Summary of Significant Accounting Policies - Summary of Supplemental Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplemental cash flows:
Cash paid for interest, net of amounts capitalized	$ 87,527	$ 107,272	$ 63,709
Cash paid for taxes	0	472	151
Noncash investing and financing activities:
Increase (decrease) in capital expenditures in payables and accrued liabilities	(6,284)	(27,932)	13,759
(Increase) decrease in accounts receivable related to acquisitions	0	9,698	(5,854)
(Increase) decrease in accounts receivable/payable related to divestitures	(289)	0	0
Repurchases under unit repurchase program	0	0	1,372
Assumptions of asset retirement obligations related to acquisitions	0	23,754	4,265
Asset retirement obligation removal related to divestitures	$ (19,669)	$ 0	$ 0