Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Goodwill [Line Items]
Goodwill and intangible assets with indefinite lives	$ 65,281		$ 66,419
Amortization expense associated with identifiable intangible assets	1,100	$ 1,100
Estimated total amortization expense 2015	2,300
Estimated total amortization expense 2016	700
Estimated total amortization expense 2017	400
Estimated total amortization expense 2018	400
Estimated total amortization expense 2019	400
Indefinite-lived Intangible Assets [Member]
Goodwill [Line Items]
Goodwill and intangible assets with indefinite lives	$ 59,700		$ 59,700