Goodwill and Intangible Assets - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Goodwill And Intangible Assets [Line Items]
Amortization of intangibles assets	$ 2,369	$ 2,176	$ 6,963	$ 6,211
Consolidated Subsidiaries
Goodwill And Intangible Assets [Line Items]
Goodwill impairment charges	0	0	0	0
Intangible assets impairment charges	$ 0	$ 0	$ 0	$ 0