Goodwill and Intangible Assets - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) Brand	Sep. 30, 2017 USD ($) Brand	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)
Goodwill and Intangible Assets Disclosure [Line Items]
Amortization expense for intangible assets	$ 44		$ 44
Estimated amortization expense in year 1	178
Estimated amortization expense in year 2	178
Estimated amortization expense in year 3	178
Estimated amortization expense in year 4	87
Estimated amortization expense in year 5	$ 87
Number of brands | Brand	13
Intangible asset, aggregate book value	$ 17,868			$ 17,671
Trademarks
Goodwill and Intangible Assets Disclosure [Line Items]
Intangible asset impairment		$ 70
Number of impaired brands | Brand	5	5
Intangible asset, aggregate book value	$ 980