Goodwill and Other Intangible Assets - Summary of Intangible Assets, Net (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Definite-lived intangible assets, net:
Investment contracts	$ 158,747	$ 157,882
Accumulated amortization	(149,380)	(145,665)
Definite-lived intangible assets, net	9,367us-gaap_FiniteLivedIntangibleAssetsNet	12,217us-gaap_FiniteLivedIntangibleAssetsNet
Indefinite-lived intangible assets	32,416	32,416
Total intangible assets, net	$ 41,783	$ 44,633	$ 48,711	$ 52,096

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

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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 after 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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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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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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