Investment in Marketable Securities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Investment in Marketable Securities (Textual) [Abstract]
Investment in marketable securities	$ 231,348		$ 231,348		$ 242,819
Impairment on securities included as a component of realized gain (loss)	154,692		154,692		171,450
Net accumulated other comprehensive income			76,656		71,369
Gross unrealized losses			1,131		3,189
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	23,394		23,394		9,304
Impairments on available for sale securities	0	0	0	0
Dividend income recognized	$ 3,669	$ 4,228	$ 7,388	$ 8,823