Property and Equipment - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ 12,435,000	$ 10,281,000
Depreciation and amortization	2,377,000	1,590,000	$ 1,990,000
Lease and Loaner Instruments [Member]
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ 867,000	$ 128,000