Supplemental Cash Flow Information (Tables)

6 Months Ended

Jun. 30, 2017

Supplemental Cash Flow Elements [Abstract]

Supplemental Cash Flow Information

	Six Months Ended June 30,
	2017		2016
	(in thousands)
Net cash provided from operating activities included:
Income taxes paid to (refunded) from taxing authorities	$	98	$	(101	)
Interest paid		84,653		69,991
Non-cash investing and financing activities included:
Increase in asset retirement costs capitalized		3,855		3,740
Increase (decrease) in accrued capital expenditures		36,926		(4,741	)