DISCONTINUED OPERATIONS - Components of the net gain on divestiture (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Common shares tendered	58,813,151
Share price of common shares tendered	$ 33.22		$ 33.22
Common shares tendered (58,813,151 shares at $33.22 per share)			$ 1,954	$ 0
Cash			707	0
Net gain on divestiture	972	0	972	0
Real Estate Divestiture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Common shares tendered (58,813,151 shares at $33.22 per share)	1,954
Cash	707
Proceeds	2,661
Net book value of contributed assets	(1,671)
Transaction costs, net of reimbursement	(18)
Net book value of contributed assets and transaction costs, net of reimbursement	(1,689)
Net gain on divestiture	$ 972