Investments (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ 1,307,000	$ 6,631,000	$ 7,477,000	$ 1,379,000
Investment in Marketable Securities (Textual) [Abstract]
Marketable Securities, Unrealized Gain (Loss)	301,000	6,026,000	(10,756,000)	774,000
Other than Temporary Impairment Losses, Investments	900,000		18,100,000
Short term investments	0		0		999,000
Marketable securities [Member]
Available-for-sale Securities
Available-for-sale Securities, Amortized Cost	17,860,000		17,860,000		34,786,000
Available-for-sales Securities, Gross Unrealized Losses	(987,000)		(987,000)		(10,443,000)
Available-for-sale Securities, Gross Unrealized Gains	743,000		743,000		2,722,000
Available-for-sale Securities, Estimated Fair Value	$ 17,616,000		$ 17,616,000		$ 27,065,000