XML 52 R40.htm IDEA: XBRL DOCUMENT v3.19.2
Fair Value Measurements - Carrying Value and Estimated Fair Value of Long-term Debt, Including Current Maturities (Detail) - USD ($)
$ in Thousands
Jun. 30, 2019
Sep. 30, 2018
Fair Value Disclosures [Abstract]    
Long-term debt, including current maturities, carrying value $ 896,730 $ 930,207
Long-term debt, including current maturities, fair value $ 917,265 $ 926,229