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Investments and Fair Value Measurements (Tables) | 6 Months Ended
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Jun. 30, 2013
Investments and Fair Value Measurements [Abstract] |
Schedule of Available-for-sale Securities Reconciliation [Table Text Block] | The amortized cost and fair value of available-for-sale investments at June 30, 2013 and December 31, 2012 were as follows:
|  |  |  | Gross |  | Gross |  |
|  | Amortized |  | Unrealized |  | Unrealized |  | Fair
|  | Cost |  | Gains |  | Losses |  | Value
|  | ( in thousands)
June 30, 2013 |  |
Long-term: |  |  |  |  |  |  |  |  |  |  |  |
Auction rate student loan educational bonds |  | $ | 11,475 |  |  | $ | — |  |  | $ | 684 |  |  | $ | 10,791 |
December 31, 2012 |  |  |  |  |  |  |  |
Long-term: |  |  |  |  |  |  |  |  |  |  |  |
Auction rate student loan educational bonds |  | $ | 21,300 |  |  | $ | — |  |  | $ | 1,284 |  |  | $ | 20,016 |
Investments Classified by Contractual Maturity Date [Table Text Block] |
|  | Fair Value |  | Amortized Cost
Due within one year |  | $ | — |  |  | $ | — |
Due after one year through five years |  | — |  |  | — |
Due after five years through ten years |  | — |  |  | — |
Due after ten years through May 1, 2040 |  | 10,791 |  |  | 11,475 |
|  | $ | 10,791 |  |  | $ | 11,475 |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] | The table below presents a rollforward for all assets and liabilities, measured at fair value, on a recurring basis using significant unobservable inputs (Level 3) during the six months ended June 30, 2013 and 2012.
|  | Available-for-sale debt securities
|  | (in thousands)
|  | 2013 |  | 2012
Balance, January 1 |  | $ | 20,016 |  |  | $ | 50,569 |
Settlements |  | (9,825 | ) |  | (31,325 | )
Purchases |  | — |  |  | — |
Issuances |  | — |  |  | — |
Sales |  | — |  |  | — |
Transfers in to (out of) Level 3 |  | — |  |  | — |
Total gains or losses (realized/unrealized): |  |  |  |  |
Included in earnings |  | — |  |  | — |
Included in other comprehensive income, net of tax |  | 600 |  |  | 1,797 |
Balance, June 30, |  | $ | 10,791 |  |  | $ | 21,041 |

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- Definition Tabular disclosure of the fair value measurement of assets using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets) and gains or losses recognized in other comprehensive income (loss), and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs), by class of asset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19279-110258 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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- Definition Tabular disclosure of maturities of an entity's investments as well as any other information pertinent to the investments. + References No definition available. + Details
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- Definition Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value. + References No definition available. + Details
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