Goodwill and Intangible Assets - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Nov. 01, 2013
Business Acquisition [Line Items]
Goodwill	$ 33,899,000	$ 38,634,000	$ 38,634,000
Other identifiable intangible assets	8,082,000
Identified intangible assets with indefinite useful life	3,721,000
Impairment of goodwill	4,735,000	$ 0	$ 0
Impairment of intangible assets	0
HCON
Business Acquisition [Line Items]
Goodwill				$ 38,600,000
Other identifiable intangible assets				8,100,000
Identified intangible assets with indefinite useful life				3,700,000
Identified intangible assets with finite useful life				$ 4,400,000
Fair value of goodwill	33,900,000
Impairment of goodwill	$ 4,700,000