Estimated Useful Life of Property Plant and Equipment (Detail)	12 Months Ended
	Mar. 31, 2018
Computer, Equipment and Software | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful life	3 years
Computer, Equipment and Software | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful life	7 years
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful life	7 years
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful life	Straight-line basis over the shorter of the useful life of the improvement or the term of the lease