Revenue Recognition - Summary of Estimated Revenue Related to Performance Obligations (Detail) $ in Millions	Feb. 28, 2021 USD ($)
Railcar sales
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue type 1	$ 600.0
Services
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue type 1	129.7
Other
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue type 1	61.5
Manufacturing | Railcar sales
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue type 1	2,125.1
Manufacturing | Marine
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue type 1	53.3
Manufacturing | Railcars for Syndication
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue type 1	$ 229.3	[1]

[1] Not a performance obligation as defined in Topic 606