Commitments and contingencies (Tables)

12 Months Ended

Sep. 30, 2019

Commitments and Contingencies Disclosure [Abstract]

Schedule of minimum future lease commitments under leases

Minimum future lease commitments under leases in effect as of September 30, 2019, are as follows (in thousands):

	Office space		Equipment		Total
Year ending September 30,
2020	$	93,119	$	8,605	$	101,724
2021	52,402		6,228		58,630
2022	33,645		2,384		36,029
2023	23,942		118		24,060
2024	9,842		77		9,919
Thereafter	7,295		—		7,295
Total minimum lease payments	$	220,245	$	17,412	$	237,657