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Stock-based Compensation - Additional Information (Detail) - USD ($)
$ in Millions
1 Months Ended 3 Months Ended 9 Months Ended
Apr. 30, 2022
Apr. 30, 2021
May 31, 2020
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Number of stock option granted           0 0
2019              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Shares issued 979,600            
Performance Units Awards              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Performance period           3 years  
Unrecognized compensation cost       $ 12.7   $ 12.7  
Weighted-average remaining vesting period           1 year 5 months 12 days  
Performance Units Awards | 2018              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Shares issued   621,400          
Performance Units Awards | Condition One [Member]              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Award description           The performance goals for the Performance Units are tied to our total shareholder return for the performance period as compared to total shareholder return for a peer group determined by the Compensation Committee. For the performance units granted in April 2022 and April 2021, the peer group includes one market index and three market indices, respectively. The performance goals are considered to be market conditions under the relevant accounting standards and the market conditions were factored into the determination of the fair value of the respective Performance Units. For the Performance Units granted beginning in April 2019, the recipients will receive the target number of shares if our total shareholder return during the performance period, when compared to the peer group, is at the 55th percentile. If our total shareholder return during the performance period, when compared to the peer group, is at the 75th percentile or higher, then the recipients will receive two times the target number of shares. If our total shareholder return during the performance period, when compared to the peer group, is at the 25th percentile, then the recipients will only receive one-half of the target number of shares. If our total shareholder return during the performance period, when compared to the peer group, is between the 25th and 55th percentile, or the 55th and 75th percentile, then the shares to be received by the recipients will be determined using linear interpolation for levels of achievement between these points.  
Phantom Share Units (PSUs)              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Award description           Mr. Hendricks may earn from 0% to 200% of a target award of 298,500 phantom units based on our achievement of the same performance conditions over the same performance period that applies to the Performance Units granted in April 2020, as described above. Earned Phantom Units, if any, will be settled in 2023, following completion of the three-year performance period, in a cash payment equal to the number of earned phantom units multiplied by our average trading price per share over the twenty consecutive trading days ending March 31, 2023.  
Performance completion year     2023        
Performance Period     3 years        
Grant date fair value     $ 1.2        
Expense recognized       1.4 $ 0.2 $ 2.3 $ 1.3
Phantom Share Units (PSUs) | Chief Executive Officer and President              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Number of units awardable based on performance conditions     298,500        
Phantom Share Units (PSUs) | Chief Executive Officer and President | Minimum              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Percentage of target award vesting rights     0.00%        
Phantom Share Units (PSUs) | Chief Executive Officer and President | Maximum              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Percentage of target award vesting rights     200.00%        
Restricted Stock Units (RSUs)              
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]              
Unrecognized compensation cost       $ 30.1   $ 30.1  
Weighted-average remaining vesting period           1 year 10 months 24 days