Commitments and Contingencies - Other Long-Term Obligations (Details) - USD ($)
Nov. 05, 2013
Jan. 31, 2016
Jul. 31, 2015
Nov. 03, 2014
Commitments and Contingencies        
Accrued expenses   $ 18,872,000 $ 15,092,000  
Jet Prep Ltd.        
Commitments and Contingencies        
Contingent consideration liability   143,000    
Assumed contingent obligation   1,138,000    
Period over which potential cash contingent consideration is payable 7 years      
International Medical Service S.r.l.        
Commitments and Contingencies        
Other long-term liabilities       $ 1,020,000
International Medical Service S.r.l. | Central bank of Italy        
Commitments and Contingencies        
Liabilities assumed   479,000   $ 843,000
Interest rate per annum (as a percent)       0.25%
International Medical Service S.r.l. | Central bank of Italy | Accrued expenses        
Commitments and Contingencies        
Liabilities assumed   159,000   $ 187,000
International Medical Service S.r.l. | Central bank of Italy | Other long-term liabilities        
Commitments and Contingencies        
Liabilities assumed   $ 320,000   $ 656,000