Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Contingency [Line Items]
Tax benefit (charge) realized from exercise of employee stock options		$ 3	$ 9	$ 1
Unamortized tax-deductible goodwill resulting from intercompany stock sales and reorganizations		$ 27
Unamortized tax-deduction rate on goodwill		28.00%
Percentage of temporary tax differences that reverse within the carryforward period		42.00%
Percentage of deferred tax asset exclusive of reversing temporary differences		58.00%
Discrete income tax charge for valuation allowances	$ 190
Valuation allowance	2,037	$ 2,037	$ 1,668	$ 1,804	$ 1,400
Foreign tax credits carry forward period		10 years
Percentage of tax rate decreased		(0.80%)	17.90%	0.60%
Noncontrolling interest	2,085	$ 2,085	$ 2,488
Income tax benefit for operational losses related to certain foreign jurisdictions that are excluded from the estimated annual effective tax rate calculation		$ 4,000
Percentage of the effect of unrecognized tax benefit, if recorded		12.00%	4.00%	(1.00%)
Interest and penalties recognized		$ 8	$ 1	$ 2
Income related to accrued interest and penalties		2	5	12
Amount accrued for payment of interest and penalties	9	$ 9	$ 9
Minimum [Member]
Income Tax Contingency [Line Items]
Percentage of tax rate decreased		15.25%
Maximum [Member]
Income Tax Contingency [Line Items]
Percentage of tax rate decreased		34.00%
Tax Year Two Thousand And Sixteen [Member]
Income Tax Contingency [Line Items]
Unamortized tax-deduction rate on goodwill		25.00%
Foreign Tax Authority [Member]
Income Tax Contingency [Line Items]
Discrete income tax charge for valuation allowances		$ 134
Valuation allowance	254	$ 254		$ 135
Foreign tax credits carry forward period		10 years
Foreign tax credits expiry period		2015
Foreign tax credits	15	$ 15
Decrease to the net deferred tax asset and noncash charge to earnings		52
Noncontrolling interest	31	$ 31
Foreign Tax Authority [Member] | Minimum [Member]
Income Tax Contingency [Line Items]
Foreign tax credits expiry period		2016		2016
Foreign Tax Authority [Member] | Maximum [Member]
Income Tax Contingency [Line Items]
Foreign tax credits expiry period		2025		2023
Iceland And Suriname [Member]
Income Tax Contingency [Line Items]
Discrete income tax charge for valuation allowances		$ 141
Suriname [Member]
Income Tax Contingency [Line Items]
Valuation allowance	85	$ 85
Suriname [Member] | Minimum [Member]
Income Tax Contingency [Line Items]
Foreign tax credits expiry period		2016
Suriname [Member] | Maximum [Member]
Income Tax Contingency [Line Items]
Foreign tax credits expiry period		2022
Iceland [Member]
Income Tax Contingency [Line Items]
Valuation allowance	56	$ 56
Iceland [Member] | Minimum [Member]
Income Tax Contingency [Line Items]
Foreign tax credits expiry period		2017
Iceland [Member] | Maximum [Member]
Income Tax Contingency [Line Items]
Foreign tax credits expiry period		2023
Spanish Consolidated Tax Group [Member]
Income Tax Contingency [Line Items]
Discrete income tax charge for valuation allowances				$ 372
Valuation allowance	$ 149	$ 149		$ 237
Spanish Consolidated Tax Group [Member] | Minimum [Member]
Income Tax Contingency [Line Items]
Deferred tax assets expiry period				2016