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Asset Retirement Obligations (Tables)
 12 Months Ended
Dec. 31, 2018
Asset Retirement Obligation Disclosure [Abstract]  
Schedule of Reconciliation of Changes in the Asset Retirement Obligations
The reconciliation of changes in the asset retirement obligations at December 31, 2018 and 2017 is as follows:
 
 
As of December 31,
 
 
2018
 
2017
Balance at Beginning of Period
 
$
258,823

 
$
272,538

Accretion Expense
 
19,468

 
18,922

Payments
 
(8,976
)
 
(10,467
)
Revisions in Estimated Cash Flows
 
(2,314
)
 
(20,529
)
Other
 
—

 
(1,641
)
Balance at End of Period
 
$
267,001

 
$
258,823