Property and Equipment - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Mar. 31, 2018
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 148,868	$ 120,948
Less: accumulated depreciation and amortization	(77,792)	(67,049)
Total property and equipment, net	71,076	53,899
Computers, software, and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	10,014	8,335
Site operation equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	56,627	37,254
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	3,408	2,981
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	37,341	34,316
Capitalized software development costs
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 41,478	$ 38,062