SHARE-BASED COMPENSATION - Summary of Share-based Compensation Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Components and classification of share-based compensation expense
Share-based compensation expense	$ 23	$ 33	$ 51	$ 97
Research and development expenses
Components and classification of share-based compensation expense
Share-based compensation expense	2	1	4	3
Selling, general and administrative expenses
Components and classification of share-based compensation expense
Share-based compensation expense	21	32	47	94
Stock options
Components and classification of share-based compensation expense
Share-based compensation expense	5	4	10	7
RSUs
Components and classification of share-based compensation expense
Share-based compensation expense	$ 18	$ 29	$ 41	$ 90