Fair Value Measurements - Summary of Carrying Amount and Fair Values of Financial Instruments Reported on the Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Balance sheet assets
Securities available for sale	$ 1,005,426	$ 1,135,317
Securities held-to-maturity, net	327,694	181,166
Carrying Amount
Balance sheet assets
Securities held-to-maturity, net	327,049	181,166
Other investments	43,456	38,044
Loans held for sale	14,032	5,570
Loans, net	6,003,037	5,271,049
State tax credits held for sale	42,497	36,802
Balance sheet liabilities
Certificates of deposit	612,045	826,447
Subordinated debentures and notes	203,510	141,258
FHLB advances	250,000	222,406
Other borrowings and notes payable	239,038	265,172
Estimated fair value
Balance sheet assets
Securities held-to-maturity, net	338,774	181,939
Other investments	43,456	38,044
Loans held for sale	14,032	5,570
Loans, net	5,961,862	5,205,651
State tax credits held for sale	48,327	39,046
Balance sheet liabilities
Certificates of deposit	617,277	825,203
Subordinated debentures and notes	193,059	130,985
FHLB advances	251,942	221,402
Other borrowings and notes payable	$ 239,038	$ 265,172