Summary of Significant Accounting Policies - Additional Information 3 (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operations And Summary Of Significant Accounting Policies [Line Items]
Conversion ratio of oil to natural gas in units of production									One barrel of oil for six thousand cubic feet of natural gas
Impairment of unproved oil and natural gas properties		$ 76,391		$ 7,753	$ 385	$ 5,090	$ 23,040	$ 40,432	$ 84,144	$ 68,947	$ 500
Impairment of oil and gas properties	$ 2,561	$ 113	$ 1,742	22,718	$ 254,246	$ 544,714	$ 1,984	$ 403	$ 27,134	$ 801,347	60,268
Impaired oil and gas properties fair value											$ 18,000
Minimum
Operations And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives									3 years
Maximum
Operations And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful lives									31 years 6 months
Other Properties
Operations And Summary Of Significant Accounting Policies [Line Items]
Impaired oil and gas properties fair value									$ 21,100
South Texas
Operations And Summary Of Significant Accounting Policies [Line Items]
Impairment of oil and gas properties				20,800					$ 20,800
Assets held for sale, fair value				$ 42,500