XML 82 R72.htm IDEA: XBRL DOCUMENT v3.8.0.1
Commitments and Contingencies - Committed Expenditures (Detail) - Vehicle Fleet Committed Capital
$ in Millions
Mar. 31, 2018
USD ($)
Unrecorded Unconditional Purchase Obligation [Line Items]  
Estimated committed capital in 2017 $ 38.3
Estimated committed capital in 2018 $ 1.1