XML 31 R41.htm IDEA: XBRL DOCUMENT v3.20.1
Fair Value Measurements - Carrying Value and Estimated Fair Value of Long-term Debt, Including Current Maturities (Detail) - USD ($)
$ in Thousands
Mar. 31, 2020
Sep. 30, 2019
Fair Value Disclosures [Abstract]    
Long-term debt and finance leases, including current maturities, carrying value $ 802,003 $ 858,145
Long-term debt and finance leases, including current maturities, fair value $ 815,500 $ 882,700