Long Term Investments Textuals (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			3 Months Ended				1 Months Ended
	Mar. 31, 2011	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Long Term Investment [Member]	Mar. 31, 2011 Long Term Investment [Member]	Mar. 31, 2012 Long Term Investment [Member] Limited Partnership [Member]	Mar. 31, 2011 Long Term Investment [Member] Limited Partnership [Member]	Jan. 31, 2012 Hedge Funds [Member]	Apr. 30, 2011 Hedge Funds [Member]	Mar. 31, 2012 Hedge Funds [Member]	Dec. 31, 2011 Hedge Funds [Member]
Schedule of Equity Method Investments [Line Items]
Distributions from liquidation of long-term investments	$ 8,886
Gain recognized	4,136
Payments to Acquire Equity Investments								5,000	10,000
Equity (loss) income on long-term investments				(114)	763	(114)	763
Equity Method Investments		$ 24,431	$ 16,499							$ 24,431	$ 16,499