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INCOME TAXES - Changes in Valuation Allowance (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016
Deferred Tax Asset, Valuation Allowance [Roll Forward] |  |
Balance at beginning of period | $ 72,705 | $ 62,333
Balance at end of period | 83,847 | 72,705
Valuation allowance increases primarily related to foreign NOLs [Member] |  |
Deferred Tax Asset, Valuation Allowance [Roll Forward] |  |
Valuation allowance, increase (decrease) | 12,861 | 12,174
Valuation allowance releases related to foreign NOLs [Member] |  |
Deferred Tax Asset, Valuation Allowance [Roll Forward] |  |
Valuation allowance, increase (decrease) | 8,035 | 3,870
Other valuation allowance changes, net [Member] |  |
Deferred Tax Asset, Valuation Allowance [Roll Forward] |  |
Valuation allowance, increase (decrease) | (4,703) | (6,557)
Valuation allowance increase related to U.S. foreign tax credits [Member] |  |
Deferred Tax Asset, Valuation Allowance [Roll Forward] |  |
Valuation allowance, increase (decrease) | $ 11,019 | $ 8,625

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- Definition Deferred Tax Asset, Valuation Allowance [Roll Forward] + References No definition available. + Details
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- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319 + Details
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- Definition Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=84176650&loc=d3e32123-109318 + Details
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