Basis of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
New accounting pronouncements
Increase in cash provided by operating activities	$ 72,215	$ 74,371
Decrease in net cash used in financing activities	(81,082)	(71,996)
Other disclosures
Early termination revenue	4,300	13,500
Abandonments	7,300	800
Foreign currency loss	1,500	1,400
ASU 2016-09
New accounting pronouncements
Increase in cash provided by operating activities		3,700
Decrease in net cash used in financing activities		$ 3,700
Cumulative effect adjustment	$ 317