Annual report pursuant to Section 13 and 15(d)

Income Taxes (Narrative) (Details)

v3.8.0.1
Income Taxes (Narrative) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Tax Contingency [Line Items]        
Provision at statutory rate   35.00% 35.00% 35.00%
Income tax benefit   $ 152.0 $ 385.0 $ 389.0
Tax benefit recognized   9.0 7.0  
Unrecognized tax benefits that would impact effective tax rate   39.0    
Federal tax effect on unrecognized tax benefits   11.0    
Significant change in unrecognized tax benefits is reasonably possible, amount of unrecorded benefit   $ 1.0    
UNITED STATES        
Income Tax Contingency [Line Items]        
Provision at statutory rate   35.00%    
Liberty | Tax Agreement        
Income Tax Contingency [Line Items]        
Capital contribution paid to parent company for taxes   $ 31.0   $ 18.0
Cash dividends paid to parent company for taxes     64.0  
Current tax payments due to related parties   60.0 $ 75.0  
Tax Year 2017        
Income Tax Contingency [Line Items]        
Income tax benefit   $ 284.6    
Subsequent Event [Member]        
Income Tax Contingency [Line Items]        
Provision at statutory rate 21.00%