Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Contingencies And Commitments [Line Items]
Estimated sales tax and related penalties and interest	$ 15.3	$ 13.5
Deductible for marine liability coverage including personal injury claims, per first occurrence	5.0
Range of deductible for liability coverage for personal injury claims, lower limit	5.0
Range of deductible for liability coverage for personal injury claims, upper limit	100.0
Total Contingent Liabilities Under Letters of Credit and Bonds [Member]
Contingencies And Commitments [Line Items]
Contingent liability under letters of credit and other bonds	26.9
Potentially Collateralized Contingent Liability Under Letters Of Credit and Bonds [Member]
Contingencies And Commitments [Line Items]
Contingent liability under letters of credit and other bonds	20.8
Uncollateralized Contingent Liability Under Letters of Credit and Bonds [Member]
Contingencies And Commitments [Line Items]
Contingent liability under letters of credit and other bonds	6.1
Collateralized Contingent Liability Under Financial Letters of Credit and Surety Bond [Member]
Contingencies And Commitments [Line Items]
Contingent liability under letters of credit and other bonds		6.0
Cash Collateralized Contingent Liability Under Letters of Credit and Bonds [Member]
Contingencies And Commitments [Line Items]
Contingent liability under letters of credit and other bonds	19.6
Personal Injury Claims [Member]
Contingencies And Commitments [Line Items]
Personal injury claims recorded	14.7	14.7
Personal Injury Claims [Member] | Accrued Liabilities [Member]
Contingencies And Commitments [Line Items]
Personal injury claims recorded	5.2	5.9
Personal Injury Claims [Member] | Other Liabilities [Member]
Contingencies And Commitments [Line Items]
Personal injury claims recorded	$ 9.5	$ 8.8