Subsequent Events (Detail) - USD ($) $ in Millions	1 Months Ended	6 Months Ended
	Aug. 03, 2017	Jun. 30, 2017	Jul. 31, 2017
Subsequent Event [Line Items]
Other commitments, remainder of fiscal year		$ 2.7
Other commitments, due year in second year		3.6
Other commitments, due year in third year		$ 2.1
Restricted Stock Units (RSUs)
Subsequent Event [Line Items]
Restricted stock units granted (in shares)		983,300
Subsequent Event
Subsequent Event [Line Items]
Other commitments, remainder of fiscal year			$ 0.5
Other commitments, due year in second year			0.5
Other commitments, due year in third year			$ 0.5
Subsequent Event | Restricted Stock Units (RSUs)
Subsequent Event [Line Items]
Restricted stock units granted (in shares)	309,965
Share-based payment award, award vesting period	4 years