Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (45,599)	$ (154,683)	$ (435,534)	$ (74,833)
Other comprehensive income, net of income taxes:
Minimum pension liability adjustments, net of income taxes of ($0.3) million and ($0.6) million for the three and nine months ended June 30, 2020, respectively, and ($0.1) million and ($0.2) million for the three and nine months ended June 30, 2019, respectively	521	226	1,553	675
Other comprehensive income	521	226	1,553	675
Comprehensive loss	$ (45,078)	$ (154,457)	$ (433,981)	$ (74,158)