Composition of Loan and Lease Portfolio (Parenthetical) (Detail) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans		$ 41,844,019	$ 40,133,861
Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	[1]	3,014,378	2,388,420
Commercial and Industrial | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans		1,742,380	1,705,308
Lease financing, unearned income
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unearned income		104,826	53,891
Non-Covered Loans		1,271,998	683,112
Specialty Finance Loans | Commercial and Industrial | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans		2,600,000	1,900,000
Other Commercial and Industrial Loans | Commercial and Industrial | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans		$ 420,100	$ 469,900

[1] Includes specialty finance loans and leases of $0.0 billion and $1.9 billion, respectively, at December 30, 2019 and 2018. Other C&I loans of $000.0 million and $469.9 million, respectively, at December 30, 2019 and 2018.