ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Contract Balances [Abstract]
Accounts receivable	$ 29,400	$ 26,400
Unbilled fee revenue	9,500	7,800
Unearned revenue	3,500	2,200
Recently Adopted Accounting Pronouncements [Abstract]
Right to use assets	34,956
Lease liability	$ 35,630
ASU 2016-02 [Member]
Recently Adopted Accounting Pronouncements [Abstract]
Right to use assets		34,200
Lease liability		$ 34,200

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Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

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Present value of lessee's discounted obligation for lease payments from operating lease.

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Amount of lessee's right to use underlying asset under operating lease.

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Unbilled amounts due for services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the entity and, at a minimum, one other party. An example would be amounts associated with contracts or programs where the recognized revenue for performance thereunder exceeds the amounts billed under the terms thereof as of the date of the balance sheet.

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