Related Party Transactions - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($) bbl
Related Party Transaction [Line Items]
Revenues from transactions with related party	$ 1,400,000	$ 95,128,000	$ 100,405,000
Due from affiliates		13,100,000
Due to Affiliate		300,000
Related party transaction, due to related party		1,200,000
Production expenses to affiliates	1,654,000	5,123,000	1,408,000
Total amount paid to related party	7,700,000	58,200,000	48,500,000
Due to affiliates		5,600,000
Amount charged to affiliate for aircraft use	9,600	51,000	55,000
Amount charged to company by affiliate for aircraft use	236,000	97,000	$ 51,000
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Number of barrels purchased from affiliate | bbl			30,000
Purchases from transactions with related party			$ 3,000,000
Expenses from transactions with related party	8,800,000	1,800,000
Capitalized costs	2,600,000	5,900,000	5,700,000
Production expenses to affiliates	1,700,000	5,100,000	1,400,000
Total amount paid to related party	9,200,000	1,900,000
Officers And Other Key Employees [Member]
Related Party Transaction [Line Items]
Revenues from transactions with related party	500,000	800,000	1,300,000
Due to affiliates	52,000	133,000
Revenues paid to related party	700,000	1,700,000	2,300,000
Due from affiliates	106,000	207,000
Other Affiliates [Member]
Related Party Transaction [Line Items]
Total amount paid to related party	221,000	34,000	238,000
Total amount received from related party	$ 33,000	39,000	379,000
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Revenues from transactions with related party		$ 95,100,000	$ 100,400,000