Supplemental Cash Flow Information (Tables)

3 Months Ended

Mar. 31, 2018

Supplemental Cash Flow Elements [Abstract]

Supplemental Cash Flow Information

	Three Months Ended March 31,
	2018			2017
	(in thousands)
Net cash provided from operating activities included:
Income taxes refunded from taxing authorities	$	7,518		$	—
Interest paid		(57,536	)		(43,864	)
Non-cash investing and financing activities included:
Increase in asset retirement costs capitalized		5,063			1,715
(Decrease) increase in accrued capital expenditures		(77,365	)		39,569