Loans and Leases Held for Investment and Credit Quality - Summary of Total Loans and Leases Held for Investment and Aging Analysis of Portfolio Segments (Parenthetical) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans and leases receivable	$ 5,142,004	$ 4,881,665
90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due loans	26,351	25,231
30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due loans	16,540	26,440
Loans Insured or Guaranteed by US Government Authorities
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans and leases receivable	2,000,000	2,070,000
Loans Insured or Guaranteed by US Government Authorities | 90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due loans	16,800	16,400
Loans Insured or Guaranteed by US Government Authorities | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due loans	10,500	18,400
Loans Insured or Guaranteed by US Government Authorities | Not Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total past due loans	$ 1,970,000	$ 2,040,000