v2.4.0.6
Investments and Fair Value Measurements (Details) (USD $)
 3 Months Ended
Mar. 31, 2013
Auction
Mar. 31, 2012
Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]      
Amortized Cost $ 48,612,000 $ 34,264,000  
Unrealized Gains (Losses) (194,000) (269,000)  
Aggregate Fair Value 48,418,000 33,995,000  
Cash and cash equivalents 55,000 1,150,000  
Short-term available-for-sale securities 47,634,000 32,122,000 32,122,000
Long-term available-for-sale securities 729,000 723,000 723,000
Aggregate fair value of short-term municipal bonds 39,200,000   26,100,000
Financial liabilities [Abstract]      
Short-term municipal security funds as a percentage of municipal securities (in hundredths) 83.00%   82.00%
Municipal revenue bonds as a percentage of municipal securities (in hundredths) 11.00%   12.00%
Municipal general obligation bonds as a percentage of municipal securities (in hundredths) 60.00%   60.00%
Reconciliation of available-for-sale ARS measured at fair value on a recurring basis using Level 3 inputs [Roll Forward]      
Beginning balance 723,000 700,000  
Total realized / unrealized losses [abstract]      
Included in earnings 0 0  
Included in OCI 6,000 3,000  
Sales and settlements 0 0  
Ending balance 729,000 703,000  
Number of investments that failed at auction 1    
Principal amount of failed ARS auction 1,000,000    
Basis points (in hundredths) 3.25%    
Cost basis 1,000,000    
Recognized gains or losses on sale of investments 0 0  
Accumulated Other Comprehensive Income, unrealized gains and losses on available for sale securities [Roll Forward]      
Balance, January 1, (180,000) 135,000  
Other comprehensive income, net of income taxes 48,000 107,000  
Balance, March 31, (132,000) 242,000  
Fair Market Value [Member]
      
Financial assets [Abstract]      
ARS 729,000 723,000  
Money market funds 55,000 1,150,000  
Municipal securities 47,634,000 [1] 32,122,000 [1]  
Foreign currency exchange contracts 401,000 952,000  
Total financial assets 48,819,000 34,947,000  
Financial liabilities [Abstract]      
Foreign currency exchange contracts 346,000 115,000  
Total financial liabilities 346,000 115,000  
Quoted Prices in Active Markets for Identical Assets (Level 1)
      
Financial assets [Abstract]      
ARS 0 0  
Money market funds 55,000 1,150,000  
Municipal securities 47,634,000 [1] 32,122,000 [1]  
Foreign currency exchange contracts 0 0  
Total financial assets 47,689,000 33,272,000  
Financial liabilities [Abstract]      
Foreign currency exchange contracts 0 0  
Total financial liabilities 0 0  
Significant Other Observable Inputs (Level 2) [Member]
      
Financial assets [Abstract]      
ARS 0 0  
Money market funds 0 0  
Municipal securities 0 [1] 0 [1]  
Foreign currency exchange contracts 401,000 952,000  
Total financial assets 401,000 952,000  
Financial liabilities [Abstract]      
Foreign currency exchange contracts 346,000 115,000  
Total financial liabilities 346,000 115,000  
Significant Other Unobservable Inputs (Level 3) [Member]
      
Financial assets [Abstract]      
ARS 729,000 723,000  
Money market funds 0 0  
Municipal securities 0 [1] 0 [1]  
Foreign currency exchange contracts 0 0  
Total financial assets 729,000 723,000  
Financial liabilities [Abstract]      
Foreign currency exchange contracts 0 0  
Total financial liabilities 0 0  
Auction Rate Securities ("ARS"), Greater Than One Year [Member]
      
Schedule of Available-for-sale Securities [Line Items]      
Amortized Cost 1,000,000 1,000,000  
Unrealized Gains (Losses) (271,000) (277,000)  
Aggregate Fair Value 729,000 723,000  
Cash and cash equivalents 0 0  
Short-term available-for-sale securities 0 0  
Long-term available-for-sale securities 729,000 723,000  
Money Market Funds, Ninety Days or Less [Member]
      
Schedule of Available-for-sale Securities [Line Items]      
Amortized Cost 55,000 1,150,000  
Unrealized Gains (Losses) 0 0  
Aggregate Fair Value 55,000 1,150,000  
Cash and cash equivalents 55,000 1,150,000  
Short-term available-for-sale securities 0 0  
Long-term available-for-sale securities 0 0  
Municipal Securities Maturing in One Year or Less [Member]
      
Schedule of Available-for-sale Securities [Line Items]      
Amortized Cost 39,900,000 [2],[3] 26,885,000 [2],[3]  
Unrealized Gains (Losses) 61,000 [2],[3] (1,000) [2],[3]  
Aggregate Fair Value 39,961,000 [2],[3] 26,884,000 [2],[3]  
Cash and cash equivalents 0 [2],[3] 0 [2],[3]  
Short-term available-for-sale securities 39,961,000 [2],[3] 26,884,000 [2],[3]  
Long-term available-for-sale securities 0 [2],[3] 0 [2],[3]  
Municipal Securities Maturing After One Year Through Three Years [Member]
      
Schedule of Available-for-sale Securities [Line Items]      
Amortized Cost 1,993,000 [2] 1,345,000 [2]  
Unrealized Gains (Losses) 13,000 [2] 7,000 [2]  
Aggregate Fair Value 2,006,000 [2] 1,352,000 [2]  
Cash and cash equivalents 0 [2] 0 [2]  
Short-term available-for-sale securities 2,006,000 [2] 1,352,000 [2]  
Long-term available-for-sale securities 0 [2] 0 [2]  
Municipal Securities Maturing Greater Than Three Years [Member]
      
Schedule of Available-for-sale Securities [Line Items]      
Amortized Cost 5,664,000 [2] 3,884,000 [2]  
Unrealized Gains (Losses) 3,000 [2] 2,000 [2]  
Aggregate Fair Value 5,667,000 [2] 3,886,000 [2]  
Cash and cash equivalents 0 [2] 0 [2]  
Short-term available-for-sale securities 5,667,000 [2] 3,886,000 [2]  
Long-term available-for-sale securities $ 0 [2] $ 0 [2]  
[1] At March 31, 2013, municipal securities consisted of a 83/11/6 percent split between holdings in short-term municipal security funds, municipal revenue bonds and municipal general obligation bonds, respectively. As part of our investment policy, during the first quarter of 2012, we began investing in debt funds comprised of short-term municipal securities. At December 31, 2012, municipal securities consisted of an 82/12/6 split between holdings in short-term municipal security funds, municipal revenue bonds and municipal general obligation bonds, respectively. In addition, the underlying credit rating of the municipal securities at March 31, 2013 and December 31, 2012 were A+, A1 or better as defined by S&P 500 and Moody's, respectively.
[2] Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties.
[3] Amounts include short-term municipal security funds that do not have a set maturity date. The aggregate fair value of short-term municipal securities was $39.2 million and $26.1 million as of March 31, 2013, and December 31, 2012, respectively.