SHARE-BASED COMPENSATION - Summary of Share-based Compensation Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Components and classification of share-based compensation expense
Share-based compensation expense	$ 19	$ 37	$ 70	$ 134
Research and development expenses
Components and classification of share-based compensation expense
Share-based compensation expense	2	2	6	5
Selling, general and administrative expenses
Components and classification of share-based compensation expense
Share-based compensation expense	17	35	64	129
Stock options
Components and classification of share-based compensation expense
Share-based compensation expense	4	4	14	11
RSUs
Components and classification of share-based compensation expense
Share-based compensation expense	$ 15	$ 33	$ 56	$ 123