XML 138 R85.htm IDEA: XBRL DOCUMENT v3.21.1
Property and Equipment - Summary of assets held for sale (Detail) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Disclosure Of Assets Held For sale [Line Items]    
Assets $ 135,542 $ 120,006
Flight Equipment [Member]    
Disclosure Of Assets Held For sale [Line Items]    
Assets 129,443 91,252
Expendable Parts And Supplies [Member]    
Disclosure Of Assets Held For sale [Line Items]    
Assets $ 6,099 $ 28,754