Property and Equipment, net (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Property and equipment-at cost:
Total property and equipment-at cost	$ 35,283,000		$ 35,283,000		$ 31,828,000
Less accumulated depreciation	(15,505,000)		(15,505,000)		(13,560,000)
Property and equipment, net	19,778,000		19,778,000		18,268,000
Depreciation expense	1,114,000	$ 797,000	2,207,000	$ 1,603,000
Plant and machinery [Member]
Property and equipment-at cost:
Total property and equipment-at cost	11,928,000		11,928,000		10,145,000
Instruments [Member]
Property and equipment-at cost:
Total property and equipment-at cost	11,286,000		11,286,000		9,869,000
Office equipment [Member]
Property and equipment-at cost:
Total property and equipment-at cost	1,751,000		1,751,000		1,714,000
Leasehold improvements [Member]
Property and equipment-at cost:
Total property and equipment-at cost	$ 10,318,000		$ 10,318,000		$ 10,100,000