Debt Subordinated debt (Details) - USD ($)
$ in Thousands
12 Months Ended
Nov. 06, 2015
Dec. 31, 2015
Sep. 30, 2015
Dec. 31, 2014
Debt Instrument [Line Items]        
Debt Instrument, Principal Value   $ 90,500   $ 104,118
Interest Payable     $ 0 17,400
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum   3.85%    
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum   4.20%    
Debt Instrument, Interest Rate, Effective Percentage Rate Range, Minimum   4.27%    
Debt Instrument, Interest Rate, Effective Percentage Rate Range, Maximum   4.61%    
Debt Instrument, Periodic Payment, Interest $ 22,100      
Subordinated Debt [Member]        
Debt Instrument [Line Items]        
Debt Instrument, Principal Value   $ 90,500   $ 90,500