Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands |
Sep. 30, 2016 |
Mar. 31, 2016 |
---|---|---|
Schedule Of Intangible Assets [Line Items] | ||
Indefinite Lived Intangible Assets, Gross Carrying Amount | $ 12,800 | $ 12,800 |
Indefinite Lived Intangible Assets, Net Carrying Amount | 12,800 | 12,800 |
Permits [Member] | ||
Schedule Of Intangible Assets [Line Items] | ||
Indefinite Lived Intangible Assets, Gross Carrying Amount | 10,300 | 10,300 |
Indefinite Lived Intangible Assets, Net Carrying Amount | 10,300 | 10,300 |
Tradename [Member] | ||
Schedule Of Intangible Assets [Line Items] | ||
Indefinite Lived Intangible Assets, Gross Carrying Amount | 2,500 | 2,500 |
Indefinite Lived Intangible Assets, Net Carrying Amount | 2,500 | 2,500 |
Customer Relationships [Member] | ||
Schedule Of Intangible Assets [Line Items] | ||
Finite-Lived Intangible Assets, Gross Carrying Amount | 2,700 | 2,700 |
Finite-Lived Intangible Assets, Accumulated Amortization | 1,042 | 952 |
Finite-Lived Intangible Assets, Net Carrying Amount | $ 1,658 | $ 1,748 |