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CAPITAL STOCK - Cash dividends declared (Details) - USD ($)
2 Months Ended 3 Months Ended 12 Months Ended 71 Months Ended
Feb. 22, 2019
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2018
Dividends Payable [Line Items]                                
Per Share Amount   $ 0.24 $ 0.25 $ 0.27 $ 0.31 $ 0.42 $ 0.42 $ 0.42 $ 0.42 $ 1.07 $ 1.68 $ 1.68        
Dividend Declared [Member]                                
Dividends Payable [Line Items]                                
Per Share Amount                   $ 1.07 $ 1.68 $ 1.68 $ 1.92 $ 2.16 $ 1.395 $ 10.065
Total                   $ 55,814,000 $ 70,717,000 $ 41,388,000 $ 38,748,000 $ 22,643,000 $ 4,662,000 $ 241,768,000
Dividend Declared [Member] | Subsequent Event [Member]                                
Dividends Payable [Line Items]                                
Per Share Amount $ 0.16                              
Total $ 7,796,000