Inventory Financing Agreements (Textual) (Detail) barrel / d in Thousands		3 Months Ended		6 Months Ended
	Jun. 01, 2015 USD ($) barrel / d extension	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)
Amortization of Intangible Assets		$ 1,000,000	$ 900,000	$ 1,600,000	$ 1,800,000
Supply and exchange agreement expenses		5,825,000	3,397,000		6,904,000
Loss on termination of financing agreements		19,229,000	0	19,229,000	0
Supply and Offtake Agreements [Member]
Supply and Offtake agreement term	3 years
Number of commitment extensions | extension	2
Commitment period	1 year
Barrels of crude per day provided by J. Aron | barrel / d	94
Handling fees		1,500,000
Supply and exchange agreement expenses		100,000
Amount of deferred payment arrangement	$ 125,000,000	78,200,000.0		78,200,000.0
Outstanding amount of deferred payment arrangement		36,000,000		36,000,000
Percentage of receivables and inventory for deferred payment arrangement	85.00%
Deferral arrangement fee	$ 1,300,000
Supply and Exchange Agreements [Member]
Handling fees		3,100,000	3,900,000	6,900,000	7,400,000
Supply and exchange agreement expenses		900,000		2,300,000
Interest expense and financing costs			$ 1,400,000		$ 2,800,000
Price variance loss on commitment	13,300,000
Accelerated deferred financing costs	5,600,000
Exit fee received	$ 1,500,000
Loss on termination of financing agreements		$ 17,400,000		$ 17,400,000
London Interbank Offered Rate (LIBOR) [Member] | Supply and Offtake Agreements [Member]
Margin on LIBOR rate	3.75%
Deferred payment availability fee	0.75%