XML 50 R39.htm IDEA: XBRL DOCUMENT v3.10.0.1
INVESTMENTS (Equity Method Investments) (Details) - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Dec. 31, 2016
Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]        
Payments to acquire equity method investments $ 0 $ 1,000,000    
Equity method investments $ 110,488,000     $ 108,597,000
Harrington Reinsurance Holdings Limited        
Schedule of Equity Method Investments [Line Items]        
Payments to acquire equity method investments     $ 108,000,000  
Equity method investment, ownership percentage     19.00%  
Equity method investment, difference between carrying amount and underlying equity     $ 5,000,000  
UNITED STATES | Other Equity Method Investments        
Schedule of Equity Method Investments [Line Items]        
Impairment charge   9,000,000    
Equity method investments   $ 0