XML 76 R64.htm IDEA: XBRL DOCUMENT v3.8.0.1
Junior Subordinated Debentures - Schedule of Maybrooke Junior Subordinated Debentures (Detail) - USD ($)
$ in Millions
9 Months Ended
Sep. 30, 2017
Dec. 31, 2016
Debt Instrument [Line Items]    
Principal $ 143.8 $ 143.8
Maybrooke Junior Subordinated Debentures [Member]    
Debt Instrument [Line Items]    
Issue Date Sep. 15, 2007  
Maturity Sep. 15, 2037  
Rate Structure 3M LIBOR + 3.15%  
Interest Rate 4.47%  
Principal $ 91.8  
Carrying Value $ 83.8