Notes and Loan Payable and Amounts Due Under Repurchase Agreements (2015 Notes, 2015 Notes Hedges and 2015 Warrants Narrative) (Details) - USD ($) $ in Thousands		12 Months Ended
	Sep. 15, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2010
Debt Instrument [Line Items]
Interest expense on convertible notes		$ 28,248	$ 28,849	$ 36,370
Convertible Debt [Member]
Debt Instrument [Line Items]
Interest expense on convertible notes			$ 1,400	9,000
2015 Notes Embedded Conversion Derivative [Member]
Debt Instrument [Line Items]
Derivative, liability, fair value at issuance					$ 37,000
Derivative liability, cash paid to settle conversion premium	$ 25,800
September 2015 Notes [Member]
Debt Instrument [Line Items]
Debt instrument, face amount					$ 200,000
Interest rate					3.50%
Deferred financing costs					$ 6,800
Extinguishment of debt, cash paid	48,200
Extinguishment of debt, amount	$ 22,400
Interest rate, effective percentage			8.90%
September 2015 Notes [Member] | Private Exchange Offers [Member]
Debt Instrument [Line Items]
Extinguishment of debt, cash paid				82,900
Extinguishment of debt, amount				69,600
Extinguishment of debt, cash paid for shares of common stock				$ 48,200
Extinguishment of debt, shares issued				2,115,055
Extinguishment of debt, carrying value at extinguishment				$ 66,000
Extinguishment of debt, gain (loss), net of tax				$ (4,800)