Investments - Components of Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Strategic investments:
Investments accounted for under the equity method	$ 86,853	$ 86,328
Investments held at fair value	1,814	4,435
Common stock or equivalent of companies representing less than 20% equity ownership held at adjusted cost	8,746	8,949
Total Strategic investments	97,413	99,712
Other investments	1,530	1,014
Total Investments	$ 98,943	$ 100,726