Asset Retirement Obligation (Tables)
|12 Months Ended|
Dec. 31, 2017
|Asset Retirement Obligation Disclosure [Abstract]|
|Schedule of Changes in Asset Retirement Obligations||
The following table provides a reconciliation of the changes in the estimated present value of asset retirement obligations for the years ended December 31, 2017 and 2016.
Tabular disclosure of the changes in carrying amount of a liability for asset retirement obligations, for changes such as new obligations, changes in estimates of existing obligations, spending on existing obligations, property dispositions, and foreign currency translation.
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef