Derivative Contracts (Details 2) (Not Designated as Hedging Instrument [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Derivative [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 3,305	$ (37,453)	$ 3,758	$ (48,351)
Common stock options/warrants
Derivative [Line Items]
Derivative, Gain (Loss) on Derivative, Net	651	(692)	388	3,152
2033 Senior Notes
Derivative [Line Items]
Derivative, Gain (Loss) on Derivative, Net	2,521	(36,603)	3,291	(51,478)
Forward Contracts
Derivative [Line Items]
Contract value	2,835		2,835		1,536
Fair value	2,914		2,914		1,585
Derivative, Gain (Loss) on Derivative, Net	133	(158)	79	(25)	49
Forward Contracts | 0 to 30
Derivative [Line Items]
Contract value	535		535		472
Fair value	568		568		489
Derivative, Gain (Loss) on Derivative, Net			33		17
Contract days until maturity, lower range			0 days		0 days
Contract days until maturity, higher range			30 days		30 days
Forward Contracts | 31 to 60
Derivative [Line Items]
Contract value	1,217		1,217		561
Fair value	1,245		1,245		579
Derivative, Gain (Loss) on Derivative, Net			28		18
Contract days until maturity, lower range			31 days		31 days
Contract days until maturity, higher range			60 days		60 days
Forward Contracts | 61 to 90
Derivative [Line Items]
Contract value	735		735		503
Fair value	748		748		517
Derivative, Gain (Loss) on Derivative, Net			13		14
Contract days until maturity, lower range			61 days		61 days
Contract days until maturity, higher range			90 days		90 days
Forward Contracts | 91 to 120
Derivative [Line Items]
Contract value	348		348		0
Fair value	353		353		0
Derivative, Gain (Loss) on Derivative, Net			5		0
Contract days until maturity, lower range			91 days		91 days
Contract days until maturity, higher range			120 days		120 days
Forward Contracts | 121 to 180
Derivative [Line Items]
Contract value	0		0		0
Fair value	0		0		0
Derivative, Gain (Loss) on Derivative, Net			0		0
Contract days until maturity, lower range			121 days		121 days
Contract days until maturity, higher range			180 days		180 days
Forward Contracts | More than 180
Derivative [Line Items]
Contract value					0
Fair value
Derivative, Gain (Loss) on Derivative, Net					$ 0
Contract days until maturity, higher range					180 days