Goodwill and Other Intangible Assets - Summary of Intangible Assets, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Definite-lived intangible assets, net:
Investment contracts	$ 158,747	$ 158,747
Accumulated amortization	(155,136)	(152,676)
Definite-lived intangible assets, net	3,611	6,071
Indefinite-lived intangible assets	34,816	34,816
Total intangible assets, net	$ 38,427	$ 40,887	$ 41,783	$ 44,633