Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Summary Of Significant Accounting Policies [Line Items]
Allowance for doubtful accounts	$ 1,900,000
Capitalized exploratory drilling costs pending evaluation	0	$ 0	$ 0
Amortization expense including write-off of debt issuance costs	22,100,000	6,100,000	4,200,000
Impairment expense	183,437,000	616,784,000	407,540,000
Capitalized interest	$ 500,000	$ 2,100,000	$ 2,800,000
Chance of tax benefit likely to be realized	greater than 50%
Customer Concentration Risk [Member] | Revenues [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of total revenue	10.00%
Minimum [Member] | Other Property & Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	3 years
Maximum [Member] | Other Property & Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	7 years
Support Equipment and Facilities [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	15 years
Support Equipment and Facilities [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	40 years