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Investments and Fair Value Measurements - Additional Information (Detail) - Level 3 [Member] - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Estimated fair value of acquisition payable		$ 9,900
Discounted cash flows, discount rate	27.50%
ETP [Member] | Europe [Member] | Minimum [Member]
Schedule of Held-to-maturity Securities [Line Items]
Projected AUM	$ 1,000,000
ETP [Member] | Europe [Member] | Maximum [Member]
Schedule of Held-to-maturity Securities [Line Items]
Projected AUM	$ 6,000,000

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Assets Under Management

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Discounted Cash Flow Discount Rate

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Estimated Fair Value of Acquisition Payable

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