XML 118 R107.htm IDEA: XBRL DOCUMENT v3.8.0.1
Income Taxes - Narrative (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended 12 Months Ended 24 Months Ended
Apr. 01, 2017
Jun. 30, 2017
Sep. 30, 2017
Dec. 31, 2016
Mar. 31, 2017
Income Taxes [Line Items]          
Realization assessment period     3 years    
Interest and penalties related to uncertain tax positions     $ 1.2 $ 2.0  
Accrued interest and penalties, uncertain tax positions   $ 37.0      
Accrued interest, uncertain tax positions     2.0 7.0  
Unrecognized tax benefits that would impact effective tax rate     $ 30.0 $ 57.0  
United States [Member]          
Income Taxes [Line Items]          
Corporate tax rate     35.00%    
United Kingdom [Member]          
Income Taxes [Line Items]          
Corporate tax rate 19.00%   19.25%   20.00%
Radian [Member]          
Income Taxes [Line Items]          
Foreign tax credits acquired     $ 19.0    
Assured Guarantee Europe (AGE) [Member]          
Income Taxes [Line Items]          
Foreign tax credits acquired     $ 1.0