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COMMITMENTS AND CONTINGENCIES (Details Textual) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Operating Leases, Rent Expense, Net [Abstract] |  |  |
Operating lease rent expense | $ 8.6 | $ 8.5 | $ 8.2
Reserve requirement | $ 35.8 | $ 31.8 |
Minimum [Member] |  |  |
Operating Leases, Rent Expense, Net [Abstract] |  |  |
Operating lease renewal period option | 4 months |  |
Maximum [Member] |  |  |
Operating Leases, Rent Expense, Net [Abstract] |  |  |
Operating lease renewal period option | 10 years |  |

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- Definition Cash deposited in a special reserve account for the exclusive benefit of customers pursuant to SEC Regulations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 305 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6478312&loc=d3e61473-112792 + Details
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- Definition Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line. + References No definition available. + Details
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