Concentrations of Credit Risk - Commercial Real Estate Loans (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Commercial Mortgages
TOTAL LOANS AND LEASES	$ 40,480.6	$ 33,759.7
Mortgages
Commercial Mortgages
Office	1,011.4	831.3
Apartment/ Multi-family	1,288.8	906.8
Retail	601.8	561.3
Industrial/ Warehouse	442.9	344.2
Other	516.8	409.9
TOTAL LOANS AND LEASES	3,861.7	3,053.5
Commercial Real Estate
Commercial Mortgages
TOTAL LOANS AND LEASES	4,326.3	3,558.4
Construction, Acquisition and Development Loans	$ 464.6	$ 504.9