Disclosure About Fair Values of Financial Instruments - Summary of Assets Recorded at Fair Value on a Nonrecurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans, net of specific allowance	$ 249,133	$ 278,587
Other real estate	2,406	7,605
Level 2
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Loans held for sale	59,461	61,359
Fair Value, Nonrecurring
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Loans held for sale	59,461	61,359
Impaired loans, net of specific allowance	71,741	65,088
Other real estate	2,406	7,605
Total assets measured on a nonrecurring basis	133,608	134,052
Fair Value, Nonrecurring | Level 2
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Loans held for sale	59,461	61,359
Total assets measured on a nonrecurring basis	59,461	61,359
Fair Value, Nonrecurring | Level 3
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Impaired loans, net of specific allowance	71,741	65,088
Other real estate	2,406	7,605
Total assets measured on a nonrecurring basis	$ 74,147	$ 72,693