Asset Disposals - Additional Information (Detail) $ in Millions |
3 Months Ended | 6 Months Ended | |
|---|---|---|---|
|
Sep. 30, 2016
USD ($)
Aircraft
|
Sep. 30, 2015
USD ($)
Aircraft
|
Jun. 30, 2016
USD ($)
Aircraft
|
|
| Assets Held For Sale And Impairments [Line Items] | |||
| Cash realized from sale of assets | $ | $ 2.2 | $ 2.3 | $ 11.0 |
| Gain (loss) on disposal of assets | $ | $ (0.1) | $ 0.2 | $ 3.9 |
| Oil and Gas [Member] | Light Aircraft [Member] | |||
| Assets Held For Sale And Impairments [Line Items] | |||
| Number of aircraft sold | Aircraft | 4 | 6 | 5 |
| Oil and Gas [Member] | Medium Aircraft [Member] | |||
| Assets Held For Sale And Impairments [Line Items] | |||
| Number of aircraft sold | Aircraft | 3 | ||