XML 70 R51.htm IDEA: XBRL DOCUMENT v3.20.4
LEASES. (Additional Information) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Leases [Abstract]      
Weighted-average remaining lease term on operating leases 4 years 9 months 18 days    
Weighted-average discount rate on operating leases 3.50%    
Operating lease expense $ 32.1 $ 29.0 $ 40.1
Variable charges related to operating leases not included in measurement of lease liability 9.3    
Cash paid included in measurement of operating lease liabilities $ 31.2