Intangible Assets, Net - Summary of Intangible Assets, Net (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Definite-lived intangible assets:
Investment contracts	$ 158,747	$ 158,747
Accumulated amortization	(150,217)	(149,380)
Definite-lived intangible assets, net	8,530us-gaap_FiniteLivedIntangibleAssetsNet	9,367us-gaap_FiniteLivedIntangibleAssetsNet
Indefinite-lived intangible assets	32,416	32,416
Total intangible assets, net	$ 40,946	$ 41,783	$ 43,528	$ 44,633

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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-Name Accounting Standards Codification

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

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Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

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