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v3.19.3.a.u2

FAIR VALUE (Details) | 12 Months Ended
--- | ---
Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($)
Assets: |  |
Total assets measured at fair value | $ 586,831,000 | $ 600,637,000
Unobservable inputs assets (level 3) [Roll forward] |  |
Temporary impairment of the auction rates security investments | (730,000) | (730,000)
Money Market Funds |  |
Assets: |  |
Total assets measured at fair value | 576,761,000 | 590,567,000
Auction Rate Securities |  |
Assets: |  |
Total assets measured at fair value | 10,070,000 | 10,070,000
Fair Value, Inputs, Level 1 |  |
Assets: |  |
Total assets measured at fair value | 576,761,000 | 590,567,000
Fair Value, Inputs, Level 1 | Money Market Funds |  |
Assets: |  |
Total assets measured at fair value | 576,761,000 | 590,567,000
Fair Value, Inputs, Level 1 | Auction Rate Securities |  |
Assets: |  |
Total assets measured at fair value | 0 | 0
Fair Value, Inputs, Level 2 |  |
Assets: |  |
Total assets measured at fair value | 0 | 0
Fair Value, Inputs, Level 2 | Money Market Funds |  |
Assets: |  |
Total assets measured at fair value | 0 | 0
Fair Value, Inputs, Level 2 | Auction Rate Securities |  |
Assets: |  |
Total assets measured at fair value | 0 | 0
Fair Value, Inputs, Level 3 |  |
Assets: |  |
Total assets measured at fair value | 10,070,000 | 10,070,000
Fair Value, Inputs, Level 3 | Money Market Funds |  |
Assets: |  |
Total assets measured at fair value | 0 | 0
Fair Value, Inputs, Level 3 | Auction Rate Securities |  |
Assets: |  |
Total assets measured at fair value | 10,070,000 | 10,070,000
Auction Rate Securities |  |
Unobservable inputs assets (level 3) [Roll forward] |  |
Beginning balance | 10,070,000 | 10,070,000
Decrease in unrealized loss included in accumulated other comprehensive loss | 0 | 0
Ending balance | $ 10,070,000 | $ 10,070,000
Auction rate securities variable rate debt instruments interest rate reset period | 28 days |
The minimum contractual maturities on the underlying securities involved in the auction rate securities (in years) | 20 years |
Par value of company held auction rate securities | $ 11,000,000 |
Temporary impairment of the auction rates security investments | $ 0 |
Weighted Average | Measurement Input, Discount Rate |  |
Unobservable inputs assets (level 3) [Roll forward] |  |
Debt securities, measurement input | 0.05 | 0.06

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- Definition Auction rate securities are variable rate investments that have the interest rate on the security set to the market rate on a contractual basis, this element defines the contractual basis period for the security market change in the interest rate. + References No definition available. + Details
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- Definition This element represents the underlying maturity dates of the securities the auction rate security is based upon. + References No definition available. + Details
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- Definition Amount, after tax, of accumulated unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=118930883&loc=d3e681-108580 + Details
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- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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- Definition The value of securities held, for which the interest rate resets through an auction process, that are categorized neither as trading nor held-to-maturity, that failed to be liquidated through auction. + References No definition available. + Details
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- Definition Value of input used to measure investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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- Definition Amount of gain (loss) recognized in other comprehensive income (OCI) from asset measured at fair value on recurring basis using unobservable input (level 3). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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