Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 30,605	$ 18,959
Other comprehensive income, net of income taxes:
Minimum pension liability adjustments, net of income taxes of ($0.2) million and ($0.1) million December 31, 2019 and 2018, respectively	516	225
Other comprehensive income	516	225
Comprehensive income	$ 31,121	$ 19,184