Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Mar. 31, 2016
Operating Leased Assets [Line Items]
Deferred rent	$ 9.4		$ 9.4		$ 5.1
Rent expense, net of sublease income, for operating leases	2.4	$ 1.7	7.3	$ 4.7
Purchase commitments	$ 24.9		$ 24.9		$ 11.9
Minimum
Operating Leased Assets [Line Items]
Non-cancelable operating lease agreements, expiration year	2017
Maximum
Operating Leased Assets [Line Items]
Non-cancelable operating lease agreements, expiration year	2023