Asset Retirement Obligations (Tables)

9 Months Ended

Sep. 30, 2017

Asset Retirement Obligation Disclosure [Abstract]

Summary of Changes in Asset Retirement Obligations

The following table provides a summary of the changes in the Company’s asset retirement obligations:

(in thousands)	Amount
Balance at January 1, 2017	$	9,370
Accretion expense	781
Balance at September 30, 2017	$	10,151