Asset Retirement Obligation (Tables)

12 Months Ended

Dec. 31, 2016

Asset Retirement Obligation Disclosure [Abstract]

Information Related to Asset Retirement Obligations

The following table reflects information related to our asset retirement obligations:

Balance at December 31, 2014	$	204,327
Additions to asset retirement obligations		1,680
Accretion expense		4,845
Liabilities settled		(4,618	)
Balance at December 31, 2015	$	206,234
Additions to asset retirement obligations		5,008
Accretion expense		4,272
Liabilities settled		(4,625	)
Balance at December 31, 2016	$	210,889