Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Benefit from (provision for) income taxes	$ 11,464	$ (3,596)	$ 20,644	$ (4,406)
Effective income tax benefit rate	43.90%	25.10%	46.90%	25.50%
Increase (decrease) in gross unrecognized tax benefits	$ 1,200		$ 2,400
Cumulative effect adjustment related to unrecognized excess tax benefits on share based compensation	$ 58,700		$ 58,700