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Commitments and Contingencies - Summary of Asset Retirement Obligations (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Aug. 31, 2017
Aug. 31, 2016
Aug. 31, 2017
Aug. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]        
Balance at the beginning of the period $ 14,319 $ 11,542 $ 13,448 $ 9,992
ARO assumed in acquisition 279 278 772 1,806
Accretion expense 201 141 558 387
Revisions to ARO during the period (3) (78) 18 (302)
Balance at the end of the period $ 14,796 $ 11,883 $ 14,796 $ 11,883