Quarterly report pursuant to Section 13 or 15(d)

Investments in Marketable Securities (Held to Maturity Securities, by Maturity) (Details)

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Investments in Marketable Securities (Held to Maturity Securities, by Maturity) (Details) (USD $)
Mar. 31, 2014
Dec. 31, 2013
Schedule of Held-to-maturity Securities [Line Items]    
Available-for-sale Securities $ 103,000 $ 103,000
Letters of Credit Outstanding, Amount 2,000,000  
Held-to-maturity Securities, Current 1,247,000 1,858,000
Held-to-maturity Securities, Noncurrent 988,000 370,000
Held-to-maturity Securities, Total 2,235,000 2,228,000
Mutual Funds [Member]
    
Schedule of Held-to-maturity Securities [Line Items]    
Available-for-sale Securities 55,000 55,000
Cash/Money Market Accounts [Member]
    
Schedule of Held-to-maturity Securities [Line Items]    
Available-for-sale Securities 48,000 48,000
Held-to-maturity Securities, Current 135,000 116,000
Held-to-maturity Securities, Noncurrent 0 0
Held-to-maturity Securities, Total 135,000 116,000
US Treasury Securities [Member]
    
Schedule of Held-to-maturity Securities [Line Items]    
Held-to-maturity Securities, Current 636,000 1,360,000
Held-to-maturity Securities, Noncurrent 841,000 370,000
Held-to-maturity Securities, Total 1,477,000 1,730,000
US Government Agencies Securities [Member]
    
Schedule of Held-to-maturity Securities [Line Items]    
Held-to-maturity Securities, Current 476,000 382,000
Held-to-maturity Securities, Noncurrent 147,000 0
Held-to-maturity Securities, Total $ 623,000 $ 382,000