SHAREHOLDERS' INTEREST - Additional Information (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2013 Rate	Aug. 13, 2014
Class of Stock [Line Items]
New shares issued	0	33,350,000	0
Stock repurchase program, shares repurchased	6,063,000	0	0
Stock repurchase program, repurchase of common stock, cash settlement	$ 203	$ 0	$ 0
Stock repurchase program 2014
Class of Stock [Line Items]
Stock repurchase program, authorized repurchase amount					700
Stock repurchase program, shares repurchased	6,062,993
Stock repurchase program, shares repurchased value	203
Stock repurchase program, remaining authorized repurchase amount	497
Preferred shares
Class of Stock [Line Items]
Preferred shares, outstanding	0	0
Preferred shares, authorized	7,000,000
Preferred shares, par value	$ 1
6.375 percent Mandatory Convertible Preference Shares, Series A
Class of Stock [Line Items]
Preferred shares, outstanding	13,800,000	13,800,000
Preferred shares, authorized	40,000,000	40,000,000
Preferred shares, par value	$ 1.00	$ 1.00		$ 1.00
New shares issued				13,800,000
Preference shares, liquidation preference	$ 50.00	$ 50.00		$ 50.00
Net proceeds from issuance of preference shares				$ 669
Preference shares, dividend rate				6.375%
Minimum | 6.375 percent Mandatory Convertible Preference Shares, Series A
Class of Stock [Line Items]
Preference shares, shares that will be issued upon conversion	1.5090
Maximum | 6.375 percent Mandatory Convertible Preference Shares, Series A
Class of Stock [Line Items]
Preference shares, shares that will be issued upon conversion	1.8107