Annual report pursuant to Section 13 and 15(d)

Goodwill and Intangible Assets - Additional Information (Details)

v3.8.0.1
Goodwill and Intangible Assets - Additional Information (Details) - USD ($)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]      
Goodwill impairment $ 0    
Amortization of intangibles 621,000,000 $ 730,000,000 $ 834,000,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]      
2018 538,000,000    
2019 105,000,000    
2020 53,000,000    
2021 0    
2022 0    
Thereafter $ 0