Investment in Securities, Part II (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 InvestmentHoldinginLossPosition	Dec. 31, 2012 InvestmentHoldinginLossPosition	Dec. 31, 2011
Available for Sale Securities, Cost, Gross Unrealized Gains, Gross Unrealized Losses and Fair Value [Abstract]
Cost	$ 39,283,000	$ 53,850,000
Gross unrealized gains	49,636,000	43,266,000
Gross unrealized losses	(154,000)	(2,000)
Total available for sale securities	88,765,000	97,114,000
Unrealized changes to fair value net of taxes included in other comprehensive income	17,301,000	3,808,000	(2,877,000)
Amount reclassified from other comprehensive income	13,400,000
Return of capital on available for sale securities	1,459,000	2,531,000	2,306,000
Proceeds from sale of investment available for sale	37,888,000	3,184,000	6,054,000
Gross realized gains on sale of investment available for sale	17,700,000	1,600,000	772,000
Gross losses on sale of investments available for sale reclassed from other comprehensive income	49,000	0	0
Investments classified as available for sale unrealized loss position [Abstract]
Cost	1,215,000	73,000
Unrealized Losses	(154,000)	(2,000)
Fair Value	1,061,000	71,000
Number of investment holding in loss positions	4	1
Investment holding impairment period (in months)	7 months	1 month
Value of impaired investment	1,100,000	71,000
Losses deemed to be other than temporary	97,000	20,000	0
Common Stock [Member]
Available for Sale Securities, Cost, Gross Unrealized Gains, Gross Unrealized Losses and Fair Value [Abstract]
Cost	13,389,000	14,822,000
Gross unrealized gains	29,657,000	18,738,000
Gross unrealized losses	0	0
Total available for sale securities	43,046,000	33,560,000
Closed-end Funds [Member]
Available for Sale Securities, Cost, Gross Unrealized Gains, Gross Unrealized Losses and Fair Value [Abstract]
Cost	23,100,000	35,868,000
Gross unrealized gains	17,654,000	22,645,000
Gross unrealized losses	(130,000)	(2,000)
Total available for sale securities	40,624,000	58,511,000
Investments classified as available for sale unrealized loss position [Abstract]
Cost	912,000	0
Unrealized Losses	(130,000)	0
Fair Value	782,000	0
Mutual Funds [Member]
Available for Sale Securities, Cost, Gross Unrealized Gains, Gross Unrealized Losses and Fair Value [Abstract]
Cost	2,794,000	3,160,000
Gross unrealized gains	2,325,000	1,883,000
Gross unrealized losses	(24,000)	0
Total available for sale securities	5,095,000	5,043,000
Investments classified as available for sale unrealized loss position [Abstract]
Cost	303,000	73,000
Unrealized Losses	(24,000)	(2,000)
Fair Value	$ 279,000	$ 71,000