Property and Equipment - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Mar. 31, 2018
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 134,455	$ 120,948
Less: accumulated depreciation and amortization	(71,717)	(67,049)
Total property and equipment, net	62,738	53,899
Computers, software, and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	9,608	8,335
Site operation equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	49,291	37,254
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	2,715	2,981
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	32,164	34,316
Capitalized software development costs
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 40,677	$ 38,062