v3.7.0.1
Revenue Recognition and Valuation Accounts - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Dec. 31, 2016
Valuation and Qualifying Accounts Disclosure [Line Items]          
Allowance for doubtful accounts $ 6.0   $ 6.0   $ 6.0
Value of services to patients who are unable to pay 2.0 $ 2.2 4.4 $ 4.7  
Estimated cost of providing charity services 0.4 $ 0.5 1.0 $ 1.2  
Valuation reserves related to obsolescence and slow moving inventory 17.7   17.7   17.3
Air Medical [Member]          
Valuation and Qualifying Accounts Disclosure [Line Items]          
Allowance for contractual discounts against outstanding accounts receivable 110.9   110.9   111.9
Allowance for uncompensated care against outstanding accounts receivable $ 46.2   $ 46.2   $ 46.3