Supplemental Cash Flow Information - Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net cash provided from operating activities included:
Income taxes (refunded from) paid to taxing authorities		$ (1,024)	$ (102)	$ 100
Interest paid		179,431	159,875	168,826
Non-cash investing and financing activities included:
Asset retirement costs capitalized, net	[1],[2]	20,245	(24,064)	22,184
Increase (decrease) in accrued capital expenditures	[1]	$ 71,739	$ 61,419	$ (225,455)

[1] For additional information on non-cash investing activities associated with the MRD Merger, see Note 3

[2] Includes cost incurred whether capitalized or expensed.