Fair Value - Fair Value Measurement (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assumed Gain/(Loss) From Loan Sale	$ 6,059
Interest Rate Movement Effect	2,105
Servicing Rights Value	11,263
Security Price Change	(1,604)
Total Fair Value Measurement Gain/(Loss)	17,823	$ 15,583
Mortgage Banking | Level 2 | Fair Value, Recurring | Rate Lock Commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure, off-balance sheet risks, face amount, liability	1,130,241
Assumed Gain/(Loss) From Loan Sale	4,469
Interest Rate Movement Effect	1,942
Servicing Rights Value	8,317
Total Fair Value Measurement Gain/(Loss)	14,728
Mortgage Banking | Level 2 | Fair Value, Recurring | Forward Sales Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value disclosure, off-balance sheet risks, face amount, liability	1,263,416
Security Price Change	(1,604)
Total Fair Value Measurement Gain/(Loss)	(1,604)
Mortgage Banking | Level 2 | Fair Value, Recurring | Mortgages Held for Sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assumed Gain/(Loss) From Loan Sale	1,590
Interest Rate Movement Effect	163
Servicing Rights Value	2,946
Fair value, option, changes in fair value, gain (loss)	4,699	10,042
Fair Value, principal amount, loans held for sale	$ 339,981	$ 439,718