Business Segments and Geographic Areas - Schedule of Financial Information Concerning Reportable Operating Segments (Parenthetical) (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Segment Reporting Information [Line Items] | |||
| Interest expense | $ 29,066 | $ 29,510 | $ 29,756 |
| Air Medical [Member] | Reportable Operating Segments [Member] | |||
| Segment Reporting Information [Line Items] | |||
| Interest expense | $ 300 | ||