STOCKHOLDERS' EQUITY (Schedule of Restricted Stock Units Activity) (Details) - Restricted Stock Units	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Number of Shares
Unvested, beginning balance (in shares) | shares	7,090,465
Granted (in shares) | shares	4,647,404
Released (in shares) | shares	(2,761,821)
Canceled (in shares) | shares	(1,726,843)
Unvested, ending balance (in shares) | shares	7,249,205
Weighted- Average Grant Date Fair Value
Unvested, beginning balance (in dollars per share) | $ / shares	$ 32.43
Granted (in dollars per share) | $ / shares	37.22
Released (in dollars per share) | $ / shares	34.06
Canceled (in dollars per share) | $ / shares	33.75
Unvested, ending balance (in dollars per share) | $ / shares	$ 34.57