Selected Quarterly Financial Data (Narrative) (Detail) - USD ($) $ in Thousands	3 Months Ended					6 Months Ended	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Data [Line Items]
Acquisition related costs								$ 4,235	$ 2,147
Severance-related expenses		$ 4,827	$ 19,402
Excise taxes			14,322
Share-based compensation expenses from accelerated vesting			8,022
Goodwill write-down								411,786
Intangible assets, accumulated impairment	$ 38,507					$ 38,351	$ 38,507	38,351
Decrease in contingent consideration							(2,623)	(22,180)	(3,450)
Synergy bonus	$ 6,498	$ 5,300
Share-based compensation expense							44,772	20,318	18,446
Share-based compensation expense, net of taxes							28,680	12,587	11,372
Exploration and Production [Member]
Quarterly Financial Data [Line Items]
Goodwill write-down					$ 411,786			411,786
Indefinite-lived intangible asset write-down					38,300	$ 38,351	156
Impairment charges							2,653	$ 67,647	$ 8,445
Impairments on long-lived assets					63,928
Decrease in contingent consideration					$ 20,642
Other Acquisition [Member]
Quarterly Financial Data [Line Items]
Acquisition related costs							1,968
Progressive Waste Solutions Ltd. [Member]
Quarterly Financial Data [Line Items]
Acquisition related costs			$ 23,037	$ 8,521			$ 31,408