Annual report pursuant to Section 13 and 15(d)

Related Party Transactions - (Narrative) (Details)

v3.8.0.1
Related Party Transactions - (Narrative) (Details) - USD ($)
$ in Thousands
 12 Months Ended
May 28, 2010
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Jun. 24, 2013
May 29, 2012
Related Party Transactions [Line Items]            
Subordinated Debt     $ 22,610      
5% Unsecured Subordinated Notes     22,610      
Subordinated debt interest rate 5.00%          
Debt Instrument, Unamortized Discount   $ 814 814      
Transaction costs   2,088 $ 290 $ 946    
Kanders & Company [Member]            
Related Party Transactions [Line Items]            
Transaction costs   1,000        
Kanders GMP Holdings, LLC [Member]            
Related Party Transactions [Line Items]            
Subordinated Debt $ 14,517         $ 365
Interest paid on transferred subordinated note   89        
Interest paid on Gregory employees subordinated notes   2        
5% Unsecured Subordinated Notes 14,517         365
Discounted subordinated notes 8,640          
Schiller Gregory Investment Company, LLC [Member]            
Related Party Transactions [Line Items]            
Subordinated Debt 7,539         189
Interest paid on Gregory employees subordinated notes   1        
5% Unsecured Subordinated Notes 7,539         $ 189
Discounted subordinated notes 4,487          
Former Employees [Member]            
Related Party Transactions [Line Items]            
Subordinated Debt 554          
5% Unsecured Subordinated Notes 554          
Discounted subordinated notes $ 316          
Robert R. Schiller 2013 Cornerstone Trust and the Deborah Schiller 2005 Revocable Trust [Member]            
Related Party Transactions [Line Items]            
Interest paid on transferred subordinated note   $ 46        
Robert R. Schiller 2013 Cornerstone Trust [Member]            
Related Party Transactions [Line Items]            
Subordinated Debt         $ 3,769  
5% Unsecured Subordinated Notes         $ 3,769