Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Oct. 01, 2018	Sep. 30, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract assets	$ 71,310		$ 71,310			$ 69,147
Work in progress	18,461		18,461			19,461
Contract liabilities	25,068		25,068			17,652
Revenue from product sales and services	348,628	$ 333,690	671,630	$ 630,740
Cost of product sales and services	253,017	$ 225,693	487,289	$ 434,364
Inventories, net	155,863		155,863			$ 134,988
Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative effect of adoption of new accounting standards					$ (1,582)
Contract assets					(6,106)
Work in progress					6,194
Contract liabilities					$ 1,773
Revenue from product sales and services	316,098		609,102
Transferred over Time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from product sales and services	133,902		248,137
Transferred over Time | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract assets	277		277
Revenue from product sales and services	1,088		894
Cost of product sales and services	349		277
Inventories, net	894		894
Revenue recognized at point in time | Transferred over Time | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from product sales and services	240		$ 1,267
Minimum | Transferred at Point in Time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from product sales and services	$ 100