DERIVATIVE INSTRUMENTS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Net gains recognized in accumulated other comprehensive loss on cash flow hedges
Net change in unrealized loss on cash flow hedges	$ 11,158	$ 14,592
Summary of aggregate notional amount and estimated net fair value of the derivative instruments
Estimated Fair Value	(78,482)		(94,063)
Foreign exchange options and forward contracts
Summary of aggregate notional amount and estimated net fair value of the derivative instruments
Notional amount	129,100		208,100
Cash Flow Hedges: | Interest rate swaps
Summary of aggregate notional amount and estimated net fair value of the derivative instruments
Notional amount	497,833		503,833
Estimated Fair Value	(79,445)		(90,618)
Free-Standing Derivatives:
Effect on income from free-standing derivatives
Realized gains (losses)	(2,445)	(4,836)
Unrealized gains (losses)	(6,559)	13,108
Total	(9,004)	8,272
Free-Standing Derivatives: | Foreign exchange options and forward contracts
Effect on income from free-standing derivatives
Realized gains (losses)	(911)	(105)
Unrealized gains (losses)	(1,920)	1,592
Total	(2,831)	1,487
Free-Standing Derivatives: | Commodity swaps
Summary of aggregate notional amount and estimated net fair value of the derivative instruments
Estimated Fair Value	946		7,056
Effect on income from free-standing derivatives
Realized gains (losses)	1,109	938
Unrealized gains (losses)	(6,109)	3,796
Total	(5,000)	4,734
Free-Standing Derivatives: | Credit Default Swaps
Effect on income from free-standing derivatives
Realized gains (losses)	(2,643)	(5,669)
Unrealized gains (losses)	1,470	7,720
Total	(1,173)	2,051
Free-Standing Derivatives: | Credit default swaps-protection sold
Summary of aggregate notional amount and estimated net fair value of the derivative instruments
Estimated Fair Value			19
Free-Standing Derivatives: | Credit default swaps-protection purchased
Summary of aggregate notional amount and estimated net fair value of the derivative instruments
Notional amount	(118,247)		(47,321)
Estimated Fair Value	(802)		(1,140)
Free-Standing Derivatives: | Foreign exchange forward contracts
Summary of aggregate notional amount and estimated net fair value of the derivative instruments
Notional amount	(259,266)		(338,313)
Estimated Fair Value	(8,001)		(20,975)
Free-Standing Derivatives: | Foreign exchange options
Summary of aggregate notional amount and estimated net fair value of the derivative instruments
Notional amount	130,207		130,207
Estimated Fair Value	5,350		8,277
Free-Standing Derivatives: | Common stock warrants
Summary of aggregate notional amount and estimated net fair value of the derivative instruments
Estimated Fair Value	$ 3,470		$ 3,318
Free-Standing Derivatives: | Natural gas positions | 2013
Fixed price swaps
Hedged volume (MMBtu)	5,188
Average price ($/MMBtu)	3.83
Free-Standing Derivatives: | Natural gas positions | 2014
Fixed price swaps
Hedged volume (MMBtu)	5,821
Average price ($/MMBtu)	4.34
Free-Standing Derivatives: | Natural gas positions | 2015
Fixed price swaps
Hedged volume (MMBtu)	4,277
Average price ($/MMBtu)	4.73
Free-Standing Derivatives: | Natural gas positions | 2016
Fixed price swaps
Hedged volume (MMBtu)	1,805
Average price ($/MMBtu)	4.44
Free-Standing Derivatives: | Natural gas liquid positions | 2013
Fixed price swaps
Hedged volume (in MBbls)	149
Average price ($/Bbl)	35.56
Free-Standing Derivatives: | Natural gas liquid positions | 2014
Fixed price swaps
Hedged volume (in MBbls)	129
Average price ($/Bbl)	20.90
Free-Standing Derivatives: | Oil positions | 2013
Fixed price swaps
Hedged volume (in MBbls)	111
Average price ($/Bbl)	91.77
Free-Standing Derivatives: | Oil positions | 2014
Fixed price swaps
Hedged volume (in MBbls)	159
Average price ($/Bbl)	89.97
Free-Standing Derivatives: | Oil positions | 2015
Fixed price swaps
Hedged volume (in MBbls)	4
Average price ($/Bbl)	95.55