Long-Term Incentive Plans - Summary of Information Regarding Restricted Stock Unit Awards (Parenthetical) (Detail) $ / shares in Units, $ in Millions	Sep. 30, 2019 USD ($) $ / shares
TSUs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate grant date fair value of restricted stock units issued | $	$ 1.9
TSUs [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grant Date Market Price	$ 4.48
TSUs [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grant Date Market Price	8.70
PSUs [Member] | Minimum [Member] | Management Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Calculated fair value price	$ 1.64
PSUs [Member] | Maximum [Member] | Management Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate grant date fair value of restricted stock units issued | $	$ 0.1
Calculated fair value price	$ 6.76