For an unclassified balance sheet, the amount due from customers or clients for goods or services that have been delivered or sold in the normal course of business, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

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Summary of Significant Accounting Policies - Impact of Changes to Condensed Consolidated Statement of Financial Condition for Adoption of New Revenue Guidance (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Assets
Accounts Receivable, Net	$ 191,820		$ 190,389
Liabilities
Deferred Revenue	5,696		382
Equity (Deficit)
Accumulated Deficit	(176,110)		$ (185,991)
Accounting Standards Update 2014-09
Assets
Accounts Receivable, Net	191,820	$ 184,708
Liabilities
Deferred Revenue	5,696	1,397
Equity (Deficit)
Accumulated Deficit		(192,687)
Accounting Standards Update 2014-09 \| Adjustments
Assets
Accounts Receivable, Net	(6,409)	(5,681)
Liabilities
Deferred Revenue	$ 945	1,015
Equity (Deficit)
Accumulated Deficit		$ (6,696)