Revenue Recognition and Valuation Accounts - Additional Information (Detail) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2017 |
Sep. 30, 2016 |
Sep. 30, 2017 |
Sep. 30, 2016 |
Dec. 31, 2016 |
|
| Valuation and Qualifying Accounts Disclosure [Line Items] | |||||
| Allowance for doubtful accounts | $ 6.1 | $ 6.1 | $ 6.0 | ||
| Value of services to patients who are unable to pay | 1.3 | $ 2.2 | 5.7 | $ 6.9 | |
| Estimated cost of providing charity services | 0.3 | $ 0.5 | 1.3 | $ 1.8 | |
| Valuation reserves related to obsolescence and slow moving inventory | 18.4 | 18.4 | 17.3 | ||
| Air Medical [Member] | |||||
| Valuation and Qualifying Accounts Disclosure [Line Items] | |||||
| Allowance for contractual discounts against outstanding accounts receivable | 129.2 | 129.2 | 111.9 | ||
| Allowance for uncompensated care against outstanding accounts receivable | $ 47.7 | $ 47.7 | $ 46.3 | ||