Investment in Affiliates (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments in Affiliates	$ 14,711	$ 14,581
Investment in OCC [Member]
Investments in Affiliates	333	333
Investment in Signal Trading [Member]
Investments in Affiliates	11,260	11,130
Investment in IPXI [Member]
Investments in Affiliates	3,118	3,118	2,500
Investment in CBSX [Member] [Member]
Investments in Affiliates	$ 0	$ 0