XML 68 R57.htm IDEA: XBRL DOCUMENT v3.10.0.1
Fair Value Measurements - Loan Notes Issued by Variable Interest Entities (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Gross written premiums $ 853.8 $ 822.1 $ 1,970.6 $ 1,820.1  
Maximum | Level 3          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Gross written premiums     61.1   $ 61.1
Reserve for losses     $ 61.9   $ 61.9
Contract period     365 days   365 days
Loan notes held by third parties 325.0   $ 325.0   $ 325.0
Minimum | Level 3          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Gross written premiums     50.1   50.1
Reserve for losses     4.2   4.2
Loan notes held by third parties 325.0   325.0   325.0
Fair Value, Measurements, Recurring          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Total 6,770.5   6,770.5   7,485.4
Loan notes held by third parties 20.3   20.3   44.2
Fair Value, Measurements, Recurring | Level 3          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Total (25.3)   (25.3)   (86.6)
Loan notes held by third parties 20.3   20.3   44.2
Fair Value, Measurements, Recurring | Level 3 | Silverton 2016          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Total         86.6
Amount of Level 3 liabilities settled   2.9   114.1  
Total change in fair value included in the statement of operations   $ 3.3   $ 6.2  
Fair Value, Measurements, Recurring | Level 3 | Silverton 2017          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Total 25.3   25.3    
Amount of Level 3 liabilities settled 17.9   63.7    
Total change in fair value included in the statement of operations 3.4   2.4    
Accrued expenses and other payables | Fair Value, Measurements, Recurring          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Loan notes held by third parties 5.0   5.0   42.4
Accrued expenses and other payables | Fair Value, Measurements, Recurring | Level 3          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Loan notes held by third parties $ 5.0   $ 5.0   $ 42.4