XML 44 R32.htm IDEA: XBRL DOCUMENT v3.8.0.1
Corporate Borrowings - Narrative (Details) - USD ($)
Aug. 23, 2017
Mar. 31, 2018
Dec. 31, 2017
Credit Agreement      
Debt Instrument [Line Items]      
Maximum borrowing capacity $ 150,000,000    
Contingent increase in borrowing capacity 25,000,000    
Outstanding borrowings under credit facility   $ 11,039,000 $ 3,298,000
Credit facility, remaining borrowing capacity   $ 138,961,000  
Note Purchase Agreement | Senior Notes      
Debt Instrument [Line Items]      
Term loan face value 75,000,000    
Proceeds from issuance of debt $ 20,000,000