Buildings and Equipment (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
ORIGINAL COST	$ 1,221.1	$ 1,612.6
ACCUMULATED DEPRECIATION	732.4	1,097.7
NET BOOK VALUE	488.7	514.9
Land and Improvements
Property, Plant and Equipment [Line Items]
ORIGINAL COST	11.5	14.5
ACCUMULATED DEPRECIATION	0.3	0.5
NET BOOK VALUE	11.2	14.0
Buildings
Property, Plant and Equipment [Line Items]
ORIGINAL COST	217.6	257.8
ACCUMULATED DEPRECIATION	136.5	163.0
NET BOOK VALUE	81.1	94.8
Equipment
Property, Plant and Equipment [Line Items]
ORIGINAL COST	478.4	816.4
ACCUMULATED DEPRECIATION	275.4	596.8
NET BOOK VALUE	203.0	219.6
Leasehold Improvements
Property, Plant and Equipment [Line Items]
ORIGINAL COST	513.6	523.9
ACCUMULATED DEPRECIATION	320.2	337.4
NET BOOK VALUE	$ 193.4	$ 186.5