Other Income (Expense), net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Investment income	$ 1,019	$ 1,332	$ 3,504	$ 4,231
Realized gain (loss) on sales of marketable securities, net	(3,393)	(1,002)	(1,430)	4,065
Realized gain (loss) on financial instrument obligations	1,346	(83)	1,063	(752)
Realized loss upon change to equity method at fair value	0	0	(2,807)	(568)
Realized gain on non-monetary exchange	9,326	0	9,326	0
Foreign exchange loss	(295)	(223)	(492)	(394)
Other	(98)	9	13	(68)
Other income (expense), net	$ 7,905	$ 33	$ 9,177	$ 6,514