Revenue from Contracts with Customers - Contract Balances (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Oct. 01, 2018	Sep. 30, 2018
Accounts Receivable, after Allowance for Credit Loss, Current [Abstract]
Accounts receivable, net	$ 163,105	$ 163,105	$ 125,200	$ 125,192
Contract with Customer, Asset, Net, Current [Abstract]
Contract assets	$ 5,200	$ 5,200	8,200
Capitalized Contract Cost [Abstract]
Sales commission amortization period	60 months	60 months
Deferred commissions	$ 900	$ 900	1,500
Deferred commission amortization expense	200	600
Contract with Customer, Liability [Abstract]
Current contract liabilities	30,598	$ 30,598	$ 28,734	$ 25,884
Change in Contract with Customer, Liability [Abstract]
Revenue recognized	$ 12,200