Property and Equipment - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Mar. 31, 2017
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 114,936	$ 97,908
Less: accumulated depreciation and amortization	(62,364)	(47,180)
Total property and equipment, net	52,572	50,728
Computers, software, and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	8,023	7,060
Site operation equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	36,396	25,874
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	2,375	1,770
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	31,943	30,586
Capitalized software development costs
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 36,199	$ 32,618