Revenue from Contracts with Customers - Contract Balances (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Oct. 01, 2018	Sep. 30, 2018
Accounts Receivable, after Allowance for Credit Loss, Current [Abstract]
Accounts receivable, net	$ 165,602	$ 125,200	$ 125,192
Contract with Customer, Asset, Net, Current [Abstract]
Contract assets	$ 14,000	12,800
Capitalized Contract Cost [Abstract]
Sales commission amortization period	60 months
Deferred commissions	$ 800	1,500
Deferred commission amortization expense	700
Contract with Customer, Liability [Abstract]
Current contract liabilities	29,435	28,734	$ 25,884
Contract liabilities	29,400	$ 28,700
Revenue recognized	$ 23,600