XML 84 R68.htm IDEA: XBRL DOCUMENT v3.20.4
Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($)
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Mar. 22, 2019
Dec. 31, 2018
Goodwill and Intangible Assets [Line Items]        
Amortization of intangible assets $ 8,300,000 $ 9,100,000    
Impairment of indefinite-lived intangible asset 6,800,000 0    
Goodwill And Other Intangible Assets        
Goodwill and Intangible Assets [Line Items]        
Goodwill, gross 213,300,000 213,000,000.0   $ 199,900,000
Goodwill, accumulated impairment loss (2,300,000) (2,300,000)    
Equity Method Investment, Nonconsolidated Investee or Group of Investees        
Goodwill and Intangible Assets [Line Items]        
Goodwill, gross 15,100,000 15,100,000   $ 15,100,000
Goodwill, accumulated impairment loss (4,500,000) $ (4,500,000)    
TMR        
Goodwill and Intangible Assets [Line Items]        
Finite-lived intangible assets     $ 11,200,000  
Indefinite-lived intangible assets $ 0   $ 6,800,000  
Low        
Goodwill and Intangible Assets [Line Items]        
Finite-lived intangible assets, useful life 2 years 3 months 18 days      
High        
Goodwill and Intangible Assets [Line Items]        
Finite-lived intangible assets, useful life 13 years 2 months 12 days      
Weighted Average or Actual        
Goodwill and Intangible Assets [Line Items]        
Finite-lived intangible assets, useful life 6 years 2 months 12 days