Supplemental Cash Flow Information - Summary of Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental cash flow information:
Cash paid for interest	$ 301,743	$ 267,384	$ 209,815
Cash paid for income taxes	30	53,457	29,017
Cash received for income tax refunds	61,403	7	174
Change in capital expenditures incurred but not paid	(519,949)	290,782	89,482
Non-cash investing activities:
Asset retirement obligation additions and revisions, net	$ 22,472	$ 18,938	$ 8,835