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Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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No definition available.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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No definition available.

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Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as noncurrent. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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FAIR VALUE MEASUREMENTS AND FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	$ 105,006	$ 149,294	$ 179,327	$ 161,361
Restricted cash	3,837	4,127
Available for sale securities	49,153	45,754
Liabilities, Fair Value Disclosure [Abstract]
Acquisition contingent consideration	0	376
Long-term debt	413,581	479,653
Fair Value, Level 1 \| Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	105,006	149,294
Restricted cash, fair value	3,837	4,127
Available for sale securities	49,153	45,754
Liabilities, Fair Value Disclosure [Abstract]
Acquisition contingent consideration	0	0
Long-term debt, fair value	0	0
Fair Value, Level 2 \| Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Restricted cash, fair value	0	0
Available for sale securities	0	0
Liabilities, Fair Value Disclosure [Abstract]
Acquisition contingent consideration	0	0
Long-term debt, fair value	407,377	474,856
Fair Value, Level 3 \| Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Restricted cash, fair value	0	0
Available for sale securities	0	0
Liabilities, Fair Value Disclosure [Abstract]
Acquisition contingent consideration	0	376
Long-term debt, fair value	$ 0	$ 0