Basis of Presentation and Summary of Significant Accounting Policies (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncurrent receivables	$ 2,110				$ 2,090				$ 2,110	$ 2,090
Advertising expense									373	338	$ 377
Provision for doubtful accounts charged to expense									$ 12	$ 9	$ 9
Earnings Per Share [Abstract]
Weighted average shares for basic EPS	424	442	451	459	469	480	490	498	444	484	550
Dilutive effect of shares issuable under stock-based compensation plans									4	5	11
Weighted average shares for diluted EPS	429	446	455	464	474	484	495	506	448	489	561
Maximum [Member]
Property, Plant and Equipment [Line Items]
Finite-lived intangible asset useful life									40 years
Minimum [Member]
Property, Plant and Equipment [Line Items]
Finite-lived intangible asset useful life									4 years
Building [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment estimated useful life									40 years
Building [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment estimated useful life									10 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Leasehold improvement estimated useful life									Shorter of lease term or useful life
Equipment and other (including capital leases) [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment estimated useful life									20 years
Equipment and other (including capital leases) [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment estimated useful life									3 years
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share									4	4	2