Commitments and Contingencies - Additional Information (Detail) $ in Millions	Dec. 31, 2017 USD ($)
Loss Contingencies [Line Items]
Contractual commitment due within the next year	$ 12.0
Contractual commitment due within two years	6.5
Contractual commitment due within three years	0.7
Software Subscription Agreement
Loss Contingencies [Line Items]
Contractual commitment due within the next year	8.4
Contractual commitment due within two years	5.3
Contractual commitment due within three years	0.5
Sponsorship Agreement With Professional Sports Franchise
Loss Contingencies [Line Items]
Contractual commitment due within the next year	0.7
Contractual commitment due within two years	$ 0.7