Guarantees, Contingencies and Commitments - Additional Information (Detail) - USD ($)	1 Months Ended		12 Months Ended
	Apr. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Jul. 25, 2011
Loss Contingencies [Line Items]
Contingent liabilities under letters of credit outstanding			$ 32,000,000	$ 54,000,000
N Y
Loss Contingencies [Line Items]
Estimated remedial design costs		$ 506,000,000
N J
Loss Contingencies [Line Items]
Estimated remedial design costs	$ 1,700,000,000
HOVENSA
Loss Contingencies [Line Items]
Interest in joint venture			50.00%
Settlement Agreement - U.S. Virgin Islands				3,500,000
Amount to be paid to U.S. Virgin Islands as per settlement agreement				$ 40,000,000
Debtor-in-possession, credit facility			$ 40,000,000
Claims settled as part of sale			40,000,000
Difference between estimated plan obligation and fair value of the asset plan			$ 30,000,000
Proposed total penalties related to violation of Virgin Islands Air Control laws					$ 210,000