Annual report pursuant to Section 13 and 15(d)

Business Combinations - Summary of Purchase Price Allocation of Fair Value of Assets Acquired and Liabilities (Detail)

v3.6.0.2
Business Combinations - Summary of Purchase Price Allocation of Fair Value of Assets Acquired and Liabilities (Detail) - USD ($)
$ in Thousands
Dec. 31, 2016
Jul. 06, 2016
Mar. 02, 2016
Jan. 11, 2016
Dec. 31, 2015
Jan. 23, 2015
Dec. 31, 2014
Business Acquisition [Line Items]              
Goodwill $ 113,112       $ 107,466   $ 96,316
RetCam [Member]              
Business Acquisition [Line Items]              
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles   $ 3,300          
Goodwill   3,200          
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities   $ 2,000          
Monarch [Member]              
Business Acquisition [Line Items]              
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles       $ 1,200      
Goodwill       $ 2,400      
NeuroQuest [Member]              
Business Acquisition [Line Items]              
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles     $ 1,300        
Goodwill     3,500        
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities     $ 100        
Global Neuro-Diagnostics [Member]              
Business Acquisition [Line Items]              
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles           $ 4,800  
Goodwill           $ 8,900