XML 75 R63.htm IDEA: XBRL DOCUMENT v3.10.0.1
DEBT, CREDIT FACILITY, AND CAPITAL LEASE OBLIGATIONS (Credit Facility) (Details) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Feb. 14, 2019
Line of Credit | Revolving Credit Facility And Letter of Credit      
Debt Instrument [Line Items]      
Line of credit facility borrowing capacity $ 250,000,000 $ 250,000,000  
Borrowed 0 35,000,000  
Available $ 250,000,000 $ 215,000,000  
Weighted Average Interest Rate (in percentage) 0.00% 2.56%  
Line of Credit | Letter of Credit      
Debt Instrument [Line Items]      
Line of credit facility borrowing capacity $ 50,000,000 $ 50,000,000  
LIBOR      
Debt Instrument [Line Items]      
Basis of variable spread (in percentage) 1.00% 1.00%  
Base Rate      
Debt Instrument [Line Items]      
Basis of variable spread (in percentage) 0.00% 0.00%  
Subsequent Event | Line of Credit | Revolving Credit Facility And Letter of Credit      
Debt Instrument [Line Items]      
Available     $ 250,000,000