Investments Other Comprehensive Income (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2015	Dec. 31, 2014
Available for Sale Securities, Noncurrent
Schedule of Available-for-sale Securities [Line Items]
Cost	$ 12,685	$ 18,224
Gross Unrealized Gains	74,495	94,500
Gross Unrealized Losses	(10)	(3)
Fair value	87,170	112,721
Available for Sale Securities, Noncurrent \| Aerospace/Defense
Schedule of Available-for-sale Securities [Line Items]
Cost	11,675	11,675
Gross Unrealized Gains	74,495	64,837
Gross Unrealized Losses	0	0
Fair value	86,170	76,512
Available for Sale Securities, Noncurrent \| Restaurants
Schedule of Available-for-sale Securities [Line Items]
Cost	0	5,974
Gross Unrealized Gains	0	29,663
Gross Unrealized Losses	0	0
Fair value	0	35,637
Available for Sale Securities, Noncurrent \| Manufacturing
Schedule of Available-for-sale Securities [Line Items]
Cost	435	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(4)	0
Fair value	431	0
Available for Sale Securities, Noncurrent \| Other
Schedule of Available-for-sale Securities [Line Items]
Cost	575	575
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(6)	(3)
Fair value	$ 569	$ 572
Nathan's Famous, Inc. \| CoSine Communications, Inc. (CoSine)
Schedule of Available-for-sale Securities [Line Items]
Dividend received	445,456
Proceeds from sale of investment	$ 33,202
Proceeds from Dividends Received	5,500
Impairment	$ 5,500

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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