Fair Value Measurements - Recurring (Details) (Level 1, USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Level 1
Investment in Global	$ 9,979	[1]	$ 19,312	[1]

[1] Global's ordinary shares are publicly traded on the Alternative Investment Market ("AIM"), a market operated by the London Stock Exchange, with quoted prices in active markets. Accordingly, the fair value measurements of these securities have been classified as Level 1.