Summary of Significant Accounting Policies (Additional Cash Flow Information) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Cash paid for interest	$ 29,003	$ 49,300	$ 124,781
Cash paid for income tax	39,852	44,140	45,352
Transfer of securities from available for sale to held to maturity	0	0	377,812
Exchange of real estate	11,036	0	0
Unsettled securities transactions	27,032	57,783	0
Loans foreclosed and transferred to other real estate owned and foreclosed assets	3,464	140	1,348
Loans to facilitate the sale of other real estate owned	0	0	847
Right-of-use lease assets obtained in exchange for lessee operating lease liabilities	12,854	18,284	319,286
Treasury stock issued to 401(k) stock purchase plan	$ 1,749	$ 10,307	$ 0