Debt Obligations (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jul. 25, 2011	Jul. 30, 2008
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 60,000,000	$ 60,000,000		$ 60,000,000
Debt Instrument, Interest Rate, Stated Percentage				3.75%
Convertible Preferred Stock, Shares Issued upon Conversion				77,241.000
Principal Amount of Note				1,000,000
Debt Instrument, Convertible, Conversion Price				$ 12,950.00
Proceeds from Debt, Net of Issuance Costs		50,249,000
Debt Instrument, Unamortized Discount	8,249,000	10,990,000
Convertible Debt, Noncurrent	51,751,000	49,010,000
StockPricePercentageOfConversionPrice					130.00%
PrincipalAmountLessThanProductOfLastReportedSalePriceOfCommonStock					98.00%
PercentageOfPrincipalAmountsBeingRepurchased					100.00%
DebtInstrumentConvertibleInitialCarryingAmountOfLiabilityComponent					45,493,000
Payments for (Proceeds from) Derivative Instrument, Financing Activities	0	0	14,507,000
Issuancecostofdebtinstrument					2,251,000
Issuance cost allocated to APIC					544,000
debtissuancecosttobeallocated					1,707,000
Contractual Interest Coupon	2,250,000	2,251,000	999,000
Amortization of Debt Discount (Premium)	2,740,000	2,486,000	1,031,000
Amortization of Financing Costs	303,000	250,000	98,000
Interest Expense, Debt	5,293,000	4,987,000	2,128,000
Warrant Strike Price				$ 17,000.00	$ 17,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights					4,634,000
Proceeds from Issuance of Warrants	0	0	7,007,000
expected life of the warrant	$ 3.0