Summary of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Apr. 24, 2013
Oil and gas properties:
Proved	$ 462,404	$ 460,255
Unproved	101,426	101,520
Total oil and gas properties	563,830	561,775
Capitalized Costs, Proved Properties	2,738,102	2,593,700	277,888
Support equipment	2,759,959	2,615,213
Total other property and equipment	3,323,789	3,176,988
Accumulated depreciation, depletion and amortization	(1,011,786)	(939,684)
Property and equipment, net (successful efforts method)	2,312,003	2,237,304
Support Equipment and Facilities [Member]
Oil and gas properties:
Support equipment	$ 21,857	$ 21,513