Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2020	Mar. 31, 2020
Leases [Abstract]
Operating lease expense	$ 15,453	$ 31,978
Variable lease expense	3,093	5,900
Total lease expense	$ 18,546	$ 37,878