XML 97 R60.htm IDEA: XBRL DOCUMENT v3.8.0.1
Investments Composition of Fixed Maturities by Maturity (Detail) - USD ($)
$ in Millions
Dec. 31, 2017
Dec. 31, 2016
Available for sale, cost    
Less than one year $ 3,964.1  
One to five years 12,706.5  
Five to ten years 3,294.4  
Ten years or greater 244.9  
Total 20,209.9 $ 16,287.1
Available for sale, Fair value    
Less than one year 3,980.0  
One to five years 12,671.3  
Five to ten years 3,306.9  
Ten years or greater 243.5  
Total $ 20,201.7 $ 16,243.8