Debt - Principal and Interest Payments on Debt (Detail) $ in Thousands	Mar. 31, 2018 USD ($)
Debt Disclosure [Abstract]
2019, Principal	$ 7,857
2020, Principal	8,571
2021, Principal	8,572
2022, Principal	5,000
Total, Principal	30,000
2018, Interest	2,062
2019, Interest	2,447
2020, Interest	1,673
2021, Interest	882
2022, Interest	2,552
Total, Interest	9,616
2018, Total	2,062
2019, Total	10,304
2020, Total	10,244
2021, Total	9,454
2022, Total	7,552
Total	$ 39,616