Fair Value Measurements - Additional Information (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) Counterparty	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Interest and dividends	$ 136	$ 109
Mark-to-market gain (loss)	259	1,400
Impairment on natural gas and oil properties	43,040	$ 0
Allowance for doubtful accounts on accounts receivable	$ 4,477		$ 4,994
Number of financial institutions included in counter parties | Counterparty	19
Number of counterparties | Counterparty	4
Net derivative asset	$ 9,500
Western Oklahoma
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impairment on natural gas and oil properties	$ 43,040