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Commitments and Contingencies - Summary of Asset Retirement Obligations (Details) - USD ($)
$ in Thousands
3 Months Ended
Feb. 28, 2018
Feb. 28, 2017
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
Balance at the beginning of the period $ 14,970 $ 13,448
Accretion expense 208 171
ARO assumed in acquisition 0 493
Revisions to ARO during the period 0 17
Balance at the end of the period $ 15,178 $ 14,129