Asset Retirement Obligation (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2016

Dec. 31, 2015

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, 2015	$	206,234
Additions to asset retirement obligations		4,562
Accretion expense		1,069
Liabilities settled		(1,605	)
Balance at March 31, 2016	$	210,260

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

Balance at December 31, 2013	$	200,831
Additions to asset retirement obligations		1,238
Accretion expense		5,262
Liabilities settled		(3,004	)
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