Cash, Cash Equivalents, and Marketable Securities [Text Block] | Note 2. Cash , Cash Equivalents and Marketable Investments The Company invests its cash primarily in money market funds, commercial paper, corporate notes and bonds, municipal bonds, and debt securities issued by the U.S. government and its agencies. The Company considers all highly liquid investments, with an original maturity of three months or less at the time of purchase, to be cash equivalents. Investments with maturities of greater than three months at the time of purchase are accounted for as “available-for-sale ,” are carried at fair value with unrealized gains and losses reported as a component of stockholders’ equity, are held for use in current operations and are classified in current assets as “marketable investments .” The following tables summarize the components, and the unrealized gains and losses position, related to the Company’s cash, cash equivalents and marketable investments (in thousands): March 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Market Value Cash and cash equivalents: Cash $ 4,734 $ — $ — $ 4,734 Money market funds 1,531 — — 1,531 Commercial paper — — — — Total cash and cash equivalents 6,265 — — 6,265 Marketable investments: U.S. government notes 10,400 18 — 10,418 U.S. government agencies 10,626 3 (5 ) 10,624 Municipal securities 3,764 6 — 3,770 Commercial paper 2,693 2 — 2,695 Corporate debt securities 10,671 9 (3 ) 10,677 Total marketable investments 38,154 38 (8 ) 38,184 Total cash, cash equivalents and marketable investments $ 44,419 $ 38 $ (8 ) $ 44,449 December 31, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Market Value Cash and cash equivalents: Cash $ 9,830 $ — $ — $ 9,830 Money market funds 1,000 — — 1,000 Commercial paper 38 — — 38 Total cash and cash equivalents 10,868 — — 10,868 Marketable investments: U.S. government notes 7,780 1 (2 ) 7,779 U.S. government agencies 12,630 3 (25 ) 12,608 Municipal securities 4,344 2 — 4,346 Commercial paper 4,041 1 (2 ) 4,040 Corporate debt securities 8,783 — (17 ) 8,766 Total marketable investments 37,578 7 (46 ) 37,539 Total cash, cash equivalents and marketable investments $ 48,446 $ 7 $ (46 ) $ 48,407 As of March 31, 2016 and December 31, 2015, total gross unrealized losses were $8 ,000 and $46,000, respectively, and were related to interest rate changes on available-for-sale marketable investments. The Company has concluded that it is more-likely-than-not that the securities will be held until maturity or the recovery of their cost basis. No securities were in an unrealized loss position for more than 12 months . The following table summarizes the contractual maturities of the Company’s available-for-sale securities, classified as marketable investments as of March 31, 2016 (in thousands): Amount Due in less than one year $ 29,795 Due in 1 to 3 years 8,389 Total marketable investments $ 38,184 |