Net Income Attributable to Company Per Share - Computation of Weighted Average Basic and Diluted Shares Outstanding (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Numerator:
Income from continuing operations	$ 310	$ 548
Income from discontinued operations		41
Net income attributable to Company	$ 310us-gaap_NetIncomeLoss	$ 589us-gaap_NetIncomeLoss
Denominator:
Basic-weighted average common shares outstanding	407	428
Dilutive effect of employee stock options and other unvested stock awards	2	1
Diluted outstanding shares	409	429
Basic:
Income from continuing operations	$ 0.76	$ 1.28
Income from discontinued operations		$ 0.10
Net income attributable to Company	$ 0.76us-gaap_EarningsPerShareBasic	$ 1.38us-gaap_EarningsPerShareBasic
Diluted:
Income from continuing operations	$ 0.76	$ 1.28
Income from discontinued operations		$ 0.09
Net income attributable to Company	$ 0.76us-gaap_EarningsPerShareDiluted	$ 1.37us-gaap_EarningsPerShareDiluted
Cash dividends per share	$ 0.46	$ 0.26

Aggregate dividends paid during the period for each share of common stock outstanding.

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