Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 5,984	$ 5,740	$ 6,070
Increase in goodwill during the period	244
Amortization expenses for other intangible assets	76	$ 78	$ 80
Indefinite-lived intangible assets	18
Expected amortization expenses related to other intangible assets in 2016	76
Expected amortization expenses related to other intangible assets in 2017	67
Expected amortization expenses related to other intangible assets in 2018	61
Expected amortization expenses related to other intangible assets in 2019	54
Expected amortization expenses related to other intangible assets in 2020	$ 47