ACCUMULATED OTHER COMPREHENSIVE LOSS - RECLASSIFICATIONS OUT OF AOCL (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Interest Charges	$ 9,160	$ 8,601
Other Income	(2,203)	(2,241)
Income Taxes	39,267	16,613
Losses (Gains) from reclassifications for the period net of tax	$ (68,187)	$ (53,853)
Combined statutory tax rate	40.00%	40.00%
Reclassification out of Accumulated Other Comprehensive Income
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Losses (Gains) from reclassifications for the period net of tax	$ 37
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gain (Loss) on Derivatives-Other
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Interest Charges	86
Income Taxes	(35)
Losses (Gains) from reclassifications for the period net of tax	51
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Loss on Available-for-Sale Securities
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other Income	(25)
Income Taxes	11
Losses (Gains) from reclassifications for the period net of tax	$ (14)