 Days Past Due | Non-Covered Loans | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	10,960	24,447
30-89 Days Past Due | Non-Covered Loans | CRE - investor owned
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,856	3,880
30-89 Days Past Due | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	6,052	10,070
30-89 Days Past Due | Non-Covered Loans | Construction and land development
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	24
30-89 Days Past Due | Non-Covered Loans | Residential real estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	578	3,181
30-89 Days Past Due | Non-Covered Loans | Other
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	22	37
90 or More Days Past Due | Non-Covered Loans
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,901	15,763
90 or More Days Past Due | Non-Covered Loans | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,227	14,158
90 or More Days Past Due | Non-Covered Loans | CRE - investor owned
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
90 or More Days Past Due | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	199	289
90 or More Days Past Due | Non-Covered Loans | Construction and land development
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
90 or More Days Past Due | Non-Covered Loans | Residential real estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	454	1,305
90 or More Days Past Due | Non-Covered Loans | Other
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	21	11
Current | Non-Covered Loans
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	9,239,807	8,960,240
Current | Non-Covered Loans | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	3,580,514	3,353,770
Current | Non-Covered Loans | CRE - investor owned
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,167,784	2,137,263
Current | Non-Covered Loans | CRE - owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,114,484	2,025,426
Current | Non-Covered Loans | Construction and land development
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	724,163	734,049
Current | Non-Covered Loans | Residential real estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	412,695	449,566
Current | Non-Covered Loans | Other
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 240,167	$ 260,166