Investments (Details 1) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Debt Instrument [Line Items]
Total interest	$ 1,768	$ 84	$ 2,202	$ 195
2.50% Convertible Notes
Debt Instrument [Line Items]
Interest expense at 2.50% coupon rate	725		725
Amortization of debt discount	921		921
Amortization of deferred debt issuance costs	97		97
Total interest	1,743		1,743
Other Borrowings
Debt Instrument [Line Items]
Total interest	$ 25	$ 84	$ 459	$ 195