Goodwill - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Line Items]
Goodwill	$ 94,781	$ 94,781	[1]

[1] Derived from the audited consolidated financial statements at December 31, 2014.