Contingencies - Tronox Litigation (Detail) (USD $)	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2014	Apr. 03, 2014
Loss Contingencies [Line Items]
Tronox-related contingent loss	$ 4,360,000,000	$ 850,000,000	$ (250,000,000)
Tronox Litigation [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Litigation-related contingent liability	5,210,000,000	0		5,150,000,000
Pre Settlement Interest Rate					6.00%
Post Settlement Interest Rate First 180 Days					1.50%
Tronox-related contingent loss	4,360,000,000	850,000,000		4,300,000,000
Tronox Litigation [Member] | Pending Litigation [Member] | London Interbank Offered Rate (LIBOR) [Member]
Loss Contingencies [Line Items]
Post Settlement Interest Rate After 180 Days					1.50%
Tronox Litigation [Member] | Pending Litigation [Member] | Excluding Pre-Judgment Interest Sought and Attorneys' Fees and Costs [Member]
Loss Contingencies [Line Items]
Damages sought				18,850,000,000
Tronox Litigation [Member] | Pending Litigation [Member] | Principal Portion Of Loss Contingency Accrual [Member]
Loss Contingencies [Line Items]
Litigation-related contingent liability					3,980,000,000
Tronox Litigation [Member] | Pending Litigation [Member] | Post Settlement Interest Expense [Member]
Loss Contingencies [Line Items]
Tronox-related contingent loss	$ 60,000,000