DEBT - Credit Agreement (Details) (USD $)			9 Months Ended		9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Credit Agreement Line of Credit Revolving Credit Facility	Sep. 30, 2014 Credit Agreement Line of Credit Letter of Credit	Sep. 30, 2014 Credit Agreement London Interbank Offered Rate (LIBOR) Line of Credit Revolving Credit Facility	Sep. 30, 2014 Credit Agreement Minimum London Interbank Offered Rate (LIBOR) Line of Credit Revolving Credit Facility	Sep. 30, 2014 Credit Agreement Maximum London Interbank Offered Rate (LIBOR) Line of Credit Revolving Credit Facility	Nov. 06, 2014 Subsequent Event Commercial Paper	Oct. 31, 2014 Subsequent Event Commercial Paper
Line of Credit Facility [Line Items]
Term			5 years
Maximum borrowing capacity			$ 1,000,000,000						$ 1,000,000,000
Interest rate spread					1.10%	0.90%	1.50%
Facility fee (percentage)					0.15%	0.10%	0.25%
Minimum level of net worth required			7,600,000,000
Actual net worth	10,125,000,000	9,316,000,000	10,100,000,000
Required maximum leverage ratio			3.0
Actual leverage ratio			1.8
Uncommitted incremental loan facility			250,000,000
Line of credit, outstanding borrowings			0
Letters of credit outstanding				5,000,000
Remaining borrowing capacity			995,000,000
Amount outstanding								$ 150,000,000