Recent Accounting Developments - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Recognized right of use asset	$ 436,927
Recognizing lease liabilities	487,555
Allowance for credit losses	$ 1,051,071	$ 1,019,444	$ 1,017,198	$ 988,997
ASU 2016-02 [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Lessee, operating lease term	12 months
Recognized right of use asset	$ 394,000
Recognizing lease liabilities	399,000
ASU 2016-13 [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Allowance for credit losses	$ 132,000