Debt (Convertible Note Interest Expenses) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Debt Conversion [Line Items]
Discount amortization	$ 3,564	$ 7,361	$ 11,489
Convertible Notes Member
Debt Conversion [Line Items]
Contractual coupon interest expense	0	2,621	5,683
Discount amortization	0	3,796	7,787
Contractual coupon interest expense	$ 0	$ 6,417	$ 13,470

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

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-Subparagraph (SX 210.5-03.8)

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Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings, excluding amortization of debt discount (premium) and financing costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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