Investment Income (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Investment Income [Abstract]
Interest and dividend income	$ 213,000	$ 153,000	$ 2,836,000	$ 2,884,000
Investment gain	9,780,000	519,000	9,780,000	1,071,000
Equity earnings (loss)	(2,000)	(497,000)	(522,000)	(665,000)
Total investment income	9,991,000	175,000	12,094,000	3,290,000
Gain associated in connection with previously written-off investment	$ 9,800,000