Long-Term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership. This does not include advances to clients.

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-Publisher FASB
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Percentage of voting equity interests acquired at the acquisition date in the business combination.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (that is, noncontrolling interest, previously referred to as minority interest).

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The cash outflow to reacquire common stock during the period.

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The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

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Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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Summary Of Major Accounting Policies - Acquisitions (Details) - USD ($) $ in Thousands		12 Months Ended
	Aug. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Sep. 30, 2017
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	60.00%
Payments for Repurchase of Common Stock		$ 0	$ 0	$ 100,459
Stockholders' Equity Attributable to Noncontrolling Interest		5,354	0
Payments to Acquire Businesses, Net of Cash Acquired	$ (12,400)	$ 11,278	$ 30,121	$ 224,018
Variable Interest Entity, Not Primary Beneficiary [Member]
Business Acquisition [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	49.00%
Subsidiaries [Member]
Business Acquisition [Line Items]
Advances to Affiliate					$ 6,400