Accumulated Other Comprehensive Loss - Change in AOCL (Details) $ in Thousands	6 Months Ended
	Mar. 31, 2019 USD ($)
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	$ (268,556)
Balance	(145,075)
Interest rate caps
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	1,365
Other comprehensive loss before reclassification, net of tax	(5,014)
Reclassification to net earnings, net of tax	44
Balance	(3,605)
Foreign exchange contracts
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive loss before reclassification, net of tax	(253)
Reclassification to net earnings, net of tax	85
Balance	(168)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(91,356)
Other comprehensive loss before reclassification, net of tax	(10,425)
Balance	(101,781)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(89,991)
Other comprehensive loss before reclassification, net of tax	(15,692)
Reclassification to net earnings, net of tax	129
Balance	$ (105,554)