Loans - Summary of Aging of Recorded Investment in Past Due Portfolio Loans by Portfolio Class and Category (Details) - Non-Covered Loans - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 45,881	$ 42,573
Current	9,070,702	7,182,362
Loans, including unearned loan fees	9,116,583	7,224,935
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	29,222	21,580
Current	3,349,949	3,067,415
Loans, including unearned loan fees	3,379,171	3,088,995
CRE - investor owned
Financing Receivable, Past Due [Line Items]
Total Past Due	298	10,035
Current	2,120,953	1,579,384
Loans, including unearned loan fees	2,121,251	1,589,419
CRE - owner occupied
Financing Receivable, Past Due [Line Items]
Total Past Due	14,460	4,975
Current	2,044,000	1,493,433
Loans, including unearned loan fees	2,058,460	1,498,408
Construction and land development
Financing Receivable, Past Due [Line Items]
Total Past Due	169	13
Current	747,590	546,673
Loans, including unearned loan fees	747,759	546,686
Residential real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	1,447	4,189
Current	541,243	314,990
Loans, including unearned loan fees	542,690	319,179
Other
Financing Receivable, Past Due [Line Items]
Total Past Due	285	1,781
Current	266,967	180,467
Loans, including unearned loan fees	267,252	182,248
Financial Asset, 30 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due	28,249	13,529
Financial Asset, 30 to 89 Days Past Due [Member] \| Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	17,470	8,652
Financial Asset, 30 to 89 Days Past Due [Member] \| CRE - investor owned
Financing Receivable, Past Due [Line Items]
Total Past Due	298	734
Financial Asset, 30 to 89 Days Past Due [Member] \| CRE - owner occupied
Financing Receivable, Past Due [Line Items]
Total Past Due	9,900	328
Financial Asset, 30 to 89 Days Past Due [Member] \| Construction and land development
Financing Receivable, Past Due [Line Items]
Total Past Due	169	13
Financial Asset, 30 to 89 Days Past Due [Member] \| Residential real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	138	2,071
Financial Asset, 30 to 89 Days Past Due [Member] \| Other
Financing Receivable, Past Due [Line Items]
Total Past Due	274	1,731
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due	17,632	29,044
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	11,752	12,928
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| CRE - investor owned
Financing Receivable, Past Due [Line Items]
Total Past Due	0	9,301
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| CRE - owner occupied
Financing Receivable, Past Due [Line Items]
Total Past Due	4,560	4,647
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	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	1,309	2,118
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Other
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 11	$ 50