XML 129 R111.htm IDEA: XBRL DOCUMENT v3.20.4
Leases - Components of Lease Expense (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Lease Cost      
Operating lease cost (ASC Topic 842) $ 9.1 $ 12.8  
Operating lease cost (ASC Topic 840)     $ 17.6
Financing lease cost:      
Depreciation of lease assets 0.8 0.1  
Interest on lease liabilities [1] 0.4 0.0  
Sublease income (ASC Topic 842) (4.1) (4.4)  
Sublease income (ASC Topic 840)     (4.9)
Net lease cost (ASC Topic 842) $ 6.2 $ 8.5  
Net lease cost (ASC Topic 840)     $ 12.7
[1] Interest on lease liabilities was less than $0.1 million for the year ended December 31, 2019.