OWNERSHIP (Details)	Dec. 31, 2017 shares
The Vanguard Group
Beneficial Ownership [Line Items]
Ownership interest (as a percent)	6.80%
Common stock deemed to be beneficially owned (in shares)	61,323,039
Blackrock, Inc
Beneficial Ownership [Line Items]
Ownership interest (as a percent)	7.20%
Common stock deemed to be beneficially owned (in shares)	64,406,363
Capital Research Global Investors
Beneficial Ownership [Line Items]
Ownership interest (as a percent)	6.40%
Common stock deemed to be beneficially owned (in shares)	57,556,990