Quarterly report pursuant to Section 13 or 15(d)

SENIOR NOTES, NET - Narrative (Details)

v3.10.0.1
SENIOR NOTES, NET - Narrative (Details) - Senior Notes [Member] - USD ($)
6 Months Ended
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Jun. 30, 2015
6.00% senior notes due 2025 [Member]        
Debt Instrument [Line Items]        
Aggregate Principal $ 400,000,000.0   $ 400,000,000.0  
Stated interest rate 6.00%   6.00% 6.00%
Senior notes, gross $ 405,727,000 [1]   $ 200,000,000 [1] $ 200,000,000
6.00% additional senior notes due 2025 [Member]        
Debt Instrument [Line Items]        
Aggregate Principal   $ 200,000,000.0    
Stated interest rate   6.00%    
Percentage of premium on debt 103.00%      
4.50% senior notes due 2018 [Member]        
Debt Instrument [Line Items]        
Stated interest rate 4.50%   4.50%  
Senior notes, gross $ 0   $ 175,000,000  
Repayments of Debt $ 175,000,000      
[1] $200.0 million of the total $400.0 million 6.00% Senior Notes due 2025 outstanding at December 31, 2017 was issued at par and had no unamortized premium.