Annual report pursuant to Section 13 and 15(d)

Leases - Additional Information (Detail)

v3.6.0.2
Leases - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Leases [Line Items]    
Pump equipment $ 13.9 $ 11.2
Accumulated depreciation related to leased assets 3.9 2.4
Depreciation expense for medical equipment 6.3 $ 4.8
Operating lease rental expenses $ 1.0  
Capital Leases [Member]    
Leases [Line Items]    
Weighted average interest rate under capital leases 5.10%